This is the microbial version of the Good Samaritan story with far greater consequences. A very common soil bacterium Clostridium sporongenes can kill off cancerous cells and can be easily harnessed into a cancer drug. Furthermore, the bacterium does no damage to the cancer patient.
The bacterium grows only in those places where oxygen is absent, like deep inside the soil or within tumors in the body. It is extremely specific in this aspect and does not grow in places where oxygen concentration exceeds a certain threshold level.
Scientists from Dutch and UK stimulated the production of an enzyme by the bacterium that can serve as a cancer drug. The studies were presented to the Society of Microbiology.
Spores of the bacterium are injected into the patients’ body. Since the microbe grows only in oxygen-depleted regions, it doesn’t grow indiscriminately and latches onto solid tumours. In this anaerobic environment, the bacterium produces a specific enzyme. A separate anti-cancer drug is injected into the patient at the same time, but in an inactive form. When this inactive drug meets the bacteria at the tumour site, the secreted enzyme activates the drug. Once activated, it destroys the cells surrounding it i.e. the tumor cells.
The Ultimate Magic Bullet
The bacterium may really be the magic bullet’ scientists have been searching for. Magic Bullet’ refers to the hypothetical medical concept in which a drug will only act on a specific type of cell or enzyme and not disturb any other component of the body. In case of cancer, the drug must target only cancer cells and not harm the healthy living tissues. C.sporogenes fits the bill perfectly. Since it grows only is low-oxygen regions, it will not grow on healthy tissues, as they are richly supplied by oxygen.
Prof. Nigel Minton explains this bizarre characteristic:
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
Thus, new age cancer treatments may be non-invasive with little or no side-effects and due to a harmless soil microbe.
The Final Answer may have been under our feet all along. Who’d have thought that the dirt that you wash off your shoes might hold the key to a cancer cure?