Journal of Experimental & Clinical Cancer Research

Abstract Background: High-grade serous ovarian cancer (HGSC) is characterized by extensive genomic heterogeneity and frequent alterations that promote replication stress (RS). Although RS has emerged as a promising therapeutic vulnerability, it remains unclear whether distinct RS-associated genomic alterations generate similar tumour states or drive unique biological programs and therapeutic dependencies. Methods: We developed and characterized a panel of syngeneic HGSC models representing recurrent RS-associated alterations, including overexpression of Ccne1, Brd4, Myc, Ndrg1, Pik3ca, and Brca1 heterozygosity, alongside previously established Pten/Nf1-deficient and Myc overexpressing models. Tumour fitness, transcriptomic programs, histopathology, extracellular matrix composition, immune organization, and therapeutic vulnerabilities were assessed using subcutaneous (s.c.) and intraperitoneal (i.p.) allografts, RNA sequencing (RNAseq), mass spectrometry (MS), cyclic-immunofluorescence (Cyc-IF), and preclinical therapeutic studies. Results: RS-associated genotypes exhibited marked differences in tumour fitness and generated distinct tumour ecosystem states despite sharing a common genetic background. Tumours harbouring BRCA1 heterozygosity displayed reduced tumour fitness, mesenchymal features, extracellular matrix remodelling, stromal expansion, and immune-excluded phenotypes. In contrast, tumours co-expressing Ccne1 and Brd4 exhibited the highest RS level together with strong activation of DNA damage response pathways and limited immune infiltration. Immune characterization identified immune-desert, immune-suppressed, and immune-excluded states across models, demonstrating substantial genotype-dependent immune heterogeneity. Elevated CD47 expression emerged as a defining feature of the Ccne1/Brd4 tumour state and was confirmed in human HGSC specimens with high CCNE1 and BRD4 protein expression. Therapeutic targeting of ATR and CD47 in intraperitoneal Ccne1/Brd4 allografts reduced tumour burden and induced histopathological responses compared with either monotherapy alone, supporting the translational relevance of this RS-high tumour state. Conclusions: Distinct RS-associated alterations do not converge on a common HGSC phenotype but instead generate diverse tumour ecosystem states with unique effects on tumour fitness, stromal remodelling, immune organization, and therapeutic vulnerabilities. These findings highlight the importance of considering the genetic origin of RS when developing therapeutic strategies and establish a framework for investigating genotype-specific vulnerabilities in HGSC.

Oral squamous cell carcinoma (OSCC), a highly aggressive subtype of head and neck cancer, remains a major clinical challenge with limited therapeutic options and poor survival outcomes. The Protein Inhibitor of Activated STAT1 (PIAS1), a SUMO E3 ligase involved in transcriptional regulation, DNA repair, and epithelial-mesenchymal transition (EMT), exhibits cancer type-specific roles, but its function in OSCC has not been well characterized. Here, we investigated the molecular and functional role of PIAS1 in OSCC progression and prognosis. All patient cohorts analysed here comprise HPV-negative disease. Analysis across multiple cohorts revealed that PIAS1 mRNA expression is significantly lower in tumor tissues than in normal oral cavity squamous epithelium, including in a cohort of 60 patient-matched tumor and normal pairs. Within the tumor compartment, protein abundance of PIAS1 correlated positively with patient survival. Functional assays using OSCC cell lines demonstrated that PIAS1 acts in a SUMO E3-dependent manner to suppress TGF{beta}-induced migration and invasion. Transcriptomic profiling of PIAS1-depleted cells revealed alterations in expression of genes with relevance in TGF{beta} signaling and pro-invasive cellular responses. Further analyses showed that 46 of these differentially altered hits intersected with The Cancer Genome Atlas (TCGA)-OSCC datasets, where four of these genes, including INHBA, associated with cell stemness-pathway. Spatial analysis of the mRNA abundance of INHBA within OSCC-derived surgical specimens showed increased abundance at the invasive front, and positively associated with aggressive tumor phenotypes, poor patients' outcomes, and resistance to immunotherapy. Single-cell RNA-seq analyses of INHBA revealed increased levels within tumor cells and cancer-associated fibroblasts (CAFs), suggesting potential tumor-intrinsic and extrinsic (tumor microenvironment) sources and hence actions. Collectively, our findings establish PIAS1 as a tumor suppressor in OSCC that restrains TGF{beta}-driven aggressive behaviour. Furthermore, we identify INHBA as a potential therapeutic target, among other genes characterized by spatially restricted, invasive tumor phenotypes.

Soft tissue sarcomas (STS) are a heterogeneous group of mesenchymal malignancies with generally poor prognosis, raising a continued interest in novel therapeutic targets. The TAM-family receptor tyrosine kinase AXL has been proposed as a therapeutic target across several cancer types, including STS. Here we revisit the clinical relevance of AXL in STS by combining in silico analyses with functional and transcriptomic characterisation of two representative AXL inhibitors, dubermatinib and bemcentinib, in the HT-1080 and SK-LMS-1 STS-derived cell models. STS ranked among the tumour types with the highest median AXL mRNA expression across The Cancer Genome Atlas, yet AXL expression was not associated with patient survival. Both dubermatinib and bemcentinib reduced cell viability and induced apoptosis but, unexpectedly, shRNA-mediated AXL knockdown failed to reproduce the antiproliferative effect of either inhibitor and did not modify cellular sensitivity to drugs treatment. Transcriptomic profiling after AXL genetic knockdown showed weak correlation with drug-induced transcriptional changes, with the large majority of drug-regulated genes being AXL-independent and largely specific to each cell line. Our data indicate that although dubermatinib and bemcentinib show clear antitumour activity in STS models, this activity is largely independent from AXL inhibition, suggesting the rationale for AXL-directed therapy may be reconsidered.

Background: Cancer patients face a significantly elevated risk of severe COVID-19 outcomes. Although vaccination is a cornerstone of prevention, data on vaccination coverage and association with survival among Russian cancer patients remain scarce. We assessed COVID-19 vaccination coverage and its association with overall survival in a population-based cohort of cancer patients in Northwest Russia. Methods: This retrospective registry-based cohort study integrated data from the Population-Based Cancer Registry (PBCR) of the Arkhangelsk Region and the Nenets Autonomous Okrug, regional vaccination records, and an artificial intelligence (AI)-based analysis of chest computed tomography (CT) scans. The cohort consisted of 1,144 cancer patients who underwent CT between August 2020 and April 2021. Vaccination status was ascertained via data linkage. Overall survival (OS) was compared between vaccinated and unvaccinated patients using Kaplan-Meier analysis and multivariable Cox proportional hazards regression, adjusted for demographic, clinical, and AI-derived CT biomarkers. To mitigate immortal time bias, the primary analysis used a landmark approach restricted to patients alive on March1, 2021 (N=1,136). A sensitivity analysis used a November1, 2021 landmark (N=894). Vaccination status was defined as receipt of at least one dose before the landmark date. Results: Only 6.6% (n=76) of patients received at least one dose of a COVID-19 vaccine (Sputnik V or Sputnik Light). Vaccinated patients were more likely to have earlier-stage cancer and were less likely to be receiving active treatment. In the primary landmark analysis, vaccination was associated with a significantly higher 3-year OS (80.3% vs. 45.7%, p<0.001). In multivariable analysis, vaccination was independently associated with a 60% lower hazard of all-cause mortality (adjusted HR 0.40, 95% CI 0.25-0.64). AI-detected COVID-19 pneumonia on baseline CT was also an independent predictor of poorer survival (adjusted HR 1.32, 95% CI 1.09-1.59). In the sensitivity analysis (November1, 2021 landmark), the adjusted HR for vaccination was 0.56 (95% CI 0.34-0.92), showing a consistent but attenuated association. Conclusion: This study reveals critically low COVID-19 vaccination coverage among cancer patients in Northwest Russia. Nevertheless, vaccination was strongly associated with a substantial survival benefit, underscoring its importance as a potentially lifesaving intervention for this vulnerable population.

Circulating tumor cells (CTCs) are key drivers of distant metastasis, while platelets facilitate this process by protecting them from immune surveillance. However, the detection of CTCs exhibiting platelet markers and their communication with monocytes has not been thoroughly investigated. This study seeks to identify the intercellular communication of CTCs that have acquired platelet traits by integrating single-cell RNA-seq data of 377 CTCs and 2,634 white blood cells. Trajectory analysis identified a subpopulation of CTCs with enhanced platelet-related functions, including platelet aggregation and resistance to NK cell-mediated cytotoxicity, termed Platelet-Programmed CTCs. The Dampened Weighted Least Squares method was implemented to estimate the platelet-programmed tumor cell proportion in 1,102 bulk RNA-seq samples from primary breast cancer tumors. A strong inverse association was found between platelet-programmed tumor cell proportion and overall survival (Cox-PH p-value =0.00419, HR=6 per 10% increase in proportion, 95% CI:1.76-20.7). However, this association did not differ significantly between early- and late-stage patients. Cell-cell communication analyses and molecular docking revealed the CD40LG-ITGA5:ITGB1 pair as a potential immune checkpoint candidate for monocytes in cancer (Hex score=-656.83; TNF-TNFR reference complex=-515). However, further experimental and clinical validation is required to translate these findings. In conclusion, these findings deepen our understanding of the immune evasion mechanisms of CTCs by acquiring platelet characteristics. This immune checkpoint axis offers a novel avenue for further experimental validation and future intervention.

