Prognostic Relevance of Thyroid-Hormone-Associated Proteins in Adenoid Cystic Carcinoma of the Head and Neck

The proteins sodium iodide symporter (NIS), μ-crystallin (CRYM), and thyroid hormone receptor beta (THRB) have been associated with prognosis in various cancer entities. While NIS and THRB may serve as possible therapeutic targets, the role of CRYM in cancer is still unclear. Protein levels of 44 patients with adenoid cystic carcinoma of the head and neck were analyzed using immunohistochemistry and correlated with clinicopathological data and outcome. NIS was positive in 72%, CRYM was positive in 55%, and THRB was positive in 39% of the patients. CRYM-positive adenoid cystic carcinomas were associated with a better cause-specific survival. Thus, our data indicate that CRYM might be a suitable positive prognostic marker in adenoid cystic carcinoma of the head and neck. Furthermore, expression of NIS was present in most patients and therefore evaluation of the use of radioiodine treatment is recommended.

The complex regulation of NIS expression and activity in thyroid and extrathyroidal tissues

The sodium iodide symporter (NIS) is an intrinsic plasma membrane protein that mediates active iodide transport into the thyroid gland and into several extrathyroidal tissues. NIS-mediated iodide uptake plays a pivotal role in the biosynthesis of thyroid hormones, of which iodide is an essential constituent. For 80 years radioiodide has been used for the diagnosis and treatment of thyroid cancer, a successful theranostic agent that is extending its use to extrathyroidal malignancies. The purpose of this review is to focus on the most recent findings regarding the mechanisms that regulate NIS both in thyroid and extra-thyroidal tissues. Among other issues, we discuss the different transcriptional regulatory elements that govern NIS transcription in different tissues, the epigenetic modifications that regulate its expression and the role that miRNAs play in fine tuning NIS after being transcribed. A review on the hormones, cytokines, and iodide itself that regulate NIS is provided. We also review the present stage of understanding NIS dysregulation in cancer, occupied mainly by convergent signaling pathways and by new insights in the route that NIS follows through different subcellular compartments to the plasma membrane. Furthermore, we cover NIS distribution and function in the increasing number of extrathyroidal tissues that express the symporter, as well as the role that NIS plays in tumor progression independently of its transport activity.

A new molecular-genetic panel in the algorithm of diagnosis and treatment in patients with tiroid nodules

The increase in the number of patients with thyroid nodules requires the development of the most effective methods of preoperative diagnosis, allowing timely detection and differentiation of follicular neoplasia and highly differentiated cancer. A comprehensive study was carried out, which made it possible to optimize the diagnosis and choice of therapeutic tactics in patients of this category through the use of a new molecular genetic panel. Results of examination and surgical treatment of 60 patients suffering from benign and malignant thyroid gland formations are analyzed, pre-operative diagnosis of which was supplemented by immunocytochemical and molecular genetic methods of studying cellular material obtained during fine-needle aspiration biopsy. The threshold value of the Galektin-3 expression level for the differential diagnosis of follicular neoplasia in the direction of adenomas or well-differentiated thyroid cancer was determined. The significance of the BRAF V600E gene mutation in the detection of papillary thyroid cancer, the features of its clinical course and the determination of rational surgical tactics was proved. The limit value of the sodium-iodide symporter for predicting the resistance of thyroid cancer to radioactive iodine therapy, which determines the need to expand the scope of surgical intervention, has been established. The place of these molecular genetic markers in the algorithm of diagnosis and treatment in patients with thyroid nodules was determined.