VHL expression in case of thyroid tumor pathology: connection with the prevalence of the disease, expression of transcription, growth factors and components of the AKT / m-TOR signaling pathway

Abstract

Introduction. The oncosuppressor protein VHL plays a decisive or at least important role in the mechanisms of tumor progression. The development of malignant neoplasms of the thyroid gland is associated with the activation of transcriptional and growth factors. However, the role of the VHL gene in the mechanisms of the development of thyroid cancer has hardly been studied. The study aimed to study the clinical and morphological features, expression of transcription, growth factors, and components of the AKT / m-TOR signaling pathway in patients with papillary thyroid cancer depending on the level of expression of the VHL gene. Material and methods. The study included 46 patients with tumor pathology of the thyroid gland: 20 patients with benign thyroid tumors and 26 patients with papillary thyroid cancer T1-4N0-2M0. The expression of parameters was determined by PCR in real-time. Mutation BRAF-V600E was determined in allele-specific PCR in real-time. Results and their discussion. The mRNA level of the VHL gene remained virtually unchanged in the tissue of papillary cancer and benign thyroid tumors. It depended on the prevalence of the disease, the defeat of regional lymph nodes, and the BRAF-V600E status. In the presence of the BRAF-V600E mutation, VHL expression increased 615 times in patients with a mutation compared with patients without this somatic mutation. It was revealed that the expression of NF-κB p65, NF-κB p50, HIF-1, HIF-2, growth factors VEGF and CAIX in patients in the group with a VHL level> 1.0 RU increased compared with patients with a VHL level <1.0 RU. A decrease in PDK, c-RAF, mTOR, 70s 6 kinase, PTEN mRNA levels were also recorded in patients with increased levels of VHL expression compared with patients with VHL expression <1.0 RU. Conclusion. That the association of the VHL expression with tumor progression in papillary thyroid cancer and the mutant protein bRAF presence was found. Also, associations between the VHL expression and the level of mRNA of transcription and growth factors are noted.