Expression of transcription, growth factors, steroid hormone receptors, LC3B in papillary thyroid cancer tissue, association with prognosis and risk of recurrence

Abstract

Introduction. Biological characteristics of the tumor play a major role in it’s development and progression. Currently, using the molecular markers aimed at resolving the problems in clinical oncology is becoming more important, including thyroid carcinomas. Heterogeneous contradictory data had been accumulated to date showing the ability of tumors genetic and biological parameters to predict the diseases outcome.Aim. To investigate prognostic value of transcription, growth factors, components of AKT / mTOR signaling pathway and autophagy protein LC3B in patients with papillary thyroid cancer in relation to recurrences and overall survival.Materials and methods. The study included 65 patients with T1–4N0–1M0 papillary thyroid cancer. According to the criteria of the American Thyroid Association (ATA) (2015), patients were divided into groups of patients with high, low and intermediate risk. 30 patients were classified as low risk, 23 as intermediate risk, and 12 as high risk. The BRAFV600 mutation was identified in 18 samples. The expression of transcription factors (p65 and p50 subunits of nuclear factor kappa B (NF-κB p65, NF-κB p50), hypoxia-inducible factor 1 (HIF-1), hypoxia-inducible factor 2 (HIF-2), growth factors (vascular endothelial growth factor (VEGF), receptor VEGF (VEGF-2), carbonic anhydrases of type 9 (CAIX)), AKT, c-RAF, GSK- 3β, p70S6, mammalian target of rapamycin (m-TOR), PDK, PTEN, 4E-BP1 in the tumor was assessed by real-time polymerase chain reaction (PCR). The BRAFV600 mutation was investigated using real-time allele-specific PCR. The content of the LC3B protein was examined using the Western Blot method.Results. As a result of the study, there is an increase in c-RAF expression with an increase in risk from low to high, which was accompanied by a decrease in 4E-BP1 expression. c-RAF mRNA levels were increased 3.0- and 2.8‑fold in the intermediate and high-risk groups, respectively, compared to low risk patients. There is a change in the expression of Brn-3α depending on the relapse risk. The maximum mRNA levels were found in patients with intermediate risk, where the figure was 4.3 and 6.2 times higher than in patients with low and high risk, respectively. An increase in LC3B expression by 56.0 and 28.0 times was shown in the tumor tissue of patients with intermediate risk compared with patients with low and high risk. This fact corresponds with an increasing content of the protein itself, which was higher in patients with intermediate risk. Patients with a negative BRAF gene status had an intermediate and high risk of tumor recurrence. The prognostic significance of the estrogen receptor β (ER-β) and NF-κB p50 expression level had been revealed in relation with relapse-free and overall survival of patients with papillary thyroid cancer.Conclusion. As a result of the study, additional molecular markers were found in order to for predict the tumors recurrence risk. The study showed the significance of ERβ and NF-κB p50 expression levels for predicting disease outcomes.