Tumor cell metabolism is considered to be a hallmark of tumorigenic progression. Pancreatic cancer cells are shown to develop addiction towards the metabolic pathways like glycolysis and mitochondrial respiration to meet energy demands. Pancreatic tumor cells predominantly utilize cytosolic aerobic glycolysis for energy production. In our previous studies, we have reported that capsaicin treatment inhibits the survival of AsPC-1 and BxPC-3 pancreatic cancer cell lines. In this study, we evaluated the effect of capsaicin on glycolysis and mitochondrial respiration in pancreatic cancer cells. Our results showed that capsaicin treatment reduced the extra-cellular acidification rate (glycolysis) and oxygen consumption rate (mitochondrial respiration) in AsPC-1 and BxPC-3 cells in a concentration-dependent manner after 24h of treatment. Capsaicin treatment caused 86% and 55% down-regulation of glycolysis process in AsPC-1and BxPC-3 cells respectively. Our results also indicate the inhibition of glycolytic capacity and glycolytic reserve by capsaicin treatment indicating the potential of capsaicin to inhibit glycolysis. In addition, capsaicin treatment reduced 98% of basal oxygen consumption rate and ATP production in AsPC-1 cells. Furthermore, capsaicin treatment inhibited spare respiratory capacity & proton leak in a concentration dependent manner in AsPC-1 cells. Treatment of AsPC-1 and BxPC-3 with capsaicin for 48h also inhibited the expression of LDH-A and its upstream regulators such as HIF-1α, pSTAT3 (Y705) and EGFR as evaluated by Western blot. Our study thus indicate that capsaicin suppresses pancreatic tumor growth by down-regulating glycolysis and mitochondrial respiration. Further mechanistic studies are in progress. [Supported in part by R01 grant CA129038, awarded to (S.K.S.) by the National Cancer Institute].
Citation Format: Sharavan Ramachandran, Sanjay K. Srivastava. Capsaicin suppresses pancreatic tumor growth by inhibiting tumor cell metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4422. doi:10.1158/1538-7445.AM2017-4422