Harmless soil bug kills cancer cellsTargets tumours
A harmless bacterium found in the soil could soon be used to deliver drugs in frontline cancer treatment, scientists have said.
Clostridium sporogenes is a bacterium that is widespread in soil, and thrives in low oxygen conditions. When spores from the microbe are injected into cancer patients, they only grow in low oxygen environments, such as those found in tumours.
Scientists at the University of Nottingham and Maastricht University have genetically engineered a strain of the bacterium to produce an improved version of an enzyme which can be used to activate an anti-cancer drug.
The anti-cancer drug is injected separately into the patient's bloodstream as an inactive 'pro-drug.' When the pro-drug arrives at the site of the tumour, the bacterial enzyme activates the drug, allowing it to destroy the cells in its vicinity - the tumour cells.
The bacterial strain is expected to be tested in cancer patients in two years time, the scientists said.
Study leader Professor Nigel Minton, at the Centre for Biomolecular Sciences, said: "Clostridia are an ancient group of bacteria that evolved on the planet before it had an oxygen-rich atmosphere and so they thrive in low oxygen conditions.
"When Clostridia spores are injected into a cancer patient, they will only grow in oxygen-depleted environments, i.e. the centre of solid tumours.
"This is a totally natural phenomenon, which requires no fundamental alterations and is exquisitely specific. We can exploit this specificity to kill tumour cells but leave healthy tissue unscathed."
The scientists say the research could lead to a safe and simple way to treat a wide range of solid tumours.
"This therapy will kill all types of tumour cell. The treatment is superior to a surgical procedure, especially for patients at high risk or with difficult tumour locations, professor Minton said.
"If the approach is successfully combined with more traditional approaches this could increase our chance of winning the battle against cancerous tumours."
The research was presented at the Society for General Microbiology’s Autumn Conference at the University of York.
This article was published on Mon 5 September 2011
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