scholarly journals A role for gelsolin in actuating epidermal growth factor receptor-mediated cell motility.

1996 ◽  
Vol 134 (3) ◽  
pp. 689-698 ◽  
Author(s):  
P Chen ◽  
J E Murphy-Ullrich ◽  
A Wells
Keyword(s):  
Cell Motility ◽  
Membrane Fraction ◽  
Growth Factor Receptor ◽  
Cell Movement ◽  
Bound State ◽  
Cell Surface Receptor ◽  
Pharmacologic Agent ◽  
Signaling Mechanism

Phospholipase C-gamma (PLC gamma) is required for EGF-induced motility (Chen, P., H. Xie, M.C. Sekar, K.B. Gupta, and A. Wells. J. Cell Biol. 1994. 127:847-857); however, the molecular basis of how PLC gamma modulates the actin filament network underlying cell motility remains undetermined. We propose that one connection to the actin cytoskeleton is direct hydrolysis of PIP2 with subsequent mobilization of membrane-associated actin modifying proteins. We used signaling-restricted EGFR mutants expressed in receptor-devoid NR6 fibroblast cells to investigate whether EGFR activation of PLC causes gelsolin mobilization from the cell membrane in vivo and whether this translocation facilitates cell movement. Gelsolin anti-sense oligonucleotide (20 microM) treatment of NR6 cells expressing the motogenic full-length (WT) and truncated c'1000 EGFR decreased endogenous gelsolin by 30-60%; this resulted in preferential reduction of EGF (25 nM)-induced cell movement by > 50% with little effect on the basal motility. As 14 h of EGF stimulation of cells did not increase total cell gelsolin content, we determined whether EGF induced redistribution of gelsolin from the membrane fraction. EGF treatment decreased the gelsolin mass associated with the membrane fraction in motogenic WT and c'1000 EGFR NR6 cells but not in cells expressing the fully mitogenic, but nonmotogenic c'973 EGFR. Blocking PLC activity with the pharmacologic agent U73122 (1 microM) diminished both this mobilization of gelsolin and EGF-induced motility, suggesting that gelsolin mobilization is downstream of PLC. Concomitantly observed was reorganization of submembranous actin filaments correlating directly with PLC activation and gelsolin mobilization. In vivo expression of a peptide that is reported to compete in vitro with gelsolin in binding to PIP2 dramatically increased basal cell motility in NR6 cells expressing either motogenic (WT and c'1000) or nonmotogenic (c'973) EGFR; EGF did not further augment cell motility and gelsolin mobilization. Cells expressing this peptide demonstrated actin reorganization similar to that observed in EGF-treated control cells; the peptide-induced changes were unaffected by U73122. These data suggest that much of the EGF-induced motility and cytoskeletal alterations can be reproduced by displacement of select actin-modifying proteins from a PIP2-bound state. This provides a signaling mechanism for translating cell surface receptor-mediated biochemical reactions to the cell movement machinery.

scholarly journals Ovulatory Induction of SCG2 in Human, Nonhuman Primate, and Rodent Granulosa Cells Stimulates Ovarian Angiogenesis

Endocrinology ◽  
2018 ◽  
Vol 159 (6) ◽  
pp. 2447-2458 ◽  
Author(s):  
Patrick R Hannon ◽  
Diane M Duffy ◽  
Katherine L Rosewell ◽  
Mats Brännström ◽  
James W Akin ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Messenger Rna ◽  
Growth Factor Receptor ◽  
Endothelial Cell Migration ◽  
Receptor Signaling ◽  
Signaling Mechanism ◽  
Lh Receptor ◽  
Vitro Fertilization

