Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California 90024, USA.
Cancer Res. 2010 Aug 1;70(15):6368-76. doi: 10.1158/0008-5472.CAN-09-4615. Epub 2010 Jul 20.
Carbohydrate metabolism via glycolysis and the tricarboxylic acid cycle is pivotal for cancer growth, and increased refined carbohydrate consumption adversely affects cancer survival. Traditionally, glucose and fructose have been considered as interchangeable monosaccharide substrates that are similarly metabolized, and little attention has been given to sugars other than glucose. However, fructose intake has increased dramatically in recent decades and cellular uptake of glucose and fructose uses distinct transporters. Here, we report that fructose provides an alternative substrate to induce pancreatic cancer cell proliferation. Importantly, fructose and glucose metabolism are quite different; in comparison with glucose, fructose induces thiamine-dependent transketolase flux and is preferentially metabolized via the nonoxidative pentose phosphate pathway to synthesize nucleic acids and increase uric acid production. These findings show that cancer cells can readily metabolize fructose to increase proliferation. They have major significance for cancer patients given dietary refined fructose consumption, and indicate that efforts to reduce refined fructose intake or inhibit fructose-mediated actions may disrupt cancer growth.
糖酵解和三羧酸循环途径的碳水化合物代谢对癌症的生长至关重要,而精制碳水化合物的消耗增加则对癌症的生存不利。传统上,葡萄糖和果糖被认为是可互换的单糖底物,它们的代谢方式相似,而很少关注除葡萄糖以外的糖。然而,近几十年来,果糖的摄入量急剧增加,细胞对葡萄糖和果糖的摄取使用不同的转运蛋白。在这里,我们报告果糖提供了一种替代底物来诱导胰腺癌增殖。重要的是,果糖和葡萄糖的代谢有很大的不同;与葡萄糖相比,果糖诱导依赖硫胺素的转酮醇酶通量,并且优先通过非氧化戊糖磷酸途径代谢,以合成核酸并增加尿酸的产生。这些发现表明,癌细胞可以很容易地代谢果糖来增加增殖。鉴于癌症患者饮食中摄入精制果糖,这些发现具有重要意义,表明减少精制果糖摄入或抑制果糖介导的作用的努力可能会破坏癌症的生长。