Effects of TROP-2 gene on adhesion and invasion of human breast cancer cells

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 cells.Methods Real time PCR was used to detect 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 with hifhest TROP-2 expression was transfected with different doses of TROP-2 siRNA.The expression of TROP-2 mRNA and protein was detected by real-time quantitative polymerase chain reaction (PCR) and immumoflurescence method.The cell adhesion was evaluated by methyl thiazol tetrazolium (MTT) assay,and invasion was exmined by boyden chamber,respectively.Results The TROP-2 mRNA in Bcap-37,LCC1,MCF-7,MDA-MB-231,MDA-MB-435,MDA-MB-468 and ZR75-1 cell lines was 1.362 ±0.057,2.207 ± 0.056,2.997 ± 0.052,0.136 ± 0.045,0.122 ± 0.025,0.194 ± 0.028 and 2.706 ± 0.039 respectively,and MCF-7 showed the highest elevation of TROP-2 mRNA.The real-time quantitative PCR and immumoflurescence method revealed that the expression of TROP-2 mRNA and protein was reduced in a time- and dose-dependent manner (P ＜ 0.01 ;P ＜ 0.01 ).The adhesive rate in siRNA groups (5,10 and 20 nmol/L) was (52.9±2.5)％,(25.6±2.3)％ and (12.8±2.2)％ (P＜0.01),respectively.The transwell results showed that the invasion cells were 78 ± 17,39 ± 15,19 ± 16,136 ± 25 and 139 ± 21 in different groups (5,10,20 umol/L siRNA,and controls),respectively (P ＜0.01 ).Conclusion TROP-2 gene might play an important role in adhesion and invasion of human breast cancer cells.siRNA targeted TROP-2 could effectively inhibit adhesion and invasion of human breast cancer cells. Key words: Breast carcinoma; Tumor-associated calcium signal transducer-2; RNA interference; Invasion