[Expression and significance of LMP2 and PPM1A in gestational trophoblastic disease]

To investigate the expression of low molecular mass polypeptide-2 (LMP2) and protein phosphatase 1A (PPM1A) in gestational trophoblastic disease and elucidate their predictive value in malignant transformation of hydatidiform mole.

The expressions of LMP2 and PPM1A protein in 196 complete hydatidiform moles (in which 28 cases with malignant transformation), 7 invasive moles, 5 choriocarcinomas and 20 normal chorionic villus were detected with the method of EnVision immunohistochemistry. Their clinicopathologic data were retrospectively analyzed.

LMP2 and PPM1A protein expressed in cytotrophocytes, syncytiotrophoblast and extravillous trophoblast. The level of LMP2 expression in deteriorative hydatidiform mole was significantly higher than that in non-deteriorative hydatidiform mole or normal chorionic villus (6.79±2.38, 5.26±2.63 and 3.10±1.65, all P<0.01), while there were no difference compared with gestational trophoblastic neoplasms (6.42±2.68, P=0.113). The level of PPM1A expression was highest in normal chorionic villus, and decreased gradually in hydatidiform mole (non-deteriorative and deteriorative) and gestational trophoblastic neoplasms (6.30±2.98, 4.93±2.50, 4.43±2.04 and 3.33±2.06, all P<0.01); the level of PPM1A expression in deteriorative hydatidiform mole was significantly lower than that in non-deteriorative hydatidiform mole (P=0.001). The expression of LMP2 protein was correlated to theca lutein ovarian cyst, the expression of PPM1A protein was related with uterine size (P<0.05). While, there was no correlation between the expressions of the two proteins (P>0.05).

High expression of LMP2 and low expression of PPM1A might play an important role in the motility and invasiveness of trophoblast cells and malignant transformation of hydatidiform mole. Testing the expression of LMP2 and PPM1A in hydatidiform mole tissues of initial uterine evacuation might be have some reference significance in judging outcomes of hydatidiform mole.