c-Myc down-regulation as a surrogate marker of cardenolide-induced anti-tumor activity.

Abstract 2415info:eu-repo/semantics/nonPublishe

UNBS1450-mediated cMyc down-regulation and nucleolar targeting in carcinoma cells through over-expressed sodium pump alpha-1 subunit.

Abstract B154info:eu-repo/semantics/nonPublishe

Cardenolide mediated cMyc down-regulation in human cancer cell lines.

Abstract 2089info:eu-repo/semantics/nonPublishe

Cardenolide-mediated nucleolar disorganisation contributes therapeutic benefits in subcutaneous and orthotopic xenograft models of human refractory prostate cancers.

Abstract 1092info:eu-repo/semantics/nonPublishe

Neurotensin is a versatile modulator of in vitro human pancreatic ductal adenocarcinoma cell (PDAC) migration.

BACKGROUND: While the neurotensin (NT) roles in pancreatic cancer growth are well documented, its effects on pancreatic cancer cell migration have not been described. METHODS: The NT-induced effects on the migration process of human pancreatic ductal adenocarcinoma cells (PDACs) were characterized by means of various assays including computer-assisted video-microscopy, fluorescence microscopy, ELISA-based, small GTPase pull-down and phosphorylation assays. RESULTS: The NT-induced modifications on in vitro PDACs migration largely depended on the extra-cellular matrix environment and cell propensity to migrate collectively or individually. While NT significantly reduced the level of migration of collectively migrating PDACs on vitronectin, it significantly increased the level of individually migrating PDACs. These effects were mainly mediated through the sortilin/NTR3 receptor. Neurotensin both induced altered expression of alphaV and beta5 integrin subunits in PDACs cultured on vitronectin resulting in modified adhesion abilities, and caused modifications to the organization of the actin cytoskeleton through the NT-mediated activation of small Rho GTPases. While the NT effects on individually migrating PDACs were mediated at least through the EGFR/ERK signaling pathways, those on collectively migrating PDACs appeared highly dependent on the PI 3-kinase pathway. CONCLUSION: This study strongly suggests the involvement of neurotensin in the modulation of human PDAC migration.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Estimates of nectar productivity through a simulation approach differ from the nectar produced in 24 h

International audienceNectar is a key resource for numerous insects. Despite its importance, nectar productivity has mainly been assessed using one sampling method, in which the volume of nectar produced by a flower is measured after 24 h of isolation from insects (‘measured 24 h volume’ hereafter). This method assumes that nectar removal by flower-visiting insects does not affect nectar productivity. Hence, a linearity in the nectar production dynamic is assumed. The effect of nectar removal could lead to an actual volume of nectar produced per flower over 24 h being higher or lower than the measured 24 h volume. Whether the nectar productivity is influenced by insect activity still therefore needs to be assessed. In a field experiment, we estimated the nectar production dynamics of lavender (Lavandula hybrida) and fennel (Foeniculum vulgare) flowers and tested whether they met the linearity assumption. Then, we developed a simulation model to identify how different scenarios of insect foraging activity: nectar removal rate (average and maximum), and flower-selection strategies (random selection or rewarding flower selection) alter the estimated 24 h volume of nectar for both crops (‘estimated 24 h volume’ hereafter). Finally, we tested whether the estimated 24 h volume differed from the measured 24 h volume for both crops. Lavender and fennel showed equal measured 24 h volume of nectar but the produced nectar volume over 6 h suggested that a flower of lavender was more productive than a flower of fennel. Both nectar production dynamics did not meet the assumption of linearity. The simulation models showed that the estimated 24 h volume increased with maximum nectar removal rate for lavender, and the opposite was found for fennel. Rewarding selection always increased the estimated 24 h volume for fennel while for lavender a positive effect was detected at average rate of nectar removal. We found that the estimated 24 h volume was always greater than the measured 24 h volume. Our model demonstrated that the effect of insect foraging activity on flower's nectar productivity should be considered while estimating the resources produced by plants. As an alternative, measures of produced nectar volume in short time spans may be compared with the measured 24 h volume to check the reliability of this widespread method