P53 MUTATIONS ARE INFREQUENT AND DO NOT CORRELATE WITH THE METASTATICPOTENTIAL OF HUMAN-MELANOMA CELLS

Eleven human melanoma cell lines with different metastatic ability (bo th spontaneous and experimental) in nude mice, were analyzed for p53 m utations. Mutations in the conserved regions of the p53 gene were iden tified by single-strand conformation polymorphism analysis of exons 5- 9 and were verified by direct DNA sequencing of polymerase chain react ion products. A mutation was detected in only one low metastatic melan oma cell line with a C->G transition at codon 278, resulting in a subs titution of arginine for proline. Only this cell line reacted immunohi stochemically with mouse monoclonal antibody PAb 1801, which is immuno reactive with human p53 protein. Another cell line with low metastatic potential showed loss of heterozygosity for p53 with the remaining al lele being normal. No mutations were detected in the highly metastatic melanoma cell lines' We conclude that p53 mutations are infrequent in human melanomas and are not a prerequisite for the acquisition of the metastatic phenotype.