Cancer-Linked Mutations Found in Alzheimer's Brains

Mutations typically associated with blood cancers may contribute to Alzheimer's disease. This finding comes from a study conducted by researchers at Boston Children's Hospital. The study suggests a new target for diagnosing and treating Alzheimer's disease.

Microglia are immune cells located in the brain. These cells accumulate mutations in specific cancer-driving genes. These mutations do not cause cancer in the brain. Instead, they may play a role in the development of Alzheimer's disease.

Researchers analyzed brain tissue from 190 individuals with Alzheimer's disease. They compared these samples to 121 healthy brain samples. The Alzheimer's samples showed more single-letter DNA changes. Many of these changes appeared in the same five cancer driver genes.

These mutations were also found in blood samples from the same Alzheimer's patients. This suggests that immune cells with cancer mutations may enter the brain. These cells could then contribute to the disease. The researchers propose that a weakened blood-brain barrier may allow these immune cells to cross into the brain. Once there, they may transform into microglia-like cells.

Protein clumps in the brain can cause microglia to multiply. Cells with a biological advantage, such as those with cancer-related mutations, are more likely to expand. These mutated cells may create an inflammatory environment. This environment can harm neurons and contribute to Alzheimer's disease progression.

This discovery could lead to new methods for detecting Alzheimer's risk. Blood tests could screen for these mutations. This could identify individuals with an increased risk of developing the disease. A follow-up study indicated these cancer driver mutations increase Alzheimer's risk independently of the APOE4 gene, a known risk factor.