Targeting of endoplasmic reticulum (ER) stress in gliomas.

Gliomas remain a group of malignant brain tumors with dismal prognosis and limited treatment options with molecular mechanisms being constantly investigated. The past decade, extracellular stress and intracellular DNA damage have been shown to disturb proteostasis leading to Endoplasmic Reticulum (ER) stress that is implicated in the regulation of gene expression and the pathogenesis of several tumor types, including gliomas. Upon ER stress induction, neoplastic cells activate the adaptive mechanism of unfolded protein response (UPR), an integrated signaling system that either restores ER homeostasis or induces cell apoptosis. Recently, the manipulation of the UPR has emerged as a new therapeutic target in glioma treatment. General UPR activators or selective GRP78, ATF6 and PERK inducers have been detected to modulate cell proliferation and induce apoptosis of glioma cells. At the same time, target-specific UPR inhibitors and small molecule proteostasis disruptors, work in reverse to increase misfolded proteins and cause a dysregulation in protein maturation and sorting, thus preventing the growth of neoplastic cells. Herein, we discuss the pathogenic implication of ER stress in gliomas onset and progression, providing an update on the current UPR modifying agents that can be potentially used in glioma treatment.