Cancer vaccine ‘can train immune system to stop tumours’

Health: Scientists make breakthrough with stem cell discovery

An anti-cancer vaccine could soon be developed after scientists discovered a certain type of stem cell could train the immune system to attack the growth of tumours.

Cells which can be manoeuvred into different types of tissue in the body, known as induced pluripotent stem cells (IPS), could in the future be injected into humans to prevent the development of cancers in patients potentially years after vaccination.

Researchers from Stanford University School of Medicine found that injecting IPS cells that genetically match the patient could prepare the immune system to target different types of cancer as they develop inside the body.

The stem cells, which are developmentally immature, were found to build an immune response against the disease in mice because they contain “remarkable” similarities to cancer cells.

They are made using cell samples from skin or blood, which are reprogrammed to mimic embryonic stem cells – meaning they can develop into any type of cell in the body.

In a study, scientists tested the IPS cells on four groups of mice with artificially induced breast cancer, injecting them once a week for four weeks.

One group was injected with a control solution, one was given a vaccine with genetically matching IPS cells, another received an injection containing adjuvant – an immune-stimulating agent, and another group was given a combination of IPS cells and adjuvant.

Within four weeks, breast cancer tumours were rejected by 70% of the injected mice, while 30% had significantly smaller tumours.

Two of the mice were able to completely reject the cancerous cells and live for more than a year after the injection. Researchers obtained similar results when they transplanted lung cancer cells into mice.

Dr Joseph Wu, director of Stanford’s Cardiovascular Institute, said: “We’ve learned that IPS cells are very similar on their surface to tumour cells.

“When we immunised an animal with genetically matching IPS cells, the immune system could be primed to reject the development of tumours in the future.

“Pending replication in humans, our findings indicate these cells may one day serve as a true patient-specific cancer vaccine.”

Researchers are next looking to test the vaccine in samples of human cancers.

“Pending replication in humans, our findings indicate these cells may one day serve as a true patientspecific cancer vaccine. DR JOSEPH WU