Mutation and expression of the p53 gene in human malignant melanoma

Melanoma Res. 1994 Feb;4(1):35-45. doi: 10.1097/00008390-199402000-00006.


Derangement of the p53 tumor suppressor gene has been implicated in the aetiology of a wide range of human neoplasias. We have previously determined that overexpression and mutation of the p53 gene in cultured metastatic melanomas is low (11%). However, two recent immunohistochemical studies have reported that > 85% of malignant melanoma specimens overexpress mutated p53 protein. In an effort to resolve this contradiction in the published literature, we have re-evaluated a range of cultured and non-cultured melanocytic lesions for the occurrence of point mutations in the p53 gene using DNA- and RNA-dependent single strand conformation polymorphism (RNA-SSCP) and direct DNA sequencing of polymerase chain reaction (PCR) amplified DNA, and overexpression of the p53 protein using immunohistochemistry. We found point mutations in 25% (9 of 36) of cultured melanomas and 0% in 34 fresh melanoma biopsies; however, increased p53 expression was found in 42% of paraffin-embedded melanoma specimens and 7% of benign lesions. The low frequency of p53 point mutations and high frequency of p53 expression suggests that derangement of the p53 gene by point mutations is not a common perturbation in the majority of melanoma cells, and that overexpression of p53 in this tumour type is due to a mechanism other than point mutation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Base Sequence
  • DNA, Single-Stranded / analysis
  • DNA, Single-Stranded / genetics
  • Exons
  • Female
  • Gene Expression
  • Genes, p53 / genetics*
  • Humans
  • Immunohistochemistry
  • Male
  • Melanoma / genetics*
  • Melanoma / pathology
  • Melanoma / secondary
  • Middle Aged
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Paraffin Embedding
  • Point Mutation*
  • Polymerase Chain Reaction
  • Polymorphism, Genetic
  • RNA, Neoplasm / analysis
  • Tumor Cells, Cultured
  • Tumor Suppressor Protein p53 / analysis
  • Tumor Suppressor Protein p53 / genetics


  • DNA, Single-Stranded
  • RNA, Neoplasm
  • Tumor Suppressor Protein p53