Watt F M, Hogan B L
Keratinocyte Laboratory, Imperial Cancer Research Fund, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
Science. 2000 Feb 25;287(5457):1427-30. doi: 10.1126/science.287.5457.1427.
Stem cells are currently in the news for two reasons: the successful cultivation of human embryonic stem cell lines and reports that adult stem cells can differentiate into developmentally unrelated cell types, such as nerve cells into blood cells. Both intrinsic and extrinsic signals regulate stem cell fate and some of these signals have now been identified. Certain aspects of the stem cell microenvironment, or niche, are conserved between tissues, and this can be exploited in the application of stem cells to tissue replacement therapy.
人类胚胎干细胞系的成功培育，以及有报道称成体干细胞可分化为发育上不相关的细胞类型，比如神经细胞分化为血细胞。内在和外在信号都调节干细胞的命运，其中一些信号现已被识别。干细胞微环境（即生态位）的某些方面在不同组织间是保守的，这一点可在干细胞用于组织替代疗法中加以利用。
