Researchers at the Massachusetts Institute of Technology, MIT, have discovered a new way to jump-start the immune system to attack tumours, which could allow cancer immunotherapy to be used against more types of cancer.
Immunotherapy is a promising strategy to treat cancer by stimulating the body’s own immune system to destroy tumor cells, but it only works for a handful of cancers. MIT researchers have now discovered a new way to jump-start the immune system to attack tumours, which they hope could allow immunotherapy to be used against more types of cancer.
Their novel approach involves removing tumour cells from the body, treating them with chemotherapy drugs, and then placing them back in the tumour. When delivered along with drugs that activate T cells, these injured cancer cells appear to act as a distress signal that spurs the T cells into action.
“When you create cells that have DNA damage but are not killed, under certain conditions those live, injured cells can send a signal that awakens the immune system,” says Michael Yaffe, a David H. Koch Professor of Science, the director of the MIT Centre for Precision Cancer Medicine, and a member of MIT’s Koch Institute for Integrative Cancer Research.
One class of drugs currently used for cancer immunotherapy is checkpoint blockade inhibitors, which take the brakes off of T cells that have become “exhausted” and unable to attack tumours. These drugs have shown success in treating a few types of cancer but do not work against many others.
Yaffe and his colleagues set out to try to improve the performance of these drugs by combining them with cytotoxic chemotherapy drugs, in hopes that the chemotherapy could help stimulate the immune system to kill tumour cells.
This approach is based on a phenomenon known as immunogenic cell death, in which dead or dying tumour cells send signals that attract the immune system’s attention.
Several clinical trials combining chemotherapy and immunotherapy drugs are underway, but little is known so far about the best way to combine these two types of treatment.
The drugs that appear to work best with this approach are drugs that cause DNA damage. The researchers found that when DNA damage occurs in tumour cells, it activates cellular pathways that respond to stress. These pathways send out distress signals that provoke T cells to leap into action and destroy not only those injured cells but any tumour cells nearby.
Culled from Vanguard