Breast Cancer Susceptibility Gene Research Articles

Pan-cancer Analysis Combined with Experiments Deciphers PHB Regulation for Breast Cancer Cell Survival and Predicts Biomarker Function.

Breast carcinoma has become the leading fatal disease among women. The location of prohibitin in the chromosome is close to the breast cancer susceptibility gene 1 (BRCA1). Accumulated research reported that prohibitin could interact with a variety of transcription factors and cell cycle-regulating proteins. This present study aims to comprehensively explore and reveal the biological functions of prohibitin on breast cancer via The Cancer Genome Atlas (TCGA) and validation experiment in vitro. Exploring the expression level of prohibitin across 27 tumors based on the TGGA database by bioinformatic methods and its relationship with tumor immune infiltration. Furthermore, we thus analyzed the biological roles of prohibitin on human breast cancer cell line MCF- 7 with pEGFP-prohibitin overexpression plasmid by western blotting and transwell-assay. Firstly, we found prohibitin is overexpressed in most tumors based on The Cancer Genome Atlas database, and the negative relationships between prohibitin and tumors infiltrating lymphocytes including B lymphocyte, CD4 T lymphocyte, CD8 T lymphocyte, Neutrophil, Macrophage and Dendritic, and its significant correlation with the prognosis of human cancer. In vitro, expression not only inhibited cell viability and invasive abilities but also increased the apoptosis percentage of cells with a decreased percentage of the S phase and an increased G2 phase. The reduction of Bcl-2 was observed when prohibitin was upregulated, although the expression of E2F-1 did not change. Although prohibitin is over-expressed in various cancer types, it functions as an important tumor suppressor that may suppress breast cancer cell proliferation and the invasive ability of MCF-7 by influencing its DNA synthesis and promoting cell apoptosis. All these may be likely associated with P53, erbB-2, and Bcl-2.

Polyvinyl chloride nanoplastics suppress homology-directed repair and promote oxidative stress to induce esophageal epithelial cellular senescence and cGAS-STING-mediated inflammation

Nanoplastics (NPs), which are characterized by plastic particles smaller than one micrometer, have emerged as pervasive environmental pollutants, raising concerns about their potential toxicity to living organisms. Numerous investigations have highlighted the tendency of NPs to accumulate in organs, resulting in toxic effects. Despite polyvinyl chloride (PVC) being one of the most prevalent NPs, its impact on the esophagus and the associated underlying mechanisms remain largely unknown. In this study, we investigated the impact of PVC NPs on the esophagus and found that PVC NPs exposure induces oxidative stress and elicits DNA damage responses. Further analysis revealed that PVC NPs inhibit the homology-directed repair (HDR) pathway by suppressing the expression of breast cancer susceptibility gene 2 (BRCA2) and growth factor receptor-bound protein 2 (GRB2), resulting in genomic instability. Additionally, the release of free DNA activates cGAS-STING and the downstream NF-κB signaling, elevating inflammatory factors and chemokines, which further leads to cellular senescence. In vivo experiments corroborated these findings, showing that PVC NPs induced oxidative stress, inflammation, and cellular senescence, subsequently impacting mouse behavior. This study contributes novel insights into the health risks associated with PVC NPs exposure and identifies potential therapeutic targets.

Efficacy and Tolerability of Olaparib Plus Paclitaxel in Patients with Gastric Cancer Associated with Hereditary Breast and Ovarian Cancer

Helicobacter pylori, a gram-negative, flagellated, helical bacterium, is a common cause of chronic gastric infection worldwide. According to the World Health Organization, H. pylori infection, a specific carcinogenic factor, was the leading cause of gastric cancer (GC) in 2014 worldwide (80%). H. pylori infection causes GC in >98% of patients in East Asian countries, including Japan. However, only some types of GCs are associated with H. pylori infection. Previous clinical studies have revealed that the bacterium secretes cytotoxin-associated gene A antigen, which inhibits the nuclear translocation of the breast cancer susceptibility gene 1 and 2 (BRCA1/2), a factor involved in DNA damage repair. This indicated an association between hereditary breast and ovarian cancers (HBOCs) and the development of GC. However, the detailed mechanisms underlying the development of GC caused by H. pylori infection remain unclear. Using the information on hereditary cancers obtained based on cancer genomic medicine, this study revealed that the incidence of GC was high in families with HBOC, with a preponderance for men from families with HBOC. Furthermore, the use of poly-adenosine diphosphate-ribose polymerase inhibitors in patients with hereditary GC is considered safe and effective. This study provides substantial evidence for guiding the establishment of early treatment for patients with advanced-stage/metastatic GC who harbored BRCA1/2 mutations.

An interpretable deep learning model for detecting BRCA pathogenic variants of breast cancer from hematoxylin and eosin-stained pathological images.

Determining the status of breast cancer susceptibility genes (BRCA) is crucial for guiding breast cancer treatment. Nevertheless, the need for BRCA genetic testing among breast cancer patients remains unmet due to high costs and limited resources. This study aimed to develop a Bi-directional Self-Attention Multiple Instance Learning (BiAMIL) algorithm to detect BRCA status from hematoxylin and eosin (H&E) pathological images. A total of 319 histopathological slides from 254 breast cancer patients were included, comprising two dependent cohorts. Following image pre-processing, 633,484 tumor tiles from the training dataset were employed to train the self-developed deep-learning model. The performance of the network was evaluated in the internal and external test sets. BiAMIL achieved AUC values of 0.819 (95% CI [0.673-0.965]) in the internal test set, and 0.817 (95% CI [0.712-0.923]) in the external test set. To explore the relationship between BRCA status and interpretable morphological features in pathological images, we utilized Class Activation Mapping (CAM) technique and cluster analysis to investigate the connections between BRCA gene mutation status and tissue and cell features. Significantly, we observed that tumor-infiltrating lymphocytes and the morphological characteristics of tumor cells appeared to be potential features associated with BRCA status. An interpretable deep neural network model based on the attention mechanism was developed to predict the BRCA status in breast cancer. Keywords: Breast cancer, BRCA, deep learning, self-attention, interpretability.

Splicing Dysregulation of Non-Canonical GC-5' Splice Sites of Breast Cancer Susceptibility Genes ATM and PALB2.

Background/Objectives: The non-canonical GC-5' splice sites (5'ss) are the most common exception (~1%) to the classical GT/AG splicing rule. They constitute weak 5'ss and can be regulated by splicing factors, so they are especially sensitive to genetic variations inducing the misrecognition of their respective exons. We aimed to investigate the GC-5'ss of the breast/ovarian cancer susceptibility genes, ATM (exon 50), BRIP1 (exon 1), and PALB2 (exon 12), and their dysregulation induced by DNA variants. Methods: Splicing assays of the minigenes, mgATM_49-52, mgBRIP1_1-2, and mgPALB2_5-12, were conducted to study the regulation of the indicated GC-5'ss. Results: A functional map of the splicing regulatory elements (SRE) formed by overlapping exonic microdeletions revealed three essential intervals, ATM c.7335_7344del, PALB2 c.3229_3258del, and c.3293_3322del, which are likely targets for spliceogenic SRE-variants. We then selected 14 ATM and 9 PALB2 variants (Hexplorer score < -40) located at these intervals that were assayed in MCF-7 cells. Nine ATM and three PALB2 variants affected splicing, impairing the recognition of exons 50 and 12, respectively. Therefore, these variants likely disrupt the active SREs involved in the inclusion of both exons in the mature mRNA. DeepCLIP predictions suggested the participation of several splicing factors in exon recognition, including SRSF1, SRSF2, and SRSF7, involved in the recognition of other GC sites. The ATM spliceogenic variants c.7336G>T (p.(Glu2446Ter)) and c.7340T>A (p.(Leu2447Ter)) produced significant amounts of full-length transcripts (55-59%), which include premature termination stop codons, so they would inactivate ATM through both splicing disruption and protein truncation mechanisms. Conclusions: ATM exon 50 and PALB2 exon 12 require specific sequences for efficient recognition by the splicing machinery. The mapping of SRE-rich intervals in minigenes is a valuable approach for the identification of spliceogenic variants that outperforms any prediction software. Indeed, 12 spliceogenic SRE-variants were identified in the critical intervals.

The effect of knowledge and person-related factors on breast cancer susceptibility genes (BRCA1/2) testing perception in Turkish women.

Genetic testing for breast cancer susceptibility genes (BRCA1/2) plays a pivotal role in risk assessment and preventive interventions. However, individuals' awareness, knowledge, and attitudes toward genetic testing can vary across different societies. This study focuses on understanding Turkish women's knowledge, perceptions, and attitudes toward BRCA1/2 testing, considering demographic factors and awareness. In this cross-sectional study, 301 Turkish participants, including breast/ovarian cancer patients and their first-degree relatives, were surveyed. Information on sociodemographics, cancer history, awareness, knowledge, and perceptions was collected. The study aimed to assess knowledge levels about breast cancer inheritance and BRCA1/2 testing, describe perspectives about testing in women with a family history of breast or ovarian cancer, and determine associations between knowledge, personal factors, anxiety, and genetic testing perspectives. Results showed a wide range in correct responses (31.6%-96.7%) for knowledge items. No significant relationship between knowledge levels and positive perception was observed. However, participants answering a specific question incorrectly showed higher negative perceptions. While most participants recognized the benefits of genetic testing, concerns centered around passing the genes to future generations. Participants who were younger, more educated, had higher income, were employed, at an earlier disease stage, and were social media users demonstrated more positive attitudes. Negative perceptions were higher among younger patients, physicians, and healthcare professionals. Interestingly, anxiety in cancer patients did not correlate with either positive or negative perceptions. In conclusion, this study identifies participant-related factors influencing perceptions of hereditary genetic tests. Understanding these factors and addressing associated issues can enhance the utilization of genetic testing and promote preventive oncology applications.

Effects of BRCA1 overexpression via the NRF2 / HO1 / NQO1 pathway on oral cancer cells proliferation, migration, and apoptosis

ObjectiveHerein, we explored the influences of breast cancer susceptibility gene 1 (BRCA1) overexpression on oral cancer cells proliferation, migration, and apoptosis via evaluation of its interactions with nuclear factor erythroid 2-like 2 (NRF2). DesignCAL-27 and DOK cells were transfected with a BRCA1 overexpressing lentivirus. Next, we utilized Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) analyses to evaluate BRCA1, NRF2, and their target gene expressions. Using cell counting kit-8 (CCK-8) assessment, we assessed cell proliferation and a scratch test detected CAL-27 cell migration. Additionally, flow cytometry was employed used to examine cell apoptosis, while an enzyme-linked immunosorbent assa (ELISA) was employed for evaluation of 8-hydroxy-2′- deoxyguanosine (8-OHdG) expression. An immunohistochemical analysis was employed to determine the NRF2 target genes and Ki-67 expressions. ResultsBRCA1 overexpression increased the NRF2 and its target gene transcript and protein expressions. CCK-8 and scratch test results showed that BRCA1 overexpression decreased cell proliferation and weakened CAL-27 cell migratory ability. Flow cytometry results showed that BRCA1 overexpression promoted cell apoptosis in a time-dependent manner, while enzyme-linked immunosorbent assay results showed that BRCA1 overexpression decreased 8-OHdG expression levels in CAL-27 and DOK cells. Immunohistochemical analysis results showed higher expression of NRF2 target genes and Ki-67 in oral squamous cell carcinoma cells. ConclusionsExperiments involving oral cancer cells confirmed that BRCA1 overexpression could up-regulate the NRF2 signalling pathway, reduce oxidative damage, and inhibit cell proliferation and other biological behaviours. The BRCA1 and NRF2 pathways might be associated with oral cancer occurrence and development.

An overview of the latest outlook of sulfamate derivatives as anticancer candidates (2020-2024).

Considering the emergence of new anticancer drugs, in this review we emphasized and highlighted the recent reports and advances related to sulfamate-incorporating compounds with potential anticancer activity during the last 5 years (2020-2024). Additionally, we discussed their structure-activity relationship, clarifying their potent bioactivity as anticancer agents. Sulfamate derivatives hold promise as effective therapeutic candidates against cancer. By targeting biological targets associated with the development of cancer, such as steroid sulfatases (STS), carbonic anhydrases (CAs), microtubules, NEDD8-activating enzyme, small ubiquitin-like modifiers(SUMO)-activating enzyme (SAE), cyclin-dependent kinases (CDKs), breast cancer susceptibility gene 1 (BRCA1), and so on, this can furnish small molecules as anticancer lead candidates serving the drug discovery field. For example, compound 2, an STS inhibitor, demonstrated superior activity compared to its reference, irosustat, by fivefold. In addition, compound 21, an SAE, is under phase I clinical trials. Continued research into sulfamate derivatives holds potential for the development of novel therapeutic agents targeting various diseases.

BRCA-DIRECT digital pathway for diagnostic germline genetic testing within a UK breast oncology setting: a randomised, non-inferiority trial

BackgroundGenetic testing to identify germline high-risk pathogenic variants in breast cancer susceptibility genes is increasingly part of the breast cancer diagnostic pathway. Novel patient-centred pathways may offer opportunity to expand capacity and reduce turnaround time.MethodsWe recruited 1140 women with unselected breast cancer to undergo germline genetic testing through the BRCA-DIRECT pathway (which includes a digital platform, postal saliva sampling and a genetic counsellor telephone helpline). Ahead of consenting to the test, participants were randomised to receive information about genetic testing digitally (569/1140, 49.9%) or via a pre-test genetic counselling consultation (571/1140, 50.1%).Results1001 (87.8%) participants progressed to receive their pre-test information and consented to testing. The primary outcome, uptake of genetic testing, was higher amongst participants randomised to receive digital information compared with those randomised to a pre-test genetic counselling consultation (90.8% (95% CI: 88.5% to 93.1%) vs 84.7% (95% CI: 81.8% to 87.6%), p = 0.002, adjusted for participant age and site). Non-inferiority was observed in relation to patient knowledge, anxiety, and satisfaction.ConclusionsFindings demonstrate that standardised, digital information offers a non-inferior alternative to conventional genetic counselling, and an end-to-end patient-centred, digital pathway (supported by genetic counselling hotline) could feasibly be implemented into breast oncology settings.Clinical trial registrationThe study is registered with, and protocol available on, ClinicalTrials.gov (NCT04842799).

Is single-port laparoscopy or vaginal natural orifice transluminal endoscopic surgery the better option for salpingo-oophorectomy?

To compare postoperative pain and recovery in patients undergoing oophorectomy with single-port laparoscopic surgery (SPLS) versus vaginal natural orifice transluminal endoscopic surgery (vNOTES). Patients who underwent salpingo-oophorectomy with SPLS or vNOTES between 2016 and 2023 were analyzed retrospectively. Oophorectomy was performed based on the presence of an adnexal mass or breast cancer susceptibility gene mutation. Fifty-two patients underwent oophorectomy with SPLS and 35 underwent vNOTES. Although the mean mass size was slightly larger in the SPLS group than in the vNOTES group (8.0 ± 4.1 vs. 6.8 ± 3.3 cm), the difference was not significant. There was no difference in operating times between SPLS and vNOTES. The mean visual analog scale and faces pain scale scores 2 and 6 h postoperatively were lower in the vNOTES group. The mean quality of recovery-40 (QoR-40) score was higher in the vNOTES group (156 ± 14 vs. 148 ± 11; p = 0.009). This analysis identified vNOTES as an independent predictor of a high QoR-40 score. The vNOTES group experienced less pain during the early postoperative period than the SPLS group. Although the operating and removal times were similar, the port setup time was longer for the vNOTES group.

Uptake of Risk-Reducing Surgeries in an International Real-World Cohort of Hispanic Women.

Women with pathogenic variants (PVs) in breast cancer (BC) and ovarian cancer (OC) associated genes are candidates for cancer risk-reducing strategies. Limited information is available regarding risk-reducing surgeries (RRS) among Hispanics. The aim of this study was to describe the uptake of RRS in an international real-world experience of Hispanic women referred for genetic cancer risk assessment (GCRA) and to identify factors affecting uptake. Between July 1997 and December 2019, Hispanic women, living in the United States or in Latin America, enrolled in the Clinical Cancer Genomics Community Research Network registry were prospectively included. Demographic characteristics and data regarding RRS were obtained from chart reviews and patient-reported follow-up questionnaires. Median follow-up was 41 months. Among 1,736 Hispanic women referred for GCRA, 27.2% women underwent risk-reducing mastectomy (RRM), 25.5% risk-reducing salpingo-oophorectomy (RRSO) and, 10.7% both surgeries. Among BRCA carriers, rates of RRM and RRSO were 47.6% and 56.7%, respectively. In the multivariate analyses, being a carrier of a BC susceptibility gene (odds ratio [OR], 3.44), personal history of BC (OR, 6.22), living in the US (OR, 3.90), age ≤50 years (OR, 1.68) and, family history of BC (OR, 1.56) were associated with a higher likelihood of undergoing RRM. Carrying an OC susceptibility gene (OR, 6.72) was associated with a higher likelihood of undergoing RRSO. The rate of RRS among Hispanic women is suboptimal. PV carriers, women with personal history of cancer, and those with a family history of cancer were more likely to have RRS, with less uptake outside the US. Understanding personal and systemic factors influencing uptake may enable interventions to increase risk appropriate uptake of RRS.

Therapeutic effects of paeonol on non‑small cell lung cancer cells via regulation of the MAPK pathway.

The present study aimed to investigate the molecular mechanisms by which paeonol impedes DNA damage repair, induces apoptosis and inhibits cell viability via the mitogen-activated protein kinase (MAPK) pathway. Firstly, normal human bronchial epithelial cells (BEAS-2B) and non-small cell lung cancer cells (H1299) were employed in the study as cellular models. Following cultivation, the cells were divided into experimental and control groups, and were treated with different concentrations of paeonol. Subsequently, various techniques, including western blotting, Cell Counting Kit-8, colony formation, TUNEL and comet assays were conducted to evaluate the effects of paeonol on cell viability, colony-forming ability, apoptosis levels and DNA damage in H1299 cells. According to the experimental results, paeonol significantly reduced the viability and colony formation ability of H1299 cells, but substantially increased apoptosis and DNA damage. These effects were enhanced in response to higher concentrations of paeonol. Furthermore, western blot analysis revealed that paeonol treatment decreased the protein levels of B-cell lymphoma 2 and breast cancer susceptibility gene 1, while it increased the expression levels of cleaved-PARP, cleaved-caspase 3, γH2AX and P21. Additionally, the phosphorylated levels of extracellular signal-regulated kinase 1, c-Jun N-terminal kinase and P38 within the MAPK signaling pathway were diminished. Collectively, the present study demonstrated that paeonol may inhibit the metabolic activity and proliferative capability of H1299 cells, and that it could promote apoptosis and obstruct DNA damage repair by modulating the MAPK signaling pathway.

Universal Genetic Testing for Newly Diagnosed Invasive Breast Cancer

Between 5% and 10% of breast cancer cases are associated with an inherited germline pathogenic or likely pathogenic variant (GPV) in a breast cancer susceptibility gene (BCSG), which could alter local and systemic therapy recommendations. Traditional genetic testing criteria misses a proportion of these cases. To evaluate the prevalence and clinicopathological associations of GPVs in 2 groups of BCSGs among an ethnically diverse cohort of women with newly diagnosed breast cancer. This cross-sectional study, conducted at 3 Montreal hospitals between September 2019 and April 2022, offered universal genetic counseling and testing to all women with a first diagnosis of invasive breast cancer. Women were offered an obligatory primary panel of BRCA1, BRCA2, and PALB2 (B1B2P2) and an optional secondary panel of 14 additional BCSGs. Eligible participants were women 18 years of age or older who received a diagnosis of a first primary invasive breast cancer not more than 6 months before the time of referral to the study. Data were analyzed from November 2023 to June 2024. Of 1017 referred patients, 805 were eligible and offered genetic counseling and testing, and 729 of those 805 (90.6%) consented to be tested. The median age at breast cancer diagnosis was 53 years (range, 23-91 years), and 65.4% were White and of European ancestry. Fifty-four GPVs were identified in 53 patients (7.3%), including 39 patients (5.3%) with B1B2P2 and 15 patients (2.1%) with 6 of the 14 secondary panel BCSGs (ATM, BARD1, BRIP1, CHEK2, RAD51D, and STK11). On multivariable analysis, clinical factors independently associated with B1B2P2-positive status included being younger than 40 years of age at diagnosis (odds ratio [OR], 6.83; 95% CI, 2.22-20.90), triple-negative breast cancer (OR, 3.19; 95% CI, 1.20-8.43), high grade disease (OR, 1.68; 95% CI, 1.05-2.70), and family history of ovarian cancer (OR, 9.75; 95% CI, 2.65-35.85). Of 39 B1B2P2-positive patients, 13 (33.3%) were eligible for poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors. In this cross-sectional universal genetic testing study of women with newly diagnosed invasive breast cancer, the prevalence of GPVs was 7.3%, with 5.3% of patients testing positive for B1B2P2. Among B1B2P2-women women, one-third were eligible for PARP inhibitors.

BaP/BPDE suppresses homologous recombination repair in human trophoblast cells to induce miscarriage: The roles of lnc-HZ08

Benzo(a)pyrene (BaP) or benzo (a) pyrene 7,8-dihydrodiol-9,10-epoxide (BPDE) exposure causes trophoblast cell dysfunctions and induces miscarriage, which is generally epigenetically regulated. Homologous recombination (HR) repair of DNA double strand break (DSB) plays a crucial role in maintenance of genetic stability and cell normal functions. However, whether BaP/BPDE might suppress HR repair in human trophoblast cells to induce miscarriage, as well as its epigenetic regulatory mechanism, is largely unclear. In this study, we find that BaP/BPDE suppresses HR repair of DSB in trophoblast cells and eventually induces miscarriage by up-regulating lnc-HZ08. In mechanism, lnc-HZ08 (1) down-regulates the expression levels of FOXA1 (forkhead box A1) and thus suppresses FOXA1-mediated mRNA transcription of BRCA1 (Breast cancer susceptibility gene 1) and CtIP (CtBP-interacting protein), (2) impairs BRCA1 and CtIP protein interactions by competitive binding with CtIP through lnc-HZ08-1 fragment, and also (3) suppresses BRCA1-mediated CtIP ubiquitination without affecting CtIP stability, three of which eventually suppress HR repair in human trophoblast cells. Supplement with murine Ctip could efficiently restore (i.e. increase) HR repair and alleviate miscarriage in BaP-exposed mouse model. Collectively, this study not only reveals the association and causality among BaP/BPDE exposure, the defective HR repair, and miscarriage, but also discovers novel mechanism in lnc-HZ08-regulated BRCA1/CtIP-mediated HR repair, bridging epigenetic regulation and genetic instability and also providing an efficient approach for treatment against BaP/BPDE-induced unexplained miscarriage.

Germline variant profiling of CHEK2 sequencing variants in breast cancer patients

The cell cycle checkpoint kinase 2 (CHEK2) is a tumor suppressor gene coding for a protein kinase with a role in the cell cycle and DNA repair pathways. Variants within CHEK2 are associated with an increased risk of developing breast, colorectal, prostate and several other types of cancer. Comprehensive genetic risk assessment leads to early detection of hereditary cancer and provides an opportunity for better survival. Multigene panel screening can identify the presence of pathogenic variants in hereditary cancer predisposition genes (HCPG), including CHEK2. Multigene panels, however, also result in large quantities of genetic data some of which cannot be interpreted and are classified as variants of uncertain significance (VUS). A VUS provides no information for use in medical management and leads to ambiguity in genetic counseling. In the absence of variant segregation data, in vitro functional analyses can be used to clarify variant annotations, aiding in accurate clinical management of patient risk and treatment plans. In this study, we performed whole exome sequencing (WES) to investigate the prevalence of germline variants in 210 breast cancer (BC) patients and conspicuously among the many variants in HCPGs that we found, we identified 16 individuals with non-synonymous or frameshift CHEK2 variants, sometimes along with additional variants within other BC susceptibility genes. Using this data, we investigated the prevalence of these CHEK2 variants in African American (AA) and Caucasian (CA) populations identifying the presence of two novel frameshift variants, c.1350delA (p.Val451Serfs*18) and c.1528delC (p.Gln510Argfs*3) and a novel missense variant, c262C>T (p.Pro88Ser). Along with the current clinical classifications, we assembled available experimental data and computational predictions of function for these CHEK2 variants, as well as explored the role these variants may play in polygenic risk assessment.

High likelihood of BRCA2 reversion mutation in pancreatic cancer post-platinum-based chemotherapy: a case study.

A 54-year-old man with resectable pancreatic cancer and abnormally high levels of carbohydrate antigen 19-9 (CA19-9) underwent 6months of platinum-based chemotherapy. This treatment substantially reduced the primary tumor size and normalized CA19-9 levels. Subsequently, radical surgery was conducted. However, eight months post-surgery, CA19-9 levels re-elevated, and lymph-node recurrence was observed. The patient underwent treatment with poly(adenosine diphosphate ribose) polymerase inhibitors (PARPi) following the detection of frameshift L1904fs*5 via BRACAnalysis CDx. This mutation revealed a stop codon, leading to the inactivation of the BRCA function. Additionally, the patient tested positive for a mutation in the breast cancer susceptibility gene 2 (BRCA2). Two months after starting PARPi, there was evidence of tumor shrinkage. Nevertheless, 5 months later, CA19-9 levels increased again, and new metastatic tumors in the liver were identified. Genomic profiling test (FoundationOne CDx) of surgically resected specimens revealed a BRCA2 pL1908fs*2 mutation, indicating its location in the cis position on the same allele as the germline BRCA2 mutation. The pL1908fs*2 deletion, alongside the original L1904fs*5, resulted in three deletions, equating to one amino acid deletion. This deletion ultimately reversed the stop codon, leading to the restoration of BRCA2 functionality. Despite treatment with PARPi for postoperative recurrence, a sustained response was not achieved owing to BRCA reversion mutations. It is essential to acknowledge the rarity of BRCA reversion mutations, which limit the effectiveness of PARPi.

Clinical significance of germline breast cancer susceptibility gene (gBRCA) testing and olaparib as maintenance therapy for patients with pancreatic cancer

BackgroundGermline breast cancer susceptibility gene (gBRCA) mutation in patients with pancreatic cancer (PC) is not common in clinical practice. Therefore, factors that efficiently show gBRCA mutations and the real-world outcomes of olaparib maintenance therapy have not been fully established. In the present study, we clarified the indicators for the effective detection of gBRCA mutation and the efficacy and safety of olaparib as maintenance therapy.MethodsWe retrospectively analyzed 84 patients with PC who underwent gBRCA testing (BRACAnalysis, Myriad Genetics, Salt Lake City, UT, USA) at our institute between January 2021 and March 2022. For each patient, clinical data were extracted from medical records.ResultsThe median patient age was 64 y (29–85 y), and 41 patients (48.8%) were male. The gBRCA mutations were identified in 10 (11.9%) patients; two patients had BRCA1 mutation and eight had BRCA2 mutation. All patients with gBRCA mutation had a family history of any cancer, and eight of them had a family history of Hereditary Breast and Ovarian Cancer syndrome (HBOC)-related cancer. The gBRCA mutation rate was higher for patients with PC with a family history of HBOC-related cancer compared to that in patients with PC having a family history of other cancers and no family history of cancer (22.9% vs. 4.1%; P = 0.014). In our study, eight out of 10 patients with gBRCA-positive PC received olaparib after platinum-based chemotherapy. The best responses to platinum-based chemotherapy included a complete response in one patient (12.5%) and a partial response in seven patients (87.5%). The median duration of treatment with platinum-based chemotherapy plus olaparib was 17.5 months (8–87 months), and the duration of treatment with olaparib maintenance therapy was 11 months (1–30 months). During olaparib maintenance therapy, three patients showed no disease progression. One of these three patients underwent conversion surgery after receiving olaparib for 12 months.ConclusionsThe gBRCA testing should be considered proactively, especially in patients with PC with a family history of HBOC-related cancer.

BRCA1/2 Mutations and Breast/Ovarian Cancer Risk: A New Insights Review.

