A Study On The Effect Of In Vitro Cultured SW620Cells On Proliferation, Cell Cycle And Apoptosis Of Ethylene Dichloride

【Abstract】 Objective To explore the effect of1,2-dichloroethane (1,2-DCE) grouping by concentration and time on in vitro instantaneous interfered and noninterfered cultured cells’proliferation, cycle and apoptosis. Methods By exposing to different concentrations of1,2-DCE in0.5or1h, using MTT assay to detect the relative number and relative activity of viable cells; using flow cytometry (FCM) assay to analyz cell cycle and apoptosis; using siRNA to instantaneously interfere SIRTl’s expression level; using RT-PCR to analyze mRNA’s expression level.Results Part1:The effect of SW620cells exposure to1,2-DCE. It is found from MTT that with the increasing of1,2-DCE’s dose and exposure time, relative growth rate decreased gradually. Compared with the DMSO group, the relative growth rate of groups, which exposed to25,75,100,125,150,175,200uM in0.5h, decreased (p<0.05or p<0.01). The relative growth rate of groups, which exposed to75、100、125、150、175、200uM in1h, decreased(p<0.05or p<0.01). Compared with the0.5h groups, the relative growth rate of groups, which exposed to175uM in1h, decreased (p<0.01). It is found from the standardized fitting curve that when exposed to1,2-DCE in0.5h the best fit IC50was89.41uM, and95%Confidence Intervals was85.23to93.79uM; When exposed to1,2-DCE in lh the best fit IC50was87.68uM, and95%Confidence Intervals was83.71to91.82uM. It is found from FCM that compared with the controlled group, the G0/G1phase of groups, which exposed to25,50,100,150,200uM in1h, decreased (p<0.05or p<0.01). The S phase of groups, which exposed to25,50,100uM in1h, decreased (p<0.05or p<0.01). The G2/M phase of groups, which exposed to25,50,100,150,200uM in1h, increased (p<0.05or p<0.01). However1,2-DCE can not induce apoptosis in each group. Part2:The effect of instantaneous interfered SIRT1’s SW620cells exposure to1,2-DCE. It is found from MTT that compared with the controlled group, the relative growth rate of groups, which instantaneously interfered for24、48、72、96h, decreased. Differences are statistically significant. Instantaneously interfering for72h, compared with the negative and wild groups, the relative growth rate of siRNA group decreased(p<0.01). Negative group compared with wild group, the difference is not statistically significant. It is found from MTT that instantaneously interfered SIRT1for72h, and then exposed to100uM1,2-DCE for1h, in the1,2-DCE group, compared with wild group, difference of siRNA group is statistically significant(p<0.05). In the siRNA group, compared with PBS and DMSO groups, differences of1,2-DCE group are statistically significant(p<0.05). Also in the controled groups, instantaneous interference or1,2-DCE exposure separately leading to cells’proliferation inhibition consistent with previous experimental results. Conclusion1,2-DCE can restrain in vitro cultured SW620cells’proliferation. Exposing to1,2-DCE in1h,1,2-DCE can arrest cell cycle at G2/M phase, but can’t induce apoptosis. Instantaneously interfering SIRT1gene, SIRT1gene’s partly loss can also restrain cells’proliferation. When instantaneous interfered cells expose to1,2-DCE, the effect of instantaneous interference and1,2-DCE to inhibition cells’proliferation are overlapped.1,2-DCE’s induction to in vitro cultured SW620cells’proliferation inhibition and cell cycle distribution changes may be associated with DNA damage and restoration.