1
|
Genetta T, Hurwitz J, Clark E, Herold B, Khalil S, Abbas T, Larner J. ZEB1 promotes non-homologous end joining double-strand break repair. Nucleic Acids Res 2023; 51:9863-9879. [PMID: 37665026 PMCID: PMC10570029 DOI: 10.1093/nar/gkad723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 07/31/2023] [Accepted: 08/21/2023] [Indexed: 09/05/2023] Open
Abstract
Repair of DSB induced by IR is primarily carried out by Non-Homologous End Joining (NHEJ), a pathway in which 53BP1 plays a key role. We have discovered that the EMT-inducing transcriptional repressor ZEB1 (i) interacts with 53BP1 and that this interaction occurs rapidly and is significantly amplified following exposure of cells to IR; (ii) is required for the localization of 53BP1 to a subset of double-stranded breaks, and for physiological DSB repair; (iii) co-localizes with 53BP1 at IR-induced foci (IRIF); (iv) promotes NHEJ and inhibits Homologous Recombination (HR); (v) depletion increases resection at DSBs and (vi) confers PARP inhibitor (PARPi) sensitivity on BRCA1-deficient cells. Lastly, ZEB1's effects on repair pathway choice, resection, and PARPi sensitivity all rely on its homeodomain. In contrast to the well-characterized therapeutic resistance of high ZEB1-expressing cancer cells, the novel ZEB1-53BP1-shieldin resection axis described here exposes a therapeutic vulnerability: ZEB1 levels in BRCA1-deficient tumors may serve as a predictive biomarker of response to PARPis.
Collapse
Affiliation(s)
- Thomas L Genetta
- Dept. of Radiation Oncology, University of Virginia School of Medicine, PO Box 800383, Charlottesville, VA 22908, USA
| | - Joshua C Hurwitz
- Dept. of Radiation Oncology, University of Virginia School of Medicine, PO Box 800383, Charlottesville, VA 22908, USA
| | - Evan A Clark
- Dept. of Radiation Oncology, University of Virginia School of Medicine, PO Box 800383, Charlottesville, VA 22908, USA
| | - Benjamin T Herold
- Dept. of Radiation Oncology, University of Virginia School of Medicine, PO Box 800383, Charlottesville, VA 22908, USA
| | - Shadi Khalil
- Dept. of Radiation Oncology, University of Virginia School of Medicine, PO Box 800383, Charlottesville, VA 22908, USA
| | - Tarek Abbas
- Dept. of Radiation Oncology, University of Virginia School of Medicine, PO Box 800383, Charlottesville, VA 22908, USA
- Dept. of Biochemistry and Molecular Genetics University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - James M Larner
- Dept. of Radiation Oncology, University of Virginia School of Medicine, PO Box 800383, Charlottesville, VA 22908, USA
| |
Collapse
|
2
|
Yu D, Lu Z, Wang R, Xiang Y, Li H, Lu J, Zhang L, Chen H, Li W, Luan X, Chen L. FXR agonists for colorectal and liver cancers, as a stand-alone or in combination therapy. Biochem Pharmacol 2023; 212:115570. [PMID: 37119860 DOI: 10.1016/j.bcp.2023.115570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/01/2023]
Abstract
Farnesoid X receptor (FXR, NR1H4) is generally considered as a tumor suppressor of colorectal and liver cancers. The interaction between FXR, bile acids (BAs) and gut microbiota is closely associated with an increased risk of colorectal and liver cancers. Increasing evidence shows that FXR agonists may be potential therapeutic agents for colorectal and liver cancers. However, FXR agonists alone do not produce the desired results due to the complicated pathogenesis and single therapeutic mechanism, which suggests that effective treatments will require a multimodal approach. Based on the principle of improvingefficacy andreducingside effects, combination therapy is currently receiving considerable attention. In this review, colorectal and liver cancers are grouped together to discuss the effects of FXR agonists alone or in combination for combating the two cancers. We hope that this review will provide a theoretical basis for the clinical application of novel FXR agonists or combination with FXR agonists against colorectal and liver cancers.
Collapse
Affiliation(s)
- Danmei Yu
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Zhou Lu
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Ruyu Wang
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Yusen Xiang
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Hongtao Li
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Jiani Lu
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Lijun Zhang
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Hongzhuan Chen
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Weihua Li
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Xin Luan
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Lili Chen
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| |
Collapse
|
3
|
Yu J, Yang K, Zheng J, Zhao P, Xia J, Sun X, Zhao W. Activation of FXR and inhibition of EZH2 synergistically inhibit colorectal cancer through cooperatively accelerating FXR nuclear location and upregulating CDX2 expression. Cell Death Dis 2022; 13:388. [PMID: 35449124 PMCID: PMC9023572 DOI: 10.1038/s41419-022-04745-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 02/09/2022] [Accepted: 03/18/2022] [Indexed: 12/13/2022]
Abstract
Our previous study indicated that colon cancer cells varied in sensitivity to pharmacological farnesoid X receptor (FXR) activation. Herein, we explore the regulatory mechanism of FXR in colorectal cancer (CRC) development and aim to design effective strategies of combined treatment based on the regulatory axis. We found that the expression of FXR was negatively correlated with enhancer of zeste homolog 2 (EZH2) in colon cancer tissues. EZH2 transcriptionally suppressed FXR via H3K27me3. The combination of FXR agonist OCA plus EZH2 inhibitor GSK126 acted in a synergistic manner across four colon cancer cells, efficiently inhibiting clonogenic growth and invasion in vitro, retarding tumor growth in vivo, preventing the G0/G1 to S phase transition, and inducing caspase-dependent apoptosis. Benign control cells FHC were growth-arrested without apoptosis induction, but retained long-term proliferation and invasion capacity. Mechanistically, the drug combination dramatically accelerated FXR nuclear location and cooperatively upregulated caudal-related homeobox transcription factor 2 (CDX2) expression. The depletion of CDX2 antagonized the synergistic effects of the drug combination on tumor inhibition. In conclusion, our study demonstrated histone modification-mediated FXR silencing by EZH2 in colorectal tumorigenesis, which offers useful evidence for the clinical use of FXR agonists combined with EZH2 inhibitors in combating CRC.
Collapse
Affiliation(s)
- Junhui Yu
- grid.452438.c0000 0004 1760 8119Department of General Surgery, First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, PR China
| | - Kui Yang
- grid.452438.c0000 0004 1760 8119Department of General Surgery, First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, PR China
| | - Jianbao Zheng
- grid.452438.c0000 0004 1760 8119Department of General Surgery, First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, PR China
| | - Pengwei Zhao
- grid.452438.c0000 0004 1760 8119Department of General Surgery, First Affiliated Hospital of Xi’an Jiaotong University, 710061 Xi’an, PR China
| | - Jie Xia
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of New Drug Research and Development, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, 100050, Beijing, PR China.
| | - Xuejun Sun
- Department of General Surgery, First Affiliated Hospital of Xi'an Jiaotong University, 710061, Xi'an, PR China.
| | - Wei Zhao
- Department of General Surgery, First Affiliated Hospital of Xi'an Jiaotong University, 710061, Xi'an, PR China.
| |
Collapse
|
4
|
Galland A, Gourain V, Habbas K, Güler Y, Martin E, Ebel C, Tavian M, Vallat L, Chenard MP, Mauvieux L, Freund JN, Duluc I, Domon-Dell C. CDX2 expression in the hematopoietic lineage promotes leukemogenesis via TGFβ inhibition. Mol Oncol 2021; 15:2318-2329. [PMID: 33960108 PMCID: PMC8410536 DOI: 10.1002/1878-0261.12982] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 12/23/2022] Open
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.
Collapse
Affiliation(s)
- Ava Galland
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| | - Victor Gourain
- Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, Germany
| | - Karima Habbas
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| | - Yonca Güler
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| | - Elisabeth Martin
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| | - Claudine Ebel
- Inserm, IGBMC, UMR-S 1258, Université de Strasbourg, Illkirch, France
| | - Manuela Tavian
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| | - Laurent Vallat
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France.,Laboratoire d'Hématologie, Centre Hospitalier Universitaire de Strasbourg, France
| | - Marie-Pierre Chenard
- Département de Pathologie, Centre Hospitalier Universitaire de Strasbourg, France
| | - Laurent Mauvieux
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France.,Laboratoire d'Hématologie, Centre Hospitalier Universitaire de Strasbourg, France
| | - Jean-Noël Freund
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| | - Isabelle Duluc
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| | - Claire Domon-Dell
- Université de Strasbourg, Inserm, IRFAC / UMR-S1113, FHU ARRIMAGE, ITI InnoVec, FMTS, Strasbourg, France
| |
Collapse
|
5
|
CDX2 inhibits epithelial-mesenchymal transition in colorectal cancer by modulation of Snail expression and β-catenin stabilisation via transactivation of PTEN expression. Br J Cancer 2020; 124:270-280. [PMID: 33239678 PMCID: PMC7782852 DOI: 10.1038/s41416-020-01148-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/21/2020] [Accepted: 10/15/2020] [Indexed: 02/07/2023] Open
Abstract
Background Emerging evidence suggests the involvement of caudal-related homoeobox transcription factor 2 (CDX2) in tumorigenesis of various cancers. Although CDX2 functions in cancer invasion and metastasis, fewer studies focus on the role of CDX2 during the induction of epithelial–mesenchymal transition (EMT) in colorectal cancer (CRC). Methods Immunohistochemical analysis of CDX2 was performed. A series of in vitro and in vivo experiments were conducted to reveal the role of CDX2 in the invasion and metastasis of CRC. Results CDX2 was downregulated in CRC tissues and reduced CDX2 correlated with poor prognosis. Knockdown of CDX2 promoted colon cancer cell invasion in vitro and facilitated liver metastasis in vivo with inducing EMT phenotypes. Further investigation indicated that CDX2 retarded Akt and GSK-3β phosphorylation, and thereby diminished Snail expression, β-catenin stabilisation and nuclear translocation. The depletion of β-catenin neutralised the regulation of Slug and ZEB1 by CDX2 knockdown. Mechanistically, CDX2 antagonised PI3K/Akt activity in CRC by modulating PTEN expression. CDX2 directly bound to the promoter of PTEN and transactivated its expression. Conclusions Our study first uncovered that CDX2 inhibits EMT and metastasis of CRC by regulation of Snail expression and β-catenin stabilisation via transactivation of PTEN expression. ![]()
Collapse
|
6
|
Wu CC, Hsu TW, Yeh CC, Huang HB. The role of transcription factor caudal-related homeobox transcription factor 2 in colorectal cancer. Tzu Chi Med J 2020; 32:305-311. [PMID: 33163374 PMCID: PMC7605288 DOI: 10.4103/tcmj.tcmj_49_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/24/2020] [Accepted: 05/06/2020] [Indexed: 12/25/2022] Open
Abstract
Colorectal cancer (CRC) is one of the most malignant tumors in humans and causes mass mortality. In the age of precise medicine, more and more subtypes of CRC were classified. The caudal-related homeobox transcription factor 2 (CDX2) is an intestine-specific transcription factor which is implicated in differentiation, proliferation, cell-adhesion, and migration. The loss of CDX2 in immunohistochemical stain was reported to be a prognostic factor of colon cancer, but the clinical application remained controversial. Most of the CRCs expressed or over-expressed CDX2. Homeobox genes can display either an oncogenic or a tumor-suppressing activity. CDX2 regulates the developing intestinal epithelium and CRC by different pathways. The complex regulation of CDX2 and its complex targets cause the difficulties of application for CDX2 in the prediction of prognosis. However, CDX2 is a potential biomarker applied in the precise classification of CRC for personalized medicine. This review partially clarifies the role of CDX2 in CRC.
Collapse
Affiliation(s)
- Chin-Chia Wu
- Division of Colorectal Surgery, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.,College of Medicine, Tzu Chi University, Hualien, Taiwan.,School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien, Taiwan
| | - Ta-Wen Hsu
- Division of Colorectal Surgery, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.,College of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Chia-Chou Yeh
- School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien, Taiwan.,Department of Chinese Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
| | - Hsien-Bing Huang
- Department of Biomedical Sciences and Institute of Molecular Biology, National Chung Cheng University, Chiayi, Taiwan
| |
Collapse
|
7
|
The H2A.Z histone variant integrates Wnt signaling in intestinal epithelial homeostasis. Nat Commun 2019; 10:1827. [PMID: 31015444 PMCID: PMC6478875 DOI: 10.1038/s41467-019-09899-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 04/02/2019] [Indexed: 12/27/2022] Open
Abstract
The Tip60/p400 chromatin-modifying complex, which is involved in the incorporation and post-translational modification of the H2A.Z histone variant, regulates cell proliferation and important signaling pathways, such as Wnt. Here, we study the involvement of H2A.Z in intestinal epithelial homeostasis, which is dependent on the finely-tuned equilibrium between stem cells renewal and differentiation, under the control of such pathway. We use cell models and inducible knock-out mice to study the impact of H2A.Z depletion on intestinal homeostasis. We show that H2A.Z is essential for the proliferation of human cancer and normal intestinal crypt cells and negatively controls the expression of a subset of differentiation markers, in cultured cells and mice. H2A.Z impairs the recruitment of the intestine-specific transcription factor CDX2 to chromatin, is itself a target of the Wnt pathway and thus, acts as an integrator for Wnt signaling in the control of intestinal epithelial cell fate and homeostasis. The histone variant, H2A.Z is known to regulate gene expression and cell proliferation. Here the authors show that H2A.Z has a central role in the control of intestinal epithelial homeostasis in mice, by preventing terminal differentiation of intestinal progenitors.
Collapse
|
8
|
CDX2 inhibits the proliferation and tumor formation of colon cancer cells by suppressing Wnt/β-catenin signaling via transactivation of GSK-3β and Axin2 expression. Cell Death Dis 2019; 10:26. [PMID: 30631044 PMCID: PMC6328578 DOI: 10.1038/s41419-018-1263-9] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/31/2018] [Accepted: 12/04/2018] [Indexed: 02/06/2023]
Abstract
Caudal-related homeobox transcription factor 2 (CDX2), an intestine-specific nuclear transcription factor, has been strongly implicated in the tumourigenesis of various human cancers. However, the functional role of CDX2 in the development and progression of colorectal cancer (CRC) is not well known. In this study, CDX2 knockdown in colon cancer cells promoted cell proliferation in vitro, accelerated tumor formation in vivo, and induced a cell cycle transition from G0/G1 to S phase, whereas CDX2 overexpression inhibited cell proliferation. TOP/FOP-Flash reporter assay showed that CDX2 knockdown or CDX2 overexpression significantly increased or decreased Wnt signaling activity. Western blot assay showed that downstream targets of Wnt signaling, including β-catenin, cyclin D1 and c-myc, were up-regulated or down-regulated in CDX2-knockdown or CDX2-overexpressing colon cancer cells. In addition, suppression of Wnt signaling by XAV-939 led to a marked suppression of the cell proliferation enhanced by CDX2 knockdown, whereas activation of this signaling by CHIR-99021 significantly enhanced the cell proliferation inhibited by CDX2 overexpression. Dual-luciferase reporter and quantitative chromatin immunoprecipitation (qChIP) assays further confirmed that CDX2 transcriptionally activates glycogen synthase kinase-3β (GSK-3β) and axis inhibition protein 2 (Axin2) expression by directly binding to the promoter of GSK-3β and the upstream enhancer of Axin2. In conclusion, these results indicated that CDX2 inhibits the proliferation and tumor formation of colon cancer cells by suppressing Wnt/β-catenin signaling.
Collapse
|
9
|
Nitta A, Hori K, Tanida I, Igarashi A, Deyama Y, Ueno T, Kominami E, Sugai M, Aoki K. Blocking LC3 lipidation and ATG12 conjugation reactions by ATG7 mutant protein containing C572S. Biochem Biophys Res Commun 2019; 508:521-526. [PMID: 30503495 DOI: 10.1016/j.bbrc.2018.11.158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 11/24/2018] [Indexed: 12/30/2022]
Abstract
Autophagy, a system for the bulk degradation of intracellular components, is essential for homeostasis and the healthy physiology and development of cells and tissues. Its deregulation is associated with human disease. Thus, methods to modulate autophagic activity are critical for analysis of its role in mammalian cells and tissues. Here we report a method to inhibit autophagy using a mutant variant of the protein ATG7, a ubiquitin E1-like enzyme essential for autophagosome formation. During autophagy, ATG7 activates the conjugation of LC3 (ATG8) with phosphatidylethanolamine (PE) and ATG12 with ATG5. Human ATG7 interactions with LC3 or ATG12 require a thioester bond involving the ATG7 cysteine residue at position 572. We generated TetOff cells expressing mutant ATG7 protein carrying a serine substitution of this critical cysteine residue (ATG7C572S). Because ATG7C572S forms stable intermediate complexes with LC3 or ATG12, its expression resulted in a strong blockage of the ATG-conjugation system and suppression of autophagosome formation. Consequently, ATG7C572S mutant protein can be used as an inhibitor of autophagy.
Collapse
Affiliation(s)
- Akari Nitta
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Kazuya Hori
- Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Isei Tanida
- Department of Cell Biology and Neuroscience, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Ayumi Igarashi
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Yasuyo Deyama
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Takashi Ueno
- Laboratory of Proteomics and Biomolecular Science, Research Support Center, Juntendo University Graduate School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Eiki Kominami
- Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Manabu Sugai
- Department of Molecular Genetics, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Koji Aoki
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Life Science Innovation Center, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; PREST, Japan Science and Technology Agency, 5-7 Chiyoda-ku, Tokyo, 102-0076, Japan.
| |
Collapse
|
10
|
Chou CF, Hsieh YH, Grubbs CJ, Atigadda VR, Mobley JA, Dummer R, Muccio DD, Eto I, Elmets CA, Garvey WT, Chang PL. The retinoid X receptor agonist, 9-cis UAB30, inhibits cutaneous T-cell lymphoma proliferation through the SKP2-p27kip1 axis. J Dermatol Sci 2018; 90:343-356. [PMID: 29599065 PMCID: PMC6329374 DOI: 10.1016/j.jdermsci.2018.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 02/15/2018] [Accepted: 03/08/2018] [Indexed: 01/09/2023]
Abstract
BACKGROUND Bexarotene (Targretin®) is currently the only FDA approved retinoid X receptor (RXR) -selective agonist for the treatment of cutaneous T-cell lymphomas (CTCLs). The main side effects of bexarotene are hypothyroidism and elevation of serum triglycerides (TGs). The novel RXR ligand, 9-cis UAB30 (UAB30) does not elevate serum TGs or induce hypothyroidism in normal subjects. OBJECTIVES To assess preclinical efficacy and mechanism of action of UAB30 in the treatment of CTCLs and compare its action with bexarotene. METHODS With patient-derived CTCL cell lines, we evaluated UAB30 function in regulating growth, apoptosis, cell cycle check points, and cell cycle-related markers. RESULTS Compared to bexarotene, UAB30 had lower half maximal inhibitory concentration (IC50) values and was more effective in inhibiting the G1 cell cycle checkpoint. Both rexinoids increased the stability of the cell cycle inhibitor, p27kip1 protein, in part, through targeting components involved in the ubiquitination-proteasome system: 1) decreasing SKP2, a F-box protein that binds and targets p27kip1 for degradation by 26S proteasome and 2) suppressing 20S proteasome activity (cell line-dependent) through downregulation of PSMA7, a component of the 20S proteolytic complex in 26S proteasome. CONCLUSIONS UAB30 and bexarotene induce both early cell apoptosis and suppress cell proliferation. Inhibition of the G1 to S cell cycle transition by rexinoids is mediated, in part, through downregulation of SKP2 and/or 20S proteasome activity, leading to increased p27kip1 protein stability. Because UAB30 has minimal effect in elevating serum TGs and inducing hypothyroidism, it is potentially a better alternative to bexarotene for the treatment of CTCLs.
Collapse
Affiliation(s)
- Chu-Fang Chou
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Yu-Hua Hsieh
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Clinton J Grubbs
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Venkatram R Atigadda
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - James A Mobley
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Reinhard Dummer
- Department of Dermatology, University Hospital of Zurich, Switzerland
| | - Donald D Muccio
- Department of Biochemistry, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Isao Eto
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Craig A Elmets
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - W Timothy Garvey
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA
| | - Pi-Ling Chang
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA; Department of Dermatology, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA.
| |
Collapse
|
11
|
Homeobox protein CDX2 as a prognostic biomarker in solid malignancies: a meta-analysis. Oncotarget 2017; 8:89160-89172. [PMID: 29179508 PMCID: PMC5687678 DOI: 10.18632/oncotarget.20808] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 08/17/2017] [Indexed: 02/06/2023] Open
Abstract
Background CDX2 is a caudal-homeobox gene and its expression is abnormal in numerous tumour cell types. Nevertheless, its prognostic value for solid tumours requires further investigation. Hence, we conducted a meta-analysis to determine the significance of CDX2 as a prognostic biomarker in solid malignancies systematically. Materials and Methods We performed a systematic literature search in PUBMED and EMBASE up to May 2017. Retrospective studies comparing the prognostic value of different CDX2 levels in human malignancies were included. Data extractions and methodological assessments were performed separately by two investigators using a standard procedure. The statistical procedures were performed using Review Manager 5.3 and STATA/MP 14.0. Results A total of 26 retrospective studies met the inclusion criteria and comprised 5008 participants. Patients with CDX2 overexpression had significantly better 3-year, 5-year, 10-year and disease-free survival outcomes in solid malignancies, regardless of the cancer type, mean age, and source region. Nevertheless, there was no significant difference in the patients from Europe. The expression level of CDX2 was not statistically associated with cancer relapse. Moreover, our analysis showed that CDX2 overexpression is correlated to better responses to chemotherapy in patients with TNM IV stage cancers. The stability of the pooled outcomes was verified by sensitivity analysis. The funnel plots, Egger's test and Begg's test jointly confirmed that there was no publication bias. Conclusions Overexpression of CDX2 is a reliable biomarker of a better prognosis in solid malignancies.
Collapse
|
12
|
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, Freund JN. Fine-tuning and autoregulation of the intestinal determinant and tumor suppressor homeobox gene CDX2 by alternative splicing. Cell Death Differ 2017; 24:2173-2186. [PMID: 28862703 DOI: 10.1038/cdd.2017.140] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 07/23/2017] [Accepted: 07/25/2017] [Indexed: 12/20/2022] Open
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.
Collapse
Affiliation(s)
- Camille Balbinot
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Marie Vanier
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Olivier Armant
- Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Postfach 3640, Karlsruhe 76021, Germany
| | - Asmaa Nair
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Julien Penichon
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Christine Soret
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Elisabeth Martin
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Thoueiba Saandi
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Jean-Marie Reimund
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Jacqueline Deschamps
- Hubrecht Institute, Developmental Biology and Stem Cell Research, Uppsalalaan 8, Utrecht 3584 CT, The Netherlands
| | - Felix Beck
- Barts and The London School of Medicine and Dentistry, London E1 2ES, UK
| | - Claire Domon-Dell
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Isabelle Gross
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Isabelle Duluc
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| | - Jean-Noël Freund
- Université de Strasbourg, Inserm, UMR_S1113, FMTS, Strasbourg 67000, France
| |
Collapse
|
13
|
Sun X, Zhu MJ. AMP-activated protein kinase: a therapeutic target in intestinal diseases. Open Biol 2017; 7:170104. [PMID: 28835570 PMCID: PMC5577448 DOI: 10.1098/rsob.170104] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/25/2017] [Indexed: 02/07/2023] Open
Abstract
Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a highly conserved energy sensor, has a crucial role in cardiovascular, neurodegenerative and inflammatory diseases, as well as in cancer and metabolic disorders. Accumulating studies have demonstrated that AMPK activation enhances paracellular junctions, nutrient transporters, autophagy and apoptosis, and suppresses inflammation and carcinogenesis in the intestine, indicating an essential role of AMPK in intestinal health. AMPK inactivation is an aetiological factor in intestinal dysfunctions. This review summarizes the favourable outcomes of AMPK activation on intestinal health, and discusses AMPK as a potential therapeutic target for intestinal diseases.
Collapse
Affiliation(s)
- Xiaofei Sun
- School of Food Science, Washington State University, Pullman, WA 99164, USA
- School of Food Science, University of Idaho, Moscow, ID 83844, USA
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA 99164, USA
- School of Food Science, University of Idaho, Moscow, ID 83844, USA
| |
Collapse
|
14
|
Platet N, Hinkel I, Richert L, Murdamoothoo D, Moufok-Sadoun A, Vanier M, Lavalle P, Gaiddon C, Vautier D, Freund JN, Gross I. The tumor suppressor CDX2 opposes pro-metastatic biomechanical modifications of colon cancer cells through organization of the actin cytoskeleton. Cancer Lett 2017; 386:57-64. [DOI: 10.1016/j.canlet.2016.10.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 10/20/2016] [Accepted: 10/25/2016] [Indexed: 02/07/2023]
|
15
|
He S, Sun XJ, Zheng JB, Qi J, Chen NZ, Wang W, Wei GB, Liu D, Yu JH, Lu SY, Wang H. Recombinant lentivirus with enhanced expression of caudal-related homeobox protein 2 inhibits human colorectal cancer cell proliferation in vitro. Mol Med Rep 2015; 12:1838-44. [PMID: 25847407 PMCID: PMC4464164 DOI: 10.3892/mmr.2015.3594] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 02/27/2015] [Indexed: 12/11/2022] Open
Abstract
Caudal-related homeobox protein 2 (CDX2), a tumor suppressor in the adult colon, is overexpressed under a non-cancer specific cytomegalovirus promoter in certain tumor cells; furthermore, non-specific expression of CDX2 may result in aberrant side effects in normal cells. The human telomerase reverse transcriptase (hTERT) promoter is active in the majority of cancer cells but not in normal cells. Hypoxia is a key feature of solid tumors, and targeted genes may be significantly upregulated by five copies of hypoxia-response elements (HREs) under hypoxic conditions. However, the effect of CDX2 overexpression, as controlled by five copies of HREs and the hTERT promoter, on human colorectal cancer (CRC) cell proliferation in vitro remains to be fully elucidated. In the current study, a recombinant lentivirus containing the CDX2 gene under the control of five HREs and the hTERT promoter was generated. An immunofluorescence assay was used to detect CDX2 expression by the 5HhC lentivirus, whereas an MTT assay was used to detect the effects of CoCl2 on the viability of LoVo cells. Western blot analysis was conducted in order to determine the relative ratios of recombinant CDX2 protein to the internal control β-actin, following 5HhC/LoVo cell culture under normoxic and hypoxic conditions (100, 200, 300, 400 or 500 µmol/l CoCl2) for 24 h, then for 12, 24 or 36 h with the optimal concentration (300 µmol/l) of CoCl2. Reverse transcription polymerase chain reaction analysis was used to determine the transcription of recombinant CDX2 mRNA following culture of 5HhC/LoVo cells under normoxic or hypoxic conditions. Finally, a cloning assay was used to detect the proliferative ability of 5HhC/LoVo and 5Hh cells. High CDX2 expression was observed in hTERT-positive LoVo cells under hypoxic conditions, an effect which was mimicked by treatment with CoCl2 to inhibit LoVo cell proliferation in vitro. High expression of CDX2 therefore provides a promising strategy for the development of novel targeted treatments and gene therapy for CRC.
Collapse
Affiliation(s)
- Sai He
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Xue-Jun Sun
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Jian-Bao Zheng
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Jie Qi
- Second Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - Nan-Zheng Chen
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Wei Wang
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Guang-Bing Wei
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Dong Liu
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Jun-Hui Yu
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Shao-Ying Lu
- Department of General Surgery, First Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Hui Wang
- Department of Anesthesiology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| |
Collapse
|
16
|
Bian B, Mongrain S, Cagnol S, Langlois MJ, Boulanger J, Bernatchez G, Carrier JC, Boudreau F, Rivard N. Cathepsin B promotes colorectal tumorigenesis, cell invasion, and metastasis. Mol Carcinog 2015; 55:671-87. [PMID: 25808857 PMCID: PMC4832390 DOI: 10.1002/mc.22312] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 02/05/2015] [Accepted: 02/21/2015] [Indexed: 12/14/2022]
Abstract
Cathepsin B is a cysteine proteinase that primarily functions as an endopeptidase within endolysosomal compartments in normal cells. However, during tumoral expansion, the regulation of cathepsin B can be altered at multiple levels, thereby resulting in its overexpression and export outside of the cell. This may suggest a possible role of cathepsin B in alterations leading to cancer progression. The aim of this study was to determine the contribution of intracellular and extracellular cathepsin B in growth, tumorigenesis, and invasion of colorectal cancer (CRC) cells. Results show that mRNA and activated levels of cathepsin B were both increased in human adenomas and in CRCs of all stages. Treatment of CRC cells with the highly selective and non‐permeant cathepsin B inhibitor Ca074 revealed that extracellular cathepsin B actively contributed to the invasiveness of human CRC cells while not essential for their growth in soft agar. Cathepsin B silencing by RNAi in human CRC cells inhibited their growth in soft agar, as well as their invasion capacity, tumoral expansion, and metastatic spread in immunodeficient mice. Higher levels of the cell cycle inhibitor p27Kip1 were observed in cathepsin B‐deficient tumors as well as an increase in cyclin B1. Finally, cathepsin B colocalized with p27Kip1 within the lysosomes and efficiently degraded the inhibitor. In conclusion, the present data demonstrate that cathepsin B is a significant factor in colorectal tumor development, invasion, and metastatic spreading and may, therefore, represent a potential pharmacological target for colorectal tumor therapy. © 2015 The Authors. Molecular Carcinogenesis, published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Benjamin Bian
- Department of Anatomy and Cell Biology, Cancer Research Pavilion, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Sébastien Mongrain
- Department of Anatomy and Cell Biology, Cancer Research Pavilion, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Sébastien Cagnol
- Department of Anatomy and Cell Biology, Cancer Research Pavilion, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Marie-Josée Langlois
- Department of Anatomy and Cell Biology, Cancer Research Pavilion, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Jim Boulanger
- Department of Anatomy and Cell Biology, Cancer Research Pavilion, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Gérald Bernatchez
- Gastroenterology Service, Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Julie C Carrier
- Gastroenterology Service, Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - François Boudreau
- Department of Anatomy and Cell Biology, Cancer Research Pavilion, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Nathalie Rivard
- Department of Anatomy and Cell Biology, Cancer Research Pavilion, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
| |
Collapse
|
17
|
Gu Z, Meng Y, Tao T, Guo G, Tan W, Xia Y, Cheng C, Liu H. Endoplasmic reticulum stress participates in the progress of senescence of bone marrow-derived mesenchymal stem cells in patients with systemic lupus erythematosus. Cell Tissue Res 2015; 361:497-508. [PMID: 25773452 DOI: 10.1007/s00441-015-2131-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 01/19/2015] [Indexed: 02/04/2023]
Abstract
Previous studies suggested that the senescence of bone marrow mesenchymal stem cells (BM-MSCs) played an important role in the pathological process of systemic lupus erythematosus (SLE). However, the molecular mechanisms that govern this phenomenon have not been fully elucidated. Recent studies reported the activation of endoplasmic reticulum stress (ERS) participated in the growth arrest in G1 phase of cell cycle. In this study, we aimed to investigate whether ERS would induce the senescence of BM-MSCs from SLE patients. We found that there was increased expression of Glucose Regulated Protein 78 (GRP 78) in BM-MSCs from SLE patients, which indicated the activation of ERS in BM-MSCs from SLE patients. Accumulation of p27 was also found in BM-MSCs from SLE patients. Interestingly, as a chemical chaperone helping the correct folding of proteins, 4-phenylbutyric acid (4-PBA) partly rescued the senescence of BM-MSCs from SLE patients and alleviated the level of p27. These results implicated ERS-mediated senescence as a critical determinant of BM-MSCs from SLE patients.
Collapse
Affiliation(s)
- Zhifeng Gu
- Department of Rheumatology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Bae JM, Lee TH, Cho NY, Kim TY, Kang GH. Loss of CDX2 expression is associated with poor prognosis in colorectal cancer patients. World J Gastroenterol 2015; 21:1457-1467. [PMID: 25663765 PMCID: PMC4316088 DOI: 10.3748/wjg.v21.i5.1457] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/04/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the clinicopathologic characteristics and prognostic implications associated with loss of CDX2 expression in colorectal cancers (CRCs).
METHODS: We immunohistochemically evaluated CDX2 expression in 713 CRCs and paired our findings to clinicopathologic and molecular characteristics of each individual. Endpoints included cytokeratin 7 and CK20 expression, microsatellite instability, CpG island methylator phenotype, and KRAS and BRAF mutation statuses. Univariate and multivariate survival analysis was performed to reveal the prognostic value of CDX2 downregulation.
RESULTS: CDX2 expression was lost in 42 (5.9%) patients. Moreover, loss of CDX2 expression was associated with proximal location, infiltrative growth, advanced T, N, M and overall stage. On microscopic examination, loss of CDX2 expression was associated with poor differentiation, increased number of tumor-infiltrating lymphocytes, luminal serration and mucin production. Loss of CDX2 expression was also associated with increased CK7 expression, decreased CK20 expression, CpG island methylator phenotype, microsatellite instability and BRAF mutation. In a univariate survival analysis, patients with loss of CDX2 expression showed worse overall survival (P < 0.001) and progression-free survival (P < 0.001). In a multivariate survival analysis, loss of CDX2 expression was an independent poor prognostic factor of overall survival [hazard ratio (HR) = 1.72, 95%CI: 1.04-2.85, P = 0.034] and progression-free survival (HR = 1.94, 95%CI: 1.22-3.07, P = 0.005).
CONCLUSION: Loss of CDX2 expression is associated with aggressive clinical behavior and can be used as a prognostic marker in CRCs.
Collapse
|
19
|
Freund JN, Duluc I, Reimund JM, Gross I, Domon-Dell C. Extending the functions of the homeotic transcription factor Cdx2 in the digestive system through nontranscriptional activities. World J Gastroenterol 2015; 21:1436-1443. [PMID: 25663763 PMCID: PMC4316086 DOI: 10.3748/wjg.v21.i5.1436] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 11/25/2014] [Accepted: 12/16/2014] [Indexed: 02/06/2023] Open
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.
Collapse
|
20
|
Olsen J, Espersen MLM, Jess P, Kirkeby LT, Troelsen JT. The clinical perspectives of CDX2 expression in colorectal cancer: a qualitative systematic review. Surg Oncol 2014; 23:167-76. [PMID: 25126956 DOI: 10.1016/j.suronc.2014.07.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/05/2014] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Homeobox genes are often deregulated in cancer. They can have both oncogenic and tumor-suppressing potential. The Caudal-related homeobox transcription factor 2 (CDX2) is an intestine-specific transcription factor. It is implicated in differentiation, proliferation, cell-adhesion, and migration. CDX2 has been proposed as a tumor suppressor in colorectal cancer but its role is still controversial. This systematic review were undertaken in order to clarify CDX2s role in colorectal cancer. METHODS A literature search was performed in the MEDLINE database from 1966 to February 2014. Only studies in which all or a part of the experimental design were performed on human colorectal cancer tissue were included. Thus, studies solely performed in cell-lines or animal models were excluded. RESULTS Fifty-two articles of relevance were identified. CDX2 expression was rarely lost in colorectal cancers, however the expression pattern may often be heterogeneous within the tumor and can be selectively down regulated at the invasive front and in tumor buddings. Loss of CDX2 expression is probably correlated to tumor grade, stage, right-sided tumor location, MMR-deficiency, CIMP, and BRAF mutations. The CDX2 gene is rarely mutated but the locus harboring the gene is often amplified and may suggest CDX2 as a linage-survival oncogene. CDX2 might be implicated in cell proliferation and migration through cross-talk with the Wnt-signaling pathway, tumor-stroma proteins, and inflammatory cytokines. CONCLUSION A clear role for CDX2 expression in colorectal cancer remains to be elucidated, and it might differ in relation to the underlying molecular pathways leading to the cancer formation.
Collapse
Affiliation(s)
- J Olsen
- Department of Science, Systems and Models, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark; Department of Surgery, Roskilde University Hospital, Roskilde Sygehus, Køgevej 7-13, DK-4000 Roskilde, Denmark.
| | - M L M Espersen
- Department of Science, Systems and Models, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark; The Molecular Unit, Department of Pathology, Herlev University Hospital, DK-2730 Herlev, Denmark.
| | - P Jess
- Department of Surgery, Roskilde University Hospital, Roskilde Sygehus, Køgevej 7-13, DK-4000 Roskilde, Denmark.
| | - L T Kirkeby
- Department of Surgery, Roskilde University Hospital, Roskilde Sygehus, Køgevej 7-13, DK-4000 Roskilde, Denmark.
| | - J T Troelsen
- Department of Science, Systems and Models, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark.
| |
Collapse
|
21
|
Yan LH, Wei WY, Xie YB, Xiao Q. New insights into the functions and localization of the homeotic gene CDX2 in gastric cancer. World J Gastroenterol 2014; 20:3960-3966. [PMID: 24744585 PMCID: PMC3983451 DOI: 10.3748/wjg.v20.i14.3960] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/22/2013] [Accepted: 02/20/2014] [Indexed: 02/06/2023] Open
Abstract
Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human gastrointestinal cancers. In addition, gastric epithelial cell mutations in CDX2 result in tumor promotion, which is characterized by cellular drug resistance and a high proclivity for developing cancer. A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance. CDX2 appears to forward control regenerating IV and the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance.
Collapse
|
22
|
Matsuzaki J, Suzuki H, Tsugawa H, Watanabe M, Hossain S, Arai E, Saito Y, Sekine S, Akaike T, Kanai Y, Mukaisho KI, Auwerx J, Hibi T. Bile acids increase levels of microRNAs 221 and 222, leading to degradation of CDX2 during esophageal carcinogenesis. Gastroenterology 2013; 145:1300-11. [PMID: 23933602 DOI: 10.1053/j.gastro.2013.08.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 08/03/2013] [Accepted: 08/05/2013] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Bile reflux contributes to development of Barrett's esophagus (BE) and could be involved in its progression to esophageal adenocarcinoma (EAC). We investigated whether bile acids affect levels or functions of microRNAs (MIRs) 221 and 222, which bind to the 3'-UTR of p27Kip1 messenger RNA to inhibit its translation. Reduced p27Kip1 increases degradation of the transcription factor CDX2; levels of CDX2 have been reported to decrease during progression of BE to EAC. METHODS We used quantitative reverse transcriptase polymerase chain reaction to compare levels of MIRs 221 and 222 and immunohistochemistry to compare levels of p27Kip1 and CDX2 proteins in areas of BE and EAC from each of 11 patients. We examined the effects of bile acid exposure on levels of MIRs 221 and 222 and CDX2 in EAC cells. We investigated the effects of inhibitors of MIRs 221 and 222 on growth of human EAC xenograft tumors in NOD/SCID/IL-2Rγ(null) mice. RESULTS Levels of MIRs 221 and 222 increased and levels of p27Kip1 and CDX2 decreased in areas of EAC vs BE. Levels of MIRs 221 and 222 increased, along with activity of nuclear bile acid receptor/farnesoid X receptor (FXR), when cultured cells were exposed to bile acids. Incubation of cells with bile acids increased degradation of CDX2; this process was reduced when cells were also incubated with proteasome inhibitors. Overexpression of MIRs 221 and 222 reduced levels of p27Kip1 and CDX2, and knockdown of these MIRs increased levels of these proteins in cultured cells. Inhibitors of MIRs 221 and 222 increased levels of p27Kip1 and CDX2 in EAC cells and reduced growth of xenograft tumors in NOD/SCID/IL-2Rγ(null) mice. CONCLUSIONS We observed increased levels of MIRs 221 and 222 in human EAC tissues, compared with areas of BE from the same patient. We found that exposure of esophageal cells to bile acids activates FXR and increases levels of MIRs 221 and 222, reducing levels of p27Kip1 and promoting degradation of CDX2 by the proteasome. Our work opened the perspective of therapeutically targeting this pathway either via FXR antagonists or inhibitors of MIRs as a treatment option for BE and EAC.
Collapse
Affiliation(s)
- Juntaro Matsuzaki
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan; Department of Internal Medicine, Saiseikai Central Hospital, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Bernatchez G, Giroux V, Lassalle T, Carpentier AC, Rivard N, Carrier JC. ERRα metabolic nuclear receptor controls growth of colon cancer cells. Carcinogenesis 2013; 34:2253-61. [PMID: 23720198 DOI: 10.1093/carcin/bgt180] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The estrogen-related receptor alpha (ERRα) is a nuclear receptor that acts primarily as a regulator of metabolic processes, particularly in tissues subjected to high-energy demand. In addition to its control of energy metabolism and mitochondrial biogenesis, ERRα has recently been associated with cancer progression. Notably, increased expression of ERRα has been shown in several cancerous tissues, including breast, ovary and colon. However, additional studies are required to gain insight into the action of ERRα in cancer biology, particularly in non-endocrine-related cancers. Therefore, using a short hairpin RNA-mediated approach, we investigated whether ERRα is required for the rapid growth of colon cancer cells and to maintain their neoplastic metabolic state. Results show that silencing ERRα significantly impaired colon cancer cell proliferation and colony formation in vitro as well as their in vivo tumorigenic capacity. A pronounced delay in G1-to-S cell cycle phase transition was observed in ERRα-depleted cells in association with reduced cyclin-dependent kinase 2 activity and hyperphosphorylated state of the retinoblastoma protein along with disturbed expression of several cell cycle regulators, including p15 and p27. Interestingly, ERRα-depleted HCT116 cells also displayed significant reduction in expression of a large set of key genes to glycolysis, tricarboxylic acid cycle and lipid synthesis. Furthermore, using (14)C isotope tracer analysis, ERRα depletion in colon cancer cells resulted in reduced glucose incorporation and glucose-mediated lipogenesis in these cells. These findings suggest that ERRα coordinates colon cancer cell proliferation and tumorigenic capacity with energy metabolism. Thus, ERRα could represent a promising therapeutic target in colon cancer.
Collapse
|
24
|
Abstract
Homeobox genes comprise a super-family of evolutionarily conserved genes that play essential roles in controlling body plan specification and cell fate determination. Substantial evidence indicates that leukemogenesis is driven by abnormal expression of homeobox genes that control hematopoiesis. In solid tumors, aberrant expression of homeobox genes has been increasingly found to modulate diverse processes such as cell proliferation, cell death, metastasis, angiogenesis and DNA repair. This review discusses how homeobox genes are deregulated in solid tumors and the functional significance of this deregulation in the hallmarks of cancer.
Collapse
Affiliation(s)
- Dhwani Haria
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, U.S.A
| | - Honami Naora
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, U.S.A
| |
Collapse
|
25
|
Wu WK, Wang XJ, Cheng AS, Luo MX, Ng SS, To KF, Chan FK, Cho CH, Sung JJ, Yu J. Dysregulation and crosstalk of cellular signaling pathways in colon carcinogenesis. Crit Rev Oncol Hematol 2013; 86:251-77. [DOI: 10.1016/j.critrevonc.2012.11.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 11/07/2012] [Accepted: 11/27/2012] [Indexed: 02/06/2023] Open
|
26
|
Olsen AK, Coskun M, Bzorek M, Kristensen MH, Danielsen ET, Jørgensen S, Olsen J, Engel U, Holck S, Troelsen JT. Regulation of APC and AXIN2 expression by intestinal tumor suppressor CDX2 in colon cancer cells. Carcinogenesis 2013; 34:1361-9. [DOI: 10.1093/carcin/bgt037] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
|
27
|
Liu X, Zhang X, Zhan Q, Brock MV, Herman JG, Guo M. CDX2 serves as a Wnt signaling inhibitor and is frequently methylated in lung cancer. Cancer Biol Ther 2012; 13:1152-7. [PMID: 22892849 PMCID: PMC3469472 DOI: 10.4161/cbt.21344] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aberrant promoter region hypermethylation of upstream transcription factors may be responsible for silencing entire anti-neoplastic gene networks. In this study, we explored whether transcription factor coding gene, caudal-related homeobox 2 (CDX2), is silenced by promoter hypermethylation in lung cancer, and examined its potential tumor-suppressive functions. Semi-quantitative RT-PCR showed that four of six lung cancer cell lines exhibited no or weak CDX2 expression. Expression of CDX2 was correlated to CDX2 promoter region methylation status, as determined by methylation-specific PCR (MSP) and bisulfite sequencing. Restoration of CDX2 expression was induced by treatment with demethylating drug 5-aza-2'-deoxycytidine (5-AZA) in lung cancer cell lines. Methylation of CDX2 was common in human primary lung cancer (61 of 110 tumors, 55.45%), but no methylation was found in normal lung tissues. Re-expression of CDX2 suppressed lung cancer cell proliferation and blocked cells in G1 phase. β-catenin/TCF activity and downstream genes expression were inhibited by re-expression of CDX2, and increased by depletion of CDX2. In conclusion, CDX2 is frequently methylated in lung cancer, and expression of CDX2 is regulated by promoter region hypermethylation. CDX2 may serve as a tumor suppressor in lung cancer and inhibits lung cancer cell proliferation by suppressing Wnt signaling.
Collapse
Affiliation(s)
- Xuefeng Liu
- Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Beijing, China
| | | | | | | | | | | |
Collapse
|
28
|
Dou W, Mukherjee S, Li H, Venkatesh M, Wang H, Kortagere S, Peleg A, Chilimuri SS, Wang ZT, Feng Y, Fearon ER, Mani S. Alleviation of gut inflammation by Cdx2/Pxr pathway in a mouse model of chemical colitis. PLoS One 2012; 7:e36075. [PMID: 22815676 PMCID: PMC3398007 DOI: 10.1371/journal.pone.0036075] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 03/25/2012] [Indexed: 01/10/2023] Open
Abstract
Pregnane X Receptor (PXR), a master regulator of drug metabolism and inflammation, is abundantly expressed in the gastrointestinal tract. Baicalein and its O-glucuronide baicalin are potent anti-inflammatory and anti-cancer herbal flavonoids that undergo a complex cycle of interconversion in the liver and gut. We sought to investigate the role these flavonoids play in inhibiting gut inflammation by an axis involving PXR and other potential factors. The consequences of PXR regulation and activation by the herbal flavonoids, baicalein and baicalin were evaluated in vitro in human colon carcinoma cells and in vivo using wild-type, Pxr-null, and humanized (hPXR) PXR mice. Baicalein, but not its glucuronidated metabolite baicalin, activates PXR in a Cdx2-dependent manner in vitro, in human colon carcinoma LS174T cells, and in the murine colon in vivo. While both flavonoids abrogate dextran sodium sulfate (DSS)-mediated colon inflammation in vivo, oral delivery of a potent bacterial β-glucuronidase inhibitor eliminates baicalin’s effect on gastrointestinal inflammation by preventing the microbial conversion of baicalin to baicalien. Finally, reduction of gastrointestinal inflammation requires the binding of Cdx2 to a specific proximal site on the PXR promoter. Pharmacological targeting of intestinal PXR using natural metabolically labile ligands could serve as effective and potent therapeutics for gut inflammation that avert systemic drug interactions.
Collapse
Affiliation(s)
- Wei Dou
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
- Shanghai Key Laboratory of Formulated Chinese Medicines and MOE Key Laboratory for Standardization Chinese Medicine, Institute of Chinese Materia Medica, Shanghai University of TCM, Shanghai, China
| | - Subhajit Mukherjee
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Hao Li
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Madhukumar Venkatesh
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Hongwei Wang
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Sandhya Kortagere
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Ariel Peleg
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
| | - Sridhar S. Chilimuri
- Department of Medicine, Bronx Lebanon Hospital Center, Bronx, New York, United States of America
| | - Zheng-Tao Wang
- Shanghai Key Laboratory of Formulated Chinese Medicines and MOE Key Laboratory for Standardization Chinese Medicine, Institute of Chinese Materia Medica, Shanghai University of TCM, Shanghai, China
- Institute of Chinese Materia Medica, Shanghai University of TCM, Shanghai, China
- * E-mail: (ZW); (SM)
| | - Ying Feng
- Division of Molecular Medicine and Genetics, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Eric R. Fearon
- Division of Molecular Medicine and Genetics, Department of Internal Medicine, Human Genetics and Pathology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sridhar Mani
- Departments of Medicine and Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
- * E-mail: (ZW); (SM)
| |
Collapse
|
29
|
Renouf B, Soret C, Saandi T, Delalande F, Martin E, Vanier M, Duluc I, Gross I, Freund JN, Domon-Dell C. Cdx2 homeoprotein inhibits non-homologous end joining in colon cancer but not in leukemia cells. Nucleic Acids Res 2011; 40:3456-69. [PMID: 22189105 PMCID: PMC3333856 DOI: 10.1093/nar/gkr1242] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cdx2, a gene of the paraHox cluster, encodes a homeodomain transcription factor that plays numerous roles in embryonic development and in homeostasis of the adult intestine. Whereas Cdx2 exerts a tumor suppressor function in the gut, its abnormal ectopic expression in acute leukemia is associated to a pro-oncogenic function. To try to understand this duality, we have hypothesized that Cdx2 may interact with different protein partners in the two tissues and set up experiments to identify them by tandem affinity purification. We show here that Cdx2 interacts with the Ku heterodimer specifically in intestinal cells, but not in leukemia cells, via its homeodomain. Ku proteins do not affect Cdx2 transcriptional activity. However, Cdx2 inhibits in vivo and in vitro the DNA repair activity mediated by Ku proteins in intestinal cells. Whereas Cdx2 does not affect the recruitment of Ku proteins and DNA-PKcs into the DNA repair complex, it inhibits DNA-PKcs activity. Thus, we report here a new function of Cdx2, acting as an inhibitor of the DNA repair machinery, that may contribute to its tumor suppressor function specifically in the gut.
Collapse
|
30
|
Lemieux E, Boucher MJ, Mongrain S, Boudreau F, Asselin C, Rivard N. Constitutive activation of the MEK/ERK pathway inhibits intestinal epithelial cell differentiation. Am J Physiol Gastrointest Liver Physiol 2011; 301:G719-30. [PMID: 21737780 DOI: 10.1152/ajpgi.00508.2010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The Ras/Raf/MEK/ERK cascade regulates intestinal epithelial cell proliferation. Indeed, while barely detectable in differentiated cells of the villi, ERK1/2-activated forms are detected in the nucleus of undifferentiated human intestinal crypt cells. In addition, we and others have reported that ERKs are selectively inactivated during enterocyte differentiation. However, whether inactivation of the ERK pathway is necessary for inhibition of both proliferation and induction of differentiation of intestinal epithelial cells is unknown. Human Caco-2/15 cells, undifferentiated crypt IEC-6 cells, and differentiating Cdx3-expressing IEC-6 cells were infected with retroviruses encoding either a hemagglutinin (HA)-tagged MEK1 wild type (wtMEK) or a constitutively active S218D/S222D MEK1 mutant (caMEK). Protein and gene expression was assessed by Western blotting, semiquantitative RT-PCR, and real-time PCR. Morphology was analyzed by transmission electron microscopy. We found that 1) IEC-6/Cdx3 cells formed multicellular layers after confluence and differentiated after 30 days in culture, as assessed by increased polarization, microvilli formation, expression of differentiation markers, and ERK1/2 inhibition; 2) while activated MEK prevented neither the inhibition of ERK1/2 activities nor the differentiation process in postconfluent Caco-2/15 cells, caMEK expression prevented ERK inhibition in postconfluent IEC-6/Cdx3 cells, thus leading to maintenance of elevated ERK1/2 activities; 3) caMEK-expressing IEC-6/Cdx3 cells exhibited altered multicellular structure organization, poorly defined tight junctions, reduced number of microvilli on the apical surface, and decreased expression of the hepatocyte nuclear factor 1α transcription factor and differentiation markers, namely apolipoprotein A-4, fatty acid-binding protein, calbindin-3, mucin 2, alkaline phosphatase, and sucrase-isomaltase; and 4) increased Cdx3 phosphorylation on serine-60 (S60) in IEC-6/Cdx3 cells expressing caMEK led to decreased Cdx2 transactivation potential. These results indicate that inactivation of the ERK pathway is required to ensure the full Cdx2/3 transcriptional activity necessary for intestinal epithelial cell terminal differentiation.
Collapse
Affiliation(s)
- Etienne Lemieux
- Canadian Institutes of Health Research Team on Digestive Epithelium, Department of Anatomy and Cellular Biology, Quebec
| | | | | | | | | | | |
Collapse
|