Featured Research

from universities, journals, and other organizations

The good, the bad and the ugly: the many roles of c-JUN in cancer

Date:
June 28, 2011
Source:
Veterinärmedizinische Universität Wien
Summary:
The process of cell division is tightly regulated, as mistakes may lead to cancer. The so-called c-JUN protein has been fingered as causing tumors in both skin and liver. It has long been known to have a direct role in reducing the expression of a gene (p53) that leads to the death of abnormal cells and to activate transcription of a further gene (CyclinD1) that directly promotes cell division. Researchers recently showed that c-JUN has a further activity by which it drives unwanted cell division: it binds the promoter of another gene involved in cell-cycle regulation, thereby preventing it from being silenced. The researchers have now uncovered a further surprising detail with the discovery that c-JUN's new function also prevents silencing of p16, an important anti-tumor factor.

The process of cell division is tightly regulated, as mistakes may lead to cancer. The so-called c-JUN protein has been fingered as causing tumours in both skin and liver. It has long been known to have a direct role in reducing the expression of a gene (p53) that leads to the death of abnormal cells and to activate transcription of a further gene (CyclinD1) that directly promotes cell division. The group of Veronika Sexl at the University of Veterinary Medicine, Vienna recently showed that c-JUN has a further activity by which it drives unwanted cell division: it binds the promoter of another gene involved in cell-cycle regulation, thereby preventing it from being silenced. The researchers have now uncovered a further surprising detail with the discovery that c-JUN's new function also prevents silencing of p16, an important anti-tumour factor. The finding adds a further layer of complexity to the regulation of cell division.

The results have recently been published in the open access journal Oncotarget.

The c-JUN protein was initially described in the late 1980s as the mammalian equivalent of a protein responsible for causing cancer in birds. Intense research in a number of labs has subsequently led to a basic understanding of how the protein works. c-JUN is a transcription factor that modifies (phosphorylates) key regulatory proteins in the cell, thereby activating or deactivating them and leading to unregulated cell division and hence cancer. It has also become clear that c-JUN acts not on its own but in conjunction with an array of further proteins that modulate its function.

Karoline Kollmann in the group of Veronika Sexl, now at the University of Veterinary Medicine, Vienna, recently discovered an additional activity of c-JUN. Together with her collaboration partners at the Medical University of Vienna and in Madrid, she showed that c-JUN can bind to the promoter of a kinase gene, known as Cdk6, thereby preventing the gene from being inactivated (by means of methylation). The result is increased activity of Cdk6, which further stimulates cell division. c-JUN only activates transcription of Cdk6 in cancer cells, where it makes the disease progress even faster. Kollmann's work was published in April in the journal Blood (2011, Vol. 117, pp. 4065-4075).

The surprising aspect of the discovery is that the "new" function of c-JUN is independent of the protein's normal activity. Kollmann has now added a further twist to the tail with the discovery that c-JUN protects not only the Cdk6 gene -- thereby accelerating tumour formation -- but also the p16 gene. p16 is a known tumour suppressor gene and its mutation or inactivation is associated with an increased risk of contracting a variety of forms of cancer. By protecting its promoter from inactivation, c-JUN seems to be helping the cells to fight the cancer.

Does this mean that the main villain of the piece is not actually as bad as we thought? Kollmann's response is fairly guarded. "I think it means that the functions of all these proteins are far more complex than we know. They all work together with many other proteins and the overall effect probably depends on a large number of factors. We have a lot more to learn before we can understand what proteins to inhibit to treat the disease."


Story Source:

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


Journal Reference:

  1. Karoline Kollmann, Gerwin Heller, Veronika Sexl. c-JUN prevents methylation of p16INK4a (and Cdk6): the villain turned bodyguard. Oncotarget, May 28, 2011

Cite This Page:

Veterinärmedizinische Universität Wien. "The good, the bad and the ugly: the many roles of c-JUN in cancer." ScienceDaily. ScienceDaily, 28 June 2011. <www.sciencedaily.com/releases/2011/06/110628094823.htm>.
Veterinärmedizinische Universität Wien. (2011, June 28). The good, the bad and the ugly: the many roles of c-JUN in cancer. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2011/06/110628094823.htm
Veterinärmedizinische Universität Wien. "The good, the bad and the ugly: the many roles of c-JUN in cancer." ScienceDaily. www.sciencedaily.com/releases/2011/06/110628094823.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) — Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) — A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) — Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) — NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
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