151
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Zhang GM, Bao CY, Wan FN, Cao DL, Qin XJ, Zhang HL, Zhu Y, Dai B, Shi GH, Ye DW. MicroRNA-302a Suppresses Tumor Cell Proliferation by Inhibiting AKT in Prostate Cancer. PLoS One 2015; 10:e0124410. [PMID: 25922934 PMCID: PMC4414271 DOI: 10.1371/journal.pone.0124410] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/13/2015] [Indexed: 11/25/2022] Open
Abstract
Micro (mi) RNAs are important regulators involved in various physical and pathological processes, including cancer. The miRNA-302 family has been documented as playing a critical role in carcinogenesis. In this study, we investigated the role of miRNA-302a in prostate cancer (PCa). MiRNA-302a expression was detected in 44 PCa tissues and 10 normal prostate tissues, and their clinicopathological significance was analyzed. Cell proliferation and cell cycle analysis were performed on PCa cells that stably expressed miRNA-302a. The target gene of miRNA-302a and the downstream pathway were further investigated. Compared with normal prostate tissues, miRNA-302a expression was downregulated in PCa tissues, and was even lower in PCa tissues with a Gleason score ≥8. Overexpression of miRNA-302a induced G1/S cell cycle arrest in PCa cells, and suppressed PCa cell proliferation both in vitro and in vivo. Furthermore, miRNA-302a inhibits AKT expression by directly binding to its 3΄ untranslated region, resulting in subsequent alterations of the AKT-GSK3β-cyclin D1 and AKT-p27Kip1 pathway. These results reveal miRNA-302a as a tumor suppressor in PCa, suggesting that miRNA-302a may be used as a potential target for therapeutic intervention in PCa.
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Affiliation(s)
- Gui-Ming Zhang
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Chun-Yang Bao
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fang-Ning Wan
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Da-Long Cao
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Xiao-Jian Qin
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Hai-Liang Zhang
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Yao Zhu
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Bo Dai
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Guo-Hai Shi
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
- * E-mail: (GHS); (DWY)
| | - Ding-Wei Ye
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
- * E-mail: (GHS); (DWY)
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152
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Yang W, Zou L, Huang C, Lei Y. Redox regulation of cancer metastasis: molecular signaling and therapeutic opportunities. Drug Dev Res 2015; 75:331-41. [PMID: 25160073 DOI: 10.1002/ddr.21216] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cancer metastasis is the major cause of cancer-related mortality. Accumulated evidence has shown that high-metastasis potential cancer cells have more reactive oxygen species (ROS) accumulation compared with low-metastasis potential cancer cells. ROS can function as second messengers to regulate multiple cancer metastasis-related signaling pathways via reversible oxidative posttranslational modifications of cysteine in key redox-sensitive proteins, which leads to the structural and functional change of these proteins. Because ROS can promote cancer metastasis, therapeutic strategies aiming at inducing/reducing cellular ROS level or targeting redox sensors involved in metastasis hold great potential in developing new efficient approaches for anticancer therapy. In this review, we summarize recent findings on regulation of tumor metastasis by key redox sensors and describe the potential of targeting redox signaling pathways for cancer therapy.
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Affiliation(s)
- Wenyong Yang
- Department of Biochemistry and Molecular Biology, and Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing, 400016, China; College of Life Sciences, Sichuan University, Chengdu, 610065, China; The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China
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153
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Li Chew C, Lunardi A, Gulluni F, Ruan DT, Chen M, Salmena L, Nishino M, Papa A, Ng C, Fung J, Clohessy JG, Sasaki J, Sasaki T, Bronson RT, Hirsch E, Pandolfi PP. In Vivo Role of INPP4B in Tumor and Metastasis Suppression through Regulation of PI3K-AKT Signaling at Endosomes. Cancer Discov 2015; 5:740-51. [PMID: 25883022 DOI: 10.1158/2159-8290.cd-14-1347] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 04/01/2015] [Indexed: 11/16/2022]
Abstract
UNLABELLED The phosphatases PTEN and INPP4B have been proposed to act as tumor suppressors by antagonizing PI3K-AKT signaling and are frequently dysregulated in human cancer. Although PTEN has been extensively studied, little is known about the underlying mechanisms by which INPP4B exerts its tumor-suppressive function and its role in tumorigenesis in vivo. Here, we show that a partial or complete loss of Inpp4b morphs benign thyroid adenoma lesions in Pten heterozygous mice into lethal and metastatic follicular-like thyroid cancer (FTC). Importantly, analyses of human thyroid cancer cell lines and specimens reveal INPP4B downregulation in FTC. Mechanistically, we find that INPP4B, but not PTEN, is enriched in the early endosomes of thyroid cancer cells, where it selectively inhibits AKT2 activation and in turn tumor proliferation and anchorage-independent growth. We therefore identify INPP4B as a novel tumor suppressor in FTC oncogenesis and metastasis through localized regulation of the PI3K-AKT pathway at the endosomes. SIGNIFICANCE Although both PTEN and INPP4B can inhibit PI3K-AKT signaling through their lipid phosphatase activities, here we demonstrate lack of an epistatic relationship between the two tumor suppressors. Instead, the qualitative regulation of PI3K-AKT2 signaling by INPP4B provides a mechanism for their cooperation in suppressing thyroid tumorigenesis and metastasis.
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Affiliation(s)
- Chen Li Chew
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Andrea Lunardi
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Federico Gulluni
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Italy
| | - Daniel T Ruan
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Ming Chen
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Leonardo Salmena
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Michiya Nishino
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Antonella Papa
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Christopher Ng
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Jacqueline Fung
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - John G Clohessy
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Junko Sasaki
- Department of Medical Biology, Akita University Graduate School of Medicine and Research Center for Biosignal, Akita University, Akita, Japan
| | - Takehiko Sasaki
- Department of Medical Biology, Akita University Graduate School of Medicine and Research Center for Biosignal, Akita University, Akita, Japan
| | - Roderick T Bronson
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts
| | - Emilio Hirsch
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Italy
| | - Pier Paolo Pandolfi
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
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154
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The roles of akt isoforms in the regulation of podosome formation in fibroblasts and extracellular matrix invasion. Cancers (Basel) 2015; 7:96-111. [PMID: 25575302 PMCID: PMC4381253 DOI: 10.3390/cancers7010096] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 12/22/2014] [Indexed: 01/15/2023] Open
Abstract
Mesenchymal cells employ actin-based membrane protrusions called podosomes and invadopodia for cross-tissue migration during normal human development such as embryogenesis and angiogenesis, and in diseases such as atherosclerosis plaque formation and cancer cell metastasis. The Akt isoforms, downstream effectors of phosphatidylinositol 3 kinase (PI3K), play crucial roles in cell migration and invasion, but their involvement in podosome formation and cell invasion is not known. In this study, we have used Akt1 and/or Akt2 knockout mouse embryonic fibroblasts and Akt3-targeted shRNA to determine the roles of the three Akt isoforms in Src and phorbol ester-induced podosome formation, and extracellular matrix (ECM) digestion. We found that deletion or knockdown of Akt1 significantly reduces Src-induced formation of podosomes and rosettes, and ECM digestion, while suppression of Akt2 has little effect. In contrast, Akt3 knockdown by shRNA increases Src-induced podosome/rosette formation and ECM invasion. These data suggest that Akt1 promotes, while Akt3 suppresses, podosome formation induced by Src, and Akt2 appears to play an insignificant role. Interestingly, both Akt1 and Akt3 suppress, while Akt2 enhances, phorbol ester-induced podosome formation. These data show that Akt1, Akt2 and Akt3 play different roles in podosome formation and ECM invasion induced by Src or phorbol ester, thus underscoring the importance of cell context in the roles of Akt isoforms in cell invasion.
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155
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Mollinedo F, Gajate C. Lipid rafts as major platforms for signaling regulation in cancer. Adv Biol Regul 2015; 57:130-146. [PMID: 25465296 DOI: 10.1016/j.jbior.2014.10.003] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 10/10/2014] [Accepted: 10/11/2014] [Indexed: 06/04/2023]
Abstract
Cell signaling does not apparently occur randomly over the cell surface, but it seems to be integrated very often into cholesterol-rich membrane domains, termed lipid rafts. Membrane lipid rafts are highly ordered membrane domains that are enriched in cholesterol, sphingolipids and gangliosides, and behave as major modulators of membrane geometry, lateral movement of molecules, traffic and signal transduction. Because the lipid and protein composition of membrane rafts differs from that of the surrounding membrane, they provide an additional level of compartmentalization, serving as sorting platforms and hubs for signal transduction proteins. A wide number of signal transduction processes related to cell adhesion, migration, as well as to cell survival and proliferation, which play major roles in cancer development and progression, are dependent on lipid rafts. Despite lipid rafts harbor mainly critical survival signaling pathways, including insulin-like growth factor I (IGF-I)/phosphatidylinositol 3-kinase (PI3K)/Akt signaling, recent evidence suggests that these membrane domains can also house death receptor-mediated apoptotic signaling. Recruitment of this death receptor signaling pathway in membrane rafts can be pharmacologically modulated, thus opening up the possibility to regulate cell demise with a therapeutic use. The synthetic ether phospholipid edelfosine shows a high affinity for cholesterol and accumulates in lipid rafts in a number of malignant hematological cells, leading to an efficient in vitro and in vivo antitumor activity by inducing translocation of death receptors and downstream signaling molecules to these membrane domains. Additional antitumor drugs have also been shown to act, at least in part, by recruiting death receptors in lipid rafts. The partition of death receptors together with downstream apoptotic signaling molecules in membrane rafts has led us to postulate the concept of a special liquid-ordered membrane platform coined as "cluster of apoptotic signaling molecule-enriched rafts" (CASMER), referring to raft platforms enriched in apoptotic molecules. CASMERs act as scaffolds for apoptosis signaling compartmentalization, facilitating and stabilizing protein-protein interactions by local assembly of cross-interacting molecules, which leads to apoptosis amplification and a decrease in apoptotic signal threshold. Edelfosine also displaced survival PI3K/Akt signaling from lipid rafts, leading to Akt inhibition, in mantle cell lymphoma cells. Thus, membrane rafts could act as scaffold structures where segregation of pro- from anti-apoptotic molecules could take place. In this review, we summarize our view of how reorganization of the protein composition of lipid raft membrane domains regulates cell death and therefore it might be envisaged as a novel target in the treatment of cancer.
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Affiliation(s)
- Faustino Mollinedo
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, E-37007 Salamanca, Spain.
| | - Consuelo Gajate
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, E-37007 Salamanca, Spain.
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156
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Sun S, Zhang G, Wu Z, Shi W, Yang B, Li Y. MicroRNA-302a functions as a putative tumor suppressor in colon cancer by targeting Akt. PLoS One 2014; 9:e115980. [PMID: 25542007 PMCID: PMC4277419 DOI: 10.1371/journal.pone.0115980] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/02/2014] [Indexed: 01/22/2023] Open
Abstract
Micro RNAs (miRNAs) are important regulators involved in various physical and pathological processes, including cancer. The miRNA-302 family has been documented as playing a critical role in carcinogenesis. In this study, we investigated the role of miRNA-302a in colon cancer. MiRNA-302a expression was detected in 44 colon cancer tissues and 10 normal colon tissues, and their clinicopathological significance was analyzed. Cell proliferation and cell cycle analysis were performed on colon cancer cells that stably expressed miRNA-302a. The target gene of miRNA-302a and the downstream pathway were further investigated. Compared with normal colon tissues, miRNA-302a expression was downregulated in colon cancer tissues. Overexpression of miRNA-302a induced G1/S cell cycle arrest in colon cancer cells, and suppressed colon cancer cell proliferation both in vitro and in vivo. Furthermore, miRNA-302a inhibited AKT expression by directly binding to its 3' untranslated region, resulting in subsequent alterations of the AKT-GSK3β-cyclin D1 pathway. These results reveal miRNA-302a as a tumor suppressor in colon cancer, suggesting that miRNA-302a may be used as a potential target for therapeutic intervention in colon cancer.
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Affiliation(s)
- Shengjie Sun
- Department of Oncology, General Hospital of People's Liberation Army, Beijing, 100853, China
| | - Guoqing Zhang
- Department of Oncology, General Hospital of People's Liberation Army, Beijing, 100853, China
| | - Zhiyong Wu
- Department of Oncology, General Hospital of People's Liberation Army, Beijing, 100853, China
| | - Weiwei Shi
- Department of Oncology, General Hospital of People's Liberation Army, Beijing, 100853, China
| | - Bo Yang
- Department of Oncology, General Hospital of People's Liberation Army, Beijing, 100853, China
| | - Ying Li
- Department of Oncology, General Hospital of People's Liberation Army, Beijing, 100853, China
- * E-mail:
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157
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Follo MY, Manzoli L, Poli A, McCubrey JA, Cocco L. PLC and PI3K/Akt/mTOR signalling in disease and cancer. Adv Biol Regul 2014; 57:10-6. [PMID: 25482988 DOI: 10.1016/j.jbior.2014.10.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 10/22/2014] [Indexed: 12/20/2022]
Abstract
Cancer cell metabolism is deregulated, and signalling pathways can be involved. For instance, PI3K/Akt/mTOR is associated with normal proliferation and differentiation, and its alteration is detectable in cancer cells, that exploit the normal mechanisms to overcome apoptosis. On the other hand, also the family of Phospholipase C (PLC) enzymes play a critical role in cell growth, and any change concerning these enzymes or their downstream targets can be associated with neoplastic transformation. Here, we review the role of PLC and PI3K/Akt/mTOR signal transduction pathways in pathophysiology.
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Affiliation(s)
- Matilde Y Follo
- Department of Biomedical and Neuromotor Sciences, Cellular Signalling Laboratory, University of Bologna, Bologna, Italy.
| | - Lucia Manzoli
- Department of Biomedical and Neuromotor Sciences, Cellular Signalling Laboratory, University of Bologna, Bologna, Italy
| | - Alessandro Poli
- Department of Biomedical and Neuromotor Sciences, Cellular Signalling Laboratory, University of Bologna, Bologna, Italy
| | - James A McCubrey
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA
| | - Lucio Cocco
- Department of Biomedical and Neuromotor Sciences, Cellular Signalling Laboratory, University of Bologna, Bologna, Italy.
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158
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McCubrey JA, Abrams SL, Fitzgerald TL, Cocco L, Martelli AM, Montalto G, Cervello M, Scalisi A, Candido S, Libra M, Steelman LS. Roles of signaling pathways in drug resistance, cancer initiating cells and cancer progression and metastasis. Adv Biol Regul 2014; 57:75-101. [PMID: 25453219 DOI: 10.1016/j.jbior.2014.09.016] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 09/13/2014] [Indexed: 11/28/2022]
Abstract
The EGFR/PI3K/PTEN/Akt/mTORC pathway plays prominent roles in malignant transformation, prevention of apoptosis, drug resistance, cancer initiating cells (CICs) and metastasis. The expression of this pathway is frequently altered in breast and other cancers due to mutations at or aberrant expression of: HER2, EGFR1, PIK3CA, and PTEN as well as other oncogenes and tumor suppressor genes. miRs and epigenetic mechanisms of gene regulation are also important events which regulate this pathway. In some breast cancer cases, mutations at certain components of this pathway (e.g., PIK3CA) are associated with a better prognosis than breast cancers lacking these mutations. The expression of this pathway has been associated with CICs and in some cases resistance to therapeutics. We will review the effects of activation of the EGFR/PI3K/PTEN/Akt/mTORC pathway primarily in breast cancer and development of drug resistance. The targeting of this pathway and other interacting pathways will be discussed as well as clinical trials with novel small molecule inhibitors as well as established drugs that are used to treat other diseases. In this manuscript, we will discuss an inducible EGFR model (v-ERB-B:ER) and its effects on cell growth, cell cycle progression, activation of signal transduction pathways, prevention of apoptosis in hematopoietic, breast and prostate cancer models.
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Affiliation(s)
- James A McCubrey
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA.
| | - Stephen L Abrams
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA
| | - Timothy L Fitzgerald
- Department of Surgery, Brody School of Medicine at East Carolina University, Greenville, NC, USA
| | - Lucio Cocco
- Cellular Signalling Laboratory, Department of Anatomical Sciences, Università di Bologna, Bologna, Italy; Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - Alberto M Martelli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - Giuseppe Montalto
- Biomedical Department of Internal Medicine and Specialties, University of Palermo, Palermo, Italy
| | - Melchiorre Cervello
- Consiglio Nazionale delle Ricerche, Istituto di Biomedicina e Immunologia Molecolare "Alberto Monroy", Palermo, Italy
| | - Aurora Scalisi
- Unit of Oncologic Diseases, ASP-Catania, Catania 95100, Italy
| | - Saverio Candido
- Department of Bio-Medical Sciences, University of Catania, Catania, Italy
| | - Massimo Libra
- Department of Bio-Medical Sciences, University of Catania, Catania, Italy
| | - Linda S Steelman
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA
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159
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The inhibitory effect of PIK-75 on inflammatory mediator response induced by hydrogen peroxide in feline esophageal epithelial cells. Mediators Inflamm 2014; 2014:178049. [PMID: 25276052 PMCID: PMC4170708 DOI: 10.1155/2014/178049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/30/2014] [Indexed: 11/17/2022] Open
Abstract
Isoform-selective inhibitors of phosphoinositide 3-kinase (PI3K) activation have an anti-inflammatory effect by reducing proinflammatory cytokines. Cultured feline esophageal epithelial cells (EEC) of passages 3~4 were treated with hydrogen peroxide and PIK-75. The cell viability was measured by a MTT incorporation assay. The distribution of PI3K isoforms, p-Akt, IL-1β, and IL-8 was inferred from Western blots. The release of IL-6 was determined by ELISA. The cell morphology was not considerably different from nontreated cells if the cells were pretreated with PIK-75 and treated with 300 μM hydrogen peroxide. The density of p110α of PI3K was increased, but that of other types was not affected after the treatment with hydrogen peroxide. The density of p-Akt, when the cells were exposed to PIK-75 and hydrogen peroxide, was diminished dose dependently more than that of hydrogen peroxide treatment only. The decrease of p-Akt showed an inhibition of PI3K by PIK-75. PIK-75 dose dependently reduced the expression of IL-1β, IL-8, and the level of IL-6 compared with hydrogen peroxide treatment only. These results suggest evidence that p110α mediates esophageal inflammation and that PIK-75 has an anti-inflammatory effect by reducing proinflammatory cytokines on feline esophageal epithelial cultured cells.
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