Abstract: Objective： To investigate the expression of Cyclin E，CDK-2 and their inhibitors P27KIP1 and P21WAF1/CIP1 in gestational trophoblastic disease（GTD）. Methods：Expression of the above indexes were determined immunohistochemically by specific antibodies for these proteins on formalin-fixed paraffin sections of 30 of normal placenta tissues，38 of hydatidiform moles and 9 of gestational trophoblastic neoplasms （GTN）， including 8 invasive moles and 1 choriocarcinoma. Results：①The expression of Cyclin E and CDK-2 in GTD was significantly higher than that in normal placentas（P＜0.01）. The expression of P27KIP1 and P21WAF1/CIP1 in GTN was significantly lower than that in hydatidiform moles and normal placenta tissues，respectively（P＜0.05）. Moreover，the expression of P27KIP1 and P21WAF1/CIP1 in hydatidiform moles which developed GTN was significantly lower than those spontaneously regressed.②Significant negative correlations between the Cyclin E and P27KIP1，P21WAF1/CIP1 staining indexes were observed（P＜0.05）. There was a positive correlation between the expression of CDK-2 and Cyclin E（P＜0.05）. Also，the expression of P27KIP1 and P21WAF1/CIP1 showed positive correlation （P＜0.05）. CDK-2 showed inverse expression pattern compared with P27KIP1 and P21WAF1/CIP1，but no statistical difference was observed（P＞0.05）. Conclusions：Disregulation of Cyclin E/CDK-2 complex and its inhibitors participated in the development of gestational trophoblastic tumor. P27KIP1 and P21WAF1/CIP1 may be used as effective indicators for the prognosis of hydatidiform moles.

Key words: Gestational trophoblastic neoplasms, Cyclin E, Cyclin-dependent kinase 2, P27KIP1, P21WAF1/CIP1