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Vasilaki, Eleftheria
Publications (7 of 7) Show all publications
Sundqvist, A., Morikawa, M., Ren, J., Vasilaki, E., Kawasaki, N., Kobayashi, M., . . . ten Dijke, P. (2018). JUNB governs a feed-forward network of TGF beta signaling that aggravates breast cancer invasion. Nucleic Acids Research, 46(3), 1180-1195
Open this publication in new window or tab >>JUNB governs a feed-forward network of TGF beta signaling that aggravates breast cancer invasion
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2018 (English)In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 46, no 3, p. 1180-1195Article in journal (Refereed) Published
Abstract [en]

It is well established that transforming growth factor-beta (TGF beta) switches its function from being a tumor suppressor to a tumor promoter during the course of tumorigenesis, which involves both cell-intrinsic and environment-mediated mechanisms. We are interested in breast cancer cells, in which SMAD mutations are rare and interactions between SMAD and other transcription factors define pro-oncogenic events. Here, we have performed chromatin immunoprecipitation (ChIP)-sequencing analyses which indicate that the genome-wide landscape of SMAD2/3 binding is altered after prolonged TGF beta stimulation. De novo motif analyses of the SMAD2/3 binding regions predict enrichment of binding motifs for activator protein (AP) 1 in addition to SMAD motifs. TGF beta-induced expression of the AP1 component JUNB was required for expression of many late invasion-mediating genes, creating a feed-forward regulatory network. Moreover, we found that several components in the WNT pathway were enriched among the late TGF beta-target genes, including the invasion-inducing WNT7 proteins. Consistently, overexpression of WNT7A or WNT7B enhanced and potentiated TGF beta-induced breast cancer cell invasion, while inhibition of the WNT pathway reduced this process. Our study thereby helps to explain how accumulation of pro-oncogenic stimuli switches and stabilizes TGF beta-induced cellular phenotypes of epithelial cells.

Place, publisher, year, edition, pages
OXFORD UNIV PRESS, 2018
National Category
Cancer and Oncology
Identifiers
urn:nbn:se:uu:diva-349356 (URN)10.1093/nar/gkx1190 (DOI)000425294400020 ()29186616 (PubMedID)
Funder
Swedish Cancer Society, 09 0773, 10 0452, 2016/445Swedish Research Council, 2015-02757
Available from: 2018-05-02 Created: 2018-05-02 Last updated: 2018-05-02Bibliographically approved
Sundqvist, A., Zieba, A., Vasilaki, E., Herrera Hidalgo, C., Söderberg, O., Koinuma, D., . . . van Dam, H. (2013). Specific interactions between Smad proteins and AP-1 components determine TGFβ-induced breast cancer cell invasion. Oncogene, 32(31), 3606-3615
Open this publication in new window or tab >>Specific interactions between Smad proteins and AP-1 components determine TGFβ-induced breast cancer cell invasion
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2013 (English)In: Oncogene, ISSN 0950-9232, E-ISSN 1476-5594, Vol. 32, no 31, p. 3606-3615Article in journal (Refereed) Published
Abstract [en]

Deregulation of the transforming growth factor β (TGFβ) signal transduction cascade is functionally linked to cancer. In early phases, TGFβ acts as a tumor suppressor by inhibiting tumor cell proliferation, whereas in late phases, it can act as a tumor promoter by stimulating tumor cell invasion and metastasis. Smad transcriptional effectors mediate TGFβ responses, but relatively little is known about the Smad-containing complexes that are important for epithelial-mesenchymal transition and invasion. In this study, we have tested the hypothesis that specific members of the AP-1 transcription factor family determine TGFβ signaling specificity in breast cancer cell invasion. Using a 3D model of collagen-embedded spheroids of MCF10A-MII premalignant human breast cancer cells, we identified the AP-1 transcription factor components c-Jun, JunB, c-Fos and Fra1 as essential factors for TGFβ-induced invasion and found that various mesenchymal and invasion-associated TGFβ-induced genes are co-regulated by these proteins. In situ proximity ligation assays showed that TGFβ signaling not only induces complexes between Smad3 and Smad4 in the nucleus but also complexes between Smad2/3 and Fra1, whereas complexes between Smad3, c-Jun and JunB could already be detected before TGFβ stimulation. Finally, chromatin immunoprecipitations showed that c-Jun, JunB and Fra1, but not c-Fos, are required for TGFβ-induced binding of Smad2/3 to the mmp-10 and pai-1 promoters. Together these results suggest that in particular formation of Smad2/3-Fra1 complexes may reflect activation of the Smad/AP-1-dependent TGFβ-induced invasion program.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-180124 (URN)10.1038/onc.2012.370 (DOI)000322638400005 ()22926518 (PubMedID)
Note

Agata Zieba & Eleftheria Vasilaki contributed equally to this work.

Available from: 2012-08-30 Created: 2012-08-30 Last updated: 2017-12-07Bibliographically approved
Papadimitriou, E., Vasilaki, E., Vorvis, C., Iliopoulos, D., Moustakas, A., Kardassis, D. & Stournaras, C. (2012). Differential regulation of the two RhoA-specific GEF isoforms Net1/Net1A by TGF-β and miR-24: role in epithelial-to-mesenchymal transition. Oncogene, 31(23), 2862-2875
Open this publication in new window or tab >>Differential regulation of the two RhoA-specific GEF isoforms Net1/Net1A by TGF-β and miR-24: role in epithelial-to-mesenchymal transition
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2012 (English)In: Oncogene, ISSN 0950-9232, E-ISSN 1476-5594, Oncogene, ISSN 1476-5594, Vol. 31, no 23, p. 2862-2875Article in journal (Refereed) Published
Abstract [en]

In the present study we analyzed the regulation of the two isoforms of the RhoA-specific guanine nucleotide exchange factor Net1 by transforming growth factor-β (TGF-β) in keratinocytes. We report that short-term TGF-β treatment selectively induced Net1 isoform2 (Net1A) but not Net1 isoform1. This led to upregulation of cytoplasmic Net1A protein levels that were necessary for TGF-β-mediated RhoA activation. Smad signaling and the MAPK/ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway were involved in Net1A upregulation by TGF-β. Interestingly, long-term TGF-β treatment resulted in Net1 mRNA downregulation and Net1A protein degradation by the proteasome. Furthermore, we identified the microRNA miR-24 as a novel post-transcriptional regulator of Net1A expression. Silencing of Net1A resulted in disruption of E-cadherin- and zonula occludens-1 (ZO-1)-mediated junctions, as well as expression of the transcriptional repressor of E-cadherin, Slug and the mesenchymal markers N-cadherin, plasminogen activator inhibitor-1 (PAI-1) and fibronectin, indicating that late TGF-β-induced downregulation of Net1A is involved in epithelial-to-mesenchymal transition (EMT). Finally, miR-24 was found to be implicated in the regulation of the EMT program in response to TGF-β and was shown to be directly involved in the TGF-β-induced breast cancer cell invasiveness through Net1A regulation. Our results emphasize the importance of Net1 isoform2 in the short- and long-term TGF-β-mediated regulation of EMT.

Keyword
TGF-beta, Net1A, RhoA, EMT, miR-24
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-159990 (URN)10.1038/onc.2011.457 (DOI)000305277900006 ()21986943 (PubMedID)
Available from: 2011-10-13 Created: 2011-10-13 Last updated: 2017-12-08Bibliographically approved
Wojciak-Stothard, B., Zhao, L., Oliver, E., Dubois, O., Wu, Y., Kardassis, D., . . . Wilkins, M. R. (2012). Role of RhoB in the Regulation of Pulmonary Endothelial and Smooth Muscle Cell Responses to Hypoxia. Circulation Research, 110(11), 1423-1434
Open this publication in new window or tab >>Role of RhoB in the Regulation of Pulmonary Endothelial and Smooth Muscle Cell Responses to Hypoxia
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2012 (English)In: Circulation Research, ISSN 0009-7330, E-ISSN 1524-4571, Vol. 110, no 11, p. 1423-1434Article in journal (Refereed) Published
Abstract [en]

