Molecular Oncology

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA (lncRNA) implicated in cancer progression. In thyroid cancer, MALAT1 has been proposed as a potential biomarker, but its role in disease progression remains incompletely understood. Here, we analyzed MALAT1 RNA levels in paired tumoral and adjacent non-tumoral thyroid samples from a Chilean patient cohort. We found a positive correlation of MALAT1 levels with lymphatic infiltration that was not replicated when modeling MALAT1 expression in a larger cohort obtained from the TCGA-THCA database. An exploratory RNA-seq comparison of one matched tumor-adjacent tissue pair confirmed higher tumor abundance of MALAT1 and the epithelial-to-mesenchymal transition-marker VIM, together with lower abundance of cell-adhesion gene PCDH10. To investigate the impact of MALAT1 on thyroid cancer and cellular metabolism, we targeted MALAT1 in the papillary thyroid cancer cell line TPC1. MALAT1 knock-down reduced proliferation and migration while enhancing mitochondrial respiration with no changes in glycolysis. Notably, although MALAT1 was not localized within mitochondria, its silencing modulated the expression of transcripts associated with mitochondrial dynamics and mitophagy. Consistent with these results, transcriptomic correlation analysis in the TCGA-THCA cohort showed that MALAT1 expression was largely uncoupled from oxidative phosphorylation and glycolysis gene programs, while negatively correlating with core regulators of mitophagy and mitochondrial dynamics, pointing to a link with mitochondrial quality control rather than direct bioenergetic reprogramming. Our findings highlight MALAT1 as a contributor to thyroid cancer aggressiveness and reveal a link between MALAT1 and mitochondrial quality control independent of direct mitochondrial localization. Besides, our results support a tissue-specific mechanism and population-specific role of MALAT1 in cancer biology.

Human papillomavirus (HPV)-related and HPV-unrelated oropharyngeal squamous cell carcinomas (OPCs) are distinct entities with different clinical outcomes. While p16 immunohistochemistry (IHC) is widely used as a surrogate marker for HPV-driven OPC, a subset of HPV-unrelated OPCs also overexpress p16, and the biological basis of this discordance remains unclear. Here, we performed integrated clinicopathological, transcriptomic, genomic, and functional analyses of OPCs and demonstrated that dysregulation of the p16-CDK6 axis characterizes HPV-unrelated p16-positive OPCs. Although these tumors closely resembled HPV-unrelated p16-negative OPCs in their clinicopathological and transcriptomic characteristics, they exhibited a more favorable prognosis. CDK6 was recurrently upregulated in HPV-unrelated OPC regardless of p16 status and was already detectable in high-grade dysplastic leukoplakia, suggesting that CDK6 activation is an early event in HPV-unrelated tumorigenesis. In experimental models, CDK6 overexpression induced compensatory p16 upregulation, creating selective pressure for subsequent CDKN2A inactivation. Consistent with this model, homozygous CDKN2A loss predominated in p16-negative tumors. We further identified CDKN2A frameshift mutations generating p14ARF-p16 chimeric proteins that retain p16 immunoreactivity despite functional loss of wild-type p16, revealing a previously unrecognized diagnostic pitfall of p16 IHC. These findings provide a biological framework for p16 overexpression in HPV-unrelated OPC and suggest that assessment of the p16-CDK6 axis may refine molecular classification and risk stratification beyond p16 IHC alone.

BCL2L13 is a mitochondrial BCL2 family protein linked to mitophagy and ceramide metabolism, but its role in NSCLC metastatic plasticity remains unclear. Human lung cancer Tissue Microarray and matched patient specimens showed subtype and site dependent BCL2L13 expression, with higher cytoplasmic granular staining in primary NSCLC and reduced, heterogeneous staining in lymph node metastases, most evident in adenocarcinoma and squamous cell carcinoma. Because Epithelial mesenchymal transition and anoikis resistance are central requirements for metastatic dissemination, this primary to node attenuation provided the rationale to test BCL2L13 knockdown and overexpression in metastasis relevant NSCLC models. In A549 and LLC cell lines. TGF beta 1 induced coordinated mitophagy and EMT with mitochondrial enrichment of BCL2L13. BCL2L13 knockdown impaired TGF beta 1 and carbonyl cyanide m chlorophenyl hydrazone associated mitophagy, reducing LC3 beta mitochondria colocalization, TOMM20, LAMP1 overlap and mitochondrial LC3 II, p62, TOMM20 turnover; BNIP3 and NIX redistribution did not compensate. BCL2L13 loss enhanced EMT marker switching and migration, whereas overexpression partially opposed these changes. During detachment, BCL2L13 knockdown reduced anoikis associated apoptosis despite preserved mitochondrial recruitment of BAX, BAK, BNIP3,NIX, altered BID processing, non parallel caspase activity and shifted FAK phosphorylation. Pharmacological autophagy modulation did not reverse this anoikis phenotype. Lipidomics identified adhesion state dependent ceramide synthases CerS2, CerS6 linked sphingolipid remodeling: BCL2L13 knockdown increased C24 linked sphingolipid species in attached cells but reduced C16, C24 ceramide related profiles during anoikis. These findings identify BCL2L13 downregulation as a metastasis associated mitochondrial-lipid state that limits mitophagic quality control while favoring EMT and detachment survival in NSCLC adenocarcinoma.

Despite advances in screening and treatment, breast cancer remains a leading cause of cancer-related mortality. APOBEC enzymes, particularly APOBEC3B (A3B), are upregulated in many cancers, contributing to a characteristic C-to-T mutational signature found in 30-50% of breast cancers. However, the relationship between A3B mutational signatures and A3B expression across subtypes, and the resulting potential biologic consequences, have not been fully defined. Using TCGA and ICGC datasets, we analyzed DNA and RNA expression data to assess the relationship between A3B mRNA expression and APOBEC enrichment scores. Pathway enrichment analyses (KEGG, GO, Reactome) were performed to identify biological processes associated with high A3B expression, specifically stratifying by breast cancer intrinsic subtypes (HR+/HER2-, HR+/HER2+, HR-/HER2+, and TNBC). Over 64% of tumors with enriched A3B mutational genomic signatures demonstrated above-median A3B mRNA expression (p < 0.001). High A3B-expressing tumors exhibited specific alterations in drug metabolism pathways. Notably, we observed reduced expression of CYP2D6 and CYP3A isoforms which is required for the conversion of tamoxifen to its active metabolites. Conversely, genes involved in pyrimidine metabolism, including IMPDH1, NME1, TK1, and DPYS, were downregulated in high A3B tumors. Elevated A3B expression correlates with mutational signatures and may contribute to impaired tamoxifen activation and endocrine resistance, while concurrently creating metabolic vulnerabilities to pyrimidine-based chemotherapies. Targeting A3B or exploiting these metabolic dependencies may improve therapeutic response in selected patient subsets.

BackgroundEpidermal growth factor receptor (EGFR) amplification occurs in [~]50% of IDH-wildtype glioblastoma (GBM) cases, frequently accompanied by expression of the oncogenic EGFRvIII variant. Although EGFR represents an attractive therapeutic target, EGFR-directed therapies have shown limited clinical efficacy in GBM. Resistance to kinase inhibitors is frequently attributed to activation of compensatory signaling pathways ("kinome rewiring"). We therefore investigated whether EGFR inhibition in GBM induces broad adaptive kinase responses that could be co-targeted to overcome resistance. MethodsWe molecularly profiled 29 patient-derived GBM cell lines for EGFR status and selected five representative models spanning EGFR amplification states for functional analyses. Cells were treated with EGFR inhibitors and responses were assessed using viability assays, time-resolved immunoblotting, and phosphoproteomics (LC-MS/MS) with kinase activity inference. ResultsEGFR inhibitors preferentially impaired viability in EGFR-driven models and transiently reduced EGFR phosphorylation during the initial response. However, partial restoration of EGFR phosphorylation and downstream signaling occurred after 24 hours of inhibitor exposure. Phosphoproteomics revealed no evidence of broad kinome rewiring within this timeframe but instead identified increased EGFR abundance, associated with partial restoration of EGFR pathway activity. The phosphorylated-to-total EGFR ratio remained stable, indicating that increased EGFR abundance may enable persistent residual kinase activity despite continued, but incomplete, target inhibition. ConclusionsEarly responses to EGFR inhibition in GBM were not characterized by broad kinome rewiring but by restoration of EGFR signaling associated with increased EGFR abundance. These findings suggest that adaptive signaling remains largely EGFR-dependent despite inhibitor exposure, identifying regulation of EGFR abundance as a potential contributor to therapeutic resistance. Key points- Early responses to EGFR inhibition occur without evidence of broad kinome rewiring. - EGFR signaling is restored during sustained inhibitor exposure. - Increased EGFR abundance is associated with restoration of pathway activity. Importance of the studyAdaptive resistance to EGFR-targeted therapies in GBM is commonly attributed to activation of alternative signaling pathways. Using patient-derived GBM models and phosphoproteomic profiling, we show that early adaptive responses to EGFR inhibition are not characterized by broad kinome signaling rewiring but instead remain centered on reactivation of EGFR signaling. Our findings suggest that increased EGFR abundance in response to inhibitor exposure may enhance residual EGFR signaling sufficiently to partially restore downstream pathway activity. These results indicate that early adaptive responses to EGFR inhibition may remain largely EGFR-dependent, potentially limiting the effectiveness of strategies primarily aimed at co-targeting alternative signaling pathways. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/744581v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@8d4ea3org.highwire.dtl.DTLVardef@125e3eeorg.highwire.dtl.DTLVardef@9742c0org.highwire.dtl.DTLVardef@9f4fa8_HPS_FORMAT_FIGEXP M_FIG C_FIG

The Hippo pathway effector YAP1 is a potent oncogenic driver in triple-negative breast cancer (TNBC) and its activity is restrained by the scaffold protein Angiomotin-p130 (AMOT). AMOT is itself short-lived, being targeted for proteasomal degradation by NEDD4-family E3 ubiquitin ligases that dock at its L/P-PxY motifs. Here we identify Profilin1 (PFN1), an actin-binding protein with established actin-independent tumour-suppressive signalling functions in TNBC as a direct binding partner and stabilizer of AMOT. PFN1 and AMOT are co-immunoprecipitated, they share 70 common interactors and NEDD4 is one of them. Protein-protein docking shows the interaction of PFN1 on the first PPxY motif of AMOT, through its actin-binding domain. We further show that PFN1s binding leaves the AMOT LPTY motif and both coiled-coil domains entirely unoccupied. Site-directed mutagenesis of AMOT PPxY motifs shows that PFN1 binding is unaffected by substitution of the PPxY tyrosines Y242 and Y287, either alone or in combination, indicating that PFN1 engages through its actin-binding domain. Functionally, PFN1 stabilizes AMOT as shown by cycloheximide-chase assay in TNBC. PFN1 induction increases cytoplasmic retention of YAP1, reduces TEAD occupancy at the CTGF promoter and thereby suppresses TNBC cell migration. Thus, this study suggests that PFN1 deregulates tumour cells migration by interacting with AMOT through its actin-binding domain, stabilizing AMOT and thereby arresting YAP in the cytoplasm, which might be an important therapeutic target to regulate TNBC.

BackgroundT-cell acute lymphoblastic leukemia (T-ALL) and peripheral T-cell lymphoma (PTCL) are aggressive hematological malignancies requiring novel therapeutic strategies. The majority of T-ALL and PTCL tumors display metabolic activation and addiction to endogenous serine/glycine synthesis (SSP), providing opportunities for targeted therapy with the clinically used antidepressant sertraline, inhibiting SSP enzymes SHMT1/2. However, sertraline monotherapy only induces cell cycle arrest and has limited efficacy in suppressing disease progression in vivo. MethodsDrug synergy of sertraline combined with clinically used proteasome inhibitors carfilzomib and bortezomib was evaluated. Drug effects on cell cycle, proliferation and apoptosis were assessed in T-ALL, PTCL and healthy blood cells using flow cytometry assays. Proteomic, lipidomic and metabolic analyses on drug treated T-ALL cells were performed to elucidate the molecular mechanisms underlying drug synergy, followed by validation of changes of interest, metabolic rescues and shRNA-knockdown of SSP enzymes in T-ALL cells. In vivo therapeutic efficacy and immune remodelling were evaluated in an immunocompetent MYCN-overexpressing PTCL mouse model. ResultsSertraline acted synergistically with clinically used proteasome inhibitor carfilzomib to induce cell cycle arrest and apoptosis in T-ALL and PTCL cells with SSP activity, with minimal effects on SSP-inactive T-ALL cells or healthy blood cells. Adding carfilzomib also enhanced the therapeutic efficacy of sertraline in an aggressive MYCN PTCL model. Sertraline rewired cell metabolism towards increased cholesterol uptake and biosynthesis in SSP-active T-ALL cells, and this effect was not obtained by other means of SSP inhibition. In contrast to sertraline, carfilzomib promoted cholesterol efflux. Moreover, carfilzomib reduced total lipid levels, further restricting nutrients in sertraline - carfilzomib treated cells. Additionally, the drug combination impaired mitochondrial respiration and elevated reactive oxygen species (ROS) levels and DNA damage in SSP-active tumor cells, which was rescued by citrate supplementation. Interestingly, these metabolic changes were associated with microenvironmental changes in our mouse model, where the drug combination elevated natural killer T-cells, neutrophils and eosinophils. ConclusionsOur study identifies synergy of sertraline - carfilzomib combination treatment mediated through metabolic impairment and is associated with remodelling of the immune microenvironment. This invites for further clinical investigation of this drug combination as a therapeutic strategy for SSP-active T-cell malignancies.

Polyaneuploid giant cells (PGCC), which occur more frequently in TP53-mutant tumors, are recognized as a driver of tumor recurrence and therapy resistance, but the mechanisms supporting their survival remain largely unknown. Our results indicate that polyaneuploid transition and subsequent PGCC maturation in drug-resistant phenotypes are associated with redox rewiring that shifts cellular homeostasis into mild pro-oxidative condition. These are accompanied by increased transcription of genes involved in protection against elevated reactive oxygen species and glutathione-dependent xenobiotic detoxification such as TXN, PRDX2/5, GPX1, and GSTP1/GSTO1. Functional studies provided evidence on the crucial role of Txn-Txnrd1 system in maintaining PGCC viability and their adaptation to increased level of reactive oxygen species. Pharmacological targeting of Txn or Txnrd1 as well as their silencing caused a decline in thiol content followed by further redox imbalance, which led to massive death of PGCC. Analysis of clinical datasets revealed direct and relatively strong link between transcription of TP53 and TXN or TXNRD1. Tumors with TP53low/TXNhigh or TP53low/TXNRD1high were associated with considerably poorer patient outcome, whereas elevated transcription of both TXN and TXNRD1 predicted reduced response to chemotherapy in glioblastoma and intestinal cancer. Concluding, Txn-Txnrd1 system enables PGCCs to tolerate pro-oxidative condition, thereby creating a therapeutically exploitable redox vulnerability of these cells, where Txnrd1 emerges as a potential target candidate to overcome PGCC-driven chemoresistance.

Introduction Patients undergoing polypectomy at colonoscopy remain at risk of metachronous neoplasia despite surveillance guided by histopathological features. Mutational profiling of adenomas, including canonical driver mutations in APC, KRAS, and TP53, may offer additional predictive value. This study aimed to determine whether mutational status in index adenomas was associated with metachronous lesion risk. Methods The INCISE cohort included patients aged 50 to 74 years who underwent polypectomy within the Scottish Bowel Screening Programme and subsequent surveillance colonoscopy within 6 years. Targeted next-generation sequencing was performed on formalin-fixed paraffin-embedded polyps. Driver mutation frequency, tumour mutational burden (TMB), and variant allele frequency (VAF) were analysed and correlated with histopathological features and metachronous outcomes using appropriate statistical models. Results A total of 895 adenomas from 723 patients were analysed. In conventional adenomas, as the number of high-risk histopathological features (size >=10mm, villous architecture, and high-grade dysplasia) increased there was a stepwise increase in the proportion of samples with a mutation in KRAS from 13% to 51% (padj<0.001) and TP53 from 8% to 35% (padj<0.001). However, neither mutation frequency (p=0.901), nor median tumour mutation burden (TMB) (2.27 vs 2.15 mut/Mb, p=0.242), in index adenomas was associated with the development of metachronous lesions. Conclusions While classical driver mutations reflect histopathological progression within adenomas, they do not predict metachronous lesion risk post-polypectomy. Targeted mutation profiling alone is insufficient for surveillance risk stratification, highlighting the need for integrated molecular approaches in this setting.

Background: Metabolic adaptation is a recognized feature of therapeutic resistance in hepatocellular carcinoma (HCC), but it is unclear whether transcriptional states exposed during acquired resistance are restricted to drug adaptation or reflect broader aggressive tumor biology. We tested whether metabolic programs derived from a lenvatinib-resistance model identify a clinically adverse transcriptional state in an independent HCC patient cohort. Methods: The discovery framework was based on GSE186191, comprising parental and acquired lenvatinib-resistant Hep3B and Huh7 cells. A pre-specified 33-gene lipid-source ledger served as a biological anchor, and three discovery-derived programs, MYC Targets V2, mTORC1 Signaling, and Fatty Acid Metabolism, were frozen before patient-level evaluation. In TCGA-LIHC, single-sample enrichment scores for the three programs were population-standardized and summed to generate an integrated metabolic score. Overall survival was assessed by Kaplan-Meier and Cox analyses. Whole-transcriptome differences between high- and low-score tumors were characterized by preranked gene set enrichment analysis (GSEA). Results: The survival cohort comprised 282 patients (118 deaths), with 141 patients in each median-defined score group. High-score patients had shorter overall survival (log-rank P=0.000419). The continuous score was associated with mortality in univariable analysis (HR 1.86, 95% CI 1.33-2.61; P=0.000293) and in the frozen model adjusted for age, sex, and stage indicators (HR 1.93, 95% CI 1.35-2.76; P=0.000350; n=277). In 327 primary tumors, Fatty Acid Metabolism was strongly depleted in high-score tumors (NES -2.06; FDR<0.001). MYC Targets V2 (NES 1.18; FDR=0.232) and mTORC1 Signaling (NES 1.11; FDR=0.229) showed positive directional enrichment without FDR significance. Conclusions: A lenvatinib-resistance-derived transcriptional program is associated with an adverse-survival state in HCC. The strongest patient-level pathway feature is depletion of canonical fatty-acid metabolism, accompanied by directional MYC/mTORC1 features rather than statistically established pathway activation. These findings support a testable model of metabolic identity remodeling but do not establish causality or clinical prediction of lenvatinib response.

Background Zinc finger protein 36-like 1 (ZFP36L1) is an AU-rich element-binding RNA-binding protein that regulates post-transcriptional gene expression and has been implicated in tumor progression, cell-cycle regulation, and DNA damage responses. However, its functional role in triple-negative breast cancer (TNBC) remains poorly understood. This study investigated the effects of CRISPR/Cas9-mediated ZFP36L1 knockout on cell proliferation, doxorubicin (DOX) sensitivity, cell-cycle progression, and DNA damage responses in MDA-MB-231 TNBC cells. Methods Wild-type (WT) and CRISPR/Cas9-generated ZFP36L1 knockout (KO) MDA-MB-231 cells were cultured under standard conditions. Cellular proliferation was evaluated by cell counting over three weeks. Cell viability following DOX treatment was determined using the MTT assay, and half-maximal inhibitory concentration (IC50) values were calculated. Cell-cycle distribution was assessed by propidium iodide flow cytometry after 24 h of DOX exposure, while DNA damage was quantified by {gamma}-H2AX flow cytometric analysis. Statistical significance was determined using Student's t-test with P < 0.05 considered significant. Results ZFP36L1 knockout reduced the proliferative capacity of MDA-MB-231 cells compared with WT cells. Both cell lines exhibited dose-dependent decreases in viability following DOX treatment. KO cells demonstrated a higher mean IC50 than WT cells (9.64 vs. 8.40 M), indicating a trend toward reduced DOX sensitivity; however, this difference was not statistically significant (P = 0.569). Flow cytometric analysis revealed enhanced accumulation of KO cells in the S and G2/M phases following DOX treatment, suggesting altered cell-cycle checkpoint regulation. Furthermore, KO cells exhibited elevated basal {gamma}-H2AX expression and greater DOX-induced {gamma}-H2AX accumulation than WT cells, indicating increased DNA damage and impaired maintenance of genomic stability. Conclusions CRISPR/Cas9-mediated loss of ZFP36L1 suppresses proliferation, alters cell-cycle checkpoint dynamics, and enhances DNA damage accumulation in MDA-MB-231 TNBC cells. These findings indicate that ZFP36L1 plays a context-dependent role in regulating genomic stability and cellular responses to genotoxic stress, highlighting its potential as a biomarker and therapeutic target in triple-negative breast cancer.

