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 New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>