Daoy medulloblastoma cells that express CD133 are radioresistant relative to CD133− cells, and the CD133+ sector is enlarged by hypoxia

Conclusions: Restoration of the original CD133+ and CD133− populations from CD133+ Daoy cells in serum is further evidence that CD133+ cells are functionally distinct from CD133− cells. The radioresistance of CD133+ compared with CD133− Daoy cells is consistent with better repair of sublethal damage. Enlargement of the CD133+ sector is a new feature of the hypoxic response.