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    Luis de la BARREDA SOLÓRZANO**

    Original Text (Spanish) PDF

    I. An outrageous present. II. The embryonic source. III. The regulation. IV. The polemic. V. Trembling and reason.


    The sunrise of the third millennium offers us a portentous present: regenerating medicine, whose therapeutic possibilities were inconceivable just a few years ago. In the adult body there are more than 200 types of specialized different cells. All of them come from the zygote —or one-cell embryo, formed with the fusion of the sperm and the ovule, with unique chromosome identity— through processes of cellular differentiation and proliferation. The zygote has omniembracing capacity or power, that is, it could create any of the 200 cellular types of the organism. In normal conditions, as the embryo’s cells divide themselves, the capacity to specialize diminishes: the more advanced in its embryonic development the organism is, the less versatility its cells have, since they are already determined in a more or less specific direction. However, it has been discovered that there are certain cells that are an exception to this rule. These are the so-called mother cells, capable of differentiating in different cellular types.

    The mother cells are found in most of the adults’ organs, and they have the capacity of self-renovation, that is, of proliferating and creating differentiated or mature cells, as well as other mother cells that perpetrate the capacity of regeneration of a certain tissue. Until recently the belief was that the mother cells of the bone marrow only blood cells could regenerate, but now we know that in the bone marrow there are other kinds of mother cells, those of the mesenchyme, capable of generating other related cellular types. Recently, the scientists have been astonished with the publication of numerous works that demonstrate that these cells have a larger potentiality than the mere production of blood. This property is known as cellular versatility or plasticity, and it consists in the capacity of a tissue’s mother cell to transform into a specialized cell of a different tissue, not related structurally nor functionally to the tissue of origin. For example, the mother cells of the central nervous system in adults are capable not only of producing neurons or other accompanying glial cells, but they can also differentiate, say, into blood cells. Isolated mother cells of the bone marrow can originate not only blood cells, but also they can differentiate into bone cells and those of cartilage, fat, neuronal and muscular cells, and even of the liver, intestine or the lung.

    It is recently known how to isolate mother cells of the umbilical cord blood of a new-born. These cells are equivalent to the mother cells of the adult’s bone marrow, and they have the advantage that the newborn’s blood contains a much larger proportion of the latter than the adult does, and they are much easier to obtain, expand and store. Besides these cells and those of the placenta, laboratories are searching for massive production that are useful for self-transplanting with the mother cell of the bone marrow of the patient. The differentiated cells the patient would receive would derive from his own cells, which would avoid one of the biggest problems of cellular therapy —and of any transplant— which is the rejection of the cells that come from a strange organism. If the mother cells obtained from an adult patient are successfully expanded in the laboratory, in order to be used in the regeneration of its injured tissues, there could be a formidable instrument for treatment of a series of congenital and degenerative diseases and malfunctions.

    Before their medical utilization, the scientists shall solve certain technological challenges, whose solution implies: a) stimulating the capacity of proliferation in vitro of the mother cells, without yielding their differentiation potentiality in order to produce in cultivation, the sufficient amount of cells to carry out the transplant successfully; b) carefully define the molecular characteristics of the mother cells in order to be capable of standardizing the isolation and purification protocols, and c) demonstrate that with the treatment using this cells, once the tissue was transplanted, it would be possible to achieve a stable functional improvement in each of the treated diseases.


    There is another origin of the mother cells: the embryonic mother cells derive from a group of cells of the new born embryo. In this phase, the mammal’s embryo is called blastocyte. Theoretically, after extracting the blastocyte, these mother cells are able of proliferating during a long time without losing their capacity of differentiation. They are part of the embryo, but they cannot create an adult organism in isolation. Their isolation necessarily implies the destruction of the embryo. The embryonic mother cells, as the adult’s, besides having the capacity of reproducing in cultivation, are susceptible of differentiating under the effect of certain chemical stimuli and of creating several cellular types.

    Since the beginning of the 1980’s, experiments were been made with mouse’s embryonic mother cells. In 1998 were published the first results of the isolation of the mother cells from human embryos, which lead to a big information display as well as comments in the mass media. The mother cells derived from human embryos were presented as the resource that could immediately lead to treatments of tissue replacement in diseases such as Parkinson, diabetes, myocardium strokes, etc. The news that the scientists were about to dominate the synthesis of artificial organs in the laboratory was erroneously diffused.

    The truth is that the mother cells of embryonic origin have much plasticity, are easy to get and cultivate, are very sensitive to the action of the differentiating agents. Besides, apparently they do not lose their capacity of proliferation along time, for which theoretically, they could be kept in cultivation indefinitely. The embryonic mother cells have the capacity of differentiating in different cellular types. This differentiation occurs spontaneously and without regulation: these mother cells create in cultivation heterogeneous masses of cells that differentiate without any order. Their vitality and capacity to proliferate represent great advantages for cellular therapy, but also, paradoxically, a risk: the embryonic mother cells are hard to control. In experiments with animals there have been tumor mashes of heterogeneous cells called teratomas, composed of formless masses of cells among which chaotically figure fragments of tissue partially or completely differentiated. Despite this, the differentiation of these cells is being partially or totally oriented, in cultivation, especially in the nervous, muscular and hematopoietic lines (formation of blood). In experiments with mice there are partial successes in the reimplantation of animal models of differentiated cells toward cardiomyocites, neurons or blood cells.

    Such accomplishments do not exempt the scientists of facing certain challenges in order to use the human embryonic mother cells in medical treatment of cellular therapy. It is necessary to: a) exert strict control over the differentiation towards a well specified cellular type, without being contaminated by any other; b) prevent the apparition of teratomas after the injection in the receiving organ; c) be sure there is no rejection after the implantation; d) demonstrate the therapeutic benefit in human beings, and e) exert control over the levels of differentiation and proliferation in order to avoid trouble derived from the differentiating and proliferating power of the embryonic mother cells.


    The Additional Pact to the Convention on the Protection of Human Rights and Human Dignity with respect to the application of biology and medicine on banning the cloning of human beings, subscribed by the Committee of Ministers of the European Council on November 6, 1997, banned in its first article, "any intervention that intends to create a human being genetically identical to another one, either alive or dead. Genetically identical to another human being means —precisely the same numeral— sharing with another one the same genetic nuclear load".

    In the resolution of September 7, 2000, the European Parliament considered that "therapeutic cloning that implies the creation of human embryos with research purposes represents a serious problem and it draws a no-return border in the research field". Therefore, it requested the European Union to promote in the United Nations Organization "a universal and specific banning of the cloning of human beings in every stage of their development".

    The regulation varies considerably from one country to another. For example, in Germany (could it be because of the memory of the Nazi nightmare?) the generation of human embryos for research is completely banned. Article 6 of the Law of Protection of the Human Embryo forbids the artificial production of a human embryo with the identical genetic information to that of another embryo, of a fetus, or of a living or dead adult. On the other hand, in Israel the Law is permissive, perhaps because the Jewish religion, with important influence in Law, does not consider the non-implanted embryo as a person.

    In the United States the public financing is authorized only for the utilization of the cellular types derived from human embryos that are already available in different laboratories of the world, but not for producing new types. This prevents new destruction of embryos for research. It is intended to prove, before analyzing a possible total liberalization, if the expectations are transformed into realities of specific therapeutic benefits. The present moment is crucial. The Chamber of Representatives decided to penalize any manipulation of embryos with medical or reproductive purposes. Now the Senate intends to discuss whether to promulgate a law that regulates cloning. The National Academy of Sciences, private organism that assists the government in scientific topics, has proposed to authorize therapeutic cloning, but it recommends to ban every project of human cloning during the following five years.

    In the United Kingdom, the Chamber of Lords has just confirmed the legality of therapeutic cloning and of experimentation with human embryos to investigate about the creation of tissues, such as nerves, cartilages and muscles. Authorization was given to some parents who wish to conceive a new child, through selection of embryos, in order to have the type of cells required to correct the disease of their other child who was already born.


    Intense debate has been created around the legitimacy of therapeutic cloning, which should be clearly distinguished from reproductive cloning. The latter —which practically has no supporters— would search to create a living being genetically identical to another one; the former —object of intense debate— has the purpose of obtaining mother cells that are genetically identical to the patient’s in order to use them, without causing rejection, for his healing.

    Therapeutic cloning is also known as cellular substitution therapy through nuclear transferring. This technique was used in the sheep Dolly’s cloning. The nucleus of an adult differentiated cell is introduced in the non-fertilized ovule, whose nucleus has previously been removed, in order to reprogramme it. This way it is possible to obtain a clonic blastocyte, from which will derive mother cells genetically identical to the patient. Theoretically here lies the solution to the problem of rejection. Mother cells for each patient would be generated, of which specifically the cells required for their transplant would be differentiated, and the damaged one would be substituted.

    What is at stake? On the one hand, the scientific progress, and what this means for health and the quality of life of millions of people. On the other, the ethical considerations about the embryo’s humanity, quality that —those who are against cloning sustain— would ethically compel to oppose its destruction, even if it was to heal or improve a patient’s health, and that rejection shall lead to a legal banning. The polemic gets even more complicated with the fact that in the assisted reproduction clinics are generated much more embryos than those which are implanted, and those embryos lie in the clinics’ refrigerators. What do they do with them?

    The Review Human Reproduction published in February 2001 a study that pictured a paradoxical situation. In order to reach efficiency of the assisted reproduction techniques, the practice of inducing a multiovulation of the woman who wishes to become a mother has been generalized and legalized: several ovules are provoked to become mature in one single cycle. In the same intervention the ovules are taken, they are fecundated and they leave developing for a few days, and some ovules are transferred to the uterus so that one of them can take in. The rest are frozen and become remaining if the first transference is successful and a baby is born. The study points out that the embryos originated by fecundation of ovules that come from a multiovulation have more difficulty to take in, and those who accomplish it develop more malformations than those originated by fecundation of an ovule which was naturally matured in the cycle. A vicious circle: in order to improve the efficiency an excess of embryos is produced, and the production of this larger number produces embryos with deficiencies, less viable to those which the mother’s uterus shelters worse and must be frozen.

    In the lecture presented in the International Symposium on Cloning and Ethics,1 Doctor Justo Aznar, Department Chief of Clinical Biopathology of the University Hospital La Fe de Valencia, opposed to the distinction between reproductive cloning and therapeutic cloning. "Cloning is always —he asserts— a reproductive action, regardless the aim of the product of such reproduction, either destroying it a few time later, as it happens in therapeutic cloning, or letting it grow and be born, as in the case of reproductive cloning". He observed that the recent news about the premature aging of sheep Dolly, specially showed in the arthrosis in one of its legs —case that, by the way, we could add a reason to worry, which is the fact that the cloned mice became obese when they became adults— have covered cloning with a cloud of doubts. The anomalies, he warns, cannot be seen in the nucleus of the donor cell, for it does not exist, nor it seems it will exist in an immediate future, methods that allow examining the complete epigenetic stage of the genome. This, in the field of health and science. In the ethical field, Aznar affirms that —setting over the basis that no scientist dares to deny that the zygote is a human being— that the intention of creating human embryos to destroy them afterwards turns therapeutic cloning into

      …a means through which certain beings are created exclusively for others’ profit; an abuse of the strongest over the weakest, a disposition of some over others, contrary to ontological equality and equality of rights of all human beings. Therefore, destroying certain human beings to save others seems to be something contradictory and opposing the presumed humanitarian aim with which therapeutic cloning wants to be justified.

    Several authors affirm that the human embryo is a human being. The volume of July-September 1997 of Cuadernos de Bioética (Santiago de Compostela, Spain), compiled several opinions in that sense, as those of the German philosophers Robert Spaeman and Ludger Honnefelder, and the Spanish philosopher Blanca Castilla. The latter states: "When there is individualized human life, there is a person in the constitutive sense". The Spanish jurist-philosopher Vicente Bellvar Capella2 considers that "...the seed is a sprouting man, therefore, is "already" and not only virtually, a man".

    Luis Montuega and Fernando Lecan pronounce themselves3 in favor of avoiding reducing the human embryo to a thing.*** Therefore, he considers essential to avoid the creation of new human embryos for experimentation means, to put a stop to the trade and commercial transference of remaining embryos for experimental protocols and to establish a record of frozen embryos. Besides, they state: "only the adult mother cells have showed their therapeutic efficiency and are commonly used in transplants of bone marrow, while the benefits of the embryonic mother cells are merely speculative until now, regarding their clinical applications".

    Several authors have pronounced themselves also in favor of therapeutic cloning. The Spanish researchers Ángel Raya Chamorro and Juan Carlos Izpusúa Belmonte, of the Salk Institute of La Jolla, California, expose their arguments in an article published in El País on December 26, 2001. They consider it should be allowed to investigate with frozen human embryos in order to advance towards therapeutic cloning, which could benefit a large number of patients with diseases that until now are incurable. Although they acknowledge there are citizens who find the destruction of human embryos for research morally reprehensible, they think this is not the belief that prevails in the European population, and that the Law shall reflect this state of opinion. "The unavoidable fact —they warn— is that in the assisted reproduction clinics much more embryos are generated than those which are implanted". These frozen embryos will not be used, neither will they be destroyed, because the Law (referring to Spain) does not allow it. "The future of these embryos is uncertain, and someone shall decide quickly whether to authorize their destruction".

    Argentinean professor Santos Cifuentes4 states: "It has been said (about the embryo) that it is more than a tissue, but less than a person as a subject of Law". As we can see, the issue is more complex and it is hard to decide which position to take.


    Let us try to reason. Let us start by asking ourselves whether the human embryo is a human being. We shall turn to the help of two of the most profound and brilliant thinkers of all times, and perhaps the most extraordinary ones of the Catholic thought: Saint August and Saint Thomas, both free of any suspect of allowing themselves to be carried by the opinions in vogue or (ugh!) politically correct.

    Saint August affirms that, according to Law, abortion could not be considered as homicide "because we cannot say there is a living soul in a body that does not have sensation, and that still has no flesh nor senses".

    Saint Thomas —whose hilomorphic doctrine was adopted by the Vienna Concile in 1312 and then abandoned by the Catholic Church— wrote in his great work Suma Teológica:

      The philosophers of ancient times, without having superior faculties than imagination, assumed that the beginning of the knowledge and movement was some kind of body. They even said that only bodies —and not what were not bodies— were beings, deducing here that the soul was some kind of body. Although the falseness of this opinion could be demonstrated in many ways, we shall not use more than one reasoning which makes evident, and which demonstrates broadly and certainly, that the soul is not body; because it is notorious that not any principle of vital operation is soul, since in that case the eye would be soul, which is certain principle of the vision, and the same could be said about the rest of the soul’s instruments.

    If we follow this reasoning, we would accept that the human embryo is not precisely a human being, but an expectation of being human or a human being in formation. The life of the being which was already born —human being—, then has more value than that of the embryo. But this does not mean, obviously, that the embryo’s life is worthless. It is, finally, a human being and therefore, a quite valuable good. Its destruction without purpose or for trivial reasons would not be justified. Though, the destruction of a frozen embryo, which will not develop itself, for investigations with more scientific interest —which could be the basis to save human beings’ lives afterwards— as United States authorizes, does not seem to be ethically reprehensible. What fate could be a better for those embryos that are, do not forget, already (in an irreversible way) in the world?

    Much harder is to discern whether cloning of new embryos is admissible in order to obtain mother cells from which incurable diseases at present could be successfully treated. Of course, accepting this possibility shall require to previously overcome the challenges described throughout this article, and that it is flawlessly demonstrated with the biggest scientific scruple that the embryonic mother cells represent the best clinical option for the patients. And what about the objection that sustains that it is not decent that some human beings are destroyed to save others? It is true that it has already said that in strict terms, an embryo is not a human being, but it has also been stated that there is human life inside it. We are facing a delicate conflict of goods, which is typical in ethical dilemmas. If we recall those English parents who obtained the authorization to conceive a child through selection of embryos in order to save their already born child, could we consider it reprehensible?

    When the creature of Doctor Frankenstein, in the immortal novel of Mary Shelley, asked him to build it a girlfriend, he asks himself if, as its creator, does not owe his creature that portion of happiness he had the power to grant it, but trembles when thinking in the possible consequences of his acceptance, and he refuses. Prometheus stole the fire from the gods to give it to men and the divine revenge was cruel and implacable.

    Regarding the ethical dilemma that cloning entails, we shall proceed with prudence. We shall not renounce to continue following the route of improving health and life quality of our species, nor should we paralyzed by the fear of the unknown, because by facing the unknown we have achieved portentous scientists that have benefited us considerably. Though, every step shall be rational, not taken only for the mere urge for novelty, in order not to go, as Dr. Frankenstein did, further than our human nature tolerates.

    * Translated by Ingrid Berlanga Vasile.
    ** Researcher at the Legal Research Institute.
    1 Which took place in Valencia, Spain, January 2002.
    2 ¿Clonar? Ética y derecho ante la clonación humana, Granada, Comares, 2000.
    3 Nueva Revista de Política, Cultura y Arte, Madrid, February 2002.
    *** In Spanish, "cosificación" (N. of the T.).
    4 "El inicio de la vida humana", Derecho civil de nuestro tiempo, Universidad de Lima, 1995.

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