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


METHODS
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.
Xie
Ying
Y
Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA.
Todd
Nevins W
NW
Liu
Zhenqiu
Z
Zhan
Min
M
Fang
Hongbin
H
Peng
Hong
H
Alattar
Mohammed
M
Deepak
Janaki
J
Stass
Sanford A
SA
Jiang
Feng
F
D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000032:analysis*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D035683:MicroRNAs / Q000032:analysis*; D009367:Neoplasm Staging; D020871:RNA Stability; D012372:ROC Curve; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013183:Sputum / Q000166:cytology / Q000378:metabolism*
D014408:Biomarkers, Tumor; C524942:MIRN155 microRNA, human; C524940:MIRN21 microRNA, human; D035683:MicroRNAs