Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Used in a new way, RNA interference permanently silences key breast cancer gene

21.04.2005


In laboratory mouse experiments, researchers at The University of Texas M. D. Anderson Cancer Center have developed a way to use RNA interference (RNAi) so that it permanently hampers breast cancer development. The technique permanently silences activated STAT3, a crucial gene found in some human breast tumors, thus reducing the cancer’s ability to become invasive.

The study, presented at the annual meeting of the American Association for Cancer Research (AACR), used a modified form of RNAi to silence STAT3 in a permanent way. Typically, only a transient effect is achieved with RNAi before the tiny bits of genetic material are become inactive as the cell population continues to expand.

"We are a long way from using this technique in patients, but this study shows that that it may be possible to use RNAi in more than just experiments that silence genes temporarily," says the study’s principal investigator, Ralph Arlinghaus, Ph.D., a professor and chair of the Department of Molecular Pathology. Details of the study appeared in the April 1 2005 issue of the journal Cancer Research. "The technique is also providing some valuable insights into the role of STAT3 and its downstream targets," adds Arlinghaus, who also will discuss the work in a mini symposium at the AACR meeting.



RNAi has been employed as a laboratory tool to knock down expression of genes in a variety of cells and organisms. It works by introducing a small double-stranded RNA (RNAi) that specifically targets a gene’s product, its messenger RNA. This action then blocks translation and production of the protein that the gene encodes.

In this study, the researchers used a lentivirus (a type of retrovirus) to deliver a specifically designed long-acting small interfering RNA (termed a short hairpin RNA, shRNA) for mouse STAT3 into a mouse breast cancer cell line. They chose STAT3 because when activated, it is involved in the formation of multiple types of tumors, including breast cancer. When hijacked by a cancer cell, the activated gene is believed to interfere with the ability of key immune cells to attack a growing tumor.

Investigators used the lentivirus to permanently insert the RNAi into the genome of the cancer cell. After a single exposure of this delivery system, they found 75 percent of laboratory breast cancer cells stopped expressing the STAT3 protein. The researchers also discovered that expression of a protein called TWIST that is known to be involved in cancer metastasis was drastically reduced in the STAT3 knockdown cells, thus greatly reducing the ability of these cancer cells to invade normal tissues like the lung. "Somehow STAT3 is controlling TWIST expression, and this is important to know with regards to activated STAT3 and its involvement in cancer metastasis," Arlinghaus says.

When the mouse breast cells transduced with STAT3, shRNA were then tested in immunocompetent mice, researchers found that the treated breast cancer cells were unable to form breast tumors either at the site of injection or at distant sites typically involved in metastatic breast cancer in this mouse model.

Arlinghaus points out that a human therapy based on these findings is not on the horizon because lentivirus delivery systems haven’t been approved for human use yet, and because of the many problems associated with treating metastatic breast cancer. But he says that proof that RNAi can be used to permanently silence such critical genes as STAT3 "has potential application for treating breast cancer."

Nancy Jensen | EurekAlert!
Further information:
http://www.mdanderson.org

More articles from Life Sciences:

nachricht Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg

nachricht Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>