scholarly journals WASP family members and formin proteins coordinate regulation of cell protrusions in carcinoma cells

2008 ◽  
Vol 180 (6) ◽  
pp. 1245-1260 ◽  
Author(s):  
Corina Sarmiento ◽  
Weigang Wang ◽  
Athanassios Dovas ◽  
Hideki Yamaguchi ◽  
Mazen Sidani ◽  
...  
Keyword(s):  
Carcinoma Cell ◽  
Carcinoma Cells ◽  
Actin Nucleation ◽  
Coordinate Regulation ◽  
Rhoa Activity ◽  
Cell Protrusion ◽  
Epidermal Growth ◽  
Nucleation Activity ◽  
Syndrome Protein

We examined the role of the actin nucleation promoters neural Wiskott-Aldrich syndrome protein (N-WASP) and WAVE2 in cell protrusion in response to epidermal growth factor (EGF), a key regulator in carcinoma cell invasion. We found that WAVE2 knockdown (KD) suppresses lamellipod formation and increases filopod formation, whereas N-WASP KD has no effect. However, simultaneous KD of both proteins results in the formation of large jagged protrusions with lamellar properties and increased filopod formation. This suggests that another actin nucleation activity is at work in carcinoma cells in response to EGF. A mammalian Diaphanous–related formin, mDia1, localizes at the jagged protrusions in double KD cells. Constitutively active mDia1 recapitulated the phenotype, whereas inhibition of mDia1 blocked the formation of these protrusions. Increased RhoA activity, which stimulates mDia1 nucleation, was observed in the N-WASP/WAVE2 KD cells and was shown to be required for the N-WASP/WAVE2 KD phenotype. These data show that coordinate regulation between the WASP family and mDia proteins controls the balance between lamellar and lamellipodial protrusion activity.

scholarly journals Mechanism of N-Wasp Activation by Cdc42 and Phosphatidylinositol 4,5-Bisphosphate

2000 ◽  
Vol 150 (6) ◽  
pp. 1299-1310 ◽  
Author(s):  
Rajat Rohatgi ◽  
Hsin-yi Henry Ho ◽  
Marc W. Kirschner
Keyword(s):  
Binding Site ◽  
Physical Interaction ◽  
Regulatory Interaction ◽  
Actin Nucleation ◽  
Sequence Element ◽  
Effector Domain ◽  
Nucleation Activity ◽  
Syndrome Protein ◽  
Upstream Regulators ◽  
Terminal Effector

Neuronal Wiskott-Aldrich Syndrome protein (N-WASP) transmits signals from Cdc42 to the nucleation of actin filaments by Arp2/3 complex. Although full-length N-WASP is a weak activator of Arp2/3 complex, its activity can be enhanced by upstream regulators such as Cdc42 and PI(4,5)P2. We dissected this activation reaction and found that the previously described physical interaction between the NH2-terminal domain and the COOH-terminal effector domain of N-WASP is a regulatory interaction because it can inhibit the actin nucleation activity of the effector domain by occluding the Arp2/3 binding site. This interaction between the NH2- and COOH termini must be intramolecular because in solution N-WASP is a monomer. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) influences the activity of N-WASP through a conserved basic sequence element located near the Cdc42 binding site rather than through the WASp homology domain 1. Like Cdc42, PI(4,5)P2 reduces the affinity between the NH2- and COOH termini of the molecule. The use of a mutant N-WASP molecule lacking this basic stretch allowed us to delineate a signaling pathway in Xenopus extracts leading from PI(4,5)P2 to actin nucleation through Cdc42, N-WASP, and Arp2/3 complex. In this pathway, PI(4,5)P2 serves two functions: first, as an activator of N-WASP; and second, as an indirect activator of Cdc42.

scholarly journals Relationship between Arp2/3 Complex and the Barbed Ends of Actin Filaments at the Leading Edge of Carcinoma Cells after Epidermal Growth Factor Stimulation

1999 ◽  
Vol 145 (2) ◽  
pp. 331-345 ◽  
Author(s):  
Maryse Bailly ◽  
Frank Macaluso ◽  
Michael Cammer ◽  
Amanda Chan ◽  
Jeffrey E. Segall ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Leading Edge ◽  
Fold Increase ◽  
Carcinoma Cells ◽  
Small Subset ◽  
Epidermal Growth Factor Stimulation ◽  
Fourfold Increase ◽  
Epidermal Growth ◽  
Nucleation Activity

Using both light and high resolution electron microscopy, we analyzed the spatial and temporal relationships between the Arp2/3 complex and the nucleation activity that is required for lamellipod extension in mammary carcinoma cells after epidermal growth factor stimulation. A rapid two- to fourfold increase in filament barbed end number occurs transiently after stimulation and remains confined almost exclusively to the extreme outer edge of the extending lamellipod (within 100–200 nm of the plasma membrane). This is accompanied by an increase in filament density at the leading edge and a general decrease in filament length, with a specific loss of long filaments. Concomitantly, the Arp2/3 complex is recruited with a 1.5-fold increase throughout the entire cortical filament network extending 1–1.5 μm in depth from the membrane at the leading edge. The recruitment of the Arp2/3 complex at the membrane of the extending lamellipod indicates that Arp2/3 may be involved in initial generation of growing filaments. However, only a small subset of the complex present in the cortical network colocalizes near free barbed ends. This suggests that the 100–200-nm submembraneous compartment at the leading edge of the extending lamellipod constitutes a special biochemical microenvironment that favors the generation and maintenance of free barbed ends, possibly through the locally active Arp2/3 complex, severing or decreasing the on-rate of capping protein. Our results are inconsistent with the hypothesis suggesting uncapping is the dominant mechanism responsible for the generation of nucleation activity. However, they support the hypothesis of an Arp2/3-mediated capture of actin oligomers that formed close to the membrane by other mechanisms such as severing. They also support pointed-end capping by the Arp2/3 complex, accounting for its wide distribution at the leading edge.

scholarly journals Enhancement of Notch receptor maturation and signaling sensitivity by Cripto-1

2009 ◽  
Vol 187 (3) ◽  
pp. 343-353 ◽  
Author(s):  
Kazuhide Watanabe ◽  
Tadahiro Nagaoka ◽  
Joseph M. Lee ◽  
Caterina Bianco ◽  
Monica Gonzales ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Notch Receptor ◽  
Carcinoma Cells ◽  
Vertebrate Development ◽  
Notch Receptors ◽  
Epidermal Growth ◽  
Signaling Activation ◽  
Lipid Raft Microdomains ◽  
Golgi Network

Nodal and Notch signaling pathways play essential roles in vertebrate development. Through a yeast two-hybrid screening, we identified Notch3 as a candidate binding partner of the Nodal coreceptor Cripto-1. Coimmunoprecipitation analysis confirmed the binding of Cripto-1 with all four mammalian Notch receptors. Deletion analyses revealed that the binding of Cripto-1 and Notch1 is mediated by the Cripto-1/FRL-1/Cryptic domain of Cripto-1 and the C-terminal region of epidermal growth factor–like repeats of Notch1. Binding of Cripto-1 to Notch1 occurred mainly in the endoplasmic reticulum–Golgi network. Cripto-1 expression resulted in the recruitment of Notch1 protein into lipid raft microdomains and enhancement of the furin-like protein convertase-mediated proteolytic maturation of Notch1 (S1 cleavage). Enhanced S1 cleavage resulted in the sensitization to ligand-induced activation of Notch signaling. In addition, knockdown of Cripto-1 expression in human and mouse embryonal carcinoma cells desensitized the ligand-induced Notch signaling activation. These results suggest a novel role of Cripto-1 in facilitating the posttranslational maturation of Notch receptors.

scholarly journals Role of the aging vasculature andErb B-2 signaling in epidermal growth factor-dependent intravasion of breast carcinoma cells

Cancer ◽  
2004 ◽  
Vol 101 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Daniel J. Price ◽  
Shalom Avraham ◽  
Shuxian Jiang ◽  
Yigong Fu ◽  
Hava Karsenty Avraham
Keyword(s):  
Growth Factor ◽  
Breast Carcinoma ◽  
Epidermal Growth Factor ◽  
Carcinoma Cells ◽  
Breast Carcinoma Cells ◽  
Epidermal Growth

scholarly journals Harnessing Carcinoma Cell Plasticity Mediated by TGF-β Signaling

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3397
Author(s):  
Xuecong Wang ◽  
Jean Paul Thiery
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Carcinoma Cell ◽  
Therapy Resistance ◽  
Carcinoma Cells ◽  
Cell Plasticity ◽  
Mesenchymal Transition ◽  
Tgfβ Receptor ◽  
Receptor Signaling Pathway ◽  
Cancer Dissemination

Epithelial cell plasticity, a hallmark of carcinoma progression, results in local and distant cancer dissemination. Carcinoma cell plasticity can be achieved through epithelial–mesenchymal transition (EMT), with cells positioned seemingly indiscriminately across the spectrum of EMT phenotypes. Different degrees of plasticity are achieved by transcriptional regulation and feedback-loops, which confer carcinoma cells with unique properties of tumor propagation and therapy resistance. Decoding the molecular and cellular basis of EMT in carcinoma should enable the discovery of new therapeutic strategies against cancer. In this review, we discuss the different attributes of plasticity in carcinoma and highlight the role of the canonical TGFβ receptor signaling pathway in the acquisition of plasticity. We emphasize the potential stochasticity of stemness in carcinoma in relation to plasticity and provide data from recent clinical trials that seek to target plasticity.

The dual role of CD44 as a functional P-selectin ligand and fibrin receptor in colon carcinoma cell adhesion

2008 ◽  
Vol 294 (4) ◽  
pp. C907-C916 ◽  
Author(s):  
Christina S. Alves ◽  
Monica M. Burdick ◽  
Susan N. Thomas ◽  
Parag Pawar ◽  
Konstantinos Konstantopoulos
Keyword(s):  
Colon Carcinoma ◽  
Carcinoma Cell ◽  
Metastatic Potential ◽  
Carcinoma Cells ◽  
Fibrinogen Receptor ◽  
Colon Carcinoma Cells ◽  
Selectin Ligand ◽  
And Control ◽  
Kinetics Of

Selectins and fibrin(ogen) play key roles in the hematogenous dissemination of tumor cells, and especially of colon carcinomas. However, the fibrin(ogen) receptor(s) on colon carcinoma cells has yet to be defined along with its relative capacity to bind fibrinogen versus fibrin under flow. Moreover, the functional P-selectin ligand has yet to be validated using intact platelets rather than purified selectin substrates. Using human CD44-knockdown and control LS174T cells, we demonstrate the pivotal involvement of CD44 in the P-selectin-mediated binding to platelets in shear flow. Quantitative comparisons of the binding kinetics of LS174T versus P-selectin glycoprotein ligand-1 (PSGL-1)-expressing THP-1 cells to activated platelets reveal that the relative avidity of P-selectin-CD44 binding is more than sevenfold lower than that of P-selectin-PSGL-1 interaction. Using CD44-knockdown LS174T cells and microspheres coated with CD44 immunoprecipitated from control LS174T cells, and purified fibrin(ogen) as substrate, we provide the first direct evidence that CD44 also acts as the major fibrin, but not fibrinogen, receptor on LS174T colon carcinoma cells. Interestingly, binding of plasma fibrin to CD44 on the colon carcinoma cell surface interferes with the P-selectin-CD44 molecular interaction and diminishes platelet-LS174T heteroaggregation in the high shear regime. Cumulatively, our data offer a novel perspective on the apparent metastatic potential associated with CD44 overexpression on colon carcinoma cells and the critical roles of P-selectin and fibrin(ogen) in metastatic spread and provide a rational basis for the design of new therapeutic strategies to impede metastasis.

scholarly journals Activation of Arp2/3 Complex by Wiskott-Aldrich Syndrome Protein Is Linked to Enhanced Binding of ATP to Arp2

2001 ◽  
Vol 276 (50) ◽  
pp. 46689-46692 ◽  
Author(s):  
Christophe Le Clainche ◽  
Dominique Didry ◽  
Marie-France Carlier ◽  
Dominique Pantaloni
Keyword(s):  
Actin Polymerization ◽  
Wiskott Aldrich Syndrome ◽  
High Affinity ◽  
Functional Assays ◽  
Cell Protrusion ◽  
Atp Analogs ◽  
Functional States ◽  
Syndrome Protein ◽  
Related Proteins

