Stem Cells = Tumor?

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A very disquieting news report that should really bother those who are strong proponents of embryonic stem cell research. It is very preliminary, but it is also very frightening.

Steven Goldman and colleagues at the University of Rochester Medical Center in New York said human stem cells injected into rat brains turned into cells that looked like early tumors.

Writing in the journal Nature Medicine, the researchers said the transplants clearly helped the rats, but some of the cells started growing in a way that could eventually lead to a tumor.

Various types of cell transplants are being tried to treat Parkinson's disease, caused when dopamine-releasing cells die in the brain.

This key neurotransmitter, or message-carrying chemical, is involved in movement and Parkinson's patients suffer muscle dysfunction that can often lead to paralysis. Drugs can slow the process for a while but there is no cure.

The idea behind brain cell transplants is to replace the dead cells. Stem cells are considered particularly promising as they can be directed to form the precise desired tissue and do not trigger an immune response.

Goldman's team used human embryonic stem cells. Taken from days-old embryos, these cells can form any kind of cell in the body. This batch had been cultured in substances aimed at making them become brain cells.

Previous groups have tried to coax stem cells into becoming dopamine-releasing cells.

Goldman's team apparently succeeded and transplanted them into the rats with an equivalent of Parkinson's damage. The animals did get better.

But the grafted cells started to show areas that no longer consisted of dopamine-releasing neurons, but of dividing cells that had the potential to give rise to tumors.

The researchers killed the rats and are very worried about the outcome they saw. This one ought to give a lot of people pause. There is a lot that is not at all understood here. It is really unfortunate that there is a political debate about science that appears to be not quite ready for prime time.

UPDATE: Additional coverage in the Washington Post this morning:

"The behavioral data validate the utility of the approach. But it also raises a cautionary flag and says we are not ready for prime time yet," said lead researcher Steven A. Goldman, a professor of neurology and neurosurgery at the University of Rochester Medical Center.

Goldman said he suspected that with modest changes in technique, researchers will be able to keep the benefits of the treatment while eliminating or reducing the chances of getting the cancerlike growths. But he conceded that much more basic research would have to be done before scientists — or regulators — were likely to be convinced of the approach's safety.

UPDATE: The Anchoress has a thorough post up discussing this. AJ Strata discusses snake oil salesmen. Dean Barnett (who has a personal stake in this type of research and still opposes based on his beliefs) is not at all pleased with the way this is a political football. Lori Byrd at Wizbang says the ad by Fox is powerful, but not truthful.

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6 Responses to Stem Cells = Tumor?

  1. Anchoress says:

    I thought they had stopped these experiments some time ago – a few years ago there were reports about embryonic stem cells being implanted into the brains of Parkinson’s patients with nightmarish results, to the point where the experiments were (as I understood it) to be cancelled. I guess they thought they could try again.

    I have a theory about these embryonic stem cells…I think they’re humanity in its purest form – very close to its divine origins…like uncut heroin, they’re just too powerful and too unpredictable for our clumsy uses. But what do I know?

  2. Gaius says:

    What is weird here is that the researchers destroyed the animals before they could be certain. Or they were certain. That sounds conspiracy theory-like, but there is really something odd about the way they did this.

  3. Ric Locke says:

    What I’m not at all sure about is why this is a surprise.

    The whole point of stem cells is that they’re plenipotent — they can turn into many other kinds of cells as they develop. And the whole reason embryonic stem cells are the ones seized upon by the imaginations of the ignorant is that they’re the most general form. Other types of stem cells have already developed enough to close off some possibilities for later growth.

    In any complex mechanism, there’s only one way for it to work right and many many ways for it to go wrong. Cells are about as complex a mechanism as there is. Cancer is cells with bad regulatory systems, i.e. something went wrong. The mystery is not that cells become cancerous. The mystery is that sometimes they don’t.


  4. Donna says:

    I agree with anchoress’ last paragraph. Years ago, when listening to some scientists talk about their work studying human body bio-electro-magnetic fields, one of the scientists said, “we are wondering if perhaps cancer is a misguided attempt at regeneration of body parts”, misguided that is, because the new growth is not obeying the healthy parameters and laws for coordination and sharing nutrients with the rest of the body.

    Gaius, I don’t think it was odd that they killed the animals if they needed to be able to look at the make-up of the cells as close as possible to the moment of their transisting themselves in a bizarre way. I guess I would ask how many test animals were there and whether they needed to see if the same or different transformation/mutation was present in each animal that exhibited the strange growth. Also, I would guess that this experiment will be repeated as often as possible, to answer even more questiong, subject to stem cell line availability. My question is, why did they not use rat embryonic stems cells in the rat experiments?

  5. Pingback: The Anchoress » Michael J Fox fighting for bad science

  6. BubbaB says:

    Excellent points, everyone. Ric, thanks for the lesson – I am sure it will come in handy in my next debate with pro-choice types…

    Anchoress, though it sounds a little bit too “mystical” to me, I think you might be on to something. What if embryonic stem cells are intended to be as close to perfection as possible? Before Death entered creation, through Adam and Eve, if we assume that not even the cells of our bodies died, they must have had amazing regeneration properties… Makes you think…

    Donna, color me “conspiracy-theorist blue”, but I think there are certain organizations that actually try to use more embryonic stem cells than they need to, in order to create a “demand” for them. And, of course, for pro-lifers like me, I can see where they are going with this… I seem to recall an article a year-or-two ago, where the claim was made that certain research scientists were using human embryonic stem cells in situations that made more scientific sense to use other animal cells. The author did not push the political issues, but it certainly left me with a distinct impression…

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