However, the T cells not only kill cancer cells – they additionally destroy the tumor blood vessel system, thus impeding the supply of nutrients to the tumor. Consequently, “escapee” mutant tumor cells are eradicated that have become resistant to drug-based treatment and are responsible for tumor recurrence. (Cancer Cell, doi10.1016/j.ccr.2011.10.019)*.
The researchers transplanted tumor cells into mice that express SV40 large T antigen (Tag), the oncogene that is critical for tumor growth. The researchers were thus able to target and inactivate the oncogene using the antibiotic drug doxycycline (dox), which has an effect similar to modern drugs currently in clinical use. Since the oncogene is also present as antigen on the surface of the tumor cells, the researchers were also able to target these tumors with oncogene-specific T cells. Thus, for the first time the effect of the two completely different therapy approaches could be compared directly with each other.
Moreover, a special feature of the study was that the tumors in the mice were large – bigger than one centimeter and containing about one billion cancer cells, comparable to clinical-size tumors in patients. Only then, according to the researchers, is the development of the tumor tissue (tumor stroma), which also includes the tumor vasculature, complete. The tumor is then considered “established”. The aim of tumor therapy is to kill all cancer cells to prevent the recurrence of cancer disease.
The researchers showed in mice that the tumor is destroyed by the drug-mediated inactivation of the oncogene, but that the tumor vasculature and thus the blood supply of the tumor remains intact. In addition, due to a high mutation rate, some cancer cells become resistant to the drug and quickly generate new tumors despite continual administration of the anti-cancer drug.
Adoptive T-cell therapy, the researchers noted, is more effective in the mice in the long term, because it destroys the blood supply of the tumor. In addition, it evidently intercepts cancer cells that have altered their characteristics via mutations and thus escape drug treatment. In adoptive T-cell therapy, the researchers modulate the cytotoxic T cells (immune cells toxic for the cell) in the test tube in such a way that the T cells recognize certain features on the surface of cancer cells and specifically destroy the tumor cells. Then these primed immune cells are transferred back into the mice. The researchers point out that techniques to produce highly specialized T cells against human tumors have recently been developed following previous studies by Professor Blankenstein’s research group. Now it will be important to determine exactly how these immune cells can be used in future clinical trials.
The researchers hope that their insights in defining optimal conditions for T cell therapy may help improve future clinical trials and thus the treatment of cancer patients.
*Oncogene-targeting T cells reject large tumors, while oncogene inactivation selects escape variants in mouse models of cancer
Kathleen Anders1, Christian Buschow2, Andreas Herrmann3, Ana Milojkovic4, Christoph Loddenkemper5, Thomas Kammertoens2, Peter Daniel4, Hua Yu3, Jehad Charo1, Thomas Blankenstein1,2,*1Max Delbrück Center for Molecular Medicine, 13092 Berlin, Germany
5Institute of Pathology, Charité Campus Benjamin Franklin, 12200, Berlin, GermanyContact:
Barbara Bachtler | Max-Delbrück-Centrum
What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society
Treating arthritis with algae
23.08.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
23.08.2017 | Materials Sciences
23.08.2017 | Automotive Engineering
23.08.2017 | Life Sciences