This article's lead section contains information that is not included elsewhere in the article.(August 2024) |
Part of a series on |
Human enhancement |
---|
The Hwang affair, [1] or Hwang scandal, [2] or Hwanggate, [3] is a case of scientific misconduct and ethical issues surrounding a South Korean biologist, Hwang Woo-suk, who claimed to have created the first human embryonic stem cells by cloning in 2004. [4] [5] Hwang and his research team at the Seoul National University reported in the journal Science that they successfully developed a somatic cell nuclear transfer method with which they made the stem cells. In 2005, they published again in Science the successful cloning of 11 person-specific stem cells using 185 human eggs. [6] The research was hailed as "a ground-breaking paper" in science. Hwang was elevated as "the pride of Korea", [7] "national hero" [of Korea], [8] and a "supreme scientist", [9] to international praise and fame. [10] [11] Recognitions and honours immediately followed, including South Korea's Presidential Award in Science and Technology, and Time magazine listing him among the "People Who Mattered 2004" [12] and the most influential people "The 2004 Time 100". [13]
Suspicion and controversy arose in late 2005, when Hwang's collaborator, Gerald Schatten at the University of Pittsburgh, came to know of the real source of oocytes (egg cells) used in the 2004 study. [14] The eggs, reportedly from several voluntary donors, were from Hwang's two researchers, a fact which Hwang denied. The ethical issues made Schatten immediately break his ties with Hwang. In December 2005, a whistleblower informed Science of reuse of the same data. As the journal probed in, it was revealed that there was a lot more data fabrication. [14] The SNU immediately investigated the research work and found that both the 2004 and 2005 papers contained fabricated results. Hwang was compelled to resign from the university, [15] and publicly confessed in January 2006 that the research papers were based on fabricated data. [14] Science immediately retracted the two papers. [16]
In 2009, the Seoul Central District Court convicted Hwang for embezzlement and bioethical violations, sentencing him to a two-year imprisonment. [17] The incident was then recorded as the scandal that "shook the world of science," [6] and became "one of the most widely reported and universally disappointing cases of scientific fraud in history". [18]
Hwang Woo-suk was a professor of veterinary biotechnology at the Seoul National University and specialised in stem cell research. In 1993, he devised an in vitro fertilisation method with which he made the first assisted reproduction in cows. [19] He rose to public notice in 1999 when he announced that he had successfully cloned a dairy cow, named Yeongrong-i, and a few months later, a Korean cow, Jin-i (also reported as Yin-i [8] ). The following year, he announced the preparation for cloning an endangered Siberian tiger. [8] It was a failed attempt, but nonetheless, his popularity in the Korean public escalated from wide media coverage. In 2002, he claimed creation of a genetically modified pig that could be used for human organ transplant. [6] In 2003, he announced the successful cloning of a BSE (bovine spongiform encephalopathy)-resistant cow. [20] However, science sceptics raised concern over the absence of research papers for any of his claims. [19]
In 2004, Hwang announced the first complete cloning of a human embryo. [13] [21] The research, published in the 12 March 2004 issue of Science, was reported as "Evidence of a pluripotent human embryonic stem cell line derived from a cloned blastocyst." [22] For its potential medical value to replace diseased and damaged cells, several scientists had previously tried to clone the human embryo, but in vain. [23] Hwang's team had developed an improved method of somatic cell nuclear transfer using which they could transfer the nuclei of somatic (non-reproductive) cells into egg cells which had their nuclei removed. [24] They used human egg cells and cumulus cells, which are found in ovaries near the developing eggs and are known to be good source of nuclear transfer. After emptying an egg of its nucleus, they transferred the nucleus of the cumulus cell into it. The new egg cell divided normally and grew into a blastocyst, an early embryo characterised by a hollow ball of cells. They isolated the outer trophoblast cells that are destined to become the placenta, discarding the inner cell mass that would form the placenta. When the trophoblast cells were cultured, they could divide and form different tissues, indicating that they were viable stem cells. [25] The report concluded: "This study shows the feasibility of generating human ES [embryonic stem] cells from a somatic cell isolated from a living person." [22] It was the first instance of cloning of adult human cells and human embryonic stem cells. [25]
Hwang publicly reported the research at the annual meeting of the American Association for the Advancement of Science (AAAS) in Seattle on 16 February 2004. [24] He specified that they used 242 eggs from 16 unpaid volunteers, creating about 100 cells from which 30 embryos were developed. [26] Since the embryos had adult DNA, the resulting stem cells became clones of the adult somatic cells. From the embryos, the stem cells were collected and grafted into mice in which they could grow into various body parts including muscle, bone, cartilage and connective tissues. [23] The method ensured that immune rejection would be avoided so that it could be used for the treatment of genetic disorders, as Hwang explained: "Our approach opens the door for the use of these specially developed cells in transplantation medicine." [26]