Breast and ovarian cancers are significant global health concerns, and understanding their genetic underpinnings is essential for effective prevention and cure. This narrative review provides a comprehensive analysis of studies conducted between 1994 and June 2024, focusing on the link between specific mutations in the breast cancer susceptibility gene 1 (BRCA1) and breast cancer susceptibility gene 2 (BRCA2) and the associated risks of both breast and ovarian cancers. It encompasses the findings of various works, including observational studies and molecular profiling analyses. Conducted on large international cohorts, these studies present compelling evidence of the relationship between different BRCA1 and BRCA2 mutations and the varying risks of breast and ovarian cancer. Furthermore, this review highlights the significance of nonsense-mediated decay mutations and their impact on cancer risk, particularly concerning the age of breast cancer onset. The implications of these findings are far-reaching, offering valuable information for risk assessment and decision-making in managing individuals who carry BRCA1 or BRCA2 mutations. The molecular subtyping profile BluePrint is discussed as a potential tool for enhancing clinical care by aiding the selection of appropriate treatment options, such as endocrine therapy or chemotherapy, based on the tumor's molecular characteristics. In conclusion, we establish a robust link between specific BRCA1 and BRCA2 gene mutations and increased susceptibility to breast and ovarian cancers. These mutations impact cancer onset age and severity, underscoring the need for targeted testing and screening. The current study enhances cancer detection, prevention, and cure strategies.

Occurrence of contralateral breast cancer in a BRCA-positive breast cancer patient who underwent free TRAM flap reconstruction: a case report

This report presents a case of contralateral breast cancer in a BRCA mutation-positive patient who had previously undergone delayed free transverse rectus abdominis myocutaneous flap reconstruction for unilateral breast cancer. Having used up the available abdominal autologous tissue in the first reconstruction, a direct-to-implant procedure was employed for the reconstruction of the second, contralateral breast. Therefore, one breast was reconstructed using autologous tissue from the abdomen, while the other was asymmetrically reconstructed with an implant. If the risk of contralateral breast cancer had been anticipated initially, we might have opted for implant-based reconstruction from the start to facilitate a more symmetrical outcome in the event of subsequent contralateral reconstruction. This case underscores the importance of reviewing the risk of contralateral breast cancer in patients with unilateral breast cancer who also carry mutations in BRCA and other breast cancer susceptibility genes. Furthermore, it encourages consideration of how mutations in breast cancer susceptibility genes, including BRCA, influence the choice of plastic surgery reconstruction techniques. The findings from genetic testing for breast cancer susceptibility are now crucial to achieving aesthetic completeness in breast reconstruction.

Systematic investigation of BRCA1-A, -B, and -C complexes and their functions in DNA damage response and DNA repair.

BRCA1, a breast cancer susceptibility gene, has emerged as a central mediator that brings together multiple signaling complexes in response to DNA damage. The A, B, and C complexes of BRCA1, which are formed based on their phosphorylation-dependent interactions with the BRCA1-C-terminal domains, contribute to the roles of BRCA1 in DNA repair and cell cycle checkpoint control. However, their functions in DNA damage response remain to be fully appreciated. Specifically, there has been no systematic investigation of the roles of BRCA1-A, -B, and -C complexes in the regulation of BRCA1 localization and functions, in part because of cellular lethality associated with loss of CtIP protein, which is an essential component in BRCA1-C complex. To systematically investigate the functions of these complexes in DNA damage response, we depleted a key component in each of these complexes. We used the degradation tag system to inducibly deplete endogenous CtIP and obtained a series of RAP80/FANCJ/CtIP single-, double-, and triple-knockout cells. We showed that loss of BRCA1-B/FANCJ and BRCA1-C/CtIP, but not BRCA1-A/RAP80, resulted in reduced cell proliferation and increased sensitivity to DNA damage. BRCA1-C/CtIP and BRCA1-A/RAP80 were involved in BRCA1 recruitment to sites of DNA damage. However, BRCA1-A/RAP80 was not essential for damage-induced BRCA1 localization. Instead, RAP80/H2AX and CtIP have redundant roles in BRCA1 recruitment. Altogether, our systematic analysis uncovers functional differences between BRCA1-A, -B, and -C complexes and provides new insights into the roles of these BRCA1-associated protein complexes in DNA damage response and DNA repair.