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Koubova K, Cizkova K, Burianova A, Tauber Z. PTEN and soluble epoxide hydrolase in intestinal cell differentiation. Biochim Biophys Acta Gen Subj 2023; 1867:130496. [PMID: 37866587 DOI: 10.1016/j.bbagen.2023.130496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/26/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
Intestinal epithelial differentiation is a highly organised process. It is influenced by a variety of signalling pathways and enzymes, such as the PI3K pathway and soluble epoxide hydrolase (sEH) from arachidonic acid metabolism. We investigated the changes in the expression of enzymes and lipid messenger from the PI3K pathway, including PTEN, during intestinal cell differentiation in vitro using HT-29 and Caco2 cells and compared them with immunohistochemical patterns of these proteins in human colon. To investigate the possible crosstalk between the PI3K pathway and sEH, we treated HT-29 and Caco2 cells with the sEH inhibitor TPPU. Administration of TPPU to differentiated cells decreased the expression of PTEN, thus reversing the change in its expression observed during cell differentiation. In addition, multiplex immunofluorescence staining confirmed the relationship between the expression of PTEN and villin, a marker of intestinal cell differentiation, ranging from a moderate correlation in undifferentiated cells to a very strong correlation in differentiated cells treated with TPPU. Furthermore, we confirm that PTEN and sEH mirrored their expression patterns in samples of prenatal and adult human intestine compared to tumours using immunohistochemical staining. Taken together, it appears that PTEN and sEH cooperate in the process of intestinal cell differentiation. A better understanding of the crosstalk between the PI3K pathway and sEH and its consequences for cell differentiation is highly desirable, as several sEH inhibitors are under clinical investigation for the treatment of various diseases.
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Affiliation(s)
- Katerina Koubova
- Department of Histology and Embryology, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Katerina Cizkova
- Department of Histology and Embryology, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic.
| | - Adela Burianova
- Department of Histology and Embryology, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Zdenek Tauber
- Department of Histology and Embryology, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
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Guerbette T, Boudry G, Lan A. Mitochondrial function in intestinal epithelium homeostasis and modulation in diet-induced obesity. Mol Metab 2022; 63:101546. [PMID: 35817394 PMCID: PMC9305624 DOI: 10.1016/j.molmet.2022.101546] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/27/2022] [Accepted: 07/06/2022] [Indexed: 11/30/2022] Open
Abstract
Background Systemic low-grade inflammation observed in diet-induced obesity has been associated with dysbiosis and disturbance of intestinal homeostasis. This latter relies on an efficient epithelial barrier and coordinated intestinal epithelial cell (IEC) renewal that are supported by their mitochondrial function. However, IEC mitochondrial function might be impaired by high fat diet (HFD) consumption, notably through gut-derived metabolite production and fatty acids, that may act as metabolic perturbators of IEC. Scope of review This review presents the current general knowledge on mitochondria, before focusing on IEC mitochondrial function and its role in the control of intestinal homeostasis, and featuring the known effects of nutrients and metabolites, originating from the diet or gut bacterial metabolism, on IEC mitochondrial function. It then summarizes the impact of HFD on mitochondrial function in IEC of both small intestine and colon and discusses the possible link between mitochondrial dysfunction and altered intestinal homeostasis in diet-induced obesity. Major conclusions HFD consumption provokes a metabolic shift toward fatty acid β-oxidation in the small intestine epithelial cells and impairs colonocyte mitochondrial function, possibly through downstream consequences of excessive fatty acid β-oxidation and/or the presence of deleterious metabolites produced by the gut microbiota. Decreased levels of ATP and concomitant O2 leaks into the intestinal lumen could explain the alterations of intestinal epithelium dynamics, barrier disruption and dysbiosis that contribute to the loss of epithelial homeostasis in diet-induced obesity. However, the effect of HFD on IEC mitochondrial function in the small intestine remains unknown and the precise mechanisms by which HFD induces mitochondrial dysfunction in the colon have not been elucidated so far.
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Affiliation(s)
| | - Gaëlle Boudry
- Institut Numecan, INSERM, INRAE, Univ Rennes, Rennes, France.
| | - Annaïg Lan
- Institut Numecan, INSERM, INRAE, Univ Rennes, Rennes, France; Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, Paris, France
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Long-Term Hypoxia Maintains a State of Dedifferentiation and Enhanced Stemness in Fetal Cardiovascular Progenitor Cells. Int J Mol Sci 2021; 22:ijms22179382. [PMID: 34502291 PMCID: PMC8431563 DOI: 10.3390/ijms22179382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 12/03/2022] Open
Abstract
Early-stage mammalian embryos survive within a low oxygen tension environment and develop into fully functional, healthy organisms despite this hypoxic stress. This suggests that hypoxia plays a regulative role in fetal development that influences cell mobilization, differentiation, proliferation, and survival. The long-term hypoxic environment is sustained throughout gestation. Elucidation of the mechanisms by which cardiovascular stem cells survive and thrive under hypoxic conditions would benefit cell-based therapies where stem cell survival is limited in the hypoxic environment of the infarcted heart. The current study addressed the impact of long-term hypoxia on fetal Islet-1+ cardiovascular progenitor cell clones, which were isolated from sheep housed at high altitude. The cells were then cultured in vitro in 1% oxygen and compared with control Islet-1+ cardiovascular progenitor cells maintained at 21% oxygen. RT-PCR, western blotting, flow cytometry, and migration assays evaluated adaptation to long term hypoxia in terms of survival, proliferation, and signaling. Non-canonical Wnt, Notch, AKT, HIF-2α and Yap1 transcripts were induced by hypoxia. The hypoxic niche environment regulates these signaling pathways to sustain the dedifferentiation and survival of fetal cardiovascular progenitor cells.
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Liu C, Huang M, Han C, Li H, Wang J, Huang Y, Chen Y, Zhu J, Fu G, Yu H, Lei Z, Chu X. A narrative review of the roles of muscle segment homeobox transcription factor family in cancer. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:810. [PMID: 34268423 PMCID: PMC8246185 DOI: 10.21037/atm-21-220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/05/2021] [Indexed: 11/23/2022]
Abstract
Deregulation of many homeobox genes has been observed in various cancers and has caused functional implications in the tumor progression. In this review, we will focus on the roles of the human muscle segment homeobox (MSX) transcription factor family in the process of tumorigenesis. The MSX transcription factors, through complex downstream regulation mechanisms, are promoters or inhibitors of diverse cancers by participating in cell proliferation, cell invasion, cell metastasis, cell apoptosis, cell differentiation, drug resistance of tumors, maintenance of tumor stemness, and tumor angiogenesis. Moreover, their upstream regulatory mechanisms in cancers may include: gene mutation and chromosome aberration; DNA methylation and chromatin modification; regulation by non-coding RNAs; regulation by other transcription factors and post-translational modification. These mechanisms may provide a better understanding of why MSX transcription factors are abnormally expressed in tumors. Notably, intermolecular interactions and post-translational modification can regulate the transcriptional activity of MSX transcription factors. It is also crucial to know what affects the transcriptional activity of MSX transcription factors in tumors for possible interventions in them in the future. This systematic summary of the regulatory patterns of the MSX transcription factor family may help to further understand the mechanisms involved in transcriptional regulation and also provide new therapeutic approaches for tumor progression.
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Affiliation(s)
- Chao Liu
- Department of Medical Oncology, Jinling Hospital, Nanjing Medical University, Nanjing, China
| | - Mengxi Huang
- Department of Medical Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China
| | - Chao Han
- Department of Medical Oncology, Jinling Hospital, Nanjing Medical University, Nanjing, China
| | - Huiyu Li
- Department of Medical Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China
| | - Jing Wang
- Department of Medical Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China
| | - Yadi Huang
- Department of Medical Oncology, Jinling Hospital, First School of Clinical Medicine, Southern Medical University, Nanjing, China
| | - Yanyan Chen
- Department of Medical Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China
| | - Jialong Zhu
- Department of Medical Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China
| | - Gongbo Fu
- Department of Medical Oncology, Jinling Hospital, Nanjing Medical University, Nanjing, China.,Department of Medical Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China
| | - Hanqing Yu
- Department of Clinical Laboratory, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zengjie Lei
- Department of Medical Oncology, Jinling Hospital, Nanjing Medical University, Nanjing, China.,Department of Medical Oncology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, China
| | - Xiaoyuan Chu
- Department of Medical Oncology, Jinling Hospital, Nanjing Medical University, Nanjing, China
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Abstract
Anoikis resistance is an essential property of cancer cells that allow the extra-cellular matrix-detached cells to survive in a suspended state in body fluid in order to metastasize and invade to distant organs. It is known that integrins play an important role in anoikis resistance, but detailed mechanisms are not well understood. Here we report that highly metastatic colon cancer cells showed a higher degree of anoikis resistance than the normal intestinal epithelial cells. These anoikis-resistant cancer cells express high-levels of integrin-α2, β1, and activated EGFR in the anchorage-independent state than the anchorage-dependent state. In contrast, normal intestinal epithelial cells failed to elevate these proteins. Interestingly, a higher co-association of EGFR with integrin-α2β1/-α5β1 was observed on the surface of anoikis-resistant cells. Thus, in the absence of extra-cellular matrix, integrins in association with EGFR activates downstream effectors ERK and AKT and suppress Caspase-3 activation to induce anoikis resistance as was confirmed from the gene-ablation and pharmacological inhibitor studies. Interestingly, these anoikis-resistant cancer cells express high-level of cancer stem cell signatures (CD24, CD44, CD133, EpCAM) and pluripotent stem cell markers (OCT-4, SOX-2, Nanog) as well as drug-resistant pumps (ABCG2, MDR1, MRP1). Altogether, our findings unravel the interplay between integrin-α2β1/-α5β1 and EGFR in anoikis resistance and suggest that the resistant cells are cancer initiating or cancer stem cells, which may serve as a promising target to combat metastasis of cancer.
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Methods for Assessing Apoptosis and Anoikis in Normal Intestine/Colon and Colorectal Cancer. Methods Mol Biol 2019; 1765:99-137. [PMID: 29589304 DOI: 10.1007/978-1-4939-7765-9_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Caspase-dependent apoptosis, including its distinct cell death subroutine known as anoikis, perform essential roles during organogenesis, as well as in the maintenance and repair of tissues. To this effect, the continuous renewal of the human intestinal/colon epithelium is characterized by the exfoliation by anoikis of differentiated cells, whereas immature/undifferentiated cells may occasionally undergo apoptosis in order to evacuate daughter cells that are damaged or defective. Dysregulated epithelial apoptosis is a significant component of inflammatory bowel diseases. Conversely, the acquisition of a resistance to apoptosis represents one of the hallmarks of cancer initiation and progression, including for colorectal cancer (CRC). Furthermore, the emergence of anoikis resistance constitutes a critical step in cancer progression (including CRC), as well as a limiting one that enables invasion and metastasis.Considering the implications of apoptosis/anoikis dysregulation in gut physiopathology, it therefore becomes incumbent to understand the functional determinants that underlie such dysregulation-all the while having to monitor, assess, or evidence apoptosis and/or anoikis. In this chapter, methodologies that are typically used to assess caspase-dependent apoptosis and anoikis in intestinal/colonic normal and CRC cells, whether in vivo, ex vivo, or in cellulo, are provided.
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Protein kinase B: emerging mechanisms of isoform-specific regulation of cellular signaling in cancer. Anticancer Drugs 2017; 28:569-580. [PMID: 28379898 DOI: 10.1097/cad.0000000000000496] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The serine/threonine protein kinase B (PKB), also known as Akt, is one of the multifaceted kinases in the human kinome, existing in three isoforms. PKB plays a vital role in phosphoinositide 3-kinase (PI3K)-mediated oncogenesis in various malignancies and is one of the attractive targets for cancer drug discovery. Recent studies have shown that the functional significance of an individual isoform of PKB is not redundant in cancer. It has been found that PKB isoforms play distinct roles in the regulation of cellular invasion and migration during tumorigenesis. PKB activation plays a central role during epithelial-mesenchymal transition, a cellular program required for the cancer cell invasion and migration. However, the differential behavior of each PKB isoform has been shown in the regulation of epithelial-mesenchymal transition. Recent studies have suggested that PKBα (Akt1) plays a conflicting role in tumorigenesis by acting either as a pro-oncogenic factor by suppressing the apoptotic machinery or by restricting tumor invasion. PKBβ (Akt2) promotes cell migration and invasion and similarly PKBγ (Akt3) has been reported to promote tumor migration. As PKB is known for its pro-oncogenic properties, it needs to be unraveled how three isoforms of PKB compensate during tumor progression. In this review, we attempted to sum up how different isoforms of PKB play a role in cancer progression, metastasis, and drug resistance.
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Peck BCE, Shanahan MT, Singh AP, Sethupathy P. Gut Microbial Influences on the Mammalian Intestinal Stem Cell Niche. Stem Cells Int 2017; 2017:5604727. [PMID: 28904533 PMCID: PMC5585682 DOI: 10.1155/2017/5604727] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/02/2017] [Indexed: 02/07/2023] Open
Abstract
The mammalian intestinal epithelial stem cell (IESC) niche is comprised of diverse epithelial, immune, and stromal cells, which together respond to environmental changes within the lumen and exert coordinated regulation of IESC behavior. There is growing appreciation for the role of the gut microbiota in modulating intestinal proliferation and differentiation, as well as other aspects of intestinal physiology. In this review, we evaluate the diverse roles of known niche cells in responding to gut microbiota and supporting IESCs. Furthermore, we discuss the potential mechanisms by which microbiota may exert their influence on niche cells and possibly on IESCs directly. Finally, we present an overview of the benefits and limitations of available tools to study niche-microbe interactions and provide our recommendations regarding their use and standardization. The study of host-microbe interactions in the gut is a rapidly growing field, and the IESC niche is at the forefront of host-microbe activity to control nutrient absorption, endocrine signaling, energy homeostasis, immune response, and systemic health.
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Affiliation(s)
- Bailey C. E. Peck
- Department of Surgery, School of Medicine, University of Michigan, Ann Arbor, MI 48105, USA
| | - Michael T. Shanahan
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Ajeet P. Singh
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Praveen Sethupathy
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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Boudjadi S, Bernatchez G, Sénicourt B, Beauséjour M, Vachon PH, Carrier JC, Beaulieu JF. Involvement of the Integrin α1β1 in the Progression of Colorectal Cancer. Cancers (Basel) 2017; 9:cancers9080096. [PMID: 28933766 PMCID: PMC5575599 DOI: 10.3390/cancers9080096] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/18/2017] [Accepted: 07/21/2017] [Indexed: 01/08/2023] Open
Abstract
Integrins are a family of heterodimeric glycoproteins involved in bidirectional cell signaling that participate in the regulation of cell shape, adhesion, migration, survival and proliferation. The integrin α1β1 is known to be involved in RAS/ERK proliferative pathway activation and plays an important role in fibroblast proliferation. In the small intestine, the integrin α1 subunit is present in the crypt proliferative compartment and absent in the villus. We have recently shown that the integrin α1 protein and transcript (ITGA1) are present in a large proportion of colorectal cancers (CRC) and that their expression is controlled by the MYC oncogenic factor. Considering that α1 subunit/ITGA1 expression is correlated with MYC in more than 70% of colon adenocarcinomas, we postulated that the integrin α1β1 has a pro-tumoral contribution to CRC. In HT29, T84 and SW480 CRC cells, α1 subunit/ITGA1 knockdown resulted in a reduction of cell proliferation associated with an impaired resistance to anoikis and an altered cell migration in HT29 and T84 cells. Moreover, tumor development in xenografts was reduced in HT29 and T84 sh-ITGA1 cells, associated with extensive necrosis, a low mitotic index and a reduced number of blood vessels. Our results show that α1β1 is involved in tumor cell proliferation, survival and migration. This finding suggests that α1β1 contributes to CRC progression.
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Affiliation(s)
- Salah Boudjadi
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
| | - Gérald Bernatchez
- Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada.
| | - Blanche Sénicourt
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
| | - Marco Beauséjour
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
| | - Pierre H Vachon
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
| | - Julie C Carrier
- Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada.
| | - Jean-François Beaulieu
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
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10
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Mikhail M, Vachon PH, D'Orléans-Juste P, Jacques D, Bkaily G. Role of endothelin-1 and its receptors, ET A and ET B, in the survival of human vascular endothelial cells. Can J Physiol Pharmacol 2017; 95:1298-1305. [PMID: 28732172 DOI: 10.1139/cjpp-2017-0412] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our previous work showed the presence of endothelin-1 (ET-1) receptors, ETA and ETB, in human vascular endothelial cells (hVECs). In this study, we wanted to verify whether ET-1 plays a role in the survival of hVECs via the activation of its receptors ETA and (or) ETB (ETAR and ETBR, respectively). Our results showed that treatment of hVECs with ET-1 prevented apoptosis induced by genistein, an effect that was mimicked by treatment with ETBR-specific agonist IRL1620. Furthermore, blockade of ETBR with the selective ETBR antagonist A-192621 prevented the anti-apoptotic effect of ET-1 in hVECs. However, activation of ETA receptor alone did not seem to contribute to the anti-apoptotic effect of ET-1. In addition, the anti-apoptotic effect of ETBR was found to be associated with caspase 3 inhibition and does not depend on the density of this type of receptor. In conclusion, our results showed that ET-1 possesses an anti-apoptotic effect in hVECs and that this effect is mediated, to a great extent, via the activation of ETBR. This study revealed a new role for ETBR in the survival of hVECs.
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Affiliation(s)
- Marianne Mikhail
- a Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Pierre H Vachon
- a Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Pedro D'Orléans-Juste
- b Department of Pharmacology and Physiology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- a Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Ghassan Bkaily
- a Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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11
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Discovery of novel antitumor nitric oxide-donating β -elemene hybrids through inhibiting the PI3K/Akt pathway. Eur J Med Chem 2017; 135:414-423. [DOI: 10.1016/j.ejmech.2017.04.045] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/16/2017] [Accepted: 04/19/2017] [Indexed: 12/18/2022]
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12
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Liu J, An H, Yuan W, Feng Q, Chen L, Ma J. Prognostic Relevance and Function of MSX2 in Colorectal Cancer. J Diabetes Res 2017; 2017:3827037. [PMID: 28286778 PMCID: PMC5327771 DOI: 10.1155/2017/3827037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/01/2016] [Indexed: 12/20/2022] Open
Abstract
Colorectal cancer patients with diabetes had the high risks of total mortality. High expression of MSX2 is related to development of diabetes. There are few reports about the clinical implications and function of MSX2 in colorectal cancer (CRC). The purpose of this study is to investigate the relationship between the expression of MSX2 and clinical relevance and discover the possible mechanism of MSX2 in the development of CRC. Compared with adjacent tissues, the expression of MSX2 was higher in tumor tissues in both mRNA and protein levels (P < 0.01). Kaplan-Meier survival analysis showed that high mRNA expression of MSX2 was associated with short survival time (P = 0.013). Chi-squared test analysis indicated that MSX2 expression was related to tumor size (P = 0.04), tumor locus (P = 0.025), clinical stage (P < 0.001), tumor invasion (P = 0.003), lymphatic metastasis (P = 0.01), and distant metastasis (P = 0.033). In vitro experiments demonstrated that knockdown of MSX2 expression attenuated cell proliferation and invasion, promoted cell cycle arrest and apoptosis, and inactivated Akt phosphorylation. In conclusion, MSX2 played a crucial role in the progression of CRC and may be a potential novel prognostic factor and therapeutic target for CRC therapy. Our work may provide certain enlightenment for investigating the mechanism of MSX2 in the process of diabetes.
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Affiliation(s)
- Jiancheng Liu
- State Key Laboratory of Molecular Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Huaying An
- State Key Laboratory of Molecular Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Wei Yuan
- State Key Laboratory of Molecular Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
- Clinical Immunology Center, Chinese Academy of Medical Science, Beijing 100730, China
| | - Qiang Feng
- Department of Colorectal Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
| | - Lianzhen Chen
- Department of Pharmacy, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
- *Lianzhen Chen: and
| | - Jie Ma
- State Key Laboratory of Molecular Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
- Clinical Immunology Center, Chinese Academy of Medical Science, Beijing 100730, China
- Beijing Hospital, National Center of Gerontology, Beijing 100730, China
- *Jie Ma:
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13
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Wang W, Lv J, Wang L, Wang X, Ye L. The impact of heterogeneity in phosphoinositide 3-kinase pathway in human cancer and possible therapeutic treatments. Semin Cell Dev Biol 2016; 64:116-124. [PMID: 27582428 DOI: 10.1016/j.semcdb.2016.08.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 08/24/2016] [Indexed: 02/07/2023]
Abstract
Phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) plays a crucial role in the initiation and progress of cancerous tumors through the overexpression of the PI3K pathway promoting uncontrollable levels of cell proliferation. In addition only Class I PI3K has been discovered to be involved in human cancer due to its unique ability to produce phosphoinositide 3,4,5 trisphosphate (PIP3), which has been discovered to play a crucial role in human oncogenesis. The role of PIK3CA is lucubrated in breast cancer and gastric cancer, but is not well characterized in lung diseases. In this review, we summarized the common biology and mutations in PIK3CA with its related signaling pathways. Furthermore, we elucidated the PIK3CA heterogeneity in different domains, between various cancers and in different lung cancers. We also take a look at current inhibitors such as KP-372-1 (KP-1), KP-372-2 (KP-2), GSK690693, etc. in order to highlight potential treatment of PIK3CA mutations in human cancer and what directions future research should focus on.
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Affiliation(s)
- William Wang
- Zhongshan Hospital Institute of Clinical Science, Fudan University, Shanghai Institute of Clinical Bioinformatics, Biomedical Research Center, Shanghai, China.
| | - Jiapei Lv
- Zhongshan Hospital Institute of Clinical Science, Fudan University, Shanghai Institute of Clinical Bioinformatics, Biomedical Research Center, Shanghai, China
| | - Lingyan Wang
- Zhongshan Hospital Institute of Clinical Science, Fudan University, Shanghai Institute of Clinical Bioinformatics, Biomedical Research Center, Shanghai, China
| | - Xiangdong Wang
- Zhongshan Hospital Institute of Clinical Science, Fudan University, Shanghai Institute of Clinical Bioinformatics, Biomedical Research Center, Shanghai, China.
| | - Ling Ye
- Zhongshan Hospital Institute of Clinical Science, Fudan University, Shanghai Institute of Clinical Bioinformatics, Biomedical Research Center, Shanghai, China
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14
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Gonzalez LM, Moeser AJ, Blikslager AT. Animal models of ischemia-reperfusion-induced intestinal injury: progress and promise for translational research. Am J Physiol Gastrointest Liver Physiol 2015; 308:G63-75. [PMID: 25414098 PMCID: PMC4297854 DOI: 10.1152/ajpgi.00112.2013] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Research in the field of ischemia-reperfusion injury continues to be plagued by the inability to translate research findings to clinically useful therapies. This may in part relate to the complexity of disease processes that result in intestinal ischemia but may also result from inappropriate research model selection. Research animal models have been integral to the study of ischemia-reperfusion-induced intestinal injury. However, the clinical conditions that compromise intestinal blood flow in clinical patients ranges widely from primary intestinal disease to processes secondary to distant organ failure and generalized systemic disease. Thus models that closely resemble human pathology in clinical conditions as disparate as volvulus, shock, and necrotizing enterocolitis are likely to give the greatest opportunity to understand mechanisms of ischemia that may ultimately translate to patient care. Furthermore, conditions that result in varying levels of ischemia may be further complicated by the reperfusion of blood to tissues that, in some cases, further exacerbates injury. This review assesses animal models of ischemia-reperfusion injury as well as the knowledge that has been derived from each to aid selection of appropriate research models. In addition, a discussion of the future of intestinal ischemia-reperfusion research is provided to place some context on the areas likely to provide the greatest benefit from continued research of ischemia-reperfusion injury.
