Abstract: Objective To investigate the effect of oxaliplatin on expressions of nuclear factor κB(NF-κB)and signal transducer and activator of transcription(STAT3)in human colon cancer cells(SW620).Methods SW620 cells in logarithmic growth period were cultured in vitro and then treated with different concentrations of oxaliplatin(40,80,160 μg/ml),and a vehicle control group was established.After the treatment(72 hours),3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was applied to assess oxaliplatin-mediated anti-proliferative effect on SW620 cells.Hoechst 33258 staining was used for observing morphological changes of the cells.Meanwhile,Western blot analysis was applied to determine endogenous protein expressions of NF-κB and STAT3 in SW620 cells.Results Compared with the control group,oxaliplatin administration at different dosages significantly inhibited the proliferation of SW620 cells,with the inhibition rates of 66.19±5.93%,86.92±7.85%,and 96.85±8.86%(P<0.05 or P<0.01),and promoted apoptosis of the cells,with the increased number of apoptosic cells of 9.46±1.05,18.57±2.16,and 27.29±3.48/per microscopic field(P<0.01 for all).In addition,oxaliplatin effectively down-regulated endogenous NF-κB and STAT3 protein expressions in SW620 cells,with the NF-κB expression level of 0.674±0.016,0.435±0.012, and 0.212±0.009 and STAT3 expression level of 0.485±0.015, 0.264±0.008,and 0.113±0.004(all P<0.01).Conclusion Oxaliplatin could inhibit proliferation of SW620 cells and the inhibitive effect may be due to the decreased expressions of NF-κB and STAT3 in SW620 cells.