Abstract: Objective To investigate the effect of long non-coding RNA (lncRNA) OSTN antisense RNA1 (OSTN-AS1) on the proliferation, migration and invasion of prostate cancer LNCaP cells and its mechanism. Methods Using prostate epithelial cell RWPE-1 as control, the expression of OSTN-AS1 and miR-4461 in LNCaP cells were detected by real-time fluorescence quantitative PCR (qRT-PCR). LNCaP cells were transfected with OSTN-AS1 small interfering RNA ( si-OSTN-AS1) or miR-4461 mimic, or co-transfected with si-OSTN-AS1 and miR-4461 inhibitor, and then cell proliferation, migration, invasion and related proteins [Ki-67, matrix metalloproteinase (MMP) -2, MMP-9] expression were detected by cell counting Kit-8 ( CCK-8) method, scratch assay, transwell and Western blotting, respectively. The dual-luciferase reporter gene experiment was used to verify the regulatory relationship between OSTN-AS1 and miR-4461. Results The expression level of OSTN-AS1 in the LNCaP cells was higher than that in the RWPE-1 cells (3. 38 ± 0. 26 vs. 1. 00 ± 0. 00, P < 0. 05), but the expression level of miR-4461 was lower than that in the RWPE-1 cells (0. 46 ± 0. 04 vs. 1. 00 ± 0. 00, P < 0. 05). After interfering with OSTN-AS1 siRNA or miR-4461 mimic, the proliferation activity, wound healing rate, and invasion number of LNCaP cells were decreased, and the expression levels of Ki-67, MMP-2, and MMP-9 were also decreased (all P < 0. 05). OSTN-AS1 targeted and bound to miR-4461, and the expression level of miR-4461 was increased in LNCaP cells that interfered with OSTN-AS1 (P< 0. 05). Down-regulation of miR-4461 reversed the effect of si-OSTN-AS1 on LNCaP cells proliferation, migration, invasion and related protein expression. Conclusion Interfering with OSTN-AS1 can inhibit the proliferation, migration and invasion of prostate cancer LNCaP cells by targetly up-regulation of miR-4461.

Key words: OSTN-AS1, miR-4461, prostate cancer, cell proliferation, migration, invasion