Background & aims: TGF-β1 is an abundant cytokine present in the tumour microenvironment. It has been shown to trigger versican expression in human osteosarcoma cells, which may account for the metastatic potential of these cells. However, the underlying mechanism of TGF-β1-mediated metastasis remains unclear. The aim of this study was to evaluate the roles of versican in TGF-β1-induced osteosarcoma cell migration and invasion.
Methods: Sixty paired osteosarcoma tumour tissues and adjacent normal tissues were obtained, and the relationship between Enneking stage and versican expression was tested by ANOVA analysis. Real-time PCR or Western blot was used to detect versican, Smad and miR-143 expression. Osteosarcoma cell migration and invasion was assessed using Boyden chambers. A luciferase reporter assay was employed to validate the miR-143-versican interaction.
Results: Both versican isoforms, V0 and V1, were significantly differentially expressed in tumours at different stages. TGF-β1 promoted osteosarcoma cell migration and invasion in vitro by up-regulating versican. Furthermore, TGF-β1 suppressed miR-143 expression through a Smad 2/3-dependent pathway. miR-143 directly targets the versican 3'-UTR, and anti-miR-143 or versican knockdown blocked the effects of TGF-β1.
Conclusion: Our results suggest that TGF-β1 up-regulates versican expression by suppressing miR-143, and this pathway is important for osteosarcoma cell migration and invasion.