Effect of cytochalasin B on growth, Multinucleation and human chorionic gonadotropin secretion in a human choriocarcinoma cell line.

Treatment of human choriocarcinoma cells with cytochalasin B at the doses of inhibiting cell division but not inhibiting nuclear division led to in vitro formation of the multinucleated syncytiotrophoblast-like ( STL ) cells. A concomitant increase in human chorionic gonadotropin (hCG) secretion per cell was noted. Immunocytochemical staining demonstrated the predominant localization of hCG in the STL cells. These results indicate that multinucleation stimulates hCG synthesis and secretion in the choriocarcinoma cells.