Effect of short-hairpin RNA expression vector-mediated osteopontin RNA interference on proliferation and invasion of prostate cancer PC-3 cells

BACKGROUND AND OBJECTIVE: Studies showed that osteopontin (OPN) regulates cell migration and invasion in a variety of cancers, which associates with the activities of matrix metalloproteinase (MMP)-2 and MMP-9. This study was to investigate the role of OPN in the proliferation and invasion of human prostate cancer PC-3 cells and the possible functions of IgammaB kinase (IKK) in nuclear factor kappa B (NF-kappaB)-mediated signaling pathways. METHODS: OPN short-hairpin RNA (shRNA) recombinant plasmids were transfected into PC-3 cells and different concentrations of IKK inhibitors were used to inhibit the activities of IKKalpha and IKKbeta. The mRNA and protein expression levers of OPN, MMP-2, and MMP-9 were detected by real-time polymerase chain reaction (PCR) and Western blot. Cell cycle was detected by flow cytometry, cell proliferation by MTT assay, and cell invasion by Transwell chamber assay. RESULTS: Compared with untreated cells, the protein levers of OPN, MMP-2, and MMP-9 in OPN shRNA-transfected PC-3 cells were reduced by 55.22%, 51.71%, and 28.35%, respectively, and the ability of cell migration and invasion were decreased by 45.48% and 51.96%, respectively (P<0.05). Moreover, the inhibition of IKKbeta inhibited the expressions of MMP-2 and MMP-9. CONCLUSION: A shRNA expression vector-mediated OPN gene silencing can inhibit the malignant biological behaviors of PC-3 cells. IKKbeta may play a crucial role in the OPN-induced activation of MMP-2 and MMP-9 via NF-kappaB-mediated IkappaB/IKKbeta pathways.