title: p53 gene mutations in human epithelial skin cancers.
abstract: In the present study we analysed 38 epithelial skin cancers, 19 basal cell carcinomas (BCCs), 13 squamous cell carcinomas (SCCs) and six Bowen diseases (BwDs), using a combination of polymerase chain reaction (PCR) and single-stranded conformation polymorphism (SSCP) techniques for the presence of p53 and RAS gene mutations. Whereas 48% (9/19) of the BCCs tested presented a mutated p53 gene, the frequency was lower (15%, 2/13) in our series of SCCs and negative in the BwDs. Nine of the 11 characterized mutations were single-nucleotide substitutions and, interestingly, seven of these involved CC dimers, where a C was changed into a T or a G (three C-->T transitions and four C-->G transversions). This mutational pattern, added to the fact that all the mutated tumors occurred at sun-exposed body sites, implicates UV light in their genesis. Furthermore, we observed two internal deletions of 6 and 24 bp whose flanking sequences contained two or three Cs on either strand. In addition to molecular detection, we searched for p53 protein accumulation, by immunocytochemical staining, in a subset of 23 epithelial skin tumors (nine bearing a mutation, 14 which scored negative in our assay). Three commercially available anti-p53 antibodies (PAb CM1, mAbs DO7 and 1801) were used, and 3/23 (all showing a mutated p53 gene) presented specific nuclear staining. In contrast to other reported data we could not detect any activating RAS gene mutation in our series of human skin cancers.
authors.affiliation: Laboratoire de Dermatologie Moléculaire, CNRS/CRBM BP 5051, Montpellier, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Molès
authors.forename: C
authors.initials: C
authors.lastname: Moyret
authors.forename: B
authors.initials: B
authors.lastname: Guillot
authors.forename: P
authors.initials: P
authors.lastname: Jeanteur
authors.forename: J J
authors.initials: JJ
authors.lastname: Guilhou
authors.forename: C
authors.initials: C
authors.lastname: Theillet
authors.forename: N
authors.initials: N
authors.lastname: Basset-Sèguin
mesh_terms: D001483:Base Sequence; D001913:Bowen's Disease / Q000235:genetics; D002280:Basal Cell Carcinoma / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009154:Mutation; D012878:Skin Neoplasms / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
chemical_list: D016159:Tumor Suppressor Protein p53