Fig. 6

AR mediates the effects of SIRT7 on prostate cancer cell proliferation and androgen-induced autophagy. a Western blot determined the modulation of AR in SIRT7-depleted prostate cancer cells cultured in media supplemented with various androgen concentrations (0, 1 and 10 nM DHT). b RT-qPCR determined the modulation of PSA and SLC45A3s in SIRT7-depleted cancer cells cultured in media supplemented with various DHT concentrations. c CCK8 assay measured the effect of SIRT7 knockdown on prostate cancer cell proliferation in media supplemented with various androgen concentrations. d Western blot data showing p-mTOR, mTOR, AR, p62, and SIRT7 expression levels and LC3-II conversion in SIRT7-depleted cancer cells cultured with various DHT concentrations. e RT-qPCR revealed the modulation of ATG4B and ATG4D (both are AR-regulated autophagy genes) in SIRT7-depleted cancer cells cultured with various DHT concentrations. f Transmission electron micrographs for detecting autophagic vacuoles in 22RV1 cells cultured with 0 and 10 nM DHT for 3 days before fixation. Arrows indicate autophagosome structures. Scale bar, 1 μm. g 22RV1 cells stably expressed the mRFP–GFP–LC3 protein and were treated for 3 days with vehicle (ethanol) or DHT. Autophagosomes (yellow) and autolysosomes (red) were co-visualized and examined by immunofluorescence microscopy. h Mean number of puncta of each cells (n = 16 cells) treated with various androgen concentrations was analyzed and plotted. Each assay was performed in triplicate and the data are shown as the means ± SD. P-values were calculated by t-test (*P < 0.05; **P < 0.01; ***P < 0.001)