Abstract C037: Characterization of cysteine dependency implicates glutathione metabolism as a critical adaptation axis in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer that is highly malignant and lethal. The treatment options are limited, contributing to its high mortality rate. PDAC is known to have profound metabolic alterations that enable its growth and survival. Here, we screened for amino acid dependency in PDAC cell lines and found that the cells cluster into cysteine highly dependent, moderately dependent, and independent cells. In the highly dependent cells, cysteine deprivation reduces viability by ∼90%, which could be rescued by glutathione (GSH) supplementation. Metabolomics revealed that cysteine deprivation led to GSH depletion, suggesting an impairment in the GSH pathway machinery in these cells. Consistently, most metabolite intermediates in the GSH pathway are downregulated in the cysteine-reliant PDAC cell lines compared to cell lines that resist cysteine deprivation, and those cells showed higher sensitivity to oxidative stress induction. Bioinformatics analysis of multiple PDAC tumor gene expression datasets indicated that the GSH pathway is strongly upregulated in PDAC and correlates with proliferation, metastasis, and oncogenic KRAS upregulation. Using CRISPR/Cas9, we found that the knockout of GSH genes enhanced sensitivity to oxidative stress. Our data implicate the GSH pathway as a critical nexus to be targeted to overcome metabolic adaptation in PDAC. Citation Format: Chiamaka J Ezeh, Matthew H Ward, Chesta Jain, Verodia Charlestin, Daeho D Kim, Andrew Yang, Maya Nassif, Nneka Mbah, Peter Sajjakulnukit, Anthony Andren, Li Zhang, Marina Pasca di Magliano, Costas A Lyssiotis, Zeribe C Nwosu. Characterization of cysteine dependency implicates glutathione metabolism as a critical adaptation axis in pancreatic cancer abstract. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84 (17 Suppl₂): Abstract nr C037.