Search Results (329)

Glioblastoma (GBM) standard of care includes surgical resection followed by ionizing radiation (IR) and Temozolomide, which induce DNA double-strand breaks. Homologous recombination (HR), a critical DNA double-strand break repair pathway, is augmented in GBM, contributing to resistance and poor patient outcomes. Here, we demonstrate that increasing deoxyribonucleoside triphosphate (dNTP) levels impairs HR-mediated double-strand break repair, rendering GBM cells sensitive to IR and Temozolomide. Interestingly, combining an elevated dNTP pool level with IR and/or Temozolomide promotes the recruitment of DNA polymerase-α/primase, which is typically involved in Okazaki fragment synthesis during DNA replication, to the DNA double-strand break site, thereby interfering with DNA end resection. Specifically, higher dNTP pool levels disrupted the recruitment of HR-associated proteins such as RPA70 and RAD51, an effect reversed by Aphidicolin, a DNA polymerase-α/primase inhibitor. Impaired HR delayed IR- and/or Temozolomide-induced DNA double-strand break repair, leading to growth arrest and apoptosis. Furthermore, higher dNTP pool levels led to downregulation of DNA replication and HR-associated genes, while upregulating several pro-apoptotic genes. Increased sensitivity to IR and Temozolomide was also observed in engineered IR-resistant GBM cell lines and in naturally recurrent patient-derived GBM cells that emerge post-therapy. These findings emphasize how dNTP pool levels regulate HR and uncover a promising vulnerability that could be exploited to overcome resistance to DNA-damaging treatments in GBM and beyond. Full article

Background: Although POLD1 exhibits oncogenic properties in multiple malignancies, its precise role and regulatory mechanisms in cisplatin resistance of bladder cancer (BC) remain elusive. This study aims to elucidate the functional involvement and upstream regulatory axis of POLD1 in BC chemoresistance. Methods: We evaluated the impact of POLD1 on chemoresistance and DNA damage repair (DDR) using public clinical databases and cisplatin-resistant cell lines, employing CCK-8, colony formation, flow cytometry, immunofluorescence, and comet assays. Protein interactions were examined via Co-IP, molecular docking, and truncation mutant analysis. ChIP-PCR and dual-luciferase reporter assays were utilized to identify the upstream transcription factor. In vivo functionality was further validated in a nude mouse xenograft model. Results: POLD1 was markedly upregulated in BC tissues and cisplatin-resistant BC cells, and its elevated expression was tightly associated with advanced tumor stage, high pathological grade, and poor patient prognosis. Functional experiments verified that POLD1 knockdown aggravated cisplatin-induced DNA damage and drastically sensitized BC cells to cisplatin in vitro, and attenuated tumor growth under cisplatin treatment in vivo, indicating that POLD1 is a key driver of cisplatin resistance. Mechanistically, POLD1 physically interacted with and activated ATM, thereby initiating homologous recombination (HR) repair signaling. Moreover, transcription factor MAZ directly bound the promoter region of POLD1 to transcriptionally upregulate its expression. Rescue experiments in vitro further validated that the MAZ-POLD1 axis facilitates cisplatin resistance by modulating the DDR pathway in BC. Conclusions: Therapeutic targeting of the POLD1-regulated DDR pathway holds great promise as an effective strategy to reverse acquired cisplatin resistance in BC. Full article

Background: Solid tumors including glioblastoma (GBM), lung cancer (LC), and triple-negative breast cancer (TNBC) exhibit marked radioresistance driven by dysregulated cell-cycle control and genomic instability. Although CDK4/6 inhibitors suppress tumor proliferation, their radiosensitizing capacity is limited by persistent DNA repair. BUB1, a mitotic checkpoint kinase overexpressed in aggressive cancers, has emerged as a regulator of DNA damage signaling. We tested whether co-targeting BUB1 and CDK4/6 enhances radiosensitivity across solid tumors. Methods: GBM, LC, and TNBC cell lines were treated with BUB1 inhibitor BAY1816032, CDK4/6 inhibitors ribociclib and abemaciclib, and radiation. Proliferation, clonogenic survival, immunoblotting, and combination index analyses assessed cytotoxicity and synergy. CDK4/6-resistant models were generated to examine resistance. In vivo efficacy was evaluated using SUM159 xenografts. DNA damage and homologous recombination repair were measured by gH2AX, RAD51, RPA, BrdU foci and comet assay. The resection branchpoint was assessed by phospho-RPA, with ATR inhibition and BLM or EXO1 depletion testing resection dependence. Results: BUB1 inhibition increased cytotoxicity in vitro and improved therapeutic response in vivo. Combined BUB1 and CDK4/6 inhibition showed strong synergy (C.I. < 1) and enhanced radiosensitization in RB+ models. CDK4/6-resistant cells displayed increased BUB1 expression, and BUB1 inhibition partially restored sensitivity. Mechanistically, dual inhibition intensified homologous recombination defects, marked by persistent gH2AX and altered RAD51, RPA, and BrdU dynamics, consistent with sustained single stranded DNA and impaired HR repair. Persistent RPA32 Ser33 phosphorylation reflects ATR-dependent resection that requires BLM and EXO1 at later stages, supporting sustained resection and unresolved repair leading to increased cell death. Conclusions: Dual inhibition of BUB1 and CDK4/6 represents a promising therapeutic strategy for enhancing radiosensitivity in GBM, lung cancer, and TNBC, particularly in Rb-intact settings. Full article

Esophageal cancer is a common malignancy of the upper gastrointestinal tract that is associated with high incidence and mortality rates. Radiotherapy constitutes a cornerstone therapeutic modality for esophageal cancer. In radiotherapy, ionizing radiation is used to eliminate tumor cells through direct DNA damage and indirect reactive oxygen species (ROS)-mediated effects. However, clinical outcomes are frequently limited by interpatient heterogeneity and intrinsic tumor radioresistance. This review systematically describes the determinants of radiosensitivity in esophageal cancer within the established radiobiological framework of the “6Rs”: DNA damage repair (Repair), which is mediated by γ-H2AX phosphorylation, PARP family enzymes, and nonhomologous end joining (NHEJ) and homologous recombination (HR) pathways; cell cycle redistribution (Redistribution), which is regulated by G1/S and G2/M checkpoint dynamics; tumor repopulation (Repopulation), which is driven by cancer stem cell activity during fractionated treatment; reoxygenation (Reoxygenation), which is modulated through HIF-1α signaling and ROS homeostasis; intrinsic radiosensitivity (Radiosensitivity), which reflects interindividual and histopathological variability; and reactivation of antitumor immune responses (Reactivation), which enhances efficacy by remodeling the tumor immune microenvironment. Furthermore, regulated cell death mechanisms, including ferroptosis, autophagy, and apoptosis, significantly modulate radiotherapeutic responses. Elucidating these interconnected mechanisms provides a robust theoretical foundation for developing targeted interventions, identifying predictive biomarkers, and advancing precision radiotherapy strategies to optimize clinical outcomes for patients with esophageal cancer. Full article

PARP1/2 inhibitors have received FDA approval for pancreatic cancer harboring BRCA1/2 mutations and homologous recombination (HR) deficiency; however, their limited indications restrict their broader clinical application. Previous studies have demonstrated that PARP7, a member of the PARP family, enhances tumor sensitivity to PARP1/2 inhibition. However, the mechanisms underlying their synergistic effects in pancreatic cancer remain unclear. Herein, we found that combined inhibition of PARP1/2 and PARP7 using Olaparib and XYL-1 significantly inhibited the proliferation of SW1990 and CFPAC cells compared with either single agent. Furthermore, XYL-1 and Olaparib cooperatively caused DNA damage and induced cell apoptosis in SW1990 cells. Consistently, combined treatment with XYL-1 and Olaparib significantly suppressed SW1990 tumor growth compared with single-agent treatment in mouse xenograft models, accompanied by elevated levels of phosphorylated H2AX in tumor tissues. Notably, bioinformatic analyses and mechanistic studies identified SCD1 and BRCA1 as key mediators of the synergistic antitumor effects of XYL-1 and Olaparib. More importantly, the combination of XYL-1 and Olaparib synergistically downregulated the expression of SCD1 and BRCA1, thereby impairing the HR-mediated DNA repair pathway. Collectively, these findings suggest that dual targeting of PARP7 and PARP1/2 may represent a promising therapeutic strategy for BRCA-proficient pancreatic cancer. Full article

