Figure 3: Effect of knockdown of endogenous miR-3691-3p target genes on the behavior of PCa cells. (a) Of the 200 target genes identified from three bioinformatic algorithms (DIANA-MICROT, Target Scan, and MIRDB), 9 were identified by all three. miR-Oncology database screening identified CDK17, PRDM1, and E2F3 as potential miR-3691-3p target genes closely related to the occurrence and development of tumors. (b and c) Western blot analysis (b) and RT-qPCR analysis (c) of CDK17, E2F3, and PRDM1 protein and mRNA expression, respectively, in PC-3 and DU145 cells at 48 h after transfection with a control or miR-3691-3p mimic. (d–f) DU145 and PC-3 cell lines were transfected with a control, E2F3-targeting, or PRDM1-targeting siRNA, and then analyzed. (d) Cell proliferation was assessed using the MTT assay on days one, two, and three after transfection. (e) Wound-healing migration assay performed on day one and day two after transfection. (f) Transwell invasion assay performed after transfection. Data are presented as the mean ± s.d. *P < 0.05, **P < 0.01, ***P < 0.001. PCa: prostate cancer; CDK17: cyclin dependent kinase 17; RT-qPCR: real-time quantitative polymerase chain reaction; PRDM1: PR domain containing 1, with ZNF domain; MTT: methyl thiazolyl tetrazolium; OD: optical density; E2F3: E2F transcription factor 3; s.d.: standard deviation.