Colon and melanoma cancers could soon be treated with a simple vaccine, if research from the University of Michigan lives up to its early promise. Using synthetic nanodiscs, scientists were able to train the immune systems of mice to better target cancerous cells, killing tumors within 10 days and preventing them from reappearing even months after treatment.

The technique works like any other vaccine: a small amount of biomarkers of the target disease are introduced into the body, which the immune system will rally against to build its defenses. In this case, those markers come in the form of tumor neoantigens that were packed onto nanodiscs measuring just 10 nanometers wide and made of high-density lipoproteins.

"We are basically educating the immune system with these nanodiscs so that immune cells can attack cancer cells in a personalized manner," says James Moon, an author of the study.

Tested in mice with existing colon and melanoma tumors, 27 percent of the mice's T cells were found to turn their attention to the cancer cells. In conjunction with their vaccine, the team used "immune checkpoint inhibitors," drugs that target certain proteins like PD-1 in order to keep T cells healthy and fighting. With both systems working together, most of the tumors vanished within 10 days, and when the researchers tried to reintroduce the tumor cells 70 days later, the test subjects' immune systems didn't give them a chance to grow.

"This suggests the immune system 'remembered' the cancer cells for long-term immunity," says Rui Kuai, lead author of the study.

Buoyed by these results, the researchers plan to increase the sample size of their vaccine, and see how it fares in animals larger than mice.

"The holy grail in cancer immunotherapy is to eradicate tumors and prevent future recurrence without systemic toxicity, and our studies have produced very promising results in mice," says Moon.

The research was published in the journal Nature Materials.