The contributory role of long non-coding RNAs (lncRNAs) in head and neck cancers: Possible biomarkers and therapeutic targets?

Along with the developments in techniques for genome study, our understanding of its sequences has completely changed. The non-coding sequences of the human genome are no longer considered as "junk" but are rather known to be the source of high-functioning molecules. Some of the most fascinating transcripts in this regard are long non-coding RNAs (lncRNAs) RNA molecules that exceed 200 nucleotides and are not transcribed from protein-coding regions of the genome. These transcripts are capable of gene regulation by various mechanisms, from epigenetic changes and chromosomal arrangements to post-transcription modulation of messenger RNAs. Furthermore, lncRNAs interact with other non-coding transcripts such as microRNAs that further affects gene expression. Considering the fact that cancer is a disease of deregulated expression, recent studies have identified lncRNAs acting as either oncogene or tumor suppressor in a wide range of human malignancies. Head and neck cancer (HNC), with a high incidence rate and unfavorable survival, is no exception in this matter and many investigations have introduced lncRNAs involved in its tumor progression and drug response, as well as those acting as promising diagnostic or prognostic markers. The present study reviews the vital regulatory roles of lncRNAs and further introduces their role in progression of HNC subtypes.