Biomedical Engineering Reference
In-Depth Information
Apparently, 30% of all genes and almost every genetic pathway involves
regulation by miRNAs (Hwang and Mendell, 2006). As discussed above, miR-
NAs can function as both oncogenes and tumor suppressors. It will, thus, be
very interesting to identify small molecule inhibitors of both the miRNA
processing pathway and individual miRNA transcription and function. Until
now, specific inhibition of individual miRNA has only been achieved by using
antisense molecules (Meister et al., 2004b). Recently, however, for the first time,
a specific small molecule inhibitor of miRNA-21 was identified (Gumireddy
et al., 2008). The investigators developed a novel method to identify inhibitors
of the miRNA pathway in live cells and uncovered Azobenzene 2 from a
screening of more than 1000 small organic molecules as a specific and efficient
inhibitor of miRNA-21 expression. This opens up a new era of tremendous
potential for therapeutics involving misregulated miRNAs in various diseases
such as cancer.
From an evolutionary standpoint, a few additional questions remain. How
did these present-day miRNAs evolve? Were they present in the prebiotic
''soup'' 4.5 billion years ago, or did they evolve as complexity in organisms
increased? What is the evolutionary pressure for these small non-coding RNAs?
These are some of the fascinating questions that should be investigated in the
future.
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