Scientists at MIT and the University of California at San Diego (UCSD) have re-engineered E. Coli bacteria to create a helpful super-microbe that attacks tumor cells. Researchers programmed human-safe E. Coli as bombers in the war against cancer, dropping toxic cocktails in affected areas. When combined with traditional cancer treatment, the altered bacteria shrank aggressive liver tumors in mice far quicker than either treatment separately.
“Tumors can be friendly environments for bacteria to grow, and we’re taking advantage of that,” says Sangeeta Bhatia, researcher at MIT and senior co-author of the recent paper that documented these findings. Boosted by a suppressed immune system, bacteria naturally gathers in areas affected by disease. Some bacteria is well adapted to a low-oxygen environment, such as that of a tumor. Harmless E. Coli fits right into this microecosystem and possesses three different mechanisms, provided by artificial genetic circuits, for attacking tumors. One circuit in the altered bacteria creates hemolysin, which damages the cell membranes of tumor cells. Another conjures a drug that tells the tumor cells to self-destruct, while the third delivers a protein which encourages the body’s immune system to attack the tumor.
In addition, the altered E. Coli possesses a genetic circuit that allows it to sense the nearby population of bacteria through a process called quorum sensing. If the population of helpful E. Coli exceeds a certain limit, bacteria are programmed to self-destruct until there is only a small population remaining. “That allows us to maintain the burden of the bacteria in the whole organism at a low level and to keep pumping the drugs only into the tumor,” says Bhatia. The research collaborators are now working to program bacteria to use other weapons against dangerous cells while refining their cancer hunting E. Coli to suit different forms of cancer.
Via MIT News
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