Abstract: Objective To study the relationship between cox-2 gene and the proliferation as well as apoptosis of esophageal squamous carcinoma EC109 cell at the gene level;also by studying the effects of aspirin(non-specific cooxygenase-2 inhibitor) on proliferation and apoptosis of esophageal squamous carcinoma EC109 cell,to investigate the mechanism of gene and medical therapies for esophageal squamous carcinoma.Methods The RNA interference method was used in this study.Short interfere RNA was synthesized targeting Cox-2 Gene.The expression of COX-2 gene in esophageal squamous cell carcinoma EC109 was specially inhibited by RNAi technique.The efficiency of RNAi technique was detected with fluorescence microscopy.The effect of RNAi technique was detected with Western blot.Cell growth was tested with MTT reduction assay.The cell apoptosis was detected with flow cytometry.EC109 growth was tested with MTT reduction assay.Results Compared with the control group,the expression of COX-2 gene in EC109 had a 40% decrease.The OD value of MTT was 0.85±0.05 in mother cell group,the OD value of MTT was 0.75±0.06 in negative control group labeld by FITC,the OD value of MTT was 0.48±0.05 in transfection group of COX-2 siRNA,the OD value of MTT was 0.28±0.04 in Aspinin combined with RNAi group.After RNAi,the effect of growth inhibition was increased in EC109 cell compared with the control groups.The growth inhibition of Aspinin combined with RNAi group was stronger than that of RNAi group.The rate of apoptosis was 1.35% in mother cell group,the rate of apoptosis was 1.72% in negative control group labeld by FITC,the rate of apoptosis was 4.33% in transfection group of COX-2 siRNA,the rate of apoptosis was 11.66% in Aspinin combined with RNAi group.After RNAi,the rate of apoptosis increased in EC109 cell compared with the control groups.The rate of apoptosis of aspinin conbined with RNAi group was stronger than that of RNAi group.Conclusion The RNAi techniques can specifically inhibit the expression of COX-2 gene.The cell proliferation has been suppressed and the cell apoptosis is stronger in EC109 after COX-2 gene has been specifically inhibited.The combined administration of aspirin and RNAi has a synergic effect on the tumor cell proliferation and apoptosis.

Key words: esophageal squamous cell carcinoma, cooxygenase-2, aspirin, apoptosis, RNA interference