101
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Laane E, Tamm KP, Buentke E, Ito K, Kharaziha P, Khahariza P, Oscarsson J, Corcoran M, Björklund AC, Hultenby K, Lundin J, Heyman M, Söderhäll S, Mazur J, Porwit A, Pandolfi PP, Zhivotovsky B, Panaretakis T, Grandér D. Cell death induced by dexamethasone in lymphoid leukemia is mediated through initiation of autophagy. Cell Death Differ 2009; 16:1018-29. [PMID: 19390558 DOI: 10.1038/cdd.2009.46] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Glucocorticoids are fundamental drugs used in the treatment of lymphoid malignancies with apoptotic cell death as the hitherto proposed mechanism of action. Recent studies, however, showed that an alternative mode of cell death, autophagy, is involved in the response to anticancer drugs. The specific role of autophagy and its relationship to apoptosis remains, nevertheless, controversial: it can either lead to cell survival or can function in cell death. We show that dexamethasone induced autophagy upstream of apoptosis in acute lymphoblastic leukemia cells. Inhibition of autophagy by siRNA-mediated repression of Beclin 1 expression inhibited apoptosis showing an important role of autophagy in dexamethasone-induced cell death. Dexamethasone treatment caused an upregulation of promyelocytic leukemia protein, PML, its complex formation with protein kinase B or Akt and a PML-dependent Akt dephosphorylation. Initiation of autophagy and the onset of apoptosis were both dependent on these events. PML knockout thymocytes were resistant to dexamethasone-induced death and upregulation of PML correlated with the ability of dexamethasone to kill primary leukemic cells. Our data reveal key mechanisms of dexamethasone-induced cell death that may inform the development of improved treatment protocols for lymphoid malignancies.
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Affiliation(s)
- E Laane
- Department of Oncology and Pathology, Cancer Centre Karolinska R8:03, Karolinska Institutet and Karolinska University Hospital, Stockholm S-171 76, Sweden
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102
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Abstract
Glucocorticoids (GCs) induce apoptosis in lymphoid lineage cells and are therefore used in the therapy of acute lymphoblastic leukemia (ALL) and related malignancies. MicroRNAs (miRNAs) and the related mirtrons are ~22 nucleotide RNAs derived from polymerase-II transcripts and implicated in the control of essential biological functions, including apoptosis. Whether GCs regulate miRNA-encoding transcription units is unknown. We investigated miRNA/mirtron expression and GC regulation in 8 leukemia/lymphoma in vitro models and 13 ALL children undergoing systemic GC monotherapy using a combination of expression profiling techniques, real time reverse transcription (RT)-PCR and northern blotting to detect mature miRNAs and/or their precursors. We found that mature miRNA regulations can be inferred from expression data of their host genes. Although a simple miRNA-initiated canonical pathway to GC-induced apoptosis or cell cycle arrest did not emerge, we identified several miRNAs/mirtrons that were regulated by GC in patients and cell lines, including the myeloid-specific miR-223 and the apoptosis and cell cycle arrest-inducing miR15 ~ 16 clusters. In an in vitro model, overexpression of miR15b ~ 16 mimics increased and silencing by miR15b ~ 16 inhibitors decreased GC sensitivity. Thus, the observed complex changes in miRNA/mirtron expression during GC treatment might contribute to the anti-leukemic GC effects in a cell context-dependent manner.
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103
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Mechanisms regulating the susceptibility of hematopoietic malignancies to glucocorticoid-induced apoptosis. Adv Cancer Res 2009; 101:127-248. [PMID: 19055945 DOI: 10.1016/s0065-230x(08)00406-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Glucocorticoids (GCs) are commonly used in the treatment of hematopoietic malignancies owing to their ability to induce apoptosis of these cancerous cells. Whereas some types of lymphoma and leukemia respond well to this drug, others are resistant. Also, GC-resistance gradually develops upon repeated treatments ultimately leading to refractory relapsed disease. Understanding the mechanisms regulating GC-induced apoptosis is therefore uttermost important for designing novel treatment strategies that overcome GC-resistance. This review discusses updated data describing the complex regulation of the cell's susceptibility to apoptosis triggered by GCs. We address both the genomic and nongenomic effects involved in promoting the apoptotic signals as well as the resistance mechanisms opposing these signals. Eventually we address potential strategies of clinical relevance that sensitize GC-resistant lymphoma and leukemia cells to this drug. The major target is the nongenomic signal transduction machinery where the interplay between protein kinases determines the cell fate. Shifting the balance of the kinome towards a state where Glycogen synthase kinase 3alpha (GSK3alpha) is kept active, favors an apoptotic response. Accumulating data show that it is possible to therapeutically modulate GC-resistance in patients, thereby improving the response to GC therapy.
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104
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Boutros T, Chevet E, Metrakos P. Mitogen-activated protein (MAP) kinase/MAP kinase phosphatase regulation: roles in cell growth, death, and cancer. Pharmacol Rev 2009; 60:261-310. [PMID: 18922965 DOI: 10.1124/pr.107.00106] [Citation(s) in RCA: 438] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mitogen-activated protein kinase dual-specificity phosphatase-1 (also called MKP-1, DUSP1, ERP, CL100, HVH1, PTPN10, and 3CH134) is a member of the threonine-tyrosine dual-specificity phosphatases, one of more than 100 protein tyrosine phosphatases. It was first identified approximately 20 years ago, and since that time extensive investigations into both mkp-1 mRNA and protein regulation and function in different cells, tissues, and organs have been conducted. However, no general review on the topic of MKP-1 exists. As the subject matter pertaining to MKP-1 encompasses many branches of the biomedical field, we focus on the role of this protein in cancer development and progression, highlighting the potential role of the mitogen-activated protein kinase (MAPK) family. Section II of this article elucidates the MAPK family cross-talk. Section III reviews the structure of the mkp-1 encoding gene, and the known mechanisms regulating the expression and activity of the protein. Section IV is an overview of the MAPK-specific dual-specificity phosphatases and their role in cancer. In sections V and VI, mkp-1 mRNA and protein are examined in relation to cancer biology, therapeutics, and clinical studies, including a discussion of the potential role of the MAPK family. We conclude by proposing an integrated scheme for MKP-1 and MAPK in cancer.
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Affiliation(s)
- Tarek Boutros
- Department of Surgery, Royal Victoria Hospital, McGill University, 687 Pine Ave. W., Montreal, QC H3A1A1, Canada.
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105
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Wang X, Chen Y, Wang Y, Zhu X, Ma Y, Zhang S, Lu J. Role of RHOB in the antiproliferative effect of glucocorticoid receptor on macrophage RAW264.7 cells. J Endocrinol 2009; 200:35-43. [PMID: 18840672 DOI: 10.1677/joe-08-0340] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although glucocorticoid (GC) has been reported to inhibit macrophage killing activity and cytokine production in response to proinflammatory stimuli, the effect of GC on macrophage proliferation is controversial. In our previous study, we found that inhibition of glucocorticoid receptor (GR) expression in murine macrophage cell line RAW264.7 cells (RAW-GR(-) cells) by RNAi significantly promoted cell proliferation. In the present study, we provide the evidence that the expression of Rhob, a member of Rho GTPases with anti-cancer character, remarkably decreased in RAW-GR(-) and RAW264.7 cells transiently transfected with GR-RNAi vector. Overexpression or constitutive activation of Rhob in RAW-GR(-) and RAW264.7 cells by transfection with wild-type Rhob expression vector (Rhob-wt) or constitutively activated Rhob plasmid (Rhob-V14) resulted in decreased proliferation of the two cell lines. Oppositely, the proliferation of RAW264.7 cells was significantly increased when the expression of Rhob by RNA interference technique or the activity of Rhob by transfection with dominant negative Rhob mutant that is defective in nucleotide binding (Rhob-N19) was inhibited. In addition, enhanced activity of Akt, but not MAPK3/1 or MAPK14, was found in RAW-GR(-) cells. Blocking the pathway of phosphatidylinositol 3-kinase (PI3K)/Akt with the specific inhibitor LY294002 decreased the proliferation and elevated RHOB protein level, indicating that PI3K/Akt signal plays its role of proliferation modulation upstream of RHOB protein. In conclusion, these results demonstrate that Rhob plays an important role in the antiproliferative effect of GR on RAW264.7 cells by GR-->Akt-->Rhob signaling and Rhob negatively regulates the proliferation of RAW264.7 cells.
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Affiliation(s)
- Xiaohui Wang
- Department of Pathophysiology, Second Military Medical University, Shanghai, People's Republic of China
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106
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Yu H, Higa F, Koide M, Haranaga S, Yara S, Tateyama M, Li H, Fujita J. Lung abscess caused by Legionella species: implication of the immune status of hosts. Intern Med 2009; 48:1997-2002. [PMID: 19952481 DOI: 10.2169/internalmedicine.48.2647] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Legionella pneumonia typically presents as lobar pneumonia with multiple-lobe involvement, but Legionella lung abscess is rare. To identify the predisposing factors for Legionella abscess, we analyzed 62 of the 79 case reports on Legionella abscess found in literature; 28 (45.2%) were of hospital-acquired infection and 28 (45.2%), community-acquired infection. Seventeen patients (27.4%) died. L. pneumophila serogroup 1 was the most common, but other serogroups of L. pneumophila, L. micdadei, L. bozemanii, L. dumoffii, and L. maceachernii were also isolated from the abscess. Corticosteroids were administered for underlying diseases to 43 (69.4%) patients. Peripheral neutrophil counts were higher in patients with abscess than in those with only pulmonary infiltration. In certain cases, Legionella abscess developed during neutropenia recovery. However, lymphocyte counts were low in most cases. Clinical factors like corticosteroid treatment, which causes impaired cellular immunity and subsequent neutrophil accumulation in the lesion, might function as predisposing factors for Legionella abscess.
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Affiliation(s)
- Hui Yu
- Department of Medicine and Therapeutics, Control and Prevention of Infectious Diseases (First Department of Internal Medicine), Faculty of Medicine, University of the Ryukyus, Okinawa, China
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107
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Abstract
Pharmacogenetics covers the genetic variation affecting pharmacokinetics and pharmacodynamics, and their influence on drug-response phenotypes. The genetic variation includes an estimated 15 million single nucleotide polymorphisms (SNPs) and is a key determinator for the interindividual differences in treatment resistance and toxic side effects. As most childhood acute lymphoblastic leukemia treatment protocols include up to 13 different chemotherapeutic agents, the impact of individual SNPs has been difficult to evaluate. So far focus has mainly been on the widely used glucocorticosteroids, methotrexate, and thiopurines, or on metabolic pathways and transport mechanisms that are common to several drugs, such as the glutathione S-transferases. However, beyond the thiopurine methyltransferase polymorphisms, the candidate-gene approach has not established clear associations between polymorphisms and treatment response. In the future, high-throughput, low-cost, genetic platforms will allow screening of hundreds or thousands of targeted SNPs to give a combined gene-dosage effect (=individual SNP risk profile), which may allow pharmacogenetic-based individualization of treatment.
