Brain tumor
Glioblastoma multiforme (GBM) is the most aggressive (grade IV) and most common form of a malignant brain tumor. Even when aggressive multimodality therapy consisting of radiotherapy, chemotherapy, and surgical excision is used, median survival is only 12–17 months. Standard therapy for glioblastoma multiforme consists of maximal surgical resection of the tumor, followed by radiotherapy between two and four weeks after the surgical procedure to remove the cancer, then by chemotherapy, such as temozolomide. Most patients with glioblastoma take a corticosteroid, typically dexamethasone, during their illness to relieve symptoms. Experimental treatments include targeted therapy, gamma knife radiosurgery, boron neutron capture therapy and gene therapy.
Glioma 261
GL261 tumors resemble ependymoblastomas on histology but show many characteristics of glioblastoma phenotypes. They contain activating mutations of the K-ras as well as mutations of p53, resulting in high expression of c-myc. GL261 tumors also highly express MHC I, explaining their partial immunogenicity and have limited expression of MHC II, B7-1, and B7-2. The tumors are invasive, are not known to be metastatic, and do not spontaneously regress.