The creation of human embryonic stem cells through the destruction of a human embryo pits the value of a potential therapeutic tool against that of an early human life. This contest of values has resulted in a polarized debate that neglects areas of common interest and perspective. We suggest that a common ground for pursuing research on human embryonic stem cells can be found by reconsidering the death of the human embryo and by applying to this research the ethical norms of essential organ donation.
Donald W. Landry, Howard A. Zucker
Submitter: Donald W. Landry | dwl1@columbia.edu
Columbia University
Published February 25, 2005
To the editor:
In our paper “Embryonic Death and the Creation of Human Embryonic Stem Cells” we noted that the life of a complex organism is more than the simple sum of the lives of its constituent cells. Conversely, the death of such an organism need not entail the death of each and every cell. Rather, death represents the irreversible loss of integrated function. For developed humans, this irreversible loss of integrated function is codified in the concept of brain death. The dichotomy between organismic life and the life of components of the organism is, of course, what undergirds the possibility of cadeveric organ transplantation.
We proposed that embryonic death, by analogy to the death of a developed organism, need not entail the death of every cell of the embryo and thus blastomeres from dead embryos might be ethically harvested. Dr. Ramelline’s analysis is in essential agreement with ours but he makes a critical contribution by noting that the ethical harvesting of blastomeres from organismically dead embryos rests on the confidence that a harvested cell does not become totipotent and, essentially, a new embryo. A blastomere derived from a two cell embryo, and placed in an environment that rekindled growth and development, would likely manifest such a totipotency and would not, under our proposal, be an appropriate subject of harvesting. A single cell derived from an 8 or 12-cell embryo would not and our proposal would be restricted to such cells that are pleuripotent but not totipotent.
Donald W. Landry, MD, PhD
Professor of Medicine
Columbia University
Howard A. Zucker, MD, JD
Associate Clinical Professor of Pediatrics
Columbia University
Submitter: Pietro Ramellini | ramellini.pietro@inwind.it
Pontifical University 'Regina Apostolorum' Rome (Italy)
Published January 24, 2005
Landry and Zucker's protocol involves both biological and ethical questions.
From the biological perspective, it must be ascertained if, as soon as we extract an alive cell from an embryo-corpse, it becomes a unicellular alive organism belonging to Homo sapiens (its actualizing a totipotency being a criterion for such a becoming); this sometimes occurs and sometimes not, and that there is still debate on the stage when the threshold is surpassed.
From the ethical perspective, it must be ascertained what are the ethically troubling actions about cells, embryos and corpses at play. According to my ethical credo, the following lines can be suggested:
- we are allowed to treat as mere research material an embryo-corpse (even if it contains still alive cells);
- we are allowed to treat as mere research material or even to kill an alive cell inside an embryo-corpse;
- we are allowed to treat as mere research material or even to kill an alive cell that, as soon as extracted from an embryo-corpse, doesn't become a unicellular alive organism belonging to Homo sapiens, and persists to be only an alive cell «belonging» to Homo sapiens (that is, as a criterion of «non-organismicity», if it actualizes either a pluripotency or multipotency or unipotency, but not a totipotency, as soon as extracted);
- we are not allowed to treat as mere research material or to kill an alive cell that, as soon as extracted from an embryo-corpse, does become a unicellular alive organism «belonging» to Homo sapiens (that is, as a criterion of «organismicity», if it actualizes a totipotency as soon as extracted).
So, I advance the following judgement about Landry and Zucker's protocol:
- to obtain a source of human embryonic stem cells, we are allowed to harvest an alive cell extracted from a human embryo-corpse, provided that, as soon as extracted, it doesn't become a unicellular alive organism belonging to Homo sapiens, and persists to be only an alive cell «belonging» to Homo sapiens (that is, as a criterion of «non- organismicity», if it actualizes either a pluripotency or multipotency or unipotency, but not a totipotency, as soon as extracted);
- to be sure that such cell doesn't become an organism, the tutiorist position must be respected, that is, we must extract the cell from embryo- corpses at a stage that, to the best of our knowledge, guarantees that such becoming doesn't occur.