Immune cells called Natural Killer (NK) cells accumulate in tumors and release chemicals that attract specialized dendritic cells (cDC1) which are white blood cells known for triggering anti-cancer immune responses - to the tumor, according to recent research at the Francis Crick Institute.
These findings could help develop better immunotherapies for cancer.
Genes associated with Natural Killer cells and cDC1 correlated with cancer patient survival in a dataset of over 2,500 patients with skin, breast, neck and lung cancers. A similar correlation was seen in an independent group of breast cancer patients, with a particularly positive outcome for women with triple-negative breast cancer, which typically has a poor prognosis.
The team also showed that prostaglandin E2 (PGE2), a molecule produced by some cancer cells, suppresses Natural Killer cell activity and reduces the responsiveness of cDC1 to the chemical attractants. This suggests that blocking PGE2 with aspirin might help boost the effectiveness of immunotherapies by restoring cDC1 levels in tumors.
"Now that we know a bit better how this key anti-cancer response works, we can look at identifying other ways in which cancers get around it," says Caetano. "This understanding will ultimately help us to develop new immunotherapy approaches to help more patients."
Professor Karen Vousden, Cancer Research UK's chief scientist, said: "This interesting research reveals more about the way the body's immune system interacts with cancer, exposing one way in which cancer can avoid attack.
"Studies like this highlight the complexity of this relationship and may reveal another way in which the immune system can be harnessed to treat cancer. It's vital that work continues to help make immunotherapies more effective and beneficial to more patients."