Abstract
Caffeine sensitizes a number of cells to ionizing radiation. The radiosensitizing effects of caffeine are believed to be associated with the disruption of DNA damage-responsive cell cycle checkpoints controlled by ATM. We investigated the effects of caffeine on non-growing G0 human fibroblast cells by determining cell survival and scoring chromosome aberrations. We found that G0 cells exposed to X-rays were sensitized by post treatment of caffeine from cell survival study. Analysis of chromosome aberrations using FISH (fluorescence in situ hybridization) revealed that high frequency of aberrant cells and misrejoining was induced by caffeine. There seems to be another mechanism of cytotoxic effects of caffeine on cell killing other than inhibition of cell cycle checkpoint control.
