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.
Glioblastoma
Furthermore, glioblastoma multiforme exhibits numerous alterations in genes that encode for ion channels, including upregulation of gBK potassium channels and ClC-3 chloride channels. It has been hypothesized that by upregulating these ion channels, glioblastoma tumor cells can facilitate increased ion movement over the cell membrane, thereby increasing HO movement through osmosis, which aids glioblastoma cells in changing cellular volume very rapidly. This is helpful in their extremely aggressive invasive behavior, because quick adaptations in cellular volume can facilitate movement through the sinuous extracellular matrix of the brain.