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Adan H, Guy S, Arulanandam R, Geletu M, Daniel J, Raptis L. Activated Src requires Cadherin-11, Rac, and gp130 for Stat3 activation and survival of mouse Balb/c3T3 fibroblasts. Cancer Gene Ther 2022; 29:1502-1513. [PMID: 35411090 PMCID: PMC9576600 DOI: 10.1038/s41417-022-00462-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/08/2022] [Accepted: 03/18/2022] [Indexed: 01/05/2023]
Abstract
We previously demonstrated that engagement of cadherins, cell to cell adhesion molecules, triggers a dramatic increase in levels and activity of the Rac/Cdc42 small GTPases, which is followed by secretion of IL6 family cytokines and activation of their common receptor, gp130, in an autocrine manner. This results in phosphorylation of the Signal Transducer and Activator of Transcription-3 (Stat3) on tyrosine-705, which then dimerizes, migrates to the nucleus, and activates transcription of genes involved in cell division and survival. In the present report we demonstrate that, in mouse Balb/c3T3 fibroblasts, mutationally activated Src527F also increases Rac levels, leading to secretion of IL6 family cytokines and gp130 activation, which triggers the Stat3-ptyr705 increase. Interestingly, our results also demonstrate that cadherin-11 is required to preserve gp130 levels for IL6 family signaling. At the same time, however, activated Src527F downregulates cadherin-11, in a quantitative manner. As a result, Src527F expression to intermediate levels allows sufficient cadherin-11, hence gp130 levels for Stat3 activation, as expected. However, expressed to high levels, Src527F eliminates cadherin-11, hence gp130 signaling, thus abolishing Stat3-ptyr705 stimulation. Taken together, these data establish for the first time a loop between Src, cadherin-11, gp130, and Stat3 activation. This fine balance between Src527F and cadherin-11 levels which is required for Stat3 activation and cellular survival could have significant therapeutic implications.
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Affiliation(s)
- Hanad Adan
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, K7L 3N6, Canada
- Department of Biology, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Stephanie Guy
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Rozanne Arulanandam
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Mulu Geletu
- Department of Chemistry, University of Toronto, Mississauga, ON, L5L 1C6, Canada
| | - Juliet Daniel
- Department of Biology, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Leda Raptis
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, K7L 3N6, Canada.
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2
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Roads to Stat3 Paved with Cadherins. Cells 2022; 11:cells11162537. [PMID: 36010614 PMCID: PMC9406956 DOI: 10.3390/cells11162537] [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: 07/01/2022] [Revised: 08/01/2022] [Accepted: 08/09/2022] [Indexed: 11/17/2022] Open
Abstract
The engagement of cadherins, cell-to-cell adhesion proteins, triggers a dramatic increase in the levels and activity of the Rac/Cdc42 GTPases, through the inhibition of proteasomal degradation. This leads to an increase in transcription and secretion of IL6 family cytokines, activation of their common receptor, gp130, in an autocrine manner and phosphorylation of the signal transducer and activator of transcription-3 (Stat3) on tyrosine-705 by the Jak kinases. Stat3 subsequently dimerizes, migrates to the nucleus and activates the transcription of genes involved in cell division and survival. The Src oncogene also increases Rac levels, leading to secretion of IL6 family cytokines and gp130 activation, which triggers a Stat3-ptyr705 increase. Interestingly, at the same time, Src downregulates cadherins in a quantitative manner, while cadherins are required to preserve gp130 levels for IL6 family signalling. Therefore, a fine balance between Src527F/Rac/IL6 and Src527F/cadherin/gp130 levels is in existence, which is required for Stat3 activation. This further demonstrates the important role of cadherins in the activation of Stat3, through preservation of gp130 function. Conversely, the absence of cadherin engagement correlates with low Stat3 activity: In sparsely growing cells, both gp130 and Stat3-ptyr705 levels are very low, despite the fact that cSrc is active in the FAK (focal adhesion kinase)/cSrc complex, which further indicates that the engagement of cadherins is important for Stat3 activation, not just their presence. Furthermore, the caveolin-1 protein downregulates Stat3 through binding and sequestration of cadherins to the scaffolding domain of caveolin-1. We hypothesize that the cadherins/Rac/gp130 axis may be a conserved pathway to Stat3 activation in a number of systems. This fact could have significant implications in Stat3 biology, as well as in drug testing and development.
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Yue P, Zhu Y, Brotherton-Pleiss C, Fu W, Verma N, Chen J, Nakamura K, Chen W, Chen Y, Alonso-Valenteen F, Mikhael S, Medina-Kauwe L, Kershaw KM, Celeridad M, Pan S, Limpert AS, Sheffler DJ, Cosford NDP, Shiao SL, Tius MA, Lopez-Tapia F, Turkson J. Novel potent azetidine-based compounds irreversibly inhibit Stat3 activation and induce antitumor response against human breast tumor growth in vivo. Cancer Lett 2022; 534:215613. [PMID: 35276290 PMCID: PMC9867837 DOI: 10.1016/j.canlet.2022.215613] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/09/2022] [Accepted: 02/27/2022] [Indexed: 01/26/2023]
Abstract
Signal transducer and activator of transcription (Stat)3 is a valid anticancer therapeutic target. We have discovered a highly potent chemotype that amplifies the Stat3-inhibitory activity of lead compounds to levels previously unseen. The azetidine-based compounds, including H172 (9f) and H182, irreversibly bind to Stat3 and selectively inhibit Stat3 activity (IC50 0.38-0.98 μM) over Stat1 or Stat5 (IC50 > 15.8 μM) in vitro. Mass spectrometry detected the Stat3 cysteine peptides covalently bound to the azetidine compounds, and the key residues, Cys426 and Cys468, essential for the high potency inhibition, were confirmed by site-directed mutagenesis. In triple-negative breast cancer (TNBC) models, treatment with the azetidine compounds inhibited constitutive and ligand-induced Stat3 signaling, and induced loss of viable cells and tumor cell death, compared to no effect on the induction of Janus kinase (JAK)2, Src, epidermal growth factor receptor (EGFR), and other proteins, or weak effects on cells that do not harbor aberrantly-active Stat3. H120 (8e) and H182 as a single agent inhibited growth of TNBC xenografts, and H278 (hydrochloric acid salt of H182) in combination with radiation completely blocked mouse TNBC growth and improved survival in syngeneic models. We identify potent azetidine-based, selective, irreversible Stat3 inhibitors that inhibit TNBC growth in vivo.
