Figure 1: mRNA expression of sirtuins in A) MCF7/Dox and MCF7/ADR-RES; B) SaOS2/Dox; C) A2780/Cis; and D) HL-60/Dox and the corresponding parental cell lines. The mRNA expression levels were measured by real-time PCR and normalized to GAPDH. Results show a consistent and significant inhibition of Sirt7 in all drugresistant cells tested. E) A representative Western blot using Anti-Sirt7 antibody showing a significant reduction of Sirt 7 expression in all drug-resistant cells (MCF7, SaOS2, A2780 and HL60) and F) corresponding densitometric quantitation of Sirt7 in these cell lines. All experiments were performed at least 4 times.