A new method to inhibit cancer cells—a mixture of engineered probiotics with vegetables

Colorectal cancer is one of the most common cancers in the world, and its incidence is predicted to rise in the next few years. Also, scientists have been working hard at finding a cure for this problem.

Researchers at the National University of Singapore have identified a way to turn a humble cocktail of bacteria and vegetables into a targeted system that seeks out and kills colorectal cancer cells. Led by Dr Chun-Loong Ho, this study had been published in Nature Biomedical Engineering.

The most important part of this cancer-targeting system is an engineered form of E. coli Nissle, a harmless type of bacteria found in the gut. They engineered the bacteria into a probiotic that attached to the surface of colorectal cancer cells and secreted an enzyme to convert a substance found in cruciferous vegetables (such as broccoli) into a potent anticancer agent.

Normal cells cannot do this conversion, and are not affected by the toxin, thus the system can be targeted only to colorectal cancer cells. The research aimed to kill cancer cells in the gut by allowing them to take up this anticancer agent.



Orally administered engineered microbes bind to the surfaces of colorectal cancer cells (a), allowing microbes to secrete myrosinase, which converts dietary glucosinolate found in cruciferous vegetables (b). When the cancer cells are cleared, the microbes are released from the surface of the intestinal wall (c).

Results find that, the mixture of engineered probiotics with a broccoli extract or water containing the dietary substance can killed more than 95% of colorectal cancer cells tested. Moreover, the mixture had no effect on cells from other types of cancer such as breast and stomach cancer.

Observably, in mice with colorectal cancer, the probiotics-veggie combination decreased tumour numbers by 75%. In addition, compared with control mice which were not fed with the mixture, the tumors found in these mice were three times smaller.

Scientists imagine that these probiotics might serve dual purposes, as prevention or clean up the cancer cells remaining after surgical removal of tumours. In the future, colorectal cancer patients may could take the probiotics as a dietary supplement along with their broccoli to prevent colorectal cancer or to reduce recurrence after cancer surgery.

"One exciting aspect of our strategy is that it just capitalizes on our lifestyle, potentially transforming our normal diet into a sustainable, low-cost therapeutic regimen. We hope that our strategy can be a useful complement to current cancer therapies." said Matthew Chang, associate professor at the National University of Singapore.

Read more, please click:

https://eurekalert.org/pub_releases/2018-01/nuos-wts011018.php

https://www.news-medical.net/news/20180111/Scientists-develop-genetically-engineered-probiotic-that-targets-and-kills-cancer-cells-in-the-gut.aspx