Novel Expression of EGFL7 in Osteosarcoma and Sensitivity to Cisplatin.
ABSTRACT: 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.
Project description:We report the cloning and characterization of a novel epidermal growth factor (EGF) domain gene that was identified in a retroviral gene entrapment screen and is expressed in endothelial cells. This gene encodes a protein of 278 amino acids with an amino-terminal signal peptide and two centrally located EGF-like domains. We have named this novel gene in accordance with the guidelines of the Mouse Genome Informatics group Egfl7, for EGF-like domain 7. Egfl7 mRNA is expressed in highly vascularized adult tissues such as the lung, heart, uterus, and ovary. In addition, Egfl7 is expressed early during mouse embryogenesis and in undifferentiated murine embryonic stem cells. The analysis of Egfl7 expression in embryonic day 9.5 embryos by in situ hybridization indicates that Egfl7 is expressed in vascular structures in both the embryo proper and the yolk sac and at sites of mesodermal precursors of angioblasts. Within the cell, EGFL7 protein is localized to the endoplasmic reticulum and Golgi apparatus, suggesting that the protein is targeted for secretion. Indeed, recombinant EGFL7 is readily detectable in the supernatant media of transiently transfected HEK293 cells. We also report the identification of an Egfl7 paralog, Egfl8, and show that EGFL8 protein shares similar domains and molecular weight with EGFL7.
Project description:Extracellular matrix (ECM) proteins secreted by blood-brain barrier (BBB) endothelial cells (ECs) are implicated in cell trafficking. We discovered that the expression of ECM epidermal growth factor-like protein 7 (EGFL7) is increased in the CNS vasculature of patients with multiple sclerosis (MS), and in mice with experimental autoimmune encephalomyelitis (EAE). Perivascular CD4 T lymphocytes colocalize with ECM-bound EGFL7 in MS lesions. Human and mouse activated T cells upregulate EGFL7 ligand ?v?3 integrin and can adhere to EGFL7 through integrin ?v?3. EGFL7-knockout (KO) mice show earlier onset of EAE and increased brain and spinal cord parenchymal infiltration of T lymphocytes. Importantly, EC-restricted EGFL7-KO is associated with a similar EAE worsening. Finally, treatment with recombinant EGFL7 improves EAE, reduces MCAM expression, and tightens the BBB in mouse. Our data demonstrate that EGFL7 can limit CNS immune infiltration and may represent a novel therapeutic avenue in MS.
Project description:Although endothelial cells have been shown to affect mouse pancreatic development, their precise function in human development remains unclear. Using a coculture system containing human embryonic stem cell (hESC)-derived progenitors and endothelial cells, we found that endothelial cells play a stage-dependent role in pancreatic development, in which they maintain pancreatic progenitor (PP) self-renewal and impair further differentiation into hormone-expressing cells. The mechanistic studies suggest that the endothelial cells act through the secretion of EGFL7. Consistently, endothelial overexpression of EGFL7 in vivo using a transgenic mouse model resulted in an increase of PP proliferation rate and a decrease of differentiation toward endocrine cells. These studies not only identified the role of EGFL7 as the molecular handle involved in the crosstalk between endothelium and pancreatic epithelium, but also provide a paradigm for using hESC stepwise differentiation to dissect the stage-dependent roles of signals controlling organogenesis.
Project description:Chondrosarcomas are malignant tumors of the cartilage that are chemoresistant and radioresistant to X-rays. This restricts the treatment options essential to surgery. In this study, we investigated the sensitivity of chondrosarcoma to X-rays and C-ions in vitro. The sensitivity of 4 chondrosarcoma cell lines (SW1353, CH2879, OUMS27, and L835) was determined by clonogenic survival assays and cell cycle progression. In addition, biomarkers of DNA damage responses were analyzed in the SW1353 cell line. Chondrosarcoma cells showed a heterogeneous sensitivity toward irradiation. Chondrosarcoma cell lines were more sensitive to C-ions exposure compared to X-rays. Using D10 values, the relative biological effectiveness of C-ions was higher (relative biological effectiveness = 5.5) with cells resistant to X-rays (CH2879) and lower (relative biological effectiveness = 3.7) with sensitive cells (L835). C-ions induced more G2 phase blockage and micronuclei in SW1353 cells as compared to X-rays with the same doses. Persistent unrepaired DNA damage was also higher following C-ions irradiation. These results indicate that chondrosarcoma cell lines displayed a heterogeneous response to conventional radiation treatment; however, treatment with C-ions irradiation was more efficient in killing chondrosarcoma cells, compared to X-rays.
