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DNA错配修复(MMR)系统是一个严格的校对者,鉴别及纠正复制时错配的DNA碱基。DNA错配修复基因在维持基因组的稳定性方面起着重要的作用。微卫星是真核基因组中含1-6个碱基的高度多态的重复序列。微卫星不稳定性(MSI)的产生就是由于DNA复制错误(RER)引起的简单重复序列的增加或丢失,它与MMR相关基因的异常有关。DNAMMR缺损的肿瘤基因组中常出现大量的MSI,也称RER阳性或RER表型。现综述有关DNA错配修复基因及MSI与遗传性非息肉病性结直肠癌(HNPCC)和散发性结直肠癌之间在肿瘤的发生、发展及预后方面的研究进展。
The DNA Mismatch Repair (MMR) system is a rigorous proofreader that identifies and corrects mismatched DNA bases for replication. DNA mismatch repair genes play an important role in maintaining the stability of the genome. Microsatellites are highly polymorphic repeats of 1-6 bases in the eukaryotic genome. Microsatellite instability (MSI) is the result of the addition or loss of simple repeats due to DNA replication errors (RERs), which are associated with abnormalities of MMR-related genes. A large number of MSIs are often found in DNAMMR-deficient tumor genomes, also known as RER-positive or RER phenotypes. This review summarizes the research progress on DNA mismatch repair gene, MSI and hereditary nonpolyposis colorectal cancer (HNPCC) and sporadic colorectal cancer in tumorigenesis, development and prognosis.