scholarly journals Rac3 regulates breast cancer invasion and metastasis by controlling adhesion and matrix degradation

2017 ◽  
Vol 216 (12) ◽  
pp. 4331-4349 ◽  
Author(s):  
Sara K. Donnelly ◽  
Ramon Cabrera ◽  
Serena P.H. Mao ◽  
John R. Christin ◽  
Bin Wu ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Initial Step ◽  
Surrounding Tissue ◽  
Matrix Degradation ◽  
Nucleotide Exchange ◽  
Invasion And Metastasis ◽  
Downstream Effector ◽  
Breast Cancer Invasion ◽  
The Matrix

The initial step of metastasis is the local invasion of tumor cells into the surrounding tissue. Invadopodia are actin-based protrusions that mediate the matrix degradation necessary for invasion and metastasis of tumor cells. We demonstrate that Rac3 GTPase is critical for integrating the adhesion of invadopodia to the extracellular matrix (ECM) with their ability to degrade the ECM in breast tumor cells. We identify two pathways at invadopodia important for integrin activation and delivery of matrix metalloproteinases: through the upstream recruiter CIB1 as well as the downstream effector GIT1. Rac3 activity, at and surrounding invadopodia, is controlled by Vav2 and βPIX. These guanine nucleotide exchange factors regulate the spatiotemporal dynamics of Rac3 activity, impacting GIT1 localization. Moreover, the GTPase-activating function of GIT1 toward the vesicular trafficking regulator Arf6 GTPase is required for matrix degradation. Importantly, Rac3 regulates the ability of tumor cells to metastasize in vivo. The Rac3-dependent mechanisms we show in this study are critical for balancing proteolytic activity and adhesive activity to achieve a maximally invasive phenotype.

scholarly journals EFEMP2 Inhibits Breast Cancer Invasion And Metastasis In Vitro And In Vivo

2019 ◽  
Vol Volume 12 ◽  
pp. 8915-8933
Author(s):  
Ning Kang ◽  
Jijun Zhou ◽  
Jia Xu ◽  
Dongsheng Zhou ◽  
Weichen Shi
Keyword(s):  
Breast Cancer ◽  
Cancer Invasion ◽  
Invasion And Metastasis ◽  
Breast Cancer Invasion

Activation of Epac stimulates integrin-dependent homing of progenitor cells

Blood ◽  
2008 ◽  
Vol 111 (5) ◽  
pp. 2640-2646 ◽  
Author(s):  
Guillaume Carmona ◽  
Emmanouil Chavakis ◽  
Ulrike Koehl ◽  
Andreas M. Zeiher ◽  
Stefanie Dimmeler
Keyword(s):  
Progenitor Cells ◽  
Progenitor Cell ◽  
Matrix Protein ◽  
Therapeutic Potential ◽  
Limb Ischemia ◽  
Β1 Integrin ◽  
Nucleotide Exchange ◽  
Β2 Integrin ◽  
The Matrix

Cell therapy is a novel promising option for treatment of ischemic diseases. Administered endothelial progenitor cells (EPCs) are recruited to ischemic regions and improve neovascularization. However, the number of cells that home to ischemic tissues is restricted. The GTPase Rap1 plays an important role in the regulation of adhesion and chemotaxis. We investigated whether pharmacologic activation of Epac1, a nucleotide exchange protein for Rap1, which is directly activated by cAMP, can improve the adhesive and migratory capacity of distinct progenitor cell populations. Stimulation of Epac by a cAMP-analog increased Rap1 activity and stimulated the adhesion of human EPCs, CD34+ hematopoietic progenitor cells, and mesenchymal stem cells (MSCs). Specifically, short-term stimulation with a specific Epac activator increased the β2-integrin–dependent adhesion of EPCs to endothelial cell monolayers, and of EPC and CD34+ cells to ICAM-1. Furthermore, the Epac activator enhanced the β1-integrin–dependent adhesion of EPCs and MSCs to the matrix protein fibronectin. In addition, Epac1 activation induced the β1- and β2-integrin–dependent migration of EPCs on fibronectin and fibrinogen. Interestingly, activation of Epac rapidly increased lateral mobility of β1- and β2-integrins, thereby inducing integrin polarization, and stimulated β1-integrin affinity, whereas the β2-integrin affinity was not increased. Furthermore, prestimulation of EPCs with the Epac activator increased homing to ischemic muscles and neovascularization-promoting capacity of intravenously injected EPCs in the model of hind limb ischemia. These data demonstrate that activation of Epac1 increases integrin activity and integrin-dependent homing functions of progenitor cells and enhances their in vivo therapeutic potential. These results may provide a platform for the development of novel therapeutic approaches to improve progenitor cell homing.

scholarly journals Pericyte–fibroblast transition promotes tumor growth and metastasis

2016 ◽  
Vol 113 (38) ◽  
pp. E5618-E5627 ◽  
Author(s):  
Kayoko Hosaka ◽  
Yunlong Yang ◽  
Takahiro Seki ◽  
Carina Fischer ◽  
Olivier Dubey ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cancer Metastasis ◽  
Cancer Invasion ◽  
Mouse Strains ◽  
Stromal Fibroblast ◽  
Loss Of Function ◽  
Invasion And Metastasis ◽  
Tumor Dissemination

Vascular pericytes, an important cellular component in the tumor microenvironment, are often associated with tumor vasculatures, and their functions in cancer invasion and metastasis are poorly understood. Here we show that PDGF-BB induces pericyte–fibroblast transition (PFT), which significantly contributes to tumor invasion and metastasis. Gain- and loss-of-function experiments demonstrate that PDGF-BB-PDGFRβ signaling promotes PFT both in vitro and in in vivo tumors. Genome-wide expression analysis indicates that PDGF-BB–activated pericytes acquire mesenchymal progenitor features. Pharmacological inhibition and genetic deletion of PDGFRβ ablate the PDGF-BB–induced PFT. Genetic tracing of pericytes with two independent mouse strains, TN-AP-CreERT2:R26R-tdTomato and NG2-CreERT2:R26R-tdTomato, shows that PFT cells gain stromal fibroblast and myofibroblast markers in tumors. Importantly, coimplantation of PFT cells with less-invasive tumor cells in mice markedly promotes tumor dissemination and invasion, leading to an increased number of circulating tumor cells and metastasis. Our findings reveal a mechanism of vascular pericytes in PDGF-BB–promoted cancer invasion and metastasis by inducing PFT, and thus targeting PFT may offer a new treatment option of cancer metastasis.

scholarly journals Ras recruits mitotic exit regulator Lte1 to the bud cortex in budding yeast

2003 ◽  
Vol 161 (5) ◽  
pp. 889-897 ◽  
Author(s):  
Satoshi Yoshida ◽  
Ryuji Ichihashi ◽  
Akio Toh-e
Keyword(s):  
Small Gtpase ◽  
Mitotic Exit ◽  
Effector Protein ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Downstream Effector ◽  
Nucleotide Exchange Factor ◽  
Family Protein

ACdc25 family protein Lte1 (low temperature essential) is essential for mitotic exit at a lowered temperature and has been presumed to be a guanine nucleotide exchange factor (GEF) for a small GTPase Tem1, which is a key regulator of mitotic exit. We found that Lte1 physically associates with Ras2-GTP both in vivo and in vitro and that the Cdc25 homology domain (CHD) of Lte1 is essential for the interaction with Ras2. Furthermore, we found that the proper localization of Lte1 to the bud cortex is dependent on active Ras and that the overexpression of a derivative of Lte1 without the CHD suppresses defects in mitotic exit of a Δlte1 mutant and a Δras1 Δras2 mutant. These results suggest that Lte1 is a downstream effector protein of Ras in mitotic exit and that the Ras GEF domain of Lte1 is not essential for mitotic exit but required for its localization.

