Stem Cell Research Questions And Answers
Stem Cell Research Questions And Answers
What are in vitro fertilization (IVF)-derived stem cells?
Human IVF-derived stem cells have the unique capacity to become any type of cell, tissue or organ as they mature and develop, yet they cannot themselves develop into a full human being. Scientists do not know why these cells alone have this ability. Because they can form any cell type of the human body, these human stem cells hold great promise for several medical therapies and scientific purposes. They are able to replicate themselves while remaining in an immature, or "undifferentiated" state, thus offering a potentially unlimited source of cells for organ transplantation, as well as provide a model system for drug discovery and the study of human development.
Does JDRF support IVF-derived stem cell research?
Yes. While IVF-derived stem cell research is at a very early stage, it appears to offer great promise to quicken the pace of discovery for a cure for diabetes. JDRF encourages the pursuit of this line of research within the framework of appropriate scientific and ethical safeguards established by representatives of the public. JDRF firmly believes that research should proceed using all types of stem cells because it is impossible to predict which will provide the most medical benefits. `
How can these IVF-derived stem cells help cure diabetes?
One of the most promising ways of curing diabetes is to biologically restore the function of islet cells. At the present time, this can occur either through islet cell transplantation or through engineering of cells to restore the insulin secreting function. In both instances, the availability of stem cells would significantly expedite research progress.
Islet cell transplantation has been largely unsuccessful for two important reasons:
Insufficient islets available for transplantation;
Recurrence of the autoimmune response that attacks the islets after transplantation.
The problem of insufficient supply of islet cells could potentially be solved through additional stem cell research. Because the cells that are being studied are so early in their development stage, scientists are hopeful they will be able to one day direct their development into any human tissue or organ. If and when scientists can specialize these cells to become insulin-producing islet cells, cell lines could be developed to produce an unlimited number of islet cells from even just a single primordial stem cell. This would effectively solve the islet cell supply problem.
In addition, in most cases, the immune system of a person with Type 1 diabetes will not tolerate an islet cell transplantation, even when an individual is given anti-rejection medications (which themselves can cause serious problems). Because stem cells are primordial, all-purpose, cells from which all tissues of the body develop, it may be possible to genetically alter them so that they will not be susceptible to an immune attack. This would negate the need for immunosuppression.
Why not only use adult stem cells, which are not as controversial?
Any stem cells isolated from humans after birth are mature cells, and are therefore called adult stem cells. They are found in the various adult body tissues they maintain. There are several approaches now in human clinical trials that utilize adult stem cells. These cells do not have the same capacity to multiply in culture as those obtained from fertilized egg sources. Moreover, adult stem cells are more limited in their potential and have not been shown to form all cell and tissue types. Unlike adult stem cells, IVF-derived stem cells contain two salient features important to research: 1) they can divide to a great extent because their proliferative capacity is far greater than adult stem cells; and 2) they can form (virtually) any cell type.
What about recent reports that adult stem cells can be isolated from fat tissue?
Recently, it has been reported that research on fat tissue could mean that stem cells derived from in vitro fertilized eggs that will otherwise be discarded may be no longer necessary. However, prominent stem cell researchers have pointed out that such a claim is extremely premature. The research on fat cells is interesting and part of a current line of research showing that mature cells have the potential to change into different types of cells. While this research holds promise for certain therapies, the fat cells have not yet been shown to be able to differentiate into cells of any kind, nor has it been shown that the cells studied are truly stem cells, that is, cells that can divide indefinitely in laboratory culture like embryonic stem cells. If the Administration permits federal funding for research on stem cells that come from fertilized eggs destined to be thrown away, such research could be pursued along with fat cell and other adult cell research so that we can maximize the opportunity of discovering new therapies for individuals suffering from juvenile diabetes, heart disease, cancer, Alzheimer?s, Parkinson?s, and spinal cord injury.
Is there controversy over using germ cells?
Germ cells are derived from tissue from terminated pregnancies before the end of the first trimester. Public funding for this research is currently allowed under a law passed by large majorities in Congress in 1993. Opponents have argued that federal support of such research will increase the number of terminated pregnancies. However, safeguards are in place to prevent this from happening, and statistics firmly establish that this is not occurring:
Informed consent to isolate the cells is obtained from donors only after they have independently made the decision to terminate their pregnancies. Further, the donors are not allowed any kind of compensation for the use of the tissue.
Voluntary induced abortion rates have actually decreased an average of 3 percent per year from 1990 to 1997-the last year for which data are available.
Besides curing disease, can stem cells be used for other things?
Stem cell research will shed light on abnormal cell growth and could help treat and perhaps prevent birth defects and cancer. Stem cells also could be used for testing pharmaceutical products on specific cell types, which would speed the development of drug therapies and reduce the number of animal studies and human clinical trials.
Is stem cell research the same thing as cloning?
No. Stem cell research aims to develop new life-saving treatments, and cannot be used to develop a human being. Stem cells derived from the inner cell mass of an early embryo cannot give rise to a placenta, so a human being could not develop, even if the stem cells were implanted into a woman's uterus.
Will federal funding be used for procuring stem cells?
In compliance with the ban on testing human embryos, scientists cannot use federal funds to derive stem cells from embryos. However, they may use federal funds to study stem cells once they have already been isolated. Scientists who procure stem cells from fetal tissue are eligible for federal funding, as fetal tissue research is not under government ban.
Will federal funding be used for procuring stem cells?
Studies on adult stem cells are important and will provide valuable insights into the use of stem cells in transplantation procedures. However, all avenues of research must remain open. Only through exploration of all types of stem cell research will scientists find the most efficient and effective ways to treat diseases.
Is the National Institutes of Health funding stem cell research now?
After careful consideration, the Department of Health and Human Services, of which the NIH is one part, recently ruled that stem cell research does not violate the 1996 prohibition on federal funding for human embryo research, and is therefore eligible for federal funding.
Because of the important ethical issues surrounding the research, an NIH advisory committee was established to develop guidelines on how to proceed with federal funding in August 2000. Advice was sought from MDs, ethicists, theologians, and patient advocates. These guidelines require, among other things, informed consent and outline strict prohibitions on buying or selling human embryos, and require oversight by a special committee, the Human Pluripotent Stem Cell Review Group (HPSCRG), that will review adherence to the guidelines. Beginning in March 2001, the NIH has accepted applications from scientists which are currently going through the peer-review system. These applications will also have to go through the second-level of review for adherence to the strict NIH guidelines by the HPSCRG.
