EFFECTS OF CAFFEINE ON NEOCARZINOSTATIN-INDUCED INHIBITION OF CELL-CYCLE TRAVERSE IN HELA-S3 CELLS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 40  (10) , 3786-3791
Abstract
Caffeine suppressed the cell cycle effects of the cancer chemotherapeutic agent neocarzinostatin (NCS). When caffeine was added with NCS to the culture of [human cervical carcinoma] HeLa-S3 cells, NCS-induced inhibition of DNA synthesis and of mitosis was markedly reduced in the presence of caffeine. Theophylline was also effective, but N6,O2''-dibutyryl cAMP was not. The caffeine-caused reduction of cell cycle effects was also observed in several other cancer chemotherapeutic agents, including bleomycin and adriamycin. The single-strand scission of cellular DNA and the final cell lethality induced by NCS were not affected by caffeine. The mechanism by which NCS inhibits the cell cycle traverse probably involves a kind of cell damage which is repairable in a manner promoted by caffeine and hence is different from single-strand scission of DNA. Such a mechanism might be common to the cell cycle effects of X-irradiation and several cancer chemotherapeutic agents including NCS.