Combination of Ad-SGE-REIC and Bevacizumab Modulates Glioma Progression by Suppressing Invasion and Angiogenesis

Abstract

\n Reduced expression in immortalized cells/Dickkopf-3 (REIC/Dkk-3) is a tumor suppressor and its overexpression has been shown to exert anti-tumor effects as a therapeutic target gene in many human cancers. Recently, we demonstrated the anti-glioma effects of an adenoviral vector carrying REIC/Dkk-3 with the super gene expression system (Ad-SGE-REIC). Anti-vascular endothelial growth factor treatments such as bevacizumab have demonstrated convincing therapeutic advantage in patients with glioblastoma. However, bevacizumab could not improve overall survival in patients with newly diagnosed glioblastoma. In this study, we examined the effects of Ad-SGE-REIC on glioma treated with bevacizumab. Treatment of Ad-SGE-REIC resulted in significant reduced numbers of invasion cells treated with bevacizumab.. Western blot analyses revealed increased expression of several endoplasmic reticulum stress markers in cells treated with both bevacizumab and Ad-SGE-REIC and decreased β-catenin protein levels. Expressions of apoptosis markers were also increased in cells with combination therapy. In malignant glioma mouse models, overall survival was extended in the combination therapy group. These results suggest that the combination therapy of Ad-SGE-REIC and bevacizumab exerts anti-glioma effects by suppressing angiogenesis and invasion of tumors. Combined Ad-SGE-REIC and bevacizumab might indicate a promising strategy for the treatment of malignant glioma.