Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Protein targeted for cancer drug development is essential for normal heart function

11.07.2013
St. Jude Children's Research Hospital discovers a role for a protein in research that has implications for treatment of cancer and heart disease

St. Jude Children's Research Hospital scientists have discovered that a protein used by cancer cells to evade death also plays a vital role in heart health. This dual role complicates efforts to develop cancer drugs that target the protein, but may lead to new therapies for heart muscle damage. The research appeared in the June 15 edition of the scientific journal Genes & Development.

The protein, MCL1, is currently the focus of widespread cancer drug development efforts. MCL1 is best known as an inhibitor of death via the cell's suicide pathway in a process called apoptosis. The protein is elevated in a variety of cancers, and a number of MCL1 inhibitors are in the cancer drug development pipeline worldwide. The protein has also been linked to drug resistance in cancer patients. Until now, however, MCL1's role in heart muscle cells was unclear.

"Our study shows that MCL1 is required for normal cardiac function and that the protein may be critical in protecting the heart from apoptosis," said Joseph Opferman, Ph.D., an associate member of the St. Jude Department of Biochemistry and the paper's corresponding author. Unlike skin or blood cells, heart muscle cells cannot be replaced, so even a small loss through apoptosis can be devastating. In this study, knocking out MCL1 in mice led to death from cardiomyopathy within weeks.

"These findings suggest that cancer-related drug development efforts should focus on reducing MCL1 expression in target cells rather than eliminating the protein's function completely," Opferman said.

The results also have implications for treating heart muscle damage following heart attacks or other insults. While limiting MCL1 in cancer cells might aid in destroying them, providing higher levels of the protein in heart muscle cells might benefit a patient recovering from a heart attack or other heart damage. "These findings have broad implications for human health," Opferman said.

MCL1 belongs to a protein family involved in regulating apoptosis. The body uses apoptosis to rid itself of damaged, dangerous or unneeded cells. MCL1 prevents apoptosis by blocking the activity of other members of the same protein family that promote the process.

This research builds on previous work from Opferman's laboratory that identified a second form of MCL1. That form works inside rather than outside the mitochondria and helps to produce the chemical energy that fuels cells. Mitochondria are specialized structures inside cells that serve as their power plants.

The latest results suggest both forms of MCL1 are necessary for normal heart function, said the paper's first author Xi Wang, a University of Tennessee Health Science Center graduate student working in Opferman's laboratory.

When investigators knocked out the mouse version of the human MCL1 gene in the heart and skeletal muscle of both embryonic and adult mice, the animals rapidly developed lethal cardiomyopathy. Without MCL1, researchers found that muscle fiber in heart muscle cells was replaced by fibrous tissue, and the pumping ability of the animals' hearts diminished. Loss of MCL1 was also associated with a rise in apoptosis sufficient to cause fatal heart muscle weakness.

To better understand MCL1's role in normal heart function, researchers blocked apoptosis by deleting genes for the proteins Bak and Bax as well as MCL1. Bak and Bax promote apoptosis. Knocking out all three genes restored normal heart function in the mice. The animals lived longer, but mitochondria in the heart muscle did not look or function normally. These results suggest that normal heart function requires both forms of MCL1. "The question is whether, with time, you would see deleterious effects from the loss of MCL1 separate from apoptosis," Opferman said.

The other authors are Madhavi Bathina, John Lynch, Brian Koss, Christopher Calabrese, Sharon Frase, John Schuetz and Jerold Rehg, all of St. Jude.

The research was funded in part by a grant (HL102175) from the National Institutes of Health (NIH), a grant (CA021765) from the National Cancer Institute (NCI) at the NIH, the National Cancer Society and ALSAC.

Summer Freeman | EurekAlert!
Further information:
http://www.stjude.org

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>