Alteration in the serum concentrations of FGF19, FGFR4 and ßKlotho in patients with thyroid cancer.

ABSTRACT

INTRODUCTION: ßKlotho (ßKL) is known to act as co-receptor for fibroblast growth factor receptor 4 (FGFR4) which is the main cognate receptor for fibroblast growth factor 19 (FGF19). Dysregulation of this FGF19/FGFR4/ßKL signaling axis has been implicated in the pathogenesis of several cancers. However, its role in the pathogenesis of thyroid cancer has not been determined. MATERIALS AND METHODS: The aim of this study was to assess FGF19, FGFR4 and ßKL concentrations in a group of 36 patients with papillary thyroid cancer (PTC), 11 patients with follicular thyroid cancer (FTC), 9 patients with anaplastic thyroid cancer (ATC) and a group of 19 subjects with multinodular nontoxic goiter (MNG). The control group consisted of 20 healthy volunteers. Serum FGF19, FGFR4 and ßKL concentrations were measured using specific ELISA methods. RESULTS: Significantly lower concentrations of ßKL and higher concentrations of FGF19 were found in patients with PTC, FTC and ATC as compared with MNG group and controls. An elevation of FGFR4 serum concentration was observed in all thyroid cancer groups in comparison to MNG group and controls; however, in FTC group it was statistically insignificant. A positive correlation was found between ßKL and FGFR4 concentrations in PTC patients. The levels of ßKL, FGF19 and FGFR4 did not differ significantly between MNG group and healthy controls. CONCLUSIONS: Our results indicate that a disrupted FGF19/FGFR4/ßKL signaling pathway may play a role in the development of thyroid cancers. However, further studies are needed to elucidate the molecular mechanism of the neoplastic transition of thyroid epithelial cells.