Effects of 5-Aza-CdR on the Proliferation of Human Breast Cancer Cell Line MCF-7 and on the Expression of Apaf-1 Gene

Hypermethylation in the promoter region of tumor suppressor genes is a common mechanism of gene silencing, which tends to occur in cancer. The effects of 5-Aza-2＇-deoxycytidine （5-Aza-CdR）, a specific DNA methyltransferase inhibitor, on the cell proliferation of human breast cancer cell line MCF-7 and on the expression of Apaf-1 gene were investigated. Human MCF-7 cells were incubated with increasing concentrations of 5-Aza-CdR for 12 to 120 h. The growth inhibition rates of MCF-7 cells were detected by MTT assay. Changes of cell cycle distribution and apoptotic rates of MCF-7 cells were determined by flow cytometry. The expressions of DNA methyltransferase 3b mRNA and Apaf-1 mRNA were measured by reverse transcription polymerase chain reaction （RT-PCR）. Meanwhile, the expression of Apaf-1 protein was detected by Western blotting. The results showed that 5-Aza-CdR significantly inhibited the growth of MCF-7 cells and the growth inhibition rate of MCF-7 cells was significantly enhanced with the concentration of 5-Aza-CdR and the action time. Flow cytometry indicated that 5-Aza-CdR could significantly induce G1/S cell cycle arrest and increase the apoptosis rate of MCF-7 cells. The mRNA and protein expressions of Apaf-1 were up-regulated in MCF-7 cells treated with 5-Aza-CdR, which was accompanied by down-regulation of DNA methyltransferase 3b mRNA. It is concluded that 5-Aza-CdR might retard the growth of tumor ceils and promote the apoptosis of MCF-7 breast cancer cells by inhibiting the expression of DNA methyltransferase 3b and re-activating the Apaf-1 gene expression.

Targeted inhibition of Notch1 gene enhances the killing effects of Paclitaxel on triple-negative breast cancer cells

Objective:To study the influence of targeted inhibition of Notch1 gene on the killing effects of Paclitaxel on triple-negative breast cancer cells.Methods:The triple-negative [estrogen receptor(ER)/progesterone receptor(PR)/human epidermal growth factor receptor 2(Her2)] breast cancer cell line MDA-MB-231 and ER/PR/HER-2-positive breast cancer cell line MCF-7 were cultured,transfected with Notch1-si RNA-overexpression plasmid and blank plasmid,and treated with different concentrations of paclitaxel,and then the cell proliferation activity and apoptosis rate as well as the m RNA expression of Caspase-3,Caspase-9 and Bcl-2 were determined.Results:Paclitaxel could decrease the MDA-MB-231 and MCF-7 cell proliferation activity as well as Bcl-2 mRNA expression,and increase MDA-MB-231 and MCF-7 cell apoptosis rate as well as Caspase-3 and Caspase-9 mRNA expression in dosedependent manners;with the same dose of paclitaxel treatment,the inhibitory effects on MDAMB-231 cell proliferation activity and Bcl-2 m RNA expression as well as the promoting effects on MDA-MB-231 cell apoptosis and mR NA expression of Caspase-3 and Caspase-9 were weaker than those on MCF-7 cell;after 0.5 μM paclitaxel combined with Notch1-siRNA treatment,MDA-MB-231 cell proliferation activity and Bcl-2 mRNA expression were significantly lower than those after 0.5 μM paclitaxel combined with control plasmid treatment while cell apoptosis rate and mR NA expression of Caspase-3 and Caspase-9 were higher than those after 0.5 μM paclitaxel combined with control plasmid treatment.Conclusions:Targeted inhibition of Notch1 gene may enhance the killing effects of paclitaxel on triple-negative breast cancer cells by up-regulating the expression of Caspase-3 and Caspase-9 and inhibiting the expression of Bcl-2.

The cancer-testis gene,MEIOB,sensitizes triple-negative breast cancer to PARP1 inhibitors by inducing homologous recombination deficiency

Objective:The newly defined cancer-testis(CT)gene,MEIOB,was previously found to play key roles in DNA double-strand break(DSB)repair.In this study,we aimed to investigate the effects and mechanisms of MEIOB in the carcinogenesis of triple-negative breast cancers(TNBCs).Methods:The Cancer Genome Atlas database was used to quantify the expression of MEIOB.Cox regression analysis was used to evaluate the association between MEIOB expression and the prognosis of human TNBC.The effects of MEIOB on cell proliferation and migration in TNBCs were also assessed in vitro.Patient-derived xenograft(PDX)models were used to assess the sensitivity of breast cancers with active MEIOB to PARP1 inhibitors.Results:We confirmed MEIOB as a CT gene whose expression was restricted to the testes and breast tumors,especially TNBCs.Its activation was significantly associated with poor survival in breast cancer patients[overall,hazard ratio(HR)=1.90(1.16–2.06);TNBCs:HR=7.05(1.16–41.80)].In addition,we found that MEIOB was oncogenic and significantly promoted the proliferation of TNBC cells.Further analysis showed that MEIOB participated in DSB repair in TNBCs.However,in contrast to its function in meiosis,it mediated homologous recombination deficiency(HRD)through the activation of poly ADP-ribose polymerase(PARP)1 by interacting with YBX1.Furthermore,activated MEIOB was shown to confer sensitivity to PARP inhibitors,which was confirmed in PDX models.Conclusions:MEIOB played an oncogenic role in TNBC through its involvement in HRD.In addition,dysregulation of MEIOB sensitized TNBC cells to PARP inhibitors,so MEIOB may be a therapeutic target of PARP1 inhibitors in TNBC.

Low Trichorhinophalangeal Syndrome 1 Gene Transcript Levels in Basal-like Breast Cancer Associate with Mesenchymal-to-epithelial Transition

Objective To investigate trichorhinophalangeal syndrome 1 gene （TRPS-1） expression patterns in different subtypes of breast cancer and its correlations with other genes and survival using microarray data sets. Methods The transcripts of TRPS-1 and its role in survival in breast cancer were analyzed using published microarray data sets-Netherlands Cancer Institute （NKI） cohort and Wang cohort.

Detection of Breast Cancer 1 (BRCA1) Gene Using an Electrochemical DNA Biosensor Based on Immobilized ZnO Nanowires

Herein we report an electrochemical DNA biosensor for the rapid detection of sequence (5’ AAT GGA TTT ATC TGC TCT TCG 3’) specific for the breast cancer 1 (BRCA1) gene. The proposed electrochemical genosensor is based on short oligonucleotide DNA probe immobilized onto zinc oxide nanowires (ZnONWs) chemically synthesized onto gold electrode via hydrothermal technique. The morphology studies of the ZnONWs, performed by field emission scanning electron microscopy (FESEM), showed that the ZnO nanowires are uniform, highly dense and oriented perpendicularly to the substrate. Recognition event between the DNA probe and the target was investigated by differential pulse voltammetry (DPV) in 0.1 M acetate buffer solution (ABS), pH 7.00;as a result of the hybridization, an oxidation signal was observed at +0.8 V. The influences of pH, target concentration, and non-complimentary DNA on biosensor performance were examined. The proposed DNA biosensor has the ability to detect the target sequence in the range of concentration between 10.0 and 100.0 μM with a detection limit of 3.32 μM. The experimental results demonstrated that the prepared ZnONWs/Au electrodes are suitable platform for the immobilization of DNA.

Polymorphisms at <i>GSTM </i>1, <i>GSTP </i>1, <i>GSTT </i>1 Detoxification Genes Loci and Risk of Breast Cancer in Kazakhstan Population

Associations of null polymorphism (copy number variation) of detoxification genes GSTM1, GSTT1 and GSTP1 (at rs2495636, 105 Ile/Val) with the breast cancer (BC) were assessed in two main ethnic groups of the Republic of Kazakhstan (Kazakhs and Russians). Total number of patients was 181, and of controls 397. Statistically significant difference was observed between BC patients and healthy individuals in alleles frequency (χ2 = 4.89, р = 0.007) of GSTP1 gene at rs2495636 (105 Ile/Val) among the Kazakhs ethnic group. Difference in genotypes distribution (χ2 =5.26, р = 0.076) at this site is approximating to be statistically significant. In the Russian group, no differences were found in genotypes and alleles atrs 2495636 of GSTP1 gene between cases and controls. There was no significant difference between null polymorphism (copy number variation) of GSTM1 and GSTT1 genes among cases and controls in both ethnic groups.

Clinical significance of breast cancer susceptibility gene 1 expression in resected non-small cell lung cancer:A meta-analysis

BACKGROUND The clinical significance of breast cancer susceptibility gene 1(BRCA1)in nonsmall cell lung cancer(NSCLC)patients undergoing surgery remains unclear up to now.AIM To explore the relation of BRCA1 expression with clinicopathological characteristics and survival in patients with resected NSCLC.METHODS EMBASE,PubMed,Web of Science,and The Cochrane Library databases were searched to identify the relevant articles.To assess the correlation between the expression of BRCA1 and clinicopathological characteristics and prognosis of patients with resected NSCLC patients,the combined relative risks or hazard ratios(HRs)with their corresponding 95%confidence intervals[CIs]were estimated.RESULTS Totally,11 articles involving 1041 patients were included in the meta-analysis.The results indicated that the expression of BRCA1 was significantly correlated with prognosis of resected NSCLC.Positive BRCA1 expression signified a shorter overall survival(HR=1.60,95%CI:1.25-2.05;P<0.001)and disease-free survival(HR=1.78,95%CI:1.42-2.23;P<0.001).However,no significant association of BRCA1 expression with any clinicopathological parameters was observed.CONCLUSION BRCA1 expression indicates a poor prognosis in resected NSCLC patients.BRCA1 might serve as an independent biomarker to predict clinical outcomes and help to customize optimal adjuvant chemotherapy for NSCLC patients who had received surgical therapy.

Associations of Polymorphisms of the <i>CYP</i>1<i>A</i>1 and <i>CYP</i>1<i>B</i>1 Cytochrome P450 Genes with Breast Cancer in Kazakhstan

Associations of polymorphisms in rs4646903 site of CYP1A1 and rs1056836 site of CYP1B1 genes with the breast cancer (BC) were studied in two main ethnic groups of Kazakhstan Republic (Kazakhs and Russians). Total number of BC patients was 181, controls—397. The statistically significant differences were revealed in allele frequencies (χ2 = 5.93, р = 0.004) and in genotypes distribution (χ2 = 8.71, р = 0.015) in rs4646903 site of CYP1A1 gene in Kazakh but not in Russian group. The study of CYP1В1 rs1056836 site demonstrated differences in genotype distributions (χ2 = 7.48, р = 0.023) between BC patients and controls in Russian but not in Kazakh ethnic group.

Association among Serum Organochlorine Pesticide Residues, Glutathione S-Transferase M1 Genetic Polymorphism and Female Breast Cancer

Background: The purpose of this study was to evaluate the association among serum organochlorine pesticide residues, glutathione S-transferase M1 genetic polymorphism and female breast cancer. Methods: A 1:1 matched case-control study of 140 newly diagnosed breast cancer patients and 140 non-cancer female patients who consulted the five largest hospitals in the Tangshan city from September 2006 to October 2007. Results: The result showed higher risk of breast cancer among subjects with higher levels of serum DDT and HCH residue, the OR was 3.18 (95%CI, 1.11 - 9.07) and 5.02 (95%CI, 1.64 - 16.56).The value of ORe associated with single environmental factor DDT high residues, and ORg associated with single GSTM1 deletion genotype were respectively 3.86 (1.20 - 12.47) and 1.34 (0.36 - 5.08). The OReg associated with combined action of two factors was 5.59 (1.63 - 18.90), and the value of interaction parameters (γ) equaled 1.24. The value of ORe associated with single environmental factor HCH higher residue and ORg associated with single GSTM1 deletion genotype were respectively 2.73 (0.84 - 8.87) and 1.48 (0.49 - 4.60). The value of OReg associated with combined action of two factors was 3.87 (1.18 - 12.68), and γ equaled 1.38. Conclusion: The results indicated that breast cancer occurrence was the combined result of environmental and genetic factors. The concurrent action of GSTM1 deletion genotype and DDT/HCH enhanced the risk of breast cancer.

The Role of HER2/Neu and BRCA1 Genes in the Diagnosis of Breast Cancer among Sudanese Women

Background: Knowledge of HER2/Neu and BRCA1 Genes might be helpful for development of strategies for decreasing the burden of risk of breast cancer. Therefore, the aim of this study to detect the role of HER2/Neu and BRCA1 Genes expression in diagnosis of breast cancer in Sudanese women. Methodology: A total of 100 tissue samples obtained from patients with breast cancer in addition to 50 tissue samples obtained from patients with benign breast lesions, were detected the expression of HER2/Neu and BRCA1 Genes by Polymerase Chain Reaction (PCR). Results: The prevalence of HER2/Neu and BRCA1 Genes, among cases was 6%, and 10% respectively. Conclusion: HER2/Neu and BRCA1 Genes have a considerable contribution to etiology of breast cancer in Sudan that requires further consideration.

