Epidermal Growth Factor-like Domain 7 Expression Research Articles

Characterization of epidermal growth factor-like domain 7 (EGFL7) expression in normal endometrium and in the endometrium of women with poor reproductive outcomes.

Could epidermal growth factor-like domain 7 (EGFL7) be a factor involved in the preparation of the endometrium for implantation and could its dysregulation be implicated in poor reproductive outcomes? EGFL7 is highly expressed in the endothelium and glandular epithelium throughout the menstrual cycle; it is upregulated by stromal cells in secretory phase and appears strongly reduced in endometrial biopsies and isolated stromal cells of women with unexplained recurrent pregnancy loss (uRPL) and recurrent implantation failure (RIF). The secreted factor EGFL7, originally identified as a gene primarily expressed in endothelial cells, is also expressed by the mouse blastocyst and by mouse and human trophoblast cells. It regulates trophoblast migration and invasion by activating NOTCH1 signaling. NOTCH1 has been demonstrated to play a fundamental role in endometrial receptivity and its dysregulation may be involved in selected pregnancy complications characterized by altered endometrial receptivity, such as uRPL. This is an exploratory study for which 84 endometrial biopsies were collected from normally fertile women, as well as from women with uRPL and RIF. Samples were collected from women in both the proliferative and secretory phases of the menstrual cycle and stratified into three sub-groups according to the patient clinical history: 20 fertile women (8 in proliferative and 12 in secretory phase), 41 women with uRPL (6 in proliferative and 35 in secretory phase), and 27 women with RIF (8 in proliferative and 19 in secretory phase). Immunohistochemistry, real-time PCR, and western blot analyses were performed to study the expression of EGFL7 and NOTCH1, as well as the NOTCH target genes. Analysis of spatial and temporal distribution of EGFL7 in endometrial biopsies from fertile women revealed higher levels of EGFL7 in samples from the secretory phase compared to proliferative phase. The expected expression of EGFL7 in endothelial cells was shown as well as the novel, not previously reported, expression in endometrial glands and stromal cells. EGFL7 was significantly reduced in the endometrium of women with uRPL and RIF in the secretory phases and this was associated with a downregulation of the NOTCH1 signaling pathway. Human recombinant EGFL7 was able to activate the NOTCH1 signaling pathway in endometrial stromal cells (EndSCs) obtained from fertile women but not in cells from uRPL or RIF patients. EndSCs from fertile women and decidualized in vitro for three days showed an upregulation of EGFL7 expression, whereas cells obtained from women with uRPL and RIF and decidualized in vitro did not. This study was conducted with a relatively small number of patient samples. Although results are highly reproducible and consistent, additional observations from multicentric cohorts would strengthen the relevance of the data. Moreover, this is an in vitro study, which might only partially represent the in vivo conditions. Our results demonstrate for the first time that EGFL7 is new player involved in decidualization and provide new insights into the pathophysiology of selected implantation defects and early pregnancy complications. Our studies have revealed that alterations in EGFL7 expression and the consequent dysregulation of NOTCH signaling are potential underlying causes of RIF and uRPL. Our results might have therapeutic relevance, as the EGFL7/NOTCH pathway may represent a potential target for medical intervention. This study has been supported by the Grant for Fertility Innovation 2017 (Merck KGaA). There are no competing interests to disclose. Not applicable.

MicroRNA-126 modulates angiogenesis and tube formation through enhancing epidermal growth factor-like domain 7 expression and phosphorylating PI3K/AKT signaling pathway

IntroductionDysregulated angiogenesis is a critical characteristic for endothelial dysfunction disorders. This study aimed to determine functions of microRNA-126 in formation of tube and investigated the potential mechanisms.Material and methodsThe synthesized microRNA-126 control and microRNA-126 inhibitor plasmids were transfected into human umbilical-vein endothelial cells (HUVECs) using lipofectamine 2000 reagent. Cell counting kit-8 (CCK-8) was employed to measure proliferative capability of HUVECs. Transwell analysis was used to evaluate HUVECs invasive ability. Real time PCR (RT-PCR) was utilized to access epidermal growth factor-like domain 7 (EGFL7) and microRNA-126 mRNA transcription. Tube-forming capability in HUVECs was determined. Dual-luciferase assay and linear-regression analysis were conducted to measure interaction between EGFL7 and microRNA-126 molecule. Phosphoinositide-3-kinase/protein kinase-B (PI3K/AKT) signaling pathway associated molecules were evaluated using western blot assay.ResultsSilencing of microRNA-126 significantly enhanced proliferative capability and invasive ability of HUVECs compared to those of microRNA-126 control group (p<0.05). microRNA-126 silencing remarkably promoted tube formation and significantly up-regulated EGFL7 compared to those of microRNA-126 control group (p<0.05). microRNA-126 could interact with EGFL7 molecule. microRNA-126 was also negatively correlated with EGFL7 molecule in HUVECs (p<0.05). Silencing of microRNA-126 significantly enhanced p-PI3K/PI3K ratio compared to that of microRNA-126 control group (p<0.05). microRNA-126 silencing also remarkably increased p-AKT/AKT ratio compared to that of microRNA-126 control group (p<0.05).ConclusionsmicroRNA-126 modulated angiogenesis and tube formation through increasing EGFL7 expression and phosphorylating PI3K/AKT signaling pathway.

Treatment of pregnancies complicated by intrauterine growth restriction with nitric oxide donors increases placental expression of Epidermal Growth Factor-Like Domain 7 and improves fetal growth: A pilot study

Intrauterine growth restriction (IUGR) is a pathological condition of pregnancy with high perinatal mortality and morbidity, characterized by inadequate fetal growth associated to altered maternal hemodynamics with impaired uteroplacental blood flow and placental insufficiency. To date, iatrogenic premature delivery remains the elective therapeutic strategy. However, in recent years the possibility of a therapeutic approach with vasodilators and myorelaxants, such as nitric oxide (NO) donors, has gained interest. NO controls many endothelial cell functions, including angiogenesis and vascular permeability, by regulating the expression of angiogenic factors, such as Vascular Endothelial Growth Factor. In the present study, we investigated if treatment of pregnancies complicated by IUGR with NO donors affects the expression of Epidermal Growth Factor-Like Domain 7 (EGFL7), a secreted endothelial factor, previously demonstrated to be expressed by both endothelial and trophoblast cells and involved in proper placental development. NO donor treatment induced placental levels of EGFL7 and, in association with oral fluids, significantly improved fetal growth. Ex vivo experiments confirmed that NO donors increased expression and secretion of EGFL7 by villous explants. To specifically investigate the potential response of trophoblast cells to NO, we treated HTR8-sVneo cells with NO donors and observed induction of EGFL7 expression. Altogether, our findings indicate that NO induces endothelial and trophoblast expression of EGFL7 in the placenta and improves fetal growth, suggesting a correlation between placental levels of EGFL7 and pregnancy outcome.

Novel Expression of EGFL7 in Osteosarcoma and Sensitivity to Cisplatin.

Epidermal growth factor-like domain 7 (EGFL7) is a protein specifically secreted by blood vessel endothelial cells, which plays an important role in angiogenesis. Considering the aberrant secretion of EGFL7 in osteosarcoma (OS) has not yet been elucidated, this study investigated the secretion of EGFL7 in OS and the changes in its secretion after chemotherapy. We observed increased varying secretion of EGFL7 in OS tissues compared with chondrosarcoma (CS) tissues. OS cell lines and HUVECs showed higher EGFL7 mRNA and protein expression than SW1353, with OS cells expressing the highest levels. In patient samples, EGFL7 was highly expressed in the cytoplasm of OS tumor cells and vascular endothelium cells. This overexpression was abolished in OS cell and tumor tissues when treated with chemotherapy. This study is a pioneering study to investigate EGFL7 expression and localization in human OS tissues and cell. Overexpression of EGFL-7 in response to chemotherapy suggests that it can be used as a therapeutic target for OS.

Epidermal Growth Factor Like-domain 7 and miR-126 are abnormally expressed in diffuse Systemic Sclerosis fibroblasts

Systemic sclerosis (SSc) is characterized by microangiopathy with impaired reparative angiogenesis and fibrosis. Epidermal Growth Factor Like-domain 7 (EGFL7), firstly described in endothelial cells plays a pivotal role in angiogenesis. Fibroblasts (FBs) are involved in vascular remodeling, under physiological and pathological conditions. In this study, we investigated: (i) the expression of EGFL7 and its miR-126 in patients affected by diffuse cutaneous SSc (dcSSc); (ii) the ability of Transforming Growth Factor-beta (TGF-β) to modulate EGFL7 expression; (iii) the ability of EGFL7 to modulate COL1A1 expression and proliferation/migration, and (iv) the functional role of EGFL7 on angiogenesis. Patients were divided in 2 subsets: patients fulfilling the classification criteria in less than one year from Raynaud’s Phenomenon onset (Early Onset Subset–EOS), and all the others (Long Standing Subset–LSS). We show that EGFL7 expression is increased in EOS dcSSc skin and cultured FBs. EGFL7 is inducible by TGF-β on Healthy Controls (HC) FBs but not in SSc-FBs. EGFL7 decreases COL1A1 expression in EOS SSc-FBs while EGFL7 silencing up-regulates COL1A1 expression. EGFL7 promotes migration/invasion of EOS SSc-FBs but not proliferation. Finally, SSc-FBs, partially inhibit angiogenesis in organotypic coculture assays, and this is reversed by treatment with human recombinant (rh)EGFL7. We conclude that EGFL7 and its specific microRNA miR-126 may be involved in the pathogenesis of SSc vasculopathy and fibrosis.

Anti-EGFL7 antibodies inhibit rat prolactinoma MMQ cells proliferation and PRL secretion

Abstract Prolactinoma is the most frequently diagnosed pituitary tumors. Dopamine agonists (DAs) are recognized as first-line therapy; however, approximately 10% patients will develop resistance to DAs therapy. Consequently, a large number of investigations have been carried out to identify novel therapeutic targets. Recently, studies have suggested that epidermal growth factor-like domain 7 (EGFL7) can promote tumor growth, invasion, and angiogenesis. We previously reported that overexpression of EGFL7 might play a crucial role in hormone-producing pituitary adenomas. In the present study, we now demonstrated a significantly higher protein expression of EGFL7 in prolactinoma compared with the normal pituitary gland. However, inhibition of EGFL7 with anti-EGFL7 antibodies significantly reduced the proliferation and PRL secretion of rat prolactinoma MMQ cells. Notably, in vitro administration of anti-EGFL7 antibodies significantly induced MMQ cells apoptosis in a dose-dependent manner. In conclusion, our finding suggests that EGFL7 is significantly overexpressed in prolactinoma and inhibition of EGFL7 with antibodies promoted MMQ cells apoptosis and inhibited PRL secretion. Thus, EGFL7 may serve as a potential novel therapeutic target for prolactinomas.

Attenuation of EGFL7 Expression Inhibits Growth Hormone-Producing Pituitary Adenomas Growth and Invasion.

Invasiveness of growth hormone-producing pituitary adenomas (GHPAs) causes difficulties in safe and complete adenoma removal during surgery and often leads to high recurrence. Epidermal growth factor-like domain 7 (EGFL7) has been shown to be able to promote tumor angiogenesis, growth, invasiveness, and metastasis through the Notch signaling pathway. It was previously demonstrated that EGFL7 was overexpressed in GHPAs. This study reports that EGFL7 and Notch2 (positive correlation with EGFL7) are overexpressed in invasive GHPA. A long-rank test (Kaplan-Meier method) shows that invasive GHPAs with EGFL7 strong expression results in reduced recurrence-free survival. Multivariate Cox regression analysis reveals that weak EGFL7 expression is an independent prognostic factor for recurrence-free survival. In addition, knockdown of EGFL7 expression suppresses proliferation and invasion of GH3 and GT1-1 cells in vitro. Moreover, attenuation of EGFL7 inhibits human GHPA growth in vivo. The data suggest that as a Notch agonist, EGFL7 may potentially be an appropriate novel molecular target for future development of GHPA medical therapy.

KSHV LANA upregulates the expression of epidermal growth factor like domain 7 to promote angiogenesis.

Kaposi’s sarcoma (KS) is a highly-vascularized tumor characterized by inflammation and extensive neo-angiogenesis. The KS tumor microenvironment is rich in inflammatory and pro-angiogenic cytokines. Here, we report that the expression of Epidermal growth factor-like domain 7 (EGFL7) is upregulated in Kaposi’s sarcoma-associated herpes virus (KSHV) infected cells. EGFL7 is a secreted pro-angiogenic cytokine that has been implicated in angiogenesis and the proliferation of endothelial cells during many pathological conditions. Our data show that KS tumors as well as primary effusion lymphoma cells have increased levels of EGFL7 compared to the uninfected cells. We determined that the expression of a KSHV latent protein, LANA (latency-associated nuclear antigen), is the main viral factor responsible for this upregulation. The modulation of EGFL7 expression by LANA involves sequestration of death domain-associated protein 6 (Daxx) from the EGFL7 promoter. Daxx acts as a suppressor of promoter activity by binding to the avian erythroblastosis virus E26 oncogene homolog 1 (Ets-1), which is the core transcription factor required for the expression of EGFL7. We additionally show that the upregulation of EGFL7 by LANA contributes to the promotion of angiogenesis since siRNA-mediated knockdown of EGFL7 reduced in vitro tubulogenesis in LANA-expressing HUVEC cells. EGFL7 promotes angiogenesis through autocrine as well as paracrine mechanisms as the supernatant from LANA expressing cells depleted of EGFL7 showed reduced tubulogenesis. This study for the first time demonstrates EGFL7 to be an important angiogenic molecule secreted during KSHV infection that could be exploited for blocking KSHV associated malignancies in conjugation with other anti-angiogenic therapies.

EGFL7 Antagonizes NOTCH Signaling, Stimulates Blast Proliferation and Confers Poor Prognosis in Cytogenetically-Normal Acute Myeloid Leukemia (CN-AML)

Epidermal growth factor-like domain 7 (EGFL7) is a secreted protein and plays an important role in angiogenesis by regulating the growth, proliferation and migration of endothelial cells. Recent studies in solid tumors have shown that EGFL7 is overexpressed and is associated with a more aggressive disease phenotype. Whether EGFL7 plays a similar role in blood cancers such as acute myeloid leukemia (AML) however, has not been previously reported. To investigate the association of EGFL7 expression with outcome in AML, we measured EGFL7 mRNA expression in newly diagnosed older (≥60 years, n=126) CN-AML patients. In these patients, those with high EGFL7 expression were less likely to achieve CR (52% v 76%, P=.009). Patients with high EGFL7 expression status had shorter event-free survival (5-year rates: 6% v 13%, P=.03) and overall survival (5-year rates: 10% v 16%, P=.009) than patients with low EGFL7 expression status.To validate our clinical data we measured EGFL7 mRNA in primary AML blasts (n=11) compared to normal bone marrow (NBM) (n=5) using RT-PCR, and found a ~2.4 fold-increase in the AML samples, P<0.05. These results were consistent with the protein levels, measured using western blots. Using both ELISA and western blotting, we observed significant increased levels of EGFL7 protein in the medium of cultured primary AML cells (n=3, 31-443 pg/mL) compared to media alone. Importantly, detection of serum EGFL7 levels by ELISA revealed variable but increased levels of EGFL7 in the sera from 3 of 5 (P<0.05) AML patients tested compared with sera from normal healthy controls (n=7). To investigate the functional consequences of EGFL7 stimulation on blast growth we treated primary AML blast cells from three patients with recombinant EGFL7 (rEGFL7) protein and performed colony forming unit (CFU) assays. Treatment with rEGFL7 led to an increase in the number of CFUs (P<0.05) and was associated with increased phosphorylation of AKT. In addition, under starvation conditions, recombinant EGFL7 protein alone promoted the survival and proliferation of MLL-PTD AML cells (n=3) but not normal BM cells (n=3) (P<0.05). To explore the underlying molecular mechanism(s) by which EGFL7 maintains the survival and proliferation of AML cells, we screened for proteins that interact with EGFL7 by using a protein antibody array on human primary AML blasts. This screen revealed that EGFL7 binds to multiple components of key signal transduction pathways important for leukemia, including NOTCH. Previous studies by Lobry C et al., (JExpMed 2013) demonstrated that although NOTCH2 and to a lesser extent, NOTCH1, mRNA was relatively abundant, NOTCH signaling was inhibited in AML blasts. Re-activation of the canonical NOTCH pathway, released a block in differentiation resulting in eradication of the leukemic blasts. Schmidt MH et al., (Nat Cell Biol. 2009) demonstrated that EGFL7 was capable of binding NOTCH receptors and blocking their subsequent activation. Therefore, we hypothesized that one mechanism by which the NOTCH pathway is kept inactive in AML is through autocrine binding of EGFL7 protein to NOTCH receptors. Co-immunoprecipitation assays confirmed binding of EGFL7 to NOTCH2 in both human primary AML cells (n=3, P<0.05) and mouse MLL-PTD AML cells (n=3, P<0.05). Moreover, stimulation of AML blasts with rEGFL7 protein suppressed the cleavage and subsequent activation of NOTCH2, resulting in decreased transcription of NOTCH downstream target genes, HES1 and NRARP (n=3, P<0.05). In summary, we show here that high EGFL7 is associated with worse prognosis in patients with CN-AML, and that EGFL7 is expressed and secreted by the AML cells in an autocrine fashion, promoting their growth in part through antagonizing NOTCH2 activation. Targeting EGFL7 with antibodies to reduce NOTCH binding might represent a novel therapeutic approach to reactivate NOTCH signaling, allowing for blast differentiation and elimination of AML. DisclosuresNo relevant conflicts of interest to declare.

Expression of epidermal growth factor-like domain 7 may be a predictive marker of the effect of neoadjuvant chemotherapy for locally advanced uterine cervical cancer.

Neoadjuvant chemotherapy (NAC) followed by hysterectomy may be effective for the treatment of locally advanced uterine cervical cancer and improve patient prognosis. It is important to identify markers that are able to predict whether NAC may be successful. Epidermal growth factor-like domain 7 (EGFL7) regulates vascular sprouting in blood vessel formation. In numerous types of human cancer, EGFL7 is upregulated and inhibits endothelial cell adhesion molecules, decreasing vascular tightness and, thus, increasing vascular permeability. It is considered that the overexpression of EGFL7 is able to inhibit drug delivery, resistance to apoptosis and the epithelial-to-mesenchymal transition. In the current study, 63 patients with locally advanced uterine cervical cancer were reviewed and classified as stage IIIA-IIIB using the International Federation of Gynecology and Obstetrics criteria. These patients (aged <70 years) were treated at Osaka City University Medical School Hospital, Japan, between 1995 and 2010. Tumor tissue samples were obtained by biopsy prior to NAC. The tissue samples were classified as group 1 or 2 depending on the efficacy of NAC. Surgery and radiotherapy were administered in group 1 (n=36), for which NAC was effective. In the patients of group 2 NAC was not effective, and radiotherapy alone was administered (n=27). The expression of EGFL7 and Snail was examined in paraffin-embedded tissue sample sections using the avidin-biotin peroxidase complex method. The results indicated that EGFL7 expression levels were significantly higher in group 2, as compared with group 1 (P<0.001). A similar result was observed for the expression levels of Snail (P=0.001). Group 1 exhibited significantly longer overall survival times compared with group 2 (P=0.001). The patients were also classified into a low EGFL7 expression level group (weighted score of ≤6) and a high EGFL7 expression level group (weighted score of ≥8). NAC was observed to be significantly more effective in the low EGFL7 expression level group (P<0.001), as compared with the high expression level group. The results suggest that the expression levels of EGFL7 may be a potential predictive marker of the efficacy of NAC for the treatment of locally advanced uterine cervical cancer.

EGFL7 is an intercellular EGFR signal messenger that plays an oncogenic role in glioma

Epidermal Growth Factor like domain 7 (EGFL7), also known as Vascular Endothelial-statin (VE-statin), is a secreted angiogenic factor. Recent data have demonstrated the potential oncogenic role and prognostic significance of EGFL7 in several human cancers. However, the clinical signature and further mechanisms of EGFL7's function in gliomagenesis are poorly understood. In the present study, we found that increased EGFL7 expression was associated with tumor grade. High expression of EGFL7 in EGFRvIII-positive glioblastoma multiforme (GBM) was determined to be a strong and independent risk factor for reduced life expectancy. EGFRvIII cells can secrete the EGFL7 protein to improve the activity of the β-catenin/TCF4 Transcription complex in EGFRwt cells, thus promoting their own EGFL7 expression. Our research demonstrates that oncogenic activation of EGFRwt in GBM is likely maintained by a continuous EGFL7 autocrine flow line, and may be an attractive target for therapeutic intervention.

Epidermal growth factor-like domain 7 promotes cell invasion and angiogenesis in pancreatic carcinoma.

Epidermal growth factor-like domain 7 (EGFL7), also known as vascular endothelial stain, was firstly identified as a modulator of smooth muscle cell migration. Though the expression of EGFL7 was reported to be up-regulated during tumorigenesis, the clinical and biological functions of EGFL7 in pancreatic carcinoma (PC) were still not fully elucidated. In this study, we found that the serum EGFL7 level in PC tissues was statistically higher than that in normal subjects (p<0.001), and its level in non-resectable patients was also higher than that in resectable ones (p=0.013). Among these resectable PC patients, the postoperative EGFL7 expression was significantly down-regulated when tumors were resected (p=0.018). Using the immunohistochemistry method, our results demonstrated that the positive expression of EGFL7 was significantly associated with the TNM stage (p=0.024), lymph node metastasis (p=0.003) and local invasion (p=0.022), and the EGFL7 expression closely correlated to the micro-vessel density (MVD) in PC tissues by Spearman analysis (r=0.941, p=0.000). In vitro, EGFL7 was silenced by the small interference RNA in PC cells, and our data indicated that down-regulation of EGFL7 did not influence the cycle progression, proliferation, colony formation and apoptosis of PC cells (p>0.05), whereas inhibition of EGFL7 expression could decrease PaCa-2 cell invasion (p<0.05). More interestingly, by tubular formation, Chick embryo chorioallantoic membrane (CAM) and ELISA assays, our results revealed that silencing EGFL7 expression represented a strong inhibiting effect on tubular formation of micro-vessels through down-regulating the protein levels of VEGF and Ang-2 (p<0.05). Our results raised the possibility of using EGFL7as a potential prognostic biomarker and therapy target of PC, and down-regulation of EGFL7 might be considered to be a potentially important molecular treatment strategy for patients with PC.

Intra-tumoural vessel area estimated by expression of epidermal growth factor-like domain 7 and microRNA-126 in primary tumours and metastases of patients with colorectal cancer: a descriptive study.

BackgroundUnderstanding the biological properties of potential drug targets are important. This is especially true for anti-angiogenic therapies in the search for potential biomarkers. The aim of the present descriptive study was to analyse the intra-tumoural expressions of epidermal growth factor-like domain 7 (EGFL7) and microRNA-126 (miRNA-126) in primary tumours from patients with stage II-IV colorectal cancer (CRC) and in paired samples of primary tumours, regional lymph node metastases and distant metastases.MethodsA total of 126 patients were included. Analyses were performed on resections of primary tumours, regional lymph node metastases, and large needle biopsies from distant metastases. EGFL7 was analysed by immunohistochemistry (IHC) and miRNA-126 by in situ hybridization (ISH). Both biomarkers were quantified by image guided analyses to determine the relative fraction estimates of vessel areas (VA).ResultsThe intra-tumoural EGFL7 VA was significantly higher in primary tumours from patients with recurrent disease than in patients without relapse in both stage II and III, p = 0.019 and p = 0.001, respectively. The EGFL7 VA was significantly higher and the miRNA-126 VA significantly lower in regional lymph node metastases compared to primary tumours, p = 0.01 and p < 10−6, respectively. Furthermore, the miRNA-126 VA in liver metastases was significantly lower than in the primary tumours, p = 0.02.ConclusionThe intra-tumoural expression of EGFL7 in early stages of CRC may influence the risk of post-surgical recurrence. Differential expression of miRNA-126 seems more pronounced in disseminated disease, which supports its role as a regulator in the metastatic process.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-014-0359-y) contains supplementary material, which is available to authorized users.

Prognostic significance of epidermal growth factor-like domain 7 in pancreatic cancer

Recent studies have shown the clinical significance of epidermal growth factor-like domain 7 (EGFL7) in a variety of cancers. However, the relationship between EGFL7 and the prognosis of pancreatic cancer (PC) remains unclear. The present study was undertaken to investigate the role of EGFL7 in the prognosis of PC. The expression of EGFL7 in nine PC cell lines was first determined by Western blotting analysis. Tissue microarray-based immunohistochemical staining was performed in paired formalin-fixed paraffin-embedded tumor and non-tumor samples from 83 patients with PC. Finally, correlations between EGFL7 expression and clinicopathological variables as well as overall survival were evaluated. EGFL7 was widely expressed in all PC cell lines tested. EGFL7 expression in tumor tissues was significantly higher than that in non-tumor tissues (P=0.040). In addition, univariate analysis revealed that high EGFL7 expression in tumor tissues was significantly associated with poor overall survival, accompanied by several conventional clinicopathological variables, such as gender, histological grade and lymph node metastasis. In a multivariate Cox regression test, EGFL7 expression was identified as an independent marker for long-term outcome of PC. Our data showed that EGFL7 is extensively expressed in PC and that EGFL7 is associated with poor prognosis.

Abstract 4812: A novel EGFL7-derived peptide, E7C13, is a potent anti-tumor agent that inhibits angiogenesis in a beta 1 integrin- and thrombospondin-dependent manner

Abstract As a tumor grows beyond 1mm, it recruits new blood vessels through the process of angiogenesis. The selective inhibition of the vascular endothelial growth factor (VEGF) pathway increases the efficacy of chemotherapy and has beneficial effects on multiple advanced cancers, but response is often limited and the disease eventually progresses. This highlights the necessity to develop novel therapeutics that target alternate angiogenic signaling pathways. The epidermal growth factor-like domain 7 (EGFL7) is a secreted protein that is up-regulated in actively remodeling endothelium, localizing to the perivascular extracellular matrix. Inhibition of EGFL7 in zebrafish disrupts vascular tube formation during vasculogenesis, while knockout of EGFL7 in mice prevents endothelial lumen formation and tubulogenesis. EGFL7 expression is associated with poor prognosis in malignant glioma, hepatocellular carcinoma and non-small cell lung cancer, and therefore is a promising therapeutic target for anti-cancer strategies. In this study we investigated the impact of tumor-localized EGFL7 in tumor growth and angiogenesis. When EGFL7 is over-expressed in HT1080 fibrosarcoma or MDA-MB-231 breast cancer we saw no effect on tumor cell proliferation yet we observed a dramatic inhibition of tumor growth and angiogenesis in animal models. Indeed, we demonstrate that EGFL7 interacts with thrombospondin, and that it promotes endothelial cell spreading and adhesion in a beta 1 integrin- and TSP-dependent manner. In an attempt to isolate the domain of EGFL7 that is responsible for this angiogenesis inhibition activity, we identified and characterized a novel EGFL7-derived peptide, E7C13. This peptide inhibited sprouting and tube formation of human endothelial cells in vitro in 2D and 3D assays, and inhibited angiogenesis induced by tumor cells in vivo in the chicken embryo CAM assay and in the mouse DIVAA assay. Treatment of HT1080 tumor-bearing mice with E7C13 peptide intravenously at 75 mg/kg led to significantly reduced tumor growth and increased survival. Tumors from E7C13-treated animals were significantly less vascularized compared to controls. These data suggest that E7C13 is a promising new anti-vascular agent, and may provide a basis for a novel anti-angiogenesis approach to treat cancer. Citation Format: Choi-Fong Cho, Laura A. Fung, Tienabe Nsiama, Lihai Yu, Alisha Kadam, Daniela F. Quail, Katia Carmine-Simmen, Desmond Pink, Lynne-Marie Postovit, Leonard G. Luyt, John D. Lewis. A novel EGFL7-derived peptide, E7C13, is a potent anti-tumor agent that inhibits angiogenesis in a beta 1 integrin- and thrombospondin-dependent manner. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4812. doi:10.1158/1538-7445.AM2014-4812

Abstract LB-174: MicroRNA-126 (miR-126) and epidermal growth factor-like domain 7 (EGFL7) in Bevacizumab-treated patients with metastatic colorectal cancer

Abstract The miR-126 gene is located within intron 7 of the EGFL7 encoding gene, and therefore miR-126 expression is dependent on the transcription of the EGFL7 gene. It has been suggested that transcription is regulated by the VEGFR pathway through Ets1 transcription factor, that miR-126 itself negatively regulates the VEGF-R signaling pathway, and that EGFL7 itself regulates Notch signaling. In cancer therapeutic settings, VEGF or VEGF-R directed therapies are thus likely to affect expression of EGFL7 and miR-126. In colorectal cancer (CRC) tissue, miR-126 and EGFL7 are highly expressed in endothelial cells. In studies of XELOX-treated patients, we have previously reported that the miR-126 expression level measured by quantitative in situ hybridization (qISH) is related to poor response (Hansen et al, BMC Cancer 2012, 12:83). Here, we have analyzed miR-126 and EGFL7 expression by qISH and quantitative immunohistochemistry (qIHC), respectively, in 158 patients from two different cohorts with mCRC after treatment with anti-VEGF therapy (Bevacizumab) in combination with chemotherapy. We found that the EGFL7 vessel area (VA) in primary tumors was closely related to treatment response with a median EGFL7 VA in responding patients of 4 (95% CI 4-6) compared to 8.5 (95% CI 7-11) in non-responders, p&amp;lt;0.001. This difference translated into a borderline significant difference in progression-free survival (PFS, p=0.06). Furthermore, a significant relationship between high EGFL7 VA and KRAS mutation was detected (p&amp;lt;0.05). The results showed no significant relationship between the miR-126 VA and the clinical endpoints. Our study suggests a predictive value of EGFL7 in regard to first-line chemotherapy and bevacizumab in patients with mCRC. The strong predictive value of miR-126 found in mCRC patients treated with chemotherapy only was absent, suggesting that the anti-VEGF directed therapy is likely to have affected a key role of miR-126 in regulating the VEGFR pathway. Citation Format: Boye S. Nielsen, Flemming B. Sorensen, Anders Johnsson, Anders Jakobsen, Torben F. Hansen. MicroRNA-126 (miR-126) and epidermal growth factor-like domain 7 (EGFL7) in Bevacizumab-treated patients with metastatic colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-174. doi:10.1158/1538-7445.AM2014-LB-174

Astragalus polysaccharides exert protective effects in newborn rats with bronchopulmonary dysplasia by upregulating the expression of EGFL7 in lung tissue.

The aim of this study was to explore the effects of Astragalus polysaccharides (APS) on the mRNA expression of epidermal growth factor-like domain 7 (EGFL7) in lung tissue in newborn rats with bronchopulmonary dysplasia (BPD). For this purpose, a total of 96 newborn SD rats were randomly divided into 4 groups (n=24): the control group, air room plus APS group, BPD group and the APS group (20 mg/kg/day). Lung tissues were obtained on days 4, 10 and 14 after birth. Morphological changes were observed and the protein and mRNA expression levels of EGFL7, Bax and Bcl-2 were determined. The rats in the BPD group (BPD induced by hyperoxia) presented with an arrest in alveolar and vascular development and low mRNA and protein expression levels of of EGFL7, Bcl-2 and high levels of Bax compared with the rats in the control group. However, lung damage in the APS intervention group was attenuated compared with the BPD group. The protein and mRNA expression levels of EGFL7 and Bcl-2 were also increased and the level of Bax was decreased in the APS intervention group (P<0.01) compared with the BPD model group after birth on days 4, 10 and 14. Our data demonstrate that APS reduce airway remodeling and alveolar damage by upregulating the expression of EGFL7 and exert protective effects against BPD in neonatal rats. Thus, APS may have potential for use as a therapeutic strategy for BPD.

Suppressive effect of microRNA-126 on oral squamous cell carcinoma invitro.

MicroRNA-126 (miR-126), an endothelial-specific miRNA located within intron 7 of epidermal growth factor‑like domain 7 (EGFL7), has been demonstrated to act as a tumor suppressor in various types of human cancer. However, its role in oral squamous cell carcinoma (OSCC) remains unclear. In the present study, we revealed that the expression of miR-126 was significantly decreased in OSCC tissues, when compared with that in their matched adjacent tissues, and its expression level was also reduced in Tca8113, OSCC-15 and CAL27 cell lines compared with normal tissues. The protein expression of EGFL7 was upregulated in OSCC tissues compared with their matched adjacent tissues as well as normal tissues, and Tca8113, OSCC-15 and CAL27 cells additionally demonstrated a positive expression of EGFL7. The overexpression of miR-126 significantly reduced the protein expression of EGFL7 in OSCC-15 cells, while transfection with the miR-126 inhibitor upregulated the EGFL7 protein level in OSCC-15 cells. Furthermore, transfection with an miR-126 mimic into OSCC-15 cells markedly suppressed cell proliferation, cell cycle progression, cell invasion and colony formation, while inducing cell apoptosis, which contrasted with the effects of transfection with an miR-126 inhibitor. The overexpression of miR-126 suppressed the secretion of two key regulators of angiogenesis, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), which was also reversed by miR-126 inhibitor transfection. In conclusion, the present study demonstrated that miR-126 acts as a tumor suppressor in OSCC cells, partially at least via the downregulation of EGFL7. Thus, miR-126 may serve as a promising candidate for the treatment of OSCC.

Novel expression of EGFL7 in placental trophoblast and endothelial cells and its implication in preeclampsia

The mammalian placenta is the site of nutrient and gas exchange between the mother and fetus, and is comprised of two principal cell types, trophoblasts and endothelial cells. Proper placental development requires invasion and differentiation of trophoblast cells, together with coordinated fetal vasculogenesis and maternal vascular remodeling. Disruption in these processes can result in placental pathologies such as preeclampsia (PE), a disease characterized by late gestational hypertension and proteinuria. Epidermal Growth Factor Like Domain 7 (EGFL7) is a largely endothelial-restricted secreted factor that is critical for embryonic vascular development, and functions by modulating the Notch signaling pathway. However, the role of EGFL7 in placental development remains unknown. In this study, we use mouse models and human placentas to begin to understand the role of EGFL7 during normal and pathological placentation. We show that Egfl7 is expressed by the endothelium of both the maternal and fetal vasculature throughout placental development. Importantly, we uncovered a previously unknown site of EGFL7 expression in the trophoblast cell lineage, including the trophectoderm, trophoblast stem cells, and placental trophoblasts. Our results demonstrate significantly reduced Egfl7 expression in human PE placentas, concurrent with a downregulation of Notch target genes. Moreover, using the BPH/5 mouse model of PE, we show that the downregulation of Egfl7 in compromised placentas occurs prior to the onset of characteristic maternal signs of PE. Together, our results implicate Egfl7 as a possible factor in normal placental development and in the etiology of PE.

High expression of epidermal growth factor-like domain 7 is correlated with poor differentiation and poor prognosis in patients with epithelial ovarian cancer

ObjectiveThe purpose of this study was to evaluate the expression of epidermal growth factor-like domain 7 (EGFL7) in epithelial ovarian cancer, and to assess its relevance to clinicopathological characteristics and patients' survival.MethodsA total of 177 patients with epithelial ovarian cancer were enrolled in the current study. For each patient, a retrospective review of medical records was conducted. Immunohistochemical staining for EGFL7 was performed using tissue microarrays made with paraffin-embedded tissue block. EGFL7 expression levels were graded on a grade of 0 to 3 based on the percentage of positive cancer cells. We analyzed the correlations between the expression of EGFL7 and various clinical parameters, and also analyzed the survival outcome according to the EGFL7 expression.ResultsThe expression of EGFL7 in ovarian cancer tissues was observed in 98 patients (55.4%). High expression of EGFL7 (grade 2 or 3) was significantly correlated with pathologic type, differentiation, stage, residual tumor after debulking surgery, lymphovascular space involvement, lymph node metastasis, high cancer antigen 125, peritoneal cytology, and ascites. Among these clinicopathologic factors, differentiation was significantly correlated with EGFL7 expression in multivariate analysis (p<0.05). Survival analysis showed that the patients with high EGFL7 expression had a poorer disease free survival than those with low EGFL7 expression (p=0.002).ConclusionOur data suggest that EGFL7 expression is a novel predictive factor for the clinical progression of epithelial ovarian cancer, and may constitute a therapeutic target for antiangiogenesis therapy in patients with epithelial ovarian cancer.