Leukaemia Inhibitory Factor (LIF) inhibits cancer stem cells tumorigenic properties through hippo kinases activation in gastric cancer

Cancer stem cells (CSCs) present chemo-resistance mechanisms contributing to tumour maintenance and recurrence, making their targeting of utmost importance in gastric cancer (GC) therapy. The Hippo pathway has been implicated in gastric CSC properties and was shown to be regulated by leukaemia inhibitory factor receptor (LIFR) and its ligand LIF in breast cancer. This study aimed to determine LIF’s effect on CSC properties in GC cell lines and patient-derived xenograft (PDX) cells, which remains unexplored. LIF’s treatment effect on CSC markers expression and tumoursphere formation was evaluated. The Hippo kinase inhibitor XMU-MP-1 and/or the JAK1 inhibitor Ruxolitinib were used to determine Hippo and canonical JAK/STAT pathway involvement in gastric CSCs’ response to LIF. Results indicate that LIF decreased tumorigenic and chemo-resistant CSCs, in both GC cell lines and PDX cells. In addition, LIF increased activation of LATS1/2 Hippo kinases, thereby decreasing downstream YAP/TAZ nuclear accumulation and TEAD transcriptional activity. LIF’s anti-CSC effect was reversed by XMU-MP-1 but not by Ruxolitinib treatment, highlighting the opposite effects of these two pathways downstream LIFR. In conclusion, LIF displays anti-CSC properties in GC, through Hippo kinases activation, and could in fine constitute a new CSCs-targeting strategy to help decrease relapse cases and bad prognosis in GC.Ministry of Tertiary Education, Research and Innovation/[]//FranciaLigue Nationale Française Contre le Cancer (French National League against Cancer)/[]//FranciaUniversidad de Costa Rica/[]/UCR/Costa RicaMinisterio de Ciencia, Innovación, Tecnología y Telecomunicaciones/[]/MICITT/Costa RicaFrench National Cancer Institute/[PLBio 2014-152]/INCa/FranciaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Cells

Stem cells isolated from the apical papilla of wisdom teeth (SCAPs) are an attractive model for tissue repair due to their availability, high proliferation rate and potential to differentiate in vitro towards mesodermal and neurogenic lineages. Adult stem cells, such as SCAPs, develop in stem cell niches in which the oxygen concentration [O] is low (3-8% compared with 21% of ambient air). In this work, we evaluate the impact of low [O] on the physiology of SCAPs isolated and processed in parallel at 21% or 3% O without any hyperoxic shock in ambient air during the experiment performed at 3% O. We demonstrate that SCAPs display a higher proliferation capacity at 3% O than in ambient air with elevated expression levels of two cell surface antigens: the alpha-6 integrin subunit (CD49f) and the embryonic stem cell marker (SSEA4). We show that the mesodermal differentiation potential of SCAPs is conserved at early passage in both [O], but is partly lost at late passage and low [O], conditions in which SCAPs proliferate efficiently without any sign of apoptosis. Unexpectedly, we show that autophagic flux is active in SCAPs irrespective of [O] and that this process remains high in cells even after prolonged exposure to 3% O

The Hippo Kinase LATS2 Controls Helicobacter pylori-Induced Epithelial-Mesenchymal Transition and Intestinal Metaplasia in Gastric Mucosa

Gastric carcinoma is related mostly to CagA+-Helicobacter pylori infection, which disrupts the gastric mucosa turnover and elicits an epithelial-mesenchymal transition (EMT) and preneoplastic transdifferentiation. The tumor suppressor Hippo pathway controls stem cell homeostasis; its core, constituted by the large tumor suppressor 2 (LATS2) kinase and its substrate Yes-associated protein 1 (YAP1), was investigated in this context.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

The FunGenES Database: A Genomics Resource for Mouse Embryonic Stem Cell Differentiation

Embryonic stem (ES) cells have high self-renewal capacity and the potential to differentiate into a large variety of cell types. To investigate gene networks operating in pluripotent ES cells and their derivatives, the “Functional Genomics in Embryonic Stem Cells” consortium (FunGenES) has analyzed the transcriptome of mouse ES cells in eleven diverse settings representing sixty-seven experimental conditions. To better illustrate gene expression profiles in mouse ES cells, we have organized the results in an interactive database with a number of features and tools. Specifically, we have generated clusters of transcripts that behave the same way under the entire spectrum of the sixty-seven experimental conditions; we have assembled genes in groups according to their time of expression during successive days of ES cell differentiation; we have included expression profiles of specific gene classes such as transcription regulatory factors and Expressed Sequence Tags; transcripts have been arranged in “Expression Waves” and juxtaposed to genes with opposite or complementary expression patterns; we have designed search engines to display the expression profile of any transcript during ES cell differentiation; gene expression data have been organized in animated graphs of KEGG signaling and metabolic pathways; and finally, we have incorporated advanced functional annotations for individual genes or gene clusters of interest and links to microarray and genomic resources. The FunGenES database provides a comprehensive resource for studies into the biology of ES cells

