Cancer vaccines aren’t a new idea. They use the same fundamentals that enable vaccines for infectious pathogens like viruses and bacteria: priming our immune system into recognizing and attacking something that’s harmful to our bodies. But cancer is a fickle thing—it emerges from the body’s own cells and can be caused by a number of different factors, which means tumors can vary wildly from person to person, and even within the body itself.
So scientists have been trying to hedge their bets around deploying cancer vaccines to stop the most aggressive and lethal kind of cancers first, before perfecting a “universal” cancer vaccine. And they may have just developed one that could stop glioblastoma—a deadly form of brain cancer—in its tracks.
In new findings published in Science Translational Medicine on Jan. 4, Harvard University scientists working at Brigham and Women’s Hospital have developed a new cancer vaccine by genetically engineering brain cancer cells themselves, which not only kills the brain tumor in mice but also prevents the resurgence of cancer later on.
ADVERTISEMENT
The new vaccine takes advantage of a strange quirk among living tumor cells: When they find themselves separated from the main tumor of their fellow cancer cells, these cells will travel even long distances across the brain to reunite with the tumor. So the Harvard team decided to use the gene-editing tool CRISPR to modify these cells into releasing a tumor-killing agent along their journey back home. As they did so, the immune system would become primed to identify and attack cancer cells in the brain.
The team tested out the new vaccine in mice strains that were developed with bone marrow, liver, and thymus cells derived from humans—emulating a human model. The team also made sure to engineer the vaccine with a safety switch that basically kills the repurposed tumor cells in case things went wrong. They found that the vaccine was effective in not only eradicating tumor cells, but also providing a path to ensuring that the immune system was primed to re-engage and prevent new cancer cells from arising once again.
More testing will be needed to really turn this approach into a viable treatment for people battling brain cancer. But the findings are an impressive step forward, for both cancer treatments as well as CRISPR-aided breakthroughs. Should follow-up trials go well, the new vaccine could lay the groundwork for treatments of a wider variety of solid tumors afflicting other parts of the body.
