Figure 5.

SIRT6 expression confers resistance to H₂O₂- and doxorubicin-induced cell death. A–C) MCF-7 cells were seeded in a 96-well plate (A) or in a 12-well plate (B, C) and exposed (or not) to 400 μM H₂O₂ for the indicated times. Cell were then fixed with trichloroacetic acid and stained with SRB to evaluate cell viability (A), or lysed to measure the intracellular NAD⁺ (B) and NADPH (C) content. D–F) MCF-7 cells were seeded in a 96-well plate (D), or in a 12-well plate (E, F) and exposed (or not) to 2.25 μM doxorubicin for 24 h. Cell were then fixed with trichloroacetic acid and stained with SRB to evaluate cell viability (D), or lysed to measure the intracellular NAD⁺ (E) and NADPH (F) content. Cell viability was determined in quadruple. Values represent the mean ± sd of 4 independent determinations. *P < 0.05, **P < 0.01.