Abstract: Objective To study the effect of shRNA mediated gene silencing of serum and glucocorticoid induced protein kinase 1(SGK1) on biologic characteristics of human breast cancer cells,MDA-MB-231,and to provide experiment and theoretical evidences for genetic therapy of human breast cancer. Methods Hairpin RNA sequence was synthesized and inserted into pGenesil-3 vector with human U6 promoter.Verified constructs were transfected into MDA-MB-231cells,and then selected by G418.Expression of SGK1 was detected by both real time PCR and Western blotting,and β-catenin expression was detected by Western blotting.MTT growth and matrigel invasion assays were used to study the effect of SGK1 gene silencing.Results Both the mRNA and protein level of SGK1 remarkably decreased after transfection of pGen-3-siSGK1.After gene silencing of SGK1,MDA-MB-231 cells shown strong inhibition of cell growth.The invasive and migratory abilities were inhibited after gene silencing of SGK1.In addition,the change of protein level of β-catenin was consistent with that of SGK1. Conclusion SGK1 inhibition suppresses the growth,invasiveness and migratory abilities of breast cancer cell

Key words: Breast cancer, SGK1, β-catenin, RNA interfering, Western blotting, Human