Tissue microRNA-182 expression level and its potential prognostic value for papillary thyroid carcinoma

In previous study, qRT-PCR analysis revealed significantly higher miR-182 levels in papillary thyroid carcinoma (PTC) than matched normal tissues. However, the clinical significance and prognostic value of miR-182 have not been investigated in PTC until now.

151 pairs of PTC and adjacent normal thyroid tissues were obtained from Affiliated Hospital of Weifang Medical University from February 2008 to January 2015. The Chi square test was used to analyze the relationship between miR-182 expression and the clinicopathological characteristics. We used the Kaplan-Meier method and the log-rank test in univariate survival analysis, and we used the Cox proportional hazards regression model in our multivariate analysis.

The relative expression of miR-182 in PTC samples was significantly higher than that of matched normal tissues (P<0.001). The high expression level of tissue miR-182 was statistically correlated with extrathyroidal invasion (P=0.009), cervical lymphnode metastasis (P=0.015), and TNM staging (P=0.001). The Kaplan-Meier method revealed that higher miR-182 expression level was correlated with significantly reduced overall survival. Furthermore, multivariate survival analysis revealed that miR-182 expression level (HR=2.882, 95% CI: 1.289-10.928, P=0.013) was significantly correlated with the poor prognosis of PTC patients.

Overexpression of miR-182 is associated with aggressive clinicopathologic characteristics of PTC, and miR-182 might be a novel prognostic molecular marker of PTC.