Calcitonin-induced NF-κB activation up-regulates fibronectin expression in MG63 osteosarcoma cells

Abstract

Salmon calcitonin has been used extensively as a therapeutic tool in the regulation of bone remodeling. However, there is a growing body of evidence indicating that the calcitonin peptides are involved in regulation of cell growth, differentiation, survival and tissue development. In the present study, we investigated the effect of calcitonin in cell matrix interactions in MG63 cell line. Our results demonstrated that calcitonin increases cell growth of MG63 osteosarcoma cells in parallel with serine/threonine protein kinase B (AKT/PKB) activation. Moreover, calcitonin induced up-regulation of fibronectin expression in a nuclear factor-kappa B (NF-κB)-dependent manner, accompanied by enhanced enzymatic activity of matrix metalloproteinase-9 (MMP-9) and increased expression of tissue inhibitors of MMP-1 and -2. MMP-9 stimulation with calcitonin was accompanied by an increase in protein expression of the α5β1 integrin receptor. To our knowledge, our results demonstrate, for the first time, that calcitonin is a potent inducer of fibronectin, an extacellular matrix component that is suggested to have a pro-oncogenic and healing effect, in a NF-κB-dependent manner.

Keywords: Calcitonin; MG63 cells; NF-κB activation; fibronectin; integrins; matrix metallo-proteinase 9.