Liquid Chromatography-Tandem Mass Spectrometry Method Revealed that Lung Cancer Cells Exhibited Distinct Metabolite Profiles upon the Treatment with Different Pyruvate Dehydrogenase Kinase Inhibitors

Abstract
Pyruvate dehydrogenase kinases (PDKs) play a pivotal role in regulating the metabolic switch between mitochondria-based respiration and cytoplasm-based glycolysis by modulating pyruvate dehydrogenase (PDH) activity. Upregulation of PDKs is a key contributor to the Warburg effect observed in cancer cells, making them an attractive therapeutic target. Among PDK inhibitors, dichloroacetate (DCA) and AZD7545 are the most well-known, each exhibiting unique pharmacological profiles. DCA has demonstrated anticancer efficacy in various preclinical and clinical studies, whereas AZD7545 has primarily been studied for its potential to improve glucose control in type II diabetes.

However, the impact of PDK inhibition on tricarboxylic acid (TCA) cycle metabolites remains largely unexplored. This study investigates the metabolite changes in lung cancer cells (A549) treated with PDK inhibitors using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The method was optimized for the sensitive and reproducible quantification of key glycolysis and TCA cycle metabolites, including glucose, pyruvate, lactate, acetyl coenzyme A, citrate, α-ketoglutarate, fumarate, succinate, malate, and oxaloacetate.

Our findings revealed that A549 cells exhibited distinct metabolite profiles in response to treatment with DCA or AZD7545, potentially reflecting the differing pharmacological actions of these two drugs.