Downregulation of osteopontin by RNA interference resulting in suppression of the proliferation and invasion of renal cancer cells in vitro

Abstract

Objective To investigate the effects of osteopontin short hairpin RNA (OPN shRNA)on the proliferation and invasion of ACHN cellsin vitro and the mechanism. Methods OPN shRNA recombinant plasmids were constructed and transfected into ACHN cells. OPN mRNA expression level was detected by reverse transcription-polymerase chain reaction (RT-PCR). Protein expression levels of OPN, matrix metalloproteinases (MMP)-2 and MMP-9 were assayed by Western blotting. The cell cycle was assessed by flow cytometry. MTT method and Transwell chamber test were used to observe the abilities of proliferation and invasion of ACHN cells. Results Compared with the untreated ACHN cells (4. 16 ±0. 12),OPN mRNA expression in the cells transfected with recombinant plasmid (1. 68 ±0. 15) was decreased by 59.6% (P＜0. 05). Compared with the control group (214.01 ± 12.08, 187.53 ±9.56, 233. 12 ±15. 78) , the protein expression levels of OPN, MMP-2 and MMP-9 in the cells transfected with recombinant plasmid (51. 15 ±6. 03, 89.26±5.15, 167.85 ±13.42) were knocked down by 76. 1% , 52.4% and 28. 0% , respectively (P ＜ 0. 05). The cells were blocked in S phase and apoptotic hypodiploid was increased significantly. Recombinant plasmid significantly suppressed the proliferation and invasion of ACHN cells. Conclusion OPN plays an important role in the proliferation and invasion of human renal cancer cells. These processes are correlated with the expression of MMP-2 and MMP-9. Key words: Osteopontin; RNA interference; Renal cancer; Cell proliferation