Increased expression of insulin‐like growth factor‐1 receptor is correlated with tumor metastasis and prognosis in patients with osteosarcoma

Abstract

The aim of this study was to investigate the association of insulin-like growth factor-1 receptor (IGF-1R) with metastasis and prognosis of osteosarcoma patients. RT-PCR and Western blot assays were performed to detect IGF-1R mRNA and protein expression in 26 osteosarcoma and noncancerous bone tissues. Immunohistochemistry was performed to analyze the correlation of IGF-1R expression in 84 osteosarcoma tissues with clinicopathological factors or survival of patients. Lentivirus-mediated RNA interference system was employed to downregulate IGF-1R expression and analyze the effects of IGF-1R downregulation on invasion and metastasis of osteosarcoma cells. The relative levels of IGF-1R mRNA and protein expression were significantly higher in osteosarcoma tissues than in corresponding noncancerous bone tissues. The expression of IGF-1R protein was closely associated with surgical stage and distant metastasis of osteosarcoma patients. Osteosarcoma patients with high IGF-1R expression had poorer survival, and multivariate Cox analyses showed that high IGF-1R expression was an independent prognostic maker. Lentivirus-mediated targeting IGF-1R could significantly inhibit adhesion, migration, invasion, and metastasis of osteosarcoma cells, which might be correlated with of inactivation of Akt signaling pathway. IGF-1R is an independent prognostic marker for osteosarcoma patients and increased expression of this molecular is correlated with metastasis of osteosarcoma.