Scientists Genetically Modifies Salmonella To Kill Cancerous Tumors [STUDY]

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A new study by biomedical engineers at Duke University, found that the bacterium "Salmonella typhimurium" can be modified to turn the food-borne bacteria into a weapon against cancerous tumors.

Salmonella makes millions of people sick every year but the new study finds that a genetically modified version of the pathogen could be used as a weapon against brain cancer. The researchers used Salmonella bacteria, which had been programmed in the laboratory to destroy the cancer cells.

It is the most common bacteria that contaminate food and can be found in undercooked meats, eggs and milk. The microbe can cause severe nausea, diarrhea, vomiting, abdominal cramps, fever and typhoid.

 "Brain tumors are tough to treat because they invade brain tissue and do not have a clear edge that allows neurosurgeons to remove all the tumor," Vinik Dean of Duke's Pratt School of Engineering, Ravi Bellamkonda said.

According to Digital Trends, the motivation for the study was to design a system with the ability to seek out and localize the metastatic tumors within the brain and only express tumor killing proteins in those sites, he added.

However, the researchers decided to turn to food poisoning as the weapon that will be used to achieve their goal. Despite its tendency for making people sick, they thought salmonella is perfectly suited for the role as it is a bacterium with the ability to move in dense tissue like the brain.

The researchers genetically modify the Salmonella so it is unable to survive in healthy tissues, but prefers to live in tumors, which have a very nutrient-rich environment where the bacteria grow rapidly and eventually kill the cancer cells within the tumor.

They make it deficient in an essential need for its survival - an organic compound known as purine, which makes salmonella to acquire an insatiable taste for brain tumors. Tumors are rich in purines which makes the bacteria only finds a good supply of its much needed food supply in rich tumor regions, according to Yahoo News.

The researchers engineered the tumor-killing cargo of the salmonella only to be expressed and released when the oxygen tension is low. Tumors grow rapidly and most of them have low oxygen tension, which makes the tumor killing proteins to be released only by the bacteria in tumor regions.

The approach shows a 20 percent cure rate which is phenomenal for the challenging condition, Bellamkonda said. The next phase of this project will focus on answering questions concerning the response rate to treatment, as well as more analysis about how the work impacts on different subsets of tumor.