149 results on '"Freund JN"'
Search Results
2. Lactase is unchanged in suckling mice fed with lactose-free milk
- Author
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Jost, B., Isabelle DULUC, Vilotte, Jl, Freund, Jn, Unité de recherche Génétique Biochimique et Cytogénétique (LGBC), Institut National de la Recherche Agronomique (INRA), and ProdInra, Migration
- Subjects
[SDV.GEN]Life Sciences [q-bio]/Genetics ,[SDV.GEN] Life Sciences [q-bio]/Genetics - Abstract
*INRA Laboratoire de génétique biochimique et cytogénétique Jouy-en-Josas (FRA); International audience
- Published
- 1998
3. Prédigestion d'un composant du lait, le lactose, dans la glande mammaire.
- Author
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Freund, JN, primary
- Published
- 1999
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4. Lactase Expression is Controlled Differently in the Jejunum and Ileum During Development in Rats
- Author
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Freund, JN, primary, Deluc, I, additional, Raul, F., additional, Montgomery, Robert K., additional, and Grand, Richard J., additional
- Published
- 1992
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5. Nutritional control of intestinal lactase in the rat
- Author
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Duluc, I., primary, Galluser, M., additional, Freund, JN, additional, and Raul, F., additional
- Published
- 1992
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6. Wnt/beta-catenin signaling regulates the expression of the homeobox gene Cdx1 in embryonic intestine
- Author
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Lickert, H., Domon, C., Huls, G., Wehrle, C., Isabelle DULUC, Clevers, H., Meyer, Bi, Freund, Jn, Kemler, R., and Hubrecht Institute for Developmental Biology and Stem Cell Research
7. RAT LACTASE ACTIVITY AND MESSENGER-RNA EXPRESSION IN RELATION TO THE THYROID AND CORTICOID STATUS
- Author
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Freund, Jn, Foltzerjourdainne, C., Isabelle DULUC, Galluser, M., Gosse, F., and Raul, F.
8. DIFFERENT EXPRESSION OF THE MESSENGER-RNA DETECTED BY THE CDNA FOR FETAL-RAT LACTASE IN THE JEJUNUM AND COLON
- Author
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Isabelle DULUC, Freund, Jn, Mantei, N., and Raul, F.
9. INTESTINAL LACTASE EXPRESSION IS DIFFERENTIALLY REGULATED IN THE RAT JEJUNUM AND COLON
- Author
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Isabelle DULUC, Freund, Jn, Foltzerjourdainne, C., Gosse, F., and Raul, F.
10. Activity of the rat lactase gene promoter in transfected human colon cancer cells
- Author
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Boukamel, R., Neuville, P., Isabelle DULUC, and Freund, Jn
11. Macrophage depletion overcomes human hematopoietic cell engraftment failure in zebrafish embryo.
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El Omar R, Abdellaoui N, Coulibaly ST, Fontenille L, Lanza F, Gachet C, Freund JN, Negroni M, Kissa K, and Tavian M
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- Animals, Humans, Embryo, Nonmammalian metabolism, Transplantation, Heterologous, Phagocytosis, Zebrafish embryology, Macrophages metabolism, Hematopoietic Stem Cells metabolism, Hematopoietic Stem Cell Transplantation methods
- Abstract
Zebrafish is widely adopted as a grafting model for studying human development and diseases. Current zebrafish xenotransplantations are performed using embryo recipients, as the adaptive immune system, responsible for host versus graft rejection, only reaches maturity at juvenile stage. However, transplanted primary human hematopoietic stem/progenitor cells (HSC) rapidly disappear even in zebrafish embryos, suggesting that another barrier to transplantation exists before the onset of adaptive immunity. Here, using a labelled macrophage zebrafish line, we demonstrated that engraftment of human HSC induces a massive recruitment of macrophages which rapidly phagocyte transplanted cells. Macrophages depletion, by chemical or pharmacological treatments, significantly improved the uptake and survival of transplanted cells, demonstrating the crucial implication of these innate immune cells for the successful engraftment of human cells in zebrafish. Beyond identifying the reasons for human hematopoietic cell engraftment failure, this work images the fate of human cells in real time over several days in macrophage-depleted zebrafish embryos., (© 2024. The Author(s).)
- Published
- 2024
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12. CD32 captures committed haemogenic endothelial cells during human embryonic development.
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Scarfò R, Randolph LN, Abou Alezz M, El Khoury M, Gersch A, Li ZY, Luff SA, Tavosanis A, Ferrari Ramondo G, Valsoni S, Cascione S, Didelon E, Passerini L, Amodio G, Brandas C, Villa A, Gregori S, Merelli I, Freund JN, Sturgeon CM, Tavian M, and Ditadi A
- Subjects
- Humans, Cell Differentiation, Cell Lineage, Cells, Cultured, Embryo, Mammalian metabolism, Embryo, Mammalian cytology, Endothelial Cells metabolism, Endothelial Cells cytology, Gene Expression Profiling, Gene Expression Regulation, Developmental, Hemangioblasts metabolism, Hemangioblasts cytology, Human Embryonic Stem Cells metabolism, Human Embryonic Stem Cells cytology, Pluripotent Stem Cells metabolism, Pluripotent Stem Cells cytology, Transcriptome, Embryonic Development genetics, Hematopoiesis genetics, Receptors, IgG metabolism, Receptors, IgG genetics
- Abstract
During embryonic development, blood cells emerge from specialized endothelial cells, named haemogenic endothelial cells (HECs). As HECs are rare and only transiently found in early developing embryos, it remains difficult to distinguish them from endothelial cells. Here we performed transcriptomic analysis of 28- to 32-day human embryos and observed that the expression of Fc receptor CD32 (FCGR2B) is highly enriched in the endothelial cell population that contains HECs. Functional analyses using human embryonic and human pluripotent stem cell-derived endothelial cells revealed that robust multilineage haematopoietic potential is harboured within CD32
+ endothelial cells and showed that 90% of CD32+ endothelial cells are bona fide HECs. Remarkably, these analyses indicated that HECs progress through different states, culminating in FCGR2B expression, at which point cells are irreversibly committed to a haematopoietic fate. These findings provide a precise method for isolating HECs from human embryos and human pluripotent stem cell cultures, thus allowing the efficient generation of haematopoietic cells in vitro., (© 2024. The Author(s).)- Published
- 2024
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13. MAGT1 Deficiency Dysregulates Platelet Cation Homeostasis and Accelerates Arterial Thrombosis and Ischemic Stroke in Mice.
- Author
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Gotru SK, Mammadova-Bach E, Sogkas G, Schuhmann MK, Schmitt K, Kraft P, Herterich S, Mamtimin M, Pinarci A, Beck S, Stritt S, Han C, Ren P, Freund JN, Klemann C, Ringshausen FC, Heemskerk JWM, Dietrich A, Nieswandt B, Stoll G, Gudermann T, and Braun A
- Subjects
- Animals, Humans, Mice, Blood Platelets metabolism, Calcium metabolism, Cations metabolism, Magnesium metabolism, Platelet Activation, Platelet Aggregation, Platelet Membrane Glycoproteins metabolism, TRPC6 Cation Channel metabolism, Homeostasis, Ischemic Stroke genetics, Ischemic Stroke complications, Ischemic Stroke metabolism, Thrombosis genetics, Thrombosis metabolism, Infarction, Middle Cerebral Artery, Cation Transport Proteins deficiency
- Abstract
Background: MAGT1 (magnesium transporter 1) is a subunit of the oligosaccharide protein complex with thiol-disulfide oxidoreductase activity, supporting the process of N-glycosylation. MAGT1 deficiency was detected in human patients with X-linked immunodeficiency with magnesium defect syndrome and congenital disorders of glycosylation, resulting in decreased cation responses in lymphocytes, thereby inhibiting the immune response against viral infections. Curative hematopoietic stem cell transplantation of patients with X-linked immunodeficiency with magnesium defect causes fatal bleeding and thrombotic complications., Methods: We studied the role of MAGT1 deficiency in platelet function in relation to arterial thrombosis and hemostasis using several in vitro experimental settings and in vivo models of arterial thrombosis and transient middle cerebral artery occlusion model of ischemic stroke., Results: MAGT1-deficient mice ( Magt1
-/y ) displayed accelerated occlusive arterial thrombus formation in vivo, a shortened bleeding time, and profound brain damage upon focal cerebral ischemia. These defects resulted in increased calcium influx and enhanced second wave mediator release, which further reinforced platelet reactivity and aggregation responses. Supplementation of MgCl2 or pharmacological blockade of TRPC6 (transient receptor potential cation channel, subfamily C, member 6) channel, but not inhibition of store-operated calcium entry, normalized the aggregation responses of Magt1-/y platelets to the control level. GP (glycoprotein) VI activation of Magt1-/y platelets resulted in hyperphosphorylation of Syk (spleen tyrosine kinase), LAT (linker for activation of T cells), and PLC (phospholipase C) γ2, whereas the inhibitory loop regulated by PKC (protein kinase C) was impaired. A hyperaggregation response to the GPVI agonist was confirmed in human platelets isolated from a MAGT1-deficient (X-linked immunodeficiency with magnesium defect) patient. Haploinsufficiency of TRPC6 in Magt1-/y mice could normalize GPVI signaling, platelet aggregation, and thrombus formation in vivo., Conclusions: These results suggest that MAGT1 and TRPC6 are functionally linked. Therefore, deficiency or impaired functionality of MAGT1 could be a potential risk factor for arterial thrombosis and stroke., Competing Interests: Disclosures None.- Published
- 2023
- Full Text
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14. General transcription factor TAF4 antagonizes epigenetic silencing by Polycomb to maintain intestine stem cell functions.
- Author
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Säisä-Borreill S, Davidson G, Kleiber T, Thevenot A, Martin E, Mondot S, Blottière H, Helleux A, Mengus G, Plateroti M, Duluc I, Davidson I, and Freund JN
- Subjects
- Mice, Animals, Cell Differentiation genetics, Transcription Factor TFIID genetics, Intestinal Mucosa metabolism, Polycomb Repressive Complex 2 metabolism, Epigenesis, Genetic, Stem Cells metabolism, Drosophila Proteins metabolism
- Abstract
Taf4 (TATA-box binding protein-associated factor 4) is a subunit of the general transcription factor TFIID, a component of the RNA polymerase II pre-initiation complex that interacts with tissue-specific transcription factors to regulate gene expression. Properly regulated gene expression is particularly important in the intestinal epithelium that is constantly renewed from stem cells. Tissue-specific inactivation of Taf4 in murine intestinal epithelium during embryogenesis compromised gut morphogenesis and the emergence of adult-type stem cells. In adults, Taf4 loss impacted the stem cell compartment and associated Paneth cells in the stem cell niche, epithelial turnover and differentiation of mature cells, thus exacerbating the response to inflammatory challenge. Taf4 inactivation ex vivo in enteroids prevented budding formation and maintenance and caused broad chromatin remodeling and a strong reduction in the numbers of stem and progenitor cells with a concomitant increase in an undifferentiated cell population that displayed high activity of the Ezh2 and Suz12 components of Polycomb Repressive Complex 2 (PRC2). Treatment of Taf4-mutant enteroids with a specific Ezh2 inhibitor restored buddings, cell proliferation and the stem/progenitor compartment. Taf4 loss also led to increased PRC2 activity in cells of adult crypts associated with modification of the immune/inflammatory microenvironment that potentiated Apc-driven tumorigenesis. Our results reveal a novel function of Taf4 in antagonizing PRC2-mediated repression of the stem cell gene expression program to assure normal development, homeostasis, and immune-microenvironment of the intestinal epithelium., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
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15. The Appendix Orchestrates T-Cell Mediated Immunosurveillance in Colitis-Associated Cancer.
- Author
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Collard MK, Tourneur-Marsille J, Uzzan M, Albuquerque M, Roy M, Dumay A, Freund JN, Hugot JP, Guedj N, Treton X, Panis Y, and Ogier-Denis E
- Subjects
- Humans, Male, Animals, Mice, Monitoring, Immunologic, Azoxymethane, Appendix pathology, Colitis-Associated Neoplasms, Appendicitis surgery, Colitis, Ulcerative pathology, Colonic Neoplasms pathology
- Abstract
Background & Aims: Although appendectomy may reduce colorectal inflammation in patients with ulcerative colitis (UC), this surgical procedure has been suggested to be associated with an increased risk of colitis-associated cancer (CAC). Our aim was to explore the mechanism underlying the appendectomy-associated increased risk of CAC., Methods: Five-week-old male BALB/c mice underwent appendectomy, appendicitis induction, or sham laparotomy. They were then exposed to azoxymethane/dextran sodium sulfate (AOM/DSS) to induce CAC. Mice were killed 12 weeks later, and colons were taken for pathological analysis and immunohistochemistry (CD3 and CD8 staining). Human colonic tumors from 21 patients with UC who underwent surgical resection for CAC were immunophenotyped and stratified according to appendectomy status., Results: Whereas appendectomy significantly reduced colitis severity and increased CAC number, appendicitis induction without appendectomy led to opposite results. Intratumor CD3+ and CD8+ T-cell densities were lower after appendectomy and higher after appendicitis induction compared with the sham laparotomy group. Blocking lymphocyte trafficking to the colon with the anti-α4β7 integrin antibody or a sphingosine-1-phosphate receptor agonist suppressed the inducing effect of the appendectomy on tumors' number and on CD3+/CD8+ intratumoral density. CD8+ or CD3+ T cells isolated from inflammatory neo-appendix and intravenously injected into AOM/DSS-treated recipient mice increased CD3+/CD8+ T-cell tumor infiltration and decreased tumor number. In UC patients with a history of appendectomy, intratumor CD3+ and CD8+ T-cell densities were decreased compared with UC patients without history of appendectomy., Conclusions: In UC, appendectomy could suppress a major site of T-cell priming, resulting in a less efficient CAC immunosurveillance., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
16. Regulation of the THRA gene, encoding the thyroid hormone nuclear receptor TRα1, in intestinal lesions.
- Author
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Giolito MV, La Rosa T, Farhat D, Bodoirat S, Guardia GDA, Domon-Dell C, Galante PAF, Freund JN, and Plateroti M
- Subjects
- Humans, Mice, Animals, Receptors, Thyroid Hormone genetics, Thyroid Hormone Receptors alpha genetics, Thyroid Hormone Receptors alpha metabolism, Thyroid Hormones metabolism, Genes, erbA, Colorectal Neoplasms genetics
- Abstract
The THRA gene, encoding the thyroid hormone nuclear receptor TRα1, is expressed in an increasing gradient at the bottom of intestinal crypts, overlapping with high Wnt and Notch activities. Importantly, THRA is upregulated in colorectal cancers, particularly in the high-Wnt molecular subtype. The basis of this specific and/or altered expression pattern has remained unknown. To define the mechanisms controlling THRA transcription and TRα1 expression, we used multiple in vitro and ex vivo approaches. Promoter analysis demonstrated that transcription factors important for crypt homeostasis and altered in colorectal cancers, such as transcription factor 7-like 2 (TCF7L2; Wnt pathway), recombining binding protein suppressor of hairless (RBPJ; Notch pathway), and homeobox protein CDX2 (epithelial cell identity), modulate THRA activity. Specifically, although TCF7L2 and CDX2 stimulated THRA, RBPJ induced its repression. In-depth analysis of the Wnt-dependent increase showed direct regulation of the THRA promoter in cells and of TRα1 expression in murine enteroids. Given our previous results on the control of the Wnt pathway by TRα1, our new results unveil a complex regulatory loop and synergy between these endocrine and epithelial-cell-intrinsic signals. Our work describes, for the first time, the regulation of the THRA gene in specific cell and tumor contexts., (© 2022 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)
- Published
- 2022
- Full Text
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17. Concurrent CDX2 cis-deregulation and UBTF::ATXN7L3 fusion define a novel high-risk subtype of B-cell ALL.
- Author
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Passet M, Kim R, Gachet S, Sigaux F, Chaumeil J, Galland A, Sexton T, Quentin S, Hernandez L, Larcher L, Bergugnat H, Ye T, Karasu N, Caye A, Heizmann B, Duluc I, Chevallier P, Rousselot P, Huguet F, Leguay T, Hunault M, Pflumio F, Freund JN, Lobry C, Lhéritier V, Dombret H, Domon-Dell C, Soulier J, Boissel N, and Clappier E
- Subjects
- Adult, Female, Genes, Homeobox, Humans, Male, Neoplasm, Residual genetics, Oncogene Proteins, Fusion, CDX2 Transcription Factor genetics, Pol1 Transcription Initiation Complex Proteins genetics, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma genetics, Precursor Cell Lymphoblastic Leukemia-Lymphoma genetics, Precursor Cell Lymphoblastic Leukemia-Lymphoma metabolism, Transcription Factors genetics
- Abstract
Oncogenic alterations underlying B-cell acute lymphoblastic leukemia (B-ALL) in adults remain incompletely elucidated. To uncover novel oncogenic drivers, we performed RNA sequencing and whole-genome analyses in a large cohort of unresolved B-ALL. We identified a novel subtype characterized by a distinct gene expression signature and the unique association of 2 genomic microdeletions. The 17q21.31 microdeletion resulted in a UBTF::ATXN7L3 fusion transcript encoding a chimeric protein. The 13q12.2 deletion resulted in monoallelic ectopic expression of the homeobox transcription factor CDX2, located 138 kb in cis from the deletion. Using 4C-sequencing and CRISPR interference experiments, we elucidated the mechanism of CDX2 cis-deregulation, involving PAN3 enhancer hijacking. CDX2/UBTF ALL (n = 26) harbored a distinct pattern of additional alterations including 1q gain and CXCR4 activating mutations. Within adult patients with Ph- B-ALL enrolled in GRAALL trials, patients with CDX2/UBTF ALL (n = 17/723, 2.4%) were young (median age, 31 years) and dramatically enriched in females (male/female ratio, 0.2, P = .002). They commonly presented with a pro-B phenotype ALL and moderate blast cell infiltration. They had poor response to treatment including a higher risk of failure to first induction course (19% vs 3%, P = .017) and higher post-induction minimal residual disease (MRD) levels (MRD ≥ 10-4, 93% vs 46%, P < .001). This early resistance to treatment translated into a significantly higher cumulative incidence of relapse (75.0% vs 32.4%, P = .004) in univariate and multivariate analyses. In conclusion, we discovered a novel B-ALL entity defined by the unique combination of CDX2 cis-deregulation and UBTF::ATXN7L3 fusion, representing a high-risk disease in young adults., (© 2022 by The American Society of Hematology.)
- Published
- 2022
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18. CDX2 controls genes involved in the metabolism of 5-fluorouracil and is associated with reduced efficacy of chemotherapy in colorectal cancer.
- Author
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Delhorme JB, Bersuder E, Terciolo C, Vlami O, Chenard MP, Martin E, Rohr S, Brigand C, Duluc I, Freund JN, and Gross I
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- Adult, Aged, Aged, 80 and over, Antimetabolites, Antineoplastic chemistry, Antimetabolites, Antineoplastic therapeutic use, CDX2 Transcription Factor genetics, CDX2 Transcription Factor metabolism, Cell Line, Tumor drug effects, Cohort Studies, Colorectal Neoplasms genetics, Colorectal Neoplasms mortality, Disease-Free Survival, Drug Resistance, Neoplasm drug effects, Female, Fluorouracil chemistry, Fluorouracil therapeutic use, France, Gene Expression Regulation, Neoplastic drug effects, Humans, Male, Middle Aged, Young Adult, Antimetabolites, Antineoplastic pharmacology, Colorectal Neoplasms drug therapy, Fluorouracil pharmacology
- Abstract
Most patients affected with colorectal cancers (CRC) are treated with 5-fluorouracil (5-FU)-based chemotherapy but its efficacy is often hampered by resistance mechanisms linked to tumor heterogeneity. A better understanding of the molecular determinants involved in chemoresistance is critical for precision medicine and therapeutic progress. Caudal type homeobox 2 (CDX2) is a master regulator of intestinal identity and acts as tumor suppressor in the colon. Here, using a translational approach, we examined the role of CDX2 in CRC chemoresistance. Unexpectedly, we discovered that the prognosis value of CDX2 for disease-free survival of patients affected with CRC is lost upon chemotherapy and that CDX2 expression enhances resistance of colon cancer cells towards 5-FU. At the molecular level, we found that CDX2 expression correlates with higher levels of genes regulating the bioavailability of 5-FU through efflux (ABCC11) and catabolism (DPYD) in patients affected with CRC and CRC cell lines. We further showed that CDX2 directly regulates the expression of ABCC11 and that the inhibition of ABCC11 improves 5-FU-sensitivity of CDX2-expressing colon cancer cells. Thus, this study illustrates how biological functions are hijacked in CRC cells and reveals the therapeutic interest of CDX2/ABCC11/DPYD to improve systemic chemotherapy in CRC., (Copyright © 2022. Published by Elsevier Masson SAS.)
- Published
- 2022
- Full Text
- View/download PDF
19. Mesalazine initiates an anti-oncogenic β-catenin / MUCDHL negative feed-back loop in colon cancer cells by cell-specific mechanisms.
- Author
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Bersuder E, Terciolo C, Lechevrel M, Martin E, Quesnelle C, Freund JN, Reimund JM, and Gross I
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- Cadherin Related Proteins, Cadherins genetics, Cadherins metabolism, Humans, Mesalamine pharmacology, Wnt Signaling Pathway, beta Catenin metabolism, Colonic Neoplasms drug therapy, Colonic Neoplasms genetics, Colonic Neoplasms metabolism, Colorectal Neoplasms genetics
- Abstract
Chronic inflammation associated with intestinal architecture and barrier disruption puts patients with inflammatory bowel disease (IBD) at increased risk of developing colorectal cancer (CRC). Widely used to reduce flares of intestinal inflammation, 5-aminosalicylic acid derivatives (5-ASAs) such as mesalazine appear to also exert more direct mucosal healing and chemopreventive activities against CRC. The mechanisms underlying these activities are poorly understood and may involve the up-regulation of the cadherin-related gene MUCDHL (CDHR5). This atypical cadherin is emerging as a new actor of intestinal homeostasis and opposes colon tumorigenesis. Here, we showed that mesalazine increase mRNA levels of MUCDHL and of other genes involved in the intestinal barrier function in most intestinal cell lines. In addition, using gain / loss of function experiments (agonists, plasmid or siRNAs transfections), luciferase reporter genes and chromatin immunoprecipitation, we thoroughly investigated the molecular mechanisms triggered by mesalazine that lead to the up-regulation of MUCDHL expression. We found that basal transcription of MUCDHL in different CRC cell lines is regulated positively by CDX2 and negatively by β-catenin through a negative feed-back loop. However, mesalazine-stimulation of MUCDHL transcription is controlled by cell-specific mechanisms, involving either enhanced activation of CDX2 and PPAR-γ or repression of the β-catenin inhibitory effect. This work highlights the importance of the cellular and molecular context in the activity of mesalazine and suggests that its efficacy against CRC depends on the genetic alterations of transformed cells., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2022
- Full Text
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20. A Core Response to the CDX2 Homeoprotein During Development and in Pathologies.
- Author
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Gourain V, Duluc I, Domon-Dell C, and Freund JN
- Abstract
Whether a gene involved in distinct tissue or cell functions exerts a core of common molecular activities is a relevant topic in evolutionary, developmental, and pathological perspectives. Here, we addressed this question by focusing on the transcription factor and regulator of chromatin accessibility encoded by the Cdx2 homeobox gene that plays important functions during embryonic development and in adult diseases. By integrating RNAseq data in mouse embryogenesis, we unveiled a core set of common genes whose expression is responsive to the CDX2 homeoprotein during trophectoderm formation, posterior body elongation and intestinal specification. ChIPseq data analysis also identified a set of common chromosomal regions targeted by CDX2 at these three developmental steps. The transcriptional core set of genes was then validated with transgenic mouse models of loss or gain of function of Cdx2. Finally, based on human cancer data, we highlight the relevance of these results by displaying a significant number of human orthologous genes to the core set of mouse CDX2-responsive genes exhibiting an altered expression along with CDX2 in human malignancies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Gourain, Duluc, Domon-Dell and Freund.)
- Published
- 2021
- Full Text
- View/download PDF
21. CDX2 expression in the hematopoietic lineage promotes leukemogenesis via TGFβ inhibition.
- Author
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Galland A, Gourain V, Habbas K, Güler Y, Martin E, Ebel C, Tavian M, Vallat L, Chenard MP, Mauvieux L, Freund JN, Duluc I, and Domon-Dell C
- Subjects
- Animals, CD11b Antigen genetics, Cell Lineage, Humans, Leukemia, Monocytic, Acute pathology, Membrane Proteins genetics, Mice, Signal Transduction, Tumor Microenvironment, CDX2 Transcription Factor genetics, Leukemia, Monocytic, Acute genetics, Transforming Growth Factor beta antagonists & inhibitors
- Abstract
The intestine-specific caudal-related homeobox gene-2 (CDX2) homeobox gene, while being a tumor suppressor in the gut, is ectopically expressed in a large proportion of acute leukemia and is associated with poor prognosis. Here, we report that turning on human CDX2 expression in the hematopoietic lineage of mice induces acute monoblastic leukemia, characterized by the decrease in erythroid and lymphoid cells at the benefit of immature monocytic and granulocytic cells. One of the highly stimulated genes in leukemic bone marrow cells was BMP and activin membrane-bound inhibitor (Bambi), an inhibitor of transforming growth factor-β (TGF-β) signaling. The CDX2 protein was shown to bind to and activate the transcription of the human BAMBI promoter. Moreover, in a leukemic cell line established from CDX2-expressing mice, reducing the levels of CDX2 or Bambi stimulated the TGF-β-dependent expression of Cd11b, a marker of monocyte maturation. Taken together, this work demonstrates the strong oncogenic potential of the homeobox gene CDX2 in the hematopoietic lineage, in contrast with its physiological tumor suppressor activity exerted in the gut. It also reveals, through BAMBI and TGF-β signaling, the involvement of CDX2 in the perturbation of the interactions between leukemia cells and their microenvironment., (© 2021 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)
- Published
- 2021
- Full Text
- View/download PDF
22. CDX2 inducible microRNAs sustain colon cancer by targeting multiple DNA damage response pathway factors.
- Author
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Priya S, Kaur E, Kulshrestha S, Pandit A, Gross I, Kumar N, Agarwal H, Khan A, Shyam R, Bhagat P, Prabhu JS, Nagarajan P, Deo SVS, Bajaj A, Freund JN, Mukhopadhyay A, and Sengupta S
- Subjects
- CDX2 Transcription Factor genetics, DNA Damage genetics, DNA-Binding Proteins genetics, Humans, Transcription Factors, Ubiquitin-Protein Ligases, Adenocarcinoma, Colonic Neoplasms genetics, MicroRNAs genetics
- Abstract
Meta-analysis of transcripts in colon adenocarcinoma patient tissues led to the identification of a DNA damage responsive miR signature called DNA damage sensitive miRs (DDSMs). DDSMs were experimentally validated in the cancerous colon tissues obtained from an independent cohort of colon cancer patients and in multiple cellular systems with high levels of endogenous DNA damage. All the tested DDSMs were transcriptionally upregulated by a common intestine-specific transcription factor, CDX2. Reciprocally, DDSMs were repressed via the recruitment of HDAC1/2-containing complexes onto the CDX2 promoter. These miRs downregulated multiple key targets in the DNA damage response (DDR) pathway, namely BRCA1, ATM, Chk1 (also known as CHEK1) and RNF8. CDX2 directly regulated the DDSMs, which led to increased tumor volume and metastasis in multiple preclinical models. In colon cancer patient tissues, the DDSMs negatively correlated with BRCA1 levels, were associated with decreased probability of survival and thereby could be used as a prognostic biomarker. This article has an associated First Person interview with the first author of the paper., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)
- Published
- 2021
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23. Deciphering the Role of Intestinal Crypt Cell Populations in Resistance to Chemotherapy.
- Author
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Frau C, Jamard C, Delpouve G, Guardia GDA, Machon C, Pilati C, Nevé CL, Laurent-Puig P, Guitton J, Galante PAF, Penalva LO, Freund JN, de la Fouchardiere C, and Plateroti M
- Subjects
- Animals, Antimetabolites, Antineoplastic pharmacology, Colorectal Neoplasms metabolism, Colorectal Neoplasms pathology, Disease Models, Animal, Female, Intestinal Mucosa metabolism, Intestinal Mucosa pathology, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Nerve Tissue Proteins genetics, Phenotype, RNA-Binding Proteins genetics, Colorectal Neoplasms drug therapy, Drug Resistance, Neoplasm, Fluorouracil pharmacology, Intestinal Mucosa drug effects, Neoplastic Stem Cells drug effects, Nerve Tissue Proteins metabolism, RNA-Binding Proteins metabolism, Receptors, G-Protein-Coupled physiology
- Abstract
Intestinal crypts are composed of heterogeneous and highly plastic cell populations. Lgr5
high -stem cells (SC) are responsible for homeostatic renewal, but other cells can revert to an SC-like phenotype to maintain epithelial integrity. Despite their distinct roles in orchestrating homeostasis, both populations have been designated as the putative "cell-of-origin" of colorectal cancer. However, their respective involvement in the emergence of drug-resistant cancer SCs (CSC), responsible for tumor relapse and associated with poor outcome of colorectal cancer, remains elusive. In this context, the intestinal SC/progenitor-marker Musashi1 (MSI1) is interesting as it plays important functions in intestinal homeostasis and is frequently overexpressed in human colorectal cancer. Therefore, our aims were: (i) to study the impact of chemotherapy on Lgr5-expressing and MSI1-expressing cell populations, (ii) to explore the effect of increased MSI1 levels in response to treatment, and (iii) to evaluate the relevance in human colorectal cancer. Engineered mouse models treated with the therapeutic agent 5-fluorouracil showed that upon increased MSI1 levels, Lgr5high SCs remain sensitive while Lgr5low progenitors reprogram to a drug-resistant phenotype. This resulted in the expansion of an MSI1-expressing cell subpopulation with improved resistance to DNA damage and increased detoxification, typical properties of dormant-CSCs that can reactivate after chemotherapy. Analysis in patients with colorectal cancer revealed a correlation between MSI1 levels and tumor grading, CSC phenotype, and chemoresistance. Altogether, these results shed new light on the biology and plasticity of normal crypt and cancer cell populations and also open new perspectives to target MSI1 to improve chemotherapy outcome. SIGNIFICANCE: This study unveils paradoxical roles for MSI1, underlining its importance in facilitating intestinal regeneration upon injury but also unraveling its new function in drug-resistant colorectal cancer stem cells., (©2021 American Association for Cancer Research.)- Published
- 2021
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24. Temporal multiomic modeling reveals a B-cell receptor proliferative program in chronic lymphocytic leukemia.
- Author
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Schleiss C, Carapito R, Fornecker LM, Muller L, Paul N, Tahar O, Pichot A, Tavian M, Nicolae A, Miguet L, Mauvieux L, Herbrecht R, Cianferani S, Freund JN, Carapito C, Maumy-Bertrand M, Bahram S, Bertrand F, and Vallat L
- Subjects
- Aged, Female, Humans, Leukemia, Lymphocytic, Chronic, B-Cell metabolism, Lymphocyte Activation genetics, Male, Middle Aged, Proteome genetics, Proteomics methods, Signal Transduction genetics, Transcription, Genetic genetics, B-Lymphocytes metabolism, Cell Proliferation genetics, Leukemia, Lymphocytic, Chronic, B-Cell genetics, Receptors, Antigen, B-Cell genetics
- Abstract
B-cell receptor (BCR) signaling is crucial for the pathophysiology of most mature B-cell lymphomas/leukemias and has emerged as a therapeutic target whose effectiveness remains limited by the occurrence of mutations. Therefore, deciphering the cellular program activated downstream this pathway has become of paramount importance for the development of innovative therapies. Using an original ex vivo model of BCR-induced proliferation of chronic lymphocytic leukemia cells, we generated 108 temporal transcriptional and proteomic profiles from 1 h up to 4 days after BCR activation. This dataset revealed a structured temporal response composed of 13,065 transcripts and 4027 proteins, comprising a leukemic proliferative signature consisting of 430 genes and 374 proteins. Mathematical modeling of this complex cellular response further highlighted a transcriptional network driven by 14 early genes linked to proteins involved in cell proliferation. This group includes expected genes (EGR1/2, NF-kB) and genes involved in NF-kB signaling modulation (TANK, ROHF) and immune evasion (KMO, IL4I1) that have not yet been associated with leukemic cells proliferation. Our study unveils the BCR-activated proliferative genetic program in primary leukemic cells. This approach combining temporal measurements with modeling allows identifying new putative targets for innovative therapy of lymphoid malignancies and also cancers dependent on ligand-receptor interactions.
- Published
- 2021
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25. Renin-angiotensin system is involved in embryonic emergence of hematopoietic stem/progenitor cells.
- Author
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Julien E, Biasch K, El Omar R, Freund JN, Gachet C, Lanza F, and Tavian M
- Subjects
- Animals, Aorta growth & development, Gene Expression Regulation, Developmental genetics, Hematopoiesis drug effects, Hematopoiesis genetics, Hematopoietic Stem Cell Transplantation, Humans, Leukocyte Common Antigens genetics, Mice, Peptides pharmacology, Peptidyl-Dipeptidase A genetics, Receptor, Angiotensin, Type 2 genetics, Renin genetics, Signal Transduction drug effects, Stem Cells cytology, Angiotensin II genetics, Angiotensinogen genetics, Hematopoietic Stem Cells cytology, Receptor, Angiotensin, Type 1 genetics, Renin-Angiotensin System genetics
- Abstract
Angiotensin-converting enzyme (ACE), a key element of the renin-angiotensin system (RAS), has recently been identified as a new marker of both adult and embryonic human hematopoietic stem/progenitor cells (HSPCs). However, whether a full renin-angiotensin pathway is locally present during the hematopoietic emergence is still an open question. In the present study, we show that this enzyme is expressed by hematopoietic progenitors in the developing mouse embryo. Furthermore, ACE and the other elements of RAS-namely angiotensinogen, renin, and angiotensin II type 1 (AT1) and type 2 (AT2) receptors-are expressed in the paraaortic splanchnopleura (P-Sp) and in its derivative, the aorta-gonad-mesonephros region, both in human and mouse embryos. Their localization is compatible with the existence of a local autocrine and/or paracrine RAS in these hemogenic sites. in vitro perturbation of the RAS by administration of a specific AT1 receptor antagonist inhibits almost totally the generation of blood CD45-positive cells from dissected P-Sp, implying that angiotensin II signaling is necessary for the emergence of hematopoietic cells. Conversely, addition of exogenous angiotensin II peptide stimulates hematopoiesis in culture, with an increase in the number of immature c-Kit
+ CD41+ CD31+ CD45+ hematopoietic progenitors, compared to the control. These results highlight a novel role of local-RAS during embryogenesis, suggesting that angiotensin II, via activation of AT1 receptor, promotes the emergence of undifferentiated hematopoietic progenitors., (©AlphaMed Press 2021.)- Published
- 2021
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26. Murine intestinal stem cells are highly sensitive to modulation of the T3/TRα1-dependent pathway.
- Author
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Godart M, Frau C, Farhat D, Giolito MV, Jamard C, Le Nevé C, Freund JN, Penalva LO, Sirakov M, and Plateroti M
- Subjects
- Amino Acid Transport Systems, Neutral genetics, Amino Acid Transport Systems, Neutral metabolism, Animals, Female, Iodide Peroxidase genetics, Iodide Peroxidase metabolism, Male, Mice, Mice, Transgenic, Stem Cells cytology, Thyroid Hormone Receptors alpha genetics, Triiodothyronine genetics, Cell Proliferation, Intestines, Signal Transduction, Stem Cells metabolism, Thyroid Hormone Receptors alpha metabolism, Triiodothyronine metabolism
- Abstract
The thyroid hormone T3 and its nuclear receptor TRα1 control gut development and homeostasis through the modulation of intestinal crypt cell proliferation. Despite increasing data, in-depth analysis on their specific action on intestinal stem cells is lacking. By using ex vivo 3D organoid cultures and molecular approaches, we observed early responses to T3 involving the T3-metabolizing enzyme Dio1 and the transporter Mct10, accompanied by a complex response of stem cell- and progenitor-enriched genes. Interestingly, specific TRα1 loss-of-function (inducible or constitutive) was responsible for low ex vivo organoid development and impaired stem cell activity. T3 treatment of animals in vivo not only confirmed the positive action of this hormone on crypt cell proliferation but also demonstrated its key action in modulating the number of stem cells, the expression of their specific markers and the commitment of progenitors into lineage-specific differentiation. In conclusion, T3 treatment or TRα1 modulation has a rapid and strong effect on intestinal stem cells, broadening our perspectives in the study of T3/TRα1-dependent signaling in these cells., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)
- Published
- 2021
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27. CDX2 regulates ACE expression in blood development and leukemia cells.
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El Omar R, Julien E, Biasch K, Guffroy B, Lioure B, Vallat L, Gross I, Domon-Dell C, Lanza F, Gachet C, Negroni M, Freund JN, and Tavian M
- Subjects
- CDX2 Transcription Factor, Humans, Homeodomain Proteins genetics, Leukemia, Myeloid, Acute
- Published
- 2021
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28. The atypical cadherin MUCDHL antagonizes colon cancer formation and inhibits oncogenic signaling through multiple mechanisms.
- Author
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Beck M, Baranger M, Moufok-Sadoun A, Bersuder E, Hinkel I, Mellitzer G, Martin E, Marisa L, Duluc I, de Reynies A, Gaiddon C, Freund JN, and Gross I
- Subjects
- Caco-2 Cells, Cadherin Related Proteins, Cadherins genetics, Colonic Neoplasms genetics, Colonic Neoplasms pathology, HEK293 Cells, Humans, Tumor Suppressor Proteins genetics, Cadherins metabolism, Colonic Neoplasms metabolism, Signal Transduction, Tumor Suppressor Proteins metabolism
- Abstract
Cadherins form a large and pleiotropic superfamily of membranous proteins sharing Ca
2+ -binding repeats. While the importance of classic cadherins such as E- or N-cadherin for tumorigenesis is acknowledged, there is much less information about other cadherins that are merely considered as tissue-specific adhesion molecules. Here, we focused on the atypical cadherin MUCDHL that stood out for its unusual features and unique function in the gut. Analyses of transcriptomic data sets (n > 250) established that MUCDHL mRNA levels are down-regulated in colorectal tumors. Importantly, the decrease of MUCDHL expression is more pronounced in the worst-prognosis subset of tumors and is associated with decreased survival. Molecular characterization of the tumors indicated a negative correlation with proliferation-related processes (e.g., nucleic acid metabolism, DNA replication). Functional genomic studies showed that the loss of MUCDHL enhanced tumor incidence and burden in intestinal tumor-prone mice. Extensive structure/function analyses revealed that the mode of action of MUCDHL goes beyond membrane sequestration of ß-catenin and targets through its extracellular domain key oncogenic signaling pathways (e.g., EGFR, AKT). Beyond MUCDHL, this study illustrates how the loss of a gene critical for the morphological and functional features of mature cells contributes to tumorigenesis by dysregulating oncogenic pathways.- Published
- 2021
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29. Actomyosin, vimentin and LINC complex pull on osteosarcoma nuclei to deform on micropillar topography.
- Author
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Tusamda Wakhloo N, Anders S, Badique F, Eichhorn M, Brigaud I, Petithory T, Vassaux M, Milan JL, Freund JN, Rühe J, Davidson PM, Pieuchot L, and Anselme K
- Subjects
- Actomyosin, Cell Nucleus, Humans, Vimentin, Bone Neoplasms, Osteosarcoma
- Abstract
Cell deformation occurs in many critical biological processes, including cell extravasation during immune response and cancer metastasis. These cells deform the nucleus, their largest and stiffest organelle, while passing through narrow constrictions in vivo and the underlying mechanisms still remain elusive. It is unclear which biochemical actors are responsible and whether the nucleus is pushed or pulled (or both) during deformation. Herein we use an easily-tunable poly-L-lactic acid micropillar topography, mimicking in vivo constrictions to determine the mechanisms responsible for nucleus deformation. Using biochemical tools, we determine that actomyosin contractility, vimentin and nucleo-cytoskeletal connections play essential roles in nuclear deformation, but not A-type lamins. We chemically tune the adhesiveness of the micropillars to show that pulling forces are predominantly responsible for the deformation of the nucleus. We confirm these results using an in silico cell model and propose a comprehensive mechanism for cellular and nuclear deformation during confinement. These results indicate that microstructured biomaterials are extremely versatile tools to understand how forces are exerted in biological systems and can be useful to dissect and mimic complex in vivo behaviour., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
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30. Severe head dysgenesis resulting from imbalance between anterior and posterior ontogenetic programs.
- Author
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Grall E, Gourain V, Naïr A, Martin E, Birling MC, Freund JN, and Duluc I
- Subjects
- Animals, Craniofacial Abnormalities physiopathology, Embryonic Development genetics, Gastrulation genetics, Gene Expression Regulation, Developmental genetics, Genes, Homeobox genetics, Head growth & development, Humans, Mice, Neural Crest growth & development, Neural Crest physiopathology, Prosencephalon growth & development, Prosencephalon pathology, CDX2 Transcription Factor genetics, Craniofacial Abnormalities genetics, Head physiopathology, Morphogenesis genetics
- Abstract
Head dysgenesis is a major cause of fetal demise and craniofacial malformation. Although mutations in genes of the head ontogenetic program have been reported, many cases remain unexplained. Head dysgenesis has also been related to trisomy or amplification of the chromosomal region overlapping the CDX2 homeobox gene, a master element of the trunk ontogenetic program. Hence, we investigated the repercussion on head morphogenesis of the imbalance between the head and trunk ontogenetic programs, by means of ectopic rostral expression of CDX2 at gastrulation. This caused severe malformations affecting the forebrain and optic structures, and also the frontonasal process associated with defects in neural crest cells colonization. These malformations are the result of the downregulation of genes of the head program together with the abnormal induction of trunk program genes. Together, these data indicate that the imbalance between the anterior and posterior ontogenetic programs in embryos is a new possible cause of head dysgenesis during human development, linked to defects in setting up anterior neuroectodermal structures.
- Published
- 2019
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31. A redox ruthenium compound directly targets PHD2 and inhibits the HIF1 pathway to reduce tumor angiogenesis independently of p53.
- Author
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Vidimar V, Licona C, Cerón-Camacho R, Guerin E, Coliat P, Venkatasamy A, Ali M, Guenot D, Le Lagadec R, Jung AC, Freund JN, Pfeffer M, Mellitzer G, Sava G, and Gaiddon C
- Subjects
- Animals, Antineoplastic Agents pharmacology, Cisplatin pharmacology, Colorectal Neoplasms blood supply, Female, HCT116 Cells, Human Umbilical Vein Endothelial Cells, Humans, Hypoxia-Inducible Factor 1, alpha Subunit metabolism, Mice, Mice, Inbred C57BL, Mice, Nude, Neovascularization, Pathologic drug therapy, Neovascularization, Pathologic metabolism, Neovascularization, Pathologic pathology, Organometallic Compounds chemistry, Oxidation-Reduction, Ruthenium chemistry, Signal Transduction drug effects, Xenograft Model Antitumor Assays, Colorectal Neoplasms drug therapy, Colorectal Neoplasms metabolism, Hypoxia-Inducible Factor 1, alpha Subunit antagonists & inhibitors, Hypoxia-Inducible Factor-Proline Dioxygenases metabolism, Organometallic Compounds pharmacology, Ruthenium pharmacology, Tumor Suppressor Protein p53 metabolism
- Abstract
Targeting specific tumor metabolic needs represents an actively investigated therapeutic strategy to bypass tumor resistance mechanisms. In this study, we describe an original approach to impact the cancer metabolism by exploiting the redox properties of a ruthenium organometallic compound. This organometallic complex induced p53-independent cytotoxicity and reduced size and vascularization of patients-derived tumor explants that are resistant to platinum drugs. At the molecular level, the ruthenium complex altered redox enzyme activities and the intracellular redox state by increasing the NAD+/NADH ratio and ROS levels. Pathway analysis pointed to HIF-1 as a top deregulated metabolite pathway. Unlike cisplatin, treatment with the ruthenium complex decreased HIF1A protein levels and expression of HIF1A target genes. The rapid downregulation of HIF1A protein levels involved a direct interaction of the ruthenium compound with the redox enzyme PHD2, a HIF1A master regulator. HIF1A inhibition led to decreased angiogenesis in patient-derived xenografted using fragments of primary human colon tumors. Altogether, our results show that a ruthenium compound impacts metabolic pathways acting as anticancer agents in colon cancer via an original mechanism of action that affects redox enzymes differently than platinum-based drugs., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2019
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32. Chromatin de-condensation by switching substrate elasticity.
- Author
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Rabineau M, Flick F, Ehlinger C, Mathieu E, Duluc I, Jung M, Senger B, Kocgozlu L, Schaaf P, Lavalle P, Freund JN, Haikel Y, and Vautier D
- Subjects
- Cell Differentiation, Cell Line, Tumor, Cell Movement genetics, Cell Survival genetics, Elasticity, Gene Expression Regulation, Neoplastic, Humans, Adaptation, Biological genetics, Cellular Reprogramming, Chromatin Assembly and Disassembly, Euchromatin metabolism, Heterochromatin metabolism, Tumor Microenvironment
- Abstract
Mechanical properties of the cellular environment are known to influence cell fate. Chromatin de-condensation appears as an early event in cell reprogramming. Whereas the ratio of euchromatin versus heterochromatin can be increased chemically, we report herein for the first time that the ratio can also be increased by purely changing the mechanical properties of the microenvironment by successive 24 h-contact of the cells on a soft substrate alternated with relocation and growth for 7 days on a hard substrate. An initial contact with soft substrate caused massive SW480 cancer cell death by necrosis, whereas approximately 7% of the cells did survived exhibiting a high level of condensed chromatin (21% heterochromatin). However, four consecutive hard/soft cycles elicited a strong chromatin de-condensation (6% heterochromatin) correlating with an increase of cellular survival (approximately 90%). Furthermore, cell survival appeared to be reversible, indicative of an adaptive process rather than an irreversible gene mutation(s). This adaptation process is associated with modifications in gene expression patterns. A completely new approach for chromatin de-condensation, based only on mechanical properties of the microenvironment, without any drug mediation is presented.
- Published
- 2018
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33. The Cdx2 homeobox gene suppresses intestinal tumorigenesis through non-cell-autonomous mechanisms.
- Author
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Balbinot C, Armant O, Elarouci N, Marisa L, Martin E, De Clara E, Onea A, Deschamps J, Beck F, Freund JN, and Duluc I
- Subjects
- Animals, Cecum pathology, Colonic Neoplasms genetics, Colonic Neoplasms pathology, Gene Expression Regulation, Neoplastic, Heterozygote, Humans, Intestines pathology, Metaplasia, Mice, NF-kappa B metabolism, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Nitric Oxide Synthase Type II metabolism, Stromal Cells metabolism, Stromal Cells pathology, Tumor Microenvironment, CDX2 Transcription Factor genetics, Carcinogenesis genetics, Carcinogenesis pathology, Intestinal Neoplasms genetics, Intestinal Neoplasms pathology
- Abstract
Developmental genes contribute to cancer, as reported for the homeobox gene Cdx2 playing a tumor suppressor role in the gut. In this study, we show that human colon cancers exhibiting the highest reduction in CDX2 expression belong to the serrated subtype with the worst evolution. In mice, mosaic knockout of Cdx2 in the adult intestinal epithelium induces the formation of imperfect gastric-type metaplastic lesions. The metaplastic knockout cells do not spontaneously become tumorigenic. However, they induce profound modifications of the microenvironment that facilitate the tumorigenic evolution of adjacent Cdx2 -intact tumor-prone cells at the surface of the lesions through NF-κB activation, induction of inducible nitric oxide synthase, and stochastic loss of function of Apc This study presents a novel paradigm in that metaplastic cells, generally considered as precancerous, can induce tumorigenesis from neighboring nonmetaplastic cells without themselves becoming cancerous. It unveils the novel property of non-cell-autonomous tumor suppressor gene for the Cdx2 gene in the gut., (© 2018 Balbinot et al.)
- Published
- 2018
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34. Fine-tuning and autoregulation of the intestinal determinant and tumor suppressor homeobox gene CDX2 by alternative splicing.
- Author
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Balbinot C, Vanier M, Armant O, Nair A, Penichon J, Soret C, Martin E, Saandi T, Reimund JM, Deschamps J, Beck F, Domon-Dell C, Gross I, Duluc I, and Freund JN
- Subjects
- Alternative Splicing, Animals, CDX2 Transcription Factor metabolism, Caco-2 Cells, Cecum metabolism, Cell Differentiation genetics, Genes, Homeobox, HCT116 Cells, HEK293 Cells, Humans, Intestinal Mucosa metabolism, Mice, Mice, Transgenic, RNA Precursors genetics, RNA Precursors metabolism, Transfection, CDX2 Transcription Factor genetics, Cecum physiology, Intestinal Mucosa physiology
- Abstract
On the basis of phylogenetic analyses, we uncovered a variant of the CDX2 homeobox gene, a major regulator of the development and homeostasis of the gut epithelium, also involved in cancer. This variant, miniCDX2, is generated by alternative splicing coupled to alternative translation initiation, and contains the DNA-binding homeodomain but is devoid of transactivation domain. It is predominantly expressed in crypt cells, whereas the CDX2 protein is present in crypt cells but also in differentiated villous cells. Functional studies revealed a dominant-negative effect exerted by miniCDX2 on the transcriptional activity of CDX2, and conversely similar effects regarding several transcription-independent functions of CDX2. In addition, a regulatory role played by the CDX2 and miniCDX2 homeoproteins on their pre-mRNA splicing is displayed, through interactions with splicing factors. Overexpression of miniCDX2 in the duodenal Brunner glands leads to the expansion of the territory of these glands and ultimately to brunneroma. As a whole, this study characterized a new and original variant of the CDX2 homeobox gene. The production of this variant represents not only a novel level of regulation of this gene, but also a novel way to fine-tune its biological activity through the versatile functions exerted by the truncated variant compared to the full-length homeoprotein. This study highlights the relevance of generating protein diversity through alternative splicing in the gut and its diseases.
- Published
- 2017
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35. Estimation of subject coregistration errors during multimodal preclinical imaging using separate instruments: origins and avoidance of artifacts.
- Author
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Dillenseger JP, Goetz C, Sayeh A, Healy C, Duluc I, Freund JN, Constantinesco A, Aubertin-Kirch G, and Choquet P
- Abstract
We use high-resolution [Formula: see text] data in multiple experiments to estimate the sources of error during coregistration of images acquired on separate preclinical instruments. In combination with experiments with phantoms, we completed in vivo imaging on mice, aimed at identifying the possible sources of registration errors, caused either by transport of the animal, movement of the animal itself, or methods of coregistration. The same imaging cell was used as a holder for phantoms and animals. For all procedures, rigid coregistration was carried out using a common landmark coregistration system, placed inside the imaging cell. We used the fiducial registration error and the target registration error to analyze the coregistration accuracy. We found that moving an imaging cell between two preclinical devices during a multimodal procedure gives an error of about [Formula: see text] at most. Therefore, it could not be considered a source of coregistration errors. Errors linked to spontaneous movements of the animal increased with time, to nearly 1 mm at most, excepted for body parts that were properly restrained. This work highlights the importance of animal intrinsic movements during a multiacquisition procedure and demonstrates a simple method to identify and quantify the sources of error during coregistration.
- Published
- 2017
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36. Histone hypoacetylation contributes to CXCL12 downregulation in colon cancer: impact on tumor growth and cell migration.
- Author
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Romain B, Benbrika-Nehmar R, Marisa L, Legrain M, Lobstein V, Oravecz A, Poidevin L, Bour C, Freund JN, Duluc I, Guenot D, and Pencreach E
- Subjects
- Acetylation, Adenocarcinoma pathology, Adenoma pathology, Adult, Aged, Animals, Cell Line, Tumor, Cell Movement genetics, Cell Proliferation genetics, Chemokine CXCL12 genetics, Colonic Neoplasms genetics, DNA Methylation, Down-Regulation, Female, Heterografts, Histones metabolism, Humans, Male, Mice, Mice, Mutant Strains, Middle Aged, Chemokine CXCL12 biosynthesis, Colonic Neoplasms pathology, Gene Expression Regulation, Neoplastic genetics, Histones genetics
- Abstract
CXCL12 has been shown to be involved in colon cancer metastasis, but its expression level and molecular mechanisms regulating its expression remain controversial. We thus evaluated CXCL12 expression in a large cohort of colon adenomas and carcinomas, investigated for an epigenetic mechanism controlling its expression and evaluated the impact of CXCL12 levels on cell migration and tumor growth. CXCL12 expression was measured in human colon adenomas and carcinomas with transcriptome array and RT-qPCR. The promoter methylation was analyzed with whole-genome DNA methylation chips and protein expression by immunohistochemistry. We confirm a reduced expression of CXCL12 in 75% of MSS carcinomas and show that the decrease is an early event as already present in adenomas. The methylome analysis shows that the CXCL12 promoter is methylated in only 30% of microsatellite-stable tumors. In vitro, treatments with HDAC inhibitors, butyrate and valproate restored CXCL12 expression in three colon cell lines, increased acetylation of histone H3 within the CXCL12 promoter and inhibited cell migration. In vivo, valproate diminished (65%) the number of intestinal tumors in APC mutant mice, slowed down xenograft tumor growth concomitant to restored CXCL12 expression. Finally we identified loss of PCAF expression in tumor samples and showed that forced expression of PCAF in colon cancer cell lines restored CXCL12 expression. Thus, reduced PCAF expression may participate to CXCL12 promoter hypoacetylation and its subsequent loss of expression. Our study is of potential clinical interest because agents that promote or maintain histone acetylation through HDAC inhibition and/or HAT stimulation, may help to lower colon adenoma/carcinoma incidence, especially in high-risk families, or could be included in therapeutic protocols to treat advanced colon cancer.
- Published
- 2017
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37. The tumor suppressor CDX2 opposes pro-metastatic biomechanical modifications of colon cancer cells through organization of the actin cytoskeleton.
- Author
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Platet N, Hinkel I, Richert L, Murdamoothoo D, Moufok-Sadoun A, Vanier M, Lavalle P, Gaiddon C, Vautier D, Freund JN, and Gross I
- Subjects
- Actin Cytoskeleton pathology, Adherens Junctions metabolism, Adherens Junctions pathology, Animals, Biomechanical Phenomena, CDX2 Transcription Factor genetics, Colonic Neoplasms genetics, Colonic Neoplasms pathology, Fluorescent Antibody Technique, Genes, APC, Genetic Predisposition to Disease, HT29 Cells, Humans, Mice, Transgenic, Microscopy, Atomic Force, Neoplasm Metastasis, Phenotype, Proto-Oncogene Proteins c-vav genetics, Proto-Oncogene Proteins c-vav metabolism, RNA Interference, Signal Transduction, Transfection, Tumor Suppressor Proteins genetics, rho GTP-Binding Proteins genetics, rho GTP-Binding Proteins metabolism, Actin Cytoskeleton metabolism, CDX2 Transcription Factor metabolism, Cell Movement, Colonic Neoplasms metabolism, Tumor Suppressor Proteins metabolism
- Abstract
The vast majority of cancer deaths are caused by the formation of metastases rather than the primary tumor itself. Despite this clinical importance, the molecular and cellular events that support the dissemination of cancer cells are not yet fully unraveled. We have previously shown that CDX2, a homeotic transcription factor essential for gut development, acts as a colon-specific tumor suppressor and opposes metastasis. Here, using a combination of biochemical, biophysical, and immunofluorescence techniques, we further investigated the mechanisms promoted by CDX2 that might antagonize tumor cell dissemination. We found that CDX2 expression regulates the transcription of RHO GEFs, thereby activating RHO signaling cascades that lead to reorganization of the actin cytoskeleton and enhanced adherent junctions. Accordingly, we observed by atomic force microscopy (AFM) that colon cancer cells expressing CDX2 are less deformable, a feature that has been shown to correlate with poor metastatic potential. Thus, this study illustrates how the loss of expression of a transcription factor during colon cancer progression modifies the biomechanical characteristics of tumor cells and hence facilitates invasion and metastasis., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
38. Enhanced Ghrelin Levels and Hypothalamic Orexigenic AgRP and NPY Neuropeptide Expression in Models of Jejuno-Colonic Short Bowel Syndrome.
- Author
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Gillard L, Billiauws L, Stan-Iuga B, Ribeiro-Parenti L, Jarry AC, Cavin JB, Cluzeaud F, Mayeur C, Thomas M, Freund JN, Lacorte JM, Le Gall M, Bado A, Joly F, and Le Beyec J
- Subjects
- Adult, Aged, Anastomosis, Surgical, Animals, Disease Models, Animal, Feeding Behavior, Female, Glucagon-Like Peptide 1 blood, Glucagon-Like Peptide 2 blood, Humans, Hyperphagia metabolism, Intestinal Mucosa metabolism, Ki-67 Antigen metabolism, Male, Middle Aged, Peptide YY blood, Proglucagon metabolism, RNA, Messenger metabolism, Rats, Rats, Wistar, Real-Time Polymerase Chain Reaction, Agouti-Related Protein metabolism, Colon pathology, Ghrelin blood, Hypothalamus metabolism, Jejunum pathology, Neuropeptide Y metabolism, Short Bowel Syndrome metabolism
- Abstract
Short bowel syndrome (SBS) patients developing hyperphagia have a better outcome. Gastrointestinal endocrine adaptations help to improve intestinal functions and food behaviour. We investigated neuroendocrine adaptations in SBS patients and rat models with jejuno-ileal (IR-JI) or jejuno-colonic (IR-JC) anastomosis with and without parenteral nutrition. Circulating levels of ghrelin, PYY, GLP-1, and GLP-2 were determined in SBS rat models and patients. Levels of mRNA for proglucagon, PYY and for hypothalamic neuropeptides were quantified by qRT-PCR in SBS rat models. Histology and immunostaining for Ki67, GLP-1 and PYY were performed in SBS rats. IR-JC rats, but not IR-JI, exhibited significantly higher crypt depths and number of Ki67-positive cells than sham. Fasting and/or postprandial plasma ghrelin and PYY concentrations were higher, or tend to be higher, in IR-JC rats and SBS-JC patients than in controls. Proglucagon and Pyy mRNA levels were significantly enhanced in IR-JC rats. Levels of mRNA coding hypothalamic orexigenic NPY and AgRP peptides were significantly higher in IR-JC than in sham rats. We demonstrate an increase of plasma ghrelin concentrations, major changes in hypothalamic neuropeptides levels and greater induction of PYY in SBS-JC rats and patients suggesting that jejuno-colonic continuity creates a peculiar environment promoting further gut-brain adaptations.
- Published
- 2016
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39. Distinct mechanisms for opposite functions of homeoproteins Cdx2 and HoxB7 in double-strand break DNA repair in colon cancer cells.
- Author
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Soret C, Martin E, Duluc I, Dantzer F, Vanier M, Gross I, Freund JN, and Domon-Dell C
- Subjects
- Animals, CDX2 Transcription Factor, Caco-2 Cells, Colonic Neoplasms metabolism, HCT116 Cells, Homeodomain Proteins metabolism, Humans, Mice, Transcription Factors metabolism, Transcription, Genetic, Transfection, Colonic Neoplasms genetics, DNA Breaks, Double-Stranded, DNA Repair, Homeodomain Proteins genetics, Transcription Factors genetics
- Abstract
Homeobox genes, involved in embryonic development and tissues homeostasis in adults, are often deregulated in cancer, but their relevance in pathology is far from being fully elucidated. In colon cancers, we report that the homeoproteins HoxB7 and Cdx2 exhibit different heterogeneous patterns, Cdx2 being localized in moderately altered neoplasic glands in contrast to HoxB7 which predominates in poorly-differentiated areas; they are coexpressed in few cancer cells. In human colon cancer cells, both homeoproteins interact with the DNA repair factor KU70/80, but functional studies reveal opposite effects: HoxB7 stimulates DNA repair and cell survival upon etoposide treatment, whereas Cdx2 inhibits both processes. The stimulatory effect of HoxB7 on DNA repair requires the transactivation domain linked to the homeodomain involved in the interaction with KU70/80, whereas the transactivation domain of Cdx2 is dispensable for its inhibitory function, which instead needs the homeodomain to interact with KU70/80 and the C-terminal domain. Thus, HoxB7 and Cdx2 respectively use transcription-dependent and -independent mechanisms to stimulate and inhibit DNA repair. In addition, in cells co-expressing both homeoproteins, Cdx2 lessens DNA repair activity through a novel mechanism of inhibition of the transcriptional function of HoxB7, whereby Cdx2 forms a molecular complex with HoxB7 and prevents it to recognize its target in the chromatin. These results point out the complex interplay between the DSB DNA repair activity and the homeoproteins HoxB7 and Cdx2 in colon cancer cells, making the balance between these factors a determinant and a potential indicator of the efficacy of genotoxic drugs., (Published by Elsevier Ireland Ltd.)
- Published
- 2016
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- View/download PDF
40. Extending the functions of the homeotic transcription factor Cdx2 in the digestive system through nontranscriptional activities.
- Author
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Freund JN, Duluc I, Reimund JM, Gross I, and Domon-Dell C
- Subjects
- Animals, CDX2 Transcription Factor, Homeodomain Proteins chemistry, Homeodomain Proteins genetics, Homeostasis, Humans, Intestinal Neoplasms metabolism, Intestinal Neoplasms pathology, Intestines pathology, Protein Conformation, Structure-Activity Relationship, Transcription, Genetic, Homeodomain Proteins metabolism, Intestinal Mucosa metabolism, Signal Transduction
- Abstract
The homeoprotein encoded by the intestinal-specific Cdx2 gene is a major regulator of gut development and homeostasis, also involved in colon cancer as well as in intestinal-type metaplasias when it is abnormally expressed outside the gut. At the molecular level, structure/function studies have demonstrated that the Cdx2 protein is a transcription factor containing a conserved homeotic DNA-binding domain made of three alpha helixes arranged in a helix-turn-helix motif, preceded by a transcriptional domain and followed by a regulatory domain. The protein interacts with several thousand sites on the chromatin and widely regulates intestinal functions in stem/progenitor cells as well as in mature differentiated cells. Yet, this transcription factor also acts trough original nontranscriptional mechanisms. Indeed, the identification of novel protein partners of Cdx2 and also of a splicing variant revealed unexpected functions in the control of signaling pathways like the Wnt and NF-κB pathways, in double-strand break DNA repair and in premessenger RNA splicing. These novel functions of Cdx2 must be considered to fully understand the complexity of the role of Cdx2 in the healthy intestine and in diseases.
- Published
- 2015
- Full Text
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41. Broader expression of the mouse platelet factor 4-cre transgene beyond the megakaryocyte lineage.
- Author
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Pertuy F, Aguilar A, Strassel C, Eckly A, Freund JN, Duluc I, Gachet C, Lanza F, and Léon C
- Subjects
- Animals, Blood Platelets metabolism, Cells, Cultured, Chromosomes, Artificial, Bacterial, Colon cytology, Colon metabolism, Epithelial Cells cytology, Epithelial Cells metabolism, Female, Gene Expression Regulation, Developmental, Genotype, Leukocytes metabolism, Male, Mice, Inbred C57BL, Mice, Nude, Mice, Transgenic, Phenotype, Platelet Factor 4 genetics, Recombination, Genetic, Signal Transduction, Thrombopoiesis, Cell Lineage, Integrases genetics, Megakaryocytes metabolism, Platelet Factor 4 metabolism
- Abstract
Background: Transgenic mice expressing cre recombinase under the control of the platelet factor 4 (Pf4) promoter, in the context of a 100-kb bacterial artificial chromosome, have become a valuable tool with which to study genetic modifications in the platelet lineage. However, the specificity of cre expression has recently been questioned, and the time of its onset during megakaryopoiesis remains unknown., Objectives/methods: To characterize the expression of this transgene, we used double-fluorescent cre reporter mice., Results: In the bone marrow, Pf4-cre-mediated recombination had occurred in all CD42-positive megakaryocytes as early as stage I of maturation, and in rare CD42-negative cells. In circulating blood, all platelets had recombined, along with only a minor fraction of CD45-positive cells. However, we found that all tissues contained recombined cells of monocyte/macrophage origin. When recombined, these cells might potentially modify the function of the tissues under particular conditions, especially inflammatory conditions, which further increase recombination in immune cells. Unexpectedly, a subset of epithelial cells from the distal colon showed signs of recombination resulting from endogenous Pf4-cre expression. This is probably the basis of the unexplained colon tumors developed by Apc(flox/flox) ;Pf4-cre mice, generated in a separate study on the role of Apc in platelet formation., Conclusion: Altogether, our results indicate early recombination with full penetrance in megakaryopoiesis, and confirm the value of Pf4-cre mice for the genetic engineering of megakaryocytes and platelets. However, care must be taken when investigating the role of platelets in processes outside hemostasis, especially when immune cells might be involved., (© 2014 International Society on Thrombosis and Haemostasis.)
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- 2015
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42. Cell guidance into quiescent state through chromatin remodeling induced by elastic modulus of substrate.
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Rabineau M, Flick F, Mathieu E, Tu A, Senger B, Voegel JC, Lavalle P, Schaaf P, Freund JN, Haikel Y, and Vautier D
- Subjects
- Animals, Cell Death drug effects, Cell Line, Cell Survival drug effects, Chromobox Protein Homolog 5, Chromosomal Proteins, Non-Histone metabolism, Cytoskeleton drug effects, Cytoskeleton metabolism, Electrolytes pharmacology, Epithelial Cells drug effects, Epithelial Cells ultrastructure, Euchromatin metabolism, Heterochromatin metabolism, Heterogeneous Nuclear Ribonucleoprotein A1, Heterogeneous-Nuclear Ribonucleoprotein Group A-B metabolism, Histone Deacetylase Inhibitors pharmacology, Histone Deacetylases metabolism, Hydroxamic Acids pharmacology, Substrate Specificity drug effects, Transcription, Genetic drug effects, Chromatin Assembly and Disassembly drug effects, Elastic Modulus drug effects, Epithelial Cells cytology, Epithelial Cells metabolism
- Abstract
Substrate stiffness is known to strongly influence the fate of adhering cells. Yet, little is known about the influence of the substrate stiffness on chromatin. Chromatin integrates a multitude of biochemical signals interpreted by activation or gene silencing. Here we investigate for the first time the organization of chromatin of epithelial cells on substrate with various mechanical properties. On stiff substrates (100-200 kPa), where cells preferentially adhere, chromatin is mainly found in its euchromatin form. Decreasing the Young modulus to 50 kPa is correlated with a partial shift from euchromatin to heterochromatin. On very soft substrates (≪10 kPa) this is accompanied by cell lysis. On these very soft substrates, histone deacetylase inhibition by adding a drug preserves acetylated histone and thus maintains the euchromatin form, thereby keeping intact the nuclear envelope as well as a residual intermediate filament network around the nucleus. This allows cells to survive in a non-adherent state without undergoing proliferation. When transfer on a stiff substrate these cells retain their capacity to adhere, to spread and to enter a novel mitotic cycle. A similar effect is observed on soft substrates (50 kPa) without need of histone deacetylase inhibition. These new results suggest that on soft substrates cells might enter in a quiescence state. Cell quiescence may thus be triggered by the Young modulus of a substrate, a major result for strategies focusing on the design of scaffold in tissue engineering., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
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43. Transcriptional regulation of the intestinal nuclear bile acid farnesoid X receptor (FXR) by the caudal-related homeobox 2 (CDX2).
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Modica S, Cariello M, Morgano A, Gross I, Vegliante MC, Murzilli S, Salvatore L, Freund JN, Sabbà C, and Moschetta A
- Subjects
- Adenomatous Polyposis Coli metabolism, Adenomatous Polyposis Coli pathology, Adenomatous Polyposis Coli Protein genetics, Adenomatous Polyposis Coli Protein metabolism, Animals, Bile Acids and Salts metabolism, Binding Sites, CDX2 Transcription Factor, Cell Line, Tumor, Homeodomain Proteins metabolism, Humans, Intestinal Mucosa metabolism, Intestines pathology, Mice, Mice, Transgenic, Promoter Regions, Genetic, Protein Binding, Receptors, Cytoplasmic and Nuclear metabolism, Signal Transduction, Transcription Factors metabolism, Adenomatous Polyposis Coli genetics, Gene Expression Regulation, Neoplastic, Homeodomain Proteins genetics, Receptors, Cytoplasmic and Nuclear genetics, Transcription Factors genetics, Transcription, Genetic
- Abstract
Farnesoid X receptor (FXR, NR1H4) is a bile acid-activated transcription factor that belongs to the nuclear receptor superfamily. It is highly expressed in the enterohepatic system, where it senses bile acid levels to consequently reduce their synthesis while inducing their detoxification. Bile acids are intestinal tumor promoters and their concentrations have to be tightly regulated. Indeed, reduced expression of FXR in the intestine increases colorectal cancer susceptibility in mice, whereas its activation can promote apoptosis in genetically modified cells. Notably, despite the broad knowledge of the FXR enterohepatic transcriptional activity, the molecular mechanisms regulating FXR expression in the intestine are still unknown. Herein, by combining both gain and loss of function approaches and FXR promoter activity studies, we identified caudal-related homeobox 2 (CDX2) transcription factor as a positive regulator of FXR expression in the enterocytes. Our results provide a putative novel tool for modulating FXR expression against bile acid-related colorectal cancer progression., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2014
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44. Combined NADPH oxidase 1 and interleukin 10 deficiency induces chronic endoplasmic reticulum stress and causes ulcerative colitis-like disease in mice.
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Tréton X, Pedruzzi E, Guichard C, Ladeiro Y, Sedghi S, Vallée M, Fernandez N, Bruyère E, Woerther PL, Ducroc R, Montcuquet N, Freund JN, Van Seuningen I, Barreau F, Marah A, Hugot JP, Cazals-Hatem D, Bouhnik Y, Daniel F, and Ogier-Denis E
- Subjects
- Animals, Blotting, Western, Case-Control Studies, Cell Proliferation, Cells, Cultured, Colitis, Ulcerative metabolism, Colitis, Ulcerative pathology, Colon immunology, Colon metabolism, Colon pathology, Endoplasmic Reticulum metabolism, Endoplasmic Reticulum pathology, Female, Flow Cytometry, Fluorescent Antibody Technique, Humans, Immunoenzyme Techniques, Inflammation metabolism, Inflammation pathology, Intestinal Mucosa metabolism, Intestinal Mucosa pathology, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, NADPH Oxidase 1, Phosphorylation, Protein Phosphatase 1 genetics, Protein Phosphatase 1 metabolism, RNA, Messenger genetics, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Unfolded Protein Response, Colitis, Ulcerative etiology, Disease Models, Animal, Endoplasmic Reticulum Stress, Inflammation etiology, Interleukin-10 physiology, NADH, NADPH Oxidoreductases physiology
- Abstract
Ulcerative colitis (UC) is a chronic inflammatory bowel disease affecting the rectum which progressively extents. Its etiology remains unknown and the number of treatments available is limited. Studies of UC patients have identified an unbalanced endoplasmic reticulum (ER) stress in the non-inflamed colonic mucosa. Animal models with impaired ER stress are sensitive to intestinal inflammation, suggesting that an unbalanced ER stress could cause inflammation. However, there are no ER stress-regulating strategies proposed in the management of UC partly because of the lack of relevant preclinical model mimicking the disease. Here we generated the IL10/Nox1dKO mouse model which combines immune dysfunction (IL-10 deficiency) and abnormal epithelium (NADPH oxidase 1 (Nox1) deficiency) and spontaneously develops a UC-like phenotype with similar complications (colorectal cancer) than UC. Our data identified an unanticipated combined role of IL10 and Nox1 in the fine-tuning of ER stress responses in goblet cells. As in humans, the ER stress was unbalanced in mice with decreased eIF2α phosphorylation preceding inflammation. In IL10/Nox1dKO mice, salubrinal preserved eIF2α phosphorylation through inhibition of the regulatory subunit of the protein phosphatase 1 PP1R15A/GADD34 and prevented colitis. Thus, this new experimental model highlighted the central role of epithelial ER stress abnormalities in the development of colitis and defined the defective eIF2α pathway as a key pathophysiological target for UC. Therefore, specific regulators able to restore the defective eIF2α pathway could lead to the molecular remission needed to treat UC.
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- 2014
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45. TAF4 inactivation reveals the 3 dimensional growth promoting activities of collagen 6A3.
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Martianov I, Cler E, Duluc I, Vicaire S, Philipps M, Freund JN, and Davidson I
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- Adaptor Proteins, Signal Transducing genetics, Adaptor Proteins, Signal Transducing metabolism, Animals, Blotting, Western, Carrier Proteins genetics, Carrier Proteins metabolism, Cell Adhesion drug effects, Cell Adhesion genetics, Cell Cycle Proteins, Cells, Cultured, Collagen Type VI genetics, Embryo, Mammalian cytology, Fibroblasts cytology, Gene Expression, Hippo Signaling Pathway, Intracellular Signaling Peptides and Proteins, Membrane Proteins genetics, Membrane Proteins metabolism, Mice, Mice, Knockout, Microscopy, Confocal, Phosphoproteins genetics, Phosphoproteins metabolism, Protein Serine-Threonine Kinases genetics, Protein Serine-Threonine Kinases metabolism, RNA Interference, Reverse Transcriptase Polymerase Chain Reaction, Spheroids, Cellular cytology, Spheroids, Cellular drug effects, Spheroids, Cellular metabolism, Transcription Factor TFIID genetics, Tretinoin pharmacology, Wnt Signaling Pathway drug effects, Wnt Signaling Pathway genetics, YAP-Signaling Proteins, Cell Proliferation, Collagen Type VI metabolism, Fibroblasts metabolism, Transcription Factor TFIID metabolism
- Abstract
Collagen 6A3 (Col6a3), a component of extracellular matrix, is often up-regulated in tumours and is believed to play a pro-oncogenic role. However the mechanisms of its tumorigenic activity are poorly understood. We show here that Col6a3 is highly expressed in densely growing mouse embryonic fibroblasts (MEFs). In MEFs where the TAF4 subunit of general transcription factor IID (TFIID) has been inactivated, elevated Col6a3 expression prevents contact inhibition promoting their 3 dimensional growth as foci and fibrospheres. Analyses of gene expression in densely growing Taf4(-/-) MEFs revealed repression of the Hippo pathway and activation of Wnt signalling. The Hippo activator Kibra/Wwc1 is repressed under dense conditions in Taf4(-/-) MEFs, leading to nuclear accumulation of the proliferation factor YAP1 in the cells forming 3D foci. At the same time, Wnt9a is activated and the Sfrp2 antagonist of Wnt signalling is repressed. Surprisingly, treatment of Taf4(-/-) MEFs with all-trans retinoic acid (ATRA) restores contact inhibition suppressing 3D growth. ATRA represses Col6a3 expression independently of TAF4 expression and Col6a3 silencing is sufficient to restore contact inhibition in Taf4(-/-) MEFs and to suppress 3D growth by reactivating Kibra expression to induce Hippo signalling and by inducing Sfrp2 expression to antagonize Wnt signalling. All together, these results reveal a critical role for Col6a3 in regulating both Hippo and Wnt signalling to promote 3D growth, and show that the TFIID subunit TAF4 is essential to restrain the growth promoting properties of Col6a3. Our data provide new insight into the role of extra cellular matrix components in regulating cell growth.
- Published
- 2014
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46. Contribution of soft substrates to malignancy and tumor suppression during colon cancer cell division.
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Rabineau M, Kocgozlu L, Dujardin D, Senger B, Haikel Y, Voegel JC, Freund JN, Schaaf P, Lavalle P, and Vautier D
- Subjects
- Cell Death, Cell Line, Tumor, Colonic Neoplasms pathology, Humans, Cell Cycle, Chromosome Aberrations, Colonic Neoplasms metabolism, Elasticity, Tumor Microenvironment
- Abstract
In colon cancer, a highly aggressive disease, progression through the malignant sequence is accompanied by increasingly numerous chromosomal rearrangements. To colonize target organs, invasive cells cross several tissues of various elastic moduli. Whether soft tissue increases malignancy or in contrast limits invasive colon cell spreading remains an open question. Using polyelectrolyte multilayer films mimicking microenvironments of various elastic moduli, we revealed that human SW480 colon cancer cells displayed increasing frequency in chromosomal segregation abnormalities when cultured on substrates with decreasing stiffness. Our results show that, although decreasing stiffness correlates with increased cell lethality, a significant proportion of SW480 cancer cells did escape from the very soft substrates, even when bearing abnormal chromosome segregation, achieve mitosis and undergo a new cycle of replication in contrast to human colonic HCoEpiC cells which died on soft substrates. This observation opens the possibility that the ability of cancer cells to overcome defects in chromosome segregation on very soft substrates could contribute to increasing chromosomal rearrangements and tumor cell aggressiveness.
- Published
- 2013
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47. Increasing the oxygen load by treatment with myo-inositol trispyrophosphate reduces growth of colon cancer and modulates the intestine homeobox gene Cdx2.
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Derbal-Wolfrom L, Pencreach E, Saandi T, Aprahamian M, Martin E, Greferath R, Tufa E, Choquet P, Lehn JM, Nicolau C, Duluc I, and Freund JN
- Subjects
- Animals, CDX2 Transcription Factor, Cell Line, Tumor, Cell Proliferation drug effects, Colonic Neoplasms mortality, Colonic Neoplasms pathology, Disease Models, Animal, Humans, Hypoxia, Inositol Phosphates administration & dosage, MAP Kinase Signaling System, Mice, Proto-Oncogene Proteins c-akt metabolism, Tumor Burden drug effects, Xenograft Model Antitumor Assays, Colonic Neoplasms genetics, Colonic Neoplasms metabolism, Gene Expression Regulation, Neoplastic drug effects, Homeodomain Proteins genetics, Inositol Phosphates pharmacology, Oxygen Consumption
- Abstract
Preventing tumor neovascularisation is one of the strategies recently developed to limit the dissemination of cancer cells and apparition of metastases. Although these approaches could improve the existing treatments, a number of unexpected negative effects have been reported, mainly linked to the hypoxic condition and the subsequent induction of the pro-oncogenic hypoxia inducible factor(s) resulting from cancer cells' oxygen starvation. Here, we checked in vivo on colon cancer cells an alternative approach. It is based on treatment with myo-inositol trispyrophosphate (ITPP), a molecule that leads to increased oxygenation of tumors. We provide evidence that ITPP increases the survival of mice in a model of carcinomatosis of human colon cancer cells implanted into the peritoneal cavity. ITPP also reduced the growth of subcutaneous colon cancer cells xenografted in nu/nu mice. In the subcutaneous tumors, ITPP stimulated the expression of the homeobox gene Cdx2 that is crucial for intestinal differentiation and that also has an anti-tumoral function. On this basis, human colon cancer cells were cultured in vitro in hypoxic conditions. Hypoxia was shown to decrease the level of Cdx2 protein, mRNA and the activity of the Cdx2 promoter. This decline was unrelated to the activation of HIF1α and HIF2α by hypoxia. However, it resulted from the activation of a phosphatidylinositol 3-kinases-like mitogen-activated protein kinase pathway, as assessed by the fact that LY294002 and U0126 restored high Cdx2 expression in hypoxia. Corroborating these results, U0126 recapitulated the increase of Cdx2 triggered by ITPP in subcutaneous colon tumor xenografts. The present study provides evidence that a chemical compound that increases oxygen pressure can antagonize the hypoxic setting and reduce the growth of human colon tumors implanted in nu/nu mice.
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- 2013
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48. Regulation of the tumor suppressor homeogene Cdx2 by HNF4α in intestinal cancer.
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Saandi T, Baraille F, Derbal-Wolfrom L, Cattin AL, Benahmed F, Martin E, Cardot P, Duclos B, Ribeiro A, Freund JN, and Duluc I
- Subjects
- Animals, CDX2 Transcription Factor, Colonic Neoplasms genetics, GATA6 Transcription Factor genetics, Gene Expression Regulation, Neoplastic, Genes, Tumor Suppressor, Hepatocyte Nuclear Factor 4 genetics, Homeodomain Proteins genetics, Mice, Promoter Regions, Genetic, Transcription Factors genetics, Colonic Neoplasms etiology, Hepatocyte Nuclear Factor 4 physiology, Homeodomain Proteins physiology, Transcription Factors physiology
- Abstract
The gut-specific homeotic transcription factor Cdx2 is a crucial regulator of intestinal development and homeostasis, which is downregulated in colorectal cancers (CRC) and exhibits a tumor suppressor function in the colon. We have previously established that several endodermal transcription factors, including HNF4α and GATA6, are involved in Cdx2 regulation in the normal gut. Here we have studied the role of HNF4α in the mechanism of deregulation of Cdx2 in colon cancers. Crossing Apc(Δ14/+) mice prone to spontaneous intestinal tumor development with pCdx2-9LacZ transgenic mice containing the LacZ reporter under the control of the 9.3-kb Cdx2 promoter showed that this promoter segment contains sequences recapitulating the decrease of Cdx2 expression in intestinal cancers. Immunohistochemistry revealed that HNF4α, unlike GATA6, exhibited a similar decrease to Cdx2 in genetic (Apc(min/+) and Apc(Δ14/+)) and chemically induced (Azoxymethane (AOM) treatment) models of intestinal tumors in mice. HNF4α and Cdx2 also exhibited a comparable deregulated pattern in human CRC. Correlated patterns were observed between HNF4α and Cdx2 in several experimental models of human colon cancer cell lines: xenografts in nude mice, wound healing and glucose starvation. Furthermore, Cdx2 decreased by knocking down HNF4α in human colon cancer cells using siRNA and in the colon of mice conditionally knocked out for the Hnf4α gene in the adult intestine (Hnf4α(f/f);VilCre(ERT2) mice). Finally, the conditionally knocked out mice Hnf4α(f/f);VilCre(ERT2) treated with the carcinogen AOM developed colorectal tumors earlier than wild-type mice, as previously reported for mice with a reduced Cdx2 expression. In conclusion, this study provides evidence that the downregulation of HNF4α is an important determinant of the reduced expression of the Cdx2 tumor suppressor gene in intestinal cancers. Consistently, similar to Cdx2, HNF4α exerts a tumor suppressor function in the colon in that its loss of function facilitates tumor progression.
- Published
- 2013
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49. Molecular and cellular effects of vitamin B12 in brain, myocardium and liver through its role as co-factor of methionine synthase.
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Guéant JL, Caillerez-Fofou M, Battaglia-Hsu S, Alberto JM, Freund JN, Dulluc I, Adjalla C, Maury F, Merle C, Nicolas JP, Namour F, and Daval JL
- Subjects
- Animals, Humans, 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase metabolism, Brain metabolism, Liver metabolism, Myocardium metabolism, Vitamin B 12 metabolism
- Abstract
Vitamin B12 (cobalamin, cbl) is a cofactor of methionine synthase (MTR) in the synthesis of methionine, the precursor of the universal methyl donor S-Adenosylmethionine (SAM), which is involved in epigenomic regulatory mechanisms. We have established a neuronal cell model with stable expression of a transcobalamin-oleosin chimer and subsequent decreased cellular availability of vitamin B12, which produces reduced proliferation, increased apoptosis and accelerated differentiation through PP2A, NGF and TACE pathways. Anti-transcobalamin antibody or impaired transcobalamin receptor expression produce also impaired proliferation in other cells. Consistently, the transcription, protein expression and activity of MTR are increased in proliferating cells of skin and intestinal epitheliums, in rat intestine crypts and in proliferating CaCo2 cells, while MTR activity correlates with DNA methylation in rat intestine villi. Exposure to nitrous oxide in animal models identified impairment of MTR reaction as the most important metabolic cause of neurological manifestations of B12 deficiency. Early vitamin B12 and folate deprivation during gestation and lactation of a 'dam-progeny' rat model developed in our laboratory is associated with long-lasting disabilities of behavior and memory capacities, with persisting hallmarks related to increased apoptosis, impaired neurogenesis and altered plasticity. We found also an epigenomic deregulation of energy metabolism and fatty acids beta-oxidation in myocardium and liver, through imbalanced methylation/acetylation of PGC-1alpha and decreased expression of SIRT1. These nutrigenomic effects display similarities with the molecular mechanisms of fetal programming. Beside deficiency, B12 loading increases the expression of MTR through internal ribosome entry sites (IRES) and down-regulates MDR-1 gene expression. In conclusion, vitamin B12 influences cell proliferation, differentiation and apoptosis in brain. Vitamin B12 and folate combined deficiency impairs fatty acid oxidation and energy metabolism in liver and heart through epigenomic mechanisms related to imbalanced acetylation/methylation. Some but not all of these effects reflect the upstream role of vitamin B12 in SAM synthesis., (Copyright © 2013. Published by Elsevier Masson SAS.)
- Published
- 2013
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50. Gastric intrinsic factor deficiency with combined GIF heterozygous mutations and FUT2 secretor variant.
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Chery C, Hehn A, Mrabet N, Oussalah A, Jeannesson E, Besseau C, Alberto JM, Gross I, Josse T, Gérard P, Guéant-Rodriguez RM, Freund JN, Devignes J, Bourgaud F, Peyrin-Biroulet L, Feillet F, and Guéant JL
- Subjects
- Adult, Anemia, Pernicious genetics, Anemia, Pernicious metabolism, Female, Genome-Wide Association Study, Helicobacter Infections genetics, Helicobacter Infections metabolism, Heterozygote, Humans, Intrinsic Factor deficiency, Intrinsic Factor metabolism, Male, Mutation, Vitamin B 12 metabolism, Young Adult, Galactoside 2-alpha-L-fucosyltransferase, Anemia, Pernicious congenital, Fucosyltransferases genetics, Intrinsic Factor genetics
- Abstract
Several genome-wide association studies (GWAS) have identified a strong association between serum vitamin B12 and fucosyltransferase 2 (FUT2), a gene associated with susceptibility to Helicobacter pylori infection. Hazra et al. conducted a meta-analysis of three GWAS and found three additional loci in MUT, CUBN and TCN1. Other GWAS conducted in Italy and China confirmed the association for FUT2 gene. Alpha-2-fucosyltransferase (FUT2) catalyzes fucose addition to form H-type antigens in exocrine secretions. FUT2 non-secretor variant produces no secretion of H-type antigens and is associated with high-plasma vitamin B12 levels. This association was explained by the influence of FUT2 on H. pylori, which is a risk factor of gastritis, a main cause of vitamin B12 impaired absorption. However, we recently showed that H. pylori serology had no influence on FUT2 association with vitamin B12, in a large sample population, suggesting the involvement of an alternative mechanism. GIF is another gene associated with plasma levels of vitamin B12 and gastric intrinsic factor (GIF) is a fucosylated protein needed for B12 absorption. Inherited GIF deficiency produces B12 deficiency unrelated with gastritis. We report 2 families with heterozygous GIF mutation, 290T>C, M97T, with decreased binding affinity of GIF for vitamin B12 and one family with heterozygous GIF mutation 435_437delGAA, K145_N146delinsN and no B12 binding activity of mutated GIF. All cases with vitamin B12 deficit carried the FUT2 rs601338 secretor variant. Ulex europeus binding to GIF was influenced by FUT2 genotypes and GIF concentration was lower, in gastric juice from control subjects with the secretor genotype. GIF290C allele was reported in 5 European cases and no Africans among 1282 ambulatory subjects and was associated with low plasma vitamin B12 and anaemia in the single case bearing the FUT2 secretor variant. We concluded that FUT2 secretor variant worsens B12 status in cases with heterozygous GIF mutations by impairing GIF secretion, independently from H. pylori-related gastritis., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
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