An Embryo by Any Other Name
July 12, 2018
by David Prentice, PhD
Some recent stories illustrate the continuing obsession, by some in the scientific community, with trying to make embryos in a way that “gets around” the ethical and legal barriers erected to protect young human life. The most recent attempt, discussed in a recent Point blog by Dr. D. Joy Riley, involved using combinations of stem cells to reconstruct a mouse embryo. While the popular news story cast the reconstructed embryos as “synthetic,” the newly-assembled embryos showed all the characteristics of a blastocyst-stage embryo. The researchers combined the two different types of stem cells found in very early mammalian embryos (embryonic stem cells from the inner cell mass, and trophoblast stem cells from the outer layer of the blastocyst; the blastocyst resembles a hollow ball with a mass of cells inside and is formed prior to implantation into the uterine wall.) The combination of the two stem cell types produced a structure that looked like an early embryo (this experiment used mouse stem cells). The stem cells, when put together in the lab culture dish, self-assembled into the embryo (blastocyst) structure, and this self-assembly seems to be a natural feature of how the two types of cells interact and associate normally during development. The researchers termed the structure a “blastoid” since it was not authentically a blastocyst derived through normal developmental growth. When they transferred the mouse blastoids into mouse wombs in an attempt to get implantation into the uterine wall, there was limited success; the constructed blastoids did seem to interact with uterine cells and start to form placental structures, but according to the authors they “did not support full bona fide embryonic development.” While they don’t clarify or give data as to the meaning of that statement, it is likely only a matter of time before any technical impediments are overcome.
Indeed, this new experiment itself is simply a refinement of previous experiments aimed at constructing early embryos using combinations of cells. Just a year ago, we discussed experiments where cells were combined in the laboratory to create embryos (again, those instances used mouse cells as starter material.) Other experiments have created human embryos and grown them in vitro for up to 13 days. All of these studies should concern us, as they highlight a cavalier attitude toward human life at its earliest stages. The standard format involves touting how such experiments could lead to increased knowledge as well as medical cures, statements that we’ve heard time and again from proponents of human embryo-destructive research.
In the most recent experiment, that attitude was expressed by some leading scientists interviewed about the research study. For example:
Prof Robin Lovell-Badge, an expert at the UK’s Francis Crick Institute, said the prospects for obtaining human embryo-like structures in this way was currently “very remote.” “This is a pity for basic research because it would be very useful to have a limitless supply of human blastocyst-like stage embryos to understand the relevant cell-cell interactions required to make normal embryos and to study mechanisms of implantation.”
The possibility certainly exists for someone to try this experiment with human stem cells, and in the U.S. there are no federal laws to prohibit such experiments creating early human life (the Dickey-Wicker amendment only prevents use of federal funds, although the Aderholt amendment would prohibit experiments at trying to gestate these embryos in the womb). In the U.K., the experiments would just need approval of a license by regulatory authority, and the British regulatory authority (the HFEA) never met an embryo experiment that they didn’t like.
The other thing of which to be aware in these stories is the attempt to dehumanize, usually by terming the constructed embryos as “synthetic,” “artificial” or “unnatural.” This terminology seeks to justify the destructive experiments. For example, cloned human embryos once created are certainly human, even if the means of their creation is artificial. Yet even Dr. Francis Collins, the current director of the NIH, has taken the unscientific view that a cloned embryo is not really an embryo, and therefore fair game for creation and experimental use since they are not created naturally.
Another recent experiment shows a similar attitude toward creation and use of embryos. In this case, the scientists did not create human embryos, but rather chimeric human-chicken embryos. The study was done by one of the labs that had previously grown human embryos up to 13 days in vitro. In that previous experiment they stopped the growth (and destroyed the human embryo) because of the “14-day rule,” an agreed-upon limit to experimenting on human embryos in the lab for more than 14 days. The limit has legal force in some countries such as the U.K., but is only followed as guidance in the U.S. Nonetheless, the desire to experiment on human embryos was the force that led to the current experiment with hybrid embryos. As the news story notes, the researchers used “a technique that sidesteps restrictions on research with human embryos by grafting human cells onto chicken embryos,” and “the team bypassed the 14-day rule by growing embryo-like structures from human embryonic stem cells.” The researchers grew human embryonic stem cells (obtained by destroying young human embryos) with specific growth factors so that early embryo-like structures were formed, but then transplanted these constructs into early chicken embryos. The result was that the human cells, which had reached a point of development roughly equivalent to a 14-day human embryo, continued to develop in the chimeric human-chicken embryo and induced formation of pre-neural structures in the hybrid embryo. While this chimeric embryo was technically not human, transplanting the human cells into the chicken embryo so early in development brings up other ethical concerns: creating chimeric animal embryos with human features, including a human brain or human gametes. Again, the NIH has proposed allowing and funding such early mixing of human and animal embryos, despite the significant ethical problems these experiments entail.
We need to recognize that human attempts to create or re-label human life in a way that justifies instrumental use are not ethically permissible, nor are they good science. It’s time we speak up against dehumanization and speak out for protection of human dignity and all human life.