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Caspa Gokulan R, Paulrasu K, Azfar J, El-Rifai W, Que J, Boutaud OG, Ban Y, Gao Z, Buitrago MG, Dikalov SI, Zaika AI. Protein adduction causes non-mutational inhibition of p53 tumor suppressor. Cell Rep 2023; 42:112024. [PMID: 36848235 PMCID: PMC9989503 DOI: 10.1016/j.celrep.2023.112024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/04/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
p53 is a key tumor suppressor that is frequently mutated in human tumors. In this study, we investigated how p53 is regulated in precancerous lesions prior to mutations in the p53 gene. Analyzing esophageal cells in conditions of genotoxic stress that promotes development of esophageal adenocarcinoma, we find that p53 protein is adducted with reactive isolevuglandins (isoLGs), products of lipid peroxidation. Modification of p53 protein with isoLGs diminishes its acetylation and binding to the promoters of p53 target genes causing modulation of p53-dependent transcription. It also leads to accumulation of adducted p53 protein in intracellular amyloid-like aggregates that can be inhibited by isoLG scavenger 2-HOBA in vitro and in vivo. Taken together, our studies reveal a posttranslational modification of p53 protein that causes molecular aggregation of p53 protein and its non-mutational inactivation in conditions of DNA damage that may play an important role in human tumorigenesis.
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Affiliation(s)
| | | | - Jamal Azfar
- Department of Surgery, University of Miami, Miami, FL, USA
| | - Wael El-Rifai
- Department of Surgery, University of Miami, Miami, FL, USA
| | - Jianwen Que
- Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | - Olivier G Boutaud
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yuguang Ban
- Department of Public Health Sciences, University of Miami, Miami, FL, USA
| | - Zhen Gao
- Department of Public Health Sciences, University of Miami, Miami, FL, USA
| | | | - Sergey I Dikalov
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alexander I Zaika
- Department of Surgery, University of Miami, Miami, FL, USA; Department of Veterans Affairs, Miami VA Healthcare System, Miami, FL, USA.
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2
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Duan X, Liu X, Zhan Z. Metabolic Regulation of Cardiac Regeneration. Front Cardiovasc Med 2022; 9:933060. [PMID: 35872916 PMCID: PMC9304552 DOI: 10.3389/fcvm.2022.933060] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/13/2022] [Indexed: 12/16/2022] Open
Abstract
The mortality due to heart diseases remains highest in the world every year, with ischemic cardiomyopathy being the prime cause. The irreversible loss of cardiomyocytes following myocardial injury leads to compromised contractility of the remaining myocardium, adverse cardiac remodeling, and ultimately heart failure. The hearts of adult mammals can hardly regenerate after cardiac injury since adult cardiomyocytes exit the cell cycle. Nonetheless, the hearts of early neonatal mammals possess a stronger capacity for regeneration. To improve the prognosis of patients with heart failure and to find the effective therapeutic strategies for it, it is essential to promote endogenous regeneration of adult mammalian cardiomyocytes. Mitochondrial metabolism maintains normal physiological functions of the heart and compensates for heart failure. In recent decades, the focus is on the changes in myocardial energy metabolism, including glucose, fatty acid, and amino acid metabolism, in cardiac physiological and pathological states. In addition to being a source of energy, metabolites are becoming key regulators of gene expression and epigenetic patterns, which may affect heart regeneration. However, the myocardial energy metabolism during heart regeneration is majorly unknown. This review focuses on the role of energy metabolism in cardiac regeneration, intending to shed light on the strategies for manipulating heart regeneration and promoting heart repair after cardiac injury.
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Affiliation(s)
- Xuewen Duan
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xingguang Liu
- Department of Pathogen Biology, Naval Medical University, Shanghai, China
- Xingguang Liu,
| | - Zhenzhen Zhan
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Institute of Heart Failure, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
- *Correspondence: Zhenzhen Zhan,
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3
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Bishop SP, Zhou Y, Nakada Y, Zhang J. Changes in Cardiomyocyte Cell Cycle and Hypertrophic Growth During Fetal to Adult in Mammals. J Am Heart Assoc 2021; 10:e017839. [PMID: 33399005 PMCID: PMC7955297 DOI: 10.1161/jaha.120.017839] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The failure of adult cardiomyocytes to reproduce themselves to repair an injury results in the development of severe cardiac disability leading to death in many cases. The quest for an understanding of the inability of cardiac myocytes to repair an injury has been ongoing for decades with the identification of various factors which have a temporary effect on cell‐cycle activity. Fetal cardiac myocytes are continuously replicating until the time that the developing fetus reaches a stage of maturity sufficient for postnatal life around the time of birth. Recent reports of the ability for early neonatal mice and pigs to completely repair after the severe injury has stimulated further study of the regulators of the cardiomyocyte cell cycle to promote replication for the remuscularization of injured heart. In all mammals just before or after birth, single‐nucleated hyperplastically growing cardiomyocytes, 1X2N, undergo ≥1 additional DNA replications not followed by cytokinesis, resulting in cells with ≥2 nuclei or as in primates, multiple DNA replications (polyploidy) of 1 nucleus, 2X2(+)N or 1X4(+)N. All further growth of the heart is attributable to hypertrophy of cardiomyocytes. Animal studies ranging from zebrafish with 100% 1X2N cells in the adult to some strains of mice with up to 98% 2X2N cells in the adult and other species with variable ratios of 1X2N and 2X2N cells are reviewed relative to the time of conversion. Various structural, physiologic, metabolic, genetic, hormonal, oxygenation, and other factors that play a key role in the inability of post‐neonatal and adult myocytes to undergo additional cytokinesis are also reviewed.
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Affiliation(s)
- Sanford P Bishop
- Department of Biomedical Engineering, School of Medicine, School of Engineering The University of Alabama at Birmingham AL
| | - Yang Zhou
- Department of Biomedical Engineering, School of Medicine, School of Engineering The University of Alabama at Birmingham AL
| | - Yuji Nakada
- Department of Biomedical Engineering, School of Medicine, School of Engineering The University of Alabama at Birmingham AL
| | - Jianyi Zhang
- Department of Biomedical Engineering, School of Medicine, School of Engineering The University of Alabama at Birmingham AL
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Kumar V, Agrawal R, Pandey A, Kopf S, Hoeffgen M, Kaymak S, Bandapalli OR, Gorbunova V, Seluanov A, Mall MA, Herzig S, Nawroth PP. Compromised DNA repair is responsible for diabetes-associated fibrosis. EMBO J 2020; 39:e103477. [PMID: 32338774 PMCID: PMC7265245 DOI: 10.15252/embj.2019103477] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 02/27/2020] [Accepted: 03/08/2020] [Indexed: 11/09/2022] Open
Abstract
Diabetes-associated organ fibrosis, marked by elevated cellular senescence, is a growing health concern. Intriguingly, the mechanism underlying this association remained unknown. Moreover, insulin alone can neither reverse organ fibrosis nor the associated secretory phenotype, favoring the exciting notion that thus far unknown mechanisms must be operative. Here, we show that experimental type 1 and type 2 diabetes impairs DNA repair, leading to senescence, inflammatory phenotypes, and ultimately fibrosis. Carbohydrates were found to trigger this cascade by decreasing the NAD+ /NADH ratio and NHEJ-repair in vitro and in diabetes mouse models. Restoring DNA repair by nuclear over-expression of phosphomimetic RAGE reduces DNA damage, inflammation, and fibrosis, thereby restoring organ function. Our study provides a novel conceptual framework for understanding diabetic fibrosis on the basis of persistent DNA damage signaling and points to unprecedented approaches to restore DNA repair capacity for resolution of fibrosis in patients with diabetes.
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Affiliation(s)
- Varun Kumar
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, Heidelberg, Germany.,European Molecular Biology Laboratory, Advanced Light Microscopy Facility, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Heidelberg, Germany
| | - Raman Agrawal
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Aparamita Pandey
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, Heidelberg, Germany
| | - Stefan Kopf
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Heidelberg, Germany
| | - Manuel Hoeffgen
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, Heidelberg, Germany
| | - Serap Kaymak
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, Heidelberg, Germany
| | - Obul Reddy Bandapalli
- Hopp Children's Cancer Center, Heidelberg, Germany.,Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Vera Gorbunova
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Andrei Seluanov
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Marcus A Mall
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany.,Department of Pediatric Pulmonology, Immunology and Critical Care Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Stephan Herzig
- German Center for Diabetes Research (DZD), Heidelberg, Germany.,Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany.,Joint Heidelberg-IDC Translational Diabetes Program, Helmholtz-Zentrum, München, Germany.,Technical University Munich, Munich, Germany
| | - Peter P Nawroth
- Department of Medicine I and Clinical Chemistry, University Hospital of Heidelberg, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Heidelberg, Germany.,Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany.,Joint Heidelberg-IDC Translational Diabetes Program, Helmholtz-Zentrum, München, Germany
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6
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Lee SB, Lee S, Park JY, Lee SY, Kim HS. Induction of p53-Dependent Apoptosis by Prostaglandin A 2. Biomolecules 2020; 10:E492. [PMID: 32213959 PMCID: PMC7175137 DOI: 10.3390/biom10030492] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/19/2020] [Accepted: 03/21/2020] [Indexed: 12/31/2022] Open
Abstract
Prostaglandin (PG) A2, one of cyclopentenone PGs, is known to induce activation of apoptosis in various cancer cells. Although PGA2 has been reported to cause activation of apoptosis by altering the expression of apoptosis-related genes, the role of p53, one of the most critical pro-apoptotic genes, on PGA2-induced apoptosis has not been clarified yet. To address this issue, we compared the apoptosis in HCT116 p53 null cells (HCT116 p53-/-) to that in HCT116 cells containing the wild type p53 gene. Cell death induced by PGA2 was associated with phosphorylation of histone H2A variant H2AX (H2AX), activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase 1 in HCT116 cells. Induction of apoptosis in PGA2-treated cells was almost completely prevented by pretreatment with a pan-caspase inhibitor, z-VAD-Fmk, or an inhibitor of protein synthesis, cycloheximide. While PGA2 induced apoptosis in HCT116 cells, phosphorylation of p53 and transcriptional induction of p53-target genes such as p21WAF1, PUMA, BAX, NOXA, and DR5 occurred. Besides, pretreatment of pifithrin-α (PFT-α), a chemical inhibitor of p53's transcriptional activity, interfered with the induction of apoptosis in PGA2-treated HCT116 cells. Pretreatment of NU7441, a small molecule inhibitor of DNA-activated protein kinase (DNA-PK) suppressed PGA2-induced phosphorylation of p53 and apoptosis as well. Moreover, among target genes of p53, knockdown of DR5 expression by RNA interference, suppressed PGA2-induced apoptosis. In the meanwhile, in HCT116 p53-/- cells, PGA2 induced apoptosis in delayed time points and with less potency. Delayed apoptosis by PGA2 in HCT116 p53-/- cells was also associated with phosphorylation of H2AX but was not inhibited by either PFT- or NU7441. Collectively, these results suggest the following. PGA2 may induce p53-dependent apoptosis in which DNA-PK activates p53, and DR5, a transcriptional target of p53, plays a pivotal role in HCT116 cells. In contrast to apoptosis in HCT116 cells, PGA2 may induce apoptosis in a fashion of less potency, which is independent of p53 and DNA-PK in HCT116 p53-/- cells.
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Affiliation(s)
- Su-Been Lee
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea; (S.-B.L.); (S.L.); (J.-Y.P.)
- Cancer Evolution Research Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Sangsun Lee
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea; (S.-B.L.); (S.L.); (J.-Y.P.)
- Cancer Evolution Research Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Ji-Young Park
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea; (S.-B.L.); (S.L.); (J.-Y.P.)
- Cancer Evolution Research Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Sun-Young Lee
- Cancer Evolution Research Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand
| | - Ho-Shik Kim
- Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea; (S.-B.L.); (S.L.); (J.-Y.P.)
- Cancer Evolution Research Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
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7
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Lee EJ, Kim SJ, Hahn YI, Yoon HJ, Han B, Kim K, Lee S, Kim KP, Suh YG, Na HK, Surh YJ. 15-Keto prostaglandin E 2 suppresses STAT3 signaling and inhibits breast cancer cell growth and progression. Redox Biol 2019; 23:101175. [PMID: 31129031 PMCID: PMC6859578 DOI: 10.1016/j.redox.2019.101175] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 12/20/2022] Open
Abstract
Overproduction of prostaglandin E2 (PGE2) has been linked to enhanced tumor cell proliferation, invasiveness and metastasis as well as resistance to apoptosis. 15-Keto prostaglandin E2 (15-keto PGE2), a product formed from 15-hydroxyprostaglandin dehydrogenase-catalyzed oxidation of PGE2, has recently been shown to have anti-inflammatory and anticarcinogenic activities. In this study, we observed that 15-keto PGE2 suppressed the phosphorylation, dimerization and nuclear translocation of signal transducer and activator of transcription 3 (STAT3) in human mammary epithelial cells transfected with H-ras (MCF10A-ras). 15-Keto PGE2 inhibited the migration and clonogenicity of MCF10A-ras cells. In addition, subcutaneous injection of 15-keto PGE2 attenuated xenograft tumor growth and phosphorylation of STAT3 induced by breast cancer MDA-MB-231 cells. However, a non-electrophilic analogue, 13,14-dihydro-15-keto PGE2 failed to inhibit STAT3 signaling and was unable to suppress the growth and transformation of MCF10A-ras cells. These findings suggest that the α,β-unsaturated carbonyl moiety of 15-keto PGE2 is essential for its suppression of STAT3 signaling. We observed that the thiol reducing agent, dithiothreitol abrogated 15-keto PGE2-induced STAT3 inactivation and disrupted the direct interaction between 15-keto PGE2 and STAT3. Furthermore, a molecular docking analysis suggested that Cys251 and Cys259 residues of STAT3 could be preferential binding sites for this lipid mediator. Mass spectral analysis revealed the covalent modification of recombinant STAT3 by 15-keto PGE2 at Cys259. Taken together, thiol modification of STAT3 by 15-keto PGE2 inactivates STAT3 which may account for its suppression of breast cancer cell proliferation and progression.
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Affiliation(s)
- Eun Ji Lee
- Department of Molecular Medicine and Biopharmaceutical Science, Seoul National University, Seoul 08826, South Korea; Tumor Microenvironment Global Core Research Center, College of Pharmacy, Seoul National University, Seoul 08826, South Korea
| | - Su-Jung Kim
- Tumor Microenvironment Global Core Research Center, College of Pharmacy, Seoul National University, Seoul 08826, South Korea
| | - Young-Il Hahn
- Department of Molecular Medicine and Biopharmaceutical Science, Seoul National University, Seoul 08826, South Korea; Tumor Microenvironment Global Core Research Center, College of Pharmacy, Seoul National University, Seoul 08826, South Korea
| | - Hyo-Jin Yoon
- Tumor Microenvironment Global Core Research Center, College of Pharmacy, Seoul National University, Seoul 08826, South Korea
| | - Bitnara Han
- Department of Applied Chemistry, Institute of Natural Science, Global Center for Pharmaceutical Ingredient Materials, Kyung Hee University, Yongin 17104, South Korea
| | - Kyeojin Kim
- College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Seungbeom Lee
- College of Pharmacy, CHA University, Gyeonggi-do 11160, South Korea
| | - Kwang Pyo Kim
- Department of Applied Chemistry, Institute of Natural Science, Global Center for Pharmaceutical Ingredient Materials, Kyung Hee University, Yongin 17104, South Korea; Department of Biomedical Science and Technology, Kyung Hee Medical Science Research Institute, Kyung Hee University, Seoul 02453, South Korea
| | - Young Ger Suh
- College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea; College of Pharmacy, CHA University, Gyeonggi-do 11160, South Korea
| | - Hye-Kyung Na
- Department of Food Science and Biotechnology, Sungshin Women's University, College of Knowledge-Based Services Engineering, Seoul 01133, South Korea.
| | - Young-Joon Surh
- Department of Molecular Medicine and Biopharmaceutical Science, Seoul National University, Seoul 08826, South Korea; Tumor Microenvironment Global Core Research Center, College of Pharmacy, Seoul National University, Seoul 08826, South Korea; Cancer Research Institute, Seoul National University, Seoul 03080, South Korea.
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8
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An Y, Quan KT, Gwak J, Ju BG, Na M, Oh S. Activation of the p53 pathway with digiferrol isolated from Rubia philippinensis induces cell cycle arrest, apoptosis, and autophagy in colon cancer cells. Food Chem Toxicol 2018; 118:514-522. [PMID: 29842910 DOI: 10.1016/j.fct.2018.05.054] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 05/14/2018] [Accepted: 05/23/2018] [Indexed: 01/02/2023]
Affiliation(s)
- Younju An
- Department of Bio and Fermentation Convergence Technology, BK21 PLUS Program, Kookmin University, Seoul, 136-702, Republic of Korea
| | - Khong Trong Quan
- College of Pharmacy, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jungsug Gwak
- Department of Life Science, Sogang University, Seoul, 121-742, Republic of Korea
| | - Bong Gun Ju
- Department of Life Science, Sogang University, Seoul, 121-742, Republic of Korea
| | - MinKyun Na
- College of Pharmacy, Chungnam National University, Daejeon, 34134, Republic of Korea.
| | - Sangtaek Oh
- Department of Bio and Fermentation Convergence Technology, BK21 PLUS Program, Kookmin University, Seoul, 136-702, Republic of Korea.
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Opposing roles of PGD 2 in GBM. Prostaglandins Other Lipid Mediat 2017; 134:66-76. [PMID: 29042181 DOI: 10.1016/j.prostaglandins.2017.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 09/06/2017] [Accepted: 10/10/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND The World Health Organization classifies glioblastoma (GBM) as a grade IV astrocytoma. Despite the advances in chemotherapy, surgery, and radiation treatments that improve a patient's length of survival, the overall trajectory of the disease remains unchanged. GBM cells produce significant levels of various types of bioactive lipids. Prostaglandin D2 (PGD2) influences both pro- and anti-tumorigenic activities in the cell; however, its role in GBM is unclear. Therefore, this study aimed to identify the impact of PGD2 on GBM cell activities in vitro. METHODS First we looked to identify the presence of the PGD2 synthesis pathway through RT-PCR, immunohistochemistry, and HPLC-MS/MS in three GBM cell lines. Then, to observe PGD2's effects on cell count and apoptosis/mitosis (Hoechst 33342 stain), and migration (Transwell Assay), the cells were treated in vitro with physiological (<1μM) and/or supraphysiological (>1μM) concentrations of PGD2 over 72h. HPLC-MS/MS was used to identify the lipid composition of patients with either Grade II/III gliomas or GBM. RESULTS We identified the presence of endogenous PGD2 with its corresponding enzymes and receptors. Exogenous PGD2 both increased cell count (<1μM) and decreased cell count (10μM) in a concentration-dependent manner. There were no significant effects on apoptosis. A significant decrease in mitotic activity was seen only in U251MG, and a significant increase was seen in migration with 5μM PGD2 treatments. A very significant increase of PGD2 was seen from Grade II/III gliomas to GBM. CONCLUSIONS Our study demonstrates that prostaglandin D2 possesses a dynamic, concentration-dependent effect in GBM cell activities. The increase of PGD2 production in GBM patients suggests a pro-tumorigenic role of PGD2 in glioma growth and invasion. Therefore, prostaglandin signaling in GBM requires further investigation to identify new targets for more effective therapies.
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Elhelaly WM, Lam NT, Hamza M, Xia S, Sadek HA. Redox Regulation of Heart Regeneration: An Evolutionary Tradeoff. Front Cell Dev Biol 2016; 4:137. [PMID: 28018900 PMCID: PMC5157008 DOI: 10.3389/fcell.2016.00137] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/07/2016] [Indexed: 11/24/2022] Open
Abstract
Heart failure is a costly and deadly disease, affecting over 23 million patients worldwide, half of which die within 5 years of diagnosis. The pathophysiological basis of heart failure is the inability of the adult heart to regenerate lost or damaged myocardium. Although limited myocyte turnover does occur in the adult heart, it is insufficient for restoration of contractile function (Nadal-Ginard, 2001; Laflamme et al., 2002; Quaini et al., 2002; Hsieh et al., 2007; Bergmann et al., 2009, 2012). In contrast to lower vertebrates (Poss et al., 2002; Poss, 2007; Jopling et al., 2010; Kikuchi et al., 2010; Chablais et al., 2011; González-Rosa et al., 2011; Heallen et al., 2011), adult mammalian heart cardiomyogenesis following injury is very limited (Nadal-Ginard, 2001; Laflamme et al., 2002; Quaini et al., 2002; Bergmann et al., 2009, 2012) and is insufficient to restore normal cardiac function. Studies in the late 90s elegantly mapped the DNA synthesis and cell cycle dynamics of the mammalian heart during development and following birth (Soonpaa et al., 1996; Soonpaa and Field, 1997, 1998), where they showed that DNA synthesis drops significantly around birth with low-level DNA synthesis few days after birth. Around P5 to P7, cardiomyocytes undergo a final round of DNA synthesis without cytokinesis, and the majority become binucleated and exit the cell cycle permanently. Therefore, due to the similarities between the immature mammalian heart and lower vertebrates (Poss, 2007; Walsh et al., 2010), it became important to determine whether they have similar regenerative abilities. Recently, we demonstrated that removal of up to 15% of the apex of the left ventricle of postnatal day 1 (P1) mice results in complete regeneration within 3 weeks without any measurable fibrosis and cardiac dysfunction (Porrello et al., 2011). This response is characterized by robust cardiomyocyte proliferation with gradual restoration of normal cardiac morphology. In addition to the histological evidence of proliferating myocytes, genetic fate-mapping studies confirmed that the majority of newly formed cardiomyocytes are derived from proliferation of preexisting cardiomyocytes (Porrello et al., 2011). More recently, we established an ischemic injury model where the left anterior descending coronary artery was ligated in P1 neonates (Porrello et al., 2013). The injury response was similar to the resection model, with robust cardiomyocyte proliferation throughout the myocardium, as well as restoration of normal morphology by 21 days. However, this regenerative capacity is lost by P7, after which injury results in the typical cardiomyocyte hypertrophy and scar-formation characteristic of the adult mammalian heart. Not surprisingly, the loss of this regenerative capacity coincides with binucleation and cell cycle exit of cardiomyocytes (Soonpaa et al., 1996; Walsh et al., 2010). An important approach toward a deeper understanding the loss of cardiac regenerative capacity in mammals is to first consider why, and not only how, this happens. Regeneration of the early postnatal heart following resection or ischemic infarction involves replacement of lost myocardium and vasculature with restoration of normal myocardial thickness and architecture, with long-term normalization of systolic function. Why would the heart permanently forego such a remarkable regenerative program shortly after birth? The answer may lie in within the fundamental principal of evolutionary tradeoff.
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Affiliation(s)
- Waleed M Elhelaly
- Department of Internal Medicine, Division of Cardiology, and Hamon Center for Regenerative Science and Medicine, The University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Nicholas T Lam
- Department of Internal Medicine, Division of Cardiology, and Hamon Center for Regenerative Science and Medicine, The University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Mohamed Hamza
- Department of Internal Medicine, Division of Cardiology, and Hamon Center for Regenerative Science and Medicine, The University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Shuda Xia
- Department of Internal Medicine, Division of Cardiology, and Hamon Center for Regenerative Science and Medicine, The University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Hesham A Sadek
- Department of Internal Medicine, Division of Cardiology, and Hamon Center for Regenerative Science and Medicine, The University of Texas Southwestern Medical Center Dallas, TX, USA
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Abstract
The ubiquitin–proteasome system has been recognized as fundamental toward protein turnover in eukaryotic cells. The system comprises the ubiquitin conjugation machinery consisting of an enzyme cascade of E1, E2, and E3 enzymes, the deubiquitinases (DUBs) and the proteasome, a multisubunit protease complex acting through an N-terminal threonine protease mechanism. A number of natural product inhibitors of the proteasome have been studied in detail and these inhibitors and their derivatives have been highly valuable in developing our understanding of this system. These efforts culminated in the successful development of bortezomib as a pharmacological agent used clinically as a cancer therapeutic in the treatment of multiple myeloma. This review is focused on natural product inhibitors of the enzymes involved in intracellular ubiquitin conjugation (ubiquitin-activating enzyme E1, ubiquitin-conjugating enzyme E2, ubiquitin ligase E3) and ubiquitin deconjugation (DUBs). Members of both of these enzyme systems have been proposed as pharmacological targets for cancer therapy and several other diseases. Furthermore compounds with activities toward enzymes from the analogous ubiquitin-like (Ubl) protein families have been identified for SUMO and NEDD8. To date natural product inhibitors have been described for members of each of these protein families and were isolated from plant, fungal, animal, and microbial sources. Insights into the mechanism of action of natural products and their derivatives will enhance our understanding of this complex system and will improve our ability to rationally design novel inhibitors. The increased availability of assays and research tools for the study of protein ubiquitination, deubiquitination, and Ubl proteins will contribute to the discovery of more potent and selective compounds. We expect that these studies will stimulate development of further potential pharmacological agents in this area.
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p53 immunoexpression in stepwise progression of cutaneous squamous cell carcinoma and correlation with angiogenesis and cellular proliferation. Pathol Res Pract 2015; 211:782-8. [PMID: 26296918 DOI: 10.1016/j.prp.2015.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/05/2015] [Accepted: 07/13/2015] [Indexed: 12/12/2022]
Abstract
Multistep carcinogenesis involves loss of function of tumor suppressor proteins such as p53 and induction of angiogenesis. Such mechanisms contribute to cutaneous squamous cell carcinoma progression and may be interconnected. We aimed to explore p53 immunoexpression in spectral stages of cutaneous squamous cell carcinoma and correlate expression to both neovascularization and cellular proliferation. We estimated the percentages of immunostained cells for p53 and Ki67 (proliferation marker) in three groups: 23 solar keratoses, 28 superficially invasive squamous cell carcinomas and 28 invasive squamous cell carcinomas. The Chalkley method was used to quantify the microvascular area by neoangiogenesis (CD105) immunomarker in each group. There was no significant difference for rate of p53- and Ki67-positive cells between groups. Significant positive correlation was found between the CD105 microvascular area and the rate of p53 positive cells in superficially invasive squamous cell carcinoma as well as between the rate of p53- and Ki67-positive cells in invasive squamous cell carcinoma. p53 and Ki67 immunoexpression did not increase with cutaneous squamous cell carcinoma progression. Neovascularization in the initial stage of invasion and proliferative activity in the frankly invasive stage were both associated with p53 immunoexpression. Loss of p53 tumor suppressor function through progressive steps may be directly involved in skin carcinogenesis.
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Activation of p53 with ilimaquinone and ethylsmenoquinone, marine sponge metabolites, induces apoptosis and autophagy in colon cancer cells. Mar Drugs 2015; 13:543-57. [PMID: 25603347 PMCID: PMC4306951 DOI: 10.3390/md13010543] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 01/07/2015] [Indexed: 12/18/2022] Open
Abstract
The tumor suppressor, p53, plays an essential role in the cellular response to stress through regulating the expression of genes involved in cell cycle arrest, apoptosis and autophagy. Here, we used a cell-based reporter system for the detection of p53 response transcription to identify the marine sponge metabolites, ilimaquinone and ethylsmenoquinone, as activators of the p53 pathway. We demonstrated that ilimaquinone and ethylsmenoquinone efficiently stabilize the p53 protein through promotion of p53 phosphorylation at Ser15 in both HCT116 and RKO colon cancer cells. Moreover, both compounds upregulate the expression of p21WAF1/CIP1, a p53-dependent gene, and suppress proliferation of colon cancer cells. In addition, ilimaquinone and ethylsmenoquinone induced G2/M cell cycle arrest and increased caspase-3 cleavage and the population of cells that positively stained with Annexin V-FITC, both of which are typical biochemical markers of apoptosis. Furthermore, autophagy was elicited by both compounds, as indicated by microtubule-associated protein 1 light chain 3 (LC3) puncta formations and LC3-II turnover in HCT116 cells. Our findings suggest that ilimaquinone and ethylsmenoquinone exert their anti-cancer activity by activation of the p53 pathway and may have significant potential as chemo-preventive and therapeutic agents for human colon cancer.
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Kimura W, Muralidhar S, Canseco DC, Puente B, Zhang CC, Xiao F, Abderrahman YH, Sadek HA. Redox signaling in cardiac renewal. Antioxid Redox Signal 2014; 21:1660-73. [PMID: 25000143 PMCID: PMC4175032 DOI: 10.1089/ars.2014.6029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
SIGNIFICANCE Utilizing oxygen (O2) through mitochondrial oxidative phosphorylation enables organisms to generate adenosine triphosphate (ATP) with a higher efficiency than glycolysis, but it results in increased reactive oxygen species production from mitochondria, which can result in stem cell dysfunction and senescence. RECENT ADVANCES In the postnatal organism, the hematopoietic system represents a classic example of the role of stem cells in cellular turnover and regeneration. However, in other organs such as the heart, both the degree and source of cellular turnover have been heavily contested. CRITICAL ISSUES Although recent evidence suggests that the major source of the limited cardiomyocyte turnover in the adult heart is cardiomyocyte proliferation, the identity and potential role of undifferentiated cardiac progenitor cells remain controversial. Several types of cardiac progenitor cells have been identified, and several studies have identified an important role of redox and metabolic regulation in survival and differentiation of cardiac progenitor cells. Perhaps a simple way to approach these controversies is to focus on the multipotentiality characteristics of a certain progenitor population, and not necessarily its ability to give rise to all cell types within the heart. In addition, it is important to note that cycling cells in the heart may express markers of differentiation or may be truly undifferentiated, and for the purpose of this review, we will refer to these cycling cells as progenitors. FUTURE DIRECTIONS We propose that hypoxia, redox signaling, and metabolic phenotypes are major regulators of cardiac renewal, and may prove to be important therapeutic targets for heart regeneration.
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Affiliation(s)
- Wataru Kimura
- 1 Division of Cardiology, Department of Internal Medicine, UT Southwestern Medical Center , Dallas, Texas
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16
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Pal HC, Athar M, Elmets CA, Afaq F. Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice. Photochem Photobiol 2014; 91:225-34. [PMID: 25169110 DOI: 10.1111/php.12337] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 08/25/2014] [Indexed: 12/26/2022]
Abstract
Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations and alterations in signaling pathways eventually leading to skin cancer. In this study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB-exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ cm(-2) of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB-exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1-EP4) and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB-exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage.
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Affiliation(s)
- Harish Chandra Pal
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL
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17
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Puente BN, Kimura W, Muralidhar SA, Moon J, Amatruda JF, Phelps KL, Grinsfelder D, Rothermel BA, Chen R, Garcia JA, Santos CX, Thet S, Mori E, Kinter MT, Rindler PM, Zacchigna S, Mukherjee S, Chen DJ, Mahmoud AI, Giacca M, Rabinovitch PS, Aroumougame A, Shah AM, Szweda LI, Sadek HA. The oxygen-rich postnatal environment induces cardiomyocyte cell-cycle arrest through DNA damage response. Cell 2014; 157:565-79. [PMID: 24766806 DOI: 10.1016/j.cell.2014.03.032] [Citation(s) in RCA: 615] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 02/17/2014] [Accepted: 03/21/2014] [Indexed: 12/15/2022]
Abstract
The mammalian heart has a remarkable regenerative capacity for a short period of time after birth, after which the majority of cardiomyocytes permanently exit cell cycle. We sought to determine the primary postnatal event that results in cardiomyocyte cell-cycle arrest. We hypothesized that transition to the oxygen-rich postnatal environment is the upstream signal that results in cell-cycle arrest of cardiomyocytes. Here, we show that reactive oxygen species (ROS), oxidative DNA damage, and DNA damage response (DDR) markers significantly increase in the heart during the first postnatal week. Intriguingly, postnatal hypoxemia, ROS scavenging, or inhibition of DDR all prolong the postnatal proliferative window of cardiomyocytes, whereas hyperoxemia and ROS generators shorten it. These findings uncover a protective mechanism that mediates cardiomyocyte cell-cycle arrest in exchange for utilization of oxygen-dependent aerobic metabolism. Reduction of mitochondrial-dependent oxidative stress should be an important component of cardiomyocyte proliferation-based therapeutic approaches.
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Affiliation(s)
- Bao N Puente
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wataru Kimura
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shalini A Muralidhar
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jesung Moon
- Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - James F Amatruda
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kate L Phelps
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David Grinsfelder
- Department of Clinical Science, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Beverly A Rothermel
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rui Chen
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Joseph A Garcia
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Celio X Santos
- Cardiovascular Division, King's College London BHF Centre of Research Excellence, School of Medicine, James Black Centre, London SE5 9NU, UK
| | - SuWannee Thet
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Eiichiro Mori
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael T Kinter
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Paul M Rindler
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Serena Zacchigna
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy
| | - Shibani Mukherjee
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David J Chen
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ahmed I Mahmoud
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Cambridge, MA 02115, USA
| | - Mauro Giacca
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy
| | | | - Asaithamby Aroumougame
- Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ajay M Shah
- Department of Clinical Science, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Luke I Szweda
- Free Radical Biology and Aging Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Hesham A Sadek
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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18
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Rao CV, Patlolla JMR, Qian L, Zhang Y, Brewer M, Mohammed A, Desai D, Amin S, Lightfoot S, Kopelovich L. Chemopreventive effects of the p53-modulating agents CP-31398 and Prima-1 in tobacco carcinogen-induced lung tumorigenesis in A/J mice. Neoplasia 2013; 15:1018-27. [PMID: 24027427 PMCID: PMC3769881 DOI: 10.1593/neo.131256] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/29/2013] [Accepted: 07/30/2013] [Indexed: 11/18/2022]
Abstract
Lung cancer is the leading cause of cancer deaths worldwide. Expression of the p53 tumor suppressor protein is frequently altered in tobacco-associated lung cancers. We studied chemopreventive effects of p53-modulating agents, namely, CP-31398 and Prima-1, on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung adenoma and adenocarcinoma formation in female A/J mice. Seven-week-old mice were treated with a single dose of NNK (10 µmol/mouse) by intraperitoneal injection and, 3 weeks later, were randomized to mice fed a control diet or experimental diets containing 50 or 100 ppm CP-31398 or 150 or 300 ppm Prima-1 for either 17 weeks (10 mice/group) or 34 weeks (15 mice/group) to assess the efficacy against lung adenoma and adenocarcinoma. Dietary feeding of 50 or 100 ppm CP-31398 significantly suppressed (P < .0001) lung adenocarcinoma by 64% and 73%, respectively, after 17 weeks and by 47% and 56%, respectively, after 34 weeks. Similarly, 150 or 300 ppm Prima-1 significantly suppressed (P < .0001) lung adenocarcinoma formation by 56% and 62%, respectively, after 17 weeks and 39% and 56%, respectively, after 34 weeks. Importantly, these results suggest that both p53 modulators cause a delay in the progression of adenoma to adenocarcinoma. Immunohistochemical analysis of lung tumors from mice exposed to p53-modulating agents showed a significantly reduced tumor cell proliferation and increased accumulation of wild-type p53 in the nucleus. An increase in p21- and apoptotic-positive cells was also observed in lung tumors of mice exposed to p53-modulating agents. These results support a chemopreventive role of p53-modulating agents in tobacco carcinogen-induced lung adenocarcinoma formation.
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Affiliation(s)
- Chinthalapally V Rao
- Center for Cancer Prevention and Drug Development, Hematology-Oncology Section, Department of Medicine, Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK
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Sullivan MA, Brooks LR, Weidenborner P, Domm W, Mattiacio J, Xu Q, Tiberio M, Wentworth T, Kobie J, Bryk P, Zheng B, Murphy M, Sanz I, Dewhurst S. Anti-idiotypic monobodies derived from a fibronectin scaffold. Biochemistry 2013; 52:1802-13. [PMID: 23394681 DOI: 10.1021/bi3016668] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mimetics of conformational protein epitopes have broad applications but have been difficult to identify using conventional peptide phage display. The 10th type III domain of human fibronectin (FNfn10) has two extended, randomizable surface-exposed loops and might be more amenable to the identification of such mimetics. We therefore selected a library of FNfn10 clones, randomized in both loops (15 residues in all), for binding to monoclonal antibodies (mAbs) that recognize the HIV-1 envelope glycoprotein. Anti-idiotypic monobodies (αIMs) mimicking both "linear" epitopes (2F5 and 4E10 mAbs) and conformational epitopes (b12 and VRC01 mAbs) were generated. αIMs selected against 2F5 and 4E10 frequently displayed sequence homology to the corresponding linear native epitopes. In the case of b12 and VRC01, we expected that the two constrained loop domains of FNfn10 would both contribute to complex conformational interactions with target antibodies. However, mutagenesis studies revealed differences from this simple model. An αIM selected against b12 was found to bind its cognate antibody via only a few residues within the BC loop of FNfn10, with minimal contribution from the FG loop. Unexpectedly, this was sufficient to generate a protein that engaged its cognate antibody in a manner very similar to that of HIV-1 Env, and with a strong KD (43 nM). In contrast, an αIM selected against VRC01 engaged its cognate antibody in a manner that was dependent on both BC and FG loop sequences. Overall, these data suggest that the FNfn10 scaffold can be used to identify complex structures that mimic conformational protein epitopes.
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Affiliation(s)
- Mark A Sullivan
- Department of Microbiology and Immunology and ‡Department of Medicine, University of Rochester School of Medicine and Dentistry , Rochester, New York 14642, United States
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20
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Yin H, Zhou Y, Zhu M, Hou S, Li Z, Zhong H, Lu J, Meng T, Wang J, Xia L, Xu Y, Wu Y. Role of mitochondria in programmed cell death mediated by arachidonic acid-derived eicosanoids. Mitochondrion 2012; 13:209-24. [PMID: 23063711 DOI: 10.1016/j.mito.2012.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 09/24/2012] [Accepted: 10/02/2012] [Indexed: 01/28/2023]
Abstract
Arachidonic acid-derived eicosanoids from cyclooxygenases, lipoxygenases, and cytochrome P450 are important lipid mediators involved in numerous homeostatic and pathophysiological processes. Most eicosanoids act primarily on their respective cell surface G-protein coupled receptors to elicit downstream signaling in an autocrine and paracrine fashion. Emerging evidence indicates that these hormones are also critical in apoptosis in a cell/tissue specific manner. In this review, we summarize the formation of eicosanoids and their roles as mediators in apoptosis, specifically on the roles of mitochondria in mediating these events and the signaling pathways involved. The biological relevance of eicosanoid-mediated apoptosis is also discussed.
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Affiliation(s)
- Huiyong Yin
- Laboratory of Lipid Metabolism in Human Nutrition and Related Diseases, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
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21
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Nieva J, Song BD, Rogel JK, Kujawara D, Altobel L, Izharrudin A, Boldt GE, Grover RK, Wentworth AD, Wentworth P. Cholesterol secosterol aldehydes induce amyloidogenesis and dysfunction of wild-type tumor protein p53. ACTA ACUST UNITED AC 2011; 18:920-7. [PMID: 21802012 DOI: 10.1016/j.chembiol.2011.02.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2009] [Revised: 01/24/2011] [Accepted: 02/15/2011] [Indexed: 01/10/2023]
Abstract
Epidemiologic and clinical evidence points to an increased risk for cancer when coupled with chronic inflammation. However, the molecular mechanisms that underpin this interrelationship remain largely unresolved. Herein we show that the inflammation-derived cholesterol 5,6-secosterol aldehydes, atheronal-A (KA) and -B (ALD), but not the polyunsaturated fatty acid (PUFA)-derived aldehydes 4-hydroxynonenal (HNE) and 4-hydroxyhexenal (HHE), induce misfolding of wild-type p53 into an amyloidogenic form that binds thioflavin T and Congo red dyes but cannot bind to a consensus DNA sequence. Treatment of lung carcinoma cells with KA and ALD leads to a loss of function of extracted p53, as determined by the analysis of extracted nuclear protein and in activation of p21. Our results uncover a plausible chemical link between inflammation and cancer and expand the already pivotal role of p53 dysfunction and cancer risk.
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Affiliation(s)
- Jorge Nieva
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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22
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Kim DH, Kundu JK, Surh YJ. Redox modulation of p53: mechanisms and functional significance. Mol Carcinog 2011; 50:222-34. [PMID: 21465572 DOI: 10.1002/mc.20709] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The tumor suppressor protein p53 functions as a stress-responsive transcription factor. In response to oxidative, nitrosative, and electrophilic insults, p53 undergoes post-translational modifications, such as oxidation and covalent modification of cysteines, nitration of tyrosines, acetylation of lysines, phosphorylation of serine/threonine residues, etc. Because p53 plays a vital role in the transcriptional regulation of genes encoding proteins involved in a wide spectrum of biochemical processes including DNA repair, cell-cycle regulation, and programmed cell death, the redox-modification of p53 appears to be an important determinant of cell fate. This review highlights the redox regulation of p53 and its consequences on cellular function.
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Affiliation(s)
- Do-Hee Kim
- College of Pharmacy, Seoul National University, Seoul, South Korea
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Abstract
Resveratrol is a naturally occurring stilbene with desirable cardioprotective and anti-cancer properties. We have demonstrated the existence of a plasma membrane receptor for resveratrol near the arginine-glycine-aspartate (RGD) recognition site on integrin α(v)β₃ that is involved in stilbene-induced apoptosis of cancer cells. Resveratrol treatment in vitro causes activation and nuclear translocation of mitogen-activated protein kinase (ERK1/2), consequent phosphorylation of Ser-15 of p53, and apoptosis. An RGD peptide blocks these actions of resveratrol. By a PD98059-inhibitable process, resveratrol causes inducible COX-2 to accumulate in the nucleus where it complexes with pERK1/2 and p53. Chromatin immunoprecipitation reveals binding of nuclear COX-2 to promoters of certain p53-responsive genes, including PIG3 and Bax. NS-398, a specific pharmacologic inhibitor of COX-2, prevents resveratrol-induced complexing of nuclear ERK1/2 with COX-2 and with pSer-15-p53 and subsequent apoptosis; cyclooxygenase enzyme activity is not involved. Molecular steps in the pro-apoptotic action of resveratrol in cancer cells include induction of intranuclear COX-2 accumulation relevant to activation of p53. Epidermal growth factor, estrogen, and thyroid hormone act downstream of ERK1/2 to prevent resveratrol-induced apoptosis.
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Affiliation(s)
- Hung-Yun Lin
- Ordway Research Institute, Albany, New York 12208, USA.
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15-Deoxy-Δ12,14-prostaglandin J2 stabilizes, but functionally inactivates p53 by binding to the cysteine 277 residue. Oncogene 2010; 29:2560-76. [DOI: 10.1038/onc.2010.8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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JS-K, a nitric oxide prodrug, has enhanced cytotoxicity in colon cancer cells with knockdown of thioredoxin reductase 1. PLoS One 2010; 5:e8786. [PMID: 20098717 PMCID: PMC2808390 DOI: 10.1371/journal.pone.0008786] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 12/30/2009] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND The selenoenzyme thioredoxin reductase 1 has a complex role relating to cell growth. It is induced as a component of the cellular response to potentially mutagenic oxidants, but also appears to provide growth advantages to transformed cells by inhibiting apoptosis. In addition, selenocysteine-deficient or alkylated forms of thioredoxin reductase 1 have also demonstrated oxidative, pro-apoptotic activity. Therefore, a greater understanding of the role of thioredoxin reductase in redox initiated apoptotic processes is warranted. METHODOLOGY The role of thioredoxin reductase 1 in RKO cells was evaluated by attenuating endogenous thioredoxin reductase 1 expression with siRNA and then either inducing a selenium-deficient thioredoxin reductase or treatment with distinct redox challenges including, hydrogen peroxide, an oxidized lipid, 4-hydroxy-2-nonenol, and a nitric oxide donating prodrug. Thioredoxin redox status, cellular viability, and effector caspase activity were measured. CONCLUSIONS/SIGNIFICANCE In cells with attenuated endogenous thioredoxin reductase 1, a stably integrated selenocysteine-deficient form of the enzyme was induced but did not alter either the thioredoxin redox status or the cellular growth kinetics. The oxidized lipid and the nitric oxide donor demonstrated enhanced cytotoxicity when thioredoxin reductase 1 was knocked-down; however, the effect was more pronounced with the nitric oxide prodrug. These results are consistent with the hypothesis that attenuation of the thioredoxin-system can promote apoptosis in a nitric oxide-dependent manner.
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Prostaglandin A2 activates intrinsic apoptotic pathway by direct interaction with mitochondria in HL-60 cells. Prostaglandins Other Lipid Mediat 2010; 91:30-7. [PMID: 20044024 DOI: 10.1016/j.prostaglandins.2009.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 12/10/2009] [Accepted: 12/18/2009] [Indexed: 11/19/2022]
Abstract
HL-60 cells treated by prostaglandin (PG) A(2) showed characteristics of apoptosis such as accumulation of hypodiploid and annexin V positive cells, condensed and fragmented nuclei, cytochrome c (Cyt C) release from mitochondria and activation of caspase-1, -2, -3, -7 and -9. PGA(2)-induced cell death was rescued by inhibitors of caspase-9 and -3, but PGA(2)-induced Cyt C release was not prevented by caspase inhibitors. During Cyt C release by PGA(2), mitochondrial transmembrane potential was maintained and mitochondrial permeability transition pore was not formed. In addition, anti-apoptotic BCL-2 family proteins like BCL-2 and BCL-XL, and ROS scavengers including ascorbic acid and 2,2,6,6-tetramethyl-1-piperidinyloxy were not able to inhibit Cyt C release as well as apoptosis by PGA(2). Finally, it was shown that PGA(2)-induced Cyt C release in vitro from purified mitochondria in the absence of cytosolic components. Furthermore, thiol-containing compounds such as N-acetylcysteine, l-cysteine and monothioglycerol prevented Cyt C release, and hence induction of apoptosis. Taken together, these results suggest that PGA(2) activates intrinsic apoptotic pathway by directly stimulating mitochondrial outer membrane permeabilization to release Cyt C, in which thiol-reactivity of PGA(2) plays a pivotal role.
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Rao CV, Steele VE, Swamy MV, Patlolla JM, Guruswamy S, Kopelovich L. Inhibition of azoxymethane-induced colorectal cancer by CP-31398, a TP53 modulator, alone or in combination with low doses of celecoxib in male F344 rats. Cancer Res 2009; 69:8175-82. [PMID: 19826045 PMCID: PMC2792897 DOI: 10.1158/0008-5472.can-09-1377] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tumor suppressor p53 plays a major role in colorectal cancer development. The present study explores the effects of p53-modulating agent CP-31398 alone and combined with celecoxib on azoxymethane-induced aberrant crypt foci (ACF) and colon adenocarcinomas in F344 rats. Maximum tolerated doses were 400 and 3,000 ppm for CP-31398 and celecoxib, respectively. ACF and tumor efficacy endpoints were carried out on azoxymethane-treated 7-week-old rats (48 per group) fed the control AIN-76A diet. Two weeks after carcinogen treatment, rats were fed the diets containing 0, 150, or 300 ppm CP-31398, 300 ppm celecoxib, or 150 ppm CP-31398 plus 300 ppm celecoxib. ACF and colon adenocarcinomas were determined at 8 and 48 weeks after azoxymethane treatment, respectively. Dietary CP-31398 was shown to suppress mean colonic total ACF by 43% and multicrypt ACF by 63%; dietary CP-31398 at 150 and 300 ppm suppressed adenocarcinoma incidence by 30.4% (P < 0.02) and 44% (P < 0.005), respectively, and adenocarcinoma multiplicity by 51% (P < 0.005) and 65% (P < 0.0001), respectively. Dietary celecoxib suppressed colon adenocarcinoma incidence (60%; P < 0.0003) and multiplicity (70%; P < 0.0001). Importantly, combination of low-dose CP-31398 and celecoxib suppressed colon adenocarcinoma incidence by 78% and multiplicity by 90%. Rats that were fed the high-dose CP-31398 or a combination of low-dose CP-31398 and celecoxib showed considerable enhancement of p53 and p21(WAF1/CIP) expression, apoptosis, and reduced tumor cell proliferation in colonic tumors. These observations show, for the first time, that CP-31398 possesses significant dose-dependent chemopreventive activity in a well-established colon cancer model and that a combination of low-dose CP-31398 and celecoxib significantly enhanced colon cancer chemopreventive efficacy.
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Affiliation(s)
- Chinthalapally V. Rao
- Department of Medicine, Hem-Onc Section, University of Oklahoma Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Vernon E. Steele
- Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD
| | - Malisetty V. Swamy
- Department of Medicine, Hem-Onc Section, University of Oklahoma Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Jagan M.R. Patlolla
- Department of Medicine, Hem-Onc Section, University of Oklahoma Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Suresh Guruswamy
- Department of Medicine, Hem-Onc Section, University of Oklahoma Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Levy Kopelovich
- Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD
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Kim DH, Kim EH, Na HK, Surh YJ. Effects of 15-Deoxy-Δ12,14-prostaglandin J2 on the Expression of p53 in MCF-7 Cells. Ann N Y Acad Sci 2009; 1171:202-9. [DOI: 10.1111/j.1749-6632.2009.04913.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Uchida K, Shibata T. 15-Deoxy-Delta(12,14)-prostaglandin J2: an electrophilic trigger of cellular responses. Chem Res Toxicol 2007; 21:138-44. [PMID: 18052108 DOI: 10.1021/tx700177j] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electrophilic molecules are endogenously generated and are causally involved in many pathophysiological effects. Prostaglandin D (20 (PGD (2)), a major cyclooxygenase product in a variety of tissues, readily undergoes dehydration to yield the cyclopentenone-type PGs of the J (2)-series such as 15-deoxy-Delta (12,14)-PGJ (2) (15d-PGJ (2)). 15d-PGJ (2) is an electrophile, which can covalently react via the Michael addition reaction with nucleophiles, such as the free sulfhydryls of glutathione and cysteine residues in cellular proteins that play an important role in the control of the redox cell-signaling pathways. Covalent binding of 15d-PGJ (2) to cellular proteins may be one of the mechanisms by which 15d-PGJ (2) induces a cellular response involved in most of the pathophysiological effects associated with inflammation. In the present perspective, we provide a comprehensive summary of 15d-PGJ (2) as an electrophilic mediator of cellular responses.
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Affiliation(s)
- Koji Uchida
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
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Fini L, Selgrad M, Fogliano V, Graziani G, Romano M, Hotchkiss E, Daoud YA, De Vol EB, Boland CR, Ricciardiello L. Annurca apple polyphenols have potent demethylating activity and can reactivate silenced tumor suppressor genes in colorectal cancer cells. J Nutr 2007; 137:2622-8. [PMID: 18029474 DOI: 10.1093/jn/137.12.2622] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The CpG island methylator phenotype is characterized by DNA hypermethylation in the promoters of tumor suppressor genes with silencing of transcription. Hypermethylation of the promoter of hMLH1 and subsequent microsatellite instability occurs in approximately 12% of sporadic colorectal cancers (CRC). Annurca apple, a variety of southern Italy, is rich in polyphenols that are associated with anticancer properties. Populations in southern Italy have lower incidences of CRC than elsewhere in the western world. We evaluated the mechanisms of putative anticancer effects of Annurca polyphenol extract (APE) in in vitro models of CRC. We extracted polyphenols from Annurca apples and treated RKO, SW48, and SW480 cells with APE and assessed the cell viability, apoptosis, and cell cycle. DNA methylation of selected tumor suppressor genes was evaluated after treatment with APE and was compared with the synthetic demethylating agent 5-aza-2'deoxycytidine (5-aza-2dC). DNA methyltransferase (DNMT)-1 and -3b levels were evaluated. Decreased cell viability and induction of apoptosis was evident after treatment. We found no significant changes in cell cycle dynamics. We observed significant increases of p53 protein expression in RKO after treatment. APE treatment strongly reduced DNA methylation in the promoters of hMLH1, p14(ARF), and p16(INK4a) with consequent restoration of normal expression. These effects were qualitatively comparable with those obtained with 5-aza-2dC. We observed a significant reduction in expression of DNMT proteins after treatment without changes in messenger RNA. In conclusion, APE have potent demethylating activity through the inhibition of DNMT proteins. The lack of toxicity in Annurca extracts makes them excellent candidates for the chemoprevention of CRC.
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Affiliation(s)
- Lucia Fini
- GI Cancer Research Laboratory, Department of Internal Medicine, Sammons Cancer Center, Dallas, TX 75246, USA
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31
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Lanas A, Ortego J, Sopeña F, Alcedo J, Barrio E, Bujanda L, Cosme A, Bajador E, Parra-Blanco A, Ferrandez A, Piazuelo E, Quintero E, Pique JM. Effects of long-term cyclo-oxygenase 2 selective and acid inhibition on Barrett's oesophagus. Aliment Pharmacol Ther 2007; 26:913-23. [PMID: 17767476 DOI: 10.1111/j.1365-2036.2007.03429.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND There is an overexpression of cyclo-oxygenase 2 (COX-2) in Barrett's oesophagus (BO). AIM To determine the long-term effect of a COX-2 inhibitor on cellular mechanisms involved in BO. METHODS A randomized controlled trial was conducted in BO patients allocated to continue the usual proton pump inhibitor (PPI) alone treatment, or PPI combined with rofecoxib (25 mg/day) for 6 months. Cell proliferation index and COX-2 expression in BO glands was determined in biopsy specimens at baseline and after treatment. Cell apoptosis, cyclin D1, p53 and vascular endothelial growth factor (VEGF) expression was also explored in a subset of patients. Student-t test and the U-Mann-Whitney test were used for quantitative and ordinal variables. RESULTS Of 62 patients, 58 completed the study. A higher proportion of patients on rofecoxib + PPI exhibited a decrease in COX-2 expression compared to those treated with PPI alone, but cell proliferation index was not affected. Unlike PPI alone, rofecoxib + PPI was associated with an increase in the apoptotic cell index, a decrease in p53 cell staining and VEGF expression in mucosal vessels. No effect on low-grade dysplasia or cyclin D1 was observed. CONCLUSIONS The addition of rofecoxib to PPI therapy does not affect cell proliferation index in BO cells after 6 months of therapy, but does reduce COX-2 and VEGF expression and increases cell apoptosis.
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Affiliation(s)
- A Lanas
- Service of Digestive Diseases, University Hospital, Instituto Aragonés de Ciencias de la Salud, CIBERehd, Zaragoza, Spain.
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Chun KS, Akunda JK, Langenbach R. Cyclooxygenase-2 inhibits UVB-induced apoptosis in mouse skin by activating the prostaglandin E2 receptors, EP2 and EP4. Cancer Res 2007; 67:2015-21. [PMID: 17332329 PMCID: PMC2083120 DOI: 10.1158/0008-5472.can-06-3617] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cyclooxygenase-2 (COX-2) is induced by UVB light and reduces UVB-induced epidermal apoptosis; however, the mechanism is unclear. Therefore, wild-type (WT) and COX-2-/- mice were acutely treated with UVB (5 kJ/m(2)), and apoptotic signaling pathways were compared. Following exposure, apoptosis was 2.5-fold higher in COX-2-/- compared with WT mice. Because prostaglandin E(2) (PGE(2)) is the major UV-induced prostaglandin and manifests its activity via four receptors, EP1 to EP4, possible differences in EP signaling were investigated in WT and COX-2-/- mice. Following UVB exposure, protein levels of EP1, EP2, and EP4 were elevated in WT mice, but EP2 and EP4 levels were 50% lower in COX-2-/- mice. Activated cyclic AMP-dependent protein kinase (PKA) and Akt are downstream in EP2 and EP4 signaling, and their levels were reduced in UVB-exposed COX-2-/- mice. Furthermore, p-Bad (Ser(136) and Ser(155)), antiapoptotic products of activated Akt and PKA, respectively, were significantly reduced in UVB-exposed COX-2-/- mice. To further study the roles of EP2 and EP4, UVB-exposed CD-1 mice were topically treated with indomethacin to block endogenous PGE(2) production, and PGE(2), the EP2 agonist (butaprost) or EP4 agonist (PGE(1) alcohol), was applied. Indomethacin reduced PKA and Akt activation by approximately 60%, but PGE(2) and the agonists restored their activities. Furthermore, both agonists decreased apoptosis in COX-2-/- mice by 50%. The data suggest that COX-2-generated PGE(2) has antiapoptotic roles in UVB-exposed mouse skin that involves EP2- and EP4-mediated signaling.
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Affiliation(s)
- Kyung-Soo Chun
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences/NIH, Research Triangle Park, NC 27709, USA
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Kim EH, Surh YJ. 15-Deoxy-Δ12,14-prostaglandin J2 as a potential endogenous regulator of redox-sensitive transcription factors. Biochem Pharmacol 2006; 72:1516-28. [PMID: 16987499 DOI: 10.1016/j.bcp.2006.07.030] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 07/27/2006] [Accepted: 07/28/2006] [Indexed: 12/18/2022]
Abstract
15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) has been known to display multifaceted cellular functions, including anti-inflammatory and cytoprotective effects. However, depending on the concentrations and intracellular microenvironment, this cyclopentenone prostaglandin can exert opposite effects. Because of the alpha,beta-unsaturated carbonyl moiety present in its cyclopentenone ring structure, 15d-PGJ(2) can act as a Michael reaction acceptor and readily interacts with critical cellular nucleophiles, such as cysteine thiol groups in proteins. Many of the biological effects induced by 15d-PGJ(2) involve redox-transcription factors as the potential targets. Thus, 15d-PGJ(2) can modulate the transcriptional activities of nuclear factor-kappaB (NF-kappaB), activator protein-1 (AP-1), nuclear factor-erythroid 2p45 (NF-E2)-related factors (Nrf2), hypoxia inducible factor (HIF), etc. 15d-PGJ(2) is also well known as an endogenous ligand of peroxisome proliferator-activated receptor gamma (PPARgamma). However, the regulation of the aforementioned redox-sensitive transcription factors by 15d-PGJ(2) is not necessarily mediated via PPARgamma activation, but rather involves covalent modification or oxidation of their critical cysteine residues acting as a redox-sensor. This commentary describes the biological and physiological functions of 15d-PGJ(2) and underlying biochemical and molecular mechanisms with emphasis on the modulation of redox-sensitive transcription factors and their regulators.
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Affiliation(s)
- Eun-Hee Kim
- National Research Laboratory of Molecular Carcinogenesis and Chemoprevention, College of Pharmacy, Seoul National University, Shinlim-dong, Kwanak-ku, Seoul 151-742, South Korea
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Tsubochi H, Sato N, Hiyama M, Kaimori M, Endo S, Sohara Y, Imai T. Combined Analysis of Cyclooxygenase-2 Expression With p53 and Ki-67 in Nonsmall Cell Lung Cancer. Ann Thorac Surg 2006; 82:1198-204. [PMID: 16996907 DOI: 10.1016/j.athoracsur.2006.04.069] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Revised: 04/14/2006] [Accepted: 04/19/2006] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cyclooxygenase-2 (COX-2) is known to play a role in carcinogenesis and tumor progression. The aim of this study was to evaluate the relationship between COX-2 expression and clinicopathologic features, and to define the importance of COX-2 expression alone and in combination with p53 and Ki-67 expression in the clinical outcome of NSCLC. METHODS A total of 219 patients with stage I-IIIB nonsmall cell lung cancer (NSCLC) who previously underwent surgery were analyzed in this study. The COX-2 expression was evaluated by means of immunohistochemistry; p53 and Ki-67 immunoreactivity were also studied. RESULTS The COX-2 expression was observed in 137 patients (63%) and was significantly associated with lymph node metastasis and the histological grade of those with adenocarcinoma (p = 0.02 and 0.04, respectively). Kaplan-Meier analyses revealed that COX-2 expression was correlated with poor survival (p = 0.005), whereas multivariate survival analysis did not reveal COX-2 expression to be an independent prognostic factor. When the patients were stratified according to gender, age, tumor histology, and disease stage, COX-2 expression was significantly associated with unfavorable prognosis in males, younger patients (< or = 65 years), and those with adenocarcinoma and stage I tumors. The prognosis of patients with tumors negative for both COX-2 and p53 expression was significantly favorable, whereas those with tumors positive for COX-2 expression and with a high Ki-67 labeling index had a significantly unfavorable prognosis. CONCLUSIONS These findings indicate that combined immunohistochemical analysis of COX-2 with p53 and Ki-67 can be useful for identifying the prognosis of NSCLC patients.
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Affiliation(s)
- Hiroyoshi Tsubochi
- Department of General Thoracic Surgery, Omiya Medical Center, Jichi Medical School, Omiya, Saitama, Japan.
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Lau L, Hansford LM, Cheng LS, Hang M, Baruchel S, Kaplan DR, Irwin MS. Cyclooxygenase inhibitors modulate the p53/HDM2 pathway and enhance chemotherapy-induced apoptosis in neuroblastoma. Oncogene 2006; 26:1920-31. [PMID: 16983334 DOI: 10.1038/sj.onc.1209981] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cyclooxygenase-2 (COX-2) is upregulated in many tumors including neuroblastoma, and its overexpression has been implicated in resistance to p53-dependent apoptosis. Although p53 is rarely mutated in neuroblastoma, the p53 protein is rendered inactive via several mechanisms including sequestration in the cytoplasm. Here, we show that COX inhibitors inhibit the growth of neuroblastoma and when combined with low doses of chemotherapy, exert synergistic effects on neuroblastoma cells. Following COX inhibitor treatment, HDM2, which targets p53 for ubiquitin-mediated degradation, is downregulated, resulting in an attenuation of p53 ubiquitination and an increase in p53 half-life. The level of HDM2 phosphorylation at ser166, which influences both HDM2 and p53 subcellular distribution, is markedly diminished in response to COX inhibitors and is associated with increased p53 nuclear localization. Combining COX inhibitors with low-dose chemotherapy potentiates apoptosis and p53 stability, nuclear localization, and activity. p53 knockdown by siRNA resulted in the rescue of COX-inhibitor-treated cells, indicating that COX inhibitor-induced apoptosis is, at least in part, p53-dependent. Taken together, these results provide the first evidence that COX inhibitors enhance chemosensitivity in neuroblastoma via downregulating HDM2 and augmenting p53 stability and nuclear accumulation.
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Affiliation(s)
- L Lau
- Division of Hematology/Oncology, Cancer Research Program, Hospital for Sick Children, Toronto, Canada
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36
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Aizu W, Belinsky GS, Flynn C, Noonan EJ, Boes CC, Godman CA, Doshi B, Nambiar PR, Rosenberg DW, Giardina C. Circumvention and reactivation of the p53 oncogene checkpoint in mouse colon tumors. Biochem Pharmacol 2006; 72:981-91. [PMID: 16949053 DOI: 10.1016/j.bcp.2006.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 06/29/2006] [Accepted: 07/17/2006] [Indexed: 01/25/2023]
Abstract
The p53 tumor suppressor protein is sequence-normal in azoxymethane (AOM)-induced mouse colon tumors, making them a good model for human colon cancers that retain a wild type p53 gene. Cellular localization and co-immunoprecipitation experiments using a cell line derived from an AOM-induced colon tumor (AJ02-NM(0) cells) pointed to constitutively expressed Mdm2 as being an important negative regulator of p53 in these cells. Although the Mdm2 inhibitory protein p19/ARF was expressed in AJ02-NM(0) cells, its level of expression was not sufficient for p53 activation. We tested the response of AJ02-NM(0) cells to the recently developed Mdm2 inhibitor, Nutlin-3. Nutlin-3 was found to activate p53 DNA binding in AJ02-NM(0) cells, to a level comparable to doxorubicin and 5-fluorouracil (5-FU). In addition, Nutlin-3 increased expression of the p53 target genes Bax and PERP to a greater extent than doxorubicin or 5-FU, and triggered a G2/M phase arrest in these cells, compared to a G1 arrest triggered by doxorubicin and 5-FU. The differences in the cellular response may be related to differences in the kinetics of p53 activation and/or its post-translational modification status. In an ex vivo experiment, Nutlin-3 was found to activate p53 target gene expression and apoptosis in AOM-induced tumor tissue, but not in normal adjacent mucosa. Our data indicate that Mdm2 inhibitors may be an effective means of selectively targeting colon cancers that retain a sequence-normal p53 gene while sparing normal tissue and that the AOM model is an appropriate model for the preclinical development of these drugs.
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Affiliation(s)
- Wataru Aizu
- Department of Molecular & Cell Biology, 91 North Eagleville Road, University of Connecticut, Storrs, CT 06269-3125, USA
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Haupt S, Kleinstern J, Haupt Y, Rubinstein A. Celecoxib can induce cell death independently of cyclooxygenase-2, p53, Mdm2, c-Abl and reactive oxygen species. Anticancer Drugs 2006; 17:609-19. [PMID: 16917206 DOI: 10.1097/01.cad.0000215055.40072.42] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Cell lines that do not overexpress functional cyclooxygenase-2 are resistant to the normal plasma levels of celecoxib achieved following oral ingestion. Cell growth inhibition was demonstrated after 24 h exposure to 80 micromol/l celecoxib while significant death was not detected at concentrations below 120 micromol/l following 24 h exposure. This growth inhibition and death induction was identified to be independent of p53 and Hdm2 in these cells, despite wild-type p53 stabilization and Hdm2 diminution in some lines. Cell death induced by celecoxib was preceded by the generation of reactive oxygen species within 4 h of drug exposure. The precise mechanism of elicitation of reactive oxygen species in these cells remains to be elucidated, although it was found to be independent of p53 and c-Abl, while in vitro, celecoxib enhanced superoxide radical production by xanthine oxidase. Importantly, the failure of anti-oxidants to protect from death indicates that celecoxib induces death independently of reactive oxygen species and that reactive oxygen species generation may be an insufficient trigger of death in p53-deficient cells.
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Affiliation(s)
- Sue Haupt
- Department of Hematology, Hadassah University Hospital, Jerusalem, Israel.
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West JD, Marnett LJ. Endogenous Reactive Intermediates as Modulators of Cell Signaling and Cell Death. Chem Res Toxicol 2006; 19:173-94. [PMID: 16485894 DOI: 10.1021/tx050321u] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James D West
- Department of Biochemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt-Ingram Comprehensive Cancer Center, Vanderbilt University School of Medicine, 23rd Avenue at Pierce, Nashville, Tennessee 37212-0146, USA
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Wagner TM, Mullally JE, Fitzpatrick FA. Reactive lipid species from cyclooxygenase-2 inactivate tumor suppressor LKB1/STK11: cyclopentenone prostaglandins and 4-hydroxy-2-nonenal covalently modify and inhibit the AMP-kinase kinase that modulates cellular energy homeostasis and protein translation. J Biol Chem 2005; 281:2598-604. [PMID: 16311241 DOI: 10.1074/jbc.m509723200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
LKB1, a unique serine/threonine kinase tumor suppressor, modulates anabolic and catabolic homeostasis, cell proliferation, and organ polarity. Chemically reactive lipids, e.g. cyclopentenone prostaglandins, formed a covalent adduct with LKB1 in MCF-7 and RKO cells. Site-directed mutagenesis implicated Cys210 in the LKB1 activation loop as the residue modified. Notably, ERK, JNK, and AKT serine/threonine kinases with leucine or methionine, instead of cysteine, in their activation loop did not form a covalent lipid adduct. 4-Hydroxy-2-nonenal, 4-oxo-2-nonenal, and cyclopentenone prostaglandin A and J, which all contain alpha,beta-unsaturated carbonyls, inhibited the AMP-kinase kinase activity of cellular LKB1. In turn, this attenuated signals throughout the LKB1 --> AMP kinase pathway and disrupted its restraint of ribosomal S6 kinases. The electrophilic beta-carbon in these lipids appears to be critical for inhibition because unreactive lipids, e.g. PGB1, PGE2, PGF2alpha, and TxB2, did not inhibit LKB1 activity (p > 0.05). Ectopic expression of cyclooxygenase-2 and endogenous biosynthesis of eicosanoids also inhibited LKB1 activity in MCF-7 cells. Our results suggested a molecular mechanism whereby chronic inflammation or oxidative stress may confer risk for hypertrophic or neoplastic diseases. Moreover, chemical inactivation of LKB1 may interfere with its physiological antagonism of signals from growth factors, insulin, and oncogenes.
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Affiliation(s)
- Tracy M Wagner
- Department of Medicinal Chemistry, University of Utah, Huntsman Cancer Institute, Salt Lake City, Utah 84112, USA
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Pachkoria K, Zhang H, Adell G, Jarlsfelt I, Sun XF. Significance of Cox-2 expression in rectal cancers with or without preoperative radiotherapy. Int J Radiat Oncol Biol Phys 2005; 63:739-44. [PMID: 16199309 DOI: 10.1016/j.ijrobp.2005.02.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Revised: 02/07/2005] [Accepted: 02/24/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE Radiotherapy has reduced local recurrence of rectal cancers, but the result is not satisfactory. Further biologic factors are needed to identify patients for more effective radiotherapy. Our aims were to investigate the relationship of cyclooxygenase-2 (Cox-2) expression to radiotherapy, and clinicopathologic/biologic variables in rectal cancers with or without radiotherapy. METHODS AND MATERIALS Cox-2 expression was immunohistochemically examined in distal normal mucosa (n = 28), in adjacent normal mucosa (n = 107), in primary cancer (n = 138), lymph node metastasis (n = 30), and biopsy (n = 85). The patients participated in a rectal cancer trial of preoperative radiotherapy. RESULTS Cox-2 expression was increased in primary tumor compared with normal mucosa (p < 0.0001), but there was no significant change between primary tumor and metastasis. Cox-2 positivity was or tended to be related to more p53 and Ki-67 expression, and less apoptosis (p < or = 0.05). In Cox-2-negative cases of either biopsy (p = 0.01) or surgical samples (p = 0.02), radiotherapy was related to less frequency of local recurrence, but this was not the case in Cox-2-positive cases. CONCLUSION Cox-2 expression seemed to be an early event involved in rectal cancer development. Radiotherapy might reduce a rate of local recurrence in the patients with Cox-2 weakly stained tumors, but not in those with Cox-2 strongly stained tumors.
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Affiliation(s)
- Ketevan Pachkoria
- Department of Oncology, Institute of Biomedicine and Surgery, University of Linköping, Linköping, Sweden
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Pande V, Ramos MJ. Molecular recognition of 15-deoxy-Δ12,14-prostaglandin J2 by nuclear factor-kappa B and other cellular proteins. Bioorg Med Chem Lett 2005; 15:4057-63. [PMID: 16006125 DOI: 10.1016/j.bmcl.2005.06.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 06/01/2005] [Accepted: 06/06/2005] [Indexed: 11/20/2022]
Abstract
15-Deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2), a dehydration product of prostaglandin D2, is an important pharmacological molecule, which with the virtue of its electrophilicity, has been reported to covalently modify some cellular proteins (such as nuclear factor-kappa B (NF-kappaB), AP-1, p53, and thioredoxin) and elicit its physiological effects. The aim of the present computational study is to understand the role molecular recognition plays in the association of 15d-PGJ2 with NF-kappaB and other proteins. Another aim is to characterize whether p53 is a direct target for covalent modification by 15d-PGJ2. A docking strategy is applied along with calculation of ab initio electrostatic potential maps to analyze the mode of binding of prostaglandin molecule with critical cysteine-containing sites in each protein. The results provide identification of important sites in the target proteins, which provide recognition and stability to the prostaglandin molecule. Fit of shape and complementarity of electrostatic interactions are derived as significant determinants of molecular recognition of 15d-PGJ2. Further, comparative results indicate that p53 protein may also be a target for direct modification by 15d-PGJ2. The molecular models obtained should allow the rational design of more specific analogs of 15d-PGJ2.
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Affiliation(s)
- Vineet Pande
- REQUIMTE/Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
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Musiek ES, Milne GL, McLaughlin BA, Morrow JD. Cyclopentenone eicosanoids as mediators of neurodegeneration: a pathogenic mechanism of oxidative stress-mediated and cyclooxygenase-mediated neurotoxicity. Brain Pathol 2005; 15:149-58. [PMID: 15912888 PMCID: PMC2881556 DOI: 10.1111/j.1750-3639.2005.tb00512.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The activation of cyclooxygenase enzymes in the brain has been implicated in the pathogenesis of numerous neurodegenerative conditions. Similarly, oxidative stress is believed to be a major contributor to many forms of neurodegeneration. These 2 distinct processes are united by a common characteristic: the generation of electrophilic cyclopentenone eicosanoids. These cyclopentenone compounds are defined structurally by the presence of an unsaturated carbonyl moiety in their prostane ring, and readily form Michael adducts with cellular thiols, including those found in glutathione and proteins. The cyclopentenone prostaglandins (PGs) PGA2, PGJ2, and 15-deoxy-delta(12,14) PGJ2, enzymatic products of cyclooxygenase-mediated arachidonic acid metabolism, exert a complex array of potent neurodegenerative, neuroprotective, and anti-inflammatory effects. Cyclopentenone isoprostanes (A2/J2-IsoPs), products of non-enzymatic, free radical-mediated arachidonate oxidation, are also highly bioactive, and can exert direct neurodegenerative effects. In addition, cyclopentenone products of docosahexaenoic acid oxidation (cyclopentenone neuroprostanes) are also formed abundantly in the brain. For the first time, the formation and biological actions of these various classes of reactive cyclopentenone eicosanoids are reviewed, with emphasis on their potential roles in neurodegeneration. The accumulating evidence suggests that the formation of cyclopentenone eicosanoids in the brain may represent a novel pathogenic mechanism, which contributes to many neurodegenerative conditions.
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Affiliation(s)
| | | | - Beth Ann McLaughlin
- Departments of Pharmacology and
- Vanderbilt Kennedy Center, Vanderbilt University School of Medicine, Nashville, Tenn
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Anderson WF, Umar A, Hawk ET. Cyclooxygenase inhibition in cancer prevention and treatment. Expert Opin Pharmacother 2005; 4:2193-204. [PMID: 14640918 DOI: 10.1517/14656566.4.12.2193] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Several lines of evidence suggest that the cyclooxygenase enzymes (specifically COX-2) might be an important molecular target for the intervention of cancer at both early and late stages of some cancers, providing an opportunity for both cancer prevention and therapy. COX-2 is overexpressed during carcinogenesis, and appears to have a role in both tumour initiation and promotion and is amenable to intervention. This review discusses the importance of COX modulation via non-specific, as well as COX-2 specific COX inhibitors (NSAIDs and COX-2 selective inhibitors [COXIB]). A brief discussion on the pharmacoeconomic considerations of NSAID and COXIB use and safety issues that have recently been the focus of debate, will be presented.
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Affiliation(s)
- William F Anderson
- Gastrointestinal & Other Cancers Research Group, Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, EPN, Room 2141, 6130 Executive Boulevard, Bethesda, MD 20892-7317, USA
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44
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Abstract
Both human gamma-herpesviruses, Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) induce neoplasia. Burkitt's and Hodgkin's lymphomas harbor EBV sequences, while KSHV has been associated with Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric castleman's disease (MCD). Each of these gamma-herpesvirus-associated malignancies displays typical characteristics of neoplasia, such as angiogenesis and cell survival. One enzyme commonly overexpressed in breast, prostate, and colon cancers is cyclooxygenase-2 (COX-2). Recently, COX-2 overexpression has been reported in herpesvirus infections in vitro. This review will outline potential mechanisms by which COX-2 may participate in herpesvirus-induced neoplasia.
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Affiliation(s)
- Bryan D Shelby
- Department of Microbiology and Immunology, Tulane University Health Sciences Center, New Orleans, Louisiana, USA
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45
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Rao CV. Nitric oxide signaling in colon cancer chemoprevention. Mutat Res 2004; 555:107-19. [PMID: 15476855 DOI: 10.1016/j.mrfmmm.2004.05.022] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Revised: 05/25/2004] [Accepted: 05/26/2004] [Indexed: 12/19/2022]
Abstract
Nitric oxide (NO) is a pleiotrophic regulator, pivotal to numerous biological processes, including vasodilation, neurotransmission, and macrophage-mediated immunity. The highly reactive free radicals, produced by NO synthases (NOS) have been implicated in the modulation of carcinogenesis. Over-expression of inducible NOS (iNOS), a common phenomenon during chronic inflammatory conditions, generates sustainable amounts of NO, that its reactive intermediates are mutagenic, causing DNA damage or impairment of DNA repair, has been well established in carcinogenesis. Recent studies also implicate NO as having a key signaling molecule that regulates processes of tumorigenesis. Increased expression of iNOS has been observed in tumors of the colon, lung, oropharynx, reproductive organs, breast, and central nervous system besides its occurrence in chronic inflammatory diseases. Progression of a large majority of human and experimental colon tumors appears to progress by NO resulting from stimulation of proinflammatory cytokines, and inactivation (nitrosylation) of p53 mediated caspase activities in the tumors, whereas in some cases it associated with induction of apoptosis and tumor regression. This dichotomy is largely explained by the complexity of signaling pathways in tumor cells, that respond to NO very differently depending on its concentration. p53 mutation, functional loss, activation, and inactivation of apoptotic proteins all have been linked with NO resistance and dependence. Evidence from both in vitro and in vivo experiments support that NO and its reactive metabolite peroxynitrite stimulate COX-2 activity leading generation of tumor growth enhancing prostaglandins. Thus, NO mediated signaling can augment the tumor growth and metastasis by promoting invasive and angiogenic properties of tumor cells, which includes triggering and activation of COX-2. Thus, developing selective inhibitors of iNOS and NO-releasing agents may lead to important strategies for chemoprevention of colon cancer. Chemoprevention studies at preclinical level with several selective inhibitors of iNOS in both chemically and transgenic models of colon cancer are encouraging.
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Affiliation(s)
- Chinthalapally V Rao
- Chemoprevention Program, American Health Foundation-Cancer Center, Institute For Cancer Prevention, Valhalla, NY 10595, USA.
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Liu XH, Kirschenbaum A, Yu K, Yao S, Levine AC. Cyclooxygenase-2 suppresses hypoxia-induced apoptosis via a combination of direct and indirect inhibition of p53 activity in a human prostate cancer cell line. J Biol Chem 2004; 280:3817-23. [PMID: 15550400 DOI: 10.1074/jbc.m406577200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Although p53-inactivating mutations have been described in the majority of human cancers, their role in prostate cancer is controversial as mutations are uncommon, particularly in early lesions. p53 is activated by hypoxia and other stressors and is primarily regulated by the Mdm2 protein. Cyclooxygenase (COX)-2, an inducible enzyme that catalyzes the conversion of arachidonic acid to prostaglandins and other eicosanoids, is also induced by hypoxia. COX-2 and resultant prostaglandins increase tumor cell proliferation, resistance to apoptosis, and angiogenesis. Previous reports indicate a complex, reciprocal relationship between p53 and COX-2. To elucidate the effects of COX-2 on p53 in response to hypoxia, we transfected the COX-2 gene into the p53-positive, COX-2-negative MDA-PCa-2b human prostate cancer cell line. The expression of functional p53 and Mdm2 was compared in COX-2+ versus COX-2- cells under normoxic and hypoxic conditions. Our results demonstrated that hypoxia increases both COX-2 protein levels and p53 transcriptional activity in these cells. Forced expression of COX-2 increased tumor cell viability and decreased apoptosis in response to hypoxia. COX-2+ cells had increased Mdm2 phosphorylation in either normoxic or hypoxic conditions. Overexpression of COX-2 abrogated hypoxia-induced p53 phosphorylation and promoted the binding of p53 to Mdm2 protein in hypoxic cells. In addition, COX-2-expressing cells exhibited decreased hypoxia-induced nuclear accumulation of p53 protein. Finally, forced expression of COX-2 suppressed both basal and hypoxia-induced p53 transcriptional activity, and this effect was mimicked by the addition of PGE2 to wild-type cells. These results demonstrated a role for COX-2 in the suppression of hypoxia-induced p53 activity via both direct effects and indirect modulation of Mdm2 activity. These data imply that COX-2-positive prostate cancer cells can have impaired p53 function even in the presence of wild-type p53 and that p53 activity can be restored in these cells via inhibition of COX-2 activity.
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Affiliation(s)
- Xin-Hua Liu
- Department of Medicine, Division of Endocrinology and Metabolism, and Urology, Mount Sinai School of Medicine, New York, New York 10029, USA.
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Moos PJ, Edes K, Mullally JE, Fitzpatrick FA. Curcumin impairs tumor suppressor p53 function in colon cancer cells. Carcinogenesis 2004; 25:1611-7. [PMID: 15090465 DOI: 10.1093/carcin/bgh163] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Curcumin (diferuloylmethane) is being considered as a potential chemopreventive agent in humans. In vitro it inhibits transcription by NF-kappaB, and the activity of lipoxygenase or cyclooxygenase enzymes, which facilitate tumor progression. In vivo it is protective in rodent models of chemical carcinogenesis. Curcumin contains an alpha,beta-unsaturated ketone, a reactive chemical substituent that is responsible for its repression of NF-kappaB. In compounds other than curcumin this same electrophilic moiety is associated with inactivation of the tumor suppressor, p53. Here we report that curcumin behaves analogously to these compounds. It disrupts the conformation of the p53 protein required for its serine phosphorylation, its binding to DNA, its transactivation of p53-responsive genes and p53-mediated cell cycle arrest.
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Affiliation(s)
- Philip J Moos
- Department of Oncological Sciences and Department of Medicinal Chemistry, University of Utah, Huntsman Cancer Institute, Salt Lake City, UT 84112, USA.
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Saydam O, Abril C, Vogt B, Ackermann M, Schwyzer M. Transactivator protein BICP0 of bovine herpesvirus 1 (BHV-1) is blocked by prostaglandin D2 (PGD2), which points to a mechanism for PGD2-mediated inhibition of BHV-1 replication. J Virol 2004; 78:3805-10. [PMID: 15047795 PMCID: PMC374247 DOI: 10.1128/jvi.78.8.3805-3810.2004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immediate-early protein, BICP0, of bovine herpesvirus 1 (BHV-1) transactivates a variety of viral and cellular genes. In a yeast two-hybrid cDNA library screening, we found that lipocalin-type prostaglandin D synthase, which catalyzes the production of prostaglandin D(2) (PGD(2)), is a cellular target of BICP0. We observed that, during wild-type BHV-1 infection, PGD(2) levels were increased intracellularly and decreased in the medium. These effects were absent upon infection with recombinant BHV-1 expressing beta-galactosidase instead of BICP0 (A2G2). Transient-expression assays showed that BICP0 alone caused a significant increase in PGD(2) levels in the cell. PGD(2) repressed BHV-1 replication in cultured cells. Antiviral activities of prostaglandins have been documented long ago, but their mode of action remains to be clarified. Here we provide evidence that PGD(2) impairs the transactivation ability of BICP0 that is necessary for efficient virus replication.
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Affiliation(s)
- Okay Saydam
- Faculty of Veterinary Medicine, Institute of Virology, University of Zurich, CH-8057 Zurich, Switzerland
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49
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Soberman RJ, Christmas P. The organization and consequences of eicosanoid signaling. J Clin Invest 2003. [DOI: 10.1172/jci200318338] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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50
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Soberman RJ, Christmas P. The organization and consequences of eicosanoid signaling. J Clin Invest 2003; 111:1107-13. [PMID: 12697726 PMCID: PMC152944 DOI: 10.1172/jci18338] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Roy J Soberman
- Renal Unit and Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 149 Navy Yard, Charlestown, MA 02129, USA.
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