The Study Of Expression Of Cyclin E And Its Related Proteins In Gestational Trophoblastic Disease

Objectives To investigate the expression of Cyclin E,CDK-2 and their inhibitors P27^KIP1and P21^WAF1/CIP1in gestational trophoblastic disease(GTD).To analyze the correlations of the above indexes expression in GTD.To observe the effect of all-trans retinoic acid(ATRA)on choriocarcinoma JEG-3 cell line.Methods Expression of the above indexes was determined immunohitochemically 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 tumors,including 8 invasive moles and 1 choriocarcinoma.JEG-3 cell line was treated with different concentrations of ATRA.MTT assay was used to observe the effect of ATRA on proliferative ability of JEG-3 cell line.RT-PCR was used to examine the mRNA expression of Cyclin E,CDK-2,P27^KIP1andP21^WAF1/CIP1before and after ATRA induction.Results 1.The expression of cyclin E and CDK-2 in GTD was significantly higher than that in normal placentas(P＜0.05).There was no statistical difference of cyclin E and CDK-2 expression between gestational trohpoblastic neoplasia(GTN)and hydatidiform mole(P＞0.05).The expression of P27^KIP1and P21^WAF1/CIP1in GTN was significantly lower than that in hydatidiform moles and normal placenta tissues,respectively(P＜0.05).Moreover,the expression of P27^KIP1and P21^WAF1/CIP1in hydatidiform moles which developed GTN was significantly lower than those spontaneously regressed.There was no significant difference(P＞0.05)in cyclin E and CDK-2 expression between 4 patients who developed invasive moles and those who did not.2.Correlations among strong positive staining rates of the above proteins were analyzed.Significant negative correlations between the cyclin E and P27^KIP1,P21^WAF1/CIP1staining 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 P27^KIP1andP21^WAF1/CIP1showed positive correlation with statistical significance(P＜0.05).CDK-2 showed inverse expression pattern compared with P27^KIP1and P21^WAF1/CIP1,but no statistical difference was observed(P＞0.05).3.The expression of CDK-2 and cyclin E in hydatidiform moles withβ-HCG≥100 000mIU/ml was higher than that in patients withβ-HCG＜100 000mIU/ml,but no statistical difference was observed(P＞0.05).The expression of P27^KIP1and P21^WAF1/CIP1was lower in the former group,without statistical difference either(P＞0.05).4.The expression of P27^KIP1and P21^WAF1/CIP1in patients aged more than 40 years was lower than that in those who were younger than 40 years,but without statistical difference(P＞0.05).The expression of CDK-2 and cyclin E was higher in the former group,without statistical difference(P＞0.05).5.ATRA could effectively inhibited the proliferative ability of choriocarcinoma JEG-3 cell line.Different concentrations of ATRA were administrated to JEG-3 cell line.There was a significantly decrease of cyclin E mRNA expression in a dose-dependent manner(P＜0.05).And upregulation of P27^KIP1and P21^WAF1/CIP1 mRNA levels was observed(P＜0.05).There was no significant changes of CDK-2 mRNA level before and after ATRA induction(P＞0.05).Conclusions 1.Disregulation of cyclin E/CDK-2 complex and its inhibitors participated in the development of gestational trophoblastic tumor.2.P27^KIP1and P21^WAF1/CIP1may be used as effective indicators for the prognosis of hydatidiform moles.3.There is no relation of the expression of above indexes to age andβ-HCG in hydatidiform moles.4.ATRA can effectively inhibited the proliferation of JEG-3 choriocacinoma cell line through downregulation of cyclin E mRNA expression and up-regulating the mRNA levels of P27^KIP1and P21^WAF1/CIP1.Therefore,ATRA can be an effective candidate agent for the treatment of choriocarcinoma.