结直肠锯齿状病变中p16基因甲基化状态和蛋白表达的研究  

p16 gene promoter methylation and protein expression in colorectal serrated lesions

作　　者：葛畅[1] 王鲁平[1] 许春伟[1] 方园[1] 张玉萍[1] 

机构地区：[1]安徽医科大学北京军区总医院临床学院病理科,北京100700

出　　处：《诊断病理学杂志》2014年第3期169-174,共6页Chinese Journal of Diagnostic Pathology

基　　金：首都卫生发展科研专项基金资助项目2011-5021-02

摘　　要：目的检测锯齿状病变组织中p16基因启动子区异常甲基化改变和p16蛋白的表达情况,探讨其在锯齿状癌变通路中的作用和临床病理意义,同时探讨p16基因在不同年龄层段甲基化程度。方法采用Taqman探针实时定量PCR(Methylight)方法检测225例锯齿状病变(包括96例HP、61例SSA/P和68例TSA)、54例TA、69例CRC和42例正常结直肠黏膜组织中的p16基因甲基化状态,并通过测序法验证扩增的目的片段;同时应用免疫组化方法检测其中随机抽取的116例锯齿状病变(包括52例HP、41例SSA/P、23例TSA)、20例TA、24例CRC和24例正常结直肠黏膜组织中p16蛋白的表达。结果 p16基因启动子甲基化状态和p16蛋白异常阳性程度在锯齿状病变和对照组中均有显著差异(P<0.05),两者比较呈负相关(P<0.05);p16基因启动子甲基化频率与不同年龄层段的相关性比较有显著差异(P<0.05),两者呈正相关。结论结直肠锯齿状病变组织中p16基因甲基化可能是诱导其蛋白表达下调的主要原因,且在结直肠"增生性息肉-锯齿状腺瘤-癌"的锯齿状癌变通路中起重要作用;同时p16基因甲基化又可能与年龄相关,随年龄增长甲基化程度越高。Objective To explore the role and clinicopathologic significance of p16 gene methylation status and protein expression in serrated cancer pathway, and to discuss p16 gene methylation level in different age paragraphes. Methods p16 promotor methylation was detected with Taqman probe based real-time PCR（Methylight） in 225 cases of serrated lesions （96 cases of hyperplastic polyps, 61 cases of sessile serrated adenoma/polyp and 68 traditional serrated adenoma）, 54 cases of tubular adenoma, 69 cases of colorectal cancers and 42 cases of normal tissues. At the same time, immunohistochemical staining was utilized to detect the expression of p16 protein in 116 cases of serrated lesions （52 cases of hyperplastic polyps, 41 cases of sessile serrated adenoma/polyp and 23 traditional serrated adenoma）, 20 cases of tubular adenoma, 24 cases of colorectal cancers and 24 cases of normal tissues. Results There was a negative correlation between p16 gene promoter methylation rate and protein positive rate compared with control groups （P 〈 0. 05 ）, while a positive correlation between p16 gene promoter methylation rate and age （ P 〈 0.05 ）. Conclusion p16 gene promoter region methylation may be the main reason of inducing protein downregulation and play an important role of ＂hyperplastic polyps-serrated adenoma-carcinoma＂ pathway in colorectal serrated lesions. Especially, it may be associated with age, the older the more frequent of methylation level.

关 键 词：DNA甲基化 P16基因 qPCR DNA探针 锯齿状病变 

分 类 号：R730.45[医药卫生—肿瘤]