Cancer treatment could halt Lyme, UMass study says
Researchers saw similarities
A type of drug used to treat some cancers could be effective in halting the symptoms of tickborne Lyme disease, a bacterial infection that affects nearly half a million Americans each year, according to a new study conducted by researchers at the University of Massachusetts Amherst.
The work grew out of a graduate student’s observation about similarities between Lyme-causing bacteria and cancer cells, and within the next decade could lead to treatments that provide relief to many thousands suffering from the illness, according to Stephen M. Rich, a UMass microbiology professor who is senior author of the new study published in the academic journal Pathogens.
Research based on health insurance records suggests about 476,000 Americans are diagnosed and treated for Lyme disease each year, according to the US Centers for Disease Control and Prevention, though there is no way to be certain how many people contract the illness.
Lyme doesn’t always respond to antibiotics, and in the short term it can cause headaches, fever, chills, fatigue, muscle and joint aches, swollen lymph nodes, and a distinctive bullseye rash that begins at the site of the infectious tick bite and expands to 1 foot or more in diameter, according to the CDC. With time, the headaches, rashes, and neck stiffness can worsen, and infected people can develop painful arthritis, facial palsy, heart palpitations, and inflammation of the brain and spinal cord, the agency said on its website.
Patrick Pearson, who had the “aha” moment that led to the research, was then a doctoral student working in Rich’s lab and now is a postdoctoral researcher at UMass’s New England Center of Excellence in Vector-borne Diseases, where Rich serves as executive director. The CDC provided the center with $10 million in funding last year “to prevent and reduce tick- and mosquito-borne diseases in New England,” UMass officials said.
“He sort of stumbled on this,” Rich said in a phone interview Thursday. Pearson, who coauthored the study, “came up with this idea that if cancer cells function this way, and Lyme disease bacteria function this way, maybe they have similar susceptibilities to chemotherapies.”
Cancer cells and the corkscrew-shaped bacteria that cause Lyme disease both produce energy by breaking down sugar, and both require a protein called lactate dehydrogenase, or LDH, to enable the process. LDH inhibitors are used as drug therapies for certain cancers, robbing cancerous cells of their food supply, and laboratory research found that some LDH inhibitors stopped Lyme bacteria from growing, Rich said.
“We tried multiple types and some worked; some didn’t work,” Rich said. “Some of the ones that worked, there were certain ones that work better than others.”
Researchers will next move on to testing on mice, and could eventually move on to companion animals or human testing if the treatments continue to prove themselves effective, Rich said.
“This doesn’t necessarily kill the cells; it prevents them from growing, which has the same outcome of curing people’s disease, theoretically,” Rich said.
Further experiments will help “make sure that it doesn’t also kill a whole bunch of other beneficial things,” such as gut bacteria in the digestive tract that help regulate the body’s microbiome.
It would take several years and much more testing before LDH inhibitors could be used as a treatment for Lyme disease, if the research ever gets that far. But if additional rounds of testing show positive results, getting the cancer drugs approved for Lyme disease should take less time than it would for a brandnew treatment, Rich said.
“One of the advantages of this approach is that these are drugs that ... are already in use for other things,” he said. “So it’s a little bit shorter path.”