CAM Assay Research Articles

Anti-proliferative and anti-angiogenic activities of ion-channel modulators: In-ovo, in-vitro and in-vivo study

ObjectiveAngiogenesis is the development of new blood vessels. The ion channels on endothelium play a vital action in cell proliferation and so in the related angiogenesis. We aimed to investigate the anti-angiogenic effects of Mefloquine (Cl− channel blocker) and 4-Aminopyridine (K+ channel blocker). MethodsThe anti-angiogenic activities of Mefloquine and 4-Aminopyridine (4-AP) were investigated by in-vivo (sponge implantation method), in-vitro (aortic ring assay) and in-ovo (CAM, Chick Chorioallantoic membrane) methods. The standard antiangiogenic drug used was Bevacizumab. ResultsIn the CAM assay, both the ion channel blockers exhibited noticeable antiangiogenic activity at the concentrations of 10−5 M and 10−4 M where they significantly exhibited ant proliferative activity by inhibiting the new blood vessel formation. For the further confirmation anti-angiogenic activity was evaluated in vitro and in vivo. In Rat aortic ring assay reduction in the area of sprouts were observed with 40 μM of 4-AP and 7 μM of Mefloquine. A significant reduction in weight of sponges, number of blood vessels formed and hemoglobin content were observed at 4.2 mg/kg of 4-AP and 20 mg/kg and 30 mg/kg of Mefloquine. ConclusionsThese scientific findings indicate the use of Mefloquine and 4-Aminopyridine in pathological situations involving excessive angiogenesis. Negative regulation of cell volume, cell migration and proliferation of blood vessels may be the underlying molecular mechanisms.

Riluzole: a potential therapeutic intervention in human brain tumor stem-like cells.

A small subpopulation of tumor stem-like cells has the capacity to initiate tumors and mediate radio- and chemoresistance in diverse cancers hence also in glioblastoma (GBM). It has been reported that this capacity of tumor initiation in the brain is mainly dependent on the body’s nutrient supply. This population of so-called brain tumor initiating or brain tumor stem-like cells (BTSCs) is able to extract nutrients like glucose with a higher affinity. Riluzole, a drug approved for treating amyotrophic lateral sclerosis (ALS), was reported to possess anticancer properties, affecting the glutamate metabolism. We report that riluzole treatment inhibits the growth of brain tumor stem-like cells enriched cultures isolated from two human glioblastomas. The effects of riluzole on these cells were associated with an inhibition of a poor prognostic indicator: glucose transporter 3 (GLUT3). A decrease in GLUT3 is associated with a decrease in the p-Akt/HIF1α pathway. Further, downregulation of the DNA (Cytosine-5-)-methyltransferase 1 (DNMT1) gene that causes hypermethylation of various tumor-suppressor genes and leads to a poor prognosis in GBM, was detected. Two hallmarks of cancer cells—proliferation and cell death—were positively influenced by riluzole treatment. Finally, we observed that riluzole reduced the tumor growth in in vivo CAM assay, suggesting it could be a possible synergistic drug for the treatment of glioblastoma.

In vitro and in vivo evaluation of anti-cancer activity: Shape-dependent properties of TiO2 nanostructures

Cancer is a complex and widespread disease, and it is going to be the first cause of death in the world. Chemotherapy has been used to treat cancer, but it is detrimental to immune cells and known to induce numerous side effects. Therefore it is imperative to develop new drugs for the treatment of cancer without any side effects and toxicity. TiO2 nanomaterials are human safe, cost effective, chemically stable and have numerous biomedical applications. Spherical TiO2 fine particles (TFP), TiO2 nanosquares (TNS) and TiO2 nanotubes (TNT) were developed and evaluated for anti-cancer activity in vitro and in vivo. Our data suggest that these nanostructured materials significantly inhibited proliferation of breast cancer MDAMB 231 cells in in vitro shape dependent manner. In addition, we found that TiO2 nanostructures inhibited the migration and colony formation of breast cancer MDAMB231 cells. More importantly, we found that TNS/TNT/TFP had anti-angiogenic effect in CAM assay and TNT had comparable anti-angiogenic effect with the positive control staurosporine. Additional qRT-PCR data suggest that TiO2 nanostructures induced the upregulation of tumor suppressor genes p53, MDA7, TRAIL and transcription factor STAT3, which suggests the probable mechanism for the anticancer activity of TiO2 nanostructures. Finally, analysis of TEM confirms the dispersion and interaction of nanostructures in the cells. Thus these materials could be potential therapeutic targets for the treatment of cancer.

Studies on wound healing potential of polyherbal formulation using in vitro and in vivo assays

BackgroundThe use of herbal plant extracts in wound healing is known through decades, but it is necessary to provide scientific data through reverse pharmacology. ObjectiveThe aim of the present study is to find the mechanism behind the healing of wounds using in vitro and in vivo assays. Material and methodsThe study was designed to determine proliferation and mobilization of fibroblast and keratinocytes at the site of injury, angiogenesis at the site of healing and reduction in oxidative stress while healing. In our earlier studies it was observed that herbal extract of Vitex negundo L. (VN), Emblica officinalis Gaertn (EO), and Tridax procumbens L. (TP) showed rapid regeneration of skin, wound contraction and collagen synthesis at the site of injury in excision wound model. In the present study the cell mobilization was monitored in the scratch assay on L929 fibroblastic cell line and HaCaT keratinocytes cell line under the influence of aqueous plant extracts and its formulation. This formulation was also assessed for its angiogenic potential using CAM assay. Study was carried out to probe synergistic effect of polyherbal formulation using excision model in rat. ResultsThe formulation was found to contain high amount of flavonoids, tannins and phenols which facilitate wound healing. At 20 μg/ml concentration of formulation, significant increase in tertiary and quaternary vessels were observed due to angiogenic potential of formulation. Formulation at the concentration of 3 μg/ml and 5 μg/ml showed significant mobilization of keratinocytes and fibroblasts respectively at the site of injury. Polyherbal formulation showed rapid regeneration of skin and wound contraction. Biochemical parameters like hydroxyproline, hexosamine and collagen turnover was increased in test drug treated animals as compared to untreated, whereas antioxidants such as catalase and GSH were increased significantly and decreased amount of tissue MDA was observed. ConclusionPolyherbal formulation prepared from the plant extracts accelerates wound healing process by proliferation and mobilization of fibroblast and keratinocytes, and angiogenesis at the site of injury. It also shows fast contraction of wound with its beneficial improvement in tissue biochemical and antioxidant parameters.

Anti-angiogenic activity and phytochemical screening of fruit fractions from Vitex agnus castus

Although the antitumour activity of Vitex agnus castus fruits has been already addressed, no work has yet assessed their anti-angiogenic potential. To this purpose, several extractive fractions of such fruits were tested on zebrafish embrios by EAP assay, so that only the bioactive fractions could be subsequently tested on the chick chorioallantoic membrane by CAM assay. Bioactive fractions were also phytochemically screened to identify those bioactive compounds responsible for anti-angiogenic activity. A marked inhibition of vessel formation was detected only in zebrafish embryos treated with chloroform or ethyl acetate fractions. Considering CAM assay, chloroform fraction induced a strong reduction of microvasculature and haemoglobin content; while lower anti-angiogenic effects of the ethyl acetate fraction were determined. Phytochemical analyses confirmed the presence of several bioactive anti-angiogenic compounds. Overall, obtained preliminary results highlighted a potential anti-angiogenic activity of V. agnus castus fruits.

Dermatopontin augments angiogenesis and modulates the expression of transforming growth factor beta 1 and integrin alpha 3 beta 1 in endothelial cells

Dermatopontin (DPT) is a matricellular protein with cardinal roles in cutaneous wound healing. The protein is also reported to be altered in various anomalies including cancer. The present study is aimed to unravel the role of DPT in angiogenesis which is imperative in many physiological and pathological processes. DPT’s capabilities on promoting angiogenesis were assessed using various in vitro and ex vivo systems. The results indicated that DPT enhances cell motility and induces lamellipodia formation in endothelial cells. Additionally, we noticed that DPT stimulates tube formation in endothelial cells when plated on a matrigel substrate. However, it was observed that DPT had no effect on the proliferation of endothelial cells even at higher concentrations and prolonged treatment periods. Additional experiments on CAM and aortic arch assays apparently depicted that DPT promotes neovascularisation and tube sprouting, thus unraveling its prominent role in angiogenesis. Further, PCR analysis revealed that endothelial cells are devoid of DPT expression, but when exogenously supplied, modulates the expression of transforming growth factor β1 and integrin α3β1 which are reported to have crucial roles in endothelial cell behaviour during angiogenesis. In conclusion, DPT possess vital pro-angiogenic properties and thus retains promising therapeutic values in managing chronic wounds and cancer.

SFRP4 signalling of apoptosis and angiostasis uses nitric oxide-cGMP-permeability axis of endothelium

Nitric oxide (NO) plays a critical role in endothelial functions such as cellular migration, vascular permeability and angiogenesis. Angiogenesis, the formation of new blood vessels from “pre-existing” ones is a carefully regulated process and essential during reproduction, development and wound healing. Previously our lab group reported that Secreted Frizzled-Related Protein 4 (sFRP4) could inhibit angiogenesis in both in vitro and in vivo conditions. sFRP4 belongs to a family of secreted glycoproteins that function as antagonists of the canonical Wnt signalling pathway. Although the pro-apoptotic role of sFRP4 is well discussed in literature, little is known in regards to its anti-angiogenic property. The objective of this study was to elucidate sFRP4 implications in NO biology of the endothelium. Results demonstrate that sFRP4 causes endothelial dysfunction by suppressing NO-cGMP signaling and elevating corresponding ROS levels. The imbalance between NO and ROS levels results in apoptosis and subsequent leakiness of endothelium as confirmed in vivo (Texas red/Annxin - CAM assay) and in vitro (Monolayer permeability assay) conditions. Furthermore utilizing peptides synthesized from the CRD domain of sFRP4, our results showed that while these peptides were able to cause endothelial dysfunctions, they did not cause apoptosis of the endothelial cells. Thereby confirming that sFRP4 can mediate its anti-angiogenic effect independent of its pro-apoptotic property. In conclusion, the current study reports that sFRP4-mediated anti-angiogenesis occurs as a result of impaired NO-cGMP signaling which in turn allow for elevation of redox levels and promotion of apoptosis of endothelial cells.

Torilis japonica extract fraction compound, EGFR-targeted inhibition of cancer abnormal metastasis in A549 lung cancer cells.

The number of patients who die from lung cancer is steadily increasing. According to the 2012 statistics, lung cancer accounts for the highest percentage of death from cancer in both sexes. Many research studies found that lung cancer can be caused not only by smoking but by outdoor pollution, and it leads to over-activation of various surface proteins in cancer cells. The over-activity of epidermal growth factor receptor(EGFR) is implicated as a crucial factor in inducing abnormal metastasis of lung cancer cells. In this study, we investigated the inhibitory effect of Torilisjaponica extract(TJE) major fraction compound in A549 lung cancer cells by inhibiting EGFR activity. We confirmed that inhibitory effect of TJE on the abnormal metastasis using invasion assay and 3D cell culture method, as well as the inhibition of EGFR signaling pathway, co-binding with Stat3 and dimer formation for translocation to the nucleus. We confirmed the EGFR targets inhibition of TJE when compared with EGFR knockdown group using siRNA transfection. The CAM assay confirmed once again the efficacy of the TJE. We suggest that TJE is a new potential reagent for EGFR-targeted therapy and anti-abnormal metastasis in A549 lung cancer cells.

Novel zinc phthalocyanine as a promising photosensitizer for photodynamic treatment of esophageal cancer.

Photodynamic therapy (PDT) has gathered much attention in the field of cancer treatment and is increasingly used as an alternative solution for esophageal cancer therapy. However, there is a constant need for improving the effectiveness and tolerability of the applied photosensitizers(PS). Here, we propose tetra-triethyleneoxysulfonyl substituted zinc phthalocyanine (ZnPc) as a promising PS for photodynamic treatment of esophageal cancer. ZnPc-induced phototoxicity was studied in two human esophageal cancer cell lines: OE-33 (adenocarcinoma) and Kyse-140 (squamous cell carcinoma). In vitro studies focused on the uptake and intracellular distribution of the novel ZnPc as well as on its growth inhibitory potential, reactive oxygen species (ROS) formation and the induction of apoptosis. The chicken chorioallantoic membrane assay (CAM assay) and studies on native Wistar rats were employed to determine the antineoplastic and antiangiogenic activity of ZnPc-PDT as well as the tolerability and safety of non-photoactivated ZnPc in vivo. ZnPc was taken up by cancer cells in a dose- and time-dependent manner and showed a homogeneous cytoplasmic distribution. Photoactivation of ZnPc-loaded (1-10µM) cells led to a dose-dependent growth inhibition of esophageal adenocarcinoma and squamous cell carcinoma cells of >90%. The antiproliferative effect was based on ROS-induced cytotoxicity and the induction of mitochondria-driven apoptosis. In vivo studies on esophageal tumor plaques grown on the CAM revealed pronounced antiangiogenic and antineoplastic effects. ZnPc-PDT caused long-lasting changes in the vascular architecture and a marked reduction of tumor feeding blood vessels. Animal studies confirmed the good tolerability and systemic safety of ZnPc, as no changes in immunological, behavioral and organic parameters could be detected upon treatment with the non-photoactivated ZnPc. Our findings show the extraordinary photoactive potential of the novel ZnPc as a photosensitizer for PDT of esophageal cancer.

Omental adipocytes enhance the invasiveness of gastric cancer cells by oleic acid-induced activation of the PI3K-Akt signaling pathway

A considerable number of patients with advanced gastric cancer have a clear predilection for metastasis to the great omentum, an organ mainly composed of adipose tissue. However, it remains unclear why tumor cells preferentially spread to and progress in the omentum. Here, we used a two-dimensional co-culture system to simulate the crosstalk between adipocytes and gastric cancer cells and showed that after co-culture with isolated omental adipocytes, gastric cancer cells exhibited a significant increase in lipid uptake and enhanced invasiveness. A lipidomic study showed that gastric cancer cells accumulated higher levels of oleic acid during the co-culture. By performing an assay of key enzymes in lipid synthesis, we demonstrated that the increased amount of oleic acid in gastric cancer cells mainly came from the adjacent adipocytes in the co-culture system. Furthermore, our data showed that at a certain concentration range, oleic acid treatment enhanced the invasiveness of gastric cancer cells in vitro and in a CAM assay, through the PI3K/Akt pathway, with the associated increased expression of the key pro-invasion factor MMP-2. Taken together, our results demonstrated that adipocytes may serve as an exogenous source of oleic acid that promotes gastric cancer cell invasion through the PI3K/Akt signaling pathway.

Anti-Invasive and Anti-Proliferative Synergism between Docetaxel and a Polynuclear Pd-Spermine Agent.

The present work is aimed at evaluating the antitumour properties of a Pd(II) dinuclear complex with the biogenic polyamine spermine, by investigating: i) the anti-angiogenic and anti-migration properties of a Pd(II) dinuclear complex with spermine (Pd2Spm); ii) the anti-proliferative activity of Pd2Spm against a triple negative human breast carcinoma (MDA-MB-231); and finally iii) the putative interaction mediated by combination of Pd2Spm with Docetaxel. Anti-invasive (anti-angiogenic and anti-migratory) as well as anti-proliferative capacities were assessed, for different combination schemes and drug exposure times, using the CAM assay and VEGFR2 activity measurement, the MatrigelTM method and the SRB proliferation test. The results thus obtained evidence the ability of Pd2Spm to restrict angiogenesis and cell migration: Pd2Spm induced a marked inhibition of migration (43.8±12.2%), and a higher inhibition of angiogenesis (81.8±4.4% for total length values, at 4 μM) as compared to DTX at the clinical dosage 4x10-2 μM (26.4±14.4%; n = 4 to 11). Combination of Pd2Spm/DTX was more effective as anti-invasive and anti-proliferative than DTX or Pd2Spm in sole administration, which is compatible with the occurrence of synergism: for the anti-angiogenic effect, IC50(Pd2Spm/DTX) = 0.5/0.5x10-2 μM vs IC50(DTX) = 1.7x10-2 μM and IC50(Pd2Spm) = 1.6 μM. In conclusion, the reported effects of Pd2Spm on angiogenesis, migration and proliferation showed that this compound is a promising therapeutic agent against this type of breast cancer. Moreover, combined administration of Pd2Spm and DTX was found to trigger a substantial synergetic effect regarding angiogenesis inhibition as well as anti-migratory and anti-proliferative activities reinforcing the putative use of Pd(II) complexes in chemotherapeutic regimens. This is a significant outcome, aiming at the application of these combined strategies towards metastatic breast cancer (or other type of resistant cancers), justifying further studies that include pre-clinical trials.

