Harmless soil bacteria destroys tumors
Cutting-edge cancer therapy is now aimed at utilizing a bacterial strain as a medium of drug delivery as it precisely targets tumors. A scientist at the Society for General Microbiology’s Autumn Conference at the University of York says that in the year 2013, cancer patients will be tested with the strain.
Frequently prevalent soil bacterium Clostridium sporogenes will be used for therapy. Bacterium spores injected in the patient grow and localize in solid tumors to produce a specific bacterial enzyme. An inactive “pro-drug” form of the anti-cancer drug is injected into the patient separately. On encountering the pro-drug at the tumor site, the bacterial enzyme activates it thereby facilitating the destruction of only the tumor cells.
Obstacles that have thus far prevented the entry of this therapy into clinical trials have now been bypassed by researchers at the University of Nottingham and the University of Maastricht. A gene capable of producing an enhanced version of the enzyme has now been inserted into the C. sporogenes DNA. This facilitates the production of larger quantities of the enzyme in the tumor thereby enhancing the efficiency of transforming the pro-drug into its active form.
Targeting cancer cells while specifically excluding healthy cells is the fundamental prerequisite for any new cancer therapy. Lead researcher Professor Nigel Minton discussed how this therapy unsurprisingly caters to this requirement.
He 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 tumors. This is a totally natural phenomenon, which requires no fundamental alterations and is exquisitely specific. We can exploit this specificity to kill tumor cells but leave healthy tissue unscathed.”
A wide range of solid tumors may witness a cure thanks to this research which would facilitate the development of simple and safe treatment procedures.
Professor Minton explained, “This therapy will kill all types of tumor cell. The treatment is superior to a surgical procedure, especially for patients at high risk or with difficult tumor locations. We anticipate that the strain we have developed will be used in a clinical trial in 2013 led by Jan Theys and Philippe Lambin at the University of Maastricht in The Netherlands. A successful outcome could lead to its adoption as a frontline therapy for treating solid tumors. If the approach is successfully combined with more traditional approaches this could increase our chance of winning the battle against cancerous tumors.”