Investigation of biomarkers of papillary thyroid carcinoma in paraffinized tissues

Purpose/Objective. Papillary thyroid carcinoma (PTC) is the most commonly occurring thyroid malignancy accounting for approximately 85-90 % of cases [1]. For the majority of patients with PTC, the prognosis is good, however, about 1020% of patients suffer cancer recurrence. Currently, there are no approved molecular biomarkers in clinical use for predicting the risk of recurrence. It is believed, that BRAFV600E mutation and miRNAs could be potential biomarkers of PTC recurrence [2]. The objectives of this study were to analyze miRNA-221 and miRNA-181b expression and BRAFV600E mutation frequency in formalin-fixed paraffin-embedded (FFPI) PTC tissues. Results. Over-expression of miRNA-221, -181b were observed in PTC tissues compared to the normal thyroid tissue (22,1 -fold, p 0,05). BRAFV600E mutation was identified in 61,5 % of PTC. BRAFV600E mutation frequency did not significantly differ in NRc-PTC (62,7 %) and Rc-PTC (59,5 %) groups (p > 0,05). The associations of miRNAs expression and BRAFV600E mutation with tumor size, regional lymph nodes metastasis and patients age were also investigated. The levels of miRNA-221,-181b correlated with tumor size (p 45 yr. (68 %), p = 0,016). In addition, the link between BRAFV600E mutation and the expression of miRNA-221, -181b was investigated in PTC. However, we did not find any correlation between the miRNA221, -181b expression and BRAFV600E -positive and BRAFV600E-negative PTC samples (p = 0,69 and p = 0,63). Conclusions. The levels of miRNA-221,-181b were significantly increased in PTC as compare[...]