An Study On Inhibitory Effect Of DcR3and EGFR Gene Corporate Silence To The Proliferation Of Human Colon Cancer Line SW480

BACKGROUND AND OBJECTIVE:Decoy receptor-3(DcR3) is a new member of tumor necrosis factor receptor(TNFR),discovered by Pitti RM in1998and named. DcR3is a kind of Secretory protein as its deficiency of transmembrane succession.it has a board application prospect with regulation cells’growth and differentiation and anti-apoptosis. Epidermal Growth Factor Receptor(EGFR), which mediated signal transduction is related closely to cells’proliferation, differentiation, survival and metastasis,is also a important target point,its targeting drug-Cetuximab has applied in clinic therapy and achieved favourable effect.RNA interference is a method of inhibition of gene expression, the gene silencing phenomenon induced by a sequence-specific ds-RNA (a fragment of RNA about21-23bp), has specificity and effectiveness.The siRNA target on monogene has achieved obviously effection,so the study is about two different siRNA co-targeting on two gene DcR3and EGFR.METHODS:The specific siRNA oligos for DcR3and EGFR gene was designed and synthesized,and transfected into sw480cells by liposome, The expression level of DcR3and EGFR mRNA was detected by realtime RT-PCR after they were incubated for24h.DcR3and EGFR protein was detected by western blot, and choose the effective siRNA of DcR3and EGFR to cosuppressed SW480cells.Then Extract DcR3and EGFR protein form SW480cell after transfection. Study DcR3and EGFR expression by western blot analysis to elevate the express level of EGFR. The cell cycles and cell proliferations of SW480cell were measured with MTT method after transfecti on. and cell apoptosis rate was detected with flow cytometry.RESULTS:The expression level of DCR and EGFR mRNA was detected by realtime RT-PCR after they were incubated for24h.and their inhibition efficiency were32%,42%,30%and39%,63%,48%; and inhibition efficiency detected by western blot almost the same.Then,use the efficicency siRNA both or single inhibit the cell SW480cell.Study by MTT and FCM show that DcR3and EGFR siRNA lead to inhibition of cell growth and enhancement of cell apoptosis.and corporate Silence of DcR3and EGFR is better than single silence.CONCLUSIONS:DcR3siRNA or EGFR siRNA down-regulate the expression of mRNA and protein of DcR3or EGFR in SW480colonic cancer cells, which also leads to inhibition of cell growth and enhancement of cell apoptosis. and corporate Silence of DcR3and EGFR had the better advantage to single silence about the inhibition of cell growth and enhancement of cell apoptosis.