Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newly identified mechanism for silencing genes points to possible anti-cancer strategies

18.05.2007
Genes provide the instructions used by the individual cells to produce the many different proteins that make up the body. Scientists are only beginning to appreciate, however, the extraordinary degree of control exercised over every step of the production process.

Only about 10 percent of human genes, for example, are actively producing proteins in a given cell at a given time. The remaining 90 percent are silenced by a various mechanisms that act to interfere with gene transcription into messenger RNA or translation of messenger RNA into protein.

In a new study published online May 16 in the journal Nature, a team of scientists at The Wistar Institute, Philadelphia, and the University of California, San Diego, report identification of an important new gene-silencing mechanism, one that blocks the cellular machinery responsible for translating messenger RNA into proteins at specific genes.

The findings suggests that small bits of RNA known as microRNAs, known to help regulate genes but not used for protein production, may be operating in a completely novel way to prevent genes from producing proteins. MicroRNAs have been implicated in a number of cancers, and the newly outlined gene-silencing mechanism offers promising potential targets for anti-cancer interventions.

... more about:
»Foundation »MicroRNAs »RNA »Shiekhattar »ribosome

“Some microRNAs closely match their sequences against particular messenger RNA sequences to target them for destruction,” explains Ramin Shiekhattar, Ph.D., a professor?in the Gene Expression and Regulation Program and the Molecular and Cellular Oncogenesis Program at Wistar and senior author on the new study. Currently, Shiekhattar is also an ICREA professor at the Centre for Genomic Regulation in Barcelona, Spain. “That’s one way we know that microRNAs can silence genes. That mechanism requires extraordinary specificity, however, and we suspected that microRNAs were also acting in some other way to inhibit gene translation into protein. By tracking the associations between molecules involved in generating microRNAs and other molecules in the cell, we uncovered an entirely new pathway, one that led us to a mechanism that blocks the cellular machinery that produces protein from messenger RNA.”

In earlier studies, Shiekhattar identified a three-molecule complex known as RISC and showed that it plays a vital role in generating microRNAs. In the current study, Shiekhattar and his colleagues extended those studies to find that RISC also interacts with another complex that includes molecules required to build functional ribosomes. Ribosomes are cellular organelles responsible for translating messenger RNA into protein. Closer investigation showed that the new complex also included a component called eIF6. This molecule is known to interfere with the proper assembly of ribosomes, which prevents them from doing the work of translating messenger RNA into protein.

“We wondered if certain microRNA-responsive genes might be attracting microRNAs that then recruited eIF6 to that location,” Shiekhattar says. “If so, the eIF6 would prevent the assembly of a competent ribosome, thus blocking messenger RNA translation at that gene. The result would be to silence that specific gene. We tested this idea in human cells and in worms and found it to be the case in both. Interestingly, this not only supported our hypothesis, but to see it in such different organisms also suggested that the mechanism involved has long been conserved in evolution.”

The lead author on the study is Thimmaiah P. Chendrimada at The Wistar Institute. The additional Wistar co-authors are David Baillat (also currently, at the Centre for Genomic Regulation in Barcelona, Spain) and Richard I. Gregory. Co-authors Xinjun Ji and Steve A. Liebhaber, who conducted the experiments involving human cells, are affiliated with the University of Pennsylvania. Kenneth J. Finn is with the University of California, San Diego, as is study collaborator Amy E. Pasquinelli, who performed the investigations involving the C. elegans worm.

The research was supported by the National Institutes of Health, the Searle Foundation, the V Foundation for Cancer Research, the Mathers Foundation, the Cooley’s Anemia Foundation, and the Commonwealth Universal Research Enhancement Program of the Pennsylvania Department of Health.

Gloria Lligadas | alfa
Further information:
http://www.crg.es

Further reports about: Foundation MicroRNAs RNA Shiekhattar ribosome

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>