Immunology experts in the US and China have discovered human stem cells that "fool" the immune system may provide a vaccination for colon cancer.
The study was led by Dr. Bei Liu and Dr. Zihai Li in collaboration with stem cell expert Dr. Renhe Xu at the University of Connecticut Stem Cell Institute and is to be published in the journal Stem Cells.
The study builds on an old notion that immunizing with embryonic materials might produce anti-tumor responses, but this has only been shown in animal studies.
However, this new groundbreaking study showed for the first time that that human embryonic stem (hES) cells injected into mice produced a consistent immune response against colon cancer cells, opening a new door for cancer vaccine research.
Long before embryonic stem cells were used for genetic and developmental studies, scientists understood that they shared similar properties with cancer cells, especially in the way they form and replicate.
Immune systems recognize antigens like proteins on the surface of tumor cells that can trigger an immune response to make antibodies to fight the tumor.
However, most of the current research on cancer vaccines target these antigens, while this study takes a different approach: what if you used stem cells into fooling the host immune system into thinking there was cancer present and trigger a tumor fighting response that way? That would open a new route to using stem cells to make a universal cell-based vaccine against cancer.
For the study the researchers vaccinated laboratory mice with human embryonic stem (hES) cells and saw a dramatic decline in tumor growth in the immunized mice.
This showed that immunized mice could generate a strong anti-tumour response through the application of hES cells.
The researchers also found that while natural hES cells triggered a strong anti-tumour response, artificially induced pluripotent stem cells (iPSC) did not.
This is a significant discovery because it challenges the idea recently put forward in a number of studies that iPSC have the potential to replace hES cells at the forefront of stem cell research.
Liu said:
"Although we have only tested the protection against colon cancer, 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."
