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Mutations in p53 are common in different cancer types and are reported to protect cancer via different mechanisms. R175H, R248Q, and R273H are the hotspot mutations of p53 and are suggested to increase aerobic glycolysis in cancer cells. Cancer cells rely mostly upon aerobic glycolysis, so it will be interesting to target these three p53 mutants for designing alternative cancer therapy. The class of compounds studied for their potential to target energy metabolism of cancer cells is called mitocans. The current study is an approach to explore if these selected 3 mutants of p53 may act as suitable target(s) for natural mitocans. Hereby, we selected 60 phytocompounds altogether from Andrographis paniculata and Centella asiatica and docked against all three p53 mutants, using Autodock vina. 11 compounds were sorted based on their binding energies and drug-like properties, and toxicity levels prediction showed asiatic acid to be the most significant. As asiatic acid was observed to significantly bind with R248Q only, R248Q-Asiatic acid was identified for molecular dynamics simulation using GROMACS which showed significant interactions. In conclusion, mutant R248Q was observed to be the best target for asiatic acid, though additional in-vitro experiments are important to validate the findings of this study.
BackgroundPancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy characterized by a complex tumor microenvironment. Angiogenesis is of paramount importance in the proliferation and metastasis of PDAC. However, currently, there are no well-defined biomarkers available to guide the prognosis and treatment of PDAC. ResultsIn this study, we investigated the interactions between tumor-associated endothelial cells (TAECs) and tumor cells in PDAC, and identified a specific subset of TAECs characterized by high expression of COL4A1. COL4A1+ endothelial cells interact with tumor cells through the COLLAGEN signaling pathway to promote tumor cell proliferation, migration, and invasion. We also observed activation of HOXD9 in COL4A1+ endothelial cells. Based on these findings, we developed a prognostic model called TaEMS, which accurately predicts patient prognosis. TaEMS identified high-risk patients enriched in cell cycle-related pathways and low-risk patients enriched in focal adhesions, smooth muscle regulation, and immune pathways. Moreover, high-risk patients displayed a reduced level of immune cell infiltration, indicating the presence of a "cold tumor" phenotype. ConclusionsOverall, our study uncovered an intricate crosstalk between TAECs and tumor cells in PDAC, emphasizing the role of HOXD9 and highlighting the potential of TaEMS as a prognostic biomarker for precise therapies.
The profiles, specificity and dynamics of tumor-specific clonotypes that are associated with clinical response to adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) remain unclear. Using single-cell RNA/TCR-sequencing, we tracked TIL clonotypes from baseline tumors to ACT products and post-ACT blood and tumor samples in melanoma patients treated with TIL-ACT. Patients with clinical responses had baseline tumors enriched in tumor-reactive TILs, which were more effectively mobilized upon in vitro expansion, yielding products with higher numbers of tumor-specific CD8+ cells, which also preferentially infiltrated tumors post-ACT. Conversely, lack of clinical responses was associated with tumors devoid of tumor-reactive resident clonotypes, and with cell products mostly composed of blood-borne clonotypes mainly persisting in blood but not in tumors post-ACT. Upon expansion, tumor-specific TILs lost the specific signatures of states originally exhibited in tumors, including exhaustion, and in responders acquired an intermediate exhausted effector state after tumor engraftment, revealing important functional cell reinvigoration.
Drug resistance results in poor outcomes for most patients with metastatic cancer. Adaptive Therapy (AT) proposes to address this by exploiting presumed fitness costs incurred by drug-resistant cells when drug is absent, and prescribing dose reductions to allow fitter, sensitive cells to re-grow and re- sensitise the tumour. However, empirical evidence for treatment-induced fitness change is lacking. We show that fitness costs in chemotherapy-resistant ovarian cancer cause selective decline and apoptosis of resistant populations in low-resource conditions. Moreover, carboplatin AT caused fluctuations in sensitive/resistant tumour population size in vitro and significantly extended survival of tumour-bearing mice. In sequential blood-derived cell-free DNA and tumour samples obtained longitudinally from ovarian cancer patients during treatment, we inferred resistant cancer cell population size through therapy and observed it correlated strongly with disease burden. These data have enabled us to launch a multicentre, phase 2 randomised controlled trial (ACTOv) to evaluate AT in ovarian cancer.
Two structurally-unrelated small molecule chemotypes, represented by compounds PAV-617 and PAV-951 with antiviral activity in cell culture against monkeypox virus (MPXV) and human immunodeficiency virus (HIV) respectively, were studied for anti-cancer efficacy. Each exhibited apparent pan-cancer cytotoxicity, reasonable pharmacokinetics, and non-toxicity in mice at active concentrations. Anti-tumor properties of both chemotypes, were validated in mouse xenografts against A549 human lung cancer and, for one of the chemotypes, against HT-29 colorectal cancer. The targets of these compounds are unconventional: each binds to a different transient, energy-dependent multi-protein complex containing the protein TRIM28/KAP1, an allosteric modulator known to regulate mechanisms underlying viral and nonviral disease states including cancer. Treatment with these compounds alters the target multi-protein complexes in a manner consistent with allosteric modulation as their mechanism of action. These compounds appear to remove a block, crucial for cancer survival and progression, on the homeostatic linkage of uncontrolled cellular proliferation to apoptosis. These compounds provide starting points for development of next-generation non-toxic, pan-cancer therapeutics.
Aneuploidy occurs in most solid tumors and has the potential to dramatically modify cellular phenotype and fitness. Despite the importance of aneuploidy in tumor evolution, quantitative understanding of the evolutionary landscape of aneuploidy is lacking. To address this question, we developed a method to infer the fitness landscape of either arm-level or whole-chromosome level karyotypes. Our method takes longitudinal single cell sequencing data from an evolving cell population as input, then estimates the fitness of thousands of karyotypes located near to the input data in karyotype space. The predictive ability of the method was validated using artificial data generated from an agent based model, as well as data from a selection of in vitro and in vivo passaged cell lines. We applied our pipeline to an in vitro dataset of serially passaged cells and - based on topological analysis of the fitness landscape around diploid and tetraploid karyotypes - found support for the hypothesis that whole genome doubling benefits tumour cells by conferring robustness against missegregations.
Dysregulation of cellular energetics, including lipid synthesis mediated through de novo lipogenesis, is a feature of many cancers. Here we report that acetyl-coenzyme A carboxylase (ACC) 1, the rate-limiting enzyme of de novo lipogenesis, is a key regulator of breast cancer progression and cancer cell phenotype. Mammary epithelial-specific deletion of ACC1 impaired tumour progression and decreased cancer cell proliferation in the PyMT model of breast cancer in vivo. ACC1 knockout in human breast cancer cell lines resulted in decreased cell number and altered cell and membrane morphology. Lipidomic profiling demonstrated reduced levels of acyl-carnitines (CARs) and several phospholipid (PL) classes, whilst also shifting the lipid profiles to exhibit more elongated and less saturated lipids in ACC1 knockout breast cancer cells. Palmitate rescue of ACC1 deletion phenotypes demonstrated a critical role for ACC1 driven de novo lipogenesis in breast cancer cell function. Analysis of human breast tumour-microarrays identified strong ACC1 expression at all breast cancer stages, grade and metastasis, compared to normal adjacent tissue. Together our data demonstrate a novel role for ACC1 in breast cancer progression and cancer cell function, mediated through its lipogenic role, that together with its expression profile, identify ACC1 as a potential therapeutic target in breast cancer. Statement of significanceThis study investigates the impact of ACC1 deletion in breast cancer progression, revealing the importance of ACC1-derived lipids in breast cancer cell phenotypes and identifies ACC1 as a potential novel therapeutic target.
The Mismatch repair (MMR) pathway is known as a tumor suppressive pathway and genes involved in MMR are commonly mutated in hereditary colorectal or other cancer types. However, the function of MMR genes/proteins in breast cancer progression and metastasis are largely unknown. We found that MSH2, but not MLH1, is highly enriched in basal-like breast cancer (BLBC) and that its protein expression is inversely correlated with overall survival time (OS). MSH2 expression is frequently elevated due to genomic amplification or gain-of-expression in BLBC, which results in increased MSH2 protein that pairs with MSH6 (collectively referred to as MutS). Genetic deletion of MSH2 or MLH1 results in a contrasting phenotype in metastasis, with MSH2-deletion leading to reduced metastasis and MLH1-deletion to enhanced liver or lung metastasis. Mechanistically, MSH2-deletion induces the expression of a panel of chemokines in BLBC via epigenetic and/or transcriptional regulation, which leads to an immune reactive tumor microenvironment (TME) and elevated immune cell infiltrations. MLH1 is not correlated with chemokine expression and/or immune cell infiltration in BLBC, but its deletion results in strong accumulation of neutrophils that are known for metastasis promotion. Our study supports the differential functions of MSH2 and MLH1 in BLBC progression and metastasis, which challenges the paradigm of the MMR pathway as a universal tumor suppressive mechanism.
A rise in blood glucose is the early warning signs of underlying pancreatic cancer (PC), which could be the externalization of genetic events in PC progression. But there is still a vacancy in the field of mechanism research on pancreatic cancer-associated new-onset diabetes (PCAND). Using siRNA-mediated gene knockdown in vitro, we made MIN6 cells incubated with conditioned media from transfected PC cells, and detected its response. Immunological techniques were used to explore the interaction between sorcin and STAT3. Human cytokine array was performed to explore the inflammatory cytokines downstream of sorcin. In the present study, we have identified a PCAND driver gene SRI. In PC cells, sorcin and STAT3 form a positive feedback loop to enhance the transcription of serpin E1 and CCL5, which can impair nearby islet {beta}-cells, likely by activating the p38 pathway. In 88 biopsies, expression of sorcin was elevated in PC tissues, especially so in PCAND patient samples. Furthermore, clinical-SRI gene combination model can better distinguish PCAND from T2DM, and serpin E1 level is higher in the peripheral blood samples from PCAND than T2DM. Thus, Sorcin could be the key driver in PCAND, and figuring out sorcin-STAT3-serpin E1/CCL5 signaling axis can help us better understand the pathogenesis of PCAND and identify potential biomarkers. Statement of significanceThis study mapped out a novel sorcin-STAT3-Serpin E1/CCL5 signaling axis in pancreatic cancer cells, which explains how early pre-symptomatic pancreatic cancer may coincide with new-onset diabetes in some patients.
Owing to the inefficacy of available treatments, the survival rate of patients with metastatic prostate cancer (mPCa) is severely decreased. Therefore, it is crucial to identify new therapeutic targets to increase their survival. This study aim was to identify the most relevant regulators of mPCa onset by performing two high-throughput CRISPR/Cas9 screenings. Furthermore, some of the top hits were validated using small interfering RNA (siRNA) technology, with protein arginine methyltransferase 7 (PRMT7) being the best candidate. Its inhibition or depletion via CRISPR significantly reduced mPCa cell capacities in vitro. Moreover, PRMT7 ablation reduced mPCa appearance in chicken chorioallantoic membrane and mouse xenograft assays. Molecularly, PRMT7 reprograms the expression of several adhesion molecules through methylation of several transcription factors, such as FoxK1 or NR1H2, which results in primary tumor PCa cell adhesion loss and motility gain. Importantly, PRMT7 is upregulated in advanced stages of Spanish PCa tumor samples and PRMT7 pharmacological inhibition reduces the dissemination of mPCa cells. Thus, here is shown that PRMT7 is a potential therapeutic target and biomarker of mPCa.
Disseminated tumour cells frequently exhibit a period of dormancy that renders them insensitive to targeting by chemotherapeutic agents, conversely the systemic delivery of chemotherapies can result in normal tissue damage. Using multiple mouse and human breast cancer models, we demonstrate that prior chemotherapy administration enhances metastatic colonisation and outgrowth. In vitro, chemotherapy treatment induces fibroblast senescence associated with a senescence associated secretory phenotype (SASP) that accelerates 3D tumour spheroid growth. These chemotherapy-treated fibroblasts, and their pro-tumourigenic function, can be effectively eliminated by targeting the anti-apoptotic protein BCL-xL. In vivo, chemotherapy treatment induces SASP expression in normal tissues, however the accumulation of senescent cells is limited and BCL-xL inhibitors are unable to reduce chemotherapy-enhanced metastasis. This likely reflects that chemotherapy-exposed normal tissues support metastatic colonisation via the secretion of pro-tumourigenic factors and remodelling of the extracellular matrix, but that damaged stromal cells do not enter a full BCL-xL-dependent senescence or switch their dependency to other anti-apoptotic BCL-2 family members. In summary, this study highlights the role of the metastatic microenvironment in controlling outgrowth of disseminated tumour cells and the need to identify novel therapeutic approaches to effectively limit the pro-tumourigenic effects of chemotherapy-induced normal tissue damage.
No targeted agents are approved for pediatric sarcomas. Tyrosine kinase (TK) inhibitors represent attractive therapeutic candidates, however, beyond rare TK-activating fusions or mutations, predictive biomarkers are lacking. RNA overexpression of TKs is more commonly observed in pediatric sarcomas, however, an unresolved question is when upregulated TK expression is associated with kinase activation and signaling dependence. We explored the TK molecular landscape of 107 sarcoma patients from the ZERO Childhood Cancer precision medicine program using whole genomic and transcriptomic sequencing. Phosphoproteomic analyses of tyrosine phosphorylation (pY) and functional in vitro and in vivo assays were also performed in cell lines and patient-derived xenografts (PDXs). Our integrated analysis shows that although novel genomic driver lesions are rare, they are present and therapeutically actionable in selected patients as exemplified by a novel LSM1-FGFR1 fusion identified in an osteosarcoma patient. We further show that in certain contexts, TK expression data can be used to indicate TK pathway activity and predict TK-inhibitor sensitivity. We exemplify the utility of FGFR-inhibitors in PAX3-FOXO1 fusion-positive rhabdomyosarcomas (FP-RMS) mediated by high FGFR4 and FGF8 RNA expression levels, and overt activation of FGFR4 (FGFR4_pY). We demonstrate marked tumor growth inhibition in all FP-RMS PDXs treated with single agent FGF401 (FGFR4-specific inhibitor) and single agent lenvatinib (multi-kinase FGFR-inhibitor). Clinical benefit of lenvatinib in a relapsed metastatic FP-RMS patient further exemplifies that FGFR-inhibitors deserve additional investigation in FP-RMS patients. Statement of significanceOur multi-omic interrogation of sarcomas in the ZERO Childhood Cancer program illustrates how an RNA-expression biomarker signature (FGFR4+/FGF8+) in association with FGFR4 activation identifies that PAX3-FOXO1-positive rhabdomyosarcoma patients could benefit from FGFR-inhibitors.
Nanoparticles functionalized with specific receptors (e.g., antibodies, peptides) are used for targeted drug delivery of anti-cancer agents but their side effects include hypersensitivity reactions, toxicity, inflammation, and life-threatening allergic reactions (Anaphylaxis) [1,2]. Consequently, double imprinted molecularly imprinted nanoparticles (nanoMIPs) against a linear epitope of breast cancer cell receptor estrogen alpha (ER) and loaded with an anti-cancer agent (doxorubicin, DOX) are synthesized via a solid-phase approach. Surface plasmon resonance (SPR) measurements reveal that the produced nanoMIPs exhibit KD values of 19 nM (against the epitope used for imprinting) and 10 nM (ER receptor), and thus rival the affinity of nanoparticles decorated with natural affinity reagents (e.g., antibodies, peptides), whilst offering the advantages of low-cost and enhanced cellular uptake due to the receptor mediated endocytosis. We present the results of in vitro flow cytometry that DOX loaded nanoMIPs can preferentially bind to MCF-7 (ER positive) breast cancer (BC) cells vs MDA-MB-231 (ER negative) BC cells. Confocal imaging witnessed the above results and showed the sequential movement of the DOX loaded nanoMIPs from membrane to the nucleus of MCF-7 BC cells and achieve delivery of DOX once internalised in the cells (directly to the nucleus). As a result, enhanced cell toxicity in MCF-7 cells ([~]80%) as compared to MDA-MB-231 cells ([~]15%) is observed via MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) cytotoxicity assay in a time dependent manner. Overall, this study provides a promising approach for the targeted drug delivery of chemotherapeutic drugs to breast cancer cells, which has the potential to significantly improve patient outcome whilst also reducing debilitating side effects of current treatment.
Non-small cell lung cancers (NSCLCs) in non-smokers are mostly driven by mutations in the oncogenes EGFR, ERBB2, and MET, and fusions involving ALK and RET. We term these "non-smoking-related oncogenes" (NSROs). In addition to occurring in non-smokers, NSRO-driven tumors also occur in smokers, and the clonal architecture and genomic landscape of these tumors remain unknown. We investigated genomic and transcriptomic alterations in 173 tumor sectors from 48 patients with NSRO-driven or typical-smoking NSCLCs. NSRO-driven NSCLCs in smokers and non-smokers have similar genomic landscapes. Surprisingly, even in patients with prominent smoking histories, the mutational signature caused by tobacco smoking was essentially absent in NSRO-driven NSCLCs. However, NSRO-driven NSCLCs in smokers had higher transcriptomic activities related to regulation of the cell cycle, suggesting that smoking still affects tumor phenotype independently of genomic alterations. Statement of significanceThis study highlights the lack of genomic scars caused by smoking in NSCLCs driven by non-smoking-related oncogenes regardless of smoking history. The impact of smoking on these tumors is mainly non-genomic. The transcriptomic features of NSCLCs associated with smoking may help in the development of therapeutic approaches.
BRCA1 is a critical tumor suppressor, mutations in which greatly increase risks for many tumors in carriers, most notably breast cancer. Luminal progenitor cells (LPs) are the currently recognized cells origin of BRCA1-deficient breast cancers. However, the reason why LPs are prone to transform with BRCA1 deficiency has not been elucidated. Here, using single-cell sequencing of human BRCA1 mutant breast cancers and RNA sequencing (RNA-seq) of BRCA1-deficient normal mammary cells, we reveal that replication stress is a feature of LPs and a driving factor during BRCA1-associated tumorigenesis. Mechanistically, replication stress and BRCA1 deficiency lead to significant upregulation of ELF3 expression. ELF3 can help suppress excessive genomic instability and promote LP transformation with BRCA1 deficiency. Moreover, ELF3 emerged as a core transcription factor regulating LP genes, leading to LP expansion. Our findings suggest that replication stress is a driving factor during BRCA1-associated tumorigenesis in luminal progenitor cells and elucidates the key role of ELF3 during this process.
Early-Onset Colorectal Carcinoma (EOCRC) is a growing concern as reports indicate a worldwide increase in the incidence of CRC among young adults (<50 years old). In an effort to understand the different mode of pathogenesis in young-onset CRC, we performed a pilot study wherein we looked at colorectal tumors from both young (< 50 years old) and old patients (>55 years old) and screened them to eliminate tumors positive for Microsatellite Instability (MSI) and showing activation of the Wnt pathway, known canonical factors in CRC pathogenesis. RNA isolated from EOCRC and Late-Onset (LOCRC) tumors and paired normal tissues without MSI, nuclear {beta}-catenin and APC mutations were sent for small RNA seq to identify miRNA alterations between the two subsets. Comparative analysis revealed differential expression of 23 miRNAs specific to EOCRC and 11 miRNAs specific to LOCRC. We validated the top 10 EOCRC DEMs in TCGA-COAD cohorts followed by validation in additional EOCRC and LOCRC cohorts. Our integrated analysis revealed upregulation of hsa-miR-1247-3p, hsa-miR-148a-3p and hsa-miR-27a-5p and downregulation of hsa-miR-326 between the two subsets. Experimentally validated targets of the above miRNAs were compared with differentially expressed genes in the TCGA dataset to identify targets with physiological significance in EOCRC development. Our analysis revealed downregulation of epithelial gene expression and intercellular junction proteins potentially leading to dissolution of epithelial intercellular junctions in EOCRC development and EMT progression. Upregulated targets included genes whose expression have been reported to correlate with CRC tumor invasion, liver metastasis, disease recurrence and poor prognosis.
Immunotherapy has dramatically transformed the cancer treatment landscape largely due to the efficacy of immune checkpoint inhibitors (ICIs). Although ICIs have shown promising results for many patients, the low response rates in many cancers highlight the ongoing challenges in cancer treatment. Cytotoxic T lymphocytes (CTLs) execute their cell-killing function via two distinct mechanisms: a fast-acting, perforin-mediated process and a slower, Fas ligand (FasL)-driven path-way. Evidence also suggests that the preferred killing mechanism of CTLs depends on the anti-genicity of tumor cells. To determine the critical factors affecting responses to ICIs, we construct an ordinary differential equation model describing in vivo tumor-immune dynamics in the presence of active or blocked PD-1/PD-L1 immune checkpoint. Specifically, we identify important aspects of the tumor-immune landscape that affect tumor size and composition in the short and long term. By generating a virtual cohort with differential tumor and immune attributes, we also simulate the therapeutic outcomes of immune checkpoint blockade in a heterogenous population. In this way, we identify key tumor and immune characteristics that are associated with tumor elimination, dor-mancy, and escape. Our analysis sheds light on which fraction of a population potentially responds well to ICIs and ways to enhance therapeutic outcomes with combination therapy.
Hypoxia in solid tumors is a source of chemoresistance that determines poor patient prognosis and relies on the presence of cancer stem cells (CSCs). Here we use ovarian cancer (OC) as a model and a combination of 2D and 3D cell cultures, xenograft models, patient samples, transcriptional databases, iPSCs and ATAC-seq, to address the mechanisms leading to hypoxia-induced CSC generation and chemoresistance. We show that hypoxia activates the expression of the PLD2 gene encoding phospholipase D2. PLD2 overexpression leads to increased CSC-like features, similar to hypoxia, while PLD2 depletion in hypoxia partially suppresses these effects, indicating a role of PLD2 in hypoxia-induced CSC generation in OC. Finally, PLD2 overexpression provokes chemoresistance that is suppressed by combination treatment with PLD2 inhibition. Altogether, our work highlights the HIF-1D-PLD2 axis in hypoxia-induced CSC generation and chemoresistance in OC and proposes an alternative treatment for patients with high PLD2 expression. Statement of SignificanceHypoxia in solid tumors is a major source of chemoresistance and cancer stem cells. We show that hypoxia-induced stemness is mediated by phospholipase D2 in ovarian tumors, generating therapy resistance that is overcome by phospholipase D inhibition. Therefore, we propose an alternative treatment for patients with high PLD2 expression.
Ferroptosis is a non-apoptotic form of cell death characterized by iron-dependent lipid peroxidation. Ferroptosis can be induced by system xc- cystine/glutamate antiporter inhibition or by direct inhibition of the phospholipid hydroperoxidase glutathione peroxidase 4 (GPX4). The regulation of ferroptosis in response to system xc- inhibition versus direct GPX4 inhibition may be distinct. Here, we show that cell cycle arrest enhances sensitivity to ferroptosis triggered by GPX4 inhibition but not system xc- inhibition. Arrested cells have increased levels of oxidizable polyunsaturated fatty acid-containing phospholipids, which drives sensitivity to GPX4 inhibition. Epithelial membrane protein 2 (EMP2) expression is reduced upon cell cycle arrest and is sufficient to enhance ferroptosis in response to direct GPX4 inhibition. An orally bioavailable GPX4 inhibitor increased markers of ferroptotic lipid peroxidation in vivo in combination with a cell cycle arresting agent. Thus, responses to different ferroptosis-inducing stimuli can be regulated by cell cycle state.
PurposeTo resist lineage-dependent therapies such as androgen receptor inhibition in prostate cancer, cancer cells often adopt a stem-like state resulting in lineage-plasticity and phenotypic heterogeneity. We assessed the dynamics of lineage determination and cellular subpopulation expansion in treatment-resistant adenocarcinoma, amphicrine, and small cell neuroendocrine castrate resistant prostate cancers (CRPCs). Experimental DesignWe developed CRPC patient-derived organoid models that preserve heterogeneity of the originating tumor, including an amphicrine model harboring epigenetic driver mutations, ARID1A and ARID1B, and displaying a range of luminal and neuroendocrine phenotypes. We used single-cell RNA-seq, barcode lineage-tracing, single-cell ATAC-seq, and RNA-FISH to delineate the subpopulation structure of the heterogeneous organoids and define the lineage hierarchy, determine potential transcriptional regulators of amphicrine lineage-plasticity, and identify subpopulation-specific molecular targets for therapeutic intervention. ResultsTranscriptionally similar stem/progenitor cells were identified for all lineage populations. Lineage tracing in amphicrine CRPC showed that heterogeneity originated from distinct subclones of infrequent stem/progenitor cells that produced mainly quiescent differentiated amphicrine progeny. Amphicrine cells were enriched for secretory luminal, mesenchymal, and enzalutamide treatment persistent signatures. By contrast, adenocarcinoma CRPC had a less defined hierarchy, as progeny originated from stem/progenitor cells and self-renewing differentiated luminal cells. NEPC was composed almost exclusively of self-renewing stem/progenitor cells. Amphicrine stem cells demonstrated concurrent transcription factor activities associated with stem/progenitor, luminal epithelial and mesenchymal lineages. Finally, the amphicrine stem/progenitor subpopulation was specifically depleted with an AURKA inhibitor, which blocked tumor growth. ConclusionsThese data illuminate distinct origins and dynamics of subtype-specific CRPC plasticity in addition to demonstrating a strategy for targeting differentiation-competent stem cells. Translational RelevanceFor advanced prostate cancer, therapeutic resistance to androgen signaling suppression increasingly involves the development of lineage plasticity. The cellular states of transition and subpopulation heterogeneity that underlie lineage-plasticity are not well understood, which is an ongoing challenge to the design of effective treatments. Using patient-derived organoid models of various CRPC lineage subtypes, we observed distinct patterns with respect to stem/progenitor activity and associated growth phenotypes. The simultaneous expression of AR-driven and neuroendocrine identities, so-called amphicrine tumors, are thought to be an early dedifferentiation stage in plasticity-mediated resistance. We observed in an epigenetically-driven, amphicrine model of CRPC that a rare but necessary bipotent stem/progenitor population is suppressed by AURKA inhibitors, leading to tumor regression, while ARPC demonstrates both self-renewing differentiated luminal cells and stem/progenitors. These data suggest that AURKA inhibition may block the amplification of a resistance dedifferentiation pathway and should be considered in combination with AR signaling inhibitors for ARPC with characteristics of lineage plasticity.
The chromosomal theory of inheritance has dominated human genetics, including cancer genetics. Genes on the same chromosome segregate together while genes on different chromosomes assort independently, providing a fundamental tenet of Mendelian inheritance. Extrachromosomal DNA (ecDNA) is a frequent event in cancer that drives oncogene amplification, dysregulated gene expression and intratumoral heterogeneity, including through random segregation during cell division. Distinct ecDNA sequences, herein termed ecDNA species, can co-exist to facilitate intermolecular cooperation in cancer cells. However, how multiple ecDNA species within a tumor cell are assorted and maintained across somatic cell generations to drive cancer cell evolution is not known. Here we show that cooperative ecDNA species can be coordinately inherited through mitotic co-segregation. Imaging and single-cell analyses show that multiple ecDNAs encoding distinct oncogenes co-occur and are correlated in copy number in human cancer cells. EcDNA species are coordinately segregated asymmetrically during mitosis, resulting in daughter cells with simultaneous copy number gains in multiple ecDNA species prior to any selection. Computational modeling reveals the quantitative principles of ecDNA co-segregation and co-selection, predicting their observed distributions in cancer cells. Finally, we show that coordinated inheritance of ecDNAs enables co-amplification of specialized ecDNAs containing only enhancer elements and guides therapeutic strategies to jointly deplete cooperating ecDNA oncogenes. Coordinated inheritance of ecDNAs confers stability to oncogene cooperation and novel gene regulatory circuits, allowing winning combinations of epigenetic states to be transmitted across cell generations.
The clinical use of potent androgen receptor (AR) inhibitors has promoted the emergence of novel subtypes of metastatic castration-resistant prostate cancer (mCRPC), including neuroendocrine prostate cancer (CRPC-NE), which is highly aggressive and lethal1. These mCRPC subtypes display increased lineage plasticity and often lack AR expression2-5. Here we show that neuroendocrine differentiation and castration-resistance in CRPC-NE are maintained by the activity of Nuclear Receptor Binding SET Domain Protein 2 (NSD2)6, which catalyzes histone H3 lysine 36 dimethylation (H3K36me2). We find that organoid lines established from genetically-engineered mice7 recapitulate key features of human CRPC-NE, and can display transdifferentiation to neuroendocrine states in culture. CRPC-NE organoids express elevated levels of NSD2 and H3K36me2 marks, but relatively low levels of H3K27me3, consistent with antagonism of EZH2 activity by H3K36me2. Human CRPC-NE but not primary NEPC tumors expresses high levels of NSD2, consistent with a key role for NSD2 in lineage plasticity, and high NSD2 expression in mCRPC correlates with poor survival outcomes. Notably, CRISPR/Cas9 targeting of NSD2 or expression of a dominant-negative oncohistone H3.3K36M mutant results in loss of neuroendocrine phenotypes and restores responsiveness to the AR inhibitor enzalutamide in mouse and human CRPC-NE organoids and grafts. Our findings indicate that NSD2 inhibition can reverse lineage plasticity and castration-resistance, and provide a potential new therapeutic target for CRPC-NE.
Due to uncertainty in tumor phylogeny inference from sequencing data, many methods infer multiple, equally-plausible phylogenies for the same cancer. To summarize the solution space [T] of tumor phylogenies, consensus tree methods seek a single best representative tree S under a specified pairwise tree distance function. One such distance function is the ancestor-descendant (AD) distance d (T, T'), which equals the symmetric difference of the transitive closures of the edge sets E (T) and E (T'). Here, we show that finding a consensus tree S for tumor phylogenies [T] that minimizes the total AD distance {sum}T [isin][T] d (S, T) is NP-hard.
Triple-Negative Breast Cancer (TNBC) is the most aggressive type of breast malignancy, with chemotherapy as the only mainstay treatment. TNBC patients have the worst prognoses as a large fraction of them do not achieve complete pathological response post-treatment and develop drug-resistant residual disease. Molecular mechanisms that trigger proliferation in drug-resistant chemo-residual TNBC cells are poorly understood due to the lack of investigations using clinically relevant cellular models. In this study, we have established TNBC subtype-specific cellular models of proliferating drug-tolerant persister (PDTP) cells using different classes of chemotherapeutic agents that recapitulate clinical residual disease with molecular heterogeneity. Analysis of total phospho-tyrosine signals in TNBC PDTPs showed an enhanced phospho-tyrosine content compared to the parental cells (PC). Interestingly, using mass-spectrometry analysis, we identified a dramatic decrease in epidermal growth factor receptor (EGFR) expression in the PDTPs, while the presence of hyper-activated tyrosine phosphorylation of EGFR compared to PC. Further, we show that EGFR has enhanced lysosomal trafficking in PDTPs with a concomitant increase in N-Myc Downstream Regulated-1 expression that co-localizes with EGFR to mediate receptor degradation. More surprisingly, we found that reduced protein levels of EGFR are coupled with a robust increase in Src family kinases, including Lyn and Fyn kinases, that creates a hyper-phosphorylation state of EGFR-Src tyrosine kinases axis in PDTPs and mediates downstream over-activation of STAT3, AKT and MAP kinases. Moreover, paclitaxel-derived PDTPs show increased sensitivity to EGFR TKI Gefitinib and its combination with paclitaxel selectively induced cell death in PDTP-P TNBC cells and 3D spheroids by strongly downregulating phosphorylation of EGFR-Src with concomitant downregulation of Lyn and Fyn tyrosine kinases. Collectively, this study identifies a unique hyper-phosphorylation cellular state of TNBC PDTPs established by switching of EGFR-Src family tyrosine kinases creating a vulnerability to EGFR TKI.
Targeting EGFR has been effective in RAS/RAF wild-type colorectal cancer (CRC) patients. However, residual tumor relapses, necessitating the importance of biomarker-guided novel therapeutics. We show elevated DKC1 in [~]88% of CRC patients with poor recurrence-free survival. Clinically, DKC1-positive patients exhibit similarity with CMS2 class, the canonical subtype with active WNT signaling. We show functional significance of DKC1 in cell proliferation, stemness, DNA repair, and survival. Further, mice bearing DKC1 knockdown xenografts show [~]81% reduction in tumor burden. Mechanistically, WNT/{beta}-catenin signaling orchestrates DKC1 expression, then, DKC1/SOX2 complex regulates SGPP2, modulating sphingolipids metabolism. Downregulation of DKC1 in CRC lead to reduced SGPP2 levels leading to dysregulation of sphingolipid biosynthesis. Of note, DKC1-high CRC patients show accumulation of ceramides, namely C23 and C24, signifying their utility in diagnosis. Collectively, we delineate the mechanistic circuitry involved in DKC1-mediated CRC progression, propose ceramides as biomarker, and underscore WNT-based therapeutics for DKC1-positive patients.
AML is a heterogenous disease caused by different mutations. We have previously shown that each mutational sub-type develops its specific gene regulatory network (GRN) with transcription factors interacting with multiple gene modules, many of which are transcription factor genes themselves. Here we hypothesized that highly connected nodes within such networks comprise crucial regulators of AML maintenance. We tested this hypothesis using FLT3-ITD mutated AML as a model and conducted an shRNA drop-out screen informed by this analysis. We show that AML-specific GRNs predict identifying crucial regulatory modules required for AML but not normal cellular growth. Furthermore, our work shows that all modules are highly connected and regulate each other. The careful multi-omic analysis of the role of one (RUNX1) module by shRNA and chemical inhibition shows that this transcription factor and its target genes stabilize the GRN of FLT3-ITD AML and that its removal leads to GRN collapse and cell death.
Ovarian high grade serous carcinoma (HGSC) remains a disease of poor prognosis that is unresponsive to current immune checkpoint inhibitors. Although PI3K pathway alterations are common in HGSC, attempts to target this pathway have been unsuccessful. We hypothesised aberrant PI3K pathway activation may alter the HGSC immune microenvironment and present a novel targeting strategy. We used both murine models and HGSC patient samples to study the impact of loss of Pten, a negative regulator of PI3K pathway signalling. We identified populations of resident macrophages specifically in Pten null omental tumours. These macrophages derive from peritoneal fluid macrophages and have a unique gene expression programme, marked by high levels of HMOX1 expression, the gene for the enzyme heme oxygenase-1. Targeting resident peritoneal macrophages prevents appearance of HMOX1hi macrophages and in doing so reduces tumour growth. Furthermore, direct inhibition of HMOX1 extends survival in vivo. HMOX1hi macrophages with corresponding gene expression programmes are also identified in human HGSC tumours and their presence correlates with activated tumoural PI3K pathway/mTOR signalling and poor overall survival in HGSC patients. In contrast, tumours with low number of HMOX1hi macrophages are marked by increased adaptive immune response gene expression. Our data suggest that HMOX1hi macrophages represent a potential therapeutic target and biomarker for poor prognosis HGSC.
Glioblastomas (GBM) are driven by malignant neural stem-like cells that display extensive heterogeneity and phenotypic plasticity, which drives tumour progression and therapeutic resistance. Here we show that the nodal extracellular matrix-cell adhesion protein integrin-linked kinase (ILK; a pseudokinase), is a key determinant of phenotypic plasticity and the mesenchymal-like, invasive cell state in mouse GBM stem cells. We found that a novel ILK-STAT3 signalling pathway is required for plasticity that enables the transition of GBM stem cells to an astrocyte-like state both in vitro and in vivo. GBM cells genetically depleted of ILK become predominantly stabilised in a transcriptionally-defined progenitor-like state that is characterised by lack of response to differentiation cues and constitutive proliferation. Loss of ILK or interference with STAT3 impairs differentiation potential, reducing phenotypic plasticity of tumour cell populations; additionally, ILK loss causes a mesenchymal- to epithelial-like morphological transition and suppression of malignancy-associated features. Our work defines ILK as a central regulator of multiple GBM phenotypes including phenotypic plasticity and mesenchymal state.
The persistence of ovarian cancer stem-like cells (OvCSCs) after chemotherapy resistance has been implicated in relapse. However, the ability of these relatively quiescent cells to produce the robust tumor regrowth necessary for relapse remains an enigma. Since normal stem cells exist in a niche, and tumor-associated macrophages (TAMs) are the highest abundance immune cell within ovarian tumors, we hypothesized that TAMs may influence OvCSC proliferation. To test this, we optimized OvCSC enrichment by sphere culture and in vitro polarization of monocytes to a TAM-like M2 phenotype. Using cocultures that permitted the exchange of only soluble factors, we found that M2 macrophages increased the proliferation of sphere cells. Longer-term exposure (5-7 days) to soluble TAM factors led to retention of some stem cell features by OvCSCs but loss of others, suggesting that TAMs may support an intermediate stemness phenotype in OvCSCs. Although TAM coculture decreased the percentage of OvCSCs surviving chemotherapy, it increased the overall number. We therefore sought to determine the influence of this interaction on chemotherapy efficacy in vivo and found that inhibiting macrophages improved chemotherapy response. Comparing the gene expression changes in OvCSCs cocultured with TAMs to publicly available patient data identified 34 genes upregulated in OvCSCs by exposure to soluble TAM factors whose expression correlates with outcome. Overall, these data suggest that TAMs may influence OvCSC proliferation and impact therapeutic response.
Major histocompatibility complex class-1-related protein (MR1), unlike human leukocyte antigen (HLA) class-1, has until recently been reported to be monomorphic. Tumor cell-specific MR1 restricted T cell receptors (TCRs) have been described, offering potential therapeutic application for cancer treatment. We show that human T cells expressing a TCR derived from an MR1-restricted T cell clone, termed MC.7.G5 (7G5.TCRT), retain MR1-directed cytotoxicity. However, activity is not pan-cancer, as initially reported with the clone MC.7.G5. Recognition is restricted by an allelic variant of MR1 (MR104) which is present at approximately 1% of the population at the heterozygote level. The 7G5 TCR is not cancer specific, as 7G5.TCRT and 7G5.TCRT-like TCRs react to both cancer and healthy cells expressing MR104 alleles. These data demonstrate that healthy individuals can harbor T cells reactive to an MR1 variant displaying self-ligands expressed in cancer and benign tissues. Targeting MR1 in cancer will require identification of cancer-specific presented ligands, and careful confirmation of cancer specificity of TCRs. MR1*04 may behave as an alloantigen warranting further study.
Head and neck squamous cell carcinoma present a high mortality rate. Melatonin has been shown to have oncostatic effects in different types of cancers. However, inconsistent results have been reported for in vivo applications. Consequently, an alternative administration route is needed to improve bioavailability and establish the optimal dosage of melatonin for cancer treatment. On the other hand, the use of patient-derived tumor models has transformed the field of drug research because they reflect the heterogeneity of patient tumor tissues. In the present study, we explore mechanisms for increasing melatonin bioavailability in tumors and investigate its potential as an adjuvant to improve the therapeutic efficacy of cisplatin in the setting of both xenotransplanted cell lines and primary human HNSCC. We analyzed the effect of two different formulations of melatonin administered subcutaneously or intratumorally in Cal-27 and SCC-9 xenografts and in patient-derived xenografts. Melatonin effects on tumor mitochondrial metabolism was also evaluated as well as melatonin actions on tumor cell migration. In contrast to the results obtained with the subcutaneous melatonin, intratumoral injection of melatonin drastically inhibited tumor progression in HNSCC-derived xenografts, as well as in patient-derived xenografts. Interestingly, intratumoral injection of melatonin potentiated CDDP effects, decreasing Cal-27 tumor growth. We demonstrated that melatonin increases ROS production and apoptosis in tumors, targeting mitochondria. Melatonin also reduces migration capacities and metastasis markers. These results illustrate the great clinical potential of intratumoral melatonin treatment and encourage a future clinical trial in cancer patients to establish a proper clinical melatonin treatment.
In tandem with the expanding obesity pandemic, the prevalence of metabolic dysfunction associated steatohepatitis (MASH, formerly known as NASH)-driven hepatocellular carcinoma (HCC) is predicted to rise globally, creating a significant need for therapeutic interventions. We previously identified the upregulation of apoptosis antagonizing transcription factor (AATF), which is implicated in facilitating the progression from MASH to HCC. The objective of this study was to examine whether the intervention of curcumin could alleviate AATF-mediated MASH, inhibit tumor growth, and elucidate the underlying mechanism. A preclinical murine model mimicking human MASH-HCC was employed, subjecting mice to either a chow diet normal water (CDNW) or western diet sugar water (WDSW) along with very low dose of carbon tetrachloride (CCl4-0.2 l/g, weekly). Mice receiving curcumin (CUR) alongside WDSW/CCl4 exhibited significant improvements, including reduced liver enzymes, dyslipidemia, steatosis, inflammation, and hepatocellular ballooning. Curcumin treatment also suppressed hepatic expression of inflammatory, fibrogenic, and oncogenic markers. Of note, there was a significant reduction in the expression of AATF upon curcumin treatment in WDSW/CCl4 mice and human HCC cells. In contrast, curcumin upregulated Kruppel-like factor 4 (KLF4) in MASH liver and HCC cells, which is known to downregulate sp1 (specificity protein-1) expression. Thus, curcumin treatment effectively inhibited the progression of MASH to HCC by downregulating the expression of AATF via the KLF4-Sp1 signaling pathway. These preclinical findings establish a novel molecular connection between curcumin and AATF in reducing hepatocarcinogenesis, and provide a strong rationale for the development of curcumin as a viable treatment for MASH-HCC in humans.
Cancer-associated fibroblasts (CAFs) have previously been shown to play a pivotal role in multiple cancer dynamics, including mediating tumor cell invasion: their pro-invasive secretory profile and ability to remodel the extracellular matrix (ECM) architecture particularly promote tumor progression through tumor cell invasion into surrounding tissue areas and beyond. Given that reduced CAF abundance in tumors correlates with improved outcomes in various cancers, we set out to identify epigenetic targets involved in CAF activation in the tumor-stromal margin to reduce overall tumor aggressiveness. Using the GLAnCE (Gels for Live Analysis of Compartmentalized Environments) co-culture platform, we performed an image-based, phenotypic screen and identified EHMT2 (also known as G9a), an epigenetic enzyme that targets the methylation of histone 3 lysine 9 (H3K9), as the most potent modulator of CAF abundance and CAF-mediated tumor cell invasion. Transcriptomic and functional analysis of EHMT2-inhibited CAFs revealed the involvement of EHMT2 in driving CAFs towards a pro-invasive phenotype. Further, EHMT2 signaling mediated CAF hyperproliferation, a feature that is typically associated with activated fibroblasts present in tumors, but the molecular basis for which has not thus far been identified. This study suggests a role for EHMT2 as a regulator of CAF hyperproliferation within the tumor mass, which in turn magnifies CAF-induced pro-invasive effects on tumor cells.
Diffuse Intrinsic Pontine Glioma (DIPG) is a lethal pediatric type of brain tumor that grows in the bm and originated from glial cells. Its location and infiltrative nature impede surgical resection and make the treatment difficult and low effective. In consequence, affected children have a short life expectancy of 12 months. The most frequent mutation is a substitution of lysine to methionine at residue 27 of histone H3 (H3K27M). Secondary mutations in additional genes, including Myc, are required for the malignancy of glial cells. The lack of studies and tumor aggressiveness make it necessary to generate new experimental models that reproduce the fundamental aspects of the disease and allow to expand the knowledge about DIPG. Drosophila melanogaster presents advantages as an experimental model and stands out for its genetic tools, easy handling, and great genetic and cellular homology with humans. Drosophila has contributed to the investigation of different diseases, including glioblastoma (GB) and neurodegenerative diseases as Alzheime[r]s or Parkinso[n]s. Here we present a new genetic model of DIPG generated in Drosophila melanogaster. It is based on the overexpression of H3K27 and Myc in glial cells that produce an increase in the number of glial cells in the ventral nerve cord and the expansion of glial membranes in early developmental stages. However, this novel DIPG model does not produce tumoral features in adult brains, in line with the pediatric nature of this disease. We have evaluated the activation of different signaling pathways active in other glial tumors, in this model of DIPG. The results show that, unlike GB, JNK pathway is not upregulated in DIPG, and it is not determinant for the progression of DIPG. Besides, glial cells in the DIPG model accumulate MMP1 and MMP2 and increase the accumulation of Liprin-{gamma}, previously associated to the formation of synaptic structures in GB cells. The results show that DIPG is a unique entity that differs from other high-grade gliomas such as GB and will require of a different therapeutic approach.
There is extensive evidence of sex differences in the susceptibility and prognosis of non-reproductive cancers. In addition to external factors, biological sex bias (e.g., sex chromosomes, hormones, and immune function) is suspected to function as a selective pressure that influences cancer initiation. However, there remains a lack of clarity concerning the extent of the effect of sex bias on cancer initiation, as well as the underlying mechanism. In this study, we show that tissue sex bias--directed by gonadotropin-releasing hormone--varies among tissues and is associated with two distinct age-specific patterns of cancer incidence: parallel and nonparallel. Additionally, we reveal that imbalances in estrogen and thyroid hormone are correlated with levels of hypoxia-inducible factors, which have three phases (hypoxia, hyperoxia, and "chaotic-oxia") that exist in most cancers and are linked to specific cancer subtypes, including cancers with microsatellites, the CpG island methylator phenotype, or hypermethylation. Our results suggest that sex-biased tissue environments and hormonal imbalances influence the evolutionary dynamics of cancer initiation, emphasizing the importance of maintaining hormonal homeostasis for cancer prevention and providing insights toward improving therapies for cancer types that involve hormonal imbalances.
Peutz-Jeghers syndrome (PJS) is a familial disorder caused by heterozygous inactivating Liver Kinase B1 (LKB1) mutations that promote gastrointestinal polyposis and enhance cancer susceptibility. How LKB1-deficiency alters the phenotypical landscape and hierarchical organization of epithelial tissues to mediate increased cancer risk remains poorly understood. Here, we employ small intestinal organoids to investigate these issues for heterozygous and homozygous Lkb1 epithelial loss. We show that Lkb1 loss causes an allele dosage-dependent activation of a transcriptional program for tissue repair that is already induced in stem cell populations and mediates alterations in secretory cell type morphology and positioning. Furthermore, this shift towards a regenerative state omits the need for EGF supplementation, thus inducing niche-independent properties. Strikingly, we uncover that heterozygous loss of Lkb1 is sufficient to push the epithelium into a premalignant program for colorectal carcinogenesis along the serrated pathway, which is further amplified by loss-of-heterozygosity (LOH) or Kras mutations. We conclude that persistent upregulation of a regenerative program due to LKB1 loss alters cellular hierarchy and induces niche independency, which predisposes PJS epithelium to uncontrolled growth along the serrated pathway.
Tumor mutations can influence the surrounding microenvironment leading to suppression of anti-tumor immune responses and thereby contributing to tumor progression and failure of cancer therapies. Here we use genetically engineered lung cancer mouse models and patient samples to dissect how LKB1 mutations accelerate tumor growth by reshaping the immune microenvironment. Comprehensive immune profiling of LKB1-mutant vs wildtype tumors revealed dramatic changes in myeloid cells, specifically enrichment of Arg1+ interstitial macrophages and SiglecFHi neutrophils. We discovered a novel mechanism whereby autocrine LIF signaling in Lkb1-mutant tumors drives tumorigenesis by reprogramming myeloid cells in the immune microenvironment. Inhibiting LIF signaling in Lkb1-mutant tumors, via gene targeting or with a neutralizing antibody, resulted in a striking reduction in Arg1+ interstitial macrophages and SiglecFHi neutrophils, expansion of antigen specific T cells, and inhibition of tumor progression. Thus, targeting LIF signaling provides a new therapeutic approach to reverse the immunosuppressive microenvironment of LKB1-mutant tumors.
Human cancers can exhibit phenotype switching, resulting in cells that are more metastatic or that are more tolerant to treatment. However, the relationship between these aggressive states is not well understood. We investigated the dynamics of phenotypic switching in human melanoma cells by monitoring the fluorescent activity from a transgenic reporter of BRN2 promoter activation. Melanoma cells exhibit heterogeneous BRN2 expression patterns that are reestablished upon isolation and clonal outgrowth. Specifically, stable BRN2 expression was generally inherited over multiple generations while undergoing occasional bidirectional interconversion. We found that BRN2 low cells were required for tumor initiation and metastasis in animal engraftment assays but were more sensitive to targeted BRAF inhibition. In contrast, the BRN2 high state was not tumorigenic, but entry into this state was uniform and persistent among cells tolerant to targeted BRAF therapy. Single-cell RNA sequencing analyses revealed core programs exclusive to either the BRN2 high or low cells, each of which is present in ex vivo tumors, demonstrating the physiological relevance of these states. Our findings emphasize that one challenge of effectively targeting phenotype switching in melanoma as a therapeutic strategy could be balancing distinct aggressive phenotypes so that sensitizing tumors to BRAF inhibition does not inadvertently lead to further dissemination. TeaserUnraveling melanomas shape-shifting behavior: insights into how cancer cells swap between metastasis and drug evasion.
Glioblastoma is the most prevalent and aggressive malignant tumor of the central nervous system. With a median overall survival of only one year, glioblastoma patients have a particularly poor prognosis, highlighting a clear need for novel therapeutic strategies to target this disease. Transcriptional cyclin-dependent kinases (tCDK), which phosphorylate key residues of RNA polymerase II (RNAPII) c-terminal domain (CTD), play a major role in sustaining aberrant transcriptional programs that are key to development and maintenance of cancer cells. Here, we show that either pharmacological inhibition or genetic ablation of the tCDKs, CDK12 and CDK13, markedly reduces both the proliferation and migratory capacity of glioma cells and patient-derived organoids. Using a xenograft mouse model, we demonstrate that CDK12/13 inhibition not only reduces glioma growth in vivo. Mechanistically, inhibition of CDK12/CDK13 leads to a genome-wide abrogation of RNAPII CTD phosphorylation, which in turn disrupts transcription and cell cycle progression in glioma cells. In summary, the results provide proof-of-concept for the potential of CDK12 and CDK13 as therapeutic targets for glioblastoma. Significance statementGlioblastoma is a common, aggressive, and invasive type of brain tumor that is usually fatal. The standard treatment for glioblastoma patients is surgical resection, radiotherapy, and chemotherapy with DNA-alkylating agents, and unfortunately current treatments only extend overall survival by a few months. It is therefore critical to identify and target additional biological processes in this disease. Here, we reveal that targeting a specific transcriptional addiction for glioma cells by inhibition of CDK12/CDK13 disrupts glioma-specific transcription and cell cycle progression and has potential to provide a new therapeutic strategy for glioblastoma.
Tumorigenesis for most high-grade serous ovarian cancers (HGSCs) likely initiates from fallopian tube (FT) epithelia. While epithelial subtypes have been characterized using single-cell RNA- sequencing (scRNA-Seq), heterogeneity of other cellular compartments and their involvement in tumor progression are poorly defined. Integrated analysis of human FT scRNA-Seq data and other relevant tissues, including HGSC tumors, revealed greater transcriptional diversity of immune and stromal cells. We identify an unprecedented abundance of monocytes in human FT myeloid cells across two independent donor cohorts. The ratio of macrophages to monocytes are relatively similar between benign FTs, ovaries, and adjacent normal tissues, but is significantly greater in tumor. FT-defined monocyte and macrophage signatures, cell-cell communication, and gene set enrichment analysis identified monocyte- and macrophage-specific ligand-receptor interactions and functional pathways in tumors and adjacent normal tissue. Further reanalysis of tumor scRNA-Seq from HGSC patients suggested different monocyte and macrophage subsets associated with neoadjuvant chemotherapy treatment. Taken together, our work provides evidence that an altered FT immune composition could inform early detection markers in HGSCs.
p53 mutation and amyloid formation are implicated with cancer pathogenesis, but the direct demonstration of the link between p53 amyloid load and cancer progression is lacking. Using multi-disciplinary techniques and a cohort of 59 tumor tissues (53 from Indian cancer patients and six normal tissues) of oral and stomach cancer types, we showed that p53 amyloid load and cancer grades are highly correlated. Further, next-generation sequencing (NGS) data suggest that not only mutant p53 (e.g., SNVs, deletions, and insertions) but wild-type p53 also formed amyloids either in the nucleus (50%) and/or in the cytoplasm in most cancer tissues. Interestingly, in all these cancer tissues, p53 displays a loss of DNA binding and transcriptional activities, which is highly aggravated with the amyloid load and cancer grades. The p53 amyloids also sequester higher amounts of p63/p73 isoforms in higher-grade of tumor tissues. The data suggest p53 misfolding/aggregation and subsequent amyloid formation lead to loss and gain of p53 tumorigenic function, aggravation of which might determine the cancers grades.
TERT promoter mutations (TPMs) are frequently found in different cancer types, including approximately 70% of sun-exposed skin melanomas. In melanoma, TPMs are among the earliest mutations and can be present during the transition from nevus to melanoma. However, the specific factors that contribute to the selection of TPMs in certain nevi subsets are not well understood. To investigate this, we analyzed a group of dysplastic nevi (DN) by sequencing genes commonly mutated in melanocytic neoplasms. We examined the relationship between the identified mutations, patient age, telomere length, histological features, and the expression of p16. Our findings reveal that TPMs are more prevalent in DN from older patients and are associated with shorter telomeres. Importantly, these TPMs were not found in nevi with BRAF V600E mutations. Conversely, DN with BRAF V600E mutations were observed in younger patients, had longer telomeres, and a higher proportion of p16-positive cells. This suggests that these nevi arrest growth independently of telomere shortening through a mechanism known as oncogene-induced senescence (OIS). These characteristics extend to melanoma sequencing data sets, where melanomas with BRAF V600E mutations were more likely to have CDKN2A inactivation, overriding OIS. In contrast, melanomas without BRAF V600E mutations showed a higher frequency of TPMs. Our data imply that TPMs are selected to bypass replicative senescence (RS) in cells that were not arrested by OIS. Overall, our results indicate that a subset of melanocytic neoplasms face constraints from RS, while others encounter OIS and RS. The order in which these barriers are overcome during progression to melanoma depends on the mutational context.
BackgroundBulk cancer and minimal residual disease (MRD) are characterised by different molecular drivers and therefore necessitate different therapeutic strategies. However, there are currently no 3D models that can faithfully recapitulate MRD ex vivo for therapy development. MethodsA microfluidic technique was implemented to construct 3D microtumours, in which tumour cells, either by themselves or with fibroblasts, were encapsulated in viscous hydrogels. The 3D microtumours were analysed for their response to first-line chemotherapeutics and characterised through RNA-Seq, by comparing them to both 2D cultures and clinical samples. ResultsOur microfluidic platform guarantees the fabrication of 3D microtumours of tailorable size and cell content, which recreate key features of tumours such as hypoxia, characteristic organization of the cytoskeleton and a dose-response to chemotherapeutics close to the physiological range. The 3D microtumours were also used to examine non-genetic heterogeneity in ovarian cancer and could fully reflect the recently described "Oxford Classic" five molecular signatures. The gene expression profile of 3D microtumours following chemotherapy treatment closely resembled that of MRD in ovarian cancer patients, showing the upregulation of genes involved in fatty acid metabolism. We demonstrate that these 3D microtumours are ideal for drug development by showing how they support the identification of a promising inhibitor of fatty acid oxidation, perhexiline, which specifically targets chemotherapy-resistant MRD ovarian cancer cells and not bulk cancer cells. ConclusionWe have obtained the first 3D model of ovarian cancer MRD by using microtumours generated through microfluidics. This system is ideal for high-throughput drug screening and, given its versatility, it can be readily extended to additional types of cancer, as well as accommodate multiple cell types to generate complex tumour microenvironments.
The signaling pathway of transforming growth factor-beta (TGF{beta}) plays crucial roles in the establishment of an immunosuppressive tumor microenvironment, making anti-TGF{beta} agents a significant area of interest in cancer immunotherapy. However, the clinical translation of current anti-TGF{beta} agents that target upstream cytokines and receptors remains challenging. Therefore, the development of small molecule inhibitors specifically targeting SMAD4, the downstream master regulator of TGF{beta} pathway, would offer an alternative approach with significant therapeutic potential for anti-TGF-{beta} signaling. In this study, we present the development of a cell lysate-based multiplexed time-resolved fluorescence resonance energy transfer (TR-FRET) assay in an ultrahigh-throughput screening (uHTS) 1536-well plate format. This assay enables simultaneous monitoring of the protein-protein interaction (PPI) between SMAD4 and SMAD3, as well as the protein-DNA interaction (PDI) between SMADs and their consensus DNA binding motif. The multiplexed TR-FRET assay exhibits high sensitivity, allowing the dynamic analysis of the SMAD4-SMAD3-DNA complex at single amino acid resolution. Moreover, the multiplexed uHTS assay demonstrates robustness for screening small molecule inhibitors. Through a pilot screening of an FDA-approved and bioactive compound library, we identified gambogic acid and gambogenic acid as potential hit compounds. These proof-of-concept findings underscore the utility of our optimized multiplexed TR-FRET platform for large-scale screening to discover small molecule inhibitors that target the SMAD4-SMAD3-DNA complex as novel anti-TGF{beta} signaling agents.
BRD4 (Bromodomain containing protein 4) is a chromatin reader binds to acetylated lysine residues on histones interacting with RNA Pol II, p-TFeb. PDGF-BB was presented here, in soft-tissue tumor, as an oncogenic factor driving cell proliferation, and aberrant BRD4 knockdown significantly reduced tumor aggressiveness and unfavorable prognosis in soft-tissue tumors. To identify suppressive key drivers impeding demoid tumor growth, shRNA drop-out screen analysis identified signature of "transcription from RNA polymerase II promoter" including DDX, Stat3, SMARCA, ATM, SIRT1, cMyc that were recruited with BRD4 interation in activating {beta}-catenin, which is a major key driver mutated in soft-tissue tumor, and its depletion ceased soft-tissue tumor cell growth. Sepcifically, BRD4 mediated PDGF-BB signaling in GSK stimulation through transcriptional regulation from RNA polymerase II activity with PI3K as target, and thus not only canonical {beta} -catenin/TCF4 signaling, but also non-canonical {beta} -catenin conjunction complex response was activated by BRD4 in nucleus involved in promoting cell proliferation. Our study delineated a signaling axis that may allow soft-tissue tumor cells to escape apoptosis during colonization by activating PDGFBB-BRD4-GSK-{beta} -catenin and non-canonical-{beta}-catenin pathway through BRD4 in cancer cells. An efficient treatment for soft-tissue tumors could be accomplished by targeting PDGF and BRD4 survival pathways on soft-tissue tumor cells.
Sex disparities have been observed in many tumor types affecting non-reproductive organs. Typically, the incidence and mortality rates of such cancers are higher in men. Although differences in lifestyle and environmental exposures are known contributors, knowledge of the molecular mechanisms driving sexual dimorphism in tumor development and therapy response remains limited. To address this question, we comprehensively studied the sex-determining region Y (SRY) gene, a male-specific gene that is critical in development. First, we screened 2,448 samples from 11 cancer types to identify those with a higher incidence in men and increased expression of SRY. In cases of high-grade glioma and melanoma, men with tumors exhibiting high SRY expression had a worse prognosis. Our results suggest that SRY target genes show altered expression when SRY is overexpressed. These gene sets are linked to cell growth, epithelial-mesenchymal transition, inflammation, and repression of tumor suppressor pathways (TP53 activation and activity of immune cells). In summary, we present the first comprehensive investigation of SRY expression and its association with clinical outcomes in men with high-grade glioma and melanoma. Our results shed light on the molecular basis for sex disparities and lay the foundation for investigation of various target genes and novel cancer treatments in men with high-grade glioma and melanoma.
Reactive oxygen species (ROS) are a double-edge sword in cancers and can both promote pro-tumorigenic signaling and also trigger oxidative stress dependent cell death. Thus, maintaining redox homeostasis to control levels of ROS within a tumor-promoting range elicits critical tumorigenic potential in cancer. Here, we show that head and neck squamous cell carcinoma (HNSCC) is uniquely characterized by its critical dependence on heightened antioxidant capacity facilitated by elevated glucose uptake to maintain survival and proliferation. Using a basal-epithelial-layer-specific GLUT1 knockout mouse model, we establish that targeting GLUT1-mediated glucose utilization in HNSCC cells of origin robustly inhibits HNSCC progression, providing strong genetic evidence that GLUT1 is indeed a targetable metabolic vulnerability. We further demonstrate that disrupting redox homeostasis with prooxidants such as high dose vitamin C and Auranofin induces potent cytotoxicity in HNSCCs by exerting profound oxidative stress when combined with GLUT1 inhibitors. Given the central role of insulin signaling in glucose homeostasis, we additionally show that circulating insulin levels modulate metabolic and oncogenic pathways of HNSCCs, providing a new perspective on events driving and sustaining HNSCC malignancy. These results establish GLUT1 as a viable therapeutic target for HNSCC in combination with prooxidant chemotherapies and define critical dependencies in HNSCC that can be utilized with existing clinical stage drugs for the treatment of HNSCC and potentially other squamous cancers.
Brain metastasis is a major cause of death in breast cancer (BC) patients.In this study, we integrated scRNA-seq data and bulk tissue mRNA data to explore the adaptation and remodeling of the tumor microenvironment by breast cancer cells during different stages of brain metastasis. Four datasets were utilized in our study, including three with mRNA-seq data from bulk BC tissue and BCBM tissue, and one with scRNA-seq data of BCBM cells. Through a series of bioinformatics analyses, we compared gene expression disparities, metabolic pathways, and functional pathways between BC cells in primary and metastatic sites, as well as between proliferating and dormant cancer cells in BCBM. We also examined the heterogeneity of cancer cells within the metastatic site and compared subgroups between proliferating and dormant cells.BCBM cells exhibited reduced functional pathways related to extracellular matrix (ECM), protein digestion and absorption, compared to primary site cells. Proliferating metastatic cells showed decreased pathways related to ECM, apoptosis, and inflammation, while pathways associated with cell cycle regulation, tumor cell proliferation, and anti-hypoxia were enhanced. Cluster 6 of dormant metastatic cells showed significant enhancement in pathways related to epithelial-mesenchymal transition, ECM, tumor inflammation, and anti-inflammatory response signaling. Cluster 3 of proliferating metastatic cells exhibited enhanced DNA replication pathways, while cluster 4 showed enhanced tumor proliferation signalin. Our study suggests that the characteristics of BC cells at different stages and the heterogeneity of subgroups play crucial roles in brain metastasis, involving adaptation to the brain microenvironment and remodeling of the tumor microenvironment.
Multi-region DNA sequencing of primary tumors and metastases from individual patients helps identify somatic aberrations driving cancer development. However, most methods to infer copy-number aberrations (CNAs) analyze individual samples. We introduce HATCHet2 to identify haplotype- and clone-specific CNAs simultaneously from multiple bulk samples. HATCHet2 introduces a novel statistic, the mirrored haplotype B-allele frequency (mhBAF), to identify mirrored-subclonal CNAs having different numbers of copies of parental haplotypes in different tumor clones. HATCHet2 also has high accuracy in identifying focal CNAs and extends the earlier HATCHet method in several directions. We demonstrate HATCHet2s improved accuracy using simulations and a single-cell sequencing dataset. HATCHet2 analysis of 50 prostate cancer samples from 10 patients reveals previously-unreported mirrored-subclonal CNAs affecting cancer genes.
p16 is a tumor suppressor encoded by the CDKN2A gene whose expression is lost in [~]50% of all human cancers. In its canonical role, p16 inhibits the G1-S phase cell cycle progression through suppression of cyclin dependent kinases. Interestingly, p16 also has roles in metabolic repro-gramming, and we previously published that loss of p16 promotes nucleotide synthesis via the pentose phosphate pathway. Whether other nucleotide metabolic genes and pathways are affected by p16/CDKN2A loss and if these can be specifically targeted in p16-low tumors has not been previously explored. Using CRISPR KO libraries in multiple isogenic melanoma cell lines with wildtype p16/CDKN2A and p16/CDKN2A knockdown, we determined that many nucleotide metabolism genes are negatively enriched in p16/CDKN2A knockdown cells compared to controls. Indeed, many of the genes that are required for survival in the context of low p16/CDKN2A expression based on our CRISPR screens are upregulated in p16/CDKN2A knockdown melanoma cells and those with endogenously low CDKN2A expression. We determined that cells with low p16 expression are sensitive to multiple inhibitors of de novo purine synthesis in vitro by inducing apoptosis. Together, our data provide evidence to reevaluate the utility of these drugs in patients with p16-low tumors as loss of p16 may provide a therapeutic window for these agents.
The majority of breast cancers are generally considered immune-deprived tumors. This lack of immunogenicity severely hinders effectiveness of current immunotherapy approaches limiting therapeutic options to control disease. Therefore, we need new biomarkers to determine and enhance immune responses to improve the outcome of cancer patients experiencing invasive disease. Our data in matched human patient biopsies show that CD47 expression increases from primary to metastatic tumors. CD47 is an integral membrane protein that impairs antitumor immunosurveillance and influences normal tissue metabolism. However, whether CD47 plays a role in regulating tumor bioenergetics is unknown. A carcinogen-induced mouse mammary carcinogenesis model demonstrates that the absence of CD47 reduces tumor burden, which is associated with a distinct metabolic signature compared to WT tumors. Depletion of several lipid metabolites was observed in the absence of CD47, and metabolic dependency experiments suggest that anti-sense blockade of CD47 limits reliance on fatty acid oxidation as a fuel supporting cellular respiration on cancer cells. Our global metabolomics analysis also implicated the absence of CD47 in downregulation of immunosuppressive metabolites of the tryptophan and prostaglandin pathways. Spatial proteomic analysis revealed increased immune infiltrate and substantial reduction in immunosuppressive immune checkpoint proteins in the absence of CD47 with the highest reduction in intra-tumoral PD-L1 expression. Since anti-PD-L1 therapy is used in the current strategy to treat triple-negative breast cancer (TNBC), we targeted CD47 in an EMT-6 syngeneic TNBC model. The in vivo knockdown of CD47 sensitized tumors to anti-PD-L1 therapy to decrease tumor burden and increase intratumoral cytotoxic T cells. Therefore, targeting CD47 may be a suitable immunotherapeutic option to limit immunosuppression and enhance the efficacy of immune checkpoint blockade.
