Integrated analyses of microRNA and mRNA expression profiles in aggressive papillary thyroid carcinoma.

microRNAs (miRNAs) are involved in the pathogenesis of diverse human cancers through its target genes, including papillary thyroid cancer (PTC). However, there are few studies regarding associations between clinicopathological features of PTC with the expression of specific miRNAs and its potential target genes. In the present study, analysis of miRNA was integrated with mRNA expression profiles in aggressive PTC. miRNA and gene expression arrays were used to identify a subset of differentially expressed miRNAs and mRNAs between aggressive and non-aggressive PTCs. These miRNAs and mRNAs were further validated by qPCR in a cohort of 20 PTCs with extrathyroidal invasion and/or distant metastases, and 20 PTCs with no extrathyroidal invasion. The target of these miRNAs was determined by luciferase reporter and bioinformatic analysis. The miRNA arrays identified 14 upregulated miRNAs and 10 downregulated miRNAs in aggressive compared with non-aggressive PTCs. Significant miRNA deregulation was confirmed in the validation cohort, with upregulation of miR-146b-5p and miR-221/222 and downregulation of miR-16 and miR-613 in aggressive PTCs. The gene arrays identified 2000 differentially expressed genes, in which TIMP3, ZNFR3, FN1 and ITGA2 were observed to be target genes inversely correlated with miR-221/222, miR-146b-5p, miR-613 and miR-16, respectively. The results of the present study indicated the potential importance of miR-221/222, miR-146b-5p, miR-16 and miR-613 in determining the aggressive properties of PTC by targeting TIMP3, ZNFR3, FN1 and ITGA2, respectively. Additional studies should be conducted to confirm the results.