FIGURE 4.

Effect of NNT knockdown on cell proliferation and sensitivity to glucose carbons. A, glucose uptake and lactate secretion rates in the panel of SkMel5 cells used. Scr control, scramble control. B, net intake of glucose carbons as determined by the difference between twice the glucose consumption and lactate production rates. C and D, cell proliferation under low glucose (C) and low glutamine (D) conditions. Cell proliferation is normalized to the corresponding control cell type grown in 5 mm glucose- and 1 mm glutamine-containing medium. E, effect of NNT knockdown on the proliferation of SkMel5 cells. F, effect of NNT knockdown of the proliferation of SkMel5 cells growing as xenograft tumors in nu/nu mice. Student's t test compared the proliferation under low glucose- or glutamine-containing medium to correspondent controls in panels C and D. Statistical significance was determined using one-tailed Student's t test in panel F, n = 5 or more.