乳腺癌组织中YY1表达与E-cadherin甲基化状态的关系

Association between YYl Methylation of E-cadherin in Breast Cancer

目的:探讨乳腺癌组织中YY1(Yin Yang-1,YY1)的表达与E-cadherin甲基化状态之间的关系。方法:采用免疫组织化学法检测42例乳腺癌原发病灶以及18例正常乳腺组织中YY1的表达情况,采用甲基化特异性聚合酶链反应法(MSP)进行E-cadherin基因甲基化检测。结果:乳腺癌中E-cadherin甲基化率为57.1%(24/42),显著高于正常乳腺组织的11.1%(2/18),差异有统计学意义(P<0.05)。乳腺癌组织中阳性YY1的表达(22/42,52.3%)显著高于正常乳腺组织(2/18,16.7%),差异有统计学意义(P<0.05),YY1阳性乳腺癌组中E-cadherin甲基化者为20/22(90.9%),而YY1阴性组的乳腺癌E-cadherin甲基化者为4/16(25%),YY1与E-cadherin甲基化状态之间呈正相关(P<0.05)。结论:乳腺癌患者E-cadherin基因启动子甲基化发生率显著高于正常乳腺组织,乳腺癌组织中YY1的高表达有可能是E-cadherin甲基化失活的主要原因。

Objectives： To determine the relationship between the methylation of the E-cadherin promoter region and YY1 expression in breast cancer. Methods： YY 1 expression was detected in the primary cancer tissues of 42 breast cancer patients and the normal breast tissues of 18 patients with benign breast tissues through immunohistochemical staining. E-cadherin gene methylation was examined using methylation-specific polymerase chain reaction （ MSP ）. Results： The rate of E-cadherin gene hypermethylation was 57.1% （ 24 / 42 ）, which is significantly higher than that in normal breast tissues （ 11.1% ; 2 / 18 ） （ P 〈 0.05 ）. The rate of positive YY 1 expression in breast cancer lesions （ 52.3 % ; 22 / 42 ） was significantly higher than in normal breast tissues （ 16.7 % ; 2 / 18） （ P 〈 0.05 ）. Hypermethylation of E-cadherin gene promoter was detected in 88 % （ 22 / 25 ） of YYl-positive cases and in 11.4 % （ 4 / 35 ） of YYl-negative cases. The difference in the methylation of the E-cadherin promoter was significantly higher among YY 1-positive patients than among YY 1-negative patients （ P 〈 0.05 ）.Conclusion： Methylation of E-cadherin gene promoter is a common molecular event in breast cancer and YY1 may be involved in the methylated regulation of E-cadherin.