DEPDC1/ EEF1A1 Complex Promotes the Progression of Human Osteosarcoma via Downregulation of FOXO3a

BackgroundOsteosarcoma is a common primary malignant bone tumor with poor prognosis. Currently there is no effective therapeutic strategies primarily due to the insufficient understanding its underlying mechanisms. Here we aimed to decipher the molecular mechanisms underlying the osteosarcoma progression.MethodsGEO data analysis, immunohistochemistry, qRT-PCR and western blotting were performed to evaluate the expression of differentially genes in human osteosarcoma tissues. Stably transfected human osteosarcoma cells were injected in mouse model to assess the effect of DEPDC1 in vivo. The function of DEPDC1–EEF1A1–FOXO3a axis was detected by mass spectrometry analysis, co-immunoprecipitation (co-IP) experiments and RNA sequencing in vitro. ResultsBy exploring differentially expressed genes, we found DEPDC1 is highly expressed in human osteosarcoma cells and tissues. Mechanistically, we found the protein expressed by DEPDC1 can directly bind to EEF1A1 through three binding regions, thus forming a complex. Importantly, DEPDC1/EEF1A1 complex can directly inhibit the transcription and expression of FOXO3a in vitro and in vivo, thus promoting the metastasis and proliferation of osteosarcoma. The clinical relevance study showed that overexpression of DEPDC1/EEF1A1 complex is correlated with reduced survival rate of osteosarcoma patients.ConclusionsCollectively, this study demonstrated the DEPDC1/EEF1A1–FOXO3a axis as a critical pathway that promotes the progression of osteosarcoma and leads to poor prognosis. Genetically targeting or pharmacologically inhibiting DEPDC1/EEF1A1–FOXO3a axis may serve a promising strategy for targeting human osteosarcoma.