Sunday, February 10, 2008

Summing Up Stem Cells by Kenneth Aldrich

As I have been traveling around the U.S. talking to editors and financial analysts about our company, International Stem Cell Corporation (“ISCO.OB), I am constantly struck by how much confusion there is about what stem cells are, what the difference is between “adult” and “embryonic” stem cells, and how they can be used in developing ways to treat dreadful diseases. Let me offer some thoughts that may be helpful.

First of all, let me refer you to what I think is the finest explanation of stem clls for the non-scientist I have ever read. It is contained in an article by Dr. Douglas Melton of Harvard University that was recently published in the Bulletin of the American Academy. ( I urge anyone interested in understanding the world of stem cells to download it and read it.

However, there is one thing not covered by the article because it was not widely known at the time. Dr. Melton speaks of the differences between adult stem cells, which are limited in their capacity to become other types of cells, and embryonic stem cells, which can become any cell in the body. Embryonic stem cells are also at the heart of all the current debate about the ethics of stem cell research because they are obtained from fertilized human eggs.

What was not widely known at the time of Dr. Melton’s article is that there is a way of creating stem cells that have the same capacity to be changed into any cell in the body that might be needed for therapy or research, but do not use fertilized eggs. These are stem cells developed by my company, International Stem Cell Corporation, created by a process called Parthenogenesis. The cells are called Parthenotes. At the risk of sounding like a commercial, let me explain why we think these cells are so important.

The first reason is obvious. By avoiding the need to use fertilized eggs, we believe we can put to rest the fears of those who believe that destroying a fertilized embryo is destroying a human life. For reasons that can get quite technical, it is generally agreed that in humans a Parthenote cannot be implanted back into the donor’s womb and grow to be a human being. It is a cluster of cells that can still produce any cell in the body, but lacks a critical element necessary to allow it to attach to the uterus and become a baby.

The second reason is even more important. Any implanting of a cell to treat a disease is like transplanting a miniature organ. If you don’t have a match with the patient’s immune system, the body will reject the cell. It is one of the big problems not yet solved in cell transplant therapy and millions of dollars have been spent trying to find ways to trick the body into not attacking the implanted cell.

We think we have a better way by far. Because Parthenotes contain only the dna of the mother from whose egg they were derived, and not that derived from a father’s sperm, it is possible to create cells from a single stem cell line that can match the immune profile of hundreds of millions of people. That means that instead of having to search through hundreds of thousands of cell lines trying to find one that matches, a very small number of lines might suffice for most of the world’s population.

I’ll have more to say on the subject in a later posting, but this is probably enough for today.

Ken Aldrich
International Stem Cell Corporation