Expression Of P16,Rb,HPV16-E7 Protein In Cervical Carcinogenesis And Their Significance

Objective In order to provide the basis of preventing and predicting prognosis the cervical carcinoma, the expression of P16, Rb, HPV16-E7 and their relationship in the carcinogenesis of cervix was studied.Methods Irnmunohistochemical streptavidin/peroxidase (SP) method was used to examine the expression of HPV16-E7, P16 , Rb in 20 cases of normal cervical tissues, 28 cervical intraepithelial neoplasias (CIN) and 59 invasive squamous cell carcinoma (SCC).Results (1) The positive expression rate of HPV16-E7 in normal cervical tissues, CIN and SCC was 5%, 39.29%, 77.97%, respectively. The expression had an increasing tendency. There was highly significant difference among the expression HPV16-E7 protein in three different tissues (P<0.01) .(2) The positive expression rate of Rb in normal cervical tissues, CIN and SCC was 90%,71.43%,38.98%, respectively. The negative expression had an increasing tendency. The expression level in SCC was lower than that in the CIN and normal cervical tissues (P<0.01) . The expression level in CIN was lower than that in normal cervical tissues (P<0.05) .(3) The overexpression rate of PI6 protein in normal cervical tissues , CIN and SCC was 25%,44%,67.24%, respectively, Which had an increasing tendency. There was significant difference between CIN and the other two group (P<0.05) . There was highly significant difference between SCC and normal cervical tissues(P<0.01) . (4) There was an inverse relationship between the expression of HPV16-E7 andRb protein in CIN tissues(P<0.05);There was an inverse relationship between theexpression of HPV16-E7 or the overexpression of P16 protein and the expression of pRb in SCC (P<0.01) . while a positive relationship between the expression of HPV16-E7 and the overexpression of P16 protein (P<0.01) .Conclusions (1) HPV16-E7 protein was consistently expressed in cervical carcinogenesis, and the expression of HPV16-E7 showed significant relation to the degree of maligenity. HPV16-E7 may be involved in malignant transformation.(2) Rb protein may be functionally inactivated in cervical carcinoma, which may be occurred in early step of cervical carcinogenesis.It is proposed that precancerous lesions with negative expression of pRb might be of higher susceptibility for cervical carcinoma.(3) The lack expression of P16 protein showed no relation to the cervical carcinogenesis-Overexpression of P16 was observed in most of high-grade dysplastic cervical lesions. There was significant relationship between the expression of HPV16-E7 and overexpression of P16. The overexpression of P16 protein may be as a biomarker for screening high risk population.(4) It is proposed that CIN with both overexpression of P16 and positive expression of HPV16-E7 and negative expression of pRb was most probably maligent...