Long non-coding RNA as potential biomarkers in non-small-cell lung cancer: What do we know so far?

Non-small-cell lung cancer (NSCLC) remains one of the most frequent types of lung cancer characterized by its local advancement at diagnosis. Therefore, identification of new prognostic biomarkers has become one of the most important issue in NSCLC therapy. It is now well understood that genetic and epigenetic alterations are responsible for NSCLC development. Moreover, it has been recently revealed that the non-protein coding regions of the genome may serve as a template for transcription of various type of RNAs, collectively referred to as non-coding RNAs. Non-coding RNAs, including long non-coding RNAs (lncRNAs) are involved in multiple cellular processes and it has been suggested that aberrant expression of lncRNAs may lead to tumour development, including NSCLC. Furthermore, some of the established risk factors for NSCLC may have an impact on expression level of several types of lncRNAs, and thus, affect the lung carcinogenesis through lncRNAs regulation. In this review, we would like to summarise the to-date knowledge about lncRNAs as potential biomarkers in NSCLC and the role of various environmental factors, such as smoking and air pollution, in development and progression of this tumour and their effect on lncRNAs expression.