Cookie Settings

We use cookies to optimize our website. These include cookies that are necessary for the operation of the site, as well as those that are only used for anonymous statistic. You can decide for yourself which categories you want to allow. Further information can be found in our data privacy protection .


These cookies are necessary to run the core functionalities of this website and cannot be disabled.

Name Webedition CMS
Purpose This cookie is required by the CMS (Content Management System) Webedition for the system to function correctly. Typically, this cookie is deleted when the browser is closed.
Name econda
Purpose Session cookie emos_jcsid for the web analysis software econda. This runs in the “anonymized measurement” mode. There is no personal reference. As soon as the user leaves the site, tracking is ended and all data in the browser are automatically deleted.

These cookies help us understand how visitors interact with our website by collecting and analyzing information anonymously. Depending on the tool, one or more cookies are set by the provider.

Name econda
Purpose Statistics
External media

Content from external media platforms is blocked by default. If cookies from external media are accepted, access to this content no longer requires manual consent.

Name YouTube
Purpose Show YouTube content
Name Twitter
Purpose activate Twitter Feeds

Binding protein prevents vascular chaos

No. 56 | 11/11/2013 | by Küh

Healing a wound requires immune cells and repair material to travel through the bloodstream to reach the site of damage. Since blood vessels in the area have been destroyed, new ones have to grow into the damaged tissue, a process stimulated by a chemical messenger called VEGF. Not all vascular cells should respond to VEGF, because this would produce a chaotic vascular network and disrupt the flow of blood. Scientists from the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) and the Medical Faculty Mannheim of Heidelberg University have now discovered a binding protein that can inhibit the effect of VEGF.

Section from a retina: Blood vessels are stained yellow, the binding protein SYNJ2BP is stained pink. The latter is mainly present in the new vascular cells (right) and is scarcely found in the tip cells.

Angiogenesis, the growth of new blood vessels, is a complex process that involves numerous signaling proteins. One of these, a growth factor called VEGF, binds to its receptor on the surface of blood vessel cells and sends a signal that they should divide. This causes the formation of a new vascular “sprout” that has a tip marked by a special type of “tip cell.” It grows toward the source of VEGF. On its surface, the tip cell produces a molecule called DLL4 that binds to Notch receptors in neighboring vascular cells; this activates the so-called Notch signaling pathway. One result is that VEGF receptors on the neighboring cells disappear. Since the Notch signaling pathway remains inactive in the tip cell, it is the only type that can respond to the growth factor.

VEGF plays a key role not only in wound healing, but also in cancer. After reaching a size of approximately two millimeters, a tumor can no longer feed directly on nutrients and oxygen in its surroundings and therefore needs to be supplied through the formation of new blood vessels. To do so, it releases VEGF. “Drugs that support cancer treatment by blocking the growth factor have been available for some time now,” says Associate Professor (PD) Dr. Andreas Fischer, who leads the Helmholtz Junior Research Group “Vascular Signaling and Cancer” at DKFZ. “However, some malignant tumors become resistant to such VEGF inhibitors. Therefore, we are searching for ways to use the Notch signaling pathway to suppress the effects of VEGF.”

The scientists focused their attention on a binding protein called SYNJ2BP. “Based on its structure, we thought that it could bind to DLL4 and either weaken or increase its effect,” says Dr. Gordian Adam, first author of the article. To pursue this question, the researchers studied the growth behavior of genetically modified vascular cells. Those which were unable to form SYNJ2BP barely activated the Notch signaling pathway; extreme large quantities of tip cells were formed, resulting in a chaotic vascular network. However, if the cells produced larger amounts of this binding protein, the Notch signaling pathway was overactive, leading to reduced levels of VEGF receptors. As a result, hardly any new blood vessels formed.

The scientists were surprised to discover where SYNJ2BP is formed: The binding protein is barely present in the tip cell, where large amounts of DLL4 are found. Instead, it is found in the cells that surround the new blood vessel. The researchers also found low levels of DLL4 in these cells, which explains the role of SYNJ2BP. “SYNJ2BP stabilizes low DLL4 protein levels in cells that immediately follow the tip cell and thus facilitates signal transduction to all other neighboring cells,” Adam says. This ensures that all cells – except the tip cell – activate the Notch signaling pathway and no longer respond to the VEGF growth factor.

Now the researchers plan to turn off the SYNJ2BP gene and investigate the impact of the resulting chaotic vascular system on tumor growth. However, the scientists think that SYNJ2BP is unlikely to serve as a potential target for therapies in the near future. “This protein has a very special structure that we have not yet been able to block effectively,” says Fischer. “We will investigate how much SYNJ2BP protein is produced in tumor tissue and whether this information can be used to assess the course of the disease.”

Adam MG, Berger C, Feldner A, Yang WJ, Wüstehube-Lausch J, Herberich SE, Pinder M, Gesierich S, Hammes HP, Augustin HG, Fischer A. Synaptojanin-2 Binding Protein Stabilizes the Notch Ligands DLL1 and DLL4 and Inhibits Sprouting Angiogenesis. Circ Res. 2013; 113 (11): 1206-1218

A picture for this press release is available at:

Caption: Section from a retina: Blood vessels are stained yellow, the binding protein SYNJ2BP is stained pink. The latter is mainly present in the new vascular cells (right) and is scarcely found in the tip cells.

Picture source: Dr. Gordian Adam/DKFZ

With more than 3,000 employees, the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) is Germany’s largest biomedical research institute. DKFZ scientists identify cancer risk factors, investigate how cancer progresses and develop new cancer prevention strategies. They are also developing new methods to diagnose tumors more precisely and treat cancer patients more successfully. The DKFZ's Cancer Information Service (KID) provides patients, interested citizens and experts with individual answers to questions relating to cancer.

To transfer promising approaches from cancer research to the clinic and thus improve the prognosis of cancer patients, the DKFZ cooperates with excellent research institutions and university hospitals throughout Germany:

  • National Center for Tumor Diseases (NCT, 6 sites)
  • German Cancer Consortium (DKTK, 8 sites)
  • Hopp Children's Cancer Center (KiTZ) Heidelberg
  • Helmholtz Institute for Translational Oncology (HI-TRON Mainz) - A Helmholtz Institute of the DKFZ
  • DKFZ-Hector Cancer Institute at the University Medical Center Mannheim
  • National Cancer Prevention Center (jointly with German Cancer Aid)
The DKFZ is 90 percent financed by the Federal Ministry of Education and Research and 10 percent by the state of Baden-Württemberg. The DKFZ is a member of the Helmholtz Association of German Research Centers.


Subscribe to our RSS-Feed.

to top
powered by webEdition CMS