BackgroundTuberous Sclerosis Complex (TSC) is a genetic disorder caused by variants in TSC1 or TSC2, leading to mTORC1 hyperactivation and autophagy suppression. Although TSC tumorigenesis typically follows a "two-hit" model, the role of TSC2 haploinsufficiency in autophagy regulation remains unclear. We evaluated autophagy markers in haploinsufficient and gene-edited TSC2 primary cells and investigated the role of metformin in modulating autophagy levels. MethodsPrimary fibroblast cultures were obtained from one healthy individual and three from patients carrying heterozygous germline TSC2 variants: the pathogenic variants c.1008T>G and c.4375C>T.A variant of uncertain significance (VUS) c.724A>T. CRISPR/Cas9-RNP editing was used to model loss of heterozygosity (LOH) in cell pools carrying each variant. Cultures were treated with rapamycin, HBSS, metformin, bafilomycin A1, or vehicle controls, and autophagy was assessed by autolysosomes formation by flow cytometry (acridine orange) and autophagosomes immunofluorescence (LC3 and p-S6K). ResultsIn wild-type cells, only HBSS increased autophagy-positive (acridine orange-positive) cells versus control (15.6% vs. 7.5%; p=0.003). In heterozygous pathogenic cells, rapamycin and metformin increased autophagic cells: c.1008T>G (16.2%, p=0.006; 17.6%, p=0.002) and c.4375C>T (12.5%, p=0.003; 13.3%, p=0.001), versus DMSO controls (9.2% and 7.1%, respectively). VUS c.724A>T cells, with rapamycin increasing autophagic cells (9.74% vs. 6.5%; p=0.0152). In CRISPR-edited cells, all treatments increased the number of autophagic cells compared to the heterozygous cells: c.1008T>G (rapamycin 27.1% vs. 16.7%, p<0.001; metformin 27.2% vs. 17.6%, p<0.001) and c.4375C>T (rapamycin 21.3% vs. 13.1%, p=0.0021; metformin 21.5% vs. 13.6%, p=0.0029). Editing also restored metformin responsiveness in VUS cells (12.5% vs. 8.4%; p=0.0055). Immunochemistry confirmed increased total LC3II and decreased p-S6K across treated cells compared to the control (DMSO). ConclusionThese findings demonstrate that TSC2 haploinsufficiency functionally impairs autophagy prior to second-hit loss. Metformin effectively restores autophagy with phenotypical changes of mTORC1 blockade, highlighting an accessible translational strategy to restore and induce autophagy in TSC cells.

Background: To date, no precision oncology approach has been established for HCC. Despite the diverse underlying causes, HCC development exhibits a uniform pathophysiology characterised by chronic hyper-proliferation, resulting from hepatocyte apoptosis and compensatory liver regeneration. This chronic hyper-proliferative pressure, termed regeneration stress, drives genomic instability during HCC onset, yet its therapeutic potential remains poorly explored. This study aimed to identify targetable vulnerabilities tied to regeneration stress and establish clinically applicable markers for treatment stratification. Methods: Weighted gene co-expression network analysis (WGCNA) was applied on external bulk RNA-seq datasets to define a LIVer REgeneration Stress Signature (LIVRESS). The signature was functionally validated using HCC patient-derived organoids (HCC-Org), and vulnerabilities were mapped using mid-throughput drug screening, single-molecule and single-cell assays, and multi-omic integration. Results: High LIVRESS scores, characterised by enrichment in replication, mitotic and DNA damage repair pathways, identified a subset of HCC patients with aggressive disease and poorer survival across aetiologies. HCC-Org with high LIVRESS scores displayed exquisite sensitivity to multiple inhibitors of the checkpoint kinase ATR. Although HCC-Org models exhibited a baseline reduction in replication fork speed, sensitivity to ATR inhibitor (ATRi) was decoupled from replication fork dynamics and rather linked to intrinsic mitotic instability. ATR inhibition triggers mitotic failure and apoptosis in LIVRESSHigh HCC-Org. This killing effect was significantly potentiated by combining ATRi with PARPi or WEE1i. Multi-omic integration identified KPNA2 as a surrogate biomarker of ATRi sensitivity. Conclusion: Our findings demonstrate that a subset of HCC-Org, characterised by high liver regeneration-associated stress, is vulnerable to ATRi-based therapies. By focusing on a comprehensive regenerative stress model, we establish a framework to stratify HCC patients and implement biomarker-driven, ATR-based therapies for HCC patients with advanced disease. Impact and implications: Regeneration stress is a key factor that drives genomic instability in HCC, providing a basis for the LIVRESS to identify patients dependent on ATR-mediated checkpoints. These findings reveal a conceptual shift for researchers and trialists: ATRi efficacy is decoupled from replication fork dynamics and instead leverages mitotic fragility. Practically, the LIVRESS and its IHC surrogate marker (KPNA2) offer a scalable roadmap for physicians to improve patient stratification in ATRi-based precision oncology trials. While requiring prospective validation, these results pave the way toward biomarker-driven therapies for advanced HCC.

