Cancer cells are prone to disguising themselves from the immune system to avoid detection. However, a new system can pinpoint cancer cells to allow the immune system to eliminate the tumour.

Immunotherapy is a cancer treatment that harnesses the body’s immune system to fight cancer cells. Although immunotherapies have completely transformed the cancer treatment landscape, they still have some considerable limitations. Some patients do not see any benefit from immunotherapy, as their immune systems are unable to recognise all of the molecular ‘disguises’ cancer cells employ to avoid detection by the immune system.

A new system, known as developed Multiplexed Activation of Endogenous Genes as an Immunotherapy (MAEGI), has been developed to solve this problem. The CRISPR activation technique was used to increase the expression levels of genes specific to tumour cells. The tumour cells then expressed higher levels of antigens on their cell surface, enabling the immune system to immediately recognise them as cancer cells.

The lead author Sidi Chen said ‘[MAGEI] is the molecular equivalent of dressing tumour cells in orange jump suits, allowing the immune system police to quickly find and eradicate the deadly cells.’

MAGEI was trialled in mice with healthy immune systems and transplanted cancer cells. It was able to eliminate the tumours in 84% of cases, whilst the remaining mice grew small tumours. MAGEI was able to reduce or eliminate melanoma, triple-negative breast and pancreatic tumours in the mice, even those located far from the primary tumour.

It is hoped MAGEI will be able to help patients who are currently resistant to immunotherapy, and the researchers now look to develop the treatment for clinical trials.