Friday, October 15, 2010

Stem Cells, Part 3

Diseases and conditions where stem cell treatment is promising or emerging. (See Wikipedia:Stem cell#Treatments). Bone marrow transplantation is, as of 2009, the only established use of stem cells. Image credit: Mikael Häggström. 

So we've explored embryonic versus somatic stem cells. We know the advantage of embryonic stem cells (tabla rasa cells, effectively) and of somatic cells (plentiful and unchallenged ethically but perhaps harder to work with). But what type of cell therapy are we talking about with stem cells? What can you do with them to fix people?

Well, you've already heard of one treatment that is proven with stem cells, even if you don't really think of it as being one: that of bone marrow transplants, which can be used to treat a huge variety of acquired and congenital diseases or disorders. But what are doctors and researchers planning to do with stem cells if the federal spending is finally freed to work with all kinds, embryonic and somatic?

I can tell you after days of researching this article that there is a huge amount of hype out there on stem cell therapy. People at centers all over the country talk about stem cell therapy as if it is already accepted, proven and fully vetted. In fact, it's not

Somatic stem cell therapy is much better understood at present and there are a number of promising indications for using somatic stem cell therapy to treat cancer patients, spinal cord patients and cardiac patients. But embryonic stem cell therapy is barely begun. In fact, the first clinical trial of an embryonic stem cell treatment started this week. And it's caused quite a lot of controversy, even among proponents of embryonic stem cell therapy.

"Without knowing more clinical detail, there's little that I can say," said Steve Goldman, chairman of the Department of Neurology at the University of Rochester in New York. "In more general terms... I remain concerned about the long-term safety of unpurified grafts of embryonic stem cell derivatives. Time will tell."

Yes, in addition to the ethical controversy, there are still a number of concerns that need to be addressed scientifically about using stem cells. If these cells are always turned "on" for division, for instance, what will stop their rapid cell division and growth? Uncontrolled cell growth is usually called cancer. Or, leaving aside that unlikely outcome, what if reprogrammed cells just somehow lose their programming? What happens if a mesoderm stem cell differentiated into ectodermal tissue reverts back? All of these are questions that have been posed at various points in time, and not just in the lay literature opposed to stem cell research, as you can see from Dr. Goldman, above. Another worrisome factor has been contamination of the stem cell lines. This has actually been reported, and was cause for concern about the present stock of embryonic stem cell lines which scientists have been using for the past decade. In 2005, a group of researchers at UC San Diego and the Salk Institute in La Jolla reported in the journal Nature Medicine that they found solid evidence that human stem cells were contaminated with non-human sialic acid as a result of the culture media which was using non-human serum to sustain the cells. Subsequent work by Robert Lanza, et al. was published in The Lancet reporting a new embryonic cell line that was grown without serum feeding and therefore less likely to be contaminated. Yet the original group's finding draws attention to the fact that there is much that needs to be refined in the field of stem cell research. How that refinement will occur without federal research dollars may turn out to be very unfortunate for anyone who needs stem cell treatment. With only private sector funding of embryonic stem cell research and therapies, one can only imagine the simply exorbitant costs that these therapies will be have when they finally are offered. It will truly be medicine for the wealthy, no doubt.

The first clinical trial of embryonic stem cell treatment in human subjects was approved by the FDA in January 2009 for transplantation of differentiated neural cells called GRNOPC1, progenitor oligodendrocytes, into patients with spinal cord injuries. The study was on hold for more than a year because of microscopic cysts found in rat test subjects. That hold was lifted in July of this year. On Monday, October 11th, 2010 Geron Corporation announced that the first spinal cord patient was treated with the differentiated stem cells in Atlanta, at the the Shepherd Center. 

There is much argument about whether embryonic stem cell therapy is safe, is ethical and even whether it is likely to be effective. What is clear, however, is that if funding is not available to sufficiently research and test, even if in non-human subjects1, that the likelihood of success on any level is poor. When contamination was reported in cell lines in 2005, within months Robert Lanza's group at the private firm American Cell Technology reported not just a potential way to grow cells without serum, but within a year, a way to extract the inner mass stem cells without destruction of an embryo. Research findings drove the science of stem cell technology forward.

If we don't publicly fund medical research in this country there will be two devastating outcomes: we will fall farther and farther behind the rest of the world, and we will end up with novel treatments that only the very wealthiest Americans will be able to afford.

Think of anyone you know who has any of the ailments in that figure above, who might potentially be treated by stem cell therapy. How much is too much to pay? 

So hopefully, when you next hear 'stem cell research' you'll ask what kind of stem cells and you'll ask whose research it is. Is it publicly funded and therefore yours, mine and ours? Or is it privately funded? And how about just saying "Yay! More research!"

Research and peer review drive science, and medicine, forward.

They are your very best hope for a healthy future.

1 Readers should remember that the Dickey Wicker Amendment prohibits any embryonic stem cell research with embryos even from other organisms to be funded with federal dollars. Specifically:  For purposes of this section, the term "human embryo or embryos" includes any organism, not protected as a human subject under 45 CFR 46 (the Human Subject Protection regulations) . . . that is derived by fertilizationparthenogenesiscloning, or any other means from one or more human gametes (sperm or egg) or human diploid cells (cells that have two sets of chromosomes, such as somatic cells).

© Bright Nepenthe, 2010

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