Department of Cancer Biology, Abramson Cancer Center, University of Pennsylvania, Room 451, BRB II/III, 421 Curie Boulevard, Philadelphia, PA 19104-6160, USA.
Proc Natl Acad Sci U S A. 2009 Dec 22;106(51):21660-5. doi: 10.1073/pnas.0911316106. Epub 2009 Dec 7.
Tumor cells are metabolically reprogrammed to fuel cell proliferation. Most transformed cells take up high levels of glucose and produce ATP through aerobic glycolysis. In cells exhibiting aerobic glycolysis, a significant fraction of glucose carbon is also directed into de novo lipogenesis and nucleotide biosynthesis. The glucose-responsive transcription factor carbohydrate responsive element binding protein (ChREBP) was previously shown to be important for redirecting glucose metabolism in support of lipogenesis in nonproliferating hepatocytes. However, whether it plays a more generalized role in reprogramming metabolism during cell proliferation has not been examined. Here, we demonstrated that the expression of ChREBP can be induced in response to mitogenic stimulation and that the induction of ChREBP is required for efficient cell proliferation. Suppression of ChREBP resulted in diminished aerobic glycolysis, de novo lipogenesis, and nucleotide biosynthesis, but stimulated mitochondrial respiration, suggesting a metabolic switch from aerobic glycolysis to oxidative phosphorylation. Cells in which ChREBP was suppressed by RNAi exhibited p53 activation and cell cycle arrest. In vivo, suppression of ChREBP led to a p53-dependent reduction in tumor growth. These results demonstrate that ChREBP plays a key role both in redirecting glucose metabolism to anabolic pathways and suppressing p53 activity.
肿瘤细胞在代谢上被重新编程以促进细胞增殖。大多数转化细胞摄取大量的葡萄糖,并通过有氧糖酵解产生 ATP。在有氧糖酵解的细胞中,葡萄糖碳的很大一部分也被定向用于从头合成脂肪和核苷酸合成。先前已经表明,葡萄糖反应性转录因子碳水化合物反应元件结合蛋白(ChREBP)对于重新定向葡萄糖代谢以支持非增殖性肝细胞中的脂肪生成是重要的。然而,它是否在细胞增殖过程中对代谢重编程发挥更普遍的作用尚未被研究。在这里,我们证明 ChREBP 的表达可以响应有丝分裂刺激而被诱导,并且 ChREBP 的诱导对于有效的细胞增殖是必需的。ChREBP 的抑制导致有氧糖酵解、从头脂肪生成和核苷酸合成减少,但刺激线粒体呼吸,表明代谢从有氧糖酵解向氧化磷酸化的转变。通过 RNAi 抑制 ChREBP 的细胞表现出 p53 激活和细胞周期停滞。在体内,ChREBP 的抑制导致 p53 依赖性肿瘤生长减少。这些结果表明,ChREBP 在重新定向葡萄糖代谢为合成代谢途径和抑制 p53 活性方面都起着关键作用。