Underexpression of miR-486-5p but not Overexpression of miR-155 is Associated with Lung Cancer Stages.

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 smoking-related diseases.

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 LC.

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.