Alzheimer’s disease and cancer are two very different illnesses.
One slowly takes away memory and thinking skills, while the other causes uncontrolled cell growth in the body.
But now, scientists at the MUSC Hollings Cancer Center have found an unexpected connection between the two.
Their study, published in the journal Cancer Research, shows that a protein linked to Alzheimer’s might actually help the immune system become stronger. This discovery could lead to new ways of treating not only cancer but also other conditions related to aging and the immune system.
For years, researchers noticed something unusual: people with Alzheimer’s disease seemed less likely to get cancer. Dr. Besim Ogretmen and his team wanted to understand why.
They worked with epidemiologist Dr. Kalyani Sonawane, who analyzed survey data from older adults. The results were surprising—people over 59 with Alzheimer’s were 21 times less likely to develop cancer than those without the disease.
To explain this strange pattern, the team looked at a protein called amyloid beta. This protein is well known for forming harmful clumps in the brains of people with Alzheimer’s, damaging brain cells.
But the researchers discovered that outside the brain, in immune cells, amyloid beta plays a different role. In immune cells called T-cells, amyloid beta actually makes them stronger and more energetic.
Amyloid beta affects a process in cells called mitophagy, which is how cells remove old or damaged parts called mitochondria. In the brain, stopping this cleanup process causes damage and leads to memory loss.
But in immune cells, less mitophagy means more mitochondria stay in the cells, giving T-cells extra power to fight cancer.
The team took mitochondria from the T-cells of Alzheimer’s patients and transplanted them into older T-cells from people without the disease. These aging T-cells started acting like young, strong cells again. This showed that boosting mitochondria can help bring older immune cells back to life.
The scientists also studied a small molecule called fumarate, which is made in mitochondria. Fumarate helps control mitophagy, acting like a brake to keep the process from going too far.
When fumarate levels drop, cells remove too many mitochondria and lose energy. Giving extra fumarate to aging T-cells helped them keep their mitochondria, boosting their cancer-fighting strength.
These findings help explain why people with Alzheimer’s are less likely to get cancer—and they also suggest new ways to treat diseases.
Instead of directly attacking cancer, future treatments might focus on helping the immune system stay strong. One method is transplanting healthy mitochondria into older immune cells. Another is giving fumarate to protect mitochondria.
These approaches could improve cancer treatments like CAR-T cell therapy and help older people stay healthier. They might even help treat Alzheimer’s by keeping the good effects of amyloid beta while avoiding the damage it causes in the brain.
This research brings together ideas from cancer science, brain science, and aging. Dr. Ogretmen says it was made possible by strong teamwork across different fields. It shows how discoveries in one area of science can lead to breakthroughs in another.
If you care about cancer, please read studies about Researchers find a new cause of cancer and findings of Scientists make a big breakthrough in prostate cancer treatment.
For more about cancer, please read studies about Research finds a new cause of cancer growth and findings of Scientists find the missing link between autoimmune diseases and blood cancer.
The study is published in Cancer Research.
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