DNMT1与RNAs交互作用调控DNA甲基化在镉致细胞转化中的作用

Cadmium is an environmental pollution metal with significant toxicity to human. Epidemiological evidences have shown that the exposure to cadmium induces many kinds of cancer. DNA methylation has been shown to be involved in cadmium-carcinogenesis. We previously found that DNA methylation modification is involved in cadmium-induced malignant transformation. However, the rules governing DNA methylation establishment and maintenance remain elusive. It has been confirmed that DNMT1-interacting RNAs (DiR) regulating gene-specific DNA methylation in 2013. So DiR selective regulation of DNA methylation mechanism being a key event cadmium-induced malignant transformation has become an urgent need for verification chemical carcinogenesis hypothesis. The project will start with reduced representation risulfite sequencing (RRBS)，RNA sequencing, RNA IP sequencing and bioinformatics intending to screen the RNAs as a candidate gene that are regulated by DiR in cadmium-induced malignant transformation, and the explore the role and mode of ecRNA (extra-coding) regulation DNA methylation in cadmium-induced malignant transformation 16HBE cells using ectopic expression (overexpression or knockdown) of ecRNA with cadmium-induced malignant transformation 16HBE cell models. Collectively, this research will delineate the nature of DNMT1-RNA interactions and gene-selective DNA methylation regulating in cadmium-induced malignant transformation 16HBE cells, which is very important to perfect the epigenetic mechanisms and the cadmium-toxic mechanism.

镉是一种毒性很强的环境污染物，严重危害人类健康，长期暴露镉会引起多种癌症的发生。而DNA甲基化异常已被证实在镉致癌过程中起着重要作用，本团队前期研究发现镉诱导细胞转化过程中DNA甲基化发生改变，但机制尚未阐明。最近的研究显示DNMT1与RNAs交互作用（DNMT1-interacting RNAs, DiR）调控靶位点DNA甲基化，因此我们在现有的研究基础上大胆提出“DiR选择性调控DNA甲基化是镉致恶性转化的关键事件”的假说。本项目通过高通量技术观察镉致细胞恶性转化过程中基因组DNA甲基化水平、转录组表达水平及与DNMT1结合的RNA变化规律，筛选出DNA甲基化受DiR调控的基因作为候选基因。接着在正常细胞中过表达或沉默该基因RNA，再结合镉致细胞恶性转化模型探讨DiR调控机制在化学致癌过程中的作用。本研究对于完善DNA甲基化调控机制和镉毒作用分子机制具有重要科学意义。