Associations of miR-146a and miR-146b expression and clinical characteristics in papillary thyroid carcinoma.

BACKGROUND: Human miRNAs have emerged as potentially useful diagnostic and prognostic markers in cancer within the past decade. Abnormal expression of microRNA-146 (miR-146) has been found in several classes of cancers.

OBJECTIVE: To explore expression and clinical associations of miR-146a and miR-146b in papillary thyroid carcinoma.

METHODS: We investigated expressions of miR-146a and miR-146b in tissues and peripheral blood among 128 patients with primary PTC, 120 patients with nodular goiter and 120 healthy controls by RT-PCR. Furthermore, the associations between the miR-146a and miR-146b expression and clinical parameters of PTC were analyzed.

RESULTS: Levels of miR-146a and miR-146b expression in PTC tissues were higher compared to the nodular goiter tissues (P=0.014 and 0.001) and perineoplastic thyroid tissues (P=0.023 and 0.002). Positive associations were found between levels of miR-146a expression in PTC tissues and gender (female), cervical lymph node metastasis, multifocality, extra tyroidal invasion and advanced clinical TNM stages (III and IV). For miR-146b, there were positive association between levels of miR-146b expression and female, extra tyroidal invasion and advanced clinical TNM stages.

CONCLUSIONS: Up-regulation of miR-146a and miR-146b expression in tissues was related to carcinogenesis and deterioration of PTC. MicroRNA-146a and miR-146b expressed in thyroid tissue may act as potential biomarkers for PTC patients.