Abstract The luteinizing hormone (LH) surge is essential for ovulation, but the intrafollicular factors induced by LH that mediate ovulatory processes (e.g., angiogenesis) are poorly understood, especially in women. The role of secretogranin II (SCG2) and its cleaved bioactive peptide, secretoneurin (SN), were investigated as potential mediators of ovulation by testing the hypothesis that SCG2/SN is induced in granulosa cells by human chorionic gonadotropin (hCG), via a downstream LH receptor signaling mechanism, and stimulates ovarian angiogenesis. Humans, nonhuman primates, and rodents were treated with hCG in vivo resulting in a significant increase in the messenger RNA and protein levels of SCG2 in granulosa cells collected early during the periovulatory period and just prior to ovulation (humans: 12 to 34 hours; monkeys: 12 to 36 hours; rodents: 4 to 12 hours post-hCG). This induction by hCG was recapitulated in an in vitro culture system utilizing granulosa-lutein cells from in vitro fertilization patients. Using this system, inhibition of downstream LH receptor signaling pathways revealed that the initial induction of SCG2 is regulated, in part, by epidermal growth factor receptor signaling. Further, human ovarian microvascular endothelial cells were treated with SN (1 to 100 ng/mL) and subjected to angiogenesis assays. SN significantly increased endothelial cell migration and new sprout formation, suggesting induction of ovarian angiogenesis. These results establish that SCG2 is increased in granulosa cells across species during the periovulatory period and that SN may mediate ovulatory angiogenesis in the human ovary. These findings provide insight into the regulation of human ovulation and fertility.

scholarly journals Cell movement elicited by epidermal growth factor receptor requires kinase and autophosphorylation but is separable from mitogenesis

1994 ◽  
Vol 124 (4) ◽  
pp. 547-555 ◽  
Author(s):  
P Chen ◽  
K Gupta ◽  
A Wells
Keyword(s):  
Cell Proliferation ◽  
Cell Motility ◽  
Kinase Activity ◽  
Egf Receptor ◽  
Growth Factor Receptor ◽  
Cell Movement ◽  
Signaling Domain ◽  
Biologic Response ◽  
Carboxy Terminal

The EGF receptor (EGFR) upon activation signals increased cell movement. However, the domains within the receptor, and the pathway which trigger movement are undefined. We expressed EGFR mutants at physiologic levels in receptor-devoid NR6 cells to investigate this biologic response. The receptors possessed kinase activity and underwent autophosphorylation as predicted by primary amino acid sequence. EGF-induced cell motility was assessed in vitro by excess migration into an acellular area and colony scatter in the presence of saturating concentrations of EGF. Wild-type (WT)-EGFR signaled increased motility. However, replacing the conserved lysine721 with methionine resulted in a kinase-inactive receptor which did not elicit movement. Removal of the entire terminus by truncation (c'973) also abrogated ligand-induced motility. Thus, we concentrated on the carboxy-terminal domains. EGF-induced movement was seen with a less-truncated mutant (c'1000) that contained a single autophosphorylated tyrosine (tyrosine992). Other mutants, c'991 and c'1000F992, in which this tyrosine was removed did not signal motility. Fusion mutants which presented other autophosphorylated tyrosine domains also exhibited EGF-induced movement. These findings suggested that the presence of both an autophosphorylated tyrosine signaling domain and the kinase activity are necessary for this biologic response. All kinase-positive mutants signaled cell proliferation but only those that contained autophosphorylatable tyrosines induced movement. The motility responses mediated by these EGFR were identical in the presence or absence of mitomycin-C, at a dose (0.5 micrograms/ml) which completely inhibited cell proliferation. On the other side, D-actinomycin (50 ng/ml) blocked EGF-induced motility but did not affect thymidine incorporation. Thus, EGF-induced mitogenesis and cell motility are mediated through different pathways.

scholarly journals FERONIA’s sensing of cell wall pectin activates ROP GTPase signaling in Arabidopsis

2018 ◽  
Author(s):  
Wenwei Lin ◽  
Wenxin Tang ◽  
Charles T. Anderson ◽  
Zhenbiao Yang
Keyword(s):  
Cell Wall ◽  
Cell Shape ◽  
Cell Surface Receptor ◽  
Pavement Cell ◽  
Signaling Mechanism ◽  
Rop Gtpase ◽  
Surface Receptor ◽  
A Cell

ABSTRACTPlant cells need to monitor the cell wall dynamic to control the wall homeostasis required for a myriad of processes in plants, but the mechanisms underpinning cell wall sensing and signaling in regulating these processes remain largely elusive. Here, we demonstrate that receptor-like kinase FERONIA senses the cell wall pectin polymer to directly activate the ROP6 GTPase signaling pathway that regulates the formation of the cell shape in the Arabidopsis leaf epidermis. The extracellular malectin domain of FER directly interacts with de-methylesterified pectin in vivo and in vitro. Both loss-of-FER mutations and defects in the pectin biosynthesis and de-methylesterification caused changes in pavement cell shape and ROP6 signaling. FER is required for the activation of ROP6 by de-methylesterified pectin, and physically and genetically interacts with the ROP6 activator, RopGEF14. Thus, our findings elucidate a cell wall sensing and signaling mechanism that connects the cell wall to cellular morphogenesis via the cell surface receptor FER.

scholarly journals 2D or 3D? How in vitro cell motility is conserved across dimensions, and predicts in vivo invasion

2019 ◽  
Author(s):  
Sualyneth Galarza ◽  
Hyuna Kim ◽  
Naciye Atay ◽  
Shelly R Peyton ◽  
Jennifer M Munson
Keyword(s):  
Cell Migration ◽  
Cell Motility ◽  
Cell Movement ◽  
Complex Model ◽  
Model Systems ◽  
Cellular Motility ◽  
Statistical Tool ◽  
3D Environments

AbstractCell motility is a critical aspect of wound healing, the immune response, and is deregulated in cancer. Current limitations in imaging tools make it difficult to study cell migration in vivo. To overcome this, and to identify drivers from the microenvironment that regulate cell migration, bioengineers have developed 2D and 3D tissue model systems in which to study cell motility in vitro, with the aim of mimicking the environments in which cells move in vivo. However, there has been no systematic study to explicitly relate and compare cell motility measurements between these geometries/systems. Here, we provide such analysis on our own data, as well as across data in existing literature to understand whether, and which, in vitro models are predictive of in vivo cell motility. To our surprise, many metrics of cell movement on 2D surfaces significantly and positively correlate with cell migration in 3D environments, and cell invasion in 3D is negatively correlated with glioblastoma invasion in vivo. Finally, to best compare across complex model systems, in vivo data, and data from different labs, we suggest that groups report an effect size, a statistical tool that is most translatable across experiments and labs, when conducting experiments that affect cellular motility.

Toxicity and efficacy evaluation of multiple targeted polymalic acid conjugates for triple-negative breast cancer treatment

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Triple Negative ◽  
Growth Factor Receptor ◽  
Engineered Nanoparticles ◽  
Efficacy Evaluation ◽  
Dual Action ◽  
Epidermal Growth ◽  
Laminin 411 ◽  
Immunologic Analysis

Engineered nanoparticles are widely used for delivery of drugs but frequently lack proof of safetyfor cancer patient's treatment. All-in-one covalent nanodrugs of the third generation have beensynthesized based on a poly(β-L-malic acid) (PMLA) platform, targeting human triple-negativebreast cancer (TNBC). They significantly inhibited tumor growth in nude mice by blockingsynthesis of epidermal growth factor receptor, and α4 and β1 chains of laminin-411, the tumorvascular wall protein and angiogenesis marker. PMLA and nanodrug biocompatibility and toxicityat low and high dosages were evaluated in vitro and in vivo. The dual-action nanodrug and singleactionprecursor nanoconjugates were assessed under in vitro conditions and in vivo with multipletreatment regimens (6 and 12 treatments). The monitoring of TNBC treatment in vivo withdifferent drugs included blood hematologic and immunologic analysis after multiple intravenousadministrations. The present study demonstrates that the dual-action nanoconju-gate is highlyeffective in preclinical TNBC treatment without side effects, supported by hematologic andimmunologic assays data. PMLA-based nanodrugs of the Polycefin™ family passed multipletoxicity and efficacy tests in vitro and in vivo on preclinical level and may prove to be optimizedand efficacious for the treatment of cancer patients in the future.

scholarly journals The roles and prognostic significance of ABI1-TSV-11 expression in patients with left-sided colorectal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Zhang ◽  
Zhaohui Zhong ◽  
Mei Li ◽  
Jingyi Chen ◽  
Tingru Lin ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Prognostic Significance ◽  
Growth Factor Receptor ◽  
The Cancer Genome Atlas ◽  
Actin Dynamics ◽  
Elevated Expression ◽  
Sw480 Cells ◽  
And Migration

AbstractAbnormally expressed and/or phosphorylated Abelson interactor 1 (ABI1) participates in the metastasis and progression of colorectal cancer (CRC). ABI1 presents as at least 12 transcript variants (TSVs) by mRNA alternative splicing, but it is unknown which of them is involved in CRC metastasis and prognosis. Here, we firstly identified ABI1-TSV-11 as a key TSV affecting the metastasis and prognosis of left-sided colorectal cancer (LsCC) and its elevated expression is related to lymph node metastasis and shorter overall survival (OS) in LsCC by analyzing data from The Cancer Genome Atlas and TSVdb. Secondly, ABI1-TSV-11 overexpression promoted LoVo and SW480 cells adhesion and migration in vitro, and accelerated LoVo and SW480 cells lung metastasis in vivo. Finally, mechanism investigations revealed that ABI1-isoform-11 interacted with epidermal growth factor receptor pathway substrate 8 (ESP8) and regulated actin dynamics to affect LoVo and SW480 cells biological behaviors. Taken together, our data demonstrated that ABI1-TSV-11 plays an oncogenic role in LsCC, it is an independent risk factor of prognosis and may be a potential molecular marker and therapeutic target in LsCC.

scholarly journals MODL-12. DEVELOPMENT OF A NOVEL IMMUNOCOMPETENT MOUSE MODEL FOR DIFFUSE INTRINSIC PONTINE GLIOMA

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii413-iii413
Author(s):  
Maggie Seblani ◽  
Markella Zannikou ◽  
Katarzyna Pituch ◽  
Liliana Ilut ◽  
Oren Becher ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Mouse Model ◽  
Growth Factor Receptor ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Time Of Application ◽  
Tumor Associated Antigen ◽  
Sarcoma Virus

Abstract Diffuse intrinsic pontine glioma (DIPG) is a devastating brain tumor affecting young children. Immunotherapies hold promise however the lack of immunocompetent models recreating a faithful tumor microenvironment (TME) remains a challenge for development of targeted immunotherapeutics. We propose to generate an immunocompetent DIPG mouse model through induced overexpression of interleukin 13 receptor alpha 2 (IL13Rα2), a tumor-associated antigen overexpressed by glioma cells. A model with an intact TME permits comprehensive preclinical assessment of IL13Rα2-targeted immunotherapeutics. Our novel model uses the retroviral avian leucosis and sarcoma virus (RCAS) for in vivo gene delivery leading to IL13Rα2 expression in proliferating progenitor cells. Transfected cells expressing IL13Rα2 and PDGFB, a ligand for platelet derived growth factor receptor, alongside induced p53 loss via the Cre-Lox system are injected in the fourth ventricle in postnatal pups. We validated the expression of PDGFB and IL13Rα2 transgenes in vitro and in vivo and will characterize the TME through evaluation of the peripheral and tumor immunologic compartments using immunohistochemistry and flow cytometry. We confirmed expression of transgenes via flow cytometry and western blotting. Comparison of survival dynamics in mice inoculated with PDGFB alone with PDGFB+IL13Rα2 demonstrated that co-expression of IL13Rα2 did not significantly affect mice survival compared to the PDGFB model. At time of application, we initiated experiments to characterize the TME. Preliminary data demonstrate establishment of tumors within and adjacent to the brainstem and expression of target transgenes. Preclinical findings in a model recapitulating the TME may provide better insight into outcomes upon translation to clinical application.

scholarly journals Imaging-Guided Therapy Simultaneously Targeting HER2 and EpCAM with Trastuzumab and EpCAM-Directed Toxin Provides Additive Effect in Ovarian Cancer Model

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3939
Author(s):  
Tianqi Xu ◽  
Anzhelika Vorobyeva ◽  
Alexey Schulga ◽  
Elena Konovalova ◽  
Olga Vorontsova ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Growth Factor Receptor ◽  
Repeated Administration ◽  
Ovarian Cancer Cells ◽  
Her2 Positive ◽  
Efficient Treatment ◽  
Pseudomonas Exotoxin A ◽  
Epidermal Growth

Efficient treatment of disseminated ovarian cancer (OC) is challenging due to its heterogeneity and chemoresistance. Overexpression of human epidermal growth factor receptor 2 (HER2) and epithelial cell adhesion molecule (EpCAM) in approx. 30% and 70% of ovarian cancers, respectively, allows for co-targeted treatment. The clinical efficacy of the monoclonal antibody trastuzumab in patients with HER2-positive breast, gastric and gastroesophageal cancers makes it readily available as the HER2-targeting component. As the EpCAM-targeting component, we investigated the designed ankyrin repeat protein (DARPin) Ec1 fused to a truncated variant of Pseudomonas exotoxin A with reduced immunogenicity and low general toxicity (LoPE). Ec1-LoPE was radiolabeled, evaluated in ovarian cancer cells in vitro and its biodistribution and tumor-targeting properties were studied in vivo. The therapeutic efficacy of Ec1-LoPE alone and in combination with trastuzumab was studied in mice bearing EpCAM- and HER2-expressing SKOV3 xenografts. SPECT/CT imaging enabled visualization of EpCAM and HER2 expression in the tumors. Co-treatment using Ec1-LoPE and trastuzumab was more effective at reducing tumor growth and prolonged the median survival of mice compared with mice in the control and monotherapy groups. Repeated administration of Ec1-LoPE was well tolerated without signs of hepatic or kidney toxicity. Co-treatment with trastuzumab and Ec1-LoPE might be a potential therapeutic strategy for HER2- and EpCAM-positive OC.

scholarly journals Rare variants in KDR, encoding VEGF Receptor 2, are associated with tetralogy of Fallot

2021 ◽  
Author(s):  
Doris Škorić-Milosavljević ◽  
Najim Lahrouchi ◽  
Fernanda M. Bosada ◽  
Gregor Dombrowsky ◽  
Simon G. Williams ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Tetralogy Of Fallot ◽  
Large Scale ◽  
Rare Variants ◽  
Growth Factor Receptor ◽  
Vegf Receptor ◽  
Loss Of Function ◽  
Endothelial Growth Factor

Abstract Purpose Rare genetic variants in KDR, encoding the vascular endothelial growth factor receptor 2 (VEGFR2), have been reported in patients with tetralogy of Fallot (TOF). However, their role in disease causality and pathogenesis remains unclear. Methods We conducted exome sequencing in a familial case of TOF and large-scale genetic studies, including burden testing, in >1,500 patients with TOF. We studied gene-targeted mice and conducted cell-based assays to explore the role of KDR genetic variation in the etiology of TOF. Results Exome sequencing in a family with two siblings affected by TOF revealed biallelic missense variants in KDR. Studies in knock-in mice and in HEK 293T cells identified embryonic lethality for one variant when occurring in the homozygous state, and a significantly reduced VEGFR2 phosphorylation for both variants. Rare variant burden analysis conducted in a set of 1,569 patients of European descent with TOF identified a 46-fold enrichment of protein-truncating variants (PTVs) in TOF cases compared to controls (P = 7 × 10-11). Conclusion Rare KDR variants, in particular PTVs, strongly associate with TOF, likely in the setting of different inheritance patterns. Supported by genetic and in vivo and in vitro functional analysis, we propose loss-of-function of VEGFR2 as one of the mechanisms involved in the pathogenesis of TOF.

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