Tumor-associated macrophages (TAMs) integrate multiple microenvironmental signals, including lectin-mediated recognition of tumor-associated glycans. Although several myeloid lectins have been implicated in tumor-macrophage interactions, their contributions to immunosuppressive TAM phenotypes remain poorly defined. We implemented a CRISPR-Cas9 ribonucleoprotein (RNP) workflow in primary human monocytes to enable comparative loss-of-function interrogation of five potentially immunosuppressive lectins we previously reported. CRISPR-Cas9 RNP delivery conditions were benchmarked in freshly isolated monocytes using CD14 as a technical target, followed by sgRNA editing efficiency screening for CLEC4E, CLEC6A, CD209, SELL, and SIGLEC9 in HeLa S3 cells. Selected guides were applied to primary monocytes before co-culture in a 3D model with BT474 breast cancer cells. Editing was quantified by Sanger-sequencing deconvolution, while co-culture-derived CD45+ macrophages were isolated by fluorescence-activated cell sorting and characterized by bulk RNA sequencing. All five lectins were successfully perturbed, although gene editing efficiency remained target- and donor-dependent. Transcriptomic analysis revealed target-specific reprogramming and recurrent immunometabolic responses. mTORC1 signaling was consistently enriched, together with the remodeling of cholesterol homeostasis, fatty acid metabolism, and oxidative phosphorylation. CLEC6A deletion achieved attenuation of hypoxia-, angiogenesis-, and TNF/NF-kB-associated programs. CD209 and SIGLEC9 deletion similarly reduced hypoxia- and angiogenesis-associated signatures while promoting lipid and oxidative metabolism. CLEC4E perturbation induced broad remodeling of lipid and oxidative metabolism and stress-response, despite comparatively limited editing efficiency. Comparative lectin perturbation thus identified CLEC6A as the strongest candidate for further mechanistic investigation, while CLEC4E showed broad transcriptional remodeling despite lower editing efficiency, supporting its prioritization for improved genetic interrogation. Responses to CD209 and SIGLEC9 targeting further support tumor glycan-myeloid signaling as a regulator of TAM state. Overall, lectin perturbation redirected TAM transcriptional states through distinct immunometabolic programs rather than a uniform pro-inflammatory polarization, highlighting lectin-dependent immunometabolic regulation as a promising axis for further investigation.

Leuprolide, a widely used androgen-deprivation therapy (ADT) for prostate cancer (PC), has been associated with increased cardiovascular events (CVE), although the underlying mechanisms remain unclear. Through integrated spatial transcriptomic analyses of murine heart and immune-stromal profiling in patient blood, we identified immune programs linked to leuprolide-associated CVE risk. Spatial analyses revealed the distinct organization of lymphoid (T+B cells) aggregates and inflammatory macrophages in the plaque following leuprolide exposure that accompanied by ventricular hypertrophy, relative to normal vasculature. Parallel profiling of circulatory soluble and cellular components in patients demonstrated CD8+T cell enriched pattern in ~44% of patients, including memory and type 1 cytotoxic subsets that linked to treatment-induced CVE, such as ventricular dysfunctions, but no contribution of adipocytokines. These translational findings highlight the stratification of leuprolide-associated CVE risk in PC patients based on circulating T cell profiling and could guide the risk mitigation with alternative ADT agents.