Background/Objectives: High-grade serous ovarian cancer (HGSOC) shows variable response to platinum-based neoadjuvant chemotherapy (NACT), with outcomes strongly linked to upfront treatment sensitivity. We evaluated whether oxidative DNA damage in pathologic samples is associated with improved clinical outcomes and reflects tumor–immune interactions. Methods: We analyzed matched pre- and post-NACT tumors from patients with stage III–IV HGSOC using Repair Assisted Damage Detection (RADD) to quantify total and oxidative DNA lesions (oxRADD). Gene expression profiling was performed on a subset of tumors using the NanoString PanCancer I/O 360. Associations with homologous recombination status, platinum sensitivity, recurrence, and survival were assessed. Results: Higher pre-NACT oxidative DNA damage was observed in tumors from patients who later recurred. Among recurrent tumors, elevated oxidative lesions were associated with improved overall survival (61.8 vs. 35.0 months; HR = 0.42, p = 0.037). Oxidative damage predicted recurrence (AUC = 0.71), supporting its utility in risk stratification. Tumors with serious oxidative damage showed reduced IDO1 and TGFβ signaling signatures, along with decreased B cell- and T cell-associated TIGIT signatures after NACT. Conclusions: These findings identify oxidative DNA damage as a potential pretreatment biomarker associated with recurrence, survival, and tumor–immune state, supporting its potential to impact therapeutic decision-making in HGSOC. Full article

Poly(ADP-ribose) polymerase inhibitors (PARPis) have demonstrated remarkable efficacy in tumors carrying BRCA1/2 pathogenic variants (PVs) through the mechanism of synthetic lethality. PVs in other homologous recombination (HR) genes may also impair homologous recombination repair and confer sensitivity to PARPis; however, their predictive value remains uncertain and appears to vary according to the affected gene and tumor type. We review and critically discuss the current evidence regarding the predictive value of non-BRCA HR gene pathogenic variants as biomarkers of PARPi sensitivity across ovarian, breast, prostate, and pancreatic cancers. A narrative review was conducted between October 2023 and December 2025, first identifying pivotal clinical trials of PARP inhibitors across ovarian, breast, prostate, and pancreatic cancers, followed by a targeted search of PubMed, Embase, Web of Science, and Google Scholar for relevant preclinical and clinical studies. Seventeen clinical studies and multiple preclinical reports were analyzed regarding genomic frequency, HRD association, and treatment response. Preclinical studies consistently demonstrated increased PARPi sensitivity in models with alterations in several non-BRCA HR genes. Clinical evidence, however, was heterogeneous. PALB2 demonstrated the strongest and most consistent association with PARPi benefit across tumor types, while RAD51C and RAD51D also showed clinically meaningful activity, particularly in ovarian cancer. In contrast, evidence supporting PARPi sensitivity in tumors harboring ATM, CHEK2, CDK12, and several other HR gene alterations remained limited or inconsistent. Differences in gene function, biallelic inactivation, variant type, and current limitations of HRD companion diagnostic assays likely contribute to the observed variability in clinical response. Non-BRCA HR gene alterations represent promising predictive biomarkers for PARPi therapy but should not be considered a homogeneous group. Future biomarker-driven studies integrating comprehensive genomic profiling and functional assessment of homologous recombination deficiency are needed to refine patient selection and optimize the clinical application of PARPis beyond BRCA1/2-associated cancers. Full article

