RAS AND P53 GENES IN MALE BREAST-CANCER

We have studied the robs of Ki-ras oncogene and p53 tumor suppressor g ene in a series of 20 cases of male breast cancer and one papilloma of the male breast. Ki-ras was detected in 50-mu m sections after digest ion with proteinase K and SDS. DNA was amplified by polymerase chain r eaction, dot blotted, and mutations were screened with labeled ras mut ation-specific oligonucleotides. Wild-type and mutant p53 protein were detected with antibodies CM1 and DO7, using the avidin-biotin-perolri dase method. Two of 17 carcinomas showed Ki-ras mutations, both in cod on 12 (gly --> lys and gly --> arg). Five of 20 male breast cancers (2 5%), including one large intraductal carcinoma, expressed mutant p53 p rotein. Although the incidence of mutant p53 expression in male breast cancer is similar to that in women, Ki-ras mutations are not signific antly increased.