Introduction: Tumors are known to develop genomic heterogeneity over time, particularly in metastatic disease, raising concerns that a single-site biopsy may be insufficient to accurately predict response to medications. Methods: We used our 3D microtumor functional profiling platform that preserves key features of the native tumor microenvironment. We tested (i) six split samples from primary tumors and (ii) seven samples from primary tumors (ovarian, colon, and breast cancer) matched with their locoregional or distant metastases. Fresh tissue specimens were processed within 24 hours after surgery and treated with NCCN guideline-recommended chemo or targeted therapies at concentrations over four orders of magnitude. Cytotoxicity was evaluated after three days to generate dose response curves. The response correlations between the split sample or between the two matched sites were quantified using the concordance correlation coefficient ({rho}c) for the drug efficacy metrics. Results: We compared a total of 275 drug responses. The six split samples resulted in a strong correlation between the two tumor areas ({rho}c=0.95, p<0.001), supporting high assay reproducibility across distinct regions of the same tumor. Locoregional metastases were highly correlated with their primaries (ovarian to omentum {rho}c=0.97, p<0.001; ovarian to liver capsule {rho}c=0.93, p<0.001; colon to peritoneum {rho}c=0.91, p<0.001). A lesser correlation was observed with lymphogenic metastases (breast to axilla {rho}c=0.87, p<0.001), and the correlations of hematogenic metastases were even lower (colon to lung {rho}c=0.69 p<0.001; ovarian to soft tissue/colon {rho}c=0.58, p<0.001). No correlation was observed among specimens that were resistant to all tested medications. Conclusion: Tumor drug responses were highly preserved in locoregional metastases, whereas somewhat greater divergence was observed in lymphogenic or hematogenic metastases. Single-site functional profiling may remain informative for identifying treatment resistance and might reduce the risk of ineffective therapy selection in metastatic disease.

Purpose: Lung metastases are the primary cause of death in osteosarcoma patients and treatment response often vary due to convergence of genetic and phenotypic influences in the context of a dynamic tumor-host tissue environment. The purpose of this study was to determine how dynamic tumor- and host-driven receptor tyrosine kinase (RTK)-ERK signaling interactions contribute to phenotypic drug response heterogeneity. Experimental Design: Live-cell time-lapse microscopy and data-driven dynamical modeling was used to resolve ERK activity, FOSL1/Fra-1 reporter expression, and spatiotemporal cell fate in living, biosensor-expressing osteosarcoma lung metastases ex vivo following MCL1 inhibitor exposure. RTK inhibitors were then evaluated for their ability to suppress adaptive signaling and enhance MCL1 inhibitor efficacy ex vivo and in vivo. Results: MCL1 inhibition induced extensive tumor-cell death; however, persistent ERKhigh/Fra-1high reporter cells emerged and were enriched at the tumor-lung interface, consistent with adaptive resistance. Experimental and computational approaches revealed that tumor-cell lysis amplified fibroblast growth factor receptor (FGFR)-mediated ERK signaling in neighboring cells, promoting a targetable drug-resistant state marked by adaptive ERK induction, FOSL1/Fra-1 expression, and correlated with upregulation of known drug resistance pathways Nrf2 and HMOX1. Combinatorial inhibition of FGFR with fexagratinib, or broad-spectrum RTK inhibitor, pazopanib, suppressed adaptive ERK activation and enhanced MCL1 inhibitor response resulting in greater efficacy ex vivo and in vivo. Conclusions: Tumor-host and tumor-cell-lysis-induced FGFR-ERK signaling contribute to spatiotemporally heterogeneous adaptive resistance in metastatic osteosarcoma. These data support combinatorial targeting of RTK signaling with cytotoxic or targeted agents as a strategy to block adaptive resistance and improve treatment efficacy.

The association of cytoplasmic localization of VDR in TNBC tumors and disease aggressivity prompted investigation of its regulation by XPO1. In TNBC cell lines, the XPO1 inhibitors selinexor and eltanexor increased nuclear VDR localization. Their effects were particularly strong when combined with vitamin D treatment. Similarly, XPO1 knockdown increased nuclear VDR levels, both alone and in combination with vitamin D. These results identify XPO1 as an important regulator of VDR subcellular distribution. XPO1 inhibition also enhanced vitamin D-dependent VDR transcriptional activity. Indeed, selinexor, eltanexor, and XPO1 silencing increased vitamin D-dependent CYP24A1 reporter activity and the expression of genes such as CYP24A1 or CDH1. RNA sequencing showed that XPO1 modulation markedly reshaped the vitamin D transcriptional response. The affected genes were mainly involved in metabolism, cell-cycle regulation, protein localization, and cellular organization. Functional analyses demonstrated that cytoplasmic VDR promoted TNBC cell proliferation. Conversely, nuclear VDR was required for the antiproliferative effects of vitamin D. Accordingly, XPO1 inhibition or depletion potentiated vitamin D-mediated growth suppression. This finding suggested functional cooperation between XPO1-dependent export and VDR activity. Finally, high VDR expression was associated with poor disease-free or overall survival only in tumors with high XPO1 expression. Overall, XPO1 negatively regulates VDR nuclear localization and vitamin D responsiveness in TNBC. Targeting XPO1 may therefore enhance the therapeutic potential of vitamin D-based strategies in TNBC.

