Analysis of Long Non-Coding RNA Expression Profiles in Non-Small Cell Lung Cancer

Background/Aims: Long non-coding RNAs (lncRNAs) play an important role in tumorigenesis. However, the role of lncRNA expression in human Non-small cell lung cancer (NSCLC) biology, prognosis and molecular classification remains unknown. Methods: We established the IncRNA profile in NSCLC by re-annotation of microarrays from the Gene expression omnibus database. Quantitative real-time PCR was used to determine expression of LINC00342. Results: 6066 differentially expressed IncRNAs were identified and we found a novel IncRNA, LINC00342 was significantly up-regulated in NSCLC tissues compared with normal tissues. We confirmed the over-expression of LINC00342 in a cohort of NSCLC patients and found LINC00342 expression level was positively correlated with lymph node metastasis and TNM stages. Furthermore, in a large online database of 1942 NSCLC patients, high expression of LINC00342 indicated poor Overall survival (HR = 1.28, 95% CI: 1.13-1.45) and post progression survival (HR = 1.43, 95% CI: 1.09-1.88). Bioinformatics analyses showed that LINC00342 was co-expressed with different protein-coding genes in NSCLC and normal tissues. Additionally, gene set enrichment analyses found that PTEN and P53 pathways genes were enriched in the groups with higher LINC00342 expression level. By small interfering RNAs mediated silence of LINC00342, proliferation ability was significantly inhibited in lung cancer cell line. Conclusion: To summary, our findings indicate that a set of IncRNAs are differentially expressed in NSCLC and we characterized a novel IncRNA, LINC00342 which is significantly up-regulated in NSCLC and could be a prognostic biomarker.