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PubMed2026

PARG inhibition reduces ssDNA levels and limits RPA loading upon replication fork collapse.

Poly(ADP-ribosyl)ation (PARylation) is a transient post-translational modification catalyzed by PARP enzymes and reversed by PARG. PARG inhibition causes sustained PARylation and is being explored as an anticancer strategy, but its cellular consequences remain incompletely understood. Here, we examine how persistent PARylation influences cellular responses to replication stress and DNA damage. We show that sustained PARylation reduces phosphorylated and chromatin-bound RPA most strongly under fork-stalling conditions that progress toward fork collapse. This effect requires PARP1 activity and is restrained by intact ATR-CHK1 signaling, as checkpoint inhibition renders otherwise resistant cells permissive for PARG inhibitor-associated phosphorylated RPA loss from the chromatin. The reduction of RPA phosphorylation is not dependent on BRCA1 and it is not accompanied by increased RAD51 loading. Instead, reduced chromatin-bound RPA coincides with decreased exposed ssDNA. Our results identify a checkpoint-dependent fork-collapse state in which sustained PARylation limits ssDNA and RPA levels.

Replication Protein A↗

PubMed2024

PARP1 UFMylation ensures the stability of stalled replication forks.

The S-phase checkpoint involving CHK1 is essential for fork stability in response to fork stalling. PARP1 acts as a sensor of replication stress and is required for CHK1 activation. However, it is unclear how the activity of PARP1 is regulated. Here, we found that UFMylation is required for the efficient activation of CHK1 by UFMylating PARP1 at K548 during replication stress. Inactivation of UFL1, the E3 enzyme essential for UFMylation, delayed CHK1 activation and inhibits nascent DNA degradation during replication blockage as seen in PARP1-deficient cells. An in vitro study indicated that PARP1 is UFMylated at K548, which enhances its catalytic activity. Correspondingly, a PARP1 UFMylation-deficient mutant (K548R) and pathogenic mutant (F553L) compromised CHK1 activation, the restart of stalled replication forks following replication blockage, and chromosome stability. Defective PARP1 UFMylation also resulted in excessive nascent DNA degradation at stalled replication forks. Finally, we observed that PARP1 UFMylation-deficient knock-in mice exhibited increased sensitivity to replication stress caused by anticancer treatments. Thus, we demonstrate that PARP1 UFMylation promotes CHK1 activation and replication fork stability during replication stress, thus safeguarding genome integrity.

DNA Replication↗

PubMed2024

RNF4 sustains Myc-driven tumorigenesis by facilitating DNA replication.

The mammalian SUMO-targeted E3 ubiquitin ligase Rnf4 has been reported to act as a regulator of DNA repair, but the importance of RNF4 as a tumor suppressor has not been tested. Using a conditional-knockout mouse model, we deleted Rnf4 in the B cell lineage to test the importance of RNF4 for growth of somatic cells. Although Rnf4-conditional-knockout B cells exhibited substantial genomic instability, Rnf4 deletion caused no increase in tumor susceptibility. In contrast, Rnf4 deletion extended the healthy lifespan of mice expressing an oncogenic c-myc transgene. Rnf4 activity is essential for normal DNA replication, and in its absence, there was a failure in ATR-CHK1 signaling of replication stress. Factors that normally mediate replication fork stability, including members of the Fanconi anemia gene family and the helicases PIF1 and RECQL5, showed reduced accumulation at replication forks in the absence of RNF4. RNF4 deficiency also resulted in an accumulation of hyper-SUMOylated proteins in chromatin, including members of the SMC5/6 complex, which contributes to replication failure by a mechanism dependent on RAD51. These findings indicate that RNF4, which shows increased expression in multiple human tumor types, is a potential target for anticancer therapy, especially in tumors expressing c-myc.

Animals↗

PubMed2026

TRIM28 regulates the G2/M transition via histone modification and DNA damage repair during mouse oocyte meiosis.

