[The combined effect of cisplatin and caffeine on human sarcoma cells in vitro]

The combined effect of cisplatin and caffeine which was reported to inhibit post-replication of DNA repair, were studied on two kinds of cultured human sarcoma cells. Cell kinetics during drug administration were analysed by flow cytometry. As the result, it was found that the combination of cisplatin with caffeine showed a synergistic effect on the sarcoma cells. Cisplatin alone caused S and G2 accumulation on DNA histograms. The growth inhibition rate was enhanced when the S and G2 accumulation was reduced by caffeine. In both cases, nuclear fragmentation was frequently observed with a light and fluorescent microscope. This fundamental study implied that caffeine would be one of useful synergistic drugs in the chemotherapy of sarcoma.