51
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Recalcati S, Gammella E, Cairo G. Dysregulation of iron metabolism in cancer stem cells. Free Radic Biol Med 2019; 133:216-220. [PMID: 30040994 DOI: 10.1016/j.freeradbiomed.2018.07.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 12/17/2022]
Abstract
Cancer stem cells (CSCs) are a distinct subpopulation of tumor cells endowed with stem-like properties. Importantly, CSCs can survive current standard therapies, resulting in metastatic disease and tumor recurrence. Here we describe the alterations of iron homeostasis occurring in CSCs, which in general are characterized by high intracellular iron content. Importantly, abnormalities of iron metabolism correlate with faster tumor growth and adverse prognosis in cancer patients. In line with the dependence of cancer on iron, we also discuss iron-dependent mechanisms as druggable pathways, as iron chelators have been considered for tumor therapy and new molecules currently proposed and studied as antineoplastic drugs may impinge on iron and its capacity to promote oxidative stress to have therapeutic value in cancer.
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Affiliation(s)
- Stefania Recalcati
- Department of Biomedical Sciences for Health, University of Milan, Via Mangiagalli 31, 20133 Milano, Italy
| | - Elena Gammella
- Department of Biomedical Sciences for Health, University of Milan, Via Mangiagalli 31, 20133 Milano, Italy
| | - Gaetano Cairo
- Department of Biomedical Sciences for Health, University of Milan, Via Mangiagalli 31, 20133 Milano, Italy.
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52
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Iron metabolism and its contribution to cancer (Review). Int J Oncol 2019; 54:1143-1154. [PMID: 30968149 DOI: 10.3892/ijo.2019.4720] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 01/21/2019] [Indexed: 01/12/2023] Open
Abstract
Iron is an essential element for biological processes. Iron homeostasis is regulated through several mechanisms, from absorption by enterocytes to recycling by macrophages and storage in hepatocytes. Iron has dual properties, which may facilitate tumor growth or cell death. Cancer cells exhibit an increased dependence on iron compared with normal cells. Macrophages potentially deliver iron to cancer cells, resulting in tumor promotion. Mitochondria utilize cellular iron to synthesize cofactors, including heme and iron sulfur clusters. The latter is composed of essential enzymes involved in DNA synthesis and repair, oxidation‑reduction reactions, and other cellular processes. However, highly increased iron concentrations result in cell death through membrane lipid peroxidation, termed ferroptosis. Ferroptosis, an emerging pathway for cancer treatment, is similar to pyroptosis, apoptosis and necroptosis. In the present review, previous studies on the physiology of iron metabolism and its role in cancer are summarized. Additionally, the significance of iron regulation, and the association between iron homeostasis and carcinogenic mechanisms are discussed.
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53
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Steiner M, Schneider L, Yillah J, Gerlach K, Kuvardina ON, Meyer A, Maring A, Bonig H, Seifried E, Zörnig M, Lausen J. FUSE binding protein 1 (FUBP1) expression is upregulated by T-cell acute lymphocytic leukemia protein 1 (TAL1) and required for efficient erythroid differentiation. PLoS One 2019; 14:e0210515. [PMID: 30653565 PMCID: PMC6336336 DOI: 10.1371/journal.pone.0210515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/23/2018] [Indexed: 11/18/2022] Open
Abstract
During erythropoiesis, haematopoietic stem cells (HSCs) differentiate in successive steps of commitment and specification to mature erythrocytes. This differentiation process is controlled by transcription factors that establish stage- and cell type-specific gene expression. In this study, we demonstrate that FUSE binding protein 1 (FUBP1), a transcriptional regulator important for HSC self-renewal and survival, is regulated by T-cell acute lymphocytic leukaemia 1 (TAL1) in erythroid progenitor cells. TAL1 directly activates the FUBP1 promoter, leading to increased FUBP1 expression during erythroid differentiation. The binding of TAL1 to the FUBP1 promoter is highly dependent on an intact GATA sequence in a combined E-box/GATA motif. We found that FUBP1 expression is required for efficient erythropoiesis, as FUBP1-deficient progenitor cells were limited in their potential of erythroid differentiation. Thus, the finding of an interconnection between GATA1/TAL1 and FUBP1 reveals a molecular mechanism that is part of the switch from progenitor- to erythrocyte-specific gene expression. In summary, we identified a TAL1/FUBP1 transcriptional relationship, whose physiological function in haematopoiesis is connected to proper erythropoiesis.
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Affiliation(s)
- Marlene Steiner
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt/Main, Germany
| | - Lucas Schneider
- Institute for Transfusion Medicine and Immunohematology, Goethe-University and German Red Cross Blood Service, Frankfurt am Main, Germany
| | - Jasmin Yillah
- Institute for Transfusion Medicine and Immunohematology, Goethe-University and German Red Cross Blood Service, Frankfurt am Main, Germany
| | - Katharina Gerlach
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt/Main, Germany
| | - Olga N. Kuvardina
- Institute for Transfusion Medicine and Immunohematology, Goethe-University and German Red Cross Blood Service, Frankfurt am Main, Germany
| | - Annekarin Meyer
- Institute for Transfusion Medicine and Immunohematology, Goethe-University and German Red Cross Blood Service, Frankfurt am Main, Germany
| | - Alisa Maring
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt/Main, Germany
| | - Halvard Bonig
- Institute for Transfusion Medicine and Immunohematology, Goethe-University and German Red Cross Blood Service, Frankfurt am Main, Germany
| | - Erhard Seifried
- Institute for Transfusion Medicine and Immunohematology, Goethe-University and German Red Cross Blood Service, Frankfurt am Main, Germany
| | - Martin Zörnig
- Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt/Main, Germany
- * E-mail: (MZ); (JL)
| | - Jörn Lausen
- Institute for Transfusion Medicine and Immunohematology, Goethe-University and German Red Cross Blood Service, Frankfurt am Main, Germany
- * E-mail: (MZ); (JL)
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54
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Santana-Codina N, Mancias JD. The Role of NCOA4-Mediated Ferritinophagy in Health and Disease. Pharmaceuticals (Basel) 2018; 11:E114. [PMID: 30360520 PMCID: PMC6316710 DOI: 10.3390/ph11040114] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 12/26/2022] Open
Abstract
Nuclear receptor coactivator 4 (NCOA4) is a selective cargo receptor that mediates the autophagic degradation of ferritin ("ferritinophagy"), the cytosolic iron storage complex. NCOA4-mediated ferritinophagy maintains intracellular iron homeostasis by facilitating ferritin iron storage or release according to demand. Ferritinophagy is involved in iron-dependent physiological processes such as erythropoiesis, where NCOA4 mediates ferritin iron release for mitochondrial heme synthesis. Recently, ferritinophagy has been shown to regulate ferroptosis, a newly described form of iron-dependent cell death mediated by excess lipid peroxidation. Dysregulation of iron metabolism and ferroptosis have been described in neurodegeneration, cancer, and infection, but little is known about the role of ferritinophagy in the pathogenesis of these diseases. Here, we will review the biochemical regulation of NCOA4, its contribution to physiological processes and its role in disease. Finally, we will discuss the potential of activating or inhibiting ferritinophagy and ferroptosis for therapeutic purposes.
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Affiliation(s)
- Naiara Santana-Codina
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Institute of Medicine, Room 221, 4 Blackfan Circle, Boston, MA 02215, USA.
| | - Joseph D Mancias
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Institute of Medicine, Room 221, 4 Blackfan Circle, Boston, MA 02215, USA.
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55
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Shi L, Guan Q, Gao X, Jin X, Xu L, Shen J, Wu C, Zhu X, Zhang C. Reaction-Based Color-Convertible Fluorescent Probe for Ferroptosis Identification. Anal Chem 2018; 90:9218-9225. [PMID: 29940728 DOI: 10.1021/acs.analchem.8b01721] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ferroptosis is an iron-mediated, caspase-independent pathway of cell death that is accompanied with the accumulations of reactive oxygen species (ROS) and oxygenases, as well as being involved in many other pathophysiological procedures. However, specific and rapid monitoring of ferroptosis in living cells or tissues has not been achieved so far. Herein, a quinoxalinone-based fluorescent probe (termed as Quinos-4, or QS-4) with a reactive aromatic thioether moiety was designed for ferroptosis identification. Upon exposing it to high levels of ROS and hemeoxygenase-1 (HO-1), which are considered as the biochemical characteristics of ferroptosis, QS-4 could be oxidized into a sulfoxide derivative (QSO-4) and its original aggregation-induced enhanced red fluorescence emission could be converted to green fluorescence emission sharply. On the basis of this unique reaction-induced color conversion, this molecular probe can be employed for identifying the occurrence of ferroptosis both in vitro and in vivo.
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Affiliation(s)
- Leilei Shi
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
| | - Qinghua Guan
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
| | - Xihui Gao
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
| | - Xin Jin
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
| | - Li Xu
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
| | - Jian Shen
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials , Nanjing Normal University , Nanjing 210046 , China
| | - Chenwei Wu
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
| | - Xinyuan Zhu
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
| | - Chuan Zhang
- School of Chemistry and Chemical Engineering , State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road , Shanghai 200240 , China
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56
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Zhou L, Zhao B, Zhang L, Wang S, Dong D, Lv H, Shang P. Alterations in Cellular Iron Metabolism Provide More Therapeutic Opportunities for Cancer. Int J Mol Sci 2018; 19:E1545. [PMID: 29789480 PMCID: PMC5983609 DOI: 10.3390/ijms19051545] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 05/16/2018] [Accepted: 05/17/2018] [Indexed: 01/19/2023] Open
Abstract
Iron is an essential element for the growth and proliferation of cells. Cellular iron uptake, storage, utilization and export are tightly regulated to maintain iron homeostasis. However, cellular iron metabolism pathways are disturbed in most cancer cells. To maintain rapid growth and proliferation, cancer cells acquire large amounts of iron by altering expression of iron metabolism- related proteins. In this paper, normal cellular iron metabolism and the alterations of iron metabolic pathways in cancer cells were summarized. Therapeutic strategies based on targeting the altered iron metabolism were also discussed and disrupting redox homeostasis by intracellular high levels of iron provides new insight for cancer therapy. Altered iron metabolism constitutes a promising therapeutic target for cancer therapy.
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Affiliation(s)
- Liangfu Zhou
- School of Life Science, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Bin Zhao
- School of Life Science, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Lixiu Zhang
- School of Life Science, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Shenghang Wang
- School of Life Science, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Dandan Dong
- School of Life Science, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Huanhuan Lv
- School of Life Science, Northwestern Polytechnical University, Xi'an 710072, China.
- Research & Development Institute in Shenzhen, Northwestern Polytechnical University, Shenzhen 518057, China.
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Peng Shang
- Research & Development Institute in Shenzhen, Northwestern Polytechnical University, Shenzhen 518057, China.
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, Northwestern Polytechnical University, Xi'an 710072, China.
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57
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Mishra P, Tang W, Ambs S. ADHFE1 is a MYC-linked oncogene that induces metabolic reprogramming and cellular de-differentiation in breast cancer. Mol Cell Oncol 2018; 5:e1432260. [PMID: 30250890 PMCID: PMC6150044 DOI: 10.1080/23723556.2018.1432260] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 12/31/2017] [Accepted: 01/03/2018] [Indexed: 01/09/2023]
Abstract
The oncometabolite, D-2-hydroxyglutarate, accumulates in various cancers because of acquired mutations in isocitrate dehydrogenase 1 & 2. Here, we describe a new mechanism for D-2-hydroxyglutarate accumulation in breast cancer. It involves c-Myc signaling and alcohol dehydrogenase, iron-containing protein 1 (ADHFE1) and leads to metabolic reprogramming, de-differentiation, and increased mammary tumorigenesis.
