Correlation between Bcl-2 protein expression and some clinicopathological features of oral squamous cell carcinoma

Bcl-2 inhibits most kinds of programmed cell death and provides a selective survival advantage to various cell types. The biological significance of Bcl-2 expression for the development and progression of oral cancer has still to be evaluated. The aim of our study was to estimate possible correlations between the Bcl-2 protein expression and some clinicopathological features of oral cancer. The study was conduced on 129 patients treated surgically for oral squamous cell carcinoma. The statistically significant relationships were observed between oral squamous cell cancer Bcl-2 expression and higher tumor grading (p<0.005), higher tumor mitotic index (p<0.005), higher index of atypical mitoses (p<0.001) as well as microfocal pattern of tumor invasive margin (p<0.001). The results suggest that positive Bcl-2 expression may be a valuable factor supplementing the established unfavorable histopathological features of oral squamous cell carcinoma.

The expression of tumorigenesis markers in oral papilloma

Oral papilloma is the most frequent benign tumor of the oral cavity but its biological potential for malignant transformation is still to be evaluated. The alteration of apoptosis and uncontrolled cell proliferation is considered to be an important factor in oral tumorigenesis. The aim of our study was to evaluate by immunohistochemistry P53, Bcl-2, CD44 and PCNA expression in oral papillomas with and without dysplasia. We examined a series of 55 oral papillomas, including 12(21.8%) cases of papillomas with epithelial dysplasia. Staining patterns were correlated with sex, age, tumor location, size and presence or absence of epithelial dysplasia. P53 showed positive reaction in 70.9%, PCNA in 80%, CD44 in 50.9% and Bcl-2 in 21.8% of papillomas. There was no correlation between sex, age, tumor size, location and presence of dysplastic epithelium in papillomas. We observed a statistically significant correlation between Bcl-2, CD44 expression and presence of epithelial dysplasia in papillomas. Coexistence of PCNA and P53 positive immunostaining was observed. Papillomas with overexpression of P53 and PCNA showed negative reaction for CD44 protein. The results of our study suggest that overexpression of P53 and PCNA might be an early event in oral tumorigenesis, whereas CD44 and Bcl-2 are potential markers of epithelial dysplasia in oral papillomas.