New treatment triggers cancer cells to produce their own anti-cancer medication


September 25, 2011

We've previously looked at the development of cancer treatments that deliver drugs directly into cancer cells before releasing their chemotherapeutic payload to reduce the damage done to healthy cells. But a new protein "switch" approach developed by researchers at Johns Hopkins University changes the game again by instructing cancer cells to produce their own cancer medication and cause the cancer cells to self-destruct while sparing healthy tissue.

The protein switch strategy would see a doctor administering a "prodrug," which is an inactive form of a cancer-fighting drug that would only be activated when it detects the presence of a cancer marker, triggering the cellular switch to turn the harmless prodrug into a potent form of chemotherapy.

"The switch in effect turns the cancer cell into a factory for producing the anti-cancer drug inside the cancer cell," said Marc Ostermeier, a Johns Hopkins chemical and biomolecular engineering professor in the Whiting School of Engineering, who supervised development of the switch. "The healthy cells will also receive the prodrug and ideally it will remain in its non-toxic form. Our hope is that this strategy will kill more cancer cells while decreasing the unfortunate side effects on healthy cells."

The research team made the cancer-fighting switch by fusing together two different proteins; one that detects a marker that cancer cells produce and another protein extracted from yeast that can turn an inactive prodrug into a cancer-cell killer.

"When the first part of the switch detects cancer, it tells its partner to activate the chemotherapy drug, destroying the cell," Ostermeier explained.

For the technique to work, the switch first needs to get inside the cancer cells. Ostermeier says this can be done in one of two ways; by delivering the switch protein itself into the cells or, alternatively, delivering the switch gene inside the cell where it serves as the blueprint from which the cell's own machinery constructs the protein switch.

Once the switches are in place, the patient would receive the inactive chemotherapy drug, which would then be activated inside the cells where the switch has been flipped on.

"The protein switch concept changes the game by providing a mechanism to target production of the anti-cancer drugs inside cancer cells instead of targeting delivery of the anti-cancer drug to cancer cells," Ostermeier said.

Although the novel cancer-fighting strategy hasn't yet been tested on human patients, the research team has successfully tested the switches on human colon cancer and breast cancer cells in the lab. The next step is animal testing, which is expected to begin within a year.

"This is a radically different tool to attack cancers," said James R. Eshleman, a professor of pathology and oncology in the Johns Hopkins School of Medicine and a co-author of the paper that appears in the Proceedings of the National Academy of Sciences, "but many experiments need to be done before we will be able to use it in patients."

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag. All articles by Darren Quick

Naturally occurring bacteria and viruses work together to balance our systems and prevent debilitating disease. Although these advancements are stupendous, why is there a gap in the development of \"phage\" type treatments? Could it be that the drug companies will make no money because these are not patentable?

Time for governments to step up and fund the proper development of non-patentable technologies that may already accomplish many of the synthetic \"breakthroughs\" that must also undergo years of testing and billions in costs.


Otto Warburg was the Noble Prize recipient in the 30s for proving cancer is anaerobic and the switch is oxygen transported across the cell membrane but why would any one from John Hopkins consider such an easy fix. Organic sulfur transports such oxygen and has addressed every cancer it has encountered in the Cellular Matrix Study of the Body Human Project. We are all sulfur deficient and organic sulfur a crystal food can address all of the modern diseases caused by it lack in our diets.

It is that simple

Got sulfur?

Patrick McGean
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