LIF-Dependent Signaling: New Pieces in the Lego

LIF, a member of the IL6 family of cytokine, displays pleiotropic effects on various cell types and organs. Its critical role in stem cell models (e.g.: murine ES, human mesenchymal cells) and its essential non redundant function during the implantation process of embryos, in eutherian mammals, put this cytokine at the core of many studies aiming to understand its mechanisms of action, which could benefit to medical applications. In addition, its conservation upon evolution raised the challenging question concerning the function of LIF in species in which there is no implantation. We present the recent knowledge about the established and potential functions of LIF in different stem cell models, (embryonic, hematopoietic, mesenchymal, muscle, neural stem cells and iPSC). We will also discuss EVO-DEVO aspects of this multifaceted cytokine

Cellules souches embryonnaires murines (identification de nouveaux acteurs impliqués dans leur maintien en pluripotence ou leur engagement en différenciation)

BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Etude sur les cellules souches embryonnaires de souris (modalités de la pluripotence, de l'engagement en différenciation et de l'établissement de la voie neuronale)

Les cellules souches embryonnaires (ES) de souris sont maintenues pluripotentes en culture en présence de la cytokine Leukemia Inhibitory Factor (LIF). Par analyses "microarray", nous avons caractérisé l'ensemble des cibles transcriptionnelles du LIF et identifié de nouveaux médiateurs impliqués dans la survie et la pluripotence de ces cellules. De plus, nous avons identifié les "gènes de compétence", impliqués dans la transition pluripotence/différenciation. Le retrait du LIF induit l'apoptose d'une partie des cellules différenciées à partir des cellules ES. Dans les cellules en apoptose, la MAPK (Mitogen Activated Protein Kinase) p38a est activée. Le blocage de l'apoptose, par l'utilisation d'un inhibiteur de p38a, entraîne une altération de l'expression des marqueurs de différenciation. Le gène bcl-2, cible directe de p38a, protège les précurseurs différenciés de l'apopotose et favorise la voie neuronale par défaut.Murine embryonic stem (ES) cells remain pluripotent in vitro when grown in the presence of Leukaemia Inhibitory Factor (LIF). By microarray analysis, we have characterized the overall LIF transcriptome and identified new mediators regulating cell survival and pluripotency. Furthermore, we identified "competence genes", involved in transition between pluripotency and commitment. LIF starvation leads to apoptosis of some of the ES-derived differentiated cells. In these apoptotic cells, MAPK (Mitogen Activated Protein Kinase) p38a is activated. Blocking apoptosis by p38a inhibitor leads to an alteration of differentiation markers. Bcl-2, a direct p38a target, protects differentiated precursors from apoptosis and favours neural default pathway.BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

Etude de la balance pluripotence-differenciation des cellules souches embryonnaires murines sous l'effet du LIF (rôle du gène MRAS)

Le LIF (Leukemia Inhibitory factor), une cytokine de la famille de l Interleukine 6, permet le maintien de la pluripotence des cellules souches embryonnaires murines (CSEm) in vitro. Dans le but de comprendre les mécanismes d action du LIF dans ce modèle d étude, une analyse sur puces à ADN a été réalisée et a permis d identifier trois signatures LIF : les gènes Pluri (pour Pluripotence), dont le niveau d expression relatif chute suite au retrait de cette cytokine, et deux catégories de gènes Lifind (pour LIF induit) dont le niveau d expression relatif augmente suite à un ajout de LIF après une culture de 24 ou 48 heures sans cette cytokine. Nous avons mis au point des tests fonctionnels permettant d étudier la fonction des gènes cibles du LIF dans notre modèle d étude. Ainsi, nous avons mis en évidence le rôle d un gène Pluri , Mras/Rras3, une petite GTPase de la famille Ras, dans la régulation de l expression d une part de marqueurs de pluripotence, tels que Oct4 et Nanog et d autre part de marqueurs de différenciation, tels que Lef1 et Fgf5.LIF (Leukemia Inhibitory factor), a cytokine Interleukin 6 family, allows maintaining the pluripotency of murine embryonic stem cells (mESC) in vitro. To understand the mechanisms of action of the LIF in this model, a microarray analysis was conducted and identified three signatures LIF : the Pluri (for Pluripotency) genes, whose the relative level of expression falls following the withdrawal of this cytokine, and two classes of Lifind (for LIF induced) genes, whose the relative expression level increases as a result of LIF addition after a culture of 24 or 48 hours without this cytokine. We have developed functional tests to study the function of the target genes of LIF in our study model. Thus, we have investigated the role of a Pluri gene, Mras/Rras3, a small GTPase of the Ras family, in the regulation of the expression on the one hand of markers of pluripotency, such as Oct4 and Nanog, and on the other hand of differentiation markers, such as Lef1 and Fgf5.BORDEAUX2-Bib. électronique (335229905) / SudocSudocFranceF