Millipore Sigma Vibrant Logo
 

cell+signaling+technology


188 Results Advanced Search  
Showing
Products (21)
Documents (132)
Site Content (35)
Can't Find What You're Looking For?
Contact Customer Service

 

  • Collective cell migration requires suppression of actomyosin at cell-cell contacts mediated by DDR1 and the cell polarity regulators Par3 and Par6. 21170030

    Collective cell migration occurs in a range of contexts: cancer cells frequently invade in cohorts while retaining cell-cell junctions. Here we show that collective invasion by cancer cells depends on decreasing actomyosin contractility at sites of cell-cell contact. When actomyosin is not downregulated at cell-cell contacts, migrating cells lose cohesion. We provide a molecular mechanism for this downregulation. Depletion of discoidin domain receptor 1 (DDR1) blocks collective cancer-cell invasion in a range of two-dimensional, three-dimensional and 'organotypic' models. DDR1 coordinates the Par3/Par6 cell-polarity complex through its carboxy terminus, binding PDZ domains in Par3 and Par6. The DDR1-Par3/Par6 complex controls the localization of RhoE to cell-cell contacts, where it antagonizes ROCK-driven actomyosin contractility. Depletion of DDR1, Par3, Par6 or RhoE leads to increased actomyosin contactility at cell-cell contacts, a loss of cell-cell cohesion and defective collective cell invasion.
    Document Type:
    Reference
    Product Catalog Number:
    07-330
    Product Catalog Name:
    Anti-Partitioning-defective 3 Antibody

  • Cell signaling pathways in the mechanisms of neuroprotection afforded by bergamot essential oil against NMDA-induced cell death in vitro. 17401440

    BACKGROUND AND PURPOSE: The effects of bergamot essential oil (BEO; Citrus bergamia, Risso) on excitotoxic neuronal damage was investigated in vitro. EXPERIMENTAL APPROACH: The study was performed in human SH-SY5Y neuroblastoma cells exposed to N-methyl-D-aspartate (NMDA). Cell viability was measured by dye exclusion. Reactive oxygen species (ROS) and caspase-3 activity were measured fluorimetrically. Calpain I activity and the activation (phosphorylation) of Akt and glycogen synthase kinase-3beta (GSK-3beta) were assayed by Western blotting. KEY RESULTS: NMDA induced concentration-dependent, receptor-mediated, death of SH-SY5Y cells, ranging from 11 to 25% (0.25-5 mM). Cell death induced by 1 mM NMDA (21%) was preceded by a significant accumulation of intracellular ROS and by a rapid activation of the calcium-activated protease calpain I. In addition, NMDA caused a rapid deactivation of Akt kinase and this preceded the detrimental activation of the downstream kinase, GSK-3beta. BEO (0.0005-0.01%) concentration dependently reduced death of SH-SY5Y cells caused by 1 mM NMDA. In addition to preventing ROS accumulation and activation of calpain, BEO (0.01%) counteracted the deactivation of Akt and the consequent activation of GSK-3beta, induced by NMDA. Results obtained by using specific fractions of BEO, suggested that monoterpene hydrocarbons were responsible for neuroprotection afforded by BEO against NMDA-induced cell death. CONCLUSIONS AND IMPLICATIONS: Our data demonstrate that BEO reduces neuronal damage caused in vitro by excitotoxic stimuli and that this neuroprotection was associated with prevention of injury-induced engagement of critical death pathways.
    Document Type:
    Reference
    Product Catalog Number:
    MAB1622
    Product Catalog Name:
    Anti-Spectrin alpha chain (nonerythroid) Antibody, clone AA6

  • MT1-MMP- and Cdc42-dependent signaling co-regulate cell invasion and tunnel formation in 3D collagen matrices. 19934222

    Complex signaling events control tumor invasion in three-dimensional (3D) extracellular matrices. Recent evidence suggests that cells utilize both matrix metalloproteinase (MMP)-dependent and MMP-independent means to traverse 3D matrices. Herein, we demonstrate that lysophosphatidic-acid-induced HT1080 cell invasion requires membrane-type-1 (MT1)-MMP-mediated collagenolysis to generate matrix conduits the width of a cellular nucleus. We define these spaces as single-cell invasion tunnels (SCITs). Once established, cells can migrate within SCITs in an MMP-independent manner. Endothelial cells, smooth muscle cells and fibroblasts also generate SCITs during invasive events, suggesting that SCIT formation represents a fundamental mechanism of cellular motility within 3D matrices. Coordinated cellular signaling events are required during SCIT formation. MT1-MMP, Cdc42 and its associated downstream effectors such as MRCK (myotonic dystrophy kinase-related Cdc42-binding kinase) and Pak4 (p21 protein-activated kinase 4), protein kinase Calpha and the Rho-associated coiled-coil-containing protein kinases (ROCK-1 and ROCK-2) coordinate signaling necessary for SCIT formation. Finally, we show that MT1-MMP and Cdc42 are fundamental components of a co-associated invasion-signaling complex that controls directed single-cell invasion of 3D collagen matrices.
    Document Type:
    Reference
    Product Catalog Number:
    MAB3211

  • Glycogen synthase kinase 3 regulates PAX3-FKHR-mediated cell proliferation in human alveolar rhabdomyosarcoma cells. 19995556

    Patients with alveolar rhabdomyosarcoma (ARMS) have poorer response to conventional chemotherapy and lower survival rates than those with embryonal RMS (ERMS). To identify compounds that preferentially block the growth of ARMS, we conducted a small-scale screen of 160 kinase inhibitors against the ARMS cell line Rh30 and ERMS cell line RD and identified inhibitors of glycogen synthase kinase 3 (GSK3), including TWS119 as ARMS-selective inhibitors. GSK3 inhibitors inhibited cell proliferation and induced apoptosis more effectively in Rh30 than RD cells. Ectopic expression of fusion protein PAX3-FKHR in RD cells significantly increased their sensitivity to TWS119. Down-regulation of GSK3 by GSK3 inhibitors or siRNA significantly reduced the transcriptional activity of PAX3-FKHR. These results suggest that GSK3 is directly involved in regulating the transcriptional activity of PAX3-FKHR. Also, GSK3 phosphorylated PAX3-FKHR in vitro, suggesting that GSK3 might regulate PAX3-FKHR activity via phosphorylation. These findings support a novel mechanism of PAX3-FKHR regulation by GSK3 and provide a novel strategy to develop GSK inhibitors as anti-ARMS therapies.
    Document Type:
    Reference
    Product Catalog Number:
    05-412
    Product Catalog Name:
    Anti-GSK3 Antibody, clone 4G-1E

  • Receptor-interacting protein shuttles between cell death and survival signaling pathways. 19955213

    Cross-talk between apoptosis and survival signaling pathways is crucial for regulating tissue processes and mitigating disease. We report that anoikis-apoptosis triggered by loss of extracellular matrix contacts-activates a CD95/Fas-mediated signaling pathway regulated by receptor-interacting protein (RIP), a kinase that shuttles between CD95/Fas-mediated cell death and integrin/focal adhesion kinase (FAK)-mediated survival pathways. RIP's death domain was critical for RIP and Fas association to mediate anoikis. Fas or RIP attenuation reduced this association and suppressed anoikis, whereas their overexpression had the reverse effect. Overexpressing FAK restored RIP and FAK association and inhibited anoikis. Thus, RIP shuttles between CD95/Fas death and FAK survival signaling to mediate anoikis.
    Document Type:
    Reference
    Product Catalog Number:
    05-182

  • Statins inhibit T-acute lymphoblastic leukemia cell adhesion and migration through Rap1b. 21233409

    Statins are known to inhibit signaling of Ras superfamily GTPases and reduce T cell adhesion to ICAM-1. Here, we address the hypothesis that statins affect T cell adhesion and migration by modulating the function of specific GTPases. Statins inhibit the synthesis of mevalonic acid, which is required for farnesyl and geranylgeranyl isoprenoid synthesis. Ras superfamily GTPases are post-translationally isoprenylated to facilitate their anchorage to membranes, where they function to stimulate signal transduction processes. We demonstrate that 1 μM statin inhibits the adhesion, migration, and chemotaxis of the T-ALL cell line CCRF-CEM and TEM of CCRF-CEM and PEER T-ALL cells, but higher statin concentrations are needed to inhibit adhesion of primary T cells. Similar effects are observed following treatment with GGTI-298 or RNA interference-mediated knockdown of Rap1b but not Rap1a, Rac1, Rac2, RhoA, or Cdc42. Statins also alter Rap1 activity and Rap1b localization. Rap1 levels are higher in primary T cells than T-ALL cells, which could explain their reduced sensitivity to statins. These results demonstrate for the first time that the closely related Rap1a and Rap1b isoforms have different functions and suggest that statins or Rap1b depletion could be used to reduce tissue invasion in T-ALL.
    Document Type:
    Reference
    Product Catalog Number:
    07-604

  • Knockdown of cancer testis antigens modulates neural stem cell marker expression in glioblastoma tumor stem cells. 20639497

    The cancer stem cell hypothesis posits that a subpopulation of cancer stem cells is frequently responsible for a tumor's progression and resistance to treatment. The differential cellular morphology and gene expression between cancer stem cells and the majority of the tumor is becoming a point of attack for research into the next generation of therapeutic agents that may work through an induction of differentiation rather than apoptosis. Advances in the field of high-content imaging (HCI), combined with modern shRNA technology and subpopulation analysis tools, have created an ideal screening system to detect these morphological changes in a subset of cells upon gene knockdown. The authors examined several glioblastoma stem cell isolates pre- and postdifferentiation to elucidate the phenotypic effects caused by both serum differentiation and gene knockdown. Neural markers were first characterized in these cells at varying states of differentiation using HCI and immunoblots. The authors then chose one of these isolates, in both the pre- and postdifferentiated forms, for further analysis and screened for morphological changes upon shRNA knockdown of a panel of cancer testis antigens (CTAs). CTAs are a family of proteins that are normally expressed in male germ cells as well as heterogeneously expressed in some metastatic tumors. This gene family has also been implicated in the differentiation of normal human stem cells, therefore making it an ideal candidate for modulation in tumor stem cells. Using their approach, the authors identified the differential effects of gene knockdown in both cell types leading to either changes in neural stem cell marker expression or a decreased cell density likely due to growth arrest or cell death. The resolution that HCI brings to a screen at the subpopulation level makes it an excellent tool for the analysis of phenotypic changes induced by shRNA knockdown in a variety of tumor stem cells.
    Document Type:
    Reference
    Product Catalog Number:
    MAB4343
    Product Catalog Name:
    Anti-SOX-2 Antibody

