p53 alterations in betel quid- and tobacco-associated oral squamous cell carcinomas from Taiwan.
Alterations of p53 have been explored in Taiwanese oral squamous cell carcinomas (OSCCs) consisting of a betel quid (BQ)/tobacco-related subgroup of 36 subjects and a tobacco-related subgroup of 13 subjects. Mutations in conserved exons were found in 12 tumors. Seven mutations were clustered in a hot-spot region mapped to a region between codons 273-282 in exon 8. The incidence of p53 mutation in BQ/tobacco tumors was 22% (8/36). The frequency of p53 allelic loss (21%, 3/14) in BQ/tobacco tumors approximates to the incidence of mutation. This is the first study demonstrating allelic deletion of p53 in such malignancies. Twenty-four of 43 samples showed positive p53 immunostaining. All tumors harboring mis-sense mutations of p53 in conserved exons exhibited nuclear protein accumulation. The incidence of mutation in conserved exons in BQ/tobacco-associated Asian OSCCs (15%) is significantly different from worldwide OSCCs (46%) related primarily to tobacco consumption (P=0.00001).
The Faculty of Dentistry and Institute of Oral Biology, National Yang-Ming University, Taipei and Taichung and Taipei Veteran General Hospital, Taiwan, ROC.
Y K
YK
Wong
T Y
TY
Liu
K W
KW
Chang
S C
SC
Lin
T W
TW
Chao
P L
PL
Li
C S
CS
Chang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001114:Areca; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D003062:Codon / Q000235:genetics; D004396:Coloring Agents; D005091:Exons / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D005787:Gene Frequency; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D019656:Loss of Heterozygosity / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D010946:Plants, Medicinal; D012907:Smoking / Q000009:adverse effects*; D013624:Taiwan
D003062:Codon; D004396:Coloring Agents; D009687:Nuclear Proteins