Over at Pacific Standard, I offer brief layman’s guide to the latest pluripotent stem cell technologies, and I argue that better stem cell technology will not make the ethical controversy go away. (In last week’s Nature, Martin Pera & Alan Trounson make a similar point.)
To understand where I’m coming from, let’s take a step back a few years, in the aftermath of the Bush Administration’s controversial decision to limit NIH-funded research on human embryonic stem cell (ESC) lines. Back then, much of the debate was over the merits and ethics of ESC’s versus lineage-restricted adult stem cells: ESCs were for the most part derived from leftover IVF embryos or aborted fetuses (and thus didn’t carry the genome of a patient). Adult stem cells could be taken from patients, but were much more restricted in their potential applications. Dolly the sheep was old news at that point, but the technology to create Dolly (and thus also create embryonic stem cells with the genome of a living adult) did not actually work with human cells.
The playing field has changed dramatically – we can now make ESCs that have custom genomes, by creating cloned embryos or by making iPS cells. ‘Adult’ stem cells, while still useful in some ways, are going to remain niche players for both research and patient treatment.
And so today the issue is not whether we should collect ESCs from aborted fetuses or perfectly viable but unwanted IVF embryos. Human embryos created by cloning (at this point) are extremely unlikely to have the capability to develop into live, much less healthy offspring, and so we have almost uniform agreement that reproductive cloning would be bad.
But we clearly now have the capability to mess around at life’s earliest stages, by creating custom human embryos that could be used to create important cell culture models for disease, or to treat patients with stem cells that have had their genomes repaired. Scientists need to be out there explaining the new parameters of the debate, and making the case that these powerful new technologies can bring great benefits that were out of technology’s reach just a few years ago.