Volume 2 Supplement 1

Metabolism, Diet and Disease 2014: Cancer and metabolism

Open Access

Chemosensitization of leukemia cells through inhibition of NAMPT

  • Theresa Gorski1,
  • Stefanie Petzold-Quinque1,
  • Susanne Schuster1,
  • Melanie Penke1,
  • Sandy Richter1,
  • Wieland Kiess1 and
  • Antje Garten1
Cancer & Metabolism20142(Suppl 1):P24

https://doi.org/10.1186/2049-3002-2-S1-P24

Published: 28 May 2014

Background

NAMPT (Nicotinamide phosphoribosyltransferase) catalyzes the rate-limiting step in the NAD-biosynthesis from nicotinamide and regulates the activity of NAD-dependent enzymes. Cancer cells are highly dependent on NAD for energy and DNA repair processes and are expected to be more susceptible to the inhibition of NAD synthesis than non-transformed cells. Can inhibition of NAMPT by FK866 sensitize leukemia cells for chemotherapeutic agents?

Materials and methods

Viability was measured using WST-1 assay. Cell death was analysed in Jurkat and Molt-4 cells by PI staining. NAD levels were measured using a colorimetric NAD/NADH Assay or HPLC. NAMPT activity was measured in leukemia cell lines and PBMCs (peripheral blood mononuclear cell) using radioactively labelled 14C-nicotinamide.

Results

NAMPT expression and enzymatic activity were significantly higher in leukemia cell lines compared to normal PBMCs. Incubation with FK866 [10nM] for 24h reduced NAMPT activity by 91.1±3.6% in Jurkat cells and by 97.8±1.2% in Molt-4 cells. NAD levels were reduced by FK866 by 83.9±1.0% (Jurkat) or 79.2±2.8% (Molt-4). The combination of etoposide and FK866 caused increased cell death compared to each substance alone. In contrast, combining FK866 and methotrexate or doxorubicin showed no increased effect on cell death. Etoposide decreased the expression of the NAD-dependent deacetylase SIRTUIN1 (SIRT1). The acetylation of the SIRT1 target p53 was increased after stimulation with etoposide and was further enhanced after combining etoposide with FK866. Concomitantly, the transcriptional activity of p53 was increased as shown by an increased expression of p21.

Conclusion

The combination of etoposide and FK866 caused increased cell death and induced acetylation and transcriptional activity of p53. Combining FK866 and etoposide could therefore be a novel therapeutic strategy to enhance the efficacy of etoposide against leukemia cells.

Authors’ Affiliations

(1)
Center for Pediatric Research Leipzig (CPL), University Hospital for Children and Adolescents, University of Leipzig

Copyright

© Gorski et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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