Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ras Gene Causes Cancer Via Different Pathways in Humans vs. Mice

15.08.2002


Finding May Present a New Target for Anti-Cancer Drugs



Researchers at the Duke Comprehensive Cancer Center have found that a known cancer-causing gene, Ras, may exert its influence through very different pathways in humans than in mice, a finding that could offer tantalizing new targets for anti-cancer therapy.

While studying the Ras, gene, Duke researchers unexpectedly found that it activates an obscure group of proteins in humans, but not in mice, in order to turn normal cells malignant. Yet many cancer treatments are based on data scientists derive from mouse models.


“Our study highlights a little-known pathway that appears to play a critical role in the ability of Ras, to transform human cells, but not mouse cells, to become tumorigenic,” said Christopher Counter, Ph.D., a cancer biologist at the Duke Comprehensive Cancer Center. “This pathway could present a new protein target for anti-cancer drugs in humans, and it reinforces the inherent differences between human and mouse cancers in terms of how they evolve.”

Results of the Duke study are being published in the Aug. 15, 2002, issue of Genes and Development.

The Duke researchers decided to study oncogenic Ras, one of the first genes found to be involved in human cancers, because it is associated with very different malignancies in humans than in mice. Ras is activated in one-third of all human cancers, and as high as 90 percent in specific cancers, like pancreatic. In mice, Ras is associated with breast, skin and lung cancers.

Despite these differences, it was assumed that Ras signals the same set of proteins in mice as it does in humans for cells to become cancerous. The Duke scientists challenged this assumption and studied, for the first time, how Ras transforms human cells.

Team members Nesrin Hamad, Ph.D., and Joel Elconin, M.D., set out to map how Ras communicates with various signaling pathways that, when over-activated, ultimately command cells to proliferate uncontrollably. The scientists placed human and mouse cells in laboratory dishes, genetically modified the cells to express mutated forms of Ras, then traced how the protein produced by the Ras gene promoted cells to transform.

As expected, Ras exerted its malignant effects in mice cells primarily through a protein called Raf, whose specific job is to modify a chain of additional proteins that direct the cell’s behavior to proliferate. Unexpectedly, Raf was not sufficient to turn normal human cells cancerous, the study found. Instead, in human cells the Ras gene appeared to activate a different protein pathway, called RalGEFs, to transform normal cells into cancer.

Little is known about RalGEFs, possibly because they have never been considered critical to human cancers, but researchers suspect that they may assist cells in ferrying molecules within and outside of cells -- a process called vesicle transport. How these functions relate to Ras’ ability to transform normal cells into cancers remains unknown, said Counter. Nevertheless, the Duke study clearly showed that RalGEFs were necessary for the ability of Ras to transform normal human cells, he added.

“We propose that there are multiple proteins that Ras signals through in order to transform human cells, but there are significant differences in the relative potency of each pathway between humans and mice” Counter said. “The Ras oncogene appears to exert its function in humans through a pathway that was largely ignored.”

Rebecca Levine | EurekAlert!
Further information:
http://cancer.duke.edu/
http://www.genesdev.org/

More articles from Health and Medicine:

nachricht Remdesivir prevents MERS coronavirus disease in monkeys
14.02.2020 | NIH/National Institute of Allergy and Infectious Diseases

nachricht Recent advances in addressing tuberculosis give hope for future
12.02.2020 | NIH/National Institute of Allergy and Infectious Diseases

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Skyrmions like it hot: Spin structures are controllable even at high temperatures

Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices

The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...

Im Focus: Making the internet more energy efficient through systemic optimization

Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.

Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.

Im Focus: New synthesis methods enhance 3D chemical space for drug discovery

After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.

"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.

Im Focus: Quantum fluctuations sustain the record superconductor

Superconductivity approaching room temperature may be possible in hydrogen-rich compounds at much lower pressures than previously expected

Reaching room-temperature superconductivity is one of the biggest dreams in physics. Its discovery would bring a technological revolution by providing...

Im Focus: New coronavirus module in SORMAS

HZI-developed app for disease control is expanded to stop the spread of the pathogen

At the end of December 2019, the first cases of pneumonia caused by a novel coronavirus were reported from the Chinese city of Wuhan. Since then, infections...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

Electric solid propellant -- can it take the heat?

14.02.2020 | Physics and Astronomy

Pitt study uncovers new electronic state of matter

14.02.2020 | Physics and Astronomy

Researchers observe quantum interferences in real-time using a new extreme ultra-violet light spectroscopy technique

14.02.2020 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>