Chemoattractant Signaling between Tumor Cells and Macrophages Regulates Cancer Cell Migration, Metastasis and Neovascularization

Tumor-associated macrophages are known to influence cancer progression by modulation of immune function, angiogenesis, and cell metastasis, however, little is known about the chemokine signaling networks that regulate this process. Utilizing CT26 colon cancer cells and RAW 264.7 macrophages as a model cellular system, we demonstrate that treatment of CT26 cells with RAW 264.7 conditioned medium induces cell migration, invasion and metastasis. Inflammatory gene microarray analysis indicated CT26-stimulated RAW 264.7 macrophages upregulate SDF-1α and VEGF, and that these cytokines contribute to CT26 migration in vitro. RAW 264.7 macrophages also showed a robust chemotactic response towards CT26-derived chemokines. In particular, microarray analysis and functional testing revealed CSF-1 as the major chemoattractant for RAW 264.7 macrophages. Interestingly, in the chick CAM model of cancer progression, RAW 264.7 macrophages localized specifically to the tumor periphery where they were found to increase CT26 tumor growth, microvascular density, vascular disruption, and lung metastasis, suggesting these cells home to actively invading areas of the tumor, but not the hypoxic core of the tumor mass. In support of these findings, hypoxic conditions down regulated CSF-1 production in several tumor cell lines and decreased RAW 264.7 macrophage migration in vitro. Together our findings suggest a model where normoxic tumor cells release CSF-1 to recruit macrophages to the tumor periphery where they secrete motility and angiogenic factors that facilitate tumor cell invasion and metastasis

REGULATORY/COORDINATION CONSIDERATIONS FACING THE IMPLEMENTATION OF A CARIBBEAN INVASIVE SPECIES STRATEGY FROM THE FAO PERSPECTIVE

The issue of invasive alien species (IAS) has long been on the agenda of the Food and Agriculture Organization of the United Nations (FAO) when the International Plant Protection Convention (IPPC) initially entered into force with the major purpose of preventing the introduction and spread of pests of plants and plant products. Today, invasive alien species (IAS) are considered under the broader umbrella of biosecurity and, for the IPPC Secretariat, interest in IAS is from the perspective of plant pests as species that may be invasive and that directly or indirectly affect plants or plant products and should be assessed, monitored and managed, if necessary, according to IPPC provisions. Several reports have indicated the threat of IAS as in the Caribbean region; recent plant pest invasives include the hibiscus mealybug, black Sigatoka disease and lethal yellowing of coconuts. FAO has recognised the disjointed and incomplete approach to the international policy and regulatory framework for biosecurity in food and agriculture and has suggested several regional and national actions to overcome the several shortcomings such as the development of common methodologies, particularly for risk-analysis, international standard-setting (including, where appropriate, environmental-related standards), and integrated management and monitoring. Further, it was recognised that broadly similar situations exist in national policy and regulatory frameworks where controls and national authority for biosecurity matters tend to be scattered over several ministries or departments. The limited resources of the several small island states in this Region militate against any individual effective action. However, collaborative and harmonized actions can certainly have an impact

GIANT AFRICAN SNAIL IN THE CARIBBEAN SUB-REGION

The giant African snail (GAS), Achatina fulica, is native to East Africa, and is now very widely distributed and established across the Indo-Pacific region. In 1984, this pest was first reported in the Caribbean sub-region in Guadeloupe and has spread since to several other countries. The only other report for the wider Caribbean Basin is for Florida, United States of America, where the pest was introduced in the late-1960s. GAS has been described as the most damaging land snail world-wide, reportedly attacking over 500 plant species inclusive of tree crops, ornamentals, vegetables and root crops; it has also been reported to vector several plant pathogens. Achatina fulica is therefore considered a major agricultural and horticultural pest species. Additionally, GAS is of public health concern being an intermediate host and vector of the parasitic rat lungworm, Angiostrongylus cantonensis, the agent of the human disease, eosinophilic meningitis (or cerebral angiostrongyliasis). However, in most of the affected countries in the Caribbean, the snail has not proved to be a major pest, mainly affecting household gardens and uncultivated or semi-wild areas; the few reports of agricultural losses involve mainly vegetables. Management of this pest in several of the affected countries consists mainly of the use of chemical baits and physical collection of snails combined with limited public awareness programmes. While its spread to date has been slow, the establishment of the giant African snail in the Caribbean is a cause for concern for the agricultural sector and, lesser so, as a potential public health problem. However, it should be noted that the spread of GAS has not been anywhere near the rapid spread of other recently introduced invasive alien species in the Caribbean sub-region, e.g. hibiscus mealybug or red palm mite and neither has the impact been as devastating

Urgent plant pest and disease problems in the caribbean

226 páginas. Miscellaneous Publications 378The Society held its first meeting from November 22-27, 1981 in Kingston, Jamaica. The theme of the meeting was "Urgent plant pests and disease problems in Caribbean Agriculture". The objectives of the meeting were to formally establish the Society for Plant Protection in the Canbbean and to initiate implementation of its objective as they relate to urgent plant pests and disease problems in the Caribbean

Guidelines for the identification and diagnosis of damage in crop plants caused by insects, diseases, weeds and nutrient disorders

The diagnosis implies an investigative approach to the problem. In any diagnostic consideration, you are first concerned with the nature of the effect. Is it biological? Causes by any physical agent? or it is due to the lack of some element or principle that is required by the plant for healthy growth and normal development. A conscious plan is developed for the ecological, biological and physical requirements of the plant