Expression of Bcl-2 in dysplastic and neoplastic cervical lesions in relation to cell proliferation and HPV infection

Expression of the bcl-2 gene has been shown to effectively confer resistanc e to programmed cell death in a variety of tumors. The bcl-2 proto-oncogene is involved in the development of human follicular lymphomas and also in a number of solid tumors such as carcinomas of prostate, breast, lung and GI T. The present study was designed to analyze the role of Bcl-2 expression i n cervical intraepithelial squamous neoplasias (CIN) and cervical invasive carcinomas. Special attention was given to the association of Bcl-2 express ion with the grade of the lesion, proliferative activity (expression of nuc lear antigen of proliferative cells - PCNA) and human papillomavirus (HPV) DNA positivity. We examined tissue samples obtained From 86 women with vary ing degrees of cervical disease. Bcl-2 and PCNA were investigated using imm unohistochemical staining and detection of HPV DNR was performed by hybridi zation in situ. Increased Bcl-2 expression was observed in advanced degrees of dysplasia and in carcinomas. We found a strong association between the presence of Bcl-2 in pathological epithelium with both the degree of dyspla sia and the proliferative activity. We also observed a significant correlat ion between the amount of Bcl-2 positive lymphocytes infiltrating the lesio ns and the degree of disease. We, therefore, suggest that Bcl-2 expression in these lymphocytes may influence the antiviral or antitumor immune respon se. On the other hand we did not detect any significant correlation between the Bcl-2 oncoprotein and the presence of HPV. These results indicate that Bcl-2 may play an important role in the development of cervical cancer.