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Background & objectives: Studies have shown that apart from hereditary breast carcinomas, breast cancer susceptibility gene 1 (BRCA1) mutations conferring to its loss are seen in sporadic breast carcinomas (SBC) as well. The aim of the present study was to assess BRCA1 methylation in females presenting at King George’s Medical University, Lucknow, with SBC by both immunohistochemistry (IHC) and methylation PCR with respect to hormonal profile and various morphological prognostic parameters. The primary objective was to look for the association between BRCA1 protein expression and DNA promoter methylation. Methods: 81 mastectomy specimens from SBC of invasive breast carcinoma (no special type) were included in this study. After a detailed morphological assessment, formalin fixed paraffin embedded tissue from a representative tumour area was selected for BRCA1 IHC by heat-mediated antigen retrieval under high pH and DNA extraction and further bisulphate treatment. BRCA1 was studied for methylation by methylated and unmethylated PCR-specific primers. Results: BRCA1 promoter methylation was present in 42/81 (51.9%) participants, with significant BRCA1 protein loss (72.7%; P=0.002). A significant association between BRCA1 loss and hormonal profile was found (P=0.001); maximum in triple negative breast carcinoma (TNBC) (72%; 18/25). Most of the TNBC also harboured methylation (68%). Although not significant grade II and III tumours, lymph vascular invasion, ductal carcinoma in situ, and nodal metastasis (?3) were seen in a higher percentage in methylated tumours. Mortality in SBC was significantly associated with BRCA1 loss (30.3%; P=0.024). Interpretation & conclusions: Study results highlight the concept of “BRCAness” in SBC as well. Hence, we can confer that identification of BRCA1 loss in SBC can make it a perfect candidate for poly ADP- ribose polymerase inhibitors or cisplatin-based therapy like hereditary ones.
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OBJECTIVE To systematically evaluate the efficacy and safety of olaparib in adjuvant therapy of breast cancer susceptibility gene （BRCA） 1/2 mutated human epidermal growth factor receptor 2 （HER2）-negative breast cancer， and to provide evidence-based reference for clinical treatment. METHODS Retrieved from CNKI， VIP， Wanfang data， PubMed， ScienceDirect， the Cochrane Library and Embase databases， randomized controlled trials about adjuvant therapy of olaparib （trial group） versus adjuvant therapy of other drugs （control group） were collected. After literature screening and data extraction， meta-analysis， publication bias analysis and sensitivity analysis were performed by using RevMan5.4 software. RESULTS A total of 5 randomized controlled trials were included， with a total of 2 633 patients， including 1 495 cases in trial group and 1 174 cases in control group. Meta-analysis showed that in terms of efficacy， compared with control group， overall survival [HR＝1.02， 95%CI （1.01，1.03）， P＝0.000 8] and progression-free survival [HR＝1.78， 95%CI（1.46，2.17）， P＜0.000 01] were longer significantly in the trial group. In terms of safety， compared with the control group， the incidence of adverse drug reactions at any level in the trial group was higher [RR＝1.41， 95%CI （1.12， 1.78）， P＝0.004]， while there was no statistically significant difference in the incidence of adverse drug reactions above level 3 between the two groups [RR＝1.75， 95%CI （0.82， 3.74）， P＝0.15]. The results of publication bias indicated that the possibility of publication bias in this study was relatively low. The results of sensitivity analysis showed that the results obtained in this study were robust. CONCLUSIONS Compared with patients without adjuvant therapy of olaparib， adjuvant therapy of olaparib can prolong overall survival and progression-free survival of patients with BRCA1/2 mutated HER2-negative breast cancer，but the risk of adverse drug reactions is relatively high.
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Hereditary breast cancer refers to malignant tumors caused by pathogenic germline mutations of breast cancer susceptibility genes (BRCA). At present, it is believed that BRCA1/2 genes are most closely related to the development of hereditary breast cancer. Mutation will lead to loss of normal function, instability of genome, and then lead to tumorigenesis. Especially for those with germline mutations, not only the risk of breast cancer will be greatly increased, but also the probability of ovarian cancer and other cancers will be increased. With the emergence and clinical application of poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors, BRCA1/2 genes have been regarded as new targets for the treatment of breast cancer. This article reviews the latest research of breast cancer with BRCA1/2 gene mutations.
