New cancer treatment can protect cells from radiation
Thursday October 22 2009
A BREAKTHROUGH in cancer treatment could allow doctors to protect healthy cells from radiotherapy and simultaneously accelerate the death of tumours.
Researchers said the treatment, which worked on bone marrow, muscle and skin, could be available within five years.
The US team found that if they blocked the action of a certain gene, it seemed to make healthy cells immune to radiation, even in very large doses. At the same time, the technique increased the death of malignant cells and prevented them from returning.
More than half of all cancer patients are given some radiation treatment to reduce tumours and stop the spread of the disease.
But the treatment can also destroy healthy cells and cause nausea and vomiting, skin sores, weakness and fatigue.
Scientists at the University of Pittsburgh School of Medicine, however, said they had stumbled on a solution.
While looking into gene treatments for heart disease, they discovered that suppressing the action of a protein known as TSP1/CD47 made cells in pigs and mice immune to the highest doses of radiation.
Further tests showed that the same action actually suppressed tumour cells' defences and made them more vulnerable to radiotherapy.
"We almost couldn't believe what we were seeing," said Dr Jeff Isenberg, the chief author of the study, which was published in the journal 'Science Translational Medicine'.
"This dramatic protective effect occurred in skin, muscle and bone marrow cells, which is very encouraging. Cells that might have died of radiation exposure remained viable and functional when pre-treated," he said.
The team, who do not know exactly why the technique works, said it could be that blocking the protein protected the body's own immune cells.
Exciting
Dr Isenberg said the technique could be used on humans in as little as five years.
However, toxicology and clinical trials would be needed before it could be adopted as a treatment.
Dr Ester Hammond, a research scientist at Oxford, said: "This work is particularly exciting because it's a step towards developing drugs that could be given alongside radiotherapy to protect healthy cells, while destroying the cancerous ones.
"But the study raises the intriguing question of why normal cells are protected from radiation when this particular cell signalling pathway is disrupted. Future work will undoubtedly shed more light on this and could lead to new treatments for cancer patients." (©Daily Telegraph, London)
- Richard Alleyne in Washington
Irish Independent
