Effects of midkine siRNA on adhesion and invasion of human breast cancer cells

Abstract

Objective To study the effects of midkine(MK)gene small interfering RNA(siRNA)on adhesion and invasion of human breast cancer cells.Methods Real time PCR was used to evaluate MK mRNA expression in 7 human breast cancer cell lines Bcap-37,LCCI,MCF-7,MDA-MB-231,MDA-MB-435,MDA-MB-468,and ZR75-1.The cell line in which MK expression was the highest was transfected with different doses of MK siRNA.The expression of MK mRNA and protein was determined by real-time quantitative PCR and immunoflurescence staining.The cell adhesion was evaluated by MTT assay and invasion was examined by Boyden chamber method.Results Cell line MCF-7 expressed the highestlevel of MK mRNA in the 7 tested breast cancer cell lines.After being transfected with MK siRNA,MK mRNA and protein level of MCF-7 decreased in timeand dose-dependent manners.The adhesive and invasive ability of MCF-7 cell transfected with MK siRNA decreased in a dose dependent manner(P<0.01,P<0.01).Conclusions MK gene might play an important role in adhesion and invasion of human breast cancer cells.siRNA transfection could effectively inhibit adhesion,migration,and invasion of human breast cancer cell. Key words: Breast cancer; Midkine; RNA interference; Adhesion; Invasion