Human Cloning Background update

 The term “cloning” is used by scientists to describe many different processes that involve making copies of biological material, such as a gene, a cell, a plant or an animal. The cloning of genes, for example, has led to new treatments developed by the biotechnology industry for diseases such as diabetes and hemophilia. In the context of this report, a human embryo produced via cloning involves the process called somatic cell1 nuclear transfer (SCNT). In SCNT, the nucleus of an egg is removed and replaced by the nucleus from a mature body cell, such as a skin cell. In cloning, the embryo is created without sexual reproduction: there is no joining of egg and sperm. Concern over the possibility of producing a human clone increased with the announcement on February 24, 1997, that scientists in Scotland had used SCNT in 1996 to produce the first cloned adult mammal, Dolly, the sheep. Ian Wilmut’s group at the Roslin Institute in Edinburgh removed the nucleus from a sheep egg and replaced it with the nucleus of a mammary gland cell from an adult sheep. The resulting embryo was then transferred to the uterus of a surrogate sheep. A total of 277 such embryos were transferred, but only one lamb was born.2 Analyses of Dolly’s genetic material confirmed that she was derived from the sheep mammary cell. Dolly was euthanized on February 14, 2003, after developing a lung infection. Although some claim that her somewhat early death at six years was related to being a clone, scientists at the Roslin Institute believe her ailment may be due to the fact that she was raised indoors (for security reasons) rather than as a pastured sheep, which can live to 11 or 12 years of age.3 Although scientists have been successful in using SCNT to produce other animals (such as a cat, goat, cow, horse, mule, pig, mouse, and rabbit), the efficiency of the procedure is still very low and frequently results in abnormal development. Proponents maintain that one day cloning may be very useful for a number of agriculture applications, including the improvement of livestock. Currently, cloned mice are used for basic research on human health applications. Cloning Attempts in South Korea. Charges of ethical and scientific misconduct have clouded the reputation of scientists involved in deriving stem cellsfrom cloned human embryos. In February 2004 scientists at the Seoul National University (SNU) in South Korea announced the first isolation of stem cells from a cloned human embryo. In May 2005 this same group announced they had achieved major advances in the efficiency of creating human cloned embryos using SCNT and in isolating human stem cells from the cloned embryos. These eleven new stem cell lines were derived using cells from patients with either spinal cord injury, diabetes, or an immune deficiency and offered the hope of one day providing treatments with patient-matched cells.4 The team attributed the improved success rate in part to the use of freshly harvested eggs from younger fertile women instead of leftover eggs from older women who received fertility treatments.5 However, serious concerns about the achievements of the SNU group began in November 2005 when a co-author of the 2005 paper, Gerald Schatten of the University of Pittsburgh, accused Woo Suk Hwang, the lead researcher of the SNU group, of ethical misconduct.6 In violation of some ethical standards and contrary to statements made in the 2005 paper, junior scientists in the SNU lab secretly donated their own eggs for the experiments and they along with other women received payment for their role. The accusation halted plans for a collaboration between the SNU scientists and US and UK labs that had been announced only one month earlier and resulted in Hwang resigning from all public positions on November 24, 2005. On December 12, 2005, Schatten asked that his name be removed from the 2005 paper when he learned that the work may have been fabricated.7 In early December, scientists in South Korea began questioning the validity of photographs and other scientific evidence presented in the 2005 paper and called for an independent analysis of the data. The University of Pittsburgh and SNU began separate investigations into the charges. On December 15, 2005, another co-author of the 2005 paper, Sung Il Roh, stated to the Korean media that the research had been fabricated and that the 2005 paper should be retracted. Hwang agreed to the retraction on December 16, but continued to defend the scientific results.8 A preliminary report released on December 23, 2005, by SNU stated that nine of the eleven stem cell lines described in the 2005 paper were deliberately fabricated. and the remaining two stem cell lines were still under investigation.9 On December 29, 2005, Seoul National University stated that the remaining stem cell lines were not patient-matched and were not derived through cloning.10 On January 10, 2006, SNU stated that results of the 2004 paper, which reported the first derivation of stem cells from a cloned human embryo, were also a deliberate fabrication.11 Cloning Attempts in the United Kingdom and United States. Scientists in the United Kingdom, at the University of Newcastle and the University of Edinburgh, and scientists in the United States, at Harvard University, Advanced Cell Technology and the University of California in San Francisco, are working on deriving patient-matched stem cells from cloned human embryos.12 In the United Kingdom, scientists performing human cloning and embryonic stem cell research are regulated by the Human Fertilization and Embryology Authority (HFEA). A team of scientists headed by Alison Murdoch at the University of Newcastle received permission from HFEA to start therapeutic cloning experiments in August 2004.13 In May 2005, the team announced that it had created a cloned human embryo but has not yet reported success in isolating stem cells from a cloned human embryo. A research team headed by Ian Wilmut at the University of Edinburgh also is seeking permission from HFEA to begin working on SCNT experiments using human embryos. Scientists at the Harvard Stem Cell Institute intend to produce cloned human embryos for research studies on juvenile diabetes, Parkinson’s disease, and several other diseases.14 In November 2003, the research group, headed by Douglas Melton and Kevin Eggan, submitted their proposal to a Harvard committee composed of ethicists, scientists and public policy experts. Preliminary permission to proceed with the research was granted in January 2005, provided that a number of specific restrictions were followed and approval was received from a second committee charged with safeguarding the use of human subjects in research.15 The restrictions include limitations on the developmental age of the cloned embryos used in experiments, a prohibition on reproductive cloning, and a limitation on paying only

for the medical expenses of women who donate eggs. In June 2006, after more than 2½ years, the Harvard group announced that they had received final approval in the review process that looked at ethical, legal and intellectual property issues and involved eight different boards and committees at five separate institutions.16 In May 2006, scientists at the University of California in San Francisco (UCSF) and Advanced Cell Technology (ACT) in Worcester, MA, independently announced that they would resume their efforts to produce cloned human embryos for research purposes.17 Both UCSF and ACT (see below) had been working separately on such experiments prior to the February 2004 South Koreans’ announcement of cloning success, but subsequently suspended their work; in the case of ACT due to lack of funding and in the case of UCSF due to lack of success. Clonaid. On December 27, 2002, a representative of Clonaid announced the birth of the first cloned human, a seven-pound baby girl nicknamed Eve. The baby was born on December 26, 2002, at an undisclosed location outside the United States. Although the company offered no proof of its claim, Dr. Brigette Boisselier, Managing Director of Clonaid, stated that genetic tests would show that the baby is the clone of the 31-year-old American woman who is the birth mother. To date the test results have not been released; the company claims that the parents fear the test results could lead to legal actions and loss of custody of the child.18 The Clonaid website indicates that “13 cloned babies are now alive,” and that “each month, between 10 and 15 implantations will be performed” in the Clonaid laboratory.19 Clonaid was founded in 1997 by the leader of the Raelians, an international sect of 55,000 people in 84 countries, which claims that life on Earth was created via genetic engineering by a human extraterrestrial race.20 The Food and Drug Administration (FDA) is investigating the company’s actions; the agency would consider any human cloning activity to be illegal if performed in the United States.21 In April 2001 FDA investigated a Clonaid laboratory in Nitro, WV; the laboratory closed shortly thereafter.22 Advanced Cell Technology. On November 25, 2001, Advanced Cell Technology (ACT) of Massachusetts announced that it had created the world’s first
human embryos produced via cloning.23 ACT used two techniques, SCNT and parthenogenesis, to produce human embryos. ACT researchers obtained eggs from seven women, ages 24 to 32, who were paid $3,000 to $5,000. In the SCNT approach, scientists removed the nucleus from 19 eggs and replaced it with a nucleus from another adult cell. The nucleus of a skin cell was used for 11 eggs, and for the remaining eight eggs, cumulus cells were used. Eggs that received a skin cell nucleus did not divide; seven of the eggs with the cumulus cell nucleus began to divide but division stopped at the four-to-six-cell stage. In parthenogenesis, an egg cell is treated with chemicals causing it to divide without being fertilized by a sperm. ACT exposed 22 human eggs to the chemicals. After five days, six eggs had matured into a larger mass of cells before division stopped. None of the embryos developed by ACT divided sufficiently to produce stem cells. ACT suspended its work in 2004. The goal of ACT’s work was to produce human embryonic stem cells and develop new therapies for diseases such as diabetes and Parkinson’s disease.24 Scientists believe that stem cells transplanted into a patient could treat disease or injury by replacing damaged tissue. If the cell nucleus used in SCNT is from the patient, the stem cells would be genetically identical to the patient, recognized by the patient’s immune system, and would avoid any tissue rejection problems that could occur in other stem cell therapeutic approaches. Because of this, many scientists believe the SCNT technique may provide the best hope of eventually treating patients using stem cells for tissue transplantation


 A somatic cell is a body cell, as opposed to a germ cell, which is an egg or sperm cell.
2 I. Wilmut et al., “Viable Offspring Derived from Fetal and Adult Mammalian Cells.” Nature, vol. 385, Feb. 27, 1997, pp. 810-813.
 3 G. Kolata, “First Mammal Clone Dies; Dolly Made Science History,” New York Times, Feb. 15, 2003, p. A4.
4 Gretchen Vogel, “Korean Team Speeds Up Creation of Cloned Human Stem Cells,” Science, vol. 308, May 20, 2005, pp. 1096-1097.
5 In both cases, women receive a series of hormone injections that stimulate the ovaries to produce multiple eggs which are removed via a surgical procedure. There is a small chance (up to 5%) that a woman will over respond to the hormone injections resulting in complications; in rare situations the outcome is fatal. The long-term consequences of the hormone injections are unknown.
6 Gretchen Vogel, “Collaborators Split over Ethics Allegations” Science, Nov. 18, 2005, p. 1100.
7 The Associated Press, “South Korean’s Cloning Research Challenged,” The New York Times, Dec. 13, 2005. 8 Gordan Fairclough, “South Korean Scientist Denies Falsifying Stem-Cell Research,” The Wall Street Journal, Dec. 17, 2005, p. A4.