Hwang's team reported another successful cloning of human cells in the 17 June 2005 issue of Science, in this case, embryonic stem cells derived from skin cells. [27] Their study claimed the creation of 11 different stem cell lines that were the exact match of DNA in people having a variety of diseases. The experiment used 185 eggs from 18 donors. [28] The report explicitly stated that: "Patients voluntarily donated oocytes and somatic cells for therapeutic cloning research and relevant applications but not for reproductive cloning ... no financial reimbursement in any form was paid." [27]
When the 2004 research was announced, it was received with praise and admiration. Donald Kennedy, editor-in-chief of Science, remarked: "the generation of stem cells by somatic cell nuclear transfer methods involving the same individuals may hold promise for advances in transplantation technology that could help people affected by many devastating conditions." [26] Michael S. Gazzaniga, neuroscientists and bioethicist at Dartmouth College, who had supported therapeutic cloning, commented it as "a major advance in biomedical cloning". [29] American scientists took the news to criticise the weakness of US government in stem cell research and its prohibitive attitude. [26] [30] As Helen Pearson reported in Nature, the cloning accomplishment turned Asians into "scientific tigers". [24]
Time reported that as a consequence of the achievement, "a medical and ethical door that had remained mostly closed was kicked wide open." [31] Hwang and his colleague Shin Yong Moon were listed by Time at number 84 in its list of most influential people "The 2004 Time 100" in April 2004. [13]
The critical issue was on bioethics, as the method ultimately wasted many human embryos [32] and could be used to create full human clones, as John T. Durkin argued in Science: "the developmental events leading from fertilized ovum, to blastula, to embryo, to fetus, to fully formed adult constitute a continuum." [33] Hwang claimed that the purpose was for medical applications only, and said in Seattle, "Reproductive cloning is strictly prohibited [in South Korea]." [30] At the time, South Korea was developing its "Bioethics and Biosafety Act" to be enforced in 2005. The regulations proscribed human reproductive cloning and experimental fusion of human and animal embryos; even therapeutic cloning for diseases would require authorised approval. Based on this situation, Sang-yong Song of the Hanyang University, criticised Hwang for not waiting the forthcoming regulations and social consensus in Korea. [34] Howard H. Kendler, psychologist at the University of California, had an unbiased viewpoint, commenting: "Although individuals will differ in their opinions, a democracy can decide whether the benefits of embryonic stem cell research outweigh any disadvantages. Science can assist in making this decision, but cannot dictate it." [35]
Hwang loved public attention and tried to establish a network of bureaucrats. To name his second cloned cow, he solicited President Kim Dae-jung, who gave the name after a celebrated Korean geisha "Hwang Jin-i." [6] As he announced the cloning of a BSE-resistant cow in 2003, [20] President Roh Moo-hyun visited his laboratory and was shown a dog cured from its injury using stem cell transfer, to which the president applauded, "this is not a science; this is a magic." [6] From that point, Hwang received escalated research funding from the government that peaked in 2005 at around US$30 million. [3] That year, Korean Ministry of Science and Technology officially honoured him as "Supreme Scientist" for the first time in Korea; the title carried US$15 million. [36] The government set up the World Stem Cell Hub at Seoul National University Hospital on 19 October 2005, created and directed by Hwang. [37] [38] On the day of opening, 3000 people registered for willingness to take stem cell therapy. [6]
In the 2004 report, Hwang's team prudently remarked that "we cannot completely exclude the possibility that the cells had a parthenogenetic origin." [22] Reference to parthenogenesis, the ability of embryo development from egg cells without fertilisation, was relevant because it had been documented that stem cells are capable of such transformation. In 1984, an experiment demonstrated that a genetic mixture (chimera) of nuclei from the stem cells, one-cell-stage embryos of mouse could develop into full embryos. [39] Researchers at Advanced Cell Technology (ACT) in Worcester, Massachusetts, further showed in 2002 that primate (in this case crab-eating macaque, Macaca fascicularis) stem cells grew into the blastocyst stage. [40] The ACT subsequently announced that they created the human parthenogenetic cells, although the cells could not reach the blastocyst stage. [41] In 2003, Gerald Schatten of the University of Pittsburgh and his team reported a failed attempt of stem cell cloning in rhesus monkey, the cell divisions were always erratic and produced abnormal chromosomes. [42] Schatten declared: "This reinforces the fact that the charlatans who claim to have cloned humans have never understood enough cell or developmental biology." [43]
In April 2023, Canadian YouTuber Kevin Mackay (known on YouTube as BobbyBroccoli) released an independently made two part documentary series covering the Hwang Woo-Suk scandal.
