Microsatellite instability and genetic alterations in ovarian cancer

Inactivation of the mismatch repair system (MMR) leads to the accumulation of mutations, particularly in highly repeated sequences (microsatellite). The resulting microsatellite instability can profoundly affect the cellular behaviour, since many genes playing important roles in the mechanisms of signal transduction, apoptosis, DNA repair and cell cycle control can be altered in tumors presenting microsatellite instability. Germline mutations in MMR genes are associated with hereditary non polyposis colon cancer. Microsatellite instability and the associated frameshift mutations in genes have been well described in sporadic colon, gastric and endometrium tumors. In this review we collected the data available on the impact of microsatellite instability in ovarian cancer and the possible consequences of this instability to the presence of mutations in genes containing in their coding regions repeated nucleotides and to the response of these tumors to chemotherapy.