Bacteria were able to attack cancer cells

Bacteria destroyed cancer tumors at study

04/24/2013

Pancreatic cancer is only rarely treatable in rare cases. However, this could change significantly in the future thanks to the latest findings of a research team at the Albert Einstein College in New York. The scientists around Claudia Gravekamp and Ekaterina Dadachova have succeeded in infiltrating radioactive isotopes for the destruction of cancer cells by means of bacteria in the organism of mice with pancreatic cancer. Their results are in the renowned journal „Proceedings of the National Academy of Sciences“ (PNAS).

„There has been no significant improvement in the treatment of pancreatic cancer over the last 25 years, highlighting the urgent need for new alternative therapies“, The US researchers justified their current investigations. They use a revolutionary method for targeted control of pancreatic cancer cells. By means of bacteria, a radioisotope was passed through the organism of cancerous mice directly to the cancer cells. The success was impressive. Much of the pancreatic cancer cells were destroyed while the healthy cells remained intact.

Bacteria against cancer cells
From previous studies it was already known that bacteria of the genus Listeria attack only tumor cells, while healthy cells usually resist the bacteria. Gravekamp and Dadachova wanted to use the effect for the targeted destruction of cancer cells and have for this purpose „the radioisotope 188 rhenium coupled to the bacteria.“ Thus, an irradiation in the cancer cells are triggered, which ideally triggers their destruction, write the US researchers. Radiology professor Ekaterina Dadachova explained that rhenium was well-suited for the novel procedure, as its effects on cancer therapy were known and the low half-life of 17 hours ensured that the organism or healthy tissue was exposed to stress only relatively briefly becomes.

The newly discovered, unique radioactive bacteria injected the US researchers in their investigations mice with metastatic pancreatic cancer. The mice received one injection daily for one week. Subsequently, the mice were given four more injections until the end of the experimental period, which was reached after 21 days, as the mice of the control group began to die. Subsequent examination of the animals revealed that injection of the radioactive bacterium caused a 90 percent reduction in metastases. The healthy cells were largely spared.

This result was possible because the bacteria were efficiently controlled by the immune system in normal tissues, „but not in the highly immunosuppressed microenvironment of metastases and primary tumors“, write the US researchers. They assume that an even shorter reduction of the metastases would have been possible with a longer trial period. In order to achieve "a 100% elimination of the metastases, the bacteria could be attached in case of doubt, even another cancer drugs." We may be at the beginning of a new era in the treatment of metastatic pancreatic cancer, concludes Gravekamp and Dadachova.

Poor prognosis in pancreatic cancer
So far, the situation with pancreatic cancer is often quite hopeless for those affected, not least because the usually asymptomatic pancreatic carcinoma is usually discovered relatively late. At the time of diagnosis, the tumors are often no longer surgically removed and it has already metastasized. The chances of success of a classical chemotherapy are considered as extremely limited. For example, the five-year survival rate for pancreatic cancer is generally extremely low. (Fp)

Image: Sebastian Karkus