唾液腺恶性多形性腺瘤细胞系中E-cadherin的表达差异及表观遗传调控机制  

E-cadherin expression and related epigenetic regulation in malignant pleomorphic carcinoma cell lines

作　　者：邓亚伟[1] 夏荣辉[1] 张春叶[1] 黄林剑[2] 顾挺[1] 田臻[1] 

机构地区：[1]上海交通大学医学院附属第九人民医院.口腔医学院口腔病理科,上海200011 [2]上海交通大学医学院附属第九人民医院.口腔医学院口腔外科上海市口腔医学重点实验室,上海200011

出　　处：《中国口腔颌面外科杂志》2015年第4期297-302,共6页China Journal of Oral and Maxillofacial Surgery

基　　金：国家自然科学基金(81272976)~~

摘　　要：目的 :检测唾液腺恶性多形性腺瘤不同癌变亚型细胞系中E-cadherin蛋白的表达,探讨E-cadherin蛋白表达差异的表观调控机制。方法:采用免疫细胞化学法、蛋白印迹法和聚合酶链反应分别检测E-cadherin蛋白和m RNA在恶性多形性腺瘤的腺癌亚型细胞系SM-AP1和肌上皮癌亚型细胞系SM-AP4中的表达差异。采用亚硫酸盐测序法和染色质免疫共沉淀法检测SM-AP1和SM-AP4细胞中E-cadherin基因启动子DNA甲基化和组蛋白H3上赖氨酸9号位点三甲基化(H3K9me3)修饰状况,探讨2个细胞系中E-cadherin表达差异与基因DNA甲基化、组蛋白甲基化修饰之间的相关性。采用SPSS16.0软件包,运用两独立样本t检验、Fisher确切概率法等对数据进行统计学分析。结果:SM-AP1细胞中,E-cadherin蛋白和m RNA(n=4.97,P<0.05)表达较SM-AP4高;E-cadherin基因启动子区甲基化程度显著低于SM-AP4细胞(P<0.05)。SM-AP4细胞较SM-AP1细胞的E-cadherin基因启动子区具有较高的H3K9me3修饰结合水平。结论 :DNA甲基化可能是恶性多形性腺瘤肌上皮癌亚型中E-cadherin表达低于腺癌亚型的主要调控机制之一,H3K9me3修饰可能在E-cadherin表达下调过程中发挥协调调控作用。PURPOSE： To investigate the expression of E-cadherin in different canceration subtype of malignant pleomorphic carcinoma（MPA） cell lines, and discuss the possible epigenetic mechanisms on differential expression of Ecadherin. METHODS： The protein and m RNA expression of E-cadherin in adenocarcinoma subtype cell lines（SM-AP1）and myoepithelial carcinoma subtype cell lines（SM-AP4） of malignant pleomorphic carcinoma were detected by immunocytochemistry, Western blot and polymerase chain reaction respectively, meanwhile, the DNA promoter methylation status and histone methylation modification H3K9 trimethylation（H3K9me3） of E-cadherin in 2 cell lines were examined by bisulfite sequencing PCR（BSP） and chromatin immunoprecipitation assay（Ch IP）. The correlationship between the expression of E-cadherin and DNA methylation as well as histone methylation modification were analyzed using SPSS16.0software package. RESULTS： The m RNA and protein expression of E-cadherin in SM-AP1 cells were significantly higher than that in SM-AP4 cells（n =4.97, P〈0.05）. The promoter methylation status of E-cadherin in SM-AP1 was significantly lower than that in SM-AP4 cells（P〈0.05）. The level of H3K9me3 on the promoter region of E-cadherin in SM-AP4 cells was significantly higher than the level in SM-AP1 cells. CONCLUSIONS： DNA methylation might be one of the major mechanism for lower E-cadherin expression in adenocarcinoma subtype than in myoepithelial carcinomasubtype in MPA. H3K9me3 modification played a coordinate role in down-regulation of E-cadherin.

关 键 词：E-CADHERIN DNA甲基化 H3K9me3 恶性多形性腺瘤 唾液腺 

分 类 号：R739.87[医药卫生—肿瘤]