Long non-coding RNAs as novel biomarkers for diagnosis of varied cancers

Background and Objective: Cellular homeostasis is defined as a condition in which cell maintained, functional and healthy and all of these achieved by regulators. If this balanced condition disrupted, the cell could transform indeed. Non-coding RNAs are the new discovered regulators that are attractive in cancer research. One group of them is Long-non coding RNA (lnc RNA), that is longer than 200 nucleotides. Like protein-coding genes, non-coding RNAs such as long non-coding RNAs comprise two general types, oncogenic and tumor-suppressor genes. Herein we systematically reviewed the published literature to shed a light on understanding of roles of lncRNAs in cancer. Search Method: Two electronic database including Google Scholar and Pubmed were searched, using Large non-coding RNA and Cancer as keywords. 25 articles published from August 2010 to October 2015 were selected based on our inclusion exclusion criteria and then systemically reviewed. Findings: The main function of lncRNA is epigenetically regulation of gene expression. Some of them act as scaffold for chromatin-remodeling complexes. Cisantisense RNA, antisense RNA and intronic RNA are examples of groups that lncRNA classified according to their position relative to host protein-coding genes. Some of these ncRNAs are antisense partners of protein-coding transcripts anddysregulation of them could cause cell transformation.GAS5, MEG3 and lincRNAp21are examples of tumor-suppressor lncRNAs. HOTAIR is an oncogenic lncRNA and involved in repression of HOXD genes by interaction with the PRC2 complex. Studies show HOTAIR overexpression in breast cancer unlike GAS5. It’s been found GAS5 is an apoptosis regulator and in GAS5 reduction condition, cell tends to be cancerous. Conclusion: According to the function and expression state of lncRNAs in cancer, lncRNAs could be used not only as novel biomarkers for diagnosis and early detection of cancer but also as targets for therapeutic approaches.

Keywords:

Long non-coding RNA , cancer , biomarker