scholarly journals Dual roles of myocardin-related transcription factors in epithelial–mesenchymal transition via slug induction and actin remodeling

2007 ◽  
Vol 179 (5) ◽  
pp. 1027-1042 ◽  
Author(s):  
Tsuyoshi Morita ◽  
Taira Mayanagi ◽  
Kenji Sobue
Keyword(s):  
Transcription Factors ◽  
Actin Cytoskeleton ◽  
Nuclear Translocation ◽  
Epithelial Mesenchymal Transition ◽  
Ectopic Expression ◽  
Cytoskeletal Proteins ◽  
Mesenchymal Transition ◽  
Cell Contacts ◽  
Tgf Β1 ◽  
Cell Cell

Epithelial–mesenchymal transition (EMT) is a critical process occurring during embryonic development and in fibrosis and tumor progression. Dissociation of cell–cell contacts and remodeling of the actin cytoskeleton are major events of the EMT. Here, we show that myocardin-related transcription factors (MRTFs; also known as MAL and MKL) are critical mediators of transforming growth factor β (TGF-β) 1–induced EMT. In all epithelial cell lines examined here, TGF-β1 triggers the nuclear translocation of MRTFs. Ectopic expression of constitutive-active MRTF-A induces EMT, whereas dominant-negative MRTF-A or knockdown of MRTF-A and -B prevents the TGF-β1–induced EMT. MRTFs form complexes with Smad3. Via Smad3, the MRTF–Smad3 complexes bind to a newly identified cis-element GCCG-like motif in the promoter region of Canis familiaris and the human slug gene, which activates slug transcription and thereby dissociation of cell–cell contacts. MRTFs also increase the expression levels of actin cytoskeletal proteins via serum response factor, thereby triggering reorganization of the actin cytoskeleton. Thus, MRTFs are important mediators of TGF-β1–induced EMT.

scholarly journals Cytoskeleton assembly at endothelial cell–cell contacts is regulated by αII-spectrin–VASP complexes

2008 ◽  
Vol 180 (1) ◽  
pp. 205-219 ◽  
Author(s):  
Peter M. Benz ◽  
Constanze Blume ◽  
Jan Moebius ◽  
Chris Oschatz ◽  
Kai Schuh ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Ectopic Expression ◽  
Sh3 Domain ◽  
Fiber Formation ◽  
Cell Junctions ◽  
Cortical Actin ◽  
Differential Proteomics ◽  
Cell Contacts ◽  
Actin Fiber ◽  
Cell Cell

Directed cortical actin assembly is the driving force for intercellular adhesion. Regulated by phosphorylation, vasodilator-stimulated phosphoprotein (VASP) participates in actin fiber formation. We screened for endothelial proteins, which bind to VASP, dependent on its phosphorylation status. Differential proteomics identified αII-spectrin as such a VASP-interacting protein. αII-Spectrin binds to the VASP triple GP5-motif via its SH3 domain. cAMP-dependent protein kinase–mediated VASP phosphorylation at Ser157 inhibits αII-spectrin–VASP binding. VASP is dephosphorylated upon formation of cell–cell contacts and in confluent, but not in sparse cells, αII-spectrin colocalizes with nonphosphorylated VASP at cell–cell junctions. Ectopic expression of the αII-spectrin SH3 domain at cell–cell contacts translocates VASP, initiates cortical actin cytoskeleton formation, stabilizes cell–cell contacts, and decreases endothelial permeability. Conversely, the permeability of VASP-deficient endothelial cells (ECs) and microvessels of VASP-null mice increases. Reconstitution of VASP-deficient ECs rescues barrier function, whereas αII-spectrin binding-deficient VASP mutants fail to restore elevated permeability. We propose that αII-spectrin–VASP complexes regulate cortical actin cytoskeleton assembly with implications for vascular permeability.

scholarly journals Early Events in Actin Cytoskeleton Dynamics and E-Cadherin-Mediated Cell-Cell Adhesion during Epithelial-Mesenchymal Transition

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 578 ◽  
Author(s):  
Irina Y. Zhitnyak ◽  
Svetlana N. Rubtsova ◽  
Nikita I. Litovka ◽  
Natalya A. Gloushankova
Keyword(s):  
Cell Adhesion ◽  
Epithelial Mesenchymal Transition ◽  
Immunofluorescent Staining ◽  
Actin Binding ◽  
Mesenchymal Transition ◽  
Actin Bundle ◽  
Cell Contacts ◽  
The Stability ◽  
E Cadherin ◽  
Cell Cell

