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Tanigawa K, Kiriya M, Hayashi Y, Shinden Y, Kijima Y, Natsugoe S, Sumimoto T, Morimoto-Kamata R, Yui S, Hama K, Yokoyama K, Nakamura Y, Suzuki K, Nojiri H, Inoue K, Karasawa K. Cathepsin G-induced malignant progression of MCF-7 cells involves suppression of PAF signaling through induced expression of PAFAH1B2. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159164. [PMID: 35462067 DOI: 10.1016/j.bbalip.2022.159164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 04/01/2022] [Accepted: 04/14/2022] [Indexed: 10/18/2022]
Abstract
Breast cancer is primarily classified into ductal and lobular types, as well as into noninvasive and invasive cancer. Invasive cancer involves lymphatic and hematogenous metastasis. In breast cancer patients with distant metastases, a neutrophil-derived serine protease; cathepsin G (Cat G), is highly expressed in breast cancer cells. Cat G induces cell migration and multicellular aggregation of MCF-7 human breast cancer cells; however, the mechanism is not clear. Recently, platelet-activating factor (PAF)-acetylhydrolase (PAF-AH), the enzyme responsible for PAF degradation, was reported to be overexpressed in some tumor types, including pancreatic and breast cancers. In this study, we investigated whether PAF-AH is involved in Cat G-induced aggregation and migration of MCF-7 cells. We first showed that Cat G increased PAF-AH activity and elevated PAFAH1B2 expression in MCF-7 cells. The elevated expression of PAFAH1B2 was also observed in human breast cancer tissue specimens by immunohistochemical analysis. Furthermore, knockdown of PAFAH1B2 in MCF-7 cells suppressed the cell migration and aggregation induced by low concentrations, but not high concentrations, of Cat G. Carbamoyl PAF (cPAF), a nonhydrolyzable PAF analog, completely suppressed Cat G-induced migration of MCF-7 cells. In addition, PAF receptor (PAFR) inhibition induced cell migration of MCF-7 cells even in the absence of Cat G, suggesting that Cat G suppresses the activation of PAFR through enhanced PAF degradation due to elevated expression of PAFAH1B2 and thereby induces malignant phenotypes in MCF-7 cells. Our findings may lead to a novel therapeutic modality for treating breast cancer by modulating the activity of Cat G/PAF signaling.
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Affiliation(s)
- Kazunari Tanigawa
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Mitsuo Kiriya
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Yasuhiro Hayashi
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Yoshiaki Shinden
- Department of Digestive Surgery, Breast and Thyroid Surgery, Kagoshima University, Kagoshima-shi, Kagoshima 890-8580, Japan
| | - Yuko Kijima
- Department of Digestive Surgery, Breast and Thyroid Surgery, Kagoshima University, Kagoshima-shi, Kagoshima 890-8580, Japan; Department of Breast Surgery, School of Medicine, Fujita Health University, Toyooka-shi, Aichi 470-1192, Japan
| | - Shoji Natsugoe
- Department of Neurosurgery, Kajiki-Onsen Hospital, Aira-shi, Kagoshima 899-5241, Japan
| | - Takahiro Sumimoto
- Department of Clinical Pharmacy, Oita University Hospital, Yufu-shi, Oita 879-5593, Japan
| | - Riyo Morimoto-Kamata
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Satoru Yui
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Kotaro Hama
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Kazuaki Yokoyama
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Yasuhiro Nakamura
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Koichi Suzuki
- Department of Clinical Laboratory Science, Faculty of Medical Technology, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Hisao Nojiri
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Keizo Inoue
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Ken Karasawa
- Faculty of Pharma-Science, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan.
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Yin H, Shi A, Wu J. Platelet-Activating Factor Promotes the Development of Non-Alcoholic Fatty Liver Disease. Diabetes Metab Syndr Obes 2022; 15:2003-2030. [PMID: 35837578 PMCID: PMC9275506 DOI: 10.2147/dmso.s367483] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/28/2022] [Indexed: 11/23/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a multifaceted clinicopathological syndrome characterised by excessive hepatic lipid accumulation that causes steatosis, excluding alcoholic factors. Platelet-activating factor (PAF), a biologically active lipid transmitter, induces platelet activation upon binding to the PAF receptor. Recent studies have found that PAF is associated with gamma-glutamyl transferase, which is an indicator of liver disease. Moreover, PAF can stimulate hepatic lipid synthesis and cause hypertriglyceridaemia. Furthermore, the knockdown of the PAF receptor gene in the animal models of NAFLD helped reduce the inflammatory response, improve glucose homeostasis and delay the development of NAFLD. These findings suggest that PAF is associated with NAFLD development. According to reports, patients with NAFLD or animal models have marked platelet activation abnormalities, mainly manifested as enhanced platelet adhesion and aggregation and altered blood rheology. Pharmacological interventions were accompanied by remission of abnormal platelet activation and significant improvement in liver function and lipids in the animal model of NAFLD. These confirm that platelet activation may accompany a critical importance in NAFLD development and progression. However, how PAFs are involved in the NAFLD signalling pathway needs further investigation. In this paper, we review the relevant literature in recent years and discuss the role played by PAF in NAFLD development. It is important to elucidate the pathogenesis of NAFLD and to find effective interventions for treatment.
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Affiliation(s)
- Hang Yin
- Key Laboratory of Microcosmic Syndrome Differentiation, Yunnan University of Chinese Medicine, Kunming, People’s Republic of China
| | - Anhua Shi
- Key Laboratory of Microcosmic Syndrome Differentiation, Yunnan University of Chinese Medicine, Kunming, People’s Republic of China
| | - Junzi Wu
- Key Laboratory of Microcosmic Syndrome Differentiation, Yunnan University of Chinese Medicine, Kunming, People’s Republic of China
- Correspondence: Junzi Wu; Anhua Shi, Key Laboratory of Microcosmic Syndrome Differentiation, Yunnan University of Chinese Medicine, Kunming, People’s Republic of China, Tel/Fax +86 187 8855 7524; +86 138 8885 0813, Email ;
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Ren J, Sui H, Fang F, Li Q, Li B. The application of Apc Min/+ mouse model in colorectal tumor researches. J Cancer Res Clin Oncol 2019; 145:1111-1122. [PMID: 30887153 DOI: 10.1007/s00432-019-02883-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 02/28/2019] [Indexed: 12/11/2022]
Abstract
PURPOSE ApcMin/+ mouse is an excellent animal model bearing multiple intestinal neoplasia, used to simulate human familial adenomatous polyposis and colorectal tumors. The key point of this model is the mutation of Apc gene, which is a significant tumor-suppressor gene in the Wnt signaling pathway. There are also some other possible mechanisms responsible for the development of colorectal tumors in the ApcMin/+ mouse model, such as tumor-associated signaling pathways activation, the changes of tumor-related genes, and the involvement of some related proteins or molecules. METHODS The relevant literatures about ApcMin/+ mouse model from PUBMED databases are reviewed in this study. RESULTS In recent years, increasing studies have focused on the application of ApcMin/+ mouse model in colorectal tumor, trying to find effective therapeutic targets for further use. CONCLUSION This article will give a brief review on the related molecular mechanisms of the ApcMin/+ mouse model and its application in colorectal tumor researches.
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Affiliation(s)
- Junze Ren
- Changhai Hospital of Traditional Chinese Medicine, Second Military Medical University, Shanghai, 200433, China
| | - Hua Sui
- Department of Medical Oncology, Cancer Institute of Integrative Medicine, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Fanfu Fang
- Changhai Hospital of Traditional Chinese Medicine, Second Military Medical University, Shanghai, 200433, China
| | - Qi Li
- Department of Medical Oncology, Cancer Institute of Integrative Medicine, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Bai Li
- Changhai Hospital of Traditional Chinese Medicine, Second Military Medical University, Shanghai, 200433, China.
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Hamel-Côté G, Lapointe F, Gendron D, Rola-Pleszczynski M, Stankova J. Regulation of platelet-activating factor-induced interleukin-8 expression by protein tyrosine phosphatase 1B. Cell Commun Signal 2019; 17:21. [PMID: 30832675 PMCID: PMC6399872 DOI: 10.1186/s12964-019-0334-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 02/22/2019] [Indexed: 12/21/2022] Open
Abstract
Background Platelet-activating factor (PAF) is a potent lipid mediator whose involvement in the onset and progression of atherosclerosis is mediated by, among others, the modulation of cytokine expression patterns. The presence of multiple potential protein-tyrosine phosphatase (PTP) 1B substrates in PAF receptor signaling pathways brought us to investigate its involvement in PAF-induced cytokine expression in monocyte-derived dendritic cells (Mo-DCs) and to study the pathways involved in this modulation. Methods We used in-vitro-matured human dendritic cells and the HEK-293 cell line in our studies. PTP1B inhibition was though siRNAs and a selective inhibitor. Cytokine expression was studied with RT-PCR, luciferase assays and ELISA. Phosphorylation status of kinases and transcription factors was studied with western blotting. Results Here, we report that PTP1B was involved in the modulation of cytokine expression in PAF-stimulated Mo-DCs. A study of the down-regulation of PAF-induced IL-8 expression, by PTP1B, showed modulation of PAF-induced transactivation of the IL-8 promoter which was dependent on the presence of the C/EBPß -binding site. Results also suggested that PTP1B decreased PAF-induced IL-8 production by a glycogen synthase kinase (GSK)-3-dependent pathway via activation of the Src family kinases (SFK). These kinases activated an unidentified pathway at early stimulation times and the PI3K/Akt signaling pathway in a later phase. This change in GSK-3 activity decreased the C/EBPß phosphorylation levels of the threonine 235, a residue whose phosphorylation is known to increase C/EBPß transactivation potential, and consequently modified IL-8 expression. Conclusion The negative regulation of GSK-3 activity by PTP1B and the consequent decrease in phosphorylation of the C/EBPß transactivation domain could be an important negative feedback loop by which cells control their cytokine production after PAF stimulation. Electronic supplementary material The online version of this article (10.1186/s12964-019-0334-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Geneviève Hamel-Côté
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada
| | - Fanny Lapointe
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada
| | - Daniel Gendron
- Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Center, 2000 College Street, Sherbrooke, QC, Canada
| | - Marek Rola-Pleszczynski
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada
| | - Jana Stankova
- Immunology Division, Department of Pediatrics, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, J1H 4N5, Canada.
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Roudebush WE, Straub RJ, Massey JB, Kort HI. Temporal Production of Platelet-Activating Factor by Brewer's Yeast. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-64-0135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Modulation of Tumor-Associated Macrophages (TAM) Phenotype by Platelet-Activating Factor (PAF) Receptor. J Immunol Res 2017; 2017:5482768. [PMID: 29445756 PMCID: PMC5763242 DOI: 10.1155/2017/5482768] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 11/07/2017] [Indexed: 12/20/2022] Open
Abstract
Platelet-activating factor (PAF) plays an important role in the pathogenesis of several types of tumors. The biological effects of PAF are mediated by the PAF receptor (PAFR), which can be expressed by tumor cells and host cells that infiltrate the tumor microenvironment. In the present study, we investigated the role of PAFR expressed by leukocytes that infiltrate two types of tumors, one that expresses PAFR (TC-1 carcinoma) and another that does not express the receptor (B16F10 melanoma) implanted in mice that express the receptor or not (PAFR KO). It was found that both tumors grew significantly less in PAFR KO than in wild-type (WT) mice. Analysis of the leukocyte infiltration shown in PAFR KO increased the frequency of neutrophils (Gr1+) and of CD8+ lymphocytes in B16F10 tumors and of CD4+ lymphocytes in TC-1 tumors. PAFR KO also had a higher frequency of M1-like (CD11c+) and lower M2-like (CD206+) macrophages infiltrated in both tumors. This was confirmed in macrophages isolated from the tumors that showed higher iNOS, lower arginase activity, and lower IL10 expression in PAFR KO tumors than WT mice. These data suggest that in the tumor microenvironment, endogenous PAF-like activity molecules bind PAFR in macrophages which acquire an M2-like profile and this promotes tumor growth.
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Abstract
This chapter is focused on the role of the plasma form of platelet-activating factor-acetylhydrolase (PAF-AH), heretofore referred to as PAF-AH, in tumorigenic responses. Biochemical and other properties of this enzyme were discussed in detail in chapter "Plasma PAF-AH (PLA2G7): Biochemical Properties, Association with LDLs and HDLs, and Regulation of Expression" by Stafforini and in other chapters. Although phospholipases tend not to be drivers of tumorigenesis themselves, these enzymes and the lipid mediators whose levels they regulate interact with a variety of oncogenes and tumor suppressors [1]. Like other phospholipases, the functions of PAF-AH in cancer likely are related to its ability to regulate the levels of lipid mediators that participate in cellular processes related to initial tumorigenic events (e.g., proliferation, growth, inflammation) and/or spreading of the disease (e.g., matrix metalloproteinase secretion, actin cytoskeleton reorganization, migration, and angiogenesis) [1]. The importance of substrates and products of PAF-AH on key cellular functions has been evaluated in cell-based analyses which revealed that these metabolites can have pro- and antitumorigenic functions. Studies in genetically engineered mice lacking PAF-AH expression and genetic manipulation of PAF-AH levels in cancer cells demonstrated diverse functions of the protein in models of melanoma, prostate cancer, colon cancer, and others. The following sections highlight lessons learned from studies in cell lines and in mouse models regarding the diversity of functions of PAF-AH in cancer, and the potential of PAFAH transcripts, protein, and/or activity levels to become cancer biomarkers and therapeutic targets.
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Affiliation(s)
- Diana M Stafforini
- Huntsman Cancer Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
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8
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Anandi VL, Ashiq KA, Nitheesh K, Lahiri M. Platelet-activating factor promotes motility in breast cancer cells and disrupts non-transformed breast acinar structures. Oncol Rep 2015; 35:179-88. [PMID: 26531049 DOI: 10.3892/or.2015.4387] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/04/2015] [Indexed: 11/06/2022] Open
Abstract
A plethora of studies have demonstrated that chronic inflammatory microenvironment influences the genesis and progression of tumors. Such microenvironments are enriched with various lipid mediators. Platelet activating factor (PAF, 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is one such lipid mediator that is secreted by different immune cell types during inflammation and by breast cancer cells upon stimulation with growth factors. Overexpression of PAF-receptor has also been observed in many other cancers. Here we report the possible roles of PAF in tumor initiation and progression. MCF10A, a non-transformed and non-malignant mammary epithelial cell line, when grown as 3D 'on-top' cultures form spheroids that have a distinct hollow lumen surrounded by a monolayer of epithelial cells. Exposure of these spheroids to PAF resulted in the formation of large deformed acinar structures with disrupted lumen, implying transformation. We then examined the response of transformed cells such as MDA-MB 231 to stimulation with PAF. We observed collective cell migration as well as motility at the single cell level on PAF induction, suggesting its role during metastasis. This increase in collective cell migration is mediated via PI3-kinase and/or JNK pathway and is independent of the MAP-kinase pathway. Taken together this study signifies a novel role of PAF in inducing transformation of non-tumorigenic cells and the vital role in promotion of breast cancer cell migration.
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Affiliation(s)
- V Libi Anandi
- Indian Institute of Science Education and Research, Pashan, Pune, Maharashtra 411008, India
| | - K A Ashiq
- Indian Institute of Science Education and Research, Pashan, Pune, Maharashtra 411008, India
| | - K Nitheesh
- Indian Institute of Science Education and Research, Pashan, Pune, Maharashtra 411008, India
| | - M Lahiri
- Indian Institute of Science Education and Research, Pashan, Pune, Maharashtra 411008, India
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Platelet-activating factor induces cell cycle arrest and disrupts the DNA damage response in mast cells. Cell Death Dis 2015; 6:e1745. [PMID: 25950475 PMCID: PMC4669695 DOI: 10.1038/cddis.2015.115] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 12/17/2022]
Abstract
Platelet-activating factor (PAF) is a potent phospholipid modulator of inflammation that has diverse physiological and pathological functions. Previously, we demonstrated that PAF has an essential role in ultraviolet (UV)-induced immunosuppression and reduces the repair of damaged DNA, suggesting that UV-induced PAF is contributing to skin cancer initiation by inducing immune suppression and also affecting a proper DNA damage response. The exact role of PAF in modulating cell proliferation, differentiation or transformation is unclear. Here, we investigated the mechanism(s) by which PAF affects the cell cycle and impairs early DNA damage response. PAF arrests proliferation in transformed and nontransformed human mast cells by reducing the expression of cyclin-B1 and promoting the expression of p21. PAF-treated cells show a dose-dependent cell cycle arrest mainly at G2–M, and a decrease in the DNA damage response elements MCPH1/BRIT-1 and ataxia telangiectasia and rad related (ATR). In addition, PAF disrupts the localization of p-ataxia telangiectasia mutated (p-ATM), and phosphorylated-ataxia telangiectasia and rad related (p-ATR) at the site of DNA damage. Whereas the potent effect on cell cycle arrest may imply a tumor suppressor activity for PAF, the impairment of proper DNA damage response might implicate PAF as a tumor promoter. The outcome of these diverse effects may be dependent on specific cues in the microenvironment.
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Xu C, Reichert EC, Nakano T, Lohse M, Gardner AA, Revelo MP, Topham MK, Stafforini DM. Deficiency of phospholipase A2 group 7 decreases intestinal polyposis and colon tumorigenesis in Apc(Min/+) mice. Cancer Res 2013; 73:2806-16. [PMID: 23361301 DOI: 10.1158/0008-5472.can-12-2374] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Platelet-activating factor (PAF) is a naturally occurring phospholipid that mediates diverse effects such as physiological and pathological inflammation, immunosuppression, and cancer. Several lines of evidence support both positive and negative roles for PAF in carcinogenesis. PAF stimulates cell growth, oncogenic transformation, and metastasis, but can also limit proliferation and induce apoptosis. The biological context and microenvironment seem to define whether PAF has pro- or anticarcinogenic effects. To investigate the role of exacerbated PAF signaling in colon cancer, we conducted cell-based and in vivo studies using genetically engineered mice lacking expression of phospholipase A2 group 7 (PLA2G7), an enzyme that specifically metabolizes PAF and structurally related glycerophospholipids. Absence of Pla2g7 robustly decreased intestinal polyposis and colon tumor formation in Apc(Min)(/+) mice, suggesting an antitumorigenic role for PAF in settings characterized by aberrant function of the tumor suppressor Adenomatous polyposis coli (Apc). In colonic epithelial cells, exposure to a PAF analog led to dephosphorylation of Akt at serine-473 and induction of apoptosis. The mechanism of this response involved formation of a complex between β-arrestin 1 and the Akt phosphatase PHLPP2, and activation of the intrinsic pathway of apoptosis. Our results suggest that strategies based on inhibiting PLA2G7 activity or increasing PAF-mediated signaling hold promise for the treatment of intestinal malignancies that harbor mutations in APC.
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Affiliation(s)
- Changxin Xu
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA
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Fragel-Madeira L, Meletti T, Mariante RM, Monteiro RQ, Einicker-Lamas M, Bernardo RR, Lopes AH, Linden R. Platelet activating factor blocks interkinetic nuclear migration in retinal progenitors through an arrest of the cell cycle at the S/G2 transition. PLoS One 2011; 6:e16058. [PMID: 21298035 PMCID: PMC3029264 DOI: 10.1371/journal.pone.0016058] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 12/06/2010] [Indexed: 02/06/2023] Open
Abstract
Nuclear migration is regulated by the LIS1 protein, which is the regulatory subunit of platelet activating factor (PAF) acetyl-hydrolase, an enzyme complex that inactivates the lipid mediator PAF. Among other functions, PAF modulates cell proliferation, but its effects upon mechanisms of the cell cycle are unknown. Here we show that PAF inhibited interkinetic nuclear migration (IKNM) in retinal proliferating progenitors. The lipid did not, however, affect the velocity of nuclear migration in cells that escaped IKNM blockade. The effect depended on the PAF receptor, Erk and p38 pathways and Chk1. PAF induced no cell death, nor a reduction in nucleotide incorporation, which rules out an intra-S checkpoint. Notwithstanding, the expected increase in cyclin B1 content during G2-phase was prevented in the proliferating cells. We conclude that PAF blocks interkinetic nuclear migration in retinal progenitor cells through an unusual arrest of the cell cycle at the transition from S to G2 phases. These data suggest the operation, in the developing retina, of a checkpoint that monitors the transition from S to G2 phases of the cell cycle.
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Affiliation(s)
| | - Tamara Meletti
- Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael M. Mariante
- Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Robson Q. Monteiro
- Institute of Medical Biochemistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Robson R. Bernardo
- Institute of Chemistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Angela H. Lopes
- Institute of Microbiology, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael Linden
- Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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Zhao D, Chu WF, Wu L, Li J, Liu QM, Lu YJ, Qiao GF, Wang ZG, Zhang ZR, Yang BF. PAF exerts a direct apoptotic effect on the rat H9c2 cardiomyocytes in Ca2+-dependent manner. Int J Cardiol 2010; 143:86-93. [PMID: 19237210 DOI: 10.1016/j.ijcard.2009.01.068] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 01/23/2009] [Accepted: 01/29/2009] [Indexed: 12/19/2022]
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13
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Poisson C, Rollin S, Véronneau S, Bousquet SM, Larrivée JF, Le Gouill C, Boulay G, Stankova J, Rola-Pleszczynski M. Caveolae Facilitate but Are Not Essential for Platelet-Activating Factor-Mediated Calcium Mobilization and Extracellular Signal-Regulated Kinase Activation. THE JOURNAL OF IMMUNOLOGY 2009; 183:2747-57. [DOI: 10.4049/jimmunol.0802651] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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14
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Kitagawa D, Taketomi A, Kayashima H, Kuroda Y, Itoh S, Yamashita YI, Maehara Y. Expression of Platelet-Activating Factor Receptor: A Novel Prognosticator in Patients with Hepatocellular Carcinoma following Hepatectomy. Oncology 2008; 72:381-7. [DOI: 10.1159/000113149] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Accepted: 07/18/2007] [Indexed: 12/25/2022]
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15
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Zhou W, Ibe BO, Raj JU. Platelet-activating factor induces ovine fetal pulmonary venous smooth muscle cell proliferation: role of epidermal growth factor receptor transactivation. Am J Physiol Heart Circ Physiol 2007; 292:H2773-81. [PMID: 17322418 DOI: 10.1152/ajpheart.01018.2006] [Citation(s) in RCA: 26] [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: 11/22/2022]
Abstract
We have previously reported that platelet-activating factor (PAF) is present in very high levels in the ovine fetal lung and circulation and that PAF serves as an important physiological vasoconstrictor of the pulmonary circulation in utero. However, it is not known whether PAF stimulates pulmonary vascular smooth muscle cell (SMC) proliferation. In this study, we used ovine fetal pulmonary venous SMCs as our model system to study the effects and mechanisms of action of PAF on SMC proliferation. We found that PAF induced SMC proliferation in a dose-dependent manner. PAF also stimulated activation of both ERK and p38 but not c-Jun NH(2) terminal kinase (JNK) mitogen-activated protein (MAP) kinase pathways. PAF (10 nM) induced phosphorylation of epidermal growth factor receptor (EGFR). Specific inhibition of EGFR by AG-1478 and by the expression of a dominant-negative EGFR mutant in SMCs attenuated PAF-stimulated cell proliferation. Inhibition of heparin-binding EGF-like growth factor (HB-EGF) release by CRM-197 and inhibition of matrix metalloproteinases (MMP) by GM-6001 abolished PAF-induced MAP kinase activation and cell proliferation. Increased alkaline phosphatase (AP) activity after PAF treatment in AP-HB-EGF fusion construct-transfected SMCs indicated that PAF induced the release of HB-EGF within 1 min. Gelatin zymography data showed that PAF stimulated MMP-2 activity and MMP-9 activity within 1 min. These results suggest that PAF promotes pulmonary vascular SMC proliferation via transactivation of EGFR through MMP activation and HB-EGF, resulting in p38 and ERK activation and that EGFR transactivation is essential for the mitogenic effect of PAF in pulmonary venous SMC.
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MESH Headings
- Animals
- Bacterial Proteins/pharmacology
- Cell Proliferation/drug effects
- Cells, Cultured
- Dipeptides/pharmacology
- Dose-Response Relationship, Drug
- Enzyme Activation
- Enzyme Inhibitors/pharmacology
- Epidermal Growth Factor/genetics
- Epidermal Growth Factor/metabolism
- ErbB Receptors/drug effects
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Heparin-binding EGF-like Growth Factor
- Intercellular Signaling Peptides and Proteins
- Matrix Metalloproteinase 2/metabolism
- Matrix Metalloproteinase 9/metabolism
- Matrix Metalloproteinase Inhibitors
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/embryology
- Muscle, Smooth, Vascular/metabolism
- Mutation
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Phosphorylation
- Platelet Activating Factor/metabolism
- Platelet Activating Factor/pharmacology
- Pulmonary Veins/cytology
- Pulmonary Veins/embryology
- Pulmonary Veins/metabolism
- Quinazolines
- Sheep
- Signal Transduction/drug effects
- Time Factors
- Transfection
- Tyrphostins/pharmacology
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Weilin Zhou
- Division of Neonatology, Harbor-University of California, Los Angeles (UCLA) Medical Center, Los Angeles Biomedical Institute, 1124 West Carson St., Torrance, CA 90502, USA.
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16
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De Plaen IG, Han XB, Liu X, Hsueh W, Ghosh S, May MJ. Lipopolysaccharide induces CXCL2/macrophage inflammatory protein-2 gene expression in enterocytes via NF-kappaB activation: independence from endogenous TNF-alpha and platelet-activating factor. Immunology 2006; 118:153-63. [PMID: 16771850 PMCID: PMC1782278 DOI: 10.1111/j.1365-2567.2006.02344.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
CXCL2 (macrophage inflammatory protein-2 (MIP-2)), a critical chemokine for neutrophils, has been shown to be produced in the rat intestine in response to platelet-activating factor (PAF) and to mediate intestinal inflammation and injury. The intestinal epithelium, constantly exposed to bacterial products, is the first line of defence against micro-organisms. It has been reported that enterocytes produce proinflammatory mediators, including tumour necrosis factor (TNF) and PAF, and we showed that lipopolysaccharide (LPS) and TNF activate nuclear factor (NF)-kappaB in enterocytes. However, it remains elusive whether enterocytes release CXCL2 in response to LPS and TNF via a NF-kappaB-dependent pathway and whether this involves the endogenous production of TNF and PAF. In this study, we found that TNF and LPS markedly induced CXCL2 gene expression in IEC-6 cells, TNF within 30 min, peaking at 45 min, while LPS more slowly, peaking after 2 hr. TNF- and LPS- induced CXCL2 gene expression and protein release were completely blocked by pyrrolidine dithiocarbamate (PDTC) and helenalin, two potent NF-kappaB inhibitors. NEMO-binding domain peptide, a specific inhibitor of inhibitor protein kappaB kinase (IKK) activation, a major upstream kinase mediating NF-kappaB activation, significantly blocked CXCL2 gene expression and protein release induced by LPS. WEB2170 (PAF antagonist) and anti-TNF antibodies had no effect on LPS-induced CXCL2 expression. In conclusion, CXCL2 gene is expressed in enterocytes in response to both TNF and LPS. LPS-induced CXCL2 expression is dependent on NF-kappaB activation via the IKK pathway. The effect of LPS is independent of endogenous TNF and PAF.
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Affiliation(s)
- Isabelle G De Plaen
- Department of Pediatrics (Neonatology), Children's Memorial Hospital, Northwestern University Medical School, Chicago, IL 60614, USA.
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17
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Wu J, Nilsson Å, Jönsson B, Stenstad H, Agace W, Cheng Y, Duan RD. Intestinal alkaline sphingomyelinase hydrolyses and inactivates platelet-activating factor by a phospholipase C activity. Biochem J 2006; 394:299-308. [PMID: 16255717 PMCID: PMC1386028 DOI: 10.1042/bj20051121] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Alkaline sphingomyelinase (alk-SMase) is a new member of the NPP (nucleotide pyrophosphatase/phosphodiesterase) family that hydrolyses SM (sphingomyelin) to generate ceramide in the intestinal tract. The enzyme may protect the intestinal mucosa from inflammation and tumorigenesis. PAF (platelet-activating factor) is a pro-inflammatory phospholipid involved in pathogenesis of inflammatory bowel diseases. We examined whether alk-SMase can hydrolyse and inactivate PAF. [3H]Octadecyl-labelled PAF was incubated with purified rat intestinal alk-SMase or recombinant human alk-SMase expressed in COS-7 cells. The hydrolytic products were assayed with TLC and MS. We found that alkSMase cleaved the phosphocholine head group from PAF and generated 1-O-alkyl-2-acetyl-sn-glycerol. Differing from the activity against SM, the activity against PAF was optimal at pH 7.5, inhibited by EDTA and stimulated by 0.1-0.25 mM Zn2+. The activity was abolished by site mutation of the predicted metal-binding sites that are conserved in all NPP members. Similar to the activity against SM, the activity against PAF was dependent on bile salt, particularly taurocholate and taurochenodeoxycholate. The V(max) for PAF hydrolysis was 374 mumol x h(-1) x (mg of protein)(-1). The hydrolysis of PAF and SM could be inhibited by the presence of SM and PAF respectively, the inhibition of PAF hydrolysis by SM being stronger. The PAF-induced MAPK (mitogen-activated protein kinase) activation and IL-8 (interleukin 8) release in HT-29 cells, and chemotaxis in leucocytes were abolished by alk-SMase treatment. In conclusion, alk-SMase hydrolyses and inactivates PAF by a phospholipase C activity. The finding reveals a novel function, by which alk-SMase may counteract the development of intestinal inflammation and colon cancer.
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Affiliation(s)
- Jun Wu
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Åke Nilsson
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Bo A. G. Jönsson
- †Department of Occupational and Environment Medicine, Institute of Laboratory Medicine, University Hospital, S-221 85 Lund, Sweden
| | - Hanna Stenstad
- ‡Immunology Unit, Lund University, S-221 84 Lund, Sweden
| | - William Agace
- ‡Immunology Unit, Lund University, S-221 84 Lund, Sweden
| | - Yajun Cheng
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Rui-Dong Duan
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
- To whom correspondence should be addressed (email )
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18
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Bücher K, Leiser R, Tiemann U, Pfarrer C. Platelet-activating factor receptor (PAF-R) and acetylhydrolase (PAF-AH) are co-expressed in immature bovine trophoblast giant cells throughout gestation, but not at parturition. Prostaglandins Other Lipid Mediat 2006; 79:74-83. [PMID: 16516811 DOI: 10.1016/j.prostaglandins.2005.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Revised: 09/28/2005] [Accepted: 10/28/2005] [Indexed: 10/25/2022]
Abstract
Platelet-activating factor (PAF) was associated with successful implantation in the cow, trophoblast invasiveness and angiogenesis. Bovine placentation is characterized by the limited invasion of trophoblast giant cells (TGC) into the maternal caruncular epithelium. TGC exhibit both endocrine activity and properties of tumor cells and may thus be targets of and mediators for the action of PAF. We examined PAF-receptor (PAF-R) and PAF-acetylhydrolase (PAF-AH) gene expression and localized mRNA and corresponding proteins in bovine placentomes throughout gestation and at parturition. PAF-R and PAF-AH protein and mRNA were highly expressed and colocalized in immature TGC from early gestation until near term, while mature TGC were negative. After the onset of parturition both PAF-R and PAF-AH were expressed in the maternal stroma, predominantly endothelial cells. The expression of PAF-R and PAF-AH in immature but not mature TGC during gestation implicates a role for PAF in the differentiation, maturation and function of bovine placentomal TGC. Placentomal angiogenesis could be mediated by binding of PAF to PAF-R present in endothelial cells. The parturition-related "switch" of PAF-R and PAF-AH from TGC to the maternal stroma suggests that PAF may participate in the regulation of parturition and in prepartum tissue programming.
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Affiliation(s)
- Karen Bücher
- Department of Veterinary Anatomy, Histology and Embryology, Justus-Liebig-University Giessen, D-35392 Giessen, Germany
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19
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Gustafsson AC, Kupershmidt I, Edlundh-Rose E, Greco G, Serafino A, Krasnowska EK, Lundeberg T, Bracci-Laudiero L, Romano MC, Parasassi T, Lundeberg J. Global gene expression analysis in time series following N-acetyl L-cysteine induced epithelial differentiation of human normal and cancer cells in vitro. BMC Cancer 2005; 5:75. [PMID: 16001974 PMCID: PMC1182358 DOI: 10.1186/1471-2407-5-75] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2004] [Accepted: 07/07/2005] [Indexed: 01/07/2023] Open
Abstract
Background Cancer prevention trials using different types of antioxidant supplements have been carried out at several occasions and one of the investigated compounds has been the antioxidant N-acetyl-L-cysteine (NAC). Studies at the cellular level have previously demonstrated that a single supplementation of NAC induces a ten-fold more rapid differentiation in normal primary human keratinocytes as well as a reversion of a colon carcinoma cell line from neoplastic proliferation to apical-basolateral differentiation [1]. The investigated cells showed an early change in the organization of the cytoskeleton, several newly established adherens junctions with E-cadherin/β-catenin complexes and increased focal adhesions, all features characterizing the differentiation process. Methods In order to investigate the molecular mechanisms underlying the proliferation arrest and accelerated differentiation induced by NAC treatment of NHEK and Caco-2 cells in vitro, we performed global gene expression analysis of NAC treated cells in a time series (1, 12 and 24 hours post NAC treatment) using the Affymetrix GeneChip™ Human Genome U95Av2 chip, which contains approximately 12,000 previously characterized sequences. The treated samples were compared to the corresponding untreated culture at the same time point. Results Microarray data analysis revealed an increasing number of differentially expressed transcripts over time upon NAC treatment. The early response (1 hour) was transient, while a constitutive trend was commonly found among genes differentially regulated at later time points (12 and 24 hours). Connections to the induction of differentiation and inhibition of growth were identified for a majority of up- and down-regulated genes. All of the observed transcriptional changes, except for seven genes, were unique to either cell line. Only one gene, ID-1, was mutually regulated at 1 hour post treatment and might represent a common mediator of early NAC action. The detection of several genes that previously have been identified as stimulated or repressed during the differentiation of NHEK and Caco-2 provided validation of results. In addition, real-time kinetic PCR analysis of selected genes also verified the differential regulation as identified by the microarray platform. Conclusion NAC induces a limited and transient early response followed by a more consistent and extensively different expression at later time points in both the normal and cancer cell lines investigated. The responses are largely related to inhibition of proliferation and stimulation of differentiation in both cell types but are almost completely lineage specific. ID-1 is indicated as an early mediator of NAC action.
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Affiliation(s)
- Anna C Gustafsson
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
| | - Ilya Kupershmidt
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
- Silicon Genetics, 2601 Spring Street, Redwood City, California 94063, USA
| | - Esther Edlundh-Rose
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
| | - Giulia Greco
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Annalucia Serafino
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Eva K Krasnowska
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Thomas Lundeberg
- Rehabilitation Medicine, Karolinska University Hospital, 117 76 Stockholm, Sweden
| | - Luisa Bracci-Laudiero
- Associazione Italiana Iniziativa Medicina Sociale, Corso Trieste 16, 00185 Roma, Italy
| | - Maria-Concetta Romano
- Associazione Italiana Iniziativa Medicina Sociale, Corso Trieste 16, 00185 Roma, Italy
| | - Tiziana Parasassi
- Istituto di Neurobiologia e Medicina Molecolare, CNR, Viale Marx 15-43, 00137 Roma, Italy
| | - Joakim Lundeberg
- Royal Institute of Technology, AlbaNova University Center, Department of Biotechnology, Roslagstullsbacken 21, SE-106 91 Stockholm, Sweden
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20
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Abir F, Alva S, Kaminski DL, Longo WE. The role of arachidonic acid regulatory enzymes in colorectal disease. Dis Colon Rectum 2005; 48:1471-83. [PMID: 15868226 DOI: 10.1007/s10350-005-0015-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE Nonsteroidal anti-inflammatory drugs have a wide ranging effect on diseases of the colon and rectum. Interestingly, nonsteroidal anti-inflammatory drugs seem to play a beneficial role in colorectal cancer chemoprevention and adenoma regression, but may have a deleterious effect in inflammatory bowel disease. Prostaglandin inhibition is central to both the beneficial and toxic effects of this class of drugs. Arachidonic acid metabolism is essential to prostaglandin synthesis. METHODS A Medline search using "nonsteroidal anti-inflammatory drugs," "colon cancer," "inflammatory bowel disease," "colitis," "COX inhibitors," "arachidonic acid," and "chemoprevention" as key words was performed for English-language articles. Further references were obtained through cross-referencing the bibliography cited in each work. RESULTS Based on numerous studies, nonsteroidal anti-inflammatory drugs have a beneficial role in colon cancer and colonic adenomas. However, they have been reported to have a deleterious effect on the colon in inflammatory bowel disease and have been shown to cause colitis. Nonsteroidal anti-inflammatory drugs work via multiple pathways, some well defined, and others unknown. CONCLUSIONS In the new millennium, nonsteroidal anti-inflammatory drugs may be used for chemoprevention of colorectal and other cancers. In addition, they may be used in combination with surgery and chemotherapy to primarily treat colorectal carcinoma. Undoubtedly, the use of novel cyclooxygenase inhibitors with less of a toxicity profile will allow more widespread use of nonsteroidal anti-inflammatory drugs for a variety of diseases. The future of this class of drugs is promising.
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Affiliation(s)
- Farshad Abir
- Department of Surgery, Yale University School of Medicine, New Haven, Connecticut 06520-8062, USA
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21
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Yoshida H, Imaizumi T, Tanji K, Sakaki H, Metoki N, Hatakeyama M, Yamashita K, Ishikawa A, Taima K, Sato Y, Kimura H, Satoh K. Platelet-activating factor enhances the expression of nerve growth factor in normal human astrocytes under hypoxia. ACTA ACUST UNITED AC 2005; 133:95-101. [PMID: 15661369 DOI: 10.1016/j.molbrainres.2004.09.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2004] [Indexed: 12/17/2022]
Abstract
Nerve growth factor (NGF) is required for the survival of neurons. We have addressed the effect of platelet-activating factor (PAF), one of the mediators of ischemic injury of the brain, on NGF expression in astrocytes. Normal human astrocytes in culture were stimulated with PAF, and levels of NGF mRNA and protein were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), real-time quantitative PCR and enzyme-linked immunosorbent assay (ELISA). PAF increased the expressions of NGF mRNA and protein in astrocytes in time- and concentration-dependent manners. After 48-h stimulation, 10 nmol/L PAF increased the levels of NGF protein in astrocyte-conditioned medium by 1.4-fold. The PAF-induced stimulation of NGF expression was further enhanced (2.1-fold of the control) in the cells under hypoxic culture condition. BN52021 (Ginkgolide B), an antagonist for PAF binding sites, suppressed the effect of PAF. We conclude that PAF enhances NGF gene expression in human astrocytes, and the PAF-induced increase in the expression of NGF under hypoxia may benefit the protection of the nervous tissue by promoting neuronal survival.
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Affiliation(s)
- Hidemi Yoshida
- Department of Vascular Biology, Institute of Brain Science, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
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22
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Abstract
The RAS-mitogen activated protein kinase (MAPK) signalling pathway has long been viewed as an attractive pathway for anticancer therapies, based on its central role in regulating the growth and survival of cells from a broad spectrum of human tumours. Small-molecule inhibitors designed to target various steps of this pathway have entered clinical trials. What have we recently learned about their safety and effectiveness? Will the MAPK pathway prove amenable to therapeutic intervention?
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Affiliation(s)
- Judith S Sebolt-Leopold
- Molecular Sciences and Technologies, Pfizer Global Research and Development, Ann Arbor Laboratories, 2800 Plymouth Road, Ann Arbor, Michigan 48105, USA.
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23
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Axelrad TW, Deo DD, Ottino P, Van Kirk J, Bazan NG, Bazan HEP, Hunt JD. Platelet‐activating factor (PAF) induces activation of matrix metalloproteinase 2 activity and vascular endothelial cell invasion and migration. FASEB J 2004; 18:568-70. [PMID: 14715700 DOI: 10.1096/fj.03-0479fje] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tumor-induced angiogenic responses lead to complex phenotypic changes in vascular endothelial cells, which must coordinate the expression of both proteases and protease inhibitors prior to the proliferation and invasion of surrounding stroma. Matrix metalloproteinase 2 (MMP2), which degrades Type IV collagen, is produced as proMMP2. proMMP2 is activated in part through its interactions with membrane Type 1 MMP (MT1-MMP) and tissue inhibitor of matrix metalloproteinase 2 (TIMP2). In this study, we demonstrate that platelet-activating factor (PAF) is a potent inducer of human umbilical vein endothelial cell (HUVEC) migration and invasion, which is attenuated by PAF receptor antagonists, and that PAF receptor antagonists inhibit the migration and invasion of HUVEC mediated by medium conditioned by a prostatic carcinoma cell line. We confirm that PAF receptor antagonists inhibit proliferation of HUVEC grown in rich growth medium. We show that PAF increases mRNA levels for MT1-MMP and TIMP2, followed by increased temporal conversion of latent proMMP2 to MMP2. Finally, we demonstrate that the ratio of MT1-MMP to TIMP2 in membrane preparations from PAF-stimulated HUVEC is 1.6:1, approximating the hypothesized ideal ratio of 2:1 necessary for the conversion of proMMP2 to MMP2. Our data support the involvement of PAF in vascular endothelial cell migration and invasion.
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Affiliation(s)
- T William Axelrad
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA
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24
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Denizot Y, Gainant A, Guglielmi L, Bouvier S, Cubertafond P, Mathonnet M. Tissue concentrations of platelet-activating factor in colorectal carcinoma: inverse relationships with Dukes' stage of patients. Oncogene 2003; 22:7222-4. [PMID: 14562051 DOI: 10.1038/sj.onc.1207032] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The lipid mediator platelet-activating factor (PAF) plays a role in cancer. We investigated its presence in human colon carcinoma by assessing the levels of tissue phospholipase A(2) (PLA(2), the key enzyme in the generation of the lyso-PAF precursor), lyso-PAF, PAF and acetylhydrolase activity (AHA, the key enzyme in PAF degradation) in colorectal cancer patients and by correlating them with Dukes' classification. The results highlighted that the tumour tissues of Dukes' A and B patients had significantly higher PLA(2), lyso-PAF, PAF and AHA levels as compared with nontumour tissues. Dukes' C patients had higher PLA(2), lyso-PAF and AHA levels but unchanged PAF. Dukes' D patients had higher AHA levels but unchanged PLA(2), lyso-PAF and PAF. A pathophysiological role for PAF is suggested in human colon carcinoma.
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Affiliation(s)
- Yves Denizot
- UMR CNRS 6101, Laboratoire d'Immunologie, Faculté de Médecine, 2 rue Dr Marcland, Limoges 87025, France.
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