Microenvironmental control of malignant growth

The tumor microenvironment (TME) comprises a complex milieu of different cell types, including cancer associated fibroblasts (CAFs) and immune cells, blood vessels, and the extracellular matrix. Through its interaction with cancer cells, it plays an essential role in cancer invasion and metastasis. The inherent complexity of the TME presents a challenge to study it within experimental model systems. It underscores the importance of complementing such research with observation from human tumor tissues, wherein this intricate complexity is preserved. In Paper IV, we introduce a new software designed to explore the Human Protein Atlas, an online database that includes image data on the protein expression across normal and cancerous tissues from immunohistochemically (IHC) stained tissues. In Paper I, we use this software to identify 12 novel proteins expressed in cancerassociated fibroblasts, four revealing connections to Rho-kinase signaling. We contrast their expression across various tumors and against normal tissue fibroblasts, uncovering expression variability among cancer types and confirm their similarities with the myofibroblastic phenotype. In Paper II, we explore the expression of the proteoglycan Decorin, abundantly present in normal connective tissue and having tumor inhibitory properties, showing its downregulation in the connective tissue surrounding tumors. In Paper III, based on our observations in Paper I of the connection of Rhosignaling in CAFs, we study the effects of knocking out the related RhoA in fibroblasts both in vitro and in vivo models. We demonstrate that the knockout fibroblasts compromise their tumor inhibitory capacity, enhancing cancer cell growth, migration, and metastasis. In Paper VI, we develop a new method for analyzing the extensive data within the Human Protein Atlas by developing a deep-learning-based image classifier. Utilizing a limited training image set, we classify all images available for the prostate, identifying 44 new markers of prostate basal cells. In Paper IV, we explore the influence of the TME on cancer cells by systematically analyzing 20 pancreatic cancer patient samples utilizing an IHC panel. We define shifts in cancer cell phenotype relative to tissue localization, including a transition to a more indolent cancer phenotype, an effect on cancer cell proliferation, and a tendency to normalize the cancer cell phenotype. In conclusion, we developed two new methods that enable us to study protein expression in normal and cancerous tissues by enhancing the capabilities of the HPA. We identified new markers of CAFs and revealed a connection to Rhosignaling. Knocking out the related RhoA in experimental systems resulted in the fibroblasts losing their cancer inhibitory capacity. Finally, we show the remarkable plasticity of cancer cells, demonstrating that their phenotype undergoes significant alterations based on their spatial localization within normal tissue

Les romans du Graal et le culte du Précieux Sang

International audiencePlusieurs thèmes de la littérature du Graal reflètent la dévotion à la Passion du Christ, et plus spécialement au Saint Sang. Après avoir esquissé l'histoire des romans français du Graal (fin XIIe -XIIIe siècle), cette communication présente l'identification du Graal et de la lance-quisaigne avec des reliques de la Passion du Christ (Graal : plat de la Cène dans lequel Joseph d'Arimathie a recueilli le sang du Christ ; la lance-qui-saigne : lance par laquelle Longin a transpercé le côté du Christ), puis les visions graaliennes qui mettent en scène le dogme de la transsubstantiation, étroitement lié au culte du sang du Christ

Le prestige des saints aquitains hors d'Aquitaine : Bilan et réflexions autour des Journées d'Études, Centre d'Études Supérieures de Civilisation Médiévale, Poitiers, 2004 et 2005.

International audienceLa quantité des saints aquitains vénérés hors de l’Aquitaine, en particulier au Nord et à l’Est de la Gaule, atteste de leur prestige formidable, comparable à la renommée des saints irlandais. Pour réexaminer les dossiers hagiographiques et pour essayer de comprendre le sens du prestige des saints originaires de l’Aquitaine, deux journées d’études ont eu lieu à Poitiers. Cet article présente les résultats et les pistes de recherche de ces rencontres. Après avoir défini l’Aquitaine chez les auteurs antiques et médiévaux (Cécile Treffort), le problème des modèles hagiographiques et le développement du topos aquitain dans cette littérature ont été traités (Anne-Marie Helvétius, Alain Dierkens, Isabelle Westeel, Philippe George, Klaus Krönert). On a pu constater une tendance à la ramification et aux apparentements hagiographiques: soit par le rattachement des fils et filles spirituels aux saints importants, soit par l’invention des liens familiaux avec eux (contributions d’Anne Wagner, d’Alain Dierkens). Parmi les saints originaires d’Aquitaine, figure aussi un certain nombre de “martyrs spéciaux”, c’est-à-dire victimes de fausses accusations ou de motivations crapuleuses (Emmeran, présenté par Thierry Lesieur, Sauve de Valenciennes, présentée par A.-M. Helvétius, Bertaire et Atalène, présentés par A. Wagner). L’influence du modèle irlandais dans l’hagiographie des saints aquitains (Jean-Michel Picard), voire la double appartenance de certains saints (Erhard, évêque de Ratisbonne, présenté par Michèle Gaillard) ont pu être soulignées. Enfin, quelques cultes de saints aquitains se sont implantés au Sud, comme par exemple celui de saint Alleaume (ou Lesmes; présenté par Angeles Garcia de la Borbolla). Un presque-saint est un certain Waltharius, héros d’une épopée latine, mais qui se retire au monastère de Novalèse dont il devient le protecteur (Edina Bozóky)

Les romans du Graal et le culte du Précieux Sang

Plusieurs thèmes de la littérature du Graal reflètent la dévotion à la Passion du Christ, et plus spécialement au Saint Sang. Après avoir esquissé l’histoire des romans français du Graal (fin XIIe-XIIIe siècle), cette communication présente l’identification du Graal et de la lance-qui-saigne avec des reliques de la Passion du Christ (Graal : plat de la Cène dans lequel Joseph d’Arimathie a recueilli le sang du Christ ; la lance-qui-saigne : lance par laquelle Longin a transpercé le côté du Christ), puis les visions graaliennes qui mettent en scène le dogme de la transsubstantiation, étroitement lié au culte du sang du Christ.Several themes in Grail literature reflect the devotion to the Passion of Christ, and especially to the Holy Blood. After outlining the development of French Grail romances (late 12th to 13th centuries) this paper will set out the ways in which the Grail and the Bleeding Lance came to be identified with relics from the Passion of Christ (the Grail as a dish from the Last Supper in which Joseph of Arimathea received Christ's blood; the Bleeding Lance as the lance with which Longinus pierced Christ’s side). Finally, visions of the Grail will be presented as the enactment of the dogma of transubstantiation, which is closely linked to the religious significance of the Blood of Christ

Les moyens de la protection privée

Un foisonnement d’usages, de coutumes, de formules et d’objets attestent que dans la pratique de la religion de tous les jours, qu’on appelle aussi « domestique », l’homme médiéval se souciait avant tout de se préserver des dangers et des maladies qui menaçaient sa propre personne, sa famille et ses biens. Pour la protection et la guérison, aux XIIIe-XVe siècles, on s’entourait d’une multitude de moyens ayant une connotation spirituelle. Censée établir une frontière invisible pour empêcher le..

Biophysical Approaches Facilitate Computational Drug Discovery for ATP-Binding Cassette Proteins

Although membrane proteins represent most therapeutically relevant drug targets, the availability of atomic resolution structures for this class of proteins has been limited. Structural characterization has been hampered by the biophysical nature of these polytopic transporters, receptors, and channels, and recent innovations to in vitro techniques aim to mitigate these challenges. One such class of membrane proteins, the ATP-binding cassette (ABC) superfamily, are broadly expressed throughout the human body, required for normal physiology and disease-causing when mutated, yet lacks sufficient structural representation in the Protein Data Bank. However, recent improvements to biophysical techniques (e.g., cryo-electron microscopy) have allowed for previously “hard-to-study” ABC proteins to be characterized at high resolution, providing insight into molecular mechanisms-of-action as well as revealing novel druggable sites for therapy design. These new advances provide ample opportunity for computational methods (e.g., virtual screening, molecular dynamics simulations, and structure-based drug design) to catalyze the discovery of novel small molecule therapeutics that can be easily translated from computer to bench and subsequently to the patient’s bedside. In this review, we explore the utility of recent advances in biophysical methods coupled with well-established in silico techniques towards drug development for diseases caused by dysfunctional ABC proteins

Development and characterization of synthetic antibodies binding to the cystic fibrosis conductance regulator

Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel in the apical surface of epithelial cells in the airway and gastrointestinal tract, and mutation of CFTR is the underlying cause of cystic fibrosis. However, the precise molecular details of the structure and function of CFTR in native and disease states remains elusive and cystic fibrosis researchers are hindered by a lack of high specificity, high affinity binding reagents for use in structural and biological studies. Here, we describe a panel of synthetic antigen-binding fragments (Fabs) isolated from a phage-displayed library that are specific for intracellular domains of CFTR that include the nucleotide-binding domains (NBD1 and NBD2), the R-region, and the regulatory insertion loop of NBD1. Binding assays performed under conditions that promote the native fold of the protein demonstrated that all Fabs recognized full-length CFTR. However, only the NBD1-specific Fab recognized denatured CFTR by western blot, suggesting a conformational epitope requirement for the other Fabs. Surface plasmon resonance experiments showed that the R-region Fab binds with high affinity to both the phosphorylated and unphosphorylated R-region. In addition, NMR analysis of bound versus unbound R-region revealed a distinct conformational effect upon Fab binding. We further defined residues involved with antibody recognition using an overlapping peptide array. In summary, we describe methodology complementary to previous hybridoma-based efforts to develop antibody reagents to CFTR, and introduce a synthetic antibody panel to aid structural and biological studies

A new platform for high-throughput therapy testing on iPSC-derived lung progenitor cells from cystic fibrosis patients

For those people with cystic fibrosis carrying rare CFTR mutations not responding to currently available therapies, there is an unmet need for relevant tissue models for therapy development. Here, we describe a new testing platform that employs patient-specific induced pluripotent stem cells (iPSCs) differentiated to lung progenitor cells that can be studied using a dynamic, high-throughput fluorescence-based assay of CFTR channel activity. Our proof-of-concept studies support the potential use of this platform, together with a Canadian bioresource that contains iPSC lines and matched nasal cultures from people with rare mutations, to advance patient-oriented therapy development. Interventions identified in the high-throughput, stem cell-based model and validated in primary nasal cultures from the same person have the potential to be advanced as therapies

RhoA knockout fibroblasts lose tumor-inhibitory capacity in vitro and promote tumor growth in vivo

Fibroblasts are a main player in the tumor-inhibitory microenvironment. Upon tumor initiation and progression, fibroblasts can lose their tumor-inhibitory capacity and promote tumor growth. The molecular mechanisms that underlie this switch have not been defined completely. Previously, we identified four proteins over-expressed in cancer-associated fibroblasts and linked to Rho GTPase signaling. Here, we show that knocking out the Ras homolog family member A (RhoA) gene in normal fibroblasts decreased their tumor-inhibitory capacity, as judged by neighbor suppression in vitro and accompanied by promotion of tumor growth in vivo. This also induced PC3 cancer cell motility and increased colony size in 2D cultures. RhoA knockout in fibroblasts induced vimentin intermediate filament reorganization, accompanied by reduced contractile force and increased stiffness of cells. There was also loss of wide F-actin stress fibers and large focal adhesions. In addition, we observed a significant loss of a-smooth muscle actin, which indicates a difference between RhoA knockout fibroblasts and classic cancer-associated fibroblasts. In 3D collagen matrix, RhoA knockout reduced fibroblast branching and meshwork formation and resulted in more compactly clustered tumor-cell colonies in coculture with PC3 cells, which might boost tumor stem-like properties. Coculturing RhoA knockout fibroblasts and PC3 cells induced expression of proinflammatory genes in both. Inflammatory mediators may induce tumor cell stemness. Network enrichment analysis of transcriptomic changes, however, revealed that the Rho signaling pathway per se was significantly triggered only after coculturing with tumor cells. Taken together, our findings in vivo and in vitro indicate that Rho signaling governs the inhibitory effects by fibroblasts on tumor-cell growth.Peer reviewe

Des saints et des martyrs

This volume of Problems in the History of Religions is dedicated to Professor Alain Dierkens, a medievalist specializing in the study of religion and director of the collection from 1991 to 2012.Ce volume des Problèmes d'histoire des religions est dédié au Professeur Alain Dierkens, médiéviste spécialisé dans l’étude du religieux et directeur de la collection de 1991 à 2012