Travaux R&D menés sur la conception et l’implantation de zones tampons réactives au sein des bassins versants agricoles pour atténuer les flux de nitrates

Dans les bassins versants marqués par une agriculture intensive, les limites imposées à l’utilisation de fertilisants et donc de nitrates ne suffiront probablement pas à obtenir un bon état des eaux de surface. Suite à la fermeture d’une usine de production d’eau potable en Bretagne (bassin versant de la rivière Ic) du fait de concentrations en nitrates supérieures à 50 mg-NO3–/L, Veolia a initié le projet de recherche Aquisafe. Son objectif était 1) de démontrer les performances épuratrices de zones réactives simples (de type fossés réactifs, lagunes, …) collectant les eaux de ruissellement et de drainage avant leur retour à la rivière, 2) de développer des outils (modèle numérique SWAT/SIG) permettant de localiser où installer les systèmes au sein des bassins versants, mais aussi 3) d’évaluer l’efficacité à attendre des stratégies envisagées à l’échelle d’un bassin versant via l’utilisation d’un modèle numérique (SWAT). Afin d’atteindre le premier objectif, de nombreux travaux ont été effectués à différentes échelles (laboratoire/plateforme expérimentale-pilote/grandeur réelle). C’est en laboratoire que plusieurs types de matériaux ainsi que les temps de résidence nécessaires à une dénitrification efficace ont été évalués (Krause Camilo et al., 2013. Ecological Engineering, 55, 101–113). À l’échelle de la plateforme expérimentale (pilote), des zones réactives construites sur la base des premiers résultats en laboratoire ont fait l’objet d’études sur l’influence de la température et des débits durant deux ans. Il a été démontré qu’une réduction de 80 % des nitrates peut être atteinte grâce à de tels systèmes. Enfin, les connaissances acquises ont pu être vérifiées in situ sur trois zones réactives installées en Bretagne dans le bassin versant de la rivière Ic. Une lagune, un bassin d’infiltration ainsi qu’un fossé réactif ont été construits et suivis durant deux saisons pluvieuses. Les règles de dimensionnement obtenues à petite échelle ont ainsi pu être validées (Wicke et al., 2014. Abstract accepted for IWA 14th International Conference on Wetland Systems for Water Pollution Control (ICWS), Oct. 2014). Au préalable, la localisation des sites en Bretagne s’est faite grâce au modèle numérique SWAT (Soil and Water Assessment Tool). Ce modèle a permis de calculer les flux d’eau et d’éléments nutritifs, et ainsi de définir les zones les plus contributrices à la pollution en nitrates, où il convenait d’installer en priorité les zones tampons. En complément, une méthode simple basée sur les Systèmes d’information Géographique (SIG), nécessitant moins de données que le modèle et permettant une localisation plus fine, a été développée et testée spécifiquement dans ce contexte et s’est avérée prometteuse (Orlikowski et al., 2011. Water Science and Technology, 892–898). Enfin, le modèle SWAT a été complété d’un module « zone réactive » pour permettre d’évaluer la performance des différentes stratégies d’aménagement et de gestion du bassin versant quant à l’amélioration de la qualité de l’eau à la prise d’eau pour la production d’eau potable. De premières simulations de scénarios ont ainsi pu être réalisées. Grâce au projet Aquisafe, les outils nécessaires à la conception et l’implantation de zones tampons pour atténuer les flux de nitrates au niveau des bassins versants sont ainsi disponibles

Cross Modulation between the Androgen Receptor Axis and Protocadherin-PC in Mediating Neuroendocrine Transdifferentiation and Therapeutic Resistance of Prostate Cancer

