Beating Bowel Cancer With Bacteria & Broccoli

A humble cocktail of bacteria and broccoli may prove to be a winning combination in the treatment of colorectal cancer.

AsianScientist (Jan. 16, 2018) – Researchers in Singapore have turned a humble cocktail of bacteria and vegetables into a targeted system that seeks out and kills colorectal cancer cells. The study has been published in Nature Biomedical Engineering.

Colorectal cancer, or bowel cancer, is one of the most common cancers globally, with high incidence rates in the developed world. Although five-year survival rates for earlier stages of this cancer are relatively good, survival goes down in later stages of the disease and the risk of cancer recurrence goes up considerably.

To help address this problem, a team of researchers led by Associate Professor Matthew Chang at the National University of Singapore developed a probiotic using a genetically engineered version of E. coli Nissle, a harmless Gram-negative strain of bacteria found in the gut.

The mechanism of action of the engineered bacteria is to attach to a protein called heparan sulphate proteoglycan on colorectal cancer cells. The bacteria then secrete an enzyme that transforms a small molecule from broccoli (glucosinolates) into a potent anticancer agent (sulphoraphane). The bacteria do not bind to healthy cells, nor are the healthy cells affected by the toxin.

When mixed with a broccoli extract, the engineered bacteria killed more than 95 percent of colorectal cancer cells in a laboratory petri dish. The mixture had no effect on breast and stomach cancer cells in the same experiment.

In animal studies, the probiotics-broccoli extract reduced tumor volumes by 75 percent in mice with colorectal cancer. Also, the mice developed new tumors that were three times smaller than those in control mice not fed the mixture.

The researchers envision that the probiotics cocktail could be used as a dietary supplement for preventive care, or to reduce tumor recurrence after surgery.

“One exciting aspect of our strategy is that it capitalizes on our lifestyle, potentially transforming a normal diet into a sustainable, low-cost therapeutic regimen. We hope that our strategy can be a useful complement to current cancer therapies,” said Prof. Chang.



The article can be found at: Ho et al. (2018) Engineered Commensal Microbes for Diet-mediated Colorectal-cancer Chemoprevention.

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Source: National University of Singapore; Photo: Pexels.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

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