Effect Of Oxaliplatin On Different Transfer Potential Human Colon Cancer Cells Proliferation And Apoptosis

ObjectiveTo investigate the effect of oxaliplatin(L-OHP) on proliferation and apoptosis in human colon cancer cell line SW480 and SW620 in vitro and its possible mechanisms.Methods1. The proliferation inhibitory effect of L-OHP at different mass concentration(2,4,8,16,32 and 64 μg/m L) for different times(24,48and72 h) on SW480 and SW620 cells was detected by MTT assay.2.DAPI staining were observed the morphological changes of cells nucleus after different mass concentration(4,16 and 64 μg/m L)L-OHP processing for 24 h.3.Cell cycle and cell apoptosis rate were detected by flow cytometry after the both cells were treated with different mass concentration(1/2IC50 and IC50)L-OHP for 48 h.4.The expression level of apoptosis related proteins Bax and Caspaes-3 protein and the expression level of DNA damage related to protein γHA2X protein were detected by Western blot assay after the both cells were treated with different mass concentration(4,16 and 64 μg/m L)L-OHP for 24 h.Results1.L-OHP inhibited proliferation of both SW480 and SW620 cell lines in a time-dose dependent manner(P<0.05).SW620 cells are more sensitive to L-OHP than SW480 cells(P<0.05).2. The both cells were treated with L-OHP for 24 h,the numbers of normal cells were reduced, while the numbers of karyopyknosis 、 multinuclear 、 nuclear fragmentation and apoptotic bodies were obviously increase with the increase of drug concentration(P<0.05).Under the action of the same mass concentration of L-OHP,the percentage of karyopyknosis、multinuclear、nuclear fragmentation and apoptotic bodies in SW620 cells were significantly high than SW480 cells(P<0.05).3.L-OHP could obvious promote early apoptosis of both cell lines in a time-dose dependent manner(P<0.05). Under the action of the same concentration of L-OHP, SW620 cells promote early apoptosis significantly greater than SW480 cells(P< 0.05).4. In wild types,the percentage of S-phase cells was lower,and that of G1-phase cells was significantly higher in SW620 cells than those in SW480 cells(P<0.05). Under the action of the different mass concentration of L-OHP for 24 h,the percentage of SW480 cells in G1-phase was significantly lower, while in G2-phase was significantly increased along with the concentration increased(P<0.05); The percentage of SW620 cells in G1-phase was significantly lower, while in S-phase cells was significantly increased along with the concentration increased(P< 0.05).5.After L-OHP treated on SW480 and SW620cells for 24 h,the cells apoptosis related proteins Bax and Caspaes-3 protein and DNA damage related to protein γHA2X protein along with the concentration increased(P<0.05). Under the same drug concentration, SW620 cells apoptosis related proteins Bax and Caspase 3 proteins and DNA damage related protein gamma HA2 X protein expression of volume greater than SW480 cells(P<0.05).Conclusions1. L-OHP can obvious inhibited proliferation of both SW480 and SW620 cell lines,the inhibitory effect of SW620 cells significantly greater than SW480 cells.2.L-OHP can inhibit the growth of two kinds of tumor cells by blocking the cells into G2-phase or S-phase and inducing apoptosis.3.the mechanism of L-OHP inducing two kinds of tumor cells apoptosis may be through up-regulation apoptosis related proteins Bax and activate Caspaes cascade reaction. DNA damage may also be one of its promoting apoptosis mechanism. But the details of the link between them still need further experiments to explore.