In response to signaling, the Arp2/3 complex (actin-related proteins 2 and 3 complex) is activated by binding the C-terminal (WA) domain of proteins of the Wiskott-Aldrich Syndrome family to promote the formation of a branched actin filament array, responsible for cell protrusion. The Arp2/3 complex exists in different structural/functional states: the inactive Arp2/3, the activated WA·Arp2/3 complex, the ternary G-actin·WA·Arp2/3 complex, which branches the filaments. This work addresses the role of ATP binding in Arp2/3 function. Using photo-cross-linking, hydrodynamic, and fluorescence techniques, we show that in the inactive Arp2/3 complex only one rapidly exchangeable ATP is tightly bound to Arp3 with an affinity of 108m−1. Upon activation of the Arp2/3 complex by WA, ATP binds to Arp2 with high affinity (107m−1), implying that a large structural change of Arp2 is linked to Arp2/3 activation. ATP is rapidly exchangeable on Arp2 and Arp3 in WA·Arp2/3 and G-actin·WA·Arp2/3 complexes. ATP is not hydrolyzed in inactive Arp2/3, in WA·Arp2/3, nor in G-actin·WA·Arp2/3. Arp2 has a greater specificity than Arp3 for ATPversusATP analogs. Using functional assays of actin polymerization in branched filaments, we show that binding of ATP to Arp2 is required for filament branching.

scholarly journals Phospholipase C and cofilin are required for carcinoma cell directionality in response to EGF stimulation

2004 ◽  
Vol 166 (5) ◽  
pp. 697-708 ◽  
Author(s):  
Ghassan Mouneimne ◽  
Lilian Soon ◽  
Vera DesMarais ◽  
Mazen Sidani ◽  
Xiaoyan Song ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Actin Polymerization ◽  
Carcinoma Cell ◽  
Cell Movement ◽  
Leading Edge ◽  
Carcinoma Cells ◽  
Epidermal Growth ◽  
Phosphoinositide 3 Kinase ◽  
Blocking Antibodies ◽  
Interfering Rna

The epidermal growth factor (EGF)–induced increase in free barbed ends, resulting in actin polymerization at the leading edge of the lamellipodium in carcinoma cells, occurs as two transients: an early one at 1 min and a late one at 3 min. Our results reveal that phospholipase (PLC) is required for triggering the early barbed end transient. Phosphoinositide-3 kinase selectively regulates the late barbed end transient. Inhibition of PLC inhibits cofilin activity in cells during the early transient, delays the initiation of protrusions, and inhibits the ability of cells to sense a gradient of EGF. Suppression of cofilin, using either small interfering RNA silencing or function-blocking antibodies, selectively inhibits the early transient. Therefore, our results demonstrate that the early PLC and cofilin-dependent barbed end transient is required for the initiation of protrusions and is involved in setting the direction of cell movement in response to EGF.

scholarly journals α-Enolase Lies Downstream of mTOR/HIF1α and Promotes Thyroid Carcinoma Progression by Regulating CST1

2021 ◽  
Vol 9 ◽  
Author(s):  
Yang Liu ◽  
Lida Liao ◽  
Changming An ◽  
Xiaolei Wang ◽  
Zhengjiang Li ◽  
...  
Keyword(s):  
Thyroid Carcinoma ◽  
Theoretical Foundation ◽  
Carcinoma Cell ◽  
Carcinoma Cells ◽  
Novel Therapy ◽  
And Migration ◽  
Therapy Strategies ◽  
Thyroid Carcinoma Cell ◽  
Proliferation And Migration

Novel therapy strategies are crucial for thyroid carcinoma treatment. It is increasingly important to clarify the mechanism of thyroid carcinoma progression. Several studies demonstrate that α-Enolase (ENO1) participates in cancer development; nevertheless, the role of ENO1 in thyroid carcinoma progression remains unclear. In the present study, we found that the expression of ENO1 was upregulated in thyroid carcinoma samples. Proliferation and migration of thyroid carcinoma cells were suppressed by depletion of ENO1; conversely, ENO1 overexpression promoted thyroid carcinoma cell growth and invasion. To elucidate the mechanisms, we found that the hypoxia-related mTOR/HIF1 pathway regulated ENO1 expression. ENO1 regulated the expression of CST1; knockdown of CST1 reversed the tumorigenicity enhanced by ENO1 overexpression. Taken together, our findings provide a theoretical foundation for thyroid carcinoma treatment.

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