OBJECTIVETo investigate the role of the tumor suppressor gene BRCA1 in response to DNA damage and to confirm that the function of the BRCA1 protein is regulated by a variety of mechanisms including transcriptional control, phosphorylation and protein-protein interaction.

METHODSWith the human breast cell line MCF7 as the positive control, we determined the subcellular distribution of BRCA1 in the prostate cancer cell lines LNCaP, DU145 and PC3 by immunohistochemical staining and Western blotting analyses.

RESULTSBRCA1 was present in the prostate cancer cell lines LNCaP, DU145 and PC3. Ionizing radiation induced BRCA1 nuclear export, increasing from 14% to 40% in the cytoplasma (P < 0.01) and decreasing from 46% to 21% in the nuclei (P < 0.01). This DNA damage-induced BRCA1 nuclear export occurred only in the p53 wild-type but not in the p53 mutant cell line. The apoptosis rate of LNCaP cells was as high as 40% after nuclear export, with an obvious increase of cleaved caspase-3, which was correlated with BRCA1 nuclear-cytoplasmic shuttling.

CONCLUSIONCytoplasmic relocalization of the BRCA1 protein may be a mechanism whereby the BRCA1 function is regulated in response to DNA damage. Its induction of a higher rate of cell apoptosis indicates BRCA1 to be another good biomarker for the treatment of prostate cancer.

BRCA1 Protein ; metabolism ; Blotting, Western ; Cell Line, Tumor ; DNA Damage ; Humans ; Immunohistochemistry ; Male ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo detect the mutations of BRCA1 and BRCA2 in sporadic breast cancer and study the relationship between BRCA1 and BRCA2 mutations and breast cancer.

METHODSBreast cancer tissues of 144 patients and breast tissues of 30 cases of healthy people who were treated from December 2000 to September 2005 were studied. DNA was extracted by the phenol-chloroform method. Fragments of exon 2, exon 3, exon 5, exon 6, exon 7, exon 8, exon 9, exon 10, exon 11, exon 12, exon 13, exon 14, exon 15, exon 16, exon 17, exon 18, exon 19, exon 20, exon 21, exon 22, exon 23 and exon 24 in the BRCA1 gene and exon 10 and exon 14 in the BRCA2 gene were amplified by polymerase chain reaction. Mutation screening was performed by single-strand conformation polymorphism analysis and alterations were confirmed by DNA sequencing.

RESULTSA total of 20 single nucleotide changes in BRCA1 were detected in the 144 cases of breast cancer patients. The total mutation rate was 13.9% and missense mutation rate was 11.1%. No mutation was detected in the BRCA2 and controls.

CONCLUSIONSMutations in BRCA1 may play an important role in evaluation of sick risk, earlier diagnosis and gene therapy of breast cancer in southern Chinese populations.

Adult ; Aged ; Apoptosis Regulatory Proteins ; BRCA1 Protein ; genetics ; metabolism ; BRCA2 Protein ; genetics ; metabolism ; Base Sequence ; Blotting, Western ; Breast Neoplasms ; genetics ; metabolism ; pathology ; DNA Mutational Analysis ; Female ; Humans ; Middle Aged ; Mutation ; Polymerase Chain Reaction ; Polymorphism, Single-Stranded Conformational

OBJECTIVETo explore the clinicopathologic characteristics and biological markers of breast carcinomas in young women.

METHODSImmunohistochemical SP method was used to study breast cancer susceptibility gene (BRCA1) and WWOX in breast carcinomas of patient ≤ 35 years of age (107 cases) and ≥ 60 years of age (112 cases). The findings were correlated with clinicopathological features. In addition, PCR amplification and direct sequencing were performed to detect the BRCA1 gene mutation of exons 2 and 20 using fresh frozen tissue samples in other 10 patients who were ≤ 35 years of age.

RESULTSThe positive rate of BRCA1 protein expression was higher in the young age group [65.4% (70/107)] than that of the old age group [35.7% (40/112)]. ER, PR, HER2, and WWOX protein expression and proliferation marker Ki-67 were no statistically different in the two groups (all P > 0.05). BRCA1 expression was significantly correlated with pTNM and axillary lymph node metastasis (both P < 0.05), but not with ER, PR, HER2 and WWOX protein expression (all P > 0.05). Ki-67 and histological grading showed no statistical correlation (P > 0.05). WWOX protein expression showed no correlation with clinicopathologic characteristics (all P > 0.05). Mutation of exons 2 and 20 of the BRCA1 gene was not detected in any of 10 cases studied.

CONCLUSIONBRCA1 cytoplasmic expression statistically correlates with the development and prognosis of breast cancer of young patients.

Adult ; Age Factors ; Aged ; Aged, 80 and over ; BRCA1 Protein ; genetics ; metabolism ; Breast Neoplasms ; metabolism ; pathology ; surgery ; Carcinoma, Ductal, Breast ; metabolism ; pathology ; surgery ; Exons ; Female ; Genes, BRCA1 ; Humans ; Ki-67 Antigen ; metabolism ; Lymphatic Metastasis ; Middle Aged ; Mutation ; Neoplasm Staging ; Oxidoreductases ; metabolism ; Receptor, ErbB-2 ; metabolism ; Receptors, Estrogen ; metabolism ; Receptors, Progesterone ; metabolism ; Tumor Suppressor Proteins ; metabolism ; WW Domain-Containing Oxidoreductase ; Young Adult

Age of Onset ; Cystadenocarcinoma, Serous ; genetics ; metabolism ; pathology ; Female ; Genes, BRCA1 ; Genes, BRCA2 ; Humans ; Immunohistochemistry ; Neoplasm Staging ; Ovarian Neoplasms ; genetics ; metabolism ; pathology ; Receptors, Progesterone ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo explore the mRNA expression of breast cancer susceptibility gene 1 (BRCA1) in tumor cells isolated from malignant pleural and peritoneal effusions, and the predictive role of BRCA1 related to the efficacy of cisplatin-based chemotherapy.

METHODSTumor cells were isolated from malignant pleural and peritoneal effusions of 31 cancer patients. The response of these tumor cells to cisplatin was determined by CCK8 assay. Real time quantitative RT-PCR was used to examine the BRCA1 mRNA level in the primary culture cancer cells.

RESULTSThe expression level of BRCA1 mRNA was 0.618 (0.014 - 18.063) in primary culture tumor cells. The IC(50) of DDP was 2.809 µg/ml in the primary culture tumor cells (0.118 - 19.439 µg/ml). Both BRCA1 mRNA expression and the tumor cells IC(50) of DDP were not significantly related with patient age, gender, the type of primary tumor, whether to accept the chemotherapy and effusion type (P > 0.05). The level of BRCA1 mRNA was negatively correlated with the chemosensitivity in terms of IC(50) of cisplatin (P < 0.001).

CONCLUSIONAssessment of expression level of BRCA1 mRNA may be useful in predicting the efficacy of cisplatin-based chemotherapy in patients with metastatic malignant effusions.

Antineoplastic Agents ; pharmacology ; Ascitic Fluid ; metabolism ; pathology ; BRCA1 Protein ; genetics ; metabolism ; Cisplatin ; pharmacology ; Drug Resistance, Neoplasm ; Female ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Male ; Middle Aged ; Pleural Effusion, Malignant ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Stomach Neoplasms ; metabolism ; pathology

Breast cancer is one of the leading causes of death in women today. Some of the patients are hereditary, with a large proportion characterized by mutation in BRCA1 and/or BRCA2 genes. In this review, we provide an overview of these two genes, focusing on their relationship with hereditary breast cancers. BRCA1/2 associated hereditary breast cancers have unique features that differ from the general breast cancers, including alterations in cellular molecules, pathological bases, biological behavior, and a different prevention strategy. But the outcome of BRCA1/2 associated hereditary breast cancers still remains controversial; further studies are needed to elucidate the nature of BRCA1/2 associated hereditary breast cancers.
Apoptosis Regulatory Proteins ; BRCA1 Protein ; genetics ; physiology ; BRCA2 Protein ; genetics ; physiology ; Breast Neoplasms ; genetics ; metabolism ; Disease Progression ; Female ; Gene Expression Regulation, Neoplastic ; Genetic Diseases, Inborn ; Genetic Predisposition to Disease ; Humans ; Mutation ; Prognosis

OBJECTIVETo study the regulatory role of BRCA1 in the expression of progesterone receptors A and B (PRA and PRB) in breast cancer cells.

METHODSBreast cancer MCF-7 cells were transfected with pFlag-CMV2-BRCA1 wt plasmid containing a full-length BRCA1 cDNA or with BRCA1-specific siRNA via lipofectamine 2000 to induce overexpression or suppressed expression of BRCA1, respectively. Twenty-four hours after the transfection, the cells were incubated in fresh culture medium containing 100 nmol/L progesterone for 24 h. The total RNA extract or whole cell lysate was prepared for detecting BRCA1, PRA and PRB expressions using RT-PCR and Western blotting.

RESULTSThe protein expressions of PRA and PRB were significantly decreased whereas their mRNA expressions remained unchanged in MCF-7 cells overexpressing BRCA1. In MCF-7 cells with BRCA1 knock-down, in contrast, the PRA and PRB protein expressions were markedly increased.

CONCLUSIONIn breast cancer cells, exogenous and endogenous BRCA1 can both down-regulate the expressions of PRA and PRB at the protein level.

BRCA1 Protein ; biosynthesis ; genetics ; Blotting, Western ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; RNA, Messenger ; biosynthesis ; genetics ; RNA, Small Interfering ; genetics ; Receptors, Progesterone ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection

We studied the expression of BRCA1, ERCC1, and RRM1 which play an important role in DNA repair systems in breast cancer. Immunohistochemical staining for EGFR, BRCA1, ERCC1, and RRM1 were performed by using a tissue microarray made from 230 breast cancer patients. Patients were classified into luminal A, luminal B, HER-2, and triple negative breast cancer (TNBC) types according to ER, PR, and HER-2 expression. The expression of ERCC1, RRM1, and BRCA1 were correlated (P < 0.05). The expression level of ERCC1 was the lowest in TNBC type (P = 0.031), ERCC1 negativity was more prominent in TNBC and luminal B groups than luminal A and HER-2 groups (P = 0.013). Cases with EGFR overexpression showed high expression of RRM1 and BRCA1 (P = 0.046, and 0.004, respectively). In conclusion, the expression of ERCC1 is particularly lower in TNBCs than other types of breast cancers.
Adult ; BRCA1 Protein/*genetics/metabolism ; Breast Neoplasms/*genetics/metabolism/pathology ; DNA Repair ; DNA-Binding Proteins/*genetics/metabolism ; Disease-Free Survival ; Endonucleases/*genetics/metabolism ; Female ; Gene Expression ; Humans ; Immunohistochemistry ; Middle Aged ; Phenotype ; Prognosis ; Protein Array Analysis ; Receptor, Epidermal Growth Factor/genetics/metabolism ; Tumor Markers, Biological/*genetics/metabolism ; Tumor Suppressor Proteins/*genetics/metabolism

