Posted: May 9th, 2012 It’s a trap! New laboratory technique captures microRNA targets ( Nanowerk News ) Human cells are thought to produce thousands of differentmicroRNAs (miRNAs) mall pieces of genetic material that helpdetermine which genes are turned on or off at a given time. miRNAsare an important part of normal cellular function, but they canalso contribute to human disease ome are elevated in certaintumors, for example, where they promote cell survival. But tobetter understand how miRNAs influence health and disease,researchers first need to know which miRNAs are acting upon whichgenes big challenge considering their sheer number and the factthat each single miRNA can regulate hundreds of target genes. EntermiR-TRAP, a new easy-to-use method to directly identify miRNAtargets in cells. This technique, developed by Tariq Rana, Ph.D., professor andprogram director at Sanford-Burnham Medical Research Institute(Sanford-Burnham), and his team, was first revealed in a paperpublished May 8 by the journal Angewandte Chemie International Edition ( “miR-TRAP: A Benchtop Chemical Biology Strategy to IdentifymicroRNA Targets” ; open access). GSM Multimedia Phone Watch
“This method could be widely used to discover miRNA targets in anynumber of disease models, under physiological conditions,” Ranasaid. “miR-TRAP will help bridge a gap in the RNA field, allowingresearchers to better understand diseases like cancer and targettheir genetic underpinnings to develop new diagnostics andtherapeutics. This will become especially important as newhigh-throughput RNA sequencing technologies increase the numbers ofknown miRNAs and their targets.” MicroRNAs suppress gene expression by binding target mRNA andjoining an RNA-induced silencing complex. A simple new techniquecalled miR-TRAP captures the complex, allowing researchers to moreeasily identify an miRNA’s target. Cellphone Signal Jammer Manufacturer
How miR-TRAP works miRNAs block gene expression not by attaching directly to the DNAitself, but by binding to messenger RNA (mRNA), the type thatnormally carries a DNA recipe out of the nucleus and into thecytoplasm, where the sequence is translated into protein. Next,these RNAs are bound by a group of proteins called the RNA-inducedsilencing complex, or RISC. This blocks production of the proteinencoded by that mRNA, an action that can have far-reachingconsequences in the cell. miR-TRAP is performed in three basic steps. Waterproof Sports Action Camera
Scientists 1) producehighly photoreactive probes by conjugating psoralen, a plantmolecule that can be activated by light, to an miRNA of interest,2) perform a long-wave UV photocrosslinking reaction, and 3) pulldown RNA and analyze it by RT-qPCR. In other words, researchers zapcells with UV light, freezing the miRNA/mRNA duo in place. Then,after extracting the RNA from the cells, they can take a closerlook at the sequence of the bound mRNA, revealing the miRNA’starget gene. Advantages of miR-TRAP miR-TRAP is easier and more accurate than current methods ofidentifying miRNA targets for three main reasons. First, miR-TRAPcan directly identify miRNA targets in live cells, under normal ordisease conditions.
Second, this technique can spot mRNA targetsthat are not only reduced by miRNAs, but also those whosetranslation into protein is repressed argets that aren’t normallypicked up by other techniques, such as qPCR or microarray analysis.Third, miR-TRAP doesn’t rely on antibodies, which can lead tononspecific background signals and complicate data interpretation. Putting miR-TRAP to the test, Rana and his team, includingpostdoctoral researcher Huricha Baigude, Ph.D., analyzed 13predicted targets of two important microRNAs. The technique notonly confirmed their known gene targets, but also revealed twonovel targets. “We’re now applying these methods to identify miRNA targets in anumber of disease models,” Rana said. “And it’s our hope thatmiR-TRAP will soon become common practice in many labs around theworld.”.