Somatic Cell Nuclear Transfer
The first cloned mammal—a Finn Dorset lamb—known as Dolly the sheep occurred in 1996, through the use of somatic cell nuclear transfer (SCNT). In that laboratory technique, the nucleus of a somatic cell, which contains the organism’s DNA, is removed and the remainder is discarded. At the same time, the nucleus of an egg cell is also removed and the somatic cell nucleus is inserted into the enucleated egg cell. This combination of the egg cell with the nucleus of a somatic cell is reprogrammed and stimulated into cellular division and forms a blastocyst. This same process can be used in stem cell research and in either therapeutic cloning (benignly referred to as regenerative) or reproductive cloning.
SCNT & STEM CELL RESEARCH
Stem cells are found in all multi-cellular organisms and possess two desirable characteristics: they areself-renewable via constant cell division and differentiating or able to develop into specialized cell types. Mammals have two broad types of stem cells—embryonic stem cells that are found in blastocysts and adult stem cells that can be obtained from adult tissue. In the embryo, stem cells are capable of differentiating into all the embryonic tissues, whereas in the adult organism they replenish specialized cells and maintain the normal turnover in certain tissues such as blood, skin, etc. By means of cell culture, stem cells can be grown and developed into specialized cells which are similar to various tissues like muscles or nerves. Embryonic cell lines, compatible (or autologous) embryonic stem cells which are the result of therapeutic cloning, and adult stem cells from umbilical chord blood or bone marrow are all aspects of the debate which hold immense promise. The use of SCNT in stem cell research is limited, though it is in use at the Stem Cell Institute of Harvard and possibly Advance Cell Technology (ACT) in Worcester.
SCNT & the VATICAN
This technique was studied by a commission of the government of Italy which included many Catholic members and even one Cardinal—Ersilio Cardinal Tonini of Ravenna. While SCNT was touted as a way to avoid the moral objections of the Church in Italy, the ruling also generated a rare public rift among various Vatican authorities and commissions. The Italian theologian Gino Concetti, who writes or vets articles with moral implications for the Vatican’s newspaper L’Osservatore Romano praised the special governmental commission’s recommendations as “substantially positive.” Mr. Concetti wrote, “It is certainly not possible to say that stem cells, before they arrive at the formation of the embryo, should be considered in the same way as the embryo….In this way the via italiana of therapeutic cloning differs substantially from other nations that allow the possibility of producing embryos as sources from which stem cells are derived.” The Holy See’s Pontifical Academy of Life took exception to what that in-house theologian said. A three-part series of articles on “Human Cloning” was also published in the Vatican newspaper from 10-24 September 2003 which opposed the use of SCNT.
THE NATURE OF THE DISPUTE
The spirited theological, philosophical and ethico-moral debate on the technique of SCNT continues. Many Catholic moralists dispute the distinction made between therapeutic vs. reproductive cloning as spurious or artificial because the SCNT technique can be used for both purposes—two intended uses of one and the same cloning process (SCNT) with the same result the human embryo. However, the debate stems over what qualifies for being designated as an embryo. Redemptorist Father Brian Johnstone who once taught moral theology at Rome’s Accademia Alfonsiana and now is at the Catholic University of America, framed the dispute in the following manner: Catholic scientists and moralists who support SCNT argue that the product used in SCNT is not an embryo “because it is not the result of the fusion of a sperm and an egg cell...Their view is that it’s very different than what results from sexual intercourse.” Opponents of SCNT see the so-called two forms of cloning as both having the same result, namely, the human embryo. Father Johnstone believes that the resolution of this matter will turn on a determination of the technical question of whether or not the cell has the capacity to become a human being. If it could be definitively established that the enucleated cell used in SCNT would not develop into a human embryo when implanted, the Church might be able to agree, in principle, and with many caveats, that SCNT is a technique that can be used in Catholic facilities. No final answer yet!