Versican silencing in BeWo cells and its implication in gestational trophoblastic diseases

Versican is a proteoglycan known to interact with cells to influence their ability to proliferate, differentiate, migrate, invade and assemble extracellular matrix, with all of these cell functions present during placentation. In the placenta, cytotrophoblast cells have the ability to differentiate into the syncytiotrophoblast, a mechanism that is greatly increased in gestational trophoblastic diseases (GTD). Nevertheless, the molecular signaling underlying the increased syncytiotrophoblast differentiation are still being unveiled and may result in novel therapeutic targets for GTD. Versican expression was investigated to establish its differential expression among GTD (partial moles, complete moles, invasive moles and choriocarcinoma) and the possible functional outcomes from versican gene silencing. Tissue samples had their versican expression evaluated using immunohistochemistry and RT-PCR. BeWo cells were employed for versican silencing with siRNA and the efficiency was confirmed by RT-PCR, immunofluorescence and flow cytometry. Cell death and forskolin-induced syncytialization were analyzed by a morphological analysis and human chorionic gonadotropin (hCG) production using immunofluorescence. Versican V0 and V1 isoforms were mainly expressed in the syncytiotrophoblast and they were the most expressed in benign rather than in malignant tumors. BeWo cells also expressed V0 and V1 isoforms, but only in cells undergoing syncytial fusion. After versican silencing, cell death was greatly increased, whereas spontaneous and forskolin-induced syncytialization decreased as well as hCG production. Versican is differentially expressed in GTD and is important for hydatidiform moles pathophysiology, protecting trophoblast cells from death and playing a role in their differentiation and functionality.