TRIM28, a member of the tripartite motif (TRIM) family, functions as a transcriptional coregulator involved in maintaining genome stability during mitosis. In this study, we explored the role of TRIM28 in mouse oocyte meiotic maturation, where transcriptional activity is barely detectable. We found that TRIM28 was constitutively expressed during the early stages of oocyte meiotic maturation, with predominant nuclear localization in germinal vesicle (GV)-stage oocytes. TRIM28 depletion caused defective germinal vesicle breakdown (GVBD), but oocytes that successfully underwent GVBD displayed unimpaired first polar body (PB1) extrusion. TRIM28 depletion impaired CDK1 activity and reduced cyclin B1 levels, leading to a delay in the G2/M transition. This delay might be caused by altered levels of HDAC2-mediated H4K12ac and H3K4me2-modulated H3K9me2 in nonsurrounded nucleolus (NSN)-type GV oocytes, which decreased transcription activity. Additionally, TRIM28-depleted oocytes exhibited elevated γ-H2A.X expression, accompanied by aberrant expression of CHK1 and CHK2, as well as dysregulated expression of RAD51, which collectively contributed to GVBD failure in mouse oocytes. In conclusion, our findings indicate that TRIM28 participates in the regulation of the G2/M transition during mouse oocyte meiotic maturation, acting through the modulation of histone modifications and DNA damage repair.

Animals↗

PubMed2026

Age-related genomic characterization and therapeutic targets in Chinese breast cancer: insights from prospective targeted sequencing and clinical data analysis.

BACKGROUND: In China, breast cancer occurs at a much younger age and has a higher recurrence and mortality rate. However, with changes in lifestyle, there has been a trend towards an older age of breast cancer incidence in Chinese women. There is a paucity of large-scale next-generation sequencing cohorts for the analysis of genomic characterization in these populations and the identification of potential therapeutic targets. METHODS: To address this gap, we performed prospective targeted sequencing of tumor and blood samples from Chinese patients and collected detailed clinical information. We then categorized patients into two groups based on age (< 40 years, n = 637; ≥ 40 years, n = 3442) and proceeded to provide comprehensive descriptions of somatic and germline mutations in both groups. RESULTS: The somatic mutation analysis revealed that PIK3CA, FOXA1, and TBX3 mutations were more prevalent in elderly patients. By leveraging the aforementioned mutational characteristics, we employed our institution's FUTURE-SUPER clinical trial, an umbrella study targeting metastatic breast cancer, to confirm the potential benefits of PI3K-AKT-mTOR pathway inhibitors among elderly patients with breast cancer. Furthermore, TP53 and ERBB2 were more likely to be co-mutated in young women. Patients with TP53 and ERBB2 co-mutation tend to have a poorer prognosis, but through investigation of the SPARK cohort, patients carrying the TP53 and ERBB2 co-mutation are more likely to benefit from immune checkpoint inhibitor combination with tyrosine kinase inhibitor therapy. In our study, we observed a higher frequency of mutations in the DNA homology-dependent recombination pathway in young patients with breast cancer, which was associated with an elevated Ki67 index. Additionally, we confirmed a significant prevalence of germline breast cancer susceptibility gene 1 (gBRCA1) mutations in young patients, whereas germline checkpoint kinase 2 (gCHEK2) mutations are more common in elderly patients. CONCLUSIONS: Our study, which makes use of the largest Chinese breast cancer sequencing cohort, sought to characterize the age-related genomic profile of breast cancer patients and identify novel therapeutic opportunities for individuals with breast cancer.

Adult↗

PubMed2026

Multiomic study of cutaneous T-cell lymphoma reveals single-cell clonal evolution in progression and therapy resistance.

Cutaneous T-cell lymphoma (CTCL) remains a challenging disease due to its significant heterogeneity, therapy resistance, and relentless progression. Multiomics technologies offer the potential to provide uniquely precise views of disease progression and response to therapy. Here, we present a comprehensive multiomics view of CTCL clonal evolution, incorporating exome, whole-genome, epigenome, bulk, single-cell T-cell receptor, and single-cell RNA sequencing of 99 clinically annotated serial skin, peripheral blood, and lymph node samples from 34 patients with CTCL. We leveraged this extensive data set to define the molecular underpinnings of CTCL progression in individual patients at single-cell resolution with the goal of identifying clinically useful biomarkers and therapeutic targets. Our studies identified recurrent progression-associated clonal genomic alterations; we highlight mutation of CCR4, phosphoinositide 3-kinase inhibitor signaling, and programmed cell death protein 1 (PD-1) checkpoint pathways as evasion tactics deployed by malignant T cells. We identified a gain-of-function mutation in STAT3 (D661Y) and demonstrated, using cleavage under targets and release using nuclease (CUT&RUN) and RNA sequencing, that it enhances binding to and transcription of genes in Rho GTPase pathways. With our previous work implicating this pathway in histone deacetylase inhibitor-resistant CTCL, these data provide further support for a previously unrecognized role for Rho GTPase pathway dysregulation in CTCL progression. Recurrent progression-associated mutations were common in the epigenetic modifier EZH2, suggesting that EZH2 inhibition may benefit patients with CTCL. Our findings support an approach in which genomic analysis is widely used for improved disease monitoring, biomarker-informed clinical trial design, and genome-guided therapeutic decision-making. Moreover, these molecular changes present new opportunities for therapeutic targeting in this challenging and incurable cancer.

