The communication system used by bacteria may soon prove to be the most innovative and harmless treatment for fighting cancer. Senthil Kumar, an assistant research professor and assistant director of the Comparative Oncology and Epigenetics Laboratory at the University of Missouri (MU) College of Veterinary Medicine, says this communication system can be used to signal cancer cells to not only take certain actions, but also to die on command.
Bacterial communication, triggered during an infection, relies on the release of molecules that contain certain messages, Kumar explained in an MU news release. “Depending on the type of molecule, the signal will tell other bacteria to multiply, escape the immune system, or even stop spreading,” he says.
In their study published in PLOS ONE, Kumar and co-author Jeffrey Bryan, an associate professor in the MU College of Veterinary Medicine, culled the “stop spreading” molecule N-3-oxo-dodecanoyl-L-homoserine lactone (O-DDHSL) from Pseudomonas aeruginosa bacteria. This commonplace bacteria causes a multitude of minor infections and about 400 deaths a year, according to the Centers for Disease Control. But when the researchers treated human pancreatic cancer cells grown in culture with its O-DDHSL molecule, the cancer cells stopped multiplying, failed to migrate, and began to die.
Luis F. Pineda, MD, a Birmingham oncologist, says the medical community has overlooked the ability of bacteria to aid the body for too long. “This is the most exciting thing happening right now,” he says. “But if I came out and said I was going to treat something with bacteria, everyone would look at me as if I was crazy.”
Pineda adds that even bacteria in the environment regularly communicate with and aid the human immune system. “The brain doesn’t know what viruses or bacteria are outside the body, but there are bacteria that know. And they get inside you through your skin, nose, eyes, and gastrointestinal tract and get in contact with the immune system cells. They exchange genetic information from the outside to your lymphocytes, and this is the way your body can prepare for infection,” he says.
Yet one of the most interesting aspects of this new use of bacteria to Pineda is that it doesn’t require the participation of the immune system. “It’s direct communication from the bacteria to the cancer cells,” he says. That could mean less impact on the body and fewer side effects.
Kumar and Bryan chose pancreatic cancer for their study because those are the most robust and hard-to-kill cancer cells that can occur in the human body. “Because this treatment shows promise in such an aggressive cancer, we believe it could be used on other types of cancer cells,” Kumar says, adding that their lab is in the process of performing that additional testing now.
The next step in their research is to find a more efficient way to introduce the molecules to the cancer cells before animal and human testing can take place. “At this time, we only are able to treat cancer cells with this molecule in a laboratory setting,” Kumar says. “We are now working on a better method that will allow us to treat animals with cancer to see if this therapy is truly effective. The early-stage results of this research are promising. If additional studies, including animal studies, are successful, then the next step would be translating this application into clinics.”
If further testing proves fruitful, Pineda can foresee the use of other bacteria and fungi as purely biological treatments for anything from acne to schizophrenia. “We’re going to see an explosion of this type of research that will be absolutely astonishing,” he says. But it will likely be at least another five years before even Kumar’s approach makes it through the FDA approval process and wins acceptance by the establishment.
“We are seeing the latest concept of how bacteria influence human cells,” Pineda says. “I really think we will see this approach come through with significant healthcare solutions in the next several years.”