The vast majority of the human genome is transcribed into RNA molecules that do not code for proteins, Non-coding RNA-based therapies is becoming a well-recognized field for strategies to design and develop breakthrough drugs in various field of medicine. Recently, ncRNA were demonstrated to play important roles in multiple biological processes by directly or indirectly interfering with gene expression, through regulating gene expression at both transcriptional and post-transcriptional levels. Dysregulation of noncoding RNAs (ncRNA) is associated with a variety of diseases.
NcRNAs are classified into (i) housekeeping, for the maintenance of normal cell functionalities (such as ribosomal (rRNA) or transfer (tRNA)); and (ii) regulatory ncRNAs. Regulatory ncRNAs include short (small) ncRNAs (<200 nucleotides, sncRNAs) and long ncRNAs (>200 nucleotides, lncRNAs). The sncRNAs (siNRA, miRNA, piRNA) are extensively studied in the last decade and have been associated with RNA interference (RNAi) pathways, which lead to silencing of specific genes and protection of the cell or genome against foreign nucleic acids[i]. For example, ncRNAs are indispensable in tumorigenesis by regulating the expression of tumor-related genes[ii]. Involvement of ncRNAs in disease processes by deregulation in the expression patterns of these ncRNA is illustrated in the figure [iii].
[i] Moazed D Review Small RNAs in transcriptional gene silencing and genome defence. Nature. 2009 Jan 22; 457(7228):413-20.
[ii] Liu, L., Wang, Q., Qiu, Z. et al. Noncoding RNAs: the shot callers in tumor immune escape. Sig Transduct Target Ther 5, 102 (2020). https://doi.org/10.1038/s41392-020-0194-y
[iii] Gomes AQ, Nolasco S, Soares H. Non-coding RNAs: multi-tasking molecules in the cell. Int J Mol Sci. 2013 Jul 31;14(8):16010-39. doi: 10.3390/ijms140816010. PMID: 23912238; PMCID: PMC3759897.