RESUMEN
Objective To investigate the expressions of miR-21 in carcinoma tissue and serum of the patients with papillary thyroid carcinoma (PTC), and to clarify its clinical significance.Methods Real-time PCR was used to detect the expression levels of miR-21 in carcinoma tissue and serum of 46 PTC patients,thyroid tissue and serum of 35 cases of nodular goiter and 18 healthy people. The correlations of miR-21 expression level with the clinicopathological features of PTC patients were analyzed.Results The relative expression levels of miR-21 in carcinoma tissue and serum of the PTC patients were 2.74±1.53 and 0.21±0.08,and they were 0.92±0.81 and 0.08±0.05 in carcinoma tissue and serum of the patients with nodular goiter,0.86 ± 0.39 and 0.07 ± 0.03 in normal papillary thyroid tissue and serum of 18 healthy people.The expression levels of miR-21 in carcinoma tissue and serum of the patients with PTC were higher than those of the patients with nodular goiter and healthy people (P<0.05).The expression level of miR-21 in serum and carcinoma tissue of PTC patients had a positive correlation with the extraglandular invasion,distant metastasis,lymph node metastasis,and TNM stages (P<0.05);and it had no correlation with gender and tumor sizes.Conclusion The expression levels of miR-21 in carcinoma tissue and serum of the PTC patients are increased. The up-regulated expression of serum miR-2 1 is correlated with the clinicopathological features of PTC patients, which indicates that miR-2 1 could be used as a potential marker for early detection of PTC.