Correlation of Kif2a and HPK1 expression in breast cancer with the oncogene and drug resistance gene expression

Objective: To investigate the correlation of Kif2a and HPK1 expression in breast cancer with the oncogene and drug resistance gene expression. Methods: A total of 91 patients with breast cancer and 85 patients with breast adenoma who accepted surgical treatment in our hospital between August 2016 and February 2018 were selected, and the breast cancer tissues and breast adenoma tissues were collected respectively as the research samples. Fluorescence quantitative PCR method was used to detect the expression of Kif2a and HPK1 genes as well as oncogenes and drug resistance genes in sample tissues, and Pearson test was used to evaluate the inner link of Kif2a and HPK1 gene expression in breast cancer tissue with oncogene and drug resistance gene expression. Results: Kif2a mRNA expression in breast cancer tissues was higher than that in breast adenoma tissues whereas HPK1 mRNA expression was lower than that in breast adenoma tissues;oncogenes DEK, iASPP-SV, Stat3, MDM2 and Fra-1 mRNA expression were higher than those in breast adenoma tissues;drug resistance genes ESR1, MDR1, P-gp, MRP1 and GST- mRNA expression were higher than those in breast adenoma tissues whereas BCRP mRNA expression was lower than that in breast adenoma tissues. Correlation analysis showed that the Kif2a and HPK1 gene expression in breast cancer tissues were directly correlated with the expression of oncogenes and drug resistance genes. Conclusion: Kif2a gene is abnormally highly expressed whereas HPK1 gene is abnormally lowly expressed in breast cancer tissues, and they are involved in the regulation of oncogene and drug resistance gene expression.

BCSG1基因在乳腺癌新辅助化疗疗效评估中的价值

目的探讨乳腺癌特异基因(BCSG1)在乳腺癌新辅助化疗疗效评估中的价值。方法采用免疫组化S-P法和荧光定量PCR方法检测36例乳腺癌患者新辅助化疗(CEF方案)前后乳腺癌组织BCSG1的表达,比较化疗前后肿瘤体积的变化情况,分析新辅助化疗前后BCSG1蛋白表达与肿瘤形态学变化的关系。结果36例乳腺癌患者新辅助化疗后肿瘤体积均有明显缩小(P<0.01),病灶缓解率(CR+PR)为85.6%;新辅助化疗后BCSG1 mRNA表达水平亦明显低于化疗前(P<0.05),BCSG1蛋白高表达率低于新辅助化疗前(P<0.01)。结论乳腺癌新辅助化疗后BCSG1在分子和蛋白水平表达均明显降低,与新辅助化疗后疗效呈负相关(r=-0.539,P<0.01),提示BCSG1可作为乳腺癌新辅助化疗疗效的预测因子。

乳癌组织中BCSG1、MMP-2及ETS-1蛋白的表达

目的:检测乳癌组织中BCSG1、MMP-2及ETS-1蛋白的表达。方法:收集人乳腺浸润性导管癌标本40例、癌周不典型增生组织40例及癌周正常乳腺组织40例,采用Westernblot法检测3种组织中BCSG1、MMP-2及ETS-1蛋白的表达情况。结果:3种组织中BCSG1、MMP-2及ETS-1蛋白的表达差异有统计学意义(FBCSG1=105.032,FETS-1=81.343,FMMP-2=112.570,P均<0.001),且乳癌组织中以上3种蛋白的表达均高于癌周不典型增生组织及癌周正常乳腺组织(P<0.05)。有淋巴结转移的乳癌组织中3者的表达均高于无淋巴结转移的乳癌组织(P<0.05)。乳癌组织中BCSG1的表达与ETS-1及MMP-2的表达呈正相关(r=0.664、0.810,P<0.05)。结论:BCSG1、MMP-2及ETS-1与乳癌的浸润转移密切相关。

