Mécanisme d'action de l'éthanol sur la prolifération et la migration des cellules cancéreuses mammaires MCF-7 : implication de la voie de signalisation des oestrogènes

Many epidemiological studies have shown that chronic alcohol consumption increases significantly the incidence of breast cancer. Moreover, in vitro and in vivo studies show that ethanol can promote not only tumorogenesis but also tumor cells migration. These effects seem to be related to the hormone dependent status of breast cancer cells. The aim of our study was to elucidate the underlying molecular mechanisms by using the MCF-7 breast cancer cell line. First, we have confirmed that ethanol can stimulate the proliferation of these cells. We demonstrated that this effect is associated to an increase in the expression of ERa, COX-2 and aromatase, the enzyme responsible for estrogen synthesis. In contrast, other alcohols, such as methanol or butanol, decrease significantly the proliferation and do not increase the aromatase protein level. In the cell migration context, we have shown that ethanol stimulates the MMP-2 and MMP-9 secretion. This ethanol-induced increase in MMP-9 secretion is dependent of ERa activation. Ethanol could act not only by an increase in the local concentration of estrogens via aromatase overexpression, but also by an ERa ligand-independent activation that we have shown to be mediated by the AMPc/PKA signalling pathway and the A2a adenosine receptor. This receptor could be a new therapeutic target in the treatment of breast carcinoma.Plusieurs études épidémiologiques ont montré qu'une consommation régulière d'alcool augmentait significativement la probabilité de développer un cancer mammaire. Les études réalisées in vitro et in vivo pour confirmer ces données indiquent que l'éthanol peut non seulement induire la cancérogenèse mammaire, mais également stimuler la tumorogenèse et l'invasion des cellules tumorales. Dans la mesure où ces effets semblent liés à l'hormono-dépendance des cellules cancéreuses, notre objectif visait à étudier les mécanismes moléculaires impliqués en utilisant la lignée MCF-7. Nous avons confirmé l'effet stimulateur de l'éthanol sur la prolifération de ces cellules. Celui-ci s'accompagne d'une augmentation du taux d'ERa, de COX-2 et de l'aromatase, enzyme responsable de la biosynthèse des oestrogènes. D'autres alcools tels que le méthanol ou le butanol-1 entraînent quant à eux une diminution significative de la prolifération cellulaire et n'induisent jamais d'augmentation du taux d'aromatase. Dans le contexte de la migration cellulaire, nous avons montré que l'éthanol stimulait la sécrétion des MMP-2 et -9 par les cellules MCF-7. La sécrétion de MMP-9 induite par l'éthanol est dépendante de l'activation de l'ERa. L'alcool pourrait agir non seulement par une production accrue d'oestrogènes liée à la surexpression d'aromatase mais aussi par une activation ligand-indépendante de l'ERa dont nous montrons qu elle est liée à la voie AMPc/PKA et au récepteur A2a à l'adénosine. Ce dernier pourrait constituer une nouvelle cible thérapeutique

Mécanisme d'action de l'éthanol sur la prolifération et la migration des cellules cancéreuses mammaires MCF-7 (implication de la voie de signalisation des oestrogènes)

Plusieurs études épidémiologiques ont montré qu'une consommation régulière d'alcool augmentait significativement la probabilité de développer un cancer mammaire. Les études réalisées in vitro et in vivo pour confirmer ces données indiquent que l'éthanol peut non seulement induire la cancérogenèse mammaire, mais également stimuler la tumorogenèse et l'invasion des cellules tumorales. Dans la mesure où ces effets semblent liés à l'hormono-dépendance des cellules cancéreuses, notre objectif visait a étudier les mécanismes moléculaires impliqués en utilisant la lignée MCF-7. Nous avons confirmé l'effet stimulateur de l'éthanol sur la prolifération de ces cellules. Celui-ci s'accompagne d'une augmentation du taux d'ERa, de COX-2 et de l'aromatase, enzyme responsable de la biosynthèse des oestrogènes. D'autres alcools tels que le méthanol ou le butanol-1 entraînent quant à eux une diminution significative de la prolifération cellulaire et n'induisent jamais d'augmentation du taux d'aromatase. Dans le contexte de la migration cellulaire, nous avons montré que l'éthanol stimulait la sécrétion des MMP-2 et -9 par les cellules MCF-7. La sécrétion de MMP-9 induite par l'éthanol est dépendante de l'activation de l'ERa. L'alcool pourrait agir non seulement par une production accrue d'oestrogènes liée à la surexpression d'aromatase mais aussi par une activation ligand-indépendante de l'ERa dont nous montrons qu elle est liée à la voie AMPc/PKA et au récepteur A2a à l'adénosine. Ce dernier pourrait constituer une nouvelle cible thérapeutique.Many epidemiological studies have shown that chronic alcohol consumption increases significantly the incidence of breast cancer. Moreover, in vitro and in vivo studies show that ethanol can promote not only tumorogenesis but also tumor cells migration. These effects seem to be related to the hormone dependent status of breast cancer cells. The aim of our study was to elucidate the underlying molecular mechanisms by using the MCF-7 breast cancer cell line. First, we have confirmed that ethanol can stimulate the proliferation of these cells. We demonstrated that this effect is associated to an increase in the expression of ERa, COX-2 and aromatase, the enzyme responsible for estrogen synthesis. In contrast, other alcohols, such as methanol or butanol, decrease significantly the proliferation and do not increase the aromatase protein level. In the cell migration context, we have shown that ethanol stimulates the MMP-2 and MMP-9 secretion. This ethanol-induced increase in MMP-9 secretion is dependent of ERa activation. Ethanol could act not only by an increase in the local concentration of estrogens via aromatase overexpression, but also by an ERa ligand-independent activation that we have shown to be mediated by the AMPc/PKA signalling pathway and the A2a adenosine receptor. This receptor could be a new therapeutic target in the treatment of breast carcinoma.NANCY1-SCD Sciences & Techniques (545782101) / SudocSudocFranceF

LRP-1: A Checkpoint for the Extracellular Matrix Proteolysis

Low-density lipoprotein receptor-related protein-(LRP-1) is a large endocytic receptor that binds more than 35 ligands and exhibits signaling properties. Proteinases capable of degrading extracellular matrix (ECM), called matrix proteinases in this paper, are mainly serine proteinases: the activators of plasminogen into plasmin, tissue-type (tPA) and urokinase-type (uPA) plasminogen activators, and the members of the matrix metalloproteinase (MMP) family. LRP-1 is responsible for clearing matrix proteinases, complexed or not with inhibitors. This paper attempts to summarize some aspects on the cellular and molecular bases of endocytic and signaling functions of LRP-1 that modulate extra- and pericellular levels of matrix proteinases

Analysis of the Effects of Different Alcohols on MCF-7 Human Breast Cancer Cells

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Bio-guided isolation of new phenolic compounds from Hippocrepis emerus flowers and investigation of their antioxidant, tyrosinase and elastase inhibitory activities

International audienceThis study presents the bio-guided chemical investigation of a 80% methanol extract of Hippocrepis emerus flowers, a perennial non-climbing shrub. Liquid-liquid partitioning in solvents of increasing polarity combined to biological screening enabled to determine the EtOAc and n-BuOH soluble fractions as the most active parts of the extract. These fractions were chemically profiled by using a 13C NMR-based dereplication method, resulting in the identification of twenty-six compounds. The dereplication process was completed by purification of some unknown or minor compounds of the n-BuOH fraction. Three new glycosylated flavonoids, namely kaempferol-3-O-β-d-glucopyranosyl-7-O-β-d-glucopyranosyl-(1→3)-α-l-rhamnopyranoside (1), isorhamnetin-3-O-β-d-glucopyranosyl-7-O-β-d-glucopyranosyl-(1→3)-α-l-rhamnopyranoside (2) and quercetin-3-O-β-d-glucopyranosyl-7,4′-O-α-l-dirhamnopyranoside (3), together with twelve known compounds (4 – 15) were isolated. Their structures were elucidated by spectroscopic methods including NMR, HR-ESI-MS and UV. The antioxidant activity of fractions and isolated compounds were evaluated using DPPH and hydroxyl radical scavenging and CUPRAC assays. In parallel, their inhibitory properties against mushroom tyrosinase and human neutrophil elastase enzymes were assessed. Three quercetin glycosides exhibited a significant radical-scavenging activity and two flavonoids showed a moderate elastase inhibitory activity

Intrinsic dynamics study identifies two amino acids of TIMP-1 critical for its LRP-1-mediated endocytosis in neurons

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A new gallium complex inhibits tumor cell invasion and matrix metalloproteinase MMP-14 expression and activity

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Low-density lipoprotein receptor-related protein-1 mediates endocytic clearance of tissue inhibitor of metalloproteinases-1 and promotes its cytokine-like activities.

Tissue inhibitor of metalloproteinases-1 (TIMP-1) regulates the extracellular matrix turnover by inhibiting the proteolytic activity of matrix metalloproteinases (MMPs). TIMP-1 also displays MMP-independent activities that influence the behavior of various cell types including neuronal plasticity, but the underlying molecular mechanisms remain mostly unknown. The trans-membrane receptor low-density lipoprotein receptor-related protein-1 (LRP-1) consists of a large extracellular chain with distinct ligand-binding domains that interact with numerous ligands including TIMP-2 and TIMP-3 and a short transmembrane chain with intracellular motifs that allow endocytosis and confer signaling properties to LRP-1. We addressed TIMP-1 interaction with recombinant ligand-binding domains of LRP-1 expressed by CHO cells for endocytosis study, or linked onto sensor chips for surface plasmon resonance analysis. Primary cortical neurons bound and internalized endogenous TIMP-1 through a mechanism mediated by LRP-1. This resulted in inhibition of neurite outgrowth and increased growth cone volume. Using a mutated inactive TIMP-1 variant we showed that TIMP-1 effect on neurone morphology was independent of its MMP inhibitory activity. We conclude that TIMP-1 is a new ligand of LRP-1 and we highlight a new example of its MMP-independent, cytokine-like functions