Endocrine Abstracts

Our research subject is to study the importance of some favorable molecular biological markers for prognosis of premalignant characteristics of Hashimoto’s thyroiditis (HT) parenchyma. To clarify the pathogenetic link between these two pathologies (HT, PTC), we choose markers, indicating, at the one hand, on the tumor cell cycle, such Cyclin D1, at the second hand, RET/PTC rearrangement in HT, in order to determine molecular changes, connecting Hashimoto’s thyroiditis with Papillary thyroid carcinoma (PTC). Basic of these concepts are follows: 1. We hypothesized, that Cyclin D1 diffuse immunoreactivites should play a role of PTC malignancies due to the mechanism of gene amplification in HT at first, while the chromosome 6p21 triggered activation of chromosome 11q23 (Cyclin D1 gene location); normal thyroid follicular cells do not show immunoreactivity for Cyclin D1 on immunohistochemistry, but Cyclin D1 is over expressed in up to 60% of PTC. 2. RET/PTC proto-oncogene is located on the long arm of chromosome 10. In the PTC pathogenesis activation of RET includes rearrangement or gene redistribution and should be typically more sensitive method of PTC detection in setting of HT. The research database includes postoperative surgical pathology material obtained 150 cases from 1065 patients, who had undergone total thyroidectomy, lobectomy, and partial resection of the thyroid gland. We reviewed all continuous thyroid histopathological reports from 2016 to 2019 years. The mean age was of 49.5 years (range 23–76). This study was reviewed and deemed exempt from written informed consent by the Ethics committee and Board of medical sciences at Tbilisi State University based on Helsinki-ethical principles declaration for medical research (2013). Immunohistochemical (IHC) studyincludes following markers: 1. Cyclin D1 (clone D-6, 1:50, Dako), 2. Ret Antibody (6E4C4, Santa Cruz Biotechnology, U.S.A.). Results were shown statistically significant correlation between RET/PTC proto-oncogene expressionin HT follicular cells nuclei and frequency of follicular epithelial dysplasia areas (χ²-test: P = 0.091; Fisher exact test: P = 0.119). In terms of Cyclin D1 activity, according data, this cells cycle marker is not crucial for the detection of malignant transformation into thyroid Hashimoto parenchyma (χ²-test: P = 0.012; Fisher exact test: P = 0.017). These results confirmed the importance of Cyclin D1 and RET/PTCproto-oncogene expression, suggesting their malignant transformation in the evaluation of HT behavior.