ABSTRACT
<p><b>BACKGROUND</b>Aberrantly expressed microRNAs are a hallmark of cancer, and microRNA expression profiling is associated with tumor progression and response to chemotherapy, suggesting their potential application as prognostic and predictive biomarkers. The role of microRNAs in lung cancer remains elusive. It has been recently reported that epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (MET) tyrosine kinase can regulate expression of specific microRNAs including miR-30b, miR-30c, miR-221, miR-222, miR-103 and miR-203, and induce tumorigenesis and gefitinib resistance in lung cancers. We intend to study the role of miR-30b and miR-30c expression in predicting response to tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC).</p><p><b>METHODS</b>We have therefore retrospectively examined expression of miR-30b miR-30c in 41 formalin fixed paraffin embedded tissue samples from NSCLC patients when TKIs were used as first line therapy.</p><p><b>RESULTS</b>We found a significant correlation between expression of miR-30b and miR-30c. Furthermore, miR-30b and miR-30c expression correlated with short-term response. Kaplan-Meier analysis further revealed that the expression of miR-30b and miR-30c predicted progression free survival and the overall survival rate in the examined cohort.</p><p><b>CONCLUSION</b>Our study identified miR-30b and miR-30c as useful prognostic predictors in NSCLC patients who underwent first line treatment with TKIs.</p>