甲基丙烯酸环氧丙酯致人支气管上皮细胞恶性转化过程中DNMT1及MBD1基因表达的变化

目的：分析甲基丙烯酸环氧丙酯（glycidyl methacrylate,GMA）致人支气管上皮16HBE细胞恶性转化过程中不同时点甲基化转移酶及甲基CpG结合蛋白家族基因的表达差异,初步探讨GMA诱导16HBE细胞发生恶性转化的表观遗传机制。方法：采用人类全基因组表达谱芯片筛选GMA诱导16HBE细胞恶性转化过程中甲基化转移酶及甲基CpG结合蛋白家族的差异表达基因,并采用实时定量PCR（Real time PCR）技术检测筛选所得差异基因DNMT1及MBD1 mRNA的表达情况。结果：芯片结果显示在转化第10代（前期）细胞中DNMT1及MBD1基因较同代龄对照细胞表达上调,实时定量PCR进一步确证DNMT1及MBD1基因表达分别上调80.60%、79.10%,与芯片结果一致。结论：甲基化可能是GMA致16HBE细胞发生恶性转化的一种机制,DNMT1及MBD1基因可能是多个甲基化相关基因转录表达下调的关键调控点,其在GMA致16HBE细胞恶性转化过程中起着重要作用。

Altered expressions of DNMT1and MBD1 genes in malignant transformation of human bronchial epithelial cells induced by glycidyl methacrylate

OBJECTIVE:To analyze the DNA methyltransferases (DNMTs) and methyl-CpG binding proteins mRNA expression levels in malignant transformation of human bronchial epithelial cells(16HBE) induced by glycidyl methacrylate(GMA),and to discuss the epigenetic mechanisms of malignant transformation of 16HBE induced by GMA. METHODS: Gene chip was used to screen the differentially expressed genes of DNMTs and methyl-CpG binding proteins,the expressions of DNMT1 and MBD1 mRNA were measured with RT-PCR. RESULTS: The expressions of DNMT1 and MBD1 were up-regulated compared with control group in the transformed 10th-generation(protophase)cells. Further RT-PCR re-examination showed that the levels of DNMT1 and MBD1 mRNA were up-regulated by 80.60% and 79.10%,respectively. CONCLUSION: Methylation may play an important role during the malignant transformation of 16HBE induced by GMA,DNMT1 and MBD1 could play important roles in the inactivation mechanisms of methylation-related genes in malignant transformation of 16HBE induced by GMA.