三阴性乳腺癌组织中EGR1、AR、H3K4me3表达与其临床病理特征及预后的相关性

目的探讨三阴性乳腺癌组织中早期生长反应基因1(EGR1)、雄激素受体(AR)、组蛋白H3第4位赖氨酸三甲基化(H3K4me3)表达与其临床病理特征及预后的相关性。方法回顾性分析89例三阴性乳腺癌患者的临床资料,所有患者均行手术治疗,采用免疫组化染色法测定EGR1、AR、H3K4me3表达,比较肿瘤组织及癌旁正常组织内EGR1、AR、H3K4me3表达差异,分析EGR1、AR、H3K4me3表达与其临床病理的关系,分析EGR1、AR、H3K4me3表达与其预后的关系。结果肿瘤组织内EGR1阳性表达率、AR阳性表达率低于对照组,H3K4me3阳性表达率高于对照组,差异有统计学意义(P<0.05);EGR1阳性表达、AR阳性表达患者临床分期Ⅰ~Ⅱ期、无淋巴结转移、中高分化占比高于EGR1阴性表达、AR阴性表达患者,H3K4me3阳性表达患者临床分期Ⅲ期、淋巴结转移、低分化占比高于H3K4me3阴性表达患者,差异有统计学意义(P<0.05);随访1年,89例患者共36例出现复发转移,发生率为40.45%(36/89);复发转移组EGR1阳性表达、AR阳性表达率低于未复发转移组,H3K4me3阳性表达率高于未复发转移组,差异有统计学意义(P<0.05)。结论EGR1、AR在三阴性乳腺癌中多呈阴性表达,H3K4me3则以阳性表达为主,三者表达均与临床分期、淋巴结转移及分化程度存在密切关系,或可作为临床治疗的新靶点。

BCSG1基因RNAi表达载体的构建与鉴定

目的:构建乳腺癌特异性基因(BCSG1)RNAi重组质粒,并检测其在三阴乳腺癌细胞株MDA-MB-321中对BCSG1基因表达的干扰效果和对细胞增殖的影响。方法:将两组干扰片段BCSG1-R1、BCSG1-R2及阴性对照片段BCSG1-C分别克隆入pGenesil-1穿梭质粒,经酶切鉴定及测序后,将测序正确的克隆转染入大肠杆菌DH5α中进行扩增Real-time PCR检测重组质粒转染MDA-MB-321细胞后,各组细胞内BCSG1-mRNA表达水平,Transwell细胞侵袭实验检测重组质粒对MDA-MB-321细胞侵袭能力的影响。结果:成功将干扰片段和阴性对照片段克隆入pGenesil-1质粒,构建出pGenesil-1-BCSG1-R1、pGenesil-1-BCSG1-R2和pGenesil-1-BCSG1-C重组质粒。与对照组相比,BCSG1-R1和BCSG1-R2组的BCSG1-mRNA表达水平明显下调(P<0.05);干扰后,MDA-MB-321细胞侵袭能力明显下降(P<0.05)。结论:成功构建BCSG1-RNAi重组质粒,可有效下调三阴乳腺癌细胞株MDA-MB-321内BCSG1的表达及细胞的侵袭能力。

乳腺癌组织BCSG1基因表达及临床意义

目的研究不同期乳腺癌组织乳腺癌特异基因1（BCSG1）的表达及其与临床分期、淋巴结转移、疗效及预后的相关性,以指导临床治疗。方法随机选取重庆医科大学附属第一医院肿瘤科2006年收治的有完整临床及病理资料的50例乳腺癌患者,采用免疫组织化学SP法检测乳腺癌组织BCSG1表达情况。结果Ⅰ~Ⅱ期乳腺癌组织BCSG1表达阳性率[38.7%（12/31）]低于Ⅲ~Ⅳ期[78.9%（15/19）],BCSG1高表达患者治疗有效率[44.4%（12/27）]低于低表达者[73.9%（17/23）],BCSG1高表达患者中治疗后出现复发、转移15例[55.6%（15/27）],低表达患者中治疗后出现复发、转移6例[26.1%（6/23）],差异均有统计学意义（P〈0.05）。结论 BCSG1在乳腺癌中的表达与临床分期及疗效有关,可作为乳腺癌治疗的新靶点。