Multiomics↗

PubMed2026

WEE1 kinase in cancer: Molecular mechanisms and inhibitor insights.

WEE1 kinase is a main regulator of the G2/M cell cycle checkpoint. It plays an important role in maintaining genomic stability by inhibiting CDK1 through a phosphorylation process at Tyr15. WEE1 is found to be overexpressed in several cancers and also act as a protective mechanism that allows cancer cells to repair DNA damage and survive under replicative stress. So, pharmacological inhibition of WEE1 has emerged as a promising therapeutic strategy. Many conventional chemotherapeutic agents act by inducing DNA damage, so it enables the activation of WEE1 in cancer cells to arrest the cell cycle and repair this damage by preventing cell death. Inhibition of WEE1 disrupts this protective checkpoint, which ultimately leads to mitotic catastrophe. Therefore, targeting WEE1 represents a promising and rational therapeutic approach, mainly in tumors with TP53 mutations. We have comprehensively discussed the structural features of WEE1, its regulation in DNA damage response, epigenetic control, and its role in cancer progression. We have also summarized the clinical development of major WEE1 inhibitors such as adavosertib, azenosertib (ZN-c3), and Debio 0123. Moreover, recently synthesized small-molecule inhibitors are also discussed with special focus on structure-activity relationship (SAR) insights, dual-target inhibitors, and PROTACs and molecular glue-based degraders. Two compounds, 8 and 11, were found to be the most potent WEE1 inhibitors with excellent enzymatic inhibition. This explains the importance of rational scaffold optimization and electron-withdrawing group insertion for enhanced activity. Overall, this review serves as a valuable reference for medicinal chemists in the development of next-generation WEE1 inhibitors. See also the graphical abstract(Fig. 1).

WEE1 kinase↗

PubMed2025

HMGA2 links morphological evolution and microenvironment dynamics to systemic therapy response in clear cell renal cell carcinoma.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) exhibits significant heterogeneity due to morphological changes and tumor microenvironment dynamics, influencing systemic therapy responses. While the role of high-mobility group AT-hook 2 (HMGA2) in tumor progression has been implicated in other cancers, its significance in ccRCC remains unclear. This study investigates the role of HMGA2 in these processes and its clinical impact. METHODS: Spatial transcriptomics (ST) was performed on primary ccRCC samples to investigate expression trajectories associated with HMGA2 expression and morphological evolution. In metastatic ccRCC cohorts treated with systemic therapy, immunohistochemistry and bulk RNA sequencing data were analyzed to evaluate molecular and clinical features in relation to HMGA2. Single-cell RNA sequencing (scRNA-seq) data were used to explore immune cell populations and their interactions. Based on these findings, multiplex immunohistochemistry (mIHC) assessed spatial distribution, cell-cell interactions, and pathological responses of key immune populations. RESULTS: HMGA2 expression was associated with aggressive morphological patterns, such as solid sheets and rhabdoid/sarcomatoid. ST revealed a progressive increase in HMGA2 expression along the morphological trajectory, marked by a shift from clear to eosinophilic cytoplasm, with eccentric nuclei and prominent nucleoli, and loss of vascular architecture. HMGA2-high tumors exhibited aggressive phenotypes driven by cell cycle, epithelial-mesenchymal transition, and inflammatory signaling pathways. Clinically, patients with high HMGA2 had worse progression-free survival but responded better to immune checkpoint inhibitor combination (Combo-ICI) therapy than to tyrosine kinase inhibitor monotherapy. To assess the immune landscape, scRNA-seq data revealed that HMGA2-high tumors were enriched with progenitor exhausted CD8+ T cells (Tpex), along with increased frequencies of conventional dendritic cell type 1 (cDC1) and inflammatory cDC type 2, which were found to interact with Tpex via ICAM-1. mIHC confirmed that Tpex were enriched among Combo-ICI responders in HMGA2-high tumors, with higher densities and closer proximity to ICAM-1+ cDC1. CONCLUSIONS: These findings suggest that dynamic HMGA2 expression contributes to morphological evolution and modulates immune responses through enhanced Tpex-cDCs engagement, serving as a potential marker for systemic therapy response in ccRCC. However, additional experimental studies are required to validate these mechanisms.

