Fig. 5

Combinatorial resveratrol and pterostilbene inhibited SIRT1 in TNBCs with no effects in breast control cells. a and d Relative real-time SIRT1 mRNA expression after 72 h of treatments in HCC1806 cells and MDA-MB-157 breast cancer cell lines, respectively. With combination treatment, there was a significant down-regulation of SIRT1 mRNA. GAPDH was used as the internal control. b and e Percent SIRT1 enzyme activity relative to DMSO control after 72 h of treatment with compounds alone as well as in combination in HCC1806 and MDA-MB-157 cells, respectively, using 20 μg of nuclear extract. With combinatorial treatment, a significant down-regulation in SIRT1 enzyme activity occurred which was found to be consistent with real-time data. c and f SIRT1 protein western blot after 72 h of treatment with compounds alone as well as in combination in HCC1806 and MDA-MB-157 cells, respectively. β-Actin was used as an internal control. With combination treatment, there was a decrease in SIRT1 protein as evident by western blot which is consistent with real-time and activity data. g No significant change observed in SIRT1 enzyme activity in MCF10A breast control cells after 72 h of treatment with compounds alone or in combination. Values are representative of three independent experiments and are shown as percent of control ± SE; *P <0.05, **P <0.01