Abstract 1429: Bioluminescent methods for investigating metabolic pathways

Abstract

Abstract Cancer cells are dependent on metabolic pathways that have been altered to support unique requirements for cancer cell growth and survival. The central role of these pathways makes them attractive targets for new treatment approaches. Rapid and sensitive assays, amenable to high-throughput screening, are needed to study the enzymes, metabolites and cofactors involved in cancer cell metabolic pathways. We developed a bioluminescent technology to address these needs and monitor changes in the fundamental metabolic co-factors nicotinamide adenine dinucleotides and key metabolites such as lactate. The bioluminescent method uses a novel proluciferin substrate for the enzyme diaphorase. Luciferin is produced in the presence of NAD(P)H, resulting in a luciferase-generated light signal proportional to the starting NAD(P)H concentration. This is a versatile technology for measuring dinucleotide concentrations, enzyme activity and also metabolite levels. When lactate dehydrogenase is included in the reaction, the cellular metabolite lactate, an indicator of glycolytic rate, can be measured. NAD, NADP, NADH and NADPH can be measured in enzyme reactions or in biological samples, such as cells and tissues, with the use of NAD- and NADP-specific cycling enzymes. Total NAD+NADH or NADP+NADPH levels in cultured cells were rapidly monitored using a one-reagent addition, in-well plate protocol without the need for cell processing. Additionally, the levels of individual dinucleotides and their ratios were determined from cell and tissue samples using a streamlined in-well acid and base-treatment protocol. The effects of small molecules on cellular dinucleotide levels can be quickly assessed, as demonstrated with FK866, an inhibitor of NAD biosynthesis. Advantages of the bioluminescent approach over other detection methods include higher sensitivity (LOD ≤ 50 nM), larger maximum signal windows (S/B > 100) and compatibility with automated, high-throughput protocols (Z' > 0.8). By providing these features, the bioluminescent assays should be useful tools for facilitating the study of cancer cell metabolic pathways and the development of therapeutics that target these pathways. Citation Format: Donna Leippe, Mary Sobol, Jolanta Vidugiriene, Wenhui Zhou, Gediminas Vidugiris, Troy Good, Laurent Bernad, Poncho Meisenheimer, James Cali. Bioluminescent methods for investigating metabolic pathways. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1429. doi:10.1158/1538-7445.AM2014-1429