Rationale: RhoA and Rho kinase contribute to pulmonary vasoconstriction and vascular remodeling in pulmonary hypertension. RhoB, a protein homologous to RhoA and activated by hypoxia, regulates neoplastic growth and vasoconstriction but its role in the regulation of pulmonary vascular function is not known.

Objective: To determine the role of RhoB in pulmonary endothelial and smooth muscle cell responses to hypoxia and in pulmonary vascular remodeling in chronic hypoxia-induced pulmonary hypertension.

Methods and Results: Hypoxia increased expression and activity of RhoB in human pulmonary artery endothelial and smooth muscle cells, coincidental with activation of RhoA. Hypoxia or adenoviral overexpression of constitutively activated RhoB increased actomyosin contractility, induced endothelial permeability, and promoted cell growth; dominant negative RhoB or manumycin, a farnesyltransferase inhibitor that targets the vascular function of RhoB, inhibited the effects of hypoxia. Coordinated activation of RhoA and RhoB maximized the hypoxia-induced stress fiber formation caused by RhoB/mammalian homolog of Drosophila diaphanous-induced actin polymerization and RhoA/Rho kinase-induced phosphorylation of myosin light chain on Ser19. Notably, RhoB was specifically required for hypoxia-induced factor-1 alpha stabilization and for hypoxia- and platelet-derived growth factor-induced cell proliferation and migration. RhoB deficiency in mice markedly attenuated development of chronic hypoxia-induced pulmonary hypertension, despite compensatory expression of RhoA in the lung.

Conclusions: RhoB mediates adaptational changes to acute hypoxia in the vasculature, but its continual activation by chronic hypoxia can accentuate vascular remodeling to promote development of pulmonary hypertension. RhoB is a potential target for novel approaches (eg, farnesyltransferase inhibitors) aimed at regulating pulmonary vascular tone and structure.

Keyword
hypoxia, pulmonary hypertension, Rho GTPases, endothelium, smooth muscle cells
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-178870 (URN)10.1161/CIRCRESAHA.112.264473 (DOI)000304867900012 ()
Available from: 2012-08-06 Created: 2012-08-02 Last updated: 2017-12-07Bibliographically approved
Wojciak-Stothard, B., Yixing, W., Kardassis, D., Vasilaki, E., Huang, M. & Prendergast, G. (2012). Role of RhoB in the regulation of pulmonary endothelial and smooth muscle responses to hypoxia. Paper presented at 6th European Meeting on Vascular Biology and Medicine (EMVBM), SEP 21-24, 2011, Krakow, POLAND. Vascular pharmacology, 56(5-6), 359-359
Open this publication in new window or tab >>Role of RhoB in the regulation of pulmonary endothelial and smooth muscle responses to hypoxia
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2012 (English)In: Vascular pharmacology, ISSN 1537-1891, E-ISSN 1879-3649, Vol. 56, no 5-6, p. 359-359Article in journal, Meeting abstract (Other academic) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-181065 (URN)10.1016/j.vph.2011.08.146 (DOI)000306889400158 ()
Conference
6th European Meeting on Vascular Biology and Medicine (EMVBM), SEP 21-24, 2011, Krakow, POLAND
Available from: 2012-09-17 Created: 2012-09-17 Last updated: 2017-12-07Bibliographically approved
Lönn, P., Vanlandewijck, M., Raja, E., Kowanetz, M., Watanabe, Y., Kowanetz, K., . . . Moustakas, A. (2012). Transcriptional induction of salt-inducible kinase 1 by transforming growth factor β leads to negative regulation of type I receptor signaling in cooperation with the Smurf2 ubiquitin ligase. Journal of Biological Chemistry, 287(16), 12867-12878
Open this publication in new window or tab >>Transcriptional induction of salt-inducible kinase 1 by transforming growth factor β leads to negative regulation of type I receptor signaling in cooperation with the Smurf2 ubiquitin ligase
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2012 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 287, no 16, p. 12867-12878Article in journal (Refereed) Published
Abstract [en]

Transforming growth factor β (TGFβ)1 regulates many physiological processes and requires control mechanisms to safeguard proper and timely action. We have previously described how negative regulation of TGFβ signaling is controlled by the serine/threonine kinase salt-inducible kinase (SIK) 1. SIK1 forms complexes with the TGFβ type I receptor and with the inhibitory Smad7 and downregulates the type I receptor. We now demonstrate that TGFβ induces SIK1 levels via a direct transcriptional mechanism that implicates the Smad proteins and we have mapped a putative enhancer element on the SIK1 gene. We provide evidence that the ubiquitin ligase Smurf2 forms complexes and functionally cooperates with SIK1. Both the kinase activity of SIK1 and the ubiquitin ligase activity of Smurf2 are important for proper type I receptor turnover. We also show that knockdown of endogenous SIK1 and Smurf2 enhances physiological signaling by TGFβ that leads to epithelial growth arrest. In conclusion, TGFβ induces expression of Smad7, Smurf2 and SIK1, the products of which physically and functionally interlink to control the activity of this pathway.

Keyword
Signal transduction, SIK1, Smad, Smurf, SNF1LK, TGFβ, Ubiquitin
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-169792 (URN)10.1074/jbc.M111.307249 (DOI)000302903700026 ()22378783 (PubMedID)
Available from: 2012-03-06 Created: 2012-03-06 Last updated: 2017-12-07Bibliographically approved
Morikawa, M., Koinuma, D., Tsutsumi, S., Vasilaki, E., Kanki, Y., Heldin, C.-H., . . . Miyazono, K. (2011). ChIP-seq reveals cell type-specific binding patterns of BMP-specific Smads and a novel binding motif. Nucleic Acids Research, 39(20), 8712-8727
Open this publication in new window or tab >>ChIP-seq reveals cell type-specific binding patterns of BMP-specific Smads and a novel binding motif
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2011 (English)In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 39, no 20, p. 8712-8727Article in journal (Refereed) Published
Abstract [en]

Dysregulated bone morphogenetic protein (BMP) signaling in endothelial cells (ECs) and pulmonary arterial smooth muscle cells (PASMCs) are implicated in human genetic disorders. Here, we generated genome-wide maps of Smad1/5 binding sites in ECs and PASMCs. Smad1/5 preferentially bound to the region outside the promoter of known genes, and the binding was associated with target gene upregulation. Cell-selective Smad1/5 binding patterns appear to be determined mostly by cell-specific differences in baseline chromatin accessibility patterns. We identified, for the first time, a Smad1/5 binding motif in mammals, and termed GC-rich Smad binding element (GC-SBE). Several sequences in the identified GC-SBE motif had relatively weak affinity for Smad binding, and were enriched in cell type-specific Smad1/5 binding regions. We also found that both GC-SBE and the canonical SBE affect binding affinity for the Smad complex. Furthermore, we characterized EC-specific Smad1/5 target genes and found that several Notch signaling pathway-related genes were induced by BMP in ECs. Among them, a Notch ligand, JAG1 was regulated directly by Smad1/5, transactivating Notch signaling in the neighboring cells. These results provide insights into the molecular mechanism of BMP signaling and the pathogenesis of vascular lesions of certain genetic disorders, including hereditary hemorrhagic telangiectasia.

Place, publisher, year, edition, pages
Oxford University Press, 2011
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-160812 (URN)10.1093/nar/gkr572 (DOI)000296343400014 ()21764776 (PubMedID)
Available from: 2011-11-01 Created: 2011-11-01 Last updated: 2017-12-08Bibliographically approved
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