A trimethoxy flavonoid isolated from stem extract of Tabebuia chrysantha suppresses angiogenesis in angiosarcoma

OBJECTIVES

This research aimed to evaluate the antiangiogenic activity of isolated flavonoid 4a,5,8,8a-tetrahydro-5-hydroxy-3,7,8-trimethoxy-2-(3,4-dimethoxyphenyl) chromen-4-one (TMF) from Tabebuia chrysantha. STAT3-MMP9 signalling is a signal transduction mechanism that promotes angiogenesis in various cancers.

METHODS

The tumour xenografting chicken embryo chorioallantoic membrane (CAM) model-based ex vivo assay was used to evaluate the activity of TMF. The Western blot, densitometric analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to evaluate the activity of the MMP9. Zebrafish embryos were used to evaluate embryotoxicity, and in vitro free radical scavenging activity of flavonoid was also elucidated.

KEY FINDINGS

This research assessed the high level of STAT3, p-ERK, VEGF-R and MMP9 in the tissue extract of the control group, and also, the suppression of angiogenesis in the treatment groups was due to scavenged ROS and RNS, dephosphorylation of STAT3 and ERK, and suppression of MMP9 gene expression.

CONCLUSION

The isolated flavonoid named TMF from T. chrysantha functions as specific regulators of target proteins of angiosarcoma. The STAT3-MMP9 signalling may be used as an effective prognostic marker of angiosarcoma.

Preliminary studies: the potential anti-angiogenic activities of two Sulawesi Island (Indonesia) propolis and their chemical characterization

Several studies have previously reported propolis, or its constituents, to inhibit tumour angiogenesis. The anti-angiogenic activity of two Indonesian stingless bee propolis extracts from Sulawesi Island on vascular cells were assessed. Sample D01 was obtained from the outer side of bee hives, while D02 was from the inner side of the same hives. The extracts were profiled by using liquid chromatography coupled to high resolution mass spectrometry. The anti-angiogenic capacity was assessed on HUVECs and placenta-derived pericytes by cell viability, multi-channel wound healing, and CoCl₂ based-hypoxia assays. The exact chemical composition has not been confirmed. The most abundant compounds in Indonesian sample D01 seem to be unusual since they do not immediately fall into a clear class. Two of the most abundant compounds have elemental compositions matching actinopyrones. Identification on the basis of elemental composition is not definitive but compounds in D01 are possibly due to unusually modified terpenoids. Sample D02 has abundant compounds which include four related diterpenes with differing degrees of oxygenation and some sesquiterpenes. However, again the profile is unusual. The anti-angiogenic assays demonstrated that D01 elicited a strong cytotoxic effect and a considerable anti-migratory activity on the vascular cells. Although D02 demonstrated a much weaker cytotoxic effect on the cell lines compared to D01, it elicited a substantial protective effect on the pericytes against CoCl₂-induced dropout in an experiment to mimic a micro-environment commonly associated with angiogenesis and tumour growth. These results demonstrate modulatory effects of these propolis samples in vascular cells, which requires further investigation.

LINC00184 silencing inhibits glycolysis and restores mitochondrial oxidative phosphorylation in esophageal cancer through demethylation of PTEN

BACKGROUND

Total lesion glycolysis has been reported to be a satisfactory predictor of survival in patients with locally advanced esophageal cancer (EC). The aim of the present study is to investigate the function of long intergenic non-protein coding RNA 184 (LINC00184) on the EC cell glycolysis and mitochondrial oxidative phosphorylation (OXPHOS).

METHODS

The expression of LINC00184 was determined to be highly expressed and PTEN was poorly expressed in EC tissues and cells by RT-qPCR. In order to evaluate the effects of LINC00184 on cellular process in vitro and in vivo, gain- and loss-of-function approaches were performed to alter the expression of LINC00184 and PTEN in EC cells.

RESULTS

Silencing of LINC00184 was observed to inhibit the proliferation, migration, invasion, colony formation, and glycolysis of EC cells and tumour growth, while the mitochondrial OXPHOS was restored. By recruiting DNMT1, LINC00184 enhanced the promoter methylation of PTEN. Inhibition of PTEN promoter methylation suppressed EC glycolysis, whereas, improved mitochondrial OXPHOS. Mechanically, LINC00184 modulated glycolysis and mitochondrial OXPHOS in EC cells through induction of the Akt phosphorylation. After blockage of Akt signaling pathway by an Akt inhibitor, LY294002, the regulatory effects of LINC00184 on the glycolysis and mitochondrial OXPHOS of EC cells were reversed.

CONCLUSION

Taken together, the LINC00184/PTEN/Akt axis mediates glycolysis and mitochondrial OXPHOS in EC cells. This study highlighted a potential intervention target for treating EC.

Torilin Inhibits Inflammation by Limiting TAK1-Mediated MAP Kinase and NF-κB Activation

Torilin, a sesquiterpene isolated from the fruits of Torilis japonica, has shown antimicrobial, anticancer, and anti-inflammatory properties. However, data on the mechanism of torilin action against inflammation is limited. This study aimed at determining the anti-inflammatory property of torilin in LPS-induced inflammation using in vitro model of inflammation. We examined torilin's effect on expression levels of inflammatory mediators and cytokines in LPS-stimulated RAW 264.7 macrophages. The involvement of NF-kB and AP-1, MAP kinases, and adaptor proteins were assessed. Torilin strongly inhibited LPS-induced NO release, iNOS, PGE₂, COX-2, NF-α, IL-1β, IL-6, and GM-CSF gene and protein expressions. In addition, MAPKs were also suppressed by torilin pretreatment. Involvement of ERK1/2, P38^MAPK, and JNK1/2 was further confirmed by PD98059, SB203580, and SP600125 mediated suppression of iNOS and COX-2 proteins. Furthermore, torilin attenuated NF-kB and AP-1 translocation, DNA binding, and reporter gene transcription. Interestingly, torilin inhibited TAK1 kinase activation with the subsequent suppression of MAPK-mediated JNK, p38, ERK1/2, and AP-1 (ATF-2 and c-jun) activation and IKK-mediated I-κBα degradation, p65/p50 activation, and translocation. Together, the results revealed the suppression of NF-κB and AP-1 regulated inflammatory mediator and cytokine expressions, suggesting the test compound's potential as a candidate anti-inflammatory agent.

Molecular Mechanisms Underlying the Inhibitory Effects of Qingzaojiufei Decoction on Tumor Growth in Lewis Lung Carcinoma

Objective: Qingzaojiufei decoction (QD) is an empirical herbal formula from traditional Chinese medicine that is used for the treatment of lung-related diseases. However, the effect of QD on the growth of lung tumor cells has not been investigated. The aim of this study was to examine the antitumor activity of QD in Lewis lung carcinomas (LLC) in vivo and in vitro, and to elucidate the underlying mechanisms. Methods: The LLC cells were used to assess the antitumor activity of QD by Cell Counting Kit-8 assay in vitro. In vivo, mice were randomly assigned to 5 groups (n = 10/group): the model control (MC) group was intragastrically administered physiological saline (0.9% NaCl) twice daily from day 2 after tumor implantation for 2 weeks. The QD groups were intragastrically administered QD twice daily from 2 weeks before to 2 weeks after tumor implantation for 4 weeks. The mRNA levels were detected by quantitative polymerase chain reaction, the proteins expression was determined by immunohistochemistry or western blotting. Results: Compared with the model group, QD showed inhibition of proliferation of LLC cells and reductions in tumor weight and proliferating cell nuclear antigen protein expression. Furthermore, QD up-regulated p53 mRNA expression, and downregulated c-myc and Bcl-2 mRNA expression, while MMP-9, VEGF, and VEGFR protein expression was suppressed. Phosphorylated ERK1/2 levels were also reduced by QD in a dose-dependent manner. Conclusion: Our findings suggest that QD inhibited lung tumor growth and proliferation, by activation of tumor suppressor genes, inactivation of oncogenes, suppressing the potential for invasion and metastasis, and attenuating angiogenesis. The ERK/VEGF/MMPs signaling pathways may play an important role in QD-induced inhibition of malignant tumor cell proliferation.

Cytotoxicity of chronic exposure to 4 cigarette smoke condensates in 2 cell lines

Tobacco use is the leading preventable cause of death. The cytotoxicity of cigarette smoke condensate (CSC), the particulate fraction of cigarette smoke without the vapor phase, has mostly been tested in short-term in vitro studies lasting from a few hours to a few days. Here, we assessed the toxicity of CSCs from 2 reference cigarettes, 3R4F and CM6, using a primary human small airway epithelial (PSAE) cell line by quantifying adenosine 5'-triphosphate (ATP), 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), total glutathione (reduced glutathione [GSH] + oxidized glutathione [GSSG]), and lactate dehydrogenase (LDH) release over the course of 28 days. The CSCs, 0.3 to 10 μg/mL, promoted cell proliferation at 120 hours of exposure, but demonstrated cytotoxicity at days 14 and 28. Interestingly, CSCs, 0.3 to 3 μg/mL, showed a cell death effect at day 14 but induced cell proliferation at day 28. Consistently, transformation associated with morphological changes began by day 14 and the transformed cells grew dramatically at day 28. The LDH assay appeared to be sensitive for assessing early cell damage, whereas the ATP, MTS, and GSH assays were more suitable for determining later stage CSCs-induced cytotoxicity. The ATP assay showed greater sensitivity than the MTS and GSH assays. We also assessed the toxicity of CSCs in an human Telomerase Reverse Transcriptase (hTERT)-immortalized Barrett esophagus cell line (CP-C). The CP-C cells demonstrated dose- and time-dependent cytotoxicity over the course of 28 days but displayed higher resistance to CSCs than PSAE cells. This study demonstrates that CSCs cause cytotoxicity and induce transformation related to cell resistance and cell invasion properties.

Torilin ameliorates type II collagen-induced arthritis in mouse model of rheumatoid arthritis

Advancements in rheumatoid-arthritis-(RA) therapies have shown considerable progresses in the comprehension of disease. However, the development of new potential agents with relative safety and efficacy continues and natural compounds have been considered as alternatives to identify new entities. Since previous in-vivo data and our in-vitro findings showed that torilin has a strong anti-inflammatory property, we further investigated its effect against collagen-induced-arthritis-(CIA) in mice. CIA-induced DBA/1J mice were treated with torilin or methotrexate (MTX) for 5-weeks. Arthritis severity was evaluated by arthritic score and joint histopathology. Draining lymph node (dLN), joint and peripheral-blood mononuclear-cell (PBMC) counts, and activation/localization of T-/B-lymphocytes, dendritic cells (DCs) and neutrophils were examined by FACS analysis. Serum anti-type-II-collagen-(CII) antibody levels and cultured-splenocyte and serum cytokines were also evaluated. Torilin markedly reduced CIA-induced arthritic score, histopathology and leukocyte counts. Besides, torilin suppressed CIA-activated T-cells including CD3+, CD3+/CD69+, CD8+, CD4+ and CD4+/CD25+ in dLNs or joints. It also modified CD19+ or CD20+/CD23+ (B-cells), MHCII+/CD11c+ (DCs) and Gr-1+/CD11b+ (neutrophil) subpopulations. It further depressed total anti-CII-IgG, anti-CII-IgG1 and anti-CII-IgG2a antibody productions. Moreover, while IFN-γ and IL-10 were not affected, torilin suppressed CIA-induced serum TNF-α, IL-1β and IL-6 levels. Interestingly, torilin also blocked IFN-γ, IL-17 and IL-6 cytokines while it did not affect IL-10 but enhanced IL-4 in splenocytes. These results show that torilin attenuated arthritis severity, modified leukocyte activations in dLNs or joints, and restored serum and splenocyte cytokine imbalances. Torilin may have immunomodulatory and anti-inflammatory properties with the capacity to ameliorate the inflammatory response in CIA-mice.

Jiedu Xiaozheng Yin, a Chinese herbal formula, inhibits tumor angiogenesis via downregulation of VEGF-A and VEGFR-2 expression in vivo and in vitro

Angiogenesis is crucial for cancer growth and metastasis and inhibition of angiogenesis has been recognized to be a promising strategy for the treatment of cancer. Traditional Chinese medicine (TCM) has been used for thousands of years to treat cancer. Jiedu Xiaozheng Yin (JXY), a polyherbal formula of TCM, has been used to treat various tumors in China. However, the mechanism of its anticancer activity has yet to be fully elucidated. Using human umbilical vein endothelial cells (HUVECs), chick chorioallantoic membrane (CAM) and a hepatoma mouse xenograft model, we investigated the underlying molecular mechanisms of ethanol extract of Jiedu Xiaozheng Yin (EE-JXY). EE-JXY treatment significantly inhibited tumor cell growth both in vitro and in the mouse xenograft model (P<0.05). Moreover, EE-JXY reduced tube formation of HUVECs and angiogenesis in the CAM (P<0.01) and microvessel density (MVD) of tumor in vivo (P<0.05). Further studies showed that EE-JXY was able to suppress the expression of vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR-2) in both HepG2 cells and HUVECs (P<0.01) and in tumor (P<0.01). Thus, JXY suppressed tumor growth at least by inhibiting angiogenesis.

Engineering approaches for investigating tumor angiogenesis: exploiting the role of the extracellular matrix

A major paradigm shift in cancer research is the emergence of multidisciplinary approaches to investigate complex cell behaviors, to elucidate regulatory mechanisms and to identify therapeutic targets. Recently, efforts are focused on the engineering of complex in vitro models, which more accurately recapitulate the growth and progression of cancer. These strategies have proven vital for investigating and targeting the events that control tumor angiogenesis. In this review, we explore how the emerging engineering approaches are being used to unlock the complex mechanisms regulating tumor angiogenesis. Emphasis is placed on models using natural and synthetic biomaterials to generate scaffolds mimicking the extracellular matrix, which is known to play a critical role in angiogenesis. While the models presented in this review are revolutionary, improvements are still necessary and concepts for advancing and perfecting engineering approaches for modeling tumor angiogenesis are proposed. Overall, the marriage between disparate scientific fields is expected to yield significant improvements in our understanding and treatment of cancer.

Brassinosteroids inhibit in vitro angiogenesis in human endothelial cells

Antiangiogenic activity of the brassinosteroid plant hormones (BRs) and their derivative cholestanon was investigated in human umbilical vein endothelial cells (HUVEC) and in human microvascular endothelial cells (HMEC-1). 24-Epibrassinolide and 28-homocastasterone from group of 21 tested natural BRs inhibited migration of HUVEC cells. Seven tested BRs decreased the number of tubes significantly. Synthetic analogue cholestanon inhibited angiogenesis in vitro more effectively than natural BRs. Because of the similarity of BRs to human steroids, we have also studied interactions of BRs with human steroid receptors. Synthetic BRs cholestanon showed agonistic effects on estrogen-receptor-α, estrogen-receptor-β and androgen receptor. Of the natural BRs, 24-epibrassinolide was found to be a weak antagonist of estrogen-receptor-α (ERα). Our results provide the first evidence that large group of BRs can inhibit in vitro angiogenesis of primary endothelial cells. BRs constitute a novel group of human steroid receptor activators or inhibitors with capacity to inhibit angiogenesis.

D-limonene rich volatile oil from blood oranges inhibits angiogenesis, metastasis and cell death in human colon cancer cells

AIMS

To identify the chemical constituents of volatile oil from blood orange (Citrus sinensis (L) Osbeck) and understand the possible mechanisms of inhibition of colon cancer cell proliferation.

MAIN METHODS

Volatile oil was obtained from blood oranges by hydro-distillation. Nineteen compounds were identified by GC-MS and d-limonene was found to be the major component. The blood orange volatile oil was formulated into an emulsion (BVOE) and examined for its effects on viability of colon cancer cells. In addition, experiments were performed to understand the possible mechanism of proliferation inhibition, angiogenesis and metasasis by BVOE.

KEY FINDINGS

BVOE exhibited dose-dependent inhibition of cell proliferation and induced apoptosis in the colon cancer cells, as confirmed by flow cytometry. Immunoblotting of colon cancer cells treated with BVOE shows dose-dependent induction of Bax/Bcl2) and inhibition of vascular endothelial growth factor (VEGF). Furthermore, treatment of serum starved SW480 and HT-29 cells with 100μg/ml BVOE suggested the inhibition of VEGF and markers associated with inhibition of angiogenesis. The antiangiogenic activity of BVOE was also confirmed by inhibition of in vitro tube formation in human umbilical vein endothelial cells. Dose-dependent anti-metastasis activity and blockage of vascular endothelial growth factor receptor 1 (VEGFR1) binding following treatment with BVOE were confirmed by cell migration assays and immunoblots to detect decreased expression of matrix metalloproteinases (MMP-9).

SIGNIFICANCE

The results of this study provide persuasive evidence of the apoptotic and anti-angiogenesis potential of BVOE in colon cancer cells. The extent of induction of apoptosis and inhibition of angiogenesis suggest that BVOE may offer great potential for prevention of cancer and may be appropriate for further studies.

Concomitant consumption of marijuana, alcohol and tobacco in oral squamous cell carcinoma development and progression: recent advances and challenges

Oral squamous cell carcinoma (OSCC) corresponds to 95% of all malignant tumours of the mouth. The association between alcohol and tobacco is the major risk factor for this disease, increasing the chances for the development of OSCC by 35-fold. The plant, Cannabis sativa is smoked as cigarettes or blunts and is commonly used in association with tobacco and alcohol. Any type of smoking habit exposes individuals to a wide range of carcinogens or pro-carcinogens, such as polycyclic aromatic hydrocarbons, as well as some ethanol derived substances such as acetaldehyde (AA), and all are genotoxic in the same way. In addition, ethanol acts in the oral mucosa as a solvent and therefore increases the cellular membrane permeability to carcinogens. Carcinogens found in tobacco are also concentrated in marijuana, but the latter also contains high levels of cannabinoids, bioactive compounds responsible for several effects such as euphoria and analgesia. However, Δ(9)-tetrahydrocannabinol (Δ(9)-THC), the major psychotropic cannabinoid found in plants, causes a reduction of cellular metabolism and induction of apoptosis, both of which are anti-neoplastic properties. Apart from limited epidemiologic and experimental data, the effects of concomitant chronic exposure to marijuana (or Δ(9)-THC), tobacco and alcohol in OSCC development and progression is poorly known. This paper reviews the most recent findings on the effects of marijuana over cellular proliferation, as well as in the risk for OSCC, with emphasis on its interaction with tobacco and ethanol consumption.

Insulin-like growth factor binding protein-3 suppresses vascular endothelial growth factor expression and tumor angiogenesis in head and neck squamous cell carcinoma

Angiogenesis, the process by which new blood vessels are recruited to existing ones, is essential for tumor development. Insulin-like growth factor (IGF) binding protein-3 (IGFBP-3), which modulates bioavailability of IGF, has been studied for its potential role in angiogenesis during tissue regeneration and cancer development. In this study, we assessed the role of IGFBP-3 in tumor angiogenesis in head and neck squamous cell carcinoma (HNSCC) and human umbilical vein endothelial cells (HUVECs) using adenoviral (Ad-BP3) and recombinant (rBP3) IGFBP-3. Using an in vivo orthotopic tongue tumor model, we confirmed that both Ad-BP3 and rBP3 suppress the growth of UMSCC38 HNSCC cells in vivo. Ad-BP3 inhibited vascularization in tongue tumors and chorio-allantoic membrane, and suppressed angiogenesis-stimulating activities in UMSCC38 cells. In HUVECs, Ad-BP3 decreased migration, invasion, and tube formation. rBP3 also suppressed production of vascular endothelial growth factor (VEGF) in HUVECs and UMSCC38 cells. IGFBP-3-GGG, a mutant IGFBP-3 with loss of IGF binding capacity, suppressed VEGF production. In addition, we found that IGFBP-3 suppressed VEGF expression, even in mouse embryonic fibroblasts from an IGF-1R-null mouse. Finally, we demonstrated that IGFBP-3-GGG inhibits tumor angiogenesis and growth to the same degree as wild-type IGFBP-3. Taken together, these results support the hypothesis that IGFBP-3 has anti-angiogenic activity in HNSCC, at least in part due to IGF-independent suppression of VEGF production from vascular endothelial cells and cancer cells.

Angiogenic Effects of the Extracts from Chinese Herbs: Angelica and ChuanXiong

Angelica and ChuanXiong are used to cure ischemic heart disease in China. Previous studies found that these two herbs could increase myocardial blood flow, oxygen-supply and keep myocardial oxygen balance, etc. However, the mechanisms of angiogenic effects of these two herbs are not well-known. The purpose of this study was to assess the effects of Angelica and ChuanXiong on vascular endothelial growth factor (VEGF) expression in rat myocardial infarction, on endothelial cell proliferation and quantity of vessels on chick embryo chorioallantoic membrane (CAM). In this study, rats were divided randomly into either pre-treatment or acute-treatment group and sacrificed at the end of the treatments. VEGF expression using Western blot analysis was significantly increased in the groups pre-treated with ChuanXiong and Angelica when compared to the control group ( p < 0.05). There was significant increase in VEGF expression in the rats treated acutely with Angelica ( p < 0.05). In the contrary, the rats treated with ChuanXiong showed a decrease in VEGF expression when compared to the acute-treatment control group ( p < 0.05). Similar results were observed in immunohistochemistry of VEGF expression in the myocardia. Our study also demonstrated that these two herbs significantly enhanced endothelial cell proliferation ( p < 0.05) and revascularity in CAM ( p < 0.05). The data showed that Angelica and ChuanXiong could affect VEGF expression in rat myocardial infarction, promote endothelial cell proliferation and stimulate quantity of vessels on CAM model. The results suggest that Angelica and ChuanXiong have angiogenic effects, and may provide some mechanisms for the treatment of myocardial infarction and peripheral ischemia.

Anti-angiogenic and anti-inflammatory properties of kahweol, a coffee diterpene

Background

Epidemiological studies have shown that unfiltered coffee consumption is associated with a low incidence of cancer. This study aims to identify the effects of kahweol, an antioxidant diterpene contained in unfiltered coffee, on angiogenesis and key inflammatory molecules.

Methodology/Principal Findings

The experimental procedures included in vivo angiogenesis assays (both the chicken and quail choriallantoic membrane assay and the angiogenesis assay with fluorescent zebrafish), the ex vivo mouse aortic ring assay and the in vitro analysis of the effects of treatment of human endothelial cells with kahweol in cell growth, cell viability, cell migration and zymographic assays, as well as the tube formation assay on Matrigel. Additionally, two inflammation markers were determined, namely, the expression levels of cyclooxygenase 2 and the levels of secreted monocyte chemoattractant protein-1. We show for the first time that kahweol is an anti-angiogenic compound with inhibitory effects in two in vivo and one ex vivo angiogenesis models, with effects on specific steps of the angiogenic process: endothelial cell proliferation, migration, invasion and tube formation on Matrigel. We also demonstrate the inhibitory effect of kahweol on the endothelial cell potential to remodel extracellular matrix by targeting two key molecules involved in the process, MMP-2 and uPA. Finally, the anti-inflammatory potential of this compound is demonstrated by its inhibition of both COX-2 expression and MCP-1 secretion in endothelial cells.

Conclusion/Significance

Taken together, our data indicate that, indeed, kahweol behaves as an anti-inflammatory and anti-angiogenic compound with potential use in antitumoral therapies. These data may contribute to the explanation of the reported antitumoral effects of kahweol, including the recent epidemiological meta-analysis showing that drinking coffee could decrease the risk of certain cancers.

The Chick Embryo Chorioallantoic Membrane as an In Vivo Assay to Study Antiangiogenesis

Antiangiogenesis, e.g., inhibition of blood vessel growth, is being investigated as a way to prevent the growth of tumors and other angiogenesis-dependent diseases. Pharmacological inhibition interferes with the angiogenic cascade or the immature neovasculature with synthetic or semi-synthetic substances, endogenous inhibitors or biological antagonists.The chick embryo chorioallantoic membrane (CAM) is an extraembryonic membrane, which serves as a gas exchange surface and its function is supported by a dense capillary network. Because its extensive vascularization and easy accessibility, CAM has been used to study morphofunctional aspects of the angiogenesis process in vivo and to study the efficacy and mechanism of action of pro- and anti-angiogenic molecules. The fields of application of CAM in the study of antiangiogenesis, including our personal experience, are illustrated in this review article.

Inhibitory effect of Torilis anthriscus on growth of microorganisms

Antibacterial and antifungal activities of aqueous, ethanol and ethyl acetate extract of Torilis anthriscus (L.) Gmel. (Apiaceae) were tested in vitro against ten species of bacteria and five of fungi. Antimicrobial properties were determined by disk diffusion and broth tube dilution method. In the minimum inhibitory concentrations (MICs), the ethanol extract showed the highest activity, followed by the ethyl acetate extract and the aqueous extract against bacterial species, while the extracts were inactive against the tested fungi species. The most active extract was chosen to examine the effects of its combinations with commercial antibiotics by checkerboard method. The obtained results showed that the interactions between ethanol extract/streptomycin and ethanol extract/chloramphenicol were additive and indifferent against the tested human-pathogenic bacteria. Synergism and antagonism were not observed.

Anticancer activities of artemisinin and its bioactive derivatives

Artemisinin, a sesquiterpene lactone derived from the sweet wormwood plant Artemisia annua, and its bioactive derivatives exhibit potent anticancer effects in a variety of human cancer cell model systems. The pleiotropic response in cancer cells includes growth inhibition by cell cycle arrest, apoptosis, inhibition of angiogenesis, disruption of cell migration, and modulation of nuclear receptor responsiveness. These effects of artemisinin and its derivatives result from perturbations of many cellular signalling pathways. This review provides a comprehensive discussion of these cellular responses, and considers the ramifications for the potential development of artemisinin-based compounds in anticancer therapeutic and preventative strategies.

Stilbene glycosides are natural product inhibitors of FGF-2-induced angiogenesis

BACKGROUND

Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with pathological processes, in particular tumour development, and is a target for the development of new therapies. We have investigated the anti-angiogenic potential of two naturally occurring stilbene glycosides (compounds 1 and 2) isolated from the medicinal plant Boswellia papyriferai using large and smallvessel-derived endothelial cells. Compound 1 (trans-4',5'-dihydroxy-3-methoxystilbene-5-O-{alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)}-beta-D-glucopyranoside was the more hydrophilic and inhibited FGF-2-induced proliferation, wound healing, invasion in Matrigel, tube formation and angiogenesis in large and small vessel-derived endothelial cells and also in the chick chorioallantoic membrane assay. Using a binding assay we were able to show compound 1 reduced binding of FGF-2 to fibroblast growth factor receptors-1 and -2. In all cases the concentration of compound 1 which caused 50% inhibition (IC50) was determined. The effect of compound 1 on EGF and VEGF-induced proliferation was also investigated.

RESULTS

Compound 1 inhibited all stages of FGF-2 induced angiogenesis with IC50 values in the range 5.8 +/- 0.18 - 48.90 +/- 0.40 microM but did not inhibit EGF or VEGF-induced angiogenesis. It also inhibited FGF-2 binding to FGF receptor-1 and -2 with IC50 values of 5.37 +/- 1.04 and 9.32 +/- 0.082 muM respectively and with concommotant down-regulation of phosphorylated-ERK-1/-2 expression. Compound 2 was an ineffective inhibitor of angiogenesis despite its structural homology to compound 1.

CONCLUSION

Compound 1 inhibited FGF-2 induced angiogenesis by binding to its cognate receptors and is an addition to the small number of natural product inhibitors of angiogenesis.

New Guaiane Sesquiterpenes from the Fruits of Torilis japonica

Three new guaiane type sesquiterpenes were isolated from the methanolic extract of the fruits of Torilis japonica together with a known compound, torilin (1). Their structures were established as 11-acetoxy-8-isobutyryl-4-guaien-3-one (2), 11-acetoxy-8-methacrylyl-4-guaien-3-one (3), and 11-acetoxy-8-propionyl-4-guaien-3-one (4) by spectroscopic methods. These compounds inhibited lipopolysaccharide (LPS)-induced nitric oxide production in murine macrophages RAW 264.7 cells.

The role of PGP9.5 as a tumor suppressor gene in human cancer

PGP9.5 is a controversial molecule from an oncologic point of view. We recently identified frequent methylation of PGP9.5 gene exclusively in primary head and neck squamous cell carcinoma (HNSCC), suggesting that it could be a tumor suppressor gene. On the other hand, PGP9.5 was reported to be overexpressed in a subset of human cancers presumably due to intrinsic oncogenic properties or as a result of transformation. To demonstrate that PGP9.5 possesses tumor suppressive activity, we examined forced expression by stable transfection of PGP9.5 in 4 HNSCC cell lines. Although all 4 cell lines demonstrated reduced log growth rates in culture after transfection, only 2 cell lines with wild type p53 (011, 022) demonstrated decreased growth in soft agar. In 2 cell lines with mutant p53 (013, 019), we observed no altered growth in soft agar and increased sensitivity to UV irradiation. We then tested for and found a high frequency of promoter methylation in a larger panel of primary tumors including HNSCC, esophageal SCC, gastric, lung, prostate and hepatocellular carcinoma. Our data support the notion that PGP9.5 is a tumor suppressor gene that is inactivated by promoter methylation or gene deletion in several types of human cancers.

Antimicrobial activity of torilin isolated from Torilis japonica fruit against Bacillus subtilis

Torilis japonica fruit has been used in therapeutic antimicrobial treatments in Korea and China since ancient times, but there is still little information on the mechanism underlying this activity. We found that the ethanol extract of T. japonica fruit showed excellent antimicrobial activity against Bacillus subtilis ATCC 6633 spores and vegetative cells. The crude ethanol extract (75%) reduced the spore concentration by 3 log cycles and the vegetative cell concentration to lower than the detection level (reduction in spore concentration by more than 6 orders of magnitude) at a concentration of 1% (w/v). The ethanol extract of T. japonica fruit was fractionated into n-hexane (H) and a water layer. The active antimicrobial compound was isolated and purified from the hexane layer, and identified as torilin (5-[1-(acetyloxy)-1-methylethyl]-3,8-dimethyl-2-oxo-1,2,4,5,6,7,8,8a-octa-hydroazulen-6-yl(2E)-2-methylbut-2-enoate; C(22)H(32)O(5)). Torilin immediately reduced vegetative cells counts by 5 to 6 orders of magnitude, and reduced spores counts by 1 order of magnitude. The integrity of structures such as the inner, middle, and outer layers of the coat and the cortex, protoplast membrane, and core are vital to spores. Torilin functions as a surfactant with hydrophilic and hydrophobic properties related to denaturalization of various proteins. The distortion of coat proteins due to direct binding polar groups of spore coats with hydrophilic groups of torilin may be responsible for the observed rapid inactivation of bacterial spores.

Antiangiogenic versus cytotoxic activity in analogues of aeroplysinin-1

A series of analogues of the potentially angiogenic inhibitor aeroplysinin-1 1 were synthesized and their in vitro antiangiogenic and cytotoxic activities evaluated. In the case of epoxy ketone 6 and azlactone 36 the relationship sprouting inhibition assay/cytotoxicity in BAE cells was enhanced by one order and two orders of magnitude, respectively, with respect to the reference. These results imply more specific antiangiogenic properties for the synthesized derivatives.

Torilin fromTorilis japonica (Houtt.) DC. Blocks hKv1.5 channel current

Torilin was purified from Torilis japonica (Houtt.) DC., and its effects on a rapidly activating delayed rectifier K+ channel (hKv1.5), cloned from human heart and stably expressed in Ltk- cells, as well as the corresponding K+ current (the ultrarapid delayed rectifier, I(KUR)) were assessed in human atrial myocytes. Using the whole cell configuration of the patch-clamp technique, torilin was found to inhibit the hKv1.5 current in time and voltage-dependent manners, with an IC50 value of 2.51+/-0.34 microM at +60 mV. Torilin accelerated the inactivation kinetics of the hKv1.5 channel, and slowed the deactivation kinetics of the hKv1.5 current, resulting in a tail crossover phenomenon. Additionally, torilin inhibited the hKv1.5 current in a use-dependent manner. These results strongly suggest that torilin is a type of open-channel blocker of the hKv1.5 channel.

Gene transfer of pigment epithelium-derived factor suppresses tumor growth and angiogenesis in a hepatoblastoma xenograft model

Normal hepatocytes express pigment epithelium-derived factor (PEDF), an endogenous antiangiogenic factor. We hypothesized that decreased PEDF expression may be one mechanism driving hepatoblastoma growth, and in vivo gene transfer of PEDF could suppress neovascularization and limit tumor growth. PEDF functional activity was determined in vitro using endothelial cell migration assays and in vivo using a subcutaneous tumor model. HUH-6 human hepatoblastoma tumors were treated with hybrid adenoviral/adeno-associated viral expression vectors for PEDF (Hyb-PEDF, n = 4) or beta-galactosidase (Hyb-betagal, n = 4) daily for 4 d. Mitotic figures, microvascular density (MVD), PEDF, and VEGF expression were assessed. Hyb-PEDF treatment inhibited in vivo tumor growth (p < 0.008) and decreased MVD (p < 0.001), the number of mitotic figures (p < 0.001), and VEGF expression when compared with Hyb-betagal-treated tumors. HUH-6 expression of PEDF was dramatically reduced when cultured under hypoxic conditions and also when grown in vivo, and the addition of neutralizing anti-PEDF antibody increased the already high baseline angiogenic activity of the HUH-6 cell secretions in vitro (p < 0.04). PEDF is an important endogenous regulator of the liver vasculature. Augmenting intra-tumoral PEDF levels inhibits tumor growth by reducing angiogenesis and VEGF expression. Potent inhibitors of angiogenesis, such as PEDF, may be an effective alternative treatment for children with hepatoblastoma.

Guaiane sesquiterpenoids from Torilis japonica and their cytotoxic effects on human cancer cell lines

A new compound 2 and two known guaiane-type sesquiterpenoids were isolated from the methylene chloride-soluble fraction of the methanolic extract of the fruits of Torilis japonica (Umbelliferae) through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as torilin (1), 11-acetoxy-8-angeloyloxy-1beta-hydroxy-4-guaien-3-one (1beta-hydroxytorilin, 2), and 11-acetoxy-8-angeloyloxy-1alpha-hydroxy-4-guaien-3-one (1alpha-hydroxytorilin, 3) by spectroscopic analysis. Compounds 1-3 exhibited cytotoxicity against human A549, SK-OV-3, SK-MEL-2, and HCT15 tumor cells.

Microarray expression profiles of angiogenesis-related genes predict tumor cell response to artemisinins

Artemisinin (ARS) and its derivatives are used for the second-line therapy of malaria infections with Plasmodium falciparum and P. vivax. ARSs also reveal profound antitumor activity in vitro and in vivo. In the present investigation, we correlated the mRNA expression data of 89 angiogenesis-related genes obtained by microarray hybridization from the database of the US National Cancer Institute with the 50% growth inhibition concentration values for eight ARSs (ARS, arteether (ARE), artesunate (ART), artemisetene, arteanuine B, dihydroartemisinylester stereoisomers 1 and 2). The constitutive expression of 30 genes correlated significantly with the cellular response to ARSs. By means of hierarchical cluster analysis and cluster image mapping expression, profiles were identified that determined significantly the cellular response to ART, ARE, artemether and dihydroartemisinylester stereoisomer 1. We have exemplarily validated the microarray data of six out of these 30 genes by real-time RT-PCR in seven cell lines. The fact that sensitivity and resistance of tumor cells could be predicted by the mRNA expression of angiogenesis-related genes indicate that ARSs reveal their antitumor effects at least in part by inhibition of tumor angiogenesis. As many chemopreventive drugs exert antiangiogenic features, ARSs might also be chemopreventive in addition to their cytotoxic effects.

Hypericin in the dark inhibits key steps of angiogenesis in vitro

Photoactivated hypericin has a potent cytotoxic effect over a wide range of cells. However, very recently hypericin has been shown to have antitumoral and antimetastatic effects in the dark. The aim of this study was to test whether hypericin in the dark affects angiogenesis. Different in vitro assays were used to study the potential effects of this compound on key steps of angiogenesis, namely, a colorimetric assay of cell proliferation/viability, a tubular formation on Matrigel assay, zymographic assays for gelatinases and urokinase, a wound assay for migration and a fluorometric assay for invasion through Matrigel. In this report, we show for the first time that hypericin kept in the dark inhibits several key steps of the angiogenic process, namely, bovine endothelial cell proliferation, formation of tubular-like structures on Matrigel, migration and invasion, as well as extracellular matrix degrading urokinase.

Anti-angiogenic effect of the seed extract of Benincasa hispida Cogniaux

Benincasa hispida in Korea was used mainly diabetes and diuresis diseases. This study was carried out to evaluate anti-angiogenic effect of the seed extract of Benincasa hispida Cogniaux. Basic fibroblast growth factor (bFGF) is a potent angiogenic factor found in various tumors. In this study, we found that the seed extract of Benincasa hispida Cogniaux decreased bFGF-induced endothelial cell proliferation and tube formation in a dose-dependent manner. Besides, Benincasa hispida seed extract showed no cytotoxicity on HUVECs and normal fibroblast cells. Furthermore, the seed extract of Benincasa hispida showed a potent inhibitory effect on bFGF-induced angiogenesis in vivo. These results suggest that the seed extract of Benincasa hispida inhibits the proliferation of endothelial cells induced by bFGF, which may explain its anti-angiogenic properties.

Hyperforin, a bio-active compound of St. John's Wort, is a new inhibitor of angiogenesis targeting several key steps of the process

Hyperforin, a phloroglucinol derivative found in St. John's wort related mainly to its antidepressant effects, has been reported recently to induce apoptosis in tumour cells and to inhibit cancer invasion and metastasis. We show that hyperforin inhibits angiogenesis in vitro in bovine aortic endothelial cells and in vivo in the chorioallantoic membrane assay. In a variety of experimental systems representing the sequential events of the angiogenic process, hyperforin treatment of endothelial cells resulted in strong inhibitory effects. Hyperforin inhibited the growth of endothelial cells in culture. Capillary tube formation on Matrigel was abrogated completely by addition of hypeforin at the low micromolar range. Hyperforin also exhibited a clear inhibitory effect on the invasive capabilities of endothelial cells. Zymographic assays showed that hyperforin treatment produced a complete inhibition of urokinase and a remarkable inhibition of matrix metalloproteinase 2. Our data indicates that hyperforin is a compound that interferes with key events in angiogenesis, confirming the recent and growing evidence about a potential role of this compound in cancer and metastasis inhibition and making it a promising drug for further evaluation in the treatment of angiogenesis-related pathologies.

Anti-protozoal efficacy of high performance liquid chromatography fractions of Torilis japonica and Sophora flavescens extracts on Neospora caninum and Toxoplasma gondii

We previously reported that alcoholic extracts of Sophora flavescens and Torilis japonica from South Korea demonstrated good efficacy in reducing replication of Toxoplasma gondii and Neospora caninum. To characterize the chemical component associated with anti-protozoal activity, specific fractions were isolated by high performance liquid chromatography (HPLC) and used for in vitro testing. These fractions were evaluated in vitro against T. gondii and N. caninum. Fractions of the herb extracts were serially diluted to final concentrations of 2.850 to 0.356 ng/ml in medium and added to wells containing replicating T. gondii and N. caninum. To determine the ability of each fraction to inhibit parasite proliferation, 3H-uracil incorporation was used to determine parasite replication. In cultures infected with T. gondii, a fraction of T. japonica (TJ2) inhibited T. gondii proliferation by 99.2, 94.4, 88.6 and 27.0% in the range from 2.850 to 0.356 ng/ml. Four fractions of S. flavescens (SF1-SF4) inhibited T. gondii proliferation by 99.6-60.6, 96.9-48.1, 92.3-68.2 and 95.4-52.9% in the range from 2.850 to 0.356 ng/ml. In cultures infected with N. caninum, a fraction of T. japonica (TJ2) inhibited N. caninum proliferation by 98.3, 95.5, 79.7 and 30.6% in the range from 2.850 to 0.356 ng/ml. Four fractions of S. flavescens (SF1-SF4) inhibited N. caninum proliferation by 97.1-25.9, 94.8-35.5, 95.9-33.7 and 95.4-49.4% in the range from 2.850 to 0.356 ng/ml. These fractions of T. japonica and S. flavescens extracts are currently undergoing in vivo evaluation in experimentally infected mice.

Effects of ursolic acid on different steps of the angiogenic process

Ursolic acid is a triterpenoid with pleiotropic biological effects. In this report, we study the effects of ursolic acid on different key steps of angiogenesis. Our results show that ursolic acid is able to inhibit key steps of angiogenesis in vitro, including endothelial cell proliferation, migration, and differentiation. At the same time, it seems to stimulate other key steps of angiogenesis, such as extracellular matrix degradation by MMP-2 and urokinase. Although ursolic acid can inhibit in vivo angiogenesis in the CAM assay, the different signs of the effects it causes on different steps of angiogenesis force one to be cautious concerning its anti-angiogenic potential.

Study of puupehenone and related compounds as inhibitors of angiogenesis

Puupehenone, a sesquiterpene produced by certain sponges, was selected in the course of a blind screening for new potential inhibitors of angiogenesis. In our study, we compare the potential anti-angiogenic activities of puupehenone and another 11 related compounds that were either natural products from marine origin or their synthetic derivatives. The effects of these compounds were determined with cell growth and differentiation assays on bovine aorta endothelial cells. Our results show that these compounds are weak inhibitors to cell growth and are not selective for endothelial cells. However, contrary to cell growth, the differentiation of endothelial cells into tubular structures was completely inhibited by 7 of these compounds at concentrations equal or lower than 3 microM. Three of these compounds, isozonarol, 8-epipuupehedione and 8 epi-9,11-dihydropuupehedione, completely inhibited the in vivo angiogenesis in the CAM assay at doses equal or lower than 30 nmol/egg. Further characterisation showed that these 3 terpenes also inhibited endothelial cell production of urokinase and invasion. One compound (8-epipuupehedione) inhibited endothelial cell migration in a dose-dependent manner. The anti-angiogenic properties of the selected compounds, the simplicity of their structures and the feasibility of their synthesis make them attractive drugs for further evaluation in the treatment of angiogenesis-related pathologies.

Angiogenesis and anti-angiogenesis activity of Chinese medicinal herbal extracts

The aqueous extracts of 24 herbs traditionally used as curing ischemic heart disease in clinic in China were screened for their in vitro angiogenic activity, another twenty-four traditionally used as anti-tumor or anti-inflammatory remedies in China were screened for their in vitro anti-angiogenic activity. The activity of angiogenesis was determined by quantitation of vessels on chick embryo chorioallantoic membrane (CAM) model and cell proliferation of cultured bovine aortic endothelial cells (BAECs). Among the herbal extracts examined, the aqueous extracts of Epimedium sagittatum, Trichosanthes kirilowii and Dalbergia odorifera showed the strong angiogenetic activity both in CAM and BAECs models; and the aqueous extracts of Berberis paraspecta, Catharanthus roseus, Coptis chinensis, Taxus chinensis, Scutellaria baicalensis, Polygonum cuspidatum and Scrophularia ningpoensis elicited significant inhibition at a concentration of 1g dry herb /ml.

Anti-angiogenic and inhibitory activity on inducible nitric oxide production of the mushroom Ganoderma lucidum

Fresh fruit bodies of Ganoderma lucidum were extracted with 70% ethanol at room temperature. The extract (GL) showed significant anti-angiogenic activity, which was detected using a chick embryo chorioallantoic membrane assay. GL significantly inhibited LPS-induced NO production in RAW 264.7 macrophages. These results support the anti-tumor effect of Ganoderma lucidum.

Anti-angiogenic, antioxidant and xanthine oxidase inhibition activities of the mushroom Phellinus linteus

Fruiting bodies of Phellinus linteus were extracted with 70% ethanol at room temperature. The Phellinus linteus extract (PL) showed strong anti-angiogenic activity, which was detected using the chick embryo chorioallantoic membrane (CAM) assay. The in vitro antioxidant activities of PL were evaluated using two different bioassays. PL was comparable to Vitamin C in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH). It also inhibited lipid peroxidation (LPO) in a concentration-dependent manner. These results suggest that antioxidant and anti-angiogenic activities of Phellinus linteus would be partly responsible for its anti-tumor effect.

Anti-protozoal efficacy of medicinal herb extracts against Toxoplasma gondii and Neospora caninum

The purpose of this study was to determine whether alcohol extracts of herbs (Sophora flavescens Aiton, Sinomenium acutum (Thunb.) Rehder and E.H. Wilson, Pulsatilla koreana (Yabe ex Nakai) Nakai ex T. Mori, Ulmus macrocarpa Hance and Torilis japonica (Houtt.) DC.) from South Korea, possess in vitro anti-protozoal activity against cultures of Toxoplasma gondii and Neospora caninum. These herbs have been used as human anti-parasitics in Asian countries for many years. Alcohol extracts of these herbs were serially diluted to final concentrations ranging from 625 to 19.5 ng/ml in media and added to wells containing either T. gondii or N. caninum tachyzoites in equine dermal (ED) cells. Parasite growth inhibition was measured using 3H-uracil incorporation as compared to untreated controls. T. japonica inhibited T. gondii proliferation by 99.3, 95.5, 73.0 and 54.0% in the range from 156 to 19.5 ng/ml, and S. flavescens inhibited T. gondii proliferation by 98.7, 83.0 and 27.2% in the range from 156 to 39 ng/ml. T. japonica inhibited N. caninum proliferation by 97.8, 97.9, 85.3 and 46.4% in the range from 156 to 19.5 ng/ml. S. flavescens inhibited N. caninum proliferation by 98.6, 97.0, 69.5 and 14.0% in the range from 156 to 19.5 ng/ml. Toxicity to host cells was noted when concentrations of T. japonica and S. flavescens exceeded 625 ng/ml. The herb extracts from S. acutum, Pulsatilla koreana, and U. macrocarpa also showed toxicity at higher levels but did not achieve the same inhibition effects at the lower concentrations against T. gondii and N. caninum as T. japonica and S. flavescens.

Suppression of tumor growth by a new glycosaminoglycan isolated from the African giant snail Achatina fulica

Acharan sulfate is a new type of glycosaminoglycan from the giant African snail, Achatina fulica. Acharan sulfate, which has a primary repeating disaccharide structure of alpha-D-N-acetylglucosaminyl-2-O-sulfo-alpha-L-iduronic acid, was studied as a potential antitumor agent in both in vivo and in vitro assays. The antiangiogenic activity of acharan sulfate was evaluated in the chorioallantoic membrane assay and by measuring its effect on the proliferation of calf pulmonary artery endothelial cells. In vivo, a matrigel plug assay showed that acharan sulfate suppressed basic fibroblast growth factor (bFGF)-stimulated angiogenesis and lowered the hemoglobin (Hb) content inside the plug. Acharan sulfate was administered s.c. at two doses for 15 days to C57BL/6 mice implanted with murine Lewis lung carcinoma in the back. It was also administered i.p. to ICR mice bearing sarcoma 180 at a dose of 30 mg/kg. Subcutaneous injection of acharan sulfate at doses of 10 and 30 mg/kg decreased tumor weight and tumor volume by 40% without toxicity or resistance. Intraperitoneal injection of acharan sulfate also decreased tumor weight and volume by 40% in sarcoma 180-bearing mice. These results suggest that the antitumor activity of acharan sulfate may be related to the inhibition of angiogenesis.

Antiangiogenic activity ofGardenia jasminoides fruit

The ethanol extract of gardenia fruit (Gardenia jasminoides Ellis), a Chinese herbal medicine, and its successive hexane, ethyl acetate, n-butanol and aqueous fractions were evaluated for their antiangiogenic activities using a chick chorioallantoic membrane (CAM) assay. The n-butanol fraction was found to be most effective in the antiangiogenic assay.

TNF-related activation-induced cytokine (TRANCE) induces angiogenesis through the activation of Src and phospholipase C (PLC) in human endothelial cells

Angiogenesis is an essential step for many physiological and pathological processes. Tumor necrosis factor (TNF) superfamily cytokines are increasingly recognized as key modulators of angiogenesis. In this study, we tested whether TNF-related activation-induced cytokine (TRANCE), a new member of the TNF superfamily, possesses angiogenic activity in vitro and in vivo. TRANCE stimulated DNA synthesis, chemotactic motility, and capillary-like tube formation in primary cultured human umbilical vein endothelial cells (HUVECs). Both Matrigel plug assay in mice and chick chorioallantoic membrane assay revealed that TRANCE potently induced neovascularization in vivo. TRANCE had no effect on vascular endothelial growth factor (VEGF) expression in HUVECs and TRANCE-induced angiogenic activity was not suppressed by VEGF-neutralizing antibody, implying that TRANCE-induced angiogenesis may be the result of its direct action on endothelial cells. TRANCE evoked a time- and dose-dependent activation of the mitogen-activated protein kinases ERK1/2 and focal adhesion kinase p125(FAK) in HUVECs, which are closely linked to angiogenesis. These signaling events were blocked by the Src inhibitor PP1 or the phospholipase C (PLC) inhibitor. Furthermore, these inhibitors and the Ca(2+) chelator BAPTA-AM suppressed TRANCE-induced HUVEC migration. These results indicate that the angiogenic activity of TRANCE is mediated through the Src-PLC-Ca(2+) signaling cascade upon receptor engagement in endothelial cells, suggesting the role of TRANCE in neovessel formation under physiological and pathological conditions.