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Sample records for adhesion kinase fak

  1. FAK dimerization controls its kinase-dependent functions at focal adhesions

    Brami-Cherrier, Karen

    2014-01-30

    Focal adhesion kinase (FAK) controls adhesion-dependent cell motility, survival, and proliferation. FAK has kinase-dependent and kinase-independent functions, both of which play major roles in embryogenesis and tumor invasiveness. The precise mechanisms of FAK activation are not known. Using x-ray crystallography, small angle x-ray scattering, and biochemical and functional analyses, we show that the key step for activation of FAK\\'s kinase-dependent functions-autophosphorylation of tyrosine-397-requires site-specific dimerization of FAK. The dimers form via the association of the N-terminal FERM domain of FAK and are stabilized by an interaction between FERM and the C-terminal FAT domain. FAT binds to a basic motif on FERM that regulates co-activation and nuclear localization. FAK dimerization requires local enrichment, which occurs specifically at focal adhesions. Paxillin plays a dual role, by recruiting FAK to focal adhesions and by reinforcing the FAT:FERM interaction. Our results provide a structural and mechanistic framework to explain how FAK combines multiple stimuli into a site-specific function. The dimer interfaces we describe are promising targets for blocking FAK activation. © 2014 The Authors.

  2. The direct effect of Focal Adhesion Kinase (FAK), dominant-negative FAK, FAK-CD and FAK siRNA on gene expression and human MCF-7 breast cancer cell tumorigenesis

    Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays an important role in survival signaling. FAK has been shown to be overexpressed in breast cancer tumors at early stages of tumorigenesis. To study the direct effect of FAK on breast tumorigenesis, we developed Tet-ON (tetracycline-inducible) system of MCF-7 breast cancer cells stably transfected with FAK or dominant-negative, C-terminal domain of FAK (FAK-CD), and also FAKsiRNA with silenced FAK MCF-7 stable cell line. Increased expression of FAK in isogenic Tet-inducible MCF-7 cells caused increased cell growth, adhesion and soft agar colony formation in vitro, while expression of dominant-negative FAK inhibitor caused inhibition of these cellular processes. To study the role of induced FAK and FAK-CD in vivo, we inoculated these Tet-inducible cells in nude mice to generate tumors in the presence or absence of doxycycline in the drinking water. FAKsiRNA-MCF-7 cells were also injected into nude mice to generate xenograft tumors. Induction of FAK resulted in significant increased tumorigenesis, while induced FAK-CD resulted in decreased tumorigenesis. Taq Man Low Density Array assay demonstrated specific induction of FAKmRNA in MCF-7-Tet-ON-FAK cells. DMP1, encoding cyclin D binding myb-like protein 1 was one of the genes specifically affected by Tet-inducible FAK or FAK-CD in breast xenograft tumors. In addition, silencing of FAK in MCF-7 cells with FAK siRNA caused increased cell rounding, decreased cell viability in vitro and inhibited tumorigenesis in vivo. Importantly, Affymetrix microarray gene profiling analysis using Human Genome U133A GeneChips revealed >4300 genes, known to be involved in apoptosis, cell cycle, and adhesion that were significantly down- or up-regulated (p < 0.05) by FAKsiRNA. Thus, these data for the first time demonstrate the direct effect of FAK expression and function on MCF-7 breast cancer tumorigenesis in vivo and reveal specific expression of genes affected by

  3. The direct effect of Focal Adhesion Kinase (FAK, dominant-negative FAK, FAK-CD and FAK siRNA on gene expression and human MCF-7 breast cancer cell tumorigenesis

    Zhang Li

    2009-08-01

    Full Text Available Abstract Background Focal adhesion kinase (FAK is a non-receptor tyrosine kinase that plays an important role in survival signaling. FAK has been shown to be overexpressed in breast cancer tumors at early stages of tumorigenesis. Methods To study the direct effect of FAK on breast tumorigenesis, we developed Tet-ON (tetracycline-inducible system of MCF-7 breast cancer cells stably transfected with FAK or dominant-negative, C-terminal domain of FAK (FAK-CD, and also FAKsiRNA with silenced FAK MCF-7 stable cell line. Increased expression of FAK in isogenic Tet-inducible MCF-7 cells caused increased cell growth, adhesion and soft agar colony formation in vitro, while expression of dominant-negative FAK inhibitor caused inhibition of these cellular processes. To study the role of induced FAK and FAK-CD in vivo, we inoculated these Tet-inducible cells in nude mice to generate tumors in the presence or absence of doxycycline in the drinking water. FAKsiRNA-MCF-7 cells were also injected into nude mice to generate xenograft tumors. Results Induction of FAK resulted in significant increased tumorigenesis, while induced FAK-CD resulted in decreased tumorigenesis. Taq Man Low Density Array assay demonstrated specific induction of FAKmRNA in MCF-7-Tet-ON-FAK cells. DMP1, encoding cyclin D binding myb-like protein 1 was one of the genes specifically affected by Tet-inducible FAK or FAK-CD in breast xenograft tumors. In addition, silencing of FAK in MCF-7 cells with FAK siRNA caused increased cell rounding, decreased cell viability in vitro and inhibited tumorigenesis in vivo. Importantly, Affymetrix microarray gene profiling analysis using Human Genome U133A GeneChips revealed >4300 genes, known to be involved in apoptosis, cell cycle, and adhesion that were significantly down- or up-regulated (p Conclusion Thus, these data for the first time demonstrate the direct effect of FAK expression and function on MCF-7 breast cancer tumorigenesis in vivo and reveal

  4. Vascular growth responses to chronic arterial occlusion are unaffected by myeloid specific focal adhesion kinase (FAK) deletion.

    Heuslein, Joshua L; Murrell, Kelsey P; Leiphart, Ryan J; Llewellyn, Ryan A; Meisner, Joshua K; Price, Richard J

    2016-01-01

    Arteriogenesis, or the lumenal expansion of pre-existing arterioles in the presence of an upstream occlusion, is a fundamental vascular growth response. Though alterations in shear stress stimulate arteriogenesis, the migration of monocytes into the perivascular space surrounding collateral arteries and their differentiation into macrophages is critical for this vascular growth response to occur. Focal adhesion kinase's (FAK) role in regulating cell migration has recently been expanded to primary macrophages. We therefore investigated the effect of the myeloid-specific conditional deletion of FAK on vascular remodeling in the mouse femoral arterial ligation (FAL) model. Using laser Doppler perfusion imaging, whole mount imaging of vascular casted gracilis muscles, and immunostaining for CD31 in gastrocnemius muscles cross-sections, we found that there were no statistical differences in perfusion recovery, arteriogenesis, or angiogenesis 28 days after FAL. We therefore sought to determine FAK expression in different myeloid cell populations. We found that FAK is expressed at equally low levels in Ly6C(hi) and Ly6C(lo) blood monocytes, however expression is increased over 2-fold in bone marrow derived macrophages. Ultimately, these results suggest that FAK is not required for monocyte migration to the perivascular space and that vascular remodeling following arterial occlusion occurs independently of myeloid specific FAK. PMID:27244251

  5. Mycosporine-Like Amino Acids Promote Wound Healing through Focal Adhesion Kinase (FAK and Mitogen-Activated Protein Kinases (MAP Kinases Signaling Pathway in Keratinocytes

    Yun-Hee Choi

    2015-11-01

    Full Text Available Mycosporine-like amino acids (MAAs are secondary metabolites found in diverse marine, freshwater, and terrestrial organisms. Evidence suggests that MAAs have several beneficial effects on skin homeostasis such as protection against UV radiation and reactive oxygen species (ROS. In addition, MAAs are also involved in the modulation of skin fibroblasts proliferation. However, the regulatory function of MAAs on wound repair in human skin is not yet clearly elucidated. To investigate the roles of MAAs on the wound healing process in human keratinocytes, three MAAs, Shinorine (SH, Mycosporine-glycine (M-Gly, and Porphyra (P334 were purified from Chlamydomonas hedlyei and Porphyra yezoensis. We found that SH, M-Gly, and P334 have significant effects on the wound healing process in human keratinocytes and these effects were mediated by activation of focal adhesion kinases (FAK, extracellular signal-regulated kinases (ERK, and c-Jun N-terminal kinases (JNK. These results suggest that MAAs accelerate wound repair by activating the FAK-MAPK signaling pathways. This study also indicates that MAAs can act as a new wound healing agent and further suggests that MAAs might be a novel biomaterial for wound healing therapies.

  6. High expression of focal adhesion kinase (p125FAK) in node-negative breast cancer is related to overexpression of HER-2/neu and activated Akt kinase but does not predict outcome

    Focal adhesion kinase (FAK) regulates multiple cellular processes including growth, differentiation, adhesion, motility and apoptosis. In breast carcinoma, FAK overexpression has been linked to cancer progression but the prognostic relevance remains unknown. In particular, with regard to lymph node-negative breast cancer it is important to identify high-risk patients who would benefit from further adjuvant therapy. We analyzed 162 node-negative breast cancer cases to determine the prognostic relevance of FAK expression, and we investigated the relationship of FAK with major associated signaling pathways (HER2, Src, Akt and extracellular regulated kinases) by immunohistochemistry and western blot analysis. Elevated FAK expression did not predict patient outcome, in contrast to tumor grading (P = 0.005), Akt activation (P = 0.0383) and estrogen receptor status (P = 0.0033). Significant positive correlations were observed between elevated FAK expression and HER2 overexpression (P = 0.001), as well as phospho-Src Tyr-215 (P = 0.021) and phospho-Akt (P < 0.001), but not with phospho-ERK1/2 (P = 0.108). Western blot analysis showed a significant correlation of FAK Tyr-861 activation and HER2 overexpression (P = 0.01). Immunohistochemical detection of FAK expression is of no prognostic significance in node-negative breast cancer but provides evidence that HER2 is involved in tumor malignancy and metastatic ability of breast cancer through a novel signaling pathway participating FAK and Src

  7. Vascular growth responses to chronic arterial occlusion are unaffected by myeloid specific focal adhesion kinase (FAK) deletion

    Heuslein, Joshua L.; Murrell, Kelsey P.; Leiphart, Ryan J.; Llewellyn, Ryan A.; Meisner, Joshua K.; Price, Richard J.

    2016-05-01

    Arteriogenesis, or the lumenal expansion of pre-existing arterioles in the presence of an upstream occlusion, is a fundamental vascular growth response. Though alterations in shear stress stimulate arteriogenesis, the migration of monocytes into the perivascular space surrounding collateral arteries and their differentiation into macrophages is critical for this vascular growth response to occur. Focal adhesion kinase’s (FAK) role in regulating cell migration has recently been expanded to primary macrophages. We therefore investigated the effect of the myeloid-specific conditional deletion of FAK on vascular remodeling in the mouse femoral arterial ligation (FAL) model. Using laser Doppler perfusion imaging, whole mount imaging of vascular casted gracilis muscles, and immunostaining for CD31 in gastrocnemius muscles cross-sections, we found that there were no statistical differences in perfusion recovery, arteriogenesis, or angiogenesis 28 days after FAL. We therefore sought to determine FAK expression in different myeloid cell populations. We found that FAK is expressed at equally low levels in Ly6Chi and Ly6Clo blood monocytes, however expression is increased over 2-fold in bone marrow derived macrophages. Ultimately, these results suggest that FAK is not required for monocyte migration to the perivascular space and that vascular remodeling following arterial occlusion occurs independently of myeloid specific FAK.

  8. Focal adhesion kinase overexpression and its impact on human osteosarcoma

    Chen, Yong; Yang, Aizhen; Chen, Hui; Zhang, Jian; Wu, Sujia; Shi, Xin; Wang, Chen; Sun, Xiaoliang

    2015-01-01

    Focal adhesion kinase (FAK) has been implicated in tumorigenesis in various malignancies. We sought to examine the expression patterns of FAK and the activated form, phosphorylated FAK (pFAK), in human osteosarcoma and to investigate the correlation of FAK expression with clinicopathologic parameters and prognosis. In addition, the functional consequence of manipulating the FAK protein level was investigated in human osteosarcoma cell lines. Immunohistochemical staining was used to detect FAK and pFAK in pathologic archived materials from 113 patients with primary osteosarcoma. Kaplan-Meier survival and Cox regression analyses were performed to evaluate the prognoses. The role of FAK in the cytological behavior of MG63 and 143B human osteosarcoma cell lines was studied via FAK protein knock down with siRNA. Cell proliferation, migration, invasiveness and apoptosis were assessed using the CCK8, Transwell and Annexin V/PI staining methods. Both FAK and pFAK were overexpressed in osteosarcoma. There were significant differences in overall survival between the FAK-/pFAK- and FAK+/pFAK- groups (P = 0.016), the FAK+/pFAK- and FAK+/pFAK+ groups (P = 0.012) and the FAK-/pFAK- and FAK+/pFAK+ groups (P < 0.001). There were similar differences in metastasis-free survival between groups. The Cox proportional hazards analysis showed that the FAK expression profile was an independent indicator of both overall and metastasis-free survival. siRNA-based knockdown of FAK not only dramatically reduced the migration and invasion of MG63 and 143B cells, but also had a distinct effect on osteosarcoma cell proliferation and apoptosis. These results collectively suggest that FAK overexpression and phosphorylation might predict more aggressive biologic behavior in osteosarcoma and may be an independent predictor of poor prognosis. PMID:26393679

  9. Novel Phosphotidylinositol 4,5-Bisphosphate Binding Sites on Focal Adhesion Kinase

    Jun Feng; Blake Mertz

    2015-01-01

    Focal adhesion kinase (FAK) is a protein tyrosine kinase that is ubiquitously expressed, recruited to focal adhesions, and engages in a variety of cellular signaling pathways. Diverse cellular responses, such as cell migration, proliferation, and survival, are regulated by FAK. Prior to activation, FAK adopts an autoinhibited conformation in which the FERM domain binds the kinase domain, blocking access to the activation loop and substrate binding site. Activation of FAK occurs through confor...

  10. FAK, talin and PIPKIγ regulate endocytosed integrin activation to polarize focal adhesion assembly.

    Nader, Guilherme P F; Ezratty, Ellen J; Gundersen, Gregg G

    2016-05-01

    Integrin endocytic recycling is critical for cell migration, yet how recycled integrins assemble into new adhesions is unclear. By synchronizing endocytic disassembly of focal adhesions (FAs), we find that recycled integrins reassemble FAs coincident with their return to the cell surface and dependent on Rab5 and Rab11. Unexpectedly, endocytosed integrins remained in an active but unliganded state in endosomes. FAK and Src kinases co-localized with endocytosed integrin and were critical for FA reassembly by regulating integrin activation and recycling, respectively. FAK sustained the active integrin conformation by maintaining talin association with Rab11 endosomes in a type I phosphatidylinositol phosphate kinase (PIPKIγ)-dependent manner. In migrating cells, endocytosed integrins reassembled FAs polarized towards the leading edge, and this polarization required FAK. These studies identify unanticipated roles for FA proteins in maintaining endocytosed integrin in an active conformation. We propose that the conformational memory of endocytosed integrin enhances polarized reassembly of FAs to enable directional cell migration. PMID:27043085

  11. Synergism of FAK and tyrosine kinase inhibition in Ph+ B-ALL

    Churchman, Michelle L.; Evans, Kathryn; Richmond, Jennifer; Robbins, Alissa; Jones, Luke; Shapiro, Irina M.; Pachter, Jonathan A.; Weaver, David T.; Houghton, Peter J.; Smith, Malcolm A.; Lock, Richard B.; Mullighan, Charles G.

    2016-01-01

    BCR-ABL1+ B progenitor acute lymphoblastic leukemia (Ph+ B-ALL) is an aggressive disease that frequently responds poorly to currently available therapies. Alterations in IKZF1, which encodes the lymphoid transcription factor Ikaros, are present in over 80% of Ph+ ALL and are associated with a stem cell–like phenotype, aberrant adhesion molecule expression and signaling, leukemic cell adhesion to the bone marrow stem cell niche, and poor outcome. Here, we show that FAK1 is upregulated in Ph+ B-ALL with further overexpression in IKZF1-altered cells and that the FAK inhibitor VS-4718 potently inhibits aberrant FAK signaling and leukemic cell adhesion, potentiating responsiveness to tyrosine kinase inhibitors, inducing cure in vivo. Thus, targeting FAK with VS-4718 is an attractive approach to overcome the deleterious effects of FAK overexpression in Ph+ B-ALL, particularly in abrogating the adhesive phenotype induced by Ikaros alterations, and warrants evaluation in clinical trials for Ph+ B-ALL, regardless of IKZF1 status. PMID:27123491

  12. Focal Adhesion Kinases in Adhesion Structures and Disease

    Pierre P. Eleniste

    2012-01-01

    Full Text Available Cell adhesion to the extracellular matrix (ECM is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases.

  13. Focal adhesion kinases in adhesion structures and disease.

    Eleniste, Pierre P; Bruzzaniti, Angela

    2012-01-01

    Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases. PMID:22888421

  14. FAK acts as a suppressor of RTK-MAP kinase signalling in Drosophila melanogaster epithelia and human cancer cells.

    Juan Pablo Macagno

    2014-03-01

    Full Text Available Receptor Tyrosine Kinases (RTKs and Focal Adhesion Kinase (FAK regulate multiple signalling pathways, including mitogen-activated protein (MAP kinase pathway. FAK interacts with several RTKs but little is known about how FAK regulates their downstream signalling. Here we investigated how FAK regulates signalling resulting from the overexpression of the RTKs RET and EGFR. FAK suppressed RTKs signalling in Drosophila melanogaster epithelia by impairing MAPK pathway. This regulation was also observed in MDA-MB-231 human breast cancer cells, suggesting it is a conserved phenomenon in humans. Mechanistically, FAK reduced receptor recycling into the plasma membrane, which resulted in lower MAPK activation. Conversely, increasing the membrane pool of the receptor increased MAPK pathway signalling. FAK is widely considered as a therapeutic target in cancer biology; however, it also has tumour suppressor properties in some contexts. Therefore, the FAK-mediated negative regulation of RTK/MAPK signalling described here may have potential implications in the designing of therapy strategies for RTK-driven tumours.

  15. Focal Adhesion Kinases in Adhesion Structures and Disease

    Pierre P. Eleniste; Angela Bruzzaniti

    2012-01-01

    Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organiza...

  16. Targeting FAK using inhibitors of Protein-Protein Interactions

    Philippe Rond?

    2015-01-01

    The Focal Adhesion Kinase (FAK) is involved in many aspects of the metastatic process including adhesion, migration, and invasion. Indeed, overexpression, hyperphosphorylation and/or elevated activity of FAK have been described in a variety of human cancers. Thus, the development of FAK antagonists as anti-cancer therapy, led to several small inhibitors of FAK kinase function that are currently undergoing clinical trials. FAK is a ubiquitously expressed non-receptor cytoplasmic tyrosine kinas...

  17. Progress in researches about focal adhesion kinase in gastrointestinal tract

    Hui Fang Hao, Yoshio Naomoto, Xiao-Hong Bao, Nobuyuki Watanabe, Kazufumi Sakurama, Kazuhiro Noma, Yasuko Tomono, Takuya Fukazawa, Yasuhiro Shirakawa, Tomoki Yamatsuji, Junji Matsuoka, Munenori Takaoka

    2009-12-01

    Full Text Available Focal adhesion kinase (FAK is a 125-kDa non-receptor protein tyrosine. Growth factors or the clustering of integrins facilitate the rapid phosphorylation of FAK at Tyr-397 and this in turn recruits Src-family protein tyrosine kinases, resulting in the phosphorylation of Tyr-576 and Tyr-577 in the FAK activation loop and full catalytic FAK activation. FAK plays a critical role in the biological processes of normal and cancer cells including the gastrointestinal tract. FAK also plays an important role in the restitution, cell survival and apoptosis and carcinogenesis of the gastrointestinal tract. FAK is over-expressed in cancer cells and its over-expression and elevated activities are associated with motility and invasion of cancer cells. FAK has been proposed as a potential target in cancer therapy. Small molecule inhibitors effectively inhibit the kinase activity of FAK and show a potent inhibitory effect for the proliferation and migration of tumor cells, indicating a high potential for application in cancer therapy.

  18. Retinoic acid induces nuclear FAK translocation and reduces breast cancer cell adhesion through Moesin, FAK, and Paxillin.

    Sanchez, Angel Matías; Shortrede, Jorge Eduardo; Vargas-Roig, Laura María; Flamini, Marina Inés

    2016-07-15

    Breast cancer is the most common malignancy in women, with metastases being the cause of death in 98%. In previous works we have demonstrated that retinoic acid (RA), the main retinoic acid receptor (RAR) ligand, is involved in the metastatic process by inhibiting migration through a reduced expression of the specific migration-related proteins Moesin, c-Src, and FAK. At present, our hypothesis is that RA also acts for short periods in a non-genomic action to cooperate with motility reduction and morphology of breast cancer cells. Here we identify that the administration of 10(-6) M RA (10-20 min) induces the activation of the migration-related proteins Moesin, FAK, and Paxillin in T-47D breast cancer cells. The phosphorylation exerted by the selective agonists for RARα and RARβ, on Moesin, FAK, and Paxillin was comparable to the activation exerted by RA. The RARγ agonist only led to a weak activation, suggesting the involvement of RARα and RARβ in this pathway. We then treated the cells with different inhibitors that are involved in cell signaling to regulate the mechanisms of cell motility. RA failed to activate Moesin, FAK, and Paxillin in cells treated with Src inhibitor (PP2) and PI3K inhibitor (WM), suggesting the participation of Src-PI3K in this pathway. Treatment with 10(-6) M RA for 20 min significantly decreased cell adhesion. However, when cells were treated with 10(-6) M RA and FAK inhibitor, the RA did not significantly inhibit adhesion, suggesting a role of FAK in the adhesion inhibited by RA. By immunofluorescence and immunoblotting analysis we demonstrated that RA induced nuclear FAK translocation leading to a reduced cellular adhesion. These findings provide new information on the actions of RA for short periods. RA participates in cell adhesion and subsequent migration, modulating the relocation and activation of proteins involved in cell migration. PMID:27130522

  19. Novel Phosphotidylinositol 4,5-Bisphosphate Binding Sites on Focal Adhesion Kinase.

    Jun Feng

    Full Text Available Focal adhesion kinase (FAK is a protein tyrosine kinase that is ubiquitously expressed, recruited to focal adhesions, and engages in a variety of cellular signaling pathways. Diverse cellular responses, such as cell migration, proliferation, and survival, are regulated by FAK. Prior to activation, FAK adopts an autoinhibited conformation in which the FERM domain binds the kinase domain, blocking access to the activation loop and substrate binding site. Activation of FAK occurs through conformational change, and acidic phospholipids such as phosphatidylinositol 4,5-bisphosphate (PIP2 are known to facilitate this process. PIP2 binding alters the autoinhibited conformation of the FERM and kinase domains and subsequently exposes the activation loop to phosphorylation. However, the detailed molecular mechanism of PIP2 binding and its role in FAK activation remain unclear. In this study, we conducted coarse-grained molecular dynamics simulations to investigate the binding of FAK to PIP2. Our simulations identified novel areas of basic residues in the kinase domain of FAK that potentially undergo transient binding to PIP2 through electrostatic attractions. Our investigation provides a molecular picture of PIP2-initiated FAK activation and introduces promising new pathways for future studies of FAK regulation.

  20. Focal adhesion kinase is required for synovial fibroblast invasion, but not murine inflammatory arthritis

    Shelef, Miriam A; Bennin, David A.; Yasmin, Nihad; Warner, Thomas F; Ludwig, Thomas; Beggs, Hilary E.; Huttenlocher, Anna

    2014-01-01

    Introduction Synovial fibroblasts invade cartilage and bone, leading to joint destruction in rheumatoid arthritis. However, the mechanisms that regulate synovial fibroblast invasion are not well understood. Focal adhesion kinase (FAK) has been implicated in cellular invasion in several cell types, and FAK inhibitors are in clinical trials for cancer treatment. Little is known about the role of FAK in inflammatory arthritis, but, given its expression in synovial tissue, its known role in invas...

  1. Targeting FAK in human cancer: from finding to first clinical trials

    Golubovskaya, Vita M.

    2014-01-01

    It is twenty years since Focal Adhesion Kinase (FAK) was found to be overexpressed in many types of human cancer. FAK plays an important role in adhesion, spreading, motility, invasion, metastasis, survival, angiogenesis, and recently has been found to play an important role as well in epithelial to mesenchymal transition (EMT), cancer stem cells and tumor microenvironment. FAK has kinase-dependent and kinase independent scaffolding, cytoplasmic and nuclear functions. Several years ago FAK wa...

  2. Focal adhesion kinase regulates expression of thioredoxin-interacting protein (TXNIP) in cancer cells.

    Ho, Baotran; Huang, Grace; Golubovskaya, Vita M

    2014-01-01

    Focal Adhesion Kinase (FAK) plays an important role in cancer cell survival. Previous microarray gene profiling study detected inverse regulation between expression of thioredoxin-interacting protein (TXNIP) and FAK, where down-regulation of FAK by siRNA in MCF-7 cells caused up-regulation of TXNIP mRNA level, and in contrast up-regulation of doxycyclin- induced FAK caused repression of TXNIP. In the present report, we show that overexpression of FAK in MCF-7 cells repressed TXNIP promoter activity. Treatment of MCF-7 cells with 1alpha, 25-dihydroxyvitamin D3 (1,25D) down-regulated endogenous FAK and up-regulated TXNIP protein level, and treatment with 5-FU decreased FAK protein expression and up-regulated TXNIP protein expression in 293 cells. Moreover, silencing of FAK with siRNA increased TXNIP protein expression, while overexpression of FAK inhibited TXNIP protein expression in 293 cells. In addition, treatment of DBTRG glioblastoma cells with FAK inhibitor Y15 increased TXNIP mRNA, decreased cancer cell viability and increased apoptosis. These results for the first time demonstrate FAK-regulated TXNIP expression which is important for apoptotic, survival and oxidative stress signaling pathways in cancer cells. PMID:23387972

  3. The Protrusive Phase and Full Development of Integrin-Dependent Adhesions in Colon Epithelial Cells Require FAK- and ERKMediated Actin Spike Formation: Deregulation in Cancer Cells

    Valerie G. Brunton

    2001-01-01

    Full Text Available Integrins play an important role in tumour progression by influencing cellular responses and matrix-dependent adhesion. However, the regulation of matrix-dependent adhesion assembly in epithelial cells is poorly understood. We have investigated the integrin and signalling requirements of cell-matrix adhesion assembly in colon carcinoma cells after plating on fibronectin. Adhesion assembly in these, and in the adenoma cells from which they were derived, was largely dependent on αvβ6 integrin and required phosphorylation of FAK on tyrosine-397. The rate of fibronectin-induced adhesion assembly and the expression of both αvβ6 integrin and FAK were increased during the adenoma-to-carcinoma transition. The matrix-dependent adhesion assembly process, particularly the final stages of complex protrusion that is required for optimal cell spreading, required the activity of extracellular signal-regulated kinase (ERK. Furthermore, phosphorylated ERK was targeted to newly forming cell-matrix adhesions in the carcinoma cells but not the adenoma cells, and inhibition of FAK-tyrosine-397 phosphorylation or MEK suppressed the appearance of phosphorylated ERK at peripheral sites. In addition, inhibition of MEK-ERK activation blocked the formation of peripheral actin microspikes that were necessary for the protrusive phase of cell-matrix adhesion assembly. Thus, MEK-ERK-dependent peripheral actin re-organization is required for the full development of integrin-induced adhesions and this pathway is stimulated in an in vitro model of colon cancer progression.

  4. Expression of focal adhesion kinase in the eutopic endometrium of women with adenomyosis varies with dysmenorrhea and pelvic pain

    Mu, Lin; Chen, Weimin; Ma, Yanyan; Zheng, Wei

    2015-01-01

    The aim of the present study was to examine whether the expression of focal adhesion kinase (FAK) is altered in the eutopic endometrium of female patients with adenomyosis, as compared with that of females without adenomyosis. The expression of FAK was assessed by immunohistochemical, western blot and reverse transcription-quantitative polymerase chain reaction analyses. An elevated expression of FAK mRNA and protein was identified in the eutopic endometrium of patients with adenomyosis compa...

  5. Recruitment of focal adhesion kinase and paxillin to β1 integrin promotes cancer cell migration via mitogen activated protein kinase activation

    Integrin-extracellular matrix interactions activate signaling cascades such as mitogen activated protein kinases (MAPK). Integrin binding to extracellular matrix increases tyrosine phosphorylation of focal adhesion kinase (FAK). Inhibition of FAK activity by expression of its carboxyl terminus decreases cell motility, and cells from FAK deficient mice also show reduced migration. Paxillin is a focal adhesion protein which is also phosphorylated on tyrosine. FAK recruitment of paxillin to the cell membrane correlates with Shc phosphorylation and activation of MAPK. Decreased FAK expression inhibits papilloma formation in a mouse skin carcinogenesis model. We previously demonstrated that MAPK activation was required for growth factor induced in vitro migration and invasion by human squamous cell carcinoma (SCC) lines. Adapter protein recruitment to integrin subunits was examined by co-immunoprecipitation in SCC cells attached to type IV collagen or plastic. Stable clones overexpressing FAK or paxillin were created using the lipofection technique. Modified Boyden chambers were used for invasion assays. In the present study, we showed that FAK and paxillin but not Shc are recruited to the β1 integrin cytoplasmic domain following attachment of SCC cells to type IV collagen. Overexpression of either FAK or paxillin stimulated cancer cell migration on type IV collagen and invasion through reconstituted basement membrane which was dependent on MAPK activity. We concluded that recruitment of focal adhesion kinase and paxillin to β1 integrin promoted cancer cell migration via the mitogen activated protein kinase pathway

  6. Recruitment of focal adhesion kinase and paxillin to β1 integrin promotes cancer cell migration via mitogen activated protein kinase activation

    Ohannessian Arthur

    2004-05-01

    Full Text Available Abstract Background Integrin-extracellular matrix interactions activate signaling cascades such as mitogen activated protein kinases (MAPK. Integrin binding to extracellular matrix increases tyrosine phosphorylation of focal adhesion kinase (FAK. Inhibition of FAK activity by expression of its carboxyl terminus decreases cell motility, and cells from FAK deficient mice also show reduced migration. Paxillin is a focal adhesion protein which is also phosphorylated on tyrosine. FAK recruitment of paxillin to the cell membrane correlates with Shc phosphorylation and activation of MAPK. Decreased FAK expression inhibits papilloma formation in a mouse skin carcinogenesis model. We previously demonstrated that MAPK activation was required for growth factor induced in vitro migration and invasion by human squamous cell carcinoma (SCC lines. Methods Adapter protein recruitment to integrin subunits was examined by co-immunoprecipitation in SCC cells attached to type IV collagen or plastic. Stable clones overexpressing FAK or paxillin were created using the lipofection technique. Modified Boyden chambers were used for invasion assays. Results In the present study, we showed that FAK and paxillin but not Shc are recruited to the β1 integrin cytoplasmic domain following attachment of SCC cells to type IV collagen. Overexpression of either FAK or paxillin stimulated cancer cell migration on type IV collagen and invasion through reconstituted basement membrane which was dependent on MAPK activity. Conclusions We concluded that recruitment of focal adhesion kinase and paxillin to β1 integrin promoted cancer cell migration via the mitogen activated protein kinase pathway.

  7. Crystallization of the focal adhesion kinase targeting (FAT) domain in a primitive orthorhombic space group

    X-ray diffraction data from the targeting (FAT) domain of focal adhesion kinase (FAK) were collected from a single crystal that diffracted to 1.99 Å resolution. X-ray diffraction data from the targeting (FAT) domain of focal adhesion kinase (FAK) were collected from a single crystal that diffracted to 1.99 Å resolution and reduced to the primitive orthorhombic lattice. A single molecule was predicted to be present in the asymmetric unit based on the Matthews coefficient. The data were phased using molecular-replacement methods using an existing model of the FAK FAT domain. All structures of human focal adhesion kinase FAT domains solved to date have been solved in a C-centered orthorhombic space group

  8. FAK and HAS Inhibition Synergistically Decrease Colon Cancer Cell Viability and Affect Expression of Critical Genes

    Heffler, Melissa; Golubovskaya, Vita; Conroy, Jeffrey; Liu, Song; Wang, Dan; Cance, William; Dunn, Kelli B.

    2013-01-01

    Focal adhesion kinase (FAK), hyaluronan (HA), and hyaluronan synthase-3 (HAS3) have been implicated in cancer growth and progression. FAK inhibition with the small molecule inhibitor Y15 decreases colon cancer cell growth in vitro and in vivo. HAS3 inhibition in colon cancer cells decreases FAK expression and activation, and exogenous HA increases FAK activation. We sought to determine the genes affected by HAS and FAK inhibition and hypothesized that dual inhibition would synergistically inh...

  9. Heat shock protein 90β stabilizes focal adhesion kinase and enhances cell migration and invasion in breast cancer cells

    Xiong, Xiangyang [Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 17 Yongwai Street, Donghu District, Nanchang, Jiangxi 330006 (China); Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi 330006 (China); State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047 (China); Wang, Yao [Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 17 Yongwai Street, Donghu District, Nanchang, Jiangxi 330006 (China); Liu, Chengmei [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047 (China); Lu, Quqin [Department of Biostatistics and Epidemiology, School of Public Health, Nanchang University, Nanchang, Jiangxi 330006 (China); Liu, Tao [Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 17 Yongwai Street, Donghu District, Nanchang, Jiangxi 330006 (China); Chen, Guoan [Department of Hematology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006 (China); Rao, Hai [Department of Molecular Medicine, University of Texas Health Science Center, San Antonio, TX 78229 (United States); Luo, Shiwen, E-mail: shiwenluo@ncu.edu.cn [Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, 17 Yongwai Street, Donghu District, Nanchang, Jiangxi 330006 (China)

    2014-08-01

    Focal adhesion kinase (FAK) acts as a regulator of cellular signaling and may promote cell spreading, motility, invasion and survival in malignancy. Elevated expression and activity of FAK frequently correlate with tumor cell metastasis and poor prognosis in breast cancer. However, the mechanisms by which the turnover of FAK is regulated remain elusive. Here we report that heat shock protein 90β (HSP90β) interacts with FAK and the middle domain (amino acids 233–620) of HSP90β is mainly responsible for this interaction. Furthermore, we found that HSP90β regulates FAK stability since HSP90β inhibitor 17-AAG triggers FAK ubiquitylation and subsequent proteasome-dependent degradation. Moreover, disrupted FAK-HSP90β interaction induced by 17-AAG contributes to attenuation of tumor cell growth, migration, and invasion. Together, our results reveal how HSP90β regulates FAK stability and identifies a potential therapeutic strategy to breast cancer. - Highlights: • HSP90β protects FAK from degradation by the ubiquitin-proteasome pathway. • Inhibition of HSP90β or FAK attenuates tumorigenesis of breast cancer cells. • Genetic repression of HSP90β or FAK inhibits tumor cell migration and proliferation. • Inhibition of HSP90β or FAK interferes cell invasion and cytoskeleton.

  10. Conformational Dynamics of the Focal Adhesion Targeting Domain Control Specific Functions of Focal Adhesion Kinase in Cells

    Kadaré, Gress

    2015-01-02

    Focal adhesion (FA) kinase (FAK) regulates cell survival and motility by transducing signals from membrane receptors. The C-terminal FA targeting (FAT) domain of FAK fulfils multiple functions, including recruitment to FAs through paxillin binding. Phosphorylation of FAT on Tyr925 facilitates FA disassembly and connects to the MAPK pathway through Grb2 association, but requires dissociation of the first helix (H1) of the four-helix bundle of FAT. We investigated the importance of H1 opening in cells by comparing the properties of FAK molecules containing wild-type or mutated FAT with impaired or facilitated H1 openings. These mutations did not alter the activation of FAK, but selectively affected its cellular functions, including self-association, Tyr925 phosphorylation, paxillin binding, and FA targeting and turnover. Phosphorylation of Tyr861, located between the kinase and FAT domains, was also enhanced by the mutation that opened the FAT bundle. Similarly phosphorylation of Ser910 by ERK in response to bombesin was increased by FAT opening. Although FAK molecules with the mutation favoring FAT opening were poorly recruited at FAs, they efficiently restored FA turnover and cell shape in FAK-deficient cells. In contrast, the mutation preventing H1 opening markedly impaired FAK function. Our data support the biological importance of conformational dynamics of the FAT domain and its functional interactions with other parts of the molecule.

  11. How to awaken your nanomachines: Site-specific activation of focal adhesion kinases through ligand interactions

    Walkiewicz, Katarzyna W.

    2015-06-17

    The focal adhesion kinase (FAK) and the related protein-tyrosine kinase 2-beta (Pyk2) are highly versatile multidomain scaffolds central to cell adhesion, migration, and survival. Due to their key role in cancer metastasis, understanding and inhibiting their functions are important for the development of targeted therapy. Because FAK and Pyk2 are involved in many different cellular functions, designing drugs with partial and function-specific inhibitory effects would be desirable. Here, we summarise recent progress in understanding the structural mechanism of how the tug-of-war between intramolecular and intermolecular interactions allows these protein ‘nanomachines’ to become activated in a site-specific manner.

  12. Dual targeting of EGFR and focal adhesion kinase in 3D grown HNSCC cell cultures

    Purpose: Epidermal growth factor receptor (EGFR) and focal adhesion kinase (FAK) show frequent overexpression and hyperactivity in various human malignancies including head and neck squamous cell carcinomas (HNSCC). To examine effects of dual EGFR/FAK inhibition on cellular radiosensitivity of HNSCC cells in a more physiological environment, we employed a previously established laminin-rich extracellular matrix (lrECM) based three-dimensional (3D) cell culture model. Materials and methods: UTSCC15 and SAS HNSCC cell lines stably transfected with EGFR-CFP or CFP were used. Single or combined EGFR (Cetuximab, siRNA) and FAK (TAE226, siRNA) inhibition were accomplished prior to measuring clonogenic survival and protein expression and phosphorylation. Immunofluorescence enabled visualization of EGFR-CFP and FAK. Results: Cetuximab resulted in higher radiosensitization in EGFR-CFP overexpressing cell lines than CFP controls. Single EGFR or FAK inhibition mediated radiosensitization, while dual EGFR/FAK targeting further augmented this effect. Despite signaling alterations upon Cetuximab and siRNA knockdown, analysis of protein expression and phosphorylation indicates EGFR and FAK signaling coexistence without obvious overlap. Conclusions: Combined EGFR/FAK targeting yielded stronger radiosensitization than either approach alone, which might be based on non-overlapping downstream signaling. Whether dual targeting of EGFR and FAK can reasonably be combined with radiotherapy and chemotherapy needs clarification.

  13. The role of focal adhesion kinase in the regulation of cellular mechanical properties

    Mierke, Claudia Tanja

    2013-12-01

    The regulation of mechanical properties is necessary for cell invasion into connective tissue or intra- and extravasation through the endothelium of blood or lymph vessels. Cell invasion is important for the regulation of many healthy processes such as immune response reactions and wound healing. In addition, cell invasion plays a role in disease-related processes such as tumor metastasis and autoimmune responses. Until now the role of focal adhesion kinase (FAK) in regulating mechanical properties of cells and its impact on cell invasion efficiency is still not well known. Thus, this review focuses on mechanical properties regulated by FAK in comparison to the mechano-regulating protein vinculin. Moreover, it points out the connection between cancer cell invasion and metastasis and FAK by showing that FAK regulates cellular mechanical properties required for cellular motility. Furthermore, it sheds light on the indirect interaction of FAK with vinculin by binding to paxillin, which then impairs the binding of paxillin to vinculin. In addition, this review emphasizes whether FAK fulfills regulatory functions similar to vinculin. In particular, it discusses the differences and the similarities between FAK and vinculin in regulating the biomechanical properties of cells. Finally, this paper highlights that both focal adhesion proteins, vinculin and FAK, synergize their functions to regulate the mechanical properties of cells such as stiffness and contractile forces. Subsequently, these mechanical properties determine cellular invasiveness into tissues and provide a source sink for future drug developments to inhibit excessive cell invasion and hence, metastases formation.

  14. The role of focal adhesion kinase in the regulation of cellular mechanical properties

    The regulation of mechanical properties is necessary for cell invasion into connective tissue or intra- and extravasation through the endothelium of blood or lymph vessels. Cell invasion is important for the regulation of many healthy processes such as immune response reactions and wound healing. In addition, cell invasion plays a role in disease-related processes such as tumor metastasis and autoimmune responses. Until now the role of focal adhesion kinase (FAK) in regulating mechanical properties of cells and its impact on cell invasion efficiency is still not well known. Thus, this review focuses on mechanical properties regulated by FAK in comparison to the mechano-regulating protein vinculin. Moreover, it points out the connection between cancer cell invasion and metastasis and FAK by showing that FAK regulates cellular mechanical properties required for cellular motility. Furthermore, it sheds light on the indirect interaction of FAK with vinculin by binding to paxillin, which then impairs the binding of paxillin to vinculin. In addition, this review emphasizes whether FAK fulfills regulatory functions similar to vinculin. In particular, it discusses the differences and the similarities between FAK and vinculin in regulating the biomechanical properties of cells. Finally, this paper highlights that both focal adhesion proteins, vinculin and FAK, synergize their functions to regulate the mechanical properties of cells such as stiffness and contractile forces. Subsequently, these mechanical properties determine cellular invasiveness into tissues and provide a source sink for future drug developments to inhibit excessive cell invasion and hence, metastases formation. (paper)

  15. Ganoderiol A-enriched extract suppresses migration and adhesion of MDA-MB-231 cells by inhibiting FAK-SRC-paxillin cascade pathway.

    Guo-Sheng Wu

    Full Text Available Cell adhesion, migration and invasion are critical steps for carcinogenesis and cancer metastasis. Ganoderma lucidum, also called Lingzhi in China, is a traditional Chinese medicine, which exhibits anti-proliferation, anti-inflammation and anti-metastasis properties. Herein, GAEE, G. lucidum extract mainly contains ganoderiol A (GA, dihydrogenated GA and GA isomer, was shown to inhibit the abilities of adhesion and migration, while have a slight influence on that of invasion in highly metastatic breast cancer MDA-MB-231 cells at non-toxic doses. Further investigation revealed that GAEE decreased the active forms of focal adhesion kinase (FAK and disrupted the interaction between FAK and SRC, which lead to deactivating of paxillin. Moreover, GAEE treatment downregulated the expressions of RhoA, Rac1, and Cdc42, and decreased the interaction between neural Wiskott-Aldrich Syndrome protein (N-WASP and Cdc42, which impair cell migration and actin assembly. To our knowledge, this is the first report to show that G.lucidum triterpenoids could suppress cell migration and adhesion through FAK-SRC-paxillin signaling pathway. Our study also suggests that GAEE may be a potential agent for treatment of breast cancer.

  16. Disruption of focal adhesion kinase and p53 interaction with small molecule compound R2 reactivated p53 and blocked tumor growth

    Golubovskaya, Vita M.; Ho, Baotran; Zheng, Min; Magis, Andrew; Ostrov, David; Morrison, Carl; Cance, William G.

    2013-01-01

    Background Focal Adhesion Kinase (FAK) is a 125 kDa non-receptor kinase that plays a major role in cancer cell survival and metastasis. Methods We performed computer modeling of the p53 peptide containing the site of interaction with FAK, predicted the peptide structure and docked it into the three-dimensional structure of the N-terminal domain of FAK involved in the complex with p53. We screened small molecule compounds that targeted the site of the FAK-p53 interaction and identified compoun...

  17. Focal adhesion kinase as a mechanotransducer during rapid brain growth of the chick embryo.

    Desmond, Mary E; Knepper, Janice E; DiBenedetto, Angela J; Malaugh, Elizabeth; Callejo, Sagrario; Carretero, Raquel; Alonso, Maria-Isabel; Gato, Angel

    2014-01-01

    Expansion of the hollow fluid-filled embryonic brain occurs by an increase in intraluminal pressure created by accumulation of cerebrospinal fluid (CSF). Experiments have shown a direct correlation between cavity pressure and cell proliferation within the neuroepithelium. These findings lead us to ask how mechanistically this might come about. Are there perhaps molecules on the luminal surface of the embryonic neuroepithelium, such as focal adhesion kinases (FAKs) known to respond to tension in other epithelial cells? Immunodetection using antibodies to total FAK and p-FAK was performed with subsequent confocal analysis of the pattern of their activation under normal intraluminal pressure and induced chronic pressure. Western analysis was also done to look at the amount of FAK expression, as well as its activation under these same conditions. Using immunolocalization, we have shown that FAK is present and activated on both apical and basolateral surfaces and within the cytoplasm of the neuroepithelial cells. This pattern changed profoundly when the neuroepithelium was under pressure. By Western blot, we have shown that FAK was upregulated and activated in the neuroepithelium of the embryos just after the neural tube becomes a closed pressurized system, with phosphorylation detected on the luminal instead of the basal surface, along with an increase in cell proliferation. Chronic hyper-pressure does not induce an increase in phosphorylation of FAK. In conclusion, here we show that neuroepithelial cells respond to intraluminal pressure via FAK phosphorylation on the luminal surface. PMID:24860993

  18. Quantitative changes in focal adhesion kinase and its inhibitor, FRNK, drive load-dependent expression of costamere components.

    Klossner, Stephan; Li, Ruowei; Ruoss, Severin; Durieux, Anne-Cécile; Flück, Martin

    2013-09-15

    Costameres are mechanosensory sites of focal adhesion in the sarcolemma that reinforce the muscle-fiber composite and provide an anchor for myofibrillogenesis. We hypothesized that elevated content of the integrin-associated regulator of costamere turnover in culture, focal adhesion kinase (FAK), drives changes in costamere component content in antigravity muscle in a load-dependent way in correspondence with altered muscle weight. The content of FAK in soleus muscle being phosphorylated at autoregulatory tyrosine 397 (FAK-pY397) was increased after 20 s of stretch. FAK-pY397 content remained elevated after 24 h of stretch-overload due to upregulated FAK content. Overexpression of FAK in soleus muscle fibers by means of gene electrotransfer increased the β1-integrin (+56%) and meta-vinculin (+88%) content. α7-Integrin (P = 0.46) and γ-vinculin (P = 0.18) content was not altered after FAK overexpression. Co-overexpression of the FAK inhibitor FAK-related nonkinase (FRNK) reduced FAK-pY397 content by 33% and increased the percentage of fast-type fibers that arose in connection with hybrid fibers with gene transfer. Transplantation experiments confirmed the association of FRNK expression with slow-to-fast fiber transformation. Seven days of unloading blunted the elevation of FAK-pY397, β1-integrin, and meta-vinculin content with FAK overexpression, and this was reversed by 1 day of reloading. The results highlight that the expression of components for costameric attachment sites of myofibrils is under load- and fiber type-related control via FAK and its inhibitor FRNK. PMID:23904105

  19. Focal adhesion kinase antisense oligodeoxynucleotides inhibit human pulmonary artery smooth muscle cells proliferation and promote human pulmonary artery smooth muscle cells apoptosis

    LIN Chun-long; ZHANG Zhen-xiang; XU Yong-jian; NI Wang; CHEN Shi-xin

    2005-01-01

    Background Pulmonary artery smooth muscle cell (PASMC) proliferation plays an important role in pulmonary vessel structural remodelling. At present, the mechanisms related to proliferation of PASMCs are not clear. Focal adhesion kinase (FAK) is a widely expressed nonreceptor protein tyrosine kinase. Recent research indicates that FAK is implicated in signalling pathways which regulate cytoskeletal organization, adhesion, migration, survival and proliferation of cells. Furthermore, there are no reports about the role of FAK in human pulmonary artery smooth muscle cells (HPASMCs). We investigated whether FAK takes part in the intracellular signalling pathway involved in HPASMCs proliferation and apoptosis, by using antisense oligodeoxynucleotides (ODNs) to selectively suppress the expression of FAK protein.Methods Cultured HPASMCs stimulated by fibronectin (40 μg/ml) were passively transfected with ODNs, sense FAK, mismatch sense and antisense-FAK respectively. Expression of FAK, Jun NH2-terminal kinase (JNK), cyclin-dependent kinase 2 (CDK 2) and caspase-3 proteins were detected by immunoprecipitation and Western blots. Cell cycle and cell apoptosis were analysed by flow cytometry. In addition, cytoplasmic FAK expression was detected by immunocytochemical staining.Results When compared with mismatch sense group, the protein expressions of FAK, JNK and CDK 2 in HPASMCs decreased in antisense-FAK ODNs group and increased in sense-FAK ODNs group significantly. Caspase-3 expression upregulated in HPASMCs when treated with antisense ODNs and downregulated when treated with sense ODNs. When compared with mismatch sense ODNs group, the proportion of cells at G1 phase decreased significantly in sense ODNs group, while the proportion of cells at S phase increased significantly. In contrast, compared with mismatch sense ODNs group, the proportion of cells at G1 phase was increased significantly in antisense-FAK ODNs group. The level of cell apoptosis in antisense-FAK group

  20. Focal Adhesion Kinase Is Required for Intestinal Regeneration and Tumorigenesis Downstream of Wnt/c-Myc Signaling

    Ashton, Gabrielle H.; Morton, Jennifer P; Myant, Kevin; Phesse, Toby J.; Ridgway, Rachel A.; Marsh, Victoria; Wilkins, Julie A.; Athineos, Dimitris; Muncan, Vanesa; Kemp, Richard; Neufeld, Kristi; Clevers, Hans; Brunton, Valerie; Winton, Douglas J.; Wang, Xiaoyan

    2010-01-01

    The intestinal epithelium has a remarkable capacity to regenerate after injury and DNA damage. Here, we show that the integrin effector protein Focal Adhesion Kinase (FAK) is dispensable for normal intestinal homeostasis and DNA damage signaling, but is essential for intestinal regeneration following DNA damage. Given Wnt/c-Myc signaling is activated following intestinal regeneration, we investigated the functional importance of FAK following deletion of the Apc tumor suppressor protein withi...

  1. The effects of CEP-37440, an inhibitor of focal adhesion kinase, in vitro and in vivo on inflammatory breast cancer cells

    Salem, Israa; Alsalahi, Manal; Chervoneva, Inna; Aburto, Lucy D.; Addya, Sankar; Ott, Gregory R.; Ruggeri, Bruce A.; Cristofanilli, Massimo; Fernandez, Sandra V.

    2016-01-01

    Background Inflammatory breast cancer (IBC) is an aggressive type of advanced breast cancer with a poor prognosis. We recently found that focal adhesion kinase 1 (FAK1) is upregulated and phosphorylated (active) in IBC. In this study, we investigated the effect of CEP-37440, a dual inhibitor of FAK1 and anaplastic lymphoma kinase (ALK), using human IBC cell lines and preclinical models of IBC. Methods Cell proliferation assays were performed in the presence of several concentrations of CEP-37...

