Cancer ‘vaccine’ could help immunise people against breast, lung and skin cancer
A staggering 360,000 people in the UK are diagnosed with cancer every year.
While most scientists are working on finding a cure for the life-changing disease, scientists from Stanford University may have just taken the first steps to developing a preventative cancer vaccine that could prevent tumours from developing altogether.
Publishing their findings in Cell Stem Cell, researchers from Stanford’s Cardiovascular Institute and Institute for Stem Cell Biology and Regenerative Medicine injected mice with “inactivated induced pluripotent stem cells”, or iPS cells.
Astonishingly, researchers were able to seemingly immunise mice from developing cancer and tumour cells, while other animals tested saw significant decreases in the sizes of tumours.
What are stem cells and iPS cells?
There are two kinds of stem cells. Embryonic stem cells are unspecialised cells that can turn into almost any type of cell in the body because they are what’s known as “pluripotent”.
They are harvested when the embryo is only a few days old. Adult stem cells are much more limited as they can only differentiate into the origin cell group. For example, if the adult stem cell was taken from a bone marrow, it would only be able to grow into a cell of the same type.
However, iPS cells are cells that have been genetically reprogrammed from adult cells to mimic the structure and effects of embryonic cells. This makes them as pluripotent as the embryonic cells, without the ethical drawbacks.
How iPS cells could work to vaccinate against cancer
Kooreman and Kim et al./Cell Stem Cell
iPS cells are produced by collecting cell samples from skin or blood which are then forced to developmentally return to their original state, something that’s achieved through a treatment of genes. This gives the cells their pluripotency, allowing them to turn into nearly any cell in the body.
These cells take on the same genetic quality of cancer cells – that’s to say, they’re developmentally immature, progenitor cells that are still able to grow. The researchers hypothesised that the injection of iPS cells, which lack the ability to replicate, should be able to effectively introduce a variety of cancers into the immune system. While cancer cells multiply rapidly to create tumours, iPS cells remove this mechanic from occurring.
To be effective as a cancer treatment, the iPS cell antigens need to be introduced into the body, so that they can bind to cancer cells if they ever develop. This means that they can produce antibodies.
How iPS cells were used in the study
In the study, scientists injected four groups of mice with differing solutions.
The first group was injected with a control solution; the second received irradiated iPS cells that had been engineered to prevent the formation of teratomas (tumours which develop from a group of tissues); the third, an adjuvant, a solution that enhances the body’s response to an antigen; and the fourth a combination of both the iPS cells and the adjuvant.
Just one week later, all of the mice had developed breast cancer. While the researchers observed how the control group’s tumours continued to grow, the opposite was observed for all the other three groups.
In the fourth group, seven out of ten of the tumours had begun to shrink and two of these vaccinated mice were able to reject the breast cancer cells altogether.
Within four weeks, an incredible 70% of the vaccinated mice had completely rejected the introduced breast cancer cells. While the remaining 30% had significantly smaller tumours.
“When we immunise an animal with genetically matching iPS cells, the immune system could be primed to reject the development of tumours in the future,” says senior author of the study, Joseph Wu. “Pending replication in humans, our findings indicate these cells may one day serve as a true patient-specific cancer vaccine.”
While the study was only tested on the three most common cancers (breast cancer, lung cancer and skin cancer), Wu tells Alphr that the vaccine should be able to target other kinds of cancers too.
“We have only tested the vaccine on these three cancer types, but we think it can be used for a larger number of cancers. This is based on the large number of cancer-related proteins that are present on IPS cells, as well as cancer cells,” he says.
Even more promising is that a cancer vaccine using iPS cells for humans could actually be possible in the near future. A patient’s blood or skin cells, for example, could be reprogrammed into iPS cells and then administered as an anti-cancer vaccine. It could also be used as a follow-up booster after chemotherapy or radiation therapy, designed to stop cancer from returning.
“We feel that this has great potential as a cancer vaccine. For example, patients could be vaccinated at a certain age (70 years old) to boost their immune system to target possible cancerous cells and limit the cancer from growing out,” Wu explains to Alphr. “We are setting up and performing in vitro experiments to validate the efficacy and safety of the vaccine on human samples. Based on these results, we will decide which cancers we should start with first, and then we can start thinking about clinical trials.”
While some people are wary of inactivated induced pluripotent stem cells, due to the supposed risk that they could mutate and turn into tumours themselves, studies have shot this theory down.
A study conducted in 2015, for example, found that the differences between iPS cells and parent cells were very small, with any mutations unlikely to be harmful or dangerous to the human body.