BRCA1、BRCA2在上皮性卵巢癌中的表达及与预后的关系

目的 探讨乳腺癌易感基因1(BRCA1)、乳腺癌易感基因2(BRCA2)在上皮性卵巢癌(EOC)中的表达水平,并分析其与预后的关系。方法 选取2019年1月—2023年6月南通市肿瘤医院收治的98例EOC患者,采集术中切除的新鲜癌组织和癌旁组织,采用实时定量聚合酶链反应(qRT-PCR)检测组织中BRCA1、BRCA2 mRNA表达情况,分析其与临床病理特征的关系,并以Kaplan-Meier生存曲线和Cox回归模型分析其对EOC患者总生存期(OS)和无进展生存期(PFS)的影响。结果 EOC组织BRCA1、BRCA2 mRNA表达量、蛋白相对表达量均低于癌旁组织(P<0.05)。腹腔积液量≥500 mL、国际妇产科学联合会(FIGO)分期Ⅲ—Ⅳ期、有淋巴结转移患者的BRCA1、BRCA2 mRNA表达低于无腹腔积液和腹腔积液量<500 mL、FIGO分期Ⅰ—Ⅱ期及无淋巴结转移患者(P<0.05)。中位随访时间27(9~50)个月,随访率95.92%(4例失访),随访期间39例(39.80%)复发,26例(26.53%)死亡。Kaplan-Meier生存分析显示,BRCA1、BRCA2 mRNA高表达者累积生存率高于低表达者(P<0.05)。BRCA1、BRCA2 mRNA高表达者累积无进展生存率高于低表达者(P<0.05)。多因素Cox回归分析显示化疗≤6疗程、腹腔积液量≥500 mL、FIGO分期Ⅲ+Ⅳ期及BRCA1、BRCA2 mRNA低表达是影响EOC患者OS的独立危险因素(P<0.05)。术后残灶>2 cm、化疗≤6疗程、腹腔积液量≥500 mL及BRCA1、BRCA2 mRNA低表达是影响EOC患者PFS的独立危险因素(P<0.05)。结论 EOC癌变组织中BRCA1、BRCA2异常低表达,BRCA1、BRCA2 mRNA低表达与患者的临床病理特征关系密切,且影响患者PFS及OS。

食管鳞癌组织中BARD1的表达及与淋巴结转移的关系

目的分析食管鳞癌(ESCC)中乳腺癌易感基因1相关环指结构域蛋白1(BARD1)的表达及与淋巴结转移的关系。方法纳入2018年1月至2021年12月本院收治且经组织病理学检查确诊的114例ESCC患者,免疫组化EnVision两步法检测癌组织与癌旁组织中BARD1的表达情况并比较BARD1阳性率,分析BARD1表达与ESCC临床病理特征的关系,建立Logistic回归模型分析BARD1表达对ESCC淋巴结转移的影响,绘制受试者工作特征(ROC)曲线分析BARD1表达对ES⁃CC淋巴结转移的预测价值。结果114例ESCC组织中BARD1阳性78例、阴性36例,对应癌旁组织中BARD1阳性23例、阴性91例,ESCC组织的BARD1阳性率为68.42%,高于癌旁组织的20.18%(χ^(2)=53.769,P<0.001)。BARD1表达与ESCC患者的T分期、分化程度和淋巴结转移有关(P<0.05),其中淋巴结转移组织的BARD1阳性率为80.36%(45/56),高于未转移组织的56.90%(33/58)。经Phi系数分析发现,BARD1表达与ESCC淋巴结转移呈正相关(r=0.276,P=0.003)。BARD1阳性是ESCC患者淋巴结转移的独立危险因素(OR=3.099,95%CI:1.339~7.175,P=0.008),且BARD1表达对ESCC患者淋巴结转移具有一定预测价值(AUC=0.636,P=0.020)。结论BARD1在ESCC中高表达,其与ESCC淋巴结转移密切相关,BARD1阳性会增加淋巴结转移风险,在评估ESCC淋巴结转移上有一定价值。

Relationship between CYP1A1 polymorphisms and invasion and metastasis of breast cancer

Objective:To investigate the relationship between CYPIA1 genetic polymorphisms and the invasion and metastasis of breast cancer.Methods:The CYP1A1 gene polymorphism(an T-C transversion at nucleotide position 3801)was detected by the polymerase chain reaction and restriction fragment length polymorphism in 80 cases with breast cancer and 60 samples of normal breast tissue.The difference in genotypic distribution frequency between the groups,the correlation between the genotypes and the factors related to prognosis were analyzed.Results:The incidence of homozygous and variant genotypes had no difference between the breast cancer group and controls group(P=0.746).The proportion of variant genotype increased as clinical stage(P=0.006)advanced,as well as with increased numbers of lymph node metastases(P=0.010).Conclusions:In patients with breast cancer there is a correlation between the CYP1A1 CC allele and some factors indicating poor prognosis,including more lymph node metastases as well as a more advanced clinical stage.

Research progress on the relationship between BRCA1 and hereditary breast cancer

Breast cancer gene 1(BRCA1) gene was the first breast cancel susceptibility gene discovered in familial breast cancer.It has been revealed that BRCA1 can be combined with an array of important protein involved in cell cycle regulation,DNA repair,gene transcription control and apoptosis regulation.It plays a down-regulation effect on tumor growth and an important role in maintaining genomic stability.New research suggests that it also associate with the breast cancer stem cells and microRNA.Its mutations,promoter methylation and ectopic expression may one of the main reasons for the generation and development of hereditary breast cancer.