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.
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy