Mitochondrial microsatellite profiles in borderline surface epithelium ovarian tumors

Cancer is a disease consisted of the accumulation of genetic changes, such as activation of oncogenes, inactivation of tumor suppressor genes, loss of heterozygosity and microsatellite instability. All of these changes cause mitochondrial and nuclear genomic instability. Microsatellite instability is a major sign of the genomic instability.In developed countries, cancer of the ovary is among the five leading sites for cancer mortality in women. Ovarian cancer is difficult to diagnose in its early stages. Thus, most of the patients (90%) is diagnosed at the advanced stages, and the survival rate in these patients are less than 30%.Borderline ovarian tumors account for 10-15% of all ovarian tumors. Ovarian tumors of low malignant potential (LMP) exhibit histopathologic features and biologic behavior between benign and malign tumors. Consequently, borderline ovarian tumors is important for clarifying the pathogenesis of epithelial ovarian tumors.The goal of our project, is to identify the unique changes in four microsatellite regions (303 np., 514 np., 16184 np. and 956 np.) which exhibited instability in common female cancers in pure cell population of borderline ovarian tumors and their matched normal tissues collected by laser capture microdissetion. Four microsatellite regions were sequenced in a series of sixteen tumors and with their matched normal tissues, eight tumor tissues and one normal tissue which were diagnosed as mucinous and serous borderline tumors. We found mutations in D310 region 65% [m.309_310insC(8), m.309_310insCC(1)], 514 np. 32% [m.523_524insCA(6)] and 956 np. 14% [m.961delTinsC(1)] of the serous borderline tumors group. Furthermore, for the mucinous borderline tumors group the mutation rate in detected as 67% for [m.309_310insC(15), m.309_310insCC(2), m.309_310insCCCC(1)], 37% for 514 np. [m.523_524insCA(8), m.522delCA(2)] and 3% [m.16189delTinsC] for 16184 np. We did not detect any genomic changes in 16184 np. of the serous borderline tumors group and 956 np. of the mucinous borderline tumors group.Up to date, there is not any research about the microsatellite regions in the pure cell populations of tumor and normal tissues in the borderline ovarian tumors. Besides, our data will support the mitochondrial genome studies in the field of pathogenesis of epithelial ovarian tumors.