Humans↗

PubMed2025

An anti-androgen resistance-related gene signature acts as a prognostic marker and increases enzalutamide efficacy via PLK1 inhibition in prostate cancer.

BACKGROUND: Anti-androgen resistance remains a major clinical challenge in the treatment of prostate cancer (PCa), leading to disease progression and treatment failure. Despite extensive research on resistance mechanisms, a reliable prognostic model for predicting patient outcomes and guiding therapeutic strategies is still lacking. This study aimed to develop a novel gene signature related to anti-androgen resistance and evaluate its prognostic and therapeutic implications. METHODS: Anti-androgen resistance-related differentially expressed genes (ARRDEGs) were identified through transcriptomic analysis of enzalutamide- and dual enzalutamide abiraterone-resistant PCa cell lines from the GEO database. Functional enrichment analysis was performed to determine the biological roles of these genes. A prognostic gene signature was developed using univariate Cox regression, LASSO, and multivariate Cox regression models. The model was validated in independent PCa cohorts from The Cancer Genome Atlas (TCGA). Additionally, we assessed the correlation between the signature, immune infiltration, immune checkpoint expression, and drug sensitivity. The efficacy of PLK1 inhibition combined with enzalutamide was further explored using in vitro and in vivo experiments. RESULTS: We identified 304 ARRDEGs, from which three key genes (LMNB1, SSPO, and PLK1) were selected to construct a prognostic signature. This gene signature effectively stratified PCa patients into high- and low-risk groups, with the high-risk group exhibiting shorter recurrence-free survival and distinct immune characteristics. High-risk patients demonstrated elevated immune checkpoint expression (B7H3, CTLA-4, B7-1, and TIGIT), increased M2 macrophage infiltration, and enhanced sensitivity to chemotherapy and targeted therapy. Mechanistically, PLK1 inhibition potentiated the antitumor effect of enzalutamide by downregulating SLC7A11 and inducing ferroptosis, providing a potential therapeutic strategy to overcome anti-androgen resistance. CONCLUSION: We established a novel ARRDEGs-based prognostic signature that predicts PCa progression and response to chemotherapy and targeted therapy. The integration of this signature with immune profiling and drug sensitivity analysis provides a valuable tool for precision oncology in PCa. Our findings highlight the potential of PLK1 inhibition as a therapeutic strategy to enhance enzalutamide efficacy and overcome resistance.

Humans↗

PubMed2025

Artificial intelligence-powered spatial analysis of tumor microenvironment in patients with non-small cell lung cancer with acquired resistance to EGFR tyrosine kinase inhibitor.

PURPOSE: This study evaluated the dynamic changes in the tumor microenvironment (TME) in patients with non-small cell lung cancer (NSCLC) and acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) using an artificial intelligence (AI)-powered spatial TME analyzer. We then assessed the predictive efficacy of immune-checkpoint inhibitors (ICIs)-based treatment. EXPERIMENTAL DESIGN: An AI-powered whole-slide image analyzer was used to segment cancer areas (CAs) and cancer stroma and to identify tumor-infiltrating lymphocytes (TILs), tertiary lymphoid structures, fibroblasts, and endothelial cells (ECs) in the tumor tissue. We analyzed 143 NSCLC samples after resistance to EGFR-TKIs from two cohorts: (1) 89 patients treated with ICI monotherapy and (2) 54 patients from the ATTLAS phase III trial comparing atezolizumab plus bevacizumab, paclitaxel, and carboplatin (ABCP) versus pemetrexed plus carboplatin. RESULTS: Post-TKI samples showed reduced TILs in the CA (p=0.045) and increased ECs in the CA (p=0.005) compared with pre-TKI samples. These changes differed according to EGFR mutation subtype. Higher TILs in CA were associated with a better overall response rate (ORR) and progression-free survival (PFS). Similarly, higher EC levels in CA correlated with improved ORR and PFS. In the ATTLAS cohort, these factors were associated with clinical benefits from ABCP, with a significant association with TILs and a marginal association with ECs. CONCLUSION: Our findings suggest that EGFR-TKIs affect the immune landscape of patients with EGFR-mutated NSCLC. Higher TILs or ECs in the CA were significantly associated with a favorable response to subsequent ICI-based treatment. TRIAL REGISTRATION NUMBER: NCT03991403.