  2. Evaluation of the Correlation between Focal Adhesion Kinase Phosphorylation and Cell Adhesion Force Using “DEP” Technology

    Huaang-Youh Hurng

    2012-05-01

    Full Text Available Dielectrophoresis (DEP is the phenomenon in which a particle, such as a living cell, is polarized and moved by electrical gravity in a non-uniform electric field. In the present study, the DEP force is utilized to act on the cells to induce spatial movement for investigating the correlation between the cell adhesion force and activation level of focal adhesion kinase (FAK. The DEP force produced by the non-uniform electric field was used to measure the cell adhesion force of ECV304 cells, on type 1 collagen (COL1- and fibronectin (FN-coated polydimethylsiloxane (PDMS membranes. For COL1-coating, ECV304 cells revealed weak and variable adhesion force (0.343–0.760 nN in the first eight hours of incubation. Interestingly, the cell adhesion force of ECV304 at two and five hours of cultivation was significantly high and matched their FAK activation level. In comparison, ECV304 on FN-coated membrane had higher and more stable cell adhesion force (0.577–2.053 nN. FN coating intensified the cell adhesion force of ECV304 with culture time and similar outcome was present on the activation level of FAK. Therefore, this study demonstrated a relationship between cell adhesion force and FAK activation level that was dependant on the choice of the extracellular matrix (ECM component. Subsequently, two tyrosine kinase inhibitors (AG18 and genistein and one PI3K inhibitor (LY294002 were applied to study the influence of protein phosphorylation on the cell adhesion force. FAK plays an important role on cell attachment and DEP force measurement is a useful technique for studying cell adhesion.

  3. Dissociation of FAK/p130CAS/c-Src Complex during Mitosis: Role of Mitosis-specific Serine Phosphorylation of FAK

    Yamakita, Yoshihiko; Totsukawa, Go; Yamashiro, Shigeko; Fry, David; Zhang, Xiaoe; Hanks, Steven K.; Matsumura, Fumio

    1999-01-01

    At mitosis, focal adhesions disassemble and the signal transduction from focal adhesions is inactivated. We have found that components of focal adhesions including focal adhesion kinase (FAK), paxillin, and p130CAS (CAS) are serine/threonine phosphorylated during mitosis when all three proteins are tyrosine dephosphorylated. Mitosis-specific phosphorylation continues past cytokinesis and is reversed during post-mitotic cell spreading. We have found two significant alterations in FAK-mediated ...

  4. Copper deficiency induced emphysema is associated with focal adhesion kinase inactivation.

    Shiro Mizuno

    Full Text Available BACKGROUND: Copper is an important regulator of hypoxia inducible factor 1 alpha (HIF-1α dependent vascular endothelial growth factor (VEGF expression, and is also required for the activity of lysyl oxidase (LOX to effect matrix protein cross-linking. Cell detachment from the extracellular matrix can induce apoptosis (anoikis via inactivation of focal adhesion kinase (FAK. METHODOLOGY: To examine the molecular mechanisms whereby copper depletion causes the destruction of the normal alveolar architecture via anoikis, Male Sprague-Dawley rats were fed a copper deficient diet for 6 weeks while being treated with the copper chelator, tetrathiomolybdate. Other groups of rats were treated with the inhibitor of auto-phosphorylation of FAK, 1,2,4,5-benzenetetraamine tetrahydrochloride (1,2,4,5-BT or FAK small interfering RNA (siRNA. PRINCIPAL FINDINGS: Copper depletion caused emphysematous changes, decreased HIF-1α activity, and downregulated VEGF expression in the rat lungs. Cleaved caspase-3, caspase-8 and Bcl-2 interacting mediator of cell death (Bim expression was increased, and the phosphorylation of FAK was decreased in copper depleted rat lungs. Administration of 1,2,4,5-BT and FAK siRNA caused emphysematous lung destruction associated with increased expression of cleaved capase-3, caspase-8 and Bim. CONCLUSIONS: These data indicate that copper-dependent mechanisms contribute to the pathogenesis of emphysema, which may be associated with decreased HIF-1α and FAK activity in the lung.

  5. Neural cell adhesion molecule-stimulated neurite outgrowth depends on activation of protein kinase C and the Ras-mitogen-activated protein kinase pathway

    Kolkova, K; Novitskaya, V; Pedersen, N;

    2000-01-01

    ), protein kinase C (PKC), and the Ras-mitogen-activated protein (MAP) kinase pathway. This was done using a coculture system consisting of PC12-E2 cells grown on fibroblasts, with or without NCAM expression, allowing NCAM-NCAM interactions resulting in neurite outgrowth. PC12-E2 cells were transiently......The signal transduction pathways associated with neural cell adhesion molecule (NCAM)-induced neuritogenesis are only partially characterized. We here demonstrate that NCAM-induced neurite outgrowth depends on activation of p59(fyn), focal adhesion kinase (FAK), phospholipase Cgamma (PLCgamma...... transfected with expression plasmids encoding constitutively active forms of Ras, Raf, MAP kinase kinases MEK1 and 2, dominant negative forms of Ras and Raf, and the FAK-related nonkinase. Alternatively, PC12-E2 cells were submitted to treatment with antibodies to the fibroblast growth factor (FGF) receptor...

  6. Focal adhesion kinase regulation in stem cell alignment and spreading on nanofibers.

    Andalib, Mohammad Nahid; Lee, Jeong Soon; Ha, Ligyeom; Dzenis, Yuris; Lim, Jung Yul

    2016-05-13

    While electrospun nanofibers have demonstrated the potential for novel tissue engineering scaffolds, very little is known about the molecular mechanism of how cells sense and adapt to nanofibers. Here, we revealed the role of focal adhesion kinase (FAK), one of the key molecular sensors in the focal adhesion complex, in regulating mesenchymal stem cell (MSC) shaping on nanofibers. We produced uniaxially aligned and randomly distributed nanofibers from poly(l-lactic acid) to have the same diameters (about 130 nm) and evaluated MSC behavior on these nanofibers comparing with that on flat PLLA control. C3H10T1/2 murine MSCs exhibited upregulations in FAK expression and phosphorylation (pY397) on nanofibrous cultures as assessed by immunoblotting, and this trend was even greater on aligned nanofibers. MSCs showed significantly elongated and well-spread morphologies on aligned and random nanofibers, respectively. In the presence of FAK silencing via small hairpin RNA (shRNA), cell elongation length in the aligned nanofiber direction (cell major axis length) was significantly decreased, while cells still showed preferred orientation along the aligned nanofibers. On random nanofibers, MSCs with FAK-shRNA showed impaired cell spreading resulting in smaller cell area and higher circularity. Our study provides new data on how MSCs shape their morphologies on aligned and random nanofibrous cultures potentially via FAK-mediated mechanism. PMID:27040763

  7. Focal adhesion kinase and Src phosphorylations in HGF-induced proliferation and invasion of human cholangiocarcinoma cell line, HuCCA-1

    Urai Pongchairerk; Jun-Lin Guan; Vijittra Leardkamolkarn

    2005-01-01

    AIM: To study the role of focal adhesion kinase (FAK) and its association with Src in hepatocyte growth factor (HGF)-induced cell signaling in cholangiocarcinoma progression.METHODS: Previously isolated HuCCA-1 cells were re-characterized by immunofluorescent staining and reverse transcriptase-polymerase chain reaction assay for the expression of cytokeratin 19, HGF and c-Met mRNA. Cultured HuCCA-1 cells were treated with HGF and determined for cell proliferation and invasion effects by MTT and invasion assays. Western blotting, immunoprecipitation, and co-immunoprecipitation were also performed to study the phosphorylation and interaction of FAK and Src. A novel Src inhibitor (AZM555130) was applied in cultures to investigate the effects on FAK phosphorylation inhibition and on cell proliferation and invasion.RESULTS: HGF enhanced HuCCA-1 cell proliferation and invasion by mediating FAK and Src phosphorylations.FAK-Src interaction occurred in a time-dependent manner that Src was proved to be an upstream signaling molecule to FAK. The inhibitor to Src decreased FAK phosphorylation level in correlation with the reduction of cell proliferation and invasion.CONCLUSION: FAK plays a significant role in signaling pathway of HGF-responsive cell line derived from cholangiocarcinoma. Autophosphorylated Src, induced by HGF, mediates Src kinase activation, which subsequently phosphorylates its substrate, FAK, and signals to cell proliferation and invasion.

  8. Doxycycline inhibits leukemic cell migration via inhibition of matrix metalloproteinases and phosphorylation of focal adhesion kinase

    WANG, CHUNHUAI; Xiang, Ru; ZHANG, XIANGZHONG; CHEN, YUNXIAN

    2015-01-01

    Doxycycline, a tetracycline-based antibiotic, has been reported to attenuate melanoma cell migration through inhibiting the focal adhesion kinase (FAK) signaling pathway. However, it remains to be elucidated whether doxycycline exerts this effect on leukemia cell migration. The present study aimed to examine the role of doxycycline in leukemia cell migration. The invasion capacities of the human leukemia cell lines KG1a (acute myelogenous leukemia) and K562 (chronic myelogenous leukemia) were...

  9. PIAS1-FAK Interaction Promotes the Survival and Progression of Non-Small Cell Lung Cancer

    Jerfiz D. Constanzo

    2016-05-01

    Full Text Available The sequence of genomic alterations acquired by cancer cells during tumor progression and metastasis is poorly understood. Focal adhesion kinase (FAK is a non-receptor tyrosine kinase that integrates cytoskeleton remodeling, mitogenic signaling and cell survival. FAK has previously been reported to undergo nuclear localization during cell migration, cell differentiation and apoptosis. However, the mechanism behind FAK nuclear accumulation and its contribution to tumor progression has remained elusive. We report that amplification of FAK and the SUMO E3 ligase PIAS1 gene loci frequently co-occur in non-small cell lung cancer (NSCLC cells, and that both gene products are enriched in a subset of primary NSCLCs. We demonstrate that endogenous FAK and PIAS1 proteins interact in the cytoplasm and the cell nucleus of NSCLC cells. Ectopic expression of PIAS1 promotes proteolytic cleavage of the FAK C-terminus, focal adhesion maturation and FAK nuclear localization. Silencing of PIAS1 deregulates focal adhesion turnover, increases susceptibility to apoptosis in vitro and impairs tumor xenograft formation in vivo. Nuclear FAK in turn stimulates gene transcription favoring DNA repair, cell metabolism and cytoskeleton regulation. Consistently, ablation of FAK by CRISPR/Cas9 editing, results in basal DNA damage, susceptibility to ionizing radiation and impaired oxidative phosphorylation. Our findings provide insight into a mechanism regulating FAK cytoplasm-nuclear distribution and demonstrate that FAK activity in the nucleus promotes NSCLC survival and progression by increasing cell-ECM interaction and DNA repair regulation.

  10. An occludin-focal adhesion kinase protein complex at the blood-testis barrier: a study using the cadmium model.

    Siu, Erica R; Wong, Elissa W P; Mruk, Dolores D; Sze, K L; Porto, Catarina S; Cheng, C Yan

    2009-07-01

    Several integral membrane proteins that constitute the blood-testis barrier (BTB) in mammalian testes, in particular rodents, are known to date. These include tight junction (TJ) proteins (e.g. occludin, junctional adhesion molecule-A, claudins), basal ectoplasmic specialization proteins (e.g. N-cadherin), and gap junction proteins (e.g. connexin43). However, the regulators (e.g. protein kinases and phosphatases) that affect these proteins, such as their interaction with the cytoskeletal actin, which in turn confer cell adhesion at the TJ, remain largely unknown. We report herein that focal adhesion kinase (FAK) is a putative interacting partner of occludin, but not claudin-11 or junctional adhesion molecule-A. Immunohistochemistry and fluorescence microscopy studies illustrated that the expression of FAK in the seminiferous epithelium of adult rat testes was stage specific. FAK colocalized with occludin at the BTB in virtually all stages of the seminiferous epithelial cycle but considerably diminished in stages VIII-IX, at the time of BTB restructuring to facilitate the transit of primary leptotene spermatocytes. Using Sertoli cells cultured in vitro with established TJ-permeability barrier and ultrastructures of TJ, basal ectoplasmic specialization and desmosome-like junction that mimicked the BTB in vivo, FAK was shown to colocalize with occludin and zonula occludens-1 (ZO-1) at the Sertoli-Sertoli cell interface. When these Sertoli cell cultures were treated with CdCl(2) to perturb the TJ-barrier function, occludin underwent endocytic-mediated internalization in parallel with FAK and ZO-1. Thus, these findings demonstrate that FAK is an integrated regulatory component of the occludin-ZO-1 protein complex, suggesting that functional studies can be performed to study the role of FAK in BTB dynamics. PMID:19213829

  11. Organization and post-transcriptional processing of focal adhesion kinase gene

    Enslen Hervé

    2006-08-01

    Full Text Available Abstract Background Focal adhesion kinase (FAK is a non-receptor tyrosine kinase critical for processes ranging from embryo development to cancer progression. Although isoforms with specific molecular and functional properties have been characterized in rodents and chicken, the organization of FAK gene throughout phylogeny and its potential to generate multiple isoforms are not well understood. Here, we study the phylogeny of FAK, the organization of its gene, and its post-transcriptional processing in rodents and human. Results A single orthologue of FAK and the related PYK2 was found in non-vertebrate species. Gene duplication probably occurred in deuterostomes after the echinoderma embranchment, leading to the evolution of PYK2 with distinct properties. The amino acid sequence of FAK and PYK2 is conserved in their functional domains but not in their linker regions, with the absence of autophosphorylation site in C. elegans. Comparison of mouse and human FAK genes revealed the existence of multiple combinations of conserved and non-conserved 5'-untranslated exons in FAK transcripts suggesting a complex regulation of their expression. Four alternatively spliced coding exons (13, 14, 16, and 31, previously described in rodents, are highly conserved in vertebrates. Cis-regulatory elements known to regulate alternative splicing were found in conserved alternative exons of FAK or in the flanking introns. In contrast, other reported human variant exons were restricted to Homo sapiens, and, in some cases, other primates. Several of these non-conserved exons may correspond to transposable elements. The inclusion of conserved alternative exons was examined by RT-PCR in mouse and human brain during development. Inclusion of exons 14 and 16 peaked at the end of embryonic life, whereas inclusion of exon 13 increased steadily until adulthood. Study of various tissues showed that inclusion of these exons also occurred, independently from each other, in a

  12. FAK Forms a Complex with MEF2 to Couple Biomechanical Signaling to Transcription in Cardiomyocytes.

    Cardoso, Alisson Campos; Pereira, Ana Helena Macedo; Ambrosio, Andre Luis Berteli; Consonni, Silvio Roberto; Rocha de Oliveira, Renata; Bajgelman, Marcio Chain; Dias, Sandra Martha Gomes; Franchini, Kleber Gomes

    2016-08-01

    Focal adhesion kinase (FAK) has emerged as a mediator of mechanotransduction in cardiomyocytes, regulating gene expression during hypertrophic remodeling. However, how FAK signaling is relayed onward to the nucleus is unclear. Here, we show that FAK interacts with and regulates myocyte enhancer factor 2 (MEF2), a master cardiac transcriptional regulator. In cardiomyocytes exposed to biomechanical stimulation, FAK accumulates in the nucleus, binds to and upregulates the transcriptional activity of MEF2 through an interaction with the FAK focal adhesion targeting (FAT) domain. In the crystal structure (2.9 Å resolution), FAT binds to a stably folded groove in the MEF2 dimer, known to interact with regulatory cofactors. FAK cooperates with MEF2 to enhance the expression of Jun in cardiomyocytes, an important component of hypertrophic response to mechanical stress. These findings underscore a connection between the mechanotransduction involving FAK and transcriptional regulation by MEF2, with potential relevance to the pathogenesis of cardiac disease. PMID:27427476

  13. Targeting the Metastasis Suppressor, N-Myc Downstream Regulated Gene-1, with Novel Di-2-Pyridylketone Thiosemicarbazones: Suppression of Tumor Cell Migration and Cell-Collagen Adhesion by Inhibiting Focal Adhesion Kinase/Paxillin Signaling.

    Wangpu, Xiongzhi; Lu, Jiaoyang; Xi, Ruxing; Yue, Fei; Sahni, Sumit; Park, Kyung Chan; Menezes, Sharleen; Huang, Michael L H; Zheng, Minhua; Kovacevic, Zaklina; Richardson, Des R

    2016-05-01

    Metastasis is a complex process that is regulated by multiple signaling pathways, with the focal adhesion kinase (FAK)/paxillin pathway playing a major role in the formation of focal adhesions and cell motility. N-myc downstream regulated gene-1 (NDRG1) is a potent metastasis suppressor in many solid tumor types, including prostate and colon cancer. Considering the antimetastatic effect of NDRG1 and the crucial involvement of the FAK/paxillin pathway in cellular migration and cell-matrix adhesion, we assessed the effects of NDRG1 on this important oncogenic pathway. In the present study, NDRG1 overexpression and silencing models of HT29 colon cancer and DU145 prostate cancer cells were used to examine the activation of FAK/paxillin signaling and the formation of focal adhesions. The expression of NDRG1 resulted in a marked and significant decrease in the activating phosphorylation of FAK and paxillin, whereas silencing of NDRG1 resulted in an opposite effect. The expression of NDRