Targeting the Glutamine Transporter SLC1A5 Enhances Sensitivity of Acute Myeloid Leukemia to MLN4924

<b>Background/Objectives</b>: Acute myeloid leukemia (AML) remains a hematologic malignancy with poor prognosis. The neddylation inhibitor MLN4924 has demonstrated potent anti-leukemic activity in preclinical models, yet its clinical translation faces significant challenges. The aim of this study was to explore combination therapy strategies that could further enhance MLN4924's anti-leukemia potential. <b>Methods</b>: AML cell lines used in this study were Kasumi-1 and MOLM-13. Cell viability was assessed using CCK-8 assays. mRNA and protein expression levels were determined through RT-qPCR and Western blot, respectively. Flow cytometry was employed to analyze surface markers (SLC1A5, CD11b, CD14, CD16), mitochondrial membrane potential (JC-1), and apoptosis (Annexin V-FITC/PI). In vivo efficacy was validated using an NCG mouse xenograft model. Transcriptomic profiling was performed to explore the potential mechanism by which MLN4924 in combination with V9302 inhibits leukemia. <b>Results</b>: Treatment with MLN4924 significantly upregulated key glutamine metabolic proteins, GLUL and the glutamine transporter SLC1A5, in AML cells. Knockdown of SLC1A5 significantly enhanced AML cell sensitivity to MLN4924. The combination of MLN4924 and the SLC1A5 inhibitor V9302 synergistically inhibited AML cell proliferation, induced monocytic differentiation, and promoted apoptosis. Transcriptomic analysis revealed that this combination therapy prominently suppressed the tricarboxylic acid (TCA) cycle. <b>Conclusions</b>: Neddylation inhibition induces compensatory upregulation of glutamine metabolism in AML. Co-targeting neddylation and glutamine transporter SLC1A5 synergistically exerts anti-leukemic effects, at least in part through disruption of the TCA cycle. This combination represents a novel and effective therapeutic strategy against AML.