Successful attack on resistant tumour cells
By blocking the cells’ own ‘recycling system’, cancer cells that are particularly resistant to radiation therapy can be made to become susceptible to this kind of treatment again, said Dr. Anja Apel of the Department of Surgery at the University Hospital in Heidelberg who has been able to prove this in laboratory experiments. The research results hint at a new strategy that might be able to kill particularly malignant tumours.
The work of the Molecular OncoSurgery Group – a cooperation involving researchers from the Department of Surgery at the University Hospital (Director: Professor Dr. Markus Büchler) and the German Cancer Research Centre (DKFZ) - headed up by Professor Dr. Ingrid Herr and researchers from Tübingen and Lausanne has been published in the current edition of the international scientific journal “Cancer Research”.
Recyling must work in all healthy cells
Dr. Anja Apel (Photo: private)
All body cells have their own recycling system: Specific tools (e.g. enzymes) are used to get rid of, i.e. digest, cellular components (proteins and whole cellular organs) and reuse the building blocks in a different place. “This happens in all healthy body cells,” said Professor Dr. Ingrid Herr. “The recycling system is also switched on in cases when the cells do not have enough nutrients at their disposal. In such cases, cellular constituents and energy will be used for vital processes.” In severely damaged cells, authophagy, which is the scientific term for this recycling process, can also lead to programmed cell death and the decomposition of cells.
Switched off genes in tumour cells that are essential for autophagy
"This might have something to do with the development of cancer,” explains Dr. Anja Apel. “If the authophagy processes no longer function properly, then damaged cells will not be discarded and can develop into tumours.” In addition, the researchers from Heidelberg assume that aggressive tumour cells use the processes of the cellular recycling system to resist radiation therapy. The scientists studied the role of autophagy in cells that do not react to radiation: They switched off a number of genes in tumour cells that are essential for autophagy and found that cells that had been almost completely resistant to radiation became more sensitive to radiotherapy due to blocked autophagy. “We did not find an effect on cancer cells that had already responded well to radiotherapy before,” reported Dr. Anja Apel.
The Heidelberg researchers will now investigate whether blocking the recycling system might be useful for treating tumours of the intestinal tract – tumours that are difficult to treat.
Literature: Blocked Autophagy Sensitizes Resistant Carcinoma Cells to Radiation Therapy.
Anja Apel, Ingrid Herr, Heinz Schwarz, H. Peter Rodemann, and Andreas Mayer. Cancer Res 2008 68: 1485-1494
Source: University Hospital Heidelberg 05.03.2008 (EJ)
Further informaiton:
Prof. Dr. Ingrid Herr
German Cancer Research Centre Heidelberg
E-mail:
i.herr@dkfz.de