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Boscaro C, Schimdt G, Cignarella A, Dal Maso L, Bolego C, Trevisi L. The antiangiogenic effect of digitoxin is dependent on a ROS-elicited RhoA/ROCK pathway activation. Biochem Pharmacol 2024; 222:116049. [PMID: 38342347 DOI: 10.1016/j.bcp.2024.116049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/16/2024] [Accepted: 02/06/2024] [Indexed: 02/13/2024]
Abstract
We previously showed that digitoxin inhibits angiogenesis and cancer cell proliferation and migration and these effects were associated to protein tyrosine kinase 2 (FAK) inhibition. Considering the interactions between FAK and Rho GTPases regulating cell cytoskeleton and movement, we investigated the involvement of RhoA and Rac1 in the antiangiogenic effect of digitoxin. Phalloidin staining of human umbilical vein endothelial cells (HUVECs) showed the formation of stress fibers in cells treated with 10 nM digitoxin. By Rhotekin- and Pak1- pull down assays, detecting the GTP-bound form of GTPases, we observed that digitoxin (10-25 nM) induced sustained (0.5-6 h) RhoA activation with no effect on Rac1. Furthermore, inhibition of HUVEC migration and capillary-like tube formation by digitoxin was counteracted by hindering RhoA-ROCK axis with RhoA silencing or Y-27632 treatment. Digitoxin did not decrease p190RhoGAP phosphorylation at Tyr1105 (a site targeted by FAK), suggesting that RhoA activation was independent from FAK inhibition. Because increasing evidence points to a redox regulation of RhoA, we measured intracellular ROS and found that digitoxin treatment enhanced ROS levels in a concentration-dependent manner (1-25 nM). Notably, the flavoprotein inhibitor DPI or the pan-NADPH oxidase (NOX) inhibitor VAS-2870 antagonized both ROS increase and RhoA activation by digitoxin. Our results provide evidence that inhibition of HUVEC migration and tube formation by digitoxin is dependent on ROS production by endothelial NOX, which leads to the activation of RhoA/ROCK pathway. Digitoxin effects on proteins regulating cytoskeletal organization and cell motility could have a wider impact on cancer progression, beyond the antiangiogenic activity.
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Affiliation(s)
| | - Gudula Schimdt
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Lucia Dal Maso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Chiara Bolego
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Lucia Trevisi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy.
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Ozugergin I, Mastronardi K, Law C, Piekny A. Diverse mechanisms regulate contractile ring assembly for cytokinesis in the two-cell Caenorhabditis elegans embryo. J Cell Sci 2022; 135:jcs258921. [PMID: 35022791 PMCID: PMC10660071 DOI: 10.1242/jcs.258921] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 12/29/2021] [Indexed: 11/20/2022] Open
Abstract
Cytokinesis occurs at the end of mitosis as a result of the ingression of a contractile ring that cleaves the daughter cells. The core machinery regulating this crucial process is conserved among metazoans. Multiple pathways control ring assembly, but their contribution in different cell types is not known. We found that in the Caenorhabditis elegans embryo, AB and P1 cells fated to be somatic tissue and germline, respectively, have different cytokinesis kinetics supported by distinct myosin levels and organization. Through perturbation of RhoA or polarity regulators and the generation of tetraploid strains, we found that ring assembly is controlled by multiple fate-dependent factors that include myosin levels, and mechanisms that respond to cell size. Active Ran coordinates ring position with the segregating chromatids in HeLa cells by forming an inverse gradient with importins that control the cortical recruitment of anillin. We found that the Ran pathway regulates anillin in AB cells but functions differently in P1 cells. We propose that ring assembly delays in P1 cells caused by low myosin and Ran signaling coordinate the timing of ring closure with their somatic neighbors. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Imge Ozugergin
- Department of Biology, Concordia University, Montreal, H4B 1R6, Canada
| | | | - Chris Law
- Department of Biology, Concordia University, Montreal, H4B 1R6, Canada
| | - Alisa Piekny
- Department of Biology, Concordia University, Montreal, H4B 1R6, Canada
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Pillet LE, Cresto N, Saillour Y, Ghézali G, Bemelmans AP, Livet J, Bienvenu T, Rouach N, Billuart P. The intellectual disability protein Oligophrenin-1 controls astrocyte morphology and migration. Glia 2020; 68:1729-1742. [PMID: 32073702 DOI: 10.1002/glia.23801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 02/06/2023]
Abstract
Astrocytes are involved in several aspects of neuronal development and properties which are altered in intellectual disability (ID). Oligophrenin-1 is a RhoGAP protein implicated in actin cytoskeleton regulation, and whose mutations are associated with X-linked ID. Oligophrenin-1 is expressed in neurons, where its functions have been widely reported at the synapse, as well as in glial cells. However, its roles in astrocytes are still largely unexplored. Using in vitro and in vivo models of oligophrenin1 disruption in astrocytes, we found that oligophrenin1 regulates at the molecular level the RhoA/ROCK/MLC2 pathway in astroglial cells. We also showed at the cellular level that oligophrenin1 modulates astrocyte morphology and migration both in vitro and in vivo, and is involved in glial scar formation. Altogether, these data suggest that oligophrenin1 deficiency alters not only neuronal but also astrocytic functions, which might contribute to the development of ID.
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Affiliation(s)
- Laure-Elise Pillet
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.,Doctoral School N°562, Paris Descartes University, Paris, France.,Institut Cochin, INSERM UMR 1016, CNRS UMR 8104, Université de Paris, Paris, France
| | - Noémie Cresto
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
| | - Yoann Saillour
- Institut Cochin, INSERM UMR 1016, CNRS UMR 8104, Université de Paris, Paris, France
| | - Grégory Ghézali
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
| | - Alexis-Pierre Bemelmans
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Département de la Recherche Fondamentale, Institut de biologie François Jacob, MIRCen, and CNRS UMR 9199, Université Paris-Sud, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | - Jean Livet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Thierry Bienvenu
- Institut Cochin, INSERM UMR 1016, CNRS UMR 8104, Université de Paris, Paris, France
| | - Nathalie Rouach
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
| | - Pierre Billuart
- Institut Cochin, INSERM UMR 1016, CNRS UMR 8104, Université de Paris, Paris, France
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Park KR, Kim EC, Hong JT, Yun HM. Dysregulation of 5-hydroxytryptamine 6 receptor accelerates maturation of bone-resorbing osteoclasts and induces bone loss. Theranostics 2018; 8:3087-3098. [PMID: 29896304 PMCID: PMC5996355 DOI: 10.7150/thno.24426] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/13/2018] [Indexed: 12/13/2022] Open
Abstract
Rationale: Characterizing the regulation of bone-resorbing osteoclasts is central to the understanding of the pathogenesis and treatment of bone diseases, such as osteoporosis and periodontitis. 5-hydroxytryptamine (5-HT) has drawn considerable attention for its role in bone; however, it remains unknown whether the intracellular signaling of 5-HT receptors (5-HTRs) is linked to any of the regulatory mechanisms in osteoclasts. Herein, we report 5-HT6R to be a key regulatory receptor for osteoclastogenesis. Methods: In order to explore the critical role of 5-HT6R in bone-resorbing osteoclasts, in vitro experiments were performed using mouse whole bone marrow cells isolated from femora and tibiae and In vivo animal experiments were performed using 5-HT6R-deficient (5-HT6RKO-/-) mice, bone resorption mice model, and osteoporosis mice model. Results: Compared to other 5HTRs, activation of 5-HT6R relatively increased TRAP (tartrate-resistant acid phosphatase) activity during osteoclastogenesis. 5-HT6RKO(-/-) mice and 5-HT6RKO(-/-) osteoclast lineages presented with an abnormal phenotype and impaired osteoclastogenesis and impaired osteoclastogenesis. Activation of 5-HT6R increased the number of TRAP-positive multinuclear osteoclasts, actin ring formation, and expression of early osteoclast markers with osteoclast lineage commitment. Intracellular 5-HT6R signaling was found to be linked to RhoA GTPase activation and was involved in the maturation of osteoclasts. This signaling pathway also showed enhanced bone destruction after lipopolysaccharide (LPS) administration in mice. Furthermore, inhibition of 5-HT6R-mediated RhoA GTPase signaling protected against ovariectomy(OVX)-induced bone loss in mice. Conclusion: Taken together, our findings place the 5-HT6R system in a new context of osteoclast lineages in both an in vitro and in vivo system, and also it may offer a novel molecular target for the treatment of bone diseases.
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Aguilar-Rojas A, Maya-Núñez G, Huerta-Reyes M, Pérez-Solis MA, Silva-García R, Guillén N, Olivo-Marin JC. Activation of human gonadotropin-releasing hormone receptor promotes down regulation of ARHGAP18 and regulates the cell invasion of MDA-MB-231 cells. Mol Cell Endocrinol 2018; 460:94-103. [PMID: 28709956 DOI: 10.1016/j.mce.2017.07.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/29/2017] [Accepted: 07/10/2017] [Indexed: 02/08/2023]
Abstract
The Gonadotropin-Releasing Hormone Receptor (GnRHR) is expressed mainly in the gonadotrope membrane of the adenohypophysis and its natural ligand, the Gonadotropin-Releasing Hormone (GnRH), is produced in anterior hypothalamus. Furthermore, both molecules are also present in the membrane of cells derived from other reproductive tissues such as the breast, endometrium, ovary, and prostate, as well as in tumors derived from these tissues. The functions of GnRH receptor and its hormone in malignant cells have been related with the decrease of proliferation and the invasiveness of those tumors however, little is known about the molecules associated with the signaling pathways regulated by both molecules in malignant cells. To further analyze the potential mechanisms employed by the GnRHR/GnRH system to reduce the tumorigenesis of the highly invasive breast cancer cell line MDA-MB-231, we performed microarrays experiments to evaluated changes in genes expression and validate these modifications by functional assays. We show that activation of human GnRHR is able to diminish the expression and therefore functions of the Rho GTPase-Activating Protein 18 (ARHGAP18). Decrease of this GAP following GnRHR activation, correlates to the higher of cell adhesion and also with reduction of tumor cell invasion, supporting the notion that GnRHR triggers intracellular signaling pathways that acts through ARHGAP18. On the contrary, although a decline of cellular proliferation was observed during GnRHR activation in MDA-MB-231, this was independent of ARHGAP18 showing the complex system in which is involved the signaling pathways regulated by the GnRHR/GnRH system.
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Affiliation(s)
- Arturo Aguilar-Rojas
- Instituto Mexicano del Seguro Social (IMSS), Unidad de Investigación Médica en Medicina Reproductiva, UMAE No. 4, Ciudad de México, Mexico; Institut Pasteur, Unité d'Analyse d'Images Biologiques, 25 Rue du Dr Roux, F-75015 Paris, France; Centre National de la Recherche Scientifique, CNRS UMR3691, 25 Rue du Dr Roux, F-75015 Paris, France.
| | - Guadalupe Maya-Núñez
- Instituto Mexicano del Seguro Social (IMSS), Unidad de Investigación Médica en Medicina Reproductiva, UMAE No. 4, Ciudad de México, Mexico
| | - Maira Huerta-Reyes
- IMSS, Unidad de Investigación Médica en Farmacología, Hospital de Especialidades, Centro Médico Nacional Siglo XXI (CMN-SXXI), Ciudad de México, Mexico
| | - Marco Allán Pérez-Solis
- Instituto Mexicano del Seguro Social (IMSS), Unidad de Investigación Médica en Medicina Reproductiva, UMAE No. 4, Ciudad de México, Mexico
| | - Raúl Silva-García
- IMSS, Unidad de Investigación Médica en Inmunología, Hospital de Pediatría, CMN-SXXI, Ciudad de México, Mexico
| | - Nancy Guillén
- Centre National de la Recherche Scientifique, CNRS-ERL9195, 25 Rue du Dr Roux, F-75015 Paris, France
| | - Jean-Christophe Olivo-Marin
- Institut Pasteur, Unité d'Analyse d'Images Biologiques, 25 Rue du Dr Roux, F-75015 Paris, France; Centre National de la Recherche Scientifique, CNRS UMR3691, 25 Rue du Dr Roux, F-75015 Paris, France
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Evans W, Filippova M, Filippov V, Bashkirova S, Zhang G, Reeves ME, Duerksen-Hughes P. Overexpression of HPV16 E6* Alters β-Integrin and Mitochondrial Dysfunction Pathways in Cervical Cancer Cells. Cancer Genomics Proteomics 2016; 13:259-273. [PMID: 27365376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/31/2016] [Indexed: 06/06/2023] Open
Abstract
BACKGROUND High-risk human papillomaviruses (HPV) cause nearly all cases of cervical cancer, as well as many types of oral and anogenital cancer. Alternative splicing increases the capacity of the HPV genome to encode the proteins necessary for successful completion of its infectious life cycle. However, the roles of these splice variants, including E6*, the smaller splice isoform of the E6 oncogene, in carcinogenesis are not clear. MATERIALS AND METHODS SiHa (HPV16(+)) and C33A (HPV(-)) cells were transfected with the E6* plasmid, and tandem mass tag-labeled protein levels were quantified by mass spectrometry. Proteomic analyses identified pathways affected by E6* in both HPV(+) and HPV(-) cells, and pathways were validated using in vitro methods. RESULTS A total of 4,300 proteins were identified and quantified in lysates of SiHa and C33A cells with and without HPV16 E6* expression. SiHa and C33A cells expressing E6* underwent changes in protein expression affecting integrin signaling and mitochondrial dysfunction pathways, respectively. Subsequent experiments were performed to validate selected E6*-mediated alterations in protein levels. CONCLUSION E6* modifies the expression of proteins involved in mitochondrial dysfunction and oxidative phosphorylation in C33A cells, and β-integrin signaling in SiHa cells.
