%0 Journal Article
%T Target enzyme mutations are the molecular basis for resistance towards pharmacological inhibition of nicotinamide phosphoribosyltransferase
%A Uffe H Olesen
%A Jakob G Petersen
%A Antje Garten
%A Wieland Kiess
%A Jun Yoshino
%A Shin-Ichiro Imai
%A Mette K Christensen
%A Peter Fristrup
%A Annemette V Thougaard
%A Fredrik Bj£¿rkling
%A Peter B Jensen
%A S£¿ren J Nielsen
%A Maxwell Sehested
%J BMC Cancer
%D 2010
%I BioMed Central
%R 10.1186/1471-2407-10-677
%X Here, we introduce an analogue of CHS-828 called TP201565 with increased potency in cellular assays. Further, we describe and characterize a panel of cell lines with acquired stable resistance towards several NAMPT inhibitors of 18 to 20,000 fold compared to their parental cell lines.We find that 4 out of 5 of the resistant sublines display mutations of NAMPT located in the vicinity of the active site or in the dimer interface of NAMPT. Furthermore, we show that these mutations are responsible for the resistance observed. All the resistant cell lines formed xenograft tumours in vivo. Also, we confirm CHS-828 and TP201565 as competitive inhibitors of NAMPT through docking studies and by NAMPT precipitation from cellular lysate by an analogue of TP201565 linked to sepharose. The NAMPT precipitation could be inhibited by addition of APO866.We found that CHS-828 and TP201565 are competitive inhibitors of NAMPT and that acquired resistance towards NAMPT inhibitors can be expected primarily to be caused by mutations in NAMPT.Drug resistance is a serious concern in the treatment of cancer [1]. It can occur as either de novo or acquired resistance following therapy. Besides multi-drug resistance (MDR) caused by ABC efflux pumps, several targeted therapies have described the development of target-specific drug resistance. Thus, up to 90% of the cases of acquired resistance to tyrosine kinase inhibitors are due to over-expression of, or mutations in, the target kinase [2-4]. Acquired resistance can be studied by inducing resistance in vitro by growing cells in the presence of increasing concentrations of drug [1].NAD is an essential cofactor in cell energy production and metabolism as well as the substrate for mono-ADP-ribosyltransferases [5], poly-(ADP-ribose) polymerases (PARPs) [6] and sirtuins [7], all of these converting NAD to nicotinamide. PARPs are involved in DNA repair whereas sirtuins can increase cancer cell survival. To survive under stress and supply metabolites
%U http://www.biomedcentral.com/1471-2407/10/677