Aged↗

PubMed2026

Lipid metabolic reprogramming of tumor-associated macrophages drives resistance to immune checkpoint blockade in lung cancer: a narrative review of mechanisms and therapeutic strategies.

BACKGROUND AND OBJECTIVE: Immune checkpoint inhibitors (ICIs), represented by programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1), have shown remarkable efficacy in non-small cell lung cancer (NSCLC); however, many patients still develop resistance to immunotherapy. Although small cell lung cancer (SCLC) is also an important histological type of lung cancer, NSCLC accounts for the majority of lung cancer cases. Current research on ICI development, first-line treatment efficacy, and the mechanisms of lipid metabolism in tumor-associated macrophages (TAMs) is predominantly focused on NSCLC. In patients with advanced NSCLC, objective response rates (ORRs) with PD-1/PD-L1 inhibitor monotherapy remain limited. Only in patients with high PD-L1 expression [tumor proportion score (TPS) ≥50%] and without sensitizing epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) rearrangements does the ORR increase to approximately 40-45%. TAMs are a key component of the immunosuppressive tumor microenvironment (TME). Lipid metabolic reprogramming profoundly influences the functional and transcriptional features of TAMs. This review aims to integrate relevant evidence, elucidate how TAM lipid metabolism promotes immunosuppression and resistance to ICIs, and outline potential therapeutic strategies. METHODS: We searched PubMed/MEDLINE, Web of Science, and Scopus for publications up to June 2026 using terms combining lung cancer, TAMs, lipid metabolism, and immune checkpoint blockade/resistance. Mechanistic, translational, and clinically relevant studies were selected by author consensus. KEY CONTENT AND FINDINGS: Lipid uptake, de novo lipogenesis, fatty acid oxidation (FAO), cholesterol remodeling, and eicosanoid metabolism are not independent processes in TAMs. Lipid metabolic reprogramming in TAMs ultimately suppresses type I interferon (IFN-I) signaling, upregulates PD-L1 expression, and impairs the function of CD8+ T cells with stem-like features, thereby establishing an immunosuppressive TME and leading to resistance to ICIs. In lung cancer, hypoxia, high lactate levels, and tobacco exposure further shape the lipid phenotype of TAMs, such as lipid raft enrichment and lipid-laden macrophage subsets like SPP1+ macrophages. Different driver genomic backgrounds differentially impact tumor cell-intrinsic metabolism and the lipid metabolic programs of myeloid cells. In preclinical models, interventions targeting these metabolic axes, including TAM-directed delivery systems, have demonstrated potential therapeutic benefit when combined with anti-PD-1/PD-L1 therapy. CONCLUSIONS: Targeting TAM lipid metabolism to convert immunologically cold tumors into more inflamed, ICI-responsive tumors is a promising strategy to overcome resistance in NSCLC. Identification of predictive biomarkers of therapeutic response and development of cell-selective drug delivery systems come to be major challenges.

Non-small cell lung cancer (NSCLC)↗

PubMed2026

An overview of the DNA damage response in female reproductive system and breast cancers: A narrative review.

The DNA damage response (DDR) is a fundamental cellular network that preserves genomic integrity, and its dysregulation drives initiation, progression, and therapeutic response in female reproductive system and breast cancers. This narrative review provides a comparative analysis of DDR alterations across ovarian, endometrial, cervical, and breast cancers, synthesizing molecular studies, clinical trials, and international guidelines from PubMed/MEDLINE, Scopus, and Web of Science. DDR alterations vary substantially among these cancers, reflecting differences in tissue origin, hormonal regulation, and viral oncogenesis. Homologous recombination repair defects, particularly in breast cancer susceptibility 1/2, partner and localizer of BRCA2, ataxia telangiectasia mutated, and checkpoint kinase 2), are prevalent in ovarian, endometrial, and breast cancers, predicting sensitivity to platinum-based chemotherapy and poly (ADP-ribose) polymerase inhibitors. In endometrial cancer, homologous recombination deficiency predominates in high-grade tumor protein p53-mutated subtypes, while Fanconi anemia pathway alterations characterize aggressive serous carcinomas. Cervical cancer exhibits virus-induced DDR disruption and replication stress. Quantitative biomarkers, including tumor mutational burden, microsatellite instability, Radiation sensitive 51, Fanconi anemia complementation group D2, excision repair cross-complementation group 1, and DDR-related microRNAs enable patient stratification. Emerging ataxia telangiectasia and Rad3-related and WEE1 inhibitors show promise in combination regimens. Understanding of tumor-specific DDR enables rational therapeutic stratification, providing a framework for precision oncology.

