NEK2 promotes the progression of osteosarcoma through the AKT/p-AKT pathway and interacts with FoxM1

Osteosarcoma is a highly invasive and metastatic primary malignant bone tumor, and resistance to chemotherapy remains a major therapeutic challenge. Our previous studies showed that increased Forkhead box protein M1 (FoxM1) expression promotes osteosarcoma progression. While NIMA-related kinase 2 (NEK2) has emerged as a potential oncogenic factor, its functional role and molecular mechanisms in osteosarcoma remain poorly understood. Pearson's correlation analysis was performed to assess the relationship between FoxM1 and NEK2 expression using the GSE33382 dataset from GEO. Coimmunoprecipitation (Co-IP) was employed to investigate FoxM1-NEK2 interactions. NEK2 expression was modulated in the HOS and U2OS osteosarcoma cell lines through pharmacological inhibition (MBM-55), siRNA-mediated knockdown, and plasmid-mediated overexpression. Cellular proliferation was evaluated via CCK-8 and colony formation assays. Transwell migration/invasion assays and flow cytometry were performed to assess the metastatic potential and apoptosis, respectively. The protein levels of FoxM1, NEK2, and AKT/p-AKT were analyzed by Western blotting. Western blot analyses of FoxM1-overexpressing cell lines and RCM-1-treated cells revealed a positive correlation between NEK2 and FoxM1 levels. Co-IP confirmed their interaction. NEK2 knockdown significantly suppressed proliferation, migration, and invasion; enhanced cisplatin sensitivity (reduced the IC₅₀); and promoted apoptosis. Conversely, NEK2 overexpression exacerbated malignant phenotypes and decreased chemosensitivity. Mechanistically, NEK2 activation was shown to drive osteosarcoma progression via AKT/p-AKT pathway activation. This study revealed that NEK2 promotes osteosarcoma proliferation, invasion, migration, and chemoresistance while inhibiting apoptosis, likely through AKT/p-AKT signaling. These effects may be regulated by FoxM1.