Genome-edited cancer cells destroy brain tumours in mice

Cancer cells have been trained using CRISPR-based genome editing to find and eradicate deadly glioblastoma brain tumours in mice.

Cancer vaccines using inactive cancer cells or proteins have previously been shown to provoke an anti-cancer immune response. Live cancer cells can track and target tumours within the body, and researchers at Brigham and Women's Hospital in Boston, Massachusetts, took advantage of this, inducing them to attack tumours.

'Our team has pursued a simple idea: to take cancer cells and transform them into cancer killers and vaccines,' said Professor Khalid Shah, who led the study which was published in Science Translational Medicine. 'We are repurposing cancer cells to develop a therapeutic that kills tumour cells and stimulates the immune system to both destroy primary tumours and prevent cancer'.

They used CRISPR/Cas9 genome editing to programme active cancer cells to release both cancer-killing and immune-stimulating agents once they had 'returned' to the site of an existing tumour. The edited cells, known as 'engineered therapeutic tumour cells' (ThTCs) were also edited to contain a double kill-switch as a safety measure so they can be eradicated in case of any problems.

The ThTCs were tested in mice that contained human-derived bone marrow and liver cells, to closely mimic the human immune system. Not only were many of the animals' tumours destroyed, but there was evidence of increased survival rates and long-term immunity against recurrent and metastatic cancer.

The researchers believe their approach could be applicable to many solid tumour types.

'Our goal is to take an innovative but translatable approach so that we can develop a therapeutic, cancer-killing vaccine that ultimately will have a lasting impact in medicine,' said Professor Shah.