Design, synthesis and biological evaluation of novel alkyl diamine linked bivalent β-carbolines as angiogenesis inhibitors

A series of novel alkyl diamine linked bivalent β-carbolines was synthesized and evaluated for antiproliferative activity, inhibition of cell migration and tube formation, and anti-angiogenic activity in vivo. The results showed that most bivalent β-carbolines displayed significant antiproliferative effect against human umbilical vein cell lines EA.HY926. Compound 2s was found to be the most potent antiproliferative agent with IC50 value of 1.06μM against EA.HY926 cell lines. Further investigations on mechanisms of action revealed that compound 2s significantly inhibited EA.HY926 cells migration and tube formation in a dose-dependent manner. Moreover compound 2s exhibited significant angiogenesis inhibitory effects in CAM assay, and the antiangiogenetic potency was comparable with the reference drug Endostar (30μM).

Synthesis and biological evaluation of novel alkyl diamine linked bivalent β-carbolines as angiogenesis inhibitors

We have synthesized and evaluated a series of novel alkyl diamine linked bivalent β-carbolines as potent angiogenesis inhibitors. The results demonstrated that most bivalent β-carbolines exhibited significant antiproliferative effects against human umbilical vein cell lines EA.HY926. Compound 4m was found to be the most potent antiproliferative agent with IC50 value of 2.16 μM against EA.HY926 cell lines. Mechanism investigations revealed that compound 4m could significantly inhibit EA.HY926 cells migration and tube formation in a dose-dependent manner. Moreover, compound 4m also showed obvious angiogenesis inhibitory effects in CAM assay, and the antiangiogenetic potency was more potent than the reference drug Endostar. The bivalent β-carbolines might be served as candidates for the development of vascular targeting antitumor drugs.

Synthesis and Biological Evaluation of some 3b-hydroxy-lup-20(29)-en-28-oic Acid Derivatives

Objective: The present study projected to the synthesis of 3b-Hydroxy-lup- 20(29)-en-28-oic acid analogues in order to evaluate their possible biological activity. In addition, the structure–activity relationship is also investigated. Method: BA derivatives were prepared by conjugating 3b-Hydroxy-lup- 20(29)-en-28-oic acid with different amines through carbomyl linkage. Structures of synthesized compounds were elucidated by spectral data. Cytotoxic evaluation was done by CAM assay and MTT assay. Results: Among the synthesized compounds, Compound 7showed a pronounced cytotoxicity in antiangiogenic assay as well as compound ECV-304 cell line. Compound 10 also showed good cytotoxic activity. While compounds 6 and 8 showed moderate activity against A-549 and MCF-7 respectively. Conclusion: It is concluded that synthesized BA analogues are biologically active and developed into useful anticancer agents. Key words: Triterpenoids, Lupenoic acid, Carbomyl Linkage, Anticancer activity, MTT Assay.

Abstract 4413: Thrombospondin-1 is a master regulator of glioblastoma vascularization and infiltration

Abstract Glioblastoma are heterogeneous tumours composed of different subpopulations of cells with different behavioral characteristics. Areas of highly angiogenic cells co-exist with populations of non-angiogenic but highly invasive and infiltrative cells. This heterogeneity is a key clinical challenge in glioma treatment. We used a large scale RNA sequencing approach to investigate the molecular components which differentiate infiltrative from angiogenic cells, in a Patient Derived Xenograft (PDX) mouse model. Our bioinformatic analysis revealed TGFβ1 to be a master regulator of tumor development, and Thrombospondin-1 (Tsp1) to be up regulated in infiltrative areas as compared to angiogenic area. Thrombospondins are known as anti-angiogenic factors, however the full roles of these multi domain proteins in tumor development remain to be elucidated. We found Tsp1 expression to be upregulated in grade IV-GBM and in silico in the GBM mesenchymal subclass. It is expressed not only in tumor cells, but also in tumor blood vessel endothelial cells (ECs). TGFβ1 transcriptionally regulated Tsp1 via Smad1 and Smad3. However, contrary to previous results, we found that Tsp1 was not involved in TGFβ1-activation in tumor cells. We showed that Tsp1 regulates cell migration and invasion both in vitro and in vivo. Inhibition of Tsp1 expression in vivo correlated with increased tumor vascularization in both the chick CAM assay and the PDX mouse model. Anti-angiogenic treatments in the PDX mouse model leads to increased tumor hypoxia and invasive tumor cell behavior, as described in our previous work. In this context, both TGFβ1 and Tsp1 were upregulated in tumor cells. Downregulation of tumor-derived Tsp1 by shRNA in the presence of anti-angiogenic therapy led to reduced tumor growth and invasion in vivo. Finally, peptide-mediated inhibition of Tsp1 activity demonstrated that Tsp1/CD47 interaction is involved in the invasive capacity of GBM cells. Taken together, our data suggest that Tsp1 inhibition may be a promising therapeutic approach to limit tumor infiltration induced by treatment with anti-angiogenic agents. Citation Format: Thomas Daubon, Celine Leon, Kim Clarke, Mathilde Poulet, Hrvoje Miletic, Francesco Falciani, Rolf Bjerkvig, Andreas Bikfalvi. Thrombospondin-1 is a master regulator of glioblastoma vascularization and infiltration. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4413.

Triethyl orthoformate covalently cross-linked chitosan-(poly vinyl) alcohol based biodegradable scaffolds with heparin-binding ability for promoting neovascularisation.

There is a need to develop pro-angiogenic biomaterials to promote wound healing and to assist in regenerative medicine. To this end, various growth factors have been exploited which have the potential to promote angiogenesis. However, these are generally expensive and labile which limits their effectiveness. An alternative approach is to immobilize heparin onto biocompatible degradable hydrogels. The heparin in turn will then bind endogenous proangiogenic growth factors to induce formation of new blood vessels.In this study, we continue our development of hydrogels for wound healing purposes by exploring covalently cross-linking chitosan and polyvinyl alcohol hydrogels using triethyl orthoformate. Two concentrations of triethyl orthoformate (4 and 16%) were compared for their effects on the structure of hydrogels - their swelling, pore size, and rate of degradation and for their ability to support the growth of cells and for their heparin-binding capacity and their effects on angiogenesis in a chick chorioallantoic membrane assay.Hydrogels formed with 4 or 16% both triethyl orthoformate cross-linker were equally cyto-compatible. Hydrogels formed with 4% triethyl orthoformate absorbed slightly more water than those made with 16% triethyl orthoformate and broke down slightly faster than non-cross-linked hydrogels. When soaked in heparin the hydrogel formed with 16% triethyl orthoformate showed more blood vessel formation in the CAM assay than that formed with 4% triethyl orthoformate.

Targeted delivery of quercetin loaded mesoporous silica nanoparticles to the breast cancer cells

BackgroundMesoporous silica nanoparticles (MSNs) have been promising vehicles for drug delivery. Quercetin (Q), a natural flavonoid, has been reported to have many useful effects. However, poor water solubility as well as less bioavailability has confined its use as a suitable anti-cancer drug. Therefore, profound approach is required to overcome these drawbacks. MethodsWe have synthesized folic acid (FA) armed mesoporous silica nanoparticles (MSN-FA-Q) loaded with quercetin and then characterized it by DLS, SEM, TEM and FTIR. MTT, confocal microscopy, flow cytometry, scratch assay and immunoblotting were employed to assess the cell viability, cellular uptake, cell cycle arrest, apoptosis, wound healing and the expression levels of different signalling molecules in breast adenocarcinoma cells. Nanoparticle distribution was investigated by using ex vivo optical imaging and CAM assay was employed to assess tumor regression. ResultsMSN-FA-Q facilitates higher cellular uptake and allows more drug bioavailability to the breast cancer cells with over-expressed folate receptors. Our experimental results suggest that the newly synthesized MSN-FA-Q nanostructure caused cell cycle arrest and apoptosis in breast cancer cells through the regulation of Akt & Bax signalling pathways. Besides, we also observed that MSN-FA-Q has a concurrent anti-migratory role as well. ConclusionThis uniquely engineered quercetin loaded mesoporous silica nanoparticle ensures a targeted delivery with enhanced bioavailability. General significanceEffective targeted therapeutic strategy against breast cancer cells.

Pigment epithelium-derived factor (PEDF): a novel trophoblast-derived factor limiting feto-placental angiogenesis in late pregnancy.

The rapidly expanding feto-placental vasculature needs tight control by paracrine and endocrine mechanisms. Here, we focused on paracrine influence by trophoblast, the placental epithelium. We aimed to identify differences in regulation of feto-placental angiogenesis in early versus late pregnancy. To this end, the effect of conditioned media (CM) from early and late pregnancy human trophoblast was tested on network formation, migration and proliferation of human feto-placental endothelial cells. Only CM of late pregnancy trophoblast reduced network formation and migration. Screening of trophoblast transcriptome for anti-angiogenic candidates identified pigment epithelium-derived factor (PEDF) with higher expression and protein secretion in late pregnancy trophoblast. Addition of a PEDF-neutralizing antibody restored the anti-angiogenic effect of CM from late pregnancy trophoblast. Notably, human recombinant PEDF reduced network formation only in combination with VEGF. Also in the CAM assay, the combination of PEDF with VEGF reduced branching of vessels below control levels. Analysis of phosphorylation of ERK1/2 and FAK, two key players in VEGF-induced proliferation and migration, revealed that PEDF altered VEGF signaling, while PEDF alone did not affect phosphorylation of ERK1/2 and FAK. These data suggest that the trophoblast-derived anti-angiogenic molecule PEDF is involved in restricting growth and expansion of the feto-placental endothelium predominantly in late pregnancy and targets to modulate the intracellular effect of VEGF.Electronic supplementary materialThe online version of this article (doi:10.1007/s10456-016-9513-x) contains supplementary material, which is available to authorized users.

L-DOPA as a small molecule surrogate to promote angiogenesis and prevent dexamethasone-induced ischemia

The foreign body response to implantable biosensors has been successfully countered through the use of corticosteroids, such as dexamethasone. However, while controlling inflammation, dexamethasone also decreases angiogenesis, which may lead to delayed analyte readings. The concurrent application of VEGF with dexamethasone increases angiogenesis, but VEGF has physical stability issues and is not cost-effective. The use of l-DOPA, a small molecule drug shown to up-regulate VEGF in the Parkinsonian brain, can potentially resolve these issues by substituting for VEGF. In this work, l-DOPA was used for the first time as a pro-angiogenic agent to counteract dexamethasone-induced ischemia. Angiogenesis was modeled using the CAM assay and changes in blood vessel formation were recorded with both manual and digital techniques. As expected, dexamethasone reduced blood vessel formation in the CAM. Application of l-DOPA, on the other hand, increased blood vessel formation when dexamethasone and l-DOPA were administered simultaneously. This novel finding suggests the utility of l-DOPA in the field of implantable medical devices, such as biosensors, as well as tissue engineering applications where both a vascularized tissue environment and control of tissue response is desired.

Vascular disrupting activity of combretastatin analogues

Tubulin binding agents (TBAs) are drugs commonly used in cancer therapy as antimitotics. In the last years it has been described that TBAs, like combretastatin A-4 (CA-4), present also vascular disrupting activity and among its derivatives we identified three analogues endowed with potent microtubule depolymerizing activity, higher than that of the lead compound. In this paper we have investigated the anti-vascular activity of these derivatives. We tested the anti-angiogenic effects in human umbilical endothelial cells (HUVEC) and in vivo in chick chorioallantoic membrane assay (CAM), and in a syngeneic tumor mouse model. The three molecules, compound 1: 1-(3,4,5-trimethoxyphenyl)-5-(4-ethoxyphenyl)-1H-1,2,4-triazole; compound 2: (1-(3,4,5-trimethoxyphenyl)-5-(4-ethoxyphenyl)-1H-tetrazole, compound-3 (4-amino-2-p-tolylaminothiazol-5-yl)-(3,4,5-trimethoxyphenyl)-methanone) showed a moderate effect on the growth of HUVEC cells at concentrations below 200nM. At lower concentrations (5–20nM), in particular compound 2, they induced inhibition of capillary tube formation, inhibition of endothelial cell migration and affected endothelial cell morphology as demonstrated by the alteration of the microfilaments network. Moreover, they also increased permeability of HUVEC cells in a time dependent manner. In addition, compounds 1 and 3, as well as the reference compound CA-4, inhibited VEGF-induced phosphorylation of VE-cadherin and in addition compound 3 prevented the VEGF-induced phosphorylation of FAK. In CAM assay, both compounds 2 and 3 efficiently counteracted the strong angiogenic response induced by bFGF, even at the lowest concentration used (1pmol/egg). Moreover in a syngenic mouse model, compounds 1–3 after a single i.p. injection (30mg/kg), showed a stronger reduction of microvascular density.Altogether our results identified these derivatives as potential new vascular disrupting agents candidates.