A tale of two stem cells

This last month there have been two developments in stem cell therapies.

One is not ethically controversial, and represents a major gain in efficiency in making effective stem cell treatments available quite soon. It received no coverage in the British media at all.

The other is ethically controversial, is at such an early stage that clinical benefit remains unlikely for at least another decade, but achieved massive coverage. What – and why?

Stem cells are primitive cells with potential to turn into other specific cell types, and obviously it would be great in medicine if we could grow our own tissues to replace those damaged by injury or disease. Stem cells come from two different sources – one controversial, one not.

‘Embryonic stem cells’ (ESCs) are derived from human embryos and have the most potential to turn into other kinds of tissue. That’s no surprise – after all, each and every one of us came from one single cell formed when dad’s sperm and mum’s egg fused at our inception.

But that enormous potential also means that trials to date have not worked – the ESCs are so lively they are uncontrollable and cannot be directed, even in cases forming tumours. And the ethical controversy? Human lives are lost as the embryos yielding ESCs are destroyed in the process.

By contrast, stem cells can be derived from many completely non-controversial sources found in our bodies already. Stem cells from non-embryonic sources are known as ‘adult stem cells’ (ASCs).

And just a couple of years ago, scientists became able to reprogramme back human skin cells into ‘induced pluripotent stem cells’ (iPS) – with the potential to make many different kinds of tissues to treat diseases.

At first, viral vectors had to be used to transfer the genes to reprogramme the skin cells, which is inefficient and has potential safety concerns.

But in the breakthrough that really is a breakthrough, scientists reported creating iPS from skin cells using modified forms of messenger RNA (natural human transmitters). The new technique appears to make producing iPS one hundred times more efficient.

The US National Institutes of Health website logs current clinical trials and lists 3,124 involving ASCs, 304 of them for spinal cord injuries. Here is an imminent therapy with no fundamental ethical concerns, which is already being tested, and which has just become a lot more efficient.

By contrast the other story concerns the first clinical trial involving embryonic stem cells. Yes, one ESC trial against over 3,000 ASC trials. After over a decade, the US biotechnology giant Geron, which has invested $170m in ESCs, has finally come up with a potential treatment for spinal cord injured patients.

Yet examining what they have done, it is only a ‘Phase 1’ trial, looking at this stage at safety and tolerability of nerve cell progenitors derived from ESCs, to be injected into the site of the spinal cord damage 7-14 days after injury. Assessing neurological function is only a secondary end point.

Now that is the accepted and proper way of testing a potential new treatment, but it is at such a very early stage that it will be years, if ever, before a treatment for spinal cord injury emerges. Meanwhile, more than 300 ethical trials are already going on for spinal cord injuries…

So why huge news coverage for one, and completely ignoring the other? The British media have been hoodwinked by sections of the science community, some of whom want the freedom to indulge in research without any boundaries.

They want to ignore the destruction of human embryos implicit in ESC work, putting concerns down to religious extremists only, and arguing that embryos are only ‘potential human beings’. They are of course ‘human beings with potential’. The media are also turning a blind eye to the scientific reality here: the unethical just doesn’t work anyway.

Amid all this hype, the British Medical Journal even reported a London professor as saying: ‘This first in man study marks the dawn of the “stem cell age”.’ Dawn? Sunset more likely…

Andrew Fergusson is Head of Communications at Christian Medical Fellowship.