Abstract

Immunohistochemical stains for bcl-2 oncoprotein and PCNA and examination of the mitosis level were perfon-ned in 76 cases of cervical intraepithelial neoplasia (CIN). We studied the expression pattern of bcl-2 protein according to histologic grades and the function of bcl-2 oncogene associated with cellular proliferation by comparing with PCNA expression and the mitosis level. The results were as follows: 1) Of 76 cervical intraepithelial neoplasias, 23 (30.3%) were CIN I, 23 (30.3%) were CIN II, and 30 (39.4%) were CIN III. 2) Of 23 CIN I cases, grade 0 and 1 mitosis level were seen in 20 (87.0%), PCNA in 16 (69.6%), and bcl-2 in 19 (82.6%) cases, respectively, which indicates that CIN I lesions have a low cellular proliferative activity. 3) Of 30 CIN III cases, grade 2 and 3 mitosis level were noted in 28 (93.3%), PCNA in 25 (83.3%) and bcl-2 in 19 (63.3%) cases, respectively, which indicates that CIN III lesions have a high cellular proliferative activity. The results suggest that progressive increase of dysfunctional proliferative activity and abnormal decrease of cell death result in increased number of neoplastic cells according to CIN grade. Also the expression rate of bcl-2, PCNA and mitosis level were significantly different between CIN I and 111, which suggest that they might be good parameters for classifying CIN into low and high grade and for prediction of the biologic behavior of the CIN lesion.

• Keywords: Bcl-2 oncoprotein;Proliferating cell nuclear antigen;Cervical intraepithelial neoplasia;Immunohistochemistry;Mitosis