Malignant gliomas: perverting glutamate and ion homeostasis for selective advantage.

The malignant transformation of astrocytes, oligodendrocytes or their progenitor cells gives rise to tumors that are collectively called gliomas. Although the vast majority of these tumors are believed to be of astrocytic origin, the actual cell of origin remains unknown. And whereas gliomas present with some genetic alterations in tumor-suppressor genes or oncogenes that are common among cancers, their biology differs significantly from other neoplasms. Most notably, they grow in a confined space defined by the bones of the skull and spinal column, and they spread by active cell migration rather than by passive, humorous spread. Recent research suggests that astrocyte-derived tumors co-opt neurotransmitters, their transporters and ion channels to support their unusual growth and invasive migration.