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Affiliation(s)
- Whitney Evans
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A
| | - Maria Filippova
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A
| | - Valery Filippov
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A
| | - Svetlana Bashkirova
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A
| | - Guangyu Zhang
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A
| | - Mark E Reeves
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Department of Surgery, Loma Linda University School of Medicine, and Surgical Oncology Research Laboratory, Loma Linda VA Medical Center, Loma Linda, CA, U.S.A
| | - Penelope Duerksen-Hughes
- Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A.
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Rozés Salvador V, Heredia F, Berardo A, Palandri A, Wojnacki J, Vivinetto AL, Sheikh KA, Caceres A, Lopez PHH. Anti-glycan antibodies halt axon regeneration in a model of Guillain Barrè Syndrome axonal neuropathy by inducing microtubule disorganization via RhoA-ROCK-dependent inactivation of CRMP-2. Exp Neurol 2016; 278:42-53. [PMID: 26804001 DOI: 10.1016/j.expneurol.2016.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
Abstract
Several reports have linked the presence of high titers of anti-Gg Abs with delayed recovery/poor prognosis in GBS. In most cases, failure to recover is associated with halted/deficient axon regeneration. Previous work identified that monoclonal and patient-derived anti-Gg Abs can act as inhibitory factors in an animal model of axon regeneration. Further studies using primary dorsal root ganglion neuron (DRGn) cultures demonstrated that anti-Gg Abs can inhibit neurite outgrowth by targeting gangliosides via activation of the small GTPase RhoA and its associated kinase (ROCK), a signaling pathway common to other established inhibitors of axon regeneration. We aimed to study the molecular basis of the inhibitory effect of anti-Gg abs on neurite outgrowth by dissecting the molecular dynamics of growth cones (GC) cytoskeleton in relation to the spatial-temporal analysis of RhoA activity. We now report that axon growth inhibition in DRGn induced by a well characterized mAb targeting gangliosides GD1a/GT1b involves: i) an early RhoA/ROCK-independent collapse of lamellipodia; ii) a RhoA/ROCK-dependent shrinking of filopodia; and iii) alteration of GC microtubule organization/and presumably dynamics via RhoA/ROCK-dependent phosphorylation of CRMP-2 at threonine 555. Our results also show that mAb 1B7 inhibits peripheral axon regeneration in an animal model via phosphorylation/inactivation of CRMP-2 at threonine 555. Overall, our data may help to explain the molecular mechanisms underlying impaired nerve repair in GBS. Future work should define RhoA-independent pathway/s and effectors regulating actin cytoskeleton, thus providing an opportunity for the design of a successful therapy to guarantee an efficient target reinnervation.
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Affiliation(s)
- Victoria Rozés Salvador
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Florencia Heredia
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Andrés Berardo
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Anabela Palandri
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Jose Wojnacki
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Ana L Vivinetto
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Kazim A Sheikh
- Department of Neurology, University of Texas Medical School at Houston, Houston, USA
| | - Alfredo Caceres
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Pablo H H Lopez
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina; Facultad de Psicología, Universidad Nacional de Córdoba, Argentina.
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Gao J, Huang T, Zhou LJ, Ge YL, Lin SY, Dai Y. Preconditioning effects of physiological cyclic stretch on pathologically mechanical stretch-induced alveolar epithelial cell apoptosis and barrier dysfunction. Biochem Biophys Res Commun 2014; 448:342-8. [PMID: 24699412 DOI: 10.1016/j.bbrc.2014.03.063] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 03/15/2014] [Indexed: 11/22/2022]
Abstract
BACKGROUND We aim to investigate the effects of preconditioning of physiological cyclic stretch on the alveolar epithelial cell apoptosis induced by pathologically mechanical stretch and barrier dysfunction and how these effects are linked to differential expression of small GTPases Rac and Rho mRNA. METHODS Pulmonary alveolar epithelial cells were subjected to different treatments of cyclic stretch (CS) at 5% and 20% elongation, respectively. Cells maintained in normal cell culture were used as negative control. On the other hand, cell apoptosis and Rac/Rho activities in cells with or without preconditioning of physiologically relevant magnitudes of CS (5% CS) with different durations (0, 15, 30, 60 and 120 min) in prior to 6-h treatment with pathological CS stimulation (20% CS) were compared and measured. RESULTS Pathological CS could cause a significant increase in apoptosis rate, which is considered to be associated with the repression of Rac mRNA and activation of Rho mRNA. In contrast, physiological 5%-CS preconditioning suppressed cell apoptosis and induced nearly complete monolayer recovery with fewer actin stress fibers and paracellular gap formation. Consistent with differential effects on cell apoptosis and epithelial cell integrity, physiological CS preconditioning enhanced expression of Rac mRNA but inhibited Rho activation. CONCLUSIONS Physiological CS preconditioning has an inhibitory effect on cell apoptosis while exerts a stimulatory impact on epithelial cell recovery via regulation of Rac and Rho activities.
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Zhang A, Wang Q, Han Z, Hu W, Xi L, Gao Q, Wang S, Zhou J, Xu G, Meng L, Chen G, Ma D. Reduced expression of Snail decreases breast cancer cell motility by downregulating the expression and inhibiting the activity of RhoA GTPase. Oncol Lett 2013; 6:339-346. [PMID: 24137327 PMCID: PMC3788855 DOI: 10.3892/ol.2013.1385] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 01/30/2013] [Indexed: 11/05/2022] Open
Abstract
Several lines of evidence support an important role for Snail, a transcriptional factor, in breast cancer. Overexpression of Snail has been associated with breast cancer metastasis, although the specific role of Snail in the process remains unclear. To address this issue, the expression levels of Snail, RhoA and fibronectin, as well as MMP-2, were reduced in the breast tumor cell lines MDA-MB-231 and MDA-MB-435S, and their biological responses were studied in vitro and in vivo. For the first time, it was observed that downregulated Snail expression is correlated with a significant inhibition of the expression and activity of RhoA GTPase, as well as MMP-2. The present data provide evidence that Snail promotes tumor cell motility and angiogenesis which is mainly mediated through the regulation of RhoA activity. In conclusion, the present findings demonstrate a key regulatory role for Snail in breast tumor growth and progression.
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Affiliation(s)
- Ali Zhang
- Cancer Biology Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030; ; Radiotherapy and Chemotherapy Department, Zhongnan Hospital, Wuhan University, Wuhan, Hubei 430000
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Abstract
ARHI is an imprinted tumor suppressor gene that is downregulated in > 60% of ovarian cancers, associated with decreased progression-free survival. ARHI encodes a 26 kDa GTPase with homology to Ras. Re-expression of ARHI inhibits ovarian cancer growth, initiates autophagy and induces tumor dormancy. Recent studies have demonstrated that ARHI also plays a particularly important role in ovarian cancer cell migration. Re-expression of ARHI decreases motility of IL-6- and EGF-stimulated SKOv3 and Hey ovarian cancer cells, inhibiting both chemotaxis and haptotaxis. ARHI inhibits cell migration by binding and sequestering STAT3 in the cytoplasm, and preventing STAT3 translocation to the nucleus and localization in focal adhesion complexes. Re-expression of ARHI inhibits FAK (Y397) phosphorylation, disrupts focal adhesions and blocks FAK-mediated RhoA signaling, resulting in decreased levels of GTP-RhoA. Re-expression of ARHI disrupts formation of actin stress fibers in a FAK- and RhoA-dependent manner. Recent studies indicate that re-expression of ARHI inhibits expression of β-1 integrin which may also contribute to inhibition of migration, adhesion and invasion.
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Affiliation(s)
- Zhen Lu
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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