Professor researching if snake venom can cure cancer

GREELEY | When Stephen Mackessy opened the door to one of his favorite rooms on the University of Northern Colorado campus, it erupted with a noise like a mix of cicadas buzzing, rain hitting a metal roof and raucous applause after a concert.

It’s enough to make many people nervous, even Mackessy’s graduate students, especially when they see what made the noise.

Mackessy sees it differently.

“They’re just saying hi,” he said, grinning widely and gesturing to a room lined with venomous snakes.

The cages had different colored tags based on their risk. Red means the highest danger, such as the rattlesnake whose venom Mackessy planned to extract.

But for Mackessy, their potential to help humanity far outweighs any risk to his own wellbeing.

Yes, their venom can kill, but Mackessy studies snake venom because he thinks it can do good. In fact, he believes the same venom that can destroy human tissue in less than a day could one day cure cancer.


“I was bitten by a venomous snake and it was radioactive. Now every time the moon comes out .” Mackessy said, trailing off with a grin.

Mackessy’s dry sense of humor helps him shrug off the fact that he puts his life, or perhaps just a limb, at risk, at least a few times a week. But he was bitten, once, when he was in high school, working for a company that imported and exported snakes from all over the world. His job was to take care of the venomous snakes.

“Of which there was a plethora,” he said.

The snake that bit him wasn’t radioactive, but it was poisonous.

He was 15 and it was April Fool’s Day, and he grabbed a baby snake by the tail — “Like you’re not supposed to do,” he said — and it reached around and bit his hand. He escaped without serious damage after a trip to the hospital and with a little more awareness of how careful he should be when handling the snakes.

The incident also did nothing to tamper his interest. In fact, it probably bolstered it. Mackessy graduated from high school knowing that he wanted to study snakes as a biologist.

If he knew then what he’d be doing in the future, Mackessy said he could have collected plenty of venom.

Because he was working with 14-foot king cobras, among other species, he figures it’s probably just as well he didn’t try. The biggest risk for being bitten, especially in the U.S., is if you’re messing with a snake, he said, just like when he grabbed the tail of the snake that bit him.

“Strangely enough, the most common demographic (to receive snake bites) is young white males,” he said, with that same dry sense of humor.

From there, he went on to study biology in college and decided to work with venom in graduate school. That meant taking chemistry, classes he’d avoided up until then. He now knows about as much about the chemical properties of rattlesnake venom as anyone in the world. He’s considered a leading expert on it: Outside Magazine recently contacted him for an article about the gruesome effects of getting bitten by a rattlesnake.

But his indecision prior to becoming a snake expert gave him a good perspective when advising students, he said, because his own journey wasn’t quite what he planned.


Mackessy could talk for hours about the toxins in snake venom and how he and his students study it, but the process basically boils down to three steps: extract snake venom, study the toxins inside it and how the snakes use the venom, and study those toxins’ possible effects on humans and cancer cells.

Almost as sinister as the snakes in that rattling room is the large, liquid-nitrogen container upstairs filled with cancer cells. Those cancer cells, of course, have killed millions more than the snakes.

Mackessy and his students can keep those cells frozen for years, but if they need to study them they can warm them up and they’ll multiply. In a week or so, they grow from a million cells to 10-20 million. Melanoma and brain cancer cells are some of the fastest multiplying, he said. Mackessy would know: He had a bit of skin cancer himself on his back, something that grew from never wearing a shirt outside when he was younger.

In a fridge near the container are vials of snake venom. The venom doesn’t change much, Mackessy said, especially once it’s freeze-dried and put in a fridge.

He has samples he collected 40 years ago, and although they’ve gone through some small changes, they’re still good to study, he said.

That sturdiness is one reason the toxins in snake venom could be useful in medicine.

“A lot of other protein drugs are inherently unstable, but venoms in particular are designed to be stable under bad conditions,” he said.

What excites him the most, however, is the way snake venom has evolved to attack the specific prey in the snakes’ diet, as well as the predators that threaten them.

“These toxins bind very specifically to these particular creatures’ receptors,” he said.

Therefore, the toxins have the potential to be used in a drug that would affect the cancer alone, unlike more conventional methods such as chemotherapy.

Mackessy, his students and a colleague made a specific discovery on that fact this summer when they published an article about two different toxins found in an Amazon puffing snake’s venom. One part immobilizes birds and lizards, and yet another affects mammals. The study made headlines.

What’s cool about the two toxins, something Mackessy said hasn’t been found in any other snake, is it indicates a closer relationship between lizards and birds, even though birds are warm-blooded like mammals.

Venom can not only tell Mackessy about how snakes evolved, but also how their prey and predators have evolved around them.


Information from: The Tribune of Greeley, Co,