The tumor evolution model posits that malignant transformation is preceded by randomly distributed driver mutations in cancer genes, which cause clonal expansions in phenotypically normal tissues. Although clonal expansions occur frequently in human epithelia and can remodel almost entire tissues, the mechanisms behind why only a small number of clones transform into malignant tumors remain enigmatic. Here, we develop an in vivo single-cell CRISPR strategy to systematically investigate tissue-wide clonal dynamics of the 150 most frequently mutated squamous cell carcinoma genes. We couple ultrasound-guided in utero lentiviral microinjections, single-cell RNA sequencing, guide capture and spatial transcriptomics to longitudinally monitor cell type-specific clonal expansions, document their underlying gene programs and contrast clonal expansions from tumor initiation. We uncover a TNF- signaling module that acts as a generalizable driver of clonal expansions in epithelial tissues. Conversely, during tumorigenesis, the TNF- signaling module is downregulated, and instead, we identify a subpopulation of invasive cancer cells that switch to an autocrine TNF- gene program. By analyzing clonally expanded perturbations and their frequency in tumors, we demonstrate that the autocrine TNF- gene program is associated with epithelial-mesenchymal transition (EMT) and is preexistent in a subpopulation of expanded epidermal stem cells, contributing to the predisposition for tumor initiation. Finally, we provide in vivo evidence that the epithelial TNF- gene program is sufficient to mediate invasive properties of epidermal stem cells and show that the TNF- signature correlates with shorter overall survival in human squamous cell carcinoma patients. Collectively, our study demonstrates the power of applying in vivo single-cell CRISPR screening to mammalian tissues and unveils distinct TNF- programs in tumor evolution. Understanding the biology of clonal expansions in phenotypically normal epithelia and the mechanisms governing their transformation will guide the development of novel strategies for early cancer detection and therapy.
Interactions between cells in the tumor microenvironment (TME) shape cancer progression and patient outcomes. To gain new insights into how the TME influences cancer outcomes, we adopt a distinct approach that exploits patterns of gene expression indicative of signalling between stromal fibroblasts and cancer cells, and demonstrate the prognostic significance of these gene signatures in multiple and independent squamous cell carcinoma cohorts. We discover that HB-EGF in cancer cells and EGFR in cancer associated fibroblasts represent a hub of tumor - stroma crosstalk through MAPK signalling and AP-1 transcription factor. We find divergent consequences for pathway activation in cancer cells compared to stromal fibroblasts that favours macrophages recruitment. Together these analyses demonstrate the utility of this new approach to interrogating the extent and consequences of TME crosstalk. By focusing on the transcriptional consequences of cancer cell-fibroblast interactions we derive prognostic signatures and uncover molecular mechanisms promoting fibroblast to macrophage communication.
B-cell lineage acute lymphoblastic leukemia (B-ALL) is comprised of diverse molecular subtypes and while transcriptional and DNA methylation profiling of B-ALL subtypes has been extensively examined, the accompanying chromatin landscape is not well characterized for many subtypes. We therefore mapped chromatin accessibility using ATAC-seq for 10 B-ALL molecular subtypes in primary ALL cells from 154 patients. Comparisons with B-cell progenitors identified candidate B-ALL cell-of-origin and AP-1-associated cis-regulatory rewiring in B-ALL. Cis-regulatory rewiring promoted B-ALL-specific gene regulatory networks impacting oncogenic signaling pathways that perturb normal B-cell development. We also identified that over 20% of B-ALL accessible chromatin sites exhibit strong subtype enrichment, with transcription factor (TF) footprint profiling identifying candidate TFs that maintain subtype-specific chromatin architectures. Over 9000 inherited genetic variants were further uncovered that contribute to variability in chromatin accessibility among individual patient samples. Overall, our data suggest that distinct chromatin architectures are driven by diverse TFs and inherited genetic variants which promote unique gene regulatory networks that contribute to transcriptional differences among B-ALL subtypes. HIGHLIGHTSO_LIPro-B progenitor cells as the most common cell-of-origin for B-ALL C_LIO_LIAP-1 TF-associated cis-regulatory rewiring in B-ALL C_LIO_LISubtype-specific accessible chromatin signatures representing 20% of all B-ALL sites C_LIO_LIRole for distinct TFs in promoting subtype-specific chromatin architectures C_LIO_LIThousands of inherited genetic variants identified impacting chromatin state C_LI
Senescent cells accumulate in multiple age-related disorders, including cancer, exacerbating the pathological manifestations, and the eradication of these cells has emerged as a promising therapeutic strategy. Despite the impact of senescence in diseases, the development of tools to monitor the senescent burden in vivo remains a challenge due to their suboptimal specificity, translatability, and tissue penetrance. Here, we have designed a nanostructured organic probe (NanoJaggs) based on biocompatible indocyanine green dye (ICG) building blocks forming J-aggregates, which possess distinct spectral properties allowing both fluorescence and photoacoustic tomography (PAT) detection. We show that NanoJaggs are taken up by an active process of endocytosis and exhibit selective accumulation at the lysosomal compartment in several in vitro models for senescence. Finally, NanoJagg probe is validated in two in vivo studies including live PAT imaging and shows remarkable specificity to tumours with chemotherapy-induced senescence compared to untreated proliferative tumors. In vitro, ex vivo and in vivo all indicate that NanoJaggs are a clinically translatable tool for detection of senescence and their robust PAT signal makes them suitable for longitudinal monitoring of the senescent burden in solid tumors after chemo or radiotherapy.
Protein phosphatase 2A (PP2A) is a versatile enzyme affecting many aspects of cellular physiology. However, it remains unclear which of the cellular processes are most perturbed upon PP2A inhibition and how these perturbations could be exploited therapeutically. We report an unanticipated sensitivity of the splicing machinery to phosphorylation changes in response to PP2A inhibition by LB-100 in colorectal adenocarcinoma. We observe enrichment for differentially phosphorylated sites within cancer-critical splicing nodes of U2 snRNP, SRSF and hnRNP proteins. Altered phosphorylation endows LB-100-treated colorectal adenocarcinoma cells with differential splicing patterns. In PP2A-inhibited cells, over 1000 events of exon skipping and intron retention affect regulators of genomic integrity. Finally, LB-100-evoked alternative splicing is predicted to be a source of neoantigens that can improve cancer treatment responses to immune modulators. Our findings provide a potential explanation for the pre-clinical and clinical observations that PP2A inhibition sensitizes cancer cells to immune checkpoint blockade and genotoxic agents.
There is an unmet medical need for new therapeutic approaches and targets for patients with non- Hodgkin lymphoma (NHL) who relapse or are refractory to anti-CD20 immunotherapy. Therefore, we developed a humanized IgG1 antibody targeting CD37, which was tailored to be afucosylated for enhanced antibody-dependent cellular cytotoxicity (ADCC) (NNV024). In line with this, NNV024 induced three-fold more potent ADCC activity against patient-derived chronic lymphocytic leukemia (CLL) cells compared with anti-CD20 obinutuzumab. Moreover, NNV024 showed 2-fold higher ADCC activity than anti-CD20 rituximab and a recombinant version of DuoHexaBody-CD37 against both NHL and CLL cells. Survival was significantly longer after NNV024 treatment than with obinutuzumab in a mouse model. In addition, NNV024 showed a favourable plasma half-life in human FcRn transgenic mice of about 9-days, which was 2-fold longer than that of obinutuzumab and DuoHexaBody-CD37. These results warrant the further development of NNV024 as a treatment for NHL.
Somatic mutants of calreticulin (CRT) drive myeloproliferative neoplasms (MPNs) via binding to the thrombopoietin receptor (MPL) and aberrant activation of the JAK/STAT pathway. Compared with healthy donors, platelets from MPN patients with CRT mutations display low cell surface MPL. Co-expression of MPL with an MPN-linked CRT mutant (CRTDel52) reduces cell surface MPL expression, indicating the involvement of induced protein degradation, a better understanding of which could lead to new therapies. We show that lysosomal degradation is relevant to the turnover of both CRTDel52 and MPL. Drug-mediated activation of lysosomal degradation reduces CRTDel52 and MPL expression, with parallel inhibition of CRTDel52-induced cell proliferation and stem cell colony formation. Thus, reduced surface MPL, a marker of platelets from MPN patients with CRT mutations, results from mutant CRT-induced lysosomal degradation of MPL. Drug-induced activation of lysosomal degradation compromises the pathogenic effects of CRTDel52, which can be further exploited for therapeutic interventions.
MYCN activates canonical MYC targets involved in ribosome biogenesis, protein synthesis and represses neuronal differentiation genes to drive oncogenesis in neuroblastoma (NB). How MYCN orchestrates global gene expression remains incompletely understood. Our study finds that MYCN binds promoters to up-regulate canonical MYC targets but binds to both enhancers and promoters to repress differentiation genes. MYCN-binding also increases H3K4me3 and H3K27ac on canonical MYC target promoters and decreases H3K27ac on neuronal differentiation gene enhancers and promoters. WDR5 is needed to facilitate MYCN promoter binding to activate canonical MYC target genes, whereas MYCN recruits G9a to enhancers to repress neuronal differentiation genes. Targeting both MYCNs active and repressive transcriptional activities using both WDR5 and G9a inhibitors synergistically suppresses NB growth. We demonstrate that MYCN cooperates with WDR5 and G9a to orchestrate global gene transcription. The targeting of both these cofactors is a novel therapeutic strategy to indirectly target the oncogenic activity of MYCN.
Ductal carcinoma in situ (DCIS) is the most common type (80%) of noninvasive breast lesions. The lack of validated prognostic markers, limited patient numbers and variable tissue quality significantly impact diagnosis, risk stratification, patient enrolment, and results of clinical studies. We performed label-free quantitative proteomics on 50 clinical formalin-fixed, paraffin embedded biopsies, validating 22 putative biomarkers from independent genetic studies. Our comprehensive proteomic phenotyping reveals more than 380 differentially expressed proteins and metabolic vulnerabilities, that can inform new therapeutic strategies for DCIS and IDC. Due to the readily druggable nature of proteins and metabolites, this study is of high interest for clinical research and pharmaceutical industry. To further evaluate our findings, and to promote the clinical translation of our study, we developed a highly multiplexed targeted proteomics assay for 90 proteins associated with cancer metabolism, RNA regulation and signature cancer pathways, such as Pi3K/AKT/mTOR and EGFR/RAS/RAF.
BACKGROUNDOncolytic adenoviruses, such as Delta-24-RGD, show promise as a potential breakthrough in treating patients with high-grade gliomas. However, their effectiveness against gliomas can be hindered by the presence of neutralizing antibodies. METHODSProduction of human neutralizing antibodies against adenoviruses was assessed in two cohorts of patients with malignant gliomas treated with Delta-24-RGD in a phase 1 clinical trial. Sera containing neutralizing antibodies were also obtained from mice immunized with intramuscular injections of wild-type Ad5. Chimeric adenovirus was constructed using molecular cloning, and its activity was assessed in vitro using quantitative PCR, western blot, and transmission electron microscopy. The therapeutic efficacy of the chimeric virus was tested in vivo using sera from patients previously treated with Delta-24-RGD and immunocompetent murine models of glioma. RESULTSExamination of sera from patients with malignant gliomas treated with Delta-24-RGD revealed that in the cohort treated with multiple injections of this oncolytic adenovirus, a higher percentage of patients developed neutralizing antibodies when compared to the patients treated with a single injection of Delta-24-RGD. Of note, long-term survival was only observed in patients who received a single injection. Delta-24-RGD-H43m, a chimeric oncolytic adenovirus engineered to overcome virus neutralization, demonstrated a potent anti-glioma effect both in vitro and in vivo. This chimeric virus showed resilience against anti-Ad5 neutralizing antibodies and conferred better therapeutic efficacy compared to Delta-24-RGD in mice with immunity against Ad5. Of further clinical relevance, Delta-24-RGD-H43m also evaded the inhibitory effects of sera from human patients treated with Delta-24-RGD. CONCLUSIONSThe development of neutralizing antibodies due to multiple virus injections was associated with lower frequency of long-term survivors in a clinical trial. The new chimeric virus shows increased resilience to inactivation by the sera of human patients compared to the parental virus. These findings lay the foundation for a novel oncolytic virus treatment approach targeting a significant percentage of glioma patients with prior exposure to adenovirus.
Improved and low toxicity treatments are urgently required to treat cancers, however cancer drug development is hindered by high drug attrition rates. Lack of tractable, reproducible, and transferrable platforms are key impediments hindering cancer drug development. Here we develop a prototype ECM, Vitronectin-Alginate-Laminin (VAL), comprised of animal free components, in defined formulations. We perform an in-depth analysis of the physical, chemical, and biological parameters of VAL and using acute lymphoblastic leukaemia (ALL) as a paradigm, optimise development of VAL-mesenchymal stroma cells (MSC)-ALL organoids. We show engraftment of patient derived leukaemia samples within our MSC-VAL organoids and find that ALL-interactions with both ECM and MSC mediate leukaemia biology. Ultimately, we show tractability of our model to study cell-cell crosstalk - we apply our model to reveal formation of TNTs between both MSC and patient-derived ALL in cells that have escaped anti-leukaemia treatment.
Acute myeloid leukemia (AML) driven by the activation of EVI1 due to chromosome 3q26/MECOM rearrangements is incurable. Since transcription factors like EVI1 are notoriously hard to target, insight into the mechanism by which EVI1 drives myeloid transformation could provide alternative avenues for therapy. Applying protein folding predictions combined with proteomics technologies we demonstrate interaction with CTBP1 and CTBP2 via a single PLDLS motif in EVI1 is indispensable for leukemic transformation. A 4x PLDLS repeat construct outcompetes binding of EVI1 to CTBP1 and CTBP2 and inhibits proliferation of 3q26/MECOM rearranged AML in vitro and in xenotransplant models. This proof-of-concept study opens the possibility to target one of the most incurable forms of AML with specific EVI1-CTBP inhibitors. Our findings may also have important implications for other tumour types with aberrant expression of EVI1 or for cancers transformed by other CTBP1/2 dependent oncogenic transcription factors.
Cancer immune evasion contributes to checkpoint immunotherapy failure in many patients with metastatic cancers. The embryonic transcription factor DUX4 was recently characterized as a suppressor of interferon-{gamma} signaling and antigen presentation that is aberrantly expressed in a small subset of primary tumors. Here, we report that DUX4 expression is a common feature of metastatic tumors, with [~]10-50% of advanced bladder, breast, kidney, prostate, and skin cancers expressing DUX4. DUX4 expression is significantly associated with immune cell exclusion and decreased objective response to PD-L1 blockade in a large cohort of urothelial carcinoma patients. DUX4 expression is a significant predictor of survival even after accounting for tumor mutational burden and other molecular and clinical features in this cohort, with DUX4 expression associated with a median reduction in survival of over one year. Our data motivate future attempts to develop DUX4 as a biomarker and therapeutic target for checkpoint immunotherapy resistance.
Meningiomas are the most common primary intracranial tumors1-3. Treatments for patients with meningiomas are limited to surgery and radiotherapy, and systemic therapies remain ineffective or experimental4,5. Resistance to radiotherapy is common in high-grade meningiomas6, and the cell types and signaling mechanisms driving meningioma tumorigenesis or resistance to radiotherapy are incompletely understood. Here we report NOTCH3 drives meningioma tumorigenesis and resistance to radiotherapy and find NOTCH3+ meningioma mural cells are conserved across meningiomas from humans, dogs, and mice. NOTCH3+ cells are restricted to the perivascular niche during meningeal development and homeostasis and in low-grade meningiomas but are expressed throughout high-grade meningiomas that are resistant to radiotherapy. Integrating single-cell transcriptomics with lineage tracing and imaging approaches across mouse genetic and xenograft models, we show NOTCH3 drives tumor initiating capacity, cell proliferation, angiogenesis, and resistance to radiotherapy to increase meningioma growth and reduce survival. An antibody stabilizing the extracellular negative regulatory region of NOTCH37,8 blocks meningioma tumorigenesis and sensitizes meningiomas to radiotherapy, reducing tumor growth and improving survival in preclinical models. In summary, our results identify a conserved cell type and signaling mechanism that underlie meningioma tumorigenesis and resistance to radiotherapy, revealing a new therapeutic vulnerability to treat meningiomas that are resistant to standard interventions.
