Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify target for cancer drugs

18.02.2005


For nearly a decade, scientists have been trying to fully understand a particular communication pathway inside of cells that contributes to many malignant brain and prostate cancers. While scientists have identified elements of this pathway, other key components have remained a mystery. Researchers at Whitehead Institute now have discovered a missing puzzle piece, a finding that may present drug makers with a significant new cancer target.



"We believe that we have identified a component that researchers have been looking for since 1996," says Whitehead Associate Member David Sabatini, who is also an Assistant Professor of Biology at MIT.

At the heart of this new research is a protein called Akt, an important player in the regulation of cell division and survival. Abnormally high activation of Akt has long been implicated in a variety of cancers. If Akt travels to the cell membrane, it is switched on and promotes cell division, often contributing to tumor growth as a result. However, as long as it stays within the cell cytoplasm, it remains relatively inactive. That’s because the tumor-suppressor protein PTEN keeps Akt in check by destroying lipids in the cell membrane that normally draw Akt to the surface. In a sense, PTEN keeps a leash on Akt and thus suppresses cell division.


But when PTEN is mutated and unable to function, Akt breaks free. It makes its way to the cell membrane where other proteins activate it, thereby enabling Akt to contribute to tumor growth. "When a cell loses PTEN through, say, a mutation, Akt goes gangbusters," says Sabatini.

The exact means by which Akt switches on when it reaches the cell membrane has only been partially understood. As a result, researchers have lacked a clear idea about how to prevent the process. However, in the February 18 issue of the journal Science, researchers from the Sabatini lab report on discovering an important missing piece of the activation process.

This missing component, a molecule called mTOR, is a protein that influences a cell’s ability to expand in size. mTOR has been widely studied as the target for the immunosuppressant drug rapamycin (in fact, mTOR is an acronym for "mammalian target of rapamycin"). In July of 2004, Dos Sarbassov, a scientist in Sabatini’s lab, discovered a new protein that mTOR interacts with called rictor, but he wasn’t yet sure of what these two proteins do together. In this latest paper, Sarbassov reports that when mTOR and rictor bind and form a complex, they help activate Akt by adding a phosphate group to a sequence of its amino acids (a process called "phosphorylation").

This process occurs not only in human cells but in other organisms such as the fruit fly. Finding this complex conserved in species as diverse as flies and humans supports the claim that the mTOR/rictor complex is indeed a missing piece of the puzzle.

According to Sarbassov, "If we find a molecule that can block the mTOR/rictor complex, then we may be able to prevent Akt from becoming active and contributing to tumor formation."

David Cameron | EurekAlert!
Further information:
http://www.wi.mit.edu

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>