Integrated Metabolomic, Proteomic, and Phosphoproteomic Profiling Reveals Metabolic and Signaling Alterations Associated with CAMKK2 Inhibition in Gastric Cancer

Abstract Gastric cancer is driven by aberrant kinase signaling that promotes uncontrolled proliferation and metabolic adaptations. Although calcium/calmodulin-dependent protein kinase 2 (CAMKK2) is overexpressed in gastric cancer, its role in regulating tumor-associated metabolic programs remains unclear. Here, we employed an integrated multiomics approach, centered on untargeted metabolomics, to investigate the effects of CAMKK2 inhibition in gastric cancer cells. Pharmacological inhibition of CAMKK2 using STO-609 resulted in G1/S phase cell cycle arrest, multinucleation, and coordinated metabolic, proteomic, and phosphoproteomic alterations. Metabolomic profiling revealed extensive metabolic reprogramming characterized by the depletion of purine and pyrimidine intermediates required for DNA synthesis. Pathway analysis demonstrated the suppression of nucleotide, lipid, and central carbon metabolism, indicating impaired biosynthetic capacity. Integration with proteomic and phosphoproteomic datasets revealed coordinated downregulation of DNA replication machinery and attenuation of signaling pathways involved in cell cycle progression. Collectively, these findings suggest that CAMKK2 contributes to the coordination of metabolic and signaling programs associated with DNA replication and proliferation in gastric cancer. CAMKK2 inhibition was associated with the coordinated depletion of nucleotide metabolites and disruption of replication-associated signaling, consistent with impaired DNA replication and a replication-stress-like phenotype. These findings highlight CAMKK2 as a potential therapeutic target for exploiting metabolic vulnerabilities in gastric cancer.