REGULATION OF MICRO-RNA IN CANCER

Cancer is a dreadful disease of mankind, the treatment for cancer is not revealed as per expectation. The illuminating way come out with understanding and grab the molecular alteration in cell. Therefore, miRNAs is a novel notation for procurement of cancer. MicroRNAs are small, highly conserved non-coding RNA molecules involved in the regulation of gene expression. MicroRNAs are transcribed by RNA polymerases II and III which forms precursors that undergoes series of cleavage to form mature microRNA. There are two types of biogenesis pathways, one nuclear and one cytoplasmic. However there are some alternative biogenesis pathways exist that differ from conventional pathway in the number of cleavage events and enzymes responsible. The mechanism of sorting of microRNA precursors to the different pathways is unclear but it can be determined by the site of origin, its sequence and thermodynamic stability. The regulatory functions of microRNAs are able through the RNA-induced silencing complex (RISC). The regulation level of miRNAs in cell i.e. up regulation and down regulation, leads to cancer. In this review, highlighted the role of miRNAs in physiological way and explain the molecular mechanism involved in development of cancer. Key words:MicroRNA, Cancer, RNA-induced silencing complex (RISC), RNA polymerases II and III.