Background: Evidence is increasing that microRNAs (miR) are particularly important in
lung homeostasis and development and have been shown to be involved in many pulmonary diseases
such as asthma, chronic obstructive pulmonary disease, sarcoidosis, Lung Cancer (LC) and other
Objective: The objective of this study was to investigate the expression of miR-155 and miR-486-5p
in tissues from LC patients and healthy endobronchial mucosa as prognostic biomarkers for diagnosing
Methods: Bronchoscopic and thoracoscopic tissue biopsies were taken from 50 LC patients and other
50 control subjects without lung mass, who were planned for a clinical bronchoscopy. The expressions
of miR-155 and miR-486-5p in both tumor tissue and healthy mucosa were detected by quantitative
real-time polymerase chain reaction.
Results: Histopathology showed that 72% of LC patients were in advanced stages III and IV, with
non-small cell lung carcinoma and adenocarcinoma being the most common diagnosis. miR-155 was
significantly overexpressed while, miR-486-5p was underexpressed, in LC patients as compared to
controls. Area under receiver operating characteristic curves of miR-155 (<-0.9) and miR-486 (>-0.62)
had sensitivity of 92 and 96% and specificity of 80 and 84%, respectively, in discriminating LC patients
from controls with benign solitary pulmonary nodules.
Conclusion: miR-155 was highly overexpressed, yet it did not correlate with stages, while miR-486-
5p was extremely underexpressed and significantly correlated with stages of LC. Thus, their detection
represents an excellent diagnostic/prognostic tool to support more established techniques linked to LC
spread locally and systemically.