Expression of miR-29c, miR-93, and miR-429 as Potential Biomarkers for Detection of Early Stage Non-Small Lung Cancer

Background: Altered expression of miRNA expression contributes to human carcinogenesis. This study was designed to detect aberrant miRNA expressions as a potential biomarker for early detection and prognosis prediction of non-small cell lung cancer (NSCLC). Methods: miRNA array was used to profile differentially expressed miRNAs and Taqman-based quantitative RT-PCR assays were used to analyze levels of miR-29c, miR-93, and miR-429 expression in NSCLC tissue samples, corresponding normal tissue samples, and serum samples from 70 NSCLC patients as well as in serum samples from 48 healthy controls. Results: Levels of miR-29c and miR-93 expression were upregulated in NSCLC tissues, while serum levels of miR-29c were also upregulated, but levels of serum miR-429 were decreased in NSCLC. Moreover, the levels of miR-429 expression in NSCLC tissues were associated with those in serum samples. Receiver operating characteristic (ROC) curve analysis showed that at the optimal cut-off point, the areas under the ROC curve for serum levels of miR-29c and miR-429 were 0.723 and 0.727, respectively, levels which are higher than that of carcinoma embryonic antigen (0.534) in diagnosis of stage I NSCLC. In addition, serum levels of miR-429 were associated with poor overall survival of NSCLC patients. Both univariate and multivariate analyses showed that serum miR-429 level was an independent prognostic predictor for NSCLC. Conclusions: The results of the current study suggest that detection of serum miR-29c and miR-429 expression should be further evaluated as a novel, non-invasive biomarker for early stage NSCLC.