Castration-resistant prostate cancers (CRPCs) that relapse after androgen deprivation therapies (ADTs) are responsible for the majority of mortalities from prostate cancer (PCa). While mechanisms enabling recurrent activity of androgen receptor (AR) are certainly involved in the development of CRPC, there may be factors that contribute to the process including acquired neuroendocrine (NE) cell-like behaviors working through alternate (non-AR) cell signaling systems or AR-dependent mechanisms. In this study, we explore the potential relationship between the AR axis and a novel putative marker of NE differentiation, the human male protocadherin-PC (PCDH-PC), in vitro and in human situations. We found evidence for an NE transdifferentiation process and PCDH-PC expression as an early-onset adaptive mechanism following ADT and elucidate AR as a key regulator of PCDH-PC expression. PCDH-PC overexpression, in turn, attenuates the ligand-dependent activity of the AR, enabling certain prostate tumor clones to assume a more NE phenotype and promoting their survival under diverse stress conditions. Acquisition of an NE phenotype by PCa cells positively correlated with resistance to cytotoxic agents including docetaxel, a taxane chemotherapy approved for the treatment of patients with metastatic CRPC. Furthermore, knockdown of PCDH-PC in cells that have undergone an NE transdifferentiation partially sensitized cells to docetaxel. Together, these results reveal a reciprocal regulation between the AR axis and PCDH-PC signals, observed both in vitro and in vivo, with potential implications in coordinating NE transdifferentiation processes and progression of PCa toward hormonal and chemoresistance

Cross modulation between the androgen receptor axis and protocadherin-PC in mediating neuroendocrine transdifferentiation and therapeutic resistance of prostate cancer.: PCDH-PC/AR cross-talk in driving NE differentiation

International audienceCastration-resistant prostate cancers (CRPCs) that relapse after androgen deprivation therapies (ADTs) are responsible for the majority of mortalities from prostate cancer (PCa). While mechanisms enabling recurrent activity of androgen receptor (AR) are certainly involved in the development of CRPC, there may be factors that contribute to the process including acquired neuroendocrine (NE) cell-like behaviors working through alternate (non-AR) cell signaling systems or AR-dependent mechanisms. In this study, we explore the potential relationship between the AR axis and a novel putative marker of NE differentiation, the human male protocadherin-PC (PCDH-PC), in vitro and in human situations. We found evidence for an NE transdifferentiation process and PCDH-PC expression as an early-onset adaptive mechanism following ADT and elucidate AR as a key regulator of PCDH-PC expression. PCDH-PC overexpression, in turn, attenuates the ligand-dependent activity of the AR, enabling certain prostate tumor clones to assume a more NE phenotype and promoting their survival under diverse stress conditions. Acquisition of an NE phenotype by PCa cells positively correlated with resistance to cytotoxic agents including docetaxel, a taxane chemotherapy approved for the treatment of patients with metastatic CRPC. Furthermore, knockdown of PCDH-PC in cells that have undergone an NE transdifferentiation partially sensitized cells to docetaxel. Together, these results reveal a reciprocal regulation between the AR axis and PCDH-PC signals, observed both in vitro and in vivo, with potential implications in coordinating NE transdifferentiation processes and progression of PCa toward hormonal and chemoresistance

Implication of NPM1 phosphorylation and preclinical evaluation of the nucleoprotein antagonist N6L in prostate cancer

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Overexpression of Nucleolin and Associated Genes in Prostate Cancer

International audienceProstate cancer (PCa) is the second most frequent cancer and the fifth leading cause of cancer death in men worldwide. If local PCa presents a favorable prognosis, available treatments for advanced PCa display limiting benefits due to therapeutic resistances. Nucleolin (NCL) is a ubiquitous protein involved in numerous cell processes, such as ribosome biogenesis, cell cycles, or angiogenesis. NCL is overexpressed in several tumor types in which it has been proposed as a diagnostic and prognostic biomarker. In PCa, NCL has mainly been studied as a target for new therapeutic agents. Nevertheless, little data are available concerning its expression in patient tissues. Here, we investigated the expression of NCL using a new cohort from Mondor Hospital and data from published cohorts. Results were then compared with NCL expression using in vitro models. NCL was overexpressed in PCa tissues compared to the normal tissues, but no prognostic values were demonstrated. Nine genes were highly co-expressed with NCL in patient tissues and tumor prostate cell lines. Our data demonstrate that NCL is an interesting diagnostic biomarker and propose a signature of genes co-expressed with NCL

Class III beta-tubulin expression predicts prostate tumor aggressiveness and patient response to docetaxel-based chemotherapy.

International audienceExpression of class III β-tubulin (βIII-tubulin) correlates with tumor progression and resistance to taxane-based therapies for several human malignancies, but its use as a biomarker of tumor behavior in prostate cancer (PCa) remains largely unexplored. Here, we describe βIII-tubulin immunohistochemical staining patterns of prostate tumors obtained from a broad spectrum of PCa patients, some of whom subsequently received docetaxel therapy for castration-resistant PCa (CRPC). Elevated βIII-tubulin expression was significantly associated with tumor aggressiveness in PCa patients with presumed localized disease, as it was found to be an independent marker of biochemical recurrence after treatment. Additionally, βIII-tubulin expression in tumor cells was an independent predictor of lower overall survival for patients receiving docetaxel-based chemotherapy for CRPC. Manipulation of βIII-tubulin expression in human PCa cell lines using a human βIII-tubulin expression vector or βIII-tubulin small interfering RNA altered cell survival in response to docetaxel treatment in a manner that supports a role for βIII-tubulin expression as a mediator of PCa cell resistance to docetaxel therapy. Our findings suggest a role for βIII-tubulin as candidate theranostic biomarker to predict the response to docetaxel-based chemotherapy as well as to target for treatment of docetaxel-resistant CRPC

BPH gene expression profile associated to prostate gland volume.

International audienceThe aim of the current study was to analyze gene expression profiles in benign prostatic hyperplasia and to compare them with phenotypic properties. Thirty-seven specimens of benign prostatic hyperplasia were obtained from symptomatic patients undergoing surgery. RNA was extracted and hybridized to Affymetrix Chips containing 54,000 gene expression probes. Gene expression profiles were analyzed using cluster, TreeView, and significance analysis of microarrays softwares. In an initial unsupervised analysis, our 37 samples clustered hierarchically in 2 groups of 18 and 19 samples, respectively. Five clinical parameters were statistically different between the 2 groups: in group 1 compared with group 2, patients had larger prostate glands, had higher prostate specific antigen levels, were more likely to be treated by alpha blockers, to be operated by prostatectomy, and to have major irritative symptoms. The sole independent parameter associated with this dichotome clustering, however, was the prostate gland volume. Therefore, the role of prostate volume was explored in a supervised analysis. Gene expression of prostate glands 60 mL were compared using significance analysis of microarrays and 227 genes were found differentially expressed between the 2 groups (>2 change and false discovery rate of <5%). Several specific pathways including growth factors genes, cell cycle genes, apoptose genes, inflammation genes, and androgen regulated genes, displayed major differences between small and large prostate glands

Comparative expression of Hedgehog ligands at different stages of prostate carcinoma progression.

International audienceRecent studies have revealed the potential involvement of Hedgehog (Hh) signalling in proliferation and invasive behaviour of prostate carcinoma (PCa). The aim of this study was to specify the role of Sonic Hh (Shh), Desert Hh (Dhh) and Indian Hh (Ihh) in the natural history of PCa. Hh ligands expression was compared in primary hormone-naive PCa (HNPC), hormone-treated PCa (HTPC) and hormone-refractory PCa (HRPC), using immunohistochemistry. Shh and Dhh were expressed by both epithelial and stromal cells of prostate tissues. Ihh was only expressed by stromal cells. For the three ligands, mRNA and immunostaining were not correlated. In HNPC, Shh epithelial expression was significantly associated with high Gleason scores (p = 0.03), metastatic lymph nodes (p = 0.004) and Dhh epithelial staining was associated with high pT stages (p = 0.003), seminal vesicle invasion (p = 0.03) and bladder neck invasion (p = 0.0008). Negative Shh staining in stromal cells was associated with high Gleason scores (p = 0.015), high pT stages (p = 0.01) and bladder neck invasion (p = 0.04). Concomitant absence of Shh and Dhh expression in stromal cells was an independent prognostic parameter for biological recurrence on multivariate analysis (p = 0.01). Epithelial expression of Shh and Dhh was increased in HTPC compared to HNPC (p = 0.02 and p = 0.04). Interestingly, in vitro, transcript analysis also showed increased expression of these 2 Hh ligands when androgen-sensitive LNCaP cells were maintained in androgen-free medium mimicking hormonal therapy. Epithelial expression of Dhh was increased (p < 0.0001) in HRPC compared to HNPC, while stromal expression of Shh and Dhh was decreased (p < 0.0001). In conclusion, the Hh signalling pathway is associated with pejorative pathological parameters in HNPC and is up-regulated in epithelial cells of HTPC and HRPC. Moreover, the lack of Hh molecules in stromal cells seems to be associated with invasive and hormone-refractory behaviours and suggests specific changes in stromal-epithelial crosstalks during PCa progression

CD8+ Cytotoxic Immune Infiltrate in Non-Muscle Invasive Bladder Cancer: A Standardized Methodology to Study Association with Clinico-Pathological Features and Prognosis.

BACKGROUND Major interest lies in the evaluation of immune infiltrate in bladder cancer. CD8+ cytotoxic lymphocytes are key effectors of adaptive immune response. OBJECTIVES The aims of the study were to set up a standardized methodology for CD8+ lymphocytes estimation in NMIBC and investigate how intra-tumoral heterogeneity influences CD8+ immune infiltrate. METHODS We considered 995 NMIBC included in the Spanish Bladder Cancer (SBC)/EPICURO Study. Duplicate 0.6mm TMA spots and paired full sections (FS) for 50 selected cases were double stained with anti-pan cytokeratin antibody and anti-CD8 antibody. Slides were digitalized and CD8+ cells were automatically counted after tissue recognition (tumor vs stroma). Spatial heterogeneity was assessed and a resampling strategy was applied to estimate the proper number of 0.6mm TMA spots providing an adequate CD8+ cell estimate. Association between CD8+ count and expression of urothelial differentiation markers was estimated. Cox regression models were performed to assess association between CD8+ cell count and risk of recurrence and progression. RESULTS Microscopic examination of full sections showed spatial heterogeneity for CD8+ infiltrates. Simulation analyses demonstrated that 5 TMA regions provided a correct sampling of tumor and stromal compartments in Ta while 2 and 6 TMA regions were necessary in T1, respectively. CD8+ cells infiltration was associated with stage, regardless of the histological compartment analyzed (median CD8+ /mm2 were 25/mm2 and 129/mm2 in tumor and stroma respectively in Ta and 111/mm2 and 344/mm2 in T1; p-value = 0.006). CD8+ infiltration in tumor compartment was significantly associated with low FGFR3 expression. CD8+/mm2 count in the tumor compartment was not associated with prognosis. CONCLUSION Differences identified between Ta and T1 tumours supported the hypothesis that rigorous efforts should be placed in proper study design. These results provide a new framework to investigate microenvironment complexity in bladder cancer.The work was partially supported by Fondo de Investigaciones Sanitarias (FIS, #PI00-0745, #PI05-1436, and #PI06-1614) and Red Tematica de Investigacion Cooperativa en Cancer (RTICC, #RD12/0036/0050 and #RD12/0036/0034), Instituto de Salud Carlos III; and Asociacion Espanola Contra el Cancer (AECC), Spain; the Intramural Research Program of the Division of Cancer Epidemiology and Genetics, National Cancer Institute, USA (Contract NCI NO2-CP-11015); and EU-FP7-HEALTH-F2-2008-201663-UROMOL and EU-7FP-HEALTH-TransBioBC #601933. AML was funded by a fellowship of the European Urological Scholarship Program from the European Association of Urology (EUSP Scholarship S-01-2013).S