Sirtuin 1 Activation Suppresses the Growth of T-lymphoblastic Leukemia Cells by Inhibiting NOTCH and NF-κB Pathways.

Abstract

The deacetylase sirtuin1 (SIRT1) inhibits tumor suppressor p53 and may promote tumorigenesis; however, SIRT1 effects on leukemia cells are controversial. The aim of this study was to clarify the activity of SIRT1 in leukemia cells. The effects of SIRT1 inhibition or activation and SIRT1 knockdown or overexpression were examined in two T cell acute lymphoblastic leukemia (T-ALL) cell lines carrying NOTCH1 mutations and three acute myeloid leukemia (AML) cell lines. The growth of T-ALL cells was promoted by SIRT1 inhibition and SIRT1 knockdown but was reduced by SIRT1 activation and overexpression; however, no effects were observed in AML cells. SIRT1 activation decreased NOTCH, NF-κB, and mTOR signaling and inhibited p53, suggesting that the possible mechanisms of T-ALL growth suppression by SIRT1 are independent of p53. SIRT1 activators acting through the down-regulation of NOTCH, NF-κB, and mTOR pathways can be novel targeted drugs for NOTCH1-mutated T-ALLs.