Dr John Maher (back right) and his lab team
Immunotherapy is a promising new type of cancer treatment where the immune system is directed to seek and attack cancer cells. However, there are risks associated with using immunotherapies, because the immune system can also attack normal non-cancer cells and cause serious side-effects. If we want patients with breast cancer to benefit from this new type of treatment, we need to ensure that immunotherapies are both safe and effective.
The science behind the project
Dr John Maher and his team work on a type of cancer immunotherapy called ‘CAR-T cell’ therapy. This uses a type of immune cell called a T cell, and forces them to make a protein which can recognise specific molecules on the surface of cancer cells.
Dr Maher has developed a CAR-T therapy which is effective against cancer cells that produce HER2, a molecule found on around 20% of breast cancers. However, HER2 is also found on some non-cancer cells, such as heart muscle, which means the T cells may also attack these cells and so could have serious side-effects if used in patients.
In this project, Dr Maher wants to adapt the CAR-T therapy to reduce the risk of serious side-effects. He aims to do this by adding in a safety mechanism which means that the T cells only attack cells which also produce a molecule called MUC1, as well as HER2. MUC1 is found on all breast cancer cells, but crucially is not found on any non-cancer cells accessible by T cells. This new therapy aims to ensure that T cells will only attack cells that produce both molecules – that is, only breast cancer cells.
He will develop the new MUC1 safety mechanism, and then test the new CAR-T cell therapy in breast cancer cells grown in the lab, and then eventually on breast cancer cells in mice.
What difference will this project make?
Dr Maher’s aim is to develop an effective and safe CAR-T cell therapy for breast cancer, which could be taken forward to be tested with breast cancer patients in clinical trials. CAR-T cell therapies have recently been approved for use in different types of blood cancer, and so Dr Maher hopes that this type of treatment will become available for breast cancer patients in the near future, to improve their chances of survival and maintain a good quality of life.