Background/Objectives: High-grade serous ovarian carcinoma (HGSC) is the most aggressive subtype of epithelial ovarian cancer and is characterized by marked heterogeneity of the tumor immune microenvironment. SET morphology has been associated with homologous recombination deficiency and BRCA1/2 mutations; however, its relationship with the immune microenvironment and progression-free survival (PFS) remains insufficiently understood. This study investigated the association between SET morphology, immune microenvironment characteristics, and PFS in patients with advanced-stage HGSC. Methods: A retrospective cohort of 305 patients with FIGO stage III–IV HGSC treated with primary surgery between 1996 and 2021 was analyzed. Histopathological assessment included evaluation of SET morphology, stromal and intraepithelial tumor-infiltrating lymphocytes (sTILs and itTILs), tumor immune phenotype, and lymphoid aggregates. Immunohistochemical analyses included CD8 and PD-L1 expression. Associations between SET morphology and immune parameters were evaluated using χ² and logistic regression analyses. PFS was assessed using Kaplan–Meier analysis, log-rank testing, and Cox proportional hazards regression. Results: SET morphology was significantly associated with higher sTIL and itTIL levels, increased stromal and intraepithelial CD8⁺ T-cell infiltration, higher PD-L1 TPS and CPS, more frequent primary and secondary lymphoid aggregates, and a predominance of the inflamed immune phenotype (all p < 0.05). Despite these features of an immune-active tumor microenvironment, SET morphology, CD8⁺ T-cell density, PD-L1 expression, lymphoid aggregates, and immune phenotype were not independently associated with prolonged PFS. In contrast, age remained an independent prognostic factor, with patients older than 55 years having a 50% higher risk of disease progression than younger patients (HR = 1.5, 95% CI: 1.1–2.1; p = 0.012). Higher intraepithelial TIL levels (>10%) were independently associated with improved PFS (HR = 2.1, 95% CI: 1.0–4.4; p = 0.045). Conclusions: SET morphology identifies an immune-active subtype of HGSC characterized by increased immune infiltration and PD-L1 expression but does not independently predict prolonged PFS. The dissociation between immune cell abundance and clinical outcome suggests that immune cell functionality, rather than immune infiltration alone, may determine prognosis. Routine histopathological assessment of SET morphology may facilitate biological characterization of HGSC and provide a practical surrogate marker for future biomarker-driven studies evaluating immunotherapy and targeted treatment strategies. Full article

DNA double-strand breaks (DSBs), caused by various endogenous and exogenous factors, pose a significant threat to genomic stability. Several conserved repair pathways address DSBs, with homologous recombination (HR) being the only mechanism capable of accurately restoring the original DNA sequence. The BRCA1 gene plays a critical role in HR and is involved in maintaining genomic stability, cell cycle regulation, transcription, and tumor angiogenesis. Germline mutations in BRCA1 are strongly associated with increased risks of breast, ovarian, and other cancers. Dysfunction of BRCA1 leads to homologous recombination deficiency (HRD), forcing cells to rely on error-prone repair pathways, which promotes genomic instability and tumorigenesis. Besides hereditary mutations, HRD can also arise in sporadic cancers through epigenetic mechanisms such as promoter hypermethylation and reduced BRCA1 expression. Although BRCA1 deficiency is uncommon in lung cancer, BRCA1 status is considered a potential biomarker for sensitivity to platinum-based chemotherapy and other cytotoxic agents used in lung cancer treatment. However, the impact of BRCA1 on treatment response and prognosis in lung cancer remains controversial and not fully understood. This review summarizes current evidence on the role of BRCA1 in modulating chemotherapy response and disease outcomes in lung cancer patients, highlighting its potential as a biomarker for personalized therapy selection. Thus, in this context, the key unresolved issues critical for the development of personalized treatment strategies for lung cancer associated with BRCA1 alterations include the identification of molecular biomarkers most reliably associated with tumor sensitivity to chemotherapy. In addition, the development of methods for identifying patients with homologous recombination deficiency specifically in lung tumors appears to be of considerable importance, as does a better understanding of how the biological and therapeutic implications of BRCA1-related parameters in lung cancer differ from those observed in other tumor types. Addressing these challenges could substantially improve the efficacy of chemotherapy and patient outcomes, while also expanding the opportunities for a personalized approach to treatment selection in patients with lung cancer. Full article

