Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A stem cell type supposed to be crucial for angiogenesis and cancer growth does not exist?

22.04.2008
It is widely believed that tumor angiogenesis and cancer growth critically depend on circulating endothelial precursor cells, mobilized from the bone marrow.

The recent study from researchers at the University of Helsinki, Finland, and Stanford University, US, now suggests that a stem cell type supposed to be crucial for blood vessel formation and cancer growth does not actually exist.

Angiogenesis, the growth of new blood vessels, is a central process in diverse physiological and pathological situations such as healing of wounds and traumas, cardiovascular disorders, inflammatory conditions such as rheumatoid arthritis, and in cancer growth. The current belief about the source of blood vessel wall endothelial cells (ECs) responsible for vascular growth in adults is that a significant and crucial part of neovascular ECs originate from circulating stem and progenitor cells that are first mobilized from the bone marrow (BM), and subsequently differentiate to mature bona fide ECs and incorporate in the vasculature. This concept has become textbook material, and a common theme in modem vascular and cancer biology.

Importantly, it is widely believed that tumor angiogenesis and cancer growth critically depend on BM derived circulating endothelial precursor cells. Endothelial precursors would thus provide a powerful novel approach to block tumor angiogenesis and cure cancer. Correspondingly, therapeutic transplantation of such stem cells would be a promising approach to restore tissue vascularization after ischemic events. Clinical trials with human patients are currently ongoing based on the circulating endothelial precursor cell dogma.

Now, researchers lead by Dr. Petri Salvén at the University of Helsinki, Finland, and the stem cell research pioneer Dr. Irving Weissman at Stanford University, California, have shown that circulating endothelial precursor cells actually do not exist, and that angiogenesis and cancer growth do not involve or depend on such hypothetical stem cells. (PNAS, in press; online 21.-25.4.). By using endothelial cell specific genomic mouse models and most modern three dimensional cellular imaging technologies, they show that endothelial differentiation is not a typical function of BM derived stem cells, and it has to be an extremely rare event if it occurs at all. However, angiogenic and tumor tissues contain large numbers of BM derived cells such as ordinary white blood cells that often are very close to blood vessel walls, and may therefore have been misinterpreted as blood vessel wall ECs in earlier studies utilizing less advanced technologies.

The results have great practical significance when researchers are trying to focus on novel approaches to cure cancer by targeting the normal cells of the body which supply tumors with blood and nutrients. "Our results will help the researchers to concentrate their efforts on molecular and cellular targets that actually exist" says Dr. Salvén, leader of the Helsinki team.

"It has been a learning experience to try to publish results that demonstrate that a number of fellow research have for years been studying nonexistent cells", Dr. Salven comments. "Issues concerning publication bias and nonaccessibility of negative data are really becoming more and more relevant, just as recently seen also in other fields of biomedicine."

Paivi Lehtinen | alfa
Further information:
http://www.helsinki.fi

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>