Identification of novel genes involved in the synergistic antitumor effect of caffeine in osteosarcoma cells using cDNA macroarray.

BACKGROUND Caffeine enhances the cytocidal effects of DNA-damaging agents. This study investigated genes involved in the synergistic effect of caffeine on osteosarcoma cells using gene-profiling analysis. MATERIALS AND METHODS Sensitivity to cisplatin and the synergistic effect of caffeine were evaluated in five osteosarcoma cell lines with different p53 gene status. Gene expression profiles were analyzed using cDNA macroarray and verified by real-time RT-PCR. RESULTS The cell lines were grouped into three types with different cytotoxic patterns. Comparison of profiling data from these groups identified twelve novel genes associated with the synergistic effect of caffeine. Real-time RT-PCR analyses verified up-regulation of two apoptosis-enhancing genes and down-regulation of two interferon-inducible genes related to the synergy of caffeine. CONCLUSION These findings provide new insights into the molecular mechanisms of the synergistic effect of caffeine related to p53 gene status in osteosarcoma, providing candidates for an assay of responsiveness to caffeine-potentiated chemotherapy for osteosarcoma.