miRNAs Expression Profiling, An Exploratory Method for Revealing First-Hand Biomarkers to Predict Disease Progression SciDoc Publishers | Open Access | Science Journals | Media Partners

Molecular techniques has proven to be a powerful tool to identify reliable predictors of treatment response or disease progression detection and early prediction. Different body cell possess various host expression profiles, and has its own specific indicators to identify different diseases/infection class. Analyzing microRNAs (miRNAs) as a promising host gene plays a critical roles in host interactions with various invaders, including their pathogenesis and host resistance through regulation of post-transcriptional translation or gene expression of related miRNAs, thus acting as a potential biomarkers of infectious diseases. Circulating miRNAs have great potential to facilitate the diagnosis of virus infection, although the discrepancy between the expression levels of intracellular and extracellular miRNAs, that has been observed in certain situations [1]. Circulating miRNAs were found to be extremely stable and protected from RNAse mediated degradation within the body fluids, therefore have emerged as candidate biomarkers for several illnesses [2]. In 1993, miRNAs were discovered in the course of an experiment in the nematode; Caenorhabditis elegans (C. elegans) [3]. Until now, human miRNA family has expanded near to 2000 mature miRNAs (miRBase v21.0; http://www.mirbase.org) with approximately 60% of human mRNA could be the targets of miRNA [4]. miRNAs constitutes about 18-22 nucleotides long noncoding RNAs, and playing a vital role in the regulation of gene expression. The production of miRNAs requires some processing phases. Firstly, primary miRNAs (pri-miRNAs) are cleaved by aribo nuclease, called Drosha to produce a precursor miRNAs (premiRNAs) which eventually, cleaved by the another ribo nuclease, termed Dicerto produce mature, single stranded miRNAs [5, 6]. At this stages, mature miRNA associate with RNA induced silencing complex (RISC) with Argonaute/EIF2C (AGO) proteins which recognizes their respective target mRNA. miRNA identify their target mRNA through specificbase-pairing interactions between the 5’ end (termed as “seed”region) of miRNA and a sites within the coding and untranslated regions (UTRs) especially 3’ UTR of mRNAs leading to mRNA destabilization. Thus, miRNAs inhibits the target gene expression either by mRNA degradation or translational repression [7, 8]. A distinctive nature of miRNAs regulation is that, each miRNA regulates hundreds of different mRNAs, whereas, a single mRNAs are targeted by multiple miRNAs, that are the focus of interest on regulatory networks that determine the cell fate decisions [9]. miRNAs involvement