Researchers have recently identified a mechanism that causes natural killer immune cells to show mercy to cancer.
Natural Killer cells are specialized white blood cells that act as the immune system’s assassins. Their job is to locate and eradicate “deviant” cells in the body that may pose a threat.
The ability to switch it off had a dramatic effect on mice with normally lethal skin, prostate and breast cancers.
Natural killer cell action against the tumor was stepped up and prevented deadly metastasis. Deadly metastasis is the spread of cancer to vital organs in the body.
In breast cancer, tumor growth in the mammary glands was significantly reduced.
Researchers are hopeful that this research will lead to new immunotherapies that supercharge the body’s natural killer cell and maintain it in a highly active state to more efficiently and specifically fight cancer.
Some of the cells targeted are infected while others show signs of becoming cancerous. Once a deviant cell is identified, the natural killer cell releases a chemical called perforin that blasts holes in its outer membrane. Other molecules fired through the holes cause the cell to fall apart or self-destruct.
The immune system also possesses a complex system of checkpoints that in certain situations tone down its responses to prevent accidental damage to healthy tissue.
Researchers found that a particular checkpoint pathway had the effect of taming natural killer cells.
An inhibitor protein made inside the cells limited their ability to respond to an activating signal that issues the “command” to kill cancer.
Once researcher silenced the protein’s gene, they were able to enhance the ability of natural killer cells to protect mice against melanoma skin cancer, prostate cancer and breast cancer.
Immunotherapy is a hot topic in cancer research.