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PubMed2026

The 1H, 15N and 13C backbone resonance assignments of an intrinsically disordered region (467-696) of breast cancer type 1 susceptibility protein (BRCA1).

The tumor suppressor protein breast cancer type 1 susceptibility protein (BRCA1) plays a central role in maintaining genome stability through its involvement in DNA damage repair, transcriptional regulation, and cell-cycle control. BRCA1 functions as an obligate heterodimer with its binding partner, the BRCA1-associated RING domain protein 1 (BARD1), to coordinate accurate DNA repair. While the structured N- and C-terminal domains of BRCA1 have been well-characterized, the large central region encoded largely by exon 11 that comprises ~ 80% of the protein, is intrinsically disordered, and remains poorly structurally characterized. This intrinsically disordered region (IDR) harbors critical interaction interfaces for key proteins involved in genome maintenance, including RAD50, RAD51, MYC, and RB. Here, we report the backbone resonance assignments of a BRCA1 IDR construct spanning residues 467-696, providing a foundation for future studies aimed at understanding how the disordered central region of BRCA1 contributes to homologous recombination, interactions with BARD1, and overall BRCA1 tumor suppressor function.

BRCA1 Protein↗

PubMed2026

The1H, 15N and13C backbone resonance assignments of an intrinsically disordered region (124-270) of BRCA1 associated RING domain 1 (BARD1).

The BRCA1-associated RING domain protein 1 (BARD1) is the obligate binding partner of the tumor suppressor breast cancer type 1 susceptibility protein (BRCA1) and plays a critical role in maintaining genome integrity. BARD1 contains structured N- and C-terminal domains that mediate heterodimerization with BRCA1, recognition of chromatin marks, and DNA repair functions. Approximately 40% of BARD1 is intrinsically disordered, particularly in the central region of the protein. This intrinsically disordered region (IDR) engages DNA and key repair proteins such as RAD51, BLM, and WRN. DNA binding through the BARD1 IDR facilitates H2A ubiquitination by the BRCA1-BARD1 complex and is essential for stimulating long-range DNA end resection during homologous recombination, underscoring its role in accurate DNA repair. Despite these insights, structural characterization of the IDR remains limited, leaving questions regarding its functional interplay with BRCA1 and other repair factors unresolved. Here, we report the backbone resonance assignments of a BARD1 IDR construct spanning residues 124-270, providing a foundation for future studies aimed at understanding how the disordered regions of BARD1 interact with various binding partners, and cooperates with itself and BRCA1 to regulate genome stability.

Nuclear Magnetic Resonance, Biomolecular↗

PubMed2026

International trends in concurrent hysterectomy at risk-reducing surgery in BRCA1/2 pathogenic variant carriers: a mixed-methods study.

BACKGROUND: BRCA1/2 pathogenic variant carriers are advised to undergo a risk-reducing salpingo-oophorectomy between the ages of 35 and 45 due to their increased risk of tubo-ovarian cancer. A concurrent hysterectomy may be performed at the time of risk-reducing salpingo-oophorectomy. Currently, the international execution of hysterectomy during risk-reducing surgery and the factors guiding related decision-making are unknown. OBJECTIVE: We aimed to evaluate the international execution of concurrent hysterectomy during risk-reducing surgery for tubo-ovarian cancer and factors guiding providers' decision-making about this. STUDY DESIGN: We conducted a mixed-methods study. First, we executed a quantitative analysis with data from the Women choosIng Surgical Prevention (WISP) and TUBectomy with delayed oophorectomy as Alternative for risk-reducing salpingo-oophorectomy in high-risk Women to assess the Safety of Prevention (TUBA-WISP II) study, both prospective preferential trials assessing surgical strategies for tubo-ovarian cancer prevention. Data were collected via electronic case report forms. Concurrent hysterectomy during risk-reducing salpingo-oophorectomy was compared between Europe, North- and South America, and Australia using Kruskal-Wallis tests. We used univariable logistic regression models to estimate the association of personal and prevention-related characteristics with the execution of hysterectomy at risk-reducing salpingo-oophorectomy in women from North- and South America. Subsequently, we conducted focus group interviews with gynecologic providers from 12 countries who provide preventive care for individuals at increased risk of tubo-ovarian cancer to identify indications, barriers, and facilitators for the execution of hysterectomy with risk-reducing salpingo-oophorectomy. RESULTS: In the quantitative analysis, we included 2181 participants, of whom 1647 (75.5%) were from Europe, 498 (22.8%) from North- and South America, and 36 (1.7%) from Australia. Execution of hysterectomy at risk-reducing salpingo-oophorectomy differed substantially between continents, with an execution of 48.8% in North- and South America, 14.2% in Australia, and 2.8% in Europe (P<.001). Execution of concurrent hysterectomy at risk-reducing salpingectomy in women from North- and South America occurred more often in women with a BRCA1 pathogenic variant compared to a BRCA2 pathogenic variant (adjusted odds ratio 0.4 [95% confidence interval, 0.2-0.7]). In the qualitative analysis, we interviewed 23 healthcare providers and identified 31 barriers and 32 facilitators regarding hysterectomy execution during risk-reducing salpingo-oophorectomy. A total of 8 different indications were mentioned, but opinions varied on the validity and weight given to each indication. Providers indicated that important barriers or facilitators for concurrent hysterectomy included a lack of clear guidelines, cultural variation between countries, (lack of) consensus within departments, and different interpretation of the endometrial cancer risk. CONCLUSION: Internationally, there is a large variation in execution of hysterectomy during risk-reducing surgery with frequent utilization in North- and South America, and rare utilization in Europe. This could be explained by the interpretation of indications for hysterectomy by providers, which might be explained by cultural variation, the absence of clear guidelines, and limited scientific evidence.

Humans↗

PubMed2026

Integrative proteomics reveals MSH6 to modulate PARP inhibitor sensitivity in BRCA1/2-proficient ovarian cancer.

Ovarian cancer remains a leading cause of gynecologic cancer-related deaths worldwide. Deficiencies in BRCA1/2 are well-established biomarkers that predict sensitivity to poly(ADP-ribose) polymerase inhibitors (PARPis). However, emerging evidence indicates that a subset of BRCA-proficient tumors also responds to PARPi therapy, suggesting the presence of additional molecular mechanisms. We hypothesized that the composition of the PARP1 protein complex and PARylation-mediated signaling contribute to PARPi response in BRCA-proficient HGSOC. We assessed PARPi response across a panel of BRCA-proficient ovarian cancer cell lines and identified distinct sensitive and resistant groups. Chemical proteomics with rucaparib revealed different PARP1 complexes including higher enrichment of MSH6 in sensitive cells. Co-immunoprecipitation analyses further confirmed differential assembly of PARP1-MSH6-PARP2 complexes between sensitive and resistant models. To explore PARylation signaling, we performed ADP-ribosylation proteomics using clickable NAD⁺ analogs, revealing distinct PARylation profiles between sensitive and resistant cell lines. CHAF1A, a known MSH6 interactor and PARP1 substrate, showed more pronounced reduction in ADP-ribosylation in PARPi-sensitive cells. Targeting MSH6 using CRISPR or siRNA decreased PARPi sensitivity. In addition, mTOR signaling was reduced in sensitive, but increased in resistant cells, following rucaparib treatment. Notably, MSH6 knockdown led to increased CHAF1A expression regardless of rucaparib treatment. Importantly, knockdown of CHAF1A significantly impaired cell viability, especially in A2780 cells, and suppressed mTOR signaling, suggesting that CHAF1A acts downstream of MSH6 to regulate the mTOR axis. Furthermore, co-treatment with mTORC1 inhibitors enhanced the cellular effects of rucaparib in resistant cells, suggesting a therapeutic potential of targeting downstream mTOR effectors to overcome intrinsic resistance. In conclusion, this study identifies the PARP1-MSH6 interaction to modulate PARPi sensitivity via CHAF1A-mTOR signaling in BRCA-proficient ovarian cancer. By integrating chemical proteomics and ADP-ribosylation proteomics, we delineate the interplay between PARP1 complex composition and signaling dynamics, highlighting MSH6 as a critical modulator of PARPi response and potential biomarker to enhance therapeutic efficacy in BRCA-proficient HGSOC.