Proapoptotic tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling as a cause of cancer cell death is a well-established mechanism. However, TRAIL-receptor (TRAIL-R) agonists have had very limited anticancer activity in humans, challenging the concept of TRAIL as a potent anticancer agent. Herein, we demonstrate that TRAIL+ cancer cells can leverage noncanonical TRAIL signaling in myeloid-derived suppressor cells (MDSCs) promoting their abundance in murine cholangiocarcinoma (CCA). In multiple immunocompetent syngeneic, orthotopic murine models of CCA, implantation of TRAIL+ murine cancer cells into Trail-r-/-mice resulted in a significant reduction in tumor volumes compared to wild type mice. Tumor bearing Trail-r-/- mice had a significant decrease in the abundance of MDSCs due to attenuation of MDSC proliferation. Noncanonical TRAIL signaling with consequent NF-{kappa}B activation in MDSCs facilitated enhanced MDSC proliferation. Single cell RNA sequencing and cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq) of CD45+ cells in murine tumors from three distinct immunocompetent CCA models demonstrated a significant enrichment of an NF-{kappa}B activation signature in MDSCs. Moreover, MDSCs were resistant to TRAIL-mediated apoptosis due to enhanced expression of cellular FLICE inhibitory protein (cFLIP), an inhibitor of proapoptotic TRAIL signaling. Accordingly, cFLIP knockdown sensitized murine MDSCs to TRAIL-mediated apoptosis. Finally, cancer cell-restricted deletion of Trail significantly reduced MDSC abundance and murine tumor burden. In summary, our findings define a noncanonical TRAIL signal in MDSCs and highlight the therapeutic potential of targeting TRAIL+ cancer cells for the treatment of a poorly immunogenic cancer.
Natural killer (NK) cells are attractive effectors for adoptive immunotherapy of cancer. Results from first-in-human studies using chimeric antigen receptor (CAR)-engineered primary NK cells and NK-92 cells are encouraging in terms of efficacy and safety. In order to further improve treatment strategies and to test the efficacy of CAR-NK cells in a personalized manner, preclinical screening assays using patient-derived tumor samples are needed. Zebrafish (Danio rerio) embryos and larvae represent an attractive xenograft model to study growth and dissemination of patient-derived tumor cells because of their superb live cell imaging properties. Injection into the organisms circulation allows investigation of metastasis, cancer cell-to-immune cell-interactions and studies of the tumor cell response to anti-cancer drugs. Here, we established a zebrafish larval xenograft model to test the efficacy of CAR-NK cells against metastatic breast cancer in vivo by injecting metastatic breast cancer cells followed by CAR-NK cell injection into the Duct of Cuvier (DoC). We validated the functionality of the system with two different CAR-NK cell lines specific for PD-L1 and ErbB2 (PD-L1.CAR NK-92 and ErbB2.CAR NK- 92 cells) against the PD-L1-expressing MDA-MB-231 and ErbB2-expressing MDA-MB-453 breast cancer cell lines. Injected cancer cells were viable and populated peripheral regions of the larvae, including the caudal hematopoietic tissue (CHT), simulating homing of cancer cells to blood forming sites. CAR-NK cells injected 2.5 hours later migrated to the CHT and rapidly eliminated individual cancer cells throughout the organism. Confocal live-cell imaging demonstrated intravascular migration and real-time interaction of CAR-NK cells with MDA-MB-231 cells, explaining the rapid and effective in vivo cytotoxicity. Thus, our data suggest that zebrafish larvae can be used for rapid and cost-effective in vivo assessment of CAR-NK cell potency and to predict patient response to therapy.
The breadth and depth at which cancer models are interrogated contribute to successful translation of drug discovery efforts to the clinic. In colorectal cancer (CRC), model availability is limited by a dearth of large-scale collections of patient-derived xenografts (PDXs) and paired tumoroids from metastatic disease, the setting where experimental therapies are typically tested. XENTURION is a unique open-science resource that combines a platform of 129 PDX models and a sister platform of 129 matched PDX-derived tumoroids (PDXTs) from patients with metastatic CRC, with accompanying multidimensional molecular and therapeutic characterization. A PDXT-based population trial with the anti-EGFR antibody cetuximab revealed variable sensitivities that were consistent with clinical response biomarkers, mirrored tumor growth changes in matched PDXs, and recapitulated the outcome of EGFR genetic deletion. Adaptive signals upregulated by EGFR blockade were computationally and functionally prioritized, and inhibition of top candidates increased the magnitude of response to cetuximab. These findings illustrate the probative value and accuracy of large ex vivo and in vivo living biobanks, highlight the importance of cross-platform and cross-methodology systematic validation, and offer avenues for molecularly informed preclinical research.
IntroductionKDM2B encodes a JmjC domain-containing histone lysine demethylase, which functions as an oncogene in several types of tumors, including TNBC. This study was initiated to address the cancer relevance of the results of our earlier work, which had shown that overexpression of KDM2B renders mouse embryonic fibroblasts (MEFs) resistant to oxidative stress by regulating antioxidant mechanisms. MethodsWe mainly employed a multi-omics strategy consisting of RNA-Seq, quantitative TMT proteomics, Mass-spectrometry-based global metabolomics, ATAC-Seq and ChIP-seq, to explore the role of KDM2B in the resistance to oxidative stress and intermediary metabolism. These data and data from existing patient datasets were analyzed using bioinformatic tools, including exon-intron-split analysis (EISA), FLUFF and clustering analyses. The main genetic strategy we employed was gene silencing with shRNAs. ROS were measured by flow cytometry, following staining with CellROX and various metabolites were measured with biochemical assays, using commercially available kits. Gene expression was monitored with qRT-PCR and immunoblotting, as indicated. ResultsThe knockdown of KDM2B in basal-like breast cancer cell lines lowers the levels of GSH and sensitizes the cells to ROS inducers, GSH targeting molecules, and DUB inhibitors. To address the mechanism of GSH regulation, we knocked down KDM2B in MDA-MB-231 cells and we examined the effects of the knockdown, using a multi-omics strategy. The results showed that KDM2B, functioning in the context of ncPRC1.1, regulates a network of epigenetic and transcription factors, which control a host of metabolic enzymes, including those involved in the SGOC, glutamate, and GSH metabolism. They also showed that KDM2B enhances the chromatin accessibility and expression of MYC and ATF4, and that it binds in concert with MYC and ATF4, the promoters of a large number of transcriptionally active genes, including many, encoding metabolic enzymes. Additionally, MYC and ATF4 binding sites were enriched in genes whose accessibility depends on KDM2B, and analysis of a cohort of TNBCs expressing high or low levels of KDM2B, but similar levels of MYC and ATF4 identified a subset of MYC targets, whose expression correlates with the expression of KDM2B. Further analyses of basal-like TNBCs in the same cohort, revealed that tumors expressing high levels of all three regulators exhibit a distinct metabolic signature that carries a poor prognosis. ConclusionsThe present study links KDM2B, ATF4, and MYC in a transcriptional network that regulates the expression of multiple metabolic enzymes, including those that control the interconnected SGOC, glutamate, and GSH metabolic pathways. The co-occupancy of the promoters of many transcriptionally active genes, by all three factors, the enrichment of MYC binding sites in genes whose chromatin accessibility depends on KDM2B, and the correlation of the levels of KDM2B with the expression of a subset of MYC target genes in tumors that express similar levels of MYC, suggest that KDM2B regulates both the expression and the transcriptional activity of MYC. Importantly, the concerted expression of all three factors also defines a distinct metabolic subset of TNBCs with poor prognosis. Overall, this study identifies novel mechanisms of SGOC regulation, suggests novel KDM2B-dependent metabolic vulnerabilities in TNBC, and provides new insights into the role of KDM2B in the epigenetic regulation of transcription. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=122 HEIGHT=200 SRC="FIGDIR/small/548031v2_ufig1.gif" ALT="Figure 1"> View larger version (34K): [email protected]@1c6977eorg.highwire.dtl.DTLVardef@103d73corg.highwire.dtl.DTLVardef@127b1ff_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsThe knockdown of KDM2B in basal-like breast cancer cell lines lowers the levels of GSH and sensitizes the cells to ROS inducers, GSH targeting molecules, and DUB inhibitors. KDM2B regulates intermediary metabolism by targeting the expression of a host of metabolic enzymes, including those in the SGOC, glutamate, and GSH metabolism. KDM2B enhances chromatin accessibility of MYC and ATF4 and promotes their expression. MYC and ATF4 binding sites are enriched in the promoters of genes whose accessibility depends on KDM2B. KDM2B functioning in the context of ncPRC1.1, binds the promoters of transcriptionally active genes, including those encoding KDM2B-regulated metabolic enzymes, in concert with MYC and ATF4. Basal-like TNBCs expressing high levels of all three regulators, exhibit a distinct metabolic signature that is associated with poor prognosis.
Studying gene regulatory networks associated with cancer provides valuable insights for therapeutic purposes, given that cancer is fundamentally a genetic disease. However, as the number of genes in the system increases, the complexity arising from the interconnections between network components grows exponentially. In this study, using Boolean logic to adjust the existing relationships between network components has facilitated simplifying the modeling process, enabling the generation of attractors that represent cell phenotypes based on breast cancer RNA-seq data. A key therapeutic objective is to guide cells, through targeted interventions, to transition from the current cancer attractor to a physiologically distinct attractor unrelated to cancer. To achieve this, we developed a computational method that identifies network nodes whose inhibition can facilitate the desired transition from one tumor attractor to another associated with apoptosis, leveraging transcriptomic data from cell lines. To validate the model, we utilized previously published in vitro experiments where the downregulation of specific proteins resulted in cell growth arrest and death of a breast cancer cell line. The method proposed in this manuscript combines diverse data sources, conducts structural network analysis, and incorporates relevant biological knowledge on apoptosis in cancer cells. This comprehensive approach aims to identify potential targets of significance for personalized medicine.
While cancer is an age-related disease, many cancer studies utilize younger animal models. Here, we uncover how a cancer, B-cell lymphoma, develops as a consequence of a naturally aged system. We show that this malignancy is associated with increased cell size, splenomegaly, and a newly discovered age-associated clonal B-cell (ACBC) population. Driven by exogenous c-Myc activation, hypermethylated promoters and somatic mutations, ACBC cells clonally expand independent of germinal centers (IgM+) and show increased biological age and hypomethylation in partially methylated domains related to mitotic solo-CpGs. Epigenetic changes in transformed mouse B cells are enriched for changes observed in human B-cell lymphomas. Mechanistically, the data suggest that cancerous ACBC cells originate from age-associated B cells, in part involving CD22 protein signaling fostered by the aging microenvironment. Transplantation assays demonstrate that ACBC evolve to become self-sufficient and support malignancy when transferred into young recipients. Inhibition of mTOR or c-Myc in old mice attenuates premalignant changes in B cells during aging and emerges as a therapeutic strategy to delay the onset of age-related lymphoma. Together, we show how aging contributes to B-cell lymphoma through a previously unrecognized mechanism involving cell-intrinsic changes and the aged microenvironment, characterize a model that captures the origin and progression of spontaneous cancer during aging and identify candidate interventions against age-associated lymphoma.
Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. In recent years, short-read single-cell RNA sequencing (scRNA-seq) has been instrumental in deciphering tumor cell heterogeneities. However, these studies only enable gene-level expression quantification but neglect alterations in transcript structures, which arise from alternative end processing or splicing, and are frequently observed in cancer. In this study, we integrated short- and long-read scRNA-seq of CRC patient samples to build the first isoform-resolution CRC transcriptomic atlas. We identified 394 dysregulated transcript structures in tumor epithelial cells, including 299 resulting from various combinations of multiple splicing events. Secondly, we characterized genes and isoforms associated with epithelial lineages and subpopulations that exhibit distinct prognoses. Finally, we built an algorithm that integrated novel peptides derived from predicted ORFs of recurrent tumor-specific transcripts with mass spectrometry data and identified a panel of recurring neoepitopes that may aid the development of neoantigen-based cancer vaccines.
Aberrations in the capacity of DNA/chromatin modifiers and transcription factors to bind non-coding regions can lead to changes in gene regulation and impact disease phenotypes. However, identifying distal regulatory elements and connecting them with their target genes remains challenging. Here, we present MethNet, a pipeline that integrates large-scale DNA methylation and gene expression data across multiple cancers, to uncover novel cis regulatory elements (CREs) in a 1Mb region around every promoter in the genome. MethNet identifies clusters of highly ranked CREs, referred to as hubs, which contribute to the regulation of multiple genes and significantly affect patient survival. Promoter-capture Hi-C confirmed that highly ranked associations involve physical interactions between CREs and their gene targets, and CRISPRi based scRNA Perturb-seq validated the functional impact of CREs. Thus, MethNet-identified CREs represent a valuable resource for unraveling complex mechanisms underlying gene expression, and for prioritizing the verification of predicted non-coding disease hotspots.
Tissues are complex environments where different cell types are in constant interaction with each other and with non-cellular components. Preserving the spatial context during proteomics analyses of tissue samples has become an important objective for different applications, one of the most important being the investigation of the tumor microenvironment. Here, we describe a multiplexed protein biomarker detection method on the COMET instrument, coined sequential ImmunoFluorescence (seqIF). The fully automated method uses successive applications of antibody incubation and elution, and in-situ imaging enabled by an integrated microscope and a microfluidic chip that provides optimized optical access to the sample. We show seqIF data on different sample types such as tumor and healthy tissue, including 40-plex on a single tissue section that is obtained in less than 24 hours, using off-the-shelf antibodies. We also present extensive characterization of the developed method, including elution efficiency, epitope stability, repeatability and reproducibility, signal uniformity, and dynamic range, in addition to marker and panel optimization strategies. The streamlined workflow using off-the-shelf antibodies, data quality enabling quantitative downstream analysis, and ease of reaching hyperplex levels make seqIF suitable for immune-oncology research and other disciplines requiring spatial analysis, paving the way for its adoption in clinical settings.
Hypoxia is a common feature of many solid tumors due to aberrant proliferation and angiogenesis and has been associated with tumor progression and metastasis. Most of the well-known hypoxia effects are mediated through hypoxia-inducible factors (HIFs), but the long-lasting effect of hypoxia beyond the immediate HIF regulation remains less understood. Here we show that hypoxia exerts a prolonged effect to promote metastasis. Using breast cancer patient-derived circulating tumor cell (CTC) lines and common breast cancer cell lines, we found that hypoxia downregulates tumor intrinsic type I interferon (IFN) signaling and its downstream antigen presentation (AP) machinery in luminal breast cancer cells, via both HIF-dependent and HIF-independent mechanisms. Hypoxia induced IFN/AP suppression can last longer than the hypoxic exposure, presenting a "hypoxic memory" phenotype. Hypoxic memory of IFN/AP downregulation is established by specific hypoxic priming, and cells with hypoxic memory have an enhanced ability for tumorigenesis and metastasis. The histone deacetylase inhibitor (HDACi) Entinostat can erase the hypoxic memory and improve the immune clearance of tumor cells when combined with checkpoint immunotherapies in a syngeneic breast cancer mouse model. These results point to a novel mechanism for hypoxia facilitated tumor progression, through a long-lasting memory that provides advantages for CTCs during the metastatic cascade. Significance: We revealed a novel hypoxic memory of prolonged suppression of tumor intrinsic type I IFN and AP signals that promote tumorigenesis and metastasis, suggesting novel mechanistic understanding of the immune evasive properties of CTCs.
Leukemia cutis or leukemic cell infiltration in skin is one of the common extramedullary manifestations of acute myeloid leukemia (AML) and signifies a poorer prognosis. However, its pathogenesis and maintenance remain understudied. Here, we report massive AML cell infiltration in the skin in a transplantation-induced MLL-AF9 AML mouse model. These AML cells could regenerate AML post-transplantation. Prospective niche characterization revealed that skin harbored mesenchymal progenitor cells (MPCs) with a similar phenotype as BM mesenchymal stem cells. These skin MPCs protected AML-initiating stem cells (LSCs) from chemotherapy in vitro partially via mitochondrial transfer. Furthermore, Lama4 deletion in skin MPCs promoted AML LSC proliferation and chemoresistance. Importantly, more chemoresistant AML LSCs appeared to be retained in Lama4-/- mouse skin post-cytarabine treatment. Our study reveals the characteristics and previously unrecognized roles of skin mesenchymal niches in maintaining and protecting AML LSCs during chemotherapy, meriting future exploration of their impact on AML relapse. A 40-word summary Sandhow et al have in transplantation-induced AML mouse models demonstrated the leukemia-regenerating capacity of AML cells infiltrated in the skin and the role of skin mesenchymal niches in maintaining/protecting AML cells, providing new insight into the pathology of leukemia cutis.
