157P Search for new markers of thyroid carcinogenesis associated with ER, AR and PR receptor status

Abstract

In recent years a plethora of new investigating methods have appeared, which allows us to fully and thoroughly observe thyroid diseases. Though, final diagnosis at the pre-operative stage remains to be difficult. Fine-needle aspiration biopsy used for pre-surgical diagnosis doesn't distinguish benign follicular tumors (adenoma) from malignant ones (carcinoma). It is known that thyroid cancer is more common in women (approximately 1: 3), but more aggressive forms of thyroid cancer are common in men. This indicates that estrogen, progesterone and androgen receptors (ER, PR and AR) can play an important role in carcinogenesis of the thyroid gland. Also miRNAs, which role in thyroid cancerogenesis processes is being actively studied, are in interest. However, certain attempts to connect disruptions in receptor expression with disruptions in miRNA expression during thyroid cancerogenesis haven’t been made yet. The expression of the miRNAs and their target-genes was analyzed by RT-PCR in 90 samples of thyroid neoplasms (TN). To find new thyroid cancer markers, we analyzed the expression levels of ER, PR, AR, miRNAs for which these receptors are targets, as well as other target genes of selected miRNAs (ID4, FOXE1, VEGFA, BCL2, ITGB3, SLC24A4, TSHR) in TN. The results has shown that benign TN can be distinguished from malignant ones by expression levels of miRNA-181a, miRNA-205 and their target genes – PR, VEGFA, BCL2, TSHR. Markers, that allow to distinguish follicular variant of papillary thyroid cancer from follicular and papillary carcinomas, have been identified as well. Moreover, it has been shown that miRNA-22 can be marker for lymph node metastases: miRNA level is reduced in patients with metastases. Furthermore, based on the results, it can be assumed that there is a relationship between miRNA-222, miRNA-19b, miRNA-22, miRNA-193b, miRNA-205, miRNA-181a, miRNA-378a levels and ER, PR, AR expression levels during thyroid tumor development. Markers that distinguish between different types of thyroid tumors have been identified (miRNA-181a, miRNA-205, PR, VEGFA, BCL2 and TSHR). The miRNA-22 level was shown to be associated with N stage.