Humans↗

PubMed2026

Prevalence of homologous recombination repair genes alterations in metastatic castration-resistant prostate cancer, a multicentric study.

INTRODUCTION: Homologous Recombination Repair (HRR) genes alterations are a resistance mechanism to therapies by taxanes or Androgen Receptor Signalling inhibitors in Metastatic Castration Resistant Prostate Cancer (mCRPC). BRCA-mutated mCRPC patients are eligible to poly adenosine diphosphateribose polymerase inhibitors (PARPi). Therefore, assessing the population-specific prevalence of HRR-related genes alterations is of public healthcare importance. METHODS: This retrospective, non-interventional, multicentric study was conducted across 6 reference French centers in a "real-life" setting. 788 paraffin-embedded mCRPC patient-samples were included and submitted to testing for BRCA1/2 in six different centers; additionally, non-BRCA HRR-related genes were investigated in two different centers. RESULTS: Among the samples, n=602 (76.4%) were contributive for molecular testing. In multivariate analysis by logistic regression and sensitivity analysis, only sample age (P<0.01), sample surface area (P=0.02) and institution (P=0.018) remained statistically significant. BRCA alterations were detected in n=39/602 (6.5%) of contributive samples, with n=35 and n=4 alterations of BRCA2 and BRCA1 respectively. Non-BRCA HRR-related genes alterations were detected in n=12/157 (7.6%) of contributive samples, with alterations of mainly ATM (n=6, 3.8%), CDK12 (n=4, 2.5%) and CHEK2 (n=2, 1.3%). DISCUSSION: In this study, testing contributivity was similar or higher that of other studies in the literature, and observed mutations prevalences were similar to that of other screenings of western populations. Harmonising per-centres protocols and enhancing molecular testing contributivity with the screening of circulating DNA samples and expanding its range by including non-BRCA HRR-related genes in all reference centres will enable more patients to be accurately treated by targeted therapies. LEVEL OF EVIDENCE: 3 (grade C).

Male↗

PubMed2026

Brazilian Society of Surgical Oncology Analysis in Cost-Effectiveness of Population-Based BRCA Testing for Ovarian Cancer in the Public Health System.

Although ovarian cancer is the most lethal among gynecological cancers, access to massive BRCA testing is still limited. Its cost-effectiveness is still a topic of discussion in several countries. In Brazil, olaparib was recently incorporated into the public health system, access to BRCA testing is still limited. In this article, we aim to review the cost-effectiveness of offering BRCA testing to the at-risk population. A working group composed of 14 specialists in surgical oncology and cancer genetics was established to discuss the cost-effectiveness of population-based BRCA testing for ovarian cancer. The project was divided into five main areas, each with subtopics assigned among the 14 participants. They were: the existing clinical testing guidelines, the current healthcare infrastructure in the Brazilian public health system, cost-effectiveness analysis, challenges in implementing prophylactic surgeries, and family counseling and risk communication. A comprehensive literature review was conducted, followed by a series of meetings among the article's contributors to reach consensus on unresolved issues. These discussions aimed to build recommendations based on the best available scientific evidence. Using as a basis the current structure already existing within the Brazilian public health service (SUS [Sistema Único de Saude]), and based on the testing of the at-risk population chosen by our experts, we estimated savings. The net savings for a population of 100 000 women would range from BRL 7030.30 (US$1255.41) to BRL 1853.92 (US$331.05). And these costs could have an even greater impact when public service PARP inhibitors are incorporated. The working group of the Brazilian Society of Surgical Oncology understands that large-scale BRCA testing is cost-effective, especially when risk-reducing surgery is implemented. Other measures are important, such as training teams of non-specialists to recognize the population at risk, in addition to creating an entire line of care for patients with ovarian cancer in the SUS.

Humans↗

PubMed2026

Copy number variants in BRCA1 and BRCA2 genes in Polish patients with breast and ovarian cancer.

PURPOSE: BRCA1 and BRCA2 are key susceptibility genes in hereditary breast and ovarian cancer (HBOC), with mutational status guiding PARP inhibitor therapy. While single-nucleotide variants (SNVs) predominate, the prevalence of copy number variants (CNVs) varies significantly across different populations. This study aims to determine the incidence of BRCA1/2 CNVs in the Polish population, where data remain scarce due to non-mandatory CNV testing. METHODS: We retrospectively analysed the results of genetic tests assessing the presence of BRCA1/2 CNVs performed in 2720 individuals tested at the Lower Silesian Oncology Centre (2021-2024), including 2702 breast/ovarian cancer patients and 18 unaffected relatives. The mean age was 54.7 ± 15.15 years. Genetic testing involved DNA extraction, NGS, and MLPA for CNV confirmation. Variants were classified according to ACMG-AMP guidelines and verified through independent testing. RESULTS: In this study, no BRCA2 CNVs were identified, consistent with previous Central European findings. Pathogenic BRCA1 CNVs were detected in 0.85% of the analyzed cohort and in 0.52% of the cancer patient subgroup, affecting 23 individuals from 13 families. Eight distinct BRCA1 CNVs were detected, the most common being exon 21 deletion. Affected families exhibited a high incidence of HBOC-related cancers, with early-onset breast cancer and a notable proportion of triple-negative breast cancer cases. CONCLUSIONS: This study highlights the clinical significance of BRCA1 CNVs in Polish patients with HBOC-spectrum cancers and their families. Although rare, these variants were associated with aggressive cancer phenotypes and early onset. Given their diagnostic and therapeutic implications, BRCA1 CNVs should be routinely analysed in high-risk families to ensure accurate detection and personalised treatment planning.

Humans↗

PubMed2026

Impact of BRCA1/2 status on young women's sexual function, relationships, and reproduction after predictive genetic testing.

The experiences and outcomes for women identified with a BRCA1/2 pathogenic variant during young adulthood are qualitatively described but not well quantified. This study investigated the impact of BRCA1/2 status on women's reproduction, intimate partner relationships, and sexual functioning. Australian women aged 18-40 years who had predictive BRCA1/2 testing, received either a positive or negative result, and had no personal cancer history, completed an online survey that used a case-control design. Outcome measures included childbearing, use of reproductive technologies, relationship status, and sexual functioning. 579 women participated (62.0% with a BRCA1/2 PV; 38.0% without a BRCA1/2 PV). More women with a BRCA1/2 PV had children compared to those who did not (49.0% c.f., 40.5%; p = 0.045). BRCA1/2 status did not predict whether women were partnered at survey completion (Odds Ratio 1.20; 95% CI 0.80, 1.78) or their sexual functioning over the previous month (β-coefficient -0.08; 95% CI -1.15, 0.98). Women with a BRCA1/2 PV were more likely to have children after genetic testing (OR 1.83: 95% CI 1.05, 3.21) and were more likely to have a greater number of children after genetic testing (β-coefficient 0.41; 95% CI 0.10, 0.73) compared to women without a BRCA1/2 PV, after adjustment for confounders. Receiving a positive predictive BRCA1/2 result is associated with an increased likelihood of childbearing and having a greater number of children compared to receiving a negative predictive BRCA1/2 result. These findings contribute to the evidence base to inform long-term follow-up for women after predictive BRCA1/2 testing.

Humans↗

PubMed2026

Risks of non-breast, non-ovarian cancers for BRCA1 and BRCA2 pathogenic variant carriers: a prospective cohort study.

