Ann B. Parson focuses on the current promise of stem cell research as a means of developing new therapies that might be more powerful and better tailored to the needs of individuals. At the same time, she gives us the larger and quite fascinating historical context of research on biological regeneration. Her account takes us back to 1740, when Abraham Trembley discovered tiny hydras in a stream near the Hague, dissected them under a microscope, then watched them miraculously regenerate.
The Proteus Effect is written in an easy journalistic style, but provides considerable scientific detail. For example, it distinguishes totipotency (a cell's property of being able to differentiate into all cell types) from pluripotency (being able to differentiate into any cell type except the cells of the umbilical and placental structures that support the embryo) and multipotency (the property of an adult stem cell that can produce more than one kind of specialised cell type). Parson explains that stem cells are so called because of the different cells that can stem from them. A totipotent cell, such as a cell from an embryo after a very small number of cell divisions, is said to have "unbounded stemness" it can produce any cell at all. The author is gifted at clearing up difficult terminology and complex issues.
The regenerative powers of many organisms, such as salamanders that can regrow tails or even eyes, lie in the ability of mature cells to dedifferentiate into pluripotency. With hydras, this is not necessary because they have so many stem cells throughout their tiny bodies. In the case of humans, stem cell research offers the prospect of a new regenerative medicine that could treat a broad range of diseases.
Parson also outlines why it is worthwhile pursuing research on embryonic stem cells, as well as adult stem cells, and why it is nonetheless inherently difficult. Briefly, younger stem cells may be longer lasting, and they can give rise to a greater range of specialised cells. At the same time, this variety may make them more prone to malignancy.
The Proteus Effect also gives us sharp pictures of many leading personalities in the exciting field of stem cell research. In all, it is perfect for anyone trying to make sense of the current controversies.
