miRNA Expression Pattern in Papillary Thyroid Cancer

The aim of this study was to conduct a comparison of tissue miRNA in thyroid cancer (papillary (PTC), follicular (FTC), and microcancer (PTMC)) and healthy thyroid tissue (Control). The expression level of 798 miRNAs using NanoString technology was examined. ROC curve analysis, and logistic regression modeling were performed. Gene ontology (GO), canonical pathways analysis were used to explore the biological functions of the miRNA target genes. The study revealed that 10 miRNAs were deregulated in samples of patients with PTC. Pathway analysis showed that miRNA target genes were mainly significantly enriched in endocrine resistance, EGFR tyrosine kinase inhibitor resistance, and pathways in cancer. ROC analysis demonstrated that miR-146-5p, miR-551b-3p, and miR-222-3p can be introduced as a diagnostic tool for PTC (AUC=0.770; 0.740; 0.720; respectively). Validation by qRT-PCR confirmed our findings. The results suggest that tissue miRNAs can potentially be used as predictive biomarkers of PTC in patients. A total of 111 FFFPE samples were included in the study. miRNA profile in 49 PTCs, 7 FTCs, 5 PTMCs and matched 50 normal thyroid samples was analyzed.