Contents
Reports of success in embryo research awaken hopes and fears. Insights into current stem cell research.
Reports of human embryos that have been artificially grown in a laboratory in Cambridge, UK, have caused astonishment in recent weeks. They aroused fears of artificially created people, but also hope for breakthroughs in medicine. And the media reports were quickly criticized for being exaggerated and misleading. But where is embryo research, what is already possible today and what is not?
If you want to understand embryos, you have to understand the first five weeks.
Embryos are small miracles. For the layperson anyway, but also, and maybe even more so, for researchers who have been dealing with them for years. Jacob Hanna is a stem cell researcher at the Weizmann Institute for Science in Rehovot in Israel: “In the first five weeks, the human embryo makes all its organs, heart, lungs, liver, all of them. After that, there is actually only maturation and growth.”
If you want to understand embryos, you have to understand these first five weeks, according to Jacob Hanna. And there’s the catch. Because relatively little is known about this period of all things. Hanna’s goal is now to create embryo-like structures in the laboratory from stem cells and thus find out more about this period. To do this, he first grows four different cell types separately from stem cells – the four that are needed for an embryo, the placenta and other tissues.
The artificial embryos are needed because there is only so much one can learn from the few natural ones that are available.
Then he brings these four cell types together and lets things take their course for a few days. The result looks almost surprisingly similar to a real embryo on day 14, reports Jacob Hanna. The cells form by themselves the structures that are characteristic of embryos, an internal architecture.
Jacob Hanna does not shy away from talking about his work and explaining it: The artificial embryos are needed, because one can only learn so much from the few natural ones that are available to researchers. But Hanna doesn’t seek the limelight.
The supposed breakthrough
His colleague Magdalena Zernicka-Goetz from the University of Cambridge has had a different impression in recent weeks: She wants to understand how “our journey through life” begins, she says at a press conference this week.
The British “Guardian” reported in mid-June that Zernicka-Goetz had created artificial embryos in his laboratory, also at the age of 14 days. This made waves, especially in the English-language media, but the report had a thin basis, as became apparent relatively quickly.
This week, Magdalena Zernicka-Goetz presented concrete data and details and backtracked: her goal is to understand how cells in the embryo communicate with each other, because that is what often goes wrong at the beginning of a pregnancy. To do this, she genetically modified embryonic stem cells, then brought them together in the laboratory and allowed them to grow. A structure was created that closely mimics some of the properties of embryos.
Still many open questions
The competition among embryo and stem cell researchers is increasing. The tone is getting sharper, also because more and more is becoming feasible in the laboratory and the ethical questions are increasing.
A driving force of the researchers is pure curiosity. But concrete use of this research is quite conceivable: Tests of new drugs for harm to unborn life. More knowledge for reproductive medicine and early miscarriages. Or also: If we better understand how embryos create organs such as the heart, liver and kidneys and allow them to thrive, this will at best be easier to do in the laboratory in the future, which could help transplantation medicine.
The Israeli researcher Jacob Hanna next wants to allow embryo structures to mature by day 21: “We know that what happens in the embryo is fascinating and seems chaotic. We have no idea what exactly happened there.”