The SAGE Encyclopedia of Stem Cell Research. Группа авторов
cells would be perfectly matched to the recipient, eliminating the need to search for compatible donors and greatly decreasing the potential for transplant complication. In addition, therapies based on such cells might be less controversial because the production of induced-pluripotent stem cells does not require the use of any embryos.
How Far Are We From the First Therapeutic Applications of Stem Cell Research?
Both pluripotent and adult stem cells hold considerable promise for the treatment and prevention of human diseases. The realization of these promises will require a constant dialog between clinicians, translational and basic scientists. Adult stem cells have been in clinical use for over 40 years. One of the most successful therapeutic uses of adult stem cells is hematopoietic stem cell transplantation which is an effective way to treat a variety of leukemias and other disorders and is starting to be used in conjunction with gene therapy to cure a number of inherited diseases. However, the use of hematopoietic stem cell transplant is limited to only the most severe diseases by a shortage of donors and by the risks associated with the transplant procedures. A better understanding of the basic biology of stem cells is necessary to develop new culture and amplification methods that will eliminate the shortage. Generally, the intimate details of the biology of all stem cells found during development and in adults are progressively being deciphered by scientists all over the world. This massive effort will eventually yield a wealth of therapies for many ailments from the most benign to the most severe.
Pluripotent stem cells hold a special place in stem cell biology because they are the source of all other cells; there are great hopes that it will eventually be possible to produce many cell types, including adult stem cells, that will be used in a wide range of therapies derived from pluripotent stem cells. Biology and pharmacology are experimental sciences which require access to experimental samples. Studies of human biology during development and in adulthood have long been hampered by the difficulties in obtaining experimental cells. In addition to potential transplantation applications, pluripotent stem cells are extremely useful as an unlimited, reproducible source of human cells that can be used experimentally to better understand the biology of many inherited and acquired diseases and to test and screen for new drugs using highly purified human target cells. These novel experimental models that can complement studies in animals are likely to speed up the development of novel diagnostic and prognostic tools, and of novel drugs and other therapeutic agents.
Differentiation of pluripotent stem cells recapitulates many aspects of human early development. The study of differentiating embryonic stem cells has already yielded novel insights in the development of the blood system and of many other organs. Such understanding is critical to understanding the pathophysiology and to eventually developing treatments for many developmental disorders.
Over 100 years elapsed between the first observations of cells and microorganisms that were made possible by the invention of microscopes, and the development of vaccines and hygiene to protect from diseases caused by these microorganisms. Another 100 years passed before the discovery of the first antibiotics which eradicated many infectious diseases. Together, these discoveries revolutionized the world by causing an unprecedented demographic explosion. The benefits of these early studies continue to accrue since new antibiotics and new vaccines such as the vaccine against papilloma virus, which prevents cervical cancer, are regularly developed.
As was the case for vaccines and antibiotics, it is likely that the benefit of stem cell research will slowly accumulate over many, many years. Hopes could first turn into reality in the fields of artificial transfusion products, an unlimited source of blood stem cells for transplantation, cures for some forms of diabetes and rare eye and liver diseases. More complex therapies involving artificial organs or the central nervous system will take longer to develop.
New technologies and considerable theoretical progress in biology has led us to a new frontier in human history. Advances in stem cell biology, molecular biology, and the new science of genomics which was born after the sequencing of the human genome, will soon give biologists the ability to control and modify the biology and the reproduction of all living organisms, including members of their own species. This will likely result in healthier, longer lives for many of us but will also change and tax the environment to a considerable extent. How long will it take for these developments to occur? What kind of society will result from these new capabilities? How can we ascertain that these technologies be used to better the life of humankind? Will the benefits be shared by all, or reserved for a privileged few? There are no definite answers to any of these questions.
In this encyclopedia we provide the readers with information about our current knowledge of basic stem cell biology, some of the current clinical trials and some of the major research institutions and companies that are engaged in stem cell research. We also highlighted a few past and current leaders in the field. We included a summary of the stem cell legislation regulating the research and discussions of the ethics of stem cell research according to various points of view. Thus, the readers can form their own opinion.
Many important concepts, discoveries, people, institutions, and companies were not included in this encyclopedia. Given the increasing size and liveliness of the stem cell biology community and given the huge impact this novel scientific knowledge and technologies will have on society, providing a fully comprehensive view was not possible. We strived to provide answers to some important questions that might be asked by the general public. We apologize for all omissions and errors in advance. We thank Geoff Golson, Michele Chase, and their team for leading the effort to create this encyclopedia.
Eric E. Bouhassira
Editor
Chronology
April 27, 1890:The Australian-born scientist Walter Heape performs the first embryonic transfer with mammals, successfully transferring an embryo from the womb of a mother rabbit to the womb of a surrogate rabbit.1902:The German scientist Hans Spemann demonstrated that all the information necessary to create a new organism was contained within a single embryonic cell of a salamander, but as that development progressed and the cells became differentiated, the cells lost this ability.June 1, 1909:The Russian American scientist Alexander Maximow presents a lecture at the Hematological Society of Berlin introducing the concept of stem cells as the common ancestors of different cellular elements in the blood.1935:The German scientist Hans Spemann receives the Nobel Prize for his work on the organizer effect, describing how embryonic induction allows cells to influence the development of nearby cells.1951:Dr. George Gay grows the first HeLa cells, taken from a cancer patient named Henrietta Lacks. The HeLa cell line is notable for the fact that, unlike most cell lines that can be expected to die out within a limited period, the HeLa cell line has continued to grow and divide for over 60 years.1952:Robert Briggs and Thomas Joseph King successfully clone a tadpole, using nuclear transfer, a technique first proposed in 1928 by Hans Spemann.1959:First successful use of stem cell transplants in humans, in three separate studies all involving hematopoietic stem cells (HSCs; immature blood cells through bone marrow grafting; E. Donnall Thomas and colleagues use syngeneic grafts (from identical twins) to treat two leukemia patients, George Mathé and colleagues perform allogeneic (from a separate individual who is not an identical twin) bone marrow transplants on five patients accidentally exposed to irradiation, and McGovern and colleagues treat a leukemia patient with autologous (from the patient) bone marrow cells.February 1961:Working at the Ontario Cancer Institute, James A. Hill and Ernest A. McCullough prove that stem cells exist in the bone marrow of mice and have the key properties of self-renewal and the potential to become any type of blood cell.June 1966:R. J. Cole, Robert G. Edwards, and John Paul isolate embryonic stem cells (ESCs) from the pre-implantation blastocysts of a rabbit. 1967:As a university student, Ian Wilmut spends a summer working in the laboratory of E. J. Chris Polge at the University of Cambridge, and becomes fascinated with the process by which an organism develops from a single cell. He later becomes famous when, working with Keith Campbell, his research leads to the birth of Dolly, a sheep born through cloning.1968:First successful use of bone marrow transplantation to treat patients with leukemia or hereditary immunodeficiency: