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Thread: WARNING: Angiostop is a fraud

  1. #1
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    Default WARNING: Angiostop is a fraud

    I examined the pdf file on presented on angiostop which really only had two citations related to Sea Cucumber (the rest just discuss this benefits of inhibiting angiogenesis which is a red herring really). One is an overview of the nutritional aspects of the Sea Cucumber which I assure you is not a "special sea cucumber." Its main finding is the presence of Chrondrotin in Sea Cucumber which is really nothing special as it's not a particularly potent source...not nearly as potent as which you might find in a supplement from your local vitamin store.

    Here is worst of it my friend

    I have full access to the International Journal of Cancer. The main article citing the benefits of their product DOES NOT EXIST. Like I said I'm going to medical school here in 10 months so I research this stuff for pure enjoyment. Anyway, I went to the May 2005 issue I couldn't find it. In fact this while the charlatan who is pushing this product did get the volume and issue numbers to match up the month doesn't correspond with the issue number he cited. On top of that The page numbers don't match the page numbers of the article. In fact Three articles overlap his ctied pages 843-853. So The Kicker is THERE IS NO ARTICLE ON THE CELL SIGNALING HE IS TALKING ABOUT!!!!!!!!!!!!!

    Here are the articles where his citation should be.

    A high-fat diet generates alterations in nuclear receptor expression: Prevention by vitamin A and links with cyclooxygenase-2 and -catenin (p 839-846)

    yclooxygenase-2 overexpression in MCF-10F human breast epithelial cells inhibits proliferation, apoptosis and differentiation, and causes partial transformation (p 847-852)

    Adam-9 expression and regulation in human skin melanoma and melanoma cell lines (p 853-859)

    This pretty much demonstrates the outright fraud of this company and its claims about this product. At $60 a bottle it's outrageous fraud. I hope Everyone here chooses to save their hard earned money and not buy this bogus supplement.

  2. #2
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    Default

    Once a fraudster, always a fraudster.

  3. #3
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    Default Int J Cancer Article

    Carcinogenesis
    Philinopside a, a novel marine-derived compound possessing dual anti-angiogenic and anti-tumor effects
    Yunguang Tong 1 2, Xiongwen Zhang 1, Fang Tian 1 2, Yanghua Yi 3, Qiangzhi Xu 3, Ling Li 3, Linjiang Tong 1, Liping Lin 1, Jian Ding 1 *
    1Division of Anti-tumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Science, Chinese Academy of Sciences; Shanghai, People's Republic of China
    2Graduate School of Chinese Academy of Sciences, Beijing, People's Republic of China
    3Research Center for Marine Drugs, School of Pharmacy, Second Military Medical University, Shanghai, People's Republic of China

    email: Jian Ding (jding@mail.shcnc.ac.cn)

    *Correspondence to Jian Ding, Division of Anti-tumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Science, Chinese Academy of Sciences; Shanghai 201203, People's Republic of China

    Fax: +86-21-50806722

    Funded by:
    High Tech Research and Development Program; Grant Number: 2002AA2Z346A, 2001AA624100
    Knowledge Innovation Program of Chinese Academy of Sciences; Grant Number: KSCX2-SW-202, No. KSCX2-3-07-8
    National Natural Science Foundation; Grant Number: 30228032

    Keywords
    philinopside A receptor tyrosine kinase tumor angiogenesis


    Abstract

    Philinopside A is a novel sulfated saponin isolated from the sea cucumber, Pentacta quadrangulari. The effects of philinopside A on angiogenesis and tumor growth were assessed in a series of models in vitro and in vivo. Our results demonstrated that philinopside A significantly inhibited the proliferation, migration and tube formation of human microvascular endothelial cells (HMECs) in a dose-dependent manner, with average IC50 values of 1.4 0.17, 0.89 0.23 and 0.98 0.19 M, respectively. Rat aortas culture assay provides a close imitation of in vivo angiogenesis process and 2-10 M philinopside A suppressed the formation of new microvessels in cultured rat aortas. Philinopside A 2-10 nmol/egg obviously inhibited angiogenesis in chick embryo chorioallantoic membrane assay. In addition, philinopside A manifested strong anti-tumor activities both in vitro and in vivo. Through immunofluorescent analysis, we found the compound reduced mouse sarcoma 180 tumor volume by inducing apoptosis of tumor and tumor-associated endothelial cells. An examination of the effects of philinopside A on the angiogenesis-related receptor tyrosine kinases (RTKs) showed that philinopside A broadly inhibited all tested RTKs, including vascular endothelial growth factor (VEGF) receptor, fibroblast growth factor (FGF) receptor-1, platelet-derived growth factor (PDGF) receptor- and epithelial growth factor (EGF) receptor, with IC50 values ranging from 2.6-4.9 M. These results suggest that philinopside A is a promising anti-cancer agent that possesses dual cytotoxic and anti-angiogenic effects that were at least partly due to its inhibitory effects on RTKs. 2004 Wiley-Liss, Inc.



    --------------------------------------------------------------------------------
    Received: 5 August 2004; Accepted: 12 October 2004
    Digital Object Identifier (DOI)

    10.1002/ijc.20804 About DOI


    Article Text



    Angiogenesis, the formation of new blood vessels from the endothelium of existing vasculature, takes place during progression of skin disease, arthritis and blindness as well as in some normal physiological processes, such as wound healing, cycling of the female reproductive system and embryonic development.[1][2][3][4] In addition, angiogenesis is central to tumor growth, progression, invasion and metastasis, making inhibition of this process a potential strategy in cancer treatment.[5][6][7][8][9][10] More than 300 agents have been reported to have anti-angiogenic potentials, and about 40 are currently undergoing clinical trials, including monoclonal antibodies,[9] synthesized small compounds[11] and nature-derived agents. Avastin was approved recently by the Federal Drug Administration (FDA) as the first anti-angiogenic antibody, leading to a renewed surge of interest in the development of new angiogenesis inhibitors.[12]

    Bioprospecting of natural marine products has yielded a considerable number of anti-cancer agents and drug candidates,[13][14] many of which are in preclinical or early clinical developments. One such compound, ET743,[15] seems to be nearing approval, providing further evidence that natural marine products are a rich source of new chemical entities and putative anti-tumor drugs. Accordingly, our lab sought to identify potential angiogenesis inhibitors and anti-cancer compounds from marine resources. Sea cucumber pentacta quadrangularis is widely distributed in the South China Sea and rich in resource. We discovered that philinopside A, a novel compound isolated from the sea cucumber pentacta quadrangularis exhibit significant anti-angiogenic activities and anti-tumor effects both in vitro and in vivo. Receptor tyrosine kinases (RTKs), consisting of vascular endothelial growth factor (VEGF) receptor, fibroblast growth factor (FGF) receptor-1, platelet-derived growth factor (PDGF) receptor- and epithelial growth factor (EGF) receptor etc. play important roles in the process of angiogenesis and tumor development. Further examinations of the underlying mechanisms for these effects showed that the bioactivity of philinopside A might involve the modulation of RTKs. This is the first report of isolation of philinopside A and characterization of its anti-angiogenic and anti-tumor effects.


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    Abbreviations:

    bFGF, basic fibroblast growth factor; CAM, chorioallantoic membrane; EGF, epidermal growth factor; Flk-1, fetal liver kinase-1; HMEC, human microvascular endothelial cell; PDGF, platelet-derived growth factor; PY99, monoclonal PTyr antibody; RTK, receptor tyrosine kinase; SRB, sulforhodamine B; VEGF, vascular endothelial growth factor.

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    Material and Methods



    Isolation and purification of philinopside A
    Specimens of sea cucumber (pentacta quadrangularis) were collected from the South China Sea near Guangdong Province, China. The organisms were identified by Prof. J.R. Fang in the Fujian Institute of Oceanic Research, China. A voucher specimen (reg. No. SA200042) is preserved at the Research Center for Marine Drugs, School of Pharmacy, Second Military Medical University, China.

    By using bioassay-guided (endothelial cell and tumor cell proliferation inhibition) separation, the sea cucumbers (5 kg, dry wt) were defrosted, homogenized by homogenizer and extracted twice with 70% EtOH (2.5 L) for 48 hr continually. The combined EtOH extracts were evaporated at 50C, and the aqueous residue (20 g) was dissolved in H2O (3 L) and the solid material was removed by filtering with Whatman filter paper. The H2O-soluble fraction was passed through a DA101 resin column (60 30 cm) and eluted with distilled water until a negative chloride ion reaction was obtained, followed by elution with 95% EtOH (8 L). The combined EtOH elute was evaporated under reduced pressure to give a glassy material (16 g), that was chromatographed on a Sephadex LH-20 column (3 50 cm) with MeOH/H2O (2:1). The fraction containing saponins was subjected to dry column (2 50 cm) chromatography on Si gel, eluting with CHCl3:MeOH:H2O (7:3:1) (lower phase). Fractions were purified by reversed-phase HPLC (Zobax SBC-18, 60% MeOH) to give the pure philinopside A (123 mg, >98% pure). The chemical structure of philinopside A was determined by using 1H and 13C NMR spectrum, ESI-MS and IR spectrum assay and shown in Figure 1. The pure philinopside A was dissolved in DMSO and diluted to desired concentrations before use, with the concentration of DMSO kept below 0.1% in treated groups.


    Figure 1. Chemical structure of philinopside A.
    [Normal View 13K | Magnified View 41K]



    Other reagents
    Suramin (an angiogenesis inhibitor under Phase III clinical development), the chemotherapeutic agent 5 Fluorouracil (5-FU), and the VEGF and PDGF-BB homodimers were purchased from Sigma (St. Louis, MO). PD153035 (4-(3-bromoanilino)- 6,7dimethoxyquinazoline), a specific inhibitor of EGF receptor tyrosine kinase, was from Calbiochem (Darmstadt, Germany). The fetal liver kinase-1 (Flk-1) inhibitor, SU5416 (3-[(2,4-dimethylpyrrol-5-yl) methylidenyl]-iodolin-2-one), was the kind gift of Dr. F. Nan (National Center for Drug Screening, Shanghai, P.R. China), and basic FGF was kindly provided by Yisheng Pharmaceutical Factory (Zhuhai, China). EGF was purchased from R&D Systems (Minneapolis, MN). Mouse monoclonal anti-phosphotyrosine antibody (PY99) and rabbit polyclonal antibodies against Flk-1, FGFR-1, PDGFR-, and EGFR were purchased from Santa Cruz Biotechnology (Santa Cruz, CA). Matrigel was obtained from Becton Dickinson Labware (Bedford, MA).


    Cell lines and cell culture
    NIH-3T3 cells highly expressing full length Flk-1 protein were the kind gift of Dr. A. Ullrich (Max-Planck-Institute fur Biochimie, Martinsried, Germany) and were cultured in DMEM (Gibco-BRL, Grand Island, NY) containing 200 g/ml G418 (Sigma). Human microvascular endothelial cells (HMECs) were purchased from the American Type Culture Collection (ATCC, Manassas, VA) and maintained in MCDB131 containing 10% FBS, 0.1 ng/ml EGF and 1 mg/ml hydrocortisone. Gastric adenocarcinoma cell line MKN-28 was obtained from the Japanese Foundation for Cancer Research (JFCR) and cultured in 1640 culture medium containing 10% FBS. Colon adenocarcinoma cell line HCT-116, and breast adenocarcinoma cell lines MDA-MB-468 and MCF-7 were obtained from the ATCC and were cultured in 5A, L-15 and MEM media, respectively, containing 10% FBS. Hepatocellular carcinoma cell line BEL-7402, lung adenocarcinoma cell line SPC-A4 and ovarian epithelioid carcinoma cell line HO-8910 were from the Shanghai Institute of Biochemistry and Cell Biology (SIBCB), and were cultured in 1640 culture medium containing 10% FBS. All cells were maintained at 37C in an incubator containing a humidified 5% CO2/95% air atmosphere.


    HMEC proliferation assay
    The effect of philinopside A on the growth of HMECs was measured using the sulforhodamine B (SRB; Sigma) method.[16] Cells were plated in 96-well plates (5 103 cells/90 l/well) and cultured at 37C for 24 hr. Serial dilutions of philinopside A (10 l volumes) in media containing 0.1% DMSO were added to each well, and the plates were incubated at 37C for 72 hr. The cells were fixed by gentle addition of 100 l of cold (4C) 10% trichloroacetic acid to each well, followed by incubation at 4C for 1 hr. The plates were washed 5 times with deionized water, allowed to air dry, and stained by addition of 100 l SRB solution [0.4% SRB (w/v) in 1% acetic acid (v/v)] to each well for 15 min. The plates were washed 5 times with 1% acetic acid to remove unbound dye and were then allowed to air dry. The bound dye in each well was dissolved in 10 mM Tris base (pH 10.5), and the OD at 515 nm was measured with a multi-well spectrophotometer (VERSAmax, Molecular Devices, Sunnyvale CA). The inhibition of proliferation was calculated as [1 - (A515 treated/A515 control)] 100%. The result was also expressed as IC50 (the drug concentration that reduced the absorbance observed in untreated cells by 50%), which was calculated by the Logit method. The mean IC50 was determined from the results of 3 independent tests. The effect of philinopside A on the growth of tumor cells was examined using similar procedures.


    HMEC migration assay
    Migration of HMECs was determined in a transwell Boyden chamber (Corning, NY) containing a polycarbonate filter (pore size = 8 m) coated with 0.2% gelatin.[17] In the standard assay, 0.1 ml of cell suspension (2 105 cells/ml) containing philinopside A or 0.1% DMSO (v/v) was added to the upper compartment of each well. To avoid the diffusion effect, the lower compartment contained 0.6 ml of culture medium supplemented with the same concentration of philinopside A or DMSO. FBS (10%) was used to stimulate migration. After incubation for 8 hr at 37C, the filter was removed and fixed with ethanol. Cells remaining on the upper surface of the filter (non-migrated) were removed by gentle scraping. Cells on the lower surface of the filter (migrated) were stained with eosin and manually counted from 5 random fields. The inhibition of migration was calculated as [1 - (migrated cellstreated/migrated cellscontrol)] 100%.


    HMEC tube formation assay
    A tube formation assay was carried out to determine the effect of philinopside A on angiogenesis in vitro. A 96-well plate coated with 0.1 ml Matrigel (Laminin = 56%, Collagen IV = 31%, Entactin = 8%) per well was allowed to solidify at 37C for 1 hr. Each well was seeded with 1 104 HMECs (0.1 ml) and cultured in medium containing various concentrations of philinopside A or 0.1% DMSO (v/v) for 24 hr. The networks of enclosed tubes were photographed from 5 randomly chosen fields under a microscope (Olympus, IX70, Japan). The total length of the tube structures in each photograph was measured using Adobe Photoshop software.[18] Inhibition of tube formation was calculated as [1 - (tube lengthtreated/tube lengthcontrol)] 100%.


    Rat aorta cultures
    The thoracic aortas of female, 10-week-old Sprague-Dawley rats were dissected into 1 mm-long rings, rinsed 8 times with culture medium, embedded in 100 l Matrigel (Laminin = 56%, Collagen IV = 31%, Entactin = 8%), and incubated in 100 l serum-free endothelial cell basal medium containing 10 g/ml gentamicin, 100 U/ml penicillin, 100 g/ml streptomycin and 0.25 g/ml amphotericin.[19][20] Serial dilutions of philinopside A were added on Day 2, and the sections were cultured for another 4 days, with replacement of the supernatant every 24 hr. Microvessel growth was photographed on Day 6. To confirm the presence of endothelial cells in the microvessels, the rat aorta sections were immunohistochemically stained with rabbit polyclonal antibodies against the endothelial cell-specific marker, CD31 (1:200) (Santa Cruz Biotech, Santa Cruz, CA).


    Chicken chorioallantoic membrane assay
    Groups of 10 fertilized chicken eggs were transferred to an egg incubator (Lyon, Chula Vista, CA) maintained at 37C and 50% humidity and allowed to grow for 9 days. For separation of the chicken chorioallantoic membrane (CAM) from the shell membrane, small holes were drilled in the shell, one at the broad end of the egg where the air sac is located and the other at a position 90 halfway down the length of the egg. The membrane was carefully pushed down from the second hole to detach the CAM from the shell. Gentle suction was applied at the hole located at the broad end of the egg to create a false air sac directly over the CAM, and a 1 cm2 window was removed from the eggshell immediately over the second hole. Filter paper disks (diameter = 0.5 cm) saturated with compounds or 0.1% DMSO (v/v) were placed on areas between pre-existing vessels, and the embryos were further incubated for 48 hr. The neovascular zones under the disks were photographed at 10 magnification under a stereomicroscope (Leica, MS5, Switzerland). Angiogenesis was quantified by counting the number of blood vessel branch points in each photo.


    Tumor growth inhibition assay
    Female KM mice (6-8 weeks of age) were used to study inhibition of tumor growth in vivo. The use of lab animals was in accordance with guidelines of Experimental Animal Association of China (certificate number: SYXK [Shanghai] 2003-0029). Sarcoma 180 cells (2.5 106) were subcutaneously implanted into the axilla of mice on Day 0, and mice were randomly grouped (8 mice/group) on Day 1. Normal saline and dilutions of philinopside A (1, 2, 4 mg/kg, dissolved in normal saline) were delivered intravenously in non-anesthesia state once daily for 7 days. Animals were sacrificed 24 hr after the last administration, and mice and tumor weights were measured. Tumor growth inhibition rates were calculated as follows:







    Tumor angiogenesis inhibition assay
    The sarcoma 180 tumor specimens were fixed in 4% paraformaldehyde in PBS (freshly prepared, pH = 7.4) and paraffin embedded for immunofluorescent analysis. TUNEL analysis was carried out following the protocol of the Apoptosis Detection System (Roche, Basel, Switzerland). The paraffin embedded tissue sections (9 m-thick) were dewaxed by heating at 60C followed by washing in xylene and rehydration through a graded series of ethanol and double distilled water washes. The slides were washed with PBS and permeabilized with 0.1% Triton X-100 and 0.1% sodium citrate (freshly prepared). The samples were then equilibrated, and DNA strand breaks were labeled with fluorescein-12-dUTP by addition of the nucleotide mix and terminal deoxynucleotidyl transferase enzyme. The slides were then washed, and apoptotic cells was detected by fluorescence microscopy. For double staining, TUNEL detection was first carried out as described, and then samples were incubated for 30 min at room temperature with a protein-blocking solution consisting of PBS and 3% bovine serum albumin. Excess blocking solution was removed, and the samples were incubated for 3 hr at 4C with a 1:200 dilution of rabbit anti-CD31 polyclonal antibody (Santa Cruz Biotechnology, Santa Cruz, CA). The samples were then rinsed with PBS and incubated for 60 min at room temperature with the appropriate dilution of Texas Red-conjugated goat anti-rabbit IgG (Vector Laboratories, Burlingame, CA). All fluorescence photographs were taken under a Leica TCS confocal microscope (Leica, Deerfield, IL) and images were analyzed with the Leica TCS SP2 2.5 1104 software.

    Fluorescence intensities were gathered from 3 random fields per slice (from 3 random slices per tumor) and presented as the mean SD. Microvessel density was measured by calculating the fluorescence intensity (FI) of CD31, and the tumor angiogenesis inhibition rate was calculated as follows:







    Cellular RTK autophosphorylation assay
    NIH 3T3 cells overexpressing Flk-1 were plated onto 96-well plates (3 104 cells/well) in DMEM plus 10% FBS and cultured overnight. The medium was removed, and the cells were cultured in DMEM for 24 hr at 37C. Serial dilutions of the various test compounds were added, and the cells were incubated for 1 hr. Phosphorylation was stimulated by the addition of 250 ng/ml human recombinant VEGF. After 5 min at 37C, the cells were washed with PBS and lysed with HNTG (20 mM HEPES [pH = 7.5], 150 mM NaCl, 0.2% Triton X-100 and 10% glycerol) containing 5 mM Na3VO4, 2 mM Na4P2O7 and 5 mM EDTA. The resulting lysates were transferred to 96-well plates precoated with polyclonal anti-Flk-1 antibody and incubated for 2 hr. Tyrosine phosphorylation was detected by sequential incubation with PY99 (1:500), biotinylated anti-mouse antibody (Vector Laboratories) (1:1,000) and horseradish-streptavidin-peroxidase (Vector Laboratories) (1:500), for 1 hr at 37C. After several washes with PBS containing 0.2% Tween-20, the wells were stained with 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) (Roche, Basel, Switzerland). The reaction was stopped by adding an equal volume of 2% (w/v) SDS, and the amount of color development was quantified in a multi-well spectrophotometer at 405 nm.[21] Enzyme-linked immunosorbent assays (ELISA) for PDGFR-, FGFR-1 and EGFR were carried out according to standard procedures,[22] the used cell lines were NIH-3T3, NIH-3T3 and MDA-MB-468, correspondingly. Phosphotyrosine protein was detected as described for the Flk-1 assay.


