Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cancer protein's surprising role as memory regulator

23.09.2011
Finding could be relevant to Alzheimer's disease treatment

Scientists at Dana-Farber Cancer Institute and Harvard Medical School have found that a common cancer protein leads a second, totally different life in normal adult brain cells: It helps regulates memory formation and may be implicated in Alzheimer's disease.

Cyclin E is a well-known culprit that drives many types of solid tumors and blood cancers. The report, published online in Developmental Cell, is the first revelation that cyclin E has a crucial role in the formation of nerve connections, or synapses, in the brain. Synapses are tiny connections between brain cells where memories are stored.

"This protein has a double life," said Peter Sicinski, PhD, a cancer biologist at Dana-Farber and senior author of the publication. "It is overexpressed in many different cancers, but it also is expressed in high levels in the human brain. We have found that cyclin E is needed for memory formation and is a very important player."

The researchers found potential evidence linking cyclin E to Alzheimer's disease, because it binds to an enzyme called Cdk5 that is involved in memory.

"There is good evidence that hyperactivity of Cdk5 contributes to Alzheimer's disease and inhibiting this enzyme can ameliorate symptoms in animals," said Sicinski, who is also a professor of Genetics at Harvard Medical School. "Manipulating cyclin E levels might be another way to accomplish this."

The scientists didn't test cyclin E in Alzheimer's mice, but they did show that when cyclin E binds to Cdk5 molecules, it locks them away in an unusable form. Moreover, when the researchers reduced cyclin E levels in mouse brain cells, fewer nerve connections formed and the animals' memories suffered.

Cyclins are a family of related proteins found in dividing cells. They serve as biological switches, controlling a cell's progression from one phase of its life cycle to the next. The actual signals to exit one phase and enter the next are issued by enzymes called cyclin-dependent kinases, or Cdks, that bind to cyclins.

Many types of cancer cells, including breast, ovarian, colon, and blood cancers, are driven by the overexpression of cyclin E, which acts like a car's accelerator pressed to the floor, speeding the cells through their growth-and-division cycle and allowing tumors to form and spread.

Though cyclin E is mainly found in dividing cells, researchers discover about a decade ago that cyclin E is also plentiful in adult, differentiated brain cells. But what it was doing there, no one knew.

In the current Developmental Cell paper, Junko Odajima, PhD, a postdoctoral fellow in the Sicinski laboratory and the paper's co-lead author (with Zachary P. Wills, PhD, from Harvard Medical School), showed that cyclin E in the brain attaches itself to the Cdk5 enzyme. When cyclin E molecules bind to and inactive Cdk5, synapses formation is increased, and, presumably, memory function improves.

Odajima tested this idea using a standard memory and learning test in which mice swimming in water must find a submerged platform to rest on, and remember its location in subsequent trials. The researchers then move the platform, requiring the animals to "forget" its previous location and learn and remember the new one.

As their hypothesis had suggested, mice deficient in cyclin E performed worse than rodents who had a normal amount of cyclin E. This contrast highlighted the importance of cyclin E for learning and memory.

Whether cyclin E levels rise and fall in the mouse brain during learning tasks is a topic of further research, said the scientists, who also plan to determine whether abnormal cyclin E levels can be linked to neurological diseases and learning disorders.

Other authors on the publication include Jarrod Marto, PhD, of Dana-Farber, Michael E. Greenberg, PhD, of Harvard Medical School, and Stephen J. Moss from Tufts University School of Medicine.

The National Institutes of Health supported the research.

Dana-Farber Cancer Institute is a principal teaching affiliate of the Harvard Medical School and is among the leading cancer research and care centers in the United States. It is a founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), designated a comprehensive cancer center by the National Cancer Institute. It provides adult cancer care with Brigham and Women's Hospital as Dana-Farber/Brigham and Women's Cancer Center and it provides pediatric care with Children's Hospital Boston as Dana-Farber/Children's Hospital Cancer Center. Dana-Farber is the top ranked cancer center in New England, according to U.S. News & World Report, and one of the largest recipients among independent hospitals of National Cancer Institute and National Institutes of Health grant funding.

Follow Dana-Farber on Twitter: @danafarber

Follow Dana-Farber on Facebook: https://www.facebook.com/danafarbercancerinstitute

Bill Schaller | EurekAlert!
Further information:
http://www.dana-farber.org/

More articles from Life Sciences:

nachricht World’s Largest Study on Allergic Rhinitis Reveals new Risk Genes
17.07.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>