[Expression of RFC2 and PCNA in different gestational trophoblastic diseases].

BACKGROUND &

OBJECTIVE

High expression of replication factor C (RFC) mRNA in hydatidiform mole and choriocarcinoma were detected previously with DNA microarray. Replication factor C subunit 2 (RFC2) was reported to be associated with DNA duplication, DNA repair, and the function of cellular checkpoint. The aim of current study was to investigate the expression levels of RFC2 and proliferating cell nuclear antigen (PCNA) in gestational trophoblastic diseases (GTD) and to explore the relationship of expressions of two proteins with GTD.

METHODS

The expression of RFC2 and PCNA were detected with immunohistochemical method in 15 cases of normal villi, 38 cases of hydatidiform moles (HM), 42 cases of invasive moles (IM), and 18 cases of choriocarcinomas (CC).

RESULTS

The expression of RFC2 and PCNA were significantly increased in HM, IM, and CC than in normal villi (P=0.000 for RFC2,P=0.004 for PCNA). There was no significant difference of the expression of RFC2 among HM, IM, and CC. The PCNA expression was significantly higher in CC than in HM (P=0.037). PCNA expression was significantly higher in the patients with malignantly transformed molar pregnancy than in the patients without malignantly transformed molar pregnancy (P=0.039). RFC2 expression in no preoperative chemotherapeutic group of gestational trophoblastic tumors (GTT) including IM and CC was significantly higher than that in the group with the chemotherapy of more than 3 cycles (P=0.028). Compared with patients at stageI, patients at stage III (WHO) had significantly increased expression of RFC2 (P=0.01). The level of RFC2 was higher in the patients with high risk in WHO prognostic scoring system than that in the patients with low risk (P=0.018). The levels of PCNA were significantly higher in the patients with high risk and middle risk than that in the patients with low risk (P=0.036 and P=0.048, respectively). The expression of PCNA protein was not associated with the preoperative chemotherapy and WHO stage of GTT. The RFC2 expression was positively correlated with the PCNA expression (P=0.000).

CONCLUSION

The over-expression of RFC2 and PCNA in GTD may be associated with the malignant transformation of HM and the behavior of trophoblastic tumor.