Long Non-coding RNAs as Diagnostic, Prognostic and Therapeutic Biomarkers in Pulmonary Diseases

Until recently, it was believed that only a small fraction of the genome contains protein-coding sequences and the rest of the DNA which considered as junk DNA has no specific function in life. Todays, there are plenty evidences that the human genome is widely transcribed and generates tens of thousands of noncoding RNAs. These ncRNAs have an important role in regulating the expression of protein-coding genes. Non coding RNAs contain small noncoding RNAs such as microRNAs (18-25 nucleotides long) and long ncRNAs with more than 200 nucleotides, both of them have important functions in different aspects of cell biology. LncRNAs have been studied much less than miRNAs, but comprise a large proportion of noncoding transcripts. They can suppress or increase the expression of proteins and many of them are associated with various diseases in humans.
Biomarkers are measurable indicators of diseases. They should be highly sensitive, specific, predictive and easily accessible. The diagnostic ability of lncRNAs in biological fluids explains their advantages as non-invasive markers for lung diseases. Accordingly, this review study highlights some key aspects of lncRNAs in pulmonary diseases as diagnostic, prognostic or therapeutic biomarkers.