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Commentary: The seven challenges of stem cell education in biochemistry

The current controversy regarding stem cells is an excellent vehicle to accomplish two very important goals. First, stem cells represent scientific lessons in developmental biology, gene regulation, hormone action, regulation of metabolic pathways, and a host of other fundamental concepts in modern biology. Second, there is the need to educate the public in general and our students in particular about the scientific facts behind the issues that are being politicized and misrepresented regarding stem cells. Any curriculum utilizing stem cells as a unifying theme begins with a definition and description of stem cells followed by a thorough discussion of the important distinction between adult and embryonic stem cells. This could be followed by lessons regarding differentiation and pathways of cellular maturity and development and the topic of cell death and apoptosis. After these basic topics, there are what might be called the “seven challenges” of stem cells, each with their own scientific lesson and entree into discussions of the ethical, political, and possibly commercial aspects of stem cell biology and therapy. Challenge 1 raises the question of what stem cells can or cannot do. They can continuously divide throughout life, but they can also differentiate into tissue. There are the concepts of multipotency, pluripotency of stem cells, and the transition into committed progenitor cells. Their remarkable versatility is the hope for their use in repair and regeneration of injured tissue. Challenge 2 raises the issue of which works best, embryonic or adult cells. Embryonic cells can be obtained from excess in vitro fertilized eggs. Their overriding advantage over adult stem cells is that they are pluripotent and in theory would be suitable for transforming into any type of tissue. They could provide a large supply of cells for human transplantation. However, there are religious, political, and ethical challenges that have thrown this scientific field into a national debate. Adult stem cells are found in all tissues, are few in number, but have the advantage that they could be used for autologous engraftment. However, the challenge is to grow adult stem cells in large enough numbers for treatment. Challenge 3 is technical and scientific. Growing stem cells in culture requires knowledge of tissue culture, growth factors, and karyotyping. A major challenge is to maintain both a replicative culture and a differentiated culture. Differentiation requires molecular and chemical induction pathways, the wnt, notch, and hedgehog transcription signaling, cell surface markers, microRNAs, and epigenetics. Challenge 4 raises the questions of ethics. Is destroying a human blastocyst, a potential embryo, the same as murder of an adult human? Are new techniques for somatic cell nuclear transfer or blastomere-derived stem cells without destroying the embryo ethical or unethical? Is it ethical to withhold from a patient a potential cure or treatment? Challenge 5 raises the legal challenges to stem cell research. In the United States, although it is not illegal to do stem cell research, it is illegal to use federal funding to do it. This was based on a law from 2001 banning federal support for such research with the exception of allowing a limited number of human embryonic stem cell lines made prior to the enactment of the law. However, studies on these lines have shown that they contain mouse genes and possibly viral genes. The longer they are passaged, the less useful they become. This has led to an initiative in California that raised state money to support human stem cell research and a federal bill from 2005 that was vetoed by the President. Challenge 6 raises the patent issue. The first successful in vitro method to grow human embryonic stem cells was patented by the University of Wisconsin, and exclusive license was given to Geron, the company that had supported the Wisconsin research team. This method has subsequently been used in the culture of all human embryonic cell lines, but the cost of licensing is seen as a hindrance to progress in developing the cells for different treatments and as providing a disincentive for companies to engage in stem cell trials. Challenge 7 raises the issue of the commercialization of stem cells. Foreign companies and researchers not inhibited by the legal challenges discussed above are in global competition with the United States for stem cell products. United States companies are moving human embryonic research to other countries. Clinical trials are being carried out in Europe, Brazil, China, and India but not in the United States. The question of how clinical trials, regulatory approval, and reimbursement issues will be handled are all keys to the future of this promising technology. In conclusion, we encourage our colleagues to suggest topics and detailed curricula exploiting the public awareness of stem cells as a rationale for teaching the basics of the life sciences of the 21st century. ‡ To whom correspondence should be addressed. E-mail: schuster@kgi.edu. © 2007 by The International Union of Biochemistry and Molecular Biology BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION Vol. 35, No. 1, p. 73, 2007