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Affiliation(s)
- Liara M. Gonzalez
- 1Department of Clinical Sciences, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina; and
| | - Adam J. Moeser
- 2Department of Population Health and Pathobiology, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina
| | - Anthony T. Blikslager
- 1Department of Clinical Sciences, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina; and
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15
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Guaragnella N, Marra E, Galli A, Moro L, Giannattasio S. Silencing of BRCA2 decreases anoikis and its heterologous expression sensitizes yeast cells to acetic acid-induced programmed cell death. Apoptosis 2014; 19:1330-41. [DOI: 10.1007/s10495-014-1006-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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16
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Wang Y, Ahmad AA, Sims CE, Magness ST, Allbritton NL. In vitro generation of colonic epithelium from primary cells guided by microstructures. LAB ON A CHIP 2014; 14:1622-31. [PMID: 24647645 PMCID: PMC4037563 DOI: 10.1039/c3lc51353j] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The proliferative compartment of the colonic epithelium in vivo is located in the basal crypt where colonic stem cells and transit-amplifying cells reside and fuel the rapid renewal of non-proliferative epithelial cells as they migrate toward the gut lumen. To mimic this tissue polarity, microstructures composed of polydimethylsiloxane (PDMS) microwells and Matrigel micropockets were used to guide a combined 2-dimensional (2D) and 3-dimensional (3D) hybrid culture of primary crypts isolated from the murine colon. The 2D and 3D culture of crypts on a planar PDMS surface was first investigated in terms of cell proliferation and stem cell activity. 3D culture of crypts with overlaid Matrigel generated enclosed, but highly proliferative spheroids (termed colonoids). 2D culture of crypts produced a spreading monolayer of cells, which were non-proliferative. A combined 2D/3D hybrid culture was generated in a PDMS microwell platform on which crypts were loaded by centrifugation into microwells (diameter = 150 μm, depth = 150 μm) followed by addition of Matrigel that formed micropockets locking the crypts within the microwells. Embedded crypts first underwent 3D expansion inside the wells. After the cells filled the microwells, they migrated onto the surrounding surface forming a 2D monolayer in the array regions without Matrigel. This unique 2D/3D hybrid culture generated a continuous, millimeter-scale colonic epithelial tissue in vitro, which resembled the polarized architecture (i.e. distinct proliferative and non-proliferative zones) and geometry of the colonic epithelium in vivo. This work initiates the construction of a "colon-on-a-chip" using primary cells/tissues with the ultimate goal of producing the physiologic structure and organ-level function of the colon.
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Affiliation(s)
- Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA.
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Wang Y, Ahmad AA, Shah PK, Sims CE, Magness ST, Allbritton NL. Capture and 3D culture of colonic crypts and colonoids in a microarray platform. LAB ON A CHIP 2013; 13:4625-34. [PMID: 24113577 PMCID: PMC3841105 DOI: 10.1039/c3lc50813g] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Crypts are the basic structural and functional units of colonic epithelium and can be isolated from the colon and cultured in vitro into multi-cell spheroids termed "colonoids". Both crypts and colonoids are ideal building blocks for construction of an in vitro tissue model of the colon. Here we proposed and tested a microengineered platform for capture and in vitro 3D culture of colonic crypts and colonoids. An integrated platform was fabricated from polydimethylsiloxane which contained two fluidic layers separated by an array of cylindrical microwells (150 μm diameter, 150 μm depth) with perforated bottoms (30 μm opening, 10 μm depth) termed "microstrainers". As fluid moved through the array, crypts or colonoids were retained in the microstrainers with a >90% array-filling efficiency. Matrigel as an extracellular matrix was then applied to the microstrainers to generate isolated Matrigel pockets encapsulating the crypts or colonoids. After supplying the essential growth factors, epidermal growth factor, Wnt-3A, R-spondin 2 and noggin, 63 ± 13% of the crypts and 77 ± 8% of the colonoids cultured in the microstrainers over a 48-72 h period formed viable 3D colonoids. Thus colonoid growth on the array was similar to that under standard culture conditions (78 ± 5%). Additionally the colonoids displayed the same morphology and similar numbers of stem and progenitor cells as those under standard culture conditions. Immunofluorescence staining confirmed that the differentiated cell-types of the colon, goblet cells, enteroendocrine cells and absorptive enterocytes, formed on the array. To demonstrating the utility of the array in tracking the colonoid fate, quantitative fluorescence analysis was performed on the arrayed colonoids exposed to reagents such as Wnt-3A and the γ-secretase inhibitor LY-411575. The successful formation of viable, multi-cell type colonic tissue on the microengineered platform represents a first step in the building of a "colon-on-a-chip" with the goal of producing the physiologic structure and organ-level function of the colon for controlled experiments.
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Affiliation(s)
- Yuli Wang
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA.
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18
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Beauséjour M, Thibodeau S, Demers MJ, Bouchard V, Gauthier R, Beaulieu JF, Vachon PH. Suppression of anoikis in human intestinal epithelial cells: differentiation state-selective roles of α2β1, α3β1, α5β1, and α6β4 integrins. BMC Cell Biol 2013; 14:53. [PMID: 24289209 PMCID: PMC4219346 DOI: 10.1186/1471-2121-14-53] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 11/26/2013] [Indexed: 12/26/2022] Open
Abstract
Background Regulation of anoikis in human intestinal epithelial cells (IECs) implicates differentiation state-specific mechanisms. Human IECs express distinct repertoires of integrins according to their state of differentiation. Therefore, we investigated whether α2β1, α3β1, α5β1, and α6β4 integrins perform differentiation state-specific roles in the suppression of IEC anoikis. Results Human (HIEC, Caco-2/15) IECs were exposed to specific antibodies that block the binding activity of integrin subunits (α2, α3, α5, α6, β1 or β4) to verify whether or not their inhibition induced anoikis. The knockdown of α6 was also performed by shRNA. Additionally, apoptosis/anoikis was induced by pharmacological inhibition of Fak (PF573228) or Src (PP2). Anoikis/apoptosis was assayed by DNA laddering, ISEL, and/or caspase activity (CASP-8, -9, or -3). Activation levels of Fak and Src, as well as functional Fak-Src interactions, were also assessed. We report herein that differentiated IECs exhibit a greater sensitivity to anoikis than undifferentiated ones. This involves an earlier onset of anoikis when kept in suspension, as well as significantly greater contributions from β1 and β4 integrins in the suppression of anoikis in differentiated cells, and functional distinctions between β1 and β4 integrins in engaging both Fak and Src, or Src only, respectively. Likewise, Fak performs significantly greater contributions in the suppression of anoikis in differentiated cells. Additionally, we show that α2β1 and α5β1 suppress anoikis in undifferentiated cells, whereas α3β1 does so in differentiated ones. Furthermore, we provide evidence that α6β4 contributes to the suppression of anoikis in a primarily α6 subunit-dependent manner in undifferentiated cells, whereas this same integrin in differentiated cells performs significantly greater contributions in anoikis suppression than its undifferentiated state-counterpart, in addition to doing so through a dependence on both of its subunits. Conclusions Our findings indicate that the suppression of human IEC anoikis implicates differentiation state-selective repertoires of integrins, which in turn results into distinctions in anoikis regulation, and sensitivity, between undifferentiated and differentiated IECs. These data further the functional understanding of the concept that the suppression of anoikis is subjected to cell differentiation state-selective mechanisms.
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Affiliation(s)
- Marco Beauséjour
- Département d'anatomie et de biologie cellulaire, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, J1H5N4 Sherbrooke, Québec, Canada.
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19
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Pongrakhananon V, Stueckle TA, Wang HYL, O'Doherty GA, Dinu CZ, Chanvorachote P, Rojanasakul Y. Monosaccharide digitoxin derivative sensitize human non-small cell lung cancer cells to anoikis through Mcl-1 proteasomal degradation. Biochem Pharmacol 2013; 88:23-35. [PMID: 24231508 DOI: 10.1016/j.bcp.2013.10.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/28/2013] [Accepted: 10/28/2013] [Indexed: 12/18/2022]
Abstract
Advanced stage cancers acquire anoikis resistance which provides metastatic potential to invade and form tumors at distant sites. Suppression of anoikis resistance by novel molecular therapies would greatly benefit treatment strategies for metastatic cancers. Recently, digitoxin and several of its novel synthetic derivatives, such as α-l-rhamnose monosaccharide derivative (D6-MA), have been synthesized and studied for their profound anticancer activity in various cancer cell lines. In this study, we investigated the anoikis sensitizing effect of D6-MA compared with digitoxin to identify their anti-metastatic mechanism of action. D6-MA sensitized NSCLC H460 cells to detachment-induced apoptosis with significantly greater cytotoxicity (IC50=11.9 nM) than digitoxin (IC50=90.7 nM) by activating caspase-9. Screening of the Bcl-2 protein family revealed that degradation of anti-apoptotic Mcl-1 protein is a favorable target. Mcl-1 over-expression and knockdown studies in D6-MA and digitoxin exposed cells resulted in rescue and enhancement, respectively, indicating a facilitative role for decreased Mcl-1 expression in NSCLC anoikis. Transfection with mutant Mcl-1S159 attenuated detachment-induced cell death and correlated with a remaining of Mcl-1 level. Furthermore, D6-MA suppressed Mcl-1 expression via ubiquitin proteasomal degradation that is dependent on activation of glycogen synthase kinase (GSK)-3β signaling. In addition, D6-MA also targeted Mcl-1 degradation causing an increased anoikis in A549 lung cancer cells. Anoikis sensitizing effect on normal small airway epithelial cells was not observed indicating the specificity of D6-MA and digitoxin for NSCLC. These results identify a novel cardiac glycoside (CG) sensitizing anoikis mechanism and provide a promising anti-metastatic target for lung cancer therapy.
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Affiliation(s)
- Varisa Pongrakhananon
- Cell-Based Drug and Health Product Development Research Unit, Department of Pharmacology and Physiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand.,Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, United States
| | - Todd A Stueckle
- Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, United States.,Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States
| | - Hua-Yu Leo Wang
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, United States
| | - George A O'Doherty
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, United States
| | - Cerasela Zoica Dinu
- Department of Chemical Engineering, West Virginia University, Morgantown, WV 26506, United States
| | - Pithi Chanvorachote
- Cell-Based Drug and Health Product Development Research Unit, Department of Pharmacology and Physiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Yon Rojanasakul
- Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, United States.,Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, WV 26506, United States
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20
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Magness ST, Puthoff BJ, Crissey MA, Dunn J, Henning SJ, Houchen C, Kaddis JS, Kuo CJ, Li L, Lynch J, Martin MG, May R, Niland JC, Olack B, Qian D, Stelzner M, Swain JR, Wang F, Wang J, Wang X, Yan K, Yu J, Wong MH. A multicenter study to standardize reporting and analyses of fluorescence-activated cell-sorted murine intestinal epithelial cells. Am J Physiol Gastrointest Liver Physiol 2013; 305:G542-51. [PMID: 23928185 PMCID: PMC3798732 DOI: 10.1152/ajpgi.00481.2012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fluorescence-activated cell sorting (FACS) is an essential tool for studies requiring isolation of distinct intestinal epithelial cell populations. Inconsistent or lack of reporting of the critical parameters associated with FACS methodologies has complicated interpretation, comparison, and reproduction of important findings. To address this problem a comprehensive multicenter study was designed to develop guidelines that limit experimental and data reporting variability and provide a foundation for accurate comparison of data between studies. Common methodologies and data reporting protocols for tissue dissociation, cell yield, cell viability, FACS, and postsort purity were established. Seven centers tested the standardized methods by FACS-isolating a specific crypt-based epithelial population (EpCAM+/CD44+) from murine small intestine. Genetic biomarkers for stem/progenitor (Lgr5 and Atoh 1) and differentiated cell lineages (lysozyme, mucin2, chromogranin A, and sucrase isomaltase) were interrogated in target and control populations to assess intra- and intercenter variability. Wilcoxon's rank sum test on gene expression levels showed limited intracenter variability between biological replicates. Principal component analysis demonstrated significant intercenter reproducibility among four centers. Analysis of data collected by standardized cell isolation methods and data reporting requirements readily identified methodological problems, indicating that standard reporting parameters facilitate post hoc error identification. These results indicate that the complexity of FACS isolation of target intestinal epithelial populations can be highly reproducible between biological replicates and different institutions by adherence to common cell isolation methods and FACS gating strategies. This study can be considered a foundation for continued method development and a starting point for investigators that are developing cell isolation expertise to study physiology and pathophysiology of the intestinal epithelium.
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Affiliation(s)
| | | | | | - James Dunn
- 3University of California Los Angeles, Los Angeles, California;
| | | | | | | | | | - Linheng Li
- 7Stowers Institute for Medical Research, Kansas City, Missouri;
| | - John Lynch
- 2University of Pennsylvania, Philadelphia, Pennsylvania;
| | | | - Randal May
- 4University of Oklahoma, Oklahoma City, Oklahoma;
| | | | | | | | | | - John R. Swain
- 8Oregon Health & Science University, Portland, Oregon; and
| | - Fengchao Wang
- 7Stowers Institute for Medical Research, Kansas City, Missouri;
| | - Jiafang Wang
- 3University of California Los Angeles, Los Angeles, California;
| | - Xinwei Wang
- 9University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kelley Yan
- 6Stanford University, Stanford, California;
| | - Jian Yu
- 9University of Pittsburgh, Pittsburgh, Pennsylvania
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21
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Chanvorachote P, Chunhacha P, Pongrakhananon V. Anoikis: a potential target to prevent lung cancer metastasis? Lung Cancer Manag 2013. [DOI: 10.2217/lmt.13.13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Pithi Chanvorachote
- Department of Pharmacology & Physiology, Faculty of Pharmaceutical Sciences & Cell-based Drug & Health Product Development Research Unit, Chulalongkorn University, Bangkok, Thailand.
| | - Preedakorn Chunhacha
- Department of Pharmacology & Physiology, Faculty of Pharmaceutical Sciences & Cell-based Drug & Health Product Development Research Unit, Chulalongkorn University, Bangkok, Thailand
| | - Varisa Pongrakhananon
- Department of Pharmacology & Physiology, Faculty of Pharmaceutical Sciences & Cell-based Drug & Health Product Development Research Unit, Chulalongkorn University, Bangkok, Thailand
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22
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Beauséjour M, Noël D, Thibodeau S, Bouchard V, Harnois C, Beaulieu JF, Demers MJ, Vachon PH. Integrin/Fak/Src-mediated regulation of cell survival and anoikis in human intestinal epithelial crypt cells: selective engagement and roles of PI3-K isoform complexes. Apoptosis 2012; 17:566-78. [PMID: 22402981 PMCID: PMC3345181 DOI: 10.1007/s10495-012-0713-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In human intestinal epithelial crypt (HIEC) cells, the PI3-K/Akt-1 pathway is crucial for the promotion of cell survival and suppression of anoikis. Class I PI3-K consists of a complex formed by a catalytic (C) and regulatory (R) subunit. Three R (p85α, β, and p55γ) and four C (p110α, β, γ and δ) isoforms are known. Herein, we analyzed the expression of PI3-K isoforms in HIEC cells and determined their roles in cell survival, as well as in the β1 integrin/Fak/Src-mediated suppression of anoikis. We report that: (1) the predominant PI3-K complexes expressed by HIEC cells are p110α/p85β and p110α/p55γ; (2) the inhibition and/or siRNA-mediated expression silencing of p110α, but not that of p110β, γ or δ, results in Akt-1 down-activation and consequent apoptosis; (3) the expression silencing of p85β or p55γ, but not that of p85α, likewise induces Akt-1 down-activation and apoptosis; however, the impact of a loss of p55γ on both Akt-1 activation and cell survival is significantly greater than that from the loss of p85β; and (4) both the p110α/p85β and p110α/p55γ complexes are engaged by β1 integrin/Fak/Src signaling; however, the engagement of p110α/p85β is primarily Src-dependent, whereas that of p110α/p55γ is primarily Fak-dependent (but Src-independent). Hence, HIEC cells selectively express PI3-K isoform complexes, translating into distinct roles in Akt-1 activation and cell survival, as well as in a selective engagement by Fak and/or Src within the context of β1 integrin/Fak/Src-mediated suppression of anoikis.
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Affiliation(s)
- Marco Beauséjour
- Département d'anatomie et de Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
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23
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Riaz A, Zeller KS, Johansson S. Receptor-specific mechanisms regulate phosphorylation of AKT at Ser473: role of RICTOR in β1 integrin-mediated cell survival. PLoS One 2012; 7:e32081. [PMID: 22384145 PMCID: PMC3284553 DOI: 10.1371/journal.pone.0032081] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 01/23/2012] [Indexed: 11/21/2022] Open
Abstract
A tight control over AKT/PKB activation is essential for cells, and they realise this in part by regulating the phosphorylation of Ser473 in the “hydrophobic motif” of the AKT carboxy-terminal region. The RICTOR-mTOR complex (TORC2) is a major kinase for AKT Ser473 phosphorylation after stimulation by several growth factors, in a reaction proposed to require p21-activated kinase (PAK) as a scaffold. However, other kinases may catalyse this reaction in stimuli-specific manners. Here we characterised the requirement of RICTOR, ILK, and PAK for AKT Ser473 phosphorylation downstream of selected family members of integrins, G protein-coupled receptors, and tyrosine-kinase receptors and analysed the importance of this phosphorylation site for adhesion-mediated survival. siRNA-mediated knockdown in HeLa and MCF7 cells showed that RICTOR-mTOR was required for phosphorylation of AKT Ser473, and for efficient phosphorylation of the downstream AKT targets FOXO1 Thr24 and BAD Ser136, in response to β1 integrin-stimulation. ILK and PAK1/2 were dispensable for these reactions. RICTOR knockdown increased the number of apoptotic MCF7 cells on β1 integrin ligands up to 2-fold after 24 h in serum-free conditions. β1 integrin-stimulation induced phosphorylation of both AKT1 and AKT2 but markedly preferred AKT2. RICTOR-mTOR was required also for LPA-induced AKT Ser473 phosphorylation in MCF7 cells, but, interestingly, not in HeLa cells. PAK was needed for the AKT Ser473 phosphorylation in response to LPA and PDGF, but not to EGF. These results demonstrate that different receptors utilise different enzyme complexes to phosphorylate AKT at Ser473, and that AKT Ser473 phosphorylation significantly contributes to β1 integrin-mediated anchorage-dependent survival of cells.
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Affiliation(s)
| | | | - Staffan Johansson
- Department of Medical Biochemistry and Microbiology, The Biomedical Center, Uppsala University, Uppsala, Sweden
- * E-mail:
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24
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Luanpitpong S, Iyer AKV, Azad N, Wang L, Rojanasakul Y. Nitrosothiol Signaling in Anoikis Resistance and Cancer Metastasis. FORUM ON IMMUNOPATHOLOGICAL DISEASES AND THERAPEUTICS 2012; 3:141-154. [PMID: 23486647 PMCID: PMC3593302 DOI: 10.1615/forumimmundisther.2012006115] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Nitric oxide (NO) has been widely recognized as an important cell-signaling molecule that regulates various physiological and pathological processes. S-nitrosylation, or covalent attachment of NO to protein sulfhydryl groups, is a key mechanism by which NO regulates protein functions and cellular processes. In this article we discuss the various roles of NO and protein nitrosylation in cancer development, with a focus on cell invasion and anoikis resistance, both of which are key determinants of cancer metastasis. We specially address some of the mechanisms by which NO-mediated S-nitrosylation modulates substrates that have putative effects on key steps of metastasis. We propose that nitrosothiol signaling is a key regulatory mechanism common to several pathways involved in cancer progression and metastasis, and identifying such a mechanism will improve our understanding of the disease process and aid in the development of novel anticancer therapeutics.
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Affiliation(s)
- Sudjit Luanpitpong
- Department of Pharmaceutical Sciences, Hampton University, Hampton, Virginia
| | - Anand Krishnan V. Iyer
- Department of Pharmaceutical Sciences, School of Pharmacy, Hampton University, Hampton, Virginia
| | - Neelam Azad
- Department of Pharmaceutical Sciences, School of Pharmacy, Hampton University, Hampton, Virginia
| | - Liying Wang
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Yon Rojanasakul
- Department of Pharmaceutical Sciences, Hampton University, Hampton, Virginia
- Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, West Virginia
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25
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Tian Y, Nan Y, Han L, Zhang A, Wang G, Jia Z, Hao J, Pu P, Zhong Y, Kang C. MicroRNA miR-451 downregulates the PI3K/AKT pathway through CAB39 in human glioma. Int J Oncol 2011; 40:1105-12. [PMID: 22179124 PMCID: PMC3584578 DOI: 10.3892/ijo.2011.1306] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/30/2011] [Indexed: 12/25/2022] Open
Abstract
The microRNA miR-451 is downregulated in gliomas, this has been suggested by several different research groups and is consistent with our data. Our previous study also confirmed that miR-451 has a repressive role in glioma by inhibiting cell growth, proliferation and by inducing cell apoptosis. In the present study, we identified a target gene of miR-451 in human glioma and investigated the mechanism for the glioma suppressive effect of miR-451 functions. Expression of miR-451 in gliomas was identified by quantitative real-time PCR and fluorescence in situ hybridization. Human glioma cell lines (U251, U87, LN229 and A172) were transfected with miR-451 mimics to restore miR-451 expression. The tumor suppressive effects of miR-451 were further verified by subcutaneous assays in nude mice, in addition to our previous in vitro data. A candidate target gene was tested by Western blotting and luciferase reporter assays. Some PI3K/AKT pathway factors were tested by Western blotting. We found that miR-451 expression was downregulated in glioma samples and was inversely correlated with WHO grades of gliomas. In vivo assays confirmed that miR-451 had tumor suppressive traits. CAB39-3′UTR luciferase reporter assay confirmed CAB39 as a direct target gene of miR-451. Significant alterations in the expression of PI3K/AKT pathway factors were observed by Western blot assays. We conclude that miR-451 represses glioma in vitro and in vivo, likely through targeting CAB39 directly and inhibiting the PI3K/AKT pathway indirectly.
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Affiliation(s)
- Yuan Tian
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, PR China
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26
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Integrin signaling, cell survival, and anoikis: distinctions, differences, and differentiation. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2011:738137. [PMID: 21785723 PMCID: PMC3139189 DOI: 10.1155/2011/738137] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Revised: 01/06/2011] [Accepted: 03/10/2011] [Indexed: 01/01/2023]
Abstract
Cell survival and apoptosis implicate an increasing complexity of players and signaling pathways which regulate not only the decision-making process of surviving (or dying), but as well the execution of cell death proper. The same complex nature applies to anoikis, a form of caspase-dependent apoptosis that is largely regulated by integrin-mediated, cell-extracellular matrix interactions. Not surprisingly, the regulation of cell survival, apoptosis, and anoikis furthermore implicates additional mechanistic distinctions according to the specific tissue, cell type, and species. Incidentally, studies in recent years have unearthed yet another layer of complexity in the regulation of these cell processes, namely, the implication of cell differentiation state-specific mechanisms. Further analyses of such differentiation state-distinct mechanisms, either under normal or physiopathological contexts, should increase our understanding of diseases which implicate a deregulation of integrin function, cell survival, and anoikis.
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27
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Nan Y, Han L, Zhang A, Wang G, Jia Z, Yang Y, Yue X, Pu P, Zhong Y, Kang C. MiRNA-451 plays a role as tumor suppressor in human glioma cells. Brain Res 2010; 1359:14-21. [PMID: 20816946 DOI: 10.1016/j.brainres.2010.08.074] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 08/03/2010] [Accepted: 08/23/2010] [Indexed: 01/12/2023]
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional and/or translational level by binding loosely complimentary sequences in the 3'untranslated regions (UTRs) of target mRNAs. Increased expressions of several miRNAs, specifically hsa-miR-21, have been reported to modulate glioma development. Here we report downregulation of miR-451 in A172, LN229 and U251 human glioblastoma cells. Increased expression of miR-451 by administration of miR-451 mimics oligonucleotides reversed the biology of each of the three cell lines, inhibiting cell growth, inducing G0/G1 phase arrest and increasing cell apoptosis. Further, treatment with miR-451 mimics oligonucleotides diminished the invasive capacity of these cells, as the number of cells invading through matrigel was significantly decreased. Akt1, CyclinD1, MMP-2, MMP-9 and Bcl-2 protein expression decreased, and p27 expression increased in a dose-dependent manner with miR-451 mimics oligonucleotides. Taken together, these studies reveal miR-451 impacts glioblastoma cell proliferation, invasion and apoptosis, perhaps via regulation of the PI3K/AKT signaling pathway. We propose an essential role for miR-451 as a tumor-suppressor of human glioma.
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Affiliation(s)
- Yang Nan
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, People's Republic of China
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28
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Benoit YD, Larrivée JF, Groulx JF, Stankova J, Vachon PH, Beaulieu JF. Integrin alpha8beta1 confers anoikis susceptibility to human intestinal epithelial crypt cells. Biochem Biophys Res Commun 2010; 399:434-9. [PMID: 20678483 DOI: 10.1016/j.bbrc.2010.07.107] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 07/27/2010] [Indexed: 01/14/2023]
Abstract
We previously reported that integrin alpha8beta1 is expressed in human intestinal epithelial crypt cells (HIECs) and represents one of the major RGD-binding integrins expressed by these cells. Moreover, the depletion of alpha8beta1 affects vinculin, but not paxillin, localization at focal adhesion points. In the present study, we show that the integrin alpha8 shRNA-mediated knockdown in HIECs leads to a decrease in anoikis susceptibility under cell suspension culture conditions, marked by a reduction in PARP cleavage and propidium iodide incorporation. Moreover, alpha8beta1-depleted HIECs exhibited an illicitly sustained activation of Fak and PI3-K/Akt-1 under anoikis conditions, rendering them refractory to anoikis. To this effect, colon cancer cells exhibiting resistance to anoikis not only displayed a loss of alpha8beta1 expression, but forced expression of alpha8beta1 in these cells decreased their resistance to anoikis. Consequently, alpha8beta1 is a prerequisite for the proper conduct of anoikis in normal HIECs, whereas its loss contributes to the illicit acquisition of anoikis resistance.
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Affiliation(s)
- Yannick D Benoit
- CIHR Team on Digestive Epithelium, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada J1H 5N4
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Brulet M, Seyer A, Edelman A, Brunelle A, Fritsch J, Ollero M, Laprévote O. Lipid mapping of colonic mucosa by cluster TOF-SIMS imaging and multivariate analysis in cftr knockout mice. J Lipid Res 2010; 51:3034-45. [PMID: 20616379 DOI: 10.1194/jlr.m008870] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cftr knockout mouse model of cystic fibrosis (CF) shows intestinal obstruction; malabsorption and inflammation; and a fatty acid imbalance in intestinal mucosa. We performed a lipid mapping of colon sections from CF and control (WT) mice by cluster time of flight secondary-ion mass spectrometry (TOF-SIMS) imaging to localize lipid alterations. Data were processed either manually or by multivariate statistical methods. TOF-SIMS analysis showed a particular localization for cholesteryl sulfate at the epithelial border, C16:1 fatty acid in Lieberkühn glands, and C18:0 fatty acid in lamina propria and submucosa. Significant increases in vitamin E (vE) and C16:0 fatty acid in the epithelial border of CF colon were detected. Principal component analysis (PCA) and partitioning clustering allowed us to characterize different structural regions of colonic mucosa according to variations in C14:0, C16:0, C16:1, C18:0, C18:1, C18:2, C20:3, C20:4, and C22:6 fatty acids; phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol glycerolipids; cholesterol; vitamin E; and cholesteryl sulfate. PCA on spectra from Lieberkühn glands led to separation of CF and WT individuals. This study shows for the first time the spatial distribution of lipids in colonic mucosa and suggests TOF-SIMS plus multivariate analyses as a powerful tool to investigate disease-related tissue spatial lipid signatures.
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Affiliation(s)
- Marc Brulet
- Centre de Recherche de Gif, Institut de Chimie des Substances Naturelles, CNRS, Gif-sur-Yvette, France
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Hausmann M. How bacteria-induced apoptosis of intestinal epithelial cells contributes to mucosal inflammation. Int J Inflam 2010; 2010:574568. [PMID: 21188215 PMCID: PMC3003958 DOI: 10.4061/2010/574568] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 05/26/2010] [Indexed: 12/14/2022] Open
Abstract
The life cycle of an intestinal epithelial cell is terminated by apoptosis and/or cell shedding. Apoptotic deletion of epithelial cells from the intact intestinal mucosa is not accompanied by detectable inflammatory response or loss of barrier function. But increased permeability of the epithelial barrier and increased apoptotic rates of epithelial cells have been reported for patients suffering from inflammatory bowel disease. Microbiota can both induce or inhibit apoptosis of intestinal epithelial cells thus contribute to mucosal inflammation or support epithelial integrity respectively. Bacteria-mediated cytokine secretion and altered cell signalling are central to epithelial injury. Tumor necrosis factor (TNF) secreted after exposure to invasive bacteria induces both apoptosis and cell shedding. TNF is the major target gene of the transcription factor nuclear factor-kappa B with both pro- and anti-apoptotic effects. Autophagy promotes both cell survival and “autophagic” cell death. If autophagy is directed against microbes it is termed xenophagy. Inhibition of xenophagy has been shown to decrease cell survival. Endoplasmic reticulum (ER) stress causes misfolded proteins to accumulate in the ER lumen. It was suggested that ER stress and autophagy may interact within intestinal epithelial cells. Apoptosis in response to infection may be well proposed by the host to delete infected epithelial cells or could be a strategy of microbial pathogens to escape from exhausted cells to invade deeper mucosal layers for a prolonged bacterial colonization.
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Affiliation(s)
- Martin Hausmann
- Division of Gastroenterology and Hepatology, Clinic of Gastroenterology and Hepatology, Department of Internal Medicine, University Hospital of Zürich, 8091 Zürich, Switzerland
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Strauss SJ, Ng T, Mendoza-Naranjo A, Whelan J, Sorensen PHB. Understanding micrometastatic disease and Anoikis resistance in ewing family of tumors and osteosarcoma. Oncologist 2010; 15:627-35. [PMID: 20479280 DOI: 10.1634/theoncologist.2010-0093] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Detection of micrometastatic tumor cells in the bone marrow or peripheral blood of patients with Ewing family of tumors (EFTs) and osteosarcoma has been shown to correlate with poor outcome. Although one of the aims of chemotherapy is eradication of micrometastatic disease, these cells vary phenotypically from primary tumor cells and appear to be more resistant to chemotherapy. As a barrier to metastasis, cells normally undergo a form of cell death termed anoikis after they lose contact with the extracellular matrix or neighboring cells. Tumor cells that acquire malignant potential have developed mechanisms to resist anoikis and thereby survive after detachment from their primary site and while traveling through the circulation. Investigating mechanisms of resistance to anoikis, therefore, provides a valuable model to investigate regulation of micrometastatic disease. This review focuses on the current understanding of the mechanisms involved in mediating cell survival and resistance to anoikis in EFTs and osteosarcoma and discusses future studies that may help to identify novel therapeutics targeted at micrometastatic disease.
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Affiliation(s)
- Sandra J Strauss
- UCL Cancer Institute, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6BT, U.K.
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Gu YJ, Ao RF, Su RJ. Hepatocellular growth factor reduces anoikis in human hepatocellular carcinoma cell line SMMC-7721. Shijie Huaren Xiaohua Zazhi 2010; 18:819-824. [DOI: 10.11569/wcjd.v18.i8.819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effects of hepatocellular growth factor (HGF) on the anoikis of SMMC-7721 cells and the role of phosphoinositide 3 kinase (PI3K) in this process.
METHODS: SMMC-7721 cells were suspended to induce anoikis. The anoikis rate of suspended cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. SMMC-7721 cells cultured in suspension were divided into three groups: control cells, cells treated with HGF, and those pretreated with LY294002 and then treated with HGF. After HGF treatment, cell survival and proliferation were evaluated by trypan blue staining and methyl thiazolyl tetrazolium (MTT) assay, respectively; anoikis was detected by flow cytometry; and the expression of Akt, phosphorylated Akt (p-Akt), focal adhesion kinase (FAK), and phosphorylated FAK (p-FAK) was detected by Western blot.
RESULTS: The anoikis rate of suspended SMMC-7721 is higher than that of adherent cells (21.72% ± 6.85% vs 66.67% ± 7.66%, P < 0.05). The survival rat of suspended SMMC-7721 treated with HGF is significantly higher than that of control cells (P< 0.05). However, HGF treatment could not significantly improve the survival of suspended SMMC-7721 pre-treated with LY294002 (P < 0.05). MTT assay showed that HGF treatment could improve the proliferation of suspended SMMC-7721 but showed little impact on the proliferation of suspended SMMC-7721 pre-treated with LY294002 (both P < 0.05). FCM and Hoechst 33258 staining results indicated that HGF could reduce the anoikis of SMMC-7721 while LY294002 could inhibit such effect (both P < 0.05). Western blot analysis showed that HGF treatment could up-regulate the expression of Akt, FAK, p-Akt and p-FAK in suspended SMMC-7721 cells but not in suspended SMMC-7721 cells pre-treated with LY294002.
CONCLUSION: HGF can reduce the anoikis of SMMC-7721 cells by activating Akt and FAK in a PI3K-dependent manner.
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Xiao L, Rao JN, Zou T, Liu L, Yu TX, Zhu XY, Donahue JM, Wang JY. Induced ATF-2 represses CDK4 transcription through dimerization with JunD inhibiting intestinal epithelial cell growth after polyamine depletion. Am J Physiol Cell Physiol 2010; 298:C1226-34. [PMID: 20181929 DOI: 10.1152/ajpcell.00021.2010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intestinal epithelium is a rapidly self-renewing tissue in the body, and its homeostasis is tightly regulated by numerous factors including polyamines. Decreased levels of cellular polyamines increase activating transcription factor (ATF)-2, but the exact role and mechanism of induced ATF-2 in the regulation of intestinal epithelial cell (IEC) growth remain elusive. Cyclin-dependent kinase (CDK) 4 is necessary for the G1-to-S phase transition during the cell cycle, and its expression is predominantly controlled at the transcription level. Here, we reported that induced ATF-2 following polyamine depletion repressed CDK4 gene transcription in IECs by increasing formation of the ATF-2/JunD heterodimers. ATF-2 formed complexes with JunD as measured by immunoprecipitation using the ATF-2 and JunD antibodies and by glutathione S-transferase (GST) pull-down assays using GST-ATF-2 fusion proteins. Studies using various mutants of GST-ATF-2 revealed that formation of the ATF-2/JunD dimers depended on the COOH-terminal basic region-leucine zipper domain of ATF-2. Polyamine depletion increased ATF-2/JunD complex and inhibited CDK4 transcription as indicated by a decrease in the levels of CDK4-promoter activity and its mRNA. ATF-2 silencing not only prevented inhibition of CDK4 transcription in polyamine-deficient cells but also abolished repression of CDK4 expression induced by ectopic JunD overexpression. ATF-2 silencing also promoted IEC growth in polyamine-depleted cells. These results indicate that induced ATF-2/JunD association following polyamine depletion represses CDK4 transcription, thus contributing to the inhibition of IEC growth.
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Affiliation(s)
- Lan Xiao
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
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Curcumin sensitizes non-small cell lung cancer cell anoikis through reactive oxygen species-mediated Bcl-2 downregulation. Apoptosis 2010; 15:574-85. [DOI: 10.1007/s10495-010-0461-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Demers MJ, Thibodeau S, Noël D, Fujita N, Tsuruo T, Gauthier R, Arguin M, Vachon PH. Intestinal epithelial cancer cell anoikis resistance: EGFR-mediated sustained activation of Src overrides Fak-dependent signaling to MEK/Erk and/or PI3-K/Akt-1. J Cell Biochem 2009; 107:639-54. [PMID: 19479902 DOI: 10.1002/jcb.22131] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Herein, we investigated the survival roles of Fak, Src, MEK/Erk, and PI3-K/Akt-1 in intestinal epithelial cancer cells (HCT116, HT29, and T84), in comparison to undifferentiated and differentiated intestinal epithelial cells (IECs). We report that: (1) cancer cells display striking anoikis resistance, as opposed to undifferentiated/differentiated IECs; (2) under anoikis conditions and consequent Fak down-activation, cancer cells nevertheless exhibit sustained Fak-Src interactions and Src/MEK/Erk activation, unlike undifferentiated/differentiated IECs; however, HCT116 and HT29 cells exhibit a PI3-K/Akt-1 down-activation, as undifferentiated/differentiated IECs, whereas T84 cells do not; (3) cancer cells require MEK/Erk for survival, as differentiated (but not undifferentiated) IECs; however, T84 cells do not require Fak and HCT116 cells do not require PI3-K/Akt-1, in contrast to the other cells studied; (4) Src acts as a cornerstone in Fak-mediated signaling to MEK/Erk and PI3-K/Akt-1 in T84 cells, as in undifferentiated IECs, whereas PI3-K/Akt-1 is Src-independent in HCT116, HT29 cells, as in differentiated IECs; and (5) EGFR activity inhibition abrogates anoikis resistance in cancer cells through a loss of Fak-Src interactions and down-activation of Src/MEK/Erk (T84, HCT116, HT29 cells) and PI3-K/Akt-1 (T84 cells). Hence, despite distinctions in signaling behavior not necessarily related to undifferentiated or differentiated IECs, intestinal epithelial cancer cells commonly display an EGFR-mediated sustained activation of Src under anoikis conditions. Furthermore, such sustained Src activation confers anoikis resistance at least in part through a consequent sustenance of Fak-Src interactions and MEK/Erk activation, thus not only overriding Fak-mediated signaling to MEK/Erk and/or PI3-K/Akt-1, but also the requirement of Fak and/or PI3-K/Akt-1 for survival.
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Affiliation(s)
- Marie-Josée Demers
- Département d'Anatomie et de Biologie Cellulaire, Université de Sherbrooke, Québec, Canada
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Cheng H, Liu P, Wang ZC, Zou L, Santiago S, Garbitt V, Gjoerup OV, Iglehart JD, Miron A, Richardson AL, Hahn WC, Zhao JJ. SIK1 couples LKB1 to p53-dependent anoikis and suppresses metastasis. Sci Signal 2009; 2:ra35. [PMID: 19622832 DOI: 10.1126/scisignal.2000369] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Resistance to anoikis, the subtype of apoptosis triggered by lack of adhesion, contributes to malignant transformation and the development of metastasis. Although several lines of evidence suggest that p53 plays a critical role in anoikis, the pathway(s) that connect cell detachment to p53 remain undefined. Here, through the use of a kinome-wide loss-of-function screen, we identify the serine-threonine kinase SIK1 (salt-inducible kinase 1) as a regulator of p53-dependent anoikis. Inactivation of SIK1 compromised p53 function in anoikis and allowed cells to grow in an anchorage-independent manner. In vivo, SIK1 loss facilitated metastatic spread and survival of disseminated cells as micrometastases in lungs. The presence of functional SIK1 was required for the activity of the kinase LKB1 in promoting p53-dependent anoikis and suppressing anchorage-independent growth, Matrigel invasion, and metastatic potential. In human cancers, decreased expression of the gene encoding SIK1 closely correlated with development of distal metastases in breast cancers from three independent cohorts. Together, these findings indicate that SIK1 links LKB1 to p53-dependent anoikis and suppresses metastasis.
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Affiliation(s)
- Hailing Cheng
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
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Bhatia V, Mula RV, Weigel NL, Falzon M. Parathyroid hormone-related protein regulates cell survival pathways via integrin alpha6beta4-mediated activation of phosphatidylinositol 3-kinase/Akt signaling. Mol Cancer Res 2009; 7:1119-31. [PMID: 19584267 DOI: 10.1158/1541-7786.mcr-08-0568] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) is expressed by human prostatic tissues and cancer cell lines. PTHrP enhances tumor cell growth and metastasis in vivo and up-regulates proinvasive integrin alpha6beta4 expression in vitro. Hallmarks of malignant tumor cells include resistance to apoptosis and anchorage-independent cell growth. In this study, we used the human prostate cancer cell lines C4-2 and PC-3 as model systems to study the effects of PTHrP on these processes. We report that PTHrP protects these cells from doxorubicin-induced apoptosis and promotes anchorage-independent cell growth via an intracrine pathway. Conversely, autocrine/paracrine PTHrP action increases apoptosis in C4-2 cells and has no effect on apoptosis in PC-3 cells. The intracrine effects of PTHrP on apoptosis are mediated via activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. PTHrP also affects the phosphorylation state of Akt substrates implicated in apoptosis suppression, including glycogen synthase kinase-3 and Bad. The prosurvival effects of PTHrP are accompanied by increases in the ratio of antiapoptotic to proapoptotic members of the Bcl-2 family and in levels of c-myc. PTHrP also increases nuclear factor-kappaB activity via a PI3K-dependent pathway. Integrin alpha6beta4 is known to activate PI3K. Here, we also show that knockdown of integrin alpha6beta4 negates the PTHrP-mediated activation of the PI3K/Akt pathway. Taken together, these observations provide evidence of a link between PTHrP and the PI3K/Akt signaling pathway through integrin alpha6beta4, resulting in the activation of survival pathways. Targeting PTHrP production in prostate cancer may thus prove therapeutically beneficial.
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Affiliation(s)
- Vandanajay Bhatia
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555-1031, USA
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Autotaxin protects MCF-7 breast cancer and MDA-MB-435 melanoma cells against Taxol-induced apoptosis. Oncogene 2008; 28:1028-39. [PMID: 19079345 DOI: 10.1038/onc.2008.442] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Autotaxin (ATX) promotes cancer cell survival, growth, migration, invasion and metastasis. ATX converts extracellular lysophosphatidylcholine (LPC) into lysophosphatidate (LPA). As these lipids have been reported to affect cell signaling through their own G-protein-coupled receptors, ATX could modify the balance of this signaling. Also, ATX affects cell adhesion independently of its catalytic activity. We investigated the interactions of ATX, LPC and LPA on the apoptotic effects of Taxol, which is commonly used in breast cancer treatment. LPC had no significant effect on Taxol-induced apoptosis in MCF-7 breast cancer cells, which do not secrete significant ATX. Addition of incubation medium from MDA-MB-435 melanoma cells, which secrete ATX, or recombinat ATX enabled LPC to inhibit Taxol-induced apoptosis of MCF-7 cells. Inhibiting ATX activity blocked this protection against apoptosis. We conclude that LPC has no significant effect in protecting MCF-7 cells against Taxol treatment unless it is converted to LPA by ATX. LPA strongly antagonized Taxol-induced apoptosis through stimulating phosphatidylinositol 3-kinase and inhibiting ceramide formation. LPA also partially reversed the Taxol-induced arrest in the G2/M phase of the cell cycle. Our results support the hypothesis that therapeutic inhibition of ATX activity could improve the efficacy of Taxol as a chemotherapeutic agent for cancer treatment.
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Gayer CP, Chaturvedi LS, Wang S, Craig DH, Flanigan T, Basson MD. Strain-induced proliferation requires the phosphatidylinositol 3-kinase/AKT/glycogen synthase kinase pathway. J Biol Chem 2008; 284:2001-11. [PMID: 19047055 DOI: 10.1074/jbc.m804576200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The intestinal epithelium is repetitively deformed by shear, peristalsis, and villous motility. Such repetitive deformation stimulates the proliferation of intestinal epithelial cells on collagen or laminin substrates via ERK, but the upstream mediators of this effect are poorly understood. We hypothesized that the phosphatidylinositol 3-kinase (PI3K)/AKT cascade mediates this mitogenic effect. PI3K, AKT, and glycogen synthase kinase-3beta (GSK-3beta) were phosphorylated by 10 cycles/min strain at an average 10% deformation, and pharmacologic blockade of these molecules or reduction by small interfering RNA (siRNA) prevented the mitogenic effect of strain in Caco-2 or IEC-6 intestinal epithelial cells. Strain MAPK activation required PI3K but not AKT. AKT isoform-specific siRNA transfection demonstrated that AKT2 but not AKT1 is required for GSK-3beta phosphorylation and the strain mitogenic effect. Furthermore, overexpression of AKT1 or an AKT chimera including the PH domain and hinge region of AKT2 and the catalytic domain and C-tail of AKT1 prevented strain activation of GSK-3beta, but overexpression of AKT2 or a chimera including the PH domain and hinge region of AKT1 and the catalytic domain and C-tail of AKT2 did not. These data delineate a role for PI3K, AKT2, and GSK-3beta in the mitogenic effect of strain. PI3K is required for both ERK and AKT2 activation, whereas AKT2 is sequentially required for GSK-3beta. Furthermore, AKT2 specificity requires its catalytic domain and tail region. Manipulating this pathway may prevent mucosal atrophy and maintain the mucosal barrier in conditions such as ileus, sepsis, and prolonged fasting when peristalsis and villous motility are decreased and the mucosal barrier fails.
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Affiliation(s)
- Christopher P Gayer
- Department of Surgery, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan 48301, USA
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Derikx JPM, Matthijsen RA, de Bruïne AP, van Bijnen AA, Heineman E, van Dam RM, Dejong CHC, Buurman WA. Rapid reversal of human intestinal ischemia-reperfusion induced damage by shedding of injured enterocytes and reepithelialisation. PLoS One 2008; 3:e3428. [PMID: 18927609 PMCID: PMC2561292 DOI: 10.1371/journal.pone.0003428] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 09/22/2008] [Indexed: 02/07/2023] Open
Abstract
Background Intestinal ischemia-reperfusion (IR) is a phenomenon related to physiological conditions (e.g. exercise, stress) and to pathophysiological events (e.g. acute mesenteric ischemia, aortic surgery). Although intestinal IR has been studied extensively in animals, results remain inconclusive and data on human intestinal IR are scarce. Therefore, an experimental harmless model for human intestinal IR was developed, enabling us to clarify the sequelae of human intestinal IR for the first time. Methods and Findings In 30 patients undergoing pancreatico-duodenectomy we took advantage of the fact that in this procedure a variable length of jejunum is removed. Isolated jejunum (5 cm) was subjected to 30 minutes ischemia followed by reperfusion. Intestinal Fatty Acid Binding Protein (I-FABP) arteriovenous concentration differences across the bowel segment were measured before and after ischemia to assess epithelial cell damage. Tissue sections were collected after ischemia and at 25, 60 and 120 minutes reperfusion and stained with H&E, and for I-FABP and the apoptosis marker M30. Bonferroni's test was used to compare I-FABP differences. Mean (SEM) arteriovenous concentration gradients of I-FABP across the jejunum revealed rapidly developing epithelial cell damage. I-FABP release significantly increased from 290 (46) pg/ml before ischemia towards 3,997 (554) pg/ml immediately after ischemia (p<0.001) and declined gradually to 1,143 (237) pg/ml within 1 hour reperfusion (p<0.001). Directly after ischemia the intestinal epithelial lining was microscopically normal, while subepithelial spaces appeared at the villus tip. However, after 25 minutes reperfusion, enterocyte M30 immunostaining was observed at the villus tip accompanied by shedding of mature enterocytes into the lumen and loss of I-FABP staining. Interestingly, within 60 minutes reperfusion the epithelial barrier resealed, while debris of apoptotic, shedded epithelial cells was observed in the lumen. At the same time, M30 immunoreactivity was absent in intact epithelial lining. Conclusions This is the first human study to clarify intestinal IR induced cell damage and repair and its direct consequences. It reveals a unique, endogenous clearing mechanism for injured enterocytes: rapid detachment of damaged apoptotic enterocytes into the lumen. This process is followed by repair of the epithelial continuity within an hour, resulting in a normal epithelial lining.
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Affiliation(s)
- Joep P. M. Derikx
- Department of Surgery, School for Nutrition & Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
- * E-mail:
| | - Robert A. Matthijsen
- Department of Surgery, School for Nutrition & Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Adriaan P. de Bruïne
- Department of Pathology, Cardiovascular Research Institute (CARIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Annemarie A. van Bijnen
- Department of Surgery, School for Nutrition & Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Erik Heineman
- Department of Surgery, School for Nutrition & Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Ronald M. van Dam
- Department of Surgery, School for Nutrition & Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Cornelis H. C. Dejong
- Department of Surgery, School for Nutrition & Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Wim A. Buurman
- Department of Surgery, School for Nutrition & Metabolism (NUTRIM), Maastricht University Medical Centre+, Maastricht, the Netherlands
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Degtyarev M, De Mazière A, Orr C, Lin J, Lee BB, Tien JY, Prior WW, van Dijk S, Wu H, Gray DC, Davis DP, Stern HM, Murray LJ, Hoeflich KP, Klumperman J, Friedman LS, Lin K. Akt inhibition promotes autophagy and sensitizes PTEN-null tumors to lysosomotropic agents. J Cell Biol 2008; 183:101-16. [PMID: 18838554 PMCID: PMC2557046 DOI: 10.1083/jcb.200801099] [Citation(s) in RCA: 345] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Accepted: 09/05/2008] [Indexed: 12/13/2022] Open
Abstract
Although Akt is known as a survival kinase, inhibitors of the phosphatidylinositol 3-kinase (PI3K)-Akt pathway do not always induce substantial apoptosis. We show that silencing Akt1 alone, or any combination of Akt isoforms, can suppress the growth of tumors established from phosphatase and tensin homologue-null human cancer cells. Although these findings indicate that Akt is essential for tumor maintenance, most tumors eventually rebound. Akt knockdown or inactivation with small molecule inhibitors did not induce significant apoptosis but rather markedly increased autophagy. Further treatment with the lysosomotropic agent chloroquine caused accumulation of abnormal autophagolysosomes and reactive oxygen species, leading to accelerated cell death in vitro and complete tumor remission in vivo. Cell death was also promoted when Akt inhibition was combined with the vacuolar H(+)-adenosine triphosphatase inhibitor bafilomycin A1 or with cathepsin inhibition. These results suggest that blocking lysosomal degradation can be detrimental to cancer cell survival when autophagy is activated, providing rationale for a new therapeutic approach to enhancing the anticancer efficacy of PI3K-Akt pathway inhibition.
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Bouchard V, Harnois C, Demers MJ, Thibodeau S, Laquerre V, Gauthier R, Vézina A, Noël D, Fujita N, Tsuruo T, Arguin M, Vachon PH. B1 integrin/Fak/Src signaling in intestinal epithelial crypt cell survival: integration of complex regulatory mechanisms. Apoptosis 2008; 13:531-42. [PMID: 18322799 DOI: 10.1007/s10495-008-0192-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The molecular determinants which dictate survival and apoptosis/anoikis in human intestinal crypt cells remain to be fully understood. To this effect, the roles of beta1 integrin/Fak/Src signaling to the PI3-K/Akt-1, MEK/Erk, and p38 pathways, were investigated. The regulation of six Bcl-2 homologs (Bcl-2, Mcl-1, Bcl-X(L), Bax, Bak, Bad) was likewise analyzed. We report that: (1) Anoikis causes a down-activation of Fak, Src, Akt-1 and Erk1/2, a loss of Fak-Src association, and a sustained/enhanced activation of p38beta, which is required as apoptosis/anoikis driver; (2) PI3-K/Akt-1 up-regulates the expression of Bcl-X(L) and Mcl-1, down-regulates Bax and Bak, drives Bad phosphorylation (both serine112/136 residues) and antagonizes p38beta activation; (3) MEK/Erk up-regulates Bcl-2, drives Bad phosphorylation (serine112 residue), but does not antagonize p38bactivation; (4) PI3-K/Akt-1 is required for survival, whereas MEK/Erk is not; (5) Src acts as a cornerstone in the engagement of both pathways by beta1 integrins/Fak, and is crucial for survival; and (6) beta1 integrins/Fak and/or Src regulate Bcl-2 homologs as both PI3-K/Atk-1 and MEK/Erk combined. Hence, beta1 integrin/Fak/Src signaling translates into integrated mediating functions of p38beta activation and regulation of Bcl-2 homologs by PI3-K/Akt-1 and MEK/Erk, consequently determining their requirement (or not) for survival.
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Affiliation(s)
- Véronique Bouchard
- Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
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43
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Shiratsuchi H, Basson MD. Akt2, but not Akt1 or Akt3 mediates pressure-stimulated serum-opsonized latex bead phagocytosis through activating mTOR and p70 S6 kinase. J Cell Biochem 2008; 102:353-67. [PMID: 17372934 DOI: 10.1002/jcb.21295] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Monocytes and macrophages play critical roles in innate host defense and are sensitive to mechanical stimuli. Tissue pressure is often altered in association with inflammation or infection. Low pressure (20 mmHg), equivalent to normal tissue pressure, increases phagocytosis by primary monocytes and PMA-differentiated THP-1 macrophages, in part by FAK and ERK inhibition and p38 activation. PI-3K is required for macrophage phagocytosis, but whether PI-3K mediates pressure-stimulated phagocytosis is not known. Furthermore, little is known about the role played by the PI-3K downstream Kinases, Akt, and p70 S6 kinase (p70S6K) in modulating macrophage phagocytosis. Thus, we studied the contribution of PI-3K, Akt, and p70S6K to pressure-increased serum-opsonized bead phagocytosis. Pressure-induced p85 PI-3K translocation from cytosolic to membrane fractions and increased Akt activation by 36.1 +/- 12.0% in THP-1 macrophages. LY294002 or Akt inhibitor IV abrogated pressure-stimulated but not basal phagocytosis. Basal Akt activation was inhibited 90% by LY294002 and 70% by Akt inhibitor IV. Each inhibitor prevented Akt activation by pressure. SiRNA targeted to Akt1, Akt2, or Akt3 reduced Akt1, Akt2, and Akt3 expression by 50%, 45%, and 40%, respectively. However, only Akt2SiRNA abrogated the pressure-stimulated phagocytosis without affecting basal. Pressure also activated mTOR and p70S6K. mTORSiRNA and p70S6K inhibition by rapamycin or p70S6KSiRNA blocked pressure-induced, but not basal, phagocytosis. Changes in tissue pressure during inflammation may regulate macrophage phagocytosis by activation of PI-3K, which activates Akt2, mTOR, and p70S6K.
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Affiliation(s)
- Hiroe Shiratsuchi
- Department of Surgery, Wayne State University, School of Medicine, and John D. Dingell VA Medical Center, Detroit, Michigan 48201, USA.
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Marasa BS, Xiao L, Rao JN, Zou T, Liu L, Wang J, Bellavance E, Turner DJ, Wang JY. Induced TRPC1 expression increases protein phosphatase 2A sensitizing intestinal epithelial cells to apoptosis through inhibition of NF-kappaB activation. Am J Physiol Cell Physiol 2008; 294:C1277-87. [PMID: 18322138 DOI: 10.1152/ajpcell.90635.2007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transient receptor potential canonical-1 (TRPC1) functions as a store-operated Ca2+ channel in intestinal epithelial cells (IECs), and induced TRPC1 expression sensitizes IECs to apoptosis by inhibiting NF-kappaB activation. However, the exact mechanism by which increased TRPC1 results in NF-kappaB inactivation remains elusive. Protein phosphatase 2A (PP2A) is a widely conserved protein serine/threonine phosphatase that is implicated in the regulation of a wide array of cellular functions including apoptosis. The present study tests the hypothesis that induced TRPC1 expression inhibits NF-kappaB activation by increasing PP2A activity through Ca2+ influx in IECs. The expression of TRPC1 induced by stable transfection with the wild-type TRPC1 gene increased PP2A activity as indicated by increases in levels of PP2A proteins and their phosphatase activity. Increased levels of PP2A activity in stable TRPC1-transfected IEC-6 cells (IEC-TRPC1) were associated with decreased nuclear levels of NF-kappaB proteins and a reduction in NF-kappaB-dependent transcriptional activity, although there were no changes in total NF-kappaB protein levels. Inhibition of PP2A activity by treatment with okadaic acid or PP2A silencing with small interfering RNA not only enhanced NF-kappaB transactivation but also prevented the increased susceptibility of IEC-TRPC1 cells to apoptosis induced by treatment with tumor necrosis factor-alpha (TNF-alpha)/cycloheximide (CHX). Decreasing Ca2+ influx by exposure to the Ca2+-free medium reduced PP2A mRNA levels, destabilized PP2A proteins, and induced NF-kappaB activation, thus blocking the increased sensitivity of IEC-TRPC1 cells to TNF-alpha/CHX-induced apoptosis. These results indicate that induced TRPC1 expression increases PP2A activity through Ca2+ influx and that increased PP2A sensitizes IECs to apoptosis as a result of NF-kappaB inactivation.
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Affiliation(s)
- Bernard S Marasa
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
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45
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Ibuki Y, Akaike M, Toyooka T, Goto R. Akt1-mediated intracellular oxidation after UVB irradiation suppresses apoptotic cell death induced by cell detachment and serum starvation. Photochem Photobiol 2008; 84:154-61. [PMID: 18173715 DOI: 10.1111/j.1751-1097.2007.00214.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Apoptosis is an important cell death system that deletes damaged and mutated cells to prevent cancer. We have previously reported that a certain dose of UVB irradiation inhibited the apoptosis induced by serum starvation and cell detachment, leading to cell transformation. This antiapoptotic effect was partially inhibited by phosphatidylinositol 3-kinase (PI3-kinase) inhibitors. UVB irradiation is known to cause the phosphorylation of Akt via the activation of PI3-kinase; however, the Akt isoform-specific relationship has not yet been clarified. Notably, the role in antiapoptotic effect of UVB has yet to be elucidated. In this study, the role of Akt1 in the UVB-induced inhibition of apoptosis was examined by Akt1 knockdown using small interfering RNA (siRNA). NIH3T3 cells showed typical apoptotic cell death by serum starvation and cell detachment, which was significantly inhibited by UVB irradiation. Akt1 knockdown decreased the antiapoptotic effect of UVB. Hydrogen peroxide-induced suppression of cell death was also decreased in Akt1 knockdown cells. An antioxidant, N-acetylcysteine, inhibited the antiapoptotic effect by UVB irradiation, whereas no inhibition was observed in Akt1 knockdown cells. Furthermore, UVB-induced intracellular peroxidation was not observed in the knockdown cells, indicating that Akt1 played an important role in mediating the intracellular redox status. Treatment with insulin had a similar antiapoptotic effect as UVB irradiation involving intracellular peroxidation, which was also attenuated in Akt1 knockdown cells. These findings suggest that appropriate intracellular oxidation after UVB irradiation prevented apoptosis, a process which might be partially regulated by the production of reactive oxygen species mediated by Akt1.
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Affiliation(s)
- Yuko Ibuki
- Laboratory of Radiation Biology, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka-shi, Japan.
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Nava P, Laukoetter MG, Hopkins AM, Laur O, Gerner-Smidt K, Green KJ, Parkos CA, Nusrat A. Desmoglein-2: a novel regulator of apoptosis in the intestinal epithelium. Mol Biol Cell 2007; 18:4565-78. [PMID: 17804817 PMCID: PMC2043542 DOI: 10.1091/mbc.e07-05-0426] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 07/19/2007] [Accepted: 08/27/2007] [Indexed: 11/11/2022] Open
Abstract
Intestinal epithelial intercellular junctions regulate barrier properties, and they have been linked to epithelial differentiation and programmed cell death (apoptosis). However, mechanisms regulating these processes are poorly defined. Desmosomes are critical elements of intercellular junctions; they are punctate structures made up of transmembrane desmosomal cadherins termed desmoglein-2 (Dsg2) and desmocollin-2 (Dsc2) that affiliate with the underlying intermediate filaments via linker proteins to provide mechanical strength to epithelia. In the present study, we generated an antibody, AH12.2, that recognizes Dsg2. We show that Dsg2 but not another desmosomal cadherin, Dsc2, is cleaved by cysteine proteases during the onset of intestinal epithelial cell (IEC) apoptosis. Small interfering RNA-mediated down-regulation of Dsg2 protected epithelial cells from apoptosis. Moreover, we report that a C-terminal fragment of Dsg2 regulates apoptosis and Dsg2 protein levels. Our studies highlight a novel mechanism by which Dsg2 regulates IEC apoptosis driven by cysteine proteases during physiological differentiation and inflammation.
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Affiliation(s)
- Porfirio Nava
- *Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322
| | - Mike G. Laukoetter
- *Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322
- Department of General Surgery, University of Muenster, D-48149 Muenster, Germany
| | - Ann M. Hopkins
- UCD School of Medicine and Medical Science, University College, Dublin 4, Ireland; and
| | - Oskar Laur
- *Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322
| | - Kirsten Gerner-Smidt
- *Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322
| | - Kathleen J. Green
- Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Charles A. Parkos
- *Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322
| | - Asma Nusrat
- *Epithelial Pathobiology Research Unit, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322
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Kato S, Iida S, Higuchi T, Ishikawa T, Takagi Y, Yasuno M, Enomoto M, Uetake H, Sugihara K. PIK3CA mutation is predictive of poor survival in patients with colorectal cancer. Int J Cancer 2007; 121:1771-8. [PMID: 17590872 DOI: 10.1002/ijc.22890] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The PI3K-AKT pathway is activated in a variety of human cancers, resulting in disturbance of cell growth, proliferation and survival. Among the factors affecting the pathway, the K-Ras mutation and PIK3CA mutation are the most common oncogenic alterations in colorectal cancer. We hypothesized that these two mutations are important in activation of the PI3K pathway and colorectal carcinogenesis. In this study, we aimed to examine the influence of PIK3CA mutation and K-Ras mutation on AKT activation, and to clarify whether PIK3CA mutation, K-Ras mutation and p-AKT expression may be used as parameters for predicting prognosis in colorectal cancer. Tissue samples from 158 colorectal cancer patients who underwent surgical resection were examined. The sequences of exon 1 of K-Ras and exons 9 and 20 of PIK3CA were determined by direct sequencing using genomic DNA extracted from paraffin-embedded blocks. Activation status of AKT was evaluated by immunohistochemical staining using phospho-specific AKT antibody (Ser473). Correlation between these factors and clinicopathologic findings/patient survival were examined. As a result, PIK3CA mutation was significantly associated with shorter relapse-free survival (RFS) in stage II/III patients (p = 0.0216) and shorter disease-specific survival in all patients (p = 0.0357). In the multivariate analysis, PIK3CA mutation was the only independent and significant prognostic factor for RFS in stage II/III patients (p = 0.0433, HR 2.478). This study revealed the prognostic value of PIK3CA mutation in colorectal cancer patients. Patients with PIK3CA mutation should be followed up carefully. Moreover, our result suggests that inhibition of PIK3CA mutant may be a new molecular target therapy.
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Affiliation(s)
- Shunsuke Kato
- Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
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Teller IC, Auclair J, Herring E, Gauthier R, Ménard D, Beaulieu JF. Laminins in the developing and adult human small intestine: relation with the functional absorptive unit. Dev Dyn 2007; 236:1980-90. [PMID: 17503455 DOI: 10.1002/dvdy.21186] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The expression of the five laminin alpha-chains was analyzed in the developing and mature human small intestine at the protein and transcript levels in order to further delineate specific involvement of individual laminins in relation to the epithelial cell state as defined along the functional crypt-villus axis. The results show that all of the alpha-laminin transcripts are expressed in significant amounts in the small intestine relative to a panel of other tissues and organs. Further analysis of their expression by indirect immunofluorescence and semi-quantitative and quantitative RT-PCR demonstrates a close correlation between transcript and protein expression, distinct epithelial and mesenchymal origins, as well as differential occurrence in intestinal basement membranes according to developmental stage, along the crypt-villus axis and in compartment-related experimental intestinal cell models. Taken together, the data point out the prime importance of alpha2-, alpha3-, and alpha5-containing laminins for the development and maintenance of the functional human intestinal epithelium.
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Affiliation(s)
- Inga C Teller
- CIHR Team on Digestive Epithelium, Département d'anatomie et de biologie cellulaire, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
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49
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Bouchard V, Demers MJ, Thibodeau S, Laquerre V, Fujita N, Tsuruo T, Beaulieu JF, Gauthier R, Vézina A, Villeneuve L, Vachon PH. Fak/Src signaling in human intestinal epithelial cell survival and anoikis: differentiation state-specific uncoupling with the PI3-K/Akt-1 and MEK/Erk pathways. J Cell Physiol 2007; 212:717-28. [PMID: 17443665 DOI: 10.1002/jcp.21096] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Human intestinal epithelial cell survival and anoikis are distinctively regulated according to the state of differentiation. In the present study, we analyzed the roles of focal adhesion kinase (Fak)/Src signaling to the PI3-K/Akt-1 and mitogen-activated protein kinase (MEK)/extracellular regulated kinases (Erk) pathways, within the context of such differentiation-state distinctions. Anoikis was induced by inhibition of beta1 integrins (antibody blocking), inhibition of Fak (pharmacologic inhibition or overexpression of dominant negative mutants), or by maintaining cells in suspension. Activation parameters of Fak, Src, Akt-1, and Erk1/2 were analyzed. Activities of Src, Akt-1, or Erk1/2 were also blocked by pharmacological inhibition or by overexpression of dominant-negative mutants. We report that: (1) the loss or inhibition of beta1 integrin binding activity causes anoikis and results in a down-activation of Fak, Src, Akt-1, and Erk1/2 in both undifferentiated, and differentiated cells; (2) the inhibition of Fak likewise causes anoikis and a down-activation of Src, Akt-1, and Erk1/2, regardless of the differentiation state; (3) Src, PI3-K/Akt-1, and MEK/Erk contribute to the survival of differentiated cells, whereas MEK/Erk does not play a role in the survival of undifferentiated ones; (4) the inhibition/loss of beta1 integrin binding and/or Fak activity results in a loss of Src engagement with Fak, regardless of the state of differentiation; and (5) Src contributes to the activation of both the PI3-K/Akt-1 and MEK/Erk pathways in undifferentiated cells, but does not influence PI3-K/Akt-1 in differentiated ones. Hence, Fak/Src signaling to the PI3-K/Akt-1 and MEK/Erk pathways undergoes a differentiation state-specific uncoupling which ultimately reflects upon the selective engagement of these same pathways in the mediation of intestinal epithelial cell survival.
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Affiliation(s)
- Véronique Bouchard
- Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
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50
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Rusovici R, Ghaleb A, Shim H, Yang VW, Chris Yun C. Lysophosphatidic acid prevents apoptosis of Caco-2 colon cancer cells via activation of mitogen-activated protein kinase and phosphorylation of Bad. Biochim Biophys Acta Gen Subj 2007; 1770:1194-203. [PMID: 17544220 PMCID: PMC1989128 DOI: 10.1016/j.bbagen.2007.04.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 04/17/2007] [Accepted: 04/24/2007] [Indexed: 01/24/2023]
Abstract
Lysophosphatidic acids (LPA) exert growth factor-like effects through specific G protein-coupled receptors. The presence of different LPA receptors often determines the specific signaling mechanisms and the physiological consequences of LPA in different environments. Among the four members of the LPA receptor family, LPA(2) has been shown to be overexpressed in colon cancer suggesting that the signaling by LPA(2) may potentiate growth and survival of tumor cells. In this study, we examined the effect of LPA on survival of colon cancer cells using Caco-2 cells as a cell model system. LPA rescued Caco-2 cells from apoptosis elicited by the chemotherapeutic drug, etoposide. This protection was accompanied by abrogation of etoposide-induced stimulation of caspase activity via a mechanism dependent on Erk and PI3K. In contrast, perturbation of cellular signaling mediated by the LPA(2) receptor by knockdown of a scaffold protein NHERF2 abrogated the protective effect of LPA. Etoposide decreased the expression of Bcl-2, which was reversed by LPA. Etoposide decreased the phosphorylation level of the proapoptotic protein Bad in an Erk-dependent manner, without changing Bad expression. We further show that LPA treatment resulted in delayed activation of Erk. These results indicate that LPA protects Caco-2 cells from apoptotic insult by a mechanism involving Erk, Bad, and Bcl-2.
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Affiliation(s)
- Raluca Rusovici
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Amr Ghaleb
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Hyunsuk Shim
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA
| | - Vincent W. Yang
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA
| | - C. Chris Yun
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA
- Department of Physiology, Emory University School of Medicine, Atlanta, GA
- Corresponding author: Tel: 1-404-712-2865,
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