Stem cells - BBC Horizon 27-10-09

The BBC’s topical science programme, Horizon, aired last night (27-10-09) with a programme exploring the potential of stem cell technology and what the future might hold in store for those living with chronic conditions. Following three individuals with different medical conditions (amputation, chronic progressive heart disease and SCI) it was the usual intercut vignettes and interviews with scientific and medical experts. Overall, it was a pretty balanced treatment of the topic, despite a tendancy towards simplifying technical hurdles and foreshortening timelines, and was careful to provide cautionary and realistic editorial on such issues as the conflict of interest that must exist when there are offers of cash in exchange for (unproven) treatments, the need for properly controlled clinical trials and the general hype inevitably surrounding stem cells.

Of note was the meeting between the subject with SCI and someone who had paid for stem cell “treatment” in India. Having watched video testimony that suggested improvement in his function, she was disappointed to find he had, in his own words, “not felt any improvement” and that what he achieved could have been achieved through rehab. His condition remained as it was before his trip to India.

She came face-to-face with one of the few western researchers (Bruce Dobkin) to examine patients before and after such unverified treatments, who told her that there was no evidence that these treatments currently work. In his view, if they did “why would you not want to conduct a small clinical trial to prove it?”. Follow this link to see a position statement – which Spinal Research endorses – from a number of eminent clinical and basic researchers on this topic which you may find interesting.

The programme ended with her meeting Hans Keirstead who, along with Geron, have developed a human embryonic stem cell line that has gained FDA approval for clinical trial in SCI. I am not sure when the programme was recorded but my own understanding is that the trial is currently on hold pending further submission of safety data to the FDA. This in itself is not unusual and a trial is very likely.

It is important to note that the cells to be transplanted in the Geron trial are not at that point stem cells. They are the product of stem cells which have been taken down a development path in culture dish to a point of relative maturity where they will only form something called an oligodendrocyte. As explained in the Horizon programme, oligodendrocytes are the cells of the central nervous system that provide the insulating material enveloping axons. The rationale for this treatment is that paralysis is due to axons being present but not functioning properly because they have become de-myelinated. There is evidence for de-myelination on some axons after SCI, but it is fair to say it is a matter of some debate amongst scientists as to the extent and significance of this in humans and it is certainly not the only or perhaps even the major cause of parlaysis. Other mechanisms by which (precursor) oligodenrocytes could provide positive effects may and probably do exist. A point conceded by Geron themselves.

At the time of posting the BBC’s iPlayer provided access to the programme.