Abstract 69: Functional metabolomic profiling of human melanocyte and melanoma cells during hypoxic adaptation

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Abstract Adaptation to hypoxia is an important part of the cellular progression from normal melanocyte to malignant melanoma. This adaptation can be comprised of short-term remodeling of the cellular metabolic network and/or the permanent, gene-driven development of a new metabolic program. In either case, low oxygen conditions require a unique metabolic program for continued survival and proliferation. However, beyond a general shift from respiration to glycolysis, the details of this permissive metabolic program in melanoma are generally unknown. In order to better understand the changes to both the metabolome and metabolic flux in this system, we applied functional metabolomic profiling to seven human melanoma cell lines and to two human melanocyte cell lines under both hypoxic and normoxic conditions. The melanoma panel consists of four cell lines driven by B-raf mutations (WM35, UACC903, WM793 and LU1205), two containing N-ras mutations (MEL501 and WM1346) and one p53 mutant (MeWo). These cells, along with the two melanocyte lines, were grown in media containing a 1:1 mixture of natural and [U-13C]-labeled glucose for 24 hours in either 1% oxygen or atmospheric conditions. We then employed GCMS, NMR and biochemical experiments to map flux through five metabolic hubs and quantify the abundance of 28 key metabolites for each cell line and condition. These maps of central carbon metabolism encompass glycolysis, the pentose phosphate pathway, fatty acid biosynthesis, the glutamate-glutamine-proline network, and glycine/serine de novo synthesis, along with a number of other important metabolites. Analyzing these data with unbiased hierarchical clustering and Ingenuity Pathway Analysis, we discovered a metabolite-derived signature for hypoxic adaptation in melanocytes. Furthermore, we found that certain hypoxic responses are unique to either the B-raf or N-ras of the cell line subset. Interestingly, the hypoxic response of the mutant p53 cell line is more like that of the B-raf mutant cell lines than the B-raf and N-ras sets are to each other. The information gained from this functional metabolomic profiling advances our ability to identify hypoxia-adapted melanomas and develop metabolism-based therapeutic interventions. This work was supported by P01 CA128814-01 from the National Cancer Institute. 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 69.