中文摘要：

DNA错配修复系统（mismatch repair system,MMR）是重要的复制后修复机制,修复各种类型的碱基错配和插入/缺失环。hMutS、hMutL是MMR中重要的两个子系统,它们的功能缺陷与多种肿瘤,尤其结直肠癌密切相关。hMutS、hMutL系统关键基因SNPs、启动子甲基化水平的变化,都会直接或间接影响MMR的功能,以及由此引起微卫星不稳定性增加,进而影响结直肠癌的发生、发展和预后。本文主要从hMutS、hMutL系统关键基因的SNPs、启动子甲基化和微卫星不稳定三个方面综述了hMutS、hMutL系统关键基因变异与结直肠癌相关性研究的进展。

英文摘要：

Mismatch repair system（MMR） is an important post-replication repair mechanisms and repairs various types of base mismatch and insertion/deletion loop.HMutS,hMutL are two important subsystems of the MMR.Their function defects associate with a variety of tumors,especially colorectal cancer.SNPs and promoter methylation level of key genes in hMutS,hMutL system would directly or indirectly affect the MMR function,further to increase microsatellite instability,and play an important role in the occurrence,development and prognosis of colorectal cancer.This article briefly reviewed the research progress on the relationship between key genes variation in hMutS,hMutL and colorectal cancer from SNPs,promoter methylation level and microsatellite instability.