Media Distortion of Stem Cell Research?

One of the biggest victories for Democrats in 2006 was the defeat of Missouri's incumbent Republican Senator Talent by Claire McCaskill. Talent's opposition to life-saving stem cell research was considered a major factor in his defeat.

Now, as Democrats in Congress flex their muscles in the wake of their massive 2006 victories, stem cell research is one of their top priorities. Tomorrow is likely to be the vote on stem cell research.

First, a brief review of stem cells. "Stem cell" refers to any cell that can both regenerate itself and differentiate in to other kinds of cells. It is this combined ability to produce more stem cells and differentiated cells that is the defining characteristic of stem cells. I happen to work on a kind of stem cell in the reproductive system of a model organism called C. elegans. There are, in humans, bone marrow stem cells that make our blood cells, intestinal stem cells that replenish the lining of our intestine, etc. These stem cells have only a limited range of potential cells they can differentiate into. These are often called multipotent or unipotent depending on the range of cells that can be formed.

Pluripotent stem cells can differentiate, under the right conditions, into pretty much any kind of cell in the body. That is clearly the holy grail of stem cell research because using these cells you can pretty much make anything if you know the right signals to provide.

The ultimate pluripotent stem cell is the fertilized egg after conception. But the early cell divisions of the fertilized egg produce further pluripotent cells that themselves can become a complete embryo. This is what happens with identical twins: a very early embryo splits in two and each partial embryo becomes a whole embryo. So powerful are these early stem cells that they are often called "totipotent." Medical science can make use of either pluripotent or multi/unipotent stem cells for treating a variety of diseases. But the goal is to find the most flexible of stem cells so that you have the most control over what cells you can make and how they develop. Bone marrow transplantation works because inside the bone marrow are multipotent stem cells that can make any kind of blood cell. But it isn't very flexible. You can't make other kinds of cells and the kinds of manipulations you can make are limited. Furthermore, that bone marrow has a history and that history can lead to some of the worst complications of bone marrow transplantation: a graft vs. host response where the transplanted cells attack the new host's body.

Pluripotent stem cells can be used for almost anything. And the biggest source of these cells are human embryos, mostly those that are left over from in vitro fertilization used for couples who are having trouble conceiving. These embryos will never be implanted and hence never become a child. But they CAN save lives. Use of pluripotent stem cells from such left over embryos can help treat nerve injuries including spinal cord injuries, Parkinson's disease and potentially Alzheimer's, Muscular Dystrophy, etc. The potential for medical treatment is HUGE.

Now let's consider amniocentesis. This is a clinical test where cells of the fetus can be recovered from the amniotic fluid and their chromosomes studied for gross chromosomal abnormalities. Other more subtle genetic defects can be screened for as well. The key here is that actual fetal cells can be recovered because the amniotic membrane forms from accessory cells that result from the same fertilized egg that forms the fetus.

Recently there has been an announcement in the media that pluripotent stem cells have just now been recovered from amniotic fluid. This is being heralded as a breakthrough that will make the use of embryonic stem cells unnecessary and it comes right before the vote in Congress.

There are major problems with all this and there is a diary on Daily Kos calling the whole thing into question.

First of all, this is not a new discovery. Earlier research, published in 2003, had already claimed that amniotic cells have markers similar to those on stem cells. So why this sudden breakthrough? Many question the timing of this media frenzy just before a vote. However, unlike some, I see no reason to question the ethics or credentials of the person who has made the more recent claim of discovering stem cell potential in amniotic cells. I think the media is distorting the whole thing because of the Congressional vote. I currently have no reason to think the researcher, Dr. Atala, distorted anything and from what I can tell he is a reasonable researcher. Personally, as I look at his publication record on Medline, I am not impressed with the journals he publishes in. None are top ranked places for publishing research. But I am not qualified to judge these publications in terms of their quality as places for clinical research. But generally, the kinds of journals he publishes in are not the best, but may well be appropriate for someone in his specialty. I can use examples from my own publication record, like the Journal of Leukocyte Biology, the first journal I ever published in. Not an impressive GENERAL journal, but not bad within a particular specialty. Infection and Immunity and Blood are other examples of journals that may be under rated by non-specialists. On the other hand, other specialist journals are non-peer reviewed and I know of at least one that publishes junk articles.

One good sign that the researcher is perfectly respectable is that he was tapped by the Annual Review of Biomedical Engineering to write a review article. I am not familiar with this particular journal, but in general the "Annual Review" series is good and taps respectable researchers.

So I am not questioning the researcher unless someone gives me a reason to do so.

I do question the use the media is putting Dr. Atala's discovery for just before a critical vote. Here's why:

1. Amniotic cells come from a more advanced stage of development than the embryos used to derive pluripotent stem cells. This means that it is LIKELY (though not certain) that they will not be usable for as wide a range of purposes as the embryo-derived cells. More research is needed BEFORE we know how flexible the amniotic stem cells are.

2. This research has just been released. Although earlier discoveries have been made pointing the way, there is no current evidence that the amniotic cells will be usable for stem cell research in general. Science doesn't move quickly but requires replication of results. This hasn't happened yet. More research is needed before we can be sure Dr. Atala's discovery is sound. Let's not forget the "cold fusion" fiasco when rushed science led to mistakes.

3. The embryos used for deriving stem cells are not used for any other purpose. They are often either left in a freezer or are disposed of as biohazardous waste. What no one is considering about Dr. Atala's discovery is that it requires sticking a needle into a pregnant woman's belly. There are complications with this procedure that can lead to the loss of the fetus or to infection. This is not as rich a source of stem cells as an embryo. It is far less likely to yield an abundant source of stem cells and a woman's belly has to be jabbed each time you want to isolate cells. This adds many complications to the use of the cells and more layers of regulation and informed consent. This means that AT BEST I see this discovery as giving us another source of stem cells, but not a primary source.

Taken together this means that this new discovery, though potentially huge, should in no way affect the vote on Thursday. Maybe a few years from now amniotic stem cells can begin replacing stem cells derived from frozen embryos, but I doubt it. The probability of less flexibility in the cells and the complications with gathering them are likely to limit, though by no means negate, the impact of this discovery. We are very likely going to continue to need embryo-derived stem cells for research and treatment for a long time to come if we want to help people with Parkinson's, Alzheimer's, spinal cord injuries, etc.

Please call Congress TODAY and ask your Congress Critters to SUPPORT LIFE SAVING STEM CELL RESEARCH. You can also write the media expressing your support of stem cell research and you can also participate in a more focused lobbying campaign for stem cell research described here.

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