Experimental Research On Enhancement Effect Of Caffeine In Cisplatin-induction Apoptosis Of Osteosarcoma

Caffeine is a alkaloid derived from tea or caffea. Being a biologic regulator, caffeine had been applied in the treament of therioma and had positive effect.Nowadays,the mechanism on enhancement effect of caffeine in chemical of bone tumor was not known clearly. Kakuyama A et al thought that the mechanism on enhancement effect of caffeine in adriamycin's curative effect was caffeine could restrain the power of drug's transfer pump so that the adriamycin's concentration in tumor cells and resisting tumor's effect were improved.Adriamycin's side effect on the level of substantia adiposa superoxide and adriamycin's concentration in normal tissues were not changed. Mariot P et al thought caffeine was excitomotor of Ryanodine receptor so that factor IV could be released. Meanwhile, caffeine could block factor IV's interal flow induced by nickel. The enabled Ryanodine receptor could induce apoptosis of LNCap cells in low-grade. It was thought presently that caffeine could restrain DNA's potential fatal recovery, release G2/M blocking,induce apoptosis of tumor cells so that caffeine could improve the effect of chemical treament and radiational treament.However, being a synergist of chemical drug, there had been a few of caffeine on the treament of osteosarcoma .further ,no document on experimental reports.Materials and methodsWe chosen human osteosarcoma OS--732 cell line in this study. Osteosarcoma OS--732 cell line were divided into four groupsxontrol group,caffeine group,cisplatin group and mixing group.Caffeine's treating concentration was S.OmM and cisplatin's was lO.Oug/ml. Osteosarcoma OS--732 cells were incubated with drug for 24 hours,48 hours.Control group was not treated . Enhancement effect of caffeine in cisplatin-induction apoptosis of osteosarcoma was observed from three aspects. Firstly, osteosarcoma OS-732 cell's morphological changes were observed by fluorescence microscope .Secondly, with flow cytometry, the percentage of apoptotic osteosarcoma cells was detected by the change of chondrosome membrane's potential after drug action.Thirdly, TUNELCThemethod of TdT-mediated duTP-biotin nick end labeling)which could label DNA fragments was used to detect apoptotic peak.Results1 Morphological change Drug treated osteosarcoma cells,cell volume decreased,membrane wrinkled, the inter-cellular space broadened.Cells separated each other under fluorescence microscope.Cell shape was round or irregular.On the other hand, osteosarcoma cellnucleus was dye homogeneously in control group.2 Percentage of apoptotic cells detected by the change of chondrosome membrane's potential Percentage of apoptotic cells in mixing group was higher than that's in other groups.3 Apoptotic peak detected by TUNEL The height of apoptotic peak in mixing group was higher than that's in other groups.Conclusions1 Caffeine could induce osteosarcoma cell apoptosis directly.2 One of the important mechanisms on enhancement effect of caffeine in cisplatin-induction apoptosis of osteosarcoma was the damage of chondrosome membrane's potential.3 Caffeine had remarkable enhancement effect in cisplatin-induction apoptosis of osteosarcoma cell.