Fig. 8.

SIRT2 overexpression inhibited both glycolysis and oxidative phosphorylation in Huh7 liver cancer cells.A, the relative expression of SIRT2 in Huh7 cells transfected with the empty vector control (pcDNA3.1) or SIRT2 (pcDNA3.1 + SIRT2) as measured by qRT-PCR. B, Western blotting analysis confirmed the overexpression of SIRT2 in cells transfected with pcDNA3.1 + SIRT2. The densities of the corresponding protein bands were measured by Image J and displayed on the right. Based on the observed molecular weights, the double bands of SIRT2 were likely formed by two alternative spliced isoforms of SIRT2, including Sirt2.1 as the canonical isoform (1–389 aa, 43 kDa) and Sirt2.2 (38–389 aa, 40 kDa). C and D, oxygen consumption rate (OCR) (C) and extracellular acidification rate (ECAR) (D) of Huh7 cells overexpressing SIRT2 and the corresponding control cells. Left panel, oligomycin, FCCP, and R/A were injected at the indicated time points. The values of basal respiration, maximal respiration, and spare respiratory capacity were calculated by the Seahorse XF24 software. Right panel, glucose, oligomycin, and 2-DG were injected at the indicated time points. The values of glycolysis, glycolytic capacity, and glycolytic reserve were calculated by the Seahorse XF24 software. Data represent mean ± s. d. of triplicate independent experiments (∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001; n.s., not significant, by two-sided Student’s t test). 2-DG, 2-deoxy-glucose; FCCP, carbonyl cyanide 4-trifluoromethoxyphenylhydrazone; qRT-PCR, quantitative real-time PCR; R/A, rotenone/antimycin A.