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Affiliation(s)
- Prachi Mishra
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Wei Tang
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Stefan Ambs
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD, USA
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58
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Lobello N, Biamonte F, Pisanu ME, Faniello MC, Jakopin Ž, Chiarella E, Giovannone ED, Mancini R, Ciliberto G, Cuda G, Costanzo F. Ferritin heavy chain is a negative regulator of ovarian cancer stem cell expansion and epithelial to mesenchymal transition. Oncotarget 2018; 7:62019-62033. [PMID: 27566559 PMCID: PMC5308708 DOI: 10.18632/oncotarget.11495] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 08/09/2016] [Indexed: 12/19/2022] Open
Abstract
Objectives Ferritin is the major intracellular iron storage protein essential for maintaining the cellular redox status. In recent years ferritin heavy chain (FHC) has been shown to be involved also in the control of cancer cell growth. Analysis of public microarray databases in ovarian cancer revealed a correlation between low FHC expression levels and shorter survival. To better understand the role of FHC in cancer, we have silenced the FHC gene in SKOV3 cells. Results FHC-KO significantly enhanced cell viability and induced a more aggressive behaviour. FHC-silenced cells showed increased ability to form 3D spheroids and enhanced expression of NANOG, OCT4, ALDH and Vimentin. These features were accompanied by augmented expression of SCD1, a major lipid metabolism enzyme. FHC apparently orchestrates part of these changes by regulating a network of miRNAs. Methods FHC-silenced and control shScr SKOV3 cells were monitored for changes in proliferation, migration, ability to propagate as 3D spheroids and for the expression of stem cell and epithelial-to-mesenchymal-transition (EMT) markers. The expression of three miRNAs relevant to spheroid formation or EMT was assessed by q-PCR. Conclusions In this paper we uncover a new function of FHC in the control of cancer stem cells.
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Affiliation(s)
- Nadia Lobello
- Centro di Ricerca di Biochimica e Biologia Molecolare Avanzata, Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi "Magna Graecia", Catanzaro, Italy
| | - Flavia Biamonte
- Centro di Ricerca di Biochimica e Biologia Molecolare Avanzata, Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi "Magna Graecia", Catanzaro, Italy
| | - Maria Elena Pisanu
- Dipartimento di Medicina Clinica e Molecolare, Sapienza Università di Roma, Italy.,Laboratorio di Biologia Cellulare e Molecolare, Dipartimento di Chirurgia "P. Valdoni", Sapienza Università di Roma, Italy
| | - Maria Concetta Faniello
- Centro di Ricerca di Biochimica e Biologia Molecolare Avanzata, Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi "Magna Graecia", Catanzaro, Italy
| | - Žiga Jakopin
- Faculty of Pharmacy, University of Ljubljana, Slovenia
| | - Emanuela Chiarella
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi "Magna Graecia", Catanzaro, Italy
| | - Emilia Dora Giovannone
- Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi "Magna Graecia", Catanzaro, Italy.,Centro Interdipartimentale di Servizi e Ricerca, Università degli Studi "Magna Graecia", Catanzaro, Italy
| | - Rita Mancini
- Dipartimento di Medicina Clinica e Molecolare, Sapienza Università di Roma, Italy.,Laboratorio di Biologia Cellulare e Molecolare, Dipartimento di Chirurgia "P. Valdoni", Sapienza Università di Roma, Italy
| | - Gennaro Ciliberto
- Istituto Nazionale per lo Studio e la Cura dei Tumori "Fondazione G. Pascale", Napoli, Italy
| | - Giovanni Cuda
- Centro di Ricerca di Biochimica e Biologia Molecolare Avanzata, Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi "Magna Graecia", Catanzaro, Italy
| | - Francesco Costanzo
- Centro di Ricerca di Biochimica e Biologia Molecolare Avanzata, Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi "Magna Graecia", Catanzaro, Italy
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59
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Gammella E, Buratti P, Cairo G, Recalcati S. The transferrin receptor: the cellular iron gate. Metallomics 2018; 9:1367-1375. [PMID: 28671201 DOI: 10.1039/c7mt00143f] [Citation(s) in RCA: 162] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The transferrin receptor (TfR1), which mediates cellular iron uptake through clathrin-dependent endocytosis of iron-loaded transferrin, plays a key role in iron homeostasis. Since the number of TfR1 molecules at the cell surface is the rate-limiting step for iron entry into cells and is essential to prevent iron overload, TfR1 expression is precisely controlled at multiple levels. In this review, we have discussed the latest advances in the molecular regulation of TfR1 expression and we have considered current understanding of TfR1 function beyond its canonical role in providing iron for erythroid precursors and rapidly proliferating cells.
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Affiliation(s)
- Elena Gammella
- Department of Biomedical Sciences for Health, University of Milan, Via Mangiagalli 31, 20133 Milano, Italy.
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60
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Zhang L, Ye Y, Tu H, Hildebrandt MA, Zhao L, Heymach JV, Roth JA, Wu X. MicroRNA-related genetic variants in iron regulatory genes, dietary iron intake, microRNAs and lung cancer risk. Ann Oncol 2018; 28:1124-1129. [PMID: 28453699 DOI: 10.1093/annonc/mdx046] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Background Genetic variations in MicroRNA (miRNA) binding sites may alter structural accessibility of miRNA binding sites to modulate risk of cancer. This large-scale integrative multistage study was aimed to evaluate the interplay of genetic variations in miRNA binding sites of iron regulatory pathway, dietary iron intake and lung cancer (LC) risk. Patients and methods The interplay of genetic variant, dietary iron intake and LC risk was assessed in large-scale case-control study. Functional characterization of the validated SNP and analysis of target miRNAs were performed. Results We found that the miRNA binding site SNP rs1062980 in 3' UTR of Iron-Responsive Element Binding protein 2 gene (IREB2) was associated with a 14% reduced LC risk (P value = 4.9×10 - 9). Comparing to AA genotype, GG genotype was associated with a 27% reduced LC risk. This association was evident in males and ever-smokers but not in females and never-smokers. Higher level of dietary iron intake was significantly associated with 39% reduced LC risk (P value = 2.0×10 - 8). This association was only present in individuals with AG + AA genotypes with a 46% reduced risk (P value = 1.0×10 - 10), but not in GG genotype. The eQTL-analysis showed that rs1062980 significantly alters IREB2 expression level. Rs1062980 is predicted to alter a miR-29 binding site on IREB2 and indeed the expression of miR-29 is inversely correlated with IREB2 expression. Further, we found that higher circulating miR-29a level was significantly associated with 78% increased LC risk. Conclusion The miRNA binding site SNP rs1062980 in iron regulatory pathway, which may alter the expression of IREB2 potentially through modulating the binding of miR-29a, together with dietary iron intake may modify risk of LC both individually and jointly. These discoveries reveal novel pathway for understanding lung cancer tumorigenesis and risk stratification.
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Affiliation(s)
- L Zhang
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - Y Ye
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - H Tu
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - M A Hildebrandt
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - L Zhao
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, USA.,Department of Radiation Oncology, The Forth Military Medical University, XiAn, China
| | - J V Heymach
- Department of Thoracic/Head and Neck Medical Oncology, University of Texas MD Anderson Cancer Center, 2130 West Holcombe Boulevard, Houston, Texas 77030, USA
| | - J A Roth
- Department of Thoracic & Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - X Wu
- Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, USA
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61
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Aron AT, Reeves AG, Chang CJ. Activity-based sensing fluorescent probes for iron in biological systems. Curr Opin Chem Biol 2018; 43:113-118. [PMID: 29306820 DOI: 10.1016/j.cbpa.2017.12.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/13/2017] [Accepted: 12/17/2017] [Indexed: 12/13/2022]
Abstract
Iron is an essential nutrient for life, and its capacity to cycle between different oxidation states is required for processes spanning oxygen transport and respiration to nucleotide synthesis and epigenetic regulation. However, this same redox ability also makes iron, if not regulated properly, a potentially dangerous toxin that can trigger oxidative stress and damage. New methods that enable monitoring of iron in living biological systems, particularly in labile Fe2+ forms, can help identify its contributions to physiology, aging, and disease. In this review, we summarize recent developments in activity-based sensing (ABS) probes for fluorescence Fe2+ detection.
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Affiliation(s)
- Allegra T Aron
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Audrey G Reeves
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Christopher J Chang
- Department of Chemistry, University of California, Berkeley, CA 94720, USA; Departments of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA.
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62
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Expression and function of nuclear receptor coactivator 4 isoforms in transformed endometriotic and malignant ovarian cells. Oncotarget 2017; 9:5344-5367. [PMID: 29435183 PMCID: PMC5797054 DOI: 10.18632/oncotarget.23747] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 12/22/2017] [Indexed: 01/10/2023] Open
Abstract
Iron is proposed to contribute to the transition from endometriosis to specific subtypes of ovarian cancers (OVCAs). Regulation of intracellular iron occurs via a ferritinophagic process involving NCOA4 (Nuclear Receptor Coactivator 4), represented by two major isoforms (NCOA4α and NCOA4β), whose contribution to ovarian cancer biology remains uninvestigated. We thus generated transformed endometriotic cells (via HRASV12A, c-MYCT58A, and p53 inactivation) whose migratory potential was increased in response to conditioned media from senescent endometriotic cells. We identified elevated NCOA4 mRNA in transformed endometriotic cells (relative to non-transformed). Knockdown of NCOA4 increased ferritin heavy chain (FTH1) and p21 protein which was accompanied by reduced cell survival while NCOA4β overexpression reduced colony formation. NCOA4α and NCOA4β mRNA were elevated in malignant versus non-malignant gynecological cells; NCOA4α protein was increased in the assessed malignant cell lines as well as in a series of OVCA subtypes (relative to normal adjacent tissues). Further, NCOA4 protein expression was regulated in a proteasome- and autophagy-independent manner. Collectively, our results implicate NCOA4 in ovarian cancer biology in which it could be involved in the transition from precursors to OVCA.
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63
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Raggi C, Gammella E, Correnti M, Buratti P, Forti E, Andersen JB, Alpini G, Glaser S, Alvaro D, Invernizzi P, Cairo G, Recalcati S. Dysregulation of Iron Metabolism in Cholangiocarcinoma Stem-like Cells. Sci Rep 2017; 7:17667. [PMID: 29247214 PMCID: PMC5732280 DOI: 10.1038/s41598-017-17804-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 11/26/2017] [Indexed: 12/13/2022] Open
Abstract
Cholangiocarcinoma (CCA) is a devastating liver tumour arising from malignant transformation of bile duct epithelial cells. Cancer stem cells (CSC) are a subset of tumour cells endowed with stem-like properties, which play a role in tumour initiation, recurrence and metastasis. In appropriate conditions, CSC form 3D spheres (SPH), which retain stem-like tumour-initiating features. Here, we found different expression of iron proteins indicating increased iron content, oxidative stress and higher expression of CSC markers in CCA-SPH compared to tumour cells growing as monolayers. Exposure to the iron chelator desferrioxamine decreased SPH forming efficiency and the expression of CSC markers and stem-like genes, whereas iron had an opposite effect. Microarray profiles in CCA samples (n = 104) showed decreased H ferritin, hepcidin and ferroportin expression in tumours respect to surrounding liver, whereas transferrin receptor was up-regulated. Moreover, we found a trend toward poorer outcome in CCA patients with elevated expression of ferritin and hepcidin, two major proteins of iron metabolism. These findings, which represent the first evidence of a role for iron in the stem cell compartment as a novel metabolic factor involved in CCA growth, may have implications for a better therapeutic approach.
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Affiliation(s)
- Chiara Raggi
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Rozzano, Italy.,Dipartimento Medicina Sperimentale e Clinica, University of Firence, Firenze, Italy
| | - Elena Gammella
- Department of Biomedical Sciences for Health, University of Milan, Milano, Italy
| | - Margherita Correnti
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Rozzano, Italy
| | - Paolo Buratti
- Department of Biomedical Sciences for Health, University of Milan, Milano, Italy
| | - Elisa Forti
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Rozzano, Italy
| | - Jesper B Andersen
- Biotech Research and Innovation Centre, Department of Health and Medical Sciences University of Copenhagen, Copenhagen, Denmark
| | - Gianfranco Alpini
- Research, Central Texas Veterans Health Care System, Baylor Scott & White Digestive Disease Research Center, Scott & White Health, Department of Medicine, Texas A&M Health Science Center, Temple, TX, USA
| | - Shannon Glaser
- Research, Central Texas Veterans Health Care System, Baylor Scott & White Digestive Disease Research Center, Scott & White Health, Department of Medicine, Texas A&M Health Science Center, Temple, TX, USA
| | - Domenico Alvaro
- Department of Internal Medicine and Medical Specialties, Sapienza University of Rome, Rome, Italy
| | - Pietro Invernizzi
- Division of Gastroenterology and Program for Autoimmune Liver Diseases, International Center for Digestive Health, Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy.
| | - Gaetano Cairo
- Department of Biomedical Sciences for Health, University of Milan, Milano, Italy.
| | - Stefania Recalcati
- Department of Biomedical Sciences for Health, University of Milan, Milano, Italy
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64
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Aron AT, Heffern MC, Lonergan ZR, Vander Wal MN, Blank BR, Spangler B, Zhang Y, Park HM, Stahl A, Renslo AR, Skaar EP, Chang CJ. In vivo bioluminescence imaging of labile iron accumulation in a murine model of Acinetobacter baumannii infection. Proc Natl Acad Sci U S A 2017; 114:12669-12674. [PMID: 29138321 PMCID: PMC5715752 DOI: 10.1073/pnas.1708747114] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Iron is an essential metal for all organisms, yet disruption of its homeostasis, particularly in labile forms that can contribute to oxidative stress, is connected to diseases ranging from infection to cancer to neurodegeneration. Iron deficiency is also among the most common nutritional deficiencies worldwide. To advance studies of iron in healthy and disease states, we now report the synthesis and characterization of iron-caged luciferin-1 (ICL-1), a bioluminescent probe that enables longitudinal monitoring of labile iron pools (LIPs) in living animals. ICL-1 utilizes a bioinspired endoperoxide trigger to release d-aminoluciferin for selective reactivity-based detection of Fe2+ with metal and oxidation state specificity. The probe can detect physiological changes in labile Fe2+ levels in live cells and mice experiencing iron deficiency or overload. Application of ICL-1 in a model of systemic bacterial infection reveals increased iron accumulation in infected tissues that accompany transcriptional changes consistent with elevations in both iron acquisition and retention. The ability to assess iron status in living animals provides a powerful technology for studying the contributions of iron metabolism to physiology and pathology.
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Affiliation(s)
- Allegra T Aron
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Marie C Heffern
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Zachery R Lonergan
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Mark N Vander Wal
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Brian R Blank
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Benjamin Spangler
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Yaofang Zhang
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232
| | - Hyo Min Park
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720
| | - Andreas Stahl
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720
| | - Adam R Renslo
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232;
| | - Christopher J Chang
- Department of Chemistry, University of California, Berkeley, CA 94720;
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
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65
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Mishra P, Tang W, Putluri V, Dorsey TH, Jin F, Wang F, Zhu D, Amable L, Deng T, Zhang S, Killian JK, Wang Y, Minas TZ, Yfantis HG, Lee DH, Sreekumar A, Bustin M, Liu W, Putluri N, Ambs S. ADHFE1 is a breast cancer oncogene and induces metabolic reprogramming. J Clin Invest 2017; 128:323-340. [PMID: 29202474 DOI: 10.1172/jci93815] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 10/17/2017] [Indexed: 12/12/2022] Open
Abstract
Metabolic reprogramming in breast tumors is linked to increases in putative oncogenic metabolites that may contribute to malignant transformation. We previously showed that accumulation of the oncometabolite, 2-hydroxyglutarate (2HG), in breast tumors was associated with MYC signaling, but not with isocitrate dehydrogenase (IDH) mutations, suggesting a distinct mechanism for increased 2HG in breast cancer. Here, we determined that D-2HG is the predominant enantiomer in human breast tumors and show that the D-2HG-producing mitochondrial enzyme, alcohol dehydrogenase, iron-containing protein 1 (ADHFE1), is a breast cancer oncogene that decreases patient survival. We found that MYC upregulates ADHFE1 through changes in iron metabolism while coexpression of both ADHFE1 and MYC strongly enhanced orthotopic tumor growth in MCF7 cells. Moreover, ADHFE1 promoted metabolic reprogramming with increased formation of D-2HG and reactive oxygen, a reductive glutamine metabolism, and modifications of the epigenetic landscape, leading to cellular dedifferentiation, enhanced mesenchymal transition, and phenocopying alterations that occur with high D-2HG levels in cancer cells with IDH mutations. Together, our data support the hypothesis that ADHFE1 and MYC signaling contribute to D-2HG accumulation in breast tumors and show that D-2HG is an oncogenic metabolite and potential driver of disease progression.
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Affiliation(s)
- Prachi Mishra
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA
| | - Wei Tang
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA
| | - Vasanta Putluri
- Department of Molecular and Cell Biology, Verna and Marrs McLean Department of Biochemistry and Alkek Center for Molecular Discovery, and.,Advanced Technology Core, Baylor College of Medicine, Houston, Texas, USA
| | - Tiffany H Dorsey
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA
| | - Feng Jin
- Department of Molecular and Cell Biology, Verna and Marrs McLean Department of Biochemistry and Alkek Center for Molecular Discovery, and.,Advanced Technology Core, Baylor College of Medicine, Houston, Texas, USA
| | - Fang Wang
- Agios Pharmaceuticals, Cambridge, Massachusetts, USA
| | - Donewei Zhu
- Agios Pharmaceuticals, Cambridge, Massachusetts, USA
| | - Lauren Amable
- National Institute of Minority Health and Health Disparities
| | - Tao Deng
- Protein Section, Laboratory of Metabolism, CCR, NCI, and
| | - Shaofei Zhang
- Protein Section, Laboratory of Metabolism, CCR, NCI, and
| | - J Keith Killian
- Genetics Branch, CCR, and Clinical Molecular Profiling Core, NCI, NIH, Bethesda, Maryland, USA
| | - Yonghong Wang
- Genetics Branch, CCR, and Clinical Molecular Profiling Core, NCI, NIH, Bethesda, Maryland, USA
| | - Tsion Z Minas
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA
| | - Harry G Yfantis
- Pathology and Laboratory Medicine, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Dong H Lee
- Pathology and Laboratory Medicine, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Arun Sreekumar
- Department of Molecular and Cell Biology, Verna and Marrs McLean Department of Biochemistry and Alkek Center for Molecular Discovery, and
| | - Michael Bustin
- Protein Section, Laboratory of Metabolism, CCR, NCI, and
| | - Wei Liu
- Agios Pharmaceuticals, Cambridge, Massachusetts, USA
| | - Nagireddy Putluri
- Department of Molecular and Cell Biology, Verna and Marrs McLean Department of Biochemistry and Alkek Center for Molecular Discovery, and.,Advanced Technology Core, Baylor College of Medicine, Houston, Texas, USA
| | - Stefan Ambs
- Laboratory of Human Carcinogenesis, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, Maryland, USA
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66
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Chen X, Zhang J, Yuan L, Lay Y, Wong YK, Lim TK, Ong CS, Lin Q, Wang J, Hua Z. Andrographolide Suppresses MV4-11 Cell Proliferation through the Inhibition of FLT3 Signaling, Fatty Acid Synthesis and Cellular Iron Uptake. Molecules 2017; 22:molecules22091444. [PMID: 28858244 PMCID: PMC6151431 DOI: 10.3390/molecules22091444] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 12/28/2022] Open
Abstract
Background: Andrographolide (ADR), the main active component of Andrographis paniculata, displays anticancer activity in various cancer cell lines, among which leukemia cell lines exhibit the highest sensitivity to ADR. In particular, ADR was also reported to have reduced drug resistance in multidrug resistant cell lines. However, the mechanism of action (MOA) of ADR’s anticancer and anti-drug-resistance activities remain elusive. Methods: In this study, we used the MV4-11 cell line, a FLT3 positive acute myeloid leukemia (AML) cell line that displays multidrug resistance, as our experimental system. We first evaluated the effect of ADR on MV4-11 cell proliferation. Then, a quantitative proteomics approach was applied to identify differentially expressed proteins in ADR-treated MV4-11 cells. Finally, cellular processes and signal pathways affected by ADR in MV4-11 cell were predicted with proteomic analysis and validated with in vitro assays. Results: ADR inhibits MV4-11 cell proliferation in a dose- and time-dependent manner. With a proteomic approach, we discovered that ADR inhibited fatty acid synthesis, cellular iron uptake and FLT3 signaling pathway in MV4-11 cells. Conclusions: ADR inhibits MV4-11 cell proliferation through inhibition of fatty acid synthesis, iron uptake and protein synthesis. Furthermore, ADR reduces drug resistance by blocking FLT3 signaling.
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Affiliation(s)
- Xiao Chen
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China.
| | - Jianbin Zhang
- Department of Oncology, Clinical Research Institute, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou 310014, China.
| | - Lixia Yuan
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
| | - Yifei Lay
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| | - Yin Kwan Wong
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| | - Teck Kwang Lim
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| | - Chye Sun Ong
- Institute of Mental Health, Education Office, Singapore 539747, Singapore.
| | - Qingsong Lin
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| | - Jigang Wang
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
- Changzhou High-Tech Research Institute of Nanjing University, Institute of Biotechnology, Jiangsu Industrial Technology Research Institute and Jiangsu Target Pharma Laboratories Inc., Changzhou 213164, China.
| | - Zichun Hua
- The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China.
- Changzhou High-Tech Research Institute of Nanjing University, Institute of Biotechnology, Jiangsu Industrial Technology Research Institute and Jiangsu Target Pharma Laboratories Inc., Changzhou 213164, China.
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67
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Fanzani A, Poli M. Iron, Oxidative Damage and Ferroptosis in Rhabdomyosarcoma. Int J Mol Sci 2017; 18:ijms18081718. [PMID: 28783123 PMCID: PMC5578108 DOI: 10.3390/ijms18081718] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/02/2017] [Accepted: 08/03/2017] [Indexed: 12/14/2022] Open
Abstract
Recent data have indicated a fundamental role of iron in mediating a non-apoptotic and non-necrotic oxidative form of programmed cell death termed ferroptosis that requires abundant cytosolic free labile iron to promote membrane lipid peroxidation. Different scavenger molecules and detoxifying enzymes, such as glutathione (GSH) and glutathione peroxidase 4 (GPX4), have been shown to overwhelm or exacerbate ferroptosis depending on their expression magnitude. Ferroptosis is emerging as a potential weapon against tumor growth since it has been shown to potentiate cell death in some malignancies. However, this mechanism has been poorly studied in Rhabdomyosarcoma (RMS), a myogenic tumor affecting childhood and adolescence. One of the main drivers of RMS genesis is the Retrovirus Associated DNA Sequences/Extracellular signal Regulated Kinases (RAS/ERK)signaling pathway, the deliberate activation of which correlates with tumor aggressiveness and oxidative stress levels. Since recent studies have indicated that treatment with oxidative inducers can significantly halt RMS tumor progression, in this review we covered different aspects, ranging from iron metabolism in carcinogenesis and tumor growth, to mechanisms of iron-mediated cell death, to highlight the potential role of ferroptosis in counteracting RMS growth.
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Affiliation(s)
- Alessandro Fanzani
- Department of Molecular and Translational Medicine (DMMT), University of Brescia, Viale Europa 11, 25123 Brescia, Italy.
| | - Maura Poli
- Department of Molecular and Translational Medicine (DMMT), University of Brescia, Viale Europa 11, 25123 Brescia, Italy.
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68
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Zhang Y, Qian Y, Zhang J, Yan W, Jung YS, Chen M, Huang E, Lloyd K, Duan Y, Wang J, Liu G, Chen X. Ferredoxin reductase is critical for p53-dependent tumor suppression via iron regulatory protein 2. Genes Dev 2017; 31:1243-1256. [PMID: 28747430 PMCID: PMC5558926 DOI: 10.1101/gad.299388.117] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/26/2017] [Indexed: 01/20/2023]
Abstract
In this study, Chen and colleagues investigated the biological function of ferredoxin reductase (FDXR), a target of p53. They generated a Fdxr-deficient mouse model and found that the signal from FDXR to iron homeostasis and the p53 pathway was transduced by ferredoxin 2, a substrate of FDXR, and that p53 played a role in iron homeostasis and was required for FDXR-mediated iron metabolism, suggesting that the FDXR–p53 loop is critical for tumor suppression via iron homeostasis. Ferredoxin reductase (FDXR), a target of p53, modulates p53-dependent apoptosis and is necessary for steroidogenesis and biogenesis of iron–sulfur clusters. To determine the biological function of FDXR, we generated a Fdxr-deficient mouse model and found that loss of Fdxr led to embryonic lethality potentially due to iron overload in developing embryos. Interestingly, mice heterozygous in Fdxr had a short life span and were prone to spontaneous tumors and liver abnormalities, including steatosis, hepatitis, and hepatocellular carcinoma. We also found that FDXR was necessary for mitochondrial iron homeostasis and proper expression of several master regulators of iron metabolism, including iron regulatory protein 2 (IRP2). Surprisingly, we found that p53 mRNA translation was suppressed by FDXR deficiency via IRP2. Moreover, we found that the signal from FDXR to iron homeostasis and the p53 pathway was transduced by ferredoxin 2, a substrate of FDXR. Finally, we found that p53 played a role in iron homeostasis and was required for FDXR-mediated iron metabolism. Together, we conclude that FDXR and p53 are mutually regulated and that the FDXR–p53 loop is critical for tumor suppression via iron homeostasis.
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Affiliation(s)
- Yanhong Zhang
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, Davis, California 95616, USA
| | - Yingjuan Qian
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, Davis, California 95616, USA.,College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China
| | - Jin Zhang
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, Davis, California 95616, USA
| | - Wensheng Yan
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, Davis, California 95616, USA
| | - Yong-Sam Jung
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, Davis, California 95616, USA.,College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China
| | - Mingyi Chen
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Eric Huang
- Department of Pathology, School of Medicine, University of California at Davis Health, Sacramento, California 95817, USA
| | - Kent Lloyd
- Department of Surgery, School of Medicine, University of California at Davis Health, Sacramento, California 95817, USA
| | - Yuyou Duan
- Department of Dermatology and Internal Medicine, University of California at Davis Health, Sacramento, California 95616, USA
| | - Jian Wang
- Department of Pathology, School of Medicine, Wayne State University, Detroit, Michigan 48201 USA
| | - Gang Liu
- Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Xinbin Chen
- Comparative Oncology Laboratory, Schools of Veterinary Medicine and Medicine, University of California at Davis, Davis, California 95616, USA
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69
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Iron-responsive element-binding protein 2 plays an essential role in regulating prostate cancer cell growth. Oncotarget 2017; 8:82231-82243. [PMID: 29137259 PMCID: PMC5669885 DOI: 10.18632/oncotarget.19288] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/03/2017] [Indexed: 01/10/2023] Open
Abstract
Iron-responsive element-binding proteins (IRPs) are master regulators of cellular iron homeostasis. Our previous work demonstrated that iron homeostasis is altered in prostate cancer and contributes to prostate cancer progression. Here we report that prostate cancer cells overexpress IRP2 and that overexpression of IRP2 drives the altered iron phenotype of prostate cancer cells. IRP2 knockdown in prostate cancer cell lines reduces intracellular iron and causes cell cycle inhibition and apoptosis. Cell cycle analysis demonstrates that IRP2-depleted prostate cancer cells accumulate in G0/G1 due to induction of p15, p21, and p27. Activation of these pathways is sufficient to significantly reduce the growth of PC3 prostate tumors in vivo. In contrast, IRP1 knockdown does not affect iron homeostasis and only modestly affects cell growth, likely through an iron-independent mechanism. These results demonstrate that upregulation of IRP2 in prostate cancer cells co-opts normal iron regulatory mechanisms to facilitate iron retention and drive enhanced tumor growth.
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70
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Horniblow RD, Bedford M, Hollingworth R, Evans S, Sutton E, Lal N, Beggs A, Iqbal TH, Tselepis C. BRAF mutations are associated with increased iron regulatory protein-2 expression in colorectal tumorigenesis. Cancer Sci 2017; 108:1135-1143. [PMID: 28281325 PMCID: PMC5480081 DOI: 10.1111/cas.13234] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 01/01/2023] Open
Abstract
A role for iron in carcinogenesis is supported by evidence that iron metabolism proteins are modulated in cancer progression. To date, however, the expression of iron regulatory protein‐2 (IRP2), which is known to regulate several iron metabolism proteins, has not been assessed in colorectal cancer. Expression of IRP2 was assessed by quantitative RT‐PCR and immunohistochemistry in human colorectal cancer tissue. By interrogating The Cancer Genome Atlas (TCGA) database, expression of IRP2 and transferrin receptor‐1 (TfR1) was assessed relative to common mutations that are known to occur in cancer. The impact of suppressing IRP2 on cellular iron metabolism was also determined by using siRNA and by using the MEK inhibitor trametinib. IRP2 was overexpressed in colorectal cancer compared to normal colonic mucosa and its expression was positively correlated with TfR1 expression. In addition, IRP2 expression was associated with mutations in BRAF. The MEK inhibitor trametinib suppressed IRP2 and this was associated with a suppression in TfR1 and the labile iron pool (LIP). Moreover, epidermal growth factor stimulation resulted in decreased ferritin expression and an increase in the LIP which were independent of IRP2. Results presented here suggest that ablating IRP2 provides a therapeutic platform for intervening in colorectal tumorigenesis.
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Affiliation(s)
- Richard D Horniblow
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Matthew Bedford
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Robert Hollingworth
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Sarah Evans
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Emily Sutton
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Neeraj Lal
- Immunity and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Andrew Beggs
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Tariq H Iqbal
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Chris Tselepis
- Institutes of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
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71
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Mitochondrial AKAP1 supports mTOR pathway and tumor growth. Cell Death Dis 2017; 8:e2842. [PMID: 28569781 PMCID: PMC5520900 DOI: 10.1038/cddis.2017.241] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 04/06/2017] [Accepted: 04/28/2017] [Indexed: 12/23/2022]
Abstract
Mitochondria are the powerhouses of energy production and the sites where metabolic pathway and survival signals integrate and focus, promoting adaptive responses to hormone stimulation and nutrient availability. Increasing evidence suggests that mitochondrial bioenergetics, metabolism and signaling are linked to tumorigenesis. AKAP1 scaffolding protein integrates cAMP and src signaling on mitochondria, regulating organelle biogenesis, oxidative metabolism and cell survival. Here, we provide evidence that AKAP1 is a transcriptional target of Myc and supports the growth of cancer cells. We identify Sestrin2, a leucine sensor and inhibitor of the mammalian target of rapamycin (mTOR), as a novel component of the complex assembled by AKAP1 on mitochondria. Downregulation of AKAP1 impaired mTOR pathway and inhibited glioblastoma growth. Both effects were reversed by concomitant depletion of AKAP1 and sestrin2. High levels of AKAP1 were found in a wide variety of high-grade cancer tissues. In lung cancer, AKAP1 expression correlates with high levels of Myc, mTOR phosphorylation and reduced patient survival. Collectively, these data disclose a previously unrecognized role of AKAP1 in mTOR pathway regulation and cancer growth. AKAP1/mTOR signal integration on mitochondria may provide a new target for cancer therapy.
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72
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Stueckle TA, Davidson DC, Derk R, Kornberg TG, Schwegler-Berry D, Pirela SV, Deloid G, Demokritou P, Luanpitpong S, Rojanasakul Y, Wang L. Evaluation of tumorigenic potential of CeO 2 and Fe 2O 3 engineered nanoparticles by a human cell in vitro screening model. NANOIMPACT 2017; 6:39-54. [PMID: 28367517 PMCID: PMC5372702 DOI: 10.1016/j.impact.2016.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
With rapid development of novel nanotechnologies that incorporate engineered nanomaterials (ENMs) into manufactured products, long-term, low dose ENM exposures in occupational settings is forecasted to occur with potential adverse outcomes to human health. Few ENM human health risk assessment efforts have evaluated tumorigenic potential of ENMs. Two widely used nano-scaled metal oxides (NMOs), cerium oxide (nCeO2) and ferric oxide (nFe2O3) were screened in the current study using a sub-chronic exposure to human primary small airway epithelial cells (pSAECs). Multi-walled carbon nanotubes (MWCNT), a known ENM tumor promoter, was used as a positive control. Advanced dosimetry modeling was employed to ascertain delivered vs. administered dose in all experimental conditions. Cells were continuously exposed in vitro to deposited doses of 0.18 μg/cm2 or 0.06 μg/cm2 of each NMO or MWCNT, respectively, over 6 and 10 weeks, while saline- and dispersant-only exposed cells served as passage controls. Cells were evaluated for changes in several cancer hallmarks, as evidence for neoplastic transformation. At 10 weeks, nFe2O3- and MWCNT-exposed cells displayed a neoplastic-like transformation phenotype with significant increased proliferation, invasion and soft agar colony formation ability compared to controls. nCeO2-exposed cells showed increased proliferative capacity only. Isolated nFe2O3 and MWCNT clones from soft agar colonies retained their respective neoplastic-like phenotypes. Interestingly, nFe2O3-exposed cells, but not MWCNT cells, exhibited immortalization and retention of the neoplastic phenotype after repeated passaging (12 - 30 passages) and after cryofreeze and thawing. High content screening and protein expression analyses in acute exposure ENM studies vs. immortalized nFe2O3 cells, and isolated ENM clones, suggested that long-term exposure to the tested ENMs resulted in iron homeostasis disruption, an increased labile ferrous iron pool, and subsequent reactive oxygen species generation, a well-established tumorigenesis promotor. In conclusion, sub-chronic exposure to human pSAECs with a cancer hallmark screening battery identified nFe2O3 as possessing neoplastic-like transformation ability, thus suggesting that further tumorigenic assessment is needed.
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Affiliation(s)
- Todd A. Stueckle
- HELD, National Institute for Occupational Safety and Health, Morgantown WV, 26505
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown WV, 26506
- Corresponding Author: Todd A. Stueckle, , Phone: 304 285-6098
| | - Donna C. Davidson
- HELD, National Institute for Occupational Safety and Health, Morgantown WV, 26505
| | - Raymond Derk
- HELD, National Institute for Occupational Safety and Health, Morgantown WV, 26505
| | - Tiffany G. Kornberg
- HELD, National Institute for Occupational Safety and Health, Morgantown WV, 26505
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown WV, 26506
| | | | - Sandra V. Pirela
- Center for Nanotechnology and Nanotoxicology, Harvard T. H. Chan School of Public Health, Boston MA
| | - Glen Deloid
- Center for Nanotechnology and Nanotoxicology, Harvard T. H. Chan School of Public Health, Boston MA
| | - Philip Demokritou
- Center for Nanotechnology and Nanotoxicology, Harvard T. H. Chan School of Public Health, Boston MA
| | - Sudjit Luanpitpong
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Yon Rojanasakul
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown WV, 26506
| | - Liying Wang
- HELD, National Institute for Occupational Safety and Health, Morgantown WV, 26505
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73
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Lemler DJ, Lynch ML, Tesfay L, Deng Z, Paul BT, Wang X, Hegde P, Manz DH, Torti SV, Torti FM. DCYTB is a predictor of outcome in breast cancer that functions via iron-independent mechanisms. Breast Cancer Res 2017; 19:25. [PMID: 28270217 PMCID: PMC5341190 DOI: 10.1186/s13058-017-0814-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 02/09/2017] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Duodenal cytochrome b (DCYTB) is a ferrireductase that functions together with divalent metal transporter 1 (DMT1) to mediate dietary iron reduction and uptake in the duodenum. DCYTB is also a member of a 16-gene iron regulatory gene signature (IRGS) that predicts metastasis-free survival in breast cancer patients. To better understand the relationship between DCYTB and breast cancer, we explored in detail the prognostic significance and molecular function of DCYTB in breast cancer. METHODS The prognostic significance of DCYTB expression was evaluated using publicly available microarray data. Signaling Pathway Impact Analysis (SPIA) of microarray data was used to identify potential novel functions of DCYTB. The role of DCYTB was assessed using immunohistochemistry and measurements of iron uptake, iron metabolism, and FAK signaling. RESULTS High DCYTB expression was associated with prolonged survival in two large independent cohorts, together totaling 1610 patients (cohort #1, p = 1.6e-11, n = 741; cohort #2, p = 1.2e-05, n = 869; log-rank test) as well as in the Gene expression-based Outcome for Breast cancer Online (GOBO) cohort (p < 1.0e-05, n = 1379). High DCYTB expression was also associated with increased survival in homogeneously treated groups of patients who received either tamoxifen or chemotherapy. Immunohistochemistry revealed that DCYTB is localized on the plasma membrane of breast epithelial cells, and that expression is dramatically reduced in high-grade tumors. Surprisingly, neither overexpression nor knockdown of DCYTB affected levels of ferritin H, transferrin receptor, labile iron or total cellular iron in breast cancer cells. Because SPIA pathway analysis of patient microarray data revealed an association between DCYTB and the focal adhesion pathway, we examined the influence of DCYTB on FAK activation in breast cancer cells. These experiments reveal that DCYTB reduces adhesion and activation of focal adhesion kinase (FAK) and its adapter protein paxillin. CONCLUSIONS DCYTB is an important predictor of outcome and is associated with response to therapy in breast cancer patients. DCYTB does not affect intracellular iron in breast cancer cells. Instead, DCYTB may retard cancer progression by reducing activation of FAK, a kinase that plays a central role in tumor cell adhesion and metastasis.
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Affiliation(s)
- David J. Lemler
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030 USA
- Present address: Department of Molecular Biomedical Sciences, North Carolina State University, CVM Research Building 474, Raleigh, NC 27695 USA
| | - Miranda L. Lynch
- Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, CT 06030 USA
- Present address: Statistical Sciences Group CCS-6, Los Alamos National Laboratory, Los Alamos, NM 87545 USA
| | - Lia Tesfay
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - Zhiyong Deng
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - Bibbin T. Paul
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - Xiaohong Wang
- Department of Pathology, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - Poornima Hegde
- Department of Pathology, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - David H. Manz
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030 USA
- School of Dental Medicine, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - Suzy V. Torti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030 USA
| | - Frank M. Torti
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030 USA
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Chifman J, Arat S, Deng Z, Lemler E, Pino JC, Harris LA, Kochen MA, Lopez CF, Akman SA, Torti FM, Torti SV, Laubenbacher R. Activated Oncogenic Pathway Modifies Iron Network in Breast Epithelial Cells: A Dynamic Modeling Perspective. PLoS Comput Biol 2017; 13:e1005352. [PMID: 28166223 PMCID: PMC5293201 DOI: 10.1371/journal.pcbi.1005352] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 01/08/2017] [Indexed: 12/21/2022] Open
Abstract
Dysregulation of iron metabolism in cancer is well documented and it has been suggested that there is interdependence between excess iron and increased cancer incidence and progression. In an effort to better understand the linkages between iron metabolism and breast cancer, a predictive mathematical model of an expanded iron homeostasis pathway was constructed that includes species involved in iron utilization, oxidative stress response and oncogenic pathways. The model leads to three predictions. The first is that overexpression of iron regulatory protein 2 (IRP2) recapitulates many aspects of the alterations in free iron and iron-related proteins in cancer cells without affecting the oxidative stress response or the oncogenic pathways included in the model. This prediction was validated by experimentation. The second prediction is that iron-related proteins are dramatically affected by mitochondrial ferritin overexpression. This prediction was validated by results in the pertinent literature not used for model construction. The third prediction is that oncogenic Ras pathways contribute to altered iron homeostasis in cancer cells. This prediction was validated by a combination of simulation experiments of Ras overexpression and catalase knockout in conjunction with the literature. The model successfully captures key aspects of iron metabolism in breast cancer cells and provides a framework upon which more detailed models can be built. Iron is required for cellular metabolism and growth, but can be toxic due to its ability to cause high oxidative stress and consequently DNA damage. To prevent damage, all organisms that require iron have developed mechanisms to tightly control iron levels. Dysregulation of iron metabolism is detrimental and can contribute to a wide range of diseases, including cancer. This paper presents a predictive mathematical model of iron regulation linked to iron utilization, oxidative stress, and the oncogenic response specific to normal breast epithelial cells. The model uses a discrete modeling framework to generate novel biological hypotheses for an investigation of how normal breast cells become malignant cells, capturing a breast cancer phenotype of iron homeostasis through overexpression and knockout simulations. The new biology discovered is (1) IRP2 overexpression alters the iron homeostasis pathway in breast cells, without affecting the oxidative stress response or oncogenic pathways, (2) an activated oncogenic pathway disrupts iron regulation in breast cancer cells.
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Affiliation(s)
- Julia Chifman
- Department of Mathematics and Statistics, American University, Washington, DC, USA
| | - Seda Arat
- The Jackson Laboratory, Bar Harbor, ME, USA
| | - Zhiyong Deng
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA
| | - Erica Lemler
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA
| | - James C. Pino
- Chemical and Physical Biology Graduate Program, Vanderbilt University, Nashville, TN, USA
| | - Leonard A. Harris
- Department of Cancer Biology, Vanderbilt University, Nashville, TN, USA
| | - Michael A. Kochen
- Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, USA
| | - Carlos F. Lopez
- Department of Cancer Biology, Vanderbilt University, Nashville, TN, USA
- Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, USA
- Center for Quantitative Science, Vanderbilt University, Nashville, TN, USA
| | - Steven A. Akman
- Cancer Program, Roper St Francis HealthCare, Charleston, SC, USA
| | - Frank M. Torti
- Department of Medicine, University of Connecticut Health Center, Farmington, CT, USA
| | - Suzy V. Torti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA
| | - Reinhard Laubenbacher
- Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, CT, USA
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
- * E-mail:
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75
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Spangler B, Fontaine SD, Shi Y, Sambucetti L, Mattis AN, Hann B, Wells JA, Renslo AR. A Novel Tumor-Activated Prodrug Strategy Targeting Ferrous Iron Is Effective in Multiple Preclinical Cancer Models. J Med Chem 2016; 59:11161-11170. [PMID: 27936709 PMCID: PMC5184369 DOI: 10.1021/acs.jmedchem.6b01470] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
Here we describe
a new approach for tumor targeting in which augmented
concentrations of Fe(II) in cancer cells and/or the tumor microenvironment
triggers drug release from an Fe(II)-reactive prodrug conjugate. The
1,2,4-trioxolane scaffold developed to enable this approach can in
principle be applied to a broad range of cancer therapeutics and is
illustrated here with Fe(II)-targeted forms of a microtubule toxin
and a duocarmycin-class DNA-alkylating agent. We show that the intrinsic
reactivity/toxicity of the duocarmycin analog is masked in the conjugated
form and this greatly reduced toxicity in mice. This in turn permitted
elevated dosing levels, leading to higher systemic exposure and a
significantly improved response in tumor xenograft models. Overall
our results suggest that Fe(II)-dependent drug delivery via trioxolane
conjugates could have significant utility in expanding the therapeutic
index of a range of clinical and preclinical stage cancer chemotherapeutics.
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Affiliation(s)
- Benjamin Spangler
- Graduate Program in Chemistry and Chemical Biology, University of California-San Francisco , San Francisco, California 94158, United States.,Department of Pharmaceutical Chemistry, University of California-San Francisco , San Francisco, California 94158, United States
| | - Shaun D Fontaine
- Department of Pharmaceutical Chemistry, University of California-San Francisco , San Francisco, California 94158, United States
| | - Yihui Shi
- SRI International , Menlo Park, California 94025-3493, United States
| | - Lidia Sambucetti
- SRI International , Menlo Park, California 94025-3493, United States
| | | | - Byron Hann
- Preclinical Therapeutic Core, University of California-San Francisco , San Francisco, California 94158, United States
| | - James A Wells
- Department of Pharmaceutical Chemistry, University of California-San Francisco , San Francisco, California 94158, United States.,Department of Cellular and Molecular Pharmacology, University of California-San Francisco , San Francisco, California 94158, United States
| | - Adam R Renslo
- Department of Pharmaceutical Chemistry, University of California-San Francisco , San Francisco, California 94158, United States
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76
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Induction of iron excess restricts malignant plasma cells expansion and potentiates bortezomib effect in models of multiple myeloma. Leukemia 2016; 31:967-970. [PMID: 27881873 DOI: 10.1038/leu.2016.346] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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77
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Aron AT, Loehr MO, Bogena J, Chang CJ. An Endoperoxide Reactivity-Based FRET Probe for Ratiometric Fluorescence Imaging of Labile Iron Pools in Living Cells. J Am Chem Soc 2016; 138:14338-14346. [PMID: 27768321 PMCID: PMC5749882 DOI: 10.1021/jacs.6b08016] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Iron is essential for sustaining
life, as its ability to cycle
between multiple oxidation states is critical for catalyzing chemical
transformations in biological systems. However, without proper regulation,
this same redox capacity can trigger oxidative stress events that
contribute to aging along with diseases ranging from cancer to cardiovascular
and neurodegenerative disorders. Despite its importance, methods for
monitoring biological iron bound weakly to cellular ligands−the
labile iron pool−to generate a response that preserves spatial
and temporal information remain limited, owing to the potent fluorescence
quenching ability of iron. We report the design, synthesis, and biological
evaluation of FRET Iron Probe 1 (FIP-1), a reactivity-based probe
that enables ratiometric fluorescence imaging of labile iron pools
in living systems. Inspired by antimalarial natural products and related
therapeutics, FIP-1 links two fluorophores (fluorescein and Cy3) through
an Fe(II)-cleavable endoperoxide bridge, where Fe(II)-triggered peroxide
cleavage leads to a decrease in fluorescence resonance energy transfer
(FRET) from the fluorescein donor to Cy3 acceptor by splitting these
two dyes into separate fragments. FIP-1 responds to Fe(II) in aqueous
buffer with selectivity over competing metal ions and is capable of
detecting changes in labile iron pools within living cells with iron
supplementation and/or depletion. Moreover, application of FIP-1 to
a model of ferroptosis reveals a change in labile iron pools during
this form of cell death, providing a starting point to study iron
signaling in living systems.
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Affiliation(s)
- Allegra T Aron
- Department of Chemistry, ‡Department of Molecular and Cell Biology, and §Howard Hughes Medical Institute, University of California, Berkeley , Berkeley, California 94720, United States
| | - Morten O Loehr
- Department of Chemistry, ‡Department of Molecular and Cell Biology, and §Howard Hughes Medical Institute, University of California, Berkeley , Berkeley, California 94720, United States
| | - Jana Bogena
- Department of Chemistry, ‡Department of Molecular and Cell Biology, and §Howard Hughes Medical Institute, University of California, Berkeley , Berkeley, California 94720, United States
| | - Christopher J Chang
- Department of Chemistry, ‡Department of Molecular and Cell Biology, and §Howard Hughes Medical Institute, University of California, Berkeley , Berkeley, California 94720, United States
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78
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A reactivity-based probe of the intracellular labile ferrous iron pool. Nat Chem Biol 2016; 12:680-5. [PMID: 27376690 PMCID: PMC4990480 DOI: 10.1038/nchembio.2116] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/12/2016] [Indexed: 12/14/2022]
Abstract
Improved methods for studying intracellular reactive iron(II) are of significant interest for studies of iron metabolism and disease relevant changes in iron homeostasis. Here we describe a highly-selective reactivity-based probe in which Fenton-type reaction with intracellular labile iron(II) leads to unmasking of the aminonucleoside puromycin. Puromycin leaves a permanent and dose-dependent mark on treated cells that can be detected with high sensitivity and precision using the high-content, plate-based immunofluorescence assay described. Using this new probe and screening approach, we detected alteration of cellular labile iron(II) in response extracellular iron conditioning, overexpression of iron storage and/or export proteins, and post-translational regulation of iron export. Finally, we utilized this new tool to demonstrate the presence of augmented labile iron(II) pools in cancer cells as compared to non-tumorigenic cells.
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79
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Yan FQ, Wang JQ, Tsai YP, Wu KJ. HSP60 overexpression increases the protein levels of the p110α subunit of phosphoinositide 3-kinase and c-Myc. Clin Exp Pharmacol Physiol 2016; 42:1092-7. [PMID: 26174078 DOI: 10.1111/1440-1681.12457] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 07/07/2015] [Accepted: 07/09/2015] [Indexed: 12/26/2022]
Abstract
Heat shock protein 60 (HSP60) is a chaperone protein which plays an essential role in facilitating the folding of many newly synthesized proteins to reach their native forms. Increased HSP60 expression is observed in various types of human cancers. However, proteins induced by HSP60 to mediate transformation remain largely unknown. Here we show that HSP60 overexpression increases the protein levels of the p110α subunit of phosphoinositide 3-kinase (PI3K). The amino acid domain 288-383 of HSP60 is used to increase the protein levels. Overexpression of HSP60 also induces the levels of phosphorylated Akt. In addition, the amino acid domain 288-383 of HSP60 is used to induce c-Myc expression. Finally, a mono-ubiquitinated form of β-catenin has a higher activity to activate β-catenin downstream targets compared to wild-type β-catenin. These results indicate that HSP60 overexpression induces the levels or activity of multiple oncogenic proteins to mediate transformation.
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Affiliation(s)
- Feng-Qin Yan
- Department of Radiotherapy, Zhejiang Cancer Hospital, Hangzhou, China
| | - Jian-Qiu Wang
- Institute of Ageing Research, School of Medicine, Hangzhou Normal University, Hangzhou, China
| | - Ya-Ping Tsai
- Genome Research Centre, National Yang-Ming University, Taipei, Taiwan
| | - Kou-Juey Wu
- Research Centre for Tumor Medical Science, Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan
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80
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Lui GYL, Kovacevic Z, Richardson V, Merlot AM, Kalinowski DS, Richardson DR. Targeting cancer by binding iron: Dissecting cellular signaling pathways. Oncotarget 2016; 6:18748-79. [PMID: 26125440 PMCID: PMC4662454 DOI: 10.18632/oncotarget.4349] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 06/12/2015] [Indexed: 12/30/2022] Open
Abstract
Newer and more potent therapies are urgently needed to effectively treat advanced cancers that have developed resistance and metastasized. One such strategy is to target cancer cell iron metabolism, which is altered compared to normal cells and may facilitate their rapid proliferation. This is supported by studies reporting the anti-neoplastic activities of the clinically available iron chelators, desferrioxamine and deferasirox. More recently, ligands of the di-2-pyridylketone thiosemicarbazone (DpT) class have demonstrated potent and selective anti-proliferative activity across multiple cancer-types in vivo, fueling studies aimed at dissecting their molecular mechanisms of action. In the past five years alone, significant advances have been made in understanding how chelators not only modulate cellular iron metabolism, but also multiple signaling pathways implicated in tumor progression and metastasis. Herein, we discuss recent research on the targeting of iron in cancer cells, with a focus on the novel and potent DpT ligands. Several key studies have revealed that iron chelation can target the AKT, ERK, JNK, p38, STAT3, TGF-β, Wnt and autophagic pathways to subsequently inhibit cellular proliferation, the epithelial-mesenchymal transition (EMT) and metastasis. These developments emphasize that these novel therapies could be utilized clinically to effectively target cancer.
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Affiliation(s)
- Goldie Y L Lui
- Department of Pathology and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Zaklina Kovacevic
- Department of Pathology and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Vera Richardson
- Department of Pathology and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Angelica M Merlot
- Department of Pathology and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Danuta S Kalinowski
- Department of Pathology and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
| | - Des R Richardson
- Department of Pathology and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
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81
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Hartl M. The Quest for Targets Executing MYC-Dependent Cell Transformation. Front Oncol 2016; 6:132. [PMID: 27313991 PMCID: PMC4889588 DOI: 10.3389/fonc.2016.00132] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/20/2016] [Indexed: 12/26/2022] Open
Abstract
MYC represents a transcription factor with oncogenic potential converting multiple cellular signals into a broad transcriptional response, thereby controlling the expression of numerous protein-coding and non-coding RNAs important for cell proliferation, metabolism, differentiation, and apoptosis. Constitutive activation of MYC leads to neoplastic cell transformation, and deregulated MYC alleles are frequently observed in many human cancer cell types. Multiple approaches have been performed to isolate genes differentially expressed in cells containing aberrantly activated MYC proteins leading to the identification of thousands of putative targets. Functional analyses of genes differentially expressed in MYC-transformed cells had revealed that so far more than 40 upregulated or downregulated MYC targets are actively involved in cell transformation or tumorigenesis. However, further systematic and selective approaches are required for determination of the known or yet unidentified targets responsible for processing the oncogenic MYC program. The search for critical targets in MYC-dependent tumor cells is exacerbated by the fact that during tumor development, cancer cells progressively evolve in a multistep process, thereby acquiring their characteristic features in an additive manner. Functional expression cloning, combinatorial gene expression, and appropriate in vivo tests could represent adequate tools for dissecting the complex scenario of MYC-specified cell transformation. In this context, the central goal is to identify a minimal set of targets that suffices to phenocopy oncogenic MYC. Recently developed genomic editing tools could be employed to confirm the requirement of crucial transformation-associated targets. Knowledge about essential MYC-regulated genes is beneficial to expedite the development of specific inhibitors to interfere with growth and viability of human tumor cells in which MYC is aberrantly activated. Approaches based on the principle of synthetic lethality using MYC-overexpressing cancer cells and chemical or RNAi libraries have been employed to search for novel anticancer drugs, also leading to the identification of several druggable targets. Targeting oncogenic MYC effector genes instead of MYC may lead to compounds with higher specificities and less side effects. This class of drugs could also display a wider pharmaceutical window because physiological functions of MYC, which are important for normal cell growth, proliferation, and differentiation would be less impaired.
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Affiliation(s)
- Markus Hartl
- Institute of Biochemistry and Center of Molecular Biosciences (CMBI), University of Innsbruck , Innsbruck , Austria
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82
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Redox cycling metals: Pedaling their roles in metabolism and their use in the development of novel therapeutics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:727-48. [PMID: 26844773 DOI: 10.1016/j.bbamcr.2016.01.026] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/29/2016] [Indexed: 12/12/2022]
Abstract
Essential metals, such as iron and copper, play a critical role in a plethora of cellular processes including cell growth and proliferation. However, concomitantly, excess of these metal ions in the body can have deleterious effects due to their ability to generate cytotoxic reactive oxygen species (ROS). Thus, the human body has evolved a very well-orchestrated metabolic system that keeps tight control on the levels of these metal ions. Considering their very high proliferation rate, cancer cells require a high abundance of these metals compared to their normal counterparts. Interestingly, new anti-cancer agents that take advantage of the sensitivity of cancer cells to metal sequestration and their susceptibility to ROS have been developed. These ligands can avidly bind metal ions to form redox active metal complexes, which lead to generation of cytotoxic ROS. Furthermore, these agents also act as potent metastasis suppressors due to their ability to up-regulate the metastasis suppressor gene, N-myc downstream regulated gene 1. This review discusses the importance of iron and copper in the metabolism and progression of cancer, how they can be exploited to target tumors and the clinical translation of novel anti-cancer chemotherapeutics.
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83
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Regulation of iron homeostasis by the p53-ISCU pathway. Sci Rep 2015; 5:16497. [PMID: 26560363 PMCID: PMC4642350 DOI: 10.1038/srep16497] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 10/15/2015] [Indexed: 11/09/2022] Open
Abstract
Accumulation of iron in tissues increases the risk of cancer, but iron regulatory mechanisms in cancer tissues are largely unknown. Here, we report that p53 regulates iron metabolism through the transcriptional regulation of ISCU (iron-sulfur cluster assembly enzyme), which encodes a scaffold protein that plays a critical role in Fe-S cluster biogenesis. p53 activation induced ISCU expression through binding to an intronic p53-binding site. Knockdown of ISCU enhanced the binding of iron regulatory protein 1 (IRP1), a cytosolic Fe-S protein, to an iron-responsive element in the 5′ UTR of ferritin heavy polypeptide 1 (FTH1) mRNA and subsequently reduced the translation of FTH1, a major iron storage protein. In addition, in response to DNA damage, p53 induced FTH1 and suppressed transferrin receptor, which regulates iron entry into cells. HCT116 p53+/+ cells were resistant to iron accumulation, but HCT116 p53−/− cells accumulated intracellular iron after DNA damage. Moreover, excess dietary iron caused significant elevation of serum iron levels in p53−/− mice. ISCU expression was decreased in the majority of human liver cancer tissues, and its reduced expression was significantly associated with p53 mutation. Our finding revealed a novel role of the p53-ISCU pathway in the maintenance of iron homeostasis in hepatocellular carcinogenesis.
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84
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Schonberg DL, Miller TE, Wu Q, Flavahan WA, Das NK, Hale JS, Hubert CG, Mack SC, Jarrar AM, Karl RT, Rosager AM, Nixon AM, Tesar PJ, Hamerlik P, Kristensen BW, Horbinski C, Connor JR, Fox PL, Lathia JD, Rich JN. Preferential Iron Trafficking Characterizes Glioblastoma Stem-like Cells. Cancer Cell 2015; 28:441-455. [PMID: 26461092 PMCID: PMC4646058 DOI: 10.1016/j.ccell.2015.09.002] [Citation(s) in RCA: 226] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 05/31/2015] [Accepted: 09/09/2015] [Indexed: 12/29/2022]
Abstract
Glioblastomas display hierarchies with self-renewing cancer stem-like cells (CSCs). RNA sequencing and enhancer mapping revealed regulatory programs unique to CSCs causing upregulation of the iron transporter transferrin, the top differentially expressed gene compared with tissue-specific progenitors. Direct interrogation of iron uptake demonstrated that CSCs potently extract iron from the microenvironment more effectively than other tumor cells. Systematic interrogation of iron flux determined that CSCs preferentially require transferrin receptor and ferritin, two core iron regulators, to propagate and form tumors in vivo. Depleting ferritin disrupted CSC mitotic progression, through the STAT3-FoxM1 regulatory axis, revealing an iron-regulated CSC pathway. Iron is a unique, primordial metal fundamental for earliest life forms, on which CSCs have an epigenetically programmed, targetable dependence.
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Affiliation(s)
- David L Schonberg
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Tyler E Miller
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Qiulian Wu
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - William A Flavahan
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Nupur K Das
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - James S Hale
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Christopher G Hubert
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Stephen C Mack
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Awad M Jarrar
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Robert T Karl
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Ann Mari Rosager
- Department of Clinical Pathology, Odense University Hospital, 5000 Odense, Denmark
| | - Anne M Nixon
- Department of Neurosurgery, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Paul J Tesar
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Petra Hamerlik
- Brain Tumor Biology Group, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
| | - Bjarne W Kristensen
- Department of Clinical Pathology, Odense University Hospital, 5000 Odense, Denmark
| | - Craig Horbinski
- Division of Neuropathology, Department of Pathology, University of Kentucky, Lexington, KY 40536, USA
| | - James R Connor
- Department of Neurosurgery, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Paul L Fox
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Justin D Lathia
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jeremy N Rich
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic, Cleveland, OH 44195, USA.
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85
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Xu W, Barrientos T, Mao L, Rockman HA, Sauve AA, Andrews NC. Lethal Cardiomyopathy in Mice Lacking Transferrin Receptor in the Heart. Cell Rep 2015; 13:533-545. [PMID: 26456827 DOI: 10.1016/j.celrep.2015.09.023] [Citation(s) in RCA: 205] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 08/21/2015] [Accepted: 09/04/2015] [Indexed: 01/26/2023] Open
Abstract
Both iron overload and iron deficiency have been associated with cardiomyopathy and heart failure, but cardiac iron utilization is incompletely understood. We hypothesized that the transferrin receptor (Tfr1) might play a role in cardiac iron uptake and used gene targeting to examine the role of Tfr1 in vivo. Surprisingly, we found that decreased iron, due to inactivation of Tfr1, was associated with severe cardiac consequences. Mice lacking Tfr1 in the heart died in the second week of life and had cardiomegaly, poor cardiac function, failure of mitochondrial respiration, and ineffective mitophagy. The phenotype could only be rescued by aggressive iron therapy, but it was ameliorated by administration of nicotinamide riboside, an NAD precursor. Our findings underscore the importance of both Tfr1 and iron in the heart, and may inform therapy for patients with heart failure.
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Affiliation(s)
- Wenjing Xu
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Duke University, Durham, NC 27705, USA
| | - Tomasa Barrientos
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Duke University, Durham, NC 27705, USA
| | - Lan Mao
- Department of Medicine, Duke University School of Medicine, Duke University, Durham, NC 27705, USA
| | - Howard A Rockman
- Department of Medicine, Duke University School of Medicine, Duke University, Durham, NC 27705, USA
| | - Anthony A Sauve
- Department of Pharmacology, Weill Cornell Medical College, Cornell University, New York, NY 10065, USA
| | - Nancy C Andrews
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Duke University, Durham, NC 27705, USA; Department of Pediatrics, Duke University School of Medicine, Duke University, Durham, NC 27705, USA.
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86
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Iron deficiency upregulates Egr1 expression. GENES AND NUTRITION 2015; 10:468. [PMID: 25981695 DOI: 10.1007/s12263-015-0468-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 05/08/2015] [Indexed: 01/21/2023]
Abstract
Iron-deficient anemia is a prevalent disease among humans. We searched for genes regulated by iron deficiency and its regulated mechanism. cDNA microarrays were performed using Hepa1c1c7 cells treated with 100 μM desferrioxamine (DFO), an iron chelator. Early growth response 1 (Egr1) was upregulated with at least 20-fold increase within 4 h and lasted for 24 h, which was confirmed by qRT-PCR. This activation was not seen by ferric ammonium citrate (FAC). DFO increased the transcriptional activity of Egr1-luc (-604 to +160) and serum response element (SRE)-luc reporters by 2.7-folds. In addition, cycloheximide lowered DFO-induced Egr1 mRNA levels. The upregulation of Egr1 by DFO was accompanied by sustained ERK signals along with phosphorylation of Elk-1. The ERK inhibitor (PD98059) prevented the DFO-induced Egr1 mRNAs. Overexpression of Elk-1 mutant (pElk-1S383A) decreased Egr1 reporter activity. DFO lowered reactive oxygen species (ROS) production and increased caspase 3/7 activity and cell death. DFO-induced iron deficiency upregulates Egr1 in part through transcriptional activation via ERK and Elk-1 signals, which may be important in the regulation of cell death in hepatoma cells. Our study demonstrated that iron depletion controlled the expression of Egr1, which might contribute to decisions about cellular fate in response to iron deficiency.
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87
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Bresgen N, Eckl PM. Oxidative stress and the homeodynamics of iron metabolism. Biomolecules 2015; 5:808-47. [PMID: 25970586 PMCID: PMC4496698 DOI: 10.3390/biom5020808] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/12/2022] Open
Abstract
Iron and oxygen share a delicate partnership since both are indispensable for survival, but if the partnership becomes inadequate, this may rapidly terminate life. Virtually all cell components are directly or indirectly affected by cellular iron metabolism, which represents a complex, redox-based machinery that is controlled by, and essential to, metabolic requirements. Under conditions of increased oxidative stress—i.e., enhanced formation of reactive oxygen species (ROS)—however, this machinery may turn into a potential threat, the continued requirement for iron promoting adverse reactions such as the iron/H2O2-based formation of hydroxyl radicals, which exacerbate the initial pro-oxidant condition. This review will discuss the multifaceted homeodynamics of cellular iron management under normal conditions as well as in the context of oxidative stress.
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Affiliation(s)
- Nikolaus Bresgen
- Department of Cell Biology, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
| | - Peter M Eckl
- Department of Cell Biology, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
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88
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Padmanabhan H, Brookes MJ, Iqbal T. Iron and colorectal cancer: evidence from in vitro and animal studies. Nutr Rev 2015; 73:308-17. [DOI: 10.1093/nutrit/nuu015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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89
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H-ferritin-regulated microRNAs modulate gene expression in K562 cells. PLoS One 2015; 10:e0122105. [PMID: 25815883 PMCID: PMC4376865 DOI: 10.1371/journal.pone.0122105] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/17/2015] [Indexed: 01/13/2023] Open
Abstract
In a previous study, we showed that the silencing of the heavy subunit (FHC) offerritin, the central iron storage molecule in the cell, is accompanied by a modification in global gene expression. In this work, we explored whether different FHC amounts might modulate miRNA expression levels in K562 cells and studied the impact of miRNAs in gene expression profile modifications. To this aim, we performed a miRNA-mRNA integrative analysis in K562 silenced for FHC (K562shFHC) comparing it with K562 transduced with scrambled RNA (K562shRNA). Four miRNAs, namely hsa-let-7g, hsa-let-7f, hsa-let-7i and hsa-miR-125b, were significantly up-regulated in silenced cells. The remarkable down-regulation of these miRNAs, following FHC expression rescue, supports a specific relation between FHC silencing and miRNA-modulation. The integration of target predictions with miRNA and gene expression profiles led to the identification of a regulatory network which includes the miRNAs up-regulated by FHC silencing, as well as91 down-regulated putative target genes. These genes were further classified in 9 networks; the highest scoring network, “Cell Death and Survival, Hematological System Development and Function, Hematopoiesis”, is composed by 18 focus molecules including RAF1 and ERK1/2. We confirmed that, following FHC silencing, ERK1/2 phosphorylation is severely impaired and that RAF1 mRNA is significantly down-regulated. Taken all together, our data indicate that, in our experimental model, FHC silencing may affect RAF1/pERK1/2 levels through the modulation of a specific set of miRNAs and add new insights in to the relationship among iron homeostasis and miRNAs.
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90
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Bordini J, Bertilaccio MTS, Ponzoni M, Fermo I, Chesi M, Bergsagel PL, Camaschella C, Campanella A. Erythroblast apoptosis and microenvironmental iron restriction trigger anemia in the VK*MYC model of multiple myeloma. Haematologica 2015; 100:834-841. [PMID: 25715406 DOI: 10.3324/haematol.2014.118000] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 02/23/2015] [Indexed: 12/30/2022] Open
Abstract
Multiple myeloma is a malignant disorder characterized by bone marrow proliferation of plasma cells and by overproduction of monoclonal immunoglobulin detectable in the sera (M-spike). Anemia is a common complication of multiple myeloma, but the underlying pathophysiological mechanisms have not been completely elucidated. We aimed to identify the different determinants of anemia using the Vk*MYC mouse, which spontaneously develops an indolent bone marrow localized disease with aging. Affected Vk*MYC mice develop a mild normochromic normocytic anemia. We excluded the possibility that anemia results from defective erythropoietin production, inflammation or increased hepcidin expression. Mature erythroid precursors are reduced in Vk*MYC bone marrow compared with wild-type. Malignant plasma cells express the apoptogenic receptor Fas ligand and, accordingly, active caspase 8 is detected in maturing erythroblasts. Systemic iron homeostasis is not compromised in Vk*MYC animals, but high expression of the iron importer CD71 by bone marrow plasma cells and iron accumulation in bone marrow macrophages suggest that iron competition takes place in the local multiple myeloma microenvironment, which might contribute to anemia. In conclusion, the mild anemia of the Vk*MYC model is mainly related to the local effect of the bone marrow malignant clone in the absence of an overt inflammatory status. We suggest that this reproduces the initial events triggering anemia in patients.
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Affiliation(s)
- Jessica Bordini
- Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | | | - Maurilio Ponzoni
- Pathology and Myeloma Units, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Isabella Fermo
- Division of Immunology, Transplants and Infectious Diseases IRCCS Ospedale San Raffaele, Milan, Italy
| | - Marta Chesi
- Comprehensive Cancer Center, Mayo Clinic AZ, USA
| | | | - Clara Camaschella
- Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy Vita-Salute San Raffaele University, Milan, Italy
| | - Alessandro Campanella
- Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy Fondazione Centro San Raffaele, Milan, Italy
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91
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McCarty MF, Contreras F. Increasing Superoxide Production and the Labile Iron Pool in Tumor Cells may Sensitize Them to Extracellular Ascorbate. Front Oncol 2014; 4:249. [PMID: 25279352 PMCID: PMC4165285 DOI: 10.3389/fonc.2014.00249] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 09/01/2014] [Indexed: 12/23/2022] Open
Abstract
Low millimolar concentrations of ascorbate are capable of inflicting lethal damage on a high proportion of cancer cells lines, yet leave non-transformed cell lines unscathed. Extracellular generation of hydrogen peroxide, reflecting reduction of molecular oxygen by ascorbate, has been shown to mediate this effect. Although some cancer cell lines express low catalase activity, this cannot fully explain the selective sensitivity of cancer cells to hydrogen peroxide. Ranzato and colleagues have presented evidence for a plausible new explanation of this sensitivity - a high proportion of cancers, via NADPH oxidase complexes or dysfunctional mitochondria, produce elevated amounts of superoxide. This superoxide, via a transition metal-catalyzed transfer of an electron to the hydrogen peroxide produced by ascorbate, can generate deadly hydroxyl radical (Haber-Weiss reaction). It thus can be predicted that concurrent measures which somewhat selectively boost superoxide production in cancers will enhance their sensitivity to i.v. ascorbate therapy. One way to achieve this is to increase the provision of substrate to cancer mitochondria. Measures which inhibit the constitutive hypoxia-inducible factor-1 (HIF-1) activity in cancers (such as salsalate and mTORC1 inhibitors, or an improvement of tumor oxygenation), or that inhibit the HIF-1-inducible pyruvate dehydrogenase kinase (such as dichloroacetate), can be expected to increase pyruvate oxidation. A ketogenic diet should provide more lipid substrate for tumor mitochondria. The cancer-killing activity of 42°C hyperthermia is to some degree contingent on an increase in oxidative stress, likely of mitochondrial origin; reports that hydrogen peroxide synergizes with hyperthermia in killing cancer cells suggest that hyperthermia and i.v. ascorbate could potentiate each other's efficacy. A concurrent enhancement of tumor oxygenation might improve results by decreasing HIF-1 activity while increasing the interaction of ascorbic acid with oxygen. An increased pool of labile iron in cancer cells may contribute to the selective susceptibility of many cancers to i.v. ascorbate; antagonism of NF-kappaB activity with salicylate, and intravenous iron administration, could be employed to further elevate free iron in cancers.
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92
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Shi ZH, Shi FF, Wang YQ, Sheftel AD, Nie G, Zhao YS, You LH, Gou YJ, Duan XL, Zhao BL, Xu HM, Li CY, Chang YZ. Mitochondrial ferritin, a new target for inhibiting neuronal tumor cell proliferation. Cell Mol Life Sci 2014; 72:983-97. [PMID: 25213357 PMCID: PMC4323545 DOI: 10.1007/s00018-014-1730-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 02/07/2023]
Abstract
Mitochondrial ferritin (FtMt) has a significant effect on the regulation of cytosolic and mitochondrial iron levels. However, because of the deficiency of iron regulatory elements (IRE) in FtMt’s gene sequence, the exact function of FtMt remains unclear. In the present study, we found that FtMt dramatically inhibited SH-SY5Y cell proliferation and tumor growth in nude mice. Interestingly, excess FtMt did not adversely affect the development of drosophila. Additionally, we found that the expression of FtMt in human normal brain tissue was significantly higher than that of neuroblastoma, but not higher than that of neurospongioma. However, the expression of transferrin receptor 1 is completely opposite. We therefore hypothesized that increased expression of FtMt may negatively affect the vitality of neuronal tumor cells. Therefore, we further investigated the underlying mechanisms of FtMt’s inhibitory effects on neuronal tumor cell proliferation. As expected, FtMt overexpression disturbed the iron homeostasis of tumor cells and significantly downregulated the expression of proliferating cell nuclear antigen. Moreover, FtMt affected cell cycle, causing G1/S arrest by modifying the expression of cyclinD1, cyclinE, Cdk2, Cdk4 and p21. Remarkably, FtMt strongly upregulated the expression of the tumor suppressors, p53 and N-myc downstream-regulated gene-1 (NDRG1), but dramatically decreased C-myc, N-myc and p-Rb levels. This study demonstrates for the first time a new role and mechanism for FtMt in the regulation of cell cycle. We thus propose FtMt as a new candidate target for inhibiting neuronal tumor cell proliferation. Appropriate regulation of FtMt expression may prevent tumor cell growth. Our study may provide a new strategy for neuronal cancer therapy.
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Affiliation(s)
- Zhen-Hua Shi
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Science, Hebei Normal University, Shijiazhuang, 050024, Hebei, China,
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93
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Wilkinson N, Pantopoulos K. The IRP/IRE system in vivo: insights from mouse models. Front Pharmacol 2014; 5:176. [PMID: 25120486 PMCID: PMC4112806 DOI: 10.3389/fphar.2014.00176] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/07/2014] [Indexed: 12/16/2022] Open
Abstract
Iron regulatory proteins 1 and 2 (IRP1 and IRP2) post-transcriptionally control the expression of several mRNAs encoding proteins of iron, oxygen and energy metabolism. The mechanism involves their binding to iron responsive elements (IREs) in the untranslated regions of target mRNAs, thereby controlling mRNA translation or stability. Whereas IRP2 functions solely as an RNA-binding protein, IRP1 operates as either an RNA-binding protein or a cytosolic aconitase. Early experiments in cultured cells established a crucial role of IRPs in regulation of cellular iron metabolism. More recently, studies in mouse models with global or localized Irp1 and/or Irp2 deficiencies uncovered new physiological functions of IRPs in the context of systemic iron homeostasis. Thus, IRP1 emerged as a key regulator of erythropoiesis and iron absorption by controlling hypoxia inducible factor 2α (HIF2α) mRNA translation, while IRP2 appears to dominate the control of iron uptake and heme biosynthesis in erythroid progenitor cells by regulating the expression of transferrin receptor 1 (TfR1) and 5-aminolevulinic acid synthase 2 (ALAS2) mRNAs, respectively. Targeted disruption of either Irp1 or Irp2 in mice is associated with distinct phenotypic abnormalities. Thus, Irp1(-/-) mice develop polycythemia and pulmonary hypertension, while Irp2(-/-) mice present with microcytic anemia, iron overload in the intestine and the liver, and neurologic defects. Combined disruption of both Irp1 and Irp2 is incombatible with life and leads to early embryonic lethality. Mice with intestinal- or liver-specific disruption of both Irps are viable at birth but die later on due to malabsorption or liver failure, respectively. Adult mice lacking both Irps in the intestine exhibit a profound defect in dietary iron absorption due to a "mucosal block" that is caused by the de-repression of ferritin mRNA translation. Herein, we discuss the physiological function of the IRE/IRP regulatory system.
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Affiliation(s)
- Nicole Wilkinson
- Lady Davis Institute for Medical Research, Jewish General Hospital, and Department of Medicine, McGill University Montreal, QC, Canada
| | - Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital, and Department of Medicine, McGill University Montreal, QC, Canada
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94
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Anderson CP, Leibold EA. Mechanisms of iron metabolism in Caenorhabditis elegans. Front Pharmacol 2014; 5:113. [PMID: 24904417 PMCID: PMC4033076 DOI: 10.3389/fphar.2014.00113] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 04/28/2014] [Indexed: 12/31/2022] Open
Abstract
Iron is involved in many biological processes essential for sustaining life. In excess, iron is toxic due to its ability to catalyze the formation of free radicals that damage macromolecules. Organisms have developed specialized mechanisms to tightly regulate iron uptake, storage and efflux. Over the past decades, vertebrate model organisms have led to the identification of key genes and pathways that regulate systemic and cellular iron metabolism. This review provides an overview of iron metabolism in the roundworm Caenorhabditis elegans and highlights recent studies on the role of hypoxia and insulin signaling in the regulation of iron metabolism. Given that iron, hypoxia and insulin signaling pathways are evolutionarily conserved, C. elegans provides a genetic model organism that promises to provide new insights into mechanisms regulating mammalian iron metabolism.
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Affiliation(s)
- Cole P Anderson
- Department of Medicine, Division of Hematology and Hematologic Malignancies and Department of Oncological Sciences, University of Utah, Salt Lake City UT, USA
| | - Elizabeth A Leibold
- Department of Medicine, Division of Hematology and Hematologic Malignancies and Department of Oncological Sciences, University of Utah, Salt Lake City UT, USA
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95
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Iron homeostasis in breast cancer. Cancer Lett 2014; 347:1-14. [DOI: 10.1016/j.canlet.2014.01.029] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/16/2013] [Accepted: 01/24/2014] [Indexed: 02/08/2023]
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96
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Aging-related changes in the iron status of skeletal muscle. Exp Gerontol 2013; 48:1294-302. [PMID: 23994517 DOI: 10.1016/j.exger.2013.08.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 07/17/2013] [Accepted: 08/21/2013] [Indexed: 11/22/2022]
Abstract
The rise in non-heme iron (NHI) concentration observed in skeletal muscle of aging rodents is thought to contribute to the development of sarcopenia. The source of the NHI has not been identified, nor have the physiological ramifications of elevated iron status in aged muscle been directly examined. Therefore, we assessed plantaris NHI and heme iron (HI) levels in addition to expression of proteins involved in iron uptake (transferrin receptor-1; TfR1), storage (ferritin), export (ferroportin; FPN), and regulation (iron regulatory protein-1 (IRP1) and -2 (IRP2)) of male F344xBN F1 rats (n=10/group) of various ages (8, 18, 28, 32, and 36 months) to further understand iron regulation in aging muscle. In a separate experiment, iron chelator (pyridoxal isonicotinoyl hydrazone; PIH) or vehicle was administered to male F344xBN F1 rats (n=8/group) beginning at 30 months of age to assess the impact on plantaris muscle mass and function at ~36 months of age. Principle findings revealed the increased NHI concentration in old age was consistent with concentrating effects of muscle atrophy and reduction in HI levels, with no change in the total iron content of the muscle. The greatest increase in muscle iron content occurred during the period of animal growth and was associated with downregulation of TfR1 and IRP2 expression. Ferritin upregulation did not occur until senescence and the protein remained undetectable during the period of muscle iron content elevation. Lastly, administration of PIH did not significantly (p>0.05) impact NHI or measures of muscle atrophy or contractile function. In summary, this study confirms that the elevated NHI concentration in old age is largely due to the loss in muscle mass. The increased muscle iron content during aging does not appear to associate with cytosolic ferritin storage, but the functional consequences of elevated iron status in old age remains to be determined.
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97
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Heath JL, Weiss JM, Lavau CP, Wechsler DS. Iron deprivation in cancer--potential therapeutic implications. Nutrients 2013; 5:2836-59. [PMID: 23887041 PMCID: PMC3775231 DOI: 10.3390/nu5082836] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/12/2013] [Accepted: 07/16/2013] [Indexed: 02/04/2023] Open
Abstract
Iron is essential for normal cellular function. It participates in a wide variety of cellular processes, including cellular respiration, DNA synthesis, and macromolecule biosynthesis. Iron is required for cell growth and proliferation, and changes in intracellular iron availability can have significant effects on cell cycle regulation, cellular metabolism, and cell division. Perhaps not surprisingly then, neoplastic cells have been found to have higher iron requirements than normal, non-malignant cells. Iron depletion through chelation has been explored as a possible therapeutic intervention in a variety of cancers. Here, we will review iron homeostasis in non-malignant and malignant cells, the widespread effects of iron depletion on the cell, the various iron chelators that have been explored in the treatment of cancer, and the tumor types that have been most commonly studied in the context of iron chelation.
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Affiliation(s)
- Jessica L. Heath
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA; E-Mails: (J.L.H.); (J.M.W.); (C.P.L.)
| | - Joshua M. Weiss
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA; E-Mails: (J.L.H.); (J.M.W.); (C.P.L.)
| | - Catherine P. Lavau
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA; E-Mails: (J.L.H.); (J.M.W.); (C.P.L.)
| | - Daniel S. Wechsler
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA; E-Mails: (J.L.H.); (J.M.W.); (C.P.L.)
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-919-684-3401; Fax: +1-919-681-7950
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98
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Intestinal iron homeostasis and colon tumorigenesis. Nutrients 2013; 5:2333-51. [PMID: 23812305 PMCID: PMC3738976 DOI: 10.3390/nu5072333] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 05/29/2013] [Accepted: 06/07/2013] [Indexed: 12/16/2022] Open
Abstract
Colorectal cancer (CRC) is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.
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99
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Abstract
Iron is an essential nutrient that facilitates cell proliferation and growth. However, iron also has the capacity to engage in redox cycling and free radical formation. Therefore, iron can contribute to both tumour initiation and tumour growth; recent work has also shown that iron has a role in the tumour microenvironment and in metastasis. Pathways of iron acquisition, efflux, storage and regulation are all perturbed in cancer, suggesting that reprogramming of iron metabolism is a central aspect of tumour cell survival. Signalling through hypoxia-inducible factor (HIF) and WNT pathways may contribute to altered iron metabolism in cancer. Targeting iron metabolic pathways may provide new tools for cancer prognosis and therapy.
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Affiliation(s)
- Suzy V Torti
- Departments of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
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100
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Quach TK, Chou HT, Wang K, Milledge GZ, Johnson CM. Genome-wide microarrray analysis reveals roles for the REF-1 family member HLH-29 in ferritin synthesis and peroxide stress response. PLoS One 2013; 8:e59719. [PMID: 23533643 PMCID: PMC3606163 DOI: 10.1371/journal.pone.0059719] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 02/17/2013] [Indexed: 12/22/2022] Open
Abstract
In Caenorhabditis elegans, the six proteins that make up the REF-1 family have been identified as functional homologs of the Hairy/Enhancer of Split (HES) proteins. These transcription factors act in both Notch dependent and Notch-independent pathways to regulate embryonic events during development; however, their post-embryonic functions are not well defined. As a first step toward understanding how the REF-1 family works together to coordinate post-embryonic events, we used gene expression microarray analysis to identify transcriptional targets of HLH-29 in L4/young adult stage animals. Here we show that HLH-29 targets are genes needed for the regulation of growth and lifespan, including genes required for oxidative stress response and fatty acid metabolism, and the ferritin genes, ftn-1 and ftn-2. We show that HLH-29 regulates ftn-1 expression via promoter sequences upstream of the iron-dependent element that is recognized by the hypoxia inducible factor, HIF-1. Additionally, hlh-29 mutants are more resistant to peroxide stress than wild-type animals and ftn-1(RNAi) animals, even in the presence of excess iron. Finally we show that HLH-29 acts parallel to DAF-16 but upstream of the microphthalmia transcription factor ortholog, HLH-30, to regulate ftn-1 expression under normal growth conditions.
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Affiliation(s)
- Thanh K. Quach
- Department of Biology, College of Arts and Sciences, Georgia State University, Atlanta, Georgia, United States of America
| | - Han Ting Chou
- Department of Biology, College of Arts and Sciences, Georgia State University, Atlanta, Georgia, United States of America
| | - Kun Wang
- Department of Environmental Health Science, Division of Biostatistics, New York University School of Medicine, New York, New York, United States of America
| | - Gaolin Zheng Milledge
- Department of Mathematics and Computer Science, North Carolina Central University Durham, North Carolina, United States of America
| | - Casonya M. Johnson
- Department of Biology, College of Arts and Sciences, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
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