Allelic losses of tumor suppressor gene on chromosome 17 in ovarian cancer

: Twenty-one human ovarian epithelial carcinomas (13 serous, 3 mucinous, 2 endometrioid and 3 clear cell type) were examined for allelic losses of p53 tumor suppressor gene, pYNZ22 or pTHH59 on chromosome 17. High-molecular-weight DNA was extracted from ovarian tumor tissues and normal ones obtained from the same patients, and was subjected to Southern blot analysis. The filters were hybridized with p53 cDNA probe or two VNTR probes on chromosome 17(pYNZ22, pTHH59). By comparing the hybridized band pattern of the normal tissue with that of the tumor, loss of heterozygosity (LOH) was detected. Frequent LOHs were detected in 5 of 14 informative cases (36%) on p53 and in 9 of 20(45%) on pYNZ22, but LOH on pTHH59 was observed less frequently than those of p53 and pYNZ22 (one of 7 cases: 14%). These results suggest that allelic loss of p53 may play an important role in the development and/or progression of ovarian carcinomas.