Featured Research

from universities, journals, and other organizations

Study details genes that control whether tumors adapt or die when faced with p53 activating drugs

Date:
May 22, 2013
Source:
University of Colorado Denver
Summary:
When turned on, the gene p53 turns off cancer. However, when existing drugs boost p53, only a few tumors die -- the rest resist the challenge. A new study shows how: tumors that live even in the face of p53 reactivation create more of the protein p21 than the protein PUMA; tumors that die have more PUMA than p21. And, for the first time, the current study shows a handful of genes that control this ratio.

When turned on, the gene p53 turns off cancer. However, when existing drugs boost p53, only a few tumors die -- the rest resist the challenge. A study published in the journal Cell Reports shows how: tumors that live even in the face of p53 reactivation create more of the protein p21 than the protein PUMA; tumors that die have more PUMA than p21. And, for the first time, the current study shows a handful of genes that control this ratio.

Related Articles


"The gene p53 is one of the most commonly mutated cancer genes. Tumors turn it off and then they can avoid controls that should kill them. Fine: we have drugs that can reactivate p53. But the bad news is when we go into the clinic with these drugs, only maybe one in ten tumors actually dies. We wanted to know what genes fine-tune this p53 effectiveness," says Joaquin Espinosa, PhD, investigator at the University of Colorado Cancer Center, associate professor in the Department of Molecular, Cellular and Developmental Biology at CU Boulder, and the paper's senior author.

To answer that question, the group including first author Zdenek Andrisyk, PhD, postdoc in the Espinosa Lab, turned off every gene in the human genome in turn and asked if there were genes that, when deactivated, would tip the balance from p21 to PUMA, thus enhancing the likelihood of cell death.

"We found a couple dozen genes involved in this ratio -- genes that with p53 activated, lead to more p21 and better survival or more PUMA and more cell death," Espinosa says.

The hope is that in addition to drugs that reactivate the tumor-suppressor gene p53, patients could be given a second drug targeting genes that control this p21/PUMA ratio, thus making first drug more effective. Likewise, in cases in which toxicity in healthy tissue limits the use of p53 activating drugs, Espinosa's research could lead to new drugs that thumb the scale of the p21/PUMA ratio toward survival in these healthy tissues. Up or down: learning to adjust the ratio has immense promise.

The group's next step is likely repeating the genetic screen with additional tumor and healthy cell lines to discover which of their newly discovered candidate genes are common controllers of the p21/PUMA ratio across cancer types. And, interestingly, the same technique could be used to make many existing drugs more effective.

"With many of these molecularly targeted therapies, you want one effect but then you end up with many other possible effects," Espinosa says. (An example is the recently-reported side effect of low testosterone in male lung cancer patient taking the molecularly targeted drug crizotinib.) The genetic screening technique used in the Espinosa lab could help disentangle effect from side effect -- showing which secondary genes regulate the desired, tumor-killing response and which secondary genes lead to undesirable side-effects.

"Not only could this technique lead to drugs that decrease the side effects of targeted therapies, but if you're not limited by these side effects, you can simply give more drug, perhaps making existing drugs much more powerful," Espinosa says.


Story Source:

The above story is based on materials provided by University of Colorado Denver. The original article was written by Garth Sundem. Note: Materials may be edited for content and length.


Journal Reference:

  1. Zdenek Andrysik, Jihye Kim, Aik Choon Tan, Joaquín M. Espinosa. A Genetic Screen Identifies TCF3/E2A and TRIAP1 as Pathway-Specific Regulators of the Cellular Response to p53 Activation. Cell Reports, 2013; DOI: 10.1016/j.celrep.2013.04.014

Cite This Page:

University of Colorado Denver. "Study details genes that control whether tumors adapt or die when faced with p53 activating drugs." ScienceDaily. ScienceDaily, 22 May 2013. <www.sciencedaily.com/releases/2013/05/130522123210.htm>.
University of Colorado Denver. (2013, May 22). Study details genes that control whether tumors adapt or die when faced with p53 activating drugs. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2013/05/130522123210.htm
University of Colorado Denver. "Study details genes that control whether tumors adapt or die when faced with p53 activating drugs." ScienceDaily. www.sciencedaily.com/releases/2013/05/130522123210.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) — The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Don't Fall For Flu Shot Myths

Don't Fall For Flu Shot Myths

Newsy (Nov. 23, 2014) — Misconceptions abound when it comes to your annual flu shot. Medical experts say most people older than 6 months should get the shot. Video provided by Newsy
Powered by NewsLook.com
WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) — Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) — Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. 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:

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