In June 2023, Netflix released the documentary film King of Clones , which covered Hwang Woo-suk and this affair.
Cloning is the process of producing individual organisms with identical genomes, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction; this reproduction of an organism by itself without a mate is known as parthenogenesis. In the field of biotechnology, cloning is the process of creating cloned organisms of cells and of DNA fragments.
Dolly was a female Finn-Dorset sheep and the first mammal that was cloned from an adult somatic cell. She was cloned by associates of the Roslin Institute in Scotland, using the process of nuclear transfer from a cell taken from a mammary gland. Her cloning proved that a cloned organism could be produced from a mature cell from a specific body part. Contrary to popular belief, she was not the first animal to be cloned.
Human cloning is the creation of a genetically identical copy of a human. The term is generally used to refer to artificial human cloning, which is the reproduction of human cells and tissue. It does not refer to the natural conception and delivery of identical twins. The possibilities of human cloning have raised controversies. These ethical concerns have prompted several nations to pass laws regarding human cloning.
In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell in a cell lineage. They are found in both embryonic and adult organisms, but they have slightly different properties in each. They are usually distinguished from progenitor cells, which cannot divide indefinitely, and precursor or blast cells, which are usually committed to differentiating into one cell type.
A genetic chimerism or chimera is a single organism composed of cells with more than one distinct genotype. Animal chimeras can be produced by the merger of two embryos. In plants and some animal chimeras, mosaicism involves distinct types of tissue that originated from the same zygote but differ due to mutation during ordinary cell division.
In genetics and developmental biology, somatic cell nuclear transfer (SCNT) is a laboratory strategy for creating a viable embryo from a body cell and an egg cell. The technique consists of taking a denucleated oocyte and implanting a donor nucleus from a somatic (body) cell. It is used in both therapeutic and reproductive cloning. In 1996, Dolly the sheep became famous for being the first successful case of the reproductive cloning of a mammal. In January 2018, a team of scientists in Shanghai announced the successful cloning of two female crab-eating macaques from foetal nuclei.
The blastocyst is a structure formed in the early embryonic development of mammals. It possesses an inner cell mass (ICM) also known as the embryoblast which subsequently forms the embryo, and an outer layer of trophoblast cells called the trophectoderm. This layer surrounds the inner cell mass and a fluid-filled cavity or lumen known as the blastocoel. In the late blastocyst, the trophectoderm is known as the trophoblast. The trophoblast gives rise to the chorion and amnion, the two fetal membranes that surround the embryo. The placenta derives from the embryonic chorion and the underlying uterine tissue of the mother. The corresponding structure in non-mammalian animals is an undifferentiated ball of cells called the blastula.
Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo. Human embryos reach the blastocyst stage 4–5 days post fertilization, at which time they consist of 50–150 cells. Isolating the inner cell mass (embryoblast) using immunosurgery results in destruction of the blastocyst, a process which raises ethical issues, including whether or not embryos at the pre-implantation stage have the same moral considerations as embryos in the post-implantation stage of development.
Hwang Woo-suk is a South Korean veterinarian and researcher. He was a professor of theriogenology and biotechnology at Seoul National University until he was dismissed on March 20, 2006. He was considered a pioneering expert in stem cell research and even called the "Pride of Korea". However, he became infamous around November 2005 for fabricating a series of stem cell experiments that were published in high-profile journals, the case known as the Hwang affair.
