Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers tease out one critical role of tumor-suppressor gene

07.01.2005


Scientists are taking the first steps to find out how a gene that is mutated in many cancer cells functions in healthy cells.



The researchers hope that learning how this gene, called Rb, operates in health cells will give them a better idea of how cancer develops and progresses. While mutations in Rb, are linked to several types of cancer including the childhood disease retinoblastoma, Rb normally keeps cell division in check. That means Rb is a tumor suppressor gene, which keeps cells from growing out of control. Scientists believe that Rb is linked to two key processes that frequently malfunction when cancer begins – proliferation (cell growth), and apoptosis (cell death). But they don’t know how Rb, which is found in every cell of the body, does this. New findings reported in the December 23 issue of Nature begin to shed light on the gene’s role in cells.

The researchers found that in mice, a lack of Rb during embryonic development kept red blood cells from fully maturing. "While we don’t think this finding has a specific link to cancer development, it is a first step to getting at the basic mechanism of how Rb works," said Gustavo Leone, a study co-author and an assistant professor with the Human Cancer Genetics Program at Ohio State University. "Knowing how Rb works in normal cells could help us to someday understand how tumor-suppressor genes function in tumor development and growth."


Leone was part of a team of researchers led by Antonio Iavarone, a professor with the Institute for Cancer Genetics at Columbia University.

The researchers studied red blood cells and macrophages taken from the liver tissue of mouse embryos bred to lack Rb. Macrophages are scavenger cells -- they eat up foreign material such as bacteria and viruses. In the developing embryo, macrophages bind to red blood cells, and this binding forces red blood cells to lose their nuclei. A mature red blood cell lacks a nucleus.

Leone and his colleagues surmised that the reason why the red blood cells from the embryos without Rb never lost their nuclei was due to a reduction in the number of macrophages in these fetal mouse livers. "Without Rb, the number of mature macrophages in the fetal liver was markedly reduced," said Leone, who is also a geneticist with Ohio State’s Comprehensive Cancer Center-Arthur G. James Cancer Hospital and Richard J. Solove Research Institute.

The researchers identified part of the molecular pathway that may help explain this reduction in mature macrophages: Cells carry a gene called Id2, an inhibitor protein that, in this case, probably kept macrophages from maturing. In a normal cell, it’s thought that Rb counterbalances Id2’s inhibitory effects. Since Id2 went unchecked, macrophages did not fully develop and therefore couldn’t bind to immature red blood cells.

In order to test this idea, the researchers created a mix of embryonic liver cells – some had the Rb gene, while others did not. Interestingly, the red blood cells from the embryos that lacked Rb immediately bound themselves to the Rb-containing macrophages. “This binding restored the red blood cells’ ability to give up their nuclei and, therefore, mature,” Leone said.

Knowing how Rb functions in normal cells could clue scientists in to the gene’s behavior as a tumor suppressor and why it mutates. It could also ultimately help scientists understand how other types of cancer progress. "Cancer cells are altered in so many different ways that it’s hard to conduct controlled experiments with them," Leone said. "That’s why we need to figure out what Rb normally does, as opposed to studying a mutated version of the gene in a cancer cell. This may also help us uncover the mechanisms that cause mutations in other tumor-suppressing genes."

Leone and Iavarone conducted the study with Emerson King and Anna Lasorella, both with Columbia University, and Xu-Ming Dai and E. Richard Stanley, both with the Albert Einstein College of Medicine in New York.

This work was supported by the National Institutes of Health.

Gustavo Leone | EurekAlert!
Further information:
http://www.osu.edu

More articles from Life Sciences:

nachricht Bare bones: Making bones transparent
27.04.2017 | California Institute of Technology

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

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...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

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...

Im Focus: Deep inside Galaxy M87

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...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

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...

Im Focus: Microprocessors based on a layer of just three atoms

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>