Glioma contains malignant cells in diverse states. Hypoxic regions are associated with a unique histology of pseudopalisading cells, while other regions appear to have limited histological organization, reflecting the diffuse nature of glioma cells. Here, we combine spatial transcriptomics with spatial proteomics and novel computational approaches to define glioma cellular states at high granularity and uncover their organization. We find three prominent modes of cellular organization. First, cells in any given state tend to be spatially clustered, such that tumors are composed of small local environments that are each typically enriched with one major cellular state. Second, specific pairs of states preferentially reside in proximity across multiple scales. Despite the unique composition of each tumor, this pairing of states remains largely consistent across tumors. Third, the pairwise interactions that we detect collectively define a global architecture composed of five layers. Hypoxia appears to drive this 5-layered organization, as it is both associated with unique states of surrounding cells and with a long-range organization that extends from the hypoxic core to the infiltrative edge of the tumor. Accordingly, tumor regions distant from any hypoxic foci and tumors that lack hypoxia such as IDH-mutant glioma are less organized. In summary, we provide a conceptual framework for the organization of gliomas at the resolution of cellular states and highlight the role of hypoxia as a long-range tissue organizer.
BackgroundA key feature distinguishing high-grade glioma (HGG) from low-grade glioma (LGG) is the extensive neovascularization and endothelial hyperproliferation. Prior work has shown that tumor endothelial cells (TEC) from HGG are molecularly and functionally distinct from normal brain EC and secrete higher levels of pro-tumorigenic factors that promote glioma growth and progression. However, it remains unclear whether TEC from LGG also express pro-tumorigenic factors, and to what extent they functionally contribute to glioma growth. MethodsTranscriptomic profiling was conducted on tumor endothelial cells (TEC) from grade II/III (LGG, IDH-mutant) and grade IV HGG (IDH-wildtype). Functional differences between LGG- and HGG-TEC were evaluated using growth assays, resistance to anti-angiogenic drugs and radiation therapy. Conditioned media and specific factors from LGG- and HGG-TEC were tested on patient-derived gliomasphere lines using growth assays in vitro and in co-transplantation studies in vivo in orthotopic xenograft models. ResultsLGG-TEC showed enrichment of extracellular matrix and cell cycle-related gene sets and sensitivity to anti-angiogenic therapy whereas HGG-TEC displayed an increase in immune response-related gene sets and anti-angiogenic resistance. LGG- and HGG-TEC displayed opposing effects on growth and proliferation of IDH-wildtype and mutant tumor cells. Asporin (ASPN), a small leucine rich proteoglycan enriched in LGG-TEC was identified as a growth suppressor of IDH-wildtype GBM by modulating TGFB1-GPM6A signaling. ConclusionsOur findings indicate that TEC from LGG and HGG are molecularly and functionally heterogeneous and differentially regulate the growth of IDH-wildtype and mutant tumors.
Cytokine storm is a life-threatening inflammatory response characterized by hyperactivation of the immune system. It can be caused by various therapies, auto-immune conditions, or pathogens, such as respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes coronavirus disease COVID-19. Here we propose a conceptual mathematical model describing the phenomenology of cytokine-immune interactions when a tumor is treated by an exogenous immune cell agonist which has the potential to cause a cytokine storm, such as CAR T cell therapy. Numerical simulations reveal that as a function of just two model parameters, the same drug dose and regimen could result in one of four outcomes: treatment success without a storm, treatment success with a storm, treatment failure without a storm, and treatment failure with a storm. We then explore a scenario in which tumor control is accompanied by a storm and ask if it is possible to modulate the duration and frequency of drug administration (without changing the cumulative dose) in order to preserve efficacy while preventing the storm. Simulations reveal existence of a "sweet spot" in protocol space (number versus spacing of doses) for which tumor control is achieved without inducing a cytokine storm. This theoretical model, which contains a number of parameters that can be estimated experimentally, contributes to our understanding of what triggers a cytokine storm, and how the likelihood of its occurrence can be mitigated.
BackgroundNotch signaling has been shown to mediate treatment resistance and support cancer stem cells (CSCs) in endocrine-resistant estrogen receptor positive (ER+) and triple negative breast cancers (TNBCs). The clinical development of GSIs, first generation Notch inhibitors, has been hindered by lack of Notch specificity and dose-limiting toxicity. Here we describe the safety and efficacy of a first-in-class, clinical stage, orally available small molecule pan-Notch inhibitor, CB-103. Due to its unique mode of action, CB-103 doesnt induce GI toxicities noted with GSIs. There is a critical need for effective, safe, targeted therapies for patients with endocrine-refractory metastatic breast cancer. Recently approved targeted therapies for TNBC are only effective for a subset of patients. Moreover, GSI-resistant, constitutively activating Notch1 or Notch2 mutations are observed in [~]10% of TNBC. Our study elucidating the synergy of CB-103 with fulvestrant and paclitaxel in preclinical models of both hormone-refractory ER+ BC and TNBC respectively provides a novel and unique opportunity to address major unmet therapeutic needs. MethodsCB-103 was screened in combination with a panel of anti-neoplastic drugs. We evaluated the anti-tumor activity of CB-103 with fulvestrant in ESR1-mutant (Y537S), endocrine-resistant BC xenografts. In the same model, we examined anti-CSC activity in mammosphere formation assays for CB-103 alone or in combination with fulvestrant or palbociclib. We also evaluated the effect of CB-103 plus paclitaxel on primary tumors and CSC in GSI-resistant TNBC model HCC1187. Comparisons between groups were performed with two-sided unpaired Students t-test. One-way or two-way ANOVA followed by Tukeys post analysis was performed to analyze in vivo efficacy study results. ResultsCB-103 showed synergism with fulvestrant in ER+ cells and with paclitaxel in TNBC cells. CB-103 combined with fulvestrant or paclitaxel potently inhibited mammosphere formation in both models. Combination of CB-103 and fulvestrant significantly reduced tumor volume in an ESR1-mutant, endocrine-resistant BC model. In a GSI-resistant TNBC model, CB-103 plus paclitaxel significantly delayed tumor growth compared to paclitaxel alone. ConclusionsOur data indicate that CB-103 is an attractive candidate for clinical investigation in endocrine resistant, recurrent breast cancers with biomarker-confirmed Notch activity in combination with SERDs and/or CDKis and in TNBCs with biomarker-confirmed Notch activity in combination with taxane-containing chemotherapy regimens.
Aberrant alternative splicing is prevalent in cancer and affects most cancer hallmarks involving proliferation, angiogenesis, and invasion. Somatic point mutations can exert their cancer-driving functions via splicing disruption. We propose "SoMAS" (Somatic Mutation associated with Alternative Splicing), an efficient computational pipeline based on principal component analysis techniques, to explore the role of somatic mutations in shaping the landscape of alternative splicing via both cis- and trans-acting mechanisms. Applying SoMAS to 33 cancer types consisting of 9,738 tumor samples in The Cancer Genome Atlas, we identified 908 somatically mutated genes significantly associated with altered isoform expression in three or more cancer types. These genes include many well-known oncogenes/suppressor genes, RNA binding protein and splicing factor genes with both biological and clinical significance. Many of our identified SoMAS genes were corroborated to affect gene splicing by independent cohorts and/or methodologies. With SoMAS, we for the first time demonstrate the potential network of somatic mutations associated with the overall splicing profiles of cancer transcriptomes, bridging the genetic and epigenetic regulation of human tumorigenesis in an innovative way.
Oncofetal transcription factor SALL4 is essential for cancer cell survival.1-5 Recently, several groups reported that immunomodulatory imide drugs (IMiDs) could degrade SALL4 in a proteasome-dependent manner.6,7 Intriguingly, we observed that IMiDs had no effect on SALL4-positive cancer cells. Further studies demonstrated that IMiDs could only degrade SALL4A, one of the SALL4 isoforms. This finding raises the possibility that SALL4B, the isoform not affected by IMiDs, may be essential for SALL4-mediated cancer cell survival. SALL4B knockdown led to an increase in apoptosis and inhibition of cancer cell growth. SALL4B gain-of-function alone led to liver tumor formation in mice. Our observation that protein degraders can possess isoform-specific effects exemplifies the importance of delineating drug action and oncogenesis at the isoform level to develop more effective cancer therapeutics.
Calcimycin (A23187) is a polyether antibiotic and divalent cation ionophore, extracted from Streptomyces chartrecensis. With wide variety of antimicrobial activities, it also exhibits cytotoxicity of tumor cells. Calcimycin exhibit therapeutic potential against tumor cell growth; however, the molecular mechanism remains to be fully elucidated. Present study explores the mechanism of calcimycin-induced apoptosis cancer cell lines. Calcimycin induces apoptosis accompanied by increased intracellular calcium-level and increased expression of purinergic receptor-P2RX4, a ligand-gated ion channel. The percentage of apoptotic cancer cells in a dose-dependent manner quickly rose as recorded with MTT assays, Phase contrast imaging, wound healing assay, fluorescence imaging by DAPI and AO/EB staining and FACS. Mitochondrial potential was analyzed by TMRM assay as Ca2+ signaling is well known to be influenced and synchronized by mitochondria also. Calcimycin treatment tends to increase the intracellular calcium level, mRNA expression of ATP receptor P2RX4, and phosphorylation of p38. Blocking of either intracellular calcium by BAPTA-AM, P2RX4 expression by antagonist 5-BDBD, and phospho-p38 by SB203580, abrogated the apoptotic activity of calcimycin. Taken together, these results show that calcimycin induces apoptosis in P2RX4 dependent ATP mediated intracellular Ca2+ and p38 MAPK mediated pathway in both the cancer cell lines.
PARP1 has been shown to regulate EBV latency. However, the therapeutic effect of PARP1 inhibitors on EBV+ lymphomagenesis has not yet been explored. Here, we show that PARPi BMN-673 has a potent anti-tumor effect on EBV-driven LCL in a mouse xenograft model. We found that PARP1 inhibition induces a dramatic transcriptional reprogramming of LCLs driven largely by the reduction of the MYC oncogene expression and dysregulation of MYC targets, both in vivo and in vitro. PARP1 inhibition also reduced the expression of viral oncoprotein EBNA2, which we previously demonstrated depends on PARP1 for activation of MYC. Further, we show that PARP1 inhibition blocks the chromatin association of MYC, EBNA2, and tumor suppressor p53. Overall, our study strengthens the central role of PARP1 in EBV malignant transformation and identifies the EBNA2/MYC pathway as a target of PARP1 inhibitors and its utility for the treatment of EBNA2-driven EBV-associated cancers. Significance StatementA promising approach to treating EBV-driven malignancies involves targeting cancer and EBV biology. However, investigating host factors that co-regulate EBV latent gene expression, such as PARP1, has been incomplete. Our study demonstrates that the PARP1 inhibitor BMN-673 effectively reduces EBV-driven tumors and metastasis in an LCL xenograft model. Additionally, we have identified potential dysregulated mechanisms associated with PARP1 inhibition. These findings strengthen the role of PARP1 in EBV+ lymphomas and establish a link between PARP1 and the EBNA2/MYC axis. This has important implications for developing therapeutic approaches to various EBV-associated malignancies.
Although preclinical studies for drug discovery and biomarker development are extensively conducted using large publicly available cancer cell line databases, there have been no reports to date that clarify the association between homologous recombination repair deficiency (HRD) and drug sensitivity using these data. We comprehensively analyzed the molecular profiles and drug response screening data from the Cancer Cell Line Encyclopedia. Unexpectedly, gene alterations in BRCA1/2 or homologous recombination repair-related genes, HRD score, or mutational signature 3 were not significantly correlated with sensitivity to platinum agents or PARP inhibitors. Rather, higher HRD scores and mutational signature 3 were significantly associated with resistance to platinum and PARP inhibitors in multiple assays. These findings were consistent when analyses were restricted to breast and ovarian cancer cell lines and when data from the COSMIC Cell Line Project dataset were used. SignificanceIn existing cancer cell line databases, the association between HRD status and sensitivity to platinum or PARP inhibitors differs from that expected from clinical tumor data. This discrepancy may also apply to other tumor characteristics, and researchers should be aware of the potential limitations of cell line data. Structural abstractO_ST_ABSBackgroundC_ST_ABSComprehensive molecular profiling and drug sensitivity screening data from over 1000 cancer cell lines are currently available for preclinical studies including targeted drug discovery and biomarker development. However, there are no reports using these cell line databases to clarify the association between homologous recombination repair deficiency (HRD) and drug sensitivity. MethodsWe investigated the association between HRD status, including gene alterations in the homologous recombination repair (HR) pathway, HRD score, and mutational signature 3, and sensitivity to platinum agents and PARP inhibitors in the Cancer Cell Line Encyclopedia (CCLE) and the COSMIC Cell Line Project (CLP) datasets. ResultsIn the CCLE dataset (n=1182), samples with BRCA alterations, including BRCA1 methylation and BRCA1/2 mutations with locus-specific loss-of-heterozygosity, exhibited higher HRD scores and mutational signature 3. These two scores were positively correlated (r=0.475, p=1.25 x10-52). Unexpectedly, neither BRCA1/2 nor HR-related gene alterations correlated with sensitivity to platinum agents or PARP inhibitors. Instead, significantly positive correlations were observed between drug-response AUC values and HRD scores in 60% (6/10) of platinum agent assays, and in 43% (6/14) PARP inhibitor assays, while no significant negative correlation was observed. Similar results were obtained in the analysis with mutational signature 3. These findings were consistent in analyses limited to ovarian and breast cancer cell lines and in the CLP dataset, indicating samples with HRD showed resistance rather than sensitivity to these drugs. ConclusionIn existing cancer cell line databases, the association between HRD status and sensitivity to platinum and PARP inhibitors differs from that expected from clinical tumor data. This discrepancy may also apply to other tumor characteristics, and investigators should be aware of the potential limitations of cell line data.
The pseudokinase Tribbles Homolog 1 (TRIB1) is a known driver of tumorigenesis in acute myeloid leukemia and is encoded upstream of the oncogene MYC at the 8q24 locus. We observed that TRIB1/MYC co-amplification is associated with decreased relapse-free and overall survival in breast cancer patients, but the role of TRIB1 in this disease has not been well characterized. TRIB1 knockdown in multiple breast cancer cell lines inhibited cell proliferation and suppressed MYC expression, implicating TRIB1 in breast cancer cell proliferation. Transcriptomic and cell cycle analysis revealed cell cycle regulation as the likely mechanism through which TRIB1 influences breast cancer cell proliferation. TRIB1 knockdown also resulted in significant changes in both estrogen receptor (ER) and {beta}-catenin associated transcription. Interrogating the TRIB1 interactome in breast cancer cells by qPLEX-RIME reinforced the known association between TRIB1 and ubiquitination, while revealing a range of previously undescribed TRIB1 associated factors. Further analysis of the association between TRIB1, {beta}-catenin and FERMT2 suggests TRIB1 may regulate {beta}-catenin activity by controlling the levels of both {beta}-catenin, and its co-factor FERMT2. Together, these results suggest that coregulation of {beta}-catenin and ER-driven transcription by TRIB1, facilitates regulation of MYC expression and breast cancer cell proliferation. SignificanceThe pseudokinase TRIB1 is frequently co-amplified in breast cancers with the potent oncogene MYC, although the functional consequences of this event are not well understood. This study demonstrates TRIB1 is a regulator of cell cycle progression and MYC expression in breast cancer cells. It also profiles TRIB1-associated proteins in breast cancer cells, demonstrating conservation of TRIB1s canonical interaction with COP1 and reveals associations with members of the wider ubiquitination machinery, a range of transcriptional regulators and chromatin remodelers. The data presented provide insight into the function of TRIB1 in breast cancer and the role of TRIB1 in transcriptional regulation.
Neuroblastoma is characterised by extensive inter- and intra-tumour genetic heterogeneity and varying clinical outcomes. One possible driver for this heterogeneity are extrachromosomal DNAs (ecDNA), which segregate independently to the daughter cells during cell division and can lead to rapid amplification of oncogenes. While ecDNA-mediated oncogene amplification has been shown to be associated with poor prognosis in many cancer entities, the effects of ecDNA copy number heterogeneity on intermediate phenotypes are still poorly understood. Here, we leverage DNA and RNA sequencing data from the same single cells in cell lines and neuroblastoma patients to investigate these effects. We utilise ecDNA amplicon structures to determine precise ecDNA copy numbers and reveal extensive intercellular ecDNA copy number heterogeneity. We further provide direct evidence for the effects of this heterogeneity on gene expression of cargo genes, including MYCN and its downstream targets, and the overall transcriptional state of neuroblastoma cells. These results highlight the potential for rapid adaptability of cellular states within a tumour cell population mediated by ecDNA copy number, emphasising the need for ecDNA-specific treatment strategies to tackle tumour formation and adaptation.
ITK is a tyrosine kinase expressed predominantly by T lymphocytes. In mice, selective knock-out of the ITK gene produces Th1 skewing of T helper cell differentiation. We synthesized a covalent ITK inhibitor, soquelitinib, that binds ITK with greater than 100-fold selectivity compared to binding to resting lymphocyte kinase (RLK). In vitro studies with normal or malignant T cells demonstrated that soquelitinib suppresses Th2 cytokine production preferentially with relative sparing of Th1 cytokines. Soquelitinib inhibits the in vivo growth of several syngeneic murine tumors including those that do not express ITK. Treatment with soquelitinib leads to increased tumor infiltration of normal CD8+ cells that possess enhanced T effector function. Soquelitinib inhibited expression of T cell exhaustion markers and was able to restore T effector function to exhausted cells. Pharmacologic selective ITK inhibition may represent a novel approach to cancer immunotherapy.
