Abstract 2353: Metabolic reprogramming by SLC1A5 downregulation in pancreatic cancer cells

Abstract

Abstract Introduction: Pancreatic cancers exhibit limited response to chemo- and radiation therapy. Identifying novel targets for pancreatic cancer treatment is important for new treatment strategies. Because pancreatic cancer cells are ‘glutamine avid' [1], targeting glutamine metabolic pathways can provide novel options for treatment. The glutamine transporter, SLC1A5, is being actively investigated as a pharmacological target in cancer [2]. Here we have engineered human pancreatic cells expressing shRNA to downregulate the glutamine transporter SLC1A5. We performed high-resolution 1H magnetic resonance spectroscopy (MRS) to understand the metabolic reprograming that occurs with SLC1A5 downregulation in these two cell lines. Method: Panc1 and Pa04C pancreatic cancer cell lines were genetically engineered to express shRNA against SLC1A5 using lentiviral transduction. Downregulation of SLC1A5 was verified with qRTPCR and immunoblotting. Control cells expressing an empty vector (EV) were also engineered. Dual phase extraction was performed as previously described [3]. High-resolution 1H MRS was performed on the aqueous phase extracts and recorded on a 750 MHz spectrometer. All data acquisition, processing and quantification was performed with TOPSPIN 3.5 software. Spectra were obtained from Panc1EV (n=4), Pa04CEV (n=4), Panc1_SLC1A5_shRNA (n=4) and Pa04C_SLC1A5_shRNA (n=4) cells. Results and Discussion: SLC1A5 downregulation significantly decreased the glutamine/glutamate ratio in Pa04C_SLC1A5_shRNA cells but not in Panc1_SLC1A5_shRNA cells. Instead, in Panc1_SLC1A5_shRNA cells, a significant decrease of the amino acids leucine, isoleucine, valine, tyrosine, histidine, and phenylalanine was observed. Lactate and fumarate also significantly decreased in Panc1_SLC1A5_shRNA cells. Other than the significant decrease of glutamine/glutamate in the Pa04C_SLC1A5_shRNA cells, no other significant metabolic differences were observed in these cells. Our data expand the understanding of the diverse metabolic reprogramming that occurs following SLC1A5 downregulation in two human pancreatic cancer cell lines that may lead to the development of additional metabolic targets. Supported by NIH R01CA193365 and R35CA209960.1. Son J et al., Nature. 2013; 2. Bhutia YD et al., Biochim Biophys Acta. 2016; 3. Winnard PT Jr. et al., J Cachexia Sarcopenia Muscle. 2020. Citation Format: Raj Kumar Sharma, Balalji Krishnamachary, Ishwarya Sivakumar, Yelena Mironchik, Santosh Kumar Bharti, Zaver M. Bhujwalla. Metabolic reprogramming by SLC1A5 downregulation in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2353.