title: Mutations of the p53 gene in nasal NK/T-cell lymphoma.
abstract: Mutations of the p53 tumor suppressor gene are reported in various kinds of malignancies including lymphomas. However, p53 gene mutations in nasal NK/T-cell lymphoma have not been reported because most parts of tumors are necrotic and a small amount of living tumor tissues is available for the molecular study. Expression and mutations of the p53 gene were examined in the paraffin-embedded specimens of the nasal lesions from 42 Chinese (Beijing and Chengdu) and Japanese (Okinawa and Osaka) patients with nasal NK/T-cell lymphoma by the immunohistochemistry and single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) amplified products followed by direct sequencing. Thirty single-nucleotide substitution mutations were observed in 20 of 42 cases (47.6%). Among the 30 mutations, 18 were missense (mainly G:C to A:T transitions), 9 were silent, and 1 was a nonsense mutation. The remaining 2 mutations involved intron 5 and exon 5 terminal points. Abnormal expression of the p53 protein was also observed in 19 of 42 (45.2%) cases. The incidence was significantly (4-fold) higher in the cases of Osaka than those in other areas, although the incidence of p53 mutations in the cases of Osaka was one-half to one-third of those in the other three areas. The results may suggest some racial, environmental, or lifestyle differences in the cause of nasal tumorigenesis.
authors.affiliation: Department of Pathology, Osaka University Medical School, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Li
authors.forename: T
authors.initials: T
authors.lastname: Hongyo
authors.forename: M
authors.initials: M
authors.lastname: Syaifudin
authors.forename: T
authors.initials: T
authors.lastname: Nomura
authors.forename: Z
authors.initials: Z
authors.lastname: Dong
authors.forename: N
authors.initials: N
authors.lastname: Shingu
authors.forename: S
authors.initials: S
authors.lastname: Kojya
authors.forename: S
authors.initials: S
authors.lastname: Nakatsuka
authors.forename: K
authors.initials: K
authors.lastname: Aozasa
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D016158:Genes, p53; D006801:Humans; D007694:Killer Cells, Natural / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000473:pathology