Last week, Magdalena Zernicka-Goetz, PhD, professor at the California Institute of Technology and the University of Cambridge, announced that her research group created a synthetic human embryo model through the reprogramming of embryonic stem cells. A media frenzy followed her talk at the International Society for Stem Cell Research’s annual meeting in Boston, filling headlines and noting the ethical questions raised by this work.

Here, GEN asks leading bioethicist Art Caplan, PhD, professor of bioethics at New York University Grossman School of Medicine, to discuss the results, the ethical implications, and the role of the media in science communication.

This interview has been edited for clarity and length. 


LeMieux: The synthetic embryo story has received a lot of media coverage. How newsworthy is it? Hasn’t a segment of the stem cell field been headed in this direction for a while?

Caplan: It is true that inducing pluripotent stem cells to produce almost any cell you can think of, including gametes, has certainly been anticipated and done in animals. But, I think the creation of an embryo is a little surprising. It was a little more of a jump than I think you would’ve expected with stem cell research.


LeMieux: Is the jump that it was done, or that it was able to be done?

Arthur L. Caplan
Arthur L. Caplan, PhD

Caplan: Both. It’s a little surprising that it was able to be done in humans. And it’s a little surprising that the announcement came that it was done.

Which leads me to a side comment… we saw something similar with the announcement of genetic engineering of human embryos at a meeting in Hong Kong in 2018. I appreciate the publicity, but I despise, hate, and would like to discourage media coverage of things announced at meetings.

We need to wait for the paper in order to see what the researchers did. I’m not saying they didn’t do it. I’m not saying it’s a hoax. But it is not very responsible when meetings allow momentous announcements without data and without access to any sort of publication. That’s just hunting headlines, which they got. But it makes it hard for people to respond unless they know what they did, how did they do it, how many times they did it, etc.

Here again, we have news that commands worldwide attention based on a pronouncement at a meeting.


LeMieux: Here at GEN, a story like this is very hard to cover, because there is no paper and we weren’t at the meeting to see the data. What can we say about the research?

Caplan: I’m not even sure if the talks at that meeting are peer-reviewed prior to acceptance. And we’ve gotten into a lot of trouble covering many announcements, all the way back to the Raëlians and their cloning claims from two decades ago, right up to He and his announcement of genetic engineering of human embryos. It seems that we are not going to learn from that and everybody is going to rush to cover something that looks startling.


LeMieux: Assuming that they did what they said they did, where does this sit on your ethical scale, from extremely unethical to not unethical at all?

Calpan: It is ethically inappropriate to do this without attention to who approved it, funded it, and where did the material that was used come from. I don’t think it’s necessarily unethical to make an embryo-like entity from a stem cell. But I do think it’s unethical and inappropriate to announce that you manipulated something to perhaps be like a human embryo without any attention to under whose auspices, approval, the money used, and where it was done. That matters in this world of stem cell research. Again, that information—filling in the sociology of how this happened—would be expected to be in a paper. But I’ve got nothing here and I don’t like that.


LeMieux: It is possible Zernicka-Goetz announced some of this information in the talk. But we don’t know because we weren’t there and it hasn’t been reported on.

Caplan: Correct. Maybe she did. I tend to think I would have seen something, somewhere, by somebody, and I haven’t seen anything. In any event, it should be prominent; not a secondary issue, given the decades of heated controversy about stem cell research and embryo research. You can’t not feature those points. That makes for panicked and inappropriate responses to the experiment.

The interesting question is, “What the hell is it?” There is a lot of talk here about human embryos. I’ve started to use the term “embryonic construct” because I don’t think they made a human embryo, based on what I have heard. It sounds like they made something that was embryo-like. Embryo-sort of. Embryo-kind of. But not something that was marching through the normal process of embryonic development.

From an ethics point of view, what usually matters is how close to a human embryo this creation is. The closer it gets, the bigger the ethics issues loom. The further away it gets, the less the ethics issues loom, but the less the scientific interest is. The less human, the less anybody is going to care.

So it’s hard to know what the ethical significance is because it’s hard to know what they got.


LeMieux: Is the goal itself unethical?

Caplan: Not necessarily. And that takes us to different ethical attitudes about embryonic research. In the United States we’ve long had, since 1996, the Dickey-Wicker Amendment, which states that no federal funds will be used for embryo research. I don’t think they anticipated this form of creation. So right away, there will be a debate about how embryo is defined.

Second, there are many states that have prohibited embryo research. Other states don’t say anything. And California has a state-funded stem cell research program. So there’s a vast array of state laws. The U.K. allows it. However, they have a limit, as does the NIH (informally) of the 14-day rule. So if these researchers had let it go in the dish for a month, that clearly would not be legal in most places. Unless they then tried to say that it’s not a human embryo so they’re not bound by those restrictions.

The FDA, even if you aren’t funded by the NIH, is supposed to review embryo research. But someone could say, this isn’t research. We’re just tinkering around… we’re just seeing if it’s possible. It’s a proof of concept. An interesting case study. Researchers could go that route and try to claim that they are not bound by any restrictions.

And in the middle of post-Dobbs America, every state is having a conniption over the question of when does life begin. What is an embryo? What’s a conceptus? Some states will read about the press coverage saying that researchers are making human embryos and they will move to ban it, not even knowing what it is.

They will say, “If it’s in a dish, and it looks like a human embryo, don’t do it.”

That could take away a valuable research tool to understand epigenesis and many aspects of human embryonic development that we don’t understand.

The answer to the question, “What did they do?” will not be settled by what the researchers say they do. It’s going to be settled in part by what legislators and pro-life people think that they did. And that gets back to the responsibility of the press and media coverage. Because how the press describes the research is what a state legislator or a federal regulator or a pro-life legal firm is going to read.

The story isn’t just what she said at the meeting. It’s how it’s reported.


LeMieux: What about restrictions in other countries?

Caplan: What other countries allow is a very mixed map around the world, with some being restrictive and others being very liberal. Some are going to see this as an interesting research tool. Other countries may want to encourage this and get ahead. They may be happy to let the countries that are worried about when life begins and protecting fetal and embryonic life do that. They will be able to get into this as a commercial area very quickly.


LeMieux: Have you seen the images of the synthetic embryos?

Caplan: The images take my breath away. Because they do appear, at least anatomically,  very similar. If you show those images to pro-life legislators, it’s over.


LeMieux: Because it is unknown how hard it would be to continue to advance the development of the synthetic embryo, do you think the unethical part is what she did today? Or what it means for the future?

Caplan: I think the unethical part would be to create an entity that had the capability of developing into some sort of adult form. That could mean an adult form with horrific disabilities.

Or, an adult form that could be used for reproductive purposes would bring up all kinds of safety and moral objections. The biggest ethical issue is trying to take something as far as you can take it in development, to see if it functions like a viable human embryo. This includes putting it into an environment—an artificial womb—where it would become adult-like. Many people would find that morally dubious. Studying something human-like at seven weeks, 14 weeks, or 21 weeks, offends many people, but not all. That’s a little less morally contentious.


LeMieux: What do you think the reaction to this will be?

Caplan: For me, it is to hold on until we see the paper. But in some circles, it is to get the lawsuit ready—to expand the definition of embryo in existing laws to cover and prohibit this. And in other circles, this looks interesting and exciting.

This is somewhat related to the experiments to try and turn stem cells into germline cells, which is equally provocative in many ways. To some extent this experiment, like those experiments, is research in search of a purpose. Because we’re not sure why they’re doing it.


LeMieux: Meaning, are they just doing it to see if they can do it?

Caplan: Exactly. Are they just messing around or are they going somewhere important for some researchers to use as a tool? It builds distrust when you go toward the, “I’m just trying to demonstrate what could be possible.” Because it looks like scientists are mucking around with the secrets of nature.

Previous articleAlex Zhavoronkov Aims to Take Over the Drug Development World with AI
Next articleGenotyping Improved by Sequencing with In Vitro Repeat Depletion