Navigation Links
Researchers discover how a mutated protein outwits evolution and fuels leukemia
Date:6/20/2013

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."

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 happenedthe stem cells continued to manufacture blood cells.

When the researchers then introduced in mice the mutated Fbxw7 into leukemic blood stem cellsthose that overproduce white blood cells and cause leukemiathe 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.


'/>"/>

Contact: Christopher Rucas
Christopher.Rucas@nyumc.org
212-404-3525
NYU Langone Medical Center / New York University School of Medicine
Source:Eurekalert

Related biology news :

1. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
2. UC Santa Barbara researchers discover genetic link between visual pathways of hydras and humans
3. Researchers attempt to solve problems of antibiotic resistance and bee deaths in one
4. UNH researchers find African farmers need better climate change data to improve farming practices
5. Ottawa researchers to lead world-first clinical trial of stem cell therapy for septic shock
6. Researchers uncover molecular pathway through which common yeast becomes fungal pathogen
7. Researchers print live cells with a standard inkjet printer
8. Columbia Engineering and Penn researchers increase speed of single-molecule measurements
9. Researchers reveal how a single gene mutation leads to uncontrolled obesity
10. Researchers discover novel therapy for Crohns disease
11. New paper by Notre Dame researchers describes method for cleaning up nuclear waste
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/24/2016)... , May 24, 2016 Ampronix facilitates superior patient care by providing unparalleled ... medical LCD display is the latest premium product recently added to the range of ... ... ... Sony 3d Imaging- LCD Medical Display- Ampronix News ...
(Date:5/9/2016)... , UAE, May 9, 2016 ... it comes to expanding freedom for high net worth ... Even in today,s globally connected world, there is still ... system could ever duplicate sealing your deal with a ... second passports by taking advantage of citizenship via investment ...
(Date:4/26/2016)... LONDON , April 26, 2016 ... a product subsidiary of Infosys (NYSE: ... to integrate the Onegini mobile security platform with ... http://photos.prnewswire.com/prnh/20151104/283829LOGO ) The integration will ... to access and transact across channels. Using this ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Mass. , June 23, 2016   ... development of novel compounds designed to target cancer ... napabucasin, has been granted Orphan Drug Designation from ... the treatment of gastric cancer, including gastroesophageal junction ... stemness inhibitor designed to inhibit cancer stemness pathways ...
(Date:6/23/2016)... -- Houston Methodist Willowbrook Hospital has signed a ... serve as their official health care provider. As ... provide sponsorship support, athletic training services, and most ... athletes and families. "We are excited ... to bring Houston Methodist quality services and programs ...
(Date:6/23/2016)... YORK , June, 23, 2016  The Biodesign ... to envision new ways to harness living systems and ... Modern Art (MoMA) in New York City ... than 130 participating students, showcased projects at MoMA,s Celeste ... Paola Antonelli , MoMA,s senior curator of architecture ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... STACS DNA ... Technical Leader at the Arkansas State Crime Laboratory, has joined STACS DNA as a ... STACS DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. “In further ...
Breaking Biology Technology: