Scientists from the Jupiter campus of The Scripps Research Institute (TSRI) have shown a novel way to dramatically raise the potency of drug candidates targeting RNA, resulting in a 2,500-fold improvement in potency and significantly increasing their potential as therapeutic agents.
The new study, published recently online ahead of print by the journal Angewandte Chemie, confirms for the first time that a small molecule actually binds to a disease-causing RNA target—a breakthrough that should help scientists identify precise RNA targets within living cells, profile their interactions, and predict drug candidates’ side effects.
“We’re trying to make tools that can target any RNA motif,” said Matthew Disney, a TSRI associate professor who authored the research with a research associate in his lab, Lirui Guan. “This study completely validates our design—it validates that our compound targets the desired RNA sequence in a complex cellular environment that contains many hundreds of thousands of RNAs.”
While targeting DNA has been used as a therapeutic strategy against cancer, few similar approaches have been attempted for disease-associated RNAs.
In the new study, the scientists created a small molecule that binds to the genetic defect in RNA that causes myotonic dystrophy type 1 and improves associated defects in cell culture.
Myotonic dystrophy type 1 involves a type of RNA defect known as a “triplet repeat,” a series of three nucleotides repeated more times than normal in an individual’s genetic code. In this case, the repetition of the cytosine-uracil-guanine (CUG) in the RNA sequence leads to disease by binding to a particular protein, MBNL1, rendering it inactive and resulting in a number of protein-splicing abnormalities.
To achieve the increase in the drug candidate’s potency, Disney and his colleagues attached a reactive molecule (a derivative of chlorambucil, a chemotherapy drug that has been used to treatment a form of leukemia) to the small molecule they had identified. As a result, the new compound not only binds to the target, it becomes a permanent part of the target—as if it were super glued to it, Disney said. Once attached, it switches off the CUG defect and prevents the cell from turning it back on.
Disney was surprised at the approximately 2,500-fold improvement in potency with the new approach.
“I was shocked by the increase,” he said. “This takes the potency into the realm where one would like to see if the compound were to have real therapeutic potential.”
As a result, the new compound, known as 2H-4-CA, is the most potent compound known to date that improves DM1-associated splicing defects. Importantly, 2H-4-CA does not affect the alternative splicing of a transcript not regulated by MBNL1, demonstrating selectivity for the CUG repeat and suggesting that it might have minimal side effects.
“We can now use this approach to attach reactive molecules to other RNA targeted small molecules,” Disney said.
The reactive molecule model also provides a potentially general method to identify cellular targets of RNA-directed small molecules. Such probes could also identify unintended targets, information that could be used to design and identify compounds with improved selectivity in an approach similar to activity-based profiling, Disney said.
The study, “Covalent Small-Molecule–RNA Complex Formation Enables Cellular Profiling of Small-Molecule–RNA Interactions,” (DOI: 10.1002/anie.201301639) was supported by the National Institutes of Health (grant RO1- GM079235) and TSRI. For more information on the paper, see http://onlinelibrary.wiley.com/doi/10.1002/anie.201301639/full
Eric Sauter | EurekAlert!
Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung
High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences