Featured Research

from universities, journals, and other organizations

Scientists Identify Molecule That Regulates Well-known Tumor Suppressor

Date:
April 11, 2005
Source:
Cell Press
Summary:
Scientists have discovered that a molecule called DJ-1 is likely to be involved in the generation of human tumors through negative regulation of the well-known tumor suppressor, PTEN. The research, published in the March issue of Cancer Cell, has important implications for determining the prognosis of some human cancers, and may prove to be a suitable target for cancer therapy.

Scientists have discovered that a molecule called DJ-1 is likely to be involved in the generation of human tumors through negative regulation of the well-known tumor suppressor, PTEN. The research, published in the March issue of Cancer Cell, has important implications for determining the prognosis of some human cancers, and may prove to be a suitable target for cancer therapy.

The phosphatidylinositol 3' kinase signaling pathway regulates cell growth and survival, and is inhibited by activity of the tumor suppressor PTEN. Research indicates that PTEN exerts its tumor suppressor activity by inhibiting PKB/Akt signaling that is critical for cell survival. Many human cancer cells exhibit mutations in the PTEN gene, but other cancers have the normal PTEN gene. While it is clear that without normal PTEN there is a loss of PKB/Akt inhibition that can lead to tumor growth, sometimes cancers with normal PTEN also exhibit abnormally high levels of PKB/Akt activity. In a quest to determine what molecules regulate normal PTEN, Dr. Tak W. Mak from the Ontario Cancer Institute and the University of Toronto and colleagues used a genetic screening method in fruit flies and identified the molecule DJ-1 as a PTEN suppressor.

In studies with mammalian cells, low levels of DJ-1 correlated with decreased PKB/Akt activity, while increased DJ-1 led to activation of PKB/Akt and enhanced cell survival. In cancer cells from breast cancer patients, elevated PKB/Akt activity and reduced PTEN expression were associated with elevated DJ-1levels. DJ-1 levels were increased in cells from lung cancer patients, and DJ-1 was associated with poor prognosis.

"Our results demonstrate that DJ-1 negatively regulates PTEN function, and that this cell survival control mechanism is conserved among various tissues and species. Taken together, our data suggest that overexpression of DJ-1 can modulate PTEN tumor expression to the point where oncogenesis may result from upregulated PKB/Akt-mediated cell survival," writes Dr. Mak. Elevated DJ-1 levels may explain why some tumors without PTEN mutations exhibit enhanced PKB/Akt activity.

The authors go on to suggest that DJ-1 may be a prognostic marker for cancer patients and be useful as a target for development of future cancer therapeutics. Interestingly, DJ-1 may play a role in other disease states, as it has also been recently identified as a predictive diagnostic for early-onset, autosomal recessive Parkinson's disease.

The other members of the research team include Raymond H. Kim, YingJu Jang, and Tak W. Mak of Ontario Cancer Institute and University of Toronto; Malte Peters, Carmela DeLuca, Jennifer Liepa, Lily Zhou, and Bryan Snow of Ontario Cancer Institute; Wei Shi, Richard C. Binari, and Armen S. Manoukian of University of Toronto; Melania Pintilie of Princess Margaret Hospital; Graham C. Fletcher and Mark R. Bray of Miikana Therapeutics Inc.; and Fei-Fei Liu and Ming-Sound Tsao of University of Toronto and Princess Margaret Hospital. The researchers are supported by the Canadian Cancer Society, the National Cancer Institute of Canada, Frank Fletcher Memorial Fund, David Rae Scholarship, Paul Starita Fellowship, and Canadian Institutes of Health Research.

###

Raymond H. Kim, Malte Peters, YingJu Jang, Wei Shi, Melania Pintilie, Graham C. Fletcher, Carmela DeLuca, Jennifer Liepa, Lily Zhou, Bryan Snow, Richard C. Binari, Armen S. Manoukian, Mark R. Bray, Fei-Fei Liu, Ming-Sound Tsao, and Tak W. Mak: "DJ-1, a novel regulator of the tumor suppressor PTEN"

Publishing in Cancer Cell, Volume 7, Number 3, March 2005, pages 263-273. http://www.cancercell.org


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Cite This Page:

Cell Press. "Scientists Identify Molecule That Regulates Well-known Tumor Suppressor." ScienceDaily. ScienceDaily, 11 April 2005. <www.sciencedaily.com/releases/2005/03/050326095808.htm>.
Cell Press. (2005, April 11). Scientists Identify Molecule That Regulates Well-known Tumor Suppressor. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2005/03/050326095808.htm
Cell Press. "Scientists Identify Molecule That Regulates Well-known Tumor Suppressor." ScienceDaily. www.sciencedaily.com/releases/2005/03/050326095808.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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:
from the past week

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