scholarly journals Rab5 GTPases are required for optimal TORC2 function

2018 ◽  
Vol 218 (3) ◽  
pp. 961-976 ◽  
Author(s):  
Melissa N. Locke ◽  
Jeremy Thorner
Keyword(s):  
Protein Kinase ◽  
Nucleotide Exchange ◽  
Gtpase Activating Protein ◽  
Yeast Saccharomyces Cerevisiae ◽  
Guanine Nucleotide Exchange ◽  
Downstream Effector ◽  
Nucleotide Exchange Factor ◽  
Pronounced Reduction

Target of rapamycin complex-2 (TORC2), a conserved protein kinase complex, is an indispensable regulator of plasma membrane homeostasis. In budding yeast (Saccharomyces cerevisiae), the essential downstream effector of TORC2 is protein kinase Ypk1 and its paralog Ypk2. Muk1, a Rab5-specific guanine nucleotide exchange factor (GEF), was identified in our prior global screen for candidate Ypk1 targets. We confirm here that Muk1 is a substrate of Ypk1 and demonstrate that Ypk1-mediated phosphorylation stimulates Muk1 function in vivo. Strikingly, yeast lacking its two Rab5 GEFs (Muk1 and Vps9) or its three Rab5 paralogs (Vps21/Ypt51, Ypt52, and Ypt53) or overexpressing Msb3, a Rab5-directed GTPase-activating protein, all exhibit pronounced reduction in TORC2-mediated phosphorylation and activation of Ypk1. Vps21 coimmunoprecipitates with TORC2, and immuno-enriched TORC2 is less active in vitro in the absence of Rab5 GTPases. Thus, TORC2-dependent and Ypk1-mediated activation of Muk1 provides a control circuit for positive (self-reinforcing) up-regulation to sustain TORC2-Ypk1 signaling.

scholarly journals CAIX Regulates Invadopodia Formation through Both a pH-Dependent Mechanism and Interplay with Actin Regulatory Proteins

2019 ◽  
Vol 20 (11) ◽  
pp. 2745 ◽  
Author(s):  
Michaela Debreova ◽  
Lucia Csaderova ◽  
Monika Burikova ◽  
Lubomira Lukacikova ◽  
Ivana Kajanova ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Actin Polymerization ◽  
Ph Regulation ◽  
Matrix Degradation ◽  
Lung Colonization ◽  
Actin Regulatory Proteins ◽  
And Migration ◽  
The Impact ◽  
Invadopodia Formation

Tumor metastasis is tightly linked with invasive membrane protrusions, invadopodia, formed by actively invading tumor cells. Hypoxia and pH modulation play a role in the invadopodia formation and in their matrix degradation ability. Tumor-associated carbonic anhydrase IX (CAIX), induced by hypoxia, is essential for pH regulation and migration, predisposing it as an active component of invadopodia. To investigate this assumption, we employed silencing and inhibition of CA9, invadopodia isolation and matrix degradation assay. Quail chorioallantoic membranes with implanted tumor cells, and lung colonization assay in murine model were used to assess efficiency of in vivo invasion and the impact of CAIX targeting antibodies. We showed that CAIX co-distributes to invadopodia with cortactin, MMP14, NBCe1, and phospho-PKA. Suppression or enzymatic inhibition of CAIX leads to impaired invadopodia formation and matrix degradation. Loss of CAIX attenuated phosphorylation of Y421-cortactin and influenced molecular machinery coordinating actin polymerization essential for invadopodia growth. Treatment of tumor cells by CAIX-specific antibodies against carbonic or proteoglycan domains results in reduced invasion and extravasation in vivo. For the first time, we demonstrated in vivo localization of CAIX within invadopodia. Our findings confirm the key role of CAIX in the metastatic process and gives rationale for its targeting during anti-metastatic therapy.

scholarly journals Soft tissue volume augmentation in the oral cavity with a collagen-based 3D matrix with orientated open pore structure

2018 ◽  
Vol 4 (1) ◽  
pp. 237-241
Author(s):  
Leon Olde Damink ◽  
Ingo Heschel ◽  
Hans Leemhuis ◽  
Martina Tortorici ◽  
Bastian Wessing
Keyword(s):  
Soft Tissue ◽  
Pore Structure ◽  
Case Series ◽  
Soft Tissue Augmentation ◽  
Surrounding Tissue ◽  
Tissue Volume ◽  
The Matrix ◽  
3D Matrix

AbstractIn this study, characteristic features of a new regenerative 3D collagen matrix with an orientated open pore structure are studied in-vitro and in-vivo. The noncrosslinked porcine-based resorbable collagen-elastin matrix is designed to provide support during coverage procedures of localized gingival recessions and for local soft tissue augmentation around teeth and implants and is designed to provide an off-the-shelf alternative to autogenous soft tissue grafts. The in-vitro studies show that the mechanical properties (e.g. suture retention, volume recovery after cyclic compression) and the observed active cell migration into the open porous structure of the matrix fulfil essential design requirements. The in-vivo pig animal study shows that the matrix is well integrated into the surrounding tissue and replaced by newly formed autogenous soft tissue without a significant loss in tissue volume. First clinical case series are being performed to further analyse the new 3D matrix in clinical settings.

scholarly journals Signal Pathways Which Promote Invasion and Metastasis: Critical and Distinct Contributions of Extracellular Signal-Regulated Kinase and Ral-Specific Guanine Exchange Factor Pathways

2001 ◽  
Vol 21 (17) ◽  
pp. 5958-5969 ◽  
Author(s):  
Yvona Ward ◽  
Warner Wang ◽  
Elisa Woodhouse ◽  
Ilona Linnoila ◽  
Lance Liotta ◽  
...  
Keyword(s):  
Dominant Negative ◽  
Signal Pathways ◽  
Nucleotide Exchange ◽  
3T3 Cells ◽  
Invasion And Metastasis ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Erk Activity

ABSTRACT Approximately 50% of metastatic tumors contain Ras mutations. Ras proteins can activate at least three downstream signaling cascades mediated by the Raf–MEK–extracellular signal-regulated kinase family, phosphatidylinositol-3 (PI3) kinase, and Ral-specific guanine nucleotide exchange factors (RalGEFs). Here we investigated the contribution of RalGEF and ERK activation to the development of experimental metastasis in vivo and associated invasive properties in vitro. Each pathway contributes distinct properties to the metastatic phenotype. Following lateral tail vein injection, 3T3 cells transformed by constitutively active Raf or MEK produced lung metastasis that displayed circumscribed, noninfiltrating borders. In contrast, 3T3 cells transformed by Ras(12V,37G), a Ras effector mutant that activates RalGEF but not Raf or P13 kinase, formed aggressive, infiltrative metastasis. Dominant negative RalB inhibited Ras(12V,37G)-activated invasion and metastasis, demonstrating the necessity of the RalGEF pathway for a fully transformed phenotype. Moreover, 3T3 cells constitutively expressing a membrane-associated form of RalGEF (RalGDS-CAAX) formed invasive tumors as well, demonstrating that activation of a RalGEF pathway is sufficient to initiate the invasive phenotype. Despite the fact that Ras(12V,37G) expression does not elevate ERK activity, inhibition of this kinase by a conditionally expressed ERK phosphatase demonstrated that ERK activity was necessary for Ras(12V,37G)-transformed cells to express matrix-degrading activity in vitro and tissue invasiveness in vivo. Therefore, these experiments have revealed a hitherto-unknown but essential interaction of the RalGEF and ERK pathways to produce a malignant phenotype. The generality of the role of the RalGEF pathway in metastasis is supported by the finding that Ras(12V,37G) increased the invasiveness of epithelial cells as well as fibroblasts.

Sign in / Sign up

Export Citation Format

Share Document