乳腺癌p16基因甲基化和蛋白表达的检测及其临床意义

目的:探讨p16基因在乳腺癌中甲基化状态、表达情况及其与临床的关系.方法:应用甲基化特异性的聚合酶链反应(methylation specific PCR,MSP)检测48例乳腺癌中p16基因甲基化状态,应用免疫组化检测p16基因的蛋白表达情况.结果:p16基因在乳腺癌中甲基化率为27.1%(13/48),有淋巴结及远处转移的甲基化率(52.6%,10/19)高于无转移的甲基化率(10.3%,3/29)(P＜0.05);13例甲基化病例中P16蛋白失表达率(76.9%,10/13)高于非甲基化病例(8.6%,3/35)(P＜0.05).结论:p16基因高甲基化是乳腺癌中常见的分子生物学改变之一,p16基因高甲基化和乳腺癌浸润及转移有相关性;P16蛋白表达和其高甲基化呈负相关,甲基化是p16抑癌基因失活的主要方式之一.

Studies of CpG Methylation of p16 Gene and Protein Expression in Breast Cancer

Objective:To investigate the CpG methylation and expression of p16 gene in breast cancer and the relationships between them.Methods:Methylation-specific PCR(MSP) was used to analyze the methylation status of p16 tumor suppressor gene in 48 breast cancers;the expression of p16 was examined by immunohistochemical staining.Results:Among the 48 breast cancers,p16 hypermethylation was detected in 13 cases(27.1%),Hypermethylation of p16 gene was more frequent in metastatic lymph node(52.6%,10/19) than that of non-metastatic lymph node(10.3%,3/29)(P<0.05).In the 13 methylated cases,loss of expression of p16 gene was 76.9%(10/13),which was higher than in the unmethylated cases 8.6%(3/35)(P<0.05).Conclusion:Hypermethylation of p16 gene is one of the frequent biological changes in breast cancer and related to p16 high gene hiper-CpG Methylation and invasaion and matastasis of the cancer,but not related to p16 gene expression and hiper-CpG Methylation.The downregulation expression of p16 was associated with hypermethylation.