Fig. 8

SIRT7 promotes AR expression via SMAD4. a Western blotting revealed the SMAD3 and SMAD4 protein levels in SIRT7-deficient prostate cancer cells. b RT-qPCR was performed to detect SMAD3 and SMAD4 mRNA levels in SIRT7-deficient prostate cancer cells. c Co-immunoprecipitation of endogenous SMAD4 with anti-SIRT7 antibodies in 22RV1 cells. Co-immunoprecipitation of endogenous SIRT7 with anti-SMAD4 antibodies in 22RV1 cells. d Immunoblots showing the acetylation levels of SMAD4 in the presence of wild-type SIRT7 and nicotinamide (NAM). Acetylatied proteins were immunoprecipitated with anti-SMAD4 and probed with pan anti acetyl antibodies. e Immunoblots showing SMAD4 levels in the presence of CHX, with or without SIRT7 depletion. f Western blot shows that SMAD4 downregulation by siRNA reversed the effect of SIRT7 on AR activity. 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)