Ananyo writes “Two dangerous things together might make a medicine for one of the hardest cancers to treat. In a mouse model of pancreatic cancer, researchers have shown that bacteria can deliver deadly radiation to tumours — exploiting the immune suppression that normally makes the disease so intractable. The researchers coated the bacterium Listeria monocytogenes with radioactive antibodies and injected the bacterium into mice with pancreatic cancer that had spread to multiple sites. After several doses, the mice that had received the radioactive bacteria had 90% fewer metastases compared with mice that had received saline or radiation alone.” …
… Scientists at the Albert Einstein College of Medicine in New York City were investigating the bacterium Listeria monocytogenes as a potential vehicle to deliver treatments for the cancer. Wild versions of the microbe are responsible for causing a dangerous form of food poisoning, but the researchers were experimenting with a weakened strain of the organism. The idea was to use a genetically modified version of the germ to carry molecules normally seen on tumors around the body so the immune system could recognize cancerous cells as threats — the biological equivalent of passing around wanted posters to police officers.
Unexpectedly, they discovered that even when weakened, Listeria could infect cancer cells. “We were very surprised to see the Listeria infecting the tumors,” says Claudia Gravekamp, an associate microbiology and immunology professor who led the research.
… The researchers expect the treatment could be improved by fine-tuning the treatment schedule, using higher doses of radiation, or by piggybacking additional anti-cancer agents onto the bacteria. Einstein has filed a patent application related to this research that is currently available for licensing to partners interested in further developing and commercializing this technology.
This work was supported by grants from the National Cancer Institute and the National Institute on Aging (AG023096-01 and CA129470-01), both parts of the National Institutes of Health.