Influence of TROP-2 gene on the ability of human breast cancer cell metastasis

Objective To study the effects of tumor-associated calcium signal transducer-2 (TROP-2) gene small interfering RNA(siRNA) on adhesion and invasion of human breast cancer cell. Methods Real time PCR was used to evaluate the TROP-2 mRNA of seven human breast cancer cell lines Bcap-37 ,LCC1 ,MCF-7 ,MDA-MB-231,MDA-MB-435, MDA-MB-468 ,and ZR75-1. The cell line of TROP-2 highest expression was transfected with different dose of TROP-2 siRNA. The expression of TROP-2 mRNA and protein were determined by Real-time quantitative PCR and immumoflurescence method. The cell adhesion was evaluated by MTT assay,and invasion was exmined by hoyden chamber,respectively. Results Cell line MCF-7 showed the highest elevation of TROP-2 mRNA in seven breast cancer cell lines. The results from real-time quantitative PCR and immumoflurescence method showed that TROP-2 mRNA and protein reduced in time-and dose-dependent manners( P ＜ 0.01 ;P ＜ 0.01 ). The adhesive rate of siRNA groups(5 nM,10 nM,and 20 nM)was(52.9 +2.5)％ ,(25.6 ±2.3)％, ( 12.8 +2.2)％ (P ＜0.01 ) ,respectively.The transwell results showed that the invasion cells was(78 ± 17), (39 ± 15), ( 19 ± 16), ( 136 +25 ) and( 139 ±21 )in different groups(5,10,20 nM siRNA,and controls) ,respectively(P ＜0.01). Conclusion TROP-2 gene might play an important role in adhesion and invasion of human breast cancer cell. siRNA targeted TROP-2 could effectively inhibit adhesion and invasion of human breast cancer cell. Key words: Breast Neoplasms; Tumor-associated calcium signal transducer-2