Every year, 500 to 700 people in the Netherlands are diagnosed with glioblastoma, a form of brain cancer for which we currently have no cure. Glioblastoma is notoriously difficult to treat due to the wide variation in tumor subtypes and immune responses. Traditional treatments often fail because glioblastoma cells are resistant and hard to target.
A team of researchers led by Leila Akkari discovered that macrophages, cells that normally help clear harmful substances from the body, behave differently in glioblastomas. They found a group of macrophages filled with fat particles in animal tissue as well as patient datasets. “In addition to the fact that these macrophages were loaded with lipids, we discovered that they suppress the immune system, which may explain why immunotherapy isn't an effective treatment for this cancer type,” postdoc Johanna Erbani explains.
But how do these macrophages acquire the lipids, Akkari and her colleagues wondered. The brain contains billions of nerve cells protected by a myelin sheath, rich in fats like cholesterol. Macrophages specialize in clearing harmful debris. “What we observe in the lab is that macrophages clear the myelin sheath of dying nerve cells and load up on cholesterol after entering glioblastoma,” PhD candidate Daan Kloosterman explains. “This cholesterol is then transferred to tumor cells that use it to divide more rapidly and grow faster.”
