Angiomodulin, a marker of cancer vasculature, is upregulated by vascular endothelial growth factor and increases vascular permeability as a ligand of integrin αvβ3

IGFBP7 promotes endothelial cell repair in the recovery phase of acute lung injury

IGFBP7 has been found to play an important role in inflammatory diseases, such as acute lung injury (ALI). However, the role of IGFBP7 in different stages of inflammation remains unclear. Transcriptome sequencing was used to identify the regulatory genes of IGFBP7, and endothelial IGFBP7 expression was knocked down using Aplnr-Dre mice to evaluate the endothelial proliferation capacity. The expression of proliferation-related genes was detected by Western blotting and RT-PCR assays. In the present study, we found that knockdown of IGFBP7 in endothelial cells significantly decreases the expression of endothelial cell proliferation-related genes and cell number in the recovery phase but not in the acute phase of ALI. Mechanistically, using bulk-RNA sequencing and CO-IP, we found that IGFBP7 promotes phosphorylation of FOS and subsequently up-regulates YAP1 molecules, thereby promoting endothelial cell proliferation. This study indicated that IGFBP7 has diverse roles in different stages of ALI, which extends the understanding of IGFBP7 in different stages of ALI and suggests that IGFBP7 as a potential therapeutic target in ALI needs to take into account the period specificity of ALI.

Duration-specific association between plasma IGFBP7 levels and diabetic complications in patients with type 2 diabetes mellitus

OBJECTIVE

Insulin-like growth factor binding protein 7 (IGFBP7) has a strong affinity to insulin. This study aimed to evaluate the relationship between IGFBP7 and complications among type 2 diabetes mellitus (T2DM) patients.

DESIGN

A total of 1449 T2DM patients were selected from a cross-sectional study for disease management registered in the National Basic Public Health Service in Changshu, China, and further tested for their plasma IGFBP7 levels. Logistic regressions and Spearman's rank correlation analyses were used to explore the associations of IGFBP7 with diabetic complications and clinical characteristics, respectively.

RESULTS

Among the 1449 included T2DM patients, 403 (27.81%) had complications. In patients with shorter duration (less than five years), the base 10 logarithms of IGFBP7 concentration were associated with T2DM complications, with an adjusted odds ratio (OR) of 2.41 [95% confidence interval (95%CI) = 1.06-5.48]; while in patients with longer duration (more than five years), plasma IGFBP7 levels were not associated with T2DM complications. Furthermore, in T2DM patients with shorter duration, those with two or more types of complications were more likely to have higher levels of IGFBP7.

CONCLUSION

IGFBP7 is positively associated with the risk of complication in T2DM patients with shorter duration.

Structural insight into CD93 recognition by IGFBP7

The CD93/IGFBP7 axis proteins are key factors expressed in endothelial cells (EC) that mediate EC angiogenesis and migration. Their upregulation contributes to tumor vascular abnormality and a blockade of this interaction promotes a favorable tumor microenvironment for therapeutic interventions. However, the interactions of these proteins with each other remain unclear. In this study, we determined a partial structure of the human CD93-IGFBP7 complex comprising the EGF1 domain of CD93 and the IB domain of IGFBP7. Mutagenesis studies confirmed interactions and specificities. Cellular and mouse tumor studies demonstrated the physiological relevance of the CD93-IGFBP7 interaction in EC angiogenesis. Our study provides leads for the development of therapeutic agents to precisely disrupt unwanted CD93-IGFBP7 signaling in the tumor microenvironment. Additionally, analysis of the CD93 full-length architecture provides insights into how CD93 protrudes on the cell surface and forms a flexible platform for binding to IGFBP7 and other ligands.

Beyond the barrier: the immune-inspired pathways of tumor extravasation

Extravasation is a fundamental step in the metastatic journey, where cancer cells exit the bloodstream and breach the endothelial cell barrier to infiltrate target tissues. The tactics cancer cells employ are sophisticated, closely reflecting those used by the immune system for tissue surveillance. Remarkably, tumor cells have been observed to form distinct associations or clusters with immune cells where neutrophils stand out as particularly crucial partners. These interactions are not accidental; they are critical for cancer cells to exploit the immune functions of neutrophils and successfully extravasate. In another strategy, tumor cells mimic the behavior and characteristics of immune cells. They release a suite of inflammatory mediators, which under normal circumstances, guide the processes of endothelium reshaping and facilitate the entry and movement of immune cells within tissues. In this review, we offer a new perspective on the tactics employed by cancer cells to extravasate and infiltrate target tissues. We delve into the myriad mechanisms that tumor cells borrow, adapt, and refine from the immune playbook. Video Abstract.

Angiogenesis modulated by CD93 and its natural ligands IGFBP7 and MMRN2: a new target to facilitate solid tumor therapy by vasculature normalization

The tumor vasculature was different from the normal vasculature in both function and morphology, which caused hypoxia in the tumor microenvironment (TME). Previous anti-angiogenesis therapy had led to a modest improvement in cancer immunotherapy. However, antiangiogenic therapy only benefitted a few patients and caused many side effects. Therefore, there was still a need to develop a new approach to affect tumor vasculature formation. The CD93 receptor expressed on the surface of vascular endothelial cells (ECs) and its natural ligands, MMRN2 and IGFBP7, were now considered potential targets in the antiangiogenic treatment because recent studies had reported that anti-CD93 could normalize the tumor vasculature without impacting normal blood vessels. Here, we reviewed recent studies on the role of CD93, IGFBP7, and MMRN2 in angiogenesis. We focused on revealing the interaction between IGFBP7-CD93 and MMRN2-CD93 and the signaling cascaded impacted by CD93, IGFBP7, and MMRN2 during the angiogenesis process. We also reviewed retrospective studies on CD93, IGFBP7, and MMRN2 expression and their relationship with clinical factors. In conclusion, CD93 was a promising target for normalizing the tumor vasculature.

Structural insight into CD93 recognition by IGFBP7

The CD93/IGFBP7 axis are key factors expressed in endothelial cells (EC) that mediate EC angiogenesis and migration. Upregulation of them contributes to tumor vascular abnormality and blockade of this interaction promotes a favorable tumor microenvironment for therapeutic interventions. However, how these two proteins associated to each other remains unclear. In this study, we solved the human CD93-IGFBP7 complex structure to elucidate the interaction between the EGF 1 domain of CD93 and the IB domain of IGFBP7. Mutagenesis studies confirmed the binding interactions and specificities. Cellular and mouse tumor studies demonstrated the physiological relevance of the CD93-IGFBP7 interaction in EC angiogenesis. Our study provides hints for development of therapeutic agents to precisely disrupt unwanted CD93-IGFBP7 signaling in the tumor microenvironment. Additionally, analysis of the CD93 full-length architecture provides insights into how CD93 protrudes on the cell surface and forms a flexible platform for binding to IGFBP7 and other ligands.

IGFBP-7 secreted by adipose-derived stem cells inhibits keloid formation via the BRAF/MEK/ERK signaling pathway

BACKGROUND

Adipose tissue-derived stem cells (ASCs) have important clinical significance as regulators of skin scar tissue regeneration. ASCs inhibit keloid formation and increase insulin-like growth factor-binding protein-7 (IGFBP-7) expression. However, whether ASCs inhibit keloid formation through IGFBP-7 remains unclear.

OBJECTIVE

We aimed to assess the roles of IGFBP-7 in keloid formation.

METHODS

We analyzed the proliferation, migration, and apoptosis of keloid fibroblasts (KFs) treated with recombinant IGFBP-7 (rIGFBP-7) or by co-culture with ASCs using CCK8 assays, transwell assays, and flow cytometry, respectively. In addition, immunohistochemical staining, quantitative polymerase chain reaction, human umbilical vein endothelial cell tube formation, and western blotting experiments were used to assess keloid formation.

