Featured Research

from universities, journals, and other organizations

How a mutated protein outwits evolution and fuels leukemia

Date:
June 20, 2013
Source:
NYU Langone Medical Center
Summary:
Scientists have discovered the survival secret to a genetic mutation that stokes leukemia cells, solving an evolutionary riddle and paving the way to a highly targeted therapy for leukemia. A new article describe how a mutated protein, called Fbxw7, behaves differently when expressed in cancer cells versus healthy cells.

Scientists have discovered the survival secret to a genetic mutation that stokes leukemia cells, solving an evolutionary riddle and paving the way to a highly targeted therapy for leukemia. In a paper published today in Cell, researchers at NYU Langone Medical Center describe how a mutated protein, called Fbxw7, behaves differently when expressed in cancer cells versus healthy cells. "Fbxw7 is essential for making blood cells, so the big mystery is why a mutation on a gene so important for survival would persist," says lead author Iannis Aifantis, PhD, chair of pathology at NYU Langone Medical Center and an Early Career Scientist at Howard Hughes Medical Institute. "What we've found is that the mutation affects cancerous cells but not healthy cells."

Related Articles


The Fbxw7 protein regulates the production of so-called hematopoietic stem cells, precursors that give rise to all types of blood cells. Without Fbxw7, the body loses the ability to produce blood and eventually succumbs to anemia. Scientists are only beginning to understand why mutated Fbxw7 appears in a significant portion of human tumors, including gastric, prostate, and some breast cancers. The mutation is especially prevalent in T-cell acute lymphoblastic leukemia, or T-ALL, a rare but lethal type of pediatric leukemia that causes the over-production of immature white blood cells.

In their experiments, Dr. Aifantis, working in collaboration with graduate student Bryan King and others, began by introducing mutated Fbxw7 into healthy blood stem cells in mice. "We thought the mutation would induce anemia, just as it does when Fbxw7 is deleted," says Dr. Aifantis. But to the researchers' surprise, nothing happened -- the stem cells continued to manufacture blood cells.

When the researchers then introduced in mice the mutated Fbxw7 into leukemic blood stem cells -- those that overproduce white blood cells and cause leukemia -- the cancer accelerated. "We found that the mutation made leukemia stem cells much more aggressive," Dr. Aifantis says.

In follow-up experiments, the researchers showed that Fbxw7 binds to and degrades a protein called Myc, which fuels leukemic stem cells, and has long been associated with many other cancers and the recurrence of cancer after treatment. When Fbxw7 is mutated, Myc is left unchecked, they found, and the population of cancer stem cells swells. This insight also helps explain why healthy blood stem cells seem to "ignore" mutated Fbxw7. Unlike leukemic stem cells, healthy blood stem cells typically lie dormant until the body requires an emergency supply of blood and they rarely express Myc. "Normal blood stem cells express very little Myc because they are not cycling. A mutation does not affect the substrate because the substrate does not exist," says Dr. Aifantis. "Leukemia stem cells, however, do express Myc and Fbxw7 mutations increase its abundance."

The researchers then wondered if eliminating Myc could potentially block leukemia. Indeed, deleting the Myc gene in mice with leukemia depleted leukemic stem cells and stopped the growth of tumors. They achieved the same results in mice and human cell and bone marrow samples of T-ALL using a new class of cancer drug called a BET inhibitor that blocks Myc. "We found that the BET inhibitor could actually kill leukemia stem cells. And without stem cells, the leukemia simply cannot grow," says Dr. Aifantis.

The researchers believe they can use the BET inhibitor to target pediatric and adult T-ALL leukemia. This work was supported by a grant from the National Cancer Institute.


Story Source:

The above story is based on materials provided by NYU Langone Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Bryan King, Thomas Trimarchi, Linsey Reavie, Luyao Xu, Jasper Mullenders, Panagiotis Ntziachristos, Beatriz Aranda-Orgilles, Arianne Perez-Garcia, Junwei Shi, Christopher Vakoc, Peter Sandy, StevenS. Shen, Adolfo Ferrando, Iannis Aifantis. The Ubiquitin Ligase FBXW7 Modulates Leukemia-Initiating Cell Activity by Regulating MYC Stability. Cell, 2013; 153 (7): 1552 DOI: 10.1016/j.cell.2013.05.041

Cite This Page:

NYU Langone Medical Center. "How a mutated protein outwits evolution and fuels leukemia." ScienceDaily. ScienceDaily, 20 June 2013. <www.sciencedaily.com/releases/2013/06/130620142852.htm>.
NYU Langone Medical Center. (2013, June 20). How a mutated protein outwits evolution and fuels leukemia. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2013/06/130620142852.htm
NYU Langone Medical Center. "How a mutated protein outwits evolution and fuels leukemia." ScienceDaily. www.sciencedaily.com/releases/2013/06/130620142852.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
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