Modeling pre-metastatic lymphvascular niche in the mouse ear sponge assay.

Lymphangiogenesis, the formation of new lymphatic vessels, occurs in primary tumors and in draining lymph nodes leading to pre-metastatic niche formation. Reliable in vivo models are becoming instrumental for investigating alterations occurring in lymph nodes before tumor cell arrival. In this study, we demonstrate that B16F10 melanoma cell encapsulation in a biomaterial, and implantation in the mouse ear, prevents their rapid lymphatic spread observed when cells are directly injected in the ear. Vascular remodeling in lymph nodes was detected two weeks after sponge implantation, while their colonization by tumor cells occurred two weeks later. In this model, a huge lymphangiogenic response was induced in primary tumors and in pre-metastatic and metastatic lymph nodes. In control lymph nodes, lymphatic vessels were confined to the cortex. In contrast, an enlargement and expansion of lymphatic vessels towards paracortical and medullar areas occurred in pre-metastatic lymph nodes. We designed an original computerized-assisted quantification method to examine the lymphatic vessel structure and the spatial distribution. This new reliable and accurate model is suitable for in vivo studies of lymphangiogenesis, holds promise for unraveling the mechanisms underlying lymphatic metastases and pre-metastatic niche formation in lymph nodes, and will provide new tools for drug testing

Aborto e (não) desejo de maternidade(s) : questões para a psicologia

A interrupção voluntária da gravidez ou abortamento induzido é um problema de saúde pública no Brasil. Mais do que suscitar opiniões pessoais, necessitamos debatê- lo à luz dos estudos que descrevem e/ou registram a prevalência do abortamento na população utilizando métodos de pesquisa reconhecidos para lidar com a especificidade do fenômeno. Dessa forma, destacamos o estudo apresentado na Pesquisa Nacional de Aborto, o qual aponta que uma dentre cada cinco brasileiras já fez pelo menos um aborto na vida. No entanto é importante destacar que, das mulheres que abortam, são as pobres (e negras) as mais atingidas pela desigualdade de acesso a formas seguras de interrupção de gravidez. Quanto aos abortamentos que são previstos em lei nos casos de gravidez decorrente de estupro, grave risco de vida à mulher/mãe e, mais recentemente, casos de anencefalia, o Estado brasileiro disponibiliza o acesso pelo Sistema de Único de Saúde (SUS). Contudo, mesmo nesses casos os estudos apontam que a mulher depara-se com grandes barreiras de acesso, além do estigma e de vários fatores que acabam por dificultar a obtenção do direito. A interrupção da gravidez toca em pelo menos dois pontos tabus em nossa cultura: de um lado, a discussão sobre quando se deve reconhecer aquela potência de vida dentro da mulher como sujeito e, por outro lado, a maternidade e os valores e ideais que a cercam, um tema importante a todos nós psicólogas e psicólogos. Tem a Psicologia refletido criticamente sobre o conceito de “maternidade”? Como tem sido pensada a mulher que não deseja ser mãe? A que não ama seus filhos? A que decide interromper uma gravidez? A presente coletânea, mais do que responder a estas questões, tem como intuito fomentar o debate e levar, às psicólogas e aos psicólogos, reflexões de profissionais que têm se debruçado sobre o tema. As organizadoras

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Contribution à l’étude de l’activation des cellules endothéliales lymphatiques au cours de la progression tumorale et développement d’un modèle in vivo de niche pré-métastatique ganglionnaire.

La lymphangiogenèse tumorale est décrite comme un processus favorisant les événements métastatiques et est associée à un faible pronostic vital. Pendant longtemps, la dissémination préférentielle des cellules tumorales par la voie lymphatique a été attribuée à la fonction drainante de ce réseau vasculaire. Cependant, des données montrent que les cellules endothéliales lymphatiques (CEL) possèdent une plasticité phénotypique et constituent une population cellulaire hétérogène qui pourrait s’intégrer au microenvironnement tumoral. Le rôle de cette plasticité phénotypique au cours de la progression tumorale ainsi que le dialogue établi entre les cellules cancéreuses et les CEL, tant au niveau de la tumeur primaire que des sites ganglionnaires, sont peu documentés.Ce travail a pour objectif de contribuer à la caractérisation des CEL dans un contexte tumoral en étudiant les interactions établies entre les CEL et les cellules tumorales. Nous avons démontré une « activation » des CEL qui se traduit par une modification de leur profil d’expression en ARNm et à une sécrétion de cytokines. Les modifications des CEL mises en évidence pendant ce travail suggèrent une transition phénotypique de ces cellules qui seraient dès lors des protagonistes dans l’élaboration d’un microenvironnement permissif aux cellules tumorales. Dans le but de caractériser les interactions cellules tumorales-CEL et l’activation des CEL dans un contexte tumoral, nous avons mis au point un nouveau modèle in vivo qui reproduit les étapes de la progression tumorale y compris les niches ganglionnaires pré-métastatiques et métastatiques.En conclusion, nos travaux mettent en lumière l’importance des CEL en tant que composants actifs du microenvironnement tumoral. Une meilleure compréhension du dialogue établi entre les CEL et les cellules tumorales est essentielle à la détermination de facteurs pronostiques de dissémination tumorale. Ces études permettront également le développement de nouvelles stratégies thérapeutiques dans le but de réduire les événements métastatiques liés au système lymphatique

Ear Sponge Assay: A Method to Investigate Angiogenesis and Lymphangiogenesis in Mice.

peer reviewedAngiogenesis and lymphangiogenesis have become important research areas in the biomedical field. The outgrowth of new blood (angiogenesis) and lymphatic (lymphangiogenesis) vessels from preexisting ones is involved in many pathologies including cancer. In-depth investigations of molecular determinants such as proteases in these complex processes require reliable in vivo models. Here we present the ear sponge assay as an easy, rapid, quantitative and reproducible model of angiogenesis and lymphangiogenesis. In this system, a gelatin sponge soaked with tumor cells, cell-conditioned medium, or a compound to be tested is implanted, for 2-4 weeks, between the two mouse ear skin layers. The two vascular networks are next examined through histological procedures

Targeting VEGFR-3/-2 signaling pathways with AD0157: a potential strategy against tumor-associated lymphangiogenesis and lymphatic metastases

International audienceAbstractBackgroundLymphatic metastasis is one of the leading causes of death in patients with different types of cancer and is the main prognostic factor for the disease survival. The formation of new lymphatic vessels (lymphangiogenesis) in primary tumors facilitates tumor cell dissemination to regional lymph nodes and correlates with distant metastases. Lymphangiogenesis has thus emerged as a suitable therapeutic target to block metastases, but no anti-lymphangiogenic compounds have been approved for clinical use to date. Therefore, new or improved therapies blocking lymphatic metastases are urgently required.MethodsWe established murine breast tumors to assess the effect of AD0157 on tumor growth, lymphangiogenesis, and lymphatic dissemination. Then, a battery of in vivo (mouse corneal neovascularization and ear sponges), ex vivo (mouse lymphatic rings and rat mesentery explants), and in vitro (proliferation, tubulogenesis, wound-healing, Boyden chambers, and spheroids) assays was used to give insight into the lymphangiogenic steps affected by AD0157. Finally, we investigated the molecular pathways controlled by this drug.ResultsAD0157 was found to inhibit the growth of human breast cancer xenografts in mice, to strongly reduce tumor-associated lymphangiogenesis and to block metastatic dissemination to both lymph nodes and distant organs. The high anti-lymphangiogenic potency of AD0157 was further supported by its inhibitory activity at low micromolar range in two in vivo pathological models and in two ex vivo assays. In addition, AD0157 inhibited lymphatic endothelial cell proliferation, migration and invasion, cellular sprouting, and tube formation. Mechanistically, this compound induced apoptosis in lymphatic endothelial cells and decreased VEGFR-3/-2, ERK1/2, and Akt phosphorylations.ConclusionsThese findings demonstrate the suitability of AD0157 to suppress tumor-associated lymphangiogenesis. Beyond discovering a new potent anti-lymphangiogenic drug that is worth considering in future clinical settings, our study supports the interest of designing anti-lymphangiogenic therapies to avoid distant metastatic processes