Pera M F
Monash Institute of Reproduction and Development, Monash University, Clayton, Victoria, Australia.
Reprod Fertil Dev. 2001;13(1):23-9. doi: 10.1071/rd00077.
The recent development of embryonic stem (ES) cells from human blastocysts has the potential to revolutionize many of our approaches to human biology and medicine. Continued objection to the use of human ES cells on ethical grounds may inhibit progress or defer this opportunity indefinitely. It is essential that the ethical discussion proceed on a sound scientific basis. The ethical controversy surrounding human ES cells concerns their origin from human blastocysts and the perception of their developmental potential. It is likely that the worldwide requirement for human ES cells will be met by the development of a small number of cell lines, as has been the case in the mouse; current rates of success for human ES cell establishment suggest that only a modest number of embryos will be required to achieve this goal. It is in the public interest that human ES cell lines be derived under circumstances that will enable their widespread distribution with minimum encumbrances to academic researchers throughout the world. In considering the developmental potential of ES cells, an important distinction exists between pluripotentiality, or the ability to develop into a wide range of somatic and extraembryonic tissues, and totipotentiality, the ability of a cell or collection of cells to give rise to a new individual given adequate maternal support. There is no evidence that ES cells from any species can give rise to a new individual except when combined with cells which are the immediate progeny of a zygote. These developmental limitations of ES cells appear to relate to their inability to undergo axis formation and to generate the body plan. Alternatives to blastocyst-derived ES cells include embryonic germ cells, adult tissue stem cells, transdetermination of committed somatic cells, and therapeutic cloning. These research areas are complimentary and synergistic to ES cell research and it is premature and counterproductive to suggest that one avenue should be pursued in preference to another. The combination of cloning and ES cell technology has the potential to address many important issues in transplantation medicine and research, but a better understanding of the reprogramming of somatic cells is required before we can regard ES cells derived from normal and nuclear transfer blastocysts as equivalent.
从人类囊胚中获取胚胎干细胞（ES细胞）的最新进展，有可能彻底改变我们在人类生物学和医学领域的许多研究方法。基于伦理理由继续反对使用人类ES细胞，可能会阻碍进展，或无限期推迟这一机遇。至关重要的是，伦理讨论要建立在坚实的科学基础之上。围绕人类ES细胞的伦理争议，涉及它们源自人类囊胚以及对其发育潜能的认知。正如在小鼠研究中那样，少量细胞系的建立可能就会满足全球对人类ES细胞的需求；目前人类ES细胞建系的成功率表明，只需少量胚胎就能实现这一目标。在能够使人类ES细胞系得以广泛传播且对全世界学术研究人员的限制最小的情况下获取这些细胞系，符合公众利益。在考虑ES细胞的发育潜能时，多能性（即发育成多种体细胞和胚外组织的能力）与全能性（一个细胞或一组细胞在获得足够母体支持后发育成一个新个体的能力）之间存在重要区别。没有证据表明，除了与受精卵的直接后代细胞结合外，任何物种的ES细胞都能发育成一个新个体。ES细胞的这些发育限制似乎与其无法进行轴形成和生成身体结构有关。囊胚来源的ES细胞的替代物包括胚胎生殖细胞、成体组织干细胞、定向体细胞的转决定以及治疗性克隆。这些研究领域与ES细胞研究相辅相成、相互促进，认为应优先选择某一途径而放弃其他途径的观点为时过早且会适得其反。克隆与ES细胞技术的结合有可能解决移植医学和研究中的许多重要问题，但在我们能够将源自正常囊胚和核移植囊胚的ES细胞视为等同之前，还需要更好地理解体细胞的重编程过程。
