Altered miRNA expression in sputum for diagnosis of non-small cell lung cancer

• Published in: Lung cancer (Amsterdam, Netherlands) Vol. 67; no. 2; pp. 170 - 176
• Main Authors: Xie, Ying, Todd, Nevins W., Liu, Zhenqiu, Zhan, Min, Fang, HongBin, Peng, Hong, Alattar, Mohammed, Deepak, Janaki, Stass, Sanford A., Jiang, Feng
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ireland Ltd 01.02.2010; Elsevier
• Subjects: Aged; Area Under Curve; Biological and medical sciences; Biomarkers, Tumor - analysis; Carcinoma, Non-Small-Cell Lung - diagnosis; Carcinoma, Non-Small-Cell Lung - genetics; Diagnosis; Female; Hematology, Oncology and Palliative Medicine; Humans; Lung cancer; Lung Neoplasms - diagnosis; Lung Neoplasms - genetics; Male; Medical sciences; MicroRNA; MicroRNAs - analysis; Neoplasm Staging; Pneumology; Pulmonary/Respiratory; Real-time RT-PCR; Reverse Transcriptase Polymerase Chain Reaction; RNA Stability; ROC Curve; Sensitivity and Specificity; Sputum; Sputum - cytology; Sputum - metabolism; Tumors; Tumors of the respiratory system and mediastinum; Real-time RT-PCR; MicroRNA; Diagnosis; Lung cancer; Sputum; Lung disease; Respiratory disease; Malignant tumor; non-small cell lung carcinoma; Gene expression; Real time; Cancerology; Bronchus disease; Molecular biology; Reverse transcription polymerase chain reaction; Cancer; Pneumology
• ISSN: 0169-5002; 1872-8332; 1872-8332
• DOI: 10.1016/j.lungcan.2009.04.004

Analysis of molecular genetic markers in biological fluids has been proposed as a useful tool for cancer diagnosis. MicroRNAs (miRNAs) are small regulatory RNAs that are frequently dysregulated in lung cancer and have shown promise as tissue-based markers for its prognostication. The aim of this study was to determine whether aberrant miRNA expression can be used as a marker in sputum specimen for the diagnosis of non-small cell lung cancer (NSCLC). Experimental design: expressions of mature miRNAs, mir-21 and mir-155, were examined by real-time reverse transcription polymerase chain reaction (RT-PCR) and normalized to that of control miRNA, U6B, in sputum of 23 patients with NSCLC and 17 cancer-free subjects. The data was compared with conventional sputum cytology for the diagnosis of lung cancer. All endogenous miRNAs were present in sputum in a remarkably stable form and sensitively and specifically detected by real-time RT-PCR. Mir-21 expression in the sputum specimens was significantly higher in cancer patients (76.32±9.79) than cancer-free individuals (62.24±3.82) (P<0.0001). Furthermore, overexpression of mir-21 showed highly discriminative receiver-operator characteristic (ROC) curve profile, clearly distinguishing cancer patients from cancer-free subjects with areas under the ROC curve at 0.902±0.054. Detection of mir-21 expression produced 69.66% sensitivity and 100.00% specificity in diagnosis of lung cancer, as compared with 47.82% sensitivity and 100.00% specificity by sputum cytology. The measurement of altered miRNA expression in sputum could be a useful noninvasive approach for the diagnosis of lung cancer.