Inhibition of COX-2, mPGES-1 and CYP4A by isoliquiritigenin blocks the angiogenic Akt signaling in glioma through ceRNA effect of miR-194-5p and lncRNA NEAT1

Abstract

Background Arachidonic acid (AA) metabolic enzymes including cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-1 (mPGES-1) and cytochrome P450 (CYP) 4A11 play important roles in glioma angiogenesis. Thus, there is an urgent need to identify the underlying mechanisms and develop strategies to overcome them. Methods A homology model of human CYP4A11 was constructed using SYBYL-X 2.0. Structure-based virtual screening against COX-2, mPGES-1 and CYP4A11was performed using the Surflex-Dock of the SYBYL suite. The candidates were further evaluated their antiangiogenic activities in a zebrafish embryo and rabbit corneal angiogenesis model. Laser doppler analysis was used to measure tumor perfusion. The expression of CD31 and α-SMA was measured by immunofluorescence. Western blot was used to measure the expression of HIF-1, Akt and p-Akt. The gene expression of FGF-2, G-CSF, PDGF, TGF-β, Tie-2, VEGF, lncRNA NEAT1 and miR-194-5p were determined using qPCR. The production of FGF-2, TGF-β and VEGF were analyzed using ELISA. Bioinformatic analysis and luciferase reporter assays confirmed the interaction between lncRNA NEAT1 and miR-194-5p. Results The nearly 36,043 compounds from the Traditional Chinese Medicine (TCM) database were screened against COX-2, mPGES-1 and CYP4A11 3D models, and the 17 top flavonoids were identified. In zebrafish screening, isoliquiritigenin (ISL) exhibited the most potent antiangiogenic activities with the EC 50 values of 5.9 μM. Conversely, the antiangiogenic effects of ISL in the zebrafish and rabbit corneal models were partly reversed by 20-hydroxyeicosatetraenoic acid (20-HETE) or prostaglandin E2 (PGE 2 ). ISL normalized glioma vasculature and improved the efficacy of temozolomide therapy in the rat C6 glioma model. Inhibition of COX-2, mPGES-1 and CYP4A by ISL decreased FGF-2, TGF-β and VEGF production in the C6 and U87 glioma cells with p-Akt downregulation, which was reversed by Akt overexpression. Furthermore, ISL downregulated lncRNA NEAT1 but upregulated miR-194-5p in the U87 glioma cell. Importantly, lncRNA NEAT1 overexpression reversed ISL-mediated increase in miR-194-5p expression, and thereby attenuated FGF-2, TGF-β and VEGF production. Conclusions Reprogramming COX-2, mPGES-1 and CYP4A mediated-AA metabolism in glioma by flavonoid ISL inhibits the angiogenic Akt- FGF-2/TGF-β/VEGF signaling through ceRNA effect of miR-194-5p and lncRNA NEAT1, and may serve as a novel therapeutic strategy for human glioma. Electronic supplementary material The online version of this article (10.1186/s13046-019-1361-2) contains supplementary material, which is available to authorized users.

Comprehensive analysis of ceRNA network related to lincRNA in glioblastoma and prediction of clinical prognosis

“…It has also been reported that MALAT1 can be used as ceRNA of miR-199a to promote the expression of ZHX1 , which in turn can regulate the proliferation of GBM cells [ 34 ]. The ceRNA effect between NEAT1 and miR-194-5p is related to the angiogenesis of glioma [ 35 ].…”

Distinguishing Glioblastoma Subtypes by Methylation Signatures

“…As a member of the cytochrome P450 superfamily of enzyme, such gene has been generally reported to participate in neurovascular function in the brain (Bylund et al, 2002). As for its correlations with GBM, recently, two successive related publications (Wang et al, 2018(Wang et al, , 2019 confirmed that CYP4X1 contributes to the inhibition of glioma angiogenesis. Glioma vasculature is quite significant for the initiation and progression of such disease (Hardee and Zagzag, 2012).…”

Immune response in glioma’s microenvironment

“…FGF can promote the division and chemotaxis of vascular endothelial cells and can participate in the PI3K/AKT signaling pathway to inhibit apoptosis of endothelial cells. Targeted inhibition of COX-2 and FGF expression down-regulates VEGF, thereby slowing the process of angiogenesis [ 67 ]. COX2 can be metabolized into prostaglandin E2 (PGE2) [ 68 ].…”