The Influence Of Dihydroartemisinin In Combination With Paclitaxel On Proliferation And Apoptosis In Human Gastric Cancer MGC-803 Cells

Objectives:By Taking human gastric cancer MGC-803 cells as researching objects, the respective effects of dihydroartemisi- nin(DHA) and paclitaxel(PTX) on the cell proliferation and apoptosis induction were observed,and if the two drugs had synergistic antitumor effects was investigated preliminarily, to provide new methods for gastric cancer chemotherapy.Methods:Human gastric cancer MGC-803 cells were cultured in vitro.CCK-8 assay was performed to detect the respective effect of DHA,PTX and their combination on cell proliferation of 24 h,then we used the Chou-Talalay method to evaluate the joint effects of these two medicines.Then we used flow cytometer to analyze the effect of cell cycle and fluorescent microscope to observe morphological changes of different treatments after AO/EB dying.Reverse transcription-polymerase chain reaction method and Western blotting method were used to analyze the expression of Bcl-2,Bax and Caspase-3.Results:1.DHA(191.082,955.410,4777.048,23885.240,119426.202ng/ ml),PTX(2.4,12,60,300,1500ng/ml) and the doublet(191.082+2.4,955.410+ 12,4777.048+60,23885.240+300,119426.202+1500ng/ml) could inhibit cell proliferation of human gastric cancer MGC-803 cells depending on concentration(p<0.05),and the combination therapy of proliferation inhibition was superior to single medicine(p<0.05).But the synergistic effect was only when the drugs combined in lower dose,when the combined dose increased,the antagonism effect was carried out.2.After treating the MGC-803 cells with different groups for 24 h,flow cytometer(FCM) results showed that DHA(955.410ng/ml) could respectively arrest cell cycles in G0/G1 and S phase(p<0.001),PTX(12ng/ml) could respectively arrest cell cycles in G2/M phase(p<0.001),and the combination(DHA955.410ng/ml+PTX12ng/ml) could arrest cell cycles in S and G2/M phase(p<0.001).When compared to PTX,the combination arrested less cells in G2/M phase(p<0.001).3.The morphology of apoptotic cells were observed under fluorescent microscope,there appeared many orange yellow and orange lake cells after being treated with differnt drugs for 24 h.These cells, compared to green cells,became cell shrinked and cytoplasmic concentrated,and apparently they are with the feature of apoptosis. In the same condition, the apoptotic cells in the combination group increased much more than the single drug group does,especially the orange lake cells.4.DHA(955.41ng/ml), PTX(12ng/ml) and their combination(DHA 955.41ng/ml+PTX12ng/ml) improved the expression of Bax,Caspase-3,also restrained the expression of Bcl-2.Even more, the combination acts better than the two single drug(p<0.05).Conclusions:1. Different concentrations of DHA,PTX have obvious inhibition on proliferation of human gastric cancer MGC-803 cells in a dose depending manner.2. The DHA combined with PTX has obvious inhibition on proliferation of human gastric cancer MGC-803 cells. The synergistic effect exits only when the drugs combined in lower dose.When the combined dose increasing,the antagonism effect carry out.3. The DHA combined with PTX may induce apoptosis through increasing the expression of Bax,Caspase-3 and decreasing the expression of Bcl-2.