Featured Research

from universities, journals, and other organizations

Cancer protein's surprising role as memory regulator

Date:
September 23, 2011
Source:
Dana-Farber Cancer Institute
Summary:
Scientists 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.

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.


Story Source:

The above story is based on materials provided by Dana-Farber Cancer Institute. Note: Materials may be edited for content and length.


Cite This Page:

Dana-Farber Cancer Institute. "Cancer protein's surprising role as memory regulator." ScienceDaily. ScienceDaily, 23 September 2011. <www.sciencedaily.com/releases/2011/09/110922134536.htm>.
Dana-Farber Cancer Institute. (2011, September 23). Cancer protein's surprising role as memory regulator. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2011/09/110922134536.htm
Dana-Farber Cancer Institute. "Cancer protein's surprising role as memory regulator." ScienceDaily. www.sciencedaily.com/releases/2011/09/110922134536.htm (accessed October 23, 2014).

Share This



More Health & Medicine News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins