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 superf icial spreading melanomas, 13 nodular malignant melanomas, 2 lentigo m aligna melanomas, 1 dysplastic nevus, 1 congenital nevus and 5 normal nevi from 38 patients for point mutations in the human p53 gene at exo ns 5-8 by polymerase chain reaction/single-strand conformation polymor phism as well as for loss of heterozygosity of p53 by restriction-frag ment-length polymorphism/polymerase chain reaction in order to determi ne whether p53 aberrations are associated with melanoma subtypes. In a ddition, we analysed six melanoma cell lines for point mutations in p5 3. Our results revealed the absence of point mutations and loss of het erozygosity 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.