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Scientists Develop Cancer-Killing Stem Cells in Lab

Toxin-producing stem cells attacking

Image credit: Khalid Shah. Toxin-producing stem cells (blue) attack a mouse brain tumor (green) that his hard to reach by other methods.

Scientists have been able to produce stem cells which could give off chemicals to kill cancer cells, thus providing the approach to the battle against serious tumors.

Stem cells have turned to be the target of medical research because of their capacity to turn into the cells which could build up the organs of our body. In addition, scientists could also engineer them to generate Pseudomonas exotoxin (PE), kind of chemical toxic to break tumors cells.

In reality, it is possible to produce PE outside our body and manage it as a means of battling against brain cancer. However such approach has its own limitations.

According to Dr. Khalid Shah of Harvard Medical School, although cancer-killing toxins have been successfully applied to treatment of different kinds of blood cancers, but they fail to deal with solid tumors because of their inaccessibility to such cancers as well as short half-life of the toxins.

In order to get round this puzzle, Shah was intended to identify an approach in to maintain production of the anti-cancer agents, which in the better way would get into the core of tumors. As a result, Shah has released his successful experiment with mice in the journal of Stem Cells.

As Shah said, from the previous study several years ago, they confirmed the application of stem cells to transmit these therapeutic toxins to tumors in the brain in the continuous way. However, at the first stage, it was necessary to genetically engineer stem cells which were capable of resisting being killed themselves by the toxins, for the time being, Shah’s team have already succeeded in obtaining the toxin-resistant stem cells that could produce and release drugs to kill cancer.

PE is capable of killing any cell into which it could get inside, but other labs have successfully produced it and other cytotoxins enter into cancer cells, but would be met with resistance from normal cells.

However, Shah has been able to move further so as to prevent the PE from acting when it is within the stem cell generating it. As Shah said, they have already tested such stem cells in clinically relevant mouse model of brain cancer, thus resecting the tumors and in the next step implanting the stem cells covered by a gel into the resection cavity. After completion of the molecular analysis and imaging to trace the inhibition of protein synthesis within brain tumors, they did identify that the toxins could kill the cancer cells, finally prolonging the survival in mouse models of brain tumors.

Before starting with tests with humans, Shah plans to work out therapies in which the PE-generating stem cells could act in connection with other cancer-fighting stem cells which his lab has ever made.

At the earlier time of this year, Shah made it public in regard to application of stem cells carrying biological weaponry instead of the chemical ones, since his project had succeeded in using stem cells that deliver the herpes virus to brain cancers housed in mice.

Source: BBC

Journal reference: Stuckey, Daniel W., et al. “Engineering toxin‐resistant therapeutic stem cells to treat brain tumors.” STEM CELLS (2014).