Open AccessSuppression of Glioma Progression by Egln3
Author(s) -
Vicki A. Sciorra,
Michael A. Sanchez,
Akemi Kunibe,
Andrew E. Wurmser
Publication year - 2012
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0040053
Subject(s) - glioma , tumor progression , cancer research , biology , carcinogenesis , hypoxia (environmental) , transcription factor , astrocytoma , tumor microenvironment , brain tumor , pathology , medicine , chemistry , cancer , biochemistry , genetics , gene , tumor cells , organic chemistry , oxygen
Grade IV astrocytoma or glioblastoma has a poor clinical outcome that can be linked to hypoxia, invasiveness and active vascular remodeling. It has recently been suggested that hypoxia-inducible factors, Hifs, increase glioma growth and aggressiveness [1] , [2] , [3] . Here, we tested the hypothesis that Egl 9 homolog 3 (Egln3), a prolyl-hydroxylase that promotes Hif degradation, suppresses tumor progression of human and rodent glioma models. Through intracranial tumorigenesis and in vitro assays, we demonstrate for the first time that Egln3 was sufficient to decrease the kinetics of tumor progression and increase survival. We also find that Klf5, a transcription factor important to vascular remodeling, was regulated by hypoxia in glioma. An analysis of the tumor vasculature revealed that elevated Egln3 normalized glioma capillary architecture, consistent with a role for Egln3 in eliciting decreases in the production of Hif-regulated, angiogenic factors. We also find that the hydroxylase-deficient mutant, Egln3 H196A partially maintained tumor suppressive activity. These results highlight a bifurcation of Egln3 signaling and suggest that Egln3 has a non-hydroxylase-dependent function in glioma. We conclude that Egln3 is a critical determinant of glioma formation and tumor vascular functionality.