Subcutaneous Matrigel Plugs Research Articles

Four-dimensional trapped ion mobility spectrometry proteomics reveals circulating extracellular vesicles encapsulated drivers of nasopharyngeal carcinoma distant dissemination

Nasopharyngeal carcinoma (NPC) is a head and neck cancer with a high propensity for early metastatic spread. Emerging evidence shows that extracellular vesicles (EVs) are key players in cancer metastasis, but their role in NPC metastasis remains poorly understood. We here present the first description of the proteomic and functional profiles of serum-derived circulating small EVs in metastatic NPC patients. To enhance the capture of low-abundance signaling proteins in EVs, timsTOF-based four-dimensional label-free quantitative proteomics was employed. We found that metastatic NPC patients (M-NPC-EVs) exhibited the highest serum EV levels compared to locoregional patients (L-NPC-EVs) and healthy subjects (Normal-EVs). The proteome of M-NPC-EVs differed substantially from L-NPC-EVs and was functionally enriched in pathways regulating cell polarity and motility, glucose metabolism, and angiogenesis. Functional assays testing individual EV samples demonstrated that M-NPC-EVs pronouncedly enhanced NPC cell migration, invasion, and the formation of lamellipodia and filopodia in vitro, and promoted angiogenesis in subcutaneous Matrigel plugs in vivo. In silico analyses suggested that PTPRA, TPI1 and GPI highly enriched in M-NPC-EVs were putative drivers underlying the motogenic and angiogenic activities of M-NPC-EVs, and their high expression levels were associated with a poor prognosis of NPC patients. The increased expression of PTPRA, TPI1 and GPI in M-NPC-EVs was then validated in an independent cohort consisting of 175 NPC patients (locoregional n = 114; metastatic n = 61). Together, utilizing patient-derived EVs, we mimicked the potential pro-metastatic functions of EVs in NPC patients in vitro and in vivo and provided novel insights into their bioactive cargoes.

Identification of an osteopontin-derived peptide that binds neuropilin-1 and activates vascular repair responses and angiogenesis

The osteopontin-derived peptide FOL-005 stimulates hair growth. Using ligand-receptor glyco-capture technology we identified neuropilin-1 (NRP-1), a known co-receptor for vascular endothelial growth factor (VEGF) receptors, as the most probable receptor for FOL-005 and the more stable analogue FOL-026. X-ray diffraction and microscale thermophoresis analysis revealed that FOL-026 shares binding site with VEGF in the NRP-1 b1-subdomain. Stimulation of human umbilical vein endothelial cells with FOL-026 resulted in phosphorylation of VEGFR-2, ERK1/2 and AKT, increased cell growth and migration, stimulation of endothelial tube formation and inhibition of apoptosis in vitro. FOL-026 also promoted angiogenesis in vivo as assessed by subcutaneous Matrigel plug and hind limb ischemia models. NRP-1 knock-down or treatment of NRP-1 antagonist EG00229 blocked the stimulatory effects of FOL-026 on endothelial cells. Exposure of human coronary artery smooth muscle cells to FOL-026 stimulated cell growth, migration, inhibited apoptosis, and induced VEGF gene expression and VEGFR-2/AKT phosphorylation by an NRP-1-dependent mechanism. RNA sequencing showed that FOL-026 activated pathways involved in tissue repair. These findings identify NRP-1 as the receptor for FOL-026 and show that its biological effects mimic that of growth factors binding to the VEGF receptor family. They also suggest that FOL-026 may have therapeutical potential in conditions that require vascular repair and/or enhanced angiogenesis.

ATP promotes resident CD34+ cell migration mainly through P2Y2-Stim1-ERK/p38 pathway.

