Professor Emily Jackson, from the London School of Economics and Political Science, delivered the Lisa Jardine Memorial Lecture at Jesus College, Cambridge, examining whether a new regulatory regime is required to address the development of stem-cell-based embryo models (SCBEMs) and brain organoids. I would highly recommend watching this lecture, which was packed with fascinating legal and ethical commentary, viewable here.
Heralding the technology behind SCBEMs as 'one of the 21st century's most dramatic scientific developments', Professor Jackson explained that these models are often derived from skin cells, reprogrammed into induced pluripotent stem cells which can then self-organise into human embryo models. There is still uncertainty about what legal status should be accorded to SCBEMs in the UK and elsewhere.
Currently, the Human Fertilisation and Embryology (HFE) Act (as amended) does not define an embryo, but simply tells us which embryos are covered: 'In this Act… embryo means a live human embryo,' considered Professor Jackson. This means it is not necessarily clear whether the Act's use of 'human embryo' encompasses only those created via the fertilisation involving a human egg and sperm, or also includes embryos created from human stem cells, aka SCBEMs.
In the absence of a written legal definition, Professor Jackson noted that the 'ordinary language meaning' would apply. It's interesting to note that in the Oxford English Dictionary, an embryo's definition includes reference to its fertilisation; and any definition obtained from a member of the public is likely to include an implicit assumption that an embryo is made from the fertilisation of human gametes.
It is possible that the ordinary language meaning of 'embryo' will evolve to include SCBEMs in future; though the fact that the scientific community has opted to refer to these as 'embryo models' or '3D models', rather than 'embryos', arguably makes this less likely. Interestingly, the original HFE Act in 1990 did include reference to fertilisation in its definition of 'embryo', but this was removed in the HFE Act 2008 in order to ensure that the wording could incorporate embryos created via cell nuclear replacement, the technology behind the cloning of Dolly the sheep in 1997.
Professor Jackson noted that the Human Fertilisation and Embryology Authority (HFEA) is working under the assumption that SCBEMs are not covered by the HFE Act, and are therefore unregulated. However, she warned that the Secretary of State for Health and Social Care, or a UK court, could move to regulate SCBEMs by declaring them covered under the Act's use of the word 'embryo'. In Professor Jackson's view, this would be 'a sledgehammer to crack that particular nut'. The effect on research would be 'immediately chilling', as scientists would be required to adhere to the strict regulations around embryo research – which require a special licence and prohibit experimentation beyond 14 days.
If the embryo's moral status depends on its origin in human sperm and egg cells, then that status would not, Professor Jackson said, extend to SCBEMs. However, if an embryo's moral status lies in its potential to become a person, then it's not clear to Professor Jackson that this status would extend to SCBEMs either. She argued that an IVF embryo in a dish has no potential on its own, as it needs to be transferred to a uterus and gestate for at least five months before it plausibly has the potential to become a person. The implication was that SCBEMs would require a comparable level of intervention to achieve personhood.
If we do grant special status to SCBEMs, she raised the issue that this might imply that our skin cells should have a special status in law, because skin cells now have the potential to become a person, via transformation into stem cells, then SCBEMs. It is interesting to note that we do not confer the same special status on human sperm and eggs cells as we do on human embryos, despite their potential to become an embryo.
Even if we do admit that any personhood potential of SCBEMs might give them a special moral status, it is not clear to Professor Jackson that SCBEMs actually have any such potential. She explained that it is currently unknown whether a SCBEM, implanted into a uterus, could in fact develop into a human. She noted that no respectable scientist would conduct the 'dangerous and unethical' experiments needed to make this determination, meaning we're at an impasse as to its potential.
However, if SCBEMs become so similar to embryos as to be indistinguishable, she acknowledged that this might constitute identity between the two, meaning SCBEMs should be treated akin to embryos. This leads to a paradox of sorts, as outlined in Reproductive BioMedicine Online: the more useful SCBEMs become in approximating the biological development of an embryo, the less useful they will be in practice – because they will be subject to more regulations restricting their use in research.
The same ambiguity about potential is also central to questions about the ethics and regulation of brain organoid research, to which the second half of Professor Jackson's talk was devoted. She defined brain organoids as 'self-organising 3D brain surrogates, again created from induced pluripotent stem cells'. One such organoid learned to play the video game Pong in 2022 (see BioNews 1163).
The issue here, according to Professor Jackson, is whether brain organoids could ever develop sentience. Brain organoids are currently treated like any other human tissue for the purposes of research; but if they have the potential for sentience, and therefore the potential for suffering, they should be subject to separate regulation. Professor Jackson endorsed using the regulation of animal research as a model for this, which promotes the minimisation of animal suffering; the need to justify the research; and the use of certain red lines, such as the 2013 EU ban on cosmetic testing.
In tackling questions about organoids as well as SCBEMs, Professor Jackson warned against an approach that is too cautionary; we wouldn't want to halt organoid research into a dementia cure due to concerns about sentience which turn out to be misplaced. However, she also stressed the need for public engagement; and I would recommend watching her lecture as a first step in that direction. There is much food for thought beyond what I have been able to cover in this review.
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