Podcast Review: BBC/Guardian – Stem-cell-based embryo models

This is a double review, covering two podcasts: one from BBC World Service's Science In Action, and one from the Guardian's Science Weekly. Both share a common theme, addressing recent advances in the generation of stem-cell-based embryo models (SCBEMs). SCBEMs have been catapulted into the media spotlight recently thanks to the labs, among others, of Professor Magdalena Zernicka-Goetz, of the California Institute of Technology and the University of Cambridge, and Professor Jacob Hanna, of the Weizmann Institute, Israel.

I won't re-hash the science, as it has been covered extensively elsewhere (see BioNews 1194, 1195 and 1196). But briefly, researchers have described the generation of models of embryo development. These models are derived entirely from stem cells that have been induced into cell types like those found in developing embryos. The researchers' aim is to permit the study of the 'black box' period of embryo development between the 14-day limit and the 35-day stage which we know little about, and a point at which many pregnancies fail.

This is a sensitive topic, raising deep ethical questions, which these podcasts attempt to wrestle with. The two are reasonably different in their content and form, but a common theme is a question that many are asking: what makes an embryo an embryo?

I will say from the outset that I think both merit a listen, especially given their relatively compact combined runtime of 43 minutes. They complement one another well, despite some slight overlap. As a pair, they provide a reasonable primer on the science, considerable insight into the minds of those involved in the work, and an initial dive into the ethical debate SCBEMs present. I am not entirely without criticism, however, particularly of the BBC's attempt. It is the longer of the two, standing at 27 minutes of interviews. These are wide-ranging, including with both Professor Zernicka-Goetz and Professor Hanna themselves, as well as with scientists and ethicists not directly involved in the research.

I will level my first criticism of this episode: it seems to flirt with the very thing scientists interviewed in the episode decry: sensationalising this advance. Host and interviewer Roland Pease opens by stating that 'human embryos are the topic for this week's episode'. This makes me a little wary, as they are not, SCBEMs are.

Despite this, there is value in the body of the podcast and the interviews. Both Professor Zernicka-Goetz and Professor Hanna are perhaps unsurprisingly articulate and passionate in describing their advances, and both are clearly thinking deeply and carefully about the ethics of what they are doing and the public's perception of it. Having the opportunity to hear the corresponding authors themselves explain their science and justify its importance to me is invaluable in furthering insight into the topic. But again, I find a hint of sensationalising. While interviewing Professor Zernicka-Goetz, it feels like Pease wants to push her into saying that SBCEMs are 'similar to human embryos', which she does not strongly rebut.

This leads to another criticism. While interviews with Professor Zernicka-Goetz and Professor Hanna are insightful, they do feel slightly like a sales pitch at points. Profesor Hanna, at least, seems more modest about the potential impacts of the advance. Given that at the time of recording these findings had not been peer-reviewed, I feel like some balance in terms of the opinions of scientists more cautious about the work, its limitations, and the scope of its impact would have brought value. Considering the central role peer review plays in our scientific system, I feel the BBC have missed the mark here, and others have offered more cautious interpretations of the results presented.

The final third of the podcast is given over to others not directly involved in the work, who offer insights into how the technology will be used by others, and its ethical and social context. It is heartening to hear Professor Sarah Franklin, chair of sociology at the University of Cambridge, talk about how she feels like the public has not had a knee-jerk 'franken-embryo' reaction thanks to the UK's considered regulatory environment.

Also of value is Professor Hank Greely from Stanford Law School, California, who explores the ethical debates surrounding SCBEMs. His perspective is refreshing, and he contextualises the findings in terms of unmet needs in embryo research. It is this section of the podcast, and his exploration of the philosophical questions raised that I find most enjoyable, redeeming to some extent the issues I have with the first half. If you are particularly time-poor and not in the mood to listen to leading scientists proselytize, skip ahead to around the 17-minute mark and at least enjoy this segment.

The Guardian podcast is shorter and does not include anyone involved in the work. Instead, it consists entirely of an interview with Dr Hannah Devlin, veteran science correspondent for the newspaper, by the podcast's host, Madeleine Finlay. The two back-and-forth on the topic in a conversational manner. Dr Devlin is clear, concise, and to me seems less eager to sensationalise than Pease, while still navigating the larger ethical implications. The core of the description of the science is sound, and she is more cautious about how similar SCBEMs are to embryos. Finlay also frames much of her questioning as host from a more sceptical perspective regarding the immediate impact of the findings than Pease.

The episode is less focused on fundamental science and is more interested in the broader implication of SCBEMs. There is some degree of cross-over with the second half of the BBC podcast, but not enough to warrant only listening to one or the other. Dr Devlin and Finlay also dive into a topic that I think many of us, and the public, have in our minds: the 'ultimate potential' of these structures. Dr Devlin describes a 'totally open question among scientists about whether these structures might eventually have the theoretical potential to fully develop'. I am less convinced, but she tempers this, exploring the fact that hurdles might not just be technical, but instead fundamental, biological ones. I agree, and think they might be jumping the gun here. Nonetheless, the concept alone is fascinating.

It closes out with what is for me the most critical part of the debate. In the words of Finlay, 'these models prompt bigger, more philosophical questions'. Here there are parallels with Professor Greely's segment from the BBC episode, and again I am drawn in. The two are insightful and engaging and raise interesting questions about why exactly we find this concept so visceral and challenging. I do find myself wishing here, as in Professor Greely's segment in the previous episode, that more time in both podcasts was given over to this aspect of SCBEMs. To me, it is the crux of what will shape public perception and ultimately adoption of these technologies, and as such what needs to be discussed most.

So, while I do have some criticisms, these podcasts are broadly engaging, and add depth to the debate surrounding SCBEMs. Personally, if I were to recommend only one, it would be the Guardian: shorter, more balanced, and less sales pitch. If you have time to spare on your commute though, consume both. I do just find myself wishing that a bit more time had been given over to the question of what makes an embryo an embryo.