Tumor-specific microsatellite instability: do distinct mechanisms underlie the MSI-L and EMAST phenotypes?

ABSTRACT: Microsatellite DNA sequences display allele length alterations or microsatellite instability (MSI) in tumor tissues, and MSI is used diagnostically for tumor detection and classification. We discuss the known types of tumor-specific MSI patterns and the relevant mechanisms underlying each pattern. Mutation rates of individual microsatellites vary greatly, and the intrinsic DNA features of motif size, sequence, and length contribute to this variation. MSI is used for detecting mismatch repair (MMR)-deficient tumors, which display an MSI-high phenotype due to genome-wide microsatellite destabilization. Because several pathways maintain microsatellite stability, tumors that have undergone other events associated with moderate genome instability may display diagnostic MSI only at specific di-

SUBMITTER: Hile SE 

PROVIDER: S-EPMC3610773 | biostudies-literature | 2013 Mar-Apr

REPOSITORIES: biostudies-literature