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In Vitro Effects of Selective COX and LOX Inhibitors and Their Combinations with Antineoplastic Drugs in the Mouse Melanoma Cell Line B16F10. Int J Mol Sci 2021; 22:ijms22126498. [PMID: 34204367 PMCID: PMC8234702 DOI: 10.3390/ijms22126498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 01/31/2023] Open
Abstract
The constitutive expression or overactivation of cyclooxygenase (COX) and lipoxygenase (LOX) enzymes results in aberrant metabolism of arachidonic acid and poor prognosis in melanoma. Our aim is to compare the in vitro effects of selective COX-1 (acetylsalicylic acid), COX-2 (meloxicam), 5-LOX (MK-886 and AA-861), 12-LOX (baicalein) and 15-LOX (PD-146176) inhibition in terms of proliferation (SRB assay), mitochondrial viability (MTT assay), caspase 3-7 activity (chemiluminescent assay), 2D antimigratory (scratch assay) and synthesis of eicosanoids (EIA) in the B16F10 cell line (single treatments). We also explore their combinatorial pharmacological space with dacarbazine and temozolomide (median effect method). Overall, our results with single treatments show a superior cytotoxic efficacy of selective LOX inhibitors over selective COX inhibitors against B16F10 cells. PD-146176 caused the strongest antiproliferation effect which was accompanied by cell cycle arrest in G1 phase and an >50-fold increase in caspases 3/7 activity. When the selected inhibitors are combined with the antineoplastic drugs, only meloxicam provides clear synergy, with LOX inhibitors mostly antagonizing. These apparent contradictions between single and combination treatments, together with some paradoxical effects observed in the biosynthesis of eicosanoids after FLAP inhibition in short term incubations, warrant further mechanistical in vitro and in vivo scrutiny.
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2
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Chen Y, Zhao H, Luo J, Liao Y, Tan K, Hu G. A drug targeting 5-lipoxygenase enhances the activity of a JAK2 inhibitor in CD34 + bone marrow cells from patients with JAK2V617F-positive polycythemia vera in vitro. Oncol Lett 2021; 21:351. [PMID: 33747208 PMCID: PMC7967924 DOI: 10.3892/ol.2021.12612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 02/10/2021] [Indexed: 11/06/2022] Open
Abstract
Janus kinase 2 (JAK2) inhibitors, the first targeted treatments for myeloproliferative neoplasms (MPNs), provide substantial benefits, including a marked reduction in splenomegaly and MPN-associated symptoms. However, these drugs rarely induce molecular remission in patients with MPNs. Zileuton, a 5-lipoxygenase (5-LO) inhibitor, has been demonstrated to selectively deplete hematopoietic stem cells (HSCs) expressing a JAK2 point mutation (JAK2V617F) in mouse models of JAK2V617F-induced polycythemia vera (PV). To determine the potential activity of 5-LO inhibitors in combination with JAK inhibitors against human PV HSCs, the present study first analyzed 5-LO expression in CD34+ bone marrow cells from patients with JAK2V617F-positive PV using western blotting and reverse transcription-quantitative PCR, and then examined the effect of zileuton combined with ruxolitinib on colony formation using a colony formation assay. Furthermore, cell cycle and apoptosis in CD34+ cells from patients with PV and healthy volunteers were determined by flow cytometry. In the present study, 5-LO expression was upregulated in CD34+ cells from patients with PV compared with in CD34+ cells from healthy volunteers. Higher levels of leukotriene B4, a product of the 5-LO signaling pathway, were detected in patients with PV compared with in healthy volunteers. Zileuton treatment suppressed the colony formation of CD34+ cells from patients with PV in a dose-dependent manner. Furthermore, zileuton and ruxolitinib exerted their anticancer effects by suppressing hematopoietic colony formation, inducing apoptosis and arresting the cell cycle of human CD34+ cells from patients with PV. The combination of these two drugs exerted a more beneficial effect than either agent alone. Based on these data, zileuton enhanced the antitumor activity of low-dose ruxolitinib in hematopoietic progenitor cells from patients with PV, providing conceptual validation for further clinical applications of combination treatment with ruxolitinib and zileuton for patients with PV.
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Affiliation(s)
- Yuan Chen
- Department of Hematology, The Affiliated Zhuzhou Hospital Xiangya Medical College CSU, Zhuzhou, Hunan 412000, P.R. China
| | - Hu Zhao
- Department of Hematology, The Affiliated Zhuzhou Hospital Xiangya Medical College CSU, Zhuzhou, Hunan 412000, P.R. China
| | - Jing Luo
- Department of Hematology, The Affiliated Zhuzhou Hospital Xiangya Medical College CSU, Zhuzhou, Hunan 412000, P.R. China
| | - Youping Liao
- Department of Hematology, The Affiliated Zhuzhou Hospital Xiangya Medical College CSU, Zhuzhou, Hunan 412000, P.R. China
| | - Kui Tan
- Department of Hematology, The Affiliated Zhuzhou Hospital Xiangya Medical College CSU, Zhuzhou, Hunan 412000, P.R. China
| | - Guoyu Hu
- Department of Hematology, The Affiliated Zhuzhou Hospital Xiangya Medical College CSU, Zhuzhou, Hunan 412000, P.R. China
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Farhadi P, Yarani R, Dokaneheifard S, Mansouri K. The emerging role of targeting cancer metabolism for cancer therapy. Tumour Biol 2020; 42:1010428320965284. [PMID: 33028168 DOI: 10.1177/1010428320965284] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Glucose, as the main consuming nutrient of the body, faces different destinies in cancer cells. Glycolysis, oxidative phosphorylation, and pentose phosphate pathways produce different glucose-derived metabolites and thus affect cells' bioenergetics differently. Tumor cells' dependency to aerobic glycolysis and other cancer-specific metabolism changes are known as the cancer hallmarks, distinct cancer cells from normal cells. Therefore, these tumor-specific characteristics receive the limelight as targets for cancer therapy. Glutamine, serine, and fatty acid oxidation together with 5-lipoxygenase are main pathways that have attracted lots of attention for cancer therapy. In this review, we not only discuss different tumor metabolism aspects but also discuss the metabolism roles in the promotion of cancer cells at different stages and their difference with normal cells. Besides, we dissect the inhibitors potential in blocking the main metabolic pathways to introduce the effective and non-effective inhibitors in the field.
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Affiliation(s)
- Pegah Farhadi
- Medical Biology Research Center, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Reza Yarani
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Sadat Dokaneheifard
- Sylvester Comprehensive Cancer Center, Department of Human Genetics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kamran Mansouri
- Medical Biology Research Center, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Department of Molecular Medicine, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Bruce JIE, James AD. Targeting the Calcium Signalling Machinery in Cancer. Cancers (Basel) 2020; 12:cancers12092351. [PMID: 32825277 PMCID: PMC7565467 DOI: 10.3390/cancers12092351] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/30/2020] [Accepted: 08/08/2020] [Indexed: 12/13/2022] Open
Abstract
Cancer is caused by excessive cell proliferation and a propensity to avoid cell death, while the spread of cancer is facilitated by enhanced cellular migration, invasion, and vascularization. Cytosolic Ca2+ is central to each of these important processes, yet to date, there are no cancer drugs currently being used clinically, and very few undergoing clinical trials, that target the Ca2+ signalling machinery. The aim of this review is to highlight some of the emerging evidence that targeting key components of the Ca2+ signalling machinery represents a novel and relatively untapped therapeutic strategy for the treatment of cancer.
