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 Tag it EASI – a new method for accurate protein analysis
20.06.2018 | Max-Planck-Institut für Biochemie

nachricht How to track and trace a protein: Nanosensors monitor intracellular deliveries
19.06.2018 | 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: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Creating a new composite fuel for new-generation fast reactors

20.06.2018 | Materials Sciences

Game-changing finding pushes 3D-printing to the molecular limit

20.06.2018 | Materials Sciences

Could this material enable autonomous vehicles to come to market sooner?

20.06.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>