This process called angiogenesis involves a number of different growth factors and their respective receptors on the vascular wall cells. The departments of Prof. Dr. Hellmut Augustin and Prof. Dirk Schadendorf of DKFZ and Mannheim Medical Faculty of the University of Heidelberg have investigated the role of a growth factor called angiopoietin-2 (Ang2) in malignant melanoma. The docking station of Ang2 is the receptor Tie2 on the surface of endothelial cells, which form the inner lining of blood vessels. Together with other signaling molecules, Ang2 induces sprouting of endothelial cells and the formation of new capillaries.
When measuring the Ang2 concentrations in blood samples of melanoma patients, the investigators discovered that larger tumors and more advanced disease stages correlate with high levels of Ang2. If one tracks the Ang2 levels of individual patients over time, a rise parallel to disease progression can be observed. In contrast, patients who have lived with the disease for a long time, i.e., whose disease is not or only slightly progressive, have lower Ang2 levels. The scientists found out that Ang2 concentration in blood serum is a more precise indicator of the progression and stage of the disease than previously used biomarkers.
This close association between melanoma progression and Ang2 level prompted the question of whether the Ang2 growth factor really only stimulates vascularization in the tumor or whether it has additional influence on the properties of the cancer cells themselves. Such an effect had not yet been proposed for any one of the various growth factors which act on the cells of the vascular walls. Melanoma cells were really found to produce both soluble Ang2 and the matching receptor, Tie2, on their own cell membrane. As a result, they are theoretically capable of activating themselves. In order to check this, researchers switched off the Ang2 production in melanoma cells using a genetic trick. Test systems in the culture dish subsequently revealed that the skin cancer cells had lost their ability to migrate. The migration tendency of cancer cells is regarded as important information about their ability to invade other tissue in the body and metastasize.
The tumor appears to seize the signaling system of vascularization and, thus, to strengthen its malignant properties. "Ang2 is a very promising candidate," Hellmut Augustin comments on the results, „both as a biomarker for better monitoring of disease progression and as a target structure for therapy measures." Blocking Ang2 might not only attack the tumor's blood supply, but also reduce its malignant growth.
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences