Introduction: The deregulation in miRNA expression has been described in thyroid tumors, and is considered an important factor in thyroid carcinogenesis. mRNA expression profiling in cancer allows identifications of signatures associated with diagnosis, staging, prognosis, and response to treatment.
Objective: We aimed to detect miRNAs species differentially expressed between tumor and peritumoral tissue in papillary thyroid carcinoma.
Materials and methods: After informed consent and study approval by ethics committee, 24 patients were included in the study: seven patients with classic papillary thyroid carcinoma (cPTC), 14 patients with follicular variant of papillary thyroid carcinomas (fvPTC) and three patients with insular and sclerosing variant of PTC, using intra-operatively obtained tumor and peritumoral normal tissue. RNA was isolated from thyroid tissue using Trizol (Invitrogen, Life Technologies). miRNA microarray analysis was performed using miRNA Microarray System with miRNA Complete Labeling and Hyb Kit and SurePrint G3 Human miRNA r21 Array Kit (Agilent Technologies). SureScan Microarray Scanner Agilent (G2600D) with Feature Extraction v11.0 and Agilent GeneSpring GX v14.5 were used for data extraction and analysis.
Results: Our analysis showed that 2570 miRNA species differ between normal and tumor tissues. From all these, a fold change (FC)>1.1 identified 2516 species, with 276 having a FC>2. Applying an asymptotic P value below 0.05 and Benjamini-Hochberg correction for false-discovery rate we found eight miRNAs significantly different between normal and tumor thyroid tissues, namely hsa-miR-181c-5p, hsa-miR-181d-5p, hsa-miR-221-3p, hsa-miR-34a-5p, hsa-miR-34b-5p, hsa-miR-5703, hsa-miR-630 and hsa-miR-744-5p, 6 of them up-regulated and two of them downregulated in tumor vs normal tissue.
Conclusion: miRNA microarrays expression profile using a specific platform allowed a very good differentiation between tumor and normal thyroid tissue, providing an important tool for the individualized, specific variant-based management of thyroid cancer.
Acknowledgement: UEFISCDI grant PN-II-PT-PCCA-2011-3.2-1337.
20 - 23 May 2017
European Society of Endocrinology