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108
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Schmiegelow K, Vestergaard T, Nielsen SM, Hjalgrim H. Etiology of common childhood acute lymphoblastic leukemia: the adrenal hypothesis. Leukemia 2008; 22:2137-41. [PMID: 18719616 DOI: 10.1038/leu.2008.212] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pattern of infections in the first years of life modulates our immune system, and a low incidence of infections has been linked to an increased risk of common childhood acute lymphoblastic leukemia (ALL). We here present a new interpretation of these observations--the adrenal hypothesis--that proposes that the risk of childhood ALL is reduced when early childhood infections induce qualitative and quantitative changes in the hypothalamus-pituitary-adrenal axis that increase plasma cortisol levels. This may directly eliminate leukemic cells as well as preleukemic cells for the ALL subsets that dominate in the first 5-7 years of life and may furthermore suppress the Th1-dominated proinflammatory response to infections, and thus lower the proliferative stress on pre-existing preleukemic cells.
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Affiliation(s)
- K Schmiegelow
- The Pediatric Clinic, The University Hospital Rigshospitalet, Copenhagen, Denmark.
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109
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Pew T, Zou M, Brickley DR, Conzen SD. Glucocorticoid (GC)-mediated down-regulation of urokinase plasminogen activator expression via the serum and GC regulated kinase-1/forkhead box O3a pathway. Endocrinology 2008; 149:2637-45. [PMID: 18239069 PMCID: PMC2329267 DOI: 10.1210/en.2007-1096] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The glucocorticoid receptor (GR) and its ligand, cortisol, play a central role in human physiology. The exact mechanisms by which GR activation regulates these processes are the subject of intensive investigation. We and others have shown that GR activation can indirectly down-regulate specific genes via serum and glucocorticoid (GC) regulated kinase-1-mediated inhibition of forkhead box O3a (FOXO3a) transcriptional activity. We previously used gene expression microarrays, together with bioinformatic analyses, to identify putative FOXO3a target genes in breast epithelial cells. In this paper we refine our analysis through the use of FOXO3a chromatin immunoprecipitation (ChIP) microarrays. ChIP microarray results reveal urokinase plasminogen activator (uPA) as a putative novel target of FOXO3a in breast epithelial and breast cancer cell lines. We further show that uPA down-regulation after GC treatment requires serum and GC regulated kinase-1-mediated inactivation of FOXO3a activity. ChIP and luciferase assays confirm that FOXO3a can both occupy and transactivate the uPA promoter. Our data suggest that inactivation of FOXO3a after GR activation is an important mechanism contributing to GC-mediated repression of uPA gene expression in breast epithelial and cancer cells.
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Affiliation(s)
- Travis Pew
- Department of Medicine and Committee on Cancer Biology, University of Chicago, 5841 South Maryland Avenue, MC 2115, Chicago, Illinois 60637, USA
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110
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Gupta V, Wagner BJ. Search for a functional glucocorticoid receptor in the mammalian lens. Exp Eye Res 2008; 88:248-56. [PMID: 18541233 DOI: 10.1016/j.exer.2008.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 03/29/2008] [Accepted: 04/07/2008] [Indexed: 10/22/2022]
Abstract
Prolonged glucocorticoid treatment of medical conditions such as rheumatoid arthritis or asthma can lead to the formation of a posterior subcapsular cataract as a negative side effect. Currently, the only treatment for this cataract is surgery because very little is known about the mechanism of glucocorticoid action in the mammalian lens. Understanding of a lens glucocorticoid response is essential for the treatment and prevention of a steroid induced cataract. It has been suggested that glucocorticoids exert their effects on the lens indirectly, non-specifically, or through non-classical mechanisms. While these modes of action may contribute to the formation of glucocorticoid induced posterior subcapsular cataract, the finding of a classical, specific, functional lens glucocorticoid receptor suggests that glucocorticoids target lens epithelial cells directly, specifically, and similar to what has been observed in other cells types. This review explores the discovery of the glucocorticoid receptor in humans lens epithelial cells and the lens specific glucocorticoid response. The distinct changes in lens epithelial cell signaling pathways (MAPK and PI3K-AKT) suggest that glucocorticoids modulate several cellular functions and may explain why a lens glucocorticoid response has been difficult to elucidate.
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Affiliation(s)
- Vanita Gupta
- Department of Pathology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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111
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Davis MC, McColl KS, Zhong F, Wang Z, Malone MH, Distelhorst CW. Dexamethasone-induced inositol 1,4,5-trisphosphate receptor elevation in murine lymphoma cells is not required for dexamethasone-mediated calcium elevation and apoptosis. J Biol Chem 2008; 283:10357-65. [PMID: 18272518 DOI: 10.1074/jbc.m800269200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Glucocorticosteroid hormones, including dexamethasone, have diverse effects on immature lymphocyte function that ultimately lead to cell death. Previous studies established that glucocorticoid-induced alterations in intracellular calcium homeostasis promote apoptosis, but the mechanism by which glucocorticoids disrupt calcium homeostasis is unknown. Through gene expression array analysis, we found that dexamethasone induces a striking elevation of inositol 1,4,5-trisphosphate receptor (IP(3)R) levels in two murine lymphoma cell lines, WEHI7.2 and S49.A2. IP(3)R elevation was confirmed at both mRNA and protein levels. However, there was not a strong correlation between IP(3)R elevation and altered calcium homeostasis in terms of either kinetics or dose response. Moreover, IP(3)R knockdown, by either antisense or small interfering RNA, did not prevent either calcium disruption or apoptosis. Finally, DT40 lymphoma cells lacking all three IP(3)R isoforms were just as sensitive to dexamethasone-induced apoptosis as wild-type DT40 cells expressing all three IP(3)R isoforms. Thus, although alterations in intracellular calcium homeostasis contribute to glucocorticoid-induced apoptosis, these calcium alterations are not directly attributable to IP(3)R elevation.
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Affiliation(s)
- Michael C Davis
- Division of Hematology/Oncology, Departments of Medicine and Pharmacology, Comprehensive Cancer Center, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio 44106, USA
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112
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Ploner C, Rainer J, Niederegger H, Eduardoff M, Villunger A, Geley S, Kofler R. The BCL2 rheostat in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia. Leukemia 2008; 22:370-7. [PMID: 18046449 PMCID: PMC4950962 DOI: 10.1038/sj.leu.2405039] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glucocorticoid (GC)-induced apoptosis is essential in the treatment of acute lymphoblastic leukemia (ALL) and related malignancies. Pro- and anti-apoptotic members of the BCL2 family control many forms of apoptotic cell death, but the extent to which this survival 'rheostat' is involved in the beneficial effects of GC therapy is not understood. We performed systematic analyses of expression, GC regulation and function of BCL2 molecules in primary ALL lymphoblasts and a corresponding in vitro model. Affymetrix-based expression profiling revealed that the response included regulations of pro-apoptotic and, surprisingly, anti-apoptotic BCL2 family members, and varied among patients, but was dominated by induction of the BH3-only molecules BMF and BCL2L11/Bim and repression of PMAIP1/Noxa. Conditional lentiviral gene overexpression and knock-down by RNA interference in the CCRF-CEM model revealed that induction of Bim, and to a lesser extent that of BMF, was required and sufficient for apoptosis. Although anti-apoptotic BCL2 members were not regulated consistently by GC in the various systems, their overexpression delayed, whereas their knock-down accelerated, GC-induced cell death. Thus, the combined clinical and experimental data suggest that GCs induce both pro- and anti-apoptotic BCL2 family member-dependent pathways, with the outcome depending on cellular context and additional signals feeding into the BCL2 rheostat.
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Affiliation(s)
- C Ploner
- Division Molecular Pathophysiology, Department Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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113
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Malam Z, Marshall JC. Apoptosis in Critical Illness: A Primer for the Intensivist. Intensive Care Med 2008. [PMCID: PMC7121320 DOI: 10.1007/978-0-387-77383-4_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The complexities of the cell cycle have occupied a prominent place in the history of cellular biology. Recognition of the process of mitosis dates back over a century, when Fol, Butschli, and Strasburger identified a network of intracellular points and lines, then called the karyokinetic figure, and today known as the mitotic apparatus. This discovery, dating to 1873, laid the foundation for the discovery of chromosomes and, later, the fundamental biologic processes of mitosis and meiosis [1]. But, while cellular growth and proliferation were understood to be essential to the emergence of multicellular organisms, the corollary — that controlled cell death must be part of this calculus of cellular homeostasis — was not appreciated until quite recently. Although cell death was first described in 1859 by Virchow, it took more than a century to appreciate the importance of programmed cell death as a physiological process that eliminated unwanted cells [2]. The term ‘apoptosis’ was coined in 1972 by Kerr, Wyllie, and Currie to describe a distinct type of cell death characterized by the degradation of cellular constituents into membrane-bound apoptotic bodies [3]. Since then, recognition of the importance of apoptosis in health and disease, and an understanding of its cellular mechanisms, has increased exponentially.
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114
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Malam Z, Marshall JC. Apoptosis in Critical Illness: A Primer for the Intensivist. YEARBOOK OF INTENSIVE CARE AND EMERGENCY MEDICINE 2008. [PMCID: PMC7123183 DOI: 10.1007/978-3-540-77290-3_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The complexities of the cell cycle have occupied a prominent place in the history of cellular biology. Recognition of the process of mitosis dates back over a century, when Fol, Butschli, and Strasburger identified a network of intracellular points and lines, then called the karyokinetic figure, and today known as the mitotic apparatus. This discovery, dating to 1873, laid the foundation for the discovery of chromosomes and, later, the fundamental biologic processes of mitosis and meiosis [1]. But, while cellular growth and proliferation were understood to be essential to the emergence of multicellular organisms, the corollary — that controlled cell death must be part of this calculus of cellular homeostasis — was not appreciated until quite recently. Although cell death was first described in 1859 by Virchow, it took more than a century to appreciate the importance of programmed cell death as a physiological process that eliminated unwanted cells [2]. The term ‘apoptosis’ was coined in 1972 by Kerr, Wyllie, and Currie to describe a distinct type of cell death characterized by the degradation of cellular constituents into membrane-bound apoptotic bodies [3]. Since then, recognition of the importance of apoptosis in health and disease, and an understanding of its cellular mechanisms, has increased exponentially.
