Glioblastoma Multiforme Angiogenesis Research Articles

Design, synthesis and biological evaluation of Nrf2 modulators for the treatment of glioblastoma multiforme

Glioblastoma multiforme (GBM) is a prevalent primary brain tumor. However, no specific therapeutic drug has been developed for it. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a crucial transcription factor involved in the cellular response to oxidative stress. Numerous studies have demonstrated that Nrf2 plays a pivotal role in GBM angiogenesis, and inhibiting Nrf2 can significantly enhance patient prognosis. Using virtual screening technology, we examined our in-house library and identified pinosylvin as a potential compound with high activity. Pinosylvin exhibited robust hydrogen bond and Π-Π interaction with Nrf2. Cell experiments revealed that pinosylvin effectively reduced the proliferation of U87 tumor cells by regulating Nrf2 and demonstrated greater inhibitory activity than temozolomide. Consequently, we believe that this study will offer valuable guidance for the future development of highly efficient therapeutic drugs for GBM.

IFITM3 promotes glioblastoma stem cell-mediated angiogenesis via regulating JAK/STAT3/bFGF signaling pathway

Interferon-induced transmembrane protein 3 (IFITM3) has been previously verified to be an endosomal protein that prevents viral infection. Recent findings suggested IFITM3 as a key factor in tumor invasion and progression. To clarify the role and molecular mechanism of IFITM3 in Glioblastoma multiforme (GBM) progression, we investigated the expression of IFITM3 in glioma datasets culled from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA). Primary GBM stem cells (GSCs) were cultured and identified in vitro. Loss-of-function and gain-of-function experiments were established by using shRNAs and lentiviral vectors targeting IFITM3. Co-culture system of GSCs and vascular endothelial cells was constructed in a Transwell chamber. Tube formation and spheroid-based angiogenesis assays were performed to determine the angiogenic capacity of endothelial cells. Results revealed that IFITM3 is elevated in GBM samples and predictive of adverse outcome. Mechanistically, GSCs-derived IFITM3 causes activation of Jak2/STAT3 signaling and leads to robust secretion of bFGF into tumor environment, which eventually results in enhanced angiogenesis. Taken together, these evidence indicated IFITM3 as an essential factor in GBM angiogenesis. Our findings provide a new insight into mechanism by which IFITM3 modulates GBM angiogenesis.

Intranasal delivery of sunitinib: A new therapeutic approach for targeting angiogenesis of glioblastoma

Glioblastoma multiforme (GBM) is one of the most vascular among solid tumors, and despite the use of multimodal therapies, the survival of these patients is poor. In order to target angiogenesis in GBM as a promising strategy, an antiangiogenic drug is required. This study was designed to evaluate the effects of sunitinib, a multityrosine kinase inhibitor with tumor proliferation and angiogenesis inhibitory properties, on GBM-bearing rats. Given the ineffective drug delivery to the brain due to the presence of the blood-brain barrier (BBB), intra-nasal (IN) drug delivery has recently been considered as a non-invasive method to bypass BBB. Therefore, in the current study, IN was used as an ideal method for the delivery of sunitinib to the brain, and the effects of this method were also compared to the OR administration of the sunitinib. GBM was induced in the brain of male Wistar rats, and they were randomly divided into 4 groups; IN-STB (sunitinib intranasal delivery), IN-sham (placebo intranasal delivery), OR-STB (sunitinib oral delivery) and OR-sham (placebo oral delivery). After the end of the treatment period, an MRI of animals' brains showed a reduction in tumor growth in the treatment groups. Immunohistochemistry revealed that sunitinib inhibits angiogenesis in GBM in both OR and IN delivery methods. Analysis of liver tissue and enzymes showed that IN delivery of sunitinib had less hepatotoxicity than the OR method. Overall, it was found that IN sunitinib delivery could be used as a potential non-hepatotoxic alternative for the treatment of GBM.

CircMTA1 promotes glioblastoma angiogenesis by encoding MTA1-134aa.

Glioblastoma multiforme (GBM) is the most malignant brain tumor with rapid angiogenesis. How to inhibit GBM angiogenesis is a key problem to be solved. To explore the targets of inhibiting GBM angiogenesis, this study confirmed that the expression of circMTA1 (hsa_circ_0033614) was significantly upregulated in human brain microvascular endothelial cells exposed to glioma cell-conditioned medium (GECs). The expression of circMTA1 in the cytoplasm was significantly higher than that in the nucleus. Upregulated circMTA1 in GECs can promote cell proliferation, migration, and tube formation. Further exploration of the circularization mechanism of circMTA1 confirmed that KHDRBS1 protein can bind to the upstream and downstream flanking sequences of circMTA1 and promote circMTA1 biogenesis by coordinating Alu element pairing. KHDRBS1 upregulated the proliferation, migration, and tube formation of GECs by promoting the biogenesis of circMTA1. CircMTA1 can encode the protein MTA1-134aa by internal ribosome entry site sequence-mediated translation mechanism, and promote the proliferation, migration, and tube formation of GECs through the encoded MTA1-134aa. This study provides a new target for inhibiting angiogenesis in brain GBM and a new strategy for improving the therapeutic efficacy of GBM.

Genetic Variants Impacting Angiogenesis Signaling Pathways in Glioblastoma Multiforme: A Systematic Review of Mutations and Polymorphisms.

Several signaling pathways are involved in the process of angiogenesis, which is one of the most important hallmarks of glioblastoma multiforme (GBM). Identifying related gene variants can help researchers work out what causes anti-angiogenesis drug resistance. The goal of this systematic analysis was to identify all mutations and polymorphisms involved in angiogenesis pathways in GBM and their impact on clinical outcomes. The keywords include glioblastoma, angiogenesis, signaling pathway, mutation, polymorphism, and related terms used to search ISI, PubMed, and Scopus for relevant articles published up to January 2022. The PRISMA protocol was used to conduct our systematic review. The related articles were taken into consideration. The risk of bias in the associated articles was surveyed, as well as the article scoring. Two authors collaborated on data extraction. The inclusion criteria were included in 32 articles out of a total of 787 articles. VEGF, HIF1a, EGFR, PI3K, and MAPK are the pathways that have been studied the most. IDH1, VEGF, VEGFR, EGFR, and HIF1a are the genes with the highest frequency of mutations or polymorphisms. In conclusion, this study found that angiogenesis in primary or recurrent GBM is linked to gene changes in eleven signaling pathways. However, some of these gene mutations have been researched numerous times in relation to angiogenesis, while others have only been studied once. Understanding these changes will help us employ combination therapies more effectively for GBM patients' survival and personal medicine.

Targeting TRAF3IP2 inhibits angiogenesis in glioblastoma.

Increased vascularization, also known as neoangiogenesis, plays a major role in many cancers, including glioblastoma multiforme (GBM), by contributing to their aggressive growth and metastasis. Although anti-angiogenic therapies provide some clinical improvement, they fail to significantly improve the overall survival of GBM patients. Since various pro-angiogenic mediators drive GBM, we hypothesized that identifying targetable genes that broadly inhibit multiple pro-angiogenic mediators will significantly promote favorable outcomes. Here, we identified TRAF3IP2 (TRAF3-interacting protein 2) as a critical regulator of angiogenesis in GBM. We demonstrated that knockdown of TRAF3IP2 in an intracranial model of GBM significantly reduces vascularization. Targeting TRAF3IP2 significantly downregulated VEGF, IL6, ANGPT2, IL8, FZGF2, PGF, IL1β, EGF, PDGFRB, and VEGFR2 expression in residual tumors. Our data also indicate that exogenous addition of VEGF partially restores angiogenesis by TRAF3IP2-silenced cells, suggesting that TRAF3IP2 promotes angiogenesis through VEGF- and non-VEGF-dependent mechanisms. These results indicate the anti-angiogenic and anti-tumorigenic potential of targeting TRAF3IP2 in GBM, a deadly cancer with limited treatment options.

Paradoxical role of β8 integrin on angiogenesis and vasculogenic mimicry in glioblastoma.

Glioblastoma multiforme (GBM) is the most aggressive and highly vascularized brain tumor with poor prognosis. Endothelial cell-dependent angiogenesis and tumor cell-dependent Vasculogenic mimicry (VM) synergistically contribute to glioma vascularization and progression. However, the mechanism underlying GBM vascularization remains unclear. In this study, GBM stem cells (GSCs) were divided into high and low β8 integrin (ITGB8) subpopulations. Co-culture assays followed by Cell Counting Kit-8 (CCK-8), migration, Matrigel tube formation, and sprouting assays were conducted to assess the proliferative, migratory and angiogenic capacity of GBM cells and human brain microvascular endothelial cells (hBMECs). An intracranial glioma model was constructed to assess the effect of ITGB8 on tumor vascularization in vivo. Our results indicated that ITGB8 expression was elevated in GSCs and positively associated with stem cell markers in glioma tissues, and could be induced by hypoxia and p38 activation. ITGB8 in GSCs inhibited the angiogenesis of hBMECs in vitro, while it promoted the ability of network formation and expression of VM-related proteins. The orthotopic GBM model showed that ITGB8 contributed to decreased angiogenesis, meanwhile enhanced invasiveness and VM formation. Mechanistic studies indicated that ITGB8-TGFβ1 axis modulates VM and epithelial-mesenchymal transition (EMT) process via Smad2/3-RhoA signaling. Together, our findings demonstrated a differential role for ITGB8 in the regulation of angiogenesis and VM formation in GBM, and suggest that pharmacological inhibition of ITGB8 may represent a promising therapeutic strategy for treatment of GBM.

Glioblastoma-associated microglia-derived exosomal circKIF18A promotes angiogenesis by targeting FOXC2.

Glioblastoma multiforme (GBM) is the most lethal primary tumor with active neovascularization in the central nervous system. Studying the novel molecular mechanisms of GBM angiogenesis is very important. The glioblastoma-associated microglia (GAM) M2 polarization was constructed, and microglia-derived exosomes (MDEs) were isolated to co-culture with human brain microvessel endothelial cells (hBMECs). CircRNA sequence and molecular biological experiments were used to detect the expression levels and regulation functions among circKIF18A, FOXC2, ITGB3, CXCR4, DLL4 and the PI3K/AKT signaling. The functional effects of silencing or overexpression of these molecules were evaluated in hBMECs viability, invasion, and tube formation in vitro and tumorigenicity in vivo. M2 microglia polarization is positively correlated with microvessels' density in GBM patients. M2 GAM can promote the angiogenesis of GBM via transporting exosomal circKIF18A into hBMECs. Mechanistically, circKIF18A can bind to, maintain the stability and nuclear translocation of FOXC2 in hBMECs. Furtherly, as a transcription factor, FOXC2 can directly bind to the promoter of ITGB3, CXCR4, and DLL4 and upregulate their expressions. Besides, FOXC2 can also activate the PI3K/AKT signaling and promote the angiogenesis of GBM. Our study identified a novel molecular mechanism for M2 GAM-derived exosomal circKIF18A participating in GBM angiogenesis via targeting FOXC2. This may provide a novel treatment target to improve the outcomes for anti-angiogenic therapies in GBM.

Ionizing Radiation-Induced GDF15 Promotes Angiogenesis in Human Glioblastoma Models by Promoting VEGFA Expression Through p-MAPK1/SP1 Signaling.

Glioblastoma multiforme (GBM), the most aggressive cancer type that has a poor prognosis, is characterized by enhanced and aberrant angiogenesis. In addition to surgical resection and chemotherapy, radiotherapy is commonly used to treat GBM. However, radiation-induced angiogenesis in GBM remains unexplored. This study examined the role of radiation-induced growth/differentiation factor-15 (GDF15) in regulating tumor angiogenesis by promoting intercellular cross-talk between brain endothelial cells (ECs) and glioblastoma cells. Radiation promoted GDF15 secretion from human brain microvascular endothelial cells (HBMVECs). Subsequently, GDF15 activated the transcriptional promoter VEGFA in the human glioblastoma cell line U373 through p-MAPK1/SP1 signaling. Upregulation of vascular endothelial growth factor (VEGF) expression in U373 cells resulted in the activation of angiogenic activity in HBMVECs via KDR phosphorylation. Wound healing, tube formation, and invasion assay results revealed that the conditioned medium of recombinant human GDF15 (rhGDF15)-stimulated U373 cell cultures promoted the angiogenic activity of HBMVECs. In the HBMVEC-U373 cell co-culture, GDF15 knockdown mitigated radiation-induced VEGFA upregulation in U373 cells and enhanced angiogenic activity of HBMVECs. Moreover, injecting rhGDF15-stimulated U373 cells into orthotopic brain tumors in mice promoted angiogenesis in the tumors. Thus, radiation-induced GDF15 is essential for the cross-talk between ECs and GBM cells and promotes angiogenesis. These findings indicate that GDF15 is a putative therapeutic target for patients with GBM undergoing radio-chemotherapy.

PSMB8 inhibition decreases tumor angiogenesis in glioblastoma through vascular endothelial growth factor A reduction.

Glioblastoma, also known as glioblastoma multiforme (GBM), is a fast‐growing tumor and the most aggressive brain malignancy. Proteasome subunit beta type‐8 (PSMB8) is one of the 17 essential subunits for the complete assembly of the 20S proteasome complex. The aim of the present study was to evaluate the role of PSMB8 expression in GBM progression and angiogenesis. PSMB8 expression in glioblastoma LN229 and U87MG was knocked down by siRNA or inducible shRNA both in vitro and in vivo. After PSMB8 reduction, cell survival, migration, invasion, angiogenesis, and the related signaling cascades were evaluated. An orthotopic mouse tumor model was also provided to examine the angiogenesis within tumors. A GEO profile analysis indicated that high expression of PSMB8 mRNA in GBM patients was correlated with a low survival rate. In immunohistochemistry analysis, PSMB8 expression was higher in high‐grade than in low‐grade brain tumors. The proliferation, migration, and angiogenesis of human GBM cells were decreased by PSMB8 knockdown in vitro. Furthermore, phosphorylated focal adhesion kinase (p‐FAK), p‐paxillin, MMP2, MMP9, and cathepsin B were significantly reduced in LN229 cells. Integrin β1 and β3 were reduced in HUVEC after incubation with LN229‐conditioned medium. In an orthotopic mouse tumor model, inducible knockdown of PSMB8 reduced the expression of vascular endothelial growth factor (VEGF), VEGF receptor, and CD31 as well as the progression of human glioblastoma. In this article, we demonstrated the role of PSMB8 in glioblastoma progression, especially neovascularization in vitro and in vivo. These results may provide a target for the anti–angiogenic effect of PSMB8 in glioblastoma therapy in the future.

The CXCL12/CXCR4 axis confers temozolomide resistance to human glioblastoma cells via up-regulation of FOXM1

Glioblastoma multiforme (GBM) is the most common primary malignancy in the adult central nervous, and is characterized by high aggressiveness and a high mortality rate. The high mortality rate is largely due to the development of drug resistance. Temozolomide (TMZ) resistance is considered to be one of the major reasons responsible for GBM therapy failure. CXCL12/CXCR4 has been demonstrated to be involved in cell proliferation, migration, invasion, angiogenesis, and radioresistance in GBM. However, its role in TMZ resistance in GBM is unknown. In this study, we aimed to evaluate the role of CXCL12/CXCR4 in mediating the TMZ resistance to GBM cells and explore the underlying mechanisms. We found that the CXCL12/CXCR4 axis enhanced TMZ resistance in GBM cells. Further study showed that CXCL12/CXCR4 conferred TMZ resistance and promoted the migration and invasion of GBM cells by up-regulating FOXM1. This resistance was partially reversed by suppressing CXCL12/CXCR4 and FOXM1 silencing. Our study revealed the vital role of CXCL12/CXCR4 in mediating the resistance of GBM cells to TMZ, and suggested that targeting CXCL12/CXCR4 axis may attenuate the resistance to TMZ in GBM.

Dual antivascular function of human fibulin-3 variant, a potential new drug discovery strategy for glioblastoma.

The ECM protein EFEMP1 (fibulin‐3) is associated with all types of solid tumor through its cell context‐dependent dual function. A variant of fibulin‐3 was engineered by truncation and mutation to alleviate its oncogenic function, specifically the proinvasive role in glioblastoma multiforme (GBM) cells at stem‐like state. ZR30 is an in vitro synthesized 39‐kDa protein of human fibulin‐3 variant. It has a therapeutic effect in intracranial xenograft models of human GBM, through suppression of epidermal growth factor receptor/AKT and NOTCH1/AKT signaling in GBM cells and extracellular MMP2 activation. Glioblastoma multiforme is highly vascular, with leaky blood vessels formed by tumor cells expressing endothelial cell markers, including CD31. Here we studied GBM intracranial xenografts, 2 weeks after intratumoral injection of ZR30 or PBS, by CD31 immunohistochemistry. We found a 70% reduction of blood vessel density in ZR30‐treated xenografts compared with that of PBS‐treated ones. Matrigel plug assays showed the effect of ZR30 on suppressing angiogenesis. We further studied the effect of ZR30 on genes involved in endothelial transdifferentiation (ETD), in 7 primary cultures derived from 3 GBMs under different culture conditions. Two GBM cultures formed mesh structures with upregulation of ETD genes shortly after culture in Matrigel Matrix, and ZR30 suppressed both. ZR30 also downregulated ETD genes in two GBM cultures with high expression of these genes. In conclusion, multifaceted tumor suppression effects of human fibulin‐3 variant include both suppression of angiogenesis and vasculogenic mimicry in GBM.

Loss of cytoskeleton protein ADD3 promotes tumor growth and angiogenesis in glioblastoma multiforme

Adducin 3 (ADD3) is a crucial assembly factor in the actin cytoskeleton and has been found to be aberrantly expressed in various cancers, including glioblastoma multiforme (GBM). It has previously been studied in array-based studies with controversial findings as to its functional role in glioma. In microarray analyses of 452 glioma specimens, we found significant downregulation of ADD3 in GBM, but not in less malignant gliomas, compared to normal brain tissue, which suggests that its downregulation might underlie critical events during malignant progression. We also found that ADD3 was functionally dependent on cell-matrix interaction. In our in vivo study, the proliferative and angiogenic capacity of ADD3-depleted GBM cells was promoted, possibly through PCNA, while p53 and p21 expression was suppressed, and pro-angiogenic signals were induced through VEGF-VEGFR-2-mediated activation in endothelial cells. With correlative in vitro, in vivo, and clinical data, we provide compelling evidence on the putative tumor-suppressive role of ADD3 in modulating GBM growth and angiogenesis. As a preclinical study, our research offers a better understanding of the pathogenesis of glioma malignant progression for the benefit of future investigations.

CircSMARCA5 Regulates VEGFA mRNA Splicing and Angiogenesis in Glioblastoma Multiforme Through the Binding of SRSF1.

Circular RNAs are a large group of RNAs whose cellular functions are still being investigated. We recently proposed that circSMARCA5 acts as sponge for the splicing factor Serine and Arginine Rich Splicing Factor 1 (SRSF1) in glioblastoma multiforme (GBM). After demonstrating by RNA immunoprecipitation a physical interaction between SRFS1 and circSMARCA5, we assayed by real-time PCR in a cohort of 31 GBM biopsies and 20 unaffected brain parenchyma controls (UC) the expression of total, pro-angiogenic (Iso8a) and anti-angiogenic (Iso8b) mRNA isoforms of Vascular Endothelial Growth Factor A (VEGFA), a known splicing target of SRSF1. The Iso8a to Iso8b ratio: (i) increased in GBM biopsies with respect to UC (p-value < 0.00001); (ii) negatively correlated with the expression of circSMARCA5 (r-value = −0.46, p-value = 0.006); (iii) decreased in U87-MG overexpressing circSMARCA5 with respect to negative control (p-value = 0.0055). Blood vascular microvessel density, estimated within the same biopsies, negatively correlated with the expression of circSMARCA5 (r-value = −0.59, p-value = 0.00001), while positively correlated with that of SRSF1 (r-value = 0.38, p-value = 0.00663) and the Iso8a to Iso8b ratio (r-value = 0.41, p-value = 0.0259). Kaplan-Meier survival analysis showed that GBM patients with low circSMARCA5 expression had lower overall and progression free survival rates than those with higher circSMARCA5 expression (p-values = 0.033, 0.012, respectively). Our data convincingly suggest that circSMARCA5 is an upstream regulator of pro- to anti-angiogenic VEGFA isoforms ratio within GBM cells and a highly promising GBM prognostic and prospective anti-angiogenic molecule.

Investigating the role of CRIPTO-1 (TDGF-1) in glioblastoma multiforme U87 cell line.

Cripto-1 has been implicated in a number of human cancers. Although there is high potential for a role of Cripto-1 in glioblastoma multiforme (GBM) pathogenesis and progression, few studies have tried to define its role in GBM. These studies were limited in that Cripto-1 expression was not studied in detail in relation to markers of cancer initiation and progression. Therefore, these correlative studies allowed limited interpretation of Criptos-1's effect on the various aspects of GBM development using the U87 GBM cell line. In this study, we sought to delineate the role of Cripto-1 in facilitating pathogenesis, stemness, proliferation, invasion, migration and angiogenesis in GBM. Our findings show that upon overexpressing Cripto-1 in U87 GBM cells, the stemness markers Nanog, Oct4, Sox2, and CD44 increased expression. Similarly, an increase in Ki67 was observed demonstrating Cripto-1's potential to induce cellular proliferation. Likewise, we report a novel finding that increased expression of the markers of migration and invasion, Vimentin and Twist, correlated with upregulation of Cripto-1. Moreover, Cripto-1 exposure led to VEGFR-2 overexpression along with higher tube formation under conditions promoting endothelial growth. Taken together our results support a role for Cripto-1 in the initiation, development, progression, and maintenance of GBM pathogenesis. The data presented here are also consistent with a role for Cripto-1 in the re-growth and invasive growth in GBM. This highlights its potential use as a predictive and diagnostic marker in GBM as well as a therapeutic target.

Coagulation Factor X Regulated by CASC2c Recruited Macrophages and Induced M2 Polarization in Glioblastoma Multiforme

Tumor-associated macrophages (TAMs) constitute a major component of inflammatory cells in the glioblastoma multiforme (GBM) tumor microenvironment. TAMs have been implicated in GBM angiogenesis, invasion, local tumor recurrence, and immunosuppression. Coagulation factor X (FX) is a vitamin K-dependent plasma protein that plays a role in the regulation of blood coagulation. In this study, we first found that FX was highly expressed and positively correlated with TAM density in human GBM. FX exhibited a potent chemotactic capacity to recruit macrophages and promoted macrophages toward M2 subtype polarization, accelerating GBM growth. FX bound to extracellular signal-related kinase (ERK)1/2 and inhibited p-ERK1/2 in GBM cells. FX was secreted in the tumor microenvironment and increased the phosphorylation and activation of ERK1/2 and AKT in macrophages, which may have been responsible for the M2 subtype macrophage polarization. Moreover, although the lncRNA CASC2c has been verified to function as a miR-101 competing endogenous RNA (ceRNA) to promote miR-101 target genes in GBM cells, we first confirmed that CASC2c did not function as a miR-338-3p ceRNA to promote FX expression, and that FX was a target gene of miR-338-3p. CASC2c interacted with and reciprocally repressed miR-338-3p. Both CASC2c and miR-388-3p bound to FX and commonly inhibited its expression and secretion. CASC2c repressed M2 subtype macrophage polarization. Taken together, our findings revealed a novel mechanism highlighting CASC2c and FX as potential therapeutic targets to improve GBM patients by altering the GBM microenvironment.

MiR-129-5p targets Wnt5a to block PKC/ERK/NF-\u03baB and JNK pathways in glioblastoma

Therapeutic application of microRNAs (miRNAs) in Wnt-driven glioma has been valuable; however, their specific roles and mechanisms have not been completely investigated. Real-time quantitative PCR (RT-qPCR) was used to analyse the expression of microRNA-129-5p (miR-129-5p) in human glioma samples. Cell-Counting Kit 8 (CCK-8), flow cytometry, EdU, angiogenesis, Transwell invasion, wound healing, in vitro 3D migration and neurosphere formation assays were employed to assess the role of miR-129-5p in glioblastoma multiforme (GBM) cells. Moreover, we performed the luciferase reporter assay and the RNA-ChIP (chromatin immunoprecipitation) assay to confirm whether Wnt5a was a direct target of miR-129-5p. We also confirmed the correlation between the expression profile of miR-129-5p and Wnt5a in glioma patients from the Chinese Glioma Genome Atlas (CGGA) and investigated the overall survival of GBM patients using two data sets, namely, TCGA and GSE16011, according to their Wnt5a expression status. MiR-129-5p expression levels were downregulated and inversely correlated with Wnt5a expression levels in CGGA glioma patients. Restored expression of miR-129-5p blocked GBM cell proliferation, invasion, migration, angiogenesis, neurosphere formation and resistance to temozolomide. We reported that miR-129-5p directly targeted Wnt5a in glioma. Furthermore, we observed that overexpression of miR-129-5p inhibited the expression of Wnt5a, thus blocking the protein kinase C(PKC)/ERK/NF-κB and JNK pathways. Inhibiting Wnt5a rescued the effects of miR-129-5p loss and increased Wnt5a expression was associated with reduced overall survival of GBM patients. We also demonstrated the inhibitory effect of miR-129-5p on tumour growth in GBM using an in vivo model. The miR-129-5p/Wnt5a-axis-mediated PKC/ERK/NF-κB and JNK pathways have therapeutic potential in GBM treatment.

IDH1 mutation is associated with lower expression of VEGF but not microvessel formation in glioblastoma multiforme.

IntroductionGlioblastoma multiforme (GBM) represents the most malignant primary brain tumor characterized by pathological vascularization. Mutations in isocitrate dehydrogenases 1 and 2 (IDH1 and IDH2) were observed in GBM. We aimed to assess the intra-tumor hypoxia, angiogenesis and microvessel formation in GBM and to find their associations with IDH1 mutation status and patients prognosis.Methods52 patients with a diagnosis of GBM were included into the study. IDH1 R132H mutation was assessed by RT-PCR from FFPE tumor samples obtained during surgery. The expression of markers of hypoxia (HIF2α), angiogenesis (VEGF), tumor microvascularity (CD31, CD34, vWF, CD105), and proliferation (Ki-67) were assessed immunohistochemically (IHC). IDH1 mutation and IHC markers were correlated with the patient survival.Results20 from 52 GBM tumor samples comprised IDH1 R132H mutation (38.5%). The majority of mutated tumors were classified as secondary glioblastomas (89.9%). Patients with IDH1 mutated tumors experienced better progression-free survival (P = 0.037) as well as overall survival (P = 0.035) compared with wild type tumors. The significantly lower expression of VEGF was observed in GBM with IDH1 mutation than in wild type tumors (P = 0.01). No such association was found for microvascular markers. The increased expression of newly-formed microvessels (ratio CD105/CD31) in tumor samples was associated with worse patient’s progression-free survival (P = 0.026).SummaryNo increase in HIF/VEGF-mediated angiogenesis was observed in IDH1-mutated GBM compared with IDH1 wild type tumors. The histological assessment of the portion of newly-formed microvessels in tumor tissue can be used for the prediction of GBM patient’s prognosis.

Molecular mechanisms involved in angiogenesis and potential target of antiangiogenesis in human glioblastomas

Glioblastoma multiforme (GBM) is the most devastating and common primary malignant brain tumor in adults. Angiogenesis as a hallmark in glioblastoma has attracted more and more attention of the research community. Over the past years, several systematic studies have provided vital results in this field discovering alterations in unanticipated number of genes and other regulatory factors and the associated signaling pathways. Recent discoveries about such genes and signaling pathway associated with angiogenesis in GBM provide a picture of the genomic routes in angiogenesis and antiangiogenesis pathways and may lay the foundation for improved antiangiogenesis therapy and clinical care. In this review, we discuss several such recent progresses in the genes associated with GBM angiogenesis/antiangiogenesis pathways and explore the potential new targets for GBM treatment.

Roles of EphA2 Receptor in Angiogenesis Signaling Pathway of Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is one of the most common primary brain tumours in adults, accounting for almost 65% of all cases. Among solid tumours, GBM is characterised by strong angiogenesis, including the highest degree of vascular proliferation and endothelial cell hyperplasia. Despite numerous improvements in existing treatment approaches, the prognosis of GBM patients remains poor, with a mean survival of only 14.6 months. Growing evidence has shown significant overexpression of the ephrin type-A receptor 2 (EphA2) receptor in various malignancies, including GBM, as well as a correlation to poor prognoses. It is believed that EphA2 receptors play important roles in mediating GBM tumourigenesis, including invasion, metastasis, and angiogenesis. Despite the clinical and pathological importance of tumour-associated vasculature, the underlying mechanism involving EphA2 is poorly known. Here, we have summarised the current knowledge in the field regarding EphA2 receptors’ roles in the angiogenesis of GBM.