Author Affiliations: Advanced Cell Technology, Worcester, Mass (Drs Lanza, Cibelli, and West); Center for Bioethics, University of Pennsylvania Medical Center, Philadelphia (Dr Caplan); Department of Molecular Biology and Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ (Dr Silver); and Ethics Institute, Dartmouth College, Hanover, NH (Dr Green).
Controversies Section Editor: Phil B. Fontanarosa,
MD, Executive Deputy Editor.
Therapeutic cloning (or cell replacement by means of nuclear transfer)
is a new biomedical technology that has the potential to transform medicine.
Therapeutic cloning involves the transfer of the nucleus from one of the patient's
cells into an enucleated donor oocyte for the purpose of making medically
useful and immunologically compatible cells and tissues (Figure 1).1 Although the phrase "therapeutic
cloning" has been most widely used in this context, we believe that it is
misleading. "Cloning" brings to mind images of the replication of a single
genome for reproductive purposes. In therapeutic cloning, however, no such
replication is involved. For this reason, we prefer the term "cell replacement
through nuclear transfer" (CRNT). In this article, we use both terms so that
readers may become accustomed to the more technically accurate terminology.
Moreover, because therapeutic cloning requires the creation and disaggregation
ex utero of blastocyst stage embryos, this technique raises complex ethical
questions.2- 4 While
these questions must be addressed and understood, we believe that a counterbalancing
and stronger ethical case can be made for therapeutic cloning research.
Lanza RP, Caplan AL, Silver LM, Cibelli JB, West MD, Green RM. The Ethical Validity of Using Nuclear Transfer in Human Transplantation. JAMA. 2000;284(24):3175-3179. doi:10.1001/jama.284.24.3175