Ethnic Differences of the p53 Genetic Alteration in Cutaneous Malignant Melanoma

ABSTRACT

BACKGROUND: There are significant differences in the clincopathologic pattern including the incidence, favor site, and histopathologic type between cutaneous malignant melanomas arising from whites, asians and blacks. These differences might suggest that there is a racial difference in the molecular tumorigenesis mechanism of malignant melanoma. METHODS: To determine the ethnic differences in tumorigenesis of malignant melanoma, we performed loss of heterozygosity (LOH) and sequencing analyses of the p53 gene in cutaneous malignant melanomas arising from 22 white American, 30 Korean and 15 black African patients. RESULTS: The frequency of LOH of the p53 gene is only 12.5% in white American patients, but the frequency is significantly higher in Korean (42.1%) and black African (61.5%) patients. We also detected 17 mutations (nonsense 1, missense 16) of the p53 gene in the cutaneous malignant melanomas of Koreans and black Africans, but none in those of white Americans among the 16 missense mutations, 10 mutations were CG to TA transitional mutations. Of these, we also detected one GG (CC) to AA (TT) tandem mutation at the pyrimidine sequence. CONCLUSION: These results strongly suggest that there might be a racial difference in molecular carcinogenesis mechanisms among the cutaneous malignant melanomas occurring in white American, Korean and black African patients. But the role of the p53 genetic alteration in the genesis of melanomas in Korean and black African patients is subject to further evaluation.