Cholesterol normally carries a negative connotation, a necessary evil in cells and a major cause of heart disease, creating a billion dollar industry of specialization and pharmaceutical products to combat the problem.
But now scientists are discovering another side of cholesterol, as a possible way to help fight difficult cancers like mesothelioma. It could lead to much-needed novel treatments, particularly for mesothelioma, which has no cure and usually comes with a poor prognosis.
Christopher Beh, an associate professor in the Biochemistry Department at Simon Fraser University in British Columbia, Canada, has specialized in studying cholesterol in his laboratory, hoping to better understand its impact on cell growth and human health.
He and three other scientists concluded recently that cholesterol, when manipulated, can slow or stop the uncontrolled growth of cancer cells.
The study was published recently in the Journal of Biological Chemistry.
According to a news release from Simon Fraser University, the scientists originally were trying to understand how cholesterol moves around inside individual cells and reinforces their outer membranes.
The most recent study uncovered a surprising mechanism in which a specific class of cholesterol-binding proteins (ORPs) determined the direction and shape of cells that were defective in metastasizing cancers.
The researchers discovered that after genetic changes were made to the ORPs, they no longer binded to the cholesterol but continued to function and move around the cells. The altered ORPs also sparked other proteins that led to cell growth.
“First, cancer cells require ORPs to survive,” Beh said. “Second, other scientists have previously shown that a new class of natural components that look like steroids or cholesterol can kill a broad spectrum of different cancer cells.”
Beh said the next step for his team will be to determine exactly which proteins will respond to ORP activation and exactly what circumstances does cholesterol turn off ORP’s activation of them.
“Given that uncontrolled cell growth is a key feature in cancer, this means gaining a better understanding of the true purpose of cholesterol binding within cells, could be important in cancer treatment,” Beh said.
Mesothelioma is relevant to his research because it has been resistant to many traditional therapies that are unable to stop the growth of tumors. Mesothelioma, which is caused almost exclusively from an exposure to asbestos fibers, often is not diagnosed until it already has spread through the thin lining surrounding the lungs or heart.
It is diagnosed in an estimated 3,000 patients annually.