UNH awarded patent for cancer treatment

By Robert Emro, CEPS

UNH has been granted a U.S. patent for a new way to kill cancer cells.
Roy Planalp, associate professor of chemistry in the UNH College of Engineering and Physical Sciences, invented the novel chemotherapy in collaboration with researchers at the National Institutes of Health (NIH) and Wake Forest University Health Sciences in Winston-Salem, N.C., which share the patent with UNH.

“This invention is exciting because it has significant potential for cancer therapy,” said Robert Dalton, director of the UNH Office of Intellectual Property Management. “It also has potential for other therapeutic areas as well.”

Planalp and his collaborators, funded by a grant from NIH’s National Cancer Institute, found that they could kill cancer cells by starving them of the essential nutrient iron. The treatment employs molecules called chelators (KEE-late-ors), which bind tightly with metal. The chelators that best bind iron are in the tachpyr family of substances and are shaped like an open, six-fingered claw. They suck iron in and then snap closed, like a spring-loaded trap.

“Iron is like money. It’s an essential nutrient that’s not always available, so cells store iron and release it as needed,” explained Planalp. “What the chelators do is come in and rob the iron bank just as the cell is making a withdrawal, so the cell makes another withdrawal, and if there are more chelators, that gets robbed, too. This continues until the bank is empty and the cell can’t function anymore.”

Encased by the chelator, the iron is no longer available to perform its role in vital jobs like transporting oxygen, and the cancer cell dies. The chelator, still holding tightly to the iron, is quickly removed from the blood by the liver and expelled from the body. Side effects are expected to be negligible as iron chelators are already used to treat people with too much iron in their blood.

Planalp stumbled on the cancer-fighting potential of chelators while experimenting with using them as diagnostic agents. While testing a chelator bound to gallium, a metal that shows up well in CAT scans, he found it discarded the gallium in favor of the iron needed by cells, causing them to die. “We didn’t expect this,” said Planalp, “so we decided to pursue it.”

Animal testing at the NIH showed that iron chelators are effective at killing several kinds of cancer cells and they are quickly removed by the liver – too quickly, in fact. Planalp and his collaborators are currently investigating ways to either keep iron chelators in the body longer or speed them up so they can finish the job before they are removed.
Chelators tailored to bind to toxic metals, such as mercury, chromium or lead, may have other therapeutic applications. “It’s all about selectivity,” said Planalp. “There’s a whole set of challenges out there for detoxification.”

Awarded in July, the patent is now being marketed by Wake Forest to companies which can turn the idea into a marketable product. Like existing chemotherapy drugs, iron chelators will most likely be used in a chemical “cocktail” containing other chemotherapy agents.