Orange lichens are source for potential anticancer drug
An orange pigment found in lichens and rhubarb called parietin may have potential as an anti-cancer drug, scientists at Winship Cancer Institute of Emory University have discovered. The results were published in Nature Cell Biology on October 19.
Parietin, also known as physcion, could slow the growth of and kill human leukemia cells obtained directly from patients, without obvious toxicity to human blood cells, the authors report. The pigment could also inhibit the growth of human cancer cell lines, derived from lung and head and neck tumors, when grafted into mice.
A team of researchers led by Jing Chen, PhD, discovered the properties of parietin because they were looking for inhibitors for the metabolic enzyme 6PGD (6-phosphogluconate dehydrogenase). 6PGD is part of the pentose phosphate pathway, which supplies cellular building blocks for rapid growth. Researchers have already found 6PGD enzyme activity increased in several types of cancer cells.
This work represents a collaboration among three laboratories at Winship led by Chen, Sumin Kang, PhD, assistant professor of hematology and medical oncology, and Jun Fan, PhD, assistant professor of radiation oncology. Co-first authors are postdoctoral fellows Ruiting Lin, PhD, and Changliang Shan, PhD, and former graduate student Shannon Elf, PhD, now at Harvard. Both Drs. Chen and Kang are faculty members in the CB and MSP programs.