Figure 7.

A. Effect of glutaminase inhibitor, BPTES, on aerobic and hypoxic P493 cell growth. Growth of control cells compared with cells treated with BPTES under both aerobic and hypoxic conditions. All cells were grown at 1 × 10⁵ cells/mL. Cell counts were performed in triplicate and shown as mean ± SD. Live cells were counted daily in a hemocytometer using trypan blue dye exclusion. B. Effect of BPTES on steady state ATP levels. P493 cells were treated with 2 μM BPTES for 20 h and counted. ATP levels (mean ± SD, n = 3 experiments) were determined by luciferin– luciferase-based assay on aliquots containing an equal number of live cells. *p = 0.0006; **p = 0.01 (t-test).C. Effects of hypoxia and glucose deprivation on oxygen consumption rates. Oxygen consumption rates of aerobic (A) or hypoxic (H) P493 cells were determined by a Clark-type oxygen electrode after culture in the presence or absence of glucose for 24 hours. Data are from duplicate experiments with standard deviation and p-values (T-test) shown. D. In vivo efficacy of BPTES. 2.0 × 10⁷ P493 human lymphoma B cells were injected subcutaneously into tumor-bearing SCID mice. When the tumor volume reached 100 mm³, 200 μg BPTES was injected every other day by i.p. administration (12.5 mg/kg bodyweight) for 20 days. Control animals were treated with daily i.p. injection of vehicle (2% (vol/vol) DMSO). BPTES inhibited lymphoma xenograft growth as compared to control. The tumor volumes were measured using digital calipers every 4 days and calculated using the following formula: [length (mm) × width (mm) × width (mm) × 0.52]. The results represent the average ± SEM (n=7 each).