Research funds moving from embryonic stemcells to adult alternatives

Research funds are moving fast from embryonic stem cells to adult alternatives.

Harvard Medical School is another center of astonishing progress in adult stem cells. Trials have shown partially restored sight in animals with retinal damage. Clinical trials are expected within five years, using adult stem cells as a treatment to cure blindness caused by macular degeneration - old-age blindness and the commonest cause of sight-loss in America. Within 10 years it is hoped that people will be able to be treated routinely with their own stem cells in a clinic using a two-hour process.

Do stem cells really repair tissue?

For several years there has been a curious and very confusing debate in editorials of publications like the New England Journal of Medicine about whether adult stem cells actually regenerate tissue or not.

The debate centers on technical questions and semantics, rather than the reality of results. Take for example heart repair. We know that bone marrow cells can land up in damaged heart and when present, the heart is repaired. It is hard to be certain what proportion of this remarkable process is due to stimulants released locally by bone marrow cells, or by the bone marrow cells actually differentiating into heart tissue.

It remains a confusing picture, not least because in the lab, cells seem to change character profoundly, but in clinical trials it appears the effects of many stem cells are stimulatory. But who cares? As a clinician I am delighted if injecting your bone marrow cells into your back means that you are walking around 3 months after a terrible injury to your spine instead of being in a wheelchair for the rest of your life. I am not so concerned with exactly how it all works, and nor will you be.

The future of stem cells

In summary, expect rapid progress in adult stem cells and slower, less intense work with embryonic stem cells. Embryonic stem cell technology is already looking rather last-century, along with therapeutic cloning. History will show that by 2020 we were already able to produce a wide range of tissues using adult stem cells, with spectacular progress in tissue building and repair. In some cases these stem cells will be actually incorporated into the new repairs as differentiated cells, in other cases, they will be temporary assistants in local repair processes.

We will also see some exciting new pharmaceutical products in the pipeline, which promise to do some of the same tricks without having to remove a single stem cell from the body. These drugs may for example activate bone marrow cells and encourage them to migrate to parts of the body where repairs are needed…

Kay Clark