Researchers use probiotics for detecting cancer in the liver

Engineers have come up with a new way to detect cancer that spreads to the liver, with the help of probiotics. This discovery has been made by engineers at MIT and the University of California at San Diego (UCSD). Probiotics are beneficial bacteria resembling those found in yogurt. Some types of cancers like colon and pancreatic are likely to metastasize to the liver. These tumors should be treated as soon as possible so as to remove them successfully on time.

According to Sangeeta Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Electrical Engineering and Computer Science at MIT, "There are interventions, like local surgery or local ablation, that physicians can perform if the spread of disease in the liver is confined, and because the liver can regenerate, these interventions are tolerated. New data are showing that those patients may have a higher survival rate”. Therefore, she added that it is especially important to detect early metastasis in the liver.

The researchers programmed the bacteria to produce a glowing signal that can be detected with a simple urine test by making use of a harmless strain of E. coli that colonizes the liver. Bhatia and Jeff Hasty, a professor of biology at UCSD have written a paper describing the new method in this week in the journal Science Translational Medicine. MIT postdoc Tal Danino and UCSD postdoc Arthur Prindle are lead authors of the study.

In order to turn bacteria into diagnostic devices, the researchers engineered the cells so as to express the gene for a naturally occurring enzyme called lacZ that breaks lactose into glucose and galactose. Here, lacZ works on a molecule injected into the mice, including galactose associated with luciferin, a luminescent protein naturally produced by fireflies.