The Effect Of AKT/mTOR Pathway On Apoptosis Of Colon Cancer Cells SW480 Induced By Cucurbitacin B Combined With Oxaliplatin

ObjectiveThis paper is to investigate the effect of cucurbitacin B(CUB)combined with oxaliplatin(OXA)on the proliferation,cell cycle and apoptosis of human colon cancer cell SW480 and the possible role of AKT/mTOR signal transduction pathway in the process of apoptosis.MethodsThe human colon cancer SW480 cells in logarithmic growth phase was taken as the research object.The effect of oxaliplatin,cucurbitacin B,cucurbitacin B and oxaliplatin,cucurbitacin B,oxaliplatin combined with PI3 K inhibitor(Wortmannin)on the proliferation of human colon cancer cell SW480 was detected by MTT assay.Hoechst33258 nuclear staining was used to observe the morphological changes.Cell apoptosis and cell cycle were detected by flow cytometry.The expression of AKT?p-AKT?mTOR?p-mTOR?Cytochrome C ? cleaved-caspase-9 ? caspase-9 ? cleaved-caspase-3 ?caspase-3?Bax and Bcl-2 protein expression in SW480 cells were analyzed by Western bloting.ResultsCucurbitacin B?oxaliplatin could inhibit the proliferation of SW480 cells(P<0.05);and the inhibitory effect of the combination of the two was more significant(P<0.05).Oxaliplatin,cucurbitacin B,oxaliplatin combined with PI3 K inhibitor can arrest cells in S phase(P<0.05);Cucurbitacin B,cucurbitacin B combined with oxaliplatin could block cells in S phase and G2/M phase(P<0.05).The expression of Cytochrome C ? Bax ?cleaved-caspase-9 ? cleaved-caspase-3 in the cucurbitacin B,oxaliplatin,group were significantly up-regulated than that in the control group;the expression of p-AKT?p-mTOR?caspase-9?caspase-3?Bcl-2 was significantly down-regulated compared with the control group,and the Bcl-2/Bax level was significantly lower(P<0.05).The above protein change trend caused by using Cucurbitacin B combined with oxaliplatin group was in the same with simply using cucurbitacin or oxaliplatin but could bring more significant effect(P<0.05).ConclusionsBoth cucurbitacin B and oxaliplatin could inhibit the proliferation and induce the apoptosis of SW480 cells,whose mechanism may be related to the inhibition of AKT/mTOR pathway,the down-regulation of Bcl-2/Bax and the up-regulation of the expression of Cytochrome C,caspase-related proteins.The cucurbitacin B combined with oxaliplatin served better function and they were at a certain synergy.