Abstract 4166: The RNA demethylase FTO promotes glutamine metabolism in clear cell renal cell carcinoma through the regulation of SLC1A5

Abstract Glutamine reprogramming is a hallmark feature of clear cell renal cell carcinoma (ccRCC). However, the regulation of glutamine reprogramming in ccRCC is incompletely understood. Here we demonstrate that the RNA demethylase enzyme, FTO, promotes glutamine reprogramming in ccRCC cells to support growth and survival. Genetic and pharmacologic inhibition of FTO reduced glutamine-derived reductive carboxylation, de novo pyrimidine synthesis and glutathione biosynthesis. FTO inhibition resulted in increased DNA damage and reduced growth and survival that were rescued by the administration of pyrimidines and the antioxidant N-acetylcysteine. Mechanistically, FTO demethylates the glutamine transporter SLC1A5 mRNA transcript to promote SLC1A5 expression and glutamine reprogramming in ccRCC cells. In FTO knockdown cells, restoration of SLC1A5 expression was sufficient to rescue glutamine-derived reductive carboxylation, glutathione levels, DNA damage as well as growth and survival. Further, we observed that the FTO inhibitor FB23-2 enhanced the efficacy of the PARP inhibitor talazoparib in vitro and in vivo. Our study reveals a novel role for FTO in glutamine reprogramming of ccRCC, highlighting the therapeutic potential of targeting the epitranscriptomic regulation of metabolic reprogramming in ccRCC. Citation Format: Man Zhao, Dalin Zhang, Haowen Jiang, Nishanth Kuganesan, Suchitra Natarajan, Leighton Pu, Kaushik N. Thakkar, Hongjuan Zhao, James D. Brooks, Donna M. Peehl, Jiangbin Ye, Erinn B. Rankin. The RNA demethylase FTO promotes glutamine metabolism in clear cell renal cell carcinoma through the regulation of SLC1A5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4166.