Prostate cancer (PC) bone metastases (PCBM) are a debilitating disease morbidity that primarily affects the axial skeleton. PCBM are predominantly osteosclerotic with mixed osteosclerotic/osteolytic features, including irregular bone deposition, loss of collagen alignment and increased porosity that mimic features of woven bone formed during development and repair. We hypothesize that progression of PCBM is driven by interactions between tumor cells and the bone microenvironment and is associated with changes in the stromal compartment. We performed tandem mass tag mass spectrometry proteomics on lumbar vertebral specimens from 32 cadaveric PCBM specimens and 3 age-matched controls. Unsupervised clustering segregated specimens into three clusters associated with benign, mixed, and osteosclerotic lesion states, characterized by distinct immune-, tumor-, and osteogenic-associated protein signatures. Histological analysis showed tumor infiltration was accompanied by marrow fibrosis and increased collagen III deposition. We identified a marker signature associated with osteosclerotic remodeling and mapped this signature to independent metastatic PC transcriptomic datasets. The proteomics-derived markers reproduced similar molecular groupings at RNA level, and robustly segregated bone PCBMs from soft tissue metastases PC in RNA data. Together, these findings define molecularly distinct states of tumor-driven changes in PCBM that extend beyond histological classification and may inform biomarker development and therapeutic stratification.

BackgroundCancer-associated fibroblasts (CAF) are major regulators of the tumor microenvironment (TME), yet the pathways governing CAF function remain incompletely understood. Type 2 deiodinase (DIO2, D2), which converts thyroxine (T4) to the active thyroid hormone triiodothyronine (T3), has not been systematically investigated in CAF across different solid tumors. MethodsWe analyzed DIO2 expression using single-cell RNA sequencing (scRNA-seq) from primary thyroid tumors, a large integrated scRNASeq thyroid cancer atlas, and publicly available scRNA-seq datasets representing six additional solid tumor types. Bulk RNA sequencing data from the Oncology Research Information Exchange Network (ORIEN) database were used to examine correlations among DIO2, CAF subtype markers, and overall survival (OS). A genetically engineered TPO-CreERT2/BrafV600E/Trp53-deficient (TBP) mouse model was evaluated for CAF-specific Dio2 expression and pharmacologic inhibition of D2 activity. TBP mice were crossed with Dio2-/- (Dio2 KO) mice to investigate the role of Dio2 in cancer development and progression. ResultsDIO2 expression was highly restricted to CAF and was largely absent from epithelial-derived cancer, immune, and endothelial cells. Across thyroid cancer and six additional malignancies, DIO2 was consistently detected in CAF, demonstrating that CAF-specific DIO2 expression is a conserved feature of multiple tumor types. Within thyroid cancer, DIO2 was enriched in myofibroblastic CAF (myCAF) compared with inflammatory CAF (iCAF), and bulk transcriptomic analyses demonstrated stronger correlations between DIO2 expression and canonical myCAF markers than iCAF markers across numerous cancers. Elevated DIO2 expression was associated with worse OS in pancreatic and bladder cancers, paralleling the adverse prognostic impact of increased myCAF abundance. In contrast, thyroid cancer demonstrated an inverse association attributable to loss of epithelial DIO2 expression during tumor dedifferentiation. The TBP mouse model recapitulated human disease, with Dio2 expression restricted to CAF, robust stromal fibrosis, and measurable D2 enzymatic activity that was suppressed by cefuroxime and lenvatinib. Genetic loss of Dio2 in the TME resulted in significantly reduced tumor growth. Conclusions DIO2 is a conserved marker of CAF, and myCAF, across multiple solid tumors and is associated with adverse clinical outcomes in some cancers. The TBP mouse provides a robust preclinical model to define the mechanistic role of DIO2 in CAF biology and to evaluate DIO2-directed therapeutic strategies targeting the tumor microenvironment.

