Abstract:

MicroRNAs (miRNA) binding to target mRNAs and having function in regulating gene expression are of 18-25 nucleotides in length and take place in the class of non-coding RNAs. Although aproximately 1900 human miRNA types have been identified so far, quite little is known about their biological functions. In some studies, it is shown that miRNA expression levels are important for many biological functions such as cell proliferation, differentiation, apoptosis and metabolism. Recent studies have pointed out that miRNAs have been used as diagnosis and prognosis biomarker in many human diseases including cancer, viral diseases, cardiovascular disorders and metabolic distrubance.Such as a miRNA type’s regulating more than one mRNA expression levels, a mRNA level has been regulated by numbers of miRNA types. Since changing the expression level of a miRNA type effects the whole metabolism, it is required to have cell-specific miRNAs. In the event of cell type- specific miRNAs are having found, it is expected that the general metabolism is better understood and, moreover, miRNAs are used more effectively in diagnosis and treatment of diseases.

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