Off-Target Inhibition of Human Dihydroorotate Dehydrogenase ( h DHODH) Highlights Challenges in the Development of Fat Mass and Obesity-Associated Protein (FTO) Inhibitors

作者：Marco Tarullo, Guillermo Fernandez Rodriguez, Alessia Iaiza, Sara Venezia, Alberto Macone, Alessio Incocciati, Silvia Masciarelli, Marcella Marchioni, Marta Giorgis, Marco L. Lolli, Federico Fornaseri, Ludovica Proietti, Florian Grebien, Serena Rosignoli, Alessandro Paiardini, Dante Rotili, Antonello Mai, Elena Bochenkova, Amedeo Caflisch, Francesco Fazi, Alessandro Fatica · 发表于：ACS Pharmacology & Translational Science · 年份：2024 · DOI：10.1021/acsptsci.4c00533 · 被引用次数：12 · 研究领域：RNA modifications and cancer、Biochemical and Molecular Research、Cancer-related gene regulation

High Resolution Image Download MS PowerPoint Slide FTO, an N 6 -methyladenosine (m 6 A) and N 6,2′- O -dimethyladenosine (m 6 A m ) RNA demethylase, is a promising target for treating acute myeloid leukemia (AML) due to the significant anticancer activity of its inhibitors in preclinical models. Here, we demonstrate that the FTO inhibitor FB23-2 suppresses proliferation across both AML and CML cell lines, irrespective of FTO dependency, indicating an alternative mechanism of action. Metabolomic analysis revealed that FB23-2 induces the accumulation of dihydroorotate (DHO), a key intermediate in pyrimidine nucleotide synthesis catalyzed by human dihydroorotate dehydrogenase ( h DHODH). Notably, structural similarities between the catalytic pockets of FTO and hDHODH enabled FB23-2 to inhibit both enzymes. In contrast, the h DHODH-inactive FB23–2 analog, ZLD115, required FTO for its antiproliferative activity. Similarly, the FTO inhibitor CS2 (brequinar), known as one of the most potent h DHODH inhibitors, exhibited FTO-independent antileukemic effects. Uridine supplementation fully rescued leukemia cells from FB23-2 and CS2-induced growth inhibition, but not ZLD115, confirming the inhibition of pyrimidine synthesis as the primary mechanism of action underlying their antileukemic activity. These findings underscore the importance of considering off-target effects on h DHODH in the development of FTO inhibitors to optimize their therapeutic potential and minimize unintended conse...