Background Therapy resistance in pancreatic ductal adenocarcinoma (PDAC) is facilitated by the desmoplastic tumor microenvironment (TME) orchestrated by cancer associated fibroblasts (CAFs). Upon activation, pancreatic stellate cells (PSCs) deplete their intracellular retinoic acid (RA)-containing lipid droplets and secrete stromal remodeling proteins like pentraxin 3 (PTX3), leading to cancer progression. Preclinical evidence indicates that all-trans RA (ATRA) reprograms the TME, while circulating vitamin A and PTX3 were proposed as biomarkers for ATRA response in PDAC. To support further clinical development of RA-based therapies in PDAC, we studied the effects of ATRA on CAFs and patient-derived organoids (PDO) and evaluated the clinical relevance of these biomarkers in PDAC patients. Methods We employed viability assays in human and murine organoid mono- and co-culture models to explore the efficacy of adding ATRA to gemcitabine (GEM). In parallel, we conducted a prospective observational study and assessed vitamin A and PTX3 as response biomarkers in peripheral blood collected before first treatment and at cycles 2 and 4 of treatment among patients with advanced PDAC receiving GEM with or without nab-paclitaxel (NAB-P). Results In PDO monocultures, a significant additive effect of ATRA in combination with GEM on viability was observed in 5 (41%) of 12 PDOs and this effect was numerically more frequent in organoids from patients who had clinically responded to GEM. In human and murine 3D PDO+PSC/CAF co-cultures, ATRA demonstrated an additional direct impact on the viability of stromal cells. Clinically, among 18 patients with PDAC treated with GEM+/-NAB-P, patients with no treatment response (n=10) showed an increase in PTX3 and concomitant decrease in vitamin A levels under therapy. In contrast, response was associated with stable vitamin A levels and a trend towards lower PTX3 levels during chemotherapy. Conclusions Our preclinical data support the repurposing of ATRA, an agent with favorable toxicity profile, to potentiate the efficacy of GEM in PDAC treatment. Complementing these results, our clinical data suggest vitamin A and PTX3 as promising response biomarkers in PDAC treatment, not restricted to ATRA containing regimens.

Background: Although PSEN1 is best known for its role in Alzheimer's disease, it also regulates neural development and cerebellar morphogenesis. Medulloblastoma (MB) is the most common malignant pediatric brain tumor and arises from disrupted cerebellar developmental programs. The clinical significance of PSEN1 in MB remains unknown. We investigated the prognostic value and transcriptional correlates of PSEN1 expression across molecular subgroups and subtypes of MB. Methods: Public bulk and single-cell transcriptomic datasets were used to examine PSEN1 expression, associations with overall survival (OS), and transcriptional correlates in MB. The SHH -associated transcriptional pattern was evaluated in an independent cohort, and PSEN1 expression was further examined in the developing human cerebellum and across pediatric brain tumor types. Genes strongly correlated with PSEN1 in SHH MB were subjected to Gene Ontology (GO) enrichment analysis. Results: High PSEN1 expression was consistently associated with significantly longer OS exclusively in SHH MB. The PSEN1-associated transcriptional pattern was reproduced in an independent SHH cohort. PSEN1 was expressed across developing cerebellar cell populations and pediatric brain tumor types, with MB showing intermediate expression among the tumor entities examined. In SHH MB, PSEN1 was associated with a coordinated transcriptional program enriched for RNA homeostasis, intracellular membrane trafficking, protein quality control, lipid and calcium signaling, and developmental pathways. Conclusions: High PSEN1 expression identifies a favorable-prognosis subset of SHH MB and is associated with a distinct transcriptional program related to endomembrane organization and cellular homeostasis rather than canonical SHH signaling. These findings suggest that PSEN1 may mark a developmentally distinct tumor state and generate new hypotheses regarding subtype-specific developmental programs in MB.

