Fig. 3

Down-regulation of IRS-1 inhibits PCa cell proliferation. a Relative expression of IRS-1 in DU145 and PC-3 cells after knocking down IRS-1 by shRNA as determined by Q-PCR. N.T: non-target control. Data represent mean ± SD with three replicates, * P < 0.05, ** P < 0.005. b Protein expression of IRS-1 in DU145 and PC-3 cells after knocking down IRS-1 as determined by Western blot. β-tubulin serves as internal control. IRS-1 levels were quantified with Image J software and normalized to the internal control. c, d Cell viability was determined by the MTT in both PC-3 and DU145 cells at the indicated time. Data represent mean ± SD with three replicates, * P < 0.05, ** P < 0.005, *** P < 0.0005. e, f Cell proliferation were detected by colony formation assay in DU145 and PC-3 cells cultured for 12–14 days. g, h EdU assay of PCa cells transfected with lentivirus vector shIRS1, or miR-203 for 24 h, followed by treatment with 10 μM EdU for another 24 h. Representative images of immunofluorescent staining were shown. Data represent mean ± SD with three replicates, **P < 0.01, ***P < 0.001, **** P < 0.0001. Scale bar = 50 μm