MSH2 [MD177]

MutS homologue 2 (MSH2) is a DNA mismatch repair protein that belongs to the MutS family. MSH2 forms two different heterodimers: MutS alpha (MSH2-MSH6) and MutS beta (MSH2-MSH3), which bind to DNA mismatches, thereby initiating DNA repair. Heterozygous mutations in the MSH2 gene are a cause of hereditary nonpolyposis colorectal cancer (HNPCC), forming a specific mispair binding complex with MSH3 and MSH6. MutS alpha may also play a role in DNA homologous recombination repair. MSH2 is found in normal cells. Loss of MSH2 is linked to hereditarynonpolyposis colorectal cancer (HNPCC) and MSI-positive endometrial and ovarian cancers. Immunohistochemical analysis of MSH2 expression has been reported to be a practical and reliable method for the routine detection of the vast majority of MSI-H colorectal adenocarcinomas.