Background: Spatial organization is increasingly recognized as a key determinant of tumor-immune interactions in head and neck squamous cell carcinoma (HNSCC). The GSE300147 Xenium spatial transcriptomic resource generated by McCord and colleagues established a framework for mapping spatially coordinated T-cell states in HNSCC. However, how tumor-enriched epithelial immune states relate to metabolic, redox, and stress-adaptive transcript programs remains incompletely defined. Methods: A secondary, data-driven reanalysis of GSE300147 was performed, focusing on 17 confirmed HNSCC Xenium sections after exclusion of a non-HNSCC ameloblastoma specimen. A total of 1,148,244 cells were analyzed, including 558,867 EpCAM+ tumor-enriched epithelial cells. Tumor-enriched epithelial cells were classified into Hot, Intermediate, and Cold states using a Composite Hotness framework integrating T-cell inflammatory signature score, checkpoint-associated signaling, CD274 expression, IFN/antigen-presentation signature score (IFN/AP), and tumor-immune proximity. Six metabolic ecosystem states, neighborhood profiling, spatial permutation testing, and an integrated Immune-Metabolic-Redox Ecosystem Score (IMRES) were then applied. Results: Immune activation was spatially heterogeneous across HNSCC sections. Immune-hot tumor-enriched epithelial regions showed not only inflammatory, checkpoint-associated, and antigen-presentation signature scores, but also coordinated metabolic, oxidative-redox, and stress-response transcript programs. IMRES, derived from available immune, metabolic, redox, and stress-response transcript components represented in the Xenium panel, increased progressively from Cold to Intermediate to Hot tumor-enriched epithelial states and was associated with NFE2L2, GDF15, HLA-DRA, CD274, KEAP1, and MDM2. Integrating IMRES with Composite Hotness identified a distinct Hot+IMREShigh ecosystem comprising 106,874 tumor-enriched epithelial cells. This state showed the strongest immune-active and stress-adaptive features and was positioned closer to immune populations than expected by random assignment. An alternative rank-based robustness analysis reproduced the IMRES-associated ecosystem axis and correlated with the original module-based score (Spearman r = 0.597). Conclusions: This secondary reanalysis extends the original spatial T-cell framework by defining a complementary tumor-centered immune-metabolic-redox ecosystem in HNSCC. IMRES provides a transcript-derived framework for identifying Hot+IMREShigh neighborhoods where immune activation, checkpoint signaling, metabolic remodeling, and stress adaptation converge, providing a hypothesis-generating framework for studying immune resistance and therapeutic vulnerability.

Carriers of germline BRCA1 or BRCA2 alterations have a substantially increased lifetime risk of high-grade serous ovarian carcinoma (HGSOC), which originates from the secretory cells of the fallopian tube. However, comparative multi-omic analyses of bulk fallopian tube tissue from BRCA1/2 carriers and the general population have, to date, revealed only limited differences. New molecular biomarkers of early malignant transformation in the FT are needed to enable non-surgical cancer interception in high-risk individuals through window-of-opportunity trials prior to risk-reducing surgery. We performed a comprehensive single-cell, multi-regional analysis of fallopian tubes from 34 women, including 15 carriers of germline BRCA1/2 alterations. Using a metacell-based approach applied to single-cell transcriptomic data, we identify both established and previously unrecognised cellular populations, and characterise phenotypic variation associated with menopausal status, menstrual cycle phase, hormonal contraception use, and anatomical region of the fallopian tube. Menopause was associated with depletion of ciliated cells, whilst both secretory (SEC) and ciliated epithelial cells (CEC) shifted to a glandular phenotype in the luteal phase. Previous hormonal contraception usage had lasting effects including depletion of CD163-positive tissue resident macrophages and progesterone-specific increase of MHC-II expression in SECs. Metacell analysis further identified distinct subpopulations of SECs, most frequently in BRCA1/2 carriers, characterised by high TP53 expression and markedly elevated histone levels. This phenotype is consistent with replication stress, cell-cycle arrest, and activation of innate immune signalling pathways. Protein-level validation in matched samples showed enrichment of cells with increased {gamma}H2AX expression and persistent 53BP1 foci in BRCA1/2 carriers. Together our data supports the role of BRCA1/2 in maintaining genomic integrity and a BRCA1/2 haploinsufficient phenotype characterised by increased replication stress in the fallopian tube epithelium. Our findings provide evidence for distinct immune responses in users of hormonal contraception and demonstrate early events in malignant transformation. They establish potential biomarkers in microscopically normal FT and a framework for measurement of cancer risk with the goal of enabling molecularly informed cancer interception in high-risk individuals.

