Objective: To study the aberrant expression and coexpression of protein p16 and Rb in cervical squamous carcinomas, and to evaluate whether these alterations provide causative information.
Methods: The expressions of p16 and Rb protein were detected by treptavidin-peroxidase(S-P) immunohistochemical methods.
Results: 1. The p16 protein expression was mainly found in cytoplasm. The positive rate in carcinoma, CIN and normal cervix were 43.1%(25/58), 62.5%(5/8) and 70%(14/20), respectively; the positive expression were decreased in lower grade and clinical advanced cases(P < 0.05). 2. The Rb protein expression was detected in nucleus. The positive rate of Rb protein were 37.9%(22/58), 75%(6/8) and 85(17/20) in tum. The difference of the expression of Rb protein between the cervical squamous carcinoma and the normal cervix was significant(P < 0.05). The positive expression were increased in lower grade cancers(P < 0.05), and decreased in advanced cases(P > 0.05). 3. The positive rates of p16 and Rb protein in cervical squamous carcinoma showed an inverse correlation (vs = -0.4301, P < 0.01).
Conclusions: 1. The abnormal p16 and Rbn expression might play an important role in the tumor genesis and the development of cervical squamous carcinoma. 2. Loss of function of both tumor suppressor genes may be an advanced event in cervical squamous carcinomas and might involve a bad prognosis.