Project description:We previously characterized VE-statin/egfl7, a protein that is exclusively secreted by endothelial cells and modulates smooth muscle cell migration. Here, we show that VE-statin/egfl7 is the first known natural negative regulator of vascular elastogenesis. Transgenic mice, expressing VE-statin/egfl7 under the control of keratin-14 promoter, showed an accumulation of VE-statin/egfl7 in arterial walls where its presence correlated with an impaired organization of elastic fibres. In vitro, fibroblasts cultured in the presence of VE-statin/egfl7 were unable to deposit elastic fibres due to a deficient conversion of soluble tropoelastin into insoluble mature elastin. VE-statin/egfl7 interacts with the catalytic domain of lysyl oxidase (LOX) enzymes and, in endothelial cells, endogenous VE-statin/egfl7 colocalizes with LoxL2 and inhibits elastic fibre deposition. In contrast, mature elastic fibres are abundantly deposited by endothelial cells that are prevented from producing endogenous VE-statin/egfl7. We propose a model where VE-statin/egfl7 produced by endothelial cells binds to the catalytic domains of enzymes of the LOX family in the vascular wall, thereby preventing the crosslink of tropoelastin molecules into mature elastin polymers and regulating vascular elastogenesis.
Project description:Chondrosarcoma (CS) is a rare cancer, but it is the second most common primary malignant bone tumor and highly resistant to conventional chemotherapy and radiotherapy. Aberrant DNA methylation in the promoter CpG island of Wnt inhibitory factor 1 (WIF1) has been observed in different cancers. However, no studies have shown the relationship between WIF1 methylation and CS. In this study, we found promoter methylated WIF1 in both CS cell lines (CS-1 and SW1353) and tumor tissues. Western blot analysis confirmed loss WIF1 expression and activation of Wnt pathway proteins (Wnt5a/b, LRP6, and Dvl2). We subsequently examined the correlation between levels of WIF1 methylation and overall survival (OS) and progression-free survival (PFS) in CS patient samples with a follow-up spanning 234 months (mean: 57.6 months). Kaplan-Meier survival curves and log-rank tests revealed that high levels of WIF1 methylation were associated with lower OS and PFS rates (p?<?0.05). Multivariate Cox hazard analysis suggested that detection of high level methylation of WIF1 could be an independent prognostic factor in OS and PFS. In conclusion, we found that WIF1 is epigenetically silenced via promoter DNA methylation in CS and propose that WIF1 methylation may serve as a potential prognostic marker for patients with CS.
Project description:The vasculature of the central nervous system (CNS) is composed of vascular endothelial and mural cells which interact closely with glial cells and neurons. The development of the CNS vascularisation is a unique process which requires the contribution of specific regulators in addition to the classical angiogenic factors. The egfl7 gene is mainly detected in endothelial cells during physiological and pathological angiogenesis. Egfl7 codes for a secreted protein which predominantly accumulates into the extracellular space where it controls vascular elastin deposition or the Notch pathway. Egfl7 is the host gene of the microRNA miR126 which is also expressed in endothelial cells and which plays major functions during blood vessel development. While the expression of egfl7 and that of miR126 were well described in endothelial cells during development, their pattern of expression during the establishment of the CNS vasculature is still unknown. By analysing the expression of egfl7 and miR126 during mouse retina vascularisation, we observed that while expression of miR126 is detected in all endothelia, egfl7 is initially expressed in all endothelial cells and then is progressively restricted to veins and to their neighbouring capillaries. The recruitment of mural cells around retina arteries coincides with the down-regulation of egfl7 in the arterial endothelial cells, suggesting that this recruitment could be involved in the loss of egfl7 expression in arteries. However, the expression pattern of egfl7 is similar when mural cell recruitment is prevented by the injection of a PDGFR? blocking antibody, suggesting that vessel maturation is not responsible for egfl7 down-regulation in retinal arteries.
Project description:LESSONS LEARNED:The lack of efficacy associated with anti-EGFL7 combined with standard bevacizumab and chemotherapy in this phase II trial in non-small cell lung carcinoma is consistent with the lack of benefit observed in colorectal carcinoma, highlighting the challenge of enhancing the efficacy of VEGF inhibition in unselected populations.Future efforts with agents like anti-EGFL7 should be guided by advances in pharmacodynamic and predictive biomarker development for antiangiogenic agents. BACKGROUND:Epidermal growth factor-like domain 7 (EGFL7) is an extracellular matrix-associated protein that is upregulated during angiogenesis and supports endothelial cell survival. This phase II trial evaluated the efficacy of the anti-EGFL7 antibody, parsatuzumab, in combination with bevacizumab plus platinum-based therapy for advanced or recurrent nonsquamous non-small cell lung cancer (NS-NSCLC). METHODS:Patients (n?=?104) were randomized to either placebo or parsatuzumab (600 mg) in combination with bevacizumab (15 mg/kg) and carboplatin/paclitaxel, administered on day 1 of each 21-day cycle. Carboplatin and paclitaxel were administered for up to six cycles. Bevacizumab and parsatuzumab/placebo were administered for a maximum of 24 months. RESULTS:The progression-free survival (PFS) hazard ratio (HR) was 1.7 (95% confidence interval [CI], 1.0-2.8; p?=?.047). The median PFS was 6.7 months for the parsatuzumab arm versus 8.1 months for the placebo arm. The hazard ratio for overall survival (OS) was 1.1 (95% CI, 0.5-2.2; p?=?.847). The objective response rate (ORR) was 29% in the parsatuzumab arm and 56% in the placebo arm. Overall safety and tolerability were consistent with the established toxicity profile of bevacizumab. CONCLUSION:There was no evidence of efficacy for the addition of parsatuzumab to the combination of bevacizumab and chemotherapy for first-line NS-NSCLC.
Project description:Epidermal growth factor-like domain 7 (Egfl7) is important for regulating tubulogenesis in zebrafish, but its role in mammals remains unresolved. We show here that endothelial overexpression of Egfl7 in transgenic mice leads to partial lethality, hemorrhaging, and altered cardiac morphogenesis. These defects are accompanied by abnormal vascular patterning and remodeling in both the embryonic and postnatal vasculature. Egfl7 overexpression in the neonatal retina results in a hyperangiogenic response, and EGFL7 knockdown in human primary endothelial cells suppresses endothelial cell proliferation, sprouting, and migration. These phenotypes are reminiscent of Notch inhibition. In addition, our results show that EGFL7 and endothelial-specific NOTCH physically interact in vivo and strongly suggest that Egfl7 antagonizes Notch in both the postnatal retina and in primary endothelial cells. Specifically, Egfl7 inhibits Notch reporter activity and down-regulates the level of Notch target genes when overexpressed. In conclusion, we have uncovered a critical role for Egfl7 in vascular development and have shown that some of these functions are mediated through modulation of Notch signaling.
Project description:High tumor expression of epidermal growth factor-like domain 7 (EGFL7) has been associated with a poor prognosis in colorectal cancer. The aim of the current study was to investigate the possible prognostic impact of circulating EGFL7 (cir-EGFL7), combined with single nucleotide polymorphism (SNP) analyses, in patients with metastatic colorectal cancer (mCRC) treated with first line chemotherapy and bevacizumab. A total of 88 patients were included. Serum was collected prior to treatment initiation, at first evaluation after 3 weeks, and at progression. Cir-EGFL7 was analysed by the enzyme-linked immunosorbent assay (ELISA) technique. The SNPs were analysed by real-time qPCR based on DNA from whole blood. Endpoints were response rate (RR), progression free survival (PFS), and overall survival (OS). Cir-EGFL7 decreases after administration of chemotherapy plus bevacizumab. Baseline levels of cir-EGFL7 were significantly related to PFS and OS, p?=?0.0431 and p?=?0.0017, respectively, with increasing cir-EGFL7 levels associated with a worse prognosis. Circulating EGFL7 was not associated with RR. The SNP analyses revealed a significant relationship between rs1051851 and OS, p?=?0.030. This study demonstrates that cir-EGFL7 changes during treatment with chemotherapy plus bevacizumab and that baseline levels and genetic variations may influence the overall prognosis of patients with mCRC. The findings call for further validation.