Cancer Stem Cells
http://www.100md.com
《新英格兰医药杂志》
To the Editor: With regard to the article by Jordan et al. (Sept. 21 issue),1 if cancer stem cells are characterized in experimental studies by their ability to regrow a tumor when injected into an immunodeficient animal, then what is evaluated is the capability of a cancer cell to reinitiate a tumor in a normal tissue.2 In such experiments, therefore, cancer stem cells behave like tumorigenic or metastatic cells. Hence, in a functional sense, the concept of the cancer stem cell might just be a restyling of the tumorigenicity concept.
Didier Wion, Ph.D.
Fran?ois Berger, M.D., Ph.D.
INSERM Unité 318
38043 Grenoble, France
didier.wion@ujf-grenoble.fr
References
Jordan CT, Guzman ML, Noble M. Cancer stem cells. N Engl J Med 2006;355:1253-1261.
Singh SK, Hawkins C, Clarke ID, et al. Identification of human brain tumour initiating cells. Nature 2004;432:396-401.
The authors reply: As we noted in our review article, not only do cancer stem cells regrow tumors, but they also undergo quantitative self-renewal, recapitulate all cell types within a tumor, and have extensive proliferative capacity. These unique properties are not usually found in most tumor cells and are not generally attributed to the tumorigenicity concept. Thus, we suggest that the explicit identification of a stem-cell compartment in tumors — whether its presence is due to transformation of a stem cell itself or to reexpression of "stemness" properties as a result of the transformation of a later cell — represents a step forward in attempts to understand the considerable problem of cancer recurrence. Nonetheless, as we noted, it is important to acknowledge that the concept is not new. Now, however, it is possible to isolate and accurately define such cells.
Craig T. Jordan, Ph.D.
Monica L. Guzman, Ph.D.
Mark Noble, Ph.D.
University of Rochester School of Medicine
Rochester, NY 14642
craig_jordan@urmc.rochester.edu
Didier Wion, Ph.D.
Fran?ois Berger, M.D., Ph.D.
INSERM Unité 318
38043 Grenoble, France
didier.wion@ujf-grenoble.fr
References
Jordan CT, Guzman ML, Noble M. Cancer stem cells. N Engl J Med 2006;355:1253-1261.
Singh SK, Hawkins C, Clarke ID, et al. Identification of human brain tumour initiating cells. Nature 2004;432:396-401.
The authors reply: As we noted in our review article, not only do cancer stem cells regrow tumors, but they also undergo quantitative self-renewal, recapitulate all cell types within a tumor, and have extensive proliferative capacity. These unique properties are not usually found in most tumor cells and are not generally attributed to the tumorigenicity concept. Thus, we suggest that the explicit identification of a stem-cell compartment in tumors — whether its presence is due to transformation of a stem cell itself or to reexpression of "stemness" properties as a result of the transformation of a later cell — represents a step forward in attempts to understand the considerable problem of cancer recurrence. Nonetheless, as we noted, it is important to acknowledge that the concept is not new. Now, however, it is possible to isolate and accurately define such cells.
Craig T. Jordan, Ph.D.
Monica L. Guzman, Ph.D.
Mark Noble, Ph.D.
University of Rochester School of Medicine
Rochester, NY 14642
craig_jordan@urmc.rochester.edu