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@#[Abstract] Objective: To investigate the effect of breast cancer susceptibility gene 1 (BRCA1) on the proliferation, migration and invasion of non-small cell lung cancer (NSCLC) H1650 cells through Wnt/β-catenin pathway. Methods: WB and qPCR were used to detect the mRNA and protein expressions of BRCA1 in NSCLC A549, H1299, H1650 cells and normal lung epithelial BEAS-2B cell. A stable BRCA1 over-expression cell line (LV-BRCA1) was constructed in H1650 cells, and blank control group (NC), negative control group (LV-BRCA1-NC), experimental group (LV-BRCA1) and inhibitor group (LV-BRCA1+XAV-939) were set up. The proliferative activity of cells in each group was detected by MTT assay, the migration ability of cells was detected by scratch test, the invasive ability of cells was detected by Transwell method, and the protein expression levels of BRCA1, cyclin D1, β-catenin, c-Myc and Cox2 were detected by WB. Results: The mRNA and protein expression levels of BRCA1 in NSCLC cells were significantly higher than those in BEAS-2B cells (all P<0.01). Up-regulation of BRCA1 expression in H1650 cells could significantly enhance cell proliferation, migration and invasion (P<0.05 or P<0.01), and increase the protein expressions of cyclin D1, β-catenin, c-Myc, Cox2 and c-Jun (P<0.05 or P<0.01). β-catenin inhibitor XAV-939 significantly down-regulated the proliferation, migration and invasion ability of H1650 cells over-expressing BRCA1, and decreased the protein expressions of cyclin D1, β-catenin, c-Myc, Cox2 and c-Jun (P<0.05 or P<0.01). Conclusion: BRCA1 can promote the proliferation, migration and invasion of NSCLC H1650 cells by activating Wnt/β-catenin pathway, and it is expected to be a potential diagnostic biomarker and treatment target for NSCLC.
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Ovarian cancer is the most fatal malignant tumor in female reproductive system tumors.In most women, it is diagnosed in a late stage, which largely leads to the poor prognosis of ovarian cancer.Breast cancer susceptibility gene (BRCA) is an important DNA homologous repair gene, which plays a major role in the normal cellular DNA repair mechanism.Its mutation will lead to homologous recombination defects, which will affect the stability of the genome and lead to occurrence of tumors.In recent years, BRCA genetic testing has become a key step in the risk assessment, prognosis, treatment and prevention of ovarian cancer.
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@#This study was aimed to design the first dual-target small-molecule inhibitor co-targeting poly (ADP-ribose) polymerase-1 (PARP1) and bromodomain containing protein 4 (BRD4), which had important cross relation in the global network of breast cancer, reflecting the synthetic lethal effect. A series of new BRD4 and PARP1 dual-target inhibitors were discovered and synthesized by fragment-based combinatorial screening and activity assays that together led to the chemical optimization. Among these compounds, 19d was selected and exhibited micromole enzymatic potencies against BRD4 and PARP1, respectively. Compound 19d was further shown to efficiently modulate the expression of BRD4 and PARP1. Subsequently, compound 19d was found to induce breast cancer cell apoptosis and stimulate cell cycle arrest at G1 phase. Following pharmacokinetic studies, compound 19d showed its antitumor activity in breast cancer susceptibility gene 1/2 (BRCA1/2) wild-type MDA-MB-468 and MCF-7 xenograft models without apparent toxicity and loss of body weight. These results together demonstrated that a highly potent dual-targeted inhibitor was successfully synthesized and indicated that co-targeting of BRD4 and PARP1 based on the concept of synthetic lethality would be a promising therapeutic strategy for breast cancer.