Background: Cancer-associated fibroblasts (CAFs) contribute to systemic therapy resistance in muscle-invasive bladder cancer (MIBC), but their functional heterogeneity and relevance to curative bladder-preserving radiotherapy, are poorly understood. Methods: Transcriptomic analysis was performed on 279 tumours from BC2001, a phase 3 radiotherapy clinical trial. To study CAF heterogeneity, we integrated bulk RNA-seq, single-cell spatial analysis of multiplex immunofluorescence images and quantification of extracellular matrix (ECM) features in 155 MIBC biopsies. The functional heterogeneity of distinct CAF populations was evaluated by single-nuclear RNA-seq. Spatial interactions between CAF populations and CD8+ T-cells was assessed and the relevance of lymphocytes to radiation responses was evaluated in a CAF-enriched murine bladder cancer model (BBN963). Results: BC2001 patients with CAF-enriched tumours had worse overall survival (HR=1.671, 95% CI 1.221-2.287, Log-rank p=0.0012). CAF abundance and antigen expression was highly heterogenous. Podoplanin (PDPN) was expressed on the majority of CAFs and was associated with inflammatory pathways. Enrichment of CAF gene signatures was associated with a significant increase in CAFs expressing fibroblast activation protein (FAP) (p=0.004) and dense ECM features (p=0.0004). Fifty-three percent of tumours exhibited stromal CD8+ T-cell exclusion with significant enrichment in FAP-dominant neighbourhoods (p<0.001). In vivo, lymphocytes were critical for radiation-induced tumour control, indicating that immune cold or excluded tumours may have limited radiotherapy responses. Conclusion: In MIBC, CAFs are associated with poor radiotherapy outcomes. Multiple mechanisms are deployed by functionally-heterogeneous CAFs, including promotion of chronic inflammation by PDPN+ CAFs and ECM remodelling by FAP+ CAFs which impact CD8+ T-cell distribution and radiation responses.

Abstract Metabolic and epigenetic reprogramming drives development of platinum resistance and disease recurrence in high-grade serous ovarian cancer (HGSC), a major clinical challenge in the field. S-adenosylmethionine (SAM) is the universal methyl group donor, synthesized by methionine adenosyltransferase 2A (MAT2A) from methionine. Prior studies have linked altered SAM-dependent DNA methylation to acquired platinum resistance in HGSC, connecting metabolism and epigenetic regulation. However, how MAT2A-driven SAM synthesis coordinates the metabolic-epigenetic remodeling axis to affect platinum sensitivity remains unclear. Here, we report that MAT2A-driven SAM synthesis is required for platinum-induced alterations in DNA methylation and the enrichment of ovarian cancer stem cells (OCSCs). We found that MAT2A upregulation correlated with poor progression-free survival in OC patients, and both pharmacological inhibition and genetic knockdown of MAT2A increased sensitivity to cisplatin. To investigate the underlying epigenetic mechanism, we profiled genome-wide changes in DNA methylation using OVCAR3 treated with cisplatin (15M, 16hr) and/or MAT2A siRNA (48hr), which showed that MAT2A knockdown reversed platinum-induced DNA methylation dynamics. Subsequent analysis revealed enrichment of pathways associated with platinum resistance, DNA repair, and stemness. Mechanistically, inhibiting MAT2A abrogated both the platinum-induced hypermethylation at promoter regions and the SAMTOR-mTOR-S6K-FANCD2 signaling axis, resulting in accumulated R-loops, attenuated DNA repair activation in response to platinum, and enhanced platinum-induced DNA damage and cell death. Using a functional DNA damage reporter assay, we directly showed that MAT2A knockdown reduced DNA repair through homologous recombination (HR) and non-homologous end joining (NHEJ) pathways. By detecting key DNA damage response kinases governing HR and NHEJ signaling, we further demonstrated that MAT2A inhibition abrogated DNA repair activation in response to platinum. Furthermore, single-sample Gene Set Enrichment Analysis of paired primary and recurrent tumors from HGSC patients revealed an association between MAT2A expression and increased OCSC features in recurrent tumors. In vitro, MAT2A inhibition prevented cisplatin-induced enrichment of OCSCs, reduced stemness markers, and inhibited spheroid-forming ability, all of which were rescued by SAM supplementation. Together, our study reveals a previously unrecognized mechanism linking metabolism to epigenetic regulation through platinum-induced remodeling and establishes the MAT2A-SAM axis as a promising therapeutic target to enhance platinum sensitivity by abrogating DNA damage response and OCSC enrichment and ultimately reduce OCSC-driven disease recurrence in HGSC.

