Pneumologie 2015; 69 - A74
DOI: 10.1055/s-0035-1556666

miR-126 is a potential diagnostic marker for malignant pulmonary nodules in endobronchial epithelial lining fluid

N Kahn 1, 2, 3, S Kaduthanam 4, U Schirmer 4, T Muley 2, 3, R Kuner 4, FJF Herth 1, 3, M Meister 2, 3, H Sueltmann 3, 4
  • 1Department of Pneumology and Respiratory Critical Care Medicine, Thoraxklinik at Heidelberg University Hospital, Germany
  • 2Translational Research Unit, Thoraxklinik at Heidelberg University Hospital, Germany
  • 3Translational Lung Research Center (TLRC) Heidelberg, Member of the German Center for Lung Research (DZL), Heidelberg, Germany
  • 4Cancer Genome Research Group, German Cancer Research Center and National Center of Tumor Diseases, Heidelberg, Germany

Background: Early detection and diagnostic clarification of indeterminate pulmonary nodules by less invasive methods could contribute to better intervention strategies and to the reduction of the high mortality in lung cancer patients. Endobronchial epithelial lining fluid (EELF) might contains molecular markers with diagnostic potential. With the bronchoscopic microsampling (BMS) technique, it is possible to collect EELF in close proximity to the suspected lesion without the risk of biopsy-associated complications. We investigated whether microRNA (miRNA) in EELF collected by BMS may be useful to facilitate preoperative diagnosis of indeterminate pulmonary nodules.

Methods: The study included 24 non-small-cell lung cancer patients with 48 EELF samples. From each patient, EELF was collected from subsegmental bronchi close to the indeterminate pulmonary nodule, which was detected by computed tomography, and from the contralateral healthy lung. Diagnosis was confirmed by transbronchial biopsy or surgery. Global miRNA expression profile analysis (754 miRNAs) was performed using quantitative real-time polymerase chain reaction (qRT-PCR) with eight sample pairs. miRNAs potentially associated with a malignant phenotype were selected for further qRT-PCR analysis in an independent validation cohort (16 sample pairs).

Results: All patients underwent BMS without complications. miRNA profiling by qRT-PCR could be reliably applied to EELF samples and resulted in potential miRNA markers for malignant pulmonary nodules. In particular, the miRNA pair miR-126/miR-126* significantly differentiated between EELF close to the indeterminate pulmonary nodules and the sample taken from the healthy contralateral lung (p < 0.0001).

Conclusions: Our study suggests that the analysis of miR-126/miR-126* in EELF collected by BMS could be a potentially useful adjunct to other diagnostic techniques aiming at the preoperative diagnosis of indeterminate pulmonary nodules.

*Presenting author