Scientists have made progress in using bacteria as a therapeutic tool in treating cancer. Researchers at the Helmholtz Centre for Infection Research in Braunschweig were able to demonstrate that a genetically modified Salmonella typhimurium colonized tumor cells, and that certain genes may be activated "remotely", in this case, by the applicaiton of L-arabinose.

Applying L-arabinose, after the salmonella bacteria have infected mice and migrated to the cancerous tissue, activates these genes. Thus far, Weiss and Loessner used genes that encode light emitting proteins. If the mice are given a dose of the sugar, bacteria that have colonized the tumor fluoresce, such that the location and size of the tumor can be analyzed. Theoretically, instead of emitting light, the bacteria in future could be triggered to produce and deliver cancer-fighting medication inside the tumor.
Alternatively, they could also deliver immune-stimulating substances that would mark the tumor for the body's own immune-defense mechanisms and induce a salutary immune response.

The study has been published in the recent issue of Cellular microbiology (doi: 10.1111/j.1462-5822.2007.00890.x).

Photo: Helmholtz Centre for Infection Research