New hope for brain cancer treatment
Malignant glioma is the most difficult to treat of all brain cancers and prognosis for patients is usually poor. But scientists from Tokyo have discovered that the growth rate of the cancer cells, when cultivated in a laboratory, is almost completely halted when injected with a particular plant protein or molecule from the jimson weed.
The molecule, known as DSA2, slowed the growth of malignant cells to such an extent that some even began to change shape to resemble healthy cells.
Cancer cells are often suspended in a permanent state of adolescence and fail to "grow up". The scientists have discovered that when DSA is applied the cells are forced to mature, or "differentiate" which results in them losing their malignancy and propensity to spread.
Dr Tasuku Sasaki, one of the Tokyo based scientists who worked on the project, says: "DSA controls glioma cells as a result of glial differentiation rather than actually killing cells. Any drug based on this concept would help patients suffering with tumours that are difficult to remove such as gliomas."
Professor John Double, head of the Cancer Research UK Unit at Bradford University, says: "This is an exciting discovery but caution is needed as the work is only at the laboratory stage. More needs to be done before we have enough evidence to commit to trials. Potential treatment, based on DSA, for this form of brain cancer is still a long way off."
Scientists also found that even when DSA was removed from the cancerous cells its effect remained and the cancer cells failed to spread.
This is important in treatment as most tumour inhibitors only work when continually present and this, in turn, risks damage to neurons. Because the effects of the molecule continue to work even after DSA has been removed, neurons are far less likely to be affected.
Malignant gliomas are particularly difficult to treat as the boundaries between tumour tissue and normal tissue are indistinct.
Cancer Research UK's chief executive, Sir Paul Nurse, says: "New discoveries such as this are always welcome and sometimes they can lead to effective new treatments. However there is much work to be done on the journey from the laboratory bench to the patient's bedside."
- British Journal of Cancer87 (9) pp.918-923
- Datura stramonium agglutinin