Fibroblast growth factor 19 level in blood plasma, thyroid tumors and metastasis

Background. The endocrine subfamily of fibroblast growth factor 19 (FGF19) consists of FGF19, FGF21, and FGF23. Numerous data indicate that FGF19 is involved in carcinogenesis, epithelial-mesenchymal transition, metastasis formation, and tumor resistance to inhibitors. The purpose of the study was to compare the levels of FGF19 in tissue samples of follicular adenoma, goiter, papillary thyroid carcinoma (PTC), metastasis (Mts), and conditionally normal tissue. Materials and methods. Postoperative samples of tissue and blood plasma, obtained from the surgical department of the IEM clinic, were used for research. The amount of FGF19 was determined using enzyme immunoassay kits. Results. The level of FGF19 in the tissue of follicular adenoma and goiter exceeded the levels in conditionally normal tissue. There was also significant difference between normal tissue and РТС tissues with and without Mts. It is important to note that the level of FGF19 in metastasis was higher than in the tumor tissue of the РТС. In blood plasma of patients with PTC and Mts, the concentration of the FGF19 significantly exceeded its level in control plasma and in the blood of patients with PTC without Mts. In plasma of patients with PTC without Mts, the concentration of the FGF19 did not differ from its concentration in blood of healthy people. Conclusions. Our data indicate significant differences in the concentration of FGF19 between tumor tissues of PTC and Mts. In blood plasma of patients with PTC and Mts, the concentration of the FGF19 exceeded its level in control plasma and the concentration of FGF19 in the blood of patients with PTC without Mts. There was no difference between level of FGF19 in the blood of patients with PTC without Mts and in control plasma. The latter facts may be useful for predicting the formation of Mts.