论文部分内容阅读
目的建立bcl-2基因甲基化特异的PCR(MSP)检测方法,检测乳腺癌发展过程中的bcl-2甲基化,并探讨bcl-2甲基化与蛋白表达的关系。方法设计bcl-2基因MSP引物,采用MSP方法检测30例正常、25例不典型增生(癌前病变)、40例腋窝淋巴结阴性(癌症初期)和45例腋窝淋巴结阳性(癌症后期)乳腺组织的bcl-2基因5′端启动子CpG岛甲基化状态。另外采用免疫组织化学S-P法检测bcl-2的蛋白表达。结果正常、不典型增生、淋巴结阴性和淋巴结阳性乳腺组织的bcl-2甲基化率分别为10.0%、32.0%、40.0%和53.3%。乳腺癌发展过程中的bcl-2甲基化率渐增(P<0.01),bcl-2蛋白表达率渐减(P<0.01)。不典型增生较正常乳腺组织的bcl-2甲基化水平显著提高(P<0.05)。在乳腺癌发展过程中的4个阶段,bcl-2甲基化与蛋白表达两者之间均呈显著负相关性(P<0.01)。结论该研究建立了bcl-2基因MSP检测方法,bcl-2基因MSP引物的设计是合理的。bcl-2启动子甲基化可能成为乳腺癌前病变的分子指标之一。在乳腺癌发展过程中,bcl-25′端调控区CpG岛甲基化可能是下调bcl-2表达的因素。
Objective To establish a methylation-specific PCR (MSP) assay for bcl-2 gene and to detect bcl-2 methylation in breast cancer and to explore the relationship between bcl-2 methylation and protein expression. Methods The MSP primers of bcl-2 gene were designed and used to detect 30 cases of normal, 25 cases of atypical hyperplasia (precancerous lesions), 40 cases of axillary lymph node negative (early stage of cancer) and 45 cases of axillary lymph node positive (later stage of cancer) CpG island methylation status of 5 ’end promoter of bcl-2 gene. In addition, immunohistochemical S-P method was used to detect the protein expression of bcl-2. Results The rates of bcl-2 methylation were 10.0%, 32.0%, 40.0% and 53.3% in normal, atypical hyperplasia, lymph node-negative and lymph node-positive breast tissues respectively. The rate of bcl-2 methylation was increased (P <0.01) and the expression of bcl-2 was decreased in breast cancer (P <0.01). Atypical hyperplasia than normal breast tissue bcl-2 methylation levels were significantly increased (P <0.05). There was a significant negative correlation between bcl-2 methylation and protein expression in the four stages of breast cancer development (P <0.01). Conclusion This study established the detection method of bcl-2 gene MSP, and the design of bcl-2 gene MSP primer was reasonable. Bcl-2 promoter methylation may be one of the molecular markers of breast precancerous lesions. In the process of breast cancer development, CpG island methylation in the regulatory region of bcl-25 ’may be a factor of down-regulating the expression of bcl-2.