Discovery of human miRNAs and their evaluation with a Dicer KO line

Unmet Need
MicroRNAs (miRNAs) are a class of small noncoding RNAs that have important developmental and regulatory roles in multicellular organisms. There is considerable evidence to indicate that miRNAs and their biogenesis protein machinery (e.g., Dicer) are involved in the development of cancer.

To identify novel miRNAs several approaches have been developed such as cloning, bioinformatics and “in silico” techniques. Direct miRNA cloning strategies have identified numerous miRNAs, however, this approach is laborious and time consuming. Bioinformatic and in silico strategies have recently been used to identify potential miRNAs predicted on the basis of various sequence and structural characteristics, but this technique also has its limitations and requires independent experimental validation. As such, there is a need to identify novel miRNAs and to characterize their regulatory functions for human health and potentially derived therapeutics.

Technology Overview
Johns Hopkins researchers created an efficient method to identify novel microRNAs. The experimental approach, ‘miRNA serial analysis of gene expression’ (miRAGE) was developed and used to perform a large scale analysis of human miRNAs. This method combines aspects of molecular cloning and serial analysis of gene expression. In essence, small RNA species are isolated, ligated to specialized linkers and subsequently sequenced. Sequence analysis of 273,966 small RNAs from human colorectal cells identified 200 known miRNAs, 133 novel miRNA candidates, and 112 previously uncharacterized miRNA* forms. As a validation tool, human colorectal cancer cell lines harboring a disrupted (knockout) Dicer locus were developed to confirm both known and novel miRNAs.

Stage of development
In vitro data is available.

Publications
Cummings JM, et al. PNAS 103(10) 3687-3692, 2006
 

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