Discovery points to one possible path to novel drug development for cancer, AIDS, some inflammation
Using a new approach, Mayo Clinic researchers have successfully "taught" an RNA molecule inside a living cell to work as a decoy to divert the actions of the protein NF-kappaB, which scientists believe promotes disease development. The findings are published in the current issue of Proceedings of the National Academy of Sciences.
Although it also plays helpful roles in the body, NF-kappaB (pronounced "en-ef-kappa-bee):
The good news is that once it is diverted by the RNA decoys, NF-kappaB should no longer be available to play its negative role in the chain of molecular events that leads to disease. Mayos experimental findings suggest that this could be a new and effective strategy for developing drugs capable of halting the disease process.
In the paper, L. James Maher, III, Ph.D., and Laura Cassiday, Ph.D., Mayo Clinic Department of Biochemistry and Molecular Biology, describe their success with yeast cells and decoy RNA. Under natural conditions in the body, RNA delivers DNAs plans to cells, which make all the worker proteins to carry out DNAs executive orders. Drs. Maher and Cassiday have used the RNA/NF-kappaB pairs to divert the NF-kappaB protein. This diversion ensures that the disease-directing capability of NF-kappaB never reaches the DNA.
"Were trying to develop a somewhat nontraditional drug that is made out of RNA -- which is similar to DNA -- because it has some advantages over other drugs," says Dr. Maher, a molecular biologist. The experiment was performed in his laboratory. "One advantage is that it can be produced by the bodys own cells using a gene-therapy approach in which cells are given the gene for this decoy RNA. But this is a long way off. Whats exciting for us at this point are two discoveries: One is that the small RNAs that we are studying can be taught to do new and exciting things inside living cells. The other is that we have found a new way to use yeast cells as a powerful test system for helping us find the RNAs that are most likely to work in mammalian cells."
"Theoretically, if we want to stop any of these diseases in which NF-kappaB is known to be involved -- cancers, AIDS, some inflammatory diseases -- wed like to stop the action of this protein; that would be a long-term goal," adds Dr. Cassiday, who is a post-doctoral fellow at Mayo Graduate School. "Our short-term goal is to learn the capabilities of these small, folded RNAs."
The Experiment: How It Works, Where It Leads
Step 1: Test tube experiments
In Dr. Mahers lab, researchers used a novel approach to finding the right decoy RNAs. Lori Lebruska, Ph.D., a graduate of Mayo Graduate School, took a random collection of one hundred thousand billion (thats one followed by 14 zeroes) small RNAs. She then mixed the RNAs with NF-kappaB protein and captured the "smartest" RNAs on a filter. After many repeated capture cycles, the RNAs that stuck best to NF-kappaB were the most likely to be competent decoys.
Step 2: Testing the RNA decoy in a living cell.
Drs. Maher and Cassiday had to see if the decoy RNA could bind NF-kappaB not just in a test tube but in the chaos of a cell.
"Its a whole different ball game in the cell, because there are thousands of other proteins that the RNA might bind to," says Dr. Cassiday. "These proteins could distract it from what we want it to do: find and bind to NF-kappaB. We werent sure the RNA was specific enough to target NF-kappaB under these conditions. Also, there are all sorts of enzymes that degrade RNA within a cell. We werent sure the RNA would be stable enough to survive and do its job. These were all considerations that needed to be resolved in our cellular experiments."
To test the RNA decoys ability to adapt to life inside cells, the researchers chose yeast, which is very similar to human cells, as a model organism.
"The rules change inside the cell," says Dr. Maher. "The real question becomes how can we send the RNA molecules back to school to adapt to these new cellular rules when all they previously knew how to do was succeed with test-tube rules?"
After simultaneously screening thousands of RNA variations in yeast, Drs. Cassiday and Maher found one RNA that had learned to do it all. Dr. Maher notes that by increasing the amount of this molecule, bigger and bigger decoy effects emerge, allowing for significant inhibition of NF-kappaBs disease capabilities.
The next step for the Mayo research team is to adapt this RNA decoy to life in mammalian cells to see if it can "learn" the additional rules necessary to survive and foil NF-kappaB in its natural setting. If it does, it might one day be a candidate for a new kind of drug therapy.
Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory
‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
11.12.2017 | Information Technology
11.12.2017 | Power and Electrical Engineering
11.12.2017 | Event News