Article

Identifying Cancer Stem Cells in Solid Tumors: Case Not Proven

Ontario Cancer Institute, Princess Margaret Hospital, University Health Network and Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
Cancer Research (Impact Factor: 9.33). 03/2006; 66(4):1891-5; discussion 1890. DOI: 10.1158/0008-5472.CAN-05-3450
Source: PubMed

ABSTRACT

Building on studies of leukemia, a number of recent articles have reported data suggesting that cancer stem cells could be isolated from solid human cancers. Some of these reports have speculated that the isolation of these cells will allow the identification of the specific molecular properties that can be targeted for therapeutic purposes. Although previous work with animal model systems also suggests the presence of stem cells in solid tumors, there remain many uncertainties, both theoretical and technical, about the interpretation of the current results. The case that a small proportion of cells in solid tumors are specific cancer stem cells and that these cells can be successfully identified and isolated has not yet been proven.

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    • "Absence of this tumor-promoting inflammatory environment in normal mouse tissues at the time of cancer cell implantation could lead to overlook certain cancer cell populations which may be critical from a therapeutic standpoint. Likewise, lack of cross-species activity between some animal and human growth factors might restrict the growth of certain essential human cancer cells in xenograft experiments [14] [16] [26]. Indeed, these drawbacks illustrate the low sensitivity of our current cancer stem cell assays and are reminiscent of Koch's postulates limitations discussed above which occur when the pathogenic microorganism cannot be grown in pure culture [31], or when there is no animal model for the corresponding infection [28] "

    Full-text · Dataset · Feb 2015
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    • "Absence of this tumor-promoting inflammatory environment in normal mouse tissues at the time of cancer cell implantation could lead to overlook certain cancer cell populations which may be critical from a therapeutic standpoint. Likewise, lack of cross-species activity between some animal and human growth factors might restrict the growth of certain essential human cancer cells in xenograft experiments [14] [16] [26]. Indeed, these drawbacks illustrate the low sensitivity of our current cancer stem cell assays and are reminiscent of Koch's postulates limitations discussed above which occur when the pathogenic microorganism cannot be grown in pure culture [31], or when there is no animal model for the corresponding infection [28] "

    Full-text · Dataset · Feb 2015
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    • "Putative CSC should be tumorigenic in vivo, reproducibly giving rise to tumors when transplanted into immunecompromised mice. The tumors should ideally recapitulate the morphology and histological characteristics of parent tumors, verifying multi-lineage differentiation and hierarchical heterogeneity (Hill, 2006; Kelly et al., 2007; Shackleton et al., 2009). It is therefore most likely that orthotopic CSC-based xenografts may represent an ideal working model for testing new agents in the preclinical setting (Maugeri-Sacca et al., 2014). "
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