A genetically modified bacterium destroys tumors by provoking an immune response, according to a study published Wednesday.
Using mice and cultures of human cancer cells, a South Korean-led scientific team demonstrated that Salmonella typhimurium engineered to make a foreign protein caused immune cells called macrophages and neutrophils to mobilize against the cancer.
Tumors shrank below detectable levels in 11 out of 20 mice injected with the modified Salmonella, said the study, published in Science Translational Medicine.
Go to j.mp/salcancer for the study. The first author was Jin Hai Zheng of Chonnam National University Hwasun Hospital, in Jeonnam, South Korea.
The engineered Salmonella provoke a sustained immune response, in addition to preventing the spread of a human colon cancer implanted in a mouse. The bacterium also were found to be nontoxic, multiplying almost exclusively inside tumors.
UC San Diego researcher Jeff Hasty has developed engineered Salmonella that deliver cancer-killing toxins inside the tumor. This bacterium periodically self-destructs when it reaches a certain population density, releasing the toxins. Some of the engineered Salmonella survive, rebuilding the population until it reaches the self-destruct density. So the tumor receives periodic doses of targeted chemotherapy.
Source: GM Salmonella destroys cancer