title: Elevated ras p21 expression in oral premalignant lesions and squamous cell carcinoma in Taiwan.
abstract: Expression of ras p21 oncoproteins was examined in histological sections of oral squamous cell carcinoma (SCC), epithelial dysplasia, epithelial hyperkeratosis and normal oral mucosa using antibodies to ras p21 with an immunoperoxidase technique. Ras p21-positive staining was found in 47 of 51 (92.2%) cases of oral SCC, 4 of 4 (100%) cases of epithelial dysplasia, 7 of 7 (100%) cases of epithelial hyperkeratosis, and 1 of 6 (16.7%) cases of normal oral mucosa. The positive staining rate of ras p21 in oral SCC, epithelial dysplasia or epithelial hyperkeratosis was significantly higher than that in normal oral mucosa (P < 0.05). No correlation was found between ras p21 expression and patient age, tumour location, tumour size, clinical staging or histological differentiation of SCC. However, a significant positive correlation was found between ras p21 expression and patients' sex (P < 0.05) or regional lymph node status (P < 0.05). A significant positive correlation was also discovered between ras p21 expression and patients' smoking habits (P < 0.01), as well as daily or total betel quid (BQ) consumption (P < 0.05). Of the 47 immunostain-positive SCC patients, specimens from 6 patients were also obtained after chemotherapy, when ras p21 expression was found to be reduced. These results indicate that ras p21 overexpression may play an important role in the initiation and progression of oral SCCs in patients who are smokers and BQ chewers.
authors.affiliation: School of Dentistry, National Taiwan University, Taipei, ROC.
authors.forename: M Y
authors.initials: MY
authors.lastname: Kuo
authors.forename: H H
authors.initials: HH
authors.lastname: Chang
authors.forename: L J
authors.initials: LJ
authors.lastname: Hahn
authors.forename: J T
authors.initials: JT
authors.lastname: Wang
authors.forename: C P
authors.initials: CP
authors.lastname: Chiang
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies; D001114:Areca; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007124:Immunoenzyme Techniques; D007972:Leukoplakia, Oral / Q000235:genetics / Q000473:pathology; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D009367:Neoplasm Staging; D015689:Oncogene Protein p21(ras) / Q000187:drug effects / Q000235:genetics*; D010946:Plants, Medicinal; D011230:Precancerous Conditions / Q000235:genetics* / Q000473:pathology; D012737:Sex Factors; D012907:Smoking / Q000235:genetics; D013194:Staining and Labeling; D013624:Taiwan
chemical_list: D000906:Antibodies; D015689:Oncogene Protein p21(ras)