Irradiation and non-lethal hypoxia promote attraction of hematopoietic stem cells towards glioma cells by HIF1-mediated induction of CXCL12

We have previously demonstrated that adult hematopoietic stem and progenitor cells (PC) migrate towards glioma cells in vitro and home to experimental gliomas in vivo, stressing the potential of PC as vectors for a cell-based therapy. We defined stromal cell-derived factor-1 (SDF-1/ CXCL12) that is released by glioma cells as the essential chemokine in this process. Because hypoxia is a critical aspect of the microenvironment of gliomas and irradiation is an essential part of the standard therapy, we aimed to investigate the impact of both on the attraction of PC by glioma cells in vitro. Supernatants of irradia…