ABSTRACT
Objective To explore the expression of miR-221/222 in non-small cell lung cancer (NSCLC) and its correlation with clinical pathological parameters. Methods The clinical pathological data and formalin fixed-paraffin embedded (FFPE) tissues of 55 NSCLC patients and 10 benign lesion patients who underwent surgery in the First Affiliated Hospital of Nanhua University from February 2012 to May 2014 were collected and followed. The relationship between miR-221/222 expression detected by real-time PCR and clinical pathological parameters and progression-free survival (PFS) were analyzed. The differential survival between the high expression group and the low expression group of miR-221/222 were compared. A Cox proportional hazard regression model was utilized to examine the prognostic factors of NSCLC. Results The expression level of miR-221/222 was significantly higher in tumor tissues than that in corresponding benign lesion tissues (Fold change=3.52, P=0.000;Fold change=2.01, P=0.000). There was a negative correlation between miR-221/222 expression and pathological grades (r=-0.732, P=0.000;r=-0.451, P=0.001). The relative expression of miR-221 showed a positive correlation with miR-222 (r=0.376, P=0.000). Patients with higher levels of miR-221/222 were closely associated with a shorter PFS (miR-221: 55.43 weeks vs. 81.29 weeks, P=0.028; miR-222: 45.00 weeks vs. 87.04 weeks, P=0.008). Finally, multivariate analysis demonstrated that miR-222 expression was independently associated with poor PFS (RR=2.808, P=0.033). Conclusions miR-221/222 is highly expressed in NSCLC tumor tissues with a positive correlation. A negative correlation is observed between the expression of miR-221/222 and tumor differentiation. The potential high expression of miR-221/222 is considered as tumor biomarkers for the prognosis of NSCLC patients.