BACKGROUND: The non-breast non-ovarian cancers associated with BRCA1 and BRCA2 pathogenic variants (PVs) are controversial. We aimed to examine this using a prospective cohort design. METHODS: This study included 1260 BRCA1 and 1058 BRCA2 PV carriers (91% were females) from two consortia: the Breast Cancer Family Registry (BCFR) and the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer Follow-Up Study (kConFab-FUS). The carriers were free of cancer other than breast or ovarian cancer at baseline and had a median baseline age of 45.5 years. For 16 types of non-breast, non-ovarian cancers, standardized incidence ratios (SIRs) relative to population incidence, the probabilities of relative risk effect size > 2 (i.e., moderate risk) and cumulative risks to age 80 years were estimated. RESULTS: During a median follow-up time of 11.4 years, 161 non-breast, non-ovarian cancers were observed. For BRCA1 PV carriers, little evidence of increased risk was observed. The prostate, pancreatic, and all non-pancreatic cancer SIRs were 1.7 (95% CI 0.7-4.2), 1.1 (95% CI 0.3-4.6) and 0.85 (95% CI 0.68-1.06), respectively; the probabilities of relative risk > 2 were 0 and 67% for prostate and pancreatic cancers, respectively. For BRCA2 PV carriers, increased risks of pancreatic (SIR = 6.6, 95% CI 3.8-11.6), prostate (SIR = 3.6, 95% CI 1.9-6.8) and stomach (SIR = 3.1, 95% CI 1.01-9.8) cancer were observed, with a cumulative risk to age 80 years of 8.3, 82.0, and 1.6%, respectively. For all the other non-breast, non-ovarian cancers combined, the SIR was 0.85 (95% CI 0.66-1.10). CONCLUSIONS: Apart from pancreatic, prostate, and possibly stomach cancers for BRCA2 PV carriers, and possibly pancreatic cancer for BRCA1 PV carriers, there is no evidence that BRCA1 and BRCA2 PV carriers have substantially increased risks of other non-breast, non-ovarian cancers. Our prospective risk estimates are informative for cancer risk assessment for people with BRCA1 and BRCA2 PVs.

Humans↗

PubMed2026

The Clinical Application of Refined Risk Estimates Study in BRCA1 and BRCA2 Pathogenic Variant Carriers: A Randomized Controlled Trial.

UNLABELLED: Individuals with germline BRCA1 or BRCA2 pathogenic variants (PV) may struggle with risk management decision-making. Advancements in technology could provide more specific risk information to patients, but the impact of this information is unknown. The Clinical Application of Refined Risk Estimates Study is a two-arm randomized controlled trial in women with a BRCA1/BRCA2 PV. The primary objective was to determine whether genotype-informed personalized cancer risk estimates (GRE) compared with standard lifetime cancer risk estimates (SRE) decreased decisional conflict related to cancer risk management decision-making. Women were recruited following the disclosure of their PV results. Participants completed a baseline survey and were randomized 1:1 to receive a GRE or SRE. After receiving their results, participants completed a follow-up survey. Likert and continuous data measures were analyzed using linear regression. There were no differences in decisional conflict between study arms at follow-up. However, individuals in the SRE arm showed an increased need for personal structure compared with those in the GRE arm (P = 0.02). Compared with baseline, individuals within the SRE arm showed decreased decisional conflict (P = 0.003) and increased perceived stress (P = 0.02) at follow-up. A more personalized cancer risk estimate did not decrease decisional conflict in women with BRCA1/BRCA2 PVs. Future studies will determine whether a GRE affects actual decision-making behaviors. PREVENTION RELEVANCE: Women with a germline PV in BRCA1 or BRCA2 have significantly elevated risks of developing breast and ovarian cancers. This randomized controlled trial evaluates the impact of polygenic risk scores on decisional conflict related to breast and ovarian cancer prevention and risk management in those with BRCA1/BRCA2 PVs.

Humans↗

PubMed2026

Updated ENIGMA recommendations for reporting germline variants in cancer susceptibility genes and their translation into twenty languages.

Genetic testing for cancer susceptibility underpins precision cancer prevention and care. Gaps in the healthcare providers' genetic literacy and an ambiguous lexicon for variant description may hinder proper delivery and clinical application of consistently trustworthy test results. The Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) international consortium supports controlled terminology and recommends a framework for reporting germline variants in cancer susceptibility genes, using breast cancer as an exemplar. Moving forward towards terminological coherence across disciplines and borders, the ENIGMA Clinical Working Group launched a multinational effort to release consortium-approved translations of the published recommendations. The herein reported Vocabulary Translation Project offered an opportunity to reappraise and align the reference text to the recent BRCA1 and BRCA2 specifications to the American College of Medical Genetics and Genomics/Association for Molecular Pathology rules by the ENIGMA Variant Curation Expert Panel and to highlight country-specific differences in breast cancer risk assessment and management. The updated recommendations and their 20 translations are now provided as easy to handle documents, covering 11 of the most widely spoken languages in the world. They will contribute to minimised erroneous inferences, more informed decision-making, improved health outcomes and equity in the use of genetic testing for cancer predisposition and in translational oncology.