The prognostic significance of next-generation sequencing (NGS) findings during the hormone-sensitive phase of prostate cancer remains incompletely characterized. This retrospective cohort study included 92 patients who underwent NGS analysis on tumor tissue between 2019 and 2025. The primary endpoint was time to castration-resistant prostate cancer (CRPC) from androgen deprivation therapy (ADT) initiation; secondary endpoints were overall survival from ADT initiation (OS-ADT) and from diagnosis. Kaplan-Meier and Cox regression analyses were performed. CRPC developed in 66 patients (71.7%) at a median of 21.1 months. The most frequently altered genes were ATR (35.9%), PTEN (28.3%), TP53 (26.1%), and BRCA2 (15.2%). KMT2C alteration (5.4%) was the strongest independent genomic predictor of shorter time to CRPC (HR = 6.804, p = 0.003) and OS-ADT (HR = 4.730, p = 0.019). TP53 alteration independently predicted shorter OS-ADT (HR = 1.810, p = 0.038). High genomic burden independently predicted shorter time to CRPC (HR = 1.917, p = 0.032). Homologous recombination repair deficiency was not associated with outcomes, attributable to high ATR alteration frequency introducing pathway heterogeneity. Mismatch repair deficiency showed a borderline association with shorter OS-ADT (20.7 vs. 44.0 months; p = 0.060). An exploratory composite risk score stratified patients into three prognostic groups with markedly different outcomes (HR = 7.904, p = 0.001). NGS analysis during the hormone-sensitive phase identifies independent predictors of castration resistance, supporting its integration at ADT initiation for risk stratification and biomarker-guided treatment planning. Full article

ARGLU1 (Arginine and Glutamate Rich1) is a newly identified nuclear protein with suggested multifunctional roles that may be implicated in the pathogenesis and therapeutic resistance of glioma, the most common primary malignant brain tumor. The high heterogeneity and treatment resistance of gliomas pose central challenges in clinical management. ARGLU1 has been implicated in maintaining genomic stability and may contribute to tumor progression by regulating RNA splicing and DNA damage repair pathways. This review systematically summarizes the structural and functional features of ARGLU1 and discusses its potential molecular mechanisms in glioma. These include its influence on the spliceosome assembly, alternative splicing events, and key DNA repair pathways such as homologous recombination (HR) and Fanconi anemia (FA). Furthermore, it discusses the hypothesis that ARGLU1 may enhance DNA repair capacity and thereby influence glioma resistance to temozolomide (TMZ) and radiotherapy. Targeting ARGLU1 may offer a strategy to overcome this resistance. Finally, the review outlines current research limitations and future directions, aiming to provide a new theoretical foundation for the precision treatment of glioma. Full article

