Penn researchers turn a toxic fungus and ‘King Tut’s curse’ into a tool for fighting cancer

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More than 100 years ago, archeologists discovered the tomb of Egyptian pharaoh Tutankhamen in the Valley of the Kings, which contained King Tut’s intact and undisturbed mummy as well as gold jewelry, clothing and other artifacts buried with him for the afterlife.

It was a major finding at the time because it helped researchers learn more about ancient Egyptian culture and embalming practices from 3,000 years ago.

But shortly after the tomb and the pharaoh’s sarcophagus was opened, several members of the archeology team and other experts who visited the site suffered untimely deaths. And so, the “mummy’s curse” was born, a superstition that foretold of perilous fates among those who dared to disturb the tombs of the ancient rulers.

Scientists later believed that the team of archeologists may have actually been exposed to fungi growing in the tomb, including Aspergillus flavus, which releases toxic spores to fight off threats and can cause lung disease and other human illnesses.

Now, bioengineers at the University of Pennsylvania say that same fungus might benefit human health and be used to fight leukemia cancer. Researchers recently published their findings in the journal, Nature Chemical Biology.

“It’s very exciting,” said Dr. Xue Sherry Gao, a chemical and biomolecular engineer at UPenn and the study’s lead author. “This fungus was toxic to humans previously, and now we’re thinking about a drug application.”

Finding medicinal uses for fungi is not new. Penicillin, one of the most common antibiotic drugs prescribed worldwide, is derived from a specific fungal species. Some statins, a class of drugs used to treat high cholesterol, also have their origins rooted in fungi.

So, it wasn’t a big leap for Gao to wonder if Aspergillus flavus could be used to help fight off human infections and diseases.

“It’s really just for our scientists to learn about them and repurpose them to be helpful to our society,” she said.

It took several years for the scientists to first map out the chemical structure of these fungal molecules and toxins and then purify them into a compound that could be tested for their effectiveness in human cells.

The research team first looked at the fungus’s ability to act as an antibiotic and fight off bacterial infections, or as an agent to clear other fungal infections, including yeast infections.

But Gao said they saw no treatment activity against those pathogens.

“Then we’re thinking about, OK, how about cancer cells?” she said.

The results were much more promising. Initial tests showed that the fungus helped stop uncontrolled cell division, which is how cancer forms and spreads, specifically in leukemia cancer cells.

The researchers then modified and engineered the fungal molecules in order to enhance their cancer fighting abilities and again tested them against leukemia cells.

“It enhanced the leukemia cell killing activity 100-fold,” Gao said, “which is very comparable with current anti-leukemia drugs on the market.”

But Gao cautioned that those results are still just within controlled laboratory environments and settings. Researchers still need to perform more tests to figure out the degree in which these modified fungal compounds can kill cancer cells before moving on to any drug development phases, including human clinical trials.

Gao said she’s optimistic that the findings could one day lead to a new type of cancer therapy. She also hopes it encourages more scientists and researchers to investigate how fungi could be used in medicine, which she said is an understudied field.

And at the very least, the new discovery means giving a fungus that was once  shrouded in superstition and fear a new purpose.