Mesure du dépôt de plutonium 239 atmosphérique sur les feuilles de Casuarina equisetifolia : comparaison entre Mururoa et l'ensemble de la zone intertropicale

Le Casuarina equisetifolia possède un feuillage qui ressemble à celui des conifères. De ce fait, il présente un bon rendement de captation des aérosols atmosphériques. Il est très répandu dans la zone intertropicale. Nous avons pu ainsi comparer le plutonium 239 de l'atmosphère des sites expérimentaux de Mururoa et de Fangataufa à celui de l'atmosphère du reste de la Polynésie française et de différents autres points de la zone intertropicale. Aucune différence significative n'a pu être mise en évidence

The estrogen-regulated anterior gradient 2 (AGR2) protein in breast cancer: a potential drug target and biomarker

Initially discovered as an estrogen-responsive gene in breast cancer cell lines, anterior gradient 2 (AGR2) is a developmentally regulated gene belonging to the protein disulfide isomerase (PDI) gene family. Developmentally, AGR2 is expressed in the mammary gland in an estrogen-dependent manner, and AGR2 knockout and overexpression mouse models indicate that the gene promotes lobuloalveolar development by stimulating cell proliferation. Although AGR2 overexpression alone seems insufficient for breast tumorigenesis in mice, several lines of investigations suggest that AGR2 promotes breast tumorigenesis. Overexpression of AGR2 in several breast cancer cell lines increases cell survival in clonogenic assays and cell proliferation, whereas AGR2 loss of function leads to decreased cell cycle progression and cell death. In addition, AGR2 was shown to promote metastasis of breast epithelial cells in an in vivo metastasis assay. As a PDI, AGR2 is thought to be involved in the unfolded protein response that alleviates endoplasmic reticulum stress. Since cancer has to overcome proteotoxic stress due to excess protein production, AGR2 may be one of many pro-survival factors recruited to assist in protein folding or degradation or both. When AGR2 is secreted, it plays a role in cellular adhesion and dissemination of metastatic tumor cells. In breast cancer, AGR2 expression is associated with estrogen receptor (ER)-positive tumors; its overexpression is a predictor of poor prognosis. The AGR2 gene is directly targeted by ER-alpha, which is preferentially bound in tumors with poor outcome. Whereas aromatase inhibitor therapy decreases AGR2 expression, tamoxifen acts as an agonist of AGR2 expression in ER-positive tumors, perhaps contributing to tamoxifen resistance. AGR2 is also overexpressed in a subset of ER-negative tumors. Furthermore, AGR2 expression is associated with the dissemination of metastatic breast cancer cells and can be used as a marker to identify circulating tumor cells and metastatic cells in sentinel lymph nodes. In conclusion, AGR2 is a promising drug target in breast cancer and may serve as a useful prognostic indicator as well as a marker of breast cancer metastasis

Toxicologie predictive: les voies du futur

National audienc

Toxicologie predictive: les voies du futur

National audienc