Alteration in morphology and induction of glutamine synthetase in rat glioma C6BU-1 cells cultured with prostaglandin D2-supplemented media

Abstract

We evaluated the effects of prostaglandins (PGs) on rat glioma C6BU-1 cells by supplementing the culture media with PGs. In the medium containing PGD(2) (15 or 20 ?M), the glial cells showed altered morphology from an elongated fibroblastic form to a spreading multipolar one within 24 h, and their growth rate was suppressed to half of that of control cultures. In these cultures, the specific activity of glutamine synthetase (GS) increased approximately twofold within 48 h in comparison to the value for vehicle-treated controls. Simultaneous treatment with actinomycin D or cycloheximide completely blocked the PGD(2)-elicited increase in GS specific activity, suggesting that the increase was due to de novo synthesis of the enzyme. PGD(2)-like prostanoids such as PGD(1) and 9-deoxy-?(9), ?(12)-13,14-dihydro-PGD(2) (?(12)-PGJ(2)), when added to the culture medium, mimicked the actions of PGD(2) on the C6BU-I cells, though their effective concentrations were not necessarily identical. PGs of the E- and F-series had almost no discernible effect on the glioma. These results might imply a possibility that PGD(2) plays a regulatory effect in growth and/or differentiation of rat glioma C6BU-1 cells.