title: Role of PTCH and p53 genes in early-onset basal cell carcinoma.
abstract: Basal cell carcinoma (BCC) is the most common skin cancer in the Western world. Ultraviolet (UV) exposure, race, age, gender, and decreased DNA repair capacity are known risk factors for the development of BCC. Of these, UVB irradiation from sunlight is the most significant risk factor. The incidence of sporadic BCC increases in individuals older than age 55, with the greatest incidence reported in individuals who are older than 70, and is rare in individuals who are younger than 30. In this study, we analyzed 24 BCC samples from individuals who had BCC diagnosed by the age of 30. Fifteen single-stranded conformation polymorphism variants in the PTCH gene were identified in 13 BCC samples. Sequence analysis of these single-stranded conformation polymorphism variants revealed 13 single nucleotide changes, one AT insertion, and one 15-bp deletion. Most of these nucleotide changes (nine of 15) were predicted to result in truncated PTCH proteins. Fifteen p53 mutations were also found in 11 of the 24 BCC samples. Thirty-three percent (five of 15) and 60% (nine of 15) of the nucleotide changes in the PTCH and p53 genes, respectively, were UV-specific C-->T and CC-->TT nucleotide changes. Our data demonstrate that the p53 and PTCH genes are both implicated in the development of early-onset BCC. The identification of UV-specific nucleotide changes in both tumor suppressor genes suggests that UV exposure is an important risk factor in early onset of BCC.
authors.affiliation: Department of Dermatology, Columbia University, College of Physicians and Surgeons, New York, New York, USA.
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: X L
authors.initials: XL
authors.lastname: Ping
authors.forename: P K
authors.initials: PK
authors.lastname: Lee
authors.forename: X L
authors.initials: XL
authors.lastname: Wu
authors.forename: Y J
authors.initials: YJ
authors.lastname: Yao
authors.forename: M J
authors.initials: MJ
authors.lastname: Zhang
authors.forename: D N
authors.initials: DN
authors.lastname: Silvers
authors.forename: D
authors.initials: D
authors.lastname: Ratner
authors.forename: R
authors.initials: R
authors.lastname: Malhotra
authors.forename: M
authors.initials: M
authors.lastname: Peacocke
authors.forename: H C
authors.initials: HC
authors.lastname: Tsou
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D019943:Amino Acid Substitution; D001483:Base Sequence; D002280:Basal Cell Carcinoma / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D017354:Point Mutation; D018807:Polymorphism, Single-Stranded Conformational; D011956:Receptors, Cell Surface; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000502:physiology
chemical_list: D004273:DNA, Neoplasm; D008565:Membrane Proteins; C000606236:PTCH1 protein, human; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D011956:Receptors, Cell Surface; D016159:Tumor Suppressor Protein p53