DNA damage response, Ovarian neoplasms, Endometria↗

PubMed2026

Multi-omics Investigations of Immune Microenvironment of Human Colorectal Cancer.

BACKGROUND/AIM: Colorectal cancer (CRC) remains a leading cause of cancer-related morbidity and mortality worldwide. Although immunotherapy has improved outcomes for a subset of patients, its limited efficacy in many cases highlights the need for a more comprehensive understanding of the CRC immune microenvironment. This study aimed to characterize the molecular landscape of the CRC immune microenvironment using an integrated multi-omics approach and to identify candidate regulatory molecules associated with immune remodelling. MATERIALS AND METHODS: We integrated structural variation, DNA methylation, chromatin accessibility, proteomic, and phosphoproteomic data generated from an in-house CRC cohort with transcriptomic data from The Cancer Genome Atlas (TCGA). Analyses focused on 1,539 immune-related genes (IRGs) associated with CD4+ T cells, B cells, and natural killer (NK) cells. Multi-layered genomic and proteomic analyses were performed to identify altered immune-related pathways, hub genes, candidate transcription factors, and upstream kinases. RESULTS: Higher infiltration of CD4+ T cells, B cells, and NK cells was associated with CRC. IRGs exhibited widespread alterations across genomic, epigenomic, transcriptomic, proteomic, and phosphoproteomic levels. IL10, LEP, ITGAM, and EGFR emerged as candidate hub genes. EGFR phosphorylation at S991 and T693 was significantly decreased in CRC. STAT2 and HSF1 were identified as candidate upstream transcription factors, while CDK2 emerged as a candidate upstream kinase associated with immune infiltration and immune checkpoint expression. CONCLUSION: This study provides a systematic multi-omics characterization of immune microenvironment remodelling in CRC and identifies candidate molecular regulators that may serve as potential targets for future immunotherapy research.

Humans↗

PubMed2025

Immune landscape and novel therapeutic targets of epidermal growth factor receptor and anaplastic lymphoma kinase wild type never-smoker lung adenocarcinoma.

BACKGROUND: Never-smoker lung adenocarcinoma (NSLA) exhibits distinct immunosuppressive profiles and a lower tumor mutation burden compared with lung adenocarcinoma in smokers. These correlate with poor responses to immune checkpoint inhibitors. In this study, we aimed to elucidate the tumor-immune microenvironment of NSLA without epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) alterations and identify novel therapeutic targets. METHODS: We analyzed genome, transcriptome, and proteomic data from 102 NSLA tumor samples and 16 normal adjacent tissues. We classified tumors into distinct immune clusters (IC) based on gene signatures by profiling the tumor-infiltrating immune cells. RESULTS: The tumors were stratified into three ICs: hot, intermediate, and cold. Notably, only 21 (20.6%) patients exhibited hot IC enriched in cytotoxic T cells, natural killer cells, and B-cell signatures, which correlated with improved recurrence-free survival. Cold ICs (37.3%) exhibited higher myeloid-derived suppressor cell (MDSC) levels and M2 macrophage signatures, with poor immune cell infiltration and relatively low stimulatory cytokines and chemokines expression. CEACAM1, and NECTIN2 were upregulated in intermediate and cold ICs and correlated with MDSC and M2 macrophage infiltration. High expression of these genes was associated with poor survival outcomes. Protein-protein network analysis of 20 upregulated molecules associated with cancer- and driver-related proteins in cold IC identified XPO 1 as a key component. CONCLUSION: Our proteogenomic analysis highlighted the immunosuppressive properties of NSLA without EGFR and ALK alterations and identified novel therapeutic targets. These findings may provide novel treatment strategies that could improve the clinical outcomes of patients with NSLA.

Humans↗

PubMed2026

Inavolisib for PIK3CA-mutated advanced endometrial cancer: a multicentric, phase II, MITO END-4 trial.

BACKGROUND: The phosphatase and tensin homolog-phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) pathway is frequently altered in gynecological tumors, notably in endometrial cancer where PIK3CA mutations are found in nearly half of patients. Despite this, evidence of clinical activity of PI3K inhibitors in endometrial cancer is poor and limited. Alpelisib, an oral PI3K alpha-selective inhibitor, showed encouraging preliminary activity in advanced gynecological tumors harboring PIK3CA alterations. Inavolisib is a highly potent and selective PI3K inhibitor. PRIMARY OBJECTIVE(S): The MITO END-4 trial aims to assess the efficacy and safety of inavolisib in patients with endometrial cancer who have received platinum-based chemotherapy and immunotherapy. The primary objective is to determine the anti-tumor activity (assessed by objective response rate) of inavolisib in patients with advanced endometrial cancer with PIK3CA mutated tumors. STUDY HYPOTHESIS: The study tests the hypothesis that inavolisib has superior anti-tumor activity compared to historically available standard therapies in previously treated patients with advanced endometrial cancer harboring a PIK3CA mutation. TRIAL DESIGN: This is a phase II, single-arm, multicenter trial in which advanced endometrial cancer patients whose tumors harbor a pathogenic PIK3CA mutation will receive inavolisib. MAJOR INCLUSION/EXCLUSION CRITERIA: Patients aged 18 years and older with documented evidence of PIK3CA mutated advanced endometrial cancer (endometrioid, serous, clear cell, carcinosarcoma or mixed histology) will be enrolled. Patients have previously received at least 1 platinum-based chemotherapy in any setting (adjuvant or advanced) with or without immune checkpoint inhibitor, alone or in combination. Not more than 4 lines of therapy are allowed. Key exclusion criteria include uterine sarcoma and prior treatment with any PI3K, AKT, or mechanistic target of rapamycin (mTOR) inhibitor. PRIMARY ENDPOINT(S): Objective response rate defined as a complete response or partial response by the Investigator using RECIST v1.1 criteria over the whole treatment period. SAMPLE SIZE: 48 patients. ESTIMATED DATES FOR COMPLETING ACCRUAL: May 2028. TRIAL REGISTRATION: MITO END-4; EU-CT NUMBER: 2025-522981-61-00; NCT07522697.

Endometrial cancer↗

PubMed2025

Paradoxical Effect of Myosteatosis on the Immune Checkpoint Inhibitor Response in Metastatic Renal Cell Carcinoma.

BACKGROUND: Treatment for metastatic renal cell carcinoma (mRCC) has shifted from tyrosine kinase inhibitor (TKI) therapy to immune checkpoint inhibitor (ICI)-based therapy, improving outcomes but with variable individual responses. This study investigated the prognostic implications of pretreatment low skeletal muscle mass (LSMM) and myosteatosis in patients with mRCC undergoing first-line ICI-based therapies, comparing outcomes between PD-1 inhibitor + CTLA-4 inhibitor and PD-1 inhibitor + TKI, incorporating single-cell RNA sequencing. METHODS: A retrospective analysis was performed on 90 patients with mRCC treated with ICI-based therapies between November 2019 and March 2023. Patients were grouped based on whether they received PD-1 inhibitor + CTLA-4 inhibitor or PD-1 inhibitor + TKI combinations. LSMM was defined as skeletal muscle index below 40.8 cm2/m2 for men and 34.9 cm2/m2 for women. Myosteatosis was defined using skeletal muscle density, with cut-off values < 41 HU for BMI < 25 kg/m2 and < 33 HU for BMI ≥ 25 kg/m2. Progression-free survival (PFS) and overall survival (OS) were compared using Kaplan-Meier curves and multivariable models. Single-cell RNA sequencing was performed on pretreatment samples to compare the immune microenvironment between patients with and without myosteatosis. RESULTS: The study cohort (26.7% female; median age: 60.5 years) included 59 patients (65.6%) treated with PD-1 inhibitor + CTLA-4 inhibitor and 31 patients (34.4%) treated with PD-1 inhibitor + TKI. LSMM was present in 18.9% of patients, and myosteatosis in 41.1%, with comparable proportions across groups. During follow-up, 29 patients (32.2%) died: 16 in the PD-1 inhibitor + CTLA-4 inhibitor group and 13 in the PD-1 inhibitor + TKI group. The overall 1-year mortality rate was 22.2%, and PFS rate was 53.3%. Myosteatosis predicted poor OS (HR, 5.389; p = 0.008) and PFS (HR, 2.930; p = 0.022) in the PD-1 inhibitor + TKI group but was protective for PFS (HR, 0.461; p = 0.049) in the PD-1 inhibitor + CTLA-4 inhibitor group. LSMM did not significantly affect outcomes in either group. Single-cell RNA sequencing revealed higher CTLA-4 expression in regulatory T cells and more effector memory CD8+ T cells in patients with myosteatosis, whereas patients without myosteatosis had more anti-tumoural non-classical monocytes. CONCLUSIONS: Myosteatosis negatively impacts OS and PFS in patients with mRCC treated with PD-1 inhibitor + TKI therapy but is protective for PFS in those treated with PD-1 inhibitor + CTLA-4 inhibitor therapy. Altered checkpoint expression and immune cell composition associated with myosteatosis may contribute to these differential responses.