  • Neuronal c-Abl activation leads to induction of cell cycle and interferon signaling pathways. 22938163

    Expression of active c-Abl in adult mouse forebrain neurons in the AblPP/tTA mice resulted in severe neurodegeneration, particularly in the CA1 region of the hippocampus. Neuronal loss was preceded and accompanied by substantial microgliosis and astrocytosis. In contrast, expression of constitutively active Arg (Abl-related gene) in mouse forebrain neurons (ArgPP/tTA mice) caused no detectable neuronal loss or gliosis, although protein expression and kinase activity were at similar levels to those in the AblPP/tTA mice.To begin to elucidate the mechanism of c-Abl-induced neuronal loss and gliosis, gene expression analysis of AblPP/tTA mouse forebrain prior to development of overt pathology was performed. Selected results from gene expression studies were validated with quantitative reverse transcription PCR , immunoblotting and bromodeoxyuridine (BrdU) labeling, and by immunocytochemistry.Two of the top pathways upregulated in AblPP/tTA mice with c-Abl expression for 2 weeks were cell cycle and interferon signaling. However, only the expression of interferon signaling pathway genes remained elevated at 4 weeks of c-Abl induction. BrdU incorporation studies confirm that, while the cell cycle pathway is upregulated in AblPP/tTA mice at 2 weeks of c-Abl induction, the anatomical localization of the pathway is not consistent with previous pathology seen in the AblPP/tTA mice. Increased expression and activation of STAT1, a known component of interferon signaling and interferon-induced neuronal excitotoxicity, is an early consequence of c-Abl activation in AblPP/tTA mice and occurs in the CA1 region of the hippocampus, the same region that goes on to develop severe neurodegenerative pathology and neuroinflammation. Interestingly, no upregulation of gene expression of interferons themselves was detected.Our data suggest that the interferon signaling pathway may play a role in the pathologic processes caused by c-Abl expression in neurons, and that the AblPP/tTA mouse may be an excellent model for studying sterile inflammation and the effects of interferon signaling in the brain.
    Document Type:
    Reference
    Product Catalog Number:
    05-844
    Product Catalog Name:
    Anti-PLK1 Antibody, clone 35-206

  • A c-Myc-SIRT1 feedback loop regulates cell growth and transformation. 19364925

    The protein deacetylase SIRT1 has been implicated in a variety of cellular functions, including development, cellular stress responses, and metabolism. Increasing evidence suggests that similar to its counterpart, Sir2, in yeast, Caenorhabditis elegans, and Drosophila melanogaster, SIRT1 may function to regulate life span in mammals. However, SIRT1's role in cancer is unclear. During our investigation of SIRT1, we found that c-Myc binds to the SIRT1 promoter and induces SIRT1 expression. However, SIRT1 interacts with and deacetylates c-Myc, resulting in decreased c-Myc stability. As a consequence, c-Myc's transformational capability is compromised in the presence of SIRT1. Overall, our experiments identify a c-Myc-SIRT1 feedback loop in the regulation of c-Myc activity and cellular transformation, supporting/suggesting a role of SIRT1 in tumor suppression.
    Document Type:
    Reference
    Product Catalog Number:
    06-933
    Product Catalog Name:
    Anti-acetyl-Lysine Antibody

  • A "traffic control" role for TGFbeta3: orchestrating dermal and epidermal cell motility during wound healing. 16549496

    Cell migration is a rate-limiting event in skin wound healing. In unwounded skin, cells are nourished by plasma. When skin is wounded, resident cells encounter serum for the first time. As the wound heals, the cells experience a transition of serum back to plasma. In this study, we report that human serum selectively promotes epidermal cell migration and halts dermal cell migration. In contrast, human plasma promotes dermal but not epidermal cell migration. The on-and-off switch is operated by transforming growth factor (TGF) beta3 levels, which are undetectable in plasma and high in serum, and by TGFbeta receptor (TbetaR) type II levels, which are low in epidermal cells and high in dermal cells. Depletion of TGFbeta3 from serum converts serum to a plasmalike reagent. The addition of TGFbeta3 to plasma converts it to a serumlike reagent. Down-regulation of TbetaRII in dermal cells or up-regulation of TbetaRII in epidermal cells reverses their migratory responses to serum and plasma, respectively. Therefore, the naturally occurring plasma--greater than serum--greater than plasma transition during wound healing orchestrates the orderly migration of dermal and epidermal cells.
    Document Type:
    Reference
    Product Catalog Number:
    AB3849
    Product Catalog Name: