Radiation Resistance of Cancer Stem Cells: The 4 R's of Radiobiology Revisited§

Authors

  • Frank Pajonk,

    Corresponding author
    1. Department of Radiation Oncology, Division of Molecular and Cellular Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
    2. Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California, USA
    • David Geffen School of Medicine at UCLA, Division of Molecular and Cellular Oncology, Department of Radiation Oncology, 10833 Le Conte Avenue, Los Angeles, California 90095-1714, USA

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    • Telephone: 1-310-206-8733, Fax: 1-310-206-1260;

  • Erina Vlashi,

    1. Department of Radiation Oncology, Division of Molecular and Cellular Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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  • William H. McBride

    1. Department of Radiation Oncology, Division of Molecular and Cellular Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
    2. Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California, USA
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  • Author contributions: F.P., E.V., and W.H.M.: manuscript writing and final approval of manuscript.

  • First published online in STEM CELLS EXPRESS February 4, 2010 available online without subscription through the open access option.

  • §

    Disclosure of potential conflicts of interest is found at the end of this article.

Abstract

There is compelling evidence that many solid cancers are organized hierarchically and contain a small population of cancer stem cells (CSCs). It seems reasonable to suggest that a cancer cure can be achieved only if this population is eliminated. Unfortunately, there is growing evidence that CSCs are inherently resistant to radiation, and perhaps other cancer therapies. In general, success or failure of standard clinical radiation treatment is determined by the 4 R's of radiobiology: repair of DNA damage, redistribution of cells in the cell cycle, repopulation, and reoxygenation of hypoxic tumor areas. We relate recent findings on CSCs to these four phenomena and discuss possible consequences. STEM CELLS 2010;28:639–648

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