%0 Journal Article
%T Ion Channels in Glioblastoma
%A Remco J. Molenaar
%J ISRN Neurology
%D 2011
%R 10.5402/2011/590249
%X Glioblastoma is the most common primary brain tumor with the most dismal prognosis. It is characterized by extensive invasion, migration, and angiogenesis. Median survival is only 15 months due to this behavior, rendering focal surgical resection ineffective and adequate radiotherapy impossible. At this moment, several ion channels have been implicated in glioblastoma proliferation, migration, and invasion. This paper summarizes studies on potassium, sodium, chloride, and calcium channels of glioblastoma. It provides an up-to-date overview of the literature that could ultimately lead to new therapeutic targets. 1. Introduction Glioblastoma (astrocytomas, WHO grade IV) is the most aggressive primary brain tumor. With an incidence of 3.5 per 100,000 people per year, it may affect children, adults, and elderly. However, it preferentially affects adults between 45 and 75 years of age [1]. Glioblastomas can either present themselves as primary glioblastomas (95%), which manifest de novo and lack precursor tumors, or secondary glioblastomas. These tumors have progressed from less malignant glioma [2]. Surgery is the initial intervention when a patient has been diagnosed with a brain tumor. This is needed to obtain a histological diagnosis and reduces the space-occupying effect of the tumor. However, in glioblastoma, surgery is of limited therapeutic value, as complete resection is impossible due to the extensive invasive, and migratory behavior of glioblastoma cells. This renders radiotherapy ineffective as well. The current treatment is concomitant administration of temozolomide and radiotherapy. However, median survival is only 15 months [3]. The understanding of molecular alterations in signaling pathways and the consequent pathology in glioblastoma has greatly increased in the last years due to the availability of new techniques, such as genome-wide sequencing. One of the pathways that are frequently affected in glioblastoma includes channels involved in transport of sodium, potassium, and calcium ions [4]. The present paper provides an overview of the current evidence of the involvement of these ion channels in glioblastoma in terms of gliomagenesis, glioma progression, and their effect on prognosis. Because of the progression of lower-grade glioma to glioblastoma, the involvement of ion channels in high-grade glioma is discussed as well. Finally, the application of these insights is discussed in the light of future prospects for experimental and clinical practice. 2. Ion Channels and Glioblastoma Glial cells express a variety of ion channels [5].
%U http://www.hindawi.com/journals/isrn.neurology/2011/590249/