Alterations of genes are known to be critical for the induction of tumorigenesis, but the mechanism of ovarian carcinogenesis is little understood and remains to be elucidated. In this study, we investigated the roles of brca1, brca2 and p53 genes in the development of ovarian cancer using conditional knockout mice generated by a Cre-loxP recombinant system. Following the application of recombinant adenovirus expressing Cre in vitro, the proliferation of ovarian surface epithelium (OSE) was increased. For instance, a significant increase in cell growth was observed in OSE cells in vitro by conditional knockout isolated from the mice bearing concurrent floxed copies of brca1 and brca2/p53. However, the proliferative effect of the ovarian cells was not observed in concurrent brca1/brca2 or p53 knockout mice in vivo, indicating that we could not observe the direct evidence of the involvement of brca1, brca2, and p53 in ovarian carcinogenesis. Since morphological changes including tumor formation were not observed in mice bearing floxed copies of concurrent brca1/brca2 or p53, the inactivation of brca1/2 or p53 is not sufficient for the induction of tumor formation. Taken together, these results suggest that the deficiency of these genes may not be involved directly in the mechanism of ovarian carcinogenesis.
Animals ; BRCA1 Protein/*genetics/metabolism ; BRCA2 Protein/*genetics/metabolism ; Cell Proliferation ; Cell Transformation, Neoplastic/*genetics ; Epithelium/*pathology ; Extracellular Matrix Proteins/genetics ; Female ; Gene Silencing ; Mice ; Mice, Knockout ; Ovarian Neoplasms/*genetics ; Protein-Lysine 6-Oxidase/genetics ; Tumor Cells, Cultured ; Tumor Suppressor Protein p53/*genetics/metabolism

OBJECTIVETo evaluate the expression of BRCA1, ERCC1, TUBB3 and PRR13 mRNA and their relationship with clinical chemosensitivity in primary ovarian cancer, and to assess the predictive value of joint detection of both BRCA1 and ERCC1 genes for the treatment of primary ovarian cancer.

METHODSPrimary epithelial ovarian tumor samples were collected from 46 patients who underwent cytoreductive surgery. Real-time quantitative PCR was used to analyze the relative expression of BRCA1, ERCC1, TUBB3 and PRR13 mRNA in those cases. The correlation of clinical chemosensitivity and the test results was statistically analyzed. The efficacy of the joint prediction of clinical chemosensitivity by combining the two drug resistance gene detection was evaluated.

RESULTSThe BRCA1 mRNA relative expression logarithm in the clinical-resistant group was 0.673±2.143, and clinical-sensitive group -1.436±2.594 (P=0.008). The ERCC1 mRNA relative expression logarithm in the clinical-resistant group was -0.529±1.982 and clinical-sensitive group -3.188±2.601 (P=0.001). BRCA1 and ERCC1 expression level is negatively correlated with platinum-based chemosensitivity. The PRR13 expressions in the two groups were not significantly different (P=0.074), and the TUBB3 expressions between the two groups were also not significantly different (P=0.619). When the intercept point value BRCA1 mRNA expression logarithm was -0.6, the predictive sensitivity, specificity, positive predictive value and negative predictive value were 73.3%, 75.0%, 84.6% and 60.0%, respectively, with the best comprehensive assessment. When the intercept point value of ERCC1 mRNA expression logarithm was -1, the predictive sensitivity, specificity, positive predictive value and negative predictive value were 80.0%, 68.8%, 82.8% and 64.7%, respectively, with the best comprehensive assessment. The combination detection of BRCA1 and ERCC1 can improve the chemotherapeutic sensitivity, specificity, positive predictive value and negative predictive value to 86.7%, 68.8%, 83.9% and 73.3%, respectively.

CONCLUSIONSBRCA1 and ERCC1 mRNA expression has a negative correlation with the clinical sensitivity of platinum-based chemotherapy. Combination detection of the two drug-resistance associated genes can improve the predictive efficacy of ovarian cancer chemosensitivity and beneficial to individual treatment of ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; BRCA1 Protein ; genetics ; metabolism ; CA-125 Antigen ; blood ; Carboplatin ; administration & dosage ; DNA-Binding Proteins ; genetics ; metabolism ; Drug Resistance, Neoplasm ; Endonucleases ; genetics ; metabolism ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasms, Glandular and Epithelial ; drug therapy ; metabolism ; surgery ; Ovarian Neoplasms ; drug therapy ; metabolism ; surgery ; Paclitaxel ; administration & dosage ; RNA, Messenger ; metabolism ; Repressor Proteins ; genetics ; metabolism ; Tubulin ; genetics ; metabolism