    Immunoblotting
    NIH-3T3 cells overexpressing Flk-1 were plated onto 6-well plates, allowed to grow to confluence (about 1 106 cells) and starved overnight. Dilutions of the test compound were added and incubated for 30 min at 37C. Flk-1 autophosphorylation was stimulated by the addition of 100 ng/ml VEGF for 5 min. The cells were lysed with HNTG, and the lysates were electrophoresed on 7.5% polyacrylamide gels (electrophoresis buffer: 25 mmol/L Tris, 250 mmol/L glycine, 0.1% [m/V] SDS) at 100 V for 2.5 hr and transferred to nitrocellulose membranes. The membranes were incubated sequentially with mouse anti-phosphotyrosine antibody (1:500) and rabbit anti-Flk-1 antibody (1:1000), and immune complexes were detected after incubation with peroxidase-conjugated anti-mouse or anti-rabbit IgG (Calbiochem, Germany). Immunoblotting experiments for the other tyrosine kinase receptors, PDGFR-, FGFR-1 and EFGR, were carried out according to similar protocols: receptor was stimulated by corresponding growth factors (PDGF-BB for PDGFR-, bFGF for FGFR-1, EGF for EGFR) and cells were harvested and subjected to immunoblotting analysis as described in the Flk-1 assay. The used primary antibodies against each receptor were all diluted by 1:1,000.


    Data analysis
    All results were expressed as mean SD, and statistical significance was assessed by Student's t-test.


    Results



    Philinopside A inhibited HMEC and tumor cell proliferation
    The effect of philinopside A on HMEC growth was examined after 24 and 72 hr incubation. No inhibition of HMEC cell proliferation was observed after treatment with 0.313 M philinopside A for 72 hr or with 0.625 or 1.25 M philinopside A for 24 hr. Treatment with philinopside A at concentrations of 0.625, 1.25, 2.5 and 5 M for 72 hr exerted dose-dependent inhibitory effects, yielding inhibition rates of 9.5, 37.1, 77.9 and 98.7%, respectively with an IC50 of 1.4 0.17 M. Similarly, treatment with 2.5 and 5 M philinopside A for 24 hr suppressed HMEC cell growth, with inhibition rates of 20.9 and 51.2%, respectively (Fig. 2a). In addition, philinopside A also inhibited the proliferation of several tumor cell lines, with IC50 values ranging from 1.5-2.4 M. Importantly, Sarcoma 180, BEL-7402, MCF-7 and HO-8910 tumor cells displayed about 2-fold less sensitivity to philinopside A than did the endothelial HMECs (Fig. 2b).


    Figure 2. Inhibitory effect of philinopside A on HMEC and tumor cell proliferation. (a) HMECs were treated with philinopside A for 24 and 72 hr, respectively, and the effect on cell growth measured using the SRB method. (b) IC50 of philinopside A on HMECs and tumor cells. Each value is the mean SD of 3 independent experiments. *p < 0.01 vs. control.
    [Normal View 10K | Magnified View 33K]



    Philinopside A inhibited HMEC migration
    Endothelial cell migration, which occurs via chemotaxis, is necessary for angiogenesis. To further examine the anti-angiogenic properties of philinopside A, we investigated its effects on HMEC migration. Incubation of control HMECs for 8 hr resulted in a large-scale migration of HMEC cells to the lower side of the filter (Fig. 3a). The migration of HMECs was markedly blocked in a concentration-dependent fashion by philinopside A at concentrations over 0.625 M; philinopside A at concentrations of 0.625, 1.25, 2.5 and 5 M yielded inhibition rates of 31.1, 60.8, 86.1 and 94.1%, respectively (Fig. 3b,c) with an IC50 of 0.89 0.23 M. Furthermore, philinopside A showed no obvious cytotoxic effects on HMECs at concentrations below 1.25 M when applied for 24 hr (Fig. 2a), indicating that inhibition of HMEC cell migration by philinopside A likely occurs in a specific fashion, independent of cytotoxicity.


    Figure 3. Effect of philinopside A on HMEC migration. HMECs seeded in transwell Boyden Chambers were incubated for 8 hr with (a) medium alone or (b) 1.25 M philinopside A. Migrated cells on the lower surface of the filter were stained with eosin and counted manually from five random fields. (c) Overall rate of philinopside A-induced inhibition of HMEC migration. Results are expressed as the mean SD of 3 separate experiments. *p < 0.01 vs. control.
    [Normal View 36K | Magnified View 170K]



    Philinopside A inhibited HMEC tube formation
    In the later stage of angiogenesis, endothelial cells rearrange themselves into tubes that will later form new small blood vessels. Similarly, HMECs incubated on Matrigel for 24 hr differentiate into extensive networks of enclosed tubes (Fig. 4a). We found that exposure to philinopside A at concentrations over 0.313 M resulted in severe disruption of the tube structure, leading to formation of incomplete, sparse tube networks (Fig. 4b). Philinopside A at concentrations of 0.313, 0.625, 1.25, 2.5 and 5 M reduced tube formation by 21, 40.6, 55.5, 72.2 and 95.1%, respectively, compared to the control group (Fig. 4c). The IC50 value of tube formation was 0.98 0.19 M. Philinopside A exhibited no obvious effect on the growth of HMECs at concentrations below 1.25 M when applied for 24 hr, suggesting that the ability of philinopside A to inhibit tube formation is not associated with general cytotoxicity, but is instead a specific effect (Fig. 2a).


    Figure 4. Effect of philinopside A on HMEC tube formation. HMECs seeded in Matrigel-coated 96-well plates were incubated for 24 hr with (a) medium alone or (b) 1.25 M philinopside A. The enclosed networks of tubes were photographed from 5 randomly chosen fields under a microscope. (c) Overall rate of philinopside A-induced inhibition of tube formation. Results are expressed as mean SD of 3 separate experiments. *p < 0.01 vs. control.
    [Normal View 39K | Magnified View 186K]



    Philinopside A inhibited microvessel outgrowth in cultured rat aortas
    To further confirm the effects of philinopside A on angiogenesis, we examined the impact of philinopside A on microvessel outgrowth in an aortic ring-sprouting assay. This ex vivo assay, which mimics the consecutive stages involved in angiogenesis (endothelial cell sprouting, migration and tube formation), closely imitates the angiogenic events observed in vivo. In fact, aortic endothelial cells have sprouted from sections of rat aorta embedded in Matrigel under certain cultivation conditions. We observed that the microvessels initially formed on Days 2 or 3, and subsequently increased in number and length (Fig. 5a). Addition of 5 M of philinopside A resulted in significantly reduced outgrowth and sprouting (Fig. 5b) of endothelial structures that were later identified as microvessels by specific positive staining by the anti-CD31 antibody. The inhibition rates in rat aorta culture assay in the presence of 2, 5, 10 M of philinopside A were 50.5%, 76.4%, and 89%, respectively (Fig. 5c).


    Figure 5. Effect of philinopside A on microvessel outgrowths arising from rat aorta sections. Fresh thoracic aorta samples from Sprague-Dawley rats were sliced into 1 mm-thick sections, which were then embedded in Matrigel and cultured in base endothelial culture medium for 24 hr. Philinopside A was added on Day 2 (a) 0 M philinopside A; (b) 5 M philinopside A and microvessel growth was photographed on Day 6. (c) Overall inhibition rate of philinopside A on rat aorta culture assay. Microvessel sprouts originating from each aortic ring were counted microscopically. Each value is the mean SD of 3 separate experiments.
    [Normal View 41K | Magnified View 197K]



    Philinopside A inhibited angiogenesis in the CAM assay
    The capacity of philinopside A to inhibit vascular development was compared to that of suramin, a well-known angiogenesis inhibitor. The reliable, repeatable CAM assay is the most widely used in vivo test system for evaluating angiogenesis, partially due to its convenience and lack of ethical issues as compared to other in vivo assays. Our results indicated that in the absence of philinopside A, the area of the CAM below the control filter disks showed no alteration in vascular density compared to surrounding tissues, with normal blood vessels branching patterns observed (Fig. 6a). Treatment with 2, 5, 10 nmol/egg philinopside A for 48 hr caused a dramatic, dose-dependent reduction (with the corresponding inhibition rates of 45.5%, 67.7% and 80.1% respectively) in blood vessels and branching patterns (Fig. 6b). Encouragingly, philinopside A (10 nM/egg) showed a much more potent anti-angiogenic activity than 125 nmol/egg suramin (Fig. 6c).


    Figure 6. Effect of philinopside A on CAM. Fertilized eggs were incubated continuously for 9 days, then a window was opened to expose the CAM, philinopside A was added [(a) solvent; (b) 5 nmol/egg philinopside A], the eggs were incubated for another 48 hr and then the treated CAM were harvested and photographed. (c) Overall inhibition rate of philinopside A on CAM. Angiogenesis was quantified by counting the number of blood vessel branch points in each photograph. Each value is the mean SD of 10 eggs. *p <0>0.05
    Philinopside A 2 7 8/8 21.1/26.3 0.97 0.33 46.1 <0.01
    Philinopside A 4 7 8/8 21.3/24.8 0.73 0.09 59.4 <0.01
    5-FU 25 7 8/8 21.0/26.0 1.06 0.54 41.1 <0.01


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    1 Drugs were administrated once daily for 7 days; on Day 8 after implantation of cells, mice were cuthanized, tumor tissues were harvested and weighted, and the tumor growth inhibition rates were calculated.



    Figure 7. Immunofluorescence evaluation of tumor tissues. (a) Apoptosis detection in tumor tissues. Sequential staining for TUNEL and CD31 was carried out in mouse sarcoma 180 tumor tissue sections taken from the PBS-, philinopside A- and 5-FU-treated groups. (b) Effect of philinopside A and 5-FU on apoptosis of tumor cells. The data were gathered from 3 random fields per slice (from 3 random slices per tumor) and are presented as apoptotic cells/field (mean SD). *p < 0.01 vs. control. (c) Effect of philinopside A and 5-FU on apoptosis of tumor associated endothelial cells. The data were gathered from 3 random fields per slice (from 3 random slices per tumor) and are expressed as the mean SD of the fluorescence intensity ratio (TUNEL/CD31). *p <0>50 >50 >50 2.6 0.9
    SU5416 2.9 0.8 >50 >50 >50


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    1 Cells were treated with various concentrations of philinopside A for 1 hr and stimulated for 5 min with their respective growth factors in the legend to Figure 3.




    Philinopside A inhibited cellular RTK autophosphorylation
    The effect of philinopside A on the autophosphorylation of various growth factor receptors was investigated in several cell lines. Preliminary testing confirmed that the optimal concentrations for stimulating autophosphorylation were as follows: 250 ng/ml VEGF for Flk-1, 125 ng/ml PDGF-BB for PDGFR-, 125 ng/ml bFGF for FGFR-1 and 62.5 ng/ml EGF for EGFR. Philinopside A possessed a broad, dose-dependent inhibitory effect on the autophosphorylation of all 4 RTKs, with IC50 of 2.6 1.1, 3.7 2.4, 4.9 1.3 and 2.9 1.5 M for Flk-1, FGFR-1, PDGFR- and EGFR, respectively (Table II). In contrast, PD153035 (a potent EGF receptor-specific inhibitor) inhibited autophosphorylation of EGFR with an IC50 of 2.6 0.9 M, but had no effect on the other RTKs. Similarly, SU5416 (a selective inhibitor of Flk-1) suppressed autophosphorylation of Flk-1 with an IC50 of 2.9 0.8 M, but failed to alter autophosphorylation of the other RTKs.

    To further show that the decreased signal could be attributed to blockage of tyrosine phosphorylation rather than downregulated phosphorylation of associated proteins or loss of RTK proteins, we used immunoblotting to detect the phosphorylation status of the RTKs. Treatment with the growth factors at defined concentrations remarkably activated phosphorylation of the RTKs, whereas 2-50 M of philinopside A obviously suppressed the relevant phosphotyrosine signals (Fig. 8). Furthermore, philinopside A specifically counteracted autophosphorylation of the four RTKs without affecting the phosphorylation levels of associated proteins (Fig. 8), suggesting that the loss of phosphotyrosine was independent of the loss of the total RTK proteins.


    Figure 8. Immunoblot detection of tyrosine phosphorylation. Cell lines were incubated with various concentrations of philinopside A for 1 hr at 37C and stimulated for 5 min with the respective growth factors. The cells were lysed and the resultant proteins were electrophoresed on 7.5% polyacrylamide gels and transferred to nitrocellulose. Membranes were incubated with anti-phosphotyrosine antibody, stripped and re-incubated with antibodies targeting the respective receptors.
    [Normal View 23K | Magnified View 80K]



    Discussion


    Angiogenesis is a multistep processes related to activation of endothelial cells by angiogenic stimulators, leading to endothelial cell proliferation, migration, and tube formation.[27] A greater understanding of angiogenesis and further development of anti-angiogenic strategies will likely lead to new breakthroughs in anti-cancer therapy. We showed that the natural marine compound, philinopside A, possesses potent anti-angiogenic activities that seem to involve blockage of the three main steps involved in angiogenesis. In particular, philinopside A inhibited HMEC migration and tube formation at non-cytotoxic concentrations, and 5 M philinopside A almost completely abrogated sprout growth from cultured rat aorta. Philinopside A also displayed marked anti-angiogenic effects in the CAM model, with an inhibition rate of 80.1% at a dose of 10 nmol/egg. In addition to this anti-angiogenic effect, philinopside A exhibited significant anti-tumor activities both in vitro and in vivo. We compared the effects of philinopside A and 5-FU on tumor growth and tumor angiogenesis using a mouse sarcoma 180 model. Although philinopside A (2 mg/kg) and 5-FU (25 mg/kg) triggered similar degrees of tumor shrinkage, the inhibitory mode of philinopside A differed from that of 5-FU. Philinopside A reduced tumor vascular density and significantly induced apoptosis of tumor associated endothelial cells, whereas 5-FU had little effect on tumor vasculature.

