Stem Cells and Huntington’s Research: Where we stand

By Dr. Harold Robertson, Chair, Research Council, Huntington Society of Canada and Shawn Mitchell, Director of Communications

Background

It is exactly one year ago that the Huntington Society of Canada featured an article on the front cover of Horizon (Horizon, #101, Summer 2001) about stem cells and Huntington disease. Written by Dr. Sam Weiss from the University of Calgary, a leading stem cell researcher and a member of the Society’s Research Council, the article talked about the potential role that stem cells could play in the development of a treatment for Huntington disease.

Since that time, the media coverage about stem cells has grown, as has the research effort. Most recently the media has focussed on the regulation of stem cell research. Who is in charge? What role should government play in providing some level of control over the use of stem cells in research? What about the moral, legal and ethical implications of such research?

In the past year the United Kingdom and the United States have both passed legislation to provide rules for stem cell research in their respective countries. Canada is about to do the same thing.

But before a country passes such laws, what are researchers supposed to do? In response to the growing demand in the research community for direction on this point, the Canadian Institutes of Health Research (CIHR) put together a Working Group on Stem Cell Research.

After collaborating with expert researchers, lawyers, ethicists and lay-people, and after public consultation, the Working Group eventually drafted the CIHR Funding Guidelines of Human Pluripotent Stem Cell Research in Canada. These guidelines clarify what kinds of stem cell related research the CIHR will fund, and what it will not fund. While these guidelines do not restrict private research, the pending legislation by the Government of Canada will soon provide controls for research that is privately funded as well.

What are (some of) the issues?

For people in the Huntington’s community, all of this still leaves some important questions unanswered. First, what makes stem cells so controversial? Second, what are the rules about this kind of research (i.e. what do the CIHR guidelines actually say)? Third, are stem cells important to Huntington’s research? And finally, what does the Huntington Society of Canada have to say about all of this?

What makes stem cells so controversial?

Broadly speaking, a stem cell is an undifferentiated cell – meaning that it hasn’t taken on an identity in the body yet, like being a skin cell, or a brain cell – that can renew itself and, with some limitations, become a more specialized type of cell.

But there are different types of stem cells, and different ways to get them, and this is where the controversy starts.

An embryonic stem cell is a stem cell that is taken from an embryo after the embryo is four or five days old. In Canada, the main source for such embryos are in vitro fertilization clinics. In such clinics, embryos which are grown from fertilized eggs are not all implanted as part of the reproductive process. These “extra” embryos can be donated to laboratories for research purposes.

These embryonic stem cells are called pluripotent because they can grow into any of the body’s hundreds of different cell types. Because these cells have the potential to become just about any cell in the body, they are seen as being the most important to stem cell research efforts. They are also controversial for some people because they are taken from unused human embryos.

There are also adult stem cells. These are stem cells that can be found in different places in the human body, and are consequently less contentious. Because they are older cells than embryonic stem cells, and because they are found in specific parts of the body, these stem cells cannot become just any cell. Typically, they can become any specialized cell type associated with the tissue where they are found.

For example, there are adult stem cells in the human brain. These adult stem cells cannot become skin cells, but they can become specific cells in the brain. Recently there was a story in the news about a private laboratory in the United States that claimed to have successfully stimulated adult stem cells in the brain of a patient with Parkinson disease to replace specific cells damaged by the disease.

When you read or hear about stem cells, people don’t often make the distinction between the different types of stem cells. But this distinction is important. It is the type of stem cell, and where it is obtained from, that makes embryonic stem cells – not all stem cells – controversial.

The other thing that makes stem cell research controversial is cloning. Ever since Dolly the sheep was created through cloning, the news is full of stories about the possibility of cloning a human being. There are two types of cloning (it’s kind of like creating a genetic photocopy): cloning an embryo to create a new source of stem cells – this is known as therapeutic cloning; and cloning to produce an embryo from a single parent for implantation into a uterus to produce offspring – known as reproductive cloning.

While stem cell research has a great deal of potential, the most promising sources for stem cells are embryos and fetuses, because they are easy to identify, relatively easy to grow, and they are known to be able to become many different types of tissue. The use of stem cells from these two sources raises important legal and ethical concerns for everyone.

What are the rules in Canada on this type of research?

As was previously mentioned, the Government of Canada will have tabled relevant legislation by the time this issue of Horizon goes to print. This legislation, which will probably not become law until Fall 2002, will govern not only stem cell research funded by government (e.g. by the CIHR), but also research that is privately funded. In particular, it will focus on rules and regulations around the use of embryonic and fetal tissue associated with various reproductive technologies.

The CIHR guidelines were produced ahead of the legislation, and were done in consultation with legislators working on the development of the government’s legislation. These guidelines are fairly long and complicated. If you’d like to review them in full, you can obtain them by contacting the CIHR at (613) 941-2672, or by going to the CIHR Web site at www.cihr.ca.

In a nutshell, CIHR will fund stem cell research under the following conditions:

When using pre-existing human embryonic stem cell lines (Meaning: researchers already have stem cells in their labs for research purposes);
When using embryos created for reproductive purposes which are no longer required (Meaning: a couple pursuing in vitro fertilization to have a child need to have many fertilized embryos created, and then implanted, before one finally develops into a pregnancy. A couple can then chose to keep the fertilized embryos that are left over in case they would like to try and have another child later, they can give the embryos to research, or they can have the embryos destroyed);
Where the persons for whom the embryos were created have given free and informed consent for their use in research (Meaning: if a couple wants to give their embryos to research, they must be fully informed of the facts about what that means); and,
When there were no commercial transactions involved in the creation and use of the embryos (Meaning: under no circumstances can money exchange hands regarding the use of the embryos. You cannot buy embryos from a couple; a couple cannot sell their embryos).

Among other things, the CIHR will not fund any research involving either therapeutic or reproductive cloning.

I think I understand all of that. But are stem cells important to Huntington’s research?

In general, there are many aspects of research where using human stem cells, particularly embryonic stem cells, could be beneficial.

The study of human development and the identification of the factors that control cellular specialization. This is particularly relevant to understanding how and why genes turn on and off during the process of human development. In the case of HD, how and why does the Huntington’s gene do what it does, and can we somehow stop it?

The development of alternative and potentially better methods for evaluating drugs. New drugs could be tested on certain human cells in a laboratory first, before being allowed to move on to further testing. In the case of HD, this could save already limited financial resources from being wasted on expensive drug trials for a drug that doesn’t work.

The development of cells and tissues for transplanting to patients who suffer from injuries to non-renewing tissues or who suffer from neurodegenerative diseases such as Huntington disease. In the case of HD, neural cell transplantation could prove to be an effective therapy for treating Huntington’s.

In short, stem cell research could potentially have a significant impact on Huntington’s research, which should give hope to everyone in the Huntington’s community.

OK, so what does the Huntington Society of Canada have to say about stem cell research?

At the April 2002 meeting of the National Board of the Huntington Society of Canada, Board members deliberated for some time about the full range of issues associated with stem cell research, including what the official position of the Huntington Society should be. Based on briefing documents that they reviewed in advance of the meeting, as well as discussions led by Dr. Harold Robertson, Chair of the Society’s Research Council, Board members unanimously decided that the Huntington Society of Canada should have a formal policy outlining its position in support of stem cell research.

The Board recognizes, however, that this policy may require some change in the future once the complete details of the new Canadian legislation are known.

Huntington Society of Canada Policy Statement : Stem Cell Research

One of the primary missions of the Huntington Society of Canada is to find treatments and, ultimately, a cure for Huntington disease. To accomplish this, the Society is committed to supporting the ethical and legal pursuit of research methodologies that have the greatest potential to achieve this mission. Consequently, the Society recognizes the importance of stem cells to the world-wide research effort in Huntington disease.

As a leading advocate and funder of HD research in Canada, the Huntington Society of Canada will only support stem cell research conducted in a manner that is consistent with the funding guidelines developed by the Canadian Institutes for Health Research (CIHR) and Canadian law, and has been approved under a relevant ethical review process.

The Huntington Society of Canada recognizes and is sensitive to the fact that members of the Huntington’s community, as well as other individuals and organizations that support the Huntington’s cause, have differing opinions about the use of stem cells in HD research, whether on religious, moral and/or ethical grounds. The Society respects ALL opinions on this issue.

The Society has always supported the ability of donors to direct their gifts to specific areas or initiatives. In keeping with this philosophy, we respect the right of donors to indicate that their donation is to NOT be used for stem cell related research.

Conclusion

The Huntington Society has a responsibility to ensure that all research options that have the potential to result in a treatment or a cure for HD – subject to Canadian law and research ethical review – are being pursued. Stem cell research is no exception.

The Society – staff and Board – is always open to hearing perspectives from the Huntington’s community on any issue. If you have any questions or concerns about the Society’s new policy regarding stem cells, please do not hesitate to contact us at 1-800-998-7398 or at [email protected].