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AIM: To explore the effect of single nucleotide polymorphism (SNP) of breast cancer susceptibility gene 1 (BRCA1) on chemotherapy sensitivity and survival prognosis of patients with metastatic esophageal squamous cell carcinoma. METHODS: A total of 153 patients with newly treated metastatic esophageal squamous cell carcinoma who were admitted to Suzhou Science and Technology City Hospital from June 2016 to February 2020 were included and administered with cisplatin combined with capecitabine chemotherapy. Before the first chemotherapy, 5 mL of venous blood was collected to extract DNA, and the TaqMan probe method was used to detect the genotypes of the BRCA1 gene rs8176318G/T, rs799917T/C and rs1799966T/C polymorphic loci. The objective response rate (ORR) and overall survival (OS) of different genotypes were analyzed. RESULTS: Rs799917T/C polymorphism was closely related to the chemosensitivity of metastatic esophageal squamous cell carcinoma. The chemotherapy response rates of TT, TC and CC genotypes increased gradually (TT 22.5%, TC 38.6%, CC 55.3%, χ
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Objective To analyze the correlation between polymorphism of the BRCA2 gene rs206115 loci and sporadic breast cancer in Inner Mongolia. Methods We enrolled patients from the Affiliated Hospital of Inner Mongolia Medical University from December 2015 to December 2016 who underwent breast surgery and were confirmed by pathology, resulting in a total of 101 cases of primary sporadic breast cancer (case group) and benign breast diseases (control group). DNA was extracted from blood samples and analyzed using polymerase chain reaction (PCR) and direct sequencing methods for determining the BRCA2 gene rs206115 loci polymorphism. SPSS 17.0 was used for statistical analysis. Results In this experiment, regardless of whether the patients were Han or Mongolian, the rs206115 loci could be detected in 3 kinds of genotypes:AA, AG, and GG. The BRCA2 gene rs206115 locus gene polymorphism was not significantly different between the case and control groups (χ2=3.490, P = 0.175). The A allele frequency of the BRCA2 gene rs206115 loci in the case group was significantly increased compared to the control group (χ2=4.259, P = 0.039). Conclusion The A allele of rs206115 may be one of the susceptibility alleles in sporadic breast cancer in Mongolian and Han populations.
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Objective BRCA1 is one of the most important susceptibility genes of breast cancer. The article aimed to investigate the expression of BRCA1 and its correlation in sporadic invasive breast cancer. Methods The expressions of BRCA1, ER, PR, HER2 and Ki67 in 618 cases of sporadic invasive breast cancer in our hospital from January 2015 to December 2017 were detected with immunohistochemistry in order to investigate and analyze the expression of BRCA1 and its correlation with molecular classification, histological type and other related molecular markers in sporadic invasive breast cancer. Results The positive rate of BRCA1 was 44.2% consisting of 30.3% weak positive(+) and 13.9% strong positive(++). The positive rates of ER, PR, and HER2 are 60.8%, 54.7%,and 24.9%. The proliferation index ≤30% of Ki67 was 70.7%, >30% was 29.3%. The expression of BRCA1 in luminal type A was significantly lower than the other four types of sporadic invasive breast cancer(P<0.05). The expression of BRCA1 in breast cancer with medullary histological features was significantly lower than those of the other types of breast cancer(P<0.05). There was significant difference between the expression of BRCA1 and the expressions of ER, HER2 and Ki67 (P<0.01). The expression of BRCA1 had positive correlation with expression of HER2 in sporadic invasive breast cancer (r=0.117,P<0.01). Conclusion The expression of BRCA1 in sporadic invasive breast cancer with triple negative subtype and medullary histological features is down-regulated and BRCA1 may affect the development and progression of sporadic invasive breast cancer.
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Genomic instability is one of the most pervasive characteristics of cancer cells,and DNA damage response (DDR) pathway plays a crucial role in genomic stability.The DDR pathway is a complex signaling network,which involves cell DNA repair,apoptosis and cell cycle regulation.Deficiencies in these repair pathways can result in several different genetic disorders,including cancer.Targeted therapy based on inhibiting the DDR pathway in cancers offers a novel therapy strategy for patients with tumors lacking specific DDR functions.Many small-mole-cule compounds targeting DDR pathway are typically developed for solid cancer therapy.The poly (ADP-ribose) polymerase (PARP) inhibitor is a kind of DDR inhibitors which exploits the principle of synthetic lethality to selectively kill cancer cells.This review highlights the molecular mechanisms of PARP inhibitor action,the progress of PARP inhibitors in cancer therapy,drug resistance and the challenge of PARP inhibitor in the future.
