Identification and validation of long noncoding RNA biomarkers in human non-small-cell lung carcinomas

Dysregulation of long noncoding RNAs (lncRNAs) has been regarded as a primary feature of several human cancers. However, the genome-wide expression and functional significance of lncRNAs in non-small-cell lung carcinomas (NSCLC) remains unclear. The aim of this study was to identify novel lncRNAs that may play an important role in contributing to NSCLC pathogenesis.

We performed an integrative analysis of two NSCLC microarray datasets comprising 165 and 90 patients, respectively. The candidate lncRNAs were identified using the GSE19188 dataset, and then confirmed in the GSE18842 dataset. In addition, an independent cohort of 73 clinical samples was analyzed to validate the selected lncRNAs by quantitative real-time polymerase chain reaction analysis.

With microarray gene expression analysis, we identified and validated a list of 64 lncRNAs significantly dysregulated in NSCLC tumors compared with normal lung tissues; and a panel of 181 lncRNAs that were specific to histological subtypes of NSCLC (adenocarcinoma, large-cell carcinoma, and squamous cell carcinoma). The quantitative real-time polymerase chain reaction analysis of six selected lncRNAs in clinical samples further confirmed the results of microarray analysis.

We have identified and validated multiple novel lncRNAs associated with tumorigenesis and histological differentiation in human NSCLC. These lncRNAs could be further exploited for the development of useful biomarkers in diagnosis, prognosis, and treatment of NSCLC.