Wildlife health surveillance: gaps, needs and opportunities.

Disease emergence represents a global threat to public health, economy and biological conservation. Most emerging zoonotic diseases have an animal origin, most commonly from wildlife. To prevent their spread and to support the implementation of control measures, disease surveillance and reporting systems are needed, and due to globalisation, these activities should be carried out at the global level. To define the main gaps affecting the performance of wildlife health surveillance and reporting systems globally, the authors analysed data from a questionnaire sent to National Focal Points of the World Organisation for Animal Health that inquired on structure and limits of wildlife surveillance and reporting systems in their territories. Responses from 103 Members, covering all areas of the globe, revealed that 54.4% have a wildlife disease surveillance programme and 66% have implemented a strategy to manage disease spread. The lack of dedicated budget affected the possibility of outbreak investigations, sample collection and diagnostic testing. Although most Members maintain records relating to wildlife mortality or morbidity events in centralised databases, data analysis and disease risk assessment are reported as priority needs. The authors' evaluation of surveillance capacity found an overall low level, with marked variability among Members that was not restricted to a specific geographical area. Increased wildlife disease surveillance globally would help in understanding and managing risks to animal and public health. Moreover, consideration of the influence of socio-economic, cultural and biodiversity aspects could improve disease surveillance under a One Health approach.

L'émergence de maladies représente une menace pour la santé publique, l'économie et la conservation de la biodiversité au niveau mondial. La plupart des maladies émergentes sont d'origine animale et proviennent de la faune sauvage. Afin de prévenir leur propagation et de soutenir la mise en oeuvre de mesures de contrôle, une surveillance des maladies et des systèmes de notification sont nécessaires - et ce à l'échelle internationale, en raison de la mondialisation. En vue de définir les lacunes principales affectant les performances de la surveillance et de la notification sanitaire relative à la faune sauvage au niveau mondial, les auteurs ont analysé les données d'un questionnaire envoyé aux Points focaux nationaux de l'Organisation mondiale de la santé animale et traitant de la structure et des limites des systèmes de surveillance et de notification applicables à la faune sauvage sur leur territoire. Selon les réponses des 103 Membres, qui représentaient toutes les régions du monde, 54,4 % disposent d'un programme de surveillance et 66 % ont mis en oeuvre une stratégie visant à gérer la propagation de maladies. L'absence de budgets dédiés affecte la possibilité d'enquêter sur l'apparition d'épidémies, de prélever des échantillons et d'effectuer des tests diagnostiques. Bien que la majorité des Membres consignent dans des bases de données centralisées les événements de mortalité et de morbidité affectant la faune sauvage, l'analyse des données et l'évaluation des risques sanitaires ont été mentionnées comme étant des besoins prioritaires. Les auteurs ont évalué les capacités de surveillance qui se situent, selon eux, à un niveau faible et se caractérisent par une grande variabilité entre les Membres, indépendamment des zones géographiques dont il s'agit. Une meilleure surveillance sanitaire de la faune sauvage au niveau mondial permettrait d'améliorer la compréhension et la gestion des risques pour la santé animale et publique. Par ailleurs, une réflexion sur l'influence des aspects socio-économiques, culturels et liés à la biodiversité améliorerait la surveillance sanitaire mise en place dans le cadre de l'approche Une seule santé.

La aparición de enfermedades representa una amenaza de dimensión mundial para la salud pública, la economía y la conservación de los recursos biológicos. La mayor parte de las enfermedades zoonóticas tienen un origen animal, por lo general localizado en la fauna silvestre. Para evitar que estas enfermedades se propaguen y apoyar la aplicación de medidas de lucha hacen falta sistemas de vigilancia y notificación de enfermedades, sistemas que, teniendo en cuenta las dinámicas de la mundialización, deben declinarse a escala planetaria. Con objeto de determinar las principales carencias que lastran el buen funcionamiento de los sistemas de vigilancia y notificación de enfermedades de la fauna silvestre a escala mundial, los autores analizaron datos extraídos de un cuestionario distribuido entre los puntos focales nacionales de la Organización Mundial de Sanidad Animal, en el cual se les preguntaba por la estructura y los límites que presentaban en su territorio dichos sistemas. Las respuestas recibidas de 103 Miembros de todas las zonas del globo pusieron de relieve que un 54,4% de ellos cuenta con un programa de vigilancia sanitaria de la fauna silvestre y que un 66% tiene implantada una estrategia para contener la propagación de enfermedades. La falta de un presupuesto asignado específicamente a estas tareas limita la posibilidad de investigar eventuales brotes, obtener muestras y practicar pruebas de diagnóstico. Aunque la mayoría de los Miembros lleva un registro de los episodios de mortalidad y morbilidad de animales salvajes en bases de datos centralizadas, el análisis de datos y la determinación del riesgo de enfermedad son dos de los aspectos mencionados como necesidad prioritaria. La evaluación de la capacidad de vigilancia realizada por los autores puso de manifiesto un nivel en general bajo, con una marcada heterogeneidad entre los Miembros que no se circunscribía a una zona geográfica en particular. Una mayor vigilancia de las enfermedades de la fauna silvestre a escala mundial ayudaría a aprehender y manejar mejor los riesgos que estas presentan para la sanidad animal y la salud pública. Además, el hecho de tener en cuenta la influencia de factores socioeconómicos, culturales y ligados a la diversidad biológica podría traducirse en una más eficaz vigilancia sanitaria en clave de Una sola salud.

Integration of wildlife and environmental health into a One Health approach.

Climate change, habitat fragmentation and pollution, and subsequent loss of biodiversity and degradation of natural environments, threaten the range of ecosystem services that support all life on this planet. These changes, among others, are also driving the emergence of infectious diseases, with negative health outcomes for humans, animals, and our shared environment. Historically, interventions aimed at human and agricultural health issues did not always integrate wildlife or environmental health as part of the solution, which has resulted in unintended consequences. One Health recognises the interdependence of humans, animals and their shared environment, and provides a conceptual framework for developing interventions that optimise outcomes for human, animal and environmental health. However, there is a need to clearly articulate the core values, goals, and objectives of One Health for all relevant sectors in order to maximise synergies for communication, coordination, collaboration and, ultimately, for joint actions on disease control and prevention. The application of systems and harm reduction approaches, focusing on the socio-economic and environmental determinants of health, and ensuring good governance and effective leadership will also maximise the opportunities to develop 'win-win-win' solutions to global health and environmental challenges. These solutions would help propel One Health forward to reach its full potential and truly optimise health outcomes for all.

Le changement climatique, la fragmentation et la pollution des habitats, parallèlement à la perte de biodiversité et à la dégradation du milieu naturel qui en résultent constituent une menace pour le large éventail de services écosystémiques dont dépend la vie sur cette planète. Ces changements, parmi d'autres, favorisent également l'émergence des maladies infectieuses, avec des effets négatifs sur la santé des humains, des animaux et de leur environnement commun. Par le passé, les interventions en matière de santé humaine, végétale et animale (ces deux dernières dans le cadre des productions agricoles) ne prenaient pas toujours en compte la santé de la faune sauvage ni celle de l'environnement, ni leur rôle en tant qu'elles font partie des solutions recherchées, omission qui a vite entraîné d'importants effets indésirables. La méthode Une seule santé tient compte de l'interdépendance entre les humains, les animaux et leur environnement commun et fournit un cadre conceptuel pour la conception d'interventions dont les résultats seront ainsi les meilleurs possibles pour la santé tant humaine qu'animale et environnementale. Toutefois, il est nécessaire d'articuler clairement les valeurs, les objectifs et les résultats essentiels recherchés via Une seule santé par chacun des secteurs concernés, afin de maximiser les synergies en termes de communication, de coordination, de collaboration et, en définitive, d'activités communes pour le contrôle et la prévention des maladies. L'application de systèmes et d'approches d'atténuation des risques, axés sur les déterminants socio-économiques et environnementaux de la santé, ainsi que l'exercice d'une bonne gouvernance et d'un leadership efficace sont également des facteurs qui contribueront favorablement à la conception de solutions « gagnant-gagnant ¼ afin de résoudre les défis sanitaires et environnementaux mondiaux. Ces solutions pourraient donner une forte impulsion à la démarche Une seule santé, lui permettant de réaliser tout son potentiel et d'optimiser les bénéfices pour la santé de tous.

El cambio climático, la fragmentación y contaminación de los hábitats y su corolario, la pérdida de diversidad biológica y la degradación del medio natural, ponen en peligro toda la panoplia de servicios ecosistémicos que sostienen la vida en nuestro planeta. Estos cambios, entre otros, también están induciendo la aparición de enfermedades infecciosas que repercuten negativamente en la salud de personas, animales y el medio ambiente común a todos. Tradicionalmente, las intervenciones destinadas a abordar problemas sanitarios o agrícolas no siempre integraban la sanidad de la fauna silvestre y la salud ambiental como parte de la solución, lo que a veces tenía consecuencias imprevistas. La noción de Una sola salud, fundada en la realidad de la dependencia recíproca entre personas, animales y el medio ambiente común a todos ellos, ofrece un marco teórico desde el cual definir intervenciones que optimicen los resultados para la salud humana, animal y ambiental. No obstante, es necesario formular claramente los valores, fines y objetivos fundamentales de Una sola salud para todos los sectores afectados con objeto de lograr la máxima sinergia posible en materia de comunicación, coordinación, colaboración y, a la postre, acción conjunta de control y prevención de enfermedades. La aplicación de métodos sistémicos y de reducción de daños, que estén centrados en los determinantes socioeconómicos y ambientales de la salud y aseguren una gobernanza adecuada y un liderazgo eficaz, también ofrecerá un máximo de posibilidades de dar con soluciones que sean beneficiosas en las tres vertientes a la vez para responder a los problemas sanitarios y ambientales del mundo. Estas soluciones ayudarían a conferir impulso a la noción de Una sola salud para así poder extraer de ella el máximo provecho y optimizar realmente los resultados sanitarios en todos los frentes.

Semi-quantitative assessment of disease risks at the human, livestock, wildlife interface for the Republic of Korea using a nationwide survey of experts: A model for other countries.

Wildlife-associated diseases and pathogens have increased in importance; however, management of a large number of diseases and diversity of hosts is prohibitively expensive. Thus, the determination of priority wildlife pathogens and risk factors for disease emergence is warranted. We used an online questionnaire survey to assess release and exposure risks, and consequences of wildlife-associated diseases and pathogens in the Republic of Korea (ROK). We also surveyed opinions on pathways for disease exposure, and risk factors for disease emergence and spread. For the assessment of risk, we employed a two-tiered, statistical K-means clustering algorithm to group diseases into three levels (high, medium and low) of perceived risk based on release and exposure risks, societal consequences and the level of uncertainty of the experts' opinions. To examine the experts' perceived risk of routes of introduction of pathogens and disease amplification and spread, we used a Bayesian, multivariate normal order-statistics model. Six diseases or pathogens, including four livestock and two wildlife diseases, were identified as having high risk with low uncertainty. Similarly, 13 diseases were characterized as having high risk with medium uncertainty with three of these attributed to livestock, six associated with human disease, and the remainder having the potential to affect human, livestock and wildlife (i.e., One Health). Lastly, four diseases were described as high risk with high certainty, and were associated solely with fish diseases. Experts identified migration of wildlife, international human movement and illegal importation of wildlife as the three routes posing the greatest risk of pathogen introduction into ROK. Proximity of humans, livestock and wildlife was the most significant risk factor for promoting the spread of wildlife-associated diseases and pathogens, followed by high density of livestock populations, habitat loss and environmental degradation, and climate change. This study provides useful information to decision makers responsible for allocating resources to address disease risks. This approach provided a rapid, cost-effective method of risk assessment of wildlife-associated diseases and pathogens for which the published literature is sparse.

Proposed attributes of national wildlife health programmes.

Wildlife health is important for conservation, healthy ecosystems, sustainable development and biosecurity. It presents unique challenges for national programme governance and delivery because wildlife health not only crosses jurisdictional responsibilities and authorities but also inherently spans multiple sectors of expertise. The World Organisation for Animal Health (OIE) encourages its Members to have wildlife disease monitoring and notification systems. Where national wildlife health surveillance programmes do exist, they vary in scope and size. Evidence-based guidance is lacking on the critical functions and roles needed to meet the OIE's recommendations and other expectations of a national programme. A literature review and consultation with national wildlife health programme leaders identified five key attributes of national programmes: 1) being knowledge and science based; 2) fostering cross-nation equivalence and harmonisation; 3) developing partnerships and national coordination; 4) providing leadership and administration of national efforts; and 5) capacity development. Proposed core purposes include: 1) establishment and communication of the national wildlife health status; 2) leading national planning; 3) centralising information and expertise; 4) developing national networks leading to harmonisation and collaborations; 5) developing wildlife health workforces; and 6) centralising administration and management of national programmes. A national wildlife health programme should aim to identify, effectively communicate and manage the risk to or from a country's wildlife populations. It should generate the appropriate knowledge required to improve the effectiveness of wildlife policies and systems, including identifying and assessing emerging priorities, thus facilitating early warning, preparedness and preventive actions.

La santé de la faune sauvage a un impact important sur la préservation des espèces et d'écosystèmes sains, sur le développement durable et sur la biosécurité. Les défis sont nombreux et complexes pour les programmes nationaux de gouvernance et de mise en oeuvre car les responsabilités et les compétences juridictionnelles sont croisées et les secteurs d'expertise sont multiples. L'Organisation mondiale de la santé animale (OIE) encourage ses Membres à mettre en place des systèmes de notification et de surveillance des maladies de la faune sauvage. Les programmes existants sont de tailles et de compétences variables et les orientations prises concernant les fonctions indispensables pour répondre aux recommandations de l'OIE et à ce qui est attendu d'un programme national ne sont pas toujours déterminées sur une base scientifique. Une revue de la littérature et des consultations auprès de responsables des programmes nationaux de santé de la faune sauvage ont permis d'identifier cinq attributs à proposer pour ces programmes nationaux. Ces programmes doivent :1) fonctionner sur la base de données scientifiques ; 2) favoriser l'équivalence et l'harmonisation transnationales ; 3) développer des partenariats et une coordination à l'échelle nationale ; 4) encadrer et administrer les efforts nationaux ; et 5) assurer le renforcement des capacités. Les missions essentielles sont : 1) déterminer et rendre publique la situation sanitaire de la faune sauvage dans le pays ; 2) encadrer le plan national ; 3) centraliser l'information et l'expertise ; 4) développer les réseaux nationaux d'harmonisation et de collaboration ; 5) former des personnels compétents dans le domaine de la faune sauvage ; et 6) centraliser l'administration et la gestion des programmes nationaux. Les objectifs d'un programme national de santé de la faune sauvage sont d'identifier, de rendre publics et de gérer les risques pour les populations d'animaux sauvages ainsi que les risques générés par ces mêmes populations. Ces programmes doivent promouvoir les connaissances nécessaires pour améliorer l'efficacité des politiques et des systèmes applicables à la faune sauvage, en particulier l'identification et l'évaluation des nouvelles priorités afin de faciliter la mise en oeuvre de systèmes d'alerte précoce, de préparation aux urgences et d'action préventive.

La salud de los animales silvestres, tan importante para la conservación del medio, el buen funcionamiento de los ecosistemas, el desarrollo sostenible y la seguridad biológica, presenta singulares dificultades desde el punto de vista de la gobernanza y aplicación de programas nacionales, dado que la fauna silvestre no solo toca a múltiples responsabilidades y atribuciones jurisdiccionales sino que, por su propia naturaleza, convoca a una plétora de especialidades técnicas. La Organización Mundial de Sanidad Animal (OIE) alienta a sus Miembros a que se doten de sistemas de vigilancia y notificación de enfermedades de la fauna silvestre. Allí donde existen, los programas nacionales en la materia son muy variopintos en cuanto a sus dimensiones y alcance. Faltan pautas científicamente sólidas sobre las funciones y atribuciones básicas que se requieren para cumplir las recomendaciones de la OIE y otras expectativas a las que pueda responder un programa nacional. Tras efectuar un estudio bibliográfico y consultar a los directivos de programas nacionales en la materia, los autores determinaron cinco atributos clave que debe reunir todo programa nacional: 1) estar basado en el saber y la ciencia; 2) favorecer la equivalencia y la armonización entre naciones; 3) crear alianzas y mecanismos de coordinación nacional; 4) encabezar y administrar las actividades a escala nacional; y 5) desarrollar los medios de acción del país. Los objetivos básicos propuestos son: 1) determinar y dar a conocer la situación sanitaria de la fauna silvestre del país; 2) dirigir las labores de planificación a escala nacional; 3) centralizar la información y las competencias especializadas; 4) instituir redes nacionales que propicien la armonización y las iniciativas de colaboración; 5) desarrollar los recursos humanos dedicados a la sanidad de la fauna silvestre; y 6) centralizar la gestión y administración de los programas nacionales. Todo programa nacional de sanidad de la fauna silvestre debe responder a la finalidad de detectar, comunicar eficazmente y gestionar los riesgos que amenacen a las poblaciones de animales silvestres del país o que provengan de ellas. A tal efecto debe generar el conocimiento adecuado y necesario para conferir más eficacia a las políticas y sistemas tocantes a la fauna silvestre, lo que supone, entre otras cosas, determinar y evaluar las nuevas prioridades, facilitando con ello la alerta anticipada y las labores de preparación y prevención.

Experimental infection of highly pathogenic avian influenza viruses, Clade 2.3.4.4 H5N6 and H5N8, in Mandarin ducks from South Korea.

Outbreaks of highly pathogenic avian influenza (HPAI) have been reported worldwide. Wild waterfowl play a major role in the maintenance and transmission of HPAI. Highly pathogenic avian influenza subtype H5N6 and H5N8 viruses simultaneously emerged in South Korea. In this study, the comparative pathogenicity and infectivity of Clade 2.3.4.4 Group B H5N8 and Group C H5N6 viruses were evaluated in Mandarin duck (Aix galericulata). None of the ducks infected with H5N6 or H5N8 viruses showed clinical signs or mortality. Serological assays revealed that the HA antigenicity of H5N8 and H5N6 viruses was similar to each other. Moreover, both the viruses did not replicate after cross-challenging with H5N8 and H5N6 viruses, respectively, as the second infection. Although both the viruses replicated in most of the internal organs of the ducks, viral replication and shedding through cloaca were higher in H5N8-infected ducks than in H5N6-infected ducks. The findings of this study provide preliminary information to help estimate the risks involved in further evolution and dissemination of Clade 2.3.4.4 HPAI viruses among wild birds.

EACR-MRS conference on Seed and Soil: In Vivo Models of Metastasis.

New experimental tools are urgently required to better understand the metastatic process. The importance of such tools is underscored by the fact that many anti-cancer therapies are generally ineffective against established metastases. This makes a major contribution to the fact that metastatic spread is responsible for over 90% of cancer patient deaths. It was therefore timely that the recent "Seed and Soil: In Vivo Models of Metastasis" conference held in Berlin, Germany (27-29 of November 2017) aimed to give an in-depth overview of the latest research models and tools for studying metastasis, and to showcase recent findings from world-leading metastasis researchers. This Meeting Report summarises the major themes of this ground-breaking conference.

Widespread detection of highly pathogenic H5 influenza viruses in wild birds from the Pacific Flyway of the United States.

A novel highly pathogenic avian influenza virus belonging to the H5 clade 2.3.4.4 variant viruses was detected in North America in late 2014. Motivated by the identification of these viruses in domestic poultry in Canada, an intensive study was initiated to conduct highly pathogenic avian influenza surveillance in wild birds in the Pacific Flyway of the United States. A total of 4,729 hunter-harvested wild birds were sampled and highly pathogenic avian influenza virus was detected in 1.3% (n = 63). Three H5 clade 2.3.4.4 subtypes were isolated from wild birds, H5N2, H5N8, and H5N1, representing the wholly Eurasian lineage H5N8 and two novel reassortant viruses. Testing of 150 additional wild birds during avian morbidity and mortality investigations in Washington yielded 10 (6.7%) additional highly pathogenic avian influenza isolates (H5N8 = 3 and H5N2 = 7). The geographically widespread detection of these viruses in apparently healthy wild waterfowl suggest that the H5 clade 2.3.4.4 variant viruses may behave similarly in this taxonomic group whereby many waterfowl species are susceptible to infection but do not demonstrate obvious clinical disease. Despite these findings in wild waterfowl, mortality has been documented for some wild bird species and losses in US domestic poultry during the first half of 2015 were unprecedented.

A link between inflammation and metastasis: serum amyloid A1 and A3 induce metastasis, and are targets of metastasis-inducing S100A4.

S100A4 is implicated in metastasis and chronic inflammation, but its function remains uncertain. Here we establish an S100A4-dependent link between inflammation and metastatic tumor progression. We found that the acute-phase response proteins serum amyloid A (SAA) 1 and SAA3 are transcriptional targets of S100A4 via Toll-like receptor 4 (TLR4)/nuclear factor-κB signaling. SAA proteins stimulated the transcription of RANTES (regulated upon activation normal T-cell expressed and presumably secreted), G-CSF (granulocyte-colony-stimulating factor) and MMP2 (matrix metalloproteinase 2), MMP3, MMP9 and MMP13. We have also shown for the first time that SAA stimulate their own transcription as well as that of proinflammatory S100A8 and S100A9 proteins. Moreover, they strongly enhanced tumor cell adhesion to fibronectin, and stimulated migration and invasion of human and mouse tumor cells. Intravenously injected S100A4 protein induced expression of SAA proteins and cytokines in an organ-specific manner. In a breast cancer animal model, ectopic expression of SAA1 or SAA3 in tumor cells potently promoted widespread metastasis formation accompanied by a massive infiltration of immune cells. Furthermore, coordinate expression of S100A4 and SAA in tumor samples from colorectal carcinoma patients significantly correlated with reduced overall survival. These data show that SAA proteins are effectors for the metastasis-promoting functions of S100A4, and serve as a link between inflammation and tumor progression.

Accumulation of small hyaluronan oligosaccharides in tumour interstitial fluid correlates with lymphatic invasion and lymph node metastasis.

BACKGROUND: Association studies have implicated the glycosaminoglycan hyaluronan (hyaluronic acid, HA) and its degrading enzymes the hyaluronidases in tumour progression and metastasis. Oligosaccharides of degraded HA have been ascribed a number of biological functions that are not exerted by high-molecular-weight HA (HMW-HA). However, whether these small HA oligosaccharides (sHA) have a role in tumour progression currently remains uncertain due to an inability to analyse their concentration in tumours. METHODS: We report a novel method to determine the concentration of sHA ranging from 6 to 25 disaccharides in tumour interstitial fluid (TIF). Levels of sHA were measured in TIF from experimental rat tumours and human colorectal tumours. RESULTS: While the majority of HA in TIF is HMW-HA, concentrations of sHA up to 6 µg ml(-1) were detected in a subset of tumours, but not in interstitial fluid from healthy tissues. In a cohort of 72 colorectal cancer patients we found that increased sHA concentrations in TIF are associated with lymphatic vessel invasion by tumour cells and the formation of lymph node metastasis. CONCLUSIONS: These data document for the first time the pathophysiological concentration of sHA in tumours, and provide evidence of a role for sHA in tumour progression.

Flow cytometry-based isolation of dermal lymphatic endothelial cells from newborn rats.

The lymphatic system plays a key role in tissue homeostasis, fatty acid transport, and immune surveillance. Pathologically, dysfunction of the lymphatic system results in edema, and increased lymphangiogenesis can contribute to tumor metastasis. Lymphatic vessels are composed of lymphatic endothelial cells (LECs) that can be identified by distinct marker molecules such as Prox-1, podoplanin, VEGFR-3 and LYVE-1. Primary LECs represent a valuable tool for the study of basic functions of the lymphatic system. However, their isolation remains a challenge, particularly if rodent tissues are used as a source. We developed a method for the isolation of rat dermal LECs from the skin of newborn rats based on sequential enzymatic digestion with trypsin and Liberase followed by flow cytometric sorting using LYVE-1 specific antibodies. Cells isolated according to this protocol expressed the lymphatic markers Prox-1, podoplanin, LYVE-1 and VEGFR-3, and displayed an endothelial-like morphology when taken into culture. These primary cells can be used for studying lymphatic biology in rat models, and the protocol we describe here therefore represents an important extension of the experimental repertoire available for rats and for modeling the human lymphatic system.

Opposing effects of high- and low-molecular weight hyaluronan on CXCL12-induced CXCR4 signaling depend on CD44.

The tumor microenvironment makes a decisive contribution to the development and dissemination of cancer, for example, through extracellular matrix components such as hyaluronan (HA), and through chemokines that regulate tumor cell behavior and angiogenesis. Here we report a molecular link between HA, its receptor CD44 and the chemokine CXCL12 in the regulation of cell motility and angiogenesis. High-molecular-weight HA (hHA) was found to augment CXCL12-induced CXCR4 signaling in both HepG2iso cells and primary human umbilical vein endothelial cells, as evidenced by enhanced ERK phosphorylation and increased cell motility. The augmentation of CXCR4 signaling translated into increased vessel sprouting and angiogenesis in a variety of assays. Small HA oligosaccharides (sHA) efficiently inhibited these effects. Both siRNA-mediated reduction of CD44 expression and antibodies that block the interaction of CD44 with HA provided evidence that CXCL12-induced CXCR4 signaling depends on the binding of hHA to CD44. Consistently, CD44 and CXCR4 were found to physically interact in the presence of CXCL12, an interaction that could be inhibited by sHA. These findings provide novel insights into how microenvironmental components interact with cell surface receptors in multi-component complexes to regulate key aspects of tumor growth and progression.

RASSF1A inhibits estrogen receptor alpha expression and estrogen-independent signalling: implications for breast cancer development.

The Ras association domain family 1 isoform A (RASSF1A) is a tumor suppressor whose inactivation is implicated in the development of many human cancers, including breast carcinomas. Little is known about the tumor-suppressive function of RASSF1A in breast tissue and whether its inactivation is mechanistically involved in the initiation and progression of breast tumors. Here, we show that RASSF1A inhibits breast cancer growth in vivo, and suppresses estrogen receptor (ERα) expression and function. Reconstitution of RASSF1A in MCF7 cells led to decreased ERα levels and reduced sensitivity to estrogen (E2). Concomitantly, we observed decreased expression of Id1 as well as the E2-responsive genes Bcl-2 and c-Myc that cooperatively contribute to the immortalization and transformation of breast epithelial cells. This downregulation was associated with induction of cell-cycle arrest and senescence that constitute early barriers to cancer initiation and progression. Knockdown of ERα showed that downregulation of ERα suffices to increase senescence and inhibit expression of Bcl-2, c-Myc and Id1. However, enforced expression of ERα only partially rescued RASSF1A-mediated growth inhibition and senescence, suggesting that suppression of ERα expression and activity is not the only mechanism by which RASSF1A inhibits growth and survival of breast cancer cells. Ectopic expression of Bcl-2, c-Myc and Id1 had little or no effect on RASSF1A-mediated growth arrest, indicating that RASSF1A acts dominantly over these oncogenes. Mechanistically, RASSF1A was found to suppress ERα expression through Akt1. It also transiently inhibited ERα-induced Ras-MAPK activity after exposure of cells to E2. Together, our data show that RASSF1A acts as a tumor suppressor in ERα+ mammary epithelial cells, in part through inhibiting ERα expression and activity. These findings suggest that RASSF1A has a key role in suppressing the transformation of human breast epithelial cells and ERα+ breast cancer initiation.

The immediate early gene Ier2 promotes tumor cell motility and metastasis, and predicts poor survival of colorectal cancer patients.

Here, we report unbiased screens for genes expressed in metastatic tumor cells that are associated with cell motility. These screens identified Ier2, an immediate early gene of unknown function, as potentially having a role in tumor cell motility and metastasis. Knockdown of Ier2 in 3T3 fibroblasts inhibited their motility upon relief of contact inhibition in monolayer wounding assays. Furthermore, ectopic Ier2 expression promoted the motility and invasiveness of poorly metastatic 1AS pancreatic tumor cells in vitro. Relief of contact inhibition was associated with translocation of the Ier2 protein from the cytoplasm to the nucleus in both 3T3 fibroblasts and 1AS tumor cells. Importantly, ectopic Ier2 expression in 1AS cells stimulated metastasis formation when cells were implanted into experimental animals. Furthermore, we found elevated Ier2 expression in a wide variety of human tumor types. This correlated with poor metastasis-free and overall survival in patients with colorectal adenocarcinomas. Together, these data reveal Ier2 as a new player in the regulation of tumor progression and metastasis, and suggest that Ier2 may be useful prognostically and therapeutically in the management of cancer.

ASAP1 promotes tumor cell motility and invasiveness, stimulates metastasis formation in vivo, and correlates with poor survival in colorectal cancer patients.

We have previously performed an unbiased screen to identify genes whose expression is associated with the metastatic phenotype. Secondary screening of these genes using custom microarray chips identified ASAP1, a multi-domain adaptor protein with ADP-ribosylation factor-GAP activity, as being potentially involved in tumor progression. Here, we show that at least three different splice forms of ASAP1 are upregulated in rodent tumor models in a manner that correlates with metastatic potential. In human cancers, we found that ASAP1 expression is strongly upregulated in a variety of tumors in comparison with normal tissue and that this expression correlates with poor metastasis-free survival and prognosis in colorectal cancer patients. Using loss and gain of function approaches, we were able to show that ASAP1 promotes metastasis formation in vivo and stimulates tumor cell motility, invasiveness, and adhesiveness in vitro. Furthermore, we show that ASAP1 interacts with the metastasis-promoting protein h-prune and stimulates its phosphodiesterase activity. In addition, ASAP1 binds to the SH3 domains of several proteins, including SLK with which it co-immunoprecipitates. These data support the notion that ASAP1 can contribute to the dissemination of a variety of tumor types and represent a potential target for cancer therapy.

The relationship between tumors and the lymphatics: what more is there to know?

Ten years ago the relationship between tumors and the lymphatic system was perceived to be rather passive. Since then, the dramatic increase in our understanding of the molecular biology of lymphatic endothelial cells and the regulation of lymphangiogenesis has revealed that tumors can actively interact with the lymphatics by inducing lymphangiogenesis. In turn, this interaction promotes the entry of tumor cells into the lymphatic vasculature and their subsequent transport to regional lymph nodes, a process that stimulates the formation of metastases. Tumor-induced lymphangiogenesis has thus emerged as an important new target in the fight against metastatic cancer. Nevertheless, there is still much to be learned about the relationship between tumors and the lymphatics that will have important ramifications for the design of clinical trials aimed at the application of anti-lymphangiogenesis therapies in the management of cancer. This Lymphangiogenesis Review focuses on these issues.

Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells.

Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy.

Dynamic targeting of protein phosphatase 1 within the nuclei of living mammalian cells.

Protein phosphatase 1 (PP1) is expressed in mammalian cells as three closely related isoforms, alpha, beta/delta and gamma1, which are encoded by separate genes. It has yet to be determined whether the separate isoforms behave in a similar fashion or play distinct roles in vivo. We report here on analyses by fluorescence microscopy of functional and fluorescently tagged PP1 isoforms in live cells. PP1alpha and PP1gamma fluorescent protein fusions show largely complimentary localization patterns, particularly within the nucleus where tagged PP1gamma accumulates in the nucleolus, whereas tagged PP1alpha is primarily found in the nucleoplasm. Overexpression of NIPP1 (nuclear inhibitor of PP1), a PP1 targeting subunit that accumulates at interchromatin granule clusters in the nucleoplasm, results in a retargeting of both isoforms to these structures, indicating that steady-state localization is based, at least in part, on relative affinities for various targeting subunits. Photobleaching analyses show that PP1gamma is rapidly exchanging between the nucleolar, nucleoplasmic and cytoplasmic compartments. Fluorescence resonance energy transfer (FRET) analyses indicate that the direct interaction of the two proteins predominantly occurs at or near interchromatin granule clusters. These data indicate that PP1 isoforms are highly mobile in cells and can be dynamically (re)localized through direct interaction with targeting subunits.

Characterization of indolinones which preferentially inhibit VEGF-C- and VEGF-D-induced activation of VEGFR-3 rather than VEGFR-2.

VEGF-C and VEGF-D are lymphangiogenic factors that bind to and activate VEGFR-3, a fms-like tyrosine kinase receptor whose expression is limited almost exclusively to lymphatic endothelium in the adult. Processed forms of VEGF-C and VEGF-D can also activate VEGFR-2, a key player in the regulation of angiogenesis. There is increasing evidence to show that these receptor-ligand interactions play a pivotal role in a number of pathological situations. Inhibition of receptor activation by VEGF-C and VEGF-D could therefore be pharmaceutically useful. Furthermore, to understand the different roles of VEGF-C, VEGF-D, VEGFR-2 and VEGFR-3 in pathological situations it will be necessary to dissect the complex interactions of these ligands and their receptors. To facilitate such studies we cloned, sequenced and characterized the expression of rat VEGF-C and VEGF-D. We showed that Cys152-->Ser mutants of processed rat VEGF-C can activate VEGFR-3 but not VEGFR-2, while the corresponding mutation in rat VEGF-D inhibits its ability to activate both VEGFR-2 and VEGFR-3. We also synthesized and characterized indolinones that differentially block VEGF-C- and VEGF-D-induced VEGFR-3 kinase activity compared to that of VEGFR-2. These tools should be useful in analysing the different activities and roles of VEGF-C, VEGF-D and their ligands, and in blocking VEGFR-3-mediated lymphangiogenesis.