Integrative proteomic and metabolomic analysis reveals that ouabain inhibits DLBCL proliferation by reprogramming arginine-driven metabolic networks

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL), with an increasing incidence in recent years. Ouabain, a cardiotonic steroid, has demonstrated anti-tumor effects in various cancers including DLBCL, but its mechanism of action is not yet fully understood. We first used liquid chromatography-tandem mass spectrometry (LC-MS) for proteomics and metabolomics to analyze changes in DLBCL cells with ouabain administration. The results revealed significant alterations in the abundance of 303 proteins and 206 metabolites between the ouabain-treated and control groups. Proteins like MYC, RAD51, AURKB, CENPF, and RRM2 were downregulated, along with metabolism-related proteins ARG2, OAT, and TYMS. Metabolite levels including glutamate, glutathione, ornithine, and taurine were significantly altered. The integrated analysis revealed that arginine metabolism serves as a central hub, coordinating changes in glutathione metabolism and nucleotide biosynthesis, contributing to increased oxidative stress, replication stress, and growth inhibition. These findings suggest that ouabain disrupts arginine-driven metabolic network to alter redox balance and inhibit tumor cell proliferation, providing a promising therapeutic rationale for targeting metabolic vulnerabilities in DLBCL.