Fig. 8.

NAMPT inhibition does not affect AICART activity but is associated with an increase in intracellular intermediates of de novo purine biosynthesis. A549 cells were transfected with either control scrambled siRNA or with NAMPT-specific siRNA. (A–C) After 72 hours under normal culture conditions, cells were subsequently harvested and intracellular concentrations of ZMP (A) and IMP (B) and the ratio of IMP/ZMP (C) were determined. Experiments were conducted in triplicate and the resulting mean ± S.D. for each experiment is presented and compared by t test analysis. NS, not significant; Scr, scrambled.