Background: Pathogenic BRCA1 and BRCA2 mutations confer a homologous recombination deficiency that underlies PARP inhibitor sensitivity. While BRCA1 mutation carriers more frequently develop triple-negative breast cancer (TNBC) and BRCA2 carriers hormone receptor-positive (HR+) disease, whether the specific protein domain harboring a pathogenic somatic mutation differs systematically between breast cancer subtypes remains uncertain. Apparent domain enrichment in earlier unfiltered analyses may be confounded by missense variants of uncertain significance (VUSs), which lack clinical actionability. Methods: We assembled three independent breast cancer cohorts via cBioPortal: TCGA-BRCA (brca_tcga_pub2015), METABRIC (brca_metabric), and MSK-CHORD (msk_chord_2024). All somatic BRCA1/2 mutations were mapped to UniProt-annotated functional domains and to Rebbeck-defined breast/ovarian cancer cluster regions (BCCR/OCCR). Per ENIGMA/ACMG guidance, pathogenic mutations (nonsense, frameshift, and canonical splice site) were analyzed inferentially, while missense and in-frame variants—predominantly VUSs—were only reported descriptively. Fisher’s exact tests with Benjamini–Hochberg FDR correction were applied across domain × subtype contingencies. Cohort heterogeneity was assessed via Cochran’s Q and I² statistics; pooled effect estimates were computed using inverse-variance fixed-effects meta-analysis. Results: A total of 394 somatic BRCA1/2 mutations were identified across the three cohorts (BRCA1 n = 166; BRCA2 n = 228), of which 147 (37.3%) met pathogenic criteria. Among 131 pathogenic mutations in HR+/HER2− or TNBC subtypes, 84 (64.1%) occurred in HR+/HER2− disease and 47 (35.9%) in TNBC. Domain-level distributions did not differ significantly between subtypes for any BRCA1 domain (BRCT: TNBC 20.0% vs. HR+ 18.8%, OR = 1.08, 95% CI 0.31–3.78, and FDR-adjusted p = 1.00) or BRCA2 domain (DBD: TNBC 17.6% vs. HR+ 30.8%, OR = 0.48, and FDR-adjusted p = 1.00). Cluster-region analyses (nine Rebbeck BCCR/OCCRs) similarly showed no significant enrichment. Post hoc power analysis indicated that the study could only reliably detect large effects (OR ≥ ~3.0 for the principal BRCT contrast), and formal equivalence testing (TOST) demonstrated equivalence within a prespecified ±20% margin for BRCA1 BRCT (TOST p = 0.031). Heterogeneity across cohorts was minimal (Cochran’s Q = 0.62, I² = 0.0%). Descriptive analyses of VUSs suggested the apparent enrichment of BRCA1 BRCT-localized missense variants in TNBC (31.8% vs. 17.9% in HR+), but this signal did not extend to pathogenic mutations. Conclusions: Within the statistical power available, our three-cohort analysis shows no evidence of large subtype-specific enrichment of pathogenic BRCA1/2 somatic mutations across protein domains or cluster regions; small to moderate effects cannot be excluded. Notably, the majority (64%) of pathogenic mutations occurred in HR+/HER2− disease, underscoring that BRCA1/2 testing should not be deprioritized in non-TNBC subtypes. The apparent BRCT enrichment observed in earlier unfiltered analyses appears to be driven by VUSs rather than pathogenic variants, highlighting the methodological necessity of pathogenicity filtering for clinically actionable inference. These findings provide cohort-scale supportive evidence for emerging clinical guidelines that recommend broader BRCA1/2 testing across breast cancer subtypes. Full article

Skeletal muscle differentiation relies on transient DNA strand breaks (DSBs), yet excessive DNA damage remains harmful to myogenic progression. The RNA-binding protein Zfp36l1 is expressed in skeletal muscle and contributes to muscle regeneration; nevertheless, its role in preserving genome stability during myogenic differentiation has not been defined. Here, we investigated the role and mechanism of Zfp36l1 in regulating DNA damage using C2C12 myoblast cells, combining loss- and gain-of-function assays, RNA-seq, and rescue experiments. The results revealed that Zfp36l1 expression is strongly induced during early myogenic differentiation, coinciding with the onset of physiological DSBs. Functional assays revealed that silencing Zfp36l1 aggravates DSB accumulation, reinforces G0/G1 cell cycle arrest, and promotes apoptosis, whereas Zfp36l1 overexpression attenuates these abnormalities. Transcriptomic profiling shows that Zfp36l1 knockdown impairs homologous recombination (HR)-mediated DNA repair by downregulating core repair factors, including Rad51 and Brca1. Gene set enrichment analysis further confirms significant suppression of the HR-dependent DSB repair pathway. Mechanistically, Zfp36l1 regulates HR repair by suppressing p21 expression, thereby relieving inhibition of E2F1-mediated Rad51 transcription. Co-silencing p21 restores Rad51 expression and reduces DNA damage in Zfp36l1-knockdown cells. Collectively, these findings identify Zfp36l1 as an essential safeguard of genome stability during myogenic differentiation by balancing DNA damage levels through the p21-E2F1-Rad51 signaling axis, and provide new insights into the regulatory basis of muscle development and genomic instability-associated muscle diseases. Full article

