FIGURE 4.

Inhibition of NAMPT leads to formation of corresponding labeled fructose 1-phosphate (F1P) and sedoheptulose 1-phosphate (S1P) from labeled glyceraldehyde and erythrose in cancer cells. HCT-116 cells were grown and treated in triplicates with FK866 (100 nm) for 24 h. After the treatment, the growth medium was replaced with a freshly prepared medium containing FK866 (100 nm), [¹³C]glyceraldehyde (1.0 mm), or [¹³C]erythrose (1.0 mm). The cells were incubated for a different period of time as described (see “Experimental Procedures”). After the treatment, cells were processed for analysis of the effects of glyceraldehyde and erythrose on the formation of fructose 1-phosphate (M3) and sedoheptulose 1-phosphate (M4) (A) and unlabeled F1P, S1P, fructose 1,6-bisphosphate (FBP), and DHAP (B) as described (see “Experimental Procedures”). The metabolites measured were expressed as nmol/mg total cellular protein. Error bars, S.D.