Stem-cell ecology and stem cells in motion

Abstract

This review highlights major scientific developments over the past 50 years or so in concepts related to stem-cell ecology and to stem cells in motion. Many thorough and eloquent reviews have been presented in the last 5 years updating progress in these issues. Some paradigms have been challenged, others validated, or new ones brought to light. In the present review, we will confine our remarks to the historical development of progress. In doing so, we will refrain from a detailed analysis of controversial data, emphasizing instead widely accepted views and some challenging novel ones.

Thalia Papayannopoulou

David T. Scadden

Figure 1

The hypothetical view of a stem-cell niche. The stem-cell daughter is a CFU-S. However, if it can find and occupy a niche, it will itself become a stem cell. Figure from Schofield R. The relationship between the spleen colony-forming cell and the haemopoietic stem cell. Blood Cells. 1978;4:7-25. Reprinted with kind permission of Springer Science and Business Media.

Figure 2

Alexander Maximow, a great visionary in hematopoiesis. He introduced the “unitarian theory of hematopoiesis”^{, page 538} (ie, “common stem cell for all blood elements”^{, page 545}) and pioneered other concepts about stem cells and their microecological niches within BM stroma. Photograph reprinted from Konstantinov IE, In Search of Alexander A. Maximow: The Man Behind the Unitarian Theory of Hematopoiesis, Perspectives in Biology and Medicine. Vol. 43. Winter 2000:269-276, with permission of Special Collections Research Center, University of Chicago Library.