RESULTS

IGFBP-7 expression was significantly lower in keloid tissues than that in normal skin tissues. Stimulation of KFs with rIGFBP-7 at different concentrations or by co-culture with ASCs resulted in decreased KF proliferation. Additionally, KF stimulation with rIGFBP-7 resulted in increased apoptosis of KFs. IGFBP-7 also reduced angiogenesis in a concentration-dependent manner, and stimulation with different rIGFBP-7 concentrations or co-culture of KFs with ASCs inhibited the expression of transforming growth factor-β1, vascular endothelial growth factor, collagen I, interleukin (IL)-6, IL-8, B-raf proto-oncogene (BRAF), mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK) in KFs.

CONCLUSION

Collectively, our findings suggested that ASC-derived IGFBP-7 prevented keloid formation by inhibiting the BRAF/MEK/ERK signaling pathway.

The Brain’s Microvascular Response to High Glycemia and to the Inhibition of Soluble Epoxide Hydrolase Is Sexually Dimorphic

Biological sex and a high glycemic diet (HGD) contribute to dementia, yet little is known about the operative molecular mechanisms. Our goal was to understand the differences between males and females in the multi-genomic response of the hippocampal microvasculature to the HGD, and whether there was vasculoprotection via the inhibition of soluble epoxide hydrolase (sEHI). Adult wild type mice fed high or low glycemic diets for 12 weeks, with or without an sEHI inhibitor (t-AUCB), had hippocampal microvessels isolated by laser-capture microdissection. Differential gene expression was determined by microarray and integrated multi-omic bioinformatic analyses. The HGD induced opposite effects in males and females: the HGD-upregulated genes were involved in neurodegeneration or neuroinflammation in males, whereas in females they downregulated the same pathways, favoring neuroprotection. In males, the HGD was associated with a greater number of clinical diseases than in females, the sEHI downregulated genes involved in neurodegenerative diseases to a greater extent with the HGD and compared to females. In females, the sEHI downregulated genes involved in endothelial cell functions to a greater extent with the LGD and compared to males. Our work has potentially important implications for sex-specific therapeutic targets for vascular dementia and cardiovascular diseases in males and females.

IGFBP7 remodels the tumor microenvironment of esophageal squamous cell carcinoma by activating the TGFβ1/SMAD signaling pathway

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer, and its development, growth, and invasiveness are regulated by the tumor microenvironment (TME). Insulin-like growth factor-binding protein-7 (IGFBP7), which is closely related to various tumors, transforming growth factor-β1 (TGFβ1), which is a key signal mediator in oncogenesis, α-smooth muscle actin (α-SMA), and collagen I are important components of the TME. IGFBP7 can upregulate the expression of TGFβ1 and activate the TGFβ1/SMAD signaling pathway, which leads to an increase in collagen I in hepatic stellate cells (HSCs). However, the contribution of IGFBP7 to TGFβ1 and the TME in the progression of ESCC remains unknown. In the present study, we investigated IGFBP7 expression and its effects on TGFβ1 and the TME in ESCC. A total of 45 patients were divided into three groups: early-tumor group (n=15), advanced-tumor group (n=15), and paracancer control group (n=15). The EC109 cell line was cultured and treated with AdIGFBP7 and LvshTGFβ1, and the expression levels of IGFBP7, TGFβ1, α-SMA, collagen I, and p-SMAD2/3 were determined by immunohistochemical staining and western blotting analysis. IGFBP7, TGFβ1, α-SMA, and collagen I were upregulated in the ESCC samples compared with the control samples (P<0.05), and the values peaked in the advanced-tumor group (P<0.05). Compared with the control group, the TGFβ1, α-SMA, p-SMAD2/3, and collagen I proteins were gradually increased from 24 to 72 h in the EC109 cells treated with AdIGFBP7 (P<0.05). Inhibition of TGFβ1 expression in the EC109 cells treated with AdIGFBP7 gradually reduced the expression of α-SMA, collagen I, and p-SMAD2/3 from 24 to 72 h (P<0.05). These findings suggest that increased IGFBP7 may accelerate the progression of ESCC by upregulating TGFβ1, α-SMA, and collagen I via activating the TGFβ1/SMAD signaling pathway, which could remodel the TME.

