Identification of EEF1A2 as a potential therapy target of osteosarcoma using novel compound 8e

Osteosarcoma (OS) is a rare malignant tumor and has the second-highest mortality rate of malignant tumors in children. Due to its unclear pathogenesis and therapeutic targets, there has been no significant progress in the targeted therapy of OS in the past 50 years. Therefore, it is critically important to develop new drug targets for OS. In this study, a covalent molecule library consisting of 61 small molecules was constructed based on our previous research. Phenotypic screening revealed that small molecule 8e effectively inhibited the proliferation of OS 143B cells, with an IC₅₀ value of 0.73 μM. Compound 8e also showed good antitumor effects and low toxicity in a xenograft model (30.1 % inhibition of OS growth in BALB/c nude mice). Using compound 9a as an efficient activity-based protein profiling (ABPP) probe, eukaryotic protein elongation factor 1 alpha 2 (EEF1A2) was then enriched and conveniently identified as a potential target. The potential target was validated by pull-down assay, cellular thermal shift assay (CETSA), mass spectrometry analysis, molecular docking, and in vitro and in vivo functional studies. Mechanistic studies suggest that compound 8e-induced 143B cell apoptotic is mediated by EEF1A2 inhibition of the AKT signaling pathway and EEF1A2 serves as a potential candidate for targeted OS therapy.