Extracellular adenosine triphosphate (ATP) is one of the most abundant biochemical constitutes within the stem cell microenvironment and is postulated to play critical roles in cell migration. However, it is unclear whether ATP regulates the cell migration of CD34+ vascular wall-resident stem/progenitor cells (VW-SCs) and participates in angiogenesis. Therefore, the biological mechanisms of cell migration mediated by ATP was determined by in vivo subcutaneous matrigel plug assay, ex vivo aortic ring assay, in vitro transwell migration assay, and other molecular methods. In the present study, ATP dose-dependently promoted CD34+ VW-SCs migration, which was more obviously attenuated by inhibiting or knocking down P2Y2 than P2Y6. Furthermore, it was confirmed that ATP potently promoted the migration of resident CD34+ cells from cultured aortic artery rings and differentiation into endothelial cells in matrigel plugs by using inducible lineage tracing Cd34-CreERT2; R26-tdTomato mice, whereas P2Y2 and P2Y6 blocker greatly inhibited the effect of ATP. In addition, ATP enhanced the protein expression of stromal interaction molecule 1 (STIM1) on cell membrane, blocking the calcium release-activated calcium (CRAC) channel with shSTIM1 or BTP2 apparently inhibited ATP-evoked intracellular Ca2+ elevation and channel opening, thereby suppressing ATP-driven cell migration. Moreover, extracellular signal-regulated protein kinase (ERK) inhibitor PD98059 and p38 inhibitor SB203580 remarkably inhibited ERK and p38 phosphorylation, cytoskeleton rearrangement, and subsequent cell migration. Unexpectedly, it was found that knocking down STIM1 greatly inhibited ATP-triggered ERK/p38 activation. Taken together, it was suggested that P2Y2 signaled through the CRAC channel mediated Ca2+ influx and ERK/p38 pathway to reorganize the cytoskeleton and promoted the migration of CD34+ VW-SCs.NEW & NOTEWORTHY In this study, we observed that the purinergic receptor P2Y2 is critical in the regulation of vascular wall-resident CD34+ cells' migration. ATP could activate STIM1-mediated extracellular Ca2+ entry by triggering STIM1 translocation to the plasma membrane, and knockdown of STIM1 prevented ERK/p38 activation-mediated cytoskeleton rearrangement and cell migration.

Conformational alteration in glycan induces phospholipase Cβ1 activation and angiogenesis

BackgroundIn endothelial cells, phospholipase C (PLC) β1-activated Ca2+ is a crucial second messenger for the signaling pathways governing angiogenesis. PLCβ1 is inactivated by complexing with an intracellular protein called translin-associated factor X (TRAX). This study demonstrates specific interactions between Globo H ceramide (GHCer) and TRAX, which highlight a new angiogenic control through PLCβ1 activation.MethodsGlobo-series glycosphingolipids (GSLs), including GHCer and stage-specific embryonic antigen-3 ceramide (SSEA3Cer), were analyzed using enzyme-linked immunosorbent assay (ELISA) and Biacore for their binding with TRAX. Angiogenic activities of GSLs in human umbilical vein endothelial cells (HUVECs) were evaluated. Molecular dynamics (MD) simulation was used to study conformations of GSLs and their molecular interactions with TRAX. Fluorescence resonance energy transfer (FRET) analysis of HUVECs by confocal microscopy was used to validate the release of PLCβ1 from TRAX. Furthermore, the in vivo angiogenic activity of extracellular vesicles (EVs) containing GHCer was confirmed using subcutaneous Matrigel plug assay in mice.ResultsThe results of ELISA and Biacore analysis showed a stable complex between recombinant TRAX and synthetic GHCer with Kd of 40.9 nM. In contrast, SSEA3Cer lacking a fucose residue of GHCer at the terminal showed ~ 1000-fold decrease in the binding affinity. These results were consistent with their angiogenic activities in HUVECs. The MD simulation indicated that TRAX interacted with the glycan moiety of GHCer at amino acid Q223, Q219, L142, S141, and E216. At equilibrium the stable complex maintained 4.6 ± 1.3 H-bonds. TRAX containing double mutations with Q223A and Q219A lost its ability to interact with GHCer in both MD simulation and Biacore assays. Removal of the terminal fucose from GHCer to become SSEA3Cer resulted in decreased H-bonding to 1.2 ± 1.0 by the MD simulation. Such specific H-bonding was due to the conformational alteration in the whole glycan which was affected by the presence or absence of the fucose moiety. In addition, ELISA, Biacore, and in-cell FRET assays confirmed the competition between GHCer and PLCβ1 for binding to TRAX. Furthermore, the Matrigel plug assay showed robust vessel formation in the plug containing tumor-secreted EVs or synthetic GHCer, but not in the plug with SSEA3Cer. The FRET analysis also indicated the disruption of colocalization of TRAX and PLCβ1 in cells by GHCer derived from EVs.ConclusionsOverall, the fucose residue in GHCer dictated the glycan conformation for its complexing with TRAX to release TRAX-sequestered PLCβ1, leading to Ca2+ mobilization in endothelial cells and enhancing angiogenesis in tumor microenvironments.

Abstract P1142: Engineering Vascular Therapies With Angiogenic Factors For Cardiac Regeneration And Tissue Remodeling

The limited regenerative capacity of the adult human heart presents a critical need to stabilize and support injured heart muscle to mitigate the progression of heart failure. The effectiveness of remuscularization therapies using human induced pluripotent stem cell derived cardiomyocytes depends host mediated angiogenesis to direct the formation of stable, perfused vascular networks within the engineered cardiac implant. We hypothesize that potent combinations of growth factors will stimulate angiogenesis in the myocardium and increase vascular development in engineered cardiac tissue. In a fractional factorial experiment, we assessed the effect of ten growth factors, cytokines and enzymes: VEGF, bFGF, Shh, PDGF, IGF-1, EGF, TGF-β1, Ang-1, MCP-1 and MMP-9 on in vivo angiogenesis in a subcutaneous Matrigel plug assay in the rat. Five factors were highly potent by metrics of vessel density and vascular cell recruitment in explants and warranted further investigation. We then designed a two-level, fractional factorial experiment using a defined collagen-alginate gel to deliver high/low doses of these 5 factors subcutaneously to elucidate main effects and two-way interactions that regulate vessel development in vivo . After 7 days, Griffonia Simplicfolia lectin I was administered to label perfused vasculature then explants were removed and processed for immunohistochemistry. Our data show that 3 unique cocktails yielded a 10-fold increase in lumen density, a 3.3-fold increase in lumen size, and a 3.7-fold increase in endothelial cell recruitment relative to unloaded controls. Ongoing analyses will determine which angiogenic cocktail to deliver in a customizable biomaterial-based vascular therapy for applications in the heart. This novel therapy will be delivered with an engineered cardiac tissue onto the epicardium in a rat I/R MI model to quantify vascular remodeling in the implant and underlying host tissue and whole heart function over 4 weeks. In conclusion, we have identified five potent angiogenic factors for modulating revascularization responses and our ongoing work aims to understand the potential synergy between revascularization and remuscularization therapies for heart regeneration.

Abstract 6331: Cloaking VEGF in small extracellular vesicles as a cause of adaptive resistance to anti-VEGF therapy

Abstract Despite the wide use of anti-vascular endothelial growth factor (VEGF) therapy (AVT) for many solid cancers, most of them become resistant to such therapy, resulting in progressive disease. Therefore, new biomarkers and strategies for blocking adaptive resistance of cancer to AVT are needed. Small extracellular vesicles (small EVs, with a size of <200 nm) have been extensively studied as crucial intercellular messengers by delivering DNA, RNA, and proteins to recipient cells. We hypothesized that the packaging of angiogenic factors, especially VEGF, into small EVs could cause adaptive resistance to AVT by evading recognition by therapeutic antiboides. In this study, we carried out a series of in vitro (immunoblot analysis, flow cytometry, tube formation, and immunofluorescence staining) and in vivo (subcutaneous mouse models and Matrigel plug angiogenesis assay) experiments to determine the roles of small EVs in AVT resistance. We found that cancer-derived small EVs increasingly package VEGF and other factors in response to AVT. Further studies showed that bevacizumab cannot recognize the VEGF packaged inside small EVs (eVEGF) and eVEGF was protected from being neutralized by bevacizumab. Notably, eVEGF was transferred to endothelial cells, triggered intracrine signaling, and subsequently increased the number of tubes formed in an in vitro angiogenesis assay. In addition, VEGF was present at higher levels in serum small EVs in mouse models of adaptive resistance of ovarian cancer to bevacizumab than in models of sensitivity to it. Ovarian cancer cell-derived eVEGF increased tumor growth despite treatment with bevacizumab. Collectively, our data provide a new mechanism whereby eVEGF evades recognition by therapeutic antibodies and promotes tumor angiogenesis and progression. These findings have implications for biomarkers and new therapeutic strategies for ovarian cancer therapy. Citation Format: Shaolin Ma, Lingegowda S. Mangala, Wen Hu, Emine Bayaktar, Wei Hu, Nicholas B. Jennings, Robert L. Coleman, Gabriel Lopez-Berestein, Anil K. Sood. Cloaking VEGF in small extracellular vesicles as a cause of adaptive resistance to anti-VEGF therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6331.

MicroRNA-326-5p enhances therapeutic potential of endothelial progenitor cells for myocardial infarction

BackgroundOur study sought to investigate the therapeutic effects and mechanisms of miR-326-5p-overexpressing endothelial progenitor cells (EPCs) on acute myocardial infarction (AMI).MethodsMouse EPCs were isolated, purified, and identified by flow cytometry and uptake of DiI-ac-LDL. The target gene of miR-326-5p was predicted using target prediction algorithms and verified by dual-luciferase reporter assay, RT-qPCR, and Western blot. After EPCs were transfected with the agomir or antagomir of miR-326-5p, tube formation assay and Matrigel plug angiogenesis assay were conducted in four groups (NC, miR-326-5p agomir, miR-326-5p antagomir, and miR-326-5p agomir+Wnt1 agonist). In addition, a mouse model of MI was established and treated with the injection of miR-326-5p-EPCs, miR-326-5p-EPCs+ Wnt1 agonist, EPCs-NC, or PBS/control into the peri-infarcted myocardium. Subsequently, cardiac function was monitored by echocardiography at 7 and 28 days postoperatively. Finally, the infarcted hearts were collected at 28 days, and the size of myocardial infarction was measured by Masson’s trichrome staining and the neovascularization in the peri-infarcted area was examined through immunofluorescence staining.ResultsLuciferase reporter assay indicated that Wnt1 was a direct target of miR-326-5p. Using RT-qPCR and Western blot analysis, we further demonstrated that the expression level of Wnt1 was negatively correlated with miR-326-5p expression in EPCs. Both in vitro study of tube formation assay and in vivo investigation of subcutaneous Matrigel plug assay revealed that the miR-326-5p agomir could significantly enhance the angiogenic capacity of EPCs, and this effect was partially inhibited by Wnt1 agonist. Meanwhile, miR-326-5p antagomir could obviously reduce the the angiogenic capacity of EPCs in vivo compared with that in the NC group. Moreover, the transplantation of miR-326-5p-overexpressing EPCs in the ischemic hearts of mice significantly enhanced the angiogenesis in the peri-infarcted zone and improved the cardiac function. However, the enhanced capacity of angiogenesis of miR-326-5p-overexpressing EPCs was remarkably neutralized by Wnt1 agonist, accompanied by the decreased improvement in cardiac function.ConclusionmiR-326-5p significantly enhanced the angiogenic capacity of EPCs. Transplantation of miR-326-5p-overexpressing EPCs improved cardiac function for AMI therapy, which can be a novel strategy for enhancing therapeutic angiogenesis in ischemic heart diseases.

Survival and functional activity examination of cardiomyocytes differentiated from human iPSCs, when transplanting in SCID mice

Conduction and heart rhythm disorders can be caused by both functional pathology and severe organic lesions of the heart. The possibility of using cell-based replacement cell therapy derived from induced pluripotent stem cells to compensate for lost myocardial tissue or the conduction system is currently being studied. The aim of the work is to study the survival and functional activity of cardiomyocytes differentiated from induced human pluripotent stem cells in intramyocardial and subcutaneous abdominal transplantation in a clots of proteins of the basement membrane matrix Matrigel to the SCID mice. After 2 and 5 weeks after intramyocardial and 2, 7, 14, 21 and 28 days after subcutaneous transplantation, the survival and activity of cardiomyocytes were studied by cytological methods. Human cardiomyocytes were detected in mice for at least 35 days. after transplantation and did not cause ectopic electrical activity of the myocardium. When assessing the functional activity of cardiomyocytes in subcutaneous matrigel plugs using the method of optical mapping of calcium ion currents for 2-28 days. after injection, it was shown that only a small fraction of cardiomyocytes after transplantation was able to spontaneously oscillate the calcium ions. We assume that contractile cardiomyocytes obtained from induced pluripotent human cells lose their ability to spontaneous excitation during in vivo transplantation, and we observe only the activity of pacemaker cardiomyocytes in optical mapping.

A targeted nanoplatform co-delivering chemotherapeutic and antiangiogenic drugs as a tool to reverse multidrug resistance in breast cancer

Several obstacles are currently impeding the successful treatment of breast cancer, namely impaired drug accumulation into the tumor site, toxicity to normal cells and narrow therapeutic index of chemotherapy, multidrug resistance (MDR) and the metastatic spread of cancer cells through the blood and lymphatic vessels. In this regard, we designed a novel multifunctional nano-sized drug delivery system based on LyP-1 peptide-modified low-molecular-weight heparin-quercetin conjugate (PLQ). This nanosystem was developed for targeted co-delivery of multiple anticancer drugs to p32-overexpressing tumor cells and peritumoral lymphatic vessels, using LyP-1 peptide as active targeting ligand, with the aim to achieve a targeted combinatorial chemo/angiostatic therapy and MDR reversal. The cellular uptake of PLQ nanoparticles by p32-overexpressing breast cancer cells was significantly higher than nonfunctionalized nanoparticles. Besides, the anti-angiogenic activity of PLQ nanoparticles was proven by the effective inhibition of the bFGF-induced neovascularization in subcutaneous Matrigel plugs. More importantly, PLQ/GA nanoparticles with better targeting ability toward p32-positive tumors, displayed a high antitumor outcome by inhibition of tumor cells proliferation and angiogenesis. Immunohistochemistry and western blot assay showed that PLQ/GA nanoparticles significantly disrupted the lymphatic formation of tumor, and inhibited the P-glycoprotein (P-gp) expression in MCF-7 tumor cells, respectively. In conclusion, PLQ/GA nanoparticles provide a synergistic strategy for effective targeted co-delivery of chemotherapeutic and antiangiogenic agents and reversing MDR and metastasis in breast cancer. Statement of SignificanceHerein, we successfully developed a novel amphiphilic nanomaterial, LyP-1-LMWH-Qu (PLQ) conjugate, consisting of a tumor-targeting moiety LyP-1, a hydrophobic quercetin (a multidrug resistance [MDR]–reversing drug) inner core, and a hydrophilic low-molecular-weight heparin (an antiangiogenic agent) outer shell for encapsulating and delivering a hydrophobic chemotherapeutic agent (gambogic acid). This versatile nanoplatform with multiple targeted features, i.e., dual chemo/angiostatic effects, destruction ability of the peritumoral lymphatic vessels, and reversal of MDR, resulted in a significantly stronger antitumor efficacy and lower toxic side effect than those of nontargeted nanoparticles and the free drug solution. Therefore, this versatile nanosystem might provide a novel insight for the treatment and palliation of breast cancer by targeted co-delivery of chemo/antiangiogenic agents and reversing MDR and metastasis.

The Role of Fibroblast Growth Factor-Binding Protein 1 in Skin Carcinogenesis and Inflammation

Fibroblast growth factor-binding protein 1 (FGFBP1) is a secreted chaperone that mobilizes paracrine-acting FGFs, stored in the extracellular matrix, and presents them to their cognate receptors. FGFBP1 enhances FGF signaling including angiogenesis during cancer progression and is upregulated in various cancers. Here we evaluated the contribution of endogenous FGFBP1 to a wide range of organ functions as well as to skin pathologies using Fgfbp1-knockout mice. Relative to wild-type littermates, knockout mice showed no gross pathologies. Still, in knockout mice a significant thickening of the epidermis associated with a decreased transepidermal water loss and increased proinflammatory gene expression in the skin was detected. Also, skin carcinogen challenge by 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoyl-phorbol-13-acetate resulted in delayed and reduced papillomatosis in knockout mice. This was paralleled by delayed healing of skin wounds and reduced angiogenic sprouting in subcutaneous matrigel plugs. Heterozygous green fluorescent protein (GFP)-knock-in mice revealed rapid induction of gene expression during papilloma induction and during wound healing. Examination of wild-type skin grafted onto Fgfbp1 GFP-knock-in reporter hosts and bone marrow transplants from the GFP-reporter model into wild-type hosts revealed that circulating Fgfbp1-expressing cells migrate into healing wounds. We conclude that tissue-resident and circulating Fgfbp1-expressing cells modulate skin carcinogenesis and inflammation.

AIBP Limits Angiogenesis Through γ-Secretase-Mediated Upregulation of Notch Signaling.

Angiogenesis improves perfusion to the ischemic tissue after acute vascular obstruction. Angiogenesis in pathophysiological settings reactivates signaling pathways involved in developmental angiogenesis. We showed previously that AIBP (apolipoprotein A-I [apoA-I]-binding protein)-regulated cholesterol efflux in endothelial cells controls zebra fish embryonic angiogenesis. This study is to determine whether loss of AIBP affects angiogenesis in mice during development and under pathological conditions and to explore the underlying molecular mechanism. In this article, we report the generation of AIBP knockout (Apoa1bp-/-) mice, which are characterized of accelerated postnatal retinal angiogenesis. Mechanistically, AIBP triggered relocalization of γ-secretase from lipid rafts to nonlipid rafts where it cleaved Notch. Consistently, AIBP treatment enhanced DLL4 (delta-like ligand 4)-stimulated Notch activation in human retinal endothelial cells. Increasing high-density lipoprotein levels in Apoa1bp-/- mice by crossing them with apoA-I transgenic mice rescued Notch activation and corrected dysregulated retinal angiogenesis. Notably, the retinal vessels in Apoa1bp-/- mice manifested normal pericyte coverage and vascular integrity. Similarly, in the subcutaneous Matrigel plug assay, which mimics ischemic/inflammatory neovascularization, angiogenesis was dramatically upregulated in Apoa1bp-/- mice and associated with a profound inhibition of Notch activation and reduced expression of downstream targets. Furthermore, loss of AIBP increased vascular density and facilitated the recovery of blood vessel perfusion function in a murine hindlimb ischemia model. In addition, AIBP expression was significantly increased in human patients with ischemic cardiomyopathy. Our data reveal a novel mechanistic connection between AIBP-mediated cholesterol metabolism and Notch signaling, implicating AIBP as a possible druggable target to modulate angiogenesis under pathological conditions.

Multifunctional Polymeric Nanosystems for Dual-Targeted Combinatorial Chemo/Angiogenesis Therapy of Tumors.

Combination of antiangiogenesis and chemotherapy holds vast promise for effective inhibition of tumor proliferation and invasion. Herein, a multifunctional self-assembled nanosystem consisting of amphiphilic c(RGDyK)-functionalized low-molecular-weight heparin-gambogic acid conjugate (cRHG) is developed, using c(RGDyK) peptide as αv β3 integrin targeting moiety to realize a double-targeted delivery to both tumor cells and angiogenic vasculature. cRHG with a markedly decreased anticoagulant activity can self-assemble into nanosized particles (around 150 nm). cRHG nanoparticles effectively inhibit vascular endothelial growth factor (VEGF)-triggered tube-like formation of HUVEC and neovascularization of subcutaneous Matrigel plugs. More importantly, the targeting ability of cRHG nanoparticles is revealed by their efficient internalization by αv β3 integrin-positive cells (U87MG and HUVEC) in vitro and obvious accumulation of Cy7/cRHG in the tumor site with strong fluorescence signals in both cancer cells and neovasculature. Besides, cRHG maintains the in vitro cytotoxic activity of gambogic acid, while achieving the highest in vivo antitumor activity in U87MG mouse xenograft model and displaying better safety profile than free drugs solutions. Mechanistic investigations reveal the substantial inhibition of hypoxia-inducible factor-1 alpha, VEGF, and CD31 expression by cRHG nanoparticles with remarkable down-regulation of VEGFR2 phosphorylation. These results suggest that cRHG nanoparticles provide a versatile nanoplatform for efficacious combinatorial tumor therapy.

Abstract 4166: Targeting NF-κB by the curcumin and its analogs EF-31 and UBS-109 decreases growth and angiogenesis of colon cancer

Abstract Purpose/Objective: NF-κB plays an essential role in cancer cell growth and metastasis by stimulating angiogenesis. Curcumin decreases the activity of several oncogenic transcriptional factors including NF-κB and HIF-1α, thus we investigated whether curcumin and its analogs EF-31 and UBS-109, could disrupt angiogenesis using colorectal cancer cells (CRC). Methods: HCT-116 and HT-29 cells were used in these experiments. HUVEC tube formation assay, Matrigel plug assay, Western blotting, and VEGF activity assay were carried out to determine the curcumin, EF-31 and UBS-109 role in angiogenesis. A subcutaneous xenograft mouse model was used to evaluate the in vivo effects of curcumin analogues. Results: Conditioned medium from HCT-116 or H-T29 cells exposed to curcumin, EF-31 and UBS-109 in vitro significantly blocked HUVEC tube assembly in comparison to control. In vivo, EF-31 and UBS-109 blocked the vascularization of subcutaneous matrigel plugs and the growth of CRC xenografts. We observed significant inhibition of VEGF synthesis and secretion in both colon cell lines treated with curcumin, EF-31 and UBS-109 in concert with the loss of HIF-1α expression, of which transcriptionally regulated by NF-κB. Similar effects were observed in tumors from animals treated with EF-31 and UBS-109. Further, EF-31 and UBS-109 treatment significantly decreased the tumor growth compared to untreated tumors. These results suggesting that curcumin, EF-31 and UBS-109 inhibits VEGF production in part through the degradation of HIF-1α and increased the cytoplasmic accumulation of NF-κB. Conclusion: Taken together, destabilization of HIF-1α and inhibition of NF-κB from cytoplasm to nuclear translocation may be important contributing factors to the antiangiogenic action of curcumin, EF-31 and UBS-109 in CRC. Note: This abstract was not presented at the meeting. Citation Format: Ganji Purnachandra Nagaraju, Mamoru Shoji, Bassel El Rayes. Targeting NF-κB by the curcumin and its analogs EF-31 and UBS-109 decreases growth and angiogenesis of colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4166. doi:10.1158/1538-7445.AM2015-4166

Therapeutic manipulation of angiogenesis with miR-27b.

BackgroundMultiple studies demonstrated pro-angiogenic effects of microRNA (miR)-27b. Its targets include Notch ligand Dll4, Sprouty (Spry)-2, PPARγ and Semaphorin (SEMA) 6A. miR-27 effects in the heart are context-dependent: although it is necessary for ventricular maturation, targeted overexpression in cardiomyocytes causes hypertrophy and dysfunction during development. Despite significant recent advances, therapeutic potential of miR-27b in cardiovascular disease and its effects in adult heart remain unexplored. Here, we assessed the therapeutic potential of miR-27b mimics and inhibitors in rodent models of ischemic disease and cancer.MethodsWe have used a number of models to demonstrate the effects of miR-27b mimicry and inhibition in vivo, including subcutaneous Matrigel plug assay, mouse models of hind limb ischemia and myocardial infarction and subcutaneous Lewis Lung carcinoma.ResultsUsing mouse model of myocardial infarction due to the coronary artery ligation, we showed that miR-27b mimic had overall beneficial effects, including increased vascularization, decreased fibrosis and increased ejection fraction. In mouse model of critical limb ischemia, miR-27b mimic also improved tissue re-vascularization and perfusion. In both models, miR-27b mimic clearly decreased macrophage recruitment to the site of hypoxic injury. In contrast, miR-27b increased the recruitment of bone marrow derived cells to the neovasculature, as was shown using mice reconstituted with fluorescence-tagged bone marrow. These effects were due, at least in part, to the decreased expression of Dll4, PPARγ and IL10. In contrast, blocking miR-27b significantly decreased vascularization and reduced growth of subcutaneous tumors and decreased BMDCs recruitment to the tumor vasculature.ConclusionsOur study demonstrates the utility of manipulating miR-27b levels in the treatment of cardiovascular disease and cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s13221-015-0031-1) contains supplementary material, which is available to authorized users.

Antiangiogenic effects of a novel synthetic curcumin analogue in pancreatic cancer

Hypoxia-inducible factors (HIFs) and NF-κB play essential roles in cancer cell growth and metastasis by promoting angiogenesis. Heat shock protein 90 (Hsp90) serves as a regulator of HIF-1α and NF-κB protein. We hypothesized that curcumin and its analogues EF31 and UBS109 would disrupt angiogenesis in pancreatic cancer (PC) through modulation of HIF-1α and NF-κB. Conditioned medium from MIA PaCa-2 or PANC-1 cells exposed to curcumin and its analogues in vitro significantly impaired angiogenesis in an egg CAM assay and blocked HUVEC tube assembly in comparison to untreated cell medium. In vivo, EF31 and UBS109 blocked the vascularization of subcutaneous matrigel plugs developed by MIA PaCa-2 in mice. Significant inhibition of VEGF, angiopoietin 1, angiopoietin 2, platelet derived growth factor, COX-2, and TGFβ secretion was observed in PC cell lines treated with UBS109, EF31 or curcumin. Treatment with UBS109, EF31 or curcumin inhibited HSP90, NF-κB, and HIF-1α transcription in PC cell lines. UBS109 and EF31 inhibited HSP90 and HIF-1α expression even when elevated due to NF-κB (p65) overexpression. Finally, we demonstrate for the first time that curcumin analogues EF31 and UBS109 induce the downregulation of HIF-1α, Hsp90, COX-2 and VEGF in tumor samples from xenograft models compared to untreated xenografts. Altogether, these results suggest that UBS109 and EF31 are potent curcumin analogues with antiangiogenic activities.

Monitoring functionality and morphology of vasculature recruited by factors secreted by fast-growing tumor-generating cells.

The subcutaneous matrigel plug assay in mice is a method of choice for the in vivo evaluation of pro- and anti-angiogenic factors. In this method, desired factors are introduced into cold-liquid ECM-mimic gel which, after subcutaneous injection, solidifies to form an environment mimicking the cancer milieu. This matrix permits the penetration of host cells, such as endothelial cells, and therefore, the formation of vasculature. Herein we propose a new modified matrigel plug assay, which can be exploited to illustrate the angiogenic potential of a pool of factors secreted by cancer cells, as opposed to a specific factor (e.g., bFGF and VEGF) or agent. The plug containing ECM-mimic gel is utilized to introduce the host (i.e., mouse) with a pool of factors secreted to the C.M. of fast-growing tumor-generating glioblastoma cells. We have previously described an extensive comparison of the angiogenic potential of U-87 MG human glioblastoma and its dormant-derived clone, in this system model, showing induced angiogenesis in the U-87 MG parental cells. The C.M. is prepared by filtering collected media from confluent tissue culture plates of either cell line following 48 hr incubation. Hence, it contains only factors secreted by the cells, without the cells themselves. Described here is the combination of two imaging modalities, microbubbles contrast-enhanced ultrasound imaging and intravital fibered-confocal endomicroscopy, for an accurate, real-time characterization of the extent, morphology and functionality of newly-formed blood vessels within the plugs.

Bidirectional cross-regulation between the endothelial nitric oxide synthase and β-catenin signalling pathways.

Aimsβ-catenin has been shown to be regulated by inducible nitric oxide synthase (NOS) in endothelial cells. We investigated here whether β-catenin interacts with and regulates endothelial NOS (eNOS) and whether eNOS activation promotes β-catenin signalling.Methods and resultsWe identified β-catenin as a novel eNOS binding protein in human umbilical vein endothelial cells (HUVECs) by mass spectroscopy and western blot analyses of β-catenin and eNOS immunoprecipitates. This was confirmed by in situ proximity ligation assay. eNOS activity, assessed by cGMP production and eNOS phosphorylation (Ser1177), was enhanced in β-catenin−/− mouse pulmonary endothelial cells (MPECs) relative to wild-type MPECs. eNOS activation (using adenosine, salbutamol, thrombin, or histamine), or application of an NO donor (spermine NONOate) or cGMP-analogue (8-bromo-cGMP) caused nuclear translocation of β-catenin in HUVEC as shown by western blotting of nuclear extracts. Exposure to spermine NONOate, 8-bromo-cGMP, or sildenafil (a phosphodiesterase type 5 inhibitor) also increased the expression of β-catenin-dependent transcripts, IL-8, and cyclin D1. Stimulation of wild-type MPECs with basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), spermine NONOate, 8-bromo-cGMP, or sildenafil increased tube length relative to controls in an angiogenesis assay. These responses were abrogated in β-catenin−/− MPECs, with the exception of that to bFGF which is NO-independent. In C57BL/6 mice, subcutaneous VEGF-supplemented Matrigel plugs containing β-catenin−/− MPECs exhibited reduced angiogenesis compared with plugs containing wild-type MPECs. Angiogenesis was not altered in bFGF-supplemented Matrigel.ConclusionThese data reveal bidirectional cross-talk and regulation between the NO-cGMP and β-catenin signalling pathways.

Abstract 81: Novel Adult Endothelial Hierarchy Defined by Endovascular Progenitor Reexpression of SOX18

Introduction: During adult life, formation of new blood vessels in response to insults or physiological signals is thought almost exclusively to result from the sprouting and extension of existing vessels defined as angiogenesis. An alternate proposal for de novo vascularization relates to endothelial progenitors and their ability to assemble the intimal layers of mature vessels. However, the cell lineage and possible hierarchy of such precursors remains controversial. We here aimed to define endothelial progenitors in vivo in situations of neo-vessel formation in adult mice. Methods and Results: Based on protein expression levels of markers CD31 and VEGFR2 using flow cytometry, three populations of endothelial cells could be identified among VECAD+CD34+CD45- cells in a variety of angiogenic situations such as wound healing, tumours, placental development, or in subcutaneous Matrigel plugs. Lineage tracing based on sox18 re-expression using a sox18CreER/Rosa-YFP reporter strategy demonstrated that the CD31loVEGFR2- endothelial population was indeed an endovascular progenitor (EVP) of an intermediate CD31intVEGFR2- transit amplifying and a definitive differentiated CD31hiVEGFR2hi population. Loss of SOX18, in a dominant-negative mouse model, did not affect levels of EVP populations in vivo, but depleted both the intermediate and definitive populations. Only the sorted CD31loVEGFR2- as opposed to the other two endothelial populations could form colonies in vitro and engraft in vivo in a Matrigel plug assay. Conclusions: These results define and characterize an in vivo endothelial hierarchy and suggest a prominent role for vessel resident EVP populations in situations of neo-vessel formation. This data opens the medium for new perspectives in modulating blood vessel formation.

25 Nitric Oxide-cGMP Signalling Promotes B-Catenin Nuclear Translocation and Transcriptional Activity in Endothelial Cells

Nitric oxide (NO) derived from endothelial NO synthase (eNOS) exerts cardioprotective effects. eNOS binds to a number of proteins that regulate its function. Using mass spectroscopy to study eNOS immunoprecipitated...

Anti‐angiogenic effects of curcumin and its novel analogs EF‐31 and UBS‐109 in colorectal cancer

Hypoxia‐inducible factors (HIFs) play essential roles in cancer cell growth and metastasis by stimulating angiogenesis. Curcumin inhibits the activity several oncogenic transcriptional factors including HIF‐1á, thus we investigated whether curcumin and its analogs EF‐31 and UBS‐109, could disrupt angiogenesis using colorectal cancer cells (CRC). HCT‐116 and HT‐29 cells were used in these experiments. HUVEC tube formation assay, Matrigel plug assay, Western blotting, QRT‐PCR, and VEGF activity assay were carried out to determine the curcumin, EF‐31 and UBS‐109 role in angiogenesis. Conditioned medium from HCT116 or HT29 cells exposed to curcumin, EF‐31 and UBS‐109 in vitro significantly blocked HUVEC tube assembly in comparison to control. In vivo, Curcumin, EF‐31 and UBS‐109 blocked the vascularization of subcutaneous matrigel plugs and the growth of CRC xenografts. We observed significant inhibition of VEGF synthesis and secretion in both colon cell lines treated with curcumin, EF‐31 and UBS‐109 in concert with the loss of HIF‐1á expression, of which transcriptionally regulate VEGF. These results suggesting that curcumin, EF‐31 and UBS‐109 inhibits VEGF production in part through the degradation of HIF‐1á. Taken together, destabilization of HIF‐1á may be important contributing factors to the antiangiogenic action of curcumin, EF‐31 and UBS‐109 in CRC.