A NOVEL 4-CM MINIMALLY DELETED REGION ON CHROMOSOME 11P15.1 ASSOCIATED WITH HIGH-GRADE NONMUCINOUS EPITHELIAL OVARIAN CARCINOMAS

Prior cytogenetic and restriction fragment length polymorphism studies have demonstrated that allelic deletion of chromosome 11p is common i n human invasive epithelial ovarian tumors. To construct a highly deta iled deletion map of chromosome 11p, we used 13 polymorphic microsatel lite CA repeat primers to identify regions harboring potential tumor s uppressor genes, Twenty-three of 48 samples (48%) of invasive epitheli al ovarian cancer showed LOH involving at least one locus, consistent with prior studies, None of the five mucinous tumors showed allelic de letion at any of the 13 primers, suggesting that loss of heterozygosit y at chromesome 11p may not be involved in the pathogenesis of mucinou s ovarian cancer, Two separate minimally deleted regions were identifi ed in nonmucinous ovarian cancer, The first is an 11-cM region on chro mosome 11p15.5-15.3 that extends from D11S2071 to D11S988 and includes the HRAS locus. The second is a novel 4-cM region on 11p15.1, defined by marker D11S1310, Deletion of both regions at 11p15.5-15.3 and 11p1 5.1 is strongly associated with high grade nonmucinous epithelial ovar ian cancer.