[Expression of MiRNA-221 in non-small cell lung cancer tissues and correlation with prognosis]

MicroRNAs were important regulators of tumors and the expression of miRNA-221 was associated with malignant proliferation and invasion in many tumors. The aim of this study is to explore the expression of miRNA-221 in non-small cell lung cancer (NSCLC) tissues and its correlation with prognosis.

We retrospectively analyzed the clinical characteristics of 117 NSCLC patients who underwent surgery in our hospital from November 2005 to January 2007. Real-time PCR was used to detect the expression of miRNA-221. Chi-square test was utilized to analyze the relationship between miRNA-221 expression and clinicopathologic features. Survival curves were plotted by using the Kaplan-Meier method and compared by the Log-rank test. A Cox proportional hazard regression model was applied to examine the joint effect of covariants. A P-value less than 0.05 was evaluated as statistically significant.

The patients were divided into two groups according to the relatively expression of miRNA-221. No statistically significance was observed between the expression of miRNA-221 and the clinicopathologic parameters, including gender (χ(2)=0.070, P=0.791), histology (χ(2)=0.414, P=0.520), p-TNM stage (χ(2)=0.068, P=0.794) and history of smoking (χ(2)=0.206, P=0.650). Kaplan-Meier analysis showed that high expression of miRNA-221 was closely associated with a shorter survival time (P<0.001). Finally, both univariate and multivariate analyses demonstrated that high miRNA-221 expression might be a poor prognostic marker of NSCLC patients.

Our results indicated that down-regulation of miRNA-221 was associated with poor prognosis of patients with NSCLC. MiRNA-221 may serve as a molecular prognosis marker for patients with NSCLC.