An anti-cancer drug used extensively in chemotherapy binds pervasively to RNA -- up to 20-fold more than it does to DNA, a surprise finding that suggests new targeting approaches might be useful, according to University of Oregon researchers.
Medical researchers have long known that cisplatin, a platinum compound used to fight tumors in nearly 70 percent of all human cancers, attaches to DNA. Its attachment to RNA had been assumed to be a fleeting thing, says UO chemist Victoria J. DeRose, who decided to take a closer look due to recent discoveries of critical RNA-based cell processes.
"We're looking at RNA as a new drug target," she said. "We think this is an important discovery because we know that RNA is very different in tumors than it is in regular healthy cells. We thought that the platinum would bind to RNA, but that the RNA would just degrade and the platinum would be shunted out of the cell. In fact, we found that the platinum was retained on the RNA and also bound quickly, being found on the RNA as fast as one hour after treatment."
The National Institutes of Health-supported research is detailed in a paper placed online ahead of regular publication in ACS Chemical Biology, a journal of the American Chemical Society. Co-authors with DeRose, a member of the UO chemistry department and Institute of Molecular Biology, were UO doctoral students Alethia A. Hostetter and Maire F. Osborn.
The researchers applied cisplatin to rapidly dividing and RNA-rich yeast cells (Saccharomyces cerevisiae, a much-used eukaryotic model organism in biology). They then extracted the DNA and RNA from the treated cells and studied the density of platinum per nucleotide with mass spectrometry. Specific locations of the metal ions were further hunted down with detailed sequencing methods. They found that the platinum was two to three times denser on DNA but that there was a much higher whole-cell concentration on RNA. Moreover, the drug bound like glue to specific sections of RNA.
DeRose is now pursuing the ramifications of the findings. "Can this drug be made to be more or less reactive to specific RNAs?" she said. "Might we be able to go after these new targets and thereby reduce the drug's toxicity?"
While cisplatin is effective in reducing tumor size, its use often is halted because of toxicity issues, including renal insufficiency, tinnitus, anemia, gastrointestinal problems and nerve damage.
The extensive roles of RNA have come under intense scrutiny since completion of the human genome opened new windows on DNA, life's building blocks. It had been assumed that RNA was simply a messenger that coded for protein activity. New technologies, DeRose said, have shown that a vast amount of RNA performs an amazing level of different functions in gene expression, controlling it in specific ways during development or disease, particularly in cancer cells.
In this project, DeRose's team only explored cisplatin's binding on two forms of RNA: ribosomes, where the highest concentration of the drug was found; and messenger RNA. There are more areas to be looked at, said DeRose, whose group initially developed experience using and mapping platinum's activity as a mimic for other metals in her research on RNA enzymes.
DeRose is now planning work with UO colleague Hui Zong, a biologist studying how cancer emerges, to extend the research into mouse cells to see if the findings in yeast RNA hold up. An additional collaboration with UO chemist Michael Haley involves the creation of new platinum-based drugs with "reaction handles" that will allow researchers to easily pull the experimental drugs out of cells, while still attached to their biological targets. New developments in 'deep' RNA sequencing, available through the UO's Genomic Core Facilities, could then provide a much broader view of platinum's preferred resting sites in the cell.
About the University of Oregon
The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.
Source: Victoria DeRose, professor of chemistry, 541-346-3568, firstname.lastname@example.org
Links:DeRose chemistry faculty page:
Jim Barlow | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences