A new study has revealed that extra amounts of a specific protein helps brain tumors to hide from the immune system's best defense fighters.
Like a stealth fighter jet, the coating means the cells evade detection by the early-warning immune system that should detect and kill them. The stealth approach lets the tumors hide until it's too late for the body to defeat them.
A research team from the University of Michigan Medical School made the discovery that a protein called galectin-1 plays a key role in some of the most dangerous brain tumors, called high grade malignant gliomas.
Researchers found that when they blocked cancer cells from making galectin-1, the tumors were eradicated; they did not grow at all. That's because the "first responders" of the body's immune system called natural killer or NK cells spotted the tumor cells almost immediately and killed them.
But when the tumor cells made their usual amounts of galectin-1, the immune cells couldn't recognize the cancerous cells as dangerous. That meant that the immune system couldn't trigger the body's "second line of defense", called T cells until the tumors had grown too large for the body to beat.
Gliomas, which make up about 80 percent of all malignant brain tumors, include anaplastic oligodendrogliomas, anaplastic astrocytomas, and glioblastoma multiforme. More than 24,000 people in the U.S. are diagnosed with a primary malignant brain tumor each year.
The new discovery opens the door to that kind of approach; however much work would still be needed to be done before the mouse-based research could help human patients.