Abstract LB-108: Glutamine addition and glucose addiction - linking metabolic abnormalities to genetic alterations in glioblastoma SF188 and hereditary leiomyomatosis renal carcinoma UOK262

Metabolic transformations of malignant cells are essential for tumor development and progression. Oncogene Akt and c-myc stimulate glucose metabolism and glutamine metabolism, respectively, and render the cancers dependent on glucose or glutamine for growth and survival (otherwise known as glucose addiction and glutamine addiction). However, many other oncogenes, tumor suppressor genes and signaling molecules also regulate glucose and glutamine metabolism, which results in various metabolic abnormalities in different cancers. The question we want to ask is how one or more genetic mutations can lead to the ultimate metabolic abnormalities of a given cancer. Toward this end, we report here the metabolic abnormalities of two human cancer cell lines, glioblastoma SF188, which is c-myc-dependent and is addicted to glutamine, and hereditary leiomyomatosis renal carcinoma (HLRCC) UOK262, which is fumarate hydratase-deficient and is addicted to glucose. We performed our metabolic analysis using the XF24 Extracellular Flux Analyzer and pharmacological modulators of cellular metabolism. The XF24 Analyzer simultaneously monitors oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), which are indicators of mitochondrial respiration and aerobic glycolysis respectively. Oxygen consumption rate is also used as an indicator for the oxidation of glucose and glutamine when they are added to the cells after baseline measurement. We found that SF188 cells showed a small increase in acidification rate upon glucose addition, suggesting a relatively low basal glycolysis rate. We estimated the glycolytic capacity of the cells by determining the acidification rate after the addition of mitochondrial ATP syntase inhibitor oligomycin. The glycoltic capacity remained high although basal glycolysis rate was low. Glucose was not oxidized at all by these cells. Most importantly, we observed significant increases in oxygen consumption rate upon addition of glutamine indicating active uptake and oxidation of glutamine. Associated with active glutamine oxidation, SF188 cells exhibited high basal reparation rate and high respiratory capacity. Finally, SF188 cells grew and survived in medium containing glutamine but no glucose; however, they started to die in the medium containing glucose but no glutamine. In contrast with glioblastoma SF188, we found that HLRCC UOK262 cells exhibit high basal glycolysis rate, which is close to its maximal capacity. Interestingly, basal mitochondrial respiration and respiratory capacity are extremely low, which is associated with reported defective mitochondrial complex I. The growth and survival of UOK262 is dependent on a high concentration of glucose in the culture medium. Collectively, we established metabolic abnormalities of glioblastama SF188 and HLRCC UOK262, which contain genetic alterations in c-myc and fumarate hydratase, respectively, that makes them addicted to glutamine and glucose. The metabolic abnormalities we found include the preferential use of glucose and glutamine, the activation or inactivation of relevant enzymatic pathways that catabolize glucose and glutamine, and the modulation of mitochondrial bioenergetic activities in the two cancer cell lines. Most of cancer cell lines that we have studied showed metabolic abnormalities falling between the two extremes. Therefore, this type of metabolic analysis coupled with the analysis of genetic abnormalities in cancers will provides a rapid means to gain insight into the aberrant metabolism of each type of cancer and improve the efficacy of cancer therapy for a cancer with a particular set of metabolic abnormalities. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-108.