The stimulation by methotrexate of human chorionic gonadotropin and placental alkaline phosphatase in cultured choriocarcinoma cells.

Treatment of the BeWo line of choriocarcinoma cells with methotrexate in doses that inhibit DNA synthesis causes a tenfold increase in synthesis of human chorionic gonadotropin and a threefold increase in activity of placental alkaline phosphatase. No concomitant increase in lactic dehydrogenase activity occurs under these conditions. This effect of methotrexate can be blocked by simultaneous addition of thymidine or folinic acid, neither of which alone increases human chorionic gonadotropin synthesis or placental alkaline phosphatase activity in BeWo cells.