AMHERST — Medication used to halt the growth of cancer cells might one day become an effective treatment for Lyme disease, according to a new study led by a University of Massachusetts Amherst team at the New England Regional Center of Vector-Borne Diseases.

“The thing I like about this story is that it started with a student in the lab,” said Stephen Rich, professor of microbiology, executive director of the vector-borne disease center and senior author of the study. “It was a graduate student in my lab that was reading up on the Lyme disease bacteria and how it makes its livelihood.”

Lyme disease, which is spread to humans through the bite of an infected deer tick, is the most common vector-borne disease in the United States. Such illnesses are transmitted to people and animals by blood-feeding arthropods like mosquitos, ticks and fleas.

Lyme disease can present with symptoms such as joint and muscle pain, fatigue, fever, headache and rash, among a host of other effects.

Antibiotics are the main treatment, and according to the Centers for Disease Control and Prevention, most cases treated in the early stages of infection clear up quickly. However, the CDC notes on its Lyme disease FAQ page that “it is not uncommon for patients treated for Lyme disease with a recommended two- to four-week course of antibiotics to have lingering symptoms. … In a small percentage of cases, these symptoms can last for more than six months.”

According to Rich, “The Lyme disease bacteria tend to be stubborn, in some cases, in response to treatment and so it’s always valuable to have more tools in the toolbox … while there are good drugs, there are seemingly some indications that some people, that their infections are not treated with the existing drugs.”

One of Rich’s students, then-Ph.D. candidate Patrick Pearson, was working in the lab when he found that the Lyme disease bacteria, called Borrelia burgdorferi, and most tumor cells both rely solely on glycolysis — the breakdown of glucose by enzymes — for their energy production. And glycolysis depends on an enzyme called lactate dehydrogenase (LDH), which is why many cancer treatments involve the use of LDH inhibitors, a type of drug therapy, to slow the growth of cancer cells. 

“Pat’s simple idea, great idea, clever idea, was maybe those can also limit the growth of Lyme disease bacteria,” said Rich, explaining that they proceeded to set up an experiment with another graduate student, Adam Lynch, to test the hypothesis.

“And lo and behold, they found a couple of those LDH inhibitors work to limit the growth of Lyme disease bacteria in culture,” he said. 

Around 476,000 people are diagnosed with Lyme disease each year in the United States, and that number is growing. Of those cases, according to Columbia University Irving Medical Center, around 5-20% of patients may develop chronic or long-term symptoms after contracting Lyme disease, a phenomenon that has proved a puzzle for doctors and researchers.

As of now, LDH inhibitors have only been tested on Lyme disease-causing bacteria in test tubes.

“The next steps will be to ... try whether it will work in real animals in real situations, so we want to know whether it will work in mice, for example,” Rich said. 

Those next phases of research will continue at the vector-borne disease center at UMass, which received a $10 million award last year from the CDC to prevent and reduce tick and mosquito-borne diseases across New England.

According to the Environmental Protection Agency, the deer ticks that infect people and animals with Lyme disease are most active when temperatures are above 45 degrees Fahrenheit, and areas with at least 85% humidity are most suitable. With warming temperatures due to climate change, ticks have more ideal conditions to survive and populate.

“There are other factors. … The ticks that transmit Lyme disease are highly dependent on white-tailed deer,” Rich said. “There are so many more deer today than there were 10 years ago … that I think that’s what’s driving the spread.”

But if continuing research shows success, the discovery at the vector-borne disease center could be a new tool in the Lyme disease treatment toolbox — and possibly a counter to the riddle of long-term Lyme.

Maddie Fabian can be reached at mfabian@gazettenet.com or on Twitter @MaddieFabian.]]>