Chronic inhalation exposure to nanoplastics, specifically polyethylene terephthalate (PET) nanoplastics (PET-NPLs) is an emerging health concern, yet the long-term consequences for genomic stability and DNA damage response (DDR) capacity in bronchial epithelial cells remain poorly characterized. For this study, human bronchial epithelial BEAS-2B cells were continuously exposed to PET-NPLs for over 20 weeks, after which elevated basal DNA genotoxic damage was observed, as assessed by the alkaline comet assay. In addition, a broad transcriptional suppression of the DDR, with 27 of 84 profiled genes involved in DDR showing reduced expression relative to passage-matched control was observed. The suppressed genes span ATM/ATR checkpoint signaling, homologous recombination (HR), base excision repair (BER), nucleotide excision repair (NER), and apoptotic pathways. To determine whether chronic PET-NPL exposure altered susceptibility to acute genotoxic challenge in a damage-type-specific manner, cells were treated with methyl methanesulfonate (MMS), ultraviolet-C (UV-C) radiation, or bleomycin. While MMS and UV-C induced comparable levels of DNA damage in control and PET-exposed cells, bleomycin produced significantly greater damage in PET-exposed cells, indicating selective sensitization to doble-strand breaks (DSB)-type and oxidative genotoxic insults. Transcriptional profiling during bleomycin challenge identified 18 DDR genes with relatively higher expression in PET-exposed cells compared to passage-matched controls, encompassing HR, BER, ATM/ATR signaling, the Fanconi anemia pathway, and apoptosis. Furthermore, PET-exposed cells retained significantly higher residual DNA damage after 3 h of bleomycin challenge, indicating a persistent early repair deficit. Together, these findings suggest that chronic PET-NPL exposure specifically compromises the bronchial epithelial DDR, with potential implications for long-term genomic stability in respiratory epithelia subjected to nanoplastic inhalation. Full article

Background/Objectives: High-grade serous ovarian carcinoma (HGSOC) is associated with high relapse rates despite aggressive multimodal treatment. BRCA mutations, present in a substantial subset of patients, confer homologous recombination deficiency and increased sensitivity to platinum-based chemotherapy. This study evaluated the association between BRCA mutation status and clinical outcomes, focusing on dissemination patterns, treatment allocation, perioperative parameters, and progression-free survival (PFS). Methods: This prospective single-center cohort included 133 consecutive patients with newly diagnosed HGSOC treated between January 2020 and December 2025. Primary treatment strategy (primary debulking surgery [PDS] or neoadjuvant chemotherapy [NACT]) was determined by multidisciplinary assessment. BRCA testing was performed using tumor tissue or germline analysis. Patients were followed for 24 months. PFS was analyzed using Kaplan–Meier estimates and Cox regression models. Results: Pathogenic BRCA mutations were identified in 39.1% of patients. BRCA-mutated tumors demonstrated significantly lower rates of peritoneal carcinomatosis (50% vs. 77.77%, p = 0.001) and were more frequently managed with PDS (59.6% vs. 41.8%, p = 0.048). Perioperative outcomes were comparable between groups. Disease progression occurred less frequently in BRCA-mutated patients (32.69% vs. 51.85%, p = 0.017). In univariate analysis, BRCA mutation was associated with a 48% reduction in progression risk (HR 0.52, 95% CI 0.27–0.99, p = 0.048). After adjustment for age, FIGO stage, and residual disease, BRCA mutation was not independently associated with progression (HR 0.57, p = 0.124), although a protective trend was observed, while residual disease remained a significant predictor. Conclusions: In this prospective cohort, BRCA mutation status was associated with distinct dissemination patterns and a significant reduction in progression risk in HGSOC. Although residual disease remained the strongest independent prognostic factor after multivariable adjustment, a trend toward improved PFS observed among BRCA-mutated patients supports the role of homologous recombination deficiency as a meaningful modifier of disease trajectory. These findings reinforce the clinical relevance of molecular stratification in the contemporary management of HGSOC. Full article