Stem Cells That “Fool” Immune System May Provide Vaccination for Cancer

A study by Health Center immunology experts Bei Liu and Zihai Li is the first to involve human stem cells in vaccinating against colon cancer.

<p>Drs. Bei Liu and Zihai Li discuss lab results. Photo by Chris DeFrancesco</p>
Drs. Bei Liu and Zihai Li discuss lab results. Photo by Chris DeFrancesco

Health Center researchers in collaboration with scientists from China have revealed the potential for human stem cells to provide a vaccination against colon cancer, reports a study published in October in STEM CELLS.

This discovery, led by immunology experts Dr. Bei Liu and Dr. Zihai Li, builds upon a century-old theory that immunizing with embryonic materials may generate an anti-tumor response. However, this theory has never before been advanced beyond the use of animal embryonic materials, and the discovery that human stem cells are able to immunize against colon cancer is both new and unexpected.

“This finding potentially opens up a new paradigm for cancer vaccine research,” says Li. “Cancer and stem cells share many molecular and biological features. By immunizing the host with stem cells, we are able to ‘fool’ the immune system to believe that cancer cells are present and thus to initiate a tumor-combating immune program.”

The research is the first of its kind to involve human stem cells in vaccinating against colon cancer, and represents a collaboration between the laboratories of Li and Dr. Renhe Xu, director of the UConn Stem Cell Institute.

The team vaccinated laboratory mice with human embryonic stem (hES) cells and discovered a consistent immune response against colon cancer cells. The team witnessed dramatic decline in tumor growth within the immunized mice. This revealed that immunized mice could generate a strong anti-tumor response through the application of hES cells.

The team also discovered that while natural embryonic stem cells are able to provide a response, artificially induced pluripotent stem cells (iPSC) are not. This is significant, as it challenges the theory that iPSC are the same as hES cells and suggests that hES cells may replace iPSC cells at the forefront of stem cell research.

“Although we have only tested the protection against colon cancer,” says Liu, “we believe that stem cells might be useful for generating an immune response against a broad spectrum of cancers, thus serving as a universal cancer vaccine.”