Effect of microRNA-21 on proliferation and regulation expression of programmed cell death 4 in prostate cancer cell PC-3

Abstract

Objective To explore effect of microRNA (miRNA, miR)-21 on proliferation and regulation expression of programmed cell death 4 (PDCD4) in prostate cancer cell PC-3. Methods Expression of miR-21 in LNCap, PC-3, DU145 prostate cancer cell and human normal prostate epithelial cell RWPE-1 was examed by reverse transcriptase-polymerase chain reaction (RT-PCR) method. miR-21 inhibitor and miR-21 NC were transfected into PC-3 cell by liposome Lipofectamine™ 2000. Cell viability was measured by MTT assay. Cell apoptosis and cell cycle was measured by flow cytometry. The expression of PDCD4 protein and mRNA was measured by Western blotting and RT-PCR. Results The expression of miR-21 in LNCap, PC-3, DU145 cell (0.36±0.03, 0.85±0.08, 1.09±0.10) was higher than that in RWPE-1 cell (0.17±0.02) (P=0.013, P=0.007, P=0.001). Compared with miR-21 NC, the expression of miR-21 was down-regulated (0.20±0.02 vs. 1.07±0.10) (P=0.006), cell viability (0.37±0.04) vs. (0.75±0.07) was reduced (P=0.006), cell early apoptotic rate [(20.40±1.97)% vs. (2.53±0.24)%] and late apoptotic rate [(16.56±1.65)% vs. (2.53±0.24)%] was increased (P=0.002, P=0.003), cell cycle was arrested in the G1 phase [(59.58±3.26)% vs. (47.33±4.35)%, P=0.000], the expression of PDCD4 protein (1.67±0.16 vs. 0.25±0.02) and mRNA (1.02±0.10 vs. 0.24±0.02) was increased in miR-21 inhibitor group (P=0.005, P=0.007). Conclusion Down-regulation of miR-21 could inhibit the proliferation and cell cycle progression in PC-3 cells via up-regulation of expression of PDCD4. Key words: MicroRNA-21; Prostate cancer cell PC-3; Proliferation; Programmed cell death 4