Bulk telomere length measured from tumour sequencing is routinely interpreted as a property of the cancer cells. However, a tumour specimen is a mixture, and the patient who supplies it has a telomere length of their own. Here I re-analyse published pan-cancer telomere estimates and ask how much of a tumour's telomere length is patient-specific. A calibration step comes first. Whole-genome and low-pass estimates recover the known cross-sectional attrition of leukocyte telomeres with age, at 26.6 bp per year in blood normals, whereas whole-exome estimates do not. After adjustment for cancer type, sequencing centre and sex, the exome slope is minus 0.6 bp per year. In 684 blood-normal aliquots sequenced by both assays, the whole-genome estimate declines at 38.9 bp per year, whereas the exome estimate from the same DNA shows no detectable decline. The difference between assays is 41.5 bp per year, with P = 3 x 10^-10. Because exome data constitute 78.6% of the original resource, downstream analyses use only whole-genome and low-pass libraries. Within those data, tumour telomere length tracks the patient's matched-normal telomere length. The Spearman correlation is 0.395 in TCGA, with positive associations in 22 of 23 cancer types. This finding replicates in PCAWG using a different telomere estimator, with a correlation of 0.472 and positive associations in all 24 histologies examined. Adjustment for cancer type, sequencing centre and library type leaves a regression coefficient of 0.385. The association is also stable after adjustment for age, sex, tumour purity, leukocyte fraction, ploidy, sequencing coverage and continental ancestry, with coefficients ranging from 0.406 to 0.429. Pure normal-cell admixture is rejected as the sole explanation. Under a two-compartment mixture model, the coefficient for host telomere length is expected to equal 1 and the host-by-purity interaction to equal minus 1. These restrictions are jointly rejected with P = 0.001. Tumour purity, leukocyte fraction and age each explain only about 1 to 3% of within-cohort variance and do not alter the cross-cancer ranking. By contrast, the between-cohort coefficient is not directly interpretable. Its apparent near one-to-one relationship with tissue-associated telomere length depends strongly on which tissue supplies the matched-normal reference and on the statistical spread of that predictor, falling to 0.44 when organ-matched solid tissue is used. Bulk tumour telomere length is therefore a composite phenotype containing a replicated patient-specific component. Telomere biomarker studies should include matched-normal telomere length as a covariate rather than treating tumour telomere length as exclusively tumour-intrinsic.

AbstractAdrenocortical carcinoma (ACC) is a rare and highly aggressive endocrine malignancy originating from the adrenal cortex with limited effective treatment options. The underlying pathophysiology of ACC is uniquely characterized by abnormal steroid production and increased metabolic activity, highlighting the critical role of mitochondria in adrenal steroid hormone biosynthesis and tumor metabolism. In this study, we investigated the therapeutic potential of TR-107, a novel and highly selective small-molecule agonist targeting the mitochondrial protease ClpP. Pharmacologic hyperactivation of ClpP disrupts mitochondrial proteostasis and bioenergetics and has shown promising antitumor activity in various preclinical models. Our results demonstrated that TR-107 induces potent dose-dependent cytotoxic effects at nanomolar concentrations in ACC cell lines NCI-H295R and mACC3 as well as short-term ACC patient-derived organoid (PDO) models, markedly reducing cell viability and confluency in vitro. Metabolic analyses revealed that TR-107 significantly impaired oxygen consumption, indicating a disruption of oxidative phosphorylation and substantial attenuation of basal cellular respiration. Mechanistic studies showed dose-dependent increases in reactive oxygen species (ROS) levels and upregulation of proteins involved in mediating the ferroptotic rheostat. Pharmacokinetic assessment uncovered that TR-107 was not a substrate of the ABCB1 (MDR1/P-glycoprotein) efflux transporter, suggesting potential to overcome common multidrug resistance mechanisms. Given the importance of IGF-2 signaling in ACC, we further explored the combinatorial effects of TR-107 with IGF-1 receptor (IGF-1R) inhibitors and discovered that co-treatment produced synergistic reductions in cell viability across NCI-H295R, mACC3, and ACC PDOs. Collectively, these findings support the potential of mitochondrial ClpP hyperactivation as a promising therapeutic strategy for ACC and demonstrate that TR-107 exhibits significant antitumor activity as a monotherapy or in combination with IGF-1R inhibitors. These findings provide a strong rationale for advancing ClpP agonists into clinical development for the management of ACC.

Large genomically annotated acute myeloid leukaemia (AML) datasets exist, but population-based contemporary cohorts remain scarce. Here we report clinicopathological, genomic, and outcome data from Danish AML patients. 2,512 AML patients were identified between 2015-2022, of whom 33.8% had available NGS data (NGS+). In patients [&le;]70 years, baseline characteristics and outcomes were comparable between NGS+ and NGS- groups. In patients >70 years, more NGS+ patients received intensive treatment, but survival was similar among intensively treated patients. The distribution of mutations varied significantly by age and sex, with older age and male sex exhibiting higher frequencies of adverse-risk gene mutations. In intensively treated NGS+ patients, ELN2017 stratified 5-year OS: 58.4% (favorable), 43.4% (intermediate), and 28.2% (adverse), with hazard ratios (HRs) of 0.63 (favorable) and 1.45 (adverse) relative to intermediate. ELN2022 yielded corresponding OS rates of 56.9%, 51.8%, and 29.7%, with HRs of 0.78 and 1.86. The two models had comparable predictive performance for OS in a time-dependent model. In conclusion, outcomes of intensively treated AML patients were comparable irrespective of NGS status, underscoring the representativeness of the REFORM-AML database for the Danish AML population. Age and male sex correlated with adverse-risk mutations, and both ELN2017 and ELN2022 robustly predicted survival.