Vascular Endothelial Growth Factor Antibody Research Articles

Analysis of various potential prognostic markers and survival data in clear cell renal cell carcinoma.

ABSTRACTPurpose Clear cell renal cell cancers frequently harbor Von Hippel-Lindau gene mutations, leading to stabilization of the hypoxia-inducible factors (HIFs) and their target genes. In this study, we investigated the relationship between vascular endothelial growth factor (VEGF), HIF-1α, HIF-2α, p53 positivity, microvessel density, and Ki-67 rates with prognostic histopathologic factors (Fuhrman nuclear grade, stage, and sarcomatoid differentiation) and survival in clear cell renal cell carcinomas.Material and Methods Seventy-two nephrectomy specimens diagnosed as clear cell renal cell carcinoma between 2000 and 2012 were reevaluated. Immunohistochemically VEGF, HIF-1α, HIF-2α, p53, CD34 (for microvessel density evaluation), and Ki-67 antibodies were applied to the tumor areas. The relationships of these antibodies with prognostic factors and survival rates were evaluated with statistical analyses.Results Mean survival time was 105.6 months in patients with ccRCC. Patients with high expression of VEGF, HIF-1α and HIF-2α positivity, a high Ki-67 proliferation index, and a high microvessel density evaluation score had a shorter survival time (p<0.05).Conclusions Our findings supported that with the use of these immunohistochemical markers, prognosis of renal cell carcinoma may be predicted at the first step of patient management. New treatment modalities targeted to HIF-1α and HIF-2α might be planned as well as VEGF-targeted therapies in the management of clear cell renal cell carcinomas.

The value of [11C]-acetate PET and [18F]-FDG PET in hepatocellular carcinoma before and after treatment with transarterial chemoembolization and bevacizumab

PurposeThis prospective study was to investigate the value of [11C]-acetate PET and [18F]-FDG PET in the evaluation of hepatocellular carcinoma (HCC) before and after treatment with transarterial chemoembolization (TACE) and vascular endothelial growth factor (VEGF) antibody (bevacizumab).MethodsTwenty-two patients (three women, 19 men; 62 ± 8 years) with HCC verified by histopathology were treated with TACE and bevacizumab (n = 11) or placebo (n = 11). [11C]-acetate PET and [18F]-FDG PET were performed before and after TACE with bevacizumab or placebo. Comparisons between groups were performed with t-tests and Chi-squared tests, where appropriate. Overall survival (OS) was defined as the time from start of bevacizumab or placebo until the date of death/last follow-up, respectively.ResultsThe patient-related sensitivity of [11C]-acetate PET, [18F]-FDG PET, and combined [11C]-acetate and [18F]-FDG PET was 68%, 45%, and 73%, respectively. There was a significantly higher rate of conversion from [11C]-acetate positive lesions to negative lesions in patients treated with TACE and bevacizumab as compared with that in patients with TACE and placebo (p < 0.05). In patients with negative acetate PET, the mean OS in patients treated with TACE and bevacizumab was 259 ± 118 days and was markedly shorter as compared with that (668 ± 217 days) in patients treated with TACE and placebo (p < 0.05). In patients treated with TACE and placebo, there was significant difference in mean OS in patients with positive FDG PET as compared with that in patients with negative FDG PET (p < 0.05). The HCC lesions had different tracer avidities showing the heterogeneity of HCC.ConclusionsOur study suggests that combining [18F]-FDG with [11C]-acetate PET could be useful for the management of HCC patients and might also provide relevant prognostic and molecular heterogeneity information.

Magnetic nanoparticles conjugated with "RPE cell -MCP-1 antibody -VEGF antibody" compounds for the targeted therapy of age-related macular degeneration: a hypothesis.

Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly throughout the world. Treatment of AMD utilizing retinal pigment epithelium (RPE) transplantation represents a promising therapy. However, simplex RPE transplantation can only replace the diseased RPE cells, but has no abilities to stop the development of AMD. It has been indicated that oxidization triggers the development of AMD by inducing the dysfunction and degeneration of RPE cells, which results in the upregulation of local monocyte chemotactic protein-1 (MCP-1) expression. MCP-1 induces macrophage recruiment which triggers local inflammation. As a result, the expression of vascular endothelial growth factor (VEGF) is upregulated by MCP-1 mediated inflammation and results in the formation of choroidal neovascularization (CNV). We accordingly propose a targeted therapy of AMD by subretinal transplanting the compound of RPE cell, MCP-1 antibody, and VEGF antibody and using a magnetic system to guide RPE cell compounds conjugated with superparamagnetic iron oxide nanoparticles (SPIONs). Furthermore, SPION-labelled RPE cells can be tracked and detected in vivo by non-invasive magnetic resonance imaging (MRI). This novel RPE cell transplantation methodology seems very promising to provide a new therapeutic approach for the treatment of AMD.

OS01.6 Glioblastoma in the era of bevacizumab: an epidemiological study in the Canton of Zurich, Switzerland

Abstract Background: The vascular endothelial growth factor antibody, bevacizumab (Avastin®), received approval for the treatment of recurrent glioblastoma in Switzerland in 2009. Here we explored the hypothesis that the approval of bevacizumab improved outcome in glioblastoma on a population level. Methods: The prognostic significance of epidemiological and clinical data, as well as molecular markers for glioblastoma patients diagnosed from 2010–2014 in the Canton of Zurich was analyzed using the log rank test and the Cox proportional hazards model. Data were compared to the years 2005–2009. Results: 310 glioblastoma patients were identified in the years 2010–2014. Median overall survival (OS) in this cohort was 13.1 months for all patients (independent of the isocitrate dehydrogenase (IDH) mutation status) and 13.5 months for patients with IDH wildtype (wt) tumors, compared with 11.3 months for all patients (p=0.554) and 11.3 months for IDH wt patients (p=0.675) before (2005–2009). In the present study, in the subgroup of IDH wt patients (n=247), 111 patients received bevacizumab at any time, half of them at time of first recurrence. Multivariate analysis demonstrated young age, high Karnofsky performance score, greater extent of resection, methylated O6-methylguanine DNA methyltransferase (MGMT) promoter, or first-line chemoradiotherapy, but not bevacizumab exposure, to be independently associated with survival. Conclusions: Despite a strong increase in bevacizumab use in the Canton of Zurich, Switzerland, on a population level, OS has moderately, but not significantly improved from 2005–2009 to 2010–2014. Our data do not support the notion that the minor increase in survival was directly linked to the availability of bevacizumab.

P08.36 TGF-β pathway-mediated escape from VEGF blockade is linked with angiogenesis and immune-suppression in murine glioma models

AbstractThe vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β are key target molecules in glioblastoma that are interdependently regulated. Both pathways drive key malignant features in glioma cells such as angiogenesis, invasiveness and immunosuppression. Here we explore whether TGF-β acts as an escape pathway from VEGF inhibition using gene expression profiling and in vitro and in vivo studies in a panel of syngeneic mouse glioma models. In vivo, single agent activity was observed for the VEGF antibody B20-4.1.1 in three (SMA-540, SMA-560 and GL-261), and for the TGF-β receptor I antagonist LY2157299 in two (SMA-540 and SMA-560) of four mouse glioma models. Transcriptomic profiling of the four mouse glioma models revealed that SMA-497 and GL-261, while unresponsive to LY2157299, were the most immunogenic tumors as defined by Gene Ontology; specifically, up-regulation of chemokine/chemoreceptors genes involved in immune cell recruitment and interferon-related genes were found. Co-targeting of VEGF and TGF-β was ineffective in one refractory model (SMA-497), in which no major changes in tumor immune-infiltrating cells were detected upon mono- or co-treatment settings. Significant prolongation of survival in the GL-261 model was associated with early stage increased infiltration of CD8+ cells, lower numbers of CD11b+ macrophages/microglia and sustained suppression of angiogenesis compared to anti-VEGF treatment alone. Phosphorylated SMAD2 was increased in both tumor cells and CD45+ leukocytes during anti-angiogenic treatment pointing to the possibility of a TGF-β-induced immunosuppressive micro-milieu that is efficiently counteracted by concomitant administration of LY2157299. In conclusion, our study highlights the biological heterogeneity of glioblastoma even among simple mouse models and illustrates that co-targeting of the VEGF and TGF-β pathways might lead to improved tumor control in subsets of glioblastoma linked with angiogenesis impairment and general reduction of the immune-suppressive phenotype.This study was supported by a grant from Oncosuisse (KFS-02694-08-2010)

Abstract B88: TGF-β pathway-mediated escape from VEGF blockade is linked with angiogenesis and immune-suppression in murine glioma models

Abstract The vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β are key target molecules in glioblastoma that are interdependently regulated. Both pathways drive key malignant features in glioma cells such as angiogenesis, invasiveness and immunosuppression. Here we explore whether TGF-β acts as an escape pathway from VEGF inhibition using gene expression profiling and in vitro and in vivo studies in a panel of syngeneic mouse glioma models. In vivo, single agent activity was observed for the VEGF antibody B20-4.1.1 in three (SMA-540, SMA-560 and GL-261), and for the TGF-β receptor I antagonist LY2157299 in two (SMA-540 and SMA-560) of four mouse glioma models. Transcriptomic profiling of the four mouse glioma models revealed that SMA-497 and GL-261, while unresponsive to LY2157299, were the most immunogenic tumors as defined by Gene Ontology; specifically, up-regulation of chemokine/chemoreceptors genes involved in immune cell recruitment and interferon-related genes were found. Co-targeting of VEGF and TGF-β was ineffective in one refractory model (SMA-497), in which no major changes in tumor immune-infiltrating cells were detected upon mono- or co-treatment settings. Significant prolongation of survival in the GL-261 model was associated with early stage increased infiltration of CD8+ cells, lower numbers of CD11b+ macrophages/microglia and sustained suppression of angiogenesis compared to anti-VEGF treatment alone. Phosphorylated SMAD2 was increased in both tumor cells and CD45+ leukocytes during anti-angiogenic treatment pointing to the possibility of a TGF-β-induced immunosuppressive micro-milieu that is efficiently counteracted by concomitant administration of LY2157299. In conclusion, our study highlights the biological heterogeneity of glioblastoma even among simple mouse models and illustrates that co-targeting of the VEGF and TGF-β pathways might lead to improved tumor control in subsets of glioblastoma linked with angiogenesis impairment and general reduction of the immune-suppressive phenotype. Note: This abstract was not presented at the conference. Citation Format: Davide Mangani, Michael Weller, Emad Seyed Sadr, Edith Willscher, Katharina Seystahl, Guido Reifenberger, Ghazaleh Tabatabai, Hans Binder, Hannah Schneider. TGF-β pathway-mediated escape from VEGF blockade is linked with angiogenesis and immune-suppression in murine glioma models. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B88.

Gene therapy for diabetic retinopathy: Are we ready to make the leap from bench to bedside?

Diabetic retinopathy (DR), a chronic and progressive complication of diabetes mellitus, is a sight-threatening disease characterized in the early stages by neuronal and vascular dysfunction in the retina, and later by neovascularization that further damages vision. A major contributor to the pathology is excess production of vascular endothelial growth factor (VEGF), a growth factor that induces formation of new blood vessels and increases permeability of existing vessels. Despite the recent availability of effective treatments for the disease, including laser photocoagulation and therapeutic VEGF antibodies, DR remains a significant cause of vision loss worldwide. Existing anti-VEGF agents, though generally effective, are limited by their short therapeutic half-lives, necessitating frequent intravitreal injections and the risk of attendant adverse events. Management of DR with gene therapies has been proposed for several years, and pre-clinical studies have yielded enticing findings. Gene therapy holds several advantages over conventional treatments for DR, such as a longer duration of therapeutic effect, simpler administration, the ability to intervene at an earlier stage of the disease, and potentially fewer side-effects. In this review, we summarize the current understanding of the pathophysiology of DR and provide an overview of research into DR gene therapies. We also examine current barriers to the clinical application of gene therapy for DR and evaluate future prospects for this approach.

ASCO 2016 - update colorectal liver metastases.

SummaryThis short review summarizes the most relevant data on colorectal liver metastases (CLM) presented at the 2016 Annual Meeting of the American Society of Clinical Oncology (ASCO). For this update, congress abstracts were grouped into three clinically relevant scenarios: CLM that are deemed upfront resectable, borderline resectable, and primarily unresectable. According to a large registry study, small, upfront resectable, solitary CLM should be resected using a parenchymal sparing technique. A prospective noninterventional study suggested that chemotherapy plus the anti-VEGF (vascular endothelial growth factor) antibody bevacizumab is effective and well tolerated in patients with borderline resectable CLM. In the setting of CLM deemed initially unresectable, a phase 2 study reported superior outcomes in terms of liver metastases resection rates as well as overall survival (OS) in patients receiving a chemotherapy triplet (FOLFIRINOX) plus a targeted agent as compared to FOLFIRI or FOLFOX4 with the same targeted therapy. Finally, a study suggested that tailoring first-line chemotherapy according to TYMS-3’UTR and ERCC1-118 polymorphism status results in higher response rates and longer progression-free survival (PFS) as well as OS.

The impact of tumor biology on survival and response to radiation therapy among patients with non–small cell lung cancer brain metastases

PurposeTo investigate the natural history and response to radiation therapy among ALK-rearranged, EGFR-mutated, wild-type adenocarcinoma, and squamous cell non–small cell lung cancer (NSCLC) brain metastases. Methods and materialsPatients with NSCLC brain metastasis diagnosed from 1989 through 2014 at a single tertiary-care institution were included. The primary outcome was overall survival, whereas secondary outcomes included local failure, distant intracranial failure, and radiation necrosis. Cox proportional hazards regression was used to model overall survival; multivariate competing risks regression was used to model secondary outcomes. ResultsWithin the study period, 1920 patients presented with 6312 brain metastases. Squamous histology was associated with poorer median survival compared with adenocarcinomas (5.4 vs 8.8 months, P < .01). Median survival was greatest among ALK+ patients (49.2 months), followed by EGFR+ (20.3 months), and wild-type adenocarcinomas (10.0 months, P < .01). Treatment with estimated glomerular filtration rate inhibitors (hazard ratio [HR], 0.66; P < .01) and vascular endothelial growth factor antibodies (HR, 0.65; P < .01) increased survival independent of mutational status. Among 2056 lesions treated with stereotactic radiosurgery, the 12-month cumulative incidence of local failure was significantly greater among squamous cell carcinomas relative to adenocarcinomas (15% vs 10%, HR, 1.26; P = .04). Patients with ALK+ metastases experienced higher rates of local failure (10%; HR, 2.00; P = .05), distant failure (39%; HR, 2.94; P < .01), and radiation necrosis (18%; HR, 5.77; P < .01), whereas EGFR+ patients experienced the lowest rates of local failure (5%; HR, 0.46; P = .04) and distant failure (3%; HR, 0.13; P = .04). ConclusionsAdvances in precision medicine have increased survival among select patients with NSCLC. In the present investigation, ALK+ and EGFR+ status were associated with improved survival. However, patients with ALK+ metastases have poor intracranial control relative to EGFR+ metastases, possibly because of limited intracranial penetration of crizotinib compared with estimated glomerular filtration rate inhibitors. Future investigations are warranted to determine the optimal management of ALK+ brain metastases with the introduction of second-generation ALK inhibitors.

Hypoxic Preconditioning Increases Blood-Brain Barrier Disruption in the Early Stages of Cerebral Ischemia.

Even though hypoxic preconditioning has been reported to produce neuroprotection, its effect on blood-brain barrier (BBB) disruption in the early stages of cerebral ischemia within the therapeutic window is not clear. Since hypoxic preconditioning increases expression of vascular endothelial growth factor (VEGF) that modulates vascular permeability, the effects of hypoxic preconditioning and VEGF on BBB permeability were investigated after one hour of focal cerebral ischemia. Rats were exposed to 8% of oxygen for two hours or room air and then 24 hours later, permanent middle cerebral artery (MCA) occlusion was performed. In some of the hypoxic preconditioned rats, a VEGF-A antibody was applied to the ischemic cortex one hour before MCA occlusion. One hour after MCA occlusion, the transfer coefficient (Ki) of 14C-α-aminoisobutyric acid was determined to measure the degree of BBB disruption. MCA occlusion increased the Ki when compared with the contralateral cortex (14.1 ± 4.0 vs 4.2 ± 1.9 μL/g/min, p < 0.0001). Hypoxic preconditioning further increased the Ki in the ischemic cortex when compared with the control rats (25.1 ± 8.7 μL/g/min, p < 0.01). Application of VEGF antibody to the ischemic cortex of the hypoxic preconditioned animals reduced the Ki to the level of the control rats (13.6 ± 5.1 μL/g/min, p < 0.01). Our data demonstrated that hypoxic preconditioning increased BBB disruption through a VEGF related pathway and suggest the possibility of aggravation of brain edema by hypoxic preconditioning in the early stages of cerebral ischemia.

Vascular Endothelial Growth Factor as an Angiogenic Marker in Malignant Astrocytoma and Oligodendroglioma: An Indian Scenario.

The role of Vascular Endothelial Growth Factor (VEGF) in angiogenesis has been extensively studied in gliomas, such as astrocytoma and oligodendrogliomas, worldwide. However, there is limited information available with regard to the Indian population. To study, whether VEGF is expressed in the Indian population in a pattern similar to that in other population. In this prospective study approved by the Institute Ethics Committee for Human Studies at Jawaharlal Institute of Post Graduate Medical Education and Research (JIPMER) the patients operated for glioma in 2014 and 2015 (n = 60) were included. Tumours were graded as per the World Health Organization (WHO) grading system. VEGF expression in various grades was analysed using immunohistochemistry. Of the 60 patients included in this study, 15 were Grade II- (diffuse astrocytomas - 12; oligodendrogliomas- 3), 15 were Grade III-(anaplastic astrocytomas- 2; anaplastic oligodendrogliomas - 13) and 30 were Grade IV-glioblastomas. For VEGF antibody staining, two patients (3.33%) showed negative results and 58 patients (96%) showed positive results. VEGF positivity was 100% in Grade II and III, while it was 93.3% (28/30) in Grade IV tumours (p=0.012). The expression of VEGF was associated with the grade of tumour, which gradually increased from Grade II to Grade IV. We conclude that VEGF-regulated angiogenesis plays an important role in tumour progression of astrocytomas and oligodendrogliomas in the Indian population as observed worldwide.

Expression of Vascular Endothelial Growth Factor in Odontogenic Cysts: Is There Any Impression on Clinical Outcome?

Background:The recent scientific reports have shown that angiogenesis can affect biological behavior of pathologic lesions.Objective:Regarding unique clinical outcome of Odontogenic keratocyst (OKC), the present study was aimed to compare angiogenesis in Odontogenic keratocyst and Dentigerous cyst (DC).Method:In this experimental study, tissue sections of 46 samples of OKC and DC were stained through immunohistochemical method using Vascular Endothelial Growth Factor (VEGF) antibody. VEGF expression was evaluated in epithelial cells, fibroblasts and endothelial cells. The average percentage of stained cells in any samples was categorized to 3 groups as follows: SCORE 0: 10% of cells or less are positive. SCORE 1: 10 to 50% of cells are positive. SCORE 2: more than 50% of cells are positive. Mann-U-Whitney, T-test and chi-square was used for statistical analysis.Result:The average of VEGF expression in 24 samples of DC was 20.2% and in 22 samples of OKC was 52.6%, respectively. The average of VEGF expression in these two cysts had statistical significant differences. (PV= 0.045). There was significant statistical differences between two cysts in the terms of VEGF SCORE (PV= 0.000). OKC samples had significantly higher SCORE for the purpose of VEGF incidence than DC. Also, there were no differences between VEGF expression in epithelial cells of two cysts (PV= 0.268) there were significant statistical differences between two cysts in terms of endothelial cell staining. The endothelial cell staining was significantly higher in OKC than DC (PV= 0.037%).Conclusion:Regarding higher expression of Vascular Endothelial Growth factor in OKC than DC, it seems that angiogenesis may have great impression on clinical outcome of OKC.

Role of Biologics in First-Line Treatment of Colorectal Cancer.

In the past decade, significant advances have been made in the treatment of advanced colorectal cancer. Multiple cytotoxic agents and targeted therapies have been approved for management of metastatic colorectal cancer, leading to improvement of median overall survival in clinical trials to more than 30 months. Of note, before the introduction of biologics into treatment algorithms for metastatic colorectal cancer, median survival in phase III trials never exceeded 24 months. In 2016, the most common treatment approach in first line is a combination of chemotherapy with a biologic agent. The choice of therapy is influenced by patient factors (eg, age, comorbidities), tumor characteristics (eg, overall tumor burden, pattern of metastatic spread, mutation signature), potential adverse effects of therapy, and goals of treatment. The choice between irinotecan- or oxaliplatin-based cytotoxic chemotherapy regimen is primarily based on differential toxicity profile because they have similar efficacy. Currently, three biologic agents-bevacizumab, cetuximab, and panitumumab-are approved for first-line treatment of metastatic colorectal cancer. For patients with mutant RAS and likely mutant BRAF V600E tumors, bevacizumab is the only biologic agent that can be used in conjunction with cytotoxic chemotherapy. The choice of anti-epidermal growth factor antibody or anti-vascular endothelial growth factor antibody in RAS wild-type tumors is based on the specific clinical scenario. Recently, some clinical and molecular biomarkers have emerged that may help in decision making. In this review, we discuss the role of biologics in the management of first-line treatment of metastatic colorectal cancer.

Angiography of the ocular fundus without dye: Optical coherence tomography based angiography in exsudative age-related macular degeneration

Vascular endothelial growth factor antibody therapy is an established treatment of exsudative age-related macular degeneration. The morphologic characterisation of the macular microvasculature after longstanding treatment. Forty-eight patients (34 women and 14 men; age, 74.4 ± 8.0 years) were enrolled in the study. During follow-up time (53.8 ± 31.0 months), 7.6 ± 4.9 injections were administered in 56 eyes. Optical coherence tomography angiographic examination was performed with AngioVue (Optovue Inc. Fremont, CA, USA). Distortion of the superficial retinal plexus and foveal avascular zone enlargement were noted in 5/56 eyes, deep retinal plexus defect was detected in 9/56 cases. Destruction of the choriocapillaries and the former neovascularisation could be found in 4 different patterns: 1. pigment epithelium and choriocapillary atrophy, 2. submacular scar, 3. active leaking choroidal neovascularisation, 4. intraretinal cysts. Optical coherence tomography angiography is a novel non-invasive method, which enables the follow up of macular degeneration. Orv. Hetil., 2016, 157(42), 1683-1690.

Apelin-13 protects neurovascular unit against ischemic injuries through the effects of vascular endothelial growth factor

Apelin-13 has protective effects on many neurological diseases, including cerebral ischemia. Here, we aimed to test Apelin-13's effects on ischemic neurovascular unit (NVU) injuries and investigate whether the effects were dependent on vascular endothelial growth factor (VEGF). We detected the expression of VEGF and its receptors (VEGFRs) induced by Apelin-13 injection at 1d, 3d, 7d and 14d after middle cerebral artery occlusion (MCAO). Meanwhile, we examined the effects of Apelin-13 on NVU in both in vivo and in vitro experiments as well as whether the effects were VEGF dependent by using VEGF antibody. We also assessed the related signal transduction pathways via multiple inhibitors. We demonstrated Apelin-13 highly increased VEGF and VEGFR-2 expression, not VEGFR-1. Importantly, Apelin-13 led to neurological functions improvement by associating with promotion of angiogenesis as well as reduction of neuronal death and astrocyte activation, which was markedly blocked by VEGF antibody. In cell cultures, Apelin-13 protected neurons, astrocytes and endothelial cells against oxygen-glucose deprivation (OGD) injuries. Moreover, the effect of Apelin-13 to up-regulate VEGF was suppressed by extracellular signal-regulated kinase (ERK) inhibitor U0126 and phosphatidylinositol 3′-kinase (PI3K) inhibitor LY294002. Our data suggest protective effects of Apelin-13 on ischemic NVU injuries are highly associated with the increase of VEGF binding to VEGFR-2, possibly acting through activation of ERK and PI3K/Akt pathways.

Limited role for transforming growth factor-β pathway activation-mediated escape from VEGF inhibition in murine glioma models.

The vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β pathways regulate key biological features of glioblastoma. Here we explore whether the TGF-β pathway, which promotes angiogenesis, invasiveness, and immunosuppression, acts as an escape pathway from VEGF inhibition. The role of the TGF-β pathway in escape from VEGF inhibition was assessed in vitro and in vivo and by gene expression profiling in syngeneic mouse glioma models. We found that TGF-β is an upstream regulator of VEGF, whereas VEGF pathway activity does not alter the TGF-β pathway in vitro. In vivo, single-agent activity was observed for the VEGF antibody B20-4.1.1 in 3 and for the TGF-β receptor 1 antagonist LY2157299 in 2 of 4 models. Reduction of tumor volume and blood vessel density, but not induction of hypoxia, correlated with benefit from B20-4.1.1. Reduction of phosphorylated (p)SMAD2 by LY2157299 was seen in all models but did not predict survival. Resistance to B20 was associated with anti-angiogenesis escape pathway gene expression, whereas resistance to LY2157299 was associated with different immune response gene signatures in SMA-497 and GL-261 on transcriptomic profiling. The combination of B20 with LY2157299 was ineffective in SMA-497 but provided prolongation of survival in GL-261, associated with early suppression of pSMAD2 in tumor and host immune cells, prolonged suppression of angiogenesis, and delayed accumulation of tumor infiltrating microglia/macrophages. Our study highlights the biological heterogeneity of murine glioma models and illustrates that cotargeting of the VEGF and TGF-β pathways might lead to improved tumor control only in subsets of glioblastoma.

GDNF secreted from adipose-derived stem cells stimulates VEGF-independent angiogenesis.

Adipose tissue stroma contains a population of mesenchymal stem cells (MSC) promote new blood vessel formation and stabilization. These adipose-derived stem cells (ASC) promote de novo formation of vascular structures in vitro. We investigated the angiogenic factors secreted by ASC and discovered that glial-derived neurotrophic factor (GDNF) is a key mediator for endothelial cell network formation. It was found that both GDNF alone or present in ASC-conditioned medium (ASC-CM) stimulated capillary network formation by using human umbilical vein endothelial cells (HUVECs) and such an effect was totally independent of vascular endothelial growth factor (VEGF) activity. Additionally, we showed stimulation of capillary network formation by GDNF, but not VEGF, could be blocked by the Ret (rearranged during transfection) receptor antagonist RPI-1, a GDNF signaling inhibitor. Furthermore, GDNF were found to be overexpressed in cancer cells that were resistant to the anti-angiogenic treatment using the VEGF antibody. Cancer cells in the liver hepatocellular carcinoma (HCC), a non-nervous related cancer, highly overexpressed GDNF as compared to normal liver cells. Our data strongly suggest that, in addition to VEGF, GDNF secreted by ASC and HCC cells, may be another important factor promoting pathological neovascularization. Thus, GDNF may be a potential therapeutic target for HCC and obesity treatments.

Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells.

Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF) antibody and ligand cluster of differentiation 80 (CD80) for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA). The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTMNPO CRL-2836) at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL) of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF). Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test) induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum species having spontaneous OSA, such as the dog, and on a human OSA cell line model.

Retinopathy of prematurity: the need for prevention.

More than 450,000 babies are born prematurely in the USA every year. The improved survival of even the most vulnerable low body weight preterm infants has, despite improving health outcomes, led to the resurgence in preterm complications including one of the major causes for blindness in children, retinopathy of prematurity (ROP). The current mainstay in ROP therapy is laser photocoagulation and the injection of vascular endothelial growth factor (VEGF) antibodies in the late stages of the disease after the onset of neovascularization. Both are proven options for ophthalmologists to treat the severe forms of late ROP. However, laser photocoagulation destroys major parts of the retina, and the injection of VEGF antibodies, although rather simple to administer, may cause a systemic suppression of normal vascularization, which has not been studied in sufficient depth. However, the use of neither VEGF antibody nor laser treatment prevents ROP, which should be the long-term goal. It should be possible to prevent ROP by more closely mimicking the intrauterine environment after preterm birth. Such preventive measures include preventing the toxic postbirth influences (eg, oxygen excess) as well as providing the missing intrauterine factors (eg, insulin growth factor 1) and are likely to also reduce other complications of premature birth as well as ROP. This review is meant to summarize the current knowledge on the prevention of ROP with a particular emphasize on the use of insulin growth factor 1 supplementation.

Inhibition of Growth and Metastasis of Tumor in Nude Mice after Intraperitoneal Injection of Bevacizumab.

ObjectiveTo explore the inhibitory effect of bevacizumab, a vascular endothelial growth factor antibody, on angiogenesis in human osteosarcoma of nude mice.MethodsTwenty‐one nude mice were inoculated with red fluorescent protein (RFP)‐labeled human osteosarcoma cell line 143B‐RFP, that is, clones that expressed RFP in the cytoplasm, and randomly assigned to one of three groups: G1 (Control group, injected with saline solution); G2 (intraperitoneal bevacizumab 2 mg/kg twice per week) and G3 (intraperitoneal bevacizumab 5 mg/kg, twice per week). The tumor‐bearing mice were examined in a fluorescence light box that was illuminated periodically. The primary tumors were measured by fluorescence imaging weekly and their volumes calculated.ResultsThe mean tumor volumes were significantly smaller in the G3 (186.4 ± 100.8 mm3) than the control group (587.0 ± 406.8 mm3) (P < 0.05) on Day 31, and again significantly smaller in the G3 (677.3 ± 461.9 mm3) than the control group (3162.6 ± 1529.2 mm3) on Day 38 (P < 0.01). The average tumor volume in the G2 group was 493.5 ± 425.4 mm3 on Day 31 and 1870.1 ± 1524.8 mm3 on Day 38. The effect on tumor volume was greater in the G3 than the G2 group. Three mice in the G2 group, four in the G3 group and four in the control group developed lung metastases that were confirmed by pathological examination; these differences were not statistically significant (P < 0.05).ConclusionsBevacizumab exhibits strong antiangiogenesis activity in experimental osteosarcoma in a nude mouse model but does not influence the incidence of lung metastasis. Our findings may have considerable potential for the treatment of osteosarcoma.