Molecular mechanisms of aberrant DNA methylation during multistage carcinogenesis

本研究的目的是检测与DNA甲基转移酶（DNMT）1相关的分子，并在人类肿瘤发生过程中诱导异常的DNA甲基化。我们使用了HepG 2细胞系，该细胞系来源于人肝癌并且显示出DNMT 1的高表达水平。用优化的DNMT 1抗体对HepG 2细胞核提取液进行免疫沉淀，并用SDS-PAGE对免疫沉淀物进行分离。通过LCMS的二维图像转换分析（2D-ICAL方法）分析共沉淀的蛋白质，并且鉴定可能与DNMT 1相关并且可能导致异常DNA甲基化的候选分子。正在评估候选分子与DNMT 1之间的直接关联。将检查候选分子如何参与DNMT 1的异常分布导致异常DNA甲基化谱的机制。

The aim of this study is to detect the molecules which associate with DNA methyltransferase (DNMT)1 and contribute to induce aberrant DNA methylation profiles during human carcinogenesis. We used HepG2 cell line which was derived from human liver cancer and showed high expression levels of DNMT1. We performed immunoprecipitation of DNMT1 using optimum antibody in HepG2 nuclear extract, and separated immunoprecipitant by SDS-PAGE. Co-precipitated proteins were analyzed by 2 Dimensional Image Converted Analysis of LCMS (2D-ICAL method), and the candidate molecule which may associate DNMT1 and may contribute aberrant DNA methylation was identified. Direct association between the candidate molecule and DNMT1 is being evaluated. Mechanisms how the candidate molecule participates in aberrant distribution of DNMT1 resulting in aberrant DNA methylation profiles will be examined.