Building a prostate cancer vaccine

Prostate Cancer UK previously funded a PhD studentship in Professor McCarthy’s lab. During the course of that research, the scientists designed and tested various parts of a prostate cancer vaccine that would stimulate the body’s own immune system to fight the cancer.

They discovered that a type of genetic material from the tumour called mRNA (whose job is to ‘read’ the DNA code to work out which genes will be turned on in any particular time and place) is more effective at stimulating an immune response than tumour DNA. However, mRNA is very unstable and breaks down very quickly. So the researchers found a way to wrap the mRNA inside a tiny protein package to keep it safe while it was delivered to the immune cells. The protein package also helps the mRNA to get inside the cell when it’s delivered through the skin.

A second part of the PhD project was to design and manufacture a method of delivering the mRNA package into the immune cells. They have done this by creating a microneedle patch. This is a small skin patch that contains tiny dissolving needles with the mRNA package inside. When the patch is applied, the needles release the vaccine package underneath the skin, where lots of immune cells are located.

Now, it’s time for the researchers to put all the parts of this system together, and test not only how well they can deliver their vaccine to immune cells, but what effect this has on the prostate cancer.

They will do this first by creating different versions of the tumour mRNA package and placing them inside the needles on the patch. They will then test that the patches, with the mRNA packages inside work as they expect; that the mRNA is released and doesn’t get broken down before it can get into the immune cells. They will then examine which immune cells and organs are targeted by the vaccine packages, and measure how strong the immune reaction is to each version of the mRNA package so they can tell which works best.

Once they know which version works best, they will test this on mice to see if it can shrink prostate tumours. They will also test it on healthy mice before trying to induce a prostate tumour to see whether the vaccine has a protective effect.

By the end of this study, the researchers hope to have enough evidence to apply for funding for a phase I clinical trial. They anticipate that their vaccine will have very low toxicity and need not replace existing treatments. Rather, they anticipate that it could be used alongside current therapies. They’d also like to test it in men who have already had primary therapy to see if it can help prevent cancer recurrence.

Grant information

Reference - RIA16-ST2-001
Researcher - Dr Helen McCarthy
Institution – Queen's University Belfast
Award - £275,992.00