Micro-RNAs (miRNAs) are measurable in tissues and also in serum and plasma in a stable form protected from endogenous RNase activity. Recent studies have shown that not only can miRNAs be used to sub-classify NSCLC, but specific miRNA profiles may also predict prognosis and disease recurrence in early-stage NSCLC. Although this finding has the potential to enhance the utility of miRNAs as biomarkers for diagnosis, prognosis and monitoring lung cancer patients following resection via non-invasive methods, few were used for clinical practice. In this study, we have performed miRNA profile analysis in lung cancer tissues and sera in order to discover new miRNAs for lung cancer diagnosis and prognosis. Total RNA was isolated from 91 lung adenocarcinoma tissues and 10 matched non-tumoral samples using miRNeasy Mini kit. Serum RNA was isolated from 0.5 ml serum using mirVana PARIS kit from 120 resected NSCLC patients, and 48 no-cancer controls. Reverse transcription reaction using Megaplex RT primers (Applied Biosystems) and pre-amplification using Megaplex PreAmp primers were performed on all the samples. ABI TagMan miRNA OpenArrays that contain more than 700 miRNAs probes were used for miRNA profile analysis on 101 lung tissues. Expressions of selected miRNAs in sera were examined by real-time quantitative polymerase chain reaction. The miRNA profiling analysis indicated that 501 out of 754 probes were detectable in more than 10% samples, and 373 probes were detected in more than 50% samples. We also found U6r RNA was constant expressed in tumor and normal than RNU44 or RNU48. Of the 373 probes, 145 probes showed a significantly different between tumor and normal controls with a p value less 0.001. More than half of them were not reported previously. Sixty five miRNAs were found to be significantly related to patient survival (p < 0.05, Cox model). Individual miRNAs were also significantly associated with other clinical variables including tumor stage, nodal metastasis, and smoking status, etc. In order to determine the potential for clinical use for diagnosis and prognosis in serum, 10 miRNAs were selected to assess the expression levels in sera of 120 NSCLC and 48 no-cancer controls using TaqMan real-time Rt-PCR. We found that all the 10 miRNAs were detectable in serum with some showing significant differences between tumor and control and others related to patient survival. Verification using additional samples for selected miRNAs and in vitro functional analyses are ongoing. This study identified new diagnostic and prognostic miRNAs in lung cancer and indicated that sera-derived miRNAs could be used for not only cancer detection, but also defining patient outcome.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4137. doi:1538-7445.AM2012-4137