Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Oncolytic viruses for targeted attack on cancer stem cells generated

07.01.2013
Scientists at the Paul-Ehrlich-Institut (PEI) have successfully created oncolytic viruses which effectively target CD133-positive cancer stem cells to infect and kill them. In animal experiments, multiple tumour foci could be completely eradicated. Cancer Research reports on the results of this research in its online edition of 4th January (Friday afternoon).

Upon infection with the CD133-specific measles virus CD133-positive tumour cells (green) die off, leaving holes in the cell layer a few hours later. Even directly adjacent CD133-negative cells (red) are protected from infection.

Source: PEI

Tumours do not consist of homogenous cell populations but contain cancer stem cells which respond poorly to chemotherapy and radiotherapy and are considered to be responsible for metastatic tumours. Scientists have therefore stepped up their efforts to find ways of identifying and eliminating these "tumour-initiating cells".

The cell surface protein CD133 is currently discussed as a characteristic marker for such cancer stem cells. The PEI President’s Research Group "Molecular Biotechnology and Gene therapy" led by Professor Christian Buchholz has modified an attenuated and thus innocuous measles virus for the targeted attack on cancer stem cells. The modified virus requires the surface protein CD133 as receptor for penetration into the cell. The scientists were able to prove that the modified virus infects only CD133-positive tumor cells even when these are cultivated in close contact with CD133-negative cells.

In collaboration with Heidelberg University and the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), the Paul-Ehrlich-Institut’s scientists tested the anti-tumoural effect of their targeted virus using mouse models reflecting glioma, colon carcinoma, and liver cancer. The modified virus showed pronounced anti-tumoural activity in all animal models tested – the tumour growth was substantially reduced or even entirely suppressed. The scientists compared the effectiveness of their modified oncolytic measles virus with that of an oncolytic measles virus currently investigated in clinical trials which does not show any specificity for subtypes of tumour cells. "We were surprised that the CD133-specific virus showed an anti-tumoural activity which was at least as good as that of the standard virus. In the liver cancer model, the anti-tumoural activity was clearly superior and led to complete tumour remission", said Professor Buchholz. In further studies, the research team aims at elucidating why their viruses turned out to be more effective in fighting tumours than conventional oncolytic viruses which are supposed to attack all tumour cell subtypes.

Is it really only cancer cells that are attacked by the CD133-specific virus? In fact, not only cancer stem cells bear the surface marker CD133 but also haematopoietic stem cells. Yet, haematopoietic stem cells were not attacked by the oncolytic measles virus. This is due to the innate immunity of these cells, which protects them from an attack by measles virus. Many tumour cell types exhibit a defect in innate immunity allowing the virus to replicate unimpaired.

One advantage of the use of oncolytic viruses in cancer therapy is their enhancer mechanism. Infected tumor cells produce progeny virus particles which are released upon cell lysis and are able to detect further tumour cells.

Dr. Susanne Stöcker | idw
Further information:
http://cancerres.aacrjournals.org/content/early/2013/01/04/0008-5472.CAN-12-2221.abstract
http://www.pei.de/EN/research/groups/presidents-groups/viral-gene-transfer-medicinal-products/pr1-viral-gene-transfer-medicinal-product

More articles from Life Sciences:

nachricht Junk DNA not as worthless as once thought
23.07.2014 | Helmholtz Centre for Environmental Research (UFZ)

nachricht Movie Shows Development of a Wound Dressing Research in Fast Motion
23.07.2014 | Universität Duisburg-Essen

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

“Lens on Life” - Artists and Scientists Explore Cell Divison

08.07.2014 | Event News

First International Conference on Consumer Research | ICCR 2014: Early bird deadline July 31, 2014

08.07.2014 | Event News

First evidence for painless atrial fibrillation treatment

04.07.2014 | Event News

 
Latest News

Junk DNA not as worthless as once thought

23.07.2014 | Life Sciences

New Study Reveals Vulnerability of Sharks as Collateral Damage in Commercial Fishing

23.07.2014 | Studies and Analyses

NASA Provides Double Vision on Typhoon Matmo

23.07.2014 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>