Objective:The development of oral cancer is a multistep process comprising genetic mutations and chromosomal abnormalities. There are several molecular markers concerned with carcinogenesis of oral squamous cell carcinoma. The aim of this article is to evaluate the immunoexpression pattern of p53, Bax andhTERT in oral epithelia dysplasia and oral squamous cell carcinoma. Material and methods:Tissue Samples of 210 formalin-fixed, paraffin-embedded biopsy specimens were retrieved. The samples were oral leukoplakia with dysplasia (n=90), oral squamous cell carcinoma (n=90) and normal oral epithelium (n=30). The quantitativeimmunohistochemistry analysis for p53, Bax and hTERT were performed for all selected samples. The percentage of positive cells, tissue and cellular localization were evaluated and analysed. Results: In oral epithelium,the expression of p53 (80%) and hTERT (82.3%)wasconfined to basal layer butBax (76.5%)expression was predominant in supra basal layers.In oral epithelial dysplasia, supra basal expression of p53 and hTERT were increased with histological grades but, it was decreased for Bax.p53 and Bax expressions were statistically significant among histological grades of dysplasia (p<0.001) whereas,hTERT expression was not significant (p-0.674). In oral squamous cell carcinoma, the expression of p53, Bax and hTERT were statistically significant between histological grades(p<0.05). Remarkably, nuclear expression of hTERT was completely shifted to nuclear and cytoplasm with grades of dysplasia and oral squamous cell carcinoma. The association of p53, Bax and hTERT expression was significant among oral epithelium, oral epithelial dysplasia and oral squamous cell carcinoma(p<0.05). Conclusion:Increased expression of mutant p53,hTERT along with decreasedBax expression were significantly associated with histological grades of oral epithelial dysplasia and oral squamous cell carcinoma. These expression pattern of markers suggest their role as surrogate markers of malignant transformation.
Key words: Tumor suppressor protein, Pro apotoic protein, Telomerase, Oral epithelial dysplasia, Oral squamous cell carcinoma.