Expression data from orthotopic U-87 MG xenograft mouse models

Glioblastoma (GBM) is classified as World Health Organization grade IV tumors of the central nervous system, and it is the most malignant form of glioma. The current GBM therapies could not completely eliminate the tumor mass and the occurrence of therapeutic resistance of surviving GBM cells is considered as an obstacle to be overcome. We used microarrays to detail the global program of gene expression underlying development of radioresistance of GBM and identified a variety of genes whose expressions were regulated during this process. 5x105 U-87 MG GBM cells were injected into the brain of seven-week-old BALB/c athymic nude mice. Fourteen days after the injection date, the brains of the mice were irradiated with 2 Gy daily for 5 days at a dose rate of 0.4 Gy/min. At the end of the treatment period, animals were euthanized and brain samples were harvested.