Submission + - This frog bacterium wiped out cancer tumors in mice with a single dose (sciencedaily.com)
fahrbot-bot writes: Science Daily has reported that scientists at the Japan Advanced Institute of Science and Technology (JAIST) have identified a naturally occurring bacterium from the intestines of Japanese tree frogs (Dryophytes japonicus) that demonstrated remarkable anticancer activity in mice. The findings, published in Gut Microbes, introduce a new approach to cancer treatment that uses living bacteria to directly target tumors rather than simply altering the gut microbiome.
In a mouse model of colorectal cancer, a single intravenous dose of E. americana completely eliminated tumors, producing a 100% complete response (CR) rate. The researchers emphasize that these findings are limited to mice, but they believe the results provide an encouraging proof of concept for developing new bacterial cancer therapies.
First, E. americana directly attacks tumors. As a facultative anaerobic bacterium, it thrives in both oxygen rich and oxygen poor environments, allowing it to multiply inside the oxygen deprived regions commonly found within tumors. Once there, the bacterial population increased by roughly 3,000 fold within 24 hours after treatment, directly damaging cancer cells.
Second, the bacterium stimulates the immune system. Its presence attracted T cells, B cells, and neutrophils into tumors. These immune cells then released inflammatory signaling molecules, including TNF- and IFN-, which strengthened the immune response and promoted cancer cell death.
One of the most striking findings was that E. americana accumulated almost exclusively inside tumors and did not colonize healthy organs.
They found that the bacteria were rapidly cleared from the bloodstream, with a half life of approximately 1.2 hours, and became undetectable within 24 hours. No bacterial colonization was detected in healthy organs, including the liver, spleen, lungs, kidneys, or heart.
The treatment caused only mild, temporary inflammation that returned to normal within 72 hours. During a 60 day observation period, the researchers found no evidence of chronic toxicity.
In a mouse model of colorectal cancer, a single intravenous dose of E. americana completely eliminated tumors, producing a 100% complete response (CR) rate. The researchers emphasize that these findings are limited to mice, but they believe the results provide an encouraging proof of concept for developing new bacterial cancer therapies.
First, E. americana directly attacks tumors. As a facultative anaerobic bacterium, it thrives in both oxygen rich and oxygen poor environments, allowing it to multiply inside the oxygen deprived regions commonly found within tumors. Once there, the bacterial population increased by roughly 3,000 fold within 24 hours after treatment, directly damaging cancer cells.
Second, the bacterium stimulates the immune system. Its presence attracted T cells, B cells, and neutrophils into tumors. These immune cells then released inflammatory signaling molecules, including TNF- and IFN-, which strengthened the immune response and promoted cancer cell death.
One of the most striking findings was that E. americana accumulated almost exclusively inside tumors and did not colonize healthy organs.
They found that the bacteria were rapidly cleared from the bloodstream, with a half life of approximately 1.2 hours, and became undetectable within 24 hours. No bacterial colonization was detected in healthy organs, including the liver, spleen, lungs, kidneys, or heart.
The treatment caused only mild, temporary inflammation that returned to normal within 72 hours. During a 60 day observation period, the researchers found no evidence of chronic toxicity.