PurposePARP inhibitors (PARPi) are effective in homologous recombination repair (HRR) defective (HRD) cancers. To (re)sensitise HRR proficient (HRP) tumours to PARPi combinations with other drugs are being explored. Our aim was to determine the mechanism underpinning the sensitisation to PARPi by inhibitors of cell cycle checkpoint kinase ATR, CHK1 and WEE1. Experimental designA panel of HRD and HRP cells (including matched BRCA1 or 2 mutant and corrected pairs) and ovarian cancer ascites cells were used. Rucaparib (PARPi) induced replication stress (RS) and HRR (immunofluorescence microscopy for {gamma}H2AX and RAD51 foci, respectively), cell cycle changes (flow cytometry), activation of ATR, CHK1 and WEE1 (Western Blot for pCHK1S345, pCHK1S296 and pCDK1Y15, respectively) and cytotoxicity (colony formation assay) was determined, followed by investigations of the impact on all of these parameters by inhibitors of ATR (VE-821, 1 M), CHK1 (PF-477736, 50 nM) and WEE1 (MK-1775, 100 nM). ResultsRucaparib induced RS (3 to10-fold), S-phase accumulation (2-fold) and ATR, CHK1 and WEE1 activation (up to 3-fold), and VE-821, PF-477736 and MK-1775 inhibited their targets and abrogated these rucaparib-induced cell cycle changes in HRP and HRD cells. Rucaparib activated HRR in HRP cells only and was (60-1,000x) more cytotoxic to HRD cells. VE-821, PF-477736 and MK-1775 blocked HRR and sensitised HRP but not HRD cells and primary ovarian ascites to rucaparib. ConclusionsOur data indicate that, rather than acting via abrogation of cell cycle checkpoints, ATR, CHK1 and WEE1 inhibitors cause an HRD phenotype and hence synthetic lethality with PARPi.
Aneuploidy, an abnormal number of chromosomes within a cell, is considered a hallmark of cancer. Patterns of aneuploidy differ across cancers, yet are similar in cancers affecting closely-related tissues. The selection pressures underlying aneuploidy patterns are not fully understood, hindering our understanding of cancer development and progression. Here, we applied interpretable machine learning (ML) methods to study tissue-selective aneuploidy patterns. We defined 20 types of features of normal and cancer tissues, and used them to model gains and losses of chromosome-arms in 24 cancer types. In order to reveal the factors that shape the tissue-specific cancer aneuploidy landscapes, we interpreted the ML models by estimating the relative contribution of each feature to the models. While confirming known drivers of positive selection, our quantitative analysis highlighted the importance of negative selection for shaping the aneuploidy landscapes of human cancer. Tumor-suppressor gene density was a better predictor of gain patterns than oncogene density, and vice-versa for loss patterns. We identified the contribution of tissue-selective features and demonstrated them experimentally for chr13q gain in colon cancer. In line with an important role for negative selection in shaping the aneuploidy landscapes, we found compensation by paralogs to be a top predictor of chromosome-arm loss prevalence, and demonstrated this relationship for one such paralog interaction. Similar factors were found to shape aneuploidy patterns in human cancer cell lines, demonstrating their relevance for aneuploidy research. Overall, our quantitative, interpretable ML models improve the understanding of the genomic properties that shape cancer aneuploidy landscapes.
Background and AimsHepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common malignant hepatocellular tumors seen in children. The aim of this work was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide information about the real-time state of tumors in response to therapies. MethodsFor this test, we utilized indocyanine green (ICG), a far-red fluorescent dye that is used clinically to identify malignant liver cells in the body during surgery. We assessed ICG accumulation in cell lines with fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, ICG, Glypican-3 (GPC3), and DAPI and tested this panel with cell lines and non-cancer control blood samples. We then used this panel to analyze whole blood samples for CTC burden with a cohort of 14 HB and HCC patients and correlated with patient characteristics and outcomes. ResultsWe showed that ICG accumulation is specific to liver cancer cells, compared to non-malignant liver cells, non-liver solid tumor cells, and non-malignant cells and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/GPC3/DAPI panel showed that it specifically tagged malignant liver cells. With patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients responses to therapy. ConclusionsOur novel ICG-based liquid biopsy test for CTCs can be used to specifically count CTCs in the blood of pediatric liver cancer patients. Impact and implicationsThis manuscript represents the first report of circulating tumor cells in the blood of pediatric liver cancer patients. The novel and innovative assay for CTCs shown in this paper will facilitate future work examining the relationship between CTC numbers and patient outcomes, forming the foundation for incorporation of liquid biopsy into routine clinical care for these patients. Graphical abstractOverview of novel liquid biopsy test for circulating tumor cells for pediatric liver cancer. Figure made with Biorender. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=39 SRC="FIGDIR/small/547557v1_ufig1.gif" ALT="Figure 1"> View larger version (10K): [email protected]@7b5b59org.highwire.dtl.DTLVardef@aa6292org.highwire.dtl.DTLVardef@2d67ca_HPS_FORMAT_FIGEXP M_FIG C_FIG
Tissue stiffness is a critical prognostic factor in breast cancer and is associated with metastatic progression. Here we show an alternative and complementary hypothesis of tumor progression whereby physiological matrix stiffness affects the quantity and protein cargo of small EVs produced by cancer cells, which in turn drive their metastasis. Primary patient breast tissue produces significantly more EVs from stiff tumor tissue than soft tumor adjacent tissue. EVs released by cancer cells on matrices that model human breast tumors (25 kPa; stiff EVs) feature increased adhesion molecule presentation (ITG2{beta}1, ITG6{beta}4, ITG6{beta}1, CD44) compared to EVs from softer normal tissue (0.5 kPa; soft EVs), which facilitates their binding to extracellular matrix (ECM) protein collagen IV, and a 3-fold increase in homing ability to distant organs in mice. In a zebrafish xenograft model, stiff EVs aid cancer cell dissemination through enhanced chemotaxis. Moreover, normal, resident lung fibroblasts treated with stiff and soft EVs change their gene expression profiles to adopt a cancer associated fibroblast (CAF) phenotype. These findings show that EV quantity, cargo, and function depend heavily on the mechanical properties of the extracellular microenvironment. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/545937v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): [email protected]@4e6814org.highwire.dtl.DTLVardef@1930790org.highwire.dtl.DTLVardef@1d5aff5_HPS_FORMAT_FIGEXP M_FIG C_FIG
Despite the revolutionary impact of immune checkpoint blockade (ICB) in cancer treatment, accurately predicting patients responses remains elusive. We analyzed eight cohorts of 2881 ICB-treated patients across 18 solid tumor types, the largest dataset to date, examining diverse clinical, pathologic, and genomic features. We developed the LOgistic Regression-based Immunotherapy-response Score (LORIS) using a transparent, compact 6-feature logistic regression model. LORIS outperforms previous signatures in ICB response prediction and can identify responsive patients, even those with low tumor mutational burden or tumor PD-L1 expression. Importantly, LORIS consistently predicts both objective responses and short-term and long-term survival across most cancer types. Moreover, LORIS showcases a near-monotonic relationship with ICB response probability and patient survival, enabling more precise patient stratification across the board. As our method is accurate, interpretable, and only utilizes a few readily measurable features, we anticipate it will help improve clinical decision-making practices in precision medicine to maximize patient benefit.
The development of single-cell omics tools has enabled scientists to study the tumor microenvironment (TME) in unprecedented detail. However, each of the different techniques may have its unique strengths and limitations. Here we directly compared two commercially available high-throughput single-cell RNA sequencing (scRNA-seq) technologies - droplet-based 10X Chromium vs. microwell-based BD Rhapsody - using paired samples from patients with localized prostate cancer (PCa) undergoing a radical prostatectomy. Although high technical consistency was observed in unraveling the whole transcriptome, the relative abundance of cell populations differed. Cells with low-mRNA content such as T cells were underrepresented in the droplet-based system, at least partly due to lower RNA capture rates. In contrast, microwell based scRNA-seq recovered less cells of epithelial origin. Moreover, we discovered platform-dependent variabilities in mRNA quantification and cell-type marker annotation. Overall, our study provides important information for selection of the appropriate scRNA-seq platform and for the interpretation of published results. SYNOPSISO_LIComparison of scRNA-seq protocols uncovers disparities in RNA-to-library conversion C_LIO_LIMicrowell-based scRNA-seq technology excels in capturing low-mRNA content cells C_LIO_LIBiased transcriptomes due to gene specific RNA detection efficacies by both platforms C_LIO_LIThe study guides in informed scRNA-seq platform selection and data interpretation C_LI
Loss of E-cadherin (CDH1) and the adherens junction (AJ) drive development and progression of invasive lobular breast cancer (ILC). However, approximately 40% retain wild type CDH1 alleles, indicating that modulation of other genes attenuates the AJ during ILC etiology. To identify alternative drivers, we performed targeted sequencing in CDH1 wild type samples, based on a defined set of 100 AJ, tight junction, and desmosome genes we designated as the Adhesome. In 146 ILC samples, we identified 62 cases (43%) with wild type CDH1 alleles in which we detected a total of 284 mutations in 36 Adhesome genes. After selection based on occurrence and potential loss of function, we identified an inactivating frameshift mutation in Afadin (AFDN; p.Lys630fs). Functional studies in E-cadherin-expressing breast cancer cells showed that Afadin knockout leads to immature AJs, and a non-cohesive phenotype accompanied by actomyosin dependent anoikis resistance, which are classical ILC hallmarks. Afadin reconstitutions show that F-actin organization critically depends on the E-catenin binding CC domain. Afadin loss in intraductal xenograft mouse breast cancer models leads to ILC-type morphologies and overt lung metastases. AFDN truncate reconstitutions revealed that deletion of the C-terminal E-catenin binding CC domain is sufficient to drive metastatic ILC. In conclusion, we identified and functionally coupled a somatic frameshift AFDN mutation in breast cancer to destabilization the epithelial AJ and the development of ILC hallmarks such as actomyosin-dependent anoikis resistance and single cell invasion. As such, Afadin represents a candidate tumor suppressor for E-cadherin-positive ILC development and progression.
Tau (MAPT) is a microtubule-associated protein causing common neurodegenerative diseases or inherited frontotemporal lobar degenerations. Emerging evidence for non-canonical functions of Tau in DNA repair and P53 regulation suggests its involvement in cancer. Indeed, preliminary studies have correlated Tau expression with cancer survival or response to therapies. To bring new evidence for a relevant role of Tau in cancer, we carried out an in silico pan-cancer analysis of MAPT transcriptomic profile in over 10000 clinical samples from 32 cancer types and over 1300 pre-clinical samples from 28 cancer types provided by the TCGA and the DEPMAP datasets respectively. MAPT expression associated with key cancer hallmarks including inflammation, proliferation, and epithelial to mesenchymal transition, showing cancer-specific patterns. In some cancer types, MAPT functional networks were affected by P53 mutational status. We identified new associations of MAPT with clinical outcomes and drug response in a context-specific manner. Overall, our findings indicate that the MAPT gene is a potential major player in multiple types of cancer. Importantly, the impact of Tau on cancer seems to be heavily influenced by the specific cellular environment.
AO_SCPLOWBSTRACTC_SCPLOWDrug resistance is a major challenge for curative cancer treatment, representing the main reason of death in patients. Evolutionary biology suggests pauses between treatment rounds as a way to delay or even avoid resistance emergence. Indeed, this approach has already shown promising preclinical and early clinical results, and stimulated the development of mathematical models for finding optimal treatment protocols. Due to their complexity, however, these models do not lend themself to a rigorous mathematical analysis, hence so far clinical recommendations generally relied on numerical simulations and ad-hoc heuristics. Here, we derive two mathematical models describing tumour growth under genetic and epigenetic treatment resistance, respectively, which are simple enough for a complete analytical investigation. First, we find key differences in response to treatment protocols between the two modes of resistance. Second, we identify the optimal treatment protocol which leads to the largest possible tumour shrinkage rate. Third, we fit the "epigenetic model" to previously published xenograft experiment data, finding excellent agreement, underscoring the biological validity of our approach. Finally, we use the fitted model to calculate the optimal treatment protocol for this specific experiment, which we demonstrate to cause curative treatment, making it superior to previous approaches which generally aimed at stabilising tumour burden. Overall, our approach underscores the usefulness of simple mathematical models and their analytical examination, and we anticipate our findings to guide future preclinical and, ultimately, clinical research in optimising treatment regimes.
Sudden cardiac deaths (SCDs) pose a formidable clinical challenge, and their underlying risk mechanisms are poorly understood. Using a gnotobiotic, germ-free mouse model, we fortuitously discovered SCD incidences resulting from occult cardiac metastases. Female germ-free C57BL/6 mice (n=22) were raised in isolation and injected with mammary Py230 cells. Significantly higher SCD probabilities (36.3%) were observed in germ-free mice compared to gut-colonized groups (0%). Extensive examinations revealed no physical anomalies but demonstrated occult cardiac sub-micrometastasis in three out of four sudden death cases. Further analysis supported the role of occult cardiac sub-micrometastasis as the leading cause of SCDs. The remaining germ-free mice exhibited minimal primary tumors but high levels of cardiac metastases and morbidity. The gnotobiotic SCD model represents a crucial milestone in our understanding of the complex interplay between the gut microbiota and the development of occult oncological processes that ultimately culminate in SCDs and warrants further investigation into their mechanisms.
Glioblastoma (GBM) represents the most aggressive subtype of glioma, noted for its profound invasiveness and molecular heterogeneity. The mesenchymal (MES) transcriptomic subtype is frequently associated with therapy resistance, rapid recurrence, and increased tumor-associated macrophages. Notably, activation of the NF-{kappa}B pathway and alterations in the PTEN gene are both associated with this malignant transition. Although PTEN aberrations have been shown to be associated with enhanced NF-{kappa}B signaling, the relationships between PTEN, NF-{kappa}B and MES transition are poorly understood in GBM. Here, we show that PTEN regulates the chromatin binding of bromodomain and extraterminal (BET) family proteins, BRD2 and BRD4, mediated by p65/RelA localization to the chromatin. By utilizing patient-derived glioblastoma stem cells and CRISPR gene editing of the RELA gene, we demonstrate a crucial role for RelA lysine 310 acetylation in recruiting BET proteins to chromatin for MES gene expression and GBM cell invasion upon PTEN loss. Remarkably, we found that BRD2 is dependent on chromatin associated acetylated RelA for its recruitment to MES gene promoters and their expression. Furthermore, loss of BRD2 results in the loss of MES signature, accompanied by an enrichment of proneural signature and enhanced therapy responsiveness. Finally, we demonstrate that disrupting the NF-{kappa}B/BRD2 interaction with a brain penetrant BET-BD2 inhibitor reduces mesenchymal gene expression, GBM invasion, and therapy resistance in GBM models. This study uncovers the role of hitherto unexplored PTEN-NF-{kappa}B-BRD2 pathway in promoting MES transition and suggests inhibiting this complex with BET-BD2 specific inhibitors as a therapeutic approach to target the MES phenotype in GBM.
Standard preclinical human tumor models lack a human tumor stroma. However, as stroma contributes to therapeutic resistance, the lack of human stroma may make current models less stringent for testing new therapies. To address this, using patient-derived tumor cells, patient derived cancer-associated mesenchymal stem/progenitor cells, and human endothelial cells, we created a Human Stroma-Patient Derived Xenograft (HS-PDX) tumor model. HS-PDX, compared to the standard PDX model, demonstrate greater resistance to targeted therapy and chemotherapy, and better reflect patient response to therapy. Furthermore, HS-PDX can be grown in mice with humanized bone marrow to create humanized immune stroma patient-derived xenograft (HIS-PDX) models. The HIS-PDX model contains human connective tissues, vascular and immune cell infiltrates. RNA sequencing analysis demonstrated a 94-96% correlation with primary human tumor. Using this model, we demonstrate the impact of human tumor stroma on response to CAR-T cell therapy and immune checkpoint inhibitor therapy. We show an immunosuppressive role for human tumor stroma and that this model can be used to identify immunotherapeutic combinations to overcome stromally mediated immunosuppression. Combined, our data confirm a critical role for human stoma in therapeutic response and indicate that HIS-PDX can be an important tool for preclinical drug testing. Statement of SignificanceWe developed a tumor model with human stromal, vascular, and immune cells. This model mirrors patient response to chemotherapy, targeted therapy, and immunotherapy, and can be used to study therapy resistance.

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