ROCK2 mediates osteosarcoma progression and TRAIL resistance by modulating O-GlcNAc transferase degradation.

Osteosarcoma is a common bone tumor, with a poor prognosis. New combinatorial therapies that sensitize anticancer drug-resistant osteosarcoma cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) are, therefore, required. The GTPase RhoA effector, Rho-associated coiled-coil forming protein kinase 2 (ROCK2), is well known for its roles in various types of cancer; however, its involvement osteosarcoma has not yet been scrutinized. In this study, we analyzed ROCK2 expression, clinicopathological features, and prognosis in osteosarcoma patients. Apoptosis, colony formation, and cell proliferation were analyzed using flow cytometry, colony formation assays, and CCK8 assays, respectively. Proteomics analysis was used to evaluate osteosarcoma progression. We found that adjacent tissues had lower ROCK2 expression levels than osteosarcoma tissues and the level of expression was related to osteosarcoma tumor size and prognosis. Osteosarcoma prognosis was associated with ROCK2 expression level, which served as an independent marker in multivariate analysis. ROCK2 silencing inhibited proliferation in vivo and in vitro and triggered apoptotic osteosarcoma cell death. ROCK2 inhibited the TRAIL-mediated apoptotic pathway in osteosarcoma cells and promoted activation. Mechanistically, ROCK2 affected osteosarcoma progression and TRAIL resistance by modifying O-GlcNAcylation through O-GlcNAc transferase degradation. Taken together, our results demonstrated a unique mechanism whereby ROCK2 influences osteosarcoma progression and TRAIL resistance, hence improving osteosarcoma management. AJCR