Investigational procedures in benign prostatic hypertrophy

Triptolide inhibits benign prostatic epithelium viability and migration and induces apoptosis via upregulation of microRNA-218

Benign prostatic hypertrophy (BPH) has become a troublesome disease for elder men. Triptolide (TPL) has been reported to be a potential anticancer agent. However, the potential effects of TPL on BPH have not been shown out. BPH-1 cells were treated with different concentrations of TPL and/or transfected with microRNA-218 (miR-218) inhibitor, pc-survivin, sh-survivin, or their corresponding controls (NC). Thereafter, cell viability was determined by CCK-8 assay. Cell migration was accessed by modified two-chamber migration assay. Cell apoptosis was checked by propidium iodide (PI) and fluorescein isothiocyanate (FITC)-conjugated Annexin V staining. In addition, messenger RNA (mRNA) and protein levels were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, respectively. BPH-1 cell viability and migration were significantly decreased, while cell apoptosis and expression of miR-218 were statistically enhanced by TPL (P < 0.05 or P < 0.01). However, downregulation of miR-218 increased cell viability and migration, while decreased cell apoptosis compared with the negative control group (P < 0.05 or P < 0.01). Furthermore, the expression of cell cycle–related proteins and cell apoptosis–related proteins were also led to the opposite results with NC. In addition, we found that miR-218 negatively regulated the expression of survivin (P < 0.01) and suppression of survivin significantly enhanced cell apoptosis (P < 0.01). Moreover, the results demonstrated that TPL could inactivate mammalian target of rapamycin (mTOR) pathway, while inhibition of miR-218 alleviated the effects. TPL inhibits viability and migration of BPH-1 cells and induces cell apoptosis and also inactivates mTOR signal pathway via upregulation of miR-218. This study provides evidence for the further studies representing triptolide as a potential agent in the treatment of human BPH.