Overexpression of TBL1XR1 confers tumorigenic capability and promotes recurrence of osteosarcoma.

Osteosarcoma is the most common malignant bone tumor in childhood and adolescence; however, the mechanism of this malignancy remains uncertain. Transducin (beta)-like 1 × -linked receptor 1 (TBL1XR1) plays an important role in controlling the transcriptional switch between gene activation and gene repression. However, the clinical significance and the precise biological function of TBL1XR1 in osteosarcoma remain unclear. In the present study, we revealed that TBL1XR1 is markedly upregulated in osteosarcoma cell lines and tissues, at both the mRNA and protein levels. Overexpression of TBL1XR1 dramatically enhanced, whereas inhibition of TBL1XR1 reduced, the cancer stem cell (CSC)-like phenotype and tumorigenicity of osteosarcoma cells, both in vitro and in vivo. Importantly, TBL1XR1 enhanced the tumorigenicity of osteosarcoma cells via activating STAT3 signaling and TBL1XR1 expression correlated significantly with STAT3 phosphorylation in osteosarcoma. Taken together, our results provide new evidence that TBL1XR1 overexpression induces CSCs-like phenotypes and tumorigenic capability of osteosarcoma and might represent a novel therapeutic target for its treatment.