Humans↗

PubMed2026

Systemic immune activation in hereditary cancer predisposition syndromes: a cross-sectional study.

BACKGROUND: Immune surveillance mechanisms contribute to the elimination of precancerous lesions in hereditary cancer predisposition syndromes (HCPSs). METHODS: By combining single-cell transcriptomics, multiparametric mass cytometry and cytokine profiling of the systemic immune environment in 391 individuals among whom 227 are living with HCPSs we investigated phenotypic alterations in cancer-free individuals with HCPS. RESULTS: A decrease in peripheral B cell abundance and their more differentiated phenotype have been confirmed both in breast cancer patients with germline pathogenic variants in BRCA1 (gpath(BRCA1)) and in patients living with Lynch syndrome (LS). Pre-cancer women with gpath(BRCA1) exhibited an activated phenotype of multiple immune cell lineages, similar to those with manifest disease. In LS, B cell phenotypes exhibited the largest changes in response to cancer eradication, while increased peripheral IL-6 levels was detected even in presymptomatic individuals with LS. CONCLUSIONS: HCPS-specific differences in the phenotype of the systemic immune system might be leveraged in future risk-reducing strategies.

Humans↗

PubMed2025

BRCA genetic testing utilization and expenditures among privately insured adults in the United States, 2013 to 2022.

PURPOSE: Recent clinical guidelines have broadened the criteria for BRCA counseling and testing for women and men, including indications based on family history, personal history, and current diagnosis of breast, ovarian, pancreatic, and prostate cancer. METHODS: Using claims data from 2013 to 2022, we identified BRCA testing using procedure codes to evaluate annual utilization, median expenditures per enrollee, and the percentage of 0 out-of-pocket expenditures by sex among enrollees aged 18 to 64 years who were continuously enrolled within calendar years. We examined BRCA utilization by metropolitan status and indications. RESULTS: Annual BRCA testing utilization among women (and men) increased 10.2% (44.5%) per year during 2014 to 2015 and 1.7% (10.0%) per year during 2016 to 2019, decreased 34.4% (44.8%) in 2020, and rebounded 8.5% (22.3%) per year during 2021 to 2022, remaining below prepandemic levels in 2022. Median expenditures for comprehensive BRCA testing per enrollee decreased by 68% from 2013 to 2022, most of whom had 0 out-of-pocket expenditures. Most BRCA testing was done based on family health history of breast, ovarian, or prostate cancer and among women aged 18 to 50 years. CONCLUSION: Health care providers who are knowledgeable about evolving indications for germline BRCA testing can help ensure that eligible individuals have access to germline BRCA testing as preventive service.

Humans↗

PubMed2022

Lurbinectedin, a selective inhibitor of oncogenic transcription, in patients with pretreated germline BRCA1/2 metastatic breast cancer: results from a phase II basket study.

