Ernest Armstrong McCulloch, a giant in the field of hematopoieis, died in Toronto on January 20, 2011, at the age of 84. Together with his long-time colleague, Dr. James Till, he is especially recognized for the discovery of hematopoietic stem cells in the 1960s.
The work arose out of a study of the radiation sensitivity of normal bone marrow cells and led to the discovery of the spleen colony-forming unit (CFU-S) in the mouse. “Bun,” as he was affectionately known by his colleagues, and Jim Till showed that a spleen colony arose from a single cell and helped to define the criteria for a stem cell. Together with others at the Ontario Cancer Institute in Toronto where they worked, they were able to show that CFU-S had the capacity to self-renew and also to differentiate along multiple lineages. Their studies laid the groundwork for defining the properties of stem cells and provided a rationale for bone marrow transplantation. Dr. McCulloch extended these fundamental studies to acute myeloid leukemia and demonstrated the hierarchical organization and cytokine dependence of the clonal disorder, paving the way for the current focus on cancer stem cells as therapeutic targets.
Dr. McCulloch was the recipient of many awards throughout his career, including membership in the Royal Society of London, the Gairdner Foundation International Award, the Thomas W. Eadie Medal, and the Order of Canada. He delivered ASH’s prestigious Henry M. Stratton Lecture in 1982 and, most recently (together with Jim Till), was presented with the Albert Lasker Award.
Despite his international prominence and formidable demeanour (the inevitable bow tie), Dr. McCulloch was a gentle and modest man. He was a wonderful teacher and an outstanding mentor. He was very interested in ensuring that all the graduate students, postdoctoral fellows, and junior faculty with whom he interacted were able to attain their highest possible level of scientific development. He inspired several generations of researchers who will remember his passion for science, his integrity, and his ability to think well beyond the immediate project. Although he leaves a remarkable legacy, his wisdom and perspective will be greatly missed.
Photo reprinted from The Lancet, 377/9765, Stephen Pincock, Ernest Armstrong McCulloch, Page 550, February 2011, with permission from Elsevier.