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115
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Hail N, Carter BZ, Konopleva M, Andreeff M. Apoptosis effector mechanisms: a requiem performed in different keys. Apoptosis 2007; 11:889-904. [PMID: 16547589 DOI: 10.1007/s10495-006-6712-8] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Apoptosis is the regulated form of cell death utilized by metazoans to remove unneeded, damaged, or potentially deleterious cells. Certain manifestations of apoptosis may be associated with the proteolytic activity of caspases. These changes are often held as hallmarks of apoptosis in dying cells. Consequently, many regard caspases as the central effectors or executioners of apoptosis. However, this "caspase-centric" paradigm of apoptotic cell death does not appear to be as universal as once believed. In fact, during apoptosis the efficacy of caspases may be highly dependent on the cytotoxic stimulus as well as genetic and epigenetic factors. An ever-increasing number of studies strongly suggest that there are effectors in addition to caspases, which are important in generating apoptotic signatures in dying cells. These seemingly caspase-independent effectors may represent evolutionarily redundant or failsafe mechanisms for apoptotic cell elimination. In this review, we will discuss the molecular regulation of caspases and various caspase-independent effectors of apoptosis, describe the potential context and/or limitations of these mechanisms, and explore why the understanding of these processes may have relevance in cancer where treatment is believed to engage apoptosis to destroy tumor cells.
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Affiliation(s)
- N Hail
- Department of Clinical Pharmacy, School of Pharmacy, Denver and Health Sciences Center, The University of Colorado, Denver, CO 80262, USA
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116
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Activation of Cdc2 contributes to apoptosis in HPV E6 expressing human keratinocytes in response to therapeutic agents. J Mol Biol 2007; 374:334-45. [PMID: 17936297 DOI: 10.1016/j.jmb.2007.09.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2007] [Revised: 09/01/2007] [Accepted: 09/09/2007] [Indexed: 12/18/2022]
Abstract
Infection with human papillomaviruses (HPV) is strongly associated with the development of cervical cancer. The HPV E6 oncogene induces apoptosis in cervical cancer precursor lesions but the mechanism is poorly understood. While it is expected that inactivation of p53 by E6 should lead to a reduction in apoptosis, E6 also sensitizes cells to apoptosis under some experimental conditions. Here, we demonstrate that expression of E6 in human keratinocytes rendered sensitization to chemotherapeutic agents. The cell death was shown to be by apoptosis involving caspase activation and the mitochondria pathway. To explore mechanisms involved in sensitization of E6 expressing cells to apoptosis, we used a proteomic approach to identify proteins differentially expressed in E6 expressing and control keratinocytes. Among nearly a thousand proteins examined, Cdc2 was demonstrated to be the most dramatically up-regulated protein in E6 expressing cells. p53 degradation appears to be important for the up-regulation of Cdc2 by E6. Using genetic, pharmacologic, and siRNA strategies, a role for Cdc2 in E6 expression-conferred apoptosis was demonstrated. Thus, these results have important therapeutic implications in enhancing the efficacy of chemotherapy.
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117
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Amaral JD, Solá S, Steer CJ, Rodrigues CP. Function of nuclear steroid receptors in apoptosis: role of ursodeoxycholic acid. Expert Rev Endocrinol Metab 2007; 2:487-501. [PMID: 30290423 DOI: 10.1586/17446651.2.4.487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Nuclear steroid receptors such as the glucocorticoid and the mineralocorticoid receptors modulate apoptosis in different cell types through transactivation-dependent and -independent mechanisms. They are involved in both the induction and prevention of apoptosis depending on cell type. However, it is unclear how nuclear steroid receptors can affect expression of the same gene in opposing ways for different cells. In addition to their function as modulators of gene expression, nuclear steroid receptors often act as nuclear transporters of other regulatory molecules, thus indirectly regulating several apoptosis-related genes. Curiously, nuclear steroid receptors are thought to cooperate with the antiapoptotic endogenous bile acid, ursodeoxycholic acid, to prevent programmed cell death. The next decade will almost certainly unveil the remarkable role of nuclear steroid receptors in modulating the life and death struggle of cells and organ systems in human development and function.
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Affiliation(s)
- Joana D Amaral
- a Research Institute for Medicines & Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
| | - Susana Solá
- b Research Institute for Medicines & Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
| | - Clifford J Steer
- c Departments of Medicine, & Genetics, Cell Biology, & Development, University of Minnesota Medical School, Minneapolis, MN, USA.
| | - Cecília P Rodrigues
- d Research Institute for Medicines & Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon, Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
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118
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Manoli I, Alesci S, Blackman MR, Su YA, Rennert OM, Chrousos GP. Mitochondria as key components of the stress response. Trends Endocrinol Metab 2007; 18:190-8. [PMID: 17500006 DOI: 10.1016/j.tem.2007.04.004] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 04/02/2007] [Accepted: 04/30/2007] [Indexed: 02/09/2023]
Abstract
The exquisitely orchestrated adaptive response to stressors that challenge the homeostasis of the cell and organism involves important changes in mitochondrial function. A complex signaling network enables mitochondria to sense internal milieu or environmental changes and to adjust their bioenergetic, thermogenic, oxidative and/or apoptotic responses accordingly, aiming at re-establishment of homeostasis. Mitochondrial dysfunction is increasingly recognized as a key component in both acute and chronic allostatic states, although the extent of its role in the pathogenesis of such conditions remains controversial. Genetic and environmental factors that determine mitochondrial function might contribute to the significant variation of the stress response. Understanding the often reciprocal interplay between stress mediators and mitochondrial function is likely to help identify potential therapeutic targets for many stress and mitochondria-related pathologies.
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Affiliation(s)
- Irini Manoli
- Human Biochemical Genetics Section, MGB, NHGRI, NIH, Bethesda, MD 20892, USA.
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119
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Voutsas IF, Gritzapis AD, Alexis MN, Katsanou ES, Perez S, Baxevanis CN, Papamichail M. A novel quantitative flow cytometric method for measuring glucocorticoid receptor (GR) in cell lines: correlation with the biochemical determination of GR. J Immunol Methods 2007; 324:110-9. [PMID: 17582432 DOI: 10.1016/j.jim.2007.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 04/11/2007] [Accepted: 05/11/2007] [Indexed: 01/01/2023]
Abstract
Currently, a time consuming biochemical method is used for GR quantification. Here we compare the biochemical approach with a newly developed flow cytometric method of measuring GR in cell lines, which is less time consuming and does not requires the use of radioactive materials. The biochemical assay is easy to apply but the cells need to be grown in media free of endogenous glucocorticoids, in order to prevent them from interfering with radiolabelled hormone binding to the receptor. The presence of endogenous GR ligands is known to reduce receptor levels and to often produce false negative results. The immunofluorescent method is free of such limitations, as it depends entirely on detecting the receptor using a highly specific monoclonal antibody. Additionally, the biochemical assay cannot measure heterogeneity in individual cells, in contrast the flow cytometric one enables the enumeration of the receptor on a per cell basis, allowing exact description of differences in receptor levels amongst intact cells. Our results demonstrate that the flow cytometric method is of similar accuracy but of higher precision compared to the biochemical one. Also, the data we obtained using the immunofluorescent method correlated well with the biochemical one (R(2)=0.9712). In conclusion, flow cytometric method requires small cell numbers, is more accurate and lesser time consuming than the biochemical one. Thus, it could be useful for the quantification of GR in lymphocyte subpopulations, in lymphoproliferative disorders and in tumor cells from cancer patients, in order to design more efficient clinical treatment protocols.
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Affiliation(s)
- Ioannis F Voutsas
- Cancer Immunology and Immunotherapy Center, Saint Savvas Cancer Hospital, 171 Alexandras Ave., 11522 Athens, Greece.
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120
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Herr I, Gassler N, Friess H, Büchler MW. Regulation of differential pro- and anti-apoptotic signaling by glucocorticoids. Apoptosis 2007; 12:271-91. [PMID: 17191112 DOI: 10.1007/s10495-006-0624-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
More than a quarter of a century ago, the phenomenon of glucocorticoid-induced apoptosis in the majority of hematological cells was first recognized. More recently, glucocorticoid-induced antiapoptotic signaling associated with apoptosis resistance has been identified in cells of epithelial origin, most of malignant solid tumors and some other tissues. Despite these huge amount of data demonstrating differential pro- and anti-apoptotic effects of glucocorticoids, the underlying mechanisms of cell type specific glucocorticoid signaling are just beginning to be described. This review summarizes our present understanding of cell type-specific pro- and anti-apoptotic signaling induced by glucocorticoids. In the first section we give a summary and update of known glucocorticoid-induced pathways mediating apoptosis in hematological cells. We shortly introduce mechanisms of glucocorticoid resistance of hematological cells. We highlight and discuss the emerging molecular evidence of a general induction of survival signaling in epithelial cells and carcinoma cells by glucocorticoids. We provide a model for glucocorticoid-induced resistance in cells growing in a tissue formation. Thus, attachment to the extracellular matrix and cell-cell contacts typical for e.g. epithelial and tumor cells may be crucially involved in switching the balance of several interacting pathways to survival upon treatment with glucocorticoids.
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Affiliation(s)
- Ingrid Herr
- Department of Surgery, University of Heidelberg, Heidelberg, Germany.
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121
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Baken KA, Arkusz J, Pennings JLA, Vandebriel RJ, van Loveren H. In vitro immunotoxicity of bis(tri-n-butyltin)oxide (TBTO) studied by toxicogenomics. Toxicology 2007; 237:35-48. [PMID: 17553608 DOI: 10.1016/j.tox.2007.04.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 04/24/2007] [Accepted: 04/27/2007] [Indexed: 11/19/2022]
Abstract
The biocide and environmental pollutant bis(tri-n-butyltin)oxide (TBTO) causes thymus atrophy in rodents. Whether the depletion of thymic lymphocytes by tributyltin compounds may be the result of inhibition of cell proliferation or induction of apoptosis is subject of debate. We examined gene expression profiles in primary rat thymocytes exposed to TBTO in vitro at dose levels of 0, 0.1, 0.3, 0.5, and 1.0microM. By measuring cell viability and apoptosis, exposure conditions were selected that would provide information on changes in gene expression preceding or accompanying functional effects of TBTO. Several processes related to TBTO-induced toxicity were detected at the transcriptome level. Effects on lipid metabolisms appeared to be the first indication of disruption of cellular function. Many transcriptional effects of TBTO at higher dose levels were related to apoptotic processes, which corresponded to present or subsequent thymocyte apoptosis observed phenotypically. The gene expression profile was, however, not unambiguous since expression of apoptosis-related genes was both increased and decreased. Stimulation of glucocorticoid receptor signaling appeared to be a relevant underlying mechanism of action. These findings suggest that TBTO exerts its toxic effects on the thymus primarily by affecting apoptotic processes, but the possibility is discussed that this may in fact represent an early effect that precedes inhibition of cell proliferation. At the highest dose level tested, TBTO additionally repressed mitochondrial function and immune cell activation. Our in vitro toxicogenomics approach thus identified several cellular and molecular targets of TBTO that may mediate the toxicity towards thymocytes and thereby its immunosuppressive effects.
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Affiliation(s)
- Kirsten A Baken
- Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Health Risk Analysis and Toxicology (GRAT), Maastricht University, Maastricht, The Netherlands; National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands.
| | - Joanna Arkusz
- Nofer Institute of Occupational Medicine, Department of Toxicology and Carcinogenesis, Lodz, Poland
| | - Jeroen L A Pennings
- National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands
| | - Rob J Vandebriel
- National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands
| | - Henk van Loveren
- Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Health Risk Analysis and Toxicology (GRAT), Maastricht University, Maastricht, The Netherlands; National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands
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122
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Jetzek-Zader M, Gudowius S, Feyen O, Stevens M, Lipfert P, Niehues T. A single intravenous dose of prednisolone induces phosphatidylserine externalization, loss of surface marker expression and a 24-h net increase in human peripheral blood lymphocytes ex vivo. Rheumatol Int 2007; 27:667-73. [PMID: 17333196 DOI: 10.1007/s00296-007-0319-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Accepted: 12/31/2006] [Indexed: 11/30/2022]
Abstract
To understand how corticosteroids act; a characterization of their effects on lymphocytes is necessary. The effect of in vivo corticosteroids on lymphocyte subpopulations, their surface molecules and externalization of phosphatidylserine (apoptosis) is examined. In a crossover study, a single, intravenous dose of 2 mg/kg prednisolone or saline was given to six male adult human volunteers. Blood samples were withdrawn before and 30 min, 2, 5, 23 and 29 h thereafter. Lymphocyte subsets were determined by FACS analysis. Externalization of phosphatidylserine was measured by Annexin-V; cell fragments were excluded by propidium iodide staining. Lymphocyte number decreased from 2,007 +/- 473 to 634 +/- 119 microl after 5 h and rose to 3,112 +/- 436 microl after 23 h. CD4, CD8 and B cell counts declined significantly after 5 h (P < or = 0.01). The expression of CD28 or CD95 on T cells and the natural killer cells were unaffected. There was a significant rebound of lymphocyte numbers above baseline 23 h after prednisolone. At baseline 9.9 +/- 3.8% of cells in the lymphocyte gate did not stain for CD3, CD20 or CD56 (referred to as "null cells"). 5 h after application of prednisolone, there was a significant increase of "null cells" (28 +/- 12%, P = 0.018). The percentage of phosphatidylserine positive CD4 cells rose from 8.1 +/- 3.3 to 19.8 +/- 8% after intravenous prednisolone, while the percentage of phosphatidylserine positive CD8, B and NK cells remained largely unchanged. Prednisolone induces a most significant depletion of CD4 cells, which to some degree is associated with apoptosis. The net increase of lymphocyte numbers 23 h after prednisolone application may be a beneficial late effect of a single i.v. prednisolone shot.
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Affiliation(s)
- Martin Jetzek-Zader
- Department of Anaesthesiology, UKD, Heinrich Heine University, Düsseldorf, Germany
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123
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Stratta P, Canavese C, Fenoglio R, Priolo G, Grillo A, Aimo G, Quaglia M, Pagni R. Dual effect of methylprednsolone pulses on apoptosis of peripheral leukocytes in patients with renal diseases. Int J Immunopathol Pharmacol 2006; 19:647-59. [PMID: 17026850 DOI: 10.1177/039463200601900321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
It is well known that change in apoptosis may modulate the natural story of illness, and that many drugs may act through modulation of apoptosis, but the role of steroids in acting through apoptosis in different settings, including renal diseases, has still to be elucidated. We studied the in vivo effects of steroids by oral assumption (10 to 25 mg/deltacortene) or by intravenous pulses (300 to 1000 mg/dose) on apoptosis and cellular subsets of peripheral lymphocytes, by evaluating DNA-fragmentation and lymphocyte subsets in 79 subjects: 22 controls and 57 patients with various renal diseases (25 Lupus-GN, 19 membranous-GN (MGN), 6 rapidly progressive-GN (RPGN), 2 acute interstitial nephritis (AIN), 5 on chronic dialysis. Baseline apoptosis was present in 1/22 (4.5%) of controls, 3/25 (12%) SLE, 2/6 (33.3%) RPGN and 10/19 (52.6%) MGN. A significant decrease in CD3+CD8+ cell count and a significant increase of the CD3+CD4/CD3+CD8+ ratio were found in apoptosis-positive subjects. DNA fragmentation did not change after oral steroids, paralleling a 22 to 32% decrease in total lymphocytes. Following intravenous methylprednisolone pulses, a deeper drop of all lymphocyte subsets was observed, while DNA fragmentation turned from present to absent in 2 MGN, but not in 2 RPGN, and from absent to present in 1 ARF and 1 SLE, independently of the dosage. We demonstrated that the presence of apoptosis in renal diseases is associated with decreased CD3+CD8+ cell count. Furthermore, steroid intravenous pulses, besides inducing a profound decrease in lymphocyte subsets, do exert a dual effect on baseline leukocyte apoptosis, eventually leading to a reversal of baseline patterns, either turning from negative to positive or from positive to negative. Oral steroid therapy did not influence baseline apoptosis.
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Affiliation(s)
- P Stratta
- Nephrology and Transplantation, Amedeo Avogadro University, Maggiore Hospital and Interdisciplinary Research Centre of Autoimmune Diseases (IRCAD) Novara, Italy.
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124
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Tanaka T, Okabe T, Gondo S, Fukuda M, Yamamoto M, Umemura T, Tani K, Nomura M, Goto K, Yanase T, Nawata H. Modification of glucocorticoid sensitivity by MAP kinase signaling pathways in glucocorticoid-induced T-cell apoptosis. Exp Hematol 2006; 34:1542-52. [PMID: 17046574 DOI: 10.1016/j.exphem.2006.06.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 06/13/2006] [Accepted: 06/27/2006] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Glucocorticoid is widely used for the treatment of diseases such as hematological malignancies. Glucocorticoid sensitivity is different from person to person and the mechanism of the regulation of glucocorticoid sensitivity is not well known. Glucocorticoid resistance is a major clinical problem. METHODS AND RESULTS Here, using glucocorticoid-induced T-cell apoptosis, a model system for the analysis of the mechanism of glucocorticoid action, we clarified that mitogen-activated protein kinases (MAPKs) modify glucocorticoid sensitivity, namely that the activation of extracellular signal-regulated protein kinase (ERK) and p38 MAP kinase reduce and enhance glucocorticoid sensitivity, respectively. CONCLUSION These findings might provide new tools for overcoming glucocorticoid-resistance.
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Affiliation(s)
- Tomoko Tanaka
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan
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125
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Schmidt S, Irving JAE, Minto L, Matheson E, Nicholson L, Ploner A, Parson W, Kofler A, Amort M, Erdel M, Hall A, Kofler R. Glucocorticoid resistance in two key models of acute lymphoblastic leukemia occurs at the level of the glucocorticoid receptor. FASEB J 2006; 20:2600-2. [PMID: 17077285 DOI: 10.1096/fj.06-6214fje] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Glucocorticoids (GCs) specifically induce apoptosis in malignant lymphoblasts and are thus pivotal in the treatment of acute lymphoblastic leukemia (ALL). However, GC-resistance is a therapeutic problem with an unclear molecular mechanism. We generated approximately 70 GC-resistant sublines from a GC-sensitive B- and a T-ALL cell line and investigated their mechanisms of resistance. In response to GCs, all GC-resistant subclones analyzed by real-time polymerase chain reaction (PCR) showed a deficient up-regulation of the GC-receptor (GR) and its downstream target, GC-induced leucine zipper. This deficiency in GR up-regulation was confirmed by Western blotting and on retroviral overexpression of GR in resistant subclones GC-sensitivity was restored. All GC-resistant subclones were screened for GR mutations using denaturing high-pressure liquid chromatography (DHPLC), DNA-fingerprinting, and fluorescence in situ hybridization (FISH). Among the identified mutations were some previously not associated with GC resistance: A484D, P515H, L756N, Y663H, L680P, and R714W. This approach revealed three genotypes, complete loss of functional GR in the mismatch repair deficient T-ALL model, apparently normal GR genes in B-ALLs, and heterozygosity in both. In the first genotype, deficiency in GR up-regulation was fully explained by mutational events, in the second by a putative regulatory defect, and in the third by a combination thereof. In all instances, GC-resistance occurred at the level of the GR in both models.
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Affiliation(s)
- Stefan Schmidt
- Tyrolean Cancer Research Institute, Innrain 66, A-6020 Innsbruck, Austria.
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126
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Petrella A, Ercolino SF, Festa M, Gentilella A, Tosco A, Conzen SD, Parente L. Dexamethasone inhibits TRAIL-induced apoptosis of thyroid cancer cells via Bcl-xL induction. Eur J Cancer 2006; 42:3287-93. [PMID: 17070682 DOI: 10.1016/j.ejca.2006.07.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 07/25/2006] [Indexed: 11/21/2022]
Abstract
We have investigated the effect of dexamethasone (DEX) on the apoptosis induced by TRAIL (tumour necrosis factor-related apoptosis inducing ligand) in follicular undifferentiated thyroid (FRO) cancer cells. Apoptosis was measured by percent hypodiploid nuclei, caspase-3 and -8 activation, and mitochondrial membrane depolarisation. DEX nearly abolished TRAIL-induced apoptosis. The DEX protective effect was reverted by the steroid receptor antagonist RU486 suggesting that the DEX action is mediated by glucocorticoid receptor (GR) activation. The role of Bcl proteins in the DEX effect was then investigated. In FRO cells DEX stimulated in a time-dependent fashion the expression of Bcl-xL, but not that of Bcl-2, Bax and Bad. In addition, Bcl-xL mRNA was significantly increased in the presence of DEX, suggesting a transcriptional regulation by the steroid. Transfection of the cells with siRNAs against Bcl-xL inhibited both basal and DEX-stimulated Bcl-xL expression and restored apoptosis in TRAIL-stimulated cells treated with DEX. These results demonstrate that dexamethasone protects thyroid cancer cells from apoptosis induced by TRAIL. DEX acts via GR activation and up-regulation of the expression of the anti-apoptotic protein Bcl-xL.
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Affiliation(s)
- Antonello Petrella
- Department of Pharmaceutical Sciences, University of Salerno, Via Ponte Don Melillo, 84084 Fisciano, Salerno, Italy
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127
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Adişen E, Gülekon A, Erdem O, Dursun A, Gürer MA. The effects of calcipotriol and methylprednisolone aseponate on bcl-2, p53 and ki-67 expression in psoriasis. J Eur Acad Dermatol Venereol 2006; 20:527-33. [PMID: 16684279 DOI: 10.1111/j.1468-3083.2006.01508.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE The decrease of physiological apoptosis in the psoriatic lesions is thought to be involved in the pathogenesis of psoriasis, and induction of apoptosis was shown to contribute to the regression of psoriatic hyperplasia. In the present study, we compared the effects of calcipotriol and methylprednisolone aseponate (MPA) treatments on bcl-2, p53 and ki-67 expressions in psoriatic patients in order to define a relationship between regulation of apoptosis and healing process in psoriasis. METHODS Thirty psoriatic patients with stable and moderate chronic plaque psoriasis applied either calcipotriol or MPA ointment for 6 weeks twice daily. Evaluation of bcl-2, p53 and ki-67 positivity was performed at baseline and was repeated at sixth week for each therapy. RESULTS The mean percentage of positive keratinocytes was 8.63 +/- 7.15% for p53, 20.66 +/- 14.45% for ki-67, and 3.74 +/- 2.83% for bcl-2 in psoriatic skin at baseline. Normal skin values were 3.27 +/- 3.21% for p53, 4.93 +/- 4.77% for ki-67, and 1.80 +/- 0.41% for bcl-2. The psoriatic skin showed higher ki-67 (P < 0.05) and bcl-2 (P < 0.05) expression rates when compared to normal skin. The p53 positivity observed in psoriatic skin and normal skin was not significantly different (P > 0.05). Following calcipotriol and MPA treatments, there was a significant reduction in p53 and ki-67 positivity accompanied by an increase in bcl-2 positivity (P < 0.05 each). No significant differences were found at sixth week between calcipotriol and MPA groups with respect to p53, ki-67 and bcl-2 positivity (P > 0.05). The post-treatment psoriatic skin showed lower expression of p53, higher expressions of ki-67 and bcl-2 when compared to normal skin (P < 0.05 each). CONCLUSION The results of this study provide evidence that both calcipotriol and MPA decrease the p53 and ki-67 expression and increase bcl-2 expression. However, it should further be elucidated if these changes were the common behaviour of psoriatic keratinocytes to any antipsoriatic medication.
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Affiliation(s)
- E Adişen
- Department of Dermatology, Gazi University Faculty of Medicine, Ankara, Turkey
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128
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Bianchini R, Nocentini G, Krausz LT, Fettucciari K, Coaccioli S, Ronchetti S, Riccardi C. Modulation of pro- and antiapoptotic molecules in double-positive (CD4+CD8+) thymocytes following dexamethasone treatment. J Pharmacol Exp Ther 2006; 319:887-97. [PMID: 16914556 DOI: 10.1124/jpet.106.108480] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glucocorticoids play a role in regulation of T lymphocytes homeostasis and development. In particular, glucocorticoid treatment induces massive apoptosis of CD4(+)CD8(+) double-positive (DP) thymocytes. This effect is due to many mechanisms, mainly driven by modulation of gene transcription. To find out which genes are modulated, we analyzed DP thymocytes treated for 3 h with dexamethasone (a synthetic glucocorticoid) by global gene expression profiling. Results indicate modulation of 163 genes, also confirmed by either RNase protection assay or real-time polymerase chain reaction. In particular, dexamethasone caused down-regulation of genes promoting DP thymocyte survival (e.g., Notch1, suppressor of cytokine signaling 1, and inhibitor of DNA binding 3) or modulation of genes activating cell death through the ceramide pathway (UDP-glucose ceramide glucosyltransferase, sphingosine 1-phosphate phosphatase, dihydroceramide desaturase, isoform 1, and G protein-coupled receptor 65) or through the mitochondrial machinery. Among the latter, there are Bcl-2 family members (Bim, Bfl-1, Bcl-xL, and Bcl-xbeta), genes involved in the control of redox status (thioredoxin reductase, thioredoxin reductase inhibitor, and NADP(+)-dependent isocitrate dehydrogenase) and genes belonging to Tis11 family that are involved in mRNA stability. Our study suggests that dexamethasone treatment of DP thymocytes modulates several genes belonging to apoptosis-related systems that can contribute to their apoptosis.
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Affiliation(s)
- Rodolfo Bianchini
- Dipartimento di Medicina Clinica e Sperimentale, Sezione di Farmacologia, Tossicologia e Chemioterapia, Università di Perugia, Istituto di Biotecnologie Trapiantologiche and Polo Scientifico e Didattico di Terni, Perugia, Italy
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129
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Tome ME, Johnson DBF, Samulitis BK, Dorr RT, Briehl MM. Glucose 6-phosphate dehydrogenase overexpression models glucose deprivation and sensitizes lymphoma cells to apoptosis. Antioxid Redox Signal 2006; 8:1315-27. [PMID: 16910779 DOI: 10.1089/ars.2006.8.1315] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glucocorticoids are one component of combined treatment regimens for many types of lymphoma due to their ability to induce apoptosis in lymphoid cells. In WEHI7.2 murine thymic lymphoma cells, altering catalase and glutathione peroxidase activity by transfection or the use of chemical agents modulates the ability of glucocorticoids to induce apoptosis. This suggests that the oxidative stress response is important in determining the glucocorticoid sensitivity of the cells. For glutathione peroxidase and catalase to detoxify reactive oxygen species (ROS), reducing equivalents in the form of nicotinamide adenine dinucleotide phosphate, reduced form (NADPH) are ultimately required. The major source of NADPH in the cell is glucose 6-phosphate dehydrogenase (G6PDH). Therefore, we created G6PDH-overexpressing WEHI7.2 variants to test whether G6PDH activity is a key determinant of glucocorticoid sensitivity in WEHI7.2 cells. G6PDH-overexpressing WEHI7.2 cells were more sensitive to oxidative stress and glucocorticoids. The G6PDH-overexpressing WEHI7.2 variants appeared similar to cells undergoing glucose deprivation with decreased adenosine triphosphate (ATP) synthesis by the mitochondria and increased basal levels of ROS. Overexpression of G6PDH also sensitized the cells to other standard lymphoma chemotherapeutics including cyclophosphamide, doxorubicin, and vincristine. The decreased ATP and elevated ROS due to G6PDH overexpression may be key factors in increasing the sensitivity of the WEHI7.2 cells to lymphoma chemotherapeutics.
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Affiliation(s)
- Margaret E Tome
- Department of Pathology, University of Arizona, Tucson, 85724, USA
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130
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Cima I, Fuhrer A, Brunner T. Antagonistic and synergistic effects of glucocorticoids and IL-7 on CD4+ T cell activation. Immunol Lett 2006; 106:99-102. [PMID: 16723155 DOI: 10.1016/j.imlet.2006.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 04/20/2006] [Accepted: 04/21/2006] [Indexed: 11/20/2022]
Abstract
Glucocorticoids (GCs) are steroidal compounds widely used to treat chronic and acute inflammatory diseases. In particular, GCs at pharmacological doses induce apoptosis of activated and naïve T cells, inhibit their proliferation and block pro-inflammatory cytokine secretion. At physiological concentrations, the effect of these steroids on T cell immunity are not yet fully understood, and various studies reported paradoxical roles exerted by GCs on T cell immunity. Here, we show that GCs surprisingly induce proliferation of activated CD4(+) T cells in the presence of IL-7, a cytokine secreted in the thymus and at mucosal sites. Increased proliferation is dependent on a GC-mediated survival of mitotic cells. Moreover, we observe a downmodulation of Th1 cytokine secretion in cells treated with GCs, an outcome which is not affected by the presence of IL-7. GCs exert thus a positive role in the presence of IL-7 by enhancing proliferation of CD4(+) T cells and simultaneously a negative role by suppressing pro-inflammatory cytokine production.
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Affiliation(s)
- Igor Cima
- Division of Immunopathology, Institute of Pathology, University of Bern, Switzerland
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131
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Kiank C, Holtfreter B, Starke A, Mundt A, Wilke C, Schütt C. Stress susceptibility predicts the severity of immune depression and the failure to combat bacterial infections in chronically stressed mice. Brain Behav Immun 2006; 20:359-68. [PMID: 16330179 DOI: 10.1016/j.bbi.2005.10.151] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 09/23/2005] [Accepted: 10/24/2005] [Indexed: 11/30/2022] Open
Abstract
Chronic psychological stress has been suggested to play a role in disorders in which the immune system unexpectedly fails to respond in a protective manner. Chronic combined acoustic and restraint stress compromises the anti-bacterial defense mechanisms of female BALB/c mice. The immunodeficiency is characterized by an apoptotic loss of lymphocytes, reduced ex vivo-inducibility of TNF but increased inducibility of IL10, reduced T-cell proliferation, and impaired phagocyte functions. Stressed mice develop depression-like behavior that was monitored by a stress severity score (SSS). Besides a strain (BALB/c>CBA) and gender (male>female) dependent susceptibility to chronic stress, inbred mice have an individual coping ability. Importantly, the individual SSS strongly correlates with Escherichia coli dissemination after infection as well as with IL10-inducibility and circulating corticosterone levels of each animal.
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Affiliation(s)
- C Kiank
- Department of Immunology, University of Greifswald, Germany
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132
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Sharabi A, Haviv A, Zinger H, Dayan M, Mozes E. Amelioration of murine lupus by a peptide, based on the complementarity determining region-1 of an autoantibody as compared to dexamethasone: Different effects on cytokines and apoptosis. Clin Immunol 2006; 119:146-55. [PMID: 16503419 DOI: 10.1016/j.clim.2006.01.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2005] [Revised: 01/02/2006] [Accepted: 01/14/2006] [Indexed: 11/25/2022]
Abstract
A peptide (hCDR1) based on the sequence of the complementarity-determining region-1 of an anti-DNA autoantibody ameliorates clinical manifestations of lupus. We analyzed the beneficial effects of hCDR1 when given alone or in combination with dexamethasone, while comparing the mechanisms of action of the latter. Treatment with either hCDR1 or dexamethasone, or a combination of the latter significantly reduced titers of dsDNA-specific autoantibodies, levels of proteinuria, and intensity of glomerular immune complex deposits. Both drugs down-regulated the secretion and expression of IFN-gamma and IL-10, but only treatment with hCDR1 up-regulated TGF-beta. While both drugs reduced the expression of Fas ligand (FasL) and caspase 8, treatment with hCDR1 resulted in reduced whereas dexamethasone administration resulted in increased rate of apoptosis. Furthermore, down-regulation of FasL appeared to play a role in cytokine modulation. We conclude that specific treatment with hCDR1 ameliorates murine lupus via distinct mechanisms of action than those of dexamethasone.
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Affiliation(s)
- Amir Sharabi
- Department of Immunology, The Weizmann Institute of Science, Rehovot 76100, Israel
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133
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Wang D, Müller N, McPherson KG, Reichardt HM. Glucocorticoids engage different signal transduction pathways to induce apoptosis in thymocytes and mature T cells. THE JOURNAL OF IMMUNOLOGY 2006; 176:1695-702. [PMID: 16424199 DOI: 10.4049/jimmunol.176.3.1695] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Glucocorticoids (GC) induce apoptosis in a variety of cells, but their exact mode of action is controversial. Although initiation relies on the GC receptor (GR) and de novo gene expression, the effector phase differs among cell types. Proteasomal degradation as well as caspase-3, - 8, and -9 activity are essential for GC-induced apoptosis in murine thymocytes, but the same enzymes are dispensable in splenic T cells. Live imaging by confocal microscopy revealed that lysosomal cathepsin B, an unrecognized component of this pathway to date, becomes rapidly activated in thymocytes after GC exposure. This is followed by leakage of cathepsin B into the cytosol, nuclear condensation, and processing of caspase-8 and -3. According to our model, activation of caspase-3 by caspase-9 in thymocytes occurs both directly as well as indirectly via a lysosomal amplification loop. Interestingly, acute T lymphoblastic leukemia cells depend on caspase activity to undergo GC-induced cell death similar to thymocytes. Collectively, the apoptotic program induced by GCs comprises cell type-specific as well as common features.
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Affiliation(s)
- Dapeng Wang
- Molecular Immunology, Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany
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134
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Zhang C, Kolb A, Büchler P, Cato ACB, Mattern J, Rittgen W, Edler L, Debatin KM, Büchler MW, Friess H, Herr I. Corticosteroid co-treatment induces resistance to chemotherapy in surgical resections, xenografts and established cell lines of pancreatic cancer. BMC Cancer 2006; 6:61. [PMID: 16539710 PMCID: PMC1434760 DOI: 10.1186/1471-2407-6-61] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Accepted: 03/15/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chemotherapy for pancreatic carcinoma often has severe side effects that limit its efficacy. The glucocorticoid (GC) dexamethasone (DEX) is frequently used as co-treatment to prevent side effects of chemotherapy such as nausea, for palliative purposes and to treat allergic reactions. While the potent pro-apoptotic properties and the supportive effects of GCs to tumour therapy in lymphoid cells are well studied, the impact of GCs to cytotoxic treatment of pancreatic carcinoma is unknown. METHODS A prospective study of DEX-mediated resistance was performed using a pancreatic carcinoma xenografted to nude mice, 20 surgical resections and 10 established pancreatic carcinoma cell lines. Anti-apoptotic signaling in response to DEX was examined by Western blot analysis. RESULTS In vitro, DEX inhibited drug-induced apoptosis and promoted the growth in all of 10 examined malignant cells. Ex vivo, DEX used in physiological concentrations significantly prevented the cytotoxic effect of gemcitabine and cisplatin in 18 of 20 freshly isolated cell lines from resected pancreatic tumours. No correlation with age, gender, histology, TNM and induction of therapy resistance by DEX co-treatment could be detected. In vivo, DEX totally prevented cytotoxicity of chemotherapy to pancreatic carcinoma cells xenografted to nude mice. Mechanistically, DEX upregulated pro-survival factors and anti-apoptotic genes in established pancreatic carcinoma cells. CONCLUSION These data show that DEX induces therapy resistance in pancreatic carcinoma cells and raise the question whether GC-mediated protection of tumour cells from cancer therapy may be dangerous for patients.
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Affiliation(s)
- Chengwen Zhang
- Research Group Molecular Urooncology,German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Armin Kolb
- Department of General Surgery,University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
| | - Peter Büchler
- Department of General Surgery,University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
| | - Andrew CB Cato
- Research Center Karlsruhe, Institute of Toxicology and Genetics, H.-v. Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Jürgen Mattern
- Research Group Molecular Urooncology,German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Clinical Cooperation Unit Nuclear Medicine,German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Werner Rittgen
- Department of Biostatistics, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Lutz Edler
- Department of Biostatistics, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | | | - Markus W Büchler
- Department of General Surgery,University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
| | - Helmut Friess
- Department of General Surgery,University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
| | - Ingrid Herr
- Research Group Molecular Urooncology,German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Department of Pediatrics, University of Ulm, Prittwitzstraße 43, 89075 Ulm, Germany
- Department of Urology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
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135
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Antoni MH, Lutgendorf SK, Cole SW, Dhabhar FS, Sephton SE, McDonald PG, Stefanek M, Sood AK. The influence of bio-behavioural factors on tumour biology: pathways and mechanisms. Nat Rev Cancer 2006; 6:240-8. [PMID: 16498446 PMCID: PMC3146042 DOI: 10.1038/nrc1820] [Citation(s) in RCA: 671] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Epidemiological studies indicate that stress, chronic depression and lack of social support might serve as risk factors for cancer development and progression. Recent cellular and molecular studies have identified biological processes that could potentially mediate such effects. This review integrates clinical, cellular and molecular studies to provide a mechanistic understanding of the interface between biological and behavioural influences in cancer, and identifies novel behavioural or pharmacological interventions that might help improve cancer outcomes.
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Affiliation(s)
- Michael H Antoni
- Department of Psychology, Sylvestor Cancer Center, University of Miami, P.O. Box 248185, Coral Gables, Florida 33124, USA
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136
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Psarra AMG, Solakidi S, Sekeris CE. The mitochondrion as a primary site of action of steroid and thyroid hormones: presence and action of steroid and thyroid hormone receptors in mitochondria of animal cells. Mol Cell Endocrinol 2006; 246:21-33. [PMID: 16388892 DOI: 10.1016/j.mce.2005.11.025] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mitochondria are key cellular organelles that regulate events related to energy production and apoptosis. These processes are modulated, in turn, by steroid and thyroid hormones in the course of their actions on metabolism, growth and development. In this context, a direct effect of these hormones on the mitochondrial-linked processes, possibly by way of cognate mitochondrial receptors, has been proposed. In this paper we review data from the literature and present new findings supporting this concept. Receptors for steroid hormones, glucocorticoids and estrogens, and for T(3), have been detected in mitochondria by immunofluorescence labeling and confocal laser microscopy, by Western blotting of mitochondrial proteins and by immunogold electron microscopy. Furthermore, the mitochondrial genome contains nucleotide sequences with high similarity to known hormone-responsive elements, which interact with the appropriate receptors to confer hormone-dependent activation of reporter genes in transfection experiments. Thus, thyroid hormone stimulates mitochondrial transcription mediated by the cognate receptor when added to an in organello mitochondrial system, capable of faithful transcription.
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Affiliation(s)
- A-M G Psarra
- Foundation for Biomedical Research of the Academy of Athens, Center for Basic Research, Athens, Greece
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137
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Machuca C, Mendoza-Milla C, Córdova E, Mejía S, Covarrubias L, Ventura J, Zentella A. Dexamethasone protection from TNF-alpha-induced cell death in MCF-7 cells requires NF-kappaB and is independent from AKT. BMC Cell Biol 2006; 7:9. [PMID: 16504042 PMCID: PMC1395311 DOI: 10.1186/1471-2121-7-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 02/21/2006] [Indexed: 11/24/2022] Open
Abstract
Background The biochemical bases for hormone dependence in breast cancer have been recognized as an important element in tumor resistance, proliferation and metastasis. On this respect, dexamethasone (Dex) dependent protection against TNF-alpha-mediated cell death in the MCF-7 cell line has been demonstrated to be a useful model for the study of this type of cancer. Recently, cytoplasmic signaling induced by steroid receptors has been described, such as the activation of the PI3K/Akt and NF-kappaB pathways. We evaluated their possible participation in the Dex-dependent protection against TNF-alpha-mediated cell death. Results Cellular cultures of the MCF-7 cell line were exposed to either, TNF-alpha or TNF-alpha and Dex, and cell viability was evaluated. Next, negative dominants of PI3K and IkappaB-alpha, designed to block the PI3K/Akt and NF-kappaB pathways, respectively, were transfected and selection and evaluation of several clones overexpressing the mutants were examined. Also, correlation with inhibitor of apoptosis proteins (IAPs) expression was examined. Independent inhibition of these two pathways allowed us to test their participation in Dex-dependent protection against TNF-alpha-cytotoxicity in MCF-7 cells. Expression of the PI3K dominant negative mutant did not alter the protection conferred by Dex against TNF-alpha mediated cell death. Contrariwise, clones expressing the IkappaB-alpha dominant negative mutant lost the Dex-conferred protection against TNF-alpha. In these clones degradation of c-IAP was accelerated, while that of XIAP was remained unaffected. Conclusion NF-kappaB, but not PI3K/Akt activation, is required for the Dex protective effect against TNF-alpha-mediated cell death, and correlates with lack of degradation of the anti-apoptotic protein c-IAP1.
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Affiliation(s)
- Catalina Machuca
- Carrera de Biología, Facultad de Estudios Superiores ZARAGOZA, UNAM. C.P. 09230, México D.F., México
- Departamento de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", Secretaría de Salud, C.P. 14000, México, D.F., México
| | - Criselda Mendoza-Milla
- Instituto Nacional de Enfermedades Respiratorias, Secretaría de Salud, C.P. 14000, México D.F., México
| | - Emilio Córdova
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, UNAM. C.P. 04510, México D.F., México
- Departamento de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", Secretaría de Salud, C.P. 14000, México, D.F., México
| | - Salvador Mejía
- Departamento de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", Secretaría de Salud, C.P. 14000, México, D.F., México
| | - Luis Covarrubias
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM. C.P. 62210, Cuernavaca Mor. México
| | - José Ventura
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, UNAM. C.P. 04510, México D.F., México
| | - Alejandro Zentella
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, UNAM. C.P. 04510, México D.F., México
- Departamento de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", Secretaría de Salud, C.P. 14000, México, D.F., México
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Nigawara T, Iwasaki Y, Asai M, Yoshida M, Kambayashi M, Sashinami H, Hashimoto K, Suda T. Inhibition of 11beta-hydroxysteroid dehydrogenase eliminates impaired glucocorticoid suppression and induces apoptosis in corticotroph tumor cells. Endocrinology 2006; 147:769-72. [PMID: 16254034 DOI: 10.1210/en.2005-0544] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cushing's disease is characterized by persistent ACTH secretion under hypercortisolemia. In an attempt to clarify the molecular mechanism, we examined the effect of 11beta-hydroxysteroid dehydrogenase (HSD) inhibition on glucocorticoid suppression of ACTH release using murine corticotroph tumor cells. We found that 11beta-HSD2, as well as -HSD1, was expressed in the cells and that its inhibition by carbenoxolone significantly improved the negative feedback effect of glucocorticoid. Carbenoxolone also enhanced apoptosis induced by cortisol. These effects are most likely attributable to inhibition of 11beta-HSD2 because only cortisol, a substrate of 11beta-HSD2, was present in these experimental conditions. We conclude that ectopic expression of 11beta-HSD2 is, at least in part, responsible for the impaired glucocorticoid suppression in corticotroph adenoma. Inhibition of 11beta-HSD2 may be applicable to the medical therapy for Cushing's disease.
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Affiliation(s)
- Takeshi Nigawara
- Departments of Clinical Pathophysiology, Nagoya University Graduate School of Medicine and Hospital, Japan
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139
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Naumann L, Feist E, Straub RH, Burmester GR, Buttgereit F. Potencies of topical glucocorticoids to mediate genomic and nongenomic effects on human peripheral blood mononuclear cells. Biochem Pharmacol 2006; 71:530-9. [PMID: 16343445 DOI: 10.1016/j.bcp.2005.10.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 10/16/2005] [Accepted: 10/20/2005] [Indexed: 11/23/2022]
Abstract
Several different genomic and nongenomic mechanisms are known to mediate the important anti-inflammatory and immunomodulatory effects of glucocorticoids (GC). Genomic effects are the most important while the clinical relevance of nongenomic actions is still a matter of debate. We therefore investigated whether beclometasone and clobetasol are particularly suitable for topical application because of their specific spectrum of genomic and nongenomic actions. For these purposes we compared effects on oxygen consumption as measured with a Clark electrode (nonspecific nongenomic glucocorticoid effects), on interleukin-6 synthesis by means of ELISA (genomic effects) and on apoptosis using flow cytometry (nongenomic and genomic effects) in quiescent and mitogen-stimulated PBMC. Beclometasone and clobetasol indeed had stronger effects on the oxygen consumption of quiescent and stimulated cells at lower concentrations (10(-10) and 10(-8) M) but were less potent at higher concentrations (10(-5) and 10(-4) M) in comparison with dexamethasone. Also in terms of genomic potency, topical GC were more effective than dexamethasone at 10(-10) and 10(-8) M but gave similar results at higher concentrations. The ability of all three GC to induce apoptosis was found to be concentration-dependent and similar at concentrations between 10(-8) and 10(-5) M. But, compared with 10(-4) M dexamethasone, topical GC at 10(-4) M were significantly more effective at inducing apoptosis in both PBMC and Jurkat T-cells. These results show that topical GC have different concentration--(genomic/nongenomic) effect--ratios compared with dexamethasone: besides to the well-known genomic effects there are also significant nongenomic effects of topical glucocorticoids that already at low concentrations might be more therapeutically relevant in certain clinical conditions than currently assumed.
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Affiliation(s)
- Lydia Naumann
- Department of Medicine (Rheumatology and Clinical Immunology), Charité University Hospital, Schumannstrasse 20/21, 10117 Berlin, Germany.
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140
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Orzechowski A, Jank M, Gajkowska B, Sadkowski T, Godlewskia MM. A Novel Antioxidant-Inhibited Dexamethasone-Mediated and Caspase-3-Independent Muscle Cell Death. Ann N Y Acad Sci 2006; 1010:205-8. [PMID: 15033721 DOI: 10.1196/annals.1299.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Dexamethasone (Dex)-mediated cell death is associated with repression of survival factors (AP-1, c-myc, NF-kappaB). Dex suppressed the activity of genes encoding antioxidant enzymes leading to impaired viability and apoptotic cell death. These findings suggest that reactive oxygen species inhibit protein synthesis and amplify m-calpain-dependent proteolysis. The events that led to death of L6 muscle cells were most likely triggered by Dex-mediated repression of antioxidative defenses on the genomic level.
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Affiliation(s)
- Arkadiusz Orzechowski
- Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw Agricultural University, Warsaw, Poland.
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141
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Abstract
Glucocorticoids (GCs) are a class of steroid hormones which regulate a variety of essential biological functions. The profound anti-inflammatory and immunosuppressive activity of synthetic GCs, combined with their power to induce lymphocyte apoptosis place them among the most commonly prescribed drugs worldwide. Endogenous GCs also exert a wide range of immunomodulatory activities, including the control of T cell homeostasis. Most, if not all of these effects are mediated through the glucocorticoid receptor, a member of the nuclear receptor superfamily. However, the signaling pathways and their cell type specificity remain poorly defined. In this review, we summarize our present knowledge on GC action, the mechanisms employed to induce apoptosis and the currently discussed models of how they may participate in thymocyte development. Although our knowledge in this field has substantially increased during recent years, we are still far from a comprehensive picture of the role that GCs play in T lymphocytes.
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Affiliation(s)
- M. J. Herold
- Molecular Immunology, Institute for Virology and Immunobiology, University of Würzburg, Versbacher Strasse 7, 97078 Würzburg, Germany
| | - K. G. McPherson
- Molecular Immunology, Institute for Virology and Immunobiology, University of Würzburg, Versbacher Strasse 7, 97078 Würzburg, Germany
| | - H. M. Reichardt
- Molecular Immunology, Institute for Virology and Immunobiology, University of Würzburg, Versbacher Strasse 7, 97078 Würzburg, Germany
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142
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Ottonello L, Bertolotto M, Montecucco F, Dapino P, Dallegri F. Dexamethasone -induced apoptosis of human monocytes exposed to immune complexes. Intervention of CD95- and XIAP-dependent pathways. Int J Immunopathol Pharmacol 2005; 18:403-15. [PMID: 16164824 DOI: 10.1177/039463200501800302] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Monocytes and macrophages play a key role in the initiation and persistence of inflammatory reactions. The possibility to interfere with the survival of these cells, once recruited and activated at sites of inflammation, is an attractive therapeutic option. Although resting monocytes are susceptible to pharmacologically induced apoptosis, no data are available about the possibility to modulate the survival of activated monocytes. The present work was planned to investigate if dexamethasone is able to promote apoptosis of human monocytes activated by immune complexes. When monocytes were cultured with immune complexes, a dose-dependent inhibition of apoptosis was observed. Dexamethasone stimulated apoptosis of resting and activated monocytes in a dose-dependent manner. Both the immune complex inhibitory activity and dexamethasone stimulatory properties depend on NF-kappaB/XIAP and Ras/MEK/ERK/CD95 pathways. In fact, the exposure of monocytes to immune complexes increased NF-kB activation and XIAP expression, which in turn were inhibited by dexamethasone. On the other hand, immune complex-stimulated monocytes displayed a reduced expression of CD95, which is prevented by dexamethasone, as well as by MEK inhibitor U0126. Furthermore, anti-CD95 ZB4 mAb prevented dexamethasone-induced apoptosis in immune complex stimulated monocytes. Similarly, ZB4 inhibited dexamethasone-mediated augmentation of caspase 3 activity. The present findings suggest that Fc triggering by insoluble immune complexes result in the activation of two intracellular pathways crucial for the survival of monocytes: 1. Ras/MEK/ERK pathway responsible for the down-regulation of CD95 expression; 2. NF-kappaB pathway governing the expression of XIAP. Both the pathways are susceptible to inhibition by monocyte treatment with pharmacologic concentrations of dexamethasone.
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Affiliation(s)
- L Ottonello
- Laboratory of Phagocyte Physiopathology and Inflammation, Department of Internal Medicine, University of Genoa, Genoa, Italy.
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143
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Nagaraj NS, Vigneswaran N, Zacharias W. Cathepsin B mediates TRAIL-induced apoptosis in oral cancer cells. J Cancer Res Clin Oncol 2005; 132:171-83. [PMID: 16362335 PMCID: PMC5774671 DOI: 10.1007/s00432-005-0053-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Accepted: 10/10/2005] [Indexed: 11/25/2022]
Abstract
PURPOSE The death ligand TRAIL (tumor necrosis factor-related apoptosis inducing ligand) triggers apoptosis in a variety of cancer cells, which implies the potential for therapeutic applications. The purpose of this study was to investigate the role of the lysosomal protease cathepsin B (CB) in mediating TRAIL-induced cell death in oral squamous cell carcinoma (OSCC) cells. METHODS OSCC cell lines from primary tumor and lymph node metastasis were examined for expression of apoptosis markers by Western blots, enzyme activity assays, nuclear fragmentation assays, and FACS analysis. Gene-specific ribozymes or chemical inhibitors were used to inhibit CB or caspases in target cells. RESULTS TRAIL-induced activation of caspase-3, cleavage of Bid and poly-ADP-ribose polymerase, release of cytochrome c, and DNA fragmentation were blocked either by a pan-caspase inhibitor (zVAD-fmk) or a CB inhibitor (CA074Me), consistent with the involvement of TRAIL as well as CB in cell death. The primary tumor cells were more susceptible to apoptosis than their corresponding lymph node metastatic cells. Stable transfection of a ribozyme which inhibited CB expression also decreased the apoptotic process. CONCLUSIONS We conclude that TRAIL-induced apoptotic cell death in OSCC cells is mediated through CB or through caspase activation. Our data point to a new tumor-suppressive role for CB in OSCC which is opposed to the invasion- and metastasis-promoting functions of lysosomal proteases.
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Affiliation(s)
- Nagathihalli S. Nagaraj
- Department of Medicine, James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, USA
| | - Nadarajah Vigneswaran
- Department of Diagnostic Sciences, Health Science Center at Houston, Dental Branch, The University of Texas, Houston, TX 77030, USA, Fax: +1-713-5004416
| | - Wolfgang Zacharias
- Department of Medicine and Department of Pharmacology & Toxicology, James Graham Brown Cancer Center, University of Louisville, Delia Baxter Bldg. 321F 580 South Preston Street, Louisville, KY 40202, USA, , Tel.: +1-502-8522579, Fax: +1-502-8522356
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144
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Zhang C, Kolb A, Mattern J, Gassler N, Wenger T, Herzer K, Debatin KM, Büchler M, Friess H, Rittgen W, Edler L, Herr I. Dexamethasone desensitizes hepatocellular and colorectal tumours toward cytotoxic therapy. Cancer Lett 2005; 242:104-11. [PMID: 16338063 DOI: 10.1016/j.canlet.2005.10.037] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 10/25/2005] [Accepted: 10/26/2005] [Indexed: 01/05/2023]
Abstract
The glucocorticoid dexamethasone is frequently used as co-treatment in cytotoxic cancer therapy, e.g. to prevent nausea, to protect normal tissue or for other reasons. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumour therapy in lymphoid cells are well studied, the impact to cytotoxic treatment of colorectal and hepatocellular carcinoma is unknown. We tested apoptosis-induction, viability, tumour growth and protein expression using 8 established cell lines, 18 surgical specimen and a xenograft on nude mice. In the presence of dexamethasone we found strong inhibition of apoptosis in response to 5-FU, cisplatin, gemcitabine or gamma-irradiation, enhanced viability and tumour growth of colorectal and hepatocellular carcinomas. No correlation with age, gender, histology, TNM, the p53 status and induction of therapy resistance by dexamethasone co-treatment could be detected. These data show that glucocorticoid-induced resistance occurs not occasionally but is common in colorectal and hepatocellular carcinomas implicating that the use of glucocorticoids may be harmful for cancer patients.
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Affiliation(s)
- C Zhang
- Molecular Urooncology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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Schmidt S, Rainer J, Riml S, Ploner C, Jesacher S, Achmüller C, Presul E, Skvortsov S, Crazzolara R, Fiegl M, Raivio T, Jänne OA, Geley S, Meister B, Kofler R. Identification of glucocorticoid-response genes in children with acute lymphoblastic leukemia. Blood 2005; 107:2061-9. [PMID: 16293608 DOI: 10.1182/blood-2005-07-2853] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The ability of glucocorticoids (GCs) to kill lymphoid cells led to their inclusion in essentially all chemotherapy protocols for lymphoid malignancies, particularly childhood acute lymphoblastic leukemia (ALL). GCs mediate apoptosis via their cognate receptor and subsequent alterations in gene expression. Previous investigations, including expression profiling studies with subgenome microarrays in model systems, have led to a number of attractive, but conflicting, hypotheses that have never been tested in a clinical setting. Here, we present a comparative whole-genome expression profiling approach using lymphoblasts (purified at 3 time points) from 13 GC-sensitive children undergoing therapy for ALL. For comparisons, expression profiles were generated from an adult patient with ALL, peripheral blood lymphocytes from GC-exposed healthy donors, GC-sensitive and -resistant ALL cell lines, and mouse thymocytes treated with GCs in vivo and in vitro. This generated an essentially complete list of GC-regulated candidate genes in clinical settings and experimental systems, allowing immediate analysis of any gene for its potential significance to GC-induced apoptosis. Our analysis argued against most of the model-based hypotheses and instead identified a small number of novel candidate genes, including PFKFB2, a key regulator of glucose metabolism; ZBTB16, a putative transcription factor; and SNF1LK, a protein kinase implicated in cell-cycle regulation.
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Affiliation(s)
- Stefan Schmidt
- Tyrolean Cancer Research Institute, Innrain 66, A-6020 Innsbruck, Austria
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146
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Solá S, Amaral JD, Castro RE, Ramalho RM, Borralho PM, Kren BT, Tanaka H, Steer CJ, Rodrigues CMP. Nuclear translocation of UDCA by the glucocorticoid receptor is required to reduce TGF-beta1-induced apoptosis in rat hepatocytes. Hepatology 2005; 42:925-34. [PMID: 16175607 DOI: 10.1002/hep.20870] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Ursodeoxycholic acid (UDCA) inhibits classical mitochondrial pathways of apoptosis by either directly stabilizing mitochondrial membranes or modulating specific upstream targets. Furthermore, UDCA regulates apoptosis-related genes from transforming growth factor beta1 (TGF-beta1)-induced hepatocyte apoptosis by a nuclear steroid receptor (NSR)-dependent mechanism. In this study, we further investigated the potential role of the glucocorticoid receptor (GR) in the anti-apoptotic function of UDCA. Our results with short interference RNA (siRNA) technology confirmed that UDCA significantly reduces TGF-beta1-induced apoptosis of primary rat hepatocytes through a GR-dependent effect. Immunoprecipitation assays and confocal microscopy showed that UDCA enhanced free GR levels with subsequent GR nuclear translocation. Interestingly, when a carboxy-terminus deleted form of GR was used, UDCA no longer increased free GR and/or GR translocation, nor did it protect against TGF-beta1-induced apoptosis. In co-transfection experiments with GR response element reporter and overexpression constructs, UDCA did not enhance the transactivation of GR with TGF-beta1. Finally, using a fluorescently labeled UDCA molecule, the bile acid appeared diffuse in the cytosol but was aggregated in the nucleus of hepatocytes. Both siRNA assays and transfection experiments with either wild-type or mutant forms of GR showed that nuclear trafficking occurs through a GR-dependent mechanism. In conclusion, these results further clarify the anti-apoptotic mechanism(s) of UDCA and suggest that GR is crucial for the nuclear translocation of this bile acid for reducing apoptosis.
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Affiliation(s)
- Susana Solá
- Centro de Patogénese Molecular, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal
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147
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Erlacher M, Michalak EM, Kelly PN, Labi V, Niederegger H, Coultas L, Adams JM, Strasser A, Villunger A. BH3-only proteins Puma and Bim are rate-limiting for gamma-radiation- and glucocorticoid-induced apoptosis of lymphoid cells in vivo. Blood 2005; 106:4131-8. [PMID: 16118324 PMCID: PMC1895232 DOI: 10.1182/blood-2005-04-1595] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Numerous p53 target genes have been implicated in DNA damage-induced apoptosis signaling, but proapoptotic Bcl-2 (B-cell leukemia 2) family members of the BH3 (Bcl-2 homolog region [BH] 3)-only subgroup appear to play the critical initiating role. In various types of cultured cells, 3 BH3-only proteins, namely Puma (p53 up-regulated modulator of apoptosis), Noxa, and Bim (Bcl-2 interacting mediator of cell death), have been shown to initiate p53-dependent as well as p53-independent apoptosis in response to DNA damage and treatment with anticancer drugs or glucocorticoids. In particular, the absence of Puma or Bim renders thymocytes and mature lymphocytes refractory to varying degrees to death induced in vitro by growth factor withdrawal, DNA damage, or glucocorticoids. To assess the in vivo relevance of these findings, we subjected mice lacking Puma, Noxa, or Bim to whole-body gamma-radiation or the glucocorticoid dexamethasone and compared lymphocyte survival with that in wild-type and BCL2-transgenic mice. Absence of Puma or Bcl-2 overexpression efficiently protected diverse types of lymphocytes from the effects of gamma-radiation in vivo, and loss of Bim provided lower but significant protection in most lymphocytes, whereas Noxa deficiency had no impact. Furthermore, both Puma and Bim were found to contribute significantly to glucocorticoid-induced killing. Our results thus establish that Puma and Bim are key initiators of gamma-radiation- and glucocorticoid-induced apoptosis in lymphoid cells in vivo.
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Affiliation(s)
- Miriam Erlacher
- Division of Experimental Pathophysiology & Immunology, Biocenter, Innsbruck Medical University, A-6020 Innsbruck, Austria
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148
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Batista J, Martins A, Moro L, Vasconcelos A. Expressão gênica de caspases 3 e 8 em timo e baço de ratas recém-desmamadas e imunossuprimidas por glicocorticóide. ARQ BRAS MED VET ZOO 2005. [DOI: 10.1590/s0102-09352005000400006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Determinou-se a expressão gênica das caspases 3 e 8 mediante transcrição reversa de mRNA total e reação em cadeia da polimerase (RT-PCR) para avaliar a apoptose em timo e baço de ratas imunossuprimidas por glicocorticóides. Utilizou-se dexametasona para indução da apoptose e atrofia linfóide. Quarenta e cinco fêmeas Wistar recém-desmamadas foram separadas em três grupos: as ratas de A (n=18) e B (n=18) foram tratadas com 250 e 500mg de glicocorticóide, via intramuscular, respectivamente, e as do C (n=9) não foram tratadas. Após 24, 48 e 72 horas, seis animais de cada grupo tratado e três do controle foram anestesiados, pesados e sacrificados. O baço e o timo foram coletados e pesados. Fragmentos dos órgãos foram fixados em formol tamponado a 10% e processados segundo técnica para inclusão em parafina. Os blocos foram seccionados em 5µm, e os cortes corados em hematoxilina e eosina. A análise histopatológica aliada ao peso dos órgãos nas diferentes doses e tempos demonstrou que a dexametasona induziu hipotrofia linfóide, que ocorreu com maior intensidade no tempo de 72 horas em animais do grupo B. Fragmentos de timo e de baço foram imediatamente congelados em nitrogênio líquido para extração de mRNA e DNA. Para a padronização da técnica de RT-PCR, utilizaram-se pool de amostras de mRNA dos animais-controle e pool de mRNA de animais tratados em cada tempo de experimento. A técnica de RT-PCR foi sensível o suficiente para a detecção dos mRNAs que codificam as caspases 3 e 8, e ambas participaram do processo de apoptose induzido por dexametasona.
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149
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Psarra AMG, Solakidi S, Trougakos IP, Margaritis LH, Spyrou G, Sekeris CE. Glucocorticoid receptor isoforms in human hepatocarcinoma HepG2 and SaOS-2 osteosarcoma cells: presence of glucocorticoid receptor alpha in mitochondria and of glucocorticoid receptor beta in nucleoli. Int J Biochem Cell Biol 2005; 37:2544-58. [PMID: 16076561 DOI: 10.1016/j.biocel.2005.06.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 11/24/2022]
Abstract
In the context of a possible direct action of glucocorticosteroids on mitochondrial transcription and/or apoptosis by way of cognate mitochondrial receptors, the possible localization of glucocorticoid receptors alpha and beta (GRalpha and GRbeta) in mitochondria was explored in human hepatocarcinoma HepG2 and osteosarcoma SaOS-2 cells, in which glucocorticoids exert an anabolic and apoptotic effect, respectively. In both cell types, GRalpha was detected in mitochondria, in nuclei and in cytosol by immunofluorescence labeling and confocal scanning microscopy, by immunogold electron microscopy and by Western blotting. GRbeta was shown to be almost exclusively restricted to the nucleus of the two cell types, being particularly concentrated in nucleoli, pointing to a solely nuclear role of this receptor isoform and to a possible function in nucleoli related processes. Computer analysis identified a putative internal mitochondrial targeting sequence within the glucocorticoid receptor. The demonstration of mitochondrially localized GRalpha in HepG2 and SaOS-2 cells corroborates previous findings in other cell types and further supports a direct role of this receptor in mitochondrial functions.
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Affiliation(s)
- Anna-Maria G Psarra
- Foundation for Biomedical Research of the Academy of Athens, Center for Basic Research, 4 Soranou Efesiou, 11527 Athens, Greece
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150
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Quadrilatero J, Hoffman-Goetz L. In vivo corticosterone administration at levels occurring with intense exercise does not induce intestinal lymphocyte apoptosis in mice. J Neuroimmunol 2005; 162:137-48. [PMID: 15833369 DOI: 10.1016/j.jneuroim.2005.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Accepted: 02/14/2005] [Indexed: 11/17/2022]
Abstract
Intestinal lymphocyte apoptosis can occur following physiological and pathophysiological stress as well as exhaustive exercise. In this study we investigated whether corticosterone (CORT) administration at physiological concentrations observed following strenuous exercise induces intestinal lymphocyte apoptosis and cell loss in mice. CORT injection (14 mg/kg; i.p.) caused a four-fold increase in plasma CORT concentrations, but did not affect intestinal lymphocyte cell loss or alter baseline intestinal lymphocyte apoptosis, as measured by phosphatidylserine externalization, cell viability, mitochondrial membrane depolarization, caspase 3, Bcl-2 and cytosolic cytochrome c protein levels. These findings indicate that CORT at levels observed following strenuous exercise is not involved in intestinal lymphocyte apoptosis and cell loss.
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Affiliation(s)
- J Quadrilatero
- Department of Health Studies and Gerontology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
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