Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify gene as protector of DNA, enemy of tumors

07.08.2006
A single gene plays a pivotal role launching two DNA damage detection and repair pathways in the human genome, suggesting that it functions as a previously unidentified tumor suppressor gene, researchers at The University of Texas M. D. Anderson Cancer Center report in Cancer Cell.

The advance online publication also reports that the gene - called BRIT1 - is under-expressed in human ovarian, breast and prostate cancer cell lines.

Defects in BRIT1 seem to be a key pathological alteration in cancer initiation and progression, the authors note, and further understanding of its function may contribute to novel, therapeutic approaches to cancer.

"Disruption of BRIT1 function abolishes DNA damage responses and leads to genomic instability," said senior author Shiaw-Yih Lin, Ph.D., assistant professor in the Department of Molecular Therapeutics at M. D. Anderson. Genomic instability fuels the initiation, growth and spread of cancer.

A signaling network of molecular checkpoint pathways protects the human genome by detecting DNA damage, initiating repair and halting division of the damaged cell so that it does not replicate.

In a series of laboratory experiments, Lin and colleagues show that BRIT1 activates two of these checkpoint pathways. The ATM pathway springs into action in response to damage caused by ionizing radiation. The ATR pathway responds to DNA damage caused by ultraviolet radiation.

By using small interfering RNA (siRNA) to silence the BRIT1 gene, the scientists shut down both checkpoint pathways in cells exposed to either type of radiation.

Researchers then used siRNA to silence the gene in normal human mammary epithelial cells (HMEC). The result: Inactivation of the gene caused chromosomal aberrations in 21.2 to 25.6 percent of cells. Control group HMEC had no cells with chromosomal aberrations. In cells with the gene silenced that were then exposed to ionizing radiation, 80 percent of cells had chromosomal aberrations.

"We also found that BRIT1 expression is aberrant in several forms of human cancer," Lin said. The team found reduced expression of the gene in 35 of 87 cases of advanced epithelial ovarian cancer. They also found reduced expression in breast and prostate cancer tissue compared with non-cancerous cells.

Genetic analysis of breast cancer specimens revealed a truncated, dysfunctional version of the BRIT1 protein in one sample.

Loss of the DNA damage checkpoint function and the ability to proliferate indefinitely are two cellular changes required for the development of cancer. Lin and colleagues have now tied the gene to both factors. They previously identified BRIT1 as a repressor of hTERT, a protein that when reactivated immortalizes cells, allowing them to multiply indefinitely.

Scott Merville | EurekAlert!
Further information:
http://www.mdanderson.org

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

12th COMPAMED Spring Convention: Innovative manufacturing processes of modern implants

28.05.2018 | Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

 
Latest News

International Workshop Sees Central Role for Solar in Transforming the World Energy Economy

28.05.2018 | Seminars Workshops

Cognitive Power Electronics 4.0 is gaining momentum

28.05.2018 | Trade Fair News

Organic light-emitting diodes become brighter and more durable

28.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>