MutS Homolog 3 (MSH3)

MSH3 forms a heterodimer with MSH2 to form MutS beta, part of the post-replicative DNA mismatch repair system. MutS beta initiates mismatch repair by binding to a mismatch and then forming a complex with MutL alpha heterodimer. Defects in this gene are a cause of susceptibility to endometrial cancer.

MSH3 mRNA was not detectable in 7 cases, including 3 of chronic myelogenous leukemia, 2 of acute myelogeneous leukemia, 1 of acute lymphocytic leukemia, and 1 of myelodysplastic syndrome. In addition, 17 cases showed significantly reduced expression of the MSH3 gene. These results suggested to the authors that inactivation of the MSH3 gene may be involved in the development of hematologic malignancies.