title: Enhancement of methotrexate activity by theophylline in HeLa cell cultures.
abstract: Treatment of HeLa cells with 1.0 mM theophylline significantly reduced the growth rate of the cell cultures without affecting cellular viability. When methotrexate was added to the theophylline-treated cultures at a concentration of 0.5 microgram/ml, the cytotoxic activity of methotrexate was enhanced. The rate of cell loss in these cultures was over 2.5 times greater than in those cultures receiving only methotrexate. This enhancement of methotrexate activity was also observed when the concentration of methotrexate was reduced to 0.1 microgram/ml. It was concluded that treatment of cells with an agent which prolongs the cell cycle, such as theophylline, may aid in the development of more effective chemotherapy.
mesh_terms: D002455:Cell Division / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects*; D006367:HeLa Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D008727:Methotrexate / Q000494:pharmacology*; D013806:Theophylline / Q000494:pharmacology*
chemical_list: D013806:Theophylline; D008727:Methotrexate