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Objective To explore the relationship between the expression levels of excision repair cross complementation group 1(ERCC1), breast cancer susceptibility gene 1(BRCA1), thymidylate synthase (TS) mRNA and clinicopathological features, prognosis in advanced colorectal cancer, and the correlation between the expression levels of ERCC1 and BRCA1. Methods The expression levels of ERCC1, BRCA1 and TS mRNA of postoperative paraffin embedded tissue were tested by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) in 49 advanced colorectal cancer cases. The results were analyzed by χ2 test of the correlation between the expression levels and clinicopathological characteristics. Patients were followed up by clinic or telephone. The prognosis was analyzed by small sample Kaplan-Meier survival analysis and Log-rank time series analysis, and P0.05). The expression level of BRCA1 mRNA had no significant correlation with the above clinical and pathological features (P>0.05) except distant metastasis (P=0.030) and differentiation degree (P=0.002). The expression level of TS mRNA had no significant correlation with the above clinical and pathological features (P>0.05) except distant metastasis (P=0.003). The expression level of ERCC1 and BRCA1 mRNA obviously correlated (P=0.002). The 1 year overall survival rate was 95.92%(47/49);the 2 year overall survival rate was 83.67%(41/49);and the 3 year overall survival rate was 73.47%(36/49). Overall survival and progression-free survival time in ERCC1 mRNA low expression group (47.8, 41.0 months) was higher than that in ERCC1 mRNA low expression group (27.3, 20.0 months) respectively (P=0.001, P=0.001). Overall survival and progression-free survival time in BRCA1 mRNA low expression group (43.7, 42.7 months) was higher than that in BRCA1 mRNA high expression group (29.3, 25.1 months) respectively (P=0.009, 0.006). Overall survival time in TS mRNA low expression group (39.8 months) was higher than that in BRCA1 mRNA high expression group (25.2 months). Conclusions The expression level of ERCC1 mRNA is not correlated with its clinical and pathological characteristics, but with its biological characteristics. BRCA1 and TS levels are correlated with invasion and metastasis. Low levels of ERCC1 and BRCA1 expression have a better prognostic effect on platinum based first-line chemotherapy for advanced colorectal cancer, and they are correlated. Low level of TS also has longer disease-free survival. Three joint detection could be used as a prognostic factor for colorectal cancer chemotherapy.
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Objective:To investigate the function of breast cancer susceptibility gene variants in predicting breast cancer risk and guid-ing clinical treatment through DNA sequencing. Methods:This study involved 146 patients, 71 high-risk cases, and 55 healthy people, totaling 272 cases. The subjects were treated in Tianjin Medical University Cancer Institute and Hospital from November 2013 to July 2015. Genomic DNA was sequenced by a second generation sequencing platform. All exon areas of six common breast cancer suscepti-bility genes (BRCA1, BRCA2, PTEN, STK11, TP53, and RAP1) were sequenced through amplicon sequencing method. Meaningful vari-ants including single nucleotide variants (SNVs), insertion-deletions (InDels) and nonsense mutations were selected and statistical methods, such as t test andχ2 test, were used to analyze the statistical differences in incidence rates among three groups. Results:A total of 177 meaningful variants were confirmed, including 50 SNVs, 8 nonsense mutations, and 9 InDels. Among the variants, 31 were recorded in the Exome Aggregation Consortium (ExAC), 40 were noted in ClinVar database, and 21 were not encoded in the present da-tabase, which were defined as new variants in this study. Conversely, 57 variants (85.1%) were found in breast cancer patients and high-risk cases, and the incidence of axillary lymph node metastasis (P=0.010) and pathological stages (P=0.002) in mutation positive patients were both higher than mutation negative patients. Moreover, the percentage of family history of cancer (P=0.005) and triple negative breast cancer (P=0.009) were both higher in patients carrying pathogenic mutations than in nonpathogenic patients. Conclu-sion:Breast cancer susceptibility gene variants may not only be a tool used to predict the risk of getting breast cancer but also a mean-ingful guideline for the clinical treatment and prognosis evaluation.
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Ovarian cancer is the leading cause of death in women suffering from cancer, with a high mortality rate in gynecological cancer. Poly(ADP-ribose)polymerase(PARP)inhibitors cause targeted tumor cell death in homologous recombination(HR)-deficient cancers, including breast cancer susceptibility gene(BRCA)tumors, and the mechanism is called “synthetic lethality”. At present, there are three PARP inhibitors approved by FDA for the treatment of advanced ovarian cancer with BRCA-mutation. This paper reviews the role of PARP inhibitors in the treatment of ovarian cancer in clinical trial, elaborates the therapeutic mechanism of PARP inhibitors, and lights the way for the development of anti-ovarian cancer drugs.
