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.
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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.
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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