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Affiliation(s)
- Jason I. E. Bruce
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
- Correspondence: ; Tel.: +44-(0)-161-275-5484
| | - Andrew D. James
- Department of Biology, University of York, Heslington, York YO10 5DD, UK;
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Oxidized lipids in the metabolic profiling of neuroendocrine tumors - Analytical challenges and biological implications. J Chromatogr A 2020; 1625:461233. [PMID: 32709312 DOI: 10.1016/j.chroma.2020.461233] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 02/08/2023]
Abstract
Untargeted metabolomics can be a great tool for exploring new scientific areas; however, wrong metabolite annotation questions the credibility and puts the success of the entire research at risk. Therefore, an effort should be made to improve the quality and robustness of the annotation despite of the challenges, especially when final identification with standards is not possible. Through non-targeted analysis of human plasma samples, from a large cancer cohort study using RP-LC-ESI-QTOF-MS/MS, we have resolved MS/MS annotation through spectral matching, directed to hydroxyeicosatetraenoic acids (HETEs) and, MS/MS structural elucidation for newly annotated oxidized lyso-phosphatidylcholines (oxLPCs). The annotation of unknowns is supported with structural information from fragmentation spectra as well as the fragmentation mechanisms involved, necessarily including data from both polarity modes and different collision energies. In this work, we present evidences that various oxidation products show significant differences between cancer patients and control individuals and we establish a workflow to help identify such modifications. We report here the upregulation of HETEs and oxLPCs in patients with neuroendocrine tumors (NETs). To our knowledge, this is the first attempt to determine HETEs in NETs and one of very few studies where oxLPCs are annotated. The obtained results provide an important insight regarding lipid oxidation in NETs, although their physiological functions still have to be established and require further research.
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Merchant N, Bhaskar LV, Momin S, Sujatha P, Reddy AB, Nagaraju GP. 5-Lipoxygenase: Its involvement in gastrointestinal malignancies. Crit Rev Oncol Hematol 2018; 127:50-55. [DOI: 10.1016/j.critrevonc.2018.05.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/16/2018] [Accepted: 05/14/2018] [Indexed: 12/11/2022] Open
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Powell WS, Rokach J. Biosynthesis, biological effects, and receptors of hydroxyeicosatetraenoic acids (HETEs) and oxoeicosatetraenoic acids (oxo-ETEs) derived from arachidonic acid. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:340-55. [PMID: 25449650 DOI: 10.1016/j.bbalip.2014.10.008] [Citation(s) in RCA: 219] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 10/10/2014] [Accepted: 10/21/2014] [Indexed: 12/14/2022]
Abstract
Arachidonic acid can be oxygenated by a variety of different enzymes, including lipoxygenases, cyclooxygenases, and cytochrome P450s, and can be converted to a complex mixture of oxygenated products as a result of lipid peroxidation. The initial products in these reactions are hydroperoxyeicosatetraenoic acids (HpETEs) and hydroxyeicosatetraenoic acids (HETEs). Oxoeicosatetraenoic acids (oxo-ETEs) can be formed by the actions of various dehydrogenases on HETEs or by dehydration of HpETEs. Although a large number of different HETEs and oxo-ETEs have been identified, this review will focus principally on 5-oxo-ETE, 5S-HETE, 12S-HETE, and 15S-HETE. Other related arachidonic acid metabolites will also be discussed in less detail. 5-Oxo-ETE is synthesized by oxidation of the 5-lipoxygenase product 5S-HETE by the selective enzyme, 5-hydroxyeicosanoid dehydrogenase. It actions are mediated by the selective OXE receptor, which is highly expressed on eosinophils, suggesting that it may be important in eosinophilic diseases such as asthma. 5-Oxo-ETE also appears to stimulate tumor cell proliferation and may also be involved in cancer. Highly selective and potent OXE receptor antagonists have recently become available and could help to clarify its pathophysiological role. The 12-lipoxygenase product 12S-HETE acts by the GPR31 receptor and promotes tumor cell proliferation and metastasis and could therefore be a promising target in cancer therapy. It may also be involved as a proinflammatory mediator in diabetes. In contrast, 15S-HETE may have a protective effect in cancer. In addition to GPCRs, higher concentration of HETEs and oxo-ETEs can activate peroxisome proliferator-activated receptors (PPARs) and could potentially regulate a variety of processes by this mechanism. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".
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Affiliation(s)
- William S Powell
- Meakins-Christie Laboratories, Department of Medicine, McGill University, 3626St. Urbain Street, Montreal, Quebec H2X 2P2, Canada.
| | - Joshua Rokach
- Claude Pepper Institute and Department of Chemistry, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901, USA
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Investigation of key genes associated with prostate cancer using RNA-seq data. Int J Biol Markers 2014; 29:e86-92. [PMID: 24366848 DOI: 10.5301/jbm.5000056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2013] [Indexed: 01/22/2023]
Abstract
We aimed to identify key genes associated with prostate cancer using RNA-sequencing (RNA-seq) data. RNA-seq data, including 1 cancer sample and 1 adjacent normal sample, were downloaded from the NCBI SRA database and the differentially expressed genes (DEGs) were identified with the software Cufflinks. Functional enrichment analysis was performed to uncover the biological functions of DEGs. Regulatory information was retrieved from the IPA database and a network was established. A total of 147 DEGs were obtained, including 96 downregulated and 51 upregulated DEGs. Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis suggested that metabolism and signal transduction were the 2 major functions that were significantly influenced. Moreover, an interaction network was built. In conclusion, a number of DEGs was identified and their roles in the pathogenesis of cancer were supported by previous studies. More studies are necessary to further validate their usefulness in the diagnosis and treatment of prostate cancer.
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9
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Powell WS, Rokach J. The eosinophil chemoattractant 5-oxo-ETE and the OXE receptor. Prog Lipid Res 2013; 52:651-65. [PMID: 24056189 DOI: 10.1016/j.plipres.2013.09.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 09/10/2013] [Indexed: 01/04/2023]
Abstract
5-Oxo-ETE (5-oxo-6,8,11,14-eicosatetraenoic acid) is formed from the 5-lipoxygenase product 5-HETE (5S-hydroxy-6,8,11,14-eicosatetraenoic acid) by 5-hydroxyeicosanoid dehydrogenase (5-HEDH). The cofactor NADP(+) is a limiting factor in the synthesis of 5-oxo-ETE because of its low concentrations in unperturbed cells. Activation of the respiratory burst in phagocytic cells, oxidative stress, and cell death all dramatically elevate both intracellular NADP(+) levels and 5-oxo-ETE synthesis. 5-HEDH is widely expressed in inflammatory, structural, and tumor cells. Cells devoid of 5-lipoxygenase can synthesize 5-oxo-ETE by transcellular biosynthesis using inflammatory cell-derived 5-HETE. 5-Oxo-ETE is a chemoattractant for neutrophils, monocytes, and basophils and promotes the proliferation of tumor cells. However, its primary target appears to be the eosinophil, for which it is a highly potent chemoattractant. The actions of 5-oxo-ETE are mediated by the highly selective OXE receptor, which signals by activating various second messenger pathways through the release of the βγ-dimer from Gi/o proteins to which it is coupled. Because of its potent effects on eosinophils, 5-oxo-ETE may be an important mediator in asthma, and, because of its proliferative effects, may also contribute to tumor progression. Selective OXE receptor antagonists, which are currently under development, could be useful therapeutic agents in asthma and other allergic diseases.
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Key Words
- 12-HHT
- 12-hydroxy-5Z,8E,10E-heptadecatrienoic acid
- 4Z,7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid
- 5,12-diHETE
- 5,15-diHETE
- 5-HEDH
- 5-HEPE
- 5-HETE
- 5-HETrE
- 5-HODE
- 5-HpETE
- 5-LO
- 5-Lipoxygenase
- 5-Oxo-ETE
- 5-hydroxyeicosanoid dehydrogenase
- 5-lipoxygenase
- 5-oxo-12-HETE
- 5-oxo-12S-hydroxy-6E,8Z,10E,14Z-eicosatetraenoic acid
- 5-oxo-15-HETE
- 5-oxo-15S-hydroxy-6E,8Z,11Z,13E-eicosatetraenoic acid
- 5-oxo-20-HETE
- 5-oxo-20-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid
- 5-oxo-6E,8Z,11Z,14Z,17Z-eicosapentaenoic acid
- 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid
- 5-oxo-6E,8Z,11Z-eicosatrienoic acid
- 5-oxo-6E,8Z-octadecadienoic acid
- 5-oxo-7-glutathionyl factor-8,11,14-eicosatrienoic acid
- 5-oxo-EPE
- 5-oxo-ETE
- 5-oxo-ETrE
- 5-oxo-ODE
- 5S,12S-dihydroxy-6E,8Z,10E,14Z-eicosatetraenoic acid
- 5S,15S-dihydroxy-6E,8Z,11Z,13E-eicosatetraenoic acid
- 5S-hydroperoxy-6E,8Z,11Z,14Z-eicosatetraenoic acid
- 5S-hydroxy-6E,8Z,11Z,14Z,17Z-eicosapentaenoic acid
- 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid
- 5S-hydroxy-6E,8Z,11Z-eicosatrienoic acid
- 5S-hydroxy-6E,8Z-octadecadienoic acid
- 5Z,8Z,11Z,14Z,17Z-eicosapentaenoic acid
- 5Z,8Z,11Z-eicosatrienoic acid
- 5Z,8Z-octadecadienoic acid
- Asthma
- Chemoattractants
- DHA
- ECL
- EPA
- Eosinophils
- FOG(7)
- G protein-coupled receptor
- GPCR
- Inflammation
- LT
- LXA(4)
- Mead acid
- PAF
- PI3K
- PLC
- PMA
- PUFA
- Sebaleic acid
- StAR
- eosinophil chemotactic lipid
- leukotriene
- lipoxin A(4)
- phorbol myristate acetate
- phosphoinositide-3 kinase
- phospholipase C
- platelet-activating
- polyunsaturated fatty acid
- steroidogenic acute regulatory protein
- uPAR
- urokinase-type plasminogen activator receptor
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Affiliation(s)
- William S Powell
- Meakins-Christie Laboratories, Department of Medicine, McGill University, 3626 St. Urbain Street, Montreal, Quebec H2X 2P2, Canada.
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Bishayee K, Khuda-Bukhsh AR. 5-lipoxygenase antagonist therapy: a new approach towards targeted cancer chemotherapy. Acta Biochim Biophys Sin (Shanghai) 2013; 45:709-19. [PMID: 23752617 DOI: 10.1093/abbs/gmt064] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Leukotrienes are the bioactive group of fatty acids and major constituents of arachidonic acid metabolism molded by the catalytic activity of 5-lipoxygenase (5-LOX). Evidence is accumulating in support of the direct involvement of 5-LOX in the progression of different types of cancer including prostate, lung, colon, and colorectal cancers. Several independent studies now support the correlation between the 5-LOX expression and cancer cell viability, proliferation, cell migration, invasion through extracellular matrix destruction, metastasis, and activation of anti-apoptotic signaling cascades. The involvement of epidermal growth factor receptor and 5-oxo-ETE receptor (OXER1) is the major talking point in the downstream of the 5-LOX pathway, which relates the cancer cells to the proliferative pathways. Antisense technology approaches and use of different kinds of blocker targeted to 5-LOX, FLAP (5-LOX-activating protein), and OXER1 have shown a greater efficiency in combating different cancer cell types. Lastly, suppression of 5-LOX activity that reduces the cell proliferation activity also induces intrinsic mitochondrial apoptotic pathway in either p53-dependent or independent manner. Pharmacological agents that specifically inhibit the LOX-mediated signaling pathways have been used during last few years to treat inflammatory diseases such as asthma and arthritis. Studies of these well-characterized agents are therefore warranted for their use as possible candidates for chemotherapeutic studies against the killer disease cancer.
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Affiliation(s)
- Kausik Bishayee
- Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani, India
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Hua S, Yao M, Vignarajan S, Witting P, Hejazi L, Gong Z, Teng Y, Niknami M, Assinder S, Richardson D, Dong Q. Cytosolic phospholipase A2α sustains pAKT, pERK and AR levels in PTEN-null/mutated prostate cancer cells. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1146-57. [PMID: 23500889 DOI: 10.1016/j.bbalip.2013.02.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Revised: 02/03/2013] [Accepted: 02/27/2013] [Indexed: 10/27/2022]
Abstract
Constitutive phosphorylation of protein kinase B (AKT) is a common feature of cancer caused by genetic alteration in the phosphatase and tensin homolog (PTEN) gene and is associated with poor prognosis. This study determined the role of cytosolic phospholipase A2α (cPLA2α) in AKT, extracellular signal-regulated kinase (ERK) and androgen receptor (AR) signaling in PTEN-null/mutated prostate cancer cells. Doxycycline (Dox)-induced expression of cPLA2α led to an increase in pAKT, pGSK3β and cyclin D1 levels in LNCaP cells that possess a PTEN frame-shift mutation. In contrast, silencing cPLA2α expression with siRNA decreased pAKT, pGSK3β and cyclin D1 levels in both PC-3 (PTEN deletion) and LNCaP cells. Silencing of cPLA2α decreased pERK and AR protein levels. The inhibitory effect of cPLA2α siRNA on pAKT and AR protein levels was reduced by the addition of arachidonic acid (AA), whereas the stimulatory effect of AA on pAKT, pERK and AR levels was decreased by an inhibitor of 5-hydroxyeicosatetraenoic acid production. Pharmacological blockade of cPLA2α with Efipladib reduced pAKT and AR levels with a concomitant inhibition of PC-3 and LNCaP cell proliferation. These results demonstrate an important role for cPLA2α in sustaining AKT, ERK and AR signaling in PTEN-null/mutated prostate cancer cells and provide a potential molecular target for treating prostate cancer.
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Affiliation(s)
- Sheng Hua
- The University of Sydney, Sydney, Australia
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Kruger WA, Monteith GR, Poronnik P. NHERF-1 regulation of EGF and neurotensin signalling in HT-29 epithelial cells. Biochem Biophys Res Commun 2013; 432:568-73. [PMID: 23454118 DOI: 10.1016/j.bbrc.2013.02.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 02/10/2013] [Indexed: 02/07/2023]
Abstract
Neurotensin receptors (NT-R) and the epidermal growth factor receptors (EGF-R) are commonly overexpressed in many epithelial origin tumours. In addition to their role as mitogenic mediators through specific cell signalling, recent studies indicate that the activity/expression of scaffold proteins responsible for the assembly and coordination of the signalling complexes may also have central roles in epithelial transformation. In particular, the "epithelial" PSD-95/Dlg/Zo-1 (PDZ) scaffold/adapter protein, Na(+)/H(+) exchanger regulatory factor isoform one (NHERF-1), has been identified as a potential regulator of cellular transformation. NHERF-1 is a known regulator of EGF-R function and plays numerous roles in G-protein-coupled receptor signalling. Because of the synergistic signalling between these two potent mitogens, we investigated a potential role for NHERF-1 in the molecular mechanism linking the aberrant proliferative phenotype initiated by some G-Protein-coupled receptor activators in the colon adenocarcinoma HT-29 cell line. Knockdown (80%) of endogenous NHERF-1 leads to significant reduction in proliferation rate; an effect that could not be recovered by exogenous application of either NT or EGF. Inhibition of the EGF-R with AG1487 also inhibited proliferation and this effect could not be recovered with NT. Knockdown of NHERF-1 significantly altered the expression of the EGF-R, and almost completely abolished the NT-mediated increases in intracellular free Ca(2+). Knockdown of NHERF-1 also attenuated UTP-mediated purinergic Ca(2+) signalling. Taken together, these data suggest that NHERF-1 plays a more central role in cell proliferation by modulating Gq-mediated signalling pathways.
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Affiliation(s)
- Wade A Kruger
- Health Innovations Research Institute, School of Medical Sciences, RMIT University, Melbourne, VIC 3083, Australia
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Mock JN, Taliaferro JP, Lu X, Patel SK, Cummings BS, Long TE. Haloenol pyranones and morpholinones as antineoplastic agents of prostate cancer. Bioorg Med Chem Lett 2012; 22:4854-8. [PMID: 22677312 PMCID: PMC3376906 DOI: 10.1016/j.bmcl.2012.05.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 05/04/2012] [Accepted: 05/08/2012] [Indexed: 10/28/2022]
Abstract
Haloenol pyran-2-ones and morpholin-2-ones were synthesized and evaluated as inhibitors of cell growth in two different prostate human cancer cell lines (PC-3 and LNCaP). Analogs derived from L- and D-phenylglycine were found to be the most effective antagonists of LNCaP and PC-3 cell growth. Additional studies reveal that the inhibitors induced G2/M arrest and the (S)-enantiomer of the phenylglycine-based derivatives was a more potent inhibitor of cytosolic iPLA(2)β.
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Affiliation(s)
- Jason N. Mock
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602-2352, USA
| | - John P. Taliaferro
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602-2352, USA
| | - Xiao Lu
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602-2352, USA
| | - Sravan Kumar Patel
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602-2352, USA
| | - Brian S. Cummings
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602-2352, USA
| | - Timothy E. Long
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602-2352, USA
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Law IKM, Murphy JE, Bakirtzi K, Bunnett NW, Pothoulakis C. Neurotensin-induced proinflammatory signaling in human colonocytes is regulated by β-arrestins and endothelin-converting enzyme-1-dependent endocytosis and resensitization of neurotensin receptor 1. J Biol Chem 2012; 287:15066-75. [PMID: 22416137 DOI: 10.1074/jbc.m111.327262] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The neuropeptide/hormone neurotensin (NT) mediates intestinal inflammation and cell proliferation by binding of its high affinity receptor, neurotensin receptor-1 (NTR1). NT stimulates IL-8 expression in NCM460 human colonic epithelial cells by both MAP kinase- and NF-κB-dependent pathways. Although the mechanism of NTR1 endocytosis has been studied, the relationship between NTR1 intracellular trafficking and inflammatory signaling remains to be elucidated. In the present study, we show that in NCM460 cells exposed to NT, β-arrestin-1 (βARR1), and β-arrestin-2 (βARR2) translocate to early endosomes together with NTR1. Endothelin-converting enzyme-1 (ECE-1) degrades NT in acidic conditions, and its activity is crucial for NTR1 recycling. Pretreatment of NCM460 cells with the ECE-1 inhibitor SM19712 or gene silencing of βARR1 or βARR2 inhibits NT-stimulated ERK1/2 and JNK phosphorylation, NF-κB p65 nuclear translocation and phosphorylation, and IL-8 secretion. Furthermore, NT-induced cell proliferation, but not IL-8 transcription, is attenuated by the JNK inhibitor, JNK(AII). Thus, NTR1 internalization and recycling in human colonic epithelial cells involves βARRs and ECE-1, respectively. Our results also indicate that βARRs and ECE-1-dependent recycling regulate MAP kinase and NF-κB signaling as well as cell proliferation in human colonocytes in response to NT.
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Affiliation(s)
- Ivy Ka Man Law
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095-7019, USA
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Ehsanian R, Van Waes C, Feller SM. Beyond DNA binding - a review of the potential mechanisms mediating quinacrine's therapeutic activities in parasitic infections, inflammation, and cancers. Cell Commun Signal 2011; 9:13. [PMID: 21569639 PMCID: PMC3117821 DOI: 10.1186/1478-811x-9-13] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Accepted: 05/15/2011] [Indexed: 01/30/2023] Open
Abstract
This is an in-depth review of the history of quinacrine as well as its pharmacokinetic properties and established record of safety as an FDA-approved drug. The potential uses of quinacrine as an anti-cancer agent are discussed with particular attention to its actions on nuclear proteins, the arachidonic acid pathway, and multi-drug resistance, as well as its actions on signaling proteins in the cytoplasm. In particular, quinacrine's role on the NF-κB, p53, and AKT pathways are summarized.
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Affiliation(s)
- Reza Ehsanian
- Tumor Biology Section, Head and Neck Surgery Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
- Stanford University School of Medicine, Stanford, CA, USA
- Cell Signalling Group, Department of Molecular Oncology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford University, Headley Way, Oxford OX3 9DS, UK
| | - Carter Van Waes
- Tumor Biology Section, Head and Neck Surgery Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Stephan M Feller
- Cell Signalling Group, Department of Molecular Oncology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford University, Headley Way, Oxford OX3 9DS, UK
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16
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Caiazza F, Harvey BJ, Thomas W. Cytosolic phospholipase A2 activation correlates with HER2 overexpression and mediates estrogen-dependent breast cancer cell growth. Mol Endocrinol 2010; 24:953-68. [PMID: 20211985 DOI: 10.1210/me.2009-0293] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Cytosolic phospholipase A(2)alpha (cPLA(2)alpha) catalyzes the hydrolysis of membrane glycerol-phospholipids to release arachidonic acid as the first step of the eicosanoid signaling pathway. This pathway contributes to proliferation in breast cancer, and numerous studies have demonstrated a crucial role of cyclooxygenase 2 and prostaglandin E(2) release in breast cancer progression. The role of cPLA(2)alpha activation is less clear, and we recently showed that 17beta-estradiol (E2) can rapidly activate cPLA(2)alpha in MCF-7 breast cancer cells. Overexpression or gene amplification of HER2 is found in approximately 30% of breast cancer patients and correlates with a poor clinical outcome and resistance to endocrine therapy. This study reports the first evidence for a correlation between cPLA(2)alpha enzymatic activity and overexpression of the HER2 receptor. The activation of cPLA(2)alpha in response to E2 treatment was biphasic with the first phase dependent on trans-activation through the matrix metalloproteinase-dependent release of heparin-bound epidermal growth factor. EGFR/HER2 heterodimerization resulted in downstream signaling through the ERK1/2 cascade to promote cPLA(2)alpha phosphorylation at Ser505. There was a correlation between HER2 and cPLA(2)alpha expression in six breast cancer cell lines examined, and inhibition of HER2 activation or expression in the SKBR3 cell line using herceptin or HER2-specific small interfering RNA, respectively, resulted in decreased activation and expression of cPLA(2)alpha. Pharmacological blockade of cPLA(2)alpha using a specific antagonist suppressed the growth of both MCF-7 and SKBR3 cells by reducing E2-induced proliferation and by stimulating cellular apoptosis and necrosis. This study highlights cPLAalpha(2) as a potential target for therapeutic intervention in endocrine-dependent and endocrine-independent breast cancer.
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Affiliation(s)
- Francesco Caiazza
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
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Sun B, Zhang X, Yonz C, Cummings BS. Inhibition of calcium-independent phospholipase A2 activates p38 MAPK signaling pathways during cytostasis in prostate cancer cells. Biochem Pharmacol 2010; 79:1727-35. [PMID: 20171194 DOI: 10.1016/j.bcp.2010.02.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 02/03/2010] [Accepted: 02/05/2010] [Indexed: 11/19/2022]
Abstract
The p38 mitogen-activated protein kinase (MAPK) signaling pathways activated during cytostasis induced by Ca(2+)-independent phospholipase A2 (iPLA2) inhibition in prostate cancer cells were investigated. iPLA2 inhibition using siRNA, or the selective inhibitor bromoenol lactone (BEL) and it's enantiomers, decreased growth in LNCaP (p53 positive) and PC-3 (p53 negative) human prostate cancer cells. Decreased cell growth correlated to time- and concentration-dependent activation of the mitogen-activated protein kinase p38 in both cell lines. Inhibition of cytosolic iPLA(2)beta using S-BEL, induced significantly higher levels of P-p53, p53, p21 and P-p38 expression than inhibition of microsomal iPLA2 gamma using R-BEL. Inhibition of p38 using SB202190 or SB203580 inhibited BEL-induced increases in P-p53 (ser15), p53 and p21, and altered the number of cells in G1 in LNCaP cells, and S-phase in PC-3 cells. BEL treatment also induced reactive species in PC-3 and LNCaP cells, which was partially reversed by pretreatment with N-acetyl-cysteine (NAC). NAC subsequently inhibited BEL-induced activation of p38 and p53 in LNCaP cells. In addition, treatment of cells with NAC partially reversed the effect of BEL on cell growth and preserved cell morphology. Collectively, these data demonstrate the novel findings that iPLA2 inhibition activates p38 by inducing reactive species, and further suggest that this signaling kinase is involved in p53 activation, cell cycle arrest and cytostasis.
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Affiliation(s)
- Bin Sun
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, United States
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Comba A, Pasqualini ME. Primers on molecular pathways - lipoxygenases: their role as an oncogenic pathway in pancreatic cancer. Pancreatology 2009; 9:724-8. [PMID: 20016244 DOI: 10.1159/000235623] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Different evidence supports a functional role of enzymes involved in lipid metabolic pathways, such as lipoxygenases (LOXs) and their metabolite derivatives, in carcinogenesis. LOX enzymes catalyze the dioxygenation of arachidonic acid into hydroxyperoxyeicosatetraenoic acids, which is followed by their conversion to their corresponding eicosanoids as hydroxyeicosatetraenoic acids, leukotrienes, lipoxins and hepoxilins, which in turn act as cellular messengers. Subcellular LOX enzyme localization varies according to the LOX and cellular type regulating different cell functions. LOX enzymes or their products may exert their biological effects in different modes, either intracellular or in other cells. Numerous clinical studies on expression of LOXs in human tumors as well as in animal models indicate different roles of distinct LOX isoforms in carcinogenesis. In fact, different LOXs exhibit either protumorigenic or antitumorigenic activities and modulate the tumor response in a tissue-specific manner. Moreover, the LOX pathways are involved in the spread and metastasis of several cancers, including pancreas, through the activation of several cellular signaling pathways which modify gene expression affecting cellular proliferation, survival, migration and extracellular matrix production. In this review we focus on the important role and different mechanisms of action of LOX pathways in the regulation of pancreatic cancer initiation and progression. A novel approach for pancreatic cancer chemoprevention would involve targeting LOX activities, alone or in combination with other pathways as a major anticancer strategy.
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Affiliation(s)
- A Comba
- Ia Cátedra de Biología Celular, Histología y Embriología, Instituto de Biología Celular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Influence of omega-6 PUFA arachidonic acid and bone marrow adipocytes on metastatic spread from prostate cancer. Br J Cancer 2009; 102:403-13. [PMID: 19997104 PMCID: PMC2816655 DOI: 10.1038/sj.bjc.6605481] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Prostate cancer (CaP) preferentially metastasises to the bone, and we have previously shown that the poly-unsaturated fatty acid (PUFA) arachidonic acid (AA) is a potent stimulator of CaP invasion. Here we present that AA promotes CaP invasion by inducing bone marrow adipocyte formation. METHODS Boyden invasion-chamber assays assessed the ability of dietary oils, their PUFA components, and specific PUFA-loaded adipocytes to induce PC-3 invasion. Lipid transfer and metabolism was followed using deuterated AA and Fourier Transform Infrared spectroscopy (FTIR). RESULTS Poly-unsaturated fatty acid constituents, but not their corresponding dietary oils, induced PC-3 invasion. PUFAs induce bone marrow adipocyte (BM-Ad) differentiation with AA inducing higher levels of BM-Ad differentiation, as compared with other PUFAs (3998+/-514.4 vs 932+/-265.8; P=0.00002), which stimulated greater PC-3 invasion than free AA (22 408.5+/-607.4 vs 16 236+/-313.9; P=0.01111) or adipocytes generated in the presence of other PUFAs. In bone marrow co-culture PC-3 and BM-Ad interactions result in direct uptake and metabolism of AA by PC-3 cells, destruction of the adipocyte and subsequent formation of a bone metastasis. CONCLUSION The data supports the hypothesis that AA not only promotes CaP invasion, it also prepares the 'soil', making it more supportive for implantation and propagation of the migrating metastatic cell.
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Radogna F, Sestili P, Martinelli C, Paolillo M, Paternoster L, Albertini M, Accorsi A, Gualandi G, Ghibelli L. Lipoxygenase-mediated pro-radical effect of melatonin via stimulation of arachidonic acid metabolism. Toxicol Appl Pharmacol 2009; 238:170-7. [DOI: 10.1016/j.taap.2009.05.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 04/21/2009] [Accepted: 05/12/2009] [Indexed: 12/15/2022]
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21
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Grant GE, Rokach J, Powell WS. 5-Oxo-ETE and the OXE receptor. Prostaglandins Other Lipid Mediat 2009; 89:98-104. [PMID: 19450703 DOI: 10.1016/j.prostaglandins.2009.05.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2009] [Accepted: 05/06/2009] [Indexed: 11/26/2022]
Abstract
5-Oxo-ETE is a product of the 5-lipoxygenase pathway that is formed by the oxidation of 5-HETE by 5-hydroxyeicosanoid dehydrogenase (5-HEDH). 5-HEDH is a microsomal NADP(+)-dependent enzyme that is highly selective for 5-HETE. 5-Oxo-ETE synthesis is regulated by intracellular NADP(+) levels and is dramatically increased under conditions that favor oxidation of NADPH to NADP(+) such as oxidative stress and the respiratory burst in phagocytic cells. 5-Oxo-ETE is a potent chemoattractant for eosinophils and has similar effects on neutrophils, basophils and monocytes. It elicits infiltration of eosinophils and, to a lesser extent, neutrophils into the skin after intradermal injection in humans. It also promotes the survival of tumor cells and has been shown to block the induction of apoptosis by 5-LO inhibitors. 5-Oxo-ETE acts by the G(i/o)-coupled OXE receptor, which was also known as TG1019, R527 and hGPCR48. Although the pathophysiological role of 5-oxo-ETE is not well understood, it may play important roles in asthma and allergic diseases, cancer, and cardiovascular disease. The availability of a selective antagonist would help to clarify the role of 5-oxo-ETE and may be of therapeutic benefit.
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Affiliation(s)
- Gail E Grant
- Meakins-Christie Laboratories, McGill University, QC, Canada
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22
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Barbieri R, Alloisio S, Ferroni S, Nobile M. Differential crosstalk between P2X7 and arachidonic acid in activation of mitogen-activated protein kinases. Neurochem Int 2008; 53:255-62. [PMID: 18804898 DOI: 10.1016/j.neuint.2008.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Accepted: 05/27/2008] [Indexed: 11/27/2022]
Abstract
Accumulating evidence indicates that astroglial syncytium plays key role in normal and pathological brain functions. Astrocytes both in vitro and in situ respond to extracellular adenine-based nucleotides via the activation of P2 receptors. Massive release of ATP from neurons and glial cells occurs as a result of pathological conditions of the brain leading to neuroinflammation and involving P2X7 receptors. In this study, we investigated whether P2X7 stimulation on cultured cortical astrocytes promoted a differential activation of mitogen-activated protein kinases (MAPKs), and whether the second messenger arachidonic acid (AA), which is also a key modulator of neuroinflammation, affected the P2X7-mediated MAPK phosphorylation. The results show that the synthetic P2X7 receptor agonist 2',3'-O-(4-benzoyl)benzoyl-ATP (BzATP), induced a concentration-dependent phosphorylation of MAPK ERK1/2, JNK and p38. Stimulation of ERK1/2, JNK and p38 phosphorylation was also obtained by pathophysiological levels of extracellularly applied AA. Interestingly, a robust potentiation of ERK1/2 phosphorylation was elicited by co-application of BzATP and AA, whereas no differences were observed in JNK or p38 phosphosignals. The kinases activation showed a differential dependence on the presence of extracellular Ca(2+). The potentiation of BzATP-mediated ERK1/2 phosphorylation was also observed in human embryonic kidney cells (HEK293) stably transfected with rat P2X7, but not in HEK cells expressing truncated P2X7 receptor lacking the full cytoplasmic carboxy-terminal or in those carrying the structurally related rat P2X2. AA and BzATP synergism in ERK1/2 activation was abolished by cyclo-oxygenase and lipoxygenase pathway inhibitors. The result that ERK1/2-mediated transduction pathway is synergistically modulated by ATP and AA signalling depicts possible novel pharmacological targets for interfering with pathological activation of astroglial cells.
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Hooks SB, Cummings BS. Role of Ca2+-independent phospholipase A2 in cell growth and signaling. Biochem Pharmacol 2008; 76:1059-67. [PMID: 18775417 DOI: 10.1016/j.bcp.2008.07.044] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 07/15/2008] [Accepted: 07/15/2008] [Indexed: 01/25/2023]
Abstract
Phospholipase A(2) (PLA(2)) are esterases that cleave glycerophospholipids to release fatty acids and lysophospholipids. Several studies demonstrate that PLA(2) regulate growth and signaling in several cell types. However, few of these studies have focused on Ca2+-independent phospholipase A(2) (iPLA(2) or Group VI PLA(2)). This class of PLA(2) was originally suggested to mediate phospholipid remodeling in several cell types including macrophages. As such, it was labeled as a housekeeping protein and thought not to play as significant of roles in cell growth as its older counterparts cytosolic PLA(2) (cPLA(2) or Group IV PLA(2)) and secretory PLA(2) (sPLA(2) or Groups I-III, V and IX-XIV PLA(2)). However, several recent studies demonstrate that iPLA(2) mediate cell growth, and do so by participating in signal transduction pathways that include epidermal growth factor receptors (EGFR), mitogen activated protein kinases (MAPK), mdm2, and even the tumor suppressor protein p53 and the cell cycle regulator p21. The exact mechanism by which iPLA(2) mediates these pathways are not known, but likely involve the generation of lipid signals such as arachidonic acid, lysophosphatidic acid (LPA) and lysophosphocholines (LPC). This review discusses the role of iPLA(2) in cell growth with special emphasis placed on their role in cell signaling. The putative lipid signals involved are also discussed.
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Affiliation(s)
- Shelley B Hooks
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, USA
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24
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Moreno JJ. New aspects of the role of hydroxyeicosatetraenoic acids in cell growth and cancer development. Biochem Pharmacol 2008; 77:1-10. [PMID: 18761324 DOI: 10.1016/j.bcp.2008.07.033] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 07/24/2008] [Accepted: 07/28/2008] [Indexed: 11/17/2022]
Abstract
Lipoxygenase (LOX) pathway leads to the formation of leukotrienes and also catalyses the conversion of arachidonic acid (AA) to hydroperoxyeicosatetraenoic acids that are then reduced to hydroxyeicosatetraenoic acids (HETE) by glutathione peroxidase. There are four mammalian LOXs that produce 5-, 8-, 12- and 15-HETE, respectively. Cytochrome P-450 isozymes are also capable of metabolising AA to HETEs either by bis-allylic oxidation (lipoxygenase-like reaction) to generate 5-, 8-, 9-, 11-, 12- and 15-HETE; or by varpi/varpi-1 hydroxylation to yield 16-, 17-, 18-, 19- and 20-HETEs. It is now widely recognised that HETEs have important physiological and pathological functions that modulate ion transport, renal and pulmonary functions, vascular tone and reactivity, and inflammatory and growth responses. They can be released during the action of growth factors and cytokines, reaching physiological concentrations higher than that of prostanoids and modulating the functions of these factors. Their effects can occur through receptor or non-receptor mechanisms. Recent reviews have summarised the effects of HETEs in vascular homeostasis or lung and renal physiology. The present review focuses on the emerging effects of HETEs on cell signalling and physiological cell growth. It also discusses current observations regarding the role of HETEs in apoptosis, angiogenesis, the proliferation of cancer cells and metastasis, which constitute a potential area for successful therapeutic intervention.
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Affiliation(s)
- Juan J Moreno
- Department of Physiology, Faculty of Pharmacy, University of Barcelona, Avda. Joan XXIII s/n, E-08028 Barcelona, Spain.
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25
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Castilla R, Gadaleta M, Castillo AF, Duarte A, Neuman I, Paz C, Cornejo Maciel F, Podestá EJ. New enzymes involved in the mechanism of action of epidermal growth factor in a clonal strain of Leydig tumor cells. Endocrinology 2008; 149:3743-52. [PMID: 18388199 DOI: 10.1210/en.2007-1580] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The studies presented herein were designed to investigate the effect of mouse epidermal growth factor (mEGF) on arachidonic acid (AA) release in a clonal strain of cultured murine Leydig cells (designed MA-10). In MA-10 cells, mEGF promotes AA release and metabolism to lipoxygenated products to induce the steroidogenic acute regulatory (StAR) protein. However, the mechanism by which mEGF releases AA in these cells is not totally elucidated. We show that mEGF produces an increment in the mitochondrial AA content in a short-term incubation (30 min). This AA is released by the action of a mitochondrial acyl-CoA thioesterase (Acot2), as demonstrated in experiments in which Acot2 was down or overexpressed. This AA in turn regulates the StAR protein expression, indirect evidence of its metabolism to lipoxygenated products. We also show that mEGF induces the expression (mRNA and protein) of Acot2 and an acyl-CoA synthetase that provides the substrate, arachidonyl-CoA, to Acot2. This effect is also observed in another steroidogenic cell line, the adrenocortical Y1 cells. Taken together, our results show that: 1) mEGF can induce the generation of AA in a specific compartment of the cells, i.e. the mitochondria; 2) mEGF can up-regulate acyl-CoA synthetase and Acot2 mRNA and protein levels; and 3) mEGF-stimulated intramitochondrial AA release leads to StAR protein induction.
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Affiliation(s)
- Rocío Castilla
- Instituto de Investigaciones Moleculares de Enfermedades Hormonales, Neurodegenerativas y Oncológicas, Department of Biochemistry, School of Medicine, University of Buenos Aires, Paraguay 2155 5th, Buenos Aires, Argentina
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Sun B, Zhang X, Talathi S, Cummings BS. Inhibition of Ca2+-Independent Phospholipase A2 Decreases Prostate Cancer Cell Growth by p53-Dependent and Independent Mechanisms. J Pharmacol Exp Ther 2008; 326:59-68. [DOI: 10.1124/jpet.108.138958] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Pidgeon GP, Lysaght J, Krishnamoorthy S, Reynolds JV, O'Byrne K, Nie D, Honn KV. Lipoxygenase metabolism: roles in tumor progression and survival. Cancer Metastasis Rev 2008; 26:503-24. [PMID: 17943411 DOI: 10.1007/s10555-007-9098-3] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The metabolism of arachidonic acid through lipoxygenase pathways leads to the generation of various biologically active eicosanoids. The expression of these enzymes vary throughout the progression of various cancers, and thereby they have been shown to regulate aspects of tumor development. Substantial evidence supports a functional role for lipoxygenase-catalyzed arachidonic and linoleic acid metabolism in cancer development. Pharmacologic and natural inhibitors of lipoxygenases have been shown to suppress carcinogenesis and tumor growth in a number of experimental models. Signaling of hydro[peroxy]fatty acids following arachidonic or linoleic acid metabolism potentially effect diverse biological phenomenon regulating processes such as cell growth, cell survival, angiogenesis, cell invasion, metastatic potential and immunomodulation. However, the effects of distinct LOX isoforms differ considerably with respect to their effects on both the individual mechanisms described and the tumor being examined. 5-LOX and platelet type 12-LOX are generally considered pro-carcinogenic, with the role of 15-LOX-1 remaining controversial, while 15-LOX-2 suppresses carcinogenesis. In this review, we focus on the molecular mechanisms regulated by LOX metabolism in some of the major cancers. We discuss the effects of LOXs on tumor cell proliferation, their roles in cell cycle control and cell death induction, effects on angiogenesis, migration and the immune response, as well as the signal transduction pathways involved in these processes. Understanding the molecular mechanisms underlying the anti-tumor effect of specific, or general, LOX inhibitors may lead to the design of biologically and pharmacologically targeted therapeutic strategies inhibiting LOX isoforms and/or their biologically active metabolites, that may ultimately prove useful in the treatment of cancer, either alone or in combination with conventional therapies.
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Affiliation(s)
- Graham P Pidgeon
- Department of Clinical Surgery, Trinity College Dublin, St. James Hospital, Dublin 8, Ireland.
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Cummings BS. Phospholipase A2 as targets for anti-cancer drugs. Biochem Pharmacol 2007; 74:949-59. [PMID: 17531957 DOI: 10.1016/j.bcp.2007.04.021] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 04/23/2007] [Accepted: 04/24/2007] [Indexed: 02/04/2023]
Abstract
Phospholipase A(2) (PLA(2)) are esterases that cleave glycerophospholipids to release fatty acids and lysophospholipids. Inhibition of PLA(2) alters cancer cell growth and death in vitro and PLA(2) expression is increased in breast, lung, and prostate cancers compared to control tissues. Thus, PLA(2) may be novel targets for chemotherapeutics. However, PLA(2) are a diverse family of enzymes, encompassing 19 members. The selectivity of these individual PLA(2) for phospholipids varies, as does their location within the cell, and tissue expression. Thus, their role in cancer may also vary. This review summarizes the expression of individual PLA(2) in cancers, focuses on the potential mechanisms by which these esterases mediate carcinogenesis, and suggests that select PLA(2) isoforms may be targets for anti-cancer drugs.
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Affiliation(s)
- Brian S Cummings
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, USA.
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29
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Vias M, Burtt G, Culig Z, Veerakumarasivam A, Neal DE, Mills IG. A role for neurotensin in bicalutamide resistant prostate cancer cells. Prostate 2007; 67:190-202. [PMID: 17044078 DOI: 10.1002/pros.20518] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Anti-androgens are administered as a principal treatment for prostate cancer. Aggressive hormone refractory disease is characterized in some cases by the development of a neuroendocrine phenotype. However little attention has been paid to resistance pathways selected for by long-term treatment with non-steroidal anti-androgens. METHODS Using a resistant sub-line, LNCaP-Bic, we performed a comparative gene expression profiling using cDNA microarrays and target validation by qRT-PCR. Targets were then explored using cell proliferation, cell cycle analysis and in vitro invasion assays using siRNA technology. RESULTS Neurotensin/Neuromedin N (NTS) was upregulated in the LNCaP-Bic line at both the transcript and protein level. The resistant line was found to have an increased proliferation rate, more rapid cell cycle progression and increased invasiveness through Matrigel. Each phenotypic difference could be reduced using siRNA knockdown of NT. CONCLUSION Increased expression of NT in bicalutamide resistant prostate cancer cells induces cell proliferation and invasion suggesting that this peptide may contribute to the development of bicalutamide resistant prostate cancer.
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Affiliation(s)
- Maria Vias
- Department of Oncology, Hutchison/MRC Research Centre, CRUK Uro-Oncology Group, University of Cambridge, Hills Road, Cambridge, United Kingdom
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30
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Carraway RE, Hassan S. Neurotensin receptor binding and neurotensin-induced growth signaling in prostate cancer PC3 cells are sensitive to metabolic stress. ACTA ACUST UNITED AC 2007; 141:140-53. [PMID: 17289170 DOI: 10.1016/j.regpep.2006.12.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 12/19/2006] [Accepted: 12/23/2006] [Indexed: 01/03/2023]
Abstract
Neurotensin (NT) stimulates the proliferation of prostate cancer PC3 cells, which express high levels of its G protein-coupled receptor NTS1. To shed light on mechanisms that might serve to coordinate mitogenic responses to metabolic status, we studied the effects of metabolic inhibitors on NTS1 function. We also related these effects to cellular ATP levels and to the activation of AMP-activated protein kinase (AMPK). Glycolytic and mitochondrial inhibitors, at concentrations that reduced cellular ATP levels, altered NT binding to the cells, inhibited NT-induced inositol phosphate formation, and inhibited NT-induced DNA synthesis. For eight of the nine inhibitors, the potencies to alter NT receptor function correlated to the potencies to decrease cellular ATP levels. In keeping with its known role to oppose metabolic stress, AMPK was activated by the metabolic inhibitors. Accordingly, the AMPK activator AICAR elevated cellular ATP levels and produced effects on NTS1 function that were opposite to those for the metabolic inhibitors. These results indicate that metabolic stress inhibited NTS1 function by a mechanism that involved a fall in cellular ATP levels and that was opposed by activation of AMPK. In a broader context, these findings are compatible with the idea that one means by which cells might coordinate mitogenic signaling to metabolic status could involve changes in growth factor receptor function.
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Affiliation(s)
- Robert E Carraway
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
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Nakanishi M, Rosenberg DW. Roles of cPLA2alpha and arachidonic acid in cancer. BIOCHIMICA ET BIOPHYSICA ACTA 2006; 1761:1335-43. [PMID: 17052951 PMCID: PMC1761949 DOI: 10.1016/j.bbalip.2006.09.005] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 09/06/2006] [Accepted: 09/08/2006] [Indexed: 12/25/2022]
Abstract
Phospholipase A(2)s (PLA(2)s) are key enzymes that catalyze the hydrolysis of membrane phospholipids to release bioactive lipids that play an important role in normal cellular homeostasis. Under certain circumstances, disrupted production of key lipid mediators may adversely impact physiological processes, leading to pathological conditions such as inflammation and cancer. In particular, cytosolic PLA(2)alpha (cPLA(2)alpha) has a high selectivity for liberating arachidonic acid (AA) that is subsequently metabolized by a panel of downstream enzymes for eicosanoid production. Although concentrations of free AA are maintained at low levels in resting cells, alterations in AA production, often resulting from dysregulation of cPLA(2)alpha activity, are observed in transformed cells. In this review, we summarize recent evidence that cPLA(2)alpha plays a role in the pathogenesis of many human cancers. Much of this evidence has been accumulated from functional studies using cPLA(2)alpha-deficient mice, as well as mechanistic studies in cell culture. We also discuss the potential contribution of cPLA(2)alpha and AA to apoptosis, and the regulatory mechanisms leading to aberrant expression of cPLA(2)alpha.
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Affiliation(s)
- Masako Nakanishi
- Center for Molecular Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 0603, USA
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Carraway RE, Plona AM. Involvement of neurotensin in cancer growth: evidence, mechanisms and development of diagnostic tools. Peptides 2006; 27:2445-60. [PMID: 16887236 DOI: 10.1016/j.peptides.2006.04.030] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2005] [Accepted: 04/06/2006] [Indexed: 12/22/2022]
Abstract
Focusing on the literature of the past 15 years, we evaluate the evidence that neurotensin and neurotensin receptors participate in cancer growth and we describe possible mechanisms. In addition, we review the progress achieved in the use of neurotensin analogs to image tumors in animals and humans. These exciting advances encourage us to pursue further research and stimulate us to consider novel ideas regarding the multiple inputs to cancer growth that neurotensin might influence.
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Affiliation(s)
- Robert E Carraway
- Department of Physiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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Amorino GP, Deeble PD, Parsons SJ. Neurotensin stimulates mitogenesis of prostate cancer cells through a novel c-Src/Stat5b pathway. Oncogene 2006; 26:745-56. [PMID: 16862179 DOI: 10.1038/sj.onc.1209814] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neuroendocrine (NE)-like cells are hypothesized to contribute to the progression of prostate cancer by producing factors that enhance the growth, survival or metastatic capabilities of surrounding tumor cells. Many of the factors known to be secreted by NE-like cells, such as neurotensin (NT), parathyroid hormone-related peptide, serotonin, bombesin, etc., are agonists for G-protein-coupled receptors, but the signaling pathways activated by these agonists in prostate tumor cells are not fully defined. Identification of such pathways could provide insights into novel methods of treating late-stage disease. Using conditioned culture medium (CM) from LNCaP-derived NE-like cells (as a source of these agonists) or NT (a prototypical component of CM) to treat PC3 cells, we found that the epidermal growth factor (EGF) receptor (EGFR) was transactivated and that such activation was required for maximal PC3 cell mitogenesis, as measured by 5-bromo-2'-deoxy-uridine incorporation or cell number. NT also induced a time-dependent increase in EGFR Tyr(845) phosphorylation and phosphorylation of c-Src and signal transducer and activator of transcription 5b (Stat5b) (a downstream effector of Tyr(845)), events that were blocked by specific inhibition of c-Src (which mediates Tyr(845) phosphorylation of EGFR) or of EGFR. Introduction of mutant forms of EGFR (Tyr(845)) or Stat5b in PC3 cells, or treatment with selective, catalytic inhibitors of EGFR, c-Src and matrix metalloproteinases (MMPs) resulted in the loss of NT-induced stimulation of DNA synthesis, relative to wild-type controls. These data indicate that the mitogenic effect of NT on prostate cancer cells requires transactivation of the EGFR by MMPs and a novel downstream pathway involving c-Src, phosphorylation of EGFR Tyr(845) and activation of Stat5b.
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Affiliation(s)
- G P Amorino
- Department of Radiation Oncology, Cancer Center, University of Virginia Health Sciences Center, Charlottesville, VA, USA
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Carraway RE, Hassan S, Cochrane DE. Regulation of neurotensin receptor function by the arachidonic acid-lipoxygenase pathway in prostate cancer PC3 cells. Prostaglandins Leukot Essent Fatty Acids 2006; 74:93-107. [PMID: 16406549 DOI: 10.1016/j.plefa.2005.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Revised: 11/04/2005] [Accepted: 11/09/2005] [Indexed: 11/19/2022]
Abstract
Neurotensin (NT) elevates leukotriene levels in animals and stimulates 5-HETE formation in prostate cancer PC3 cells. PC3 cell growth is stimulated by NT and inhibited by lipoxygenase (LOX) blockers. This led us to test LOX blockers (NDGA, MK886, ETYA, Rev5901, AA861 and others) for effects on NT binding and signaling. LOX blockers dramatically enhanced 125I-neurotensin binding to NT receptor NTR1 in PC3 cells, whereas they inhibited NT-induced inositol phosphate formation. These effects were indirect (binding to isolated membranes was unaffected), receptor-specific (binding to beta2-adrenergic, V1a-vasopressin, EGF and bombesin receptor was unaffected) and pathway-specific (cyclooxygenase inhibitors were inactive). NT receptor affinity was increased but receptor number and % internalization were unchanged. Also supporting the involvement of arachidonic acid metabolism in NTR1 regulation was the finding that inhibitors of PLA2 and DAG lipase enhanced NT binding. These findings suggest that NTR1 is regulated by specific feedback mechanism(s) involving lipid peroxidation and/or LOX-dependent processes.
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Affiliation(s)
- Robert E Carraway
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
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