Figure 6.

Reduction of glucose uptake by HDACI does not reduce ATP levels but instead results in metabolism of amino acids. A, OPM2 cells were treated 44 h with VPA or SAHA before determining the number of remaining intact cells by trypan blue staining. An equal number of live cells was included in a chemiluminescent assay using luciferase activity to determine the relative levels of ATP in each sample. The data are expressed as mean percent ± sd relative to control where control equals 100% and are representative of three independent experiments. B, OPM2 cells were treated 48 h with VPA (0.5, 1, or 2 mm), SAHA (1, 2.5 or 5 μm), or Dox (25, 50, or 100 nm). Amino acid levels present in whole-cell extracts were determined using MS-MS analysis of deproteinated lysates and normalized to protein concentrations in the original lysates. C, Before lysis, apoptosis in cells analyzed in A was measured as in Fig. 2A. D, OPM2 cells were treated 96 h with vehicle or VPA in the presence or absence of supplemental nonessential amino acids. Apoptosis was analyzed as in Fig. 2A. Results are representative of at least three independent experiments, and graphed values represent calculated mean ± sd of triplicate samples.