It is rare to see people with cancer and Alzheimer’s disease at the same time. Now, scientists believe they may have discovered the reason, by identifying a molecule in cancer cells that eliminates problematic proteins from the brain.
After 15 years of research, scientists at the University of Toronto discovered a specific molecule present in cancer cells which can degrade misfolded proteins in the brain, allowing them to be eliminated instead of accumulating.
In the disease of Alzheimerthe accumulation of misfolded beta-amyloid plaques and tau tangles destroys brain cells and leads to cognitive decline.
Although the discovery was made using an animal model in mice, it is the closest we have ever come to understanding the strange link between two of our most devastating diseases.
While it may seem counterproductive that one can actually protect us from the development of the other, there is growing evidence that this is the case. To the point that scientists have discovered that some cancer treatments have shown positive results in slowing cognitive decline.
The secret may be in cystatin C
In the new study, last week at Cellresearchers discovered that some cancers release a protein called cistatina C (Cyst-C)which travels through the body and helps the brain eliminate toxic clumps of amyloid — the sticky build-up of proteins associated with Alzheimer’s disease.
As explained by , Cyst-C binds to these small harmful amyloid clumps and activates the brain’s immune cells — the microglia — recruiting them to help degrade the plaques.
When the researchers disabled the Cyst-C pathway, this apparently protective effect disappeared. This was enough to convince them that the interaction between cancer protein and the immune system is essential for eliminating plaques and, consequently, for reducing the risk of developing Alzheimer’s.
Although many scientists have believed for some time that there is a mysterious relationship between this disease and cancer, the pathology of the diseases has made it difficult to understand. Although cancer patients generally have a reduced incidence of Alzheimer’s, there are many factors at play — including the fact that individuals may die well before the age at which the disease associated with aging would be expected.
The study focused on three types of human tumors: lung, prostate and colon.
