Scientists work to unlock sharks' cancer-fighting secret

SARASOTA - For over 60 years, Mote Marine Laboratory and Aquarium in Sarasota has been educating the public about sharks. During most of that time, senior scientists Carl Luer and Cathy Walsh have learned a lot about these mysterious marine creatures -- specifically, the shark immune system.

"They are doing some amazing things health-wise. Observations in the wild tell us they rarely ever get cancer," said Luer. 

Their secret lies in an organ called the epigonal. No other animal group has it. The epigonal pumps out immune cells much like bone marrow in humans.  When scientists harvest these particular cells, something incredible happens. 

"If we change these compounds from the shark medium environment to a human medium environment and then expose them to human cancer cells, it will kill the human cancer cells," Luer explained. 

Cathy Walsh says making these cells happy in the lab was a giant step in the team's research. "That was a lot of trial and error, a lot of tedious work changing one component at a time. It took about 18 months."

Unlike chemotherapy, their shark mixture doesn't kill all cells in a targeted area. They will kill certain types of human cancer cells very efficiently, but leave the normal cells alone. 

All sharks have an epigonal organ, but this team's work revolves around the bonnethead shark. It continuously gives them the best, most active compounds.

"The good news about that is the bonnethead is the most common shark in our waters. Taking the few that we do during the year for this organ doesn't put any kind of dent into the population," Luer continued.

It's unique research that could one day lead to improved cancer therapies. However, being unique has a downside. "Makes it hard to get funding, because the federal government likes to fund projects that a lot of people are working on," Luer added.  

Therefore, progress is slow. But they are hopeful clinical trials in animals aren’t too far off. Then, pharmaceutical companies would surely take a greater interest. 

Until then, the team continues their journey investigating the ocean's top predator and how it can help humankind.