Last week’s news of the teenage boy with spinal and brain tumors resulting from stem cell therapy broke just in time. A failure for stem cell therapy in the eyes of the media. Opponents of embryonic stem cell research now have new ammunition against the recent FDA decision to allow clinical embryonic stem cell trials to progress.
But, would they still have the ammo if the story had been told a different way? What if the researchers hadn’t used the words “neural stem cells” in the title of their paper? Maybe a tale of reckless research methods would be better for everyone.
Here are the facts as we know them:
1) The boy received injections of fetal neural cells.
2) The boy has tumors.
3) The tumors are derived from the injected cells.
It looks like an open and shut case against this therapy treatment, but it’s not. Instead, it a very complex situation that is also a harbinger of the trouble to come without proper regulation.
First, the boy was being treated for a genetic disorder called ataxia telangiectasia in which the area of the brain responsible for movement deteriorates over time until the individual is no longer able to move and eventually dies. Exactly why the boy’s parents enrolled their child in the therapy trial is unclear; aside from the hope that this treatment, any treatment would help their ailing son.
Considering that the disorder is genetic, there is no reason to expect that injecting stem cells would be beneficial. There is no evidence that injected stem cells would migrate to the deteriorating locations, and once there, whether they would or even could act to replace the problematic tissue. According to Wired Science, the boy’s condition did not improve, so it can be inferred that the cells did not fix the implicated brain tissue.
The second issue here is the legitimacy of using fetal stem cells in the treatment of brain disorders and injuries. The cells used in this study were from the neural tissue of 8-12 week old aborted fetuses. At this stage of development, it is assumed that the cells within different tissues have already begun the differentiation process. Once differentiation has occurred it is unlikely that stem cells from the brain will turn into liver cells. By working with differentiated cells, researchers hope to have tighter control of the activity of the cells.
However, stem cells have a propensity to divide. In this manner they are very similar to cancer cells. In fact, there is evidence that points to stem cells as the culprits in certain kinds of cancer. The injected fetal cells were expected to divide (hopefully to create helpful neural tissue), but the scientists had no way of knowing for certain where the division would lead.
The final, and possibly the most crucial, question regarding this case is whether or not the cells were actually neural stem cells. Dr. Evan Y. Snyder, Professor at the Burnham Institute for Medical Research, and Director of the Program in Stem Cell & Regenerative Biology and the Stem Cell Research Center, whose lab was the first to isolate human neural stem cells way back in 1998, is familiar with the Russian scientists who ran the stem cell study. His analysis is that their therapeutic protocol lacked methodological rigor.
“Although the Russians claim to be using “neural stem cells”, they are not. They essentially take whole fetal brain, put in a Cuisinart, and inject it uncharacterized as a graft slurry,” wrote Dr. Snyder on The-Scientist.com.
When I asked him how he knew so much about their method, he said that he visited the Russian research site when they were initiating their investigations. He spoke with the surgeons about their methods and how the cells were provided to them.
“We told them they were doing it wrong. They found our procedures too tedious.”
Dr. Snyder and his colleagues have a paper in revision at the New England Journal of Medicine in which they analyzed the cells used in a similar case from the same group, and concluded that they were not likely to be neural stem cells.
“I am actually disappointed that the Israeli scientists who analyzed this material did not do a more careful characterization of the actual donor-derived tissue and cells. Had they done so, they would have known, as well, that what they saw could not have come from a rigorously defined neural stem cell,” says Dr. Snyder.
It is therefore possible that Israeli report is in fact inaccurate in its attribution of the tumor to “neural stem cells.” They found the abnormal growth to be made up of several different cell types, which is unusual for cancerous tumors. The variety of cell types, making up a neoplasm, is more in line with the development of undifferentiated stem cells than what would be expected from the injection of truly differentiated neural stem cells.
“This case has no bearing whatsoever on the legitimate biology and uses of stem cells, particularly neural stem cells,” wrote Dr. Snyder.
He further elaborated by saying, “The Israeli authors were not sufficiently skeptical or inquisitive enough… True normal neural stem cells likely do not have the capacity, without a series of mutations, to give rise to neoplasms. I do not believe it is part of their biology.”
Taken as a whole, this is a tragic story, which can hopefully be taken as a lesson. Proper regulation, not cessation, of stem cell therapy research will reduce the number of casualties from improper research methods. It will legitimize the research and reduce the number of rogue laboratories in foreign countries where people are almost certain to lose their lives in the search for a cure. And, it will speed the process of finding therapies that actually work.
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