Towards a personalised vaccine for pancreatic cancer

Researchers from Queen Mary University of London and Zhengzhou University have developed a personalised vaccine system that could prevent pancreatic cancer in high-risk individuals and slow down tumour growth in patients who are affected by it. Their work has been published in the journal Clinical Cancer Research.

Vaccines work by training the immune system to recognise and kill pathogens within the body. To do this, immune cells must recognise molecules on the surface of the pathogens, called antigens. By injecting these antigens as a vaccine, the immune system can safely learn how to recognise them as foreign objects — and remember this should they be found in the body again.

“Development of a preventative vaccine against non-viral cancers is hugely limited by the lack of appropriate tumour antigens and an effective approach to induce robust anti-tumour immunity against those antigens,” said Professor Yaohe Wang from Queen Mary University of London and the Sino-British Research Centre at Zhengzhou University, who led the study. “Through this international collaboration we have made progress towards the development of a prophylactic cancer vaccine against pancreatic cancer.”

To make the vaccine, researchers took cells from mice and turned them into pancreatic cancer cells by adding two errors into their genetic code. These errors, or mutations, are known drivers of pancreatic cancer. The team then infected these cells with viruses, which have an important role in the vaccine system. Not only do the viruses kill the cells to remove their ability to form tumours within the body, they do so in a way that activates the immune system against these cells.

As the cells die following injection into the subject, they release antigens specific to these pancreatic cancer cells, priming the immune system to recognise the initiation of cancer and prevent its development within the body. By injecting these virus-infected cells into mice that were destined to develop pancreatic cancer, the team were able to delay the onset of disease, doubling their survival time when compared with mice who did not receive the vaccine.

Potential for personalisation

The genetic make-up of cancer varies from individual to individual, which means treatments that are effective for one patient’s cancer may not be effective against another’s. Notably, because the cells were derived from the mice that were going to receive the vaccine, the cells created were genetically similar to the cancer that was going to develop in these mice. This suggests that cells could be taken from at-risk individuals and used to create matching tumour cells for use in a vaccine regime tailored to those individuals.

The vaccine also provides an opportunity to combat pancreatic cancer’s extremely low survival rate, with less than 5% of those diagnosed surviving for longer than five years. One reason for this low survival rate is lack of symptoms, explained Dr Louisa Chard Dunmall, meaning diagnosis is often not made until the cancer is at an advanced stage.

“This suggests a window of opportunity for the application of preventative vaccine strategies,” said Dr Chard Dunmall, a senior postdoctoral research fellow at Queen Mary. “Although this research is at the early developmental stages, it provides strong evidence that the creation of a vaccine against pancreatic cancer is possible.”

The team will now look at different ways of improving the regime — including increasing the number of vaccinations or combining the vaccine with other therapies such as immunotherapies.

Image credit: ©stock.adobe.com/au/Csák István

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