    When a tumor reaches a volume of 1 mm,[3] the nutrient and oxygen supply becomes limited, forming a hypoxic environment that drives tumor cells to secret cytokines including VEGF, bFGF and PDGF, which bind to their corresponding receptors and stimulate quiescent endothelial cells to form new vessels.[28] Of the cytokine-RTK signaling pathways involved in angiogenesis, the VEGF-Flk-1 pathway is of particular importance,[29][30] as VEGF and Flk-1 have been strongly implicated in angiogenesis for solid tumors, including gliomas, breast cancer, bladder cancer and gastrointestinal cancer, and VEGF expression has been closely correlated with vessel density.[31][32][33][34] In addition, other RTK signaling pathways, including the FGF-FGFR, PDGF-PDGFR and EGF-EGFR pathways are also involved in promoting angiogenesis and tumor growth.[33][35][36][37][38][39][40][41][42] We showed that philinopside A inhibited autophosphorylation of 4 RTKs with IC50 ranging from 2.6-4.9 M, suggesting that the anti-angiogenic and cytotoxic effects of philinopside A were at least partly due to its inhibition of RTKs. Several RTK inhibitors, both specific and non-specific, are currently undergoing clinical trials as possible cancer therapeutic agents, but evidence suggests that specific RTK inhibitors may not be effective in suppressing angiogenesis both in vitro and in vivo.[43][44][45] For example, although the specific Flk-1 inhibitor, SU5416, inhibited VEGF-driven mitogenesis of HUVECs with an IC50 equivalent to 0.04 0.02 M, the inhibitor exhibited little effect on FGF-dependent mitogenesis in these same cells (IC50 = 50 M).[43] Furthermore, SU5416 has been found to only partially block EGF-induced neovascularization in the mouse cornea, in contrast to ZD1839, a selective inhibitor of EGFR, which almost completely inhibits the activity of EGF in this model.[44] These data seem to indicate that growth factors involved in angiogenesis might critically overlap in such a way that blockage of one RTK is not sufficient to fully suppress angiogenesis.[45] In this model, simultaneous inhibition of several growth factors would likely be more effective than inhibition of each individually, so a wide spectrum RTK inhibitor such as philinopside A might be a more effective inhibitor of angiogenesis in these cases. It is also possible, however, that such a wide spectrum kinase inhibitor might generate unexpected adverse effects, complicating its use as a therapeutic agent. This possibility must be taken into account when considering new therapeutic candidates.

    Such candidates are increasingly being found in the oceans, where a huge number of natural products and novel chemical entities have been identified. Of them, angiogenesis inhibitors and RTK inhibitors have drawn particular attention. Aeroplysinin-1, a brominated compound isolated from a marine sponge, was reported to possess significant anti-angiogenic effects in vitro and in vivo; this compound acts by disrupting the proteolytic balance required for angiogenesis.[46] Halenaquinone, a polyketide natural product from marine sponge, significantly antagonized EGFR with an IC50 of 19 M,[47] whereas stypoquinonic acid, an agent from the marine brown alga Stylopodium zonale, was illustrated to be a new kind of tyrosine kinase inhibitor (p56lck, IC50 187 M).[48] Notably, the novel compound philinopside A displayed a much stronger bioactivity, with wider RTK inhibition than most of the previously described marine-origin RTK inhibitors. Furthermore, our results suggest that, unlike anti-angiogenic agents that solely target angiogenesis, philinopside A affords dual anti-tumor and anti-angiogenetic activities consistent with those of conventional anti-cancer drugs such as camptothecin, docetaxel and cyclophosphamide.[49][50][51][52]

    Recent studies have suggested that the real power of anti-angiogenic agents in cancer therapy resides in synergistic combinations of multiple drugs, or combinations of drugs with chemotherapy, radiation, or other tumor-targeting agents. The most convincing evidence of successful synergy is the recent FDA approval of the specific VEGF trapper, Avastin, which was shown to extend the lives of colon cancer patients when given intravenously in combination with standard chemotherapy drugs (irinotecan, 5-FU and leucovorin), but did not seem to be effective when given alone.[53] These previous studies and our present results suggest that philinopside A maybe clinically relevant as a potential new therapeutic agent. Further work is currently underway to identify the structure-activity relationship and structural optimization of philinopside A, in the hopes that this natural marine compound will prove the basis for new, effective anti-cancer therapies.


    Acknowledgements


    The authors wish to thank Dr. A. Ullrich (Department of Molecular Biology, Max-Planck-Institute fur Biochimie, Martinsried, Germany) for donating the Flk-1 3T3 cells, and Dr. F. Nan (National Center for Drug Screening, Shanghai, P.R. China) for providing compound SU5416.

    References

    1 Folkman J. Angiogenesis in cancer, vascular, rheumatoid and other disease. Nat Med 1995; 1: 27-31. Links
    2 Benn SI, Whitsitt JS, Broadley KN, Nanney LB, Perkins D, He L, Patel M, Morgan JR, Swain WF, Davidson JM. Particle-mediated gene transfer with transforming growth factor-beta1 cDNAs enhances wound repair in rat skin. J Clin Invest 1996; 98: 2894-902. Links
    3 Yamamoto S, Konishi I, Tsuruta Y, Nanbu K, Mandai M, Kuroda H, Matsu****a K, Hamid AA, Yura Y, Mori T. Expression of vascular endothelial growth factor (VEGF) during folliculogenesis and corpus luteum formation in the human ovary. Gynecol Endocrinol 1997; 11: 371-81. Links
    4 Reynolds LP, Redmer DA. Expression of the angiogenic factors, basic fibroblast growth factor and vascular endothelial growth factor, in the ovary. J Anim Sci 1998; 76: 1671-81. Links
    5 Shawver LK, Lipson KE, Annie T, Fong T, McMahon G, Plowman GD, Strawn LM. Receptor tyrosine kinases as targets for inhibition of angiogenesis. Drug Discov Today 1997; 2: 50-63. Links
    6 Kaban K, Herbst RS. Angiogenesis as a target for cancer therapy. Hematol Oncol Clin North Am 2002; 16: 1125-71. Links
    7 Matter A. Tumor angiogenesis as a therapeutic target. Drug Discov Today 2001; 6: 1005-24. Links
    8 Ferrara N. VEGF: an update on biological and therapeutic aspects. Curr Opin Biotechnol 2000; 11: 617-24. Links
    9 Hicklin DJ, Witte L, Zhu Z, Liao F, Wu Y, Li Y, Bohlen P. Monoclonal antibody strategies to block angiogenesis. Drug Discov Today 2001; 6: 517-28. Links
    10 Sun L, McMahon G. Inhibition of tumor angiogenesis by synthetic receptor tyrosine kinase inhibitors. Drug Discov Today 2000; 5: 344-53. Links
    11 Hamby JM, Showalter HD. Small molecule inhibitors of tumor-promoted angiogenesis, including protein tyrosine kinase inhibitors. Pharmacol Ther 1999; 82: 169-93. Links
    12 Salgaller ML. Technology evaluation: bevacizumab, Genentech/Roche. Curr Opin Mol Ther 2003; 5: 657-67. Links
    13 Proksch P, Edrada RA, Ebel R. Drugs from the seas - current status and microbiological implications. Appl Microbiol Biotechnol 2002; 59: 125-34. Links
    14 Haefner B. Drugs from the deep: marine natural products as drug candidates. Drug Discov Today 2003; 8: 536-44. Links
    15 Blay JY, Le Cesne A, Verweij J, Scurr M, Seynaeve C, Bonvalot S, Hogendoorn P, Jimeno J, Evrard V, van Glabbeke M, Judson I. A phase II study of ET-743/trabectedin (Yondelis) for patients with advanced gastrointestinal stromal tumors. Eur J Cancer 2004; 40: 1327-31. Links
    16 Rubinstein LV, Shoemaker RH, Paull KD, Simon RM, Tosini S, Skehan P, Scudiero DA, Monks A, Boyd MR. Comparison of in vitro anticancer-drug-screening data generated with a tetrazolium assay versus a protein assay against a diverse panel of human tumor cell lines. J Natl Cancer Inst 1990; 82: 1113-8. Links
    17 Koyama S, Takagi H, Otani A, Suzuma K, Nishimura K, Honda Y. Tranilast inhibits protein kinase C-dependent signalling pathway linked to angiogenic activities and gene expression of retinal microcapillary endothelial cells. Br J Pharmacol 1999; 127: 537-45. Links
    18 Soeda S, Kozako T, Iwata K, Shimeno H. Oversulfated fucoidan inhibits the basic fibroblast growth factor-induced tube formation by human umbilical vein endothelial cells: its possible mechanism of action. Biochim Biophys Acta 2000; 1497: 127-34. Links
    19 Nicosia RF, Ottinetti A. Growth of microvessels in serum-free matrix culture of rat aorta. A quantitative assay of angiogenesis in vitro. Lab Invest 1990; 63: 115-22. Links
    20 Carlini RG, Reyes AA, Rothstein M. Recombinant human erythropoietin stimulates angiogenesis in vitro. Kidney Int 1995; 47: 740-5. Links
    21 Zaman GJ, Vink PM, van den Doelen AA, Veeneman GH, Theunissen HJ. Tyrosine kinase activity of purified recombinant cytoplasmic domain of platelet-derived growth factor beta-receptor (beta-PDGFR) and discovery of a novel inhibitor of receptor tyrosine kinases. Biochem Pharmacol 1999; 57: 57-64. Links
    22 Strawn LM, McMahon G, App H, Schreck R, Kuchler WR, Longhi MP, Hui TH, Tang C, Levitzki A, Gazit A, Chen I, Keri G, et al. Flk-1 as a target for tumor growth inhibition. Cancer Res 1996; 56: 3540-5. Links
    23 Tanaka NG, Sakamoto N, Tohgo A, Nishiyama Y, Ogawa H. Inhibitory effects of anti-angiogenic agents on neovascularization and growth of the chorioallantoic membrane (CAM). The possibility of a new CAM assay for angiogenesis inhibition. Exp Pathol 1986; 30: 143-50. Links
    24 Pasi A, Qu B, Messiha FS. Classifying cytostatics on the basis of their angiocidal and angiostatic effects. J Med 1993; 24: 289-300. Links
    25 Yonekura K, Basaki Y, Chikahisa L, Okabe S, Hashimoto A, Miyadera K, Wierzba K, Yamada Y. UFT and its metabolites inhibit the angiogenesis induced by murine renal cell carcinoma, as determined by a dorsal air sac assay in mice. Clin Cancer Res 1999; 5: 2185-91. Links
    26 Schirner M, Hoffmann J, Menrad A, Schneider MR. Antiangiogenic chemotherapeutic agents: characterization in comparison to their tumor growth inhibition in human renal cell carcinoma models. Clin Cancer Res 1998; 4: 1331-6. Links
    27 Cao Y. Endogenous angiogenesis inhibitors and their therapeutic implications. Int J Biochem Cell Biol 2001; 33: 357-69. Links
    28 Pugh CW, Ratcliffe PJ. Regulation of angiogenesis by hypoxia: role of the HIF system. Nat Med 2003; 9: 677-84. Links
    29 Veikkola T, Alitalo K. VEGFs, receptors and angiogenesis. Semin Cancer Biol 1999; 9: 211-20. Links
    30 Ferrara N. Vascular endothelial growth factor: molecular and biological aspects. Curr Top Microbiol Immunol 1999; 237: 1-30. Links
    31 Takahashi A, Sasaki H, Kim SJ, Tobisu K, Kakizoe T, Tsukamoto T, Kumamoto Y, Sugimura T, Terada M. Markedly increased amounts of messenger RNAs for vascular endothelial growth factor and placenta growth factor in renal cell carcinoma associated with angiogenesis. Cancer Res 1994; 54: 4233-7. Links
    32 Takahashi Y, Kitadai Y, Bucana CD, Cleary KR, Ellis LM. Expression of vascular endothelial growth factor and its receptor, KDR, correlates with vascularity, metastasis, and proliferation of human colon cancer. Cancer Res 1995; 55: 3964-8. Links
    33 Anan K, Morisaki T, Katano M, Ikubo A, Kitsuki H, Uchiyama A, Kuroki S, Tanaka M, Torisu M. Vascular endothelial growth factor and platelet-derived growth factor are potential angiogenic and metastatic factors in human breast cancer. Surgery 1996; 119: 333-9. Links
    34 Strawn LM, McMahon G, App H, Schreck R, Kuchler WR, Longhi MP, Hui TH, Tang C, Levitzki A, Gazit A, Chen I, Keri Get al. Flk-1 as a target for tumor growth inhibition. Cancer Res 1996; 56: 3540-5. Links
    35 Folkman J. Angiogenic zip code. Nat Biotechnol 1999; 17: 749. Links
    36 Mignatti P, Tsuboi R, Robbins E, Rifkin DB. in vitro angiogenesis on the human amniotic membrane: requirement for basic fibroblast growth factor-induced proteinases. J Cell Biol 1989; 108: 671-82. Links
    37 Sato Y, Shimada T, Takaki R. Autocrinological role of basic fibroblast growth factor on tube formation of vascular endothelial cells in vitro. Biochem Biophys Res Commun 1991; 180: 1098-102. Links
    38 Li LY, Safran M, Aviezer D, Bohlen P, Seddon AP, Yayon A. Diminished heparin binding of a basic fibroblast growth factor mutant is associated with reduced receptor binding, mitogenesis, plasminogen activator induction, and in vitro angiogenesis. Biochemistry 1994; 33: 10999-1007. Links
    39 Dunn IF, Heese O, Black PM. Growth factors in glioma angiogenesis: FGFs, PDGF, EGF, and TGFs. J Neurooncol 2000; 50: 121-37. Links
    40 Sundberg C, Ljungstrom M, Lindmark G, Gerdin B, Rubin K. Microvascular pericytes express platelet-derived growth factor-beta receptors in human healing wounds and colorectal adenocarcinoma. Am J Pathol 1993; 143: 1377-88. Links
    41 Sato N, Beitz JG, Kato J, Yamamoto M, Clark JW, Calabresi P, Raymond A, Frackelton AR Jr. Platelet-derived growth factor indirectly stimulates angiogenesis in vitro. Am J Pathol 1993; 142: 1119-30. Links
    42 Nelson J, Allen WE, Scott WN, Bailie JR, Walker B, McFerran NV, Wilson DJ. Murine epidermal growth factor (EGF) fragment (33-42) inhibits both EGF- and laminin-dependent endothelial cell motility and angiogenesis. Cancer Res 1995; 55: 3772-6. Links
    43 Fong TA, Shawver LK, Sun L, Tang C, App H, Powell TJ, Kim YH, Schreck R, Wang X, Risau W, Ullrich A, Hirth KP, et al. SU5416 is a potent and selective inhibitor of the vascular endothelial growth factor receptor (Flk-1/KDR) that inhibits tyrosine kinase catalysis, tumor vascularization, and growth of multiple tumor types. Cancer Res 1999; 59: 99-106. Links
    44 Hirata A, Ogawa S, Kometani T, Kuwano T, Naito S, Kuwano M, Ono M. ZD1839 (Iressa) induces antiangiogenic effects through inhibition of epidermal growth factor receptor tyrosine kinase. Cancer Res 2002; 62: 2554-60. Links
    45 Hanahan D, Folkman J. Patterns and emerging mechanisms of the angiogenic switch during tumorigenesis. Cell 1996; 86: 353-64. Links
    46 Rodriguez-Nieto S, Gonzalez-Iriarte M, Carmona R, Munoz-Chapuli R, Medina MA, Quesada AR. Antiangiogenic activity of aeroplysinin-1, a brominated compound isolated from a marine sponge. FASEB J 2002; 16: 261-3. Links
    47 Lee RH, Slate DL, Moretti R, Alvi KA, Crews P. Marine sponge polyketide inhibitors of protein tyrosine kinase. Biochem Biophys Res Commun 1992; 184: 765-72. Links
    48 Wessels M, Konig GM, Wright AD. A new tyrosine kinase inhibitor from the marine brown alga Stylopodium zonale. J Nat Prod 1999; 62: 927-30. Links
    49 Kakeji Y, Teicher BA. Preclinical studies of the combination of angiogenic inhibitors with cytotoxic agents. Invest New Drugs 1997; 15: 39-48. Links
    50 Te Velde EA, Vogten JM, Gebbink MF, van Gorp JM, Voest EE, Borel RI. Enhanced antitumor efficacy by combining conventional chemotherapy with angiostatin or endostatin in a liver metastasis model. Br J Surg 2002; 89: 1302-9. Links
    51 Teicher BA, Holden SA, Ara G, Korbut T, Menon K. Comparison of several antiangiogenic regimens alone and with cytotoxic therapies in the Lewis lung carcinoma. Cancer Chemother Pharmacol 1996; 38: 169-77. Links
    52 Reimer CL, Agata N, Tammam JG, Bamberg M, Dickerson WM, Kamphaus GD, Rook SL, Milhollen M, Fram R, Kalluri R, Kufe D, Kharbanda S. Antineoplastic effects of chemotherapeutic agents are potentiated by NM-3, an inhibitor of angiogenesis. Cancer Res 2002; 62: 789-95. Links
    53 Kabbinavar F, Hurwitz HI, Fehrenbacher L, Meropol NJ, Novotny WF, Lieberman G, Griffing S, Bergsland E. Phase II, randomized trial comparing bevacizumab plus fluorouracil (FU)/leucovorin (LV) with FU/LV alone in patients with metastatic colorectal cancer. J Clin Oncol 2003; 21: 60-5. Links

  4. #4
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    Not impressed...Not in the journal it is purported to be in...

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    You're very welcome.
    p.s. Not trying to impress you, as apparently you're confused but I found the article with ease (and it's where it claims to be, too).

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    I am glad there is some ease in your life. I do owe you an apology on the article. so I'm sorry.

    This really is a damning article anyway now that I have had a chance to examine it.

    delivered intravenously

    1). It's never been tested in humans
    2). We don't know the bioavailability or for that matter if it is even bioavailable since the researchers injected it directly into the veins of the mice
    3). In vitro studies prove a substance's potential nothing more and particularly this study doesn't deal with metobolic factors in vivo because it by-passes this part of the equation altogether.
    4). This is clearly not a "special sea cucumber."
    5). This is one study...I don't think any responsible clinician would advise people to take a supplement based on one study.
    6). There are many MANY compounds that have an anti-angiogenic effect. I don't see what's so special about this one.
    7). I don't see any data on heptatoxicy, genotoxicity renal toxicity hemeolytic effects....it needs more toxicology research...
    8). It's $60 dollars a bottle


    Angiostop is a natural supplement that is a potent inhibitor of angiogenesis (blood vessel growth). Angiostop is extracted from a special sea cucumber in the South China seas. Its active fraction has been shown through in vitro studies, in vivo studies and clinical studies to inhibit blood vessel regrowth up to 90%. This nutraceutical also blocks several inflammatory pathways in the skin which makes it ideal for post-laser treatment of rosacea and maintenance treatment to retain rosacea symptom clearance. 60 capsules per bottle.

    Hmmm, in clinical studies..first of all one study does not constitute "studies" second the ICJ study was not clinical and that's the only study referenced.

    In fact in one PDF I read it said "subsequent studies it was found to be more potent than Sumarin," and then cites the same exact study--the one study done on Philinopside A.

    It talks about it being more "potent" than anti-angiogenic drugs but it forgets to mention these drugs were proven in actual FDA clinical trials

    It again talks about further studies and cited the same study a third time. And as I mentioned in the first post where I admit I was wrong about the existence of the article it cited the only one studies and then inflates it with talk of other RTK inhibiting drugs.

    This also is the website that touts taking Angiostop after laser surgery but it doesn't explain why or how it came to this conclusion.

    So save your money folks and if you do want to try Sea Cucumber Extract I'd get off a reputable company that doesn't charge an arm and a leg.

  7. #7
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    What website are you referring to?

  8. #8
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    Here it is...the chi enterprise website has a very similar PDF but I don't recall it actually trying to magically turn one study into three.

    https://secure.aestheticmultilaser.c...products_id=72

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    I dont know whats suprising really cause all supplements are more or less useless. Supplements that actually are as beneficial as they claim arent supplements for long..they become meds! If people eat healthy they dont need supplements, thats just how it is...vitamin c, vitamin b, zinc,omega 3 etc etc etc..you get all that stuff if you just eat healthy food, its not very complicated really.

  10. #10
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    That is the website of Dr. Nielsen and Geoffrey Nase. Its no surprise that they sell this junk.

    Quote Originally Posted by JtothaK
    Here it is...the chi enterprise website has a very similar PDF but I don't recall it actually trying to magically turn one study into three.

    https://secure.aestheticmultilaser.c...products_id=72

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