In this review, the authors question the interpretation of data in a much-cited article by Shideng Bao and 8 co-authors, including Jeremy N Rich, entitled: Glioma stem cells promote radioresistance by preferential activation of the DNA damage response, Nature 2006(Dec 7); 444(7120): 756-60 [Epub 2006 Oct 18][PubMed Citation][Full text PDF is publicly accessible (via Gratis OA)][Another publicly accessible version].
Excerpt from the review by Baumann et al. 2009:
However, interpretation of these data [of Boa et al] is limited by several factors including the fact that enrichment of CD133+ cells after irradiation may possibly reflect differences in proliferative capability rather than differences in radiosensitivity, and that the irradiation dose of 2 Gy might not be sufficient to generate detectable differences in the transplantation assay used (Baumann et al. 2008).[PubMed Citation for the reference to Baumann et al. 2008].
Another excerpt from Baumann et al. 2009:
In summary, a higher radioresistance of cancer stem cells compared to non-stem cells has not been proven. More experiments, comparing the results of surface-marker based quantitative transplantation assays with and without irradiation after different doses in different tumours, are necessary before firm conclusions on the radioresistance of cancer stem cells can be drawn.Comment: The intrinsic radiosensitivity of cancer stem cells compared to non-stem cells is, from the perspective of radiation oncology, an important issue that has been investigated for many years. Some of this history is reviewed by Baumann et al. 2009. The issue needs to be resolved.