UCLA

Tracer-based metabolomics is a special form of targeted metabolomics in which the isotopomer distributions of carbon 13 (13C) from a labeled precursor is used to perform quantitative analysis of metabolic phenotypes in cells. The objective of the study is to develop a novel tracer-based metabolomics methodology to investigate the metabolic alterations between cancer and normal cells as well as between high and low invasive cancer cells by tracing 13C in consumed glucose and its integration into protein synthesis. Our hypothesis is that the incorporation of 13C from glucose into the backbones of cellular proteins reflects the metabolic phenotypes of cancer cells. To test the hypothesis, we developed a mass spectrometry (MS) based methodology that traces the incorporation of 13C labels in newly synthesized proteins allowing the understanding of the process of partial protein synthesis through the consumption of glucose. Next, we implemented a set of bioinformatics tools to analyze the tracer-based metabolomics data and compare the metabolic regulation of protein synthesis between normal pancreas epithelial cells and pancreatic cancer cells. Lastly, we applied this new methodology to investigate the metabolic regulation of protein synthesis between high and low invasive head and neck cancer cells and revealed signature proteins that showed significant difference in the glucose utilization for their protein synthesis. Our studies have demonstrated that this novel tracer-based metabolomics methodology is a powerful tool for studying the metabolic regulation

of protein synthesis in cancer cells.