Integrated Metabolomic, Proteomic, and Phosphoproteomic Profiling Reveals CAMKK2-Dependent Regulation of Cell Cycle and Nucleotide Metabolism in Gastric Cancer

Gastric cancer is driven by aberrant kinase signaling that supports uncontrolled proliferation and metabolic adaptation. Calcium/calmodulin dependent protein kinase kinase 2 (CAMKK2) is overexpressed in gastric cancer; however, its role in regulating metabolic programs that sustain tumor growth remains incompletely understood. In this study, we employed an integrated multi-omics approach with a primary focus on untargeted metabolomics to investigate the consequences of CAMKK2 inhibition in gastric cancer cells. Pharmacological inhibition of CAMKK2 using STO-609 in AGS cells resulted in significant suppression of proliferation, clonogenic growth, migration, and invasion, accompanied by pronounced nuclear abnormalities and multinucleation indicative of mitotic defects. Global metabolomic profiling revealed extensive and time-dependent metabolic reprogramming following CAMKK2 inhibition, characterized by a marked depletion of nucleotide intermediates, including purine and pyrimidine metabolites required for DNA synthesis. Pathway enrichment analysis highlighted suppression of nucleotide metabolism, lipid metabolism, and central carbon metabolic pathways, indicating a broad impairment of biosynthetic capacity. Integration with proteomic and phosphoproteomic datasets demonstrated that metabolic alterations were accompanied by downregulation of DNA replication machinery and attenuation of kinase signaling pathways governing cell cycle progression. Protein metabolite interaction and docking analyses further supported functional coupling between nucleotide metabolites and key replication-associated enzymes, revealing disruption of metabolite enzyme interactions upon CAMKK2 inhibition. Collectively, these findings identify CAMKK2 as a critical regulator of metabolic programs that support DNA replication and cell cycle progression. Its inhibition induces replication stress through coordinated depletion of nucleotide pools and disruption of replication-associated signaling, leading to impaired proliferation and mitotic failure. These results highlight CAMKK2 as a potential therapeutic target for exploiting metabolic vulnerabilities in gastric cancer.