Cartilago de Tiburón
Cartílago de tiburón
El cartílago de tiburón es un producto natural controvertido y polémico, eficaz para unos y placebo para otros, acerca del cual en los últimos treinta años eminentes científicos han realizado y publicado no pocos estudios de laboratorio, y que cuenta asimismo con un número considerable de experiencias satisfactorias para los usuarios de un método, de riesgo escaso o nulo para la mayoría de adultos, complementario de los convencionales para inhibir el desarrollo de tumores y otras afecciones degenerativas o asociadas al envejecimiento.
En diciembre de 1991 el Doctor I. William Lane , graduado en Ciencias de la Nutrición y bioquímico, recibió del Food and Drug Administration (FDA, departamento que regula los alimentos y fármacos) la patente nº 5075112 de Estados Unidos para la comercialización como suplemento alimenticio del cartílago de tiburón. Sólo hay 3 patentes de uso concedidas a la industria de alimentos dietéticos, que no suele solicitarlas como hace la industria farmacéutica. El Dr. Lane considera que es difícil obtener patente para este tipo de alimentos porque no es frecuente conseguir pruebas fehacientes sobre su eficacia: “Muchos suplementos alimenticios son efectivos, pero demostrar su efectividad es difícil y a veces no existen procedimientos para probarlos”. Según el FDA un suplemento alimentario es algo que se añade a los alimentos o a la dieta, los más conocidos son las vitaminas y minerales, la fibra, el ajo y los aceites insaturados de pescado. Éstos y otros suplementos de la alimentación están regulados por las normas de la FDA para los alimentos, no por las que regulan los medicamentos.
La patente concedida al doctor Lane dice, entre otros extremos: “Este invento concierne en general a un método y a una dosis para inhibir la angiogénesis o la vascularización en un animal poseedor de pared intestinal, empleando una cantidad eficaz de cartílago de tiburón puro y sustancialmente libre de tejido adherente, dividido en partículas especialmente menudas para pasar a través de la pared intestinal en forma de suspensión e inhibir así, entre otros, el crecimiento tumoral y las metástasis, la artritis, en particular la artritis reumatoide, la retinopatía diabética y el glaucoma neovascular, la psoriasis y las enfermedades inflamatorias con componente vascular”.
Composición del cartílago
Un análisis químico simple muestra que el cartílago seco no adulterado de tiburón consta aproximadamente de un 41% de ceniza, un 39% de proteína, un 12% de hidratos de carbono, un 7% de agua, menos del 1% de fibra y menos del 0,3% de grasa. La ceniza está formada por un 60% de calcio y fósforo, a razón de 2 partes de calcio por 1 de fósforo. Los niveles elevados de calcio y fósforo son consecuencia de la calcificación del cartílago, sobre todo el del espinazo. Aunque la proteína inhibidora de la angiogénesis es diluida hasta cierto grado por el calcio, el fósforo, los hidratos de carbono y otros componentes naturales, estos diluyentes presentan también un papel activo en el control de la enfermedad. Al ejercer un efecto inmunorregulador y antiinflamatorio los mucopolisacáridos de los hidratos de carbono complejos estimulan el sistema inmunitario, que trabaja sinérgicamente con la proteína, y el calcio y fósforo orgánicos son utilizados por el metabolismo como sustancias nutritivas.
A diferencia de otros seres vivos, terrestres o acuáticos, el tiburón no tiene ni un solo hueso en el cuerpo, su esqueleto está formado por cartílago puro. Los huesos tienen canales microscópicos que permiten el paso de fibras nerviosas y vasos sanguíneos, de los que el cartílago carece. Los tiburones poseen un sistema inmunitario potente y muy eficaz, sus heridas curan con rapidez y no suelen presentar infecciones pues los anticuerpos de su sangre combaten con éxito las infecciones bacterianas y víricas y le protegen de muchas sustancias químicas letales para muchos mamíferos. El tiburón es una de las pocas criaturas vivas que casi nunca enferma de cáncer, lo que podría explicarse por la abundancia de cartílago en ellos.
William Lane afirma que las investigaciones efectuadas durante más de 30 años han demostrado que al inhibir el desarrollo de los tumores, el cartílago de tiburón constituye un tratamiento preventivo eficaz para el cáncer. Los estudios, de laboratorio y clínicos, demuestran además que posee una sustancia capaz de controlar diversos trastornos degenerativos o asociados al envejecimiento que como la artritis (inflamación de las articulaciones), enteritis (inflamación del tracto o revestimiento intestinal), degeneración macular, oclusión venosa de la circulación de la retina y retinopatía diabética (dilatación y rotura de los vasos sanguíneos de la retina del ojo) y psoriasis (afección de la piel con placas y escamas de piel muerta) derivan en cierto modo de la angiogénesis, es decir, dependen de la formación de nuevos vasos sanguíneos.
Un tumor es un tejido nuevo formado por células que proliferan sin control. Puede ser benigno o maligno, en cuyo caso se extiende e invade los tejidos normales de su alrededor y produce metástasis o propagación a otros lugares del cuerpo a través de los vasos sanguíneos y el sistema linfático. Los tumores tienen y requieren un aporte rico de sangre para su crecimiento. La angiogénesis o vascularización es la formación de nuevos vasos sanguíneos o el reemplazo de los lesionados en un tejido ya existente. Ocurre con muy poca frecuencia, durante la ovulación y el embarazo, en la cicatrización de las heridas y fracturas y en ciertas enfermedades del corazón y de la circulación, pero vuelve a ocurrir durante el desarrollo de un tumor o en otra dolencia que necesite de la presencia de una nueva red sanguínea.
El cartílago es antiangiogénico porque la sustancia que inhibe la vascularización está presente en el cartílago durante toda la vida del tejido. Hace más de 30 años quedó demostrada la eficacia del cartílago de tiburón como inhibidor de la angiogénesis. También la aparición de metástasis depende de la angiogénesis, las posibilidades de metástasis se incrementan cuando aumenta el número de vasos sanguíneos. En opinión de cuantos investigan y trabajan con el cartílago, al consumirlo entero se aprovechan sus cuatro proteínas, muy activas contra la angiogénesis, y la capacidad inmunoestimulante y antiinflamatoria de los mucopolisacáridos, produciéndose además un efecto sinérgico por el cual el resultado es superior al conseguido usando cada componente por separado.
La doctora Patricia Amore (Facultad de Medicina de Harvard), el Dr. Michael Klagsbrun (Hospital de Pediatría de Boston), y el Dr. Judah Folkman (MIT, Instituto de Tecnología de Massachussets), entre otros, se muestran convencidos de que del estudio de la angiogénesis pueden surgir terapias para muchas enfermedades. La angiogénesis normalmente va asociada con funciones positivas del cuerpo como la cicatrización de las heridas y el desarrollo embrionario, pero hay enfermedades que son causadas por o dependen de la angiogénesis, motivo por el que proponen su denominación como enfermedades angiogénicas: “La psoriasis, la retinopatía diabética, el glaucoma neovascular, la osteoartritis, la artritis reumatoide y las inflamaciones son algunas de las enfermedades más comunes asociadas con este proceso y que, por lo tanto, podrían controlarse mediante la angiogénesis, en otras palabras, con el cartílago de tiburón”.
La artritis reumatoide o crónica es una enfermedad inflamatoria que afecta principalmente a las articulaciones en forma de trastornos articulares, atrofia muscular y destrucción del hueso y del cartílago. De gravedad variable, desde un malestar relativamente poco importante y ocasional hasta un trastorno crónico que afecta a una o varias articulaciones o una forma que ocasiona una invalidez total. La medicina poco puede hacer para curar lo que ha sido dañado, los analgésicos ofrecen cierto alivio de los síntomas aunque su administración crónica puede causar otros problemas relacionados con la salud, que pueden llegar a ser graves. Tampoco parece haber regresión natural del daño, por ser el cartílago uno de los tejidos más lentos del cuerpo en reemplazarse. La operación, con prótesis total o parcial, produce una mejoría rápida y espectacular, pero es cara, emplea recursos valiosos, no siempre tiene éxito total y comporta riesgos sobre todo en personas mayores. Desconocida la causa de la artritis sí se sabe que el desarrollo capilar anormal puede destruir el cartílago articular, por lo que parece haber en la raíz de la enfermedad un proceso de angiogénesis crónico. De los estudios realizados con cartílago como único tratamiento de personas con artritis se deducen muy buenos resultados.
Es una enfermedad articular degenerativa, trastorno crónico muy frecuente que destruye el cartílago de las articulaciones y afecta sobre todo a la zona lumbar, los brazos, las piernas, los dedos, las rodillas y los hombros, en un proceso que prácticamente llega a inmovilizar a muchas personas al ser el trastorno reumático más común del sistema músculoesquelético. Al menos en parte la osteoartritis es consecuencia de una reacción del sistema inmunitario que puede provocar una inflamación, hinchazón y síntomas dolorosos donde existe una tensión excesiva que fragmenta el cartílago. También puede comenzar con la degeneración y adelgazamiento del cartílago articular y la consiguiente invasión de los vasos sanguíneos en el cartílago, que normalmente es avascular y no los tiene, produciendo a la larga su calcificación: la angiogénesis acelera la destrucción del cartílago al ser invadido por nuevos capilares, por lo que si se puede inhibir la formación de nuevos vasos sanguíneos puede también detenerse la destrucción del cartílago. El cartílago de tiburón administrado oralmente obstaculiza el proceso angiogénico y reduce significativamente la inflamación y la inmovilidad y el dolor articulares, efecto que se produce debido en parte a la gran cantidad de mucopolisacáridos que contiene y que actúan junto con las proteínas inhibidoras de la angiogénesis, en un efecto sinérgico que impide una mayor destrucción del cartílago. Diversos estudios clínicos efectuados en los últimos años, con personas y con perros (para evitar un posible efecto placebo, más psicológico que real), en Bélgica, Checoeslovaquia y Alemania, Estados Unidos, Costa Rica y México apoyan estas teorías: los investigadores han comprobado que consigue reducir el dolor en un 70% de los casos de osteoartritis y en un 60% de los de artritis reumatoide. Además, insisten, la doble acción del cartílago, estimulación del sistema inmunitario e inhibición de la formación de nuevos vasos sanguíneos, no obstaculiza otras terapias por drásticas o sencillas que sean y, lo más importante, el cartílago de tiburón no tiene ninguno de los efectos secundarios propios de los medicamentos más corrientemente utilizados.
Enteritis y trastornos oculares
Se ha empleado también con éxito la administración oral del cartílago ante la inflamación de la mucosa del intestino delgado o enteritis regional: las personas ganan peso, energía y optimismo. En otros estudios las personas afectadas de enteritis por candida albicans respondieron rápidamente tras la ingesta de cartílago de tiburón, que también logra muy buenas respuestas en todo tipo de inflamaciones intestinales.
En opinión de distintos investigadores, trastornos oculares caracterizados por la formación de nuevos vasos sanguíneos en la retina y que pueden culminar en ceguera como la retinopatía diabética, la degeneración macular o la oclusión venosa de la circulación retiniana, están causados por la angiogénesis. En condiciones normales existen mecanismos vasoconstrictores que actúan para prevenir la formación de microvasos, pero al comienzo de la enfermedad esos mecanismos están algo deprimidos y aparece la neovascularización.
En la retinopatía diabética , por ejemplo, se dilatan y rompen los microvasos que atraviesan la retina, roturas que dejan unos residuos que impiden la visión, y también empiezan a formarse nuevos vasos sanguíneos, que se extienden por toda la zona dañada del ojo, obstaculizando la visión.
La degeneración macular , causa frecuente de ceguera irreversible en mayores de 65 años, es el deterioro de la mácula lútea, una zona de la retina cercana al nervio óptico que es esencial para una visión nítida. La degeneración comienza por una proliferación de vasos sanguíneos por debajo de la parte central de la retina, donde producen lesiones y cicatrices que finalmente conducen a la ceguera: es fundamental la detección y eliminación precoz de esos vasos, ya que las células maculares detectoras de la luz no pueden recuperarse después que la sangre filtrada ha producido las lesiones. Se emplea rayos láser para cauterizar los nuevos vasos sanguíneos e impedir la alteración de la retina, tratamiento que no es eficaz en muchos casos y que destruye también parte de la retina, afectando por tanto a la visión.
Los investigadores creen que puede prevenirse estos trastornos oculares y el glaucoma neovascular o aumento de la presión sobre el ojo debida a la angiogénesis, con la administración oral de cartílago de tiburón, que puede actuar de manera preventiva o profiláctica, eliminando los vasos antes de que se desarrollen.
Psoriasis y afecciones de la piel
La psoriasis afecta sobre todo al cuero cabelludo, codos y rodillas, pero también en el resto del cuerpo. Se caracteriza por un desarrollo excesivo de la capa exterior de la piel, con descamación, trastorno que podría depender de un desarrollo capilar anormal en la piel, que produciría un aumento insólito de su grosor por encima de la red de capilares. Es irregular y no muy eficaz la respuesta al tratamiento consistente en cremas y ungüentos a base de corticoides, preparaciones con alquitrán de hulla y luz ultravioleta, y en casos extremos medicamentos que pueden dañar el hígado.
El resultado de la utilización del cartílago en forma de crema o gel varía mucho según la psicología de las personas, que suelen ser bastante pesimistas y escépticas respecto a sus posibilidades de curación, porque han sufrido mucho y normalmente han probado muchos tratamientos sin éxito, pero a la vez tienen la firme esperanza de que pueden curarse, combinación que hace difícil asegurar un seguimiento constante.
Se han aplicado preparaciones de cartílago, también con éxito, a un buen número de personas en casos de alergias graves o irritaciones producidas por plantas urticantes, y en otros trastornos de la piel como acné o prurito anal, así como para prevenir reacciones alérgicas.
Por precaución no debe tomar cartílago de tiburón quien acaba de sufrir un ataque al corazón, tampoco una embarazada que está construyendo una red de vasos sanguíneos para alimentar al feto en desarrollo, ni las mujeres que desean ser madres porque el cartílago podría obstaculizar la vascularización durante el ciclo menstrual. No debe usarlo una persona sometida a una intervención quirúrgica importante, por necesitar nuevos vasos sanguíneos para acelerar la curación, ni quien sigue un programa intensivo de esculturismo, ni los niños por estar sus vasos sanguíneos aún en fase de desarrollo.
|1: Int Immunopharmacol. 2005 Jun;5(6):961-70.
Low molecular weight fraction of shark cartilage can modulate immune responses and abolish angiogenesis.
|Shark cartilage has proven to have inhibitory effects on angiogenesis. In this research, we studied the effects of shark cartilage on the immune system. Firstly, we isolated and purified a shark cartilage protein fraction with the most immunostimulatory effects. Our fraction was composed of two proteins with molecular weights of about 14 and 15 kDa. This fraction highly augments delayed-type hypersensitivity response against sRBC in mice, and decreases the cytotoxic activity of Natural Killer cells. Furthermore, intraperitoneal injection of this fraction to tumor-bearing mice could increase T-cell infiltration into the tumor, and decrease the tumor lesion size. Also, this fraction has strong inhibitory effect on HBMEC proliferation and migration in fibrin matrix. According to these results, we suppose that this fraction is a good candidate for further studies in cancer therapy.|
|2: J Microbiol. 2005 Feb;43(1):11-6.
Neovastat (AE-941) inhibits the airway inflammation and hyperresponsiveness in a murine model of asthma.
|Matrix metalloproteinase (MMP)-9 plays an important role in the pathogenesis of bronchial asthma. Neovastat, having significant antitumor and antimetastatic properties, is classified as a naturally occurring multifunctional antiangiogenic agent. We evaluated the therapeutic effect of Neovastat on airway inflammation in a mouse model of asthma. BALB/c mice were immunized subcutaneously with ovalbumin (OVA) on days 0, 7, 14, and 21 and challenged with inhaled OVA on days 26, 29, and 31. Neovastat was administrated by gavage (5 mg/kg body weight) three times with 12 h intervals, beginning 30 min before OVA inhalation. On day 32, mice were challenged with inhaled methacholine, and enhanced pause (Penh) was measured as an index of airway hyperresponsiveness. The severity of airway inflammation was determined by differential cell count of bronchoalveolar lavage (BAL) fluid. The MMP-9 concentration in BAL fluid samples was measured by ELISA, and MMP-9 activity was measured by zymography. The untreated asthma group showed an increased inflammatory cell count in BAL fluid and Penh value compared with the normal control group. Mice treated with Neovastat had significantly reduced Penh values and inflammatory cell counts in BAL fluid compared with untreated asthmatic mice. Furthermore, mice treated with Neovastat showed significantly reduced MMP-9 concentrations and activity in BAL fluid. These results demonstrate that Neovastat might have new therapeutic potential for airway asthmatic inflammation .|
|3: Thromb Res. 2005;115(1-2):143-52.
Direct-acting fibrinolytic enzymes in shark cartilage extract: potential therapeutic role in vascular disorders.
Ratel D , Glazier G , Provencal M . Laboratoire de Medecine Moleculaire Ste-Justine-UQAM, Centre de Cancerologie Charles-Bruneau, Hopital Ste-Justine et Universite du Quebec a Montreal, Chemin Cote-Ste-Catherine, Montreal, QC, Canada.
|Fibrinogen and fibrin are molecules with overlapping roles in blood clotting, fibrinolysis, wound healing, inflammation, matrix and cellular interactions and neoplasia. There is currently much interest in the possible use of fibrinolytic agents in human therapeutics. In this study, we report the presence of fibrinolytic activities in shark cartilage extract (SCE). In vitro, SCE at 100 microg/ml completely degraded fibrin gel in an aprotinin-insensitive manner, suggesting a non-plasmin molecular nature. SCE was able to cleave all chains of fibrinogen and fibrin and the cleavage was completely inhibited by 1,10-phenanthroline, suggesting an essential role for metalloprotease(s) in this process. Using fibrinogen zymography, we show that SCE contains two plasmin-independent fibrinolytic activities and that these activities are correlated with the presence of 58 and 62 kDa proteases in the extract. SCE-fibrinolytic activities are inhibited by dithiothreitol, suggesting that disulfide bonds are necessary for the protease structure. Finally, using thromboelastography, SCE markedly induced retraction of human platelet-rich plasma (PRP) clot, this process being completely abolished by 1,10-phenanthroline. These data suggest the presence of novel non-plasmin fibrinolytic activities within SCE. This extract may thus represent a potential source of new therapeutic molecules to prevent and treat vaso-occlusive and thromboembolic disorders.|
|4: Arch Biochem Biophys. 2004 Nov 15;431(2):197-206.
Purification and characterization of a stimulator of plasmin generation from the antiangiogenic agent Neovastat: identification as immunoglobulin kappa light chain.
Boivin D , Provencal M , Gendron S . Laboratoire de medecine moleculaire, Hopital Sainte-Justine-UQAM, Centre de cancerologie, Charles-Bruneau, Centre de Recherche de l’Hopital Sainte-Justine, Chemin Cote-Sainte-Catherine, Montreal, Que., Canada.
|We have recently shown that Neovastat, an antiangiogenic extract from shark cartilage, stimulates the in vitro activation of plasminogen by facilitating the tissue-type plasminogen activator (tPA)-dependent conversion of plasminogen to plasmin . In this report, we describe the purification and characterization of the stimulatory molecules. Neovastat was subjected to a three-step purification procedure including gel filtration, preparative isoelectric focusing, and preparative SDS-PAGE. Two 28-kDa proteins with pIs of approximately 4.5 and 6.5 were purified to apparent homogeneity and identified as immunoglobulin (Ig) kappa light chains by N-terminal microsequencing. Ig light chains do not directly stimulate the activity of tPA or plasmin, suggesting a mechanism of action involving an interaction with plasminogen. Kinetic analysis showed that both Ig light chains accelerate the in vitro tPA-dependent conversion of plasminogen in plasmin by increasing the affinity of tPA for plasminogen by 32- and 38-fold (Km decrease from 456 nM to 12-14 nM). Shark Ig light chains also stimulated the degradation of fibrin by the tPA/plasminogen system in an in vitro assay. A direct interaction between Ig light chains and plasminogen (KA=4.0-5.5 x 10(7) M(-1); KD=18-25 nM) and with tPA (KA=2.8 x 10(7) M(-1); KD=36 nM) was demonstrated using real time binding measured by surface plasmon resonance. Ig light chain is the first molecule associated with the antiangiogenic activity of Neovastat to be purified and identified.|
|5: Drugs R D. 2004;5(2):83-9.
AE 941 [Arthrovas, Neoretna, Psovascar] is shark cartilage extract that inhibits angiogenesis. AE 941 acts by blocking the two main pathways that contribute to the process of angiogenesis, matrix metalloproteases and the vascular endothelial growth factor signalling pathway . When initial development of AE 941 was being conducted, AEterna assigned the various indications different trademarks. Neovastat was used for oncology, Psovascar was used for dermatology, Neoretna was used for ophthalmology and Arthrovas was used for rheumatology. However, it is unclear if these trademarks will be used in the future and AEterna appears to only be using the Neovastat trademark in its current publications regardless of the indication. AEterna Laboratories signed commercialisation agreements with Grupo Ferrer Internacional SA of Spain and Medac GmbH of Germany in February 2001. Under the terms of the agreement, AEterna has granted exclusive commercialisation and distribution rights to AE 941 in oncology to Grupo Ferrer Internacional for the Southern European countries of France, Belgium, Spain, Greece, Portugal and Italy. It also has rights in Central and South America. Medac GmbH will have marketing rights in Germany, the UK, Scandinavia, Switzerland, Austria, Ireland, the Netherlands and Eastern Europe. In October 2002, AEterna Laboratories announced that it had signed an agreement with Australian healthcare products and services company Mayne Group for marketing AE 941 (as Neovastat) in Australia, New Zealand, Canada and Mexico. In March 2003, AEterna Laboratories announced it has signed an agreement with Korean based LG Life Sciences Ltd for marketing AE 941 (as Neovastat) in South Korea. The agreement provides AEterna with upfront and milestone payments, as well as a return on manufacturing and sales of AE 941. AEterna Laboratories had granted Alcon Laboratories an exclusive worldwide licence for AE 941 for ophthalmic products. However, this licence has been terminated. In 1999, AEterna secured funding for AE 941, part of which is from Technology Partnerships Canada (TPC), a research support programme run by Canada’s federal government. Industry Canada will contribute $Can 1 for every $Can3 spent by AEterna on the development of AE 941, up to a total figure of $Can29.4 million. AEterna will reimburse TPC upon commercialisation of AE 941-derived products as a royalty on income generated. In January 2004 AEterna announced that development of AE 941 would be focusing on non-small cell lung cancer and that development for renal cell carcinoma would be discontinued. AEterna had previously announced in January 2003, following its acquisition of Zentaris, that development of AE 941 would be “strictly focused” on renal and non-small cell lung cancer, suggesting that development for all other indications has been discontinued, at least for the foreseeable future.
• Review, Tutorial
6: Curr Opin Investig Drugs. 2004 Jun;5(6):668-77.
Dredge K . Centre for Immunology and Cancer Research, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Brisbane, QLD, Australia.
AEterna is developing AE-941, an angiogenesis inhibitor derived from the ultrafiltration of liquid shark cartilage, with matrix metalloprotease (MMP)-2, MMP-9 and vascular endothelial growth factor inhibitory properties , for the potential treatment of non-small-cell lung cancer.
|7 : Biochem Biophys Res Commun. 2004 Jul 16;320(1):205-12.
Activation of tissue plasminogen activator gene transcription by Neovastat, a multifunctional antiangiogenic agent.
Gingras D , Nyalendo C , Di Tomasso G . Laboratoire de medecine moleculaire, Hopital Ste-Justine-UQAM, Centre de cancerologie Charles-Bruneau, Centre de Recherche de l’Hopital Ste-Justine, Chemin Cote-Ste-Catherine, Montreal, Que., Canada.
|We recently reported that Neovastat, an antiangiogenic drug that is currently undergoing Phase III clinical trials for the treatment of non-small cell lung cancer, may inhibit angiogenesis through an increase in tPA activity. Here, we show that Neovastat also stimulates tPA gene transcription in endothelial cells , in a TNFalpha-like manner. RT-PCR analysis and gene reporter assays using the human tPA promoter indicated that upregulation of the tPA gene transcription by both Neovastat and TNFalpha was correlated with the phosphorylation of JNK1/2 and of IkappaB and that SP600125 and BAY11-7082, inhibitors of JNK and IkappaK, respectively, inhibit the increase of tPA gene transcription induced by Neovastat and TNFalpha. These results suggest that Neovastat induces tPA gene transcription through activation of the JNK and NFkappaB signaling pathways, leading to an increase of tPA secretion by endothelial cells . This may lead to the localized destruction of the fibrin provisional matrix that is necessary for neovessel formation and thus contribute to the reported antiangiogenic properties of this compound.|
|8 : Invest New Drugs. 2004 Jan;22(1):17-26.
The antiangiogenic agent Neovastat (AE-941) stimulates tissue plasminogen activator activity.
Gingras D , Labelle D , Nyalendo C . Laboratoire de medecine moleculaire, Hopital Ste-Justine-UQAM, Centre de cancerologie Charles-Bruneau, Centre de Recherche de l’Hopital Ste-Justine, Chemin Cote-Ste-Catherine, Montreal, Quebec, (Canada).
|The plasminogen activator/plasmin system represents a key component of the proteolytic machinery underlying angiogenesis. In this work, we investigated the effect of Neovastat (AE-941), a naturally occurring multifunctional antiangiogenic agent that is currently in Phase III clinical trials, on tissue and urokinase plasminogen activator activities. We found that in vitro, Neovastat at 100 microg/ml markedly stimulates t-PA-mediated plasmin generation , while it slightly inhibits the generation of plasmin mediated by uPA. The stimulatory effect of Neovastat on t-PA activity was markedly increased by a heat treatment, resulting in a 15-fold increase in the rate of activation of plasminogen. Neovastat did not directly stimulate the activity of t-PA or plasmin towards exogenous substrates, suggesting that its effect requires the presence of plasminogen. Accordingly, kinetic analysis showed that Neovastat increases both the k(cat) of t-PA as well as its affinity for plasminogen by 10-fold. The stimulation of t-PA activity by Neovastat was also correlated with a direct interaction of Neovastat with plasminogen as monitored by the surface plasmon resonance technology. Overall, these results identify Neovastat as a potent stimulator of t-PA-dependent activation of plasminogen , further emphasizing its pleiotropic mechanism of action on several molecular events involved in angiogenesis.|
|9 : Clin Lung Cancer. 2003 Jan;4(4):231-6.
Phase I/II trial of the safety and efficacy of AE-941 (Neovastat) in the treatment of non-small-cell lung cancer.
|AE-941 (Neovastat), an antiangiogenic component extracted from cartilage, selectively competes for the binding of vascular endothelial growth factor to its receptor, inhibits matrix metalloproteinases, stimulates tissue plasminogen activator enzymatic activities, and induces apoptotic activities in endothelial cells. A phase I/II study was conducted to obtain information on its safety and efficacy in patients with advanced cancer refractory to treatment or for which no standard treatments were available. Eighty patients with histologically confirmed lung cancer were enrolled in a multicenter, open-label, dose-escalation study of AE-941 (30, 60, 120, or 240 mL/day) administered orally b.i.d. as monotherapy. No dose-limiting toxicity was reported . The most frequent adverse events were nausea (9%), pruritus (5%), anorexia (4%), and vomiting (4%). All adverse events were grade 1/2 except grade 3 constipation (n = 1). A survival analysis was conducted in the 48 patients with unresectable stage IIIA, IIIB, or IV non-small-cell lung cancer. A significant survival advantage was observed for patients receiving doses > 2.6 mL/kg/day (which correspond to approximately 180 mL/day in a 70-kg patient) compared to patients receiving lower doses (median, 6.1 months vs. 4.6 months; P = 0.026). No tumor responses were observed. On the other hand, 26% of the patients in the high-dose group had stable disease compared to 14% in the low-dose group. AE-941 is well tolerated in patients with advanced lung cancer. The higher dose of AE-941 explored in this phase I/II trial may confer a survival benefit.|
|10: Expert Opin Investig Drugs. 2003 Aug;12(8):1403-11.
AE-941, a multifunctional antiangiogenic compound: trials in renal cell carcinoma.
Bukowski RM . Experimental Therapeutics Program, The Cleveland Clinic Taussig Cancer Center, Cleveland, OH, USA.
|The therapy of renal cell carcinoma remains a challenge for medical oncologists and urologists. During the past 10 years, the molecular abnormalities occurring in various subtypes of renal cancer, such as clear cell renal carcinoma, have been well described. The genetic abnormalities found in clear cell tumours involve chromosome 3p and, additionally, hypermethylation of the von Hippel-Lindau (VHL) gene can be detected. The VHL protein is involved in the angiogenic cascade in non-hypoxic conditions, and the possible role of mutant or hypermethylated VHL protein in promoting angiogenesis is, therefore, of interest. The majority of patients with renal cell carcinoma who receive treatment, such as IL-2 and/or IFN, fail and develop progressive disease. Therapy is therefore inadequate and novel approaches, such as those inhibiting angiogenesis, are of interest. The agent AE-941 (Neovostat trade mark; AEterna) was developed based on the observation that shark cartilage may contain biologically active inhibitors of angiogenesis. A variety of in vitro and in vivo activities of this preparation have been identified. At the molecular level, AE-941 appears to exhibit four different potential mechanisms of action: modulation of matrix proteases; inhibition of vascular endothelial growth factor binding to its receptor; induction of endothelial cell apoptosis; and stimulation of angiostatin production. The antitumour effects of AE-941 are seen in multiple murine models and involve not only effects on primary tumour growth but also on development of metastases. AE-941 is administered orally and has an excellent toxicity profile. Of interest are the findings in patients with renal cell carcinoma. Preliminary trials in this setting have suggested that responses to AE-941 occur and that patients receiving higher doses of this agent may have improved survival . Based on these preliminary data, a large, multi-institutional, randomised, Phase III trial of this agent has now been conducted in patients with metastatic clear cell carcinoma of the kidney. Over 300 patients have been entered into this trial, accrual is complete and results still remain preliminary. The clinical studies in a malignancy such as renal cell carcinoma will provide sentinel and potentially important observations on the clinical effectiveness of this agent.
• Review, Tutorial
|11 : Int Immunopharmacol. 2003 Jul;3(7):921-6.
Modulation of CD(4)(+) and CD(8)(+) tumor infiltrating lymphocytes by a fraction isolated from shark cartilage: shark cartilage modulates anti-tumor immunity.
|Shark cartilage has proven to have some inhibitory effects on angiogenesis, metastasis, cell adhesion and proteolysis . In this study, we wanted to study some of the effects of shark cartilage on tumor immune response. Firstly, by means of chromatographic methods and delayed type hypersensitivity (DTH) test, we optimized a procedure for isolation and purification of a shark cartilage protein fraction with most immunostimulatory effects. Then, we examined its effect on the infiltration of CD(4)(+) and CD(8)(+) lymphocytes into a murine tumor model. Our fraction was composed of two major proteins with molecular weights (MWs) of about 14 and 15 kDa. This fraction highly increases delayed type hypersensitivity response against sRBC in mice. Furthermore, intraperitoneal injection of this fraction to tumor-bearing mice could increase T-cell infiltration into the tumor . Also, there was a significant increase in the CD(4)/CD(8) ratio in tumor infiltrating lymphocytes , but no such changes were found in the peripheral blood lymphocytes. According to these results, we suppose that this fraction is a good candidate for further studies in cancer therapy. Also, we concluded that this fraction, with previously proven anti-angiogenic effects, can augment cellular immune response and T-cell infiltration into the tumor and thus, there may be a direct relationship between angiogenesis inhibition and T-cell infiltration.|
|12 : Int Immunopharmacol. 2003 May;3(5):657-69.
Immunomodulating principles from shark cartilage. Part 1. Isolation and biological assessment in vitro.
|Extracts from shark cartilage exhibiting powerful immunostimulating activity in vitro are described. The study shows that a simple extraction with water is very effective in producing the immunostimulating principles and implies that it is ideal for scale-up and manufacturing on a large scale. The extracts are potent stimulators of B cells and macrophages isolated from BALB/c mice spleen while stimulation of T cells was insignificant in our in vitro models. The study demonstrates that the active principles are thermally stable proteoglycans with molecular masses exceeding 100 kDa. This in vitro study represents an important step needed for further assessment of the products in vivo and their value for nutraceutical use.|
|13 : J Cutan Med Surg. 2003 May-Jun;7(3):208-16.
Modulation of the contact hypersensitivity response by AE-941 (Neovastat), a novel antiangiogenic agent.
|BACKGROUND: AE-941 (Neovastat) is an angiogenesis inhibitor noted to have antiinflammatory properties. OBJECTIVE: We tested Neovastat in a contact hypersensitivity (CHS) model to determine the mechanism of action of its antiinflammatory effects. METHODS: Neovastat was orally administered (200 mg/kg/day) during the sensitization and challenge phases of a murine CHS assay and inflammatory responses were measured. Subsequent assays were performed on mice treated with Neovastat or Cortisone (120 mg/kg/day, IP) and differential mRNA expression of several pro- and antiinflammatory cytokines was quantified using RT-PCR. RESULTS: Neovastat decreased inflammation by 39% when administered during sensitization but did not alter the CHS response when given during the challenge phase. Neovastat significantly induced IL-10 expression in skin and skin-draining lymph nodes (49% and 45%, respectively) and decreased IFNgamma expression in the lymph nodes (35%). CONCLUSION: Antiinflammatory effects of Neovastat observed in CHS could be linked to modulation of cytokines early in the sensitization phase.|
|14 : Anticancer Drugs. 2003 Feb;14(2):91-6.
Neovastat–a novel antiangiogenic drug for cancer therapy.
Gingras D , Boivin D , Deckers C . Laboratoire de medecine moleculaire Hopital Ste-Justine-UQAM, Centre de cancerologie Charles-Bruneau, Centre de Recherche de l’Hopital Ste-Justine, Montreal, Quebec, Canada.
|Neovastat (AE-941) is an antiangiogenic drug isolated from marine cartilage. It interferes with several steps associated with the development of angiogenesis through its ability to induce endothelial cell apoptosis, and to inhibit matrix metalloproteinase activities and vascular endothelial growth factor-mediated signaling pathways , suggesting that Neovastat behaves as a multifunctional antiangiogenic drug. Neovastat is orally bioavailable, and shows significant antitumor and antimetastatic properties in animal models . An excellent safety profile with few side effects has been monitored in more than 800 patients who have been exposed to Neovastat, some of whom for more than 4 years . This indicates that Neovastat is suitable for long-term use , either alone or in combination with other anticancer therapies. Accordingly, Neovastat is currently under evaluation in three pivotal clinical studies with two phase III clinical trials in patients with lung and renal carcinoma, and a phase II clinical trial in patients with multiple myeloma is ongoing.
• Review, Tutorial
|15 : Mol Cancer Ther. 2002 Aug;1(10):795-802.
The antiangiogenic agent Neovastat (AE-941) induces endothelial cell apoptosis.
Boivin D , Gendron S , Beaulieu E . Laboratoire de medecine moleculaire, Hopital Ste-Justine-Universite du Quebec a Montreal, Centre de cancerologie Charles-Bruneau, Centre de Recherche de l’Hopital Ste-Justine, Montreal, Quebec, Canada.
|Neovastat (AE-941), a naturally occurring multifunctional antiangiogenic agent, has been shown to inhibit key components of the angiogenic process, including matrix metalloproteinases and vascular endothelial growth factor-mediated signaling events. In this study, we report the presence of a proapoptotic activity within this compound. Neovastat treatment of bovine aortic endothelial cells caused cell death with characteristics of apoptosis, including chromatin condensation and DNA fragmentation. Neovastat markedly induced caspase-3, caspase-8, and caspase-9 activities , at similar levels to those measured in cells treated with tumor necrosis factor-alpha . Activation of caspases by Neovastat appears to be essential for its proapoptotic effects because all apoptotic features were blocked by zVAD-fmk, a broad-spectrum caspase inhibitor. The activation of caspases was correlated with the cleavage of the nuclear substrate poly(ADP-ribose) polymerase, and by a concomitant release of cytochrome c from mitochondria to the cytoplasm. Neovastat-induced apoptosis appears to be specific to endothelial cells because treatment of other cell types such as U-87, COS-7, NIH-3T3, and SW1353 did not result in increased caspase-3 activity. These results demonstrate that Neovastat contains a proapoptotic factor that specifically induces the activation of caspases in endothelial cells and the resulting apoptosis of these cells .|
|16 : J Am Acad Dermatol. 2002 Oct;47(4):535-41.
Neovastat (AE-941), an inhibitor of angiogenesis: Randomized phase I/II clinical trial results in patients with plaque psoriasis.
|There is considerable evidence to support an immunopathogenic basis of psoriasis. However, changes such as altered angiogenesis have also been implicated in the pathogenesis of psoriasis. AE-941 (Neovastat; Aeterna Laboratories, Quebec City Quebec, Canada) is a naturally occurring product currently in clinical investigation that blocks two main mechanisms of angiogenesis activation, namely, vascular endothelial growth factor and matrix metalloproteinase. We hypothesized that psoriasis could be modulated by inhibiting the neovascularization of psoriatic plaques. We conducted a randomized dose-comparison trial to evaluate the safety and potential therapeutic benefit of AE-941, administered orally to patients with psoriasis. Forty-nine patients with psoriasis were enrolled and assigned to receive AE-941 at 30, 60, 120, or 240 mL/d for 12 weeks. Patients were followed up for another 12-week period. Improvement in the Psoriasis Area and Severity Index (PASI) score was observed in 50%, 41.7%, and 30.8% of the patients receiving 240, 120, and 60 mL/d, respectively. No patients receiving a dosage 30 mL/d showed a PASI score improvement. A statistically significant improvement with increasing dose was observed for the PASI score, severity of itch, and the physician’s global assessment . The most commonly reported nonserious drug-related adverse events affected the gastrointestinal system in 12 of 49 patients (primarily nausea, diarrhea, vomiting, flatulence, and constipation) and the skin and appendages in 4 of 49 patients (primarily acne and rash). This randomized phase I/II study provides evidence that the antiangiogenic agent AE-941 offers a new therapeutic approach to the management of psoriasis.
Publication Types: Clinical Trial, Clinical Trial, Phase I, Clinical Trial, Phase II, Randomized Controlled Trial
|17 : Ann Oncol. 2002 Aug;13(8):1259-63.
Neovastat (AE-941) in refractory renal cell carcinoma patients: report of a phase II trial with two dose levels.
|BACKGROUND: renal cell carcinoma (RCC) is a potential target for anti-angiogenic drugs because of its high vascularization. Neovastat (AE-941) is an inhibitor of angiogenesis with a mechanism of action that could prove beneficial in the treatment of RCC. Patients and design A phase II trial was conducted to identify the long-term safety profile of Neovastat in advanced cancer patients and to obtain preliminary information on its efficacy in solid tumors refractory to standard treatments. Neovastat (60 or 240 ml/day) was administered orally (b.i.d.) to 144 patients with solid tumors refractory to standard therapies or for whom no standard treatments were available. RESULTS: A survival analysis was conducted on 22 patients with a primary diagnosis of refractory RCC to determine whether the dose of Neovastat had any effect. A significant relationship between dose and survival was observed; the median survival time was significantly longer (16.3 versus 7.1 months; P = 0.01) in patients treated with Neovastat 240 ml/day (n = 14) compared with patients receiving 60 ml/day (n = 8). No dose-limiting toxicity was reported. The most frequent adverse event was taste alteration (13.6%). CONCLUSIONS: Neovastat is well tolerated by advanced cancer patients at doses of 60 and 240 ml/day. The higher dose of Neovastat administered in this trial is associated with a survival benefit in RCC, which is not explained by differences in major prognostic factors.
• Clinical Trial
• Clinical Trial, Phase II
• Multicenter Study
|18 : Expert Rev Anticancer Ther. 2001 Oct;1(3):341-7.
AE-941 (Neovastat): a novel multifunctional antiangiogenic compound.
Gingras D , Batist G , Beliveau R . Laboratiore de medicine moleculaire Hopital Ste-Justine-UQAM, Centre de cancerologie Charles-Bruneau, Centre de Recherche de l’Hopital Ste-Justine, Chemin Cote-Ste-Catherine, Montreal, Quebec, Canada.
|AE-941 (Neovastat) is a naturally occurring product extracted from cartilage and has antiangiogenic properties. It has reached Phase III clinical trial evaluation for the treatment of solid tumors (non-small cell lung cancer and renal cell carcinoma) and a pivotal Phase II clinical trial in multiple myeloma is ongoing. AE-941 inhibits several steps of the angiogenesis process, including matrix metalloproteinase activities and VEGF signaling pathways. Moreover, AE-941 induces endothelial cell apoptosis and tissue-type plasminogen activator activity, thus suggesting that it is a multifunctional antiangiogenic drug. Results from Phase I/II clinical trials indicate that AE-941, given orally, is well tolerated. Moreover, the median survival time in patients with renal cell carcinoma and non-small cell lung cancer was significantly longer in patients receiving high doses of AE-941 compared to low doses.|
|19 : Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai). 2000;32(1):43-48.
Purification and Functional Characterization of a Shark Cartilage Factor Inhibitory to Angiogenesis.
SCAIF-I, an inhibitor of angiogenesis from shark cartilage was purified to homogeneity. The 4 mol/L guanidinium chloride extract of shark cartilage was fractionally precipitated with 35%-65% acetone, then purified by Resource Q ion exchange chromatography, Sephacryl S-300 gel filtration, and reverse-phase high performance liquid chromatography. The pure inhibitor was homogeneous as a single band on a silver-stained 15% sodium dodecyl sulfate-polyacrylamide gel. SCAIF-I had an molecular weight of 18 kD. It specifically inhibited proliferation of endothelial cells, and strongly blocked endothelial cell movement and angiogenesis in the chorioallantoic membrane of chick embryos. Systemic administration of SCAIF-I at the dose of 5 mg/kg.d suppressed 87.93% of the growth of Lewis lung carcinoma implanted in C57BL/6 mice.
|20 : Clin Exp Metastasis. 2002;19(2):145-53.
Antiangiogenic and antimetastatic properties of Neovastat (AE-941), an orally active extract derived from cartilage tissue.
|A novel naturally occurring antiangiogenic agent isolated from cartilage, referred to as Neovastat (AE-941), was examined for its efficacy against tumor neovascularization and progression. Exposure to Neovastat results in ex ovo antiangiogenic properties in the chorioallantoid membrane of chicken embryo (71% decrease in the angiogenic index as compared to the basic fibroblast growth factor (bFGF) treated control embryos, P < 0.0001). Oral administration of Neovastat inhibits bFGF-induced angiogenesis in the Matrigel mouse model (87.5% decrease in hemoglobin as compared to the bFGF-treated control implants, P < 0.0001). Neovastat also induces a dose response decrease of lung metastases in the Lewis lung carcinoma model (oral administration; 69.1% of inhibition obtained at the maximal dose of 0.5 ml/day, P < 0.0001). Combined with a sub-optimal dose of cisplatinum (2 mg/kg, i.p.), Neovastat (0.5 ml/day) improved the therapeutic index by increasing the antimetastatic efficacy and by exerting a protective activity against cisplatinum-induced body weight loss and myelosuppression . In summary, our experimental data provide evidence of antiangiogenic and antimetastatic properties of Neovastat, following oral administration.|
|21 : Clin Cancer Res. 2002 Apr;8(4):1242-50.
The antiangiogenic agent neovastat (AE-941) inhibits vascular endothelial growth factor-mediated biological effects.
Beliveau R , Gingras D , Kruger EA . Laboratoire de Medecine Moleculaire, Hopital Ste-Justine-UQAM, Centre de Cancerologie Charles-Bruneau, Centre de Recherche de l’Hopital Ste-Justine, Montreal, Quebec, Canada.
|PURPOSE: Vascular endothelial growth factor (VEGF) is a potent regulator of angiogenesis, which exerts direct effects on vascular endothelial cells, including endothelial cell proliferation and survival, tubulogenesis, and vascular permeability. In this study, we examined whether Neovastat, a naturally occurring multifunctional antiangiogenic drug, could inhibit the endothelial cell response to VEGF stimulation. RESULTS: We demonstrated that Neovastat was able to block the VEGF-dependent microvessel sprouting from Matrigel-embedded rat aortic rings, and it also blocked the VEGF-induced endothelial cell tubulogenesis in vitro. In vivo studies showed that Neovastat was able to specifically inhibit VEGF-induced plasma extravasation in numerous tissues , including pancreas and skin. The mechanism of action of Neovastat on VEGF-mediated effects was also evaluated at the molecular level. Neovastat was shown to compete against the binding of VEGF to its receptor in endothelial cells and significantly inhibited the VEGF-dependent tyrosine phosphorylation of VEGF receptor-2 , whereas it had no significant effect on VEGF receptor-1 activity. Moreover, the inhibition of receptor phosphorylation was correlated with a marked decrease in the ability of VEGF to induce pERK activation. Neovastat does not compete against the binding of basic fibroblast growth factor, indicating a preferential inhibitory effect on the VEGF receptor. CONCLUSIONS: Because Neovastat was shown previously to inhibit metalloproteinase activities, these results suggest that Neovastat is able to target multiple steps in tumor neovascularization, further emphasizing its use as a pleiotropic, multifunctional antiangiogenic drug.|
|22 : Int J Oncol. 2002 Feb;20(2):299-303.
The effect of Neovastat (AE-941) on an experimental metastatic bone tumor model.
|Bone metastases are generally associated with bone destruction which occurs in response to factors secreted by metastatic cells. Some of these factors secreted by the metastatic cells activate osteoclats while others are proteases that degrade bone collagen. To determine if Neovastat (AE-941), a naturally occurring multi-functional inhibitor of angiogenesis, is able to regulate properties that are thought to have relevance to their propensity to form bone metastases in vivo, we used the human breast cancer MDA-MB-231 cell line which can metastasize to bone. We showed that Neovastat prevented the degradation of osteoid-like radiolabeled extracellular matrices which was induced by incubation of human SaOS-2 osteoblast-like cells with MDA-MB-231 cells. Moreover, Neovastat was demonstrated to inhibit the gelatinolytic activity of matrix metalloproteinase (MMP)-9 expressed by MDA-MB-231 cells. The potential of Neovastat to retard the spread, growth, and osteolysis of MDA-MB-231 cells was then estimated in vivo. Histomorphometric analysis of the vertebral bodies indicated that MDA-MB-231 cells inoculated in nude mice (intracardiac) successfully generate osteolytic metastases with an 83% reduction of the volume of medullary bone (p< or =0.01). However, when tumor-bearing animals were treated orally with Neovastat, there was only a 19% decrease in medullary bone thus indicating that Neovastat can prevent bone metastasis in this model . Consistent with histological results, radiographic analysis indicated that Neovastat decreased the number of osteolytic lesions by 33% (p< or =0.3). Moreover, a decrease in the tumor volume in bone was observed in Neovastat-treated animals . These results indicate that Neovastat may be useful in preventing bone metastasis in cancer patients.|
|23 : Semin Oncol. 2001 Dec;28(6):620-5.
Neovastat, a naturally occurring multifunctional antiangiogenic drug, in phase III clinical trials.
Recent studies have indicated that bone marrow angiogenesis is increased in multiple myeloma, suggesting that treatment with an antiangiogenic agent might be useful. Among the new antiangiogenic drugs in development, Neovastat (AE-941; Aeterna Laboratories, Quebec City, Canada) can be classified as a naturally occurring multifunctional antiangiogenic agent. It has a marked inhibitory effect on the formation of blood vessels in the chicken embryo vascularization assay (EVT) and endothelial cell proliferation. Furthermore, in vivo experiments showed that oral administration of Neovastat blocks the formation of blood vessels in Matrigel implants containing basic fibroblast growth factor (bFGF). The antiangiogenic activity of Neovastat was found to be associated with two mechanisms of action. In addition to the inhibition of the matrix metalloproteinase activities (MMP-2, MMP-9, and MMP-12), Neovastat inhibits vascular endothelial growth factor (VEGF) binding to endothelial cells, VEGF-dependent tyrosine phosphorylation, and VEGF-induced vascular permeability in mice. Neovastat was also found to have a significant antitumor activity. Oral administration of Neovastat in mice with subcutaneous grafted breast cancer (DA3) cells showed a significant reduction in tumor volume. Neovastat also decreased the number of lung metastases in the Lewis lung carcinoma model. Interestingly, the effect of Neovastat was additive to cisplatin in this model. Furthermore, no treatment-related mortality or loss of body weight was observed. Also, toxicology studies in rats and monkeys demonstrate no dose-limiting toxicity or target organ damage after 1 year of chronic exposure, thus suggesting that Neovastat could be safely administered in humans. Four clinical studies have been conducted to establish the dosing, safety, and early efficacy of Neovastat administered orally. In the oncology field, 482 patients have received Neovastat, of which 146 with solid tumors were exposed to the drug for more than 6 months . Two phase III clinical trials are currently underway. A phase III double-blind placebo-controlled study is being conducted to evaluate the efficacy of Neovastat in addition to induction chemotherapy/radiotherapy combined modality treatment in patients with unresectable non-small cell lung cancer stage IIIA and IIIB. A second phase III randomized, double-blind placebo-controlled study evaluates the efficacy of Neovastat as a monotherapy in metastatic renal cell carcinoma patients who have progressed following a first-line immunotherapy. Neovastat efficacy is also being evaluated in a registration phase II trial in patients with early relapse or refractory multiple myeloma.
• Review, Tutorial
|24 : Anticancer Res. 2001 Jan-Feb;21(1A):145-55.
Matrix proteinase inhibition by AE-941, a multifunctional antiangiogenic compound.
Gingras D , Renaud A , Mousseau N . Laboratoire de medecine moleculaire, Hopital Ste-Justine-UQAM, Centre de cancerologie Charles-Bruneau, Centre de Recherche de l’Hopital Ste-Justine, Chemin Cote-Ste-Catherine, Montreal, Quebec, Canada.
|BACKGROUND: Matrix metalloproteinases (MMPs) play an important role in tissue remodeling under normal physiological and pathological conditions and are thus attractive targets for both diagnostic and therapeutic purposes. Here, we examined the effect of AE-941, an orally bioavailable standardized extract made of cartilage that shows significant antiangiogenic and antimetastatic properties in vivo, on the activity of various members of the MMP family. MATERIALS AND METHODS: The effect of AE-941 on the activity of MMPs was assessed by fluorimetric assays and by substrate gel zymography. RESULTS: AE-941 markedly inhibits the gelatinolytic activity of MMP-2 and to a lesser extent those of MMP-1, MMP-7, MMP-9 and MMP-13 . AE-941 also inhibited the elastinolytic activities of MMP-2 and MMP-9 as well as MMP-12 (metalloelastase), porcine pancreatic elastase (PPE), and human leukocyte elastase (HLE). Western blot analysis revealed the presence within AE-941 of immunoreactive TIMP-like proteins, suggesting that these proteins may be at least partly responsible for the observed MMP inhibition. CONCLUSIONS: Taken together, these results demonstrate that AE-941 contains TIMP-like proteins that could be responsible for the specific inhibition of MMPs. Given the recent studies suggesting the presence within this compound of specific inhibitor(s) of endothelial cell proliferation, AE-941 appears as a pleotropic agent able to interfere with several biochemical steps leading to angiogenesis and to other physiopathological conditions. Since AE-941 is currently under Phase III clinical investigations, these findings are also of considerable importance for our understanding of its anticancer properties.|
|25 : Biol Pharm Bull. 2001 Feb;24(2):151-4.
Demonstration of inhibitory effect of oral shark cartilage on basic fibroblast growth factor-induced angiogenesis in the rabbit cornea.
Gonzalez RP , Soares FS , Farias RF . Department of Physiology and Pharmacology, Federal University of Ceara, Fortaleza, CE, Brazil.
|26: J Cell Biochem. 2000 Jun 6;78(3):417-28.
Shark cartilage extract interferes with cell adhesion and induces reorganization of focal adhesions in cultured endothelial cells.
|In this study, we examined the effects of shark cartilage extract on the attachment and spreading properties and the focal adhesion structure of cultured bovine pulmonary artery endothelial cells. Treatment with cartilage extract resulted in cell detachment from the substratum. Immunofluorescence staining of those treated cells that remained attached showed that, instead of being present in both central and peripheral focal adhesions as in control cells, both integrin alpha(v)beta(3) and vinculin were found only in peripheral focal adhesion and thinner actin filament bundles were seen. In addition to causing cell detachment, cartilage extract partially inhibited the initial adherence of the cells to the substratum in a dose-dependent manner. Integrin alpha(v)beta(3) and vinculin staining of these cells also showed a peripheral focal adhesion distribution pattern. Vitronectin induced cell spreading in the absence of serum, but was blocked by simultaneous incubation with cartilage extract, which was shown to inhibit both integrin alpha(v)beta(3) and vinculin recruitment to focal adhesion and the formation of stress fibers. Dot binding assays showed that these inhibitory effects on cell attachment and spreading were not due to direct binding of cartilage extract components to integrin alpha(v)beta(3) or vitronectin. Shark cartilage chondroitin sulfate had no inhibitory effect on either cell attachment or spreading of endothelial cells. These results show that the inhibitory effects of cartilage extract on cell attachment and spreading are mediated by modification of the organization of focal adhesion proteins.|
|27 : Br J Radiol. 2000 Apr;73(868):429-34.
Boron neutron capture therapy of the rat 9L gliosarcoma: evaluation of the effects of shark cartilage.
|A number of anti-angiogenic substances are now under evaluation, both experimentally and clinically, as potential agents for the treatment of cancer. It has recently been demonstrated that anti-angiogenic agents can increase the therapeutic potential of photon irradiation in a range of tumour models. In the present communication a preliminary assessment is made of the effects of shark cartilage on the response of the rat 9L gliosarcoma to boron neutron capture therapy (BNCT). Shark cartilage was administered orally as an aqueous suspension at a daily dose of approximately 2000 mg kg-1 body weight. The mean survival time of rats receiving no treatment was 20.7 +/- 0.5 days post intracranial tumour implantation. Administration of shark cartilage alone extended the survival time. Two of the rats treated with shark cartilage were healthy and fully active at the end of the evaluation period (43 days post implantation). At autopsy the brain tumours of these animals were a factor of approximately 4 smaller than controls. In a repeat study with shark cartilage alone the survival time was extended by approximately 30%. After boronophenylalanine-mediated BNCT, with or without shark cartilage, the survival time of rats that eventually became moribund was increased by a factor of approximately 2 relative to controls. In both treatment groups approximately 20% of rats were healthy at 1 year after BNCT. There was no evidence of residual tumour at post-mortem. It was concluded that shark cartilage, when given alone, significantly increased the survival time of tumour-bearing rats, presumably owing to an anti-angiogenic effect . However, the survival data suggested that boronophenylalanine-mediated BNCT did not appear to be enhanced by the administration of shark cartilage.|
|28 : Anticancer Res. 1998 Nov-Dec;18(6A):4435-41.
Effect of U-995, a potent shark cartilage-derived angiogenesis inhibitor, on anti-angiogenesis and anti-tumor activities.
|BACKGROUND: A potent angiogenesis inhibitor, U-995, has been purified from the cartilage of the blue shark (Prionace glauca). U-995 is composed of two single peptides with molecular mass of 10 and 14 kDa, respectively. MATERIALS AND METHODS: U-995 was designed to study human umbilical vein endothelial cell (HUVEC) migration and proliferation in vitro and angiogenesis induced by TNF alpha in chicken chorioallantoic membrane (CAM). Furthermore, we determined the ability of U-995 to inhibiting tumor cell growth and metastasis. RESULTS: U-995 (15 and 30 micrograms/ml) markedly inhibited HUVEC migration and, at 15-50 micrograms/ml produced a dose-dependent decline in [3H]-thymidine incorporation. 30 and 50 micrograms/ml of U-995, when added to TNF alpha-induced angiogenesis caused discontinuous and disrupted blood vessels . Moreover, U-995 (30 micrograms/ml) markedly prevented collagenase-induced collagenolysis . In addition, when 200 micrograms U-995 was injected i.p. into mice it suppressed sarcoma-180 cell growth and B16-F10 mouse melanoma cell metastasis in vivo . CONCLUSIONS: These results suggest that the anti-angiogenic effects of U-995 may be be due to interference with the proliferation and migration of HUVECs as well as inhibition of collagenolysis, thereby leading to inhibition of both angiogenesis and tumor cell growth.|
|29 : Food Chem Toxicol. 1998 Dec;36(12):1079-84.
Shark cartilage-containing preparation: protection against reactive oxygen species.
|There is overwhelming evidence to indicate that free radicals cause oxidative damage to lipids, proteins and nucleic acids and are involved in the pathogenesis of several degenerative diseases. Therefore, antioxidants, which can neutralize free radicals, may be of central importance in the prevention of these disease states. The protection that fruits and vegetables provide against disease has been attributed to the various antioxidants contained in them. Recently, an anti-inflammatory and analgesic activity of a water-soluble fraction from shark cartilage has been described. Using electrophoretical assays, bacteria survival and transformation and the Salmonella/mammalian-microsome assay, we investigated the putative role of shark cartilage-containing preparation in protecting cells against reactive oxygen species induced DNA damage and mutagenesis. If antimutagens are to have any impact on human disease, it is essential that they are specifically directed against the most common mutagens in daily life. Our data suggest that shark cartilage-containing preparation can play a scavenger role for reactive oxygen species and protects cells against inactivation and mutagenesis.|
|30 : J Cutan Med Surg. 1998 Jan;2(3):146-52.
Antiangiogenic properties of a novel shark cartilage extract: potential role in the treatment of psoriasis.
BACKGROUND: A number of inflammatory and immune diseases are associated with vascular changes. Psoriasis, as an example, is a common inflammatory skin disease with dilation of capillaries as an early histological change. In more developed psoriatic lesions there is proliferation of blood vessels and neovascularization. The use of agents that target these vascular changes represents a novel therapeutic strategy in the treatment of inflammatory diseases. Since cartilage is an avascular tissue, it has been hypothesized that there may be factors found in cartilage that inhibit blood vessel formation. OBJECTIVE: The objectives of this study were 1) to determine whether extracts of cartilage could inhibit angiogenesis, and 2) since altered angiogenesis is associated with certain diseases, including psoriasis, to examine whether inhibition of angiogenesis could potentially contribute to the treatment of psoriasis. METHODS: Extracts of shark cartilage were prepared by homogenization and ultrafiltration to derive the active agent termed AE -941. This agent was tested for antiangiogenesis activity using the embryonic vascularization test, which is a modification of the ex vivo chick embryo culture (CAM). Since one of the first steps in angiogenesis is degradation by metalloproteinases of the basement membrane of capillaries, AE -941 was tested for collagenase activity using a fluorogenic peptide substrate. Anti-inflammatory properties were tested using a cutaneous irritation model in humans. RESULTS: A dose dependent inhibition in embryonic neovascularization as well as in collagenase activity by AE -941 was demonstrated. When test compounds were applied on the forearms of test subjects, AE -941 was shown to have anti-inflammatory properties. Anecdotal data suggested that topical AE -941 had a beneficial effect in psoriasis. CONCLUSION: Our results show that AE -941 has anti-angiogenic and anti-inflammatory properties . Antiangiogenesis agents such as AE -941 provide an entirely new class of agents to treat cutaneous and systemic diseases associated with altered vascularity.
The analgesic and anti-inflammatory effects of shark cartilage are due to a peptide molecule and are nitric oxide (NO) system dependent.
The present work shows an antinociceptive and dose-dependent effect of shark cartilage hydrosoluble fraction (HF) on writhing and formalin tests in mice. The effect was not altered by thalidomide, a known inhibitor of tumor necrosis factor-alfa (TNF-alfa) synthesis. Similarly, the antinociceptive effect did not change in the presence of naloxone, indicating that the opioid system is not involved. However, the effect observed was blocked by L-arginine, a NO synthesis substrate, and it was potentiated by L-NAME, suggesting a role of the NO system in the shark cartilage antinociceptive effect . Effects similar to those seen with the HF were detected with peak II from gel filtration chromatography. The increase in vascular permeability induced by serotonin in rats was significantly abolished by the HF at the dose of 2 mg/kg, p.o., and again it was not potentiated by thalidomide. The observed blockade in the vascular permeability increase induced by histamine was detected only with a higher dose (10 mg/kg, p.o.).
32: Braz J Med Biol Res. 1996 May;29(5):643-6.
Anti-inflammatory and analgesic activity of a water-soluble fraction from shark cartilage.
The anti-inflammatory and analgesic activities of a water-soluble fraction (WSF), extracted with 0.1 M ammonium bicarbonate, pH 8.0, from shark cartilage were studied in several experimental models. Orally administered WSF (10 mg/kg) caused 25.7 and 23.6% inhibition of the paw edema produced in female Wistar rats (200-250 g) by carrageenan and dextran, respectively, after 3 h, as compared to controls. WSF administered orally had no effect on acetic acid-induced writhings in male Swiss mice (25-30 g) at the dose of 0.01 mg/kg but caused 52.8 and 61.4% inhibition at the doses of 0.1 and 0.5 mg/kg, respectively, compared to controls (No. of writhings/20 min, means +/- SEM: treated groups = 18.6 +/- 2.5, N = 12 and 15.2 +/- 1.4, N = 12, respectively; controls = 39.3 +/- 1.3, N = 77). In the formalin test (male Swiss mice, 25-30 g), orally administered WSF (0.5 and 1 mg/kg) caused 12.0 and 46.6% inhibition of licking time, respectively, only in the 2nd phase (inflammatory) of the test (licking time, means +/- SEM: treated group = 18.3 +/- 4.4 sec, N = 7 and 11.1 +/- 3.4 sec, N = 13; controls = 20.8 +/- 2.4 sec, N = 44). The results suggest that a molecule of a protein nature in shark cartilage is probably responsible for the effects observed.
|32 : Mutat Res. 1996 Apr 6;367(4):204-8.
Shark-cartilage containing preparation protects cells against hydrogen peroxide induced damage and mutagenesis.
|Natural products from flora and fauna are frequently used as nutritional supplements and medicaments. Two short-term assays were carried out and negative results were obtained for shark-cartilage containing preparation. The tests employed were the Salmonella/mammalian microsome assay using tester strains TA97, TA98, TA100, TA102 and TA1535 with or without S9 mix and the SOS-Chromotest with Escherichia coli strain PQ37. Evidence for shark-cartilage containing preparation functioning as an antimutagen was detected. Using bacterial survival assays with Escherichia coli fpg (BH20) and xthA (BW9091), we investigated the putative role of shark-cartilage containing preparation in protecting cells against lesions induced by hydrogen peroxide in normal and low iron level conditions. Our data suggest that shark-cartilage containing preparation can play a scavenger role for reactive oxygen species and protect against DNA lesions in both conditions.|
|33 : Pharmacotherapy. 1996 Mar-Apr;16(2):237-44.
Antiproliferative activity of shark cartilage with and without tumor necrosis factor-alpha in human umbilical vein endothelium.
|We evaluated the antiangiogenic activity of shark cartilage, tumor necrosis factor-alpha (TNF-alpha), and a combination of the two using a human umbilical vein endothelial cell proliferation assay. Proliferation of endothelium is a hallmark of angiogenesis, and inhibition of endothelial cell proliferation indicates potential antiangiogenic activity. Shark cartilage produced a concentration-dependent decline in endothelial cell 3H-thymidine incorporation . This activity was heat stable and was found in molecular weight fractions of less than 10 kd. The antiproliferative effect of shark cartilage was specific for vascular endothelium and did not affect the proliferative rate of human astrocytoma cells or human skin fibroblasts. Shark cartilage at a concentration of 500 mu g/ml and TNF-alpha at a concentration of 10 ng/ml reduced endothelial cell proliferation by 32% and 29%, respectively. Treatment of endothelial cells with the combination of shark cartilage and TNF-alpha resulted in a 44% reduction in endothelial cell proliferation. The isolation and identification of the active components of shark cartilage is continuing.|
|34 : Cancer Lett. 1990 Jun 15;51(3):181-6.
A novel angiogenic inhibitor derived from Japanese shark cartilage (I). Extraction and estimation of inhibitory activities toward tumor and embryonic angiogenesis.
|Guanidine extraction and crude fractionation of Japanese shark cartilage by ultrafiltration on a molecular weight basis were conducted and the antiangiogenic activities were assayed as to the inhibitions of tumor and embryonic angiogenesis. Significant inhibition of angiogenesis was found, and there was a linear relationship between the results of the two assays. The inhibitory activities were concentrated in the fraction in the molecular weight range of 103 to 104, and were resistant to heat treatment.|
|35 : Science. 1983 Sep 16;221(4616):1185-7.
Shark cartilage contains inhibitors of tumor angiogenesis.
Shark cartilage contains a substance that strongly inhibits the growth of new blood vessels toward solid tumors, thereby restricting tumor growth.
Los tiburones no enferman de cáncer, I. William Lane, Urano, Barcelona, 1996.
Compuestos naturales de última generación, Javier Moscardó M., Valencia, 1998.
Remedios naturales, Karl Baumgärtner, Valencia, 1998.
Shark Cartilage Information Center. The healing network, Emma Romeu, 1997.
(artículo publicado en Conocer Arganzuela nº 113, marzo de 2002)