Prostate cancer (PCa) is the most commonly diagnosed cancer and the second leading cause of cancer death among US men. Metastatic castration-resistant PCa (mCRPC) is a clinically advanced form of PCa, often associated with increased aggressiveness, metastatic potential, morbidity, and a higher risk of developing resistance to taxanes (TX), the first-line chemotherapy for mCRPC. Furthermore, cancer stemness and epithelial to mesenchymal trans-differentiation (EMT) potentially contribute to aggressiveness and the development of drug resistance in mCRPC. Here, we applied our drug development pipeline, secDrug, which utilizes a pharmacogenomics data-driven computational algorithm, to demonstrate that TAK-715 - a dual inhibitor of p38 MAPK and Casein kinase {delta}/{epsilon}, is a promising treatment for these advanced/lethal variants of PCa. Using in vitro cytotoxicity assays followed by cell-based functional assays in a panel of mCRPC cell lines representing TX-sensitive mCRPC, clonally derived TX-resistant lines, and a highly aggressive metastatic variant of mCRPC, we demonstrated the efficacy of TAK-715 treatment as a single agent and in combination with TX, including cancer stem-like cells. Further, we showed that the apoptotic effects of TAK-715 occur via a mitochondrial-mediated pathway. Bulk tumor RNA sequencing followed by pathway analysis identified genes associated with mitochondrial dysfunction and cell cycle arrest as the top molecular networks associated with TAK-715 single-treatment. HES1, a gene associated with nodal metastasis and PCa progression, was the top differentially expressed gene. Single-cell transcriptomics analysis revealed that TAK-715 treatment erodes the subclonal populations responsible for cancer stemness, metastasis, and drug resistance. The clinical significance of these findings was validated in silico using multiple patient datasets. Our results suggest that TAK-715 treatment has the potential to decrease oncogenic progression and cancer stem cell-like activity in drug-resistant, aggressive, and stem-like mCRPC cells.

Background Muscle wasting, systemic inflammation, and functional decline are highly prevalent and detrimental in patients with advanced-stage non small cell lung cancer (NSCLC). Methods: In this cross sectional study, we investigated NSCLC associated muscle remodeling by analyzing skeletal muscle biopsies from patients with NSCLC (n = 18) and matched controls (n = 18) using quantitative proteomics, histology, fluorescence-activated cell sorting, gene expression profiling, and high resolution respirometry. Findings: NSCLC muscle was characterized by type II muscle fiber atrophy, greater collagen deposition, and redistribution of lipids to the extracellular matrix (ECM), together with remodeling of the inflammatory, immune, ECM and mitochondrial proteome. Additionally, mitochondrial respiratory capacity and morphology were altered in patients with NSCLC, which was associated with increased oxidative stress and dysregulated calcium handling. Concomitantly, we detected STAT3 activation and immune cell alterations, which may negatively impact skeletal muscle health in patients with NSCLC. Finally, we identified a shift in fibro-adipogenic progenitors (FAPs), favoring the CD90 subtype. Mechanistically, conditioned media from patient-derived FAPs reduced myotube width in vitro, uncovering a novel mechanism by which altered paracrine signaling from the muscle resident stromal compartment drives atrophy in cancer cachexia. Interpretation: These findings provide human evidence that altered FAP composition, mitochondrial homeostasis, calcium handling, and immune cell landscape accompany muscle wasting in NSCLC, which may inform therapeutic strategies to preserve skeletal muscle health in patients with cancer.

Background: Biopsy-measurable biomarkers that stratify colorectal cancer (CRC) by therapeutic responsiveness remain scarce. We asked whether dual MDM2 promoter (P1/P2) usage acts as a molecular switch separating two opposed CRC phenotypes: a chromosomal instability type and an environment-adaptive type (microsatellite instability-like/serrated pathway with gastric metaplasia). Methods: Sixty three organoid samples from 22 CRC patients were classified by deep-learning morphology (VGG16) and an array based MDM2 Splicing Index. P1 and P2 signatures were evaluated in TCGA-COAD/READ (n = 624) and GSE39582 (n = 519), and drug responses were examined in cell lines (GDSC2, DepMap) and 65 independent CRC organoid lines. Statistics used Wilcoxon, Kruskal Wallis and Spearman tests (Benjamini Hochberg-corrected) and patient-level mixed models. Results: Deep earning classification reached 98.5% test accuracy; morphology corresponded to isoform usage: Type1 (compact glandular) morphology predominated in P1-dominant samples (median Type1 fraction 0.826 versus

