Figure 1.

Pharmacological inhibition of NAMPT (by FK866) or NAMPT KD reduces NAD⁺ levels and cell viability (cell count), independent of p53 status. (a) U2OS (p53 wild-type (wt) and p53 KD), Jurkat, H1299 and Saos2 cells were treated with 5 or 10 nM of FK866 for 48 h. Intracellular levels of NAD⁺ were measured using the NAD⁺/NADH Quantification Kit. (b and c) Cells treated with FK866 (5 nM) for 24 or 48 h were stained with Trypan blue and counted to determine the percentage of viable cells. Results represent three independent experiments. Statistical analysis was performed with one-way analysis of variance (ANOVA) followed by paired ‘t'-test; *P-values ⩽0.05 obtained by comparing the respective data with the untreated control. (d) Western blot analysis of lysates from various cells exposed to FK866 for 48 h or (e) from NAMPT KD cells showing levels of p-ERK, p-JNK, p-P38 and p-Akt