Lack of p53 mutations and loss of heterozygosity in non-cultured human melanocytic lesions.

In this study we analysed snap-frozen surgical resections of 16 superficial spreading melanomas, 13 nodular malignant melanomas, 2 lentigo maligna melanomas, 1 dysplastic nevus, 1 congenital nevus and 5 normal nevi from 38 patients for point mutations in the human p53 gene at exons 5-8 by polymerase chain reaction/single-strand conformation polymorphism as well as for loss of heterozygosity of p53 by restriction-fragment-length polymorphism/polymerase chain reaction in order to determine whether p53 aberrations are associated with melanoma subtypes. In addition, we analysed six melanoma cell lines for point mutations in p53. Our results revealed the absence of point mutations and loss of heterozygosity in all fresh resected lesions. However, a TAC (Tyr) to TGC (Cys) transition at codon 163 in exon 5 was found in one cell line.