HYPOXIA-INDUCIBLE FACTOR-1α LEVEL IN BLOOD PLASMA, THYROID TUMORS AND METASTASES

Abstract

Metastases are the leading cause of death from malignant tumors. Hypoxia is a hallmark of all solid tumors and their metastases, including papillary thyroid carcinoma (PTC). This leads to activation of the hypoxia-inducible factor (HIF) family of transcription factors, which modulate gene expression within both tumor cells and immune cells within the tumor microenvironment, influencing tumor progression and treatment response.

The aim of the study was to compare the levels of HIF-1α in blood and tissue samples of follicular adenoma, goiter, papillary thyroid carcinoma, metastases, and conditionally normal tissue.

Materials and methods. Postoperative samples of tissue and blood plasma, obtained from the surgical department of the Institute's clinic, were used for research. Patients with РТС, PTC + metastases, follicular adenoma and goiters (88 samples in total) participated in the study. Plasma from 5 individuals without thyroid disease and other chronic diseases, representative for age, was used as a control. The amount of HIF-1α was determined using enzyme immunoassay kits. Student's t-test was used to compare data groups. Values of P < 0.05 were considered significant.

Results. The level of HIF-1α in the tissue of nodular goiter exceeded the levels in conditionally normal tissue by 2 times. A more then 2.5 ratio was observed in РТС tissues without metastases. The concentration of HIF-1α in the tumor tissue of the РТС with metastases was higher than in the conditionally normal tissue by more then 3.5 times. The level of HIF-1α in metastases was much lower comparing tumor tissue. In blood plasma of patients with PTC and metastases the concentration of the HIF-1α was more then 3 times higher than in control (healthy people) and more then 2 times higher than in tumor tissue of РТС without metastases.

Conclusions. Our data indicate significant differences in the concentration of HIF-1α between tumor tissues of papillary thyroid carcinoma with and without metastasis. It should be emphasized the fact that in the blood plasma the level of HIF-1α was also significantly higher in papillary thyroid carcinoma patients with metastasis than in healthy people and papillary thyroid carcinoma patients without metastases. The latter circumstance can become the basis for the preoperative prognosis of the development of metastases in papillary thyroid carcinoma.