Elevated ras p21 expression in oral premalignant lesions and squamous cell carcinomas 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.

Areca Nut Components Affect COX-2, Cyclin B1/cdc25C and Keratin Expression, PGE2 Production in Keratinocyte Is Related to Reactive Oxygen Species, CYP1A1, Src, EGFR and Ras Signaling

“…Similarly, recent study has found that BQ ingredients may stimulate Src activation in oral cancer epithelial cells to promote cell migration and tumor invasion [39]. An elevated expression of Ras and mutation of Ras in oral premalignant lesions and OSCC of BQ chewers has been reported [14], [40]. This indicates that activation of Src and Ras is important in the BQ carcinogenesis.…”

Univariate and multivariate analysis of prognostic significance of betel quid chewing in squamous cell carcinoma of buccal mucosa in Taiwan

“…Previous studies in our laboratory discovered that the expression of p53, PCNA and p21 ras was often higher in oral cancers and precancerous lesions from BQ chewers as compared to that of non-chewers [24][25][26][27]. Lee et al [28] showed that the average proportion of deleted mtDNA was significantly higher in non-tumor oral tissues from BQ chewers comparing to those of non-chewers.…”

Arsenic Exposure and Age- and Sex-Specific Risk for Skin Lesions: A Population-Based Case–Referent Study in Bangladesh

“…Also, As skin lesions in Inner Mongolia were shown to be related to markers of oxidative DNA damage (Fujino et al 2005). However, no association was found between smoking and As-related skin cancer (Chen et al 2003) or cutaneous squamous cell carcinoma (Odenbro et al 2005), although overexpression of ras p21 oncoproteins has been suggested to play a role in the initiation and progression of oral squamous cell carcinoma in smokers (Kuo et al 1995). …”