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Purpose To investigate the protein expression of breast cancer susceptibility gene (BRCA1) in triple negative breast canc-er ( TNBC) and to analyze the prognostic impact on outcome of TNBC by BRCA1 protein. Methods The expression of BRCA1 and p53 in 95 cases TNBCs was detected by immunohistochemistry. The correlation analysis and evaluation of prognosis were conducted in consideration of patients clinical and pathological characteristics. Results The positive rate of BRCA1 protein expression in TNBCs was 31. 6%. Compared with BRCA1 negative expression, those patients with BRCA1 positive expression were associated with younger age (P=0. 047) and higher expression of p53 (P=0. 001). There was no significant difference in outcome between BRCA1 positive and negative expression (HR=1. 10,95%CI=0. 552~2. 235, P=0. 769). Conclusion The expression of BRCA1 protein may have no impact on the outcome of TNBC. There is possible correlationship between p53 pathway and BRCA1 in inhibiting tumor growth.
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Objective To study the occurrence of BRCA1 MSI in endometrial cancer and its relationship with clinic pathologic features; to explore the correlation between MSI and protein expression in BRCA1 gene. Methods Application of PCR-SSCP and DNA sequence analysis method was used to study D17S579 and D17S1349 in 49 sporadic endometrial cancer tissues, 20 cases with endometrial atypical hyperplasia and 28 cases with normal endometrial tissues. Results In the total samples of D17S579 and D17S1349, the three groups were significantly different: 34.69%(17/49) in the endometrial cancer group, 10%(2/20) in the endometrial atypical hyperplasia group and 7.14%(2/28) in the normal endometrium group (χ2= 11.208, P = 0.004). BRCA1 MSI positive rate related to the pathology grade and clinical stage, but no relationship was found in muscular infiltration depth, lymph node metastasis and histopathology types. In the endometrial cancer group, BRCA1 MSI positive rate and BRCA1 protein expression were in moderate correlated negatively (r = -0.779, P = 0.000). Conclusion BRCA1 MSI might play a role in the development of endometrial cancer, and low expression of BRCA1 protein. BRCA1 MSI might be associated with pathology grade and clinical stages in EC.
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As an important surgical approach,breast cancer conservation therapy is still controversial in breast cancer patients with BRCA1/2 mutations.Since the risk of unilateral multiple and contralateral incidences is high in the familial breast cancer patients with BRCA1/2 mutations,breast cancer conservation therapy is not recommended but mastectomy and/or immediate mamoplasty.However,if carriers have a strong desire of breast cancer conservation therapy,it is feasible if they are fully informed the risks that may exist.At that time,we should need bilateral oophorectomy,tamoxifen therapy,and more interventions for the prevention of contralateral breast incidences.
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BRCA1-associated RING domain 1(BARD1) is composed with ring finger,ankyrin repeats and BRCT (BRCA1 C-terminus) domain.The special structure is involved in many essential biological processes such as DNA repair,cell survival and apoptosis,proteasome dependent protein degradation and so on.The abnormal expression of BARD1 is closely related with the occurrence and progression of carcinoma.Aberrant splice variants of BARD1 are very potential tumor markers for cancer diagnosis.
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Objective To study the relationship between the expression of breast cancer susceptibility gene (BRCA)1 and the pathological parameters in sporadic breast cancer. Method Immunohistochemistry was used to detect the expression of BRCA1 in 42 cases of breast cancer tissues and 30 cases of breast fibroadenoma tissues and analyzed the correlation of the results with other parameters which included tumor size,tumor type,histological grade and axillary lymph nodes metastases. Results The positive expression rate of BRCA1 was 52.4% (22/42) in breast cancer patients and 85.7% (36/42) in breast fibroadenoma patients. The lower positive expression rate of BRCA1 was found in axillary lymph nodes metastases (P < 0.05). The positive expression rate in stage Ⅲ of breast cancer was lower than that in stage Ⅰ (P < 0.05 ) and was also lower than that in stage Ⅱ (P < 0.05 ), but there was no significant difference between stage Ⅰ and stage Ⅱ (P > 0.05). No significant correlation was observed among expression of BRCA1 and tumor size, tumor type (P > 0.05). Conclusions BRCA1 plays an important role in pathogenesis and development of breast cancer.BRCA1 maybe a adjuvant index for treating breast cancer and estimating prognosis.
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Triple-negative breast cancer (TNBC) is a subgroup of breast cancers defined by a lack of the expressions of estrogen,progesterone and HER2 receptors,with more aggressive biological and clinicopathological characteristics and a close relationship with basal-like and breast cancer susceptibility gene-1 (BRCA1)-related breast cancers.TNBC is insensitive to most available hormonal or standard therapeutic agents,associated with increased risk for distant metastases and with poorer prognosis than other types of breast cancer.A deeper insight into the biology of TNBC may lead to improved therapies and better clinical outcomes of the disease.