How Effective Is Bacteria For Treating Cancer? The therapeutic role of bacteria in fighting cancer is not a novel concept. Beginning in the 19th century, William Coley used bacterial toxins to treat patients with soft-tissue cancers.
Despite the relative success, the high risk of uncontrollable infections and the lack of antibiotics at the time forced scientists to move away from this method. Now, with new technological advancements which combine innate properties of bacteria with synthetic biology, scientists have regained enthusiasm for bacteria as the future for treating cancer.
Some bacteria possess properties that make them a natural therapeutic choice for fighting cancer.
Bacteria stimulate the patient’s immune system, allowing the immune system to prepare to ward off cancer cells. In addition, bacteria has the ability to selectively grow within solid tumors, providing them with protection from the tumor’s defense. The bacteria then reproduce within the tumor, ultimately competing with the tumor for nutrients.
This production and competition between the two ultimately leads to immune cell infiltration, causing an anti-cancer response by the body. To date, these properties have proven most successful in combating bladder cancer. More testing is needed to increase the efficacy with other types of cancer.
Scientists have begun to implement nanotechnology in order to further augment the natural ability of bacteria to treat cancer.
Nanotechnology, or technology on a molecular level, allows scientists to have more control over a bacteria’s actions.
For example, Columbia University microbiologists and immunologists used nanotechnology to mutate bacteria in order to produce molecules that block immune checkpoints. This mutation allowed the body to become familiar with the cancer and prepare t-cells for future confrontations.
With nanotechnology, scientists can genetically engineer bacteria so that they may serve as a carrier for recombinant payloads which include anticancer toxins, cytokines, and cell-killing chemicals.
Selective targeting of cancer cells will limit the harmful side effects caused by other treatment methods. Scientists have begun to develop ways to control the movements of bacteria.
Synthetic biologists have worked on creating genetic circuits, using positive and negative feedback loops in order to control the movements of bacteria and to limit the inaccuracy of bacterial navigation.
While bacteria is currently used as a diagnostic marker for certain cancers, its combination with
nanotechnology to treat cancer has given scientists a reason to expand bacteria’s role in the medical world.
Biomedical companies are currently conducting clinical trials in order to assess its efficacy. Trials have included rats, dogs and the first human patients, with one trial concluding that the treatment showed “precise, robust, and reproducible antitumor responses” (Roberts et al).
Although early results have been encouraging, everyday use of nanotechnology and bacteria is still under development. Nevertheless, this technology shows promise for bacteria to be instrumental in the future of cancer therapy.