Stem cell vaccine for cancer step nearer

The medical holy grail of an anti-cancer jab has moved a step closer after scientists developed a potential vaccine made from stem cells.

By Richard Alleyne, Science Correspondent
Published: 7:30AM BST 08 Oct 2009

Anti-cancer jab a step closer Photo: REUTERS

Researchers have engineered stem cells to mimic some characteristics of cancer that when injected trick the body into building up a natural immunity to the disease.

The work focuses on colon cancer but the scientists believe it could be widened to provide a "universal cancer vaccine".

The novel approach by scientists in America and China is based on the principle that stem cells and cancer cells share many characteristics.

The theory is similar to a normal vaccine which mimics the disease it is vaccinating against and so builds up natural immunity.

Then when the patient is exposed to, or in danger of developing, the actual disease the body is ready to fight back.

Dr Zihai Li, of the University of Connecticut Stem Cell Institute, said the findings opened up a whole new model approach to cancer research.

"Cancer and stem cells share many molecular and biological features", he said.

"By immunising 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 tumour-combating immune programme.

The immunologist's colleague Dr Bei Liu, added: "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."

The latest research is the first to use human stem cells to vaccinate against cancer.

The team witnessed a 'dramatic' decline in tumour growth within the immunised mice.

The findings published in the journal Stem Cell, come just two months after scientists found a link between bacteria and many cases of colon cancer.

The breakthrough also pointed the way to vaccines or drugs to fight the disease, one of the most common forms of cancer in Britain. More than 37,000 people are diagnosed with colon cancer every year in Britain

Researchers at Johns Hopkins University in Baltimore believed that they have uncovered how the bacteria could be a trigger for cancer.

Dr Julie Sharp, Cancer Research UK's science information manager, said: "This is an interesting study and suggests a new approach to cancer vaccines – however scientists will need to test these ideas in clinical studies before we know if this approach can be used to treat cancer patients."

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Stem cells which 'fool immune system' may provide vaccination for cancer

October 8th, 2009

Scientists from the United States and China have revealed the potential for human stem cells to provide a vaccination against colon cancer, reports a study published in Stem Cells.

This discovery, led by experts in immunology, Dr. Bei Liu and Dr. Zihai Li, builds upon a century old theory that immunizing with embryonic materials may generate an anti-tumour response. However, this theory has never before been advanced beyond animal research so 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," said Dr. Zihai 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 implicate the role of human stem cells in vaccinating against colon cancer, and represents collaboration between the prestigious laboratories of Dr. Zihai Li and stem cell expert Dr. Renhe Xu at the University of Connecticut 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-tumour 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 may replace them at the forefront of stem cell research.

"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." " concluded Dr. Bei Liu.

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