Could Pine Bark Substance Be New Melanoma Treatment?

Researchers at the Penn State College of Medicine believe that a substance derived from pine bark could potentially help treat patients suffering from melanoma. The substance, leelamine, was discovered during a screening of 480 different natural compounds and has since undergone tests at the university on mice.

Many current melanoma treatments target single proteins. While these treatments initially have success, their effectiveness eventually drops as cancer cells mutate, in turn becoming less reliant on the protein that the drug is acting upon. The melanoma cancer cells also use different pathways to avoid the point on which the drug is acting.

Gavin Robertson, professor of pharmacology, pathology, dermatology, and surgery and director of the Penn State Hershey Melanoma Center, described the process, saying, “To a cancer cell, resistance is like a traffic problem in its circuitry. Cancer cells see treatment with a single drug as a road closure and use a detour or other roads to bypass the closure.”

Robertson went on to say that leelamine could be able to create many road closures at once, making it more difficult for melanoma to mutate and avoid the cancer treatment’s effects. Leelamine is unique in that it simultaneously targets several protein pathways at once. These pathways include Pl3K, MAPK, and STAT3. Those pathways are involved in the development and progression of 70 percent of melanomas. “Over 60 percent of anti-cancer agents are derived from plants, animals, marine sources or microorganisms. However, leelamine is unique in the way that it acts,” said Robertson. “The cancer cell is addicted to these pathways. And when they are shut down, the bypass routes cannot be used. The result is the cancer cells die.”

The next step for researchers, who have already tested the drug on mice, is to test it on humans. Leelamine was found to inhibit tumor development in mice. The drug will be licensed to Melanovus Oncology for the next series of experiments.