Stem cells (so-called “master cells”) are unique and important in the body because they can do almost anything, and scientists have only begun to discover their potential. That’s why researchers’ use of them has created controversy, attracting the attention of scientists, policymakers, and bioethicists across the globe.
Stem cells can transform into any of the body’s more than 200 cell types — they can become muscle cells, red blood cells, or brain cells. Embryonic stem cells are what allow fertilized eggs to grow into babies.
In early 2017, it was reported that scientists had used two types of stem cells from mice to create the world’s first artificial embryo.
With a little more fine-tuning, it seems possible that stem cells could be coaxed into something that is indistinguishable from a natural embryo. In fact, “embryo models” have already been transferred into the wombs of mice, where they begin to implant (though they stop developing after a few days).
The creation of embryo models from stem cells raises important ethical questions.
One of the bioethicists who has recently weighed in on this thorny issue is legal scholar and ethicist Rosario Isasi, J.D., MPH, a research assistant professor at the University of Miami Miller School of Medicine with appointments in the Dr. John T. Macdonald Foundation Department of Human Genetics, the Institute for Bioethics and Health Policy, the John P. Hussman Institute for Human Genomics, and the Interdisciplinary Stem Cell Institute.
She and colleagues published a commentary on December 12 in the journal Nature urging international discussion that will establish clear ethical guidelines for researchers.
The authors outlined some major upsides:
“Studying mouse and human embryogenesis in the lab could lead to better infertility treatments or contraceptives, more-effective and safer in vitro fertilization procedures, the prevention and treatment of developmental disorders and even the creation of organs for people who need a transplant.”
But they also warn that “future progress depends on addressing now the ethical and legal issues that could arise.”
Their article poses four questions and makes four recommendations that medical ethicists, lawmakers, and society at large should ponder carefully:
1. Should embryo models be treated legally and ethically as human embryos, now or in the future?
2. Which research applications involving human embryo models are ethically acceptable?
3. How far should attempts to develop an intact human embryo in a dish be allowed to proceed?
4. Does a modelled part of a human embryo have an ethical and legal status similar to that of a complete embryo?
1. Consider the intention(s) of a study.
2. Ban the use of stem-cell-based entities for reproductive purposes.
3. Models that replicate anatomical structures or restricted parts of development should not have the ethical status of embryos.
4. All scientists must abide by existing guidelines, including those created by the International Society for Stem Cell Research.
“If managed responsibly, the use of stem cells to create embryo models has the potential to vastly improve human health,” the authors wrote. “That is why it is so critical we continue to discuss the ethics of medical research. A lack of transparency or consensus could lead to unwanted outcomes and/or set the field back decades.”