Abstract Background Migrasomes, the newly discovered vesicular organelles, have long been speculated to originate from membrane dynamics during cell migration. Here we present integrated imaging and multi-omics evidence supporting a ciliary origin of migrasomes. The shared vesicular trafficking pathways between ciliogenesis and migrasome biogenesis (trans-Golgi/endosomal systems) prompted us to investigate their spatiotemporal coupling mechanism in disease models. Methods Using high-resolution SEM and fluorescence confocal microscopy (FCM), we visualized cilium-like structures with enlarged tips adjacent to migrasome-like vesicles across multiple cell types. TMT-based quantitative proteomics was used to identify proteins shared among migrasomes from different cell types and examine their associations with ciliary proteins. DMBA-induced breast cancer and femoral fracture models were used to investigate the cilia-migrasome association during tumor metastasis and fracture healing. Results Bioinformatics analysis showed a highly positive incidence correlation between cilia and migrasome genes in 31 types of 7858 human normal tissues and organs and various cell types. In 32 cancer tissues, cilia and migrasome genes were still strongly but abnormally correlated. Signaling enrichment by ARL13B and TSPAN4 showed that cilia-migrasome association is related to epithelial-mesenchymal transition (EMT). By analyzing the ARL13B and PIGK expression, we found the abnormal cilia-migrasome association in metastatic breast cancer and positive cilia-migrasome association in fracture healing bone. Conclusion Our findings support a ciliary origin of migrasomes, pointing to a previously unrecognized pathway of organelle biogenesis. Notably, the ciliary-migrasomal association correlates with two distinct pathological/physiological contexts: (1) aberrant epithelial-mesenchymal transition (EMT) in metastatic breast cancer, and (2) accelerated regeneration during fracture healing and tissue repair. This dual correlation not only establishes a mechanistic link between ciliary function and migrasome biogenesis but also highlights their divergent roles in disease progression versus tissue homeostasis. Investigating the spatiotemporal dynamics of this association may provide novel therapeutic targets for metastatic malignancies and regenerative medicine.

Palmitate-associated lipotoxic stress activates the endoplasmic-reticulum stress sensor protein IRE1, but how IRE1 signaling influences genotoxic-stress responses in triple-negative breast cancer remains unclear. Here, we investigated IRE1 and XBP1 signaling in MDA-MB-231 cells exposed to palmitate and etoposide. Under combined lipotoxic and genotoxic stress, XBP1 depletion increased DNA-damage accumulation in IRE1 wild-type cells but not in IRE1-deficient cells, whereas IRE1 re-expression reduced DNA damage. Pharmacologic IRE1 RNase inhibition also increased etoposide-associated DNA damage, supporting a protective role for IRE1 RNase-dependent signaling. IRE1 status and XBP1 manipulation differentially affected H2A.X and {gamma}H2A.X abundance, indicating context-dependent regulation of chromatin-associated DNA-damage signaling. At the RNA level, H2A.X was enriched in IRE1 immunoprecipitates, and the H2A.X-linked DNA-damage-response transcripts HUWE1 and BRCA2 also associated with IRE1 under combined stress. These findings link palmitate-activated IRE1-XBP1 signaling to genome-protective responses during genotoxic stress and identify a network of IRE1-associated DNA-damage-response transcripts in triple-negative breast cancer cells. Direct IRE1-mediated cleavage of these transcripts remains to be established.

Venetoclax combined with azacitidine has improved treatment outcomes in acute myeloid leukemia (AML), yet relapse and treatment persistence remain major clinical challenges. To investigate proteomic mechanisms associated with venetoclax-azacitidine response and adaptation, we applied a multi-layer combinatorial proteome integral solubility/stability alteration analysis (CoPISA) strategy in SKM-1 AML cells. Cells were treated with venetoclax, azacitidine, their combination, or vehicle control and profiled across four orthogonal layers: short-term lysate CoPISA, short-term intact-cell CoPISA, long-term intact-cell CoPISA after 5 days of treatment, and long-term expression proteomics of surviving cells. The venetoclax-azacitidine combination induced treatment-specific protein solubility and abundance changes that were not fully reproduced by either single agent. Long-term surviving cells displayed extensive proteomic remodeling, consistent with the emergence of an adaptive drug-tolerant state, although contributions from pre-existing resilient cell populations cannot be excluded. Integration of short- and long-term solubility changes with abundance remodeling revealed distinct adaptive regimes, including retained biochemical targets, dosage-compensated targets, sensitive-state-specific targets, and remodeled adaptive targets. This framework prioritized candidate resistance-associated proteins, including NRP2, RPL18, PLP2, RPS28, and NOTCH1. NRP2 emerged as a top candidate across all proteomics layers, consistently showing increased abundance. Overall, this study shows that combining CoPISA with expression proteomics can resolve temporally distinct proteomic states of venetoclax-azacitidine response and identify candidate adaptive vulnerabilities in AML.