Vaish Minal, Mittal B
Department of Medical Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow 226 014, India.
Indian J Exp Biol. 2002 Sep;40(9):989-94.
Mismatch (MMR) repair system plays a significant role in restoration of stability in the genome. Mutations in mismatch repair genes hamper their activity thus bring about a defect in mismatch repair (MMR) mechanism thereby conferring instability in the microsatellite sequences of both the coding and non-coding regions of the genome. Mutated mismatch repair genes result in the expansion or contraction of microsatellite sequence and confer microsatellite unstable or replication error positive phenotype. Hypermethylation of promoter regions of some of the MMR genes also causes inactivation of these genes and thus contribute to MSI. Microsatellite instability is an indicator of MMR deficiency and is a prime cause of varied tumorogenesis.
错配修复(MMR)系统在恢复基因组稳定性方面发挥着重要作用。错配修复基因的突变会阻碍其活性,从而导致错配修复(MMR)机制出现缺陷,进而使基因组编码区和非编码区的微卫星序列产生不稳定性。突变的错配修复基因会导致微卫星序列的扩增或收缩,并赋予微卫星不稳定或复制错误阳性表型。一些MMR基因启动子区域的高甲基化也会导致这些基因失活,从而导致微卫星高度不稳定(MSI)。微卫星不稳定性是MMR缺陷的一个指标,也是多种肿瘤发生的主要原因。