Expression of microRNA-30b-5p in prostate cancer and its effects on proliferation of prostate cancer cells

Abstract

Objective To explore the expression of microRNA (miRNA, miR)-30b-5p in prostate cancer (PCa) and its impact on prostate cancer cells. Methods The expression of miR-30b-5p in 41 cases of PCa tissues and 41 cases of adjacent non-tumor tissues was detected by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR). The relationship between the expression of miR-30b-5p and clinicopathological features was analyzed. Human prostate cancer PC-3 cells were divided into three groups: control group, negative control group and over-expression group. The expression of miR-30b-5p in PC-3 cells was detected by RT-qPCR. The cell proliferation was measured by cell counting kit-8 (CCK-8) assay and colony formation and anchorage-independent growth assay. The protein expression of proliferation cell nuclear antigen (Ki-67), β-catenin and Cyclin D1 was detected by Western blotting. Results The expression of miR-30b-5p in prostate cancer tissues (0.469±0.032) was significantly lower than that in adjacent tissues (0.997±0.016) (t=14.499, P=0.000). In addition, the rate of low miR-30b-5p expression in clinical state Ⅲ-Ⅳ [65.2% (15/23) vs. 33.3% (6/18), χ2=4.108, P=0.043], pathological grading G3-G4 [72.7% (16/22) vs. 26.3% (5/19), χ2=6.145, P=0.013] and Gleason scores ≥8 [72.0% (18/25) vs. 18.8% (3/16), χ2=11.072, P=0.001] groups were higher than those in clinical stage Ⅰ-Ⅱ, pathological grading G1-G2 and Gleason scores ≤7 groups. However, there were no difference in the rate of low miR-30b-5p expression in different age groups [54.5% (12/22) vs. 47.4% (9/19), χ2=0.210, P=0.647]. After transfection, the expression of miR-30b-5p in over-expression group (4.088±0.229) was higher than that in negative control group (1.028±0.054) (F=168.200, P=0.000). At 48 h and 72 h, the A450 in over-expression group measured by CCK-8 assay (0.308±0.040, 0.512±0.033) were lower than those in negative control group (0.494±0.035, 0.840±0.087) (F=6.514, P=0.001). The protein expressions of Ki-67, β-catenin and Cyclin D1 in negative control froup were 1.681±0.062, 1.067±0.188, 0.665±0.083. However, the protein expressions of them in over-expression group were remarkably decreased (Ki-67: 0.622±0.095, F=38.490, P=0.000; β-Catenin: 0.437±0.071, F=6.570, P=0.031; Cyclin D1: 0.237±0.049, F=13.510, P=0.006). Conclusion miR-30b-5p is low-expressed in prostate cancer cells, and over-expression of miR-30b-5p could inhibit the proliferation ability of prostate cancer cell, which may be related to the deactivation of Wnt/β-catenin signaling pathway. Key words: Prostate cancer; MicroRNA-30b-5p; Cell proliferation; Wnt/β-catenin signaling pathway