GROWTH-INHIBITION OF RAT GLIOMA-CELLS IN-VITRO AND IN-VIVO BY ASPIRIN

The effect of non-steroidal anti-inflammatory drugs (NSAIDs), acetylsa licylic acid (commonly known as aspirin), salicylic acid, piroxicam an d indomethacin on the growth of rat glioma cells (RG 2) in vitro and a spirin in vivo was studied. The in vitro studies reveal that aspirin a nd salicylic acid strongly inhibit growth of rat glioma (RG 2) cells i n concentrations used in medicine for treatment of rheumatic diseases. On the other hand, indomethacin and piroxicam had no effect, indicati ng that the inhibitory effect on tumor growth is not due to the inhibi tion of prostaglandin synthesis. The synthesis of ATP was markedly red uced (34 % of control) in the presence of drugs, whereas protein synth esis measured as H-3-leucine incorporation was slightly more inhibited (73% of control) than cell growth. Aspirin administered to Fischer 34 4 rats inhibited growth of RG 2 cells inoculated into the caudate nucl eus in vivo, both when administered the day before inoculation of tumo r cells and when tumors had formed, i.e. 5 days post inoculation.