BACKGROUND: Lurbinectedin, a selective inhibitor of oncogenic transcription, has shown preclinical antitumor activity against homologous recombination repair-deficient models and preliminary clinical activity in BRCA1/2 breast cancer. PATIENTS AND METHODS: This phase II basket multitumor trial (NCT02454972) evaluated lurbinectedin 3.2 mg/m2 1-h intravenous infusion every 3 weeks in a cohort of 21 patients with pretreated germline BRCA1/2 breast cancer. Patients with any hormone receptor and human epidermal growth factor receptor 2 status were enrolled. The primary efficacy endpoint was overall response rate (ORR) according to RECIST v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety. RESULTS: Confirmed partial response (PR) was observed in six patients [ORR = 28.6%; 95% confidence interval (CI) 11.3% to 52.2%] who had received a median of two prior advanced chemotherapy lines. Lurbinectedin was active in both BRCA mutations: four PRs in 11 patients (36.4%) with BRCA2 and two PRs in 10 patients (20.0%) with BRCA1. Median DoR was 8.6 months, median PFS was 4.1 months and median OS was 16.1 months. Stable disease (SD) was observed in 10 patients (47.6%), including 3 with unconfirmed response in a subsequent tumor assessment [ORR unconfirmed = 42.9% (95% CI 21.8% to 66.0%)]. Clinical benefit rate (PR + SD ≥ 4 months) was 76.2% (95% CI 52.8% to 91.8%). No objective response was observed among patients who had received prior poly (ADP-ribose) polymerase inhibitors. The most common treatment-related adverse events (AEs) were nausea (61.9%), fatigue (38.1%) and vomiting (23.8%). These AEs were mostly grade 1/2. The most common grade 3/4 toxicity was neutropenia (42.9%: grade 4, 23.8%: with no febrile neutropenia). CONCLUSIONS: This phase II study met its primary endpoint and showed activity of lurbinectedin in germline BRCA1/2 breast cancer. Lurbinectedin showed a predictable and manageable safety profile. Considering the exploratory aim of this trial as well as previous results in other phase II studies, further development of lurbinectedin in this indication is warranted.

Humans↗

PubMed2025

BRCA1 Exon 11 Mutations in Breast Cancer: A Study From Pakistan.

Breast cancer ranks among the top causes of cancer-related deaths in women around the globe, with genetic mutations in the BRCA1 gene being a frequent cause of breast or ovarian cancer. This study investigates hotspot mutations in exon 11 of the BRCA1 gene among Pakistani women diagnosed with breast cancer. Thirty clinically diagnosed breast cancer patients, all women, were enrolled in the current study, and high-quality DNA was extracted from peripheral blood samples. Two of the twenty-five successfully sequenced samples had a homozygous missense variant (c.2312T > C: p.Leu771Ser) detected by Sanger sequencing after PCR amplification. Upon investigation in the ClinVar database, the identified variant showed conflicting interpretations of pathogenicity. Demographic data highlighted an early disease onset, showing that 56% of patients were under 50 years of age. The need for genetic screening was further supported by the fact that 24% of the patients had a positive family history of cancer. Our study emphasizes the necessity of screening BRCA1 gene mutations to better understand the pathogenic potential of the identified variants in the Pakistani population.

Humans↗

PubMed2026

[BRCA1 Gene's Mutations And Hereditary Breast Cancer: Genetic, Biological, And Clinical Aspects].

INTRODUCTION: Hereditary breast cancer accounts for approximately 5 to 10% of all breast cancer cases. Mutations in the BRCA1 gene, which plays a central role in DNA repair and cell cycle regulation, are the main cause of these familial forms and are strongly associated with aggressive subtypes, particularly triple-negative breast cancer. METHODS: A narrative literature review was conducted using biomedical databases (PubMed, Scopus, Web of Science, Google Scholar) between January 2024 and June 2025. Eligible publications addressed the genetic, biological, epidemiological, and clinical aspects of BRCA1 in hereditary breast cancer. RESULTS: BRCA1 ensures genomic stability through its roles in DNA repair, cell cycle checkpoints, and transcriptional regulation. Most mutations are truncating or missense variants, with some reported as founder mutations (e.g., c.68_69delAG, c.5266dupC, 943ins10). Women carrying germline BRCA1 mutations have an estimated lifetime risk of 56-87% of developing breast cancer, with a strong association with aggressive molecular subtypes, especially triple-negative breast cancer. CONCLUSION: A comprehensive understanding of BRCA1 mutations is crucial to enhance prevention, screening, and personalized management of hereditary breast cancer. In low-resource settings, the integration of genetic testing and counseling remains a major challenge and a public health priority to reduce disparities in cancer care.

Humans↗

PubMed2026

BRCA1-A and LIG4 complexes mediate ecDNA biogenesis and cancer drug resistance.