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Affiliation(s)
- Peibin Yue
- Department of Medicine, Division of Medical Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angenes, CA, 90048, USA,Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Yinsong Zhu
- Department of Medicine, Division of Medical Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angenes, CA, 90048, USA,Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Christine Brotherton-Pleiss
- Cancer Biology Program, University of Hawaii Cancer Center, 701 Ilalo St, Honolulu, HI, 96813, USA,Department of Chemistry, University of Hawaii, Manoa, 2545 McCarthy Mall, Honolulu, HI, 96825, USA
| | - Wenzhen Fu
- Cancer Biology Program, University of Hawaii Cancer Center, 701 Ilalo St, Honolulu, HI, 96813, USA,Department of Chemistry, University of Hawaii, Manoa, 2545 McCarthy Mall, Honolulu, HI, 96825, USA
| | - Nagendra Verma
- Department of Medicine, Division of Medical Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angenes, CA, 90048, USA,Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Jasmine Chen
- Cancer Biology Program, University of Hawaii Cancer Center, 701 Ilalo St, Honolulu, HI, 96813, USA
| | - Kayo Nakamura
- Department of Chemistry, University of Hawaii, Manoa, 2545 McCarthy Mall, Honolulu, HI, 96825, USA
| | - Weiliang Chen
- Department of Chemistry, University of Hawaii, Manoa, 2545 McCarthy Mall, Honolulu, HI, 96825, USA
| | - Yue Chen
- Department of Medicine, Division of Medical Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angenes, CA, 90048, USA,Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Felix Alonso-Valenteen
- Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA,Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Simoun Mikhael
- Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA,Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Lali Medina-Kauwe
- Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA,Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Kathleen M. Kershaw
- Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA,Department of Radiation Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Maria Celeridad
- Cell and Molecular Biology of Cancer Program, Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Songqin Pan
- W. M. Keck Proteomics Laboratory, University of California, Riverside, CA, 92521, USA
| | - Allison S. Limpert
- Cell and Molecular Biology of Cancer Program, Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Douglas J. Sheffler
- Cell and Molecular Biology of Cancer Program, Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Nicholas D. P. Cosford
- Cell and Molecular Biology of Cancer Program, Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Stephen L. Shiao
- Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA,Department of Radiation Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA
| | - Marcus A. Tius
- Cancer Biology Program, University of Hawaii Cancer Center, 701 Ilalo St, Honolulu, HI, 96813, USA,Department of Chemistry, University of Hawaii, Manoa, 2545 McCarthy Mall, Honolulu, HI, 96825, USA
| | - Francisco Lopez-Tapia
- Department of Medicine, Division of Medical Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angenes, CA, 90048, USA,Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA,Corresponding author. Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA. (J. Turkson)
| | - James Turkson
- Department of Medicine, Division of Medical Oncology, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angenes, CA, 90048, USA; Cancer Biology Program, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Los Angeles, CA, 90048, USA.
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MicroRNA-503 Exacerbates Myocardial Ischemia/Reperfusion Injury via Inhibiting PI3K/Akt- and STAT3-Dependent Prosurvival Signaling Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:3449739. [PMID: 35620576 PMCID: PMC9130001 DOI: 10.1155/2022/3449739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 04/07/2022] [Accepted: 04/21/2022] [Indexed: 12/28/2022]
Abstract
Acute myocardial infarction is a leading cause of death worldwide, while restoration of blood flow to previously ischemic myocardium may lead to ischemia/reperfusion (I/R) injury. Accumulated evidence shows that microRNAs play important roles in cardiovascular diseases. However, the potential role of microRNA-503 (miR-503) in myocardial I/R injury is little known. Thus, this study is aimed at determining whether and how miR-503 affects myocardial I/R injury in vivo and in vitro. A mouse model of myocardial I/R injury and H9c2 cell model of hypoxia/reoxygenation (H/R) injury were established. The postischemic cardiac miR-503 was downregulated in vivo and in vitro. Mechanistically, PI3K p85 and Bcl-2 are miR-503 targets. The post-ischemic cardiac PI3K p85 protein level was decreased in vivo. Agomir-503 treatment exacerbated H/R-induced injuries manifested as decreased cell viability, increased lactate dehydrogenase activity, and cell apoptosis. Agomir-503 treatment reduced cell viability under normoxia as well and reduced both PI3K p85 and Bcl-2 protein levels under either normoxia or H/R condition. It reduced phosphorylation of Stat3 (p-Stat3-Y705) and Akt (T450) in cells subjected to H/R. In contrast, Antagomir-503 treatment attenuated H/R injury and increased p-Stat3 (Y705) under normoxia and increased p-Akt (T450) under either normoxia or H/R condition. It is concluded that miR-503 exacerbated I/R injury via inactivation of PI3K/Akt and STAT3 pathways and may become a therapeutic target in preventing myocardial I/R injury.
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Geletu M, Adan H, Niit M, Arulanandam R, Carefoot E, Hoskin V, Sina D, Elliott B, Gunning P, Raptis L. Modulation of Akt vs Stat3 activity by the focal adhesion kinase in non-neoplastic mouse fibroblasts. Exp Cell Res 2021; 411:112731. [PMID: 34270980 DOI: 10.1016/j.yexcr.2021.112731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Adhesion of cells to each other and to the extracellular matrix (ECM) are both required for cellular functions. Cell-to-cell adhesion is mediated by cadherins, and their engagement triggers the activation of Stat3, which offers a potent survival signal. Adhesion to the ECM on the other hand, activates FAK which attracts and activates Src, as well as receptor tyrosine kinases (RTKs), the PI3k/Akt and Ras/Erk pathways. However, the effect of cell density upon FAK and Akt activity has not been examined. We now demonstrate that, interestingly, despite being potent Stat3 activators, Src and RTKs are unable to activate Stat3 in sparsely growing (i.e., without cadherin engagement), non-neoplastic cells attached to the ECM. In contrast, cell aggregation (i.e., cadherin engagement in the absence of adhesion to a solid substratum) was found to activate both Stat3 and Akt. Pharmacologic or genetic reduction of FAK activity abolished Akt activity at low densities, indicating that FAK is an important activator of Akt in this setting. Notably, FAK knockout increased cellular sensitivity to the Stat3 inhibitor CPA7, while FAK reintroduction restored resistance to this drug. These findings suggest a complementary role of integrin/FAK/Akt and cadherin/Stat3-mediated pro-survival pathways, which may be of significance during neoplastic transformation and metastasis.
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Affiliation(s)
- Mulu Geletu
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada.
| | - Hanad Adan
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Maximillian Niit
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Rozanne Arulanandam
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Esther Carefoot
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Victoria Hoskin
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Diana Sina
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Bruce Elliott
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Patrick Gunning
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Leda Raptis
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Mdicine, Queen's University, Kingston, ON, K7L 3N6, Canada
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6
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Geletu M, Adan H, Niit M, Arulanandam R, Carefoot E, Hoskin V, Sina D, Elliott B, Gunning P, Raptis L. Modulation of Akt vs Stat3 activity by the focal adhesion kinase in non-neoplastic mouse fibroblasts. Exp Cell Res 2021; 404:112601. [PMID: 33957118 DOI: 10.1016/j.yexcr.2021.112601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 12/28/2022]
Abstract
Adhesion of cells to each other and to the extracellular matrix (ECM) are both required for cellular functions. Cell-to-cell adhesion is mediated by cadherins and their engagement triggers the activation of Stat3, which offers a potent survival signal. Adhesion to the ECM on the other hand, activates FAK which attracts and activates Src, as well as receptor tyrosine kinases (RTKs), the PI3k/Akt and Ras/Erk pathways. However, the effect of cell density upon FAK and Akt activity has not been examined. We now demonstrate that, interestingly, despite being potent Stat3 activators, Src and RTKs are unable to activate Stat3 in sparsely growing (i.e., without cadherin engagement), non-neoplastic cells attached to the ECM. In contrast, cell aggregation (i.e., cadherin engagement in the absence of adhesion to a solid substratum) was found to activate both Stat3 and Akt. Pharmacologic or genetic reduction of FAK activity abolished Akt activity at low densities, indicating that FAK is an important activator of Akt in this setting. Notably, FAK knockout increased cellular sensitivity to the Stat3 inhibitor CPA7, while FAK reintroduction restored resistance to this drug. These findings suggest a complementary role of integrin/FAK/Akt and cadherin/Stat3-mediated pro-survival pathways, which may be of significance during neoplastic transformation and metastasis.
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Affiliation(s)
- Mulu Geletu
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada; Department of Chemical and Physical Sciences, University of Toronto, Mississauga, Ontario, L5L 1C6, Canada.
| | - Hanad Adan
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Maximillian Niit
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Rozanne Arulanandam
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada; Department of Pathology and Molecular Medicine, Centre for Innovative Cancer Therapeutics, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Ontario, K1H 8L6, Canada
| | - Esther Carefoot
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Victoria Hoskin
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Diana Sina
- Department of Chemical and Physical Sciences (CPS), University of Toronto Mississauga, 3359 Mississauga Rd, Mississauga, ON, L5L 1C6, Canada
| | - Bruce Elliott
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Patrick Gunning
- Department of Chemical and Physical Sciences, University of Toronto, Mississauga, Ontario, L5L 1C6, Canada
| | - Leda Raptis
- Department of Biomedical and Molecular Sciences and Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada
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Involvement of MicroRNA-296 in the Inhibitory Effect of Epigallocatechin Gallate against the Migratory Properties of Anoikis-Resistant Nasopharyngeal Carcinoma Cells. Cancers (Basel) 2020; 12:cancers12040973. [PMID: 32326395 PMCID: PMC7226234 DOI: 10.3390/cancers12040973] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 01/02/2023] Open
Abstract
Short noncoding endogenous RNAs, including microRNAs (miRNAs), are associated with the development and metastasis of multiple cancers. Epigallocatechin gallate (EGCG), the most active and abundant polyphenol in green tea, plays a crucial role in the modulation of miRNA expression, which is related to changes in cancer progression. In the present study, we explore whether EGCG exerts its suppressive effects on nasopharyngeal carcinoma (NPC) cells through miRNA regulation. The anoikis-resistant sphere-forming NPC cells grown under anchorage-independent conditions exhibit enhanced migratory properties, which were inhibited by EGCG treatment. The miR-296 level was lower in the anoikis-resistant cells than in the monolayer parental cells; however, miR-296 was significantly upregulated after EGCG treatment. We demonstrate that miR-296 is involved in the inhibitory effects of EGCG on the anoikis-resistant NPC cells through the downregulation of signal transducer and activator of transcription 3 (STAT3) activation. Our study is the first to demonstrate that EGCG inhibited the migratory properties of anoikis-resistant cells by modulating the expression of miRNA in NPC cells. Our results indicate the novel effects of EGCG on miRNA regulation to inhibit an invasive phenotype of NPC as well as the regulatory role of miR-296.
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Geletu M, Taha Z, Arulanandam R, Mohan R, Assi HH, Castro MG, Nabi IR, Gunning PT, Raptis L. Effect of caveolin-1 on Stat3-ptyr705 levels in breast and lung carcinoma cells. Biochem Cell Biol 2019; 97:638-646. [PMID: 30986357 DOI: 10.1139/bcb-2018-0367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We recently demonstrated that Cav1 (caveolin-1) is a negative regulator of Stat3 (signal transducer and activator of transcription-3) activity in mouse fibroblasts and human lung carcinoma SHP77 cells. We now examined whether the cellular context may affect their levels as well as the relationship between them, by assessing Cav1 and Stat3-ptyr705 amounts in different cell lines. In MDA-MB-231, A549, and HaCat cells, Cav1 levels were high and Stat3-ptyr705 levels were low, consistent with the notion of a negative effect of endogenous Cav1 on Stat3-ptyr705 levels in these lines. In addition, manipulation of Cav1 levels revealed a negative effect in MCF7 and mouse fibroblast cells, while Cav1 upregulation induced apoptosis in MCF7 cells. In contrast, however, line MRC9 had high Cav1 and high Stat3-ptyr705 levels, indicating that high Cav1 is insufficient to reduce Stat3-ptyr705 levels in this line. MCF7 and LuCi6 cells had very low Cav1 and Stat3-ptyr705 levels, indicating that the low Stat3-ptyr705 can be independent from Cav1 levels altogether. Our results reveal a further level of complexity in the relationship between Cav1 and Stat3-ptyr705 than previously thought. In addition, we demonstrate that in a feedback loop, Stat3 inhibition upregulates Cav1 in HeLa cells but not in other lines tested.
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Affiliation(s)
- Mulu Geletu
- Department of Biomedical and Molecular Sciences, Pathology and Molecular Medicine, and Queen's University Cancer Research Institute, Queen's University, Kingston, ON K7L 3N6, Canada.,Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.,Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - Zaid Taha
- Ottawa Hospital Research Institute - Cancer Therapeutics, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
| | - Rozanne Arulanandam
- Ottawa Hospital Research Institute - Cancer Therapeutics, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada
| | - Reva Mohan
- Department of Biomedical and Molecular Sciences, Pathology and Molecular Medicine, and Queen's University Cancer Research Institute, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Hikmat H Assi
- Department of Neurosurgery and Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48019, USA
| | - Maria G Castro
- Department of Neurosurgery and Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48019, USA
| | - Ivan Robert Nabi
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Patrick T Gunning
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.,Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - Leda Raptis
- Department of Biomedical and Molecular Sciences, Pathology and Molecular Medicine, and Queen's University Cancer Research Institute, Queen's University, Kingston, ON K7L 3N6, Canada
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9
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PI3k and Stat3: Oncogenes that are Required for Gap Junctional, Intercellular Communication. Cancers (Basel) 2019; 11:cancers11020167. [PMID: 30717267 PMCID: PMC6406562 DOI: 10.3390/cancers11020167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/21/2019] [Accepted: 01/26/2019] [Indexed: 12/12/2022] Open
Abstract
Gap junctional, intercellular communication (GJIC) is interrupted in cells transformed by oncogenes such as activated Src. The Src effector, Ras, is required for this effect, so that Ras inhibition restores GJIC in Src-transformed cells. Interestingly, the inhibition of the Src effector phosphatidyl-inositol-3 kinase (PI3k) or Signal Transducer and Activator of Transcription-3 (Stat3) pathways does not restore GJIC. In the contrary, inhibition of PI3k or Stat3 in non-transformed rodent fibroblasts or epithelial cells or certain human lung carcinoma lines with extensive GJIC inhibits communication, while mutational activation of PI3k or Stat3 increases GJIC. Therefore, it appears that oncogenes such as activated Src have a dual role upon GJIC; acting as inhibitors of communication through the Ras pathway, and as activators through activation of PI3k or Stat3. In the presence of high Src activity the inhibitory functions prevail so that the net effect is gap junction closure. PI3k and Stat3 constitute potent survival signals, so that their inhibition in non-transformed cells triggers apoptosis which, in turn, has been independently demonstrated to suppress GJIC. The interruption of gap junctional communication would confine the apoptotic event to single cells and this might be essential for the maintenance of tissue integrity. We hypothesize that the GJIC activation by PI3k or Stat3 may be linked to their survival function.
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Geletu M, Mohan R, Arulanandam R, Berger-Becvar A, Nabi IR, Gunning PT, Raptis L. Reciprocal regulation of the Cadherin-11/Stat3 axis by caveolin-1 in mouse fibroblasts and lung carcinoma cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:794-802. [PMID: 29458077 DOI: 10.1016/j.bbamcr.2018.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/09/2018] [Accepted: 02/15/2018] [Indexed: 01/05/2023]
Abstract
Caveolin-1 (Cav1) is an integral plasma membrane protein and a complex regulator of signal transduction. The Signal Transducer and Activator of Transcription-3 (Stat3) is activated by a number of receptor and non-receptor tyrosine kinases and is positively implicated in cancer. Despite extensive efforts, the relationship between Cav1 and Stat3 has been a matter of controversy. We previously demonstrated that engagement of E- or N-cadherin or cadherin-11 cell to cell adhesion molecules, as occurs with confluence of cultured cells, triggers a dramatic increase in the levels of tyr705 phosphorylated i.e. activated Stat3, by a mechanism requiring the cRac1 small GTPase. Since confluence was not taken into account in previous studies, we revisited the question of the relationship between Cav1 and Stat3-ptyr705 in non-transformed mouse fibroblasts and in human lung carcinoma cells, by examining their effect at different cell densities. Our results unequivocally demonstrate that Cav1 downregulates cadherin-11, by a mechanism which requires the Cav1 scaffolding domain. This cadherin-11 downregulation, in turn, leads to a reduction in cRac1 and Stat3 activity levels. Furthermore, in a feedback loop possibly through p53 upregulation, Stat3 downregulation increases Cav1 levels. Our data reveal the presence of a potent, negative regulatory loop between Cav1 and cadherin-11/Stat3, leading to Stat3 inhibition and apoptosis.
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Affiliation(s)
- M Geletu
- Department of Biomedical and Molecular Sciences, Pathology and Molecular Medicine, Queen's University Cancer Research Institute, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Rd N., Mississauga, Ontario L5L 1C6, Canada; Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada.
| | - R Mohan
- Department of Biomedical and Molecular Sciences, Pathology and Molecular Medicine, Queen's University Cancer Research Institute, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - R Arulanandam
- Department of Biomedical and Molecular Sciences, Pathology and Molecular Medicine, Queen's University Cancer Research Institute, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - A Berger-Becvar
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Rd N., Mississauga, Ontario L5L 1C6, Canada; Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada
| | - I R Nabi
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - P T Gunning
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Rd N., Mississauga, Ontario L5L 1C6, Canada; Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada
| | - L Raptis
- Department of Biomedical and Molecular Sciences, Pathology and Molecular Medicine, Queen's University Cancer Research Institute, Queen's University, Kingston, Ontario K7L 3N6, Canada
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11
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Niit M, Arulanandam R, Cass J, Geletu M, Hoskin V, Côté G, Gunning P, Elliott B, Raptis L. Regulation of HC11 mouse breast epithelial cell differentiation by the E-cadherin/Rac axis. Exp Cell Res 2017; 361:112-125. [PMID: 29031557 DOI: 10.1016/j.yexcr.2017.10.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 09/29/2017] [Accepted: 10/08/2017] [Indexed: 10/18/2022]
Abstract
It was previously demonstrated that differentiation of some established breast epithelial cell lines requires confluence and stimulation with hydrocortisone, insulin and prolactin inducers. We and others previously demonstrated that E-cadherin engagement, which is favored under conditions of confluence, increases the levels and activity of the Rac small GTPase. To investigate the functional relationship between the transforming ability of Rac and its role as an integral component of the differentiative E-cadherin signaling pathway, we introduced a mutationally activated form of Rac, RacV12, into the mouse breast epithelium-derived cell line, HC11. Our results demonstrate that the strength of the Rac signal is key for the outcome of the differentiation process; cRac1 is critically required for differentiation, and at low levels, mutationally activated RacV12 is able to increase differentiation, presumably reinforcing the E-cadherin/Rac differentiative signal. However, high RacV12 expression blocked differentiation concomitant with E-cadherin downregulation, while inducing neoplastic transformation. Therefore, the intensity of the Rac signal is a central determinant in the balance between cell proliferation vs differentiation, two fundamentally opposed processes, a finding which could also have important therapeutic implications.
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Affiliation(s)
- Maximilian Niit
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6; Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada K7L3N6
| | - Rozanne Arulanandam
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6; Centre for Innovative Cancer Therapeutics, Ottawa Hospital Research Institute, Ottawa, ON, Canada K1H 8L6
| | - Jamaica Cass
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - Mulu Geletu
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6; Department of Chemical and Physical Sciences, University of Toronto, Mississauga, Ontario, Canada L5L 1C6
| | - Victoria Hoskin
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada K7L3N6
| | - Graham Côté
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - Patrick Gunning
- Department of Chemical and Physical Sciences, University of Toronto, Mississauga, Ontario, Canada L5L 1C6
| | - Bruce Elliott
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada K7L3N6
| | - Leda Raptis
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6; Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario, Canada K7L3N6.
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12
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Lin CH, Chiang MC, Chen YJ. STAT3 mediates resistance to anoikis and promotes invasiveness of nasopharyngeal cancer cells. Int J Mol Med 2017; 40:1549-1556. [PMID: 28949390 DOI: 10.3892/ijmm.2017.3151] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 09/08/2017] [Indexed: 11/06/2022] Open
Abstract
Nasopharyngeal carcinoma (NPC), a tumor arising from the epithelial cells of the nasopharynx, is endemic in Southeast Asia and Taiwan. The prognosis of NPC patients with local recurrence and metastasis is poor. Resistance to anoikis is a primary characteristic of tumor cells that metastasize. However, the mechanism through which NPC cells resist anoikis and are able to metastasize has not been fully elucidated. In the present study, the acquisition of anoikis resistance was analyzed in the TW01 and TW06 human NPC cell lines growing under anchorage-independent conditions. A considerable number of TW01 and TW06 cells was found to be resistant to anoikis and exhibited a higher capability of migration and invasion. These anoikis-resistant NPC cells exhibited significantly increased expression of signal transducer and activation of transcription 3 (Stat3) compared with adherent cells. Furthermore, blockade of STAT3 expression by STAT3 inhibitors or STAT3 silencing significant increased anoikis in anoikis-resistant NPC cells. Moreover, silencing STAT3 not only reduced the capacity of NPC cells to resist anoikis, but also reversed their invasive properties. The expression of epithelial‑to-mesenchymal transition‑related proteins and CD44 was also significantly decreased following STAT3 knockdown. The results of the present study established that STAT3 mediates anoikis resistance, with enhanced cell migration and invasion of NPC cells, and that activation of STAT3 may increase metastatic capacity, indicating the crucial role of STAT3 in conferring anoikis resistance and enhanced invasive properties to NPC cells.
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Affiliation(s)
- Chien-Hung Lin
- Institute of Clinical Medicine, National Yang-Ming University, Taipei 112, Taiwan, R.O.C
| | - Ming-Chang Chiang
- Department of Life Science, College of Science and Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan, R.O.C
| | - Yann-Jang Chen
- Institute of Clinical Medicine, National Yang-Ming University, Taipei 112, Taiwan, R.O.C
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von Manstein V, Groner B. Tumor cell resistance against targeted therapeutics: the density of cultured glioma tumor cells enhances Stat3 activity and offers protection against the tyrosine kinase inhibitor canertinib. MEDCHEMCOMM 2016; 8:96-102. [PMID: 30108694 PMCID: PMC6072326 DOI: 10.1039/c6md00463f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 10/04/2016] [Indexed: 01/03/2023]
Abstract
Tumor cell resistance to drug treatment severely limits the therapeutic success of treatment.
Tumor cell resistance to drug treatment severely limits the therapeutic success of treatment. Tumor cells, exposed to chemotherapeutic drugs, have developed intricate strategies to escape the cytotoxic effects and adapt to adverse conditions. The molecular mechanisms causing drug resistance can be based upon modifications of drug transport or metabolism, structural alterations of drug targets or adaptation of cellular signaling. An important component in the transformation of cells and the emergence of drug resistance is the activation of the transcription factor Stat3. The persistent, inappropriate activation of Stat3 causes the expression of target genes which promote tumor cell proliferation, survival, invasion and immune suppression, and it is instrumental in the process of the emergence of resistance to both conventional chemotherapeutic agents and novel targeted compounds. For these reasons, Stat3 inhibition is being pursued as a promising therapeutic strategy. We have investigated the effects of the tyrosine kinase inhibitor canertinib on the glioma cell line Tu-2449. In these cells Stat3 is persistently phosphorylated and activated downstream of the oncogenic driver v-Src and its effector, the cytoplasmic tyrosine kinase Bmx. Canertinib exposure of Tu-2449 cells rapidly caused the inhibition of the Bmx kinase and the deactivation of Stat3. Prolonged exposure of the cells to canertinib caused the death of the large majority of the cells. Only a few cells became resistant to canertinib and survived in tight clusters. These cells have become drug resistant. When the canertinib resistant cells were expanded and cultured at lower cell densities, they regained their sensitivity towards canertinib. We measured the extent of Stat3 activation as a function of cell density and found that higher cell densities are accompanied by increased Stat3 activation and a higher expression of Stat3 target genes. We suggest that Stat3 induction through tight cell–cell interactions, most likely through the engagement of cadherins, can counteract the inhibitory effects exerted by canertinib on Bmx. Cell–cell interactions induced Stat3 and compensated for the suppression of Stat3 by canertinib, thus transiently protecting the cells from the cytotoxic effects of the inhibitor.
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Affiliation(s)
- V von Manstein
- Georg Speyer Haus , Institute for Tumor Biology and Experimental Therapy , Paul Ehrlich Str. 42 , 60596 Frankfurt am Main , Germany . ; Tel: +49 6963395180
| | - B Groner
- Georg Speyer Haus , Institute for Tumor Biology and Experimental Therapy , Paul Ehrlich Str. 42 , 60596 Frankfurt am Main , Germany . ; Tel: +49 6963395180
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The Mycoplasma hyorhinis p37 Protein Rapidly Induces Genes in Fibroblasts Associated with Inflammation and Cancer. PLoS One 2015; 10:e0140753. [PMID: 26512722 PMCID: PMC4626034 DOI: 10.1371/journal.pone.0140753] [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: 06/25/2015] [Accepted: 09/30/2015] [Indexed: 01/25/2023] Open
Abstract
The p37 protein at the surface of Mycoplasma hyorhinis cells forms part of a high-affinity transport system and has been found associated with animal and human cancers. Here we show in NIH3T3 fibroblasts, p37 rapidly induces the expression of genes implicated in inflammation and cancer progression. This gene activation was principally via the Tlr4 receptor. Activity was lost from p37 when the C-terminal 20 amino acids were removed or the four amino acids specific for the hydrogen bonding of thiamine pyrophosphate had been replaced by valine. Blocking the IL6 receptor or inhibiting STAT3 signalling resulted in increased p37-induced gene expression. Since cancer associated fibroblasts support growth, invasion and metastasis via their ability to regulate tumour-related inflammation, the rapid induction in fibroblasts of pro-inflammatory genes by p37 might be expected to influence cancer development.
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García-Hernández V, Flores-Maldonado C, Rincon-Heredia R, Verdejo-Torres O, Bonilla-Delgado J, Meneses-Morales I, Gariglio P, Contreras RG. EGF Regulates Claudin-2 and -4 Expression Through Src and STAT3 in MDCK Cells. J Cell Physiol 2014; 230:105-15. [DOI: 10.1002/jcp.24687] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 05/22/2014] [Indexed: 12/20/2022]
Affiliation(s)
- Vicky García-Hernández
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Catalina Flores-Maldonado
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Ruth Rincon-Heredia
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
- Department of Pharmacology; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Odette Verdejo-Torres
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
| | - José Bonilla-Delgado
- Laboratory of Genetics and Molecular Diagnosis; Research Unit; Hospital Juárez de México; México City México
| | - Ivan Meneses-Morales
- Breast Cancer investigation program; National Autonomous University of México (UNAM); México
- Department of Molecular Biology and Biotechnology; Biomedical Research Institute; National Autonomous University of México (UNAM); México
| | - Patricio Gariglio
- Department of Genetics and Molecular Biology; Center for Research and Advanced Studies (Cinvestav); México City México
| | - Rubén G. Contreras
- Department of Physiology; Biophysics and Neurosciences; Center for Research and Advanced Studies (Cinvestav); México City México
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16
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Stat3 and gap junctions in normal and lung cancer cells. Cancers (Basel) 2014; 6:646-62. [PMID: 24670366 PMCID: PMC4074796 DOI: 10.3390/cancers6020646] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/11/2014] [Accepted: 02/27/2014] [Indexed: 01/04/2023] Open
Abstract
Gap junctions are channels linking the interiors of neighboring cells. A reduction in gap junctional intercellular communication (GJIC) correlates with high cell proliferation, while oncogene products such as Src suppress GJIC, through the Ras/Raf/Erk and other effector pathways. High Src activity was found to correlate with high levels of the Src effector, Signal Transducer and Activator of Transcription-3 (Stat3) in its tyrosine-705 phosphorylated, i.e., transcriptionally activated form, in the majority of Non-Small Cell Lung Cancer lines examined. However, Stat3 inhibition did not restore GJIC in lines with high Src activity. In the contrary, Stat3 inhibition in normal cells or in lines with low Src activity and high GJIC eliminated gap junctional communication. Therefore, despite the fact that Stat3 is growth promoting and in an activated form acts like an oncogene, it is actually required for junctional permeability.
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17
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Geletu M, Guy S, Arulanandam R, Feracci H, Raptis L. Engaged for survival: From cadherin ligation to STAT3 activation. JAKSTAT 2013; 2:e27363. [PMID: 24470979 DOI: 10.4161/jkst.27363] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/26/2013] [Accepted: 11/27/2013] [Indexed: 12/15/2022] Open
Abstract
In normal tissues or tumors, cells have extensive opportunities for adhesion to their neighbors. This state is mimicked by dense cell cultures. In this review, we integrate some recent findings on a key signal transducer, STAT3 (signal transducer and activator of transcription-3), whose activity is dramatically increased following cadherin-mediated cell to cell adhesion. Cadherin engagement, favored in dense cell cultures, causes a dramatic increase in total Rac/Cdc42 protein levels through inhibition of proteasomal degradation, which is followed by activation of IL-6 and STAT3. The cadherin/Rac/IL-6/STAT3 axis offers a potent survival signal that is a prerequisite for neoplastic transformation, as well as normal tissue function.
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Affiliation(s)
- Mulu Geletu
- Department of Pathology; Queen's University; Kingston, ON Canada
| | - Stephanie Guy
- Department of Pathology; Queen's University; Kingston, ON Canada
| | | | - Hélène Feracci
- Université Bordeaux 1; Centre de Recherche Paul Pascal; CNRS UPR 8641; Pessac, France
| | - Leda Raptis
- Department of Pathology; Queen's University; Kingston, ON Canada ; Department of Biomedical and Molecular Sciences; Queen's University; Kingston, ON Canada
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18
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Geletu M, Arulanandam R, Chevalier S, Saez B, Larue L, Feracci H, Raptis L. Classical cadherins control survival through the gp130/Stat3 axis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1947-59. [DOI: 10.1016/j.bbamcr.2013.03.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 03/14/2013] [Accepted: 03/18/2013] [Indexed: 01/02/2023]
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Dipaolo BC, Davidovich N, Kazanietz MG, Margulies SS. Rac1 pathway mediates stretch response in pulmonary alveolar epithelial cells. Am J Physiol Lung Cell Mol Physiol 2013; 305:L141-53. [PMID: 23686855 DOI: 10.1152/ajplung.00298.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Alveolar epithelial cells (AECs) maintain the pulmonary blood-gas barrier integrity with gasketlike intercellular tight junctions (TJ) that are anchored internally to the actin cytoskeleton. We have previously shown that AEC monolayers stretched cyclically and equibiaxially undergo rapid magnitude- and frequency-dependent actin cytoskeletal remodeling to form perijunctional actin rings (PJARs). In this work, we show that even 10 min of stretch induced increases in the phosphorylation of Akt and LIM kinase (LIMK) and decreases in cofilin phosphorylation, suggesting that the Rac1/Akt pathway is involved in these stretch-mediated changes. We confirmed that Rac1 inhibitors wortmannin or EHT-1864 decrease stretch-stimulated Akt and LIMK phosphorylation and that Rac1 agonists PIP3 or PDGF increase phosphorylation of these proteins in unstretched cells. We also confirmed that Rac1 pathway inhibition during stretch modulated stretch-induced changes in occludin content and monolayer permeability, actin remodeling and PJAR formation, and cell death. As further validation, overexpression of Rac GTPase-activating protein β2-chimerin also preserved monolayer barrier properties in stretched monolayers. In summary, our data suggest that constitutive activity of Rac1, which is necessary for stretch-induced activation of the Rac1 downstream proteins, mediates stretch-induced increases in permeability and PJAR formation.
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Affiliation(s)
- Brian C Dipaolo
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
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20
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Geletu M, Arulanandam R, Greer S, Trotman-Grant A, Tomai E, Raptis L. Stat3 is a positive regulator of gap junctional intercellular communication in cultured, human lung carcinoma cells. BMC Cancer 2012; 12:605. [PMID: 23244248 PMCID: PMC3575370 DOI: 10.1186/1471-2407-12-605] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 12/13/2012] [Indexed: 01/05/2023] Open
Abstract
Background Neoplastic transformation of cultured cells by a number of oncogenes such as src suppresses gap junctional, intercellular communication (GJIC); however, the role of Src and its effector Signal transducer and activator of transcription-3 (Stat3) upon GJIC in non small cell lung cancer (NSCLC) has not been defined. Immunohistochemical analysis revealed high Src activity in NSCLC biopsy samples compared to normal tissues. Here we explored the potential effect of Src and Stat3 upon GJIC, by assessing the levels of tyr418-phosphorylated Src and tyr705-phosphorylated Stat3, respectively, in a panel of NSCLC cell lines. Methods Gap junctional communication was examined by electroporating the fluorescent dye Lucifer yellow into cells grown on a transparent electrode, followed by observation of the migration of the dye to the adjacent, non-electroporated cells under fluorescence illumination. Results An inverse relationship between Src activity levels and GJIC was noted; in five lines with high Src activity GJIC was absent, while two lines with extensive GJIC (QU-DB and SK-LuCi6) had low Src levels, similar to a non-transformed, immortalised lung epithelial cell line. Interestingly, examination of the mechanism indicated that Stat3 inhibition in any of the NSCLC lines expressing high endogenous Src activity levels, or in cells where Src was exogenously transduced, did not restore GJIC. On the contrary, Stat3 downregulation in immortalised lung epithelial cells or in the NSCLC lines displaying extensive GJIC actually suppressed junctional permeability. Conclusions Our findings demonstrate that although Stat3 is generally growth promoting and in an activated form it can act as an oncogene, it is actually required for gap junctional communication both in nontransformed lung epithelial cells and in certain lung cancer lines that retain extensive GJIC.
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Affiliation(s)
- Mulu Geletu
- Department of Microbiology, Queen's University, Kingston, Ontario, K7L3N6, Canada
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Sokalska A, Cress A, Bruner-Tran KL, Osteen KG, Taylor HS, Ortega I, Duleba AJ. Simvastatin decreases invasiveness of human endometrial stromal cells. Biol Reprod 2012; 87:2, 1-6. [PMID: 22492974 DOI: 10.1095/biolreprod.111.098806] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Recently we reported that statins, the competitive inhibitors of the key enzyme regulating the mevalonate pathway, 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), decrease proliferation of human endometrial stromal (HES) cells. Furthermore, we found that simvastatin treatment reduces the number and the size of endometrial implants in a nude mouse model of endometriosis. The present study was undertaken to investigate the effect of simvastatin on HES cell invasiveness and on expression of selected genes relevant to invasiveness: matrix metalloproteinase 2 (MMP2), MMP3, tissue inhibitor of matrix metalloproteinase 2 (TIMP2), and CD44. Because statin-induced inhibition of HMGCR reduces the production of substrates for isoprenylation-geranylgeranyl pyrophosphate (GGPP) and farnesyl pyrophosphate (FPP)-the effects of GGPP and FPP were also evaluated. Simvastatin induced a concentration-dependent reduction of invasiveness of HES cells. This effect of simvastatin was abrogated by GGPP but not by FPP. Simvastatin also reduced the mRNA levels of MMP2, MMP3, and CD44, but increased TIMP2 mRNA; all these effects of simvastatin were partly or entirely reversed in the presence of GGPP. The present findings provide a novel mechanism of action of simvastatin on endometrial stroma that may explain reduction of endometriosis in animal models of this disease. Furthermore, the presently described effects of simvastatin are likely mediated, at least in part, by inhibition of geranylgeranylation.
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Affiliation(s)
- Anna Sokalska
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of California Davis, Sacramento, California 95817, USA
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22
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Michaud-Levesque J, Bousquet-Gagnon N, Béliveau R. Quercetin abrogates IL-6/STAT3 signaling and inhibits glioblastoma cell line growth and migration. Exp Cell Res 2012; 318:925-35. [PMID: 22394507 DOI: 10.1016/j.yexcr.2012.02.017] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 02/13/2012] [Accepted: 02/20/2012] [Indexed: 01/05/2023]
Abstract
Evidence has suggested that STAT3 functions as an oncogene in gliomagenesis. As a consequence, changes in the inflammatory microenvironment are thought to promote tumor development. Regardless of its origin, cancer-related inflammation has many tumor-promoting effects, such as the promotion of cell cycle progression, cell proliferation, cell migration and cell survival. Given that IL-6, a major cancer-related inflammatory cytokine, regulates STAT3 activation and is upregulated in glioblastoma, we sought to investigate the inhibitory effects of the chemopreventive flavonoid quercetin on glioblastoma cell proliferation and migration triggered by IL-6, and to determine the underlying mechanisms of action. In this study, we show that quercetin is a potent inhibitor of the IL-6-induced STAT3 signaling pathway in T98G and U87 glioblastoma cells. Exposure to quercetin resulted in the reduction of GP130, JAK1 and STAT3 activation by IL-6, as well as a marked decrease of the proliferative and migratory properties of glioblastoma cells induced by IL-6. Interestingly, quercetin also modulated the expression of two target genes regulated by STAT3, i.e. cyclin D1 and matrix metalloproteinase-2 (MMP-2). Moreover, quercetin reduced the recruitment of STAT3 at the cyclin D1 promoter and inhibited Rb phosphorylation in the presence of IL-6. Overall, these results provide new insight into the role of quercetin as a blocker of the STAT3 activation pathway stimulated by IL-6, with a potential role in the prevention and treatment of glioblastoma.
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Affiliation(s)
- Jonathan Michaud-Levesque
- Laboratoire de Médecine Moléculaire, Université du Québec à Montréal, Centre-ville, Montréal, Québec, Canada
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Feracci H, Gutierrez BS, Hempel W, Gil IS. Organic Nanoparticles. NANOBIOTECHNOLOGY - INORGANIC NANOPARTICLES VS ORGANIC NANOPARTICLES 2012. [DOI: 10.1016/b978-0-12-415769-9.00008-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Raptis L, Arulanandam R, Geletu M, Turkson J. The R(h)oads to Stat3: Stat3 activation by the Rho GTPases. Exp Cell Res 2011; 317:1787-95. [PMID: 21619876 DOI: 10.1016/j.yexcr.2011.05.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 05/09/2011] [Accepted: 05/10/2011] [Indexed: 02/09/2023]
Abstract
The signal transducer and activator of transcription-3 (Stat3) is a member of the STAT family of cytoplasmic transcription factors. Overactivation of Stat3 is detected with high frequency in human cancer and is considered a molecular abnormality that supports the tumor phenotype. Despite concerted investigative efforts, the molecular mechanisms leading to the aberrant Stat3 activation and Stat3-mediated transformation and tumorigenesis are still not clearly defined. Recent evidence reveals a crosstalk close relationship between Stat3 signaling and members of the Rho family of small GTPases, including Rac1, Cdc42 and RhoA. Specifically, Rac1, acting in a complex with the MgcRacGAP (male germ cell RacGAP), promotes tyrosine phosphorylation of Stat3 by the IL6-receptor family/Jak kinase complex, as well as its translocation to the nucleus. Studies have further revealed that the mutational activation of Rac1 and Cdc42 results in Stat3 activation, which occurs in part through the upregulation of IL6 family cytokines that in turn stimulates Stat3 through the Jak kinases. Interestingly, evidence also shows that the engagement of cadherins, cell to cell adhesion molecules, specifically induces a striking increase in Rac1 and Cdc42 protein levels and activity, which in turn results in Stat3 activation. In this review we integrate recent findings clarifying the role of the Rho family GTPases in Stat3 activation in the context of malignant progression.
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Affiliation(s)
- Leda Raptis
- Department of Microbiology and Immunology and Pathology, Queen's University, Kingston, Ontario, Canada.
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Abstract
The lack of effective conventional therapies for the treatment of advanced stage melanoma has stimulated interest in the development of novel strategies for the management of patients with malignant melanoma. Among them, immunotherapy has attracted much attention because of the potential role played by immunological events in the clinical course of melanoma. For many years, T cell-based immunotherapy has been emphasized in part because of the disappointing results of the monoclonal antibody (mAb)-based clinical trials conducted in the early 1980s and in part because of the postulated major role played by T cells in tumor growth control. More recently, mAb-based therapies have gained in popularity given their clinical and commercial success for a variety of malignant diseases. As a result, there has been increased interest in identifying and characterizing antibody-defined melanoma antigens. Among them, the chondroitin sulfate proteoglycan 4 (CSPG4), also known as high molecular weight-melanoma associated antigen (HMW-MAA) or melanoma chondroitin sulfate proteoglycan (MCSP), has attracted much attention in recent years because of the growing experimental evidence that it fulfills two requirements for immunotherapy to be therapeutically effective: (1) targeting of cancer stem cells (CSC) and (2) development of combinatorial therapies to counteract the escape mechanisms driven by the genetic instability of tumor cells. With this in mind, in this chapter, we have reviewed recent information related to the distribution of CSPG4 on various types of tumors, including CSC, its expression on pericytes in the tumor microenvironment, its recognition by T cells, its role in cell biology as well as the potential mechanisms underlying the ability of CSPG4-specific immunity to control malignant cell growth.
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Sokalska A, Wong DH, Cress A, Piotrowski PC, Rzepczynska I, Villanueva J, Duleba AJ. Simvastatin induces apoptosis and alters cytoskeleton in endometrial stromal cells. J Clin Endocrinol Metab 2010; 95:3453-9. [PMID: 20427495 PMCID: PMC2928904 DOI: 10.1210/jc.2010-0072] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Statins are competitive inhibitors of 3-hydroxy-3methylglutaryl-coenzyme A reductase, with antimitotic, antioxidant, antiinflammatory, and immunomodulatory properties. Recent studies have shown that statins reduce the growth of human endometrial stromal (HES) cells and protect from the development of endometriosis in animal models. OBJECTIVES The present study was conducted to evaluate the effects of simvastatin on apoptosis and cytoskeleton of HES cells. DESIGN AND SETTING In vitro experiments were performed in the university research laboratory. PATIENTS HES cells were obtained from endometrial biopsies collected from nine subjects in the proliferative phase of their menstrual cycle. MAIN OUTCOME MEASURES The effect of simvastatin (10 and 30 mum) and/or geranylgeranyl pyrophosphate (GGPP, 30 mum) on caspase 3 and 7 activity, DNA fragmentation, and HES cell morphology was evaluated. RESULTS Simvastatin induced significant time- and concentration-dependent apoptotic effects on HES cells as determined by increased activity of executioner caspases and DNA fragmentation. Simvastatin also caused profound alterations in HES cell morphology and F-actin cytoskeleton. This effect was abrogated by geranylgeranyl pyrophosphate, an important product of the mevalonate pathway. CONCLUSIONS Simvastatin induces apoptosis and disruption of the cytoskeleton of HES cells by reducing isoprenylation in cultures of human endometrial stroma. The present findings may lead to the development of novel treatments for endometriosis involving statins.
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Affiliation(s)
- Anna Sokalska
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of California Davis, Sacramento, CA 95817, USA
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Greer S, Honeywell R, Geletu M, Arulanandam R, Raptis L. Housekeeping genes; expression levels may change with density of cultured cells. J Immunol Methods 2010; 355:76-9. [PMID: 20171969 DOI: 10.1016/j.jim.2010.02.006] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 02/05/2010] [Accepted: 02/10/2010] [Indexed: 10/19/2022]
Abstract
Western blotting is a powerful technique to characterize a multitude of cellular proteins. As an internal control, the blots are commonly probed for "housekeeping" gene products. In this communication, we show that cell confluence significantly affects the levels of two such widely used proteins, alpha-tubulin and Glyceraldehyde-3-Phosphate Dehydrogenase. On the other hand the levels of heat-shock protein-90 and beta-actin remained unchanged at a wide range of cell densities, making these proteins into more reliable loading controls.
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Affiliation(s)
- Samantha Greer
- Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada K7L 3N6
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Arulanandam R, Geletu M, Feracci H, Raptis L. Activated Rac1 requires gp130 for Stat3 activation, cell proliferation and migration. Exp Cell Res 2009; 316:875-86. [PMID: 19852956 DOI: 10.1016/j.yexcr.2009.10.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 10/15/2009] [Accepted: 10/16/2009] [Indexed: 10/20/2022]
Abstract
Rac1 (Rac) is a member of the Rho family of small GTPases which controls cell migration by regulating the organization of actin filaments. Previous results suggested that mutationally activated forms of the Rho GTPases can activate the Signal Transducer and Activator of Transcription-3 (Stat3), but the exact mechanism is a matter of controversy. We recently demonstrated that Stat3 activity of cultured cells increases dramatically following E-cadherin engagement. To better understand this pathway, we now compared Stat3 activity levels in mouse HC11 cells before and after expression of the mutationally activated Rac1 (Rac(V12)), at different cell densities. The results revealed for the first time a dramatic increase in protein levels and activity of both the endogenous Rac and Rac(V12) with cell density, which was due to inhibition of proteasomal degradation. In addition, Rac(V12)-expressing cells had higher Stat3, tyrosine-705 phosphorylation and activity levels at all densities, indicating that Rac(V12) is able to activate Stat3. Further examination of the mechanism of Stat3 activation showed that Rac(V12) expression caused a surge in mRNA of Interleukin-6 (IL6) family cytokines, known potent Stat3 activators. Knockdown of gp130, the common subunit of this family reduced Stat3 activity, indicating that these cytokines may be responsible for the Stat3 activation by Rac(V12). The upregulation of IL6 family cytokines was required for cell migration and proliferation induced by Rac(V12), as shown by gp130 knockdown experiments, thus demonstrating that the gp130/Stat3 axis represents an essential effector of activated Rac for the regulation of key cellular functions.
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Affiliation(s)
- Rozanne Arulanandam
- Departments of Microbiology and Immunology and Pathology and Molecular Medicine, and Queen's University Cancer Institute, Queen's University, Botterell Hall, Rm. 713, Kingston, Ontario, Canada K7L3N6
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