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They are small and do not encode proteins, yet microRNAs play an important role in gene regulation. These small RNAs, mostly 21 to 23 nucleotides long, regulate translation by binding to mRNAs. This regulation thereby influences the development and function of the cell, attracting the attention of more and more bioscience researchers. The function of miRNAs and their mere existence provide profound insights into the regulatory functions of the cell (1). Consequently, miRNAs are ideally suited for use as biomarkers – a notion that is supported by recent research data.
miRNA DATABASES
The rapidly increasing number of publications on miRNAs and the surge of available sequences illustrate the rapid evolution of miRNA research. The sequences are collected in the miRBase online database – www.mirbase.org. In the space of a few years, a total of 10,000 miRNAs have been identified by conventional cloning and bioinformatics (see Figure 1). The database is not limited to Homo sapiens. It also covers miRNAs of interesting model organisms like Mus musculus and Rattus norvegicus. In addition, due to the growing knowledge about the function and relevance of miRNAs for an increasing number of diseases, the Human miRNA Disease Database (HMDD) has been established. It already contains data representing more than 100 human diseases, more than 400 miRNAs and over 2,000 pairwise interactions which show how miRNA deregulation is linked to disease development. |