Extrachromosomal circular DNA (ecDNA) is frequently generated within the nucleus, contributing to genome dynamics and heterogeneity, thereby promoting cancer cell evolution and adaptation. However, the mechanisms underlying ecDNA biogenesis remain poorly understood. Here, using genome-wide CRISPR screening in human cells, we identified the BRCA1-A and the LIG4 complexes as key drivers of ecDNA production. Following DNA segmentation, the upstream BRCA1-A complex protects DNA ends from excessive resection, promoting end-joining for circularization. Conversely, the MRN complex, which mediates end resection and thus antagonizes the BRCA1-A complex, suppresses ecDNA formation. Downstream, LIG4 conservatively mediates ecDNA production by joining the free ends of the DNA fragments. Furthermore, ecDNA from patient tumors harbors junction sites with a LIG4 signature. Notably, disruption of either LIG4 or the BRCA1-A complex in cancer cells impairs ecDNA-mediated adaptation, hindering the development of resistance to both chemotherapy and targeted therapies. Together, our study reveals the roles of the LIG4 and BRCA1-A complexes in ecDNA biogenesis, and uncovers therapeutic targets to block ecDNA-mediated adaptation for cancer treatment.

Humans↗

PubMed2025

Integrating network pharmacology and experimental validation to uncover the synergistic effects of Huangqi ()-Ezhu () with 5-fluorouracil in colorectal cancer models.

OBJECTIVE: To evaluate the effects of Huangqi (Radix Astragali Mongolici)-Ezhu (Rhizoma Curcumae Phaeocaulis) (HQEZ) on colorectal cancer therapies and to elucidate the potential mechanisms of HQEZ, especially in combination with 5-Fluorouracil (5-FU). METHODS: The anti-tumor effects of HQEZ were evaluated in colorectal cancer models both in vivo and in vitro. The network pharmacological assay was used to investigate potential mechanisms of HQEZ. Potential target genes were selected by Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, protein-protein interaction network (PPI) and molecular docking. Within key targets, potential targets related to drug sensitivity, especially the sensitivity to 5-FU, were evaluated in HCT116 in vitro by immunofluorescence, quantitative real-time polymerase chain reaction (qPCR) and Western-blot. Then, changes in potential targets were assessed in tumors from tumor-bearing mice and the expression of these targets was also evaluated in colorectal cancer (COAD) patients from the Cancer Genome Atlas Program (TCGA) database. RESULTS: HQEZ significantly enhanced the anti-tumor activity of 5-FU in vivo and inhibit the growth of HCT116 in vitro. By network pharmacological analysis, key targets, such as protein kinase B (AKT1), epidermal growth factor receptor (EGFR), adenosine triphosphate (ATP) binding cassette subfamily B member 1 (ABCB1, also named multidrug resistance protein 1, MDR1), ATP binding cassette subfamily G member 2 (ABCG2), thymidylate synthetase (TYMS, also named TS), prostaglandin-endoperoxide synthase 2 (PTGS2), matrix metallopeptidase 2 (MMP2), MMP9, toll like receptor 4 (TLR4), TLR9 and dihydropyrimidine dehydrogenase (DPYD), were identified. Additionally, 4 potential core active ingredients (Folate, Curcumin, quercetin and kaempferol) were identified to be important for the treatment of colorectal cancer with HQEZ. In key targets, chemoresistance related targets were validated to be affected by HQEZ. Furthermore, 5-FU sensitivity related targets, including MDR1, TS, EGFR, ribonucleotide reductase catalytic subunit M1, Breast and Ovarian Cancer Susceptibility Protein 1 (BRCA1) and mutl homolog 1 were also significantly reduced by HQEZ both in vitro and in vivo. Finally, these validated key targets and 5-FU sensitivity related targets were demonstrated to be up-regulated in COAD patients based on TCGA database. CONCLUSION: HQEZ has synergistic effects on the anti-tumor activity of 5-FU in the treatment of colorectal cancer both in vivo and in vitro. The beneficial effect of HQEZ results from the inhibition of the drug sensitivity targets associated with 5-FU. The combination therapy of HQEZ with 5-FU or other chemotherapeutic drugs will also improve the anti-tumor efficacy of chemotherapy.

Humans↗