Epithelial-mesenchymal transition (EMT) plays an important role in development and also in initiation of metastasis during cancer. Disruption of cell-cell contacts during EMT allowing cells to detach from and migrate away from their neighbors remains poorly understood. Using immunofluorescent staining and live-cell imaging, we analyzed early events during EMT induced by epidermal growth factor (EGF) in IAR-20 normal epithelial cells. Control cells demonstrated stable adherens junctions (AJs) and robust contact paralysis, whereas addition of EGF caused rapid dynamic changes at the cell-cell boundaries: fragmentation of the circumferential actin bundle, assembly of actin network in lamellipodia, and retrograde flow. Simultaneously, an actin-binding protein EPLIN was phosphorylated, which may have decreased the stability of the circumferential actin bundle. Addition of EGF caused gradual replacement of linear E-cadherin–based AJs with dynamic and unstable punctate AJs, which, unlike linear AJs, colocalized with the mechanosensitive protein zyxin, confirming generation of centripetal force at the sites of cell-cell contacts during EMT. Our data show that early EMT promotes heightened dynamics at the cell-cell boundaries—replacement of stable AJs and actin structures with dynamic ones—which results in overall weakening of cell-cell adhesion, thus priming the cells for front-rear polarization and eventual migration.

Loss of vitamin D receptor in chronic kidney disease: a potential mechanism linking inflammation to epithelial-to-mesenchymal transition

2012 ◽  
Vol 303 (7) ◽  
pp. F1107-F1115 ◽  
Author(s):  
Min Xiong ◽  
Junbo Gong ◽  
Youhua Liu ◽  
Rong Xiang ◽  
Xiaoyue Tan
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Kidney Diseases ◽  
Ectopic Expression ◽  
Mesenchymal Transition ◽  
Tnf Α ◽  
Tgf Β1

Both peritubular inflammation and tubular epithelial-to-mesenchymal transition (EMT) are critical events during the pathogenesis of renal fibrosis. However, the relationship between these two processes is unclear. Here, we investigated the potential role of the vitamin D receptor (VDR) in coupling peritubular inflammation and EMT. In a mouse model of unilateral ureteral obstruction (UUO), loss of VDR was observed as early as 1 day after surgery. In cultured proximal tubular epithelial HK-2 cells, proinflammatory TNF-α inhibited the expression of VDR in a dose- and time-dependant manner. Treatment with TNF-α sensitized HK-2 cells to EMT stimulated by transforming growth factor (TGF)-β1. Ectopic expression of VDR counteracted the synergistic effect of TNF-α and TGF-β1 on EMT. Furthermore, knockdown of VDR using a small interfering RNA strategy mimicked the effect of TNF-α on facilitating EMT. Either TNF-α treatment or a loss of VDR induced β-catenin activation and its nuclear translocation. The VDR ligand calcitriol reversed the VDR loss and inhibited EMT in the mouse UUO model, and late administration of active vitamin D was effective in restoring VDR expression as well, and reduced collagen accumulation and deposition compared with the vehicle control. β-Catenin expression induced by UUO was also significantly inhibited after the late administration of vitamin D. These results indicate that the early loss of VDR in chronic kidney diseases was likely mediated by proinflammatory TNF-α, which renders tubular cells susceptible to EMT. Our data suggest that loss of VDR couples peritubular inflammation and EMT, two key events in renal fibrogenesis.

scholarly journals Estrogen Modulates Epithelial Breast Cancer Cell Mechanics and Cell-to-Cell Contacts

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2897
Author(s):  
Barbara Zbiral ◽  
Andreas Weber ◽  
Jagoba Iturri ◽  
Maria d. M. Vivanco ◽  
José L. Toca-Herrera
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Epithelial Mesenchymal Transition ◽  
Estrogen Signaling ◽  
Free Medium ◽  
Mesenchymal Transition ◽  
Cell Contacts ◽  
Estrogen Exposure ◽  
Increased Risk ◽  
Cell Cell

Excessive estrogen exposure is connected with increased risk of breast cancer and has been shown to promote epithelial-mesenchymal-transition. Malignant cancer cells accumulate changes in cell mechanical and biochemical properties, often leading to cell softening. In this work we have employed atomic force microscopy to probe the influence of estrogen on the viscoelastic properties of MCF-7 breast cancer cells cultured either in normal or hormone free-medium. Estrogen led to a significant softening of the cells in all studied cases, while growing cells in hormone free medium led to an increase in the studied elastic and viscoelastic moduli. In addition, fluorescence microscopy shows that E-cadherin distribution is changed in cells when culturing them under estrogenic conditions. Furthermore, cell-cell contacts seemed to be weakened. These results were supported by AFM imaging showing changes in surfaces roughness, cell-cell contacts and cell height as result of estrogen treatment. This study therefore provides further evidence for the role of estrogen signaling in breast cancer.

scholarly journals αvβ3 Integrin induces partial EMT independent of TGF-β signaling

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yoshinobu Kariya ◽  
Midori Oyama ◽  
Takato Suzuki ◽  
Yukiko Kariya
Keyword(s):  
Lung Cancer ◽  
Cancer Progression ◽  
Epithelial Mesenchymal Transition ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Αvβ3 Integrin ◽  
Poor Survival ◽  
Mesenchymal Transition ◽  
Intermediate States ◽  
Tgf Β1

AbstractEpithelial–mesenchymal transition (EMT) plays a pivotal role for tumor progression. Recent studies have revealed the existence of distinct intermediate states in EMT (partial EMT); however, the mechanisms underlying partial EMT are not fully understood. Here, we demonstrate that αvβ3 integrin induces partial EMT, which is characterized by acquiring mesenchymal phenotypes while retaining epithelial markers. We found αvβ3 integrin to be associated with poor survival in patients with lung adenocarcinoma. Moreover, αvβ3 integrin-induced partial EMT promoted migration, invasion, tumorigenesis, stemness, and metastasis of lung cancer cells in a TGF-β-independent fashion. Additionally, TGF-β1 promoted EMT progression synergistically with αvβ3 integrin, while a TGF-β signaling inhibitor showed no effect on αvβ3 integrin-induced partial EMT. Meanwhile, the microRNA-200 family abolished the αvβ3 integrin-induced partial EMT by suppressing αvβ3 integrin cell surface expression. These findings indicate that αvβ3 integrin is a key inducer of partial EMT, and highlight a new mechanism for cancer progression.

scholarly journals Distinct Ring1b complexes defined by DEAD-box helicases and EMT transcription factors synergistically enhance E-cadherin silencing in breast cancer

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Yawei Wang ◽  
Yingying Sun ◽  
Chao Shang ◽  
Lili Chen ◽  
Hongyu Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Transcription Factors ◽  
Cancer Cells ◽  
Epithelial Mesenchymal Transition ◽  
Epigenetic Mechanism ◽  
Regulation Mechanism ◽  
Rna Helicases ◽  
Mesenchymal Transition ◽  
Dead Box ◽  
E Cadherin

AbstractRing1b is a core subunit of polycomb repressive complex 1 (PRC1) and is essential in several high-risk cancers. However, the epigenetic mechanism of Ring1b underlying breast cancer malignancy is poorly understood. In this study, we showed increased expression of Ring1b promoted metastasis by weakening cell–cell adhesions of breast cancer cells. We confirmed that Ring1b could downregulate E-cadherin and contributed to an epigenetic rewiring via PRC1-dependent function by forming distinct complexes with DEAD-box RNA helicases (DDXs) or epithelial-mesenchymal transition transcription factors (EMT TFs) on site-specific loci of E-cadherin promoter. DDXs-Ring1b complexes moderately inhibited E-cadherin, which resulted in an early hybrid EMT state of epithelial cells, and EMT TFs-Ring1b complexes cooperated with DDXs-Ring1b complexes to further repress E-cadherin in mesenchymal-like cancer cells. Clinically, high expression of Ring1b with DDXs or EMT TFs predicted low levels of E-cadherin, metastatic behavior, and poor prognosis. These findings provide an epigenetic regulation mechanism of Ring1b complexes in E-cadherin expression. Ring1b complexes may be potential therapeutic targets and biomarkers for diagnosis and prognosis in invasion breast cancer.

scholarly journals Long non-coding (lnc)RNA profiling and the role of a key regulator lnc-PNRC2-1 in the transforming growth factor-β1-induced epithelial–mesenchymal transition of CNE1 nasopharyngeal carcinoma cells

2021 ◽  
Vol 49 (3) ◽  
pp. 030006052199651
Author(s):  
Jie Yang ◽  
Enzi Feng ◽  
Yanxin Ren ◽  
Shun Qiu ◽  
Liufang Zhao ◽  
...  
Keyword(s):  
Growth Factor ◽  
Nasopharyngeal Carcinoma ◽  
Rna Sequencing ◽  
Western Blotting ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Carcinoma Cells ◽  
Mesenchymal Transition ◽  
Emt Markers ◽  
Tgf Β1

Objectives To identify key long non-coding (lnc)RNAs responsible for the epithelial–mesenchymal transition (EMT) of CNE1 nasopharyngeal carcinoma cells and to investigate possible regulatory mechanisms in EMT. Methods CNE1 cells were divided into transforming growth factor (TGF)-β1-induced EMT and control groups. The mRNA and protein expression of EMT markers was determined by real-time quantitative PCR and western blotting. Differentially expressed genes (DEGs) between the two groups were identified by RNA sequencing analysis, and DEG functions were analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses. EMT marker expression was re-evaluated by western blotting after knockdown of a selected lncRNA. Results TGF-β1-induced EMT was characterized by decreased E-cadherin and increased vimentin, N-cadherin, and Twist expression at both mRNA and protein levels. Sixty lncRNA genes were clustered in a heatmap, and mRNA expression of 14 dysregulated lncRNAs was consistent with RNA sequencing. Knockdown of lnc-PNRC2-1 increased expression of its antisense gene MYOM3 and reduced expression of EMT markers, resembling treatment with the TGF-β1 receptor inhibitor LY2109761. Conclusion Various lncRNAs participated indirectly in the TGF-β1-induced EMT of CNE1 cells. Lnc-PNRC2-1 may be a key regulator of this and is a potential target to alleviate CNE1 cell EMT.

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