论文部分内容阅读
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。
OBJECTIVE: To detect the expression of E-cadherin protein in different cancerous subtypes of salivary gland malignant pleomorphic adenoma and to explore the mechanism of E-cadherin protein differential expression. Methods: Immunohistochemistry, Western blot and polymerase chain reaction were used to detect the expression of E-cadherin protein and m RNA in adenocarcinoma subtype SM-AP1 and myoepithelial carcinoma subtypes SM in malignant pleomorphic adenoma -AP4 expression differences. Methylation of E-cadherin gene promoter in SM-AP1 and SM-AP4 cells and trimethylation of lysine 9 site on histone H3 were detected by sulfite sequencing and chromatin immunoprecipitation H3K9me3) to investigate the relationship between E-cadherin expression and DNA methylation and histone methylation in two cell lines. Using SPSS16.0 software package, using two independent sample t test, Fisher exact probability method for statistical analysis of the data. Results: The expression of E-cadherin protein and m RNA (n = 4.97, P <0.05) in SM-AP1 cells was higher than that in SM-AP4 cells. The methylation of E-cadherin gene promoter region was significantly lower than that in SM-AP4 cells P <0.05). SM-AP4 cells have a higher level of H3K9me3 modification binding than the E-cadherin gene promoter region of SM-AP1 cells. Conclusion: DNA methylation may be one of the major regulatory mechanisms of E-cadherin expression in subtypes of malignant pleomorphic adenoma with low expression of E-cadherin. H3K9me3 modification may play a coordinating role in the down-regulation of E-cadherin expression effect.