Navigation Links
Upending a cancer dogma
Date:7/2/2014

Researchers at the University of California, San Diego School of Medicine say a protein essential to regulating cell cycle progression the process of cell division and replication activates a key tumor suppressor, rather than inactivating it as previously thought.

"The finding is the result of literally 20 years of work in my lab," said Steven F. Dowdy, PhD, professor in the Department of Cellular and Molecular Medicine at UC San Diego. "It completely turns upside-down what was thought to be a fundamental aspect of cell cycle progression in all cancer cells driven by one of the most common genetic pathways mutated in cancer, namely the p16-cyclin D pathway."

The findings are published in the journal eLife.

Cyclin D is synthesized during the first stage of cell replication and is believed to help drive the complex, multi-stage process, including interaction with the retinoblastoma (Rb) protein, whose function is to prevent excessive cell growth by inhibiting cell cycle progression until a cell is ready to divide. Rb acts as a tumor suppressor.

But mutated or dysfunctional Rb is associated with several major cancers and Cyclin D has long been described as an oncogene that promotes cancer because it was believed to inactivate the Rb tumor suppressor function through a process called phosphorylation, which involves phosphate molecules being added to proteins, essentially turning them on or off.

Dowdy and colleagues painstakingly counted the number of phosphates added to Rb during cell cycle progression. There are as many as 14, but the scientists found that cyclin D adds just a single phosphate at one, and only one, of the 14 locations during the early G1 phase of cell cycle progression, essentially make 14 different versions of the Rb tumor suppressor. The single phosphate serves to activate Rb, not inactivate it as had been thought for over 20 years.

The researchers said the findings fundamentally change the understanding of G1 cell cycle regulation and the molecular origins of many associated cancers. It is critically important to understand how a genetic pathway actually functions and the consequences of interrupting it, especially in this case where there are multiple drug inhibitors of cyclin D being tested in clinical trials for breast cancer.

Moreover, how the next cyclin, cyclin E, that actually does inactivate Rb becomes activated has not been heavily investigated because it was thought to be the less important second domino, whereas we now know it is the first domino, added Dowdy.


'/>"/>

Contact: Jackie Carr
jcarr@ucsd.edu
619-543-6163
University of California - San Diego
Source:Eurekalert  

Related medicine news :

1. Cancer Research UKs new funding scheme to nurture future world-leading scientists
2. Biomarker predicts effectiveness of brain cancer treatment
3. GW researcher receives more than $1 million in grants to study epigenetics of pancreatic cancer
4. For cancer patients, sugar-coated cells are deadly
5. Mayo Clinic: Proton therapy has advantages over IMRT for advanced head and neck cancers
6. Mayo Clinic researchers reveal treasure trove of genes key to kidney cancer
7. Enlightening cancer cells
8. Cancer risk: Aspirin and smoking affect aging of genes
9. EORTC presents European solution for effective cancer drug development
10. New approach identifies cancer mutations as targets of effective melanoma immunotherapy
11. Case Western Reserve, University Hospitals fundraising for adolescent, young adult cancer
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Upending a cancer dogma
(Date:6/27/2016)... ... June 27, 2016 , ... A revolution ... the emergency ambulance transport experience for the millions of people who require these ... disrupted the taxi industry through the use of technology. Now, SmartEMS has put ...
(Date:6/26/2016)... North Carolina (PRWEB) , ... June 26, 2016 , ... ... release of a new product that was developed to enhance the health of felines. ... for centuries. , The two main herbs in the PawPaws Cat Kidney Support ...
(Date:6/25/2016)... ... June 25, 2016 , ... The temporary closing of Bruton Memorial Library on June 21 due ... up a new, often overlooked aspect of head lice: the parasite’s ability to live away ... a common occurrence, but a necessary one in the event that lice have simply gotten ...
(Date:6/25/2016)... ... , ... On Friday, June 10, Van Mitchell, Secretary of the Maryland Department ... in recognition of their exemplary accomplishments in worksite health promotion. , The Wellness at ... Wellness Symposium at the BWI Marriott in Linthicum Heights. iHire was one of 42 ...
(Date:6/24/2016)... ... , ... Marcy was in a crisis. Her son James, eight, was out of control. Prone ... physically. , “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If ... at my other children and say he was going to kill them. If we ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... FRANCISCO, Calif. , June 24, 2016 /PRNewswire/ ... ), a biopharmaceutical company developing novel therapeutics for ... unmet needs, today announced the closing of its ... of common stock, at the public offering price ... in the offering were offered by GBT. GBT ...
(Date:6/24/2016)... Dublin - ... " Global Markets for Spectroscopy Equipment" report ... This report focuses on the global market of ... applications in various applications. The report deals with spectroscopy ... industries: pharmaceutical and biotechnology, food and beverage, and environmental ...
(Date:6/24/2016)... , June 24, 2016 The Academy of ... recommendations that would allow biopharmaceutical companies to ... entities that make formulary and coverage decisions, a move ... of new medicines. The recommendations address restrictions ... appear on the drug label, a prohibition that hinders ...
Breaking Medicine Technology: