1
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VanSlyke JK, Boswell BA, Musil LS. TGFβ overcomes FGF-induced transinhibition of EGFR in lens cells to enable fibrotic secondary cataract. Mol Biol Cell 2024; 35:ar75. [PMID: 38598298 PMCID: PMC11238076 DOI: 10.1091/mbc.e24-01-0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/29/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
To cause vision-disrupting fibrotic secondary cataract (PCO), lens epithelial cells that survive cataract surgery must migrate to the posterior of the lens capsule and differentiate into myofibroblasts. During this process, the cells become exposed to the FGF that diffuses out of the vitreous body. In normal development, such relatively high levels of FGF induce lens epithelial cells to differentiate into lens fiber cells. It has been a mystery as to how lens cells could instead undergo a mutually exclusive cell fate, namely epithelial to myofibroblast transition, in the FGF-rich environment of the posterior capsule. We and others have reported that the ability of TGFβ to induce lens cell fibrosis requires the activity of endogenous ErbBs. We show here that lens fiber-promoting levels of FGF induce desensitization of ErbB1 (EGFR) that involves its phosphorylation on threonine 669 mediated by both ERK and p38 activity. Transinhibition of ErbB1 by FGF is overcome by a time-dependent increase in ErbB1 levels induced by TGFβ, the activation of which is increased after cataract surgery. Our studies provide a rationale for why TGFβ upregulates ErbB1 in lens cells and further support the receptor as a therapeutic target for PCO.
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Affiliation(s)
- Judy K. VanSlyke
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239
| | - Bruce A. Boswell
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239
| | - Linda S. Musil
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239
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2
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Pardo-Pastor C, Rosenblatt J. Piezo1 activates noncanonical EGFR endocytosis and signaling. SCIENCE ADVANCES 2023; 9:eadi1328. [PMID: 37756411 PMCID: PMC10530101 DOI: 10.1126/sciadv.adi1328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023]
Abstract
EGFR-ERK signaling controls cell cycle progression during development, homeostasis, and disease. While EGF ligand and mechanical inputs can activate EGFR-ERK signaling, the molecules linking mechanical force to this axis have remained mysterious. We previously found that stretch promotes mitosis via the stretch-activated ion channel Piezo1 and ERK signaling. Here, we show that Piezo1 provides the missing link between mechanical signals and EGFR-ERK activation. While both EGF- and Piezo1-dependent activation trigger clathrin-mediated EGFR endocytosis and ERK activation, EGF relies on canonical tyrosine autophosphorylation, whereas Piezo1 involves Src-p38 kinase-dependent serine phosphorylation. In addition, unlike EGF, ex vivo lung slices treated with Piezo1 agonist promoted cell cycle re-entry via nuclear ERK, AP-1 (FOS and JUN), and YAP accumulation, typical of regenerative and malignant signaling. Our results suggest that mechanical activation via Piezo1, Src, and p38 may be more relevant to controlling repair, regeneration, and cancer growth than tyrosine kinase signaling via canonical EGF signaling, suggesting an alternative therapeutic approach.
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Affiliation(s)
- Carlos Pardo-Pastor
- Randall Centre for Cell & Molecular Biophysics, New Hunt’s House, School of Basic & Medical Sciences, Faculty of Life Sciences & Medicine, King’s College London, SE1 1UL London, UK
| | - Jody Rosenblatt
- Randall Centre for Cell & Molecular Biophysics, New Hunt’s House, School of Basic & Medical Sciences, Faculty of Life Sciences & Medicine, King’s College London, SE1 1UL London, UK
- School of Cancer & Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King’s College London, SE1 1UL London, UK
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3
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Masaki T, Habara M, Shibutani S, Hanaki S, Sato Y, Tomiyasu H, Shimada M. Dephosphorylation of the EGFR protein by calcineurin at serine 1046/1047 enhances its stability. Biochem Biophys Res Commun 2023; 641:84-92. [PMID: 36525928 DOI: 10.1016/j.bbrc.2022.12.017] [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: 11/25/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
The epidermal growth factor receptor (EGFR) is highly expressed or abnormally activated in several types of cancers, such as lung and colorectal cancers. Inhibitors that suppress the tyrosine kinase activity of EGFR have been used in the treatment of lung cancer. However, resistance to these inhibitors has become an issue in cancer treatment, and the development of new therapies that inhibit EGFR is desired. We found that calcineurin, a Ca2+/calmodulin-activated serine/threonine phosphatase, is a novel regulator of EGFR. Inhibition of calcineurin by FK506 treatment or calcineurin depletion promoted EGFR degradation in cancer cells. In addition, we found that calcineurin dephosphorylates EGFR at serine (S)1046/1047, which in turn stabilizes EGFR. Furthermore, in human colon cancer cells transplanted into mice, the inhibition of calcineurin by FK506 decreased EGFR expression. These results indicate that calcineurin stabilizes EGFR by dephosphorylating S1046/1047 and promotes tumor growth. These findings suggest that calcineurin may be a new therapeutic target for cancers with high EGFR expression or activation.
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Affiliation(s)
- Takahiro Masaki
- Department of Veterinary Biochemistry, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi, 753-8511, Japan
| | - Makoto Habara
- Department of Veterinary Biochemistry, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi, 753-8511, Japan
| | - Shusaku Shibutani
- Department of Veterinary Hygiene, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi, 753-8511, Japan
| | - Shunsuke Hanaki
- Department of Veterinary Biochemistry, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi, 753-8511, Japan
| | - Yuki Sato
- Department of Veterinary Biochemistry, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi, 753-8511, Japan
| | - Haruki Tomiyasu
- Department of Veterinary Biochemistry, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi, 753-8511, Japan
| | - Midori Shimada
- Department of Veterinary Biochemistry, Yamaguchi University, 1677-1 Yoshida, Yamaguchi, Yamaguchi, 753-8511, Japan.
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4
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Metz C, Oyanadel C, Jung J, Retamal C, Cancino J, Barra J, Venegas J, Du G, Soza A, González A. Phosphatidic acid-PKA signaling regulates p38 and ERK1/2 functions in ligand-independent EGFR endocytosis. Traffic 2021; 22:345-361. [PMID: 34431177 DOI: 10.1111/tra.12812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 07/27/2021] [Accepted: 08/16/2021] [Indexed: 12/16/2022]
Abstract
Ligand-independent epidermal growth factor receptor (EGFR) endocytosis is inducible by a variety of stress conditions converging upon p38 kinase. A less known pathway involves phosphatidic acid (PA) signaling toward the activation of type 4 phosphodiesterases (PDE4) that decrease cAMP levels and protein kinase A (PKA) activity. This PA/PDE4/PKA pathway is triggered with propranolol used to inhibit PA hydrolysis and induces clathrin-dependent and clathrin-independent endocytosis, followed by reversible accumulation of EGFR in recycling endosomes. Here we give further evidence of this signaling pathway using biosensors of PA, cAMP, and PKA in live cells and then show that it activates p38 and ERK1/2 downstream the PKA inhibition. Clathrin-silencing and IN/SUR experiments involved the activity of p38 in the clathrin-dependent route, while ERK1/2 mediates clathrin-independent EGFR endocytosis. The PA/PDE4/PKA pathway selectively increases the EGFR endocytic rate without affecting LDLR and TfR constitute endocytosis. This selectiveness is probably because of EGFR phosphorylation, as detected in Th1046/1047 and Ser669 residues. The EGFR accumulates at perinuclear recycling endosomes colocalizing with TfR, fluorescent transferrin, and Rab11, while a small proportion distributes to Alix-endosomes. A non-selective recycling arrest includes LDLR and TfR in a reversible manner. The PA/PDE4/PKA pathway involving both p38 and ERK1/2 expands the possibilities of EGFR transmodulation and interference in cancer.
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Affiliation(s)
- Claudia Metz
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Claudia Oyanadel
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Juan Jung
- Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudio Retamal
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Jorge Cancino
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Jonathan Barra
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Jaime Venegas
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Guangwei Du
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Andrea Soza
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Alfonso González
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile.,Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile.,Fundación Ciencia y Vida, Santiago, Chile
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5
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Jie Z, Xie Z, Zhao X, Sun X, Yu H, Pan X, Shen S, Qin A, Fang X, Fan S. Glabridin inhibits osteosarcoma migration and invasion via blocking the p38- and JNK-mediated CREB-AP1 complexes formation. J Cell Physiol 2018; 234:4167-4178. [PMID: 30146723 DOI: 10.1002/jcp.27171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 07/17/2018] [Indexed: 01/11/2023]
Abstract
Osteosarcoma is the most common bone malignancy, and it seriously affects the quality of life of affected children and adolescents. Glabridin (GLA), a major component of licorice root extract, has been reported to exert antitumor effects against a variety of tumor types; however, its effects on osteosarcoma have not been elucidated. In the current study, we investigate the effects and potential antimetastatic mechanisms of GLA on osteosarcoma in vitro and in vivo. Flow cytometry showed that GLA induced G2/M cell cycle phase arrest and promoted cell apoptosis. Transwell and wound-healing assays showed that GLA significantly decreased the migration and invasion of osteosarcoma cells. Further western blotting and quantitative real-time polymerase chain reaction showed that the expression of matrix metalloproteinase (MMP)-2 and MMP-9 in MG63 and HOS cells were reduced after GLA treatment. Moreover, western blotting demonstrated that GLA downregulated the phosphorylation of p38 mitogen-activated protein kinases and c-Jun N-terminal kinase. A coimmunoprecipitation assay illustrated that formation of cAMP response element-binding protein (CREB)-activating protein 1 (AP1) complexes and the DNA binding activities of CREB and AP1 in MG63 and HOS cells were impaired following treatment with GLA. Finally, GLA inhibited tumor growth and suppressed osteosarcoma cell metastasis in vivo. Overall, our findings highlight the potential of GLA as a therapeutic agent for the prevention and treatment of tumor metastasis.
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Affiliation(s)
- Zhiwei Jie
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Ziang Xie
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Xiangde Zhao
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Xuewu Sun
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Hejun Yu
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xin Pan
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Shuying Shen
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - An Qin
- Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai, China
| | - Xiangqian Fang
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shunwu Fan
- Department of Orthopaedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
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6
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Tanaka T, Ozawa T, Oga E, Muraguchi A, Sakurai H. Cisplatin-induced non-canonical endocytosis of EGFR via p38 phosphorylation of the C-terminal region containing Ser-1015 in non-small cell lung cancer cells. Oncol Lett 2018; 15:9251-9256. [PMID: 29805654 DOI: 10.3892/ol.2018.8485] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/22/2018] [Indexed: 12/12/2022] Open
Abstract
The aberrant activation of receptor tyrosine kinases (RTKs) is associated with tumor initiation in various types of human cancer, including non-small cell lung cancers (NSCLCs). Tyrosine kinase-independent non-canonical RTK regulation has also been investigated in tumor malignant alterations, including cellular stress responses. It was recently reported that the phosphorylation of epidermal growth factor receptor (EGFR) at C-terminal Ser-1015 serves a critical role in growth factor and cytokine signaling. In the present study, the role of non-canonical EGFR regulation has been investigated in NSCLC cells treated with cisplatin, a common chemotherapeutic agent. Cisplatin-induced p38 activation triggered the Ser-1015 phosphorylation of EGFR, with similar kinetics to previously reported Ser-1047 phosphorylation, in a tyrosine kinase-independent manner. In addition, phosphorylation around Ser-1015 triggered endocytosis of a dimer deficient mutant of EGFR. The non-canonical endocytosis of EGFR monomers was primarily controlled by the region around Ser-1015 only; however, Ser-1047 on internalized EGFR was equally phosphorylated. The results of the present study provide mechanistic evidence for the cisplatin-induced non-canonical regulation of EGFR.
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Affiliation(s)
- Tomohiro Tanaka
- Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Tatsuhiko Ozawa
- Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Eiji Oga
- Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Atsushi Muraguchi
- Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Hiroaki Sakurai
- Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
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7
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Soeda A, Lathia J, Williams BJ, Wu Q, Gallagher J, Androutsellis-Theotokis A, Giles AJ, Yang C, Zhuang Z, Gilbert MR, Rich JN, Park DM. The p38 signaling pathway mediates quiescence of glioma stem cells by regulating epidermal growth factor receptor trafficking. Oncotarget 2018; 8:33316-33328. [PMID: 28410196 PMCID: PMC5464870 DOI: 10.18632/oncotarget.16741] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 03/19/2017] [Indexed: 12/21/2022] Open
Abstract
EGFR pathway is upregulated in malignant gliomas, and its downstream signaling is important for self-renewal of glioma cancer stem-like cells (GSC). p38 mitogen-activated protein kinase (MAPK) signaling, a stress-activated signaling cascade with suppressive and permissive effects on tumorigenesis, can promote internalization and ubiquitin ligase mediated degradation of EGFR. In this study, we investigated the role of p38 MAPK signaling on the self-renewal of GSCs with the hypothesis that inhibition may lead to enhanced self-renewal capacity by retention of EGFR. Inhibition of p38 MAPK pathway led to increase in EGFR expression but surprisingly, reduced proliferation. Additional functional evaluation revealed that p38 inhibition was associated with decrease in cell death and maintenance of undifferentiated state. Further probing the effect of p38 inhibition demonstrated attenuation of EGFR downstream signaling activity in spite of prolonged surface expression of the receptor. In vitro observations were confirmed in xenograft in vivo experiments. These data suggest that p38 MAPK control of EGFR signaling activity may alter GSC cell cycle state by regulating quiescence and passage into transit amplifying state.
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Affiliation(s)
- Akio Soeda
- Department of Neurosurgery, Gifu University, Gifu, Japan
| | - Justin Lathia
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Brian J Williams
- Department of Neurosurgery, University of Louisville, Louisville, KY, USA
| | - Qiulian Wu
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Joseph Gallagher
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
| | | | - Amber J Giles
- Neuro-Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Chunzhang Yang
- Neuro-Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Zhengping Zhuang
- Neuro-Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Mark R Gilbert
- Neuro-Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Jeremy N Rich
- Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Deric M Park
- Neuro-Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, USA
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8
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Kim JH, Park JJ, Lee BJ, Joo MK, Chun HJ, Lee SW, Bak YT. Astaxanthin Inhibits Proliferation of Human Gastric Cancer Cell Lines by Interrupting Cell Cycle Progression. Gut Liver 2017; 10:369-74. [PMID: 26470770 PMCID: PMC4849689 DOI: 10.5009/gnl15208] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background/Aims Astaxanthin is a carotenoid pigment that has antioxidant, antitumoral, and anti-inflammatory properties. In this in vitro study, we investigated the mechanism of anticancer effects of astaxanthin in gastric carcinoma cell lines. Methods The human gastric adenocarcinoma cell lines AGS, KATO-III, MKN-45, and SNU-1 were treated with various concentrations of astaxanthin. A cell viability test, cell cycle analysis, and immunoblotting were performed. Results The viability of each cancer cell line was suppressed by astaxanthin in a dose-dependent manner with significantly decreased proliferation in KATO-III and SNU-1 cells. Astaxanthin increased the number of cells in the G0/G1 phase but reduced the proportion of S phase KATO-III and SNU-1 cells. Phosphorylated extracellular signal-regulated kinase (ERK) was decreased in an inverse dose-dependent correlation with astaxanthin concentration, and the expression of p27kip-1 increased the KATO-III and SNU-1 cell lines in an astaxanthin dose-dependent manner. Conclusions Astaxanthin inhibits proliferation by interrupting cell cycle progression in KATO-III and SNU-1 gastric cancer cells. This may be caused by the inhibition of the phosphorylation of ERK and the enhanced expression of p27kip-1.
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Affiliation(s)
- Jung Ha Kim
- Division of Gastroenterology, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
| | - Jong-Jae Park
- Division of Gastroenterology, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
| | - Beom Jae Lee
- Division of Gastroenterology, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
| | - Moon Kyung Joo
- Division of Gastroenterology, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
| | - Hoon Jai Chun
- Division of Gastroenterology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea
| | - Sang Woo Lee
- Division of Gastroenterology, Department of Internal Medicine, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea
| | - Young-Tae Bak
- Division of Gastroenterology, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
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9
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González L, Miquet JG, Irene PE, Díaz ME, Rossi SP, Sotelo AI, Frungieri MB, Hill CM, Bartke A, Turyn D. Attenuation of epidermal growth factor (EGF) signaling by growth hormone (GH). J Endocrinol 2017; 233:175-186. [PMID: 28223314 DOI: 10.1530/joe-16-0606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 02/21/2017] [Indexed: 01/20/2023]
Abstract
Transgenic mice overexpressing growth hormone (GH) show increased hepatic protein content of the epidermal growth factor receptor (EGFR), which is broadly associated with cell proliferation and oncogenesis. However, chronically elevated levels of GH result in desensitization of STAT-mediated EGF signal and similar response of ERK1/2 and AKT signaling to EGF compared to normal mice. To ascertain the mechanisms involved in GH attenuation of EGF signaling and the consequences on cell cycle promotion, phosphorylation of signaling mediators was studied at different time points after EGF stimulation, and induction of proteins involved in cell cycle progression was assessed in normal and GH-overexpressing transgenic mice. Results from kinetic studies confirmed the absence of STAT3 and 5 activation and comparable levels of ERK1/2 phosphorylation upon EGF stimulation, which was associated with diminished or similar induction of c-MYC, c-FOS, c-JUN, CYCLIN D1 and CYCLIN E in transgenic compared to normal mice. Accordingly, kinetics of EGF-induced c-SRC and EGFR phosphorylation at activating residues demonstrated that activation of these proteins was lower in the transgenic mice with respect to normal animals. In turn, EGFR phosphorylation at serine 1046/1047, which is implicated in the negative regulation of the receptor, was increased in the liver of GH-overexpressing transgenic mice both in basal conditions and upon EGF stimulus. Increased basal phosphorylation and activation of the p38-mitogen-activated protein kinase might account for increased Ser 1046/1047 EGFR. Hyperphosphorylation of EGFR at serine residues would represent a compensatory mechanism triggered by chronically elevated levels of GH to mitigate the proliferative response induced by EGF.
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Affiliation(s)
- Lorena González
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Johanna G Miquet
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Pablo E Irene
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - M Eugenia Díaz
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Soledad P Rossi
- Instituto de Biología y Medicina ExperimentalCONICET, Ciudad de Buenos Aires, Argentina
| | - Ana I Sotelo
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Mónica B Frungieri
- Instituto de Biología y Medicina ExperimentalCONICET, Ciudad de Buenos Aires, Argentina
| | - Cristal M Hill
- Departments of Internal Medicine and PhysiologyGeriatrics Research, School of Medicine, Southern Illinois University, Springfield, Illinois, USA
| | - Andrzej Bartke
- Departments of Internal Medicine and PhysiologyGeriatrics Research, School of Medicine, Southern Illinois University, Springfield, Illinois, USA
| | - Daniel Turyn
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
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10
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Peng K, Dai Q, Wei J, Shao G, Sun A, Yang W, Lin Q. Stress-induced endocytosis and degradation of epidermal growth factor receptor are two independent processes. Cancer Cell Int 2016; 16:25. [PMID: 27034618 PMCID: PMC4815059 DOI: 10.1186/s12935-016-0301-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 03/24/2016] [Indexed: 12/23/2022] Open
Abstract
Background Epidermal growth factor receptor (EGFR) is an important oncogenic protein in multiple types of cancer. Endocytosis and degradation of epidermal growth factor receptor (EGFR) are two key steps for down-regulation of cell surface level of EGFR and modulation of EGFR signaling. Stress conditions induce ligand-independent endocytosis and degradation of EGFR. However, it is not clear whether stress-induced endocytosis and degradation are consequential or two independent events. Methods Endocytosis and degradation of EGFR in response to stress treatment and effects of the p38 inhibitor, the Caspase-3 inhibitor and the proteasomal inhibitor in cervical cancer HeLa cells were determined using immunoblotting and immunofluorescent staining assays. Results Stress conditions, such as protein biosynthesis inhibition, UV light irradiation, and hyper-osmosis, induced both ligand-independent endocytosis and degradation of EGFR. Stress-induced endocytosis of EGFR relies on p38 kinase activity, while stress-induced degradation of EGFR is catalyzed by Caspase-3 activity. Inhibiting p38 kinase impairs only the endocytosis but not the degradation, while inhibiting Caspase-3 results in the opposite effect to inhibiting p38. Furthermore, proteasomal activity is required for stress-induced degradation of EGFR and cell death, but not for endocytosis. Conclusions The results indicate that stress-induced endocytosis and degradation are two independent events and suggest stress signaling may utilize a double-secure mechanism to down-regulate cell surface EGFR in cancer cells.
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Affiliation(s)
- Ke Peng
- School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, China
| | - Qian Dai
- School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, China
| | - Jing Wei
- School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, China
| | - Genbao Shao
- School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, China
| | - Aiqin Sun
- School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, China
| | - Wannian Yang
- School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, China
| | - Qiong Lin
- School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, China
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11
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Kim KK, Han A, Yano N, Ribeiro JR, Lokich E, Singh RK, Moore RG. Tetrathiomolybdate mediates cisplatin-induced p38 signaling and EGFR degradation and enhances response to cisplatin therapy in gynecologic cancers. Sci Rep 2015; 5:15911. [PMID: 26568478 PMCID: PMC4644948 DOI: 10.1038/srep15911] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 09/30/2015] [Indexed: 12/18/2022] Open
Abstract
Cisplatin and its analogs are among the most widely used chemotherapeutic agents against various types of cancer. It is known that cisplatin can activate epidermal growth factor receptor (EGFR), which may provide a survival benefit in cancers. Tetrathiomolybdate (TM) is a potent anti-cancer and anti-angiogenic agent and has been investigated in a number of clinical trials for cancer. In this study, we explore the therapeutic potential of TM on cisplatin-mediated EGFR regulation. Our study shows that TM is not cytotoxic, but exerts an anti-proliferative effect in ECC-1 cells. However, TM treatment prior to cisplatin markedly improves cisplatin-induced cytotoxicity. TM suppressed cisplatin-induced activation of EGFR while potentiating activation of p38; the activation of p38 signaling appeared to promote cisplatin-induced EGFR degradation. These results are in contrast to what we saw when cells were co-treated with cisplatin plus an EGFR tyrosine kinase inhibitor, where receptor activation was inhibited but receptor degradation was also blocked. Our current study is in agreement with previous findings that TM may have a therapeutic benefit by inhibiting EGFR activation. We furthermore provide evidence that TM may provide an additional benefit by potentiating p38 activation following cisplatin treatment, which may in turn promote receptor degradation by cisplatin.
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Affiliation(s)
- Kyu Kwang Kim
- Molecular Therapeutics Laboratory, Program in Women's Oncology, Departments of Obstetrics and Gynecology, Women and Infants Hospital, Alpert Medical School, Brown University, Providence, RI, USA
| | - Alex Han
- Molecular Therapeutics Laboratory, Program in Women's Oncology, Departments of Obstetrics and Gynecology, Women and Infants Hospital, Alpert Medical School, Brown University, Providence, RI, USA
| | - Naohiro Yano
- Molecular Therapeutics Laboratory, Program in Women's Oncology, Departments of Obstetrics and Gynecology, Women and Infants Hospital, Alpert Medical School, Brown University, Providence, RI, USA
| | - Jennifer R Ribeiro
- Molecular Therapeutics Laboratory, Program in Women's Oncology, Departments of Obstetrics and Gynecology, Women and Infants Hospital, Alpert Medical School, Brown University, Providence, RI, USA
| | - Elizabeth Lokich
- Molecular Therapeutics Laboratory, Program in Women's Oncology, Departments of Obstetrics and Gynecology, Women and Infants Hospital, Alpert Medical School, Brown University, Providence, RI, USA
| | - Rakesh K Singh
- Molecular Therapeutics Laboratory, Program in Women's Oncology, Departments of Obstetrics and Gynecology, Women and Infants Hospital, Alpert Medical School, Brown University, Providence, RI, USA
| | - Richard G Moore
- Molecular Therapeutics Laboratory, Program in Women's Oncology, Departments of Obstetrics and Gynecology, Women and Infants Hospital, Alpert Medical School, Brown University, Providence, RI, USA
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12
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Pest MA, Pest CA, Bellini MR, Feng Q, Beier F. Deletion of Dual Specificity Phosphatase 1 Does Not Predispose Mice to Increased Spontaneous Osteoarthritis. PLoS One 2015; 10:e0142822. [PMID: 26562438 PMCID: PMC4643037 DOI: 10.1371/journal.pone.0142822] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/27/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Osteoarthritis (OA) is a degenerative joint disease with poorly understood etiology and pathobiology. Mitogen activated protein kinases (MAPKs) including ERK and p38 play important roles in the mediation of downstream pathways involved in cartilage degenerative processes. Dual specificity phosphatase 1 (DUSP1) dephosphorylates the threonine/serine and tyrosine sites on ERK and p38, causing deactivation of downstream signalling. In this study we examined the role of DUSP1 in spontaneous OA development at 21 months of age using a genetically modified mouse model deficient in Dusp1 (DUSP1 knockout mouse). RESULTS Utilizing histochemical stains of paraffin embedded knee joint sections in DUSP1 knockout and wild type female and male mice, we showed similar structural progression of cartilage degeneration associated with OA at 21 months of age. A semi-quantitative cartilage degeneration scoring system also demonstrated similar scores in the various aspects of the knee joint articular cartilage in DUSP1 knockout and control mice. Examination of overall articular cartilage thickness in the knee joint demonstrated similar results between DUSP1 knockout and wild type mice. Immunostaining for cartilage neoepitopes DIPEN, TEGE and C1,2C was similar in the cartilage lesion sites and chondrocyte pericellular matrix of both experimental groups. Likewise, immunostaining for phosphoERK and MMP13 showed similar intensity and localization between groups. SOX9 immunostaining demonstrated a decreased number of positive cells in DUSP1 knockout mice, with correspondingly decreased staining intensity. Analysis of animal walking patterns (gait) did not show a discernable difference between groups. CONCLUSION Loss of DUSP1 does not cause changes in cartilage degeneration and gait in a mouse model of spontaneous OA at 21 months of age. Altered staining was observed in SOX9 immunostaining which may prove promising for future studies examining the role of DUSPs in cartilage and OA, as well as models of post-traumatic OA.
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Affiliation(s)
- Michael Andrew Pest
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Courtney Alice Pest
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | | | - Qingping Feng
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Frank Beier
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
- Children’s Health Research Institute, London, ON, Canada
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13
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Tong J, Taylor P, Moran MF. Proteomic analysis of the epidermal growth factor receptor (EGFR) interactome and post-translational modifications associated with receptor endocytosis in response to EGF and stress. Mol Cell Proteomics 2014; 13:1644-58. [PMID: 24797263 DOI: 10.1074/mcp.m114.038596] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aberrant expression, activation, and stabilization of epidermal growth factor receptor (EGFR) are causally associated with several human cancers. Post-translational modifications and protein-protein interactions directly modulate the signaling and trafficking of the EGFR. Activated EGFR is internalized by endocytosis and then either recycled back to the cell surface or degraded in the lysosome. EGFR internalization and recycling also occur in response to stresses that activate p38 MAP kinase. Mass spectrometry was applied to comprehensively analyze the phosphorylation, ubiquitination, and protein-protein interactions of wild type and endocytosis-defective EGFR variants before and after internalization in response to EGF ligand and stress. Prior to internalization, EGF-stimulated EGFR accumulated ubiquitin at 7 K residues and phosphorylation at 7 Y sites and at S(1104). Following internalization, these modifications diminished and there was an accumulation of S/T phosphorylations. EGFR internalization and many but not all of the EGF-induced S/T phosphorylations were also stimulated by anisomycin-induced cell stress, which was not associated with receptor ubiquitination or elevated Y phosphorylation. EGFR protein interactions were dramatically modulated by ligand, internalization, and stress. In response to EGF, different E3 ubiquitin ligases became maximally associated with EGFR before (CBL, HUWE1, and UBR4) or after (ITCH) internalization, whereas CBLB was distinctively most highly EGFR associated following anisomycin treatment. Adaptin subunits of AP-1 and AP-2 clathrin adaptor complexes also became EGFR associated in response to EGF and anisomycin stress. Mutations preventing EGFR phosphorylation at Y(998) or in the S(1039) region abolished or greatly reduced EGFR interactions with AP-2 and AP-1, and impaired receptor trafficking. These results provide new insight into spatial, temporal, and mechanistic aspects of EGFR regulation.
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Affiliation(s)
- Jiefei Tong
- From the ‡The Hospital For Sick Children, Program in Molecular Structure and Function, Princess Margaret Cancer Centre, and Department of Molecular Genetics, University of Toronto. Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto M5G 0A4, Canada
| | - Paul Taylor
- From the ‡The Hospital For Sick Children, Program in Molecular Structure and Function, Princess Margaret Cancer Centre, and Department of Molecular Genetics, University of Toronto. Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto M5G 0A4, Canada
| | - Michael F Moran
- From the ‡The Hospital For Sick Children, Program in Molecular Structure and Function, Princess Margaret Cancer Centre, and Department of Molecular Genetics, University of Toronto. Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto M5G 0A4, Canada
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14
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De Cesare M, Lauricella C, Veronese SM, Cominetti D, Pisano C, Zunino F, Zaffaroni N, Zuco V. Synergistic antitumor activity of cetuximab and namitecan in human squamous cell carcinoma models relies on cooperative inhibition of EGFR expression and depends on high EGFR gene copy number. Clin Cancer Res 2013; 20:995-1006. [PMID: 24327272 DOI: 10.1158/1078-0432.ccr-13-1684] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Despite the frequent overexpression of epidermal growth factor receptor (EGFR) in squamous cell carcinoma (SCC), the efficacy of cetuximab alone is limited. Given the marked activity of namitecan, a hydrophilic camptothecin, against SCC models, the present study was performed to explore the efficacy of the cetuximab-namitecan combination in a panel of SCC models. EXPERIMENTAL DESIGN We examined the antiproliferative and antitumor activities of the cetuximab-namitecan combination in four SCC models characterized by a different EGFR gene copy number/EGFR protein level. We also assessed the effects of the combination on EGFR expression at both mRNA and protein levels and investigated the molecular basis of the interaction between the two agents. RESULTS Cetuximab and namitecan exhibited synergistic effects, resulting in potentiation of cell growth inhibition and, most importantly, enhanced therapeutic efficacy, with high cure rates in three SCC models characterized by high EGFR gene copy number, without increasing toxicity. The synergistic antitumor effect was also observed with the cetuximab-irinotecan combination. At the molecular level, the two agents produced a cooperative effect resulting in complete downregulation of EGFR. Interestingly, when singly administered, the camptothecin was able to strongly decrease EGFR expression mainly by transcriptional inhibition. CONCLUSIONS Our results (i) demonstrate a marked efficacy of the cetuximab-namitecan combination, which reflects a complete abrogation of EGFR expression as a critical determinant of the therapeutic improvement, in SCC preclinical models, and (ii) suggest EGFR gene copy number as a possible marker to be used for patient selection in the clinical setting.
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Affiliation(s)
- Michelandrea De Cesare
- Authors' Affiliations: Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale per lo Studio e la Cura dei Tumori; Molecular Pathology Unit, Ospedale Niguarda Ca' Grande, Milan; and Sigma-Tau S.p.A., Pomezia, Italy
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15
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Sato K, Shin MS, Sakimura A, Zhou Y, Tanaka T, Kawanishi M, Kawasaki Y, Yokoyama S, Koizumi K, Saiki I, Sakurai H. Inverse correlation between Thr-669 and constitutive tyrosine phosphorylation in the asymmetric epidermal growth factor receptor dimer conformation. Cancer Sci 2013; 104:1315-22. [PMID: 23822636 DOI: 10.1111/cas.12225] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 06/19/2013] [Accepted: 06/19/2013] [Indexed: 01/16/2023] Open
Abstract
We have recently identified tumor necrosis factor (TNF)-α-induced phosphorylation of epidermal growth factor receptor (EGFR) at Thr-669 and Ser-1046/1047 via ERK and p38 pathways, respectively. In the present study, we investigated the roles of ligand-induced phosphorylation of serine and threonine residues in EGFR-overexpressing MDA-MB-468 breast cancer cells. Epidermal growth factor and heregulin, an ErbB3 ligand, induced the phosphorylation of Thr-669 and Ser-1046/1047. Inversely, constitutive tyrosine phosphorylation of the C-terminal domain, including Tyr-1068, was significantly downregulated on ligand stimulation. Inhibition of the ERK pathway by U0126 blocked ligand-induced Thr-669 phosphorylation as well as Tyr-1068 dephosphorylation. Downregulation of constitutive tyrosine phosphorylation of EGFR in HEK293 cells stably expressing the wild type was abolished by substitution of Thr-669 for Ala. In an asymmetric EGFR homodimer structure, one Thr-669 in the receiver kinase of the dimer was involved in downregulation. Similarly, Thr-669 in an EGFR-ErbB3 heterodimer also participated in tyrosine dephosphorylation. These results indicate that ERK-mediated Thr-669 phosphorylation suppresses constitutive tyrosine phosphosphorylation in the homo- and heterodimer asymmetric conformations of the EGFR.
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Affiliation(s)
- Kanae Sato
- Division of Pathogenic Biochemistry, Institute of Natural Medicine, University of Toyama, Toyama, Japan
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16
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Kyriakakis E, Maslova K, Frachet A, Ferri N, Contini A, Pfaff D, Erne P, Resink TJ, Philippova M. Cross-talk between EGFR and T-cadherin: EGFR activation promotes T-cadherin localization to intercellular contacts. Cell Signal 2013; 25:1044-53. [DOI: 10.1016/j.cellsig.2013.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 01/17/2013] [Accepted: 02/05/2013] [Indexed: 01/09/2023]
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17
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Bektas M, Jolly PS, Berkowitz P, Amagai M, Rubenstein DS. A pathophysiologic role for epidermal growth factor receptor in pemphigus acantholysis. J Biol Chem 2013; 288:9447-56. [PMID: 23404504 DOI: 10.1074/jbc.m112.438010] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The pemphigus family of autoimmune bullous disorders is characterized by autoantibody binding to desmoglein 1 and/or 3 (dsg1/dsg3). In this study we show that EGF receptor (EGFR) is activated following pemphigus vulgaris (PV) IgG treatment of primary human keratinocytes and that EGFR activation is downstream of p38 mitogen-activated protein kinase (p38). Inhibition of EGFR blocked PV IgG-triggered dsg3 endocytosis, keratin intermediate filament retraction, and loss of cell-cell adhesion in vitro. Significantly, inhibiting EGFR prevented PV IgG-induced blister formation in the passive transfer mouse model of pemphigus. These data demonstrate cross-talk between dsg3 and EGFR, that this cross-talk is regulated by p38, and that EGFR is a potential therapeutic target for pemphigus. Small-molecule inhibitors and monoclonal antibodies directed against EGFR are currently used to treat several types of solid tumors. This study provides the experimental rationale for investigating the use of EGFR inhibitors in pemphigus.
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Affiliation(s)
- Meryem Bektas
- Department of Dermatology, University of North Carolina, Chapel Hill, NC 27599-7287, USA
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18
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A potential peptide therapeutic derived from the juxtamembrane domain of the epidermal growth factor receptor. PLoS One 2012; 7:e49702. [PMID: 23166750 PMCID: PMC3499488 DOI: 10.1371/journal.pone.0049702] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 10/12/2012] [Indexed: 12/31/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) is involved in many cancers and EGFR has been heavily pursued as a drug target. Drugs targeting EGFR have shown promising clinical results for several cancer types. However, resistance to EGFR inhibitors often occurs, such as with KRAS mutant cancers, therefore new methods of targeting EGFR are needed. The juxtamembrane (JXM) domain of EGFR is critical for receptor activation and targeting this region could potentially be a new method of inhibiting EGFR. We hypothesized that the structural role of the JXM region could be mimicked by peptides encoding a JXM amino acid sequence, which could interfere with EGFR signaling and consequently could have anti-cancer activity. A peptide encoding EGFR 645-662 conjugated to the Tat sequence (TE-64562) displayed anti-cancer activity in multiple human cancer cell types with diminished activity in non-EGFR expressing cells and non-cancerous cells. In nude mice, TE-64562 delayed MDA-MB-231 tumor growth and prolonged survival, without inducing toxicity. TE-64562 induced non-apoptotic cell death after several hours and caspase-3-mediated apoptotic cell death with longer treatment. Mechanistically, TE-64562 bound to EGFR, inhibited its dimerization and caused its down-regulation. TE-64562 reduced phosphorylated and total EGFR levels but did not inhibit kinase activity and instead prolonged it. Our analysis of patient data from The Cancer Genome Atlas supported the hypothesis that down-regulation of EGFR is a potential therapeutic strategy, since phospho- and total-EGFR levels were strongly correlated in a large majority of patient tumor samples, indicating that lower EGFR levels are associated with lower phospho-EGFR levels and presumably less proliferative signals in breast cancer. Akt and Erk were inhibited by TE-64562 and this inhibition was observed in vivo in tumor tissue upon treatment with TE-64562. These results are the first to indicate that the JXM domain of EGFR is a viable drug target for several cancer types.
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19
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Kano F, Nakatsu D, Noguchi Y, Yamamoto A, Murata M. A resealed-cell system for analyzing pathogenic intracellular events: perturbation of endocytic pathways under diabetic conditions. PLoS One 2012; 7:e44127. [PMID: 22952896 PMCID: PMC3430665 DOI: 10.1371/journal.pone.0044127] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 07/30/2012] [Indexed: 12/25/2022] Open
Abstract
Cell-based assay systems that can serve as cellular models of aberrant function in pathogenic organs would be novel and useful tools for screening drugs and clarifying the molecular mechanisms of various diseases. We constructed model cells that replicated the conditions in diabetic hepatocytes by using the cell resealing technique, which enables the exchange of cytosol. The plasma membrane of HeLa cells was permeabilized with the streptococcal toxin streptolysin O, and cytosol that had been prepared from wild-type or db/db diabetic mice was introduced into the resulting semi-intact cells. By resealing the plasma membrane by exposure to Ca2+, we created WT or Db model cells, in which the cytosolic conditions replicated those of healthy or diabetic liver. Interestingly, phosphorylation of p38 MAPK was promoted, whereas the level of endosomal phosphatidylinositol-3-phosphate was decreased, in Db cells. We investigated several endocytic pathways in WT and Db cells, and found that retrograde endosome-to-Golgi transport was delayed in a p38 MAPK-dependent manner in Db cells. Furthermore, the degradation pathway of the EGF receptor from endosomes to lysosomes was enhanced in Db cells, and this did not depend on the activation of p38 MAPK. The disease model cell system should become a powerful tool for the detection of aberrant processes in cells under pathogenic conditions and for therapeutic applications.
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Affiliation(s)
- Fumi Kano
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
- PRESTO, Japan Science and Technology Agency, Saitama, Japan
| | - Daiki Nakatsu
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Yoshiyuki Noguchi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Akitsugu Yamamoto
- Department of Cell Biology, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga, Japan
| | - Masayuki Murata
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
- * E-mail:
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20
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Galan-Moya EM, de la Cruz-Morcillo MA, Valero ML, Callejas-Valera JL, Melgar-Rojas P, Losa JH, Salcedo M, Fernández-Aramburo A, Cajal SRY, Sánchez-Prieto R. Balance between MKK6 and MKK3 mediates p38 MAPK associated resistance to cisplatin in NSCLC. PLoS One 2011; 6:e28406. [PMID: 22164285 PMCID: PMC3229586 DOI: 10.1371/journal.pone.0028406] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/07/2011] [Indexed: 12/29/2022] Open
Abstract
The p38 MAPK signaling pathway has been proposed as a critical mediator of the therapeutic effect of several antitumor agents, including cisplatin. Here, we found that sensitivity to cisplatin, in a system of 7 non-small cell lung carcinoma derived cell lines, correlated with high levels of MKK6 and marked activation of p38 MAPK. However, knockdown of MKK6 modified neither the response to cisplatin nor the activation of p38 MAPK. Deeper studies showed that resistant cell lines also displayed higher basal levels of MKK3. Interestingly, MKK3 knockdown significantly decreased p38 phosphorylation upon cisplatin exposure and consequently reduced the response to the drug. Indeed, cisplatin poorly activated MKK3 in resistant cells, while in sensitive cell lines MKK3 showed the opposite pattern in response to the drug. Our data also demonstrate that the low levels of MKK6 expressed in resistant cell lines are the consequence of high basal activity of p38 MAPK mediated by the elevated levels of MKK3. This finding supports the existence of a regulatory mechanism between both MAPK kinases through their MAPK. Furthermore, our results were also mirrored in head and neck carcinoma derived cell lines, suggesting our observations boast a potential universal characteristic in cancer resistance of cisplatin. Altogether, our work provides evidence that MKK3 is the major determinant of p38 MAPK activation in response to cisplatin and, hence, the resistance associated with this MAPK. Therefore, these data suggest that the balance between both MKK3 and MKK6 could be a novel mechanism which explains the cellular response to cisplatin.
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Affiliation(s)
- Eva M. Galan-Moya
- Laboratorio de Oncología Molecular, Centro Regional de Investigaciones Biomédicas, PCYTA/ UCLM, Albacete, Spain
| | | | - Maria Llanos Valero
- Laboratorio de Oncología Molecular, Centro Regional de Investigaciones Biomédicas, PCYTA/ UCLM, Albacete, Spain
| | - Juan L. Callejas-Valera
- Laboratorio de Oncología Molecular, Centro Regional de Investigaciones Biomédicas, PCYTA/ UCLM, Albacete, Spain
| | - Pedro Melgar-Rojas
- Laboratorio de Oncología Molecular, Centro Regional de Investigaciones Biomédicas, PCYTA/ UCLM, Albacete, Spain
| | - Javier Hernadez Losa
- Pathology Department, Fundació Institut de Recerca Hospital Vall d'Hebron, Barcelona, Spain
| | - Mayte Salcedo
- Pathology Department, Fundació Institut de Recerca Hospital Vall d'Hebron, Barcelona, Spain
| | - Antonio Fernández-Aramburo
- Laboratorio de Oncología Molecular, Centro Regional de Investigaciones Biomédicas, PCYTA/ UCLM, Albacete, Spain
- Servicio de Oncología CHUA, Albacete, Spain
| | | | - Ricardo Sánchez-Prieto
- Laboratorio de Oncología Molecular, Centro Regional de Investigaciones Biomédicas, PCYTA/ UCLM, Albacete, Spain
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21
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Nakashima M, Adachi S, Yasuda I, Yamauchi T, Kawaguchi J, Itani M, Yoshioka T, Matsushima-Nishiwaki R, Hirose Y, Kozawa O, Moriwaki H. Phosphorylation status of heat shock protein 27 plays a key role in gemcitabine-induced apoptosis of pancreatic cancer cells. Cancer Lett 2011; 313:218-25. [PMID: 21999932 DOI: 10.1016/j.canlet.2011.09.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 08/31/2011] [Accepted: 09/07/2011] [Indexed: 02/05/2023]
Abstract
Gemcitabine, an antitumor drug, is currently considered to be the standard of care for the treatment of advanced pancreatic cancer, but the clinical outcome is still not satisfactory. Although heat shock protein (HSP) 27 is implicated in the resistance to chemotherapy in several types of cancers, the precise role of phosphorylated HSP27 in cancer cells remains to be clarified. In this study, we investigated the relationship between the effect of gemcitabine and the phosphorylation status of HSP27 in pancreatic cancer cells, Panc1 and KP3. Gemcitabine suppressed pancreatic cancer cell growth and induced apoptosis. Gemcitabine caused activation of p38 mitogen-activated protein kinase (MAPK), MAPK-activated protein kinase 2 (MAPKAPK-2) and subsequently phosphorylation of HSP27 at Ser15, 78 and 82 without affecting total HSP27 levels. The inhibitions of p38 MAPK and MAPKAPK-2 reduced the phosphorylation of HSP27 and apoptosis in gemcitabine-treated cells. To further investigate the role of phosphorylated HSP27, we established Panc1 cell lines which were stably transfected with empty vector (empty cells), wild-type HSP27-encoding vector (WT cells) and 2 mutant HSP27-encoding vectors that mimic non-phosphorylated (3A), and phosphorylated (3D), respectively. In comparison of empty cells with WT cells, there was no difference in cell growth rate and the sensitivity to gemcitabine. Interestingly, cell growth of 3D cells was retarded as compared to that of 3A cells. Taken together, our results strongly suggest that phosphorylation status of HSP27 plays a key role in gemcitabine-induced growth suppression of pancreatic cancer.
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Affiliation(s)
- Masanori Nakashima
- Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan
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22
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Yamauchi T, Adachi S, Yasuda I, Nakashima M, Kawaguchi J, Nishii Y, Yoshioka T, Okano Y, Hirose Y, Kozawa O, Moriwaki H. UVC radiation induces downregulation of EGF receptor via phosphorylation at serine 1046/1047 in human pancreatic cancer cells. Radiat Res 2011; 176:565-74. [PMID: 21692654 DOI: 10.1667/rr2445.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Epidermal growth factor receptor (EGFR) is overexpressed in human pancreatic cancer and is one of the clinical targets in its treatment. In the present study we investigated the mechanism underlying ultraviolet C (UVC)-radiation-induced cell growth inhibition and downregulation of EGFR in human pancreatic cancer cells (Panc1 and KP3). The cell proliferation assay indicated that Panc1 and KP3 cells were more sensitive to UVC radiation, and their growth was significantly inhibited compared to cells of the normal human pancreatic epithelial cell line, PE. Although EGFR levels was extremely low in PE cells, EGFR were highly overexpressed in Panc1 and KP3 cells, and UVC radiation downregulated the expression of EGFR in a time-dependent manner and induced phosphorylation of EGFR at Ser1046/1047 (S1046/7) in Panc1 and KP3 cells. UVC radiation induced activation of p38 mitogen-activated protein kinase (MAPK), and EGFR phosphorylation at S1046/7 induced by UVC radiation was markedly attenuated by the inhibition of p38 MAPK. Moreover, fluorescence microscopy revealed that p38 MAPK activated by UVC radiation triggered EGFR internalization and that this was not correlated with c-Cbl, an ubiquitin ligase, which plays an important role in EGF-induced EGFR downregulation. Taken together, our results suggest that in pancreatic cancer cells UVC radiation induced desensitization of the cells to EGFR stimuli via phosphorylation of EGFR at S1046/7 by activation of p38 MAPK, independent of c-Cbl.
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Affiliation(s)
- Takahiro Yamauchi
- Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu, Japan
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23
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Adachi S, Yasuda I, Nakashima M, Yamauchi T, Kawaguchi J, Shimizu M, Itani M, Nakamura M, Nishii Y, Yoshioka T, Hirose Y, Okano Y, Moriwaki H, Kozawa O. Ultraviolet irradiation can induce evasion of colon cancer cells from stimulation of epidermal growth factor. J Biol Chem 2011; 286:26178-87. [PMID: 21646361 DOI: 10.1074/jbc.m111.240630] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Receptor down-regulation is the most prominent regulatory system of EGF receptor (EGFR) signal attenuation and a critical target for therapy against colon cancer, which is highly dependent on the function of the EGFR. In this study, we investigated the effect of ultraviolet-C (UV-C) on down-regulation of EGFR in human colon cancer cells (SW480, HT29, and DLD-1). UV-C caused inhibition of cell survival and proliferation, concurrently inducing the decrease in cell surface EGFR and subsequently its degradation. UV-C, as well as EGFR kinase inhibitors, decreased the expression level of cyclin D1 and the phosphorylated level of retinoblastoma, indicating that EGFR down-regulation is correlated to cell cycle arrest. Although UV-C caused a marked phosphorylation of EGFR at Ser-1046/1047, UV-C also induced activation of p38 MAPK, a stress-inducible kinase believed to negatively regulate tumorigenesis, and the inhibition of p38 MAPK canceled EGFR phosphorylation at Ser-1046/1047, as well as subsequent internalization and degradation, suggesting that p38 MAPK mediates EGFR down-regulation by UV-C. In addition, phosphorylation of p38 MAPK induced by UV-C was mediated through transforming growth factor-β-activated kinase-1. Moreover, pretreatment of the cells with UV-C suppressed EGF-induced phosphorylation of EGFR at tyrosine residues in addition to cell survival signal, Akt. Together, these results suggest that UV-C irradiation induces the removal of EGFRs from the cell surface that can protect colon cancer cells from oncogenic stimulation of EGF, resulting in cell cycle arrest. Hence, UV-C might be applied for clinical strategy against human colon cancers.
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Affiliation(s)
- Seiji Adachi
- Department of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan.
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Rahimi M, Toth TA, Tang CK. CXCR4 suppression attenuates EGFRvIII-mediated invasion and induces p38 MAPK-dependent protein trafficking and degradation of EGFRvIII in breast cancer cells. Cancer Lett 2011; 306:43-51. [PMID: 21454012 DOI: 10.1016/j.canlet.2011.02.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 02/15/2011] [Accepted: 02/16/2011] [Indexed: 11/19/2022]
Abstract
Our previous report has shown that the constitutively activated EGFR variant, EGFRvIII, up-regulates the pro-metastatic chemokine receptor CXCR4 in breast cancer cells. Here we evaluated the biological effect and cell signaling effects of silencing CXCR4 expression in EGFRvIII-expressing breast cancer cells. Short hairpin RNA (shRNA)-mediated suppression of CXCR4 expression significantly reduced the invasive potential and proliferation of EGFRvIII-expressing breast cancer cells. These cells exhibited a reduction of EGFRvIII activity and protein expression due to increased protein degradation and altered protein trafficking. In conclusion, suppression of CXCR4 inhibits EGFRvIII-mediated breast cancer cell invasion and proliferation.
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Affiliation(s)
- Massod Rahimi
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University Medical Center, Washington, DC 20057, United States
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Adachi S, Yasuda I, Nakashima M, Yamauchi T, Yoshioka T, Okano Y, Moriwaki H, Kozawa O. Rho-kinase inhibitor upregulates migration by altering focal adhesion formation via the Akt pathway in colon cancer cells. Eur J Pharmacol 2010; 650:145-50. [PMID: 20959118 DOI: 10.1016/j.ejphar.2010.10.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 09/27/2010] [Accepted: 10/06/2010] [Indexed: 01/04/2023]
Abstract
Although Rho-kinase is reportedly implicated in carcinogenesis and the progression of human cancers, its precise mechanism has not been fully elucidated. We recently reported that Rho-kinase negatively regulates epidermal growth factor (EGF)-stimulated cancer progression in SW480 colon cancer cells. In the present study, we investigated the effect of Rho-kinase on the migration of SW480 colon cancer cells and the mechanism underlying the involvement of Rho-kinase. Interestingly, (R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide, 2HCl (Y27632), a specific inhibitor of Rho-kinase, dose-dependently enhanced cell migration. SW480 cells spontaneously release vascular endothelial growth factor (VEGF), however, Y27632 had little effect on its release. While Rho-kinase, which is generally phosphorylated in unstimulated cells, was clearly suppressed by Y27632, exogenous VEGF did not affect its phosphorylation. Immunofluorescence microscopy revealed that Y27632 caused a dramatic change in the localization of focal adhesion components, vinculin, phosphorylated caveolin-1 and tyrosine-phosphorylated proteins in SW480 cells. Furthermore, Akt inhibitor restored the loss of vinculin-stained focal adhesion formation induced by Y27632. We also observed similar effects for Y27632 on the migration and localization of focal adhesion components such as vinculin in another colon cancer cell line, HT29. Taken together, these results strongly suggest that Rho-kinase negatively regulates the migration of colon cancer cells by altering focal adhesion formation via the Akt pathway.
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Affiliation(s)
- Seiji Adachi
- Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan.
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Dedieu S, Canron X, Rezvani HR, Bouchecareilh M, Mazurier F, Sinisi R, Zanda M, Moenner M, Bikfalvi A, North S. The cytoprotective drug amifostine modifies both expression and activity of the pro-angiogenic factor VEGF-A. BMC Med 2010; 8:19. [PMID: 20334641 PMCID: PMC2859403 DOI: 10.1186/1741-7015-8-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 03/24/2010] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Amifostine (WR-2721, delivered as Ethyol) is a phosphorylated aminothiol compound clinically used in addition to cis-platinum to reduce the toxic side effects of therapeutic treatment on normal cells without reducing their efficacy on tumour cells. Its mechanism of action is attributed to the free radical scavenging properties of its active dephosphorylated metabolite WR-1065. However, amifostine has also been described as a potent hypoxia-mimetic compound and as a strong p53 inducer; both effects are known to potently modulate vascular endothelial growth factor (VEGF-A) expression. The angiogenic properties of this drug have not been clearly defined. METHODS Cancer cell lines and endothelial cells were used in culture and treated with Amifostine in order to study (i) the expression of angiogenesis related genes and proteins and (ii) the effects of the drug on VEGF-A induced in vitro angiogenesis. RESULTS We demonstrated that the treatment of several human cancer cell lines with therapeutical doses of WR-1065 led to a strong induction of different VEGF-A mRNA isoforms independently of HIF-1alpha. VEGF-A induction by WR-1065 depends on the activation of the eIF2alpha/ATF4 pathway. This up-regulation of VEGF-A mRNA was accompanied by an increased secretion of VEGF-A proteins fully active in stimulating vascular endothelial cells (EC). Nevertheless, direct treatment of EC with amifostine impaired their ability to respond to exogenous VEGF-A, an effect that correlated to the down-regulation of VEGFR-2 expression, to the reduction in cell surface binding of VEGF-A and to the decreased phosphorylation of the downstream p42/44 kinases. CONCLUSIONS Taken together, our results indicate that amifostine treatment modulates tumour angiogenesis by two apparently opposite mechanisms - the increased VEGF-A expression by tumour cells and the inhibition of EC capacity to respond to VEGF-A stimulation.
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Affiliation(s)
- S Dedieu
- Inserm, U920, Talence, F-33400, France
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Preconditioning mesenchymal stem cells with transforming growth factor-alpha improves mesenchymal stem cell-mediated cardioprotection. Shock 2010; 33:24-30. [PMID: 19996917 DOI: 10.1097/shk.0b013e3181b7d137] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mesenchymal stem cells (MSCs) are a promising therapy for acute organ ischemia in part due to their paracrine production of growth factors. However, transplanted cells encounter an inflammatory environment that mitigates their function and survival, and treating the cells with exogenous agents during ex vivo expansion before transplantation is one strategy for overcoming this limitation by enhancing paracrine function. We hypothesized that preconditioning bone marrow MSCs with TGF-alpha would 1) increase MSC production of the critical paracrine factor, vascular endothelial growth factor (VEGF), via a p38 mitogen-activated protein kinase (MAPK)-dependent mechanism and 2) enhance myocardial functional recovery in a rat model of acute myocardial I/R injury. To study this, bone marrow MSCs were harvested from adult male mice (C57BL/6J) and treated in vitro for 24 h according to the following groups: 1) control, 2) TGF-alpha (250 ng mL (-1)), 3) TNF-alpha (50 ng mL (-1)), 4) TGF-alpha + TNF-alpha, 5) hypoxia, and 6) TGF-alpha + hypoxia. For the isolated heart perfusion experiments, adult male Sprague-Dawley rat hearts were isolated, perfused via the Langendorff model, and subjected to I/R. Vehicle or MSCs with or without TGF-alpha preconditioning were infused immediately before ischemia. Mesenchymal stem cells were also treated with TGF-alpha alone or in combination with a p38 MAPK inhibitor (SB202190). In vitro, TGF-alpha increased MSC VEGF production alone (157.9 +/- 1.11 - 291.0 +/- 3.74 pg 10 (-5); P < 0.05) and, to a greater extent, in combination with TNF-alpha or hypoxia (364.5 +/- 0.868 and 342.0 +/- 7.92 pg 10(-5) cells, respectively; P < 0.05 vs. TGF-alpha alone). Postischemic myocardial functional recovery was greater in hearts infused with TGF-alpha-preconditioned MSCs compared with untreated MSCs or vehicle. Myocardial IL-1beta and TNF-alpha production and activation of caspase 3 were significantly decreased after infusion of both cell groups. p38 MAPK inhibition suppressed TGF-alpha-stimulated MSC VEGF production and postischemic myocardial recovery. These results suggest that TGF-alpha stimulates MSC VEGF production in part via a p38 MAPK-dependent mechanism, and preconditioning MSCs with TGF-alpha may enhance their ability to protect myocardium during I/R injury.
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TAK1-mediated serine/threonine phosphorylation of epidermal growth factor receptor via p38/extracellular signal-regulated kinase: NF-{kappa}B-independent survival pathways in tumor necrosis factor alpha signaling. Mol Cell Biol 2009; 29:5529-39. [PMID: 19687304 DOI: 10.1128/mcb.00375-09] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The kinase TAK1, a mitogen-activated protein kinase kinase kinase (MAP3K), has been widely accepted as a key kinase activating NF-kappaB and MAPKs in tumor necrosis factor alpha (TNF-alpha) signaling. We have recently reported that TAK1 regulates the transient phosphorylation and endocytosis of epidermal growth factor receptor (EGFR) in a tyrosine kinase activity-independent manner. In the present study, we found that Thr-669 in the juxtamembrane domain and Ser-1046/1047 in the carboxyl-terminal regulatory domain were transiently phosphorylated in response to TNF-alpha. Experiments using chemical inhibitors and small interfering RNA demonstrated that TNF-alpha-mediated phosphorylation of Thr-669 and Ser-1046/7 were differently regulated via TAK1-extracellular signal-regulated kinase (ERK) and TAK1-p38 pathways, respectively. In addition, p38, but not ERK, was involved in the endocytosis of EGFR. Surprisingly, modified EGFR was essential to prevent apoptotic cellular responses; however, the EGFR pathway was independent of the NF-kappaB antiapoptotic pathway. These results demonstrated that TAK1 controls two different signaling pathways, IkappaB kinase-NF-kappaB and MAPK-EGFR, leading to the survival of cells exposed to the death signal from the TNF-alpha receptor.
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Adachi S, Shimizu M, Shirakami Y, Yamauchi J, Natsume H, Matsushima-Nishiwaki R, To S, Weinstein IB, Moriwaki H, Kozawa O. (-)-Epigallocatechin gallate downregulates EGF receptor via phosphorylation at Ser1046/1047 by p38 MAPK in colon cancer cells. Carcinogenesis 2009; 30:1544-52. [PMID: 19578043 DOI: 10.1093/carcin/bgp166] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We previously reported that (-)-epigallocatechin gallate (EGCG) in green tea alters plasma membrane organization and causes internalization of epidermal growth factor receptor (EGFR), resulting in the suppression of colon cancer cell growth. In the present study, we investigated the detailed mechanism underlying EGCG-induced downregulation of EGFR in SW480 colon cancer cells. Prolonged exposure to EGCG caused EGFR degradation. However, EGCG required neither an ubiquitin ligase (c-Cbl) binding to EGFR nor a phosphorylation of EGFR at tyrosine residues, both of which are reportedly necessary for EGFR degradation induced by epidermal growth factor. In addition, EGCG induced phosphorylation of p38 mitogen-activated protein kinase (MAPK), a stress-inducible kinase believed to negatively regulate tumorigenesis, and the inhibition of p38 MAPK by SB203580, a specific p38 MAPK inhibitor, or the gene silencing using p38 MAPK-small interfering RNA (siRNA) suppressed the internalization and subsequent degradation of EGFR induced by EGCG. EGFR underwent a gel mobility shift upon treatment with EGCG and this was canceled by SB203580, indicating that EGCG causes EGFR phosphorylation via p38 MAPK. Moreover, EGCG caused phosphorylation of EGFR at Ser1046/1047, a site that is critical for its downregulation and this was also suppressed by SB203580 or siRNA of p38 MAPK. Taken together, our results strongly suggest that phosphorylation of EGFR at serine 1046/1047 via activation of p38 MAPK plays a pivotal role in EGCG-induced downregulation of EGFR in colon cancer cells.
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Affiliation(s)
- Seiji Adachi
- Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan
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