Liquid profiling in lung cancer -quantification of extracellular miRNAs in bronchial lavage

Abstract

Extracellular miRNAs cannot only be isolated from different body fluids like plasma and serum, but also from bronchial lavage samples (BL) obtained by bronchoscopy. Alterations in the expression of microRNAs might be useful for a discrimination of lung cancer patients from patients with a benign lung disease. We profiled extracellular microRNAs from three BL pools of lung cancer patients and three BL pools from a control group (patients with a benign lung disease) with TaqMan MicroRNA Array cards. For the confirmation of these results, we analyzed a panel of eight miRNAs in a qRT-PCR of the BL of 30 different lung cancer and non-cancerous patients. For the data normalization, we used exogenously added cel-miR-39 RNA. Using microRNA arrays, we found a panel of eight microRNAs (hsa-miR 19b-1, 1285, 1289, 1303, 217, 29a-5p, 5483p, 650) that were differentially expressed between the lung cancer and the non-cancerous group. Further investigation by qPCR revealed five microRNAs (U6 snRNA, hsa-miR 1285, 1303, 29a-5p, 650) that were significantly up-regulated in patients with lung cancer. In bronchial lavage samples, the five microRNAs identified in this study may have a diagnostic potential to be used as biomarkers in lung cancer.