When developing new drugs, monitoring cellular responses to candidate compounds is essential for assessing their efficacy and safety. Researchers from the RIKEN Center for Life Science Technologies report a new method to monitor and quantify the activity of gene promoters during the response to a drug, using the advanced gene expression analysis method CAGE followed by single-molecule sequencing. This research paves the way to a more precise analysis of cellular responses to drugs, at the level of individual promoters.
The study is published this week in the journal CPT: Pharmacometrics & Systems Pharmacology.
Microarray-based technologies are widely used to monitor cellular changes in response to drug administration at the level of genes. However, microarrays have several limitations due to the fact that they rely on pre-designed oligonucleotide probes and detection based on hybridization.
In order to circumvent the limitations imposed by the use of microarray-based technology for the development of new drugs, Dr Harukazu Suzuki and his team at CLST developed a new technique combining Cap Analysis of Gene Expression (CAGE) with 3rd generation, single-molecule sequencing.
CAGE is a method developed at RIKEN to comprehensively map human transcription start sites and their promoters, and quantify the set of mRNAs in a cell, also called the transcriptome.
During CAGE the 5’-end of mRNAs is sequenced in order to produce a series of 20-30 nucleotide sequences that can then be mapped onto the genome and provide information about the level of expression of genes.
Dr Suzuki and his team used CAGE, combined with a single-molecule sequencer, to monitor the effect of three drugs, U0126, wortmannin and gefitinib on human breast cancer cells.
U0126 and wortmannin are known to inhibit the Ras-ERK and phosphatidylinositol-3-kinase (PI3K)-Akt signalling pathways within cells. Gefinitib is a potent inhibitor of the epidermal growth factor receptor kinase (EGFR kinase) and mainly inhibits the Ras-ERK and PI3K-Akt pathways downstream of EGFR.
The researchers identified a distinct set of promoters that were affected by low doses of the drugs, and therefore showed sensitivity to a weak inhibition of the Ras-ERK and PI3K-Akt signal-transduction pathways. This level of precision would would have been very difficult to achieve using microarray-based profiling.
Furthermore, a quantitative analysis showed that the inhibitory profiles of both U0126 and wortmannin are constitutive components of the transcriptome profile obtained by inhibition of the EGFR kinase. Using a regression model, the researchers were able to quantitatively predict the promoter activity profile of gefitinib, based on the U0126 and wortmannin profiles.
These results demonstrate the potential utility of highly quantitative promoter activity profiling in drug research.
“Quantitative transcriptome analysis is potentially widely applicable to determine the target proteins and action mechanisms of uncharacterized compounds,” concludes Dr Suzuki. “Our study paves the wayfor quantitative analysis of drug responses at the promoter level, and moreover, is potentially applicable for the evaluation of combinatorial or serial drug treatment in a clinical setting,” he adds.
This press release is available online at: http://www.riken.jp/en/pr/press/2013/20131003_3/
Dr Suzuki is available for interviews on the phone at +81 45-503-9222 or by email at email@example.com
Alternatively please contact:
Kazuhiro Kajiyama et al.
“Capturing drug responses by quantitative promoter activity profiling”
CPT: Pharmacometrics & Systems Pharmacology, 2013 DOI: 10.1038/psp.2013.53
The paper is available at
RIKEN is Japan's flagship research institute for basic and applied
research. Over 2500 papers by RIKEN researchers are published every year
in reputable scientific and technical journals, covering topics ranging
across a broad spectrum of disciplines including physics, chemistry,
biology, medical science and engineering. RIKEN's advanced research
environment and strong emphasis on interdisciplinary collaboration has
earned an unparalleled reputation for scientific excellence in Japan and
around the world.
About the Center for Life Science technologies
The RIKEN Center for Life Science Technologies aims to develop key
technologies for breakthroughs in the medical and pharmaceutical
applications of life science as well as conduct ground-breaking research
and development for the next-generation life sciences.
More articles from Life Sciences:
Estrogen: Not just produced by the ovaries
05.12.2013 | University of Wisconsin-Madison
Iranian biodiversity was underestimated, several new candidate species found
05.12.2013 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere
The Light: Global study gets underway with online user survey
Light has a fundamental impact on our sense of well-being and performance. In cooperation with Zumtobel, a supplier of lighting solutions, Fraunhofer IAO has launched a global user survey of lighting quality in offices. The objective is to identify the best lighting conditions for a variety of spaces and lighting ...
Quantum entanglement, a perplexing phenomenon of quantum mechanics that Albert Einstein once referred to as “spooky action at a distance,” could be even spookier than Einstein perceived.
Physicists at the University of Washington and Stony Brook University in New York believe the phenomenon might be intrinsically linked with wormholes, hypothetical features of space-time that in popular science fiction can provide a much-faster-than-light shortcut from one part of the universe to another.
But here’s the catch: One couldn’t actually ...
A star is formed when a large cloud of gas and dust condenses and eventually becomes so dense that it collapses into a ball of gas, where the pressure heats the matter, creating a glowing gas ball – a star is born.
New research from the Niels Bohr Institute, among others, shows that a young, newly formed star in the Milky Way had such an explosive growth, that it was initially about 100 times brighter than it is now. The results are published in the scientific journal, Astrophysical Journal Letters.
The young ...
EPFL scientists have shown how to achieve a dramatic increase in the capacity of optical fibers; Their simple, innovative solution reduces the amount of space required between the pulses of light that transport data
Optical fibers carry data in the form of pulses of light over distances of thousands of miles at amazing speeds. They are one of the glories of modern telecommunications technology.
However, their capacity is limited, because the pulses of light need to be lined up one after the other in ...
NASA's Hurricane and Severe Storms Sentinel airborne mission known as HS3 wrapped up for the 2013 Atlantic Ocean hurricane season at the end of September, and had several highlights. HS3 will return to NASA’s Wallops Flight Facility in Wallops Island, Va., for the 2014 Atlantic hurricane season.
During the 2013 mission, two unmanned Global Hawks flew from Wallops for the first time. The mission highlights included studying the Saharan Air Layer, following the genesis of a tropical storm, finding a unique hybrid core or center circulation in a redeveloped storm, obtaining measurements on the strongest side of ...
05.12.2013 | Health and Medicine
05.12.2013 | Ecology, The Environment and Conservation
05.12.2013 | Information Technology
05.12.2013 | Event News
04.12.2013 | Event News
12.11.2013 | Event News