A stem cell line is a group of stem cells that is cultured in vitro and can be propagated indefinitely. Stem cell lines are derived from either animal or human tissues and come from one of three sources: embryonic stem cells, adult stem cells, or induced pluripotent stem cells. They are commonly used in research and regenerative medicine.
Gerald Schatten is an American stem cell researcher with interests in cell, developmental, and reproductive biology. He is Professor and vice-chair of Obstetrics, Gynecology and Reproductive Sciences and Professor of Cell Biology and of Bioengineering in the Schools of Medicine and Engineering at the University of Pittsburgh, where he is also Director of the Division of Developmental and Regenerative Medicine at the university's School of Medicine. Additionally, he is deputy director of the Magee-Women's Research Institute and Director of the Pittsburgh Development Center.. He is a member of the NCI-designated University of Pittsburgh Cancer Center and the McGowan Institute for Regenerative Medicine.
The stem cell controversy concerns the ethics of research involving the development and use of human embryos. Most commonly, this controversy focuses on embryonic stem cells. Not all stem cell research involves human embryos. For example, adult stem cells, amniotic stem cells, and induced pluripotent stem cells do not involve creating, using, or destroying human embryos, and thus are minimally, if at all, controversial. Many less controversial sources of acquiring stem cells include using cells from the umbilical cord, breast milk, and bone marrow, which are not pluripotent.
Stem cell research policy varies significantly throughout the world. There are overlapping jurisdictions of international organizations, nations, and states or provinces. Some government policies determine what is allowed versus prohibited, whereas others outline what research can be publicly financed. Of course, all practices not prohibited are implicitly permitted. Some organizations have issued recommended guidelines for how stem cell research is to be conducted.
Parthenogenesis is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization. In animals, parthenogenesis means development of an embryo from an unfertilized egg cell. In plants, parthenogenesis is a component process of apomixis. In algae, parthenogenesis can mean the development of an embryo from either an individual sperm or an individual egg.
Samuel H. Wood is a scientist and fertility specialist. In 2008, he became the first man to clone himself, donating his own DNA via somatic cell nuclear transfer (SCNT) to produce mature human embryos that were his clones.
Stemagen is a corporation headed by Dr. Samuel Wood, notable for cloning adult skin cells In January 2008, Dr. Andrew French, Stemagen's chief scientific officer and Wood in California, announced that they successfully created the first 5 mature human embryos using DNA from adult skin cells, aiming to provide a less-controversial source of viable embryonic stem cells. Dr. Wood and a colleague donated skin cells, and DNA from those cells was transferred to human eggs. It is not clear if the embryos produced would have been capable of further development, but Dr. Wood stated that if that were possible, using the technology for reproductive cloning would be both unethical and illegal. The 5 cloned embryos, created in Stemagen Corporation lab, in La Jolla, were later destroyed to confirm the nuclear transfer process.
Embryomics is the identification, characterization and study of the diverse cell types which arise during embryogenesis, especially as this relates to the location and developmental history of cells in the embryo. Cell type may be determined according to several criteria: location in the developing embryo, gene expression as indicated by protein and nucleic acid markers and surface antigens, and also position on the embryogenic tree.
The laws and policies regarding stem cell research in the People's Republic of China are relatively relaxed in comparison to that of other nations. The reason for this is due to different traditional and cultural views in relation to that of the West.
Cell potency is a cell's ability to differentiate into other cell types. The more cell types a cell can differentiate into, the greater its potency. Potency is also described as the gene activation potential within a cell, which like a continuum, begins with totipotency to designate a cell with the most differentiation potential, pluripotency, multipotency, oligopotency, and finally unipotency.
Yi Zhang is a Chinese-American biochemist who specializes in the fields of epigenetics, chromatin, and developmental reprogramming. He is a Fred Rosen Professor of Pediatrics and professor of genetics at Harvard Medical School, a senior investigator of Program in Cellular and Molecular Medicine at Boston Children's Hospital, and an investigator of the Howard Hughes Medical Institute. He is also an associate member of the Harvard Stem Cell Institute, as well as the Broad Institute of MIT and Harvard. He is best known for his discovery of several classes of epigenetic enzymes and the identification of epigenetic barriers of SCNT cloning.