美国犹他大学（the University of Utah）Huntsman癌症研究所的研究人员，提出了一个新的想法，他们认为肿瘤细胞的能量来源就是糖，这项研究或许也对其他疾病，例如：糖尿病，也会有更多的了解，此研究表于近期的Proceedings of the National Academy of Sciences期刊。
Ayer表示：自1923年，研究人员就已经知道肿瘤细胞会比正常细胞使用更多的葡萄糖（glucose），而这份研究则协助我们了解这个过程是如何发生的，以及如何利用糖类来达到控制肿瘤生长的目的。研究人员表示：在肿瘤细胞或正常细胞生长的过程中，都需要利用到葡萄糖及谷胺酰胺（glutamine），长久以来，大家都认为这两种细胞生长的必要成份毫不相关，但是，Ayer研究团队却发现它们是相互依赖的，研究中发现当限制了glutamine的可利用性时，glucose也被停止使用，从实质上来讲，细胞没有了glutamine，也就丧失了glucose，于是肿瘤细胞的生长也就停止了。
研究人员将目标集中在MondoA蛋白上，这个蛋白能调控基因的表现与否，当glutamine存在，MondoA就会阻止TXNIP基因（注：TXNIP基因为一个抑癌基因，suppressor）的表现，此时细胞就会被允许利用glucose，以驱动肿瘤的生长。目前，研究团队正以MondoA、TXNIP或是glutamine的利用性作为标靶，找寻具潜力治疗癌症的新药，下一步将进行动物试验，以确认这个概念的真实性与应用性。(生物谷www.bioon.com)
Bioon推荐原始出处：
PNAS September 1, 2009 vol. 106 no. 35 14878-14883
Glutamine-dependent anapleurosis dictates glucose uptake and cell growth by regulating MondoA transcriptional activity
Mohan R. Kaadigea, Ryan E. Looperb, Sadhaasivam Kamalanaadhana and Donald E. Ayera,1
aHuntsman Cancer Institute, Department of Oncological Sciences and
bDepartment of Chemistry, University of Utah, 2000 Circle of Hope, Room 4365, Salt Lake City, UT 84112-5550
Glucose and glutamine are abundant nutrients required for cell growth, yet how cells sense and adapt to changes in their levels is not well understood. The MondoA transcription factor forms a heterocomplex with its obligate partner Mlx to regulate ≈75% of glucose-dependent transcription. By mediating glucose-induced activation of thioredoxin-interacting protein (TXNIP), MondoA:Mlx complexes directly repress glucose uptake. We show here that glutamine inhibits transcriptional activation of TXNIP by triggering the recruitment of a histone deacetylase-dependent corepressor to the amino terminus of MondoA. Therefore, in the presence of both glucose and glutamine, TXNIP expression is low, which favors glucose uptake and aerobic glycolysis; the Warburg effect. Consistent with MondoA functioning upstream of TXNIP, MondoA knockdown reduces TXNIP expression, elevates glucose uptake and stimulates cell proliferation. Although glutamine has many intracellular fates, a cell permeable analog of a tricarboxylic acid cycle (TCA) intermediate, α-ketoglutarate, also blocks the transcriptional activity of MondoA at the TXNIP promoter and stimulates glucose uptake. Together our data suggest that glutamine-dependent mitochondrial anapleurosis dictates glucose uptake and aerobic glycolysis by blocking MondoA:Mlx-dependent transcriptional activation of TXNIP. We propose that this previously unappreciated coordination between glutamine and glucose utilization defines a metabolic checkpoint that restricts cell growth when subthreshold levels of these essential nutrients are available.
