DETAILED DELETION MAPPING OF CHROMOSOME 9P AND P16 GENE ALTERATIONS IN HUMAN BORDERLINE AND INVASIVE EPITHELIAL OVARIAN-TUMORS

We used PCR amplification of tandem repeats to study the pattern of al lelic loss in borderline and invasive ovarian epithelial tumors using 12 primer pairs to generate a detailed deletion map of chromosome 9p. In the invasive ovarian carcinomas, there were three regions displayin g high frequency of loss of heterozygosity (LOH) ranging from 31-38%. In contrast, LOH was a rare event among the borderline ovarian tumors, with one region revealing a rate of 20% and the remaining regions onl y 0-8% LOH. Therefore, allelic loss does not seem to be important for the development of borderline ovarian tumors. We also examined p16 gen e expression and mutations in ovarian cancer cell lines and invasive a nd borderline ovarian tumor tissues. Southern blot analysis revealed n o losses of the p16 gene in either the invasive or borderline ovarian tumors. However, the ovarian carcinoma cell lines showed a 50% homozyg ous deletion rate, SSCP analysis detected a mobility shift in only one (borderline) tumor. Since the primary invasive ovarian tumors did not show any deletions or mutations, it appears that p16 does not play a role in the pathogenesis of these tumors.