Humans↗

PubMed2025

Reconsidering the definition of triple-negative breast cancer in the immune checkpoint inhibitor era: an optimal cut-off value for hormone receptor percentage of HER2-negative invasive breast cancer.

The optimal cut-off values of estrogen receptor (ER) and progesterone receptor (PgR) expression to define the positivity of ER and PgR have been under discussion for over a decade but remain controversial. The American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) and the St. Gallen International Expert Consensus recommended that breast cancers with ≥1% of ER or PgR expression should be considered hormone receptor (HR)-positive tumors but ER/PR expression of 1% to 10% should be reported as HR-low positive; however, among HER2-negative disease, data on the overall benefit of adjuvant endocrine therapies for patients with HR-low positive disease is limited, resulting in the revisiting of the definition of triple-negative breast cancer (TNBC). Defining HR-low positive disease by better understanding the biology is essential because of the recent advancement of neoadjuvant and adjuvant systemic therapy strategies, including immune checkpoint inhibitors (ICIs) for TNBC. Additionally, identifying who should be treated with adjuvant endocrine therapy, particularly those who have HR-low HER2-negative disease, which is currently treated as TNBC without adjuvant endocrine therapy, is a clinical unmet need. In clinical practice, treating physicians have tailored systemic treatment strategies using other clinical and pathological factors (i.e., age, grade, Ki-67, tumor size, lymph node involvement). There is no universal practice to treat patients with HR-low HER2-negative breast cancer. This review summarized the currently available data to define the clinically relevant optimal cut-off values of ER/PgR in neoadjuvant- and adjuvant-setting. We recommend considering creating a novel category of triple-negative like breast cancer (TN-like BC), which will require a therapeutic strategy different from conventional TNBC.

Humans↗

PubMed2020

Combination of cyclin-dependent kinase and immune checkpoint inhibitors for the treatment of bladder cancer.

BACKGROUND: Perturbation of the CDK4/6 pathway is frequently observed in advanced bladder cancer. We investigated the potential of targeting this pathway alone or in combination with chemotherapy or immunotherapy as a therapeutic approach for the treatment of bladder cancer METHODS: The genetic alterations of the CDK4/6 pathway in bladder cancer were first analyzed with The Cancer Genome Atlas database and validated in our bladder cancer patient-derived tumor xenografts (PDXs). Bladder cancer cell lines and mice carrying PDXs with the CDK4/6 pathway perturbations were treated with a CDK4/6 inhibitor palbociclib to determine its anticancer activity and the underlying mechanisms. The combination index method was performed to assess palbociclib and gemcitabine drug-drug interactions. Syngeneic mouse bladder cancer model BBN963 was used to assess whether palbociclib could potentiate anti-PD1 immunotherapy. RESULTS: Of the 413 bladder cancer specimens, 79.2% harbored pertubations along the CDK4/6 pathway. Palbociclib induced G0/G1 cell cycle arrest but with minimal apoptosis in vitro. In mice carrying PDXs, palbociclib treatment reduced tumor growth and prolonged survival from 14 to 32 days compared to vehicle only controls (p = 0.0001). Palbociclib treatment was associated with a decrease in Rb phosphorylation in both cell lines and PDXs. Palbociclib and gemcitabine exhibited antagonistic cytotoxicity in vitro (CI > 3) and in vivo, but palbociclib significantly enhanced the treatment efficacy of anti-PD1 immunotherapy and induced CD8+ T lymphocyte infiltration in syngeneic mouse models. CONCLUSIONS: The CDK4/6 pathway is feasible as a potential target for the treatment of bladder cancer, especially in combination with immunotherapy. A CDK4/6 inhibitor should not be combined with gemcitabine.

Animals↗