CD93 Correlates With Immune Infiltration and Impacts Patient Immunotherapy Efficacy: A Pan-Cancer Analysis

Background: The clinical implementation of immune-checkpoint inhibitors (ICIs) targeting CTLA4, PD-1, and PD-L1 has revolutionized the treatment of cancer. However, the majority of patients do not derive clinical benefit. Further development is needed to optimize the approach of ICI therapy. Immunotherapy combined with other forms of treatment is a rising strategy for boosting antitumor responses. CD93 was found to sensitize tumors to immune-checkpoint blocker therapy after the blockade of its pathway. However, its role in immune and ICB therapy across pan-cancer has remained unexplored.

Methods: In this study, we provide a comprehensive investigation of CD93 expression in a pan-cancer manner involving 33 cancer types. We evaluated the association of CD93 expression with prognosis, mismatch repair, tumor mutation burden, and microsatellite instability, immune checkpoints, tumor microenvironment, and immune using multiple online datasets, including The Cancer Genome Atlas, Cancer Cell Line Encyclopedia, Genotype Tissue-Expression, cBioPortal, Tumor Immune Estimation Resource database, and Tumor Immune Single-cell Hub.

Results: CD93 expression varied strongly among cancer types, and increased CD93 gene expression was associated with poor prognosis as well as higher immune factors in most cancer types. Additionally, the level of CD93 was significantly correlated with MMR, TMB, MSI, immune checkpoints, TME, and immune cell infiltration. Noticeably, our results mediated a strong positive contact between CD93 and CAFs, endothelial cells, myeloid dendritic cells, hematopoietic stem cells, mononuclear/macrophage subsets, and neutrophils while a negative correlation with Th1, MDSC, NK, and T-cell follicular helper in almost all cancers. Function analysis on CD93 revealed a link between itself and promoting cancers, inflammation, and angiogenesis.

Conclusion: CD93 can function as a prognostic marker in various malignant tumors and is integral in TME and immune infiltration. Inhibition of the CD93 pathway may be a novel and promising strategy for immunotherapy in human cancer. Further explorations of the mechanisms of CD93 in the immune system may help improve cancer therapy methods.

Comparative Proteomic Analysis Reveals Metformin Improves the Expression of Biomarkers of Endometrial Receptivity in Infertile Women with Minimal/Mild Endometriosis

The prevalence of endometriosis is approximately 10% in women of reproductive age, and 30-50% of women with endometriosis are infertile. Metformin has been reported to inhibit the growth of ectopic lesions in endometriosis. However, its effect on the eutopic endometrium of endometriosis is unknown. This study aimed to identify whether metformin affects endometrial receptivity in infertile women with minimal/mild endometriosis. We enrolled 10 infertile women who were diagnosed with minimal/mild endometriosis through laparoscopy. Paired endometrial tissues of the secretory phase from participants were collected during surgery and after 2 months of metformin treatment (n = 5) or no medical treatment (n = 5). Protein expression profiles of the paired endometrium were detected by proteomics and compared using the self-control method (2 months later vs. in surgery). Proteomics data revealed six proteins associated with endometrial receptivity among the significantly upregulated proteins after metformin treatment (fold change > 1.5, P < 0.05). Insulin-like growth factor binding protein 7 (IGFBP-7) showed the most robust increase in these six endometrial receptivity-related proteins (fold change: 8.668, P < 0.05), while there was no significant change in the controls (fold change: 1.906, P > 0.05). The upregulation of IGFBP-7 has been validated through target proteomics, immunohistochemistry, and further demonstrated in endometriosis mouse models induced by autotransplantation. This study revealed that metformin upregulated the expression of IGFBP-7 in the endometrium of human and mouse models of endometriosis. Metformin potentially affects endometrial receptivity of minimal/mild endometriosis by improving the expression of the endometrial receptivity marker IGFBP-7.

Blockade of the CD93 pathway normalizes tumor vasculature to facilitate drug delivery and immunotherapy

The immature and dysfunctional vascular network within solid tumors poses a substantial obstacle to immunotherapy because it creates a hypoxic tumor microenvironment that actively limits immune cell infiltration. The molecular basis underpinning this vascular dysfunction is not fully understood. Using genome-scale receptor array technology, we showed here that insulin-like growth factor binding protein 7 (IGFBP7) interacts with its receptor CD93, and we subsequently demonstrated that this interaction contributes to abnormal tumor vasculature. Both CD93 and IGFBP7 were up-regulated in tumor-associated endothelial cells. IGFBP7 interacted with CD93 via a domain different from multimerin-2, the known ligand for CD93. In two mouse tumor models, blockade of the CD93/IGFBP7 interaction by monoclonal antibodies promoted vascular maturation to reduce leakage, leading to reduced tumor hypoxia and increased tumor perfusion. CD93 blockade in mice increased drug delivery, resulting in an improved antitumor response to gemcitabine or fluorouracil. Blockade of the CD93 pathway triggered a substantial increase in intratumoral effector T cells, thereby sensitizing mouse tumors to immune checkpoint therapy. Last, analysis of samples from patients with cancer under anti-programmed death 1/programmed death-ligand 1 treatment revealed that overexpression of the IGFBP7/CD93 pathway was associated with poor response to therapy. Thus, our study identified a molecular interaction involved in tumor vascular dysfunction and revealed an approach to promote a favorable tumor microenvironment for therapeutic intervention.

Gene expression profile of the murine ischemic retina and its response to Aflibercept (VEGF-Trap)

Ischemic retinal dystrophies are leading causes of acquired vision loss. Although the dysregulated expression of the hypoxia-responsive VEGF-A is a major driver of ischemic retinopathies, implication of additional VEGF-family members in their pathogenesis has led to the development of multivalent anti-angiogenic tools. Designed as a decoy receptor for all ligands of VEGFR1 and VEGFR2, Aflibercept is a potent anti-angiogenic agent. Notwithstanding, the molecular mechanisms mediating Aflibercept's efficacy remain only partially understood. Here, we used the oxygen-induced retinopathy (OIR) mouse as a model system of pathological retinal vascularization to investigate the transcriptional response of the murine retina to hypoxia and of the OIR retina to Aflibercept. While OIR severely impaired transcriptional changes normally ensuing during retinal development, analysis of gene expression patterns hinted at alterations in leukocyte recruitment during the recovery phase of the OIR protocol. Moreover, the levels of Angiopoietin-2, a major player in the progression of diabetic retinopathy, were elevated in OIR tissues and consistently downregulated by Aflibercept. Notably, GO term, KEGG pathway enrichment, and expression dynamics analyses revealed that, beyond regulating angiogenic processes, Aflibercept also modulated inflammation and supported synaptic transmission. Altogether, our findings delineate novel mechanisms potentially underlying Aflibercept's efficacy against ischemic retinopathies.

Regulation of vascular permeability in cancer metastasis

Enhancement of vascular permeability is indispensable for cancer metastasis. Weakened endothelial barrier function enhances vascular permeability. Circulating tumor cells moving in the microvasculature tend to invade into stromal tissue at the location where vascular permeability is enhanced. Many basic studies have identified permeability factors by using gene‐modified animals and cells. These factors directly/indirectly interact with endothelial cells. Here, we review vascular permeability factors and their molecular mechanisms. Interactions between tumor cells and endothelial cells are also discussed in the process of extravasation, one of the most critical steps in tumor metastasis. In some cases, primary tumors can manipulate permeability in a remote organ by secreting permeability factors. In addition, the importance of glycocalyx, which covers the endothelial cell surface, in controlling vascular permeability and tumor metastasis is also described. Furthermore, analysis of the hyperpermeable region found in a mouse model study is introduced. It clearly showed that tumor‐bearing mouse lungs had a hyperpermeable region due to the influence of a remote primary tumor, and fibrinogen deposition was observed in that region. Given that fibrinogen was reported to be a permeability factor and a key regulator of inflammation, eliminating fibrinogen deposition may prevent future metastasis.

MiR-206 promotes extracellular matrix accumulation and relieves infantile hemangioma through targeted inhibition of DNMT3A

MiR-206 is abnormally expressed in infant hemangioma endothelial cells (HemECs), but the mechanism is not clear. We explored the intervention of miR-206 in HemECs in relation to extracellular matrix (ECM) metabolism. We selected 48 cases of infantile hemangioma (IH) from volunteer organizations. After the isolated and extracted HemECs were interfered with overexpressed or silenced miR-206, the effects of miR-206 on the proliferation, migration and invasion of HemECs were examined through basic cell function experiments. The expression differences of miR-206, DNA Methyltransferase 3A (DNMT3A) and ECM-related genes were analyzed as needed by qRT-PCR or Western blot. TargetScan and dual-luciferase experiments were applied to predict and confirm the binding relationship between miR-206 and DNMT3A. The correlation between miR-206 and DNMT3A was analyzed in IH tissues by Pearson correlation coefficient, and further confirmed in HemECs by conducting rescue experiments. A nude mouse model of xenograft tumor was constructed to verify the results of in vitro experiments. MiR-206, which was downregulated in proliferative hemangioma, suppressed the malignant development of HemECs by regulating ECM-related genes. As the target gene of miR-206, DNMT3A was high-expressed in IH tissues and was negatively correlated with miR-206. Overexpressed DNMT3A counteracted the inhibitory effect of miR-206 mimic on HemECs and its regulatory effect on ECM. The results of in vivo experiments were consistent with those from cell experiments. Thus, miR-206 could promote ECM accumulation through targeted inhibition of DNMT3A, further inhibiting the malignant development of HemECs and relieving IH.

An Integrated Transcriptome Analysis Reveals IGFBP7 Upregulation in Vasculature in Traumatic Brain Injury

Vasculature plays critical roles in the pathogenesis and neurological repair of traumatic brain injury (TBI). However, how vascular endothelial cells respond to TBI at the molecular level has not been systematically reviewed. Here, by integrating three transcriptome datasets including whole cortex of mouse brain, FACS-sorted mouse brain endothelial cells, and single cell sequencing of mouse brain hippocampus, we revealed the key molecular alteration of endothelial cells characterized by increased Myc targets and Epithelial-Mesenchymal Transition signatures. In addition, immunofluorescence staining of patients’ samples confirmed that IGFBP7 was up-regulated in vasculature in response to TBI. TGFβ1, mainly derived from microglia and endothelial cells, sufficiently induces IGFBP7 expression in cultured endothelial cells, and is significantly upregulated in response to TBI. Our results identified IGFBP7 as a potential biomarker of vasculature in response to TBI, and indicate that TGFβ signaling may contribute to the upregulation of IGFBP7 in the vasculature.

Natural products remodel cancer-associated fibroblasts in desmoplastic tumors

Desmoplastic tumors have an abundance of stromal cells and the extracellular matrix which usually result in therapeutic resistance. Current treatment prescriptions for desmoplastic tumors are usually not sufficient to eliminate the malignancy. Recently, through modulating cancer-associated fibroblasts (CAFs) which are the most abundant cell type among all stromal cells, natural products have improved chemotherapies and the delivery of nanomedicines to the tumor cells, showing promising ability to improve treatment effects on desmoplastic tumors. In this review, we discussed the latest advances in inhibiting desmoplastic tumors by modeling CAFs using natural products, highlighting the potential therapeutic abilities of natural products in targeting CAFs for cancer treatment.

Angiomodulin (IGFBP7) is a cerebral specific angiocrine factor, but is probably not a blood-brain barrier inducer

BACKGROUND

Several secreted factors have been identified as drivers of cerebral vasculature development and inducers of blood-brain barrier (BBB) differentiation. Vascular endothelial growth factor A (VEGF-A) is central for driving cerebral angiogenesis and Wnt family factors (Wnt7a, Wnt7b and norrin) are central for induction and maintenance of barrier properties. Expressed by developing neural tissue (neuron and glia progenitors), they influence the formation of central nervous system (CNS) vascular networks. Another type of factors are tissue-specific paracrine factors produced by endothelial cells (ECs), also known as 'angiocrine' factors, that provide instructive signals to regulate homeostatic and regenerative processes. Very little is known about CNS angiocrine factors and their role in BBB development. Angiomodulin (AGM) was reported to be expressed by developing vasculature and by pathological tumor vasculature. Here we investigated AGM in the developing CNS and its function as a potential BBB inducer.

METHODS

We analyzed microarray data to identify potential angiocrine factors specifically expressed at early stages of barrier formation. We then tested AGM expression with immunofluorescence and real-time PCR in various organs during development, post-natal and in adults. Permeability induction with recombinant proteins (Miles assay) was used to test potential interaction of AGM with VEGF-A.

RESULTS

Several angiocrine factors are differentially expressed by CNS ECs and AGM is a prominent CNS-specific angiocrine candidate. Contrary to previous reports, we found that AGM protein expression is specific to developing CNS endothelium and not to highly angiogenic developing vasculature in general. In skin vasculature we found that AGM antagonizes VEGF-A-induced vascular hyperpermeability. Finally, CNS AGM expression is not specific to BBB vasculature and AGM is highly expressed in non-BBB choroid-plexus vasculature.

CONCLUSIONS

We propose AGM as a developmental CNS vascular-specific marker. AGM is not a pan-endothelial marker, nor a general marker for developing angiogenic vasculature. Thus, AGM induction in the developing CNS might be distinct from its induction in pathology. While AGM is able to antagonize VEGF-A-induced vascular hyperpermeability in the skin, its high expression levels in non-BBB CNS vasculature does not support its potential role as a BBB inducer. Further investigation including loss-of-function approaches might elucidate AGM function in the developing CNS.

Long non-coding RNA ERICH3-AS1 is an unfavorable prognostic factor for gastric cancer

Long non-coding RNAs (lncRNAs) play important roles in gastric cancer (GC), but the mechanism is not fully clear. ERICH3-AS1 (ERICH3 antisense RNA1) is affiliated with the non-coding RNA class which has proven to be involved in the prognostic of GC, but the function of ERICH3-AS1 is still unclear. In this study, we aim to explore the potential function of ERICH3-AS1 in the development of GC and analyze the prognostic role of ERICH3-AS1 in GC. We found that the lncRNA ERICH3-AS1 was significantly up-regulated in GC tissues in the analysis of The Cancer Genome Atlas (TCGA) data; the Kaplan-Meier analysis showed that the higher the expression of ERICH3-AS1 was, the earlier the recurrence and the poorer the prognosis would be in patients. Cox univariate and multivariate analyses revealed that ERICH3-AS1 was a risk factor of disease-free survival (DFS) (p < 0.05) and overall survival (OS) (p < 0.05) of patients. Through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, it demonstrated that the ERBB pathways, the mitogen-activated protein kinase (MAPK) pathways, the MTOR pathways, p53 pathways and Wnt pathways were differentially enriched in ERICH3-AS1 high expression phenotype. Furthermore, the correlation analysis showed that ERICH3-AS1 had significant correlations with apoptosis-related proteins such as BCL2L10 and CASP14; cell cycle-associated proteins CDK14 and invasion and migration-associated proteins such as MMP20, MMP26 and MMP27. In summary, we identified that increased ERICH3-AS1 might be a potential biomarker for diagnosis and independent prognostic factor of GC. Moreover, ERICH3-AS1 might participate in the oncogenesis and development of tumors via cell cycle and apoptosis pathway mediated by ERBB, MAPK, MTOR, p53 and Wnt pathways.

Cancer-associated fibroblast regulation of tumor neo-angiogenesis as a therapeutic target in cancer

Adequate blood supply is essential for tumor survival, growth and metastasis. The tumor microenvironment (TME) is dynamic and complex, comprising cancer cells, cancer-associated stromal cells and their extracellular products. The TME serves an important role in tumor progression. Cancer-associated fibroblasts (CAFs) are the principal component of stromal cells within the TME, and contribute to tumor neo-angiogenesis by altering the proteome and degradome. The present paper reviews previous studies of the molecular signaling pathways by which CAFs promote tumor neo-angiogenesis and highlights therapeutic response targets. Also discussed are potential strategies for antitumor neo-angiogenesis to improve tumor treatment efficacy.

VE-cadherin cleavage by ovarian cancer microparticles induces β-catenin phosphorylation in endothelial cells

Microparticles (MPs) are increasingly recognized as important mediators of cell-cell communication in tumour growth and metastasis by facilitating angiogenesis-related processes. While the effects of the MPs on recipient cells are usually well described in the literature, the leading process remains unclear. Here we isolated MPs from ovarian cancer cells and investigated their effect on endothelial cells. First, we demonstrated that ovarian cancer MPs trigger β-catenin activation in endothelial cells, inducing the upregulation of Wnt/β-catenin target genes and an increase of angiogenic properties. We showed that this MPs mediated activation of β-catenin in ECs was Wnt/Frizzled independent; but dependent on VE-cadherin localization disruption, αVβ3 integrin activation and MMP activity. Finally, we revealed that Rac1 and AKT were responsible for β-catenin phosphorylation and translocation to the nucleus. Overall, our results indicate that MPs released from cancer cells could play a major role in neo-angiogenesis through activation of beta catenin pathway in endothelial cells.

Tissue and serum IGFBP7 protein as biomarker in high-grade soft tissue sarcoma

Soft-tissue sarcomas (STS) are a heterogeneous group of mesenchymal tumors whose classification and treatment is complicated by molecular heterogeneity within the histological subtypes and by the lack of prognostic/therapeutic biomarkers. This study analyses expression of target proteins involved in insulin-like growth factor pathway (IGF1Rβ, IRS1 S612 and IGFBP7) in high-grade STS to stratify patients with the worst prognosis. Tissue microarray analysis performed on 145 high-grade STS samples revealed a uniform expression of IGF1Rβ and IRS1 S612, while IGFBP7 was more strongly expressed in metastatic than in metastasis-free patients. This was confirmed by multivariate regression analysis that demonstrated the independent poor prognostic role of IGFBP7 overexpression with a significant increase of risk of metastasis (HR = 6.358, 95% CI = 2.946-13.721; P < 0.0005). Given the evidence that circulating protein may generate from tissue tumor cells, in 59/145 patients who had available serum we measured IGFBP7 concentration. The ELISA assay revealed significantly higher levels in tumor patients than in the control with a possible threshold value of 25 ng/ml. Differentiating sera according to primary tumor histotype, significantly higher IGFBP7 concentration was found in synovial sarcoma and liposarcoma than in other STS histotypes. This study revealed that tissue expression of IGFBP7, considered a tumor stroma marker in mesenchymal derived cells, was highly prognostic in poor metastasis-free survival. In parallel, the determination of serum protein levels might contribute to STS diagnosis. Subsequent analyses will be crucial to understand the clinical relevance of IGFBP7 protein in STS.

Inhibitory effect of insulin-like growth factor-binding protein-7 (IGFBP7) on in vitro angiogenesis of vascular endothelial cells in the rat corpus luteum

Angiogenesis in the developing corpus luteum (CL) is a prerequisite for establishment and maintenance of an early pregnancy. To explore the physiological significance of insulin-like growth factor-binding protein-7 (IGFBP7) in the developing CL, the effects of IGFBP7 on vascular endothelial growth factor (VEGFA)- and luteinizing hormone (LH)-induced in vitro tube formation were tested using isolated luteal microvascular endothelial cells (LECs). Capillary-like tube formation of LECs and their proliferation were stimulated by both VEGFA and LH. IGFBP7 treatment suppressed VEGFA- or LH-induced tube formation. The proliferation and migration of LECs, and phosphorylation of mitogen-activated protein kinase kinase and extracellular signal-regulated kinase 1/2 were inhibited by IGFBP7. Furthermore, IGFBP7 attenuated VEGFA-enhanced cyclooxygenase (COX)-2 mRNA expression and prostaglandin E₂ secretion. These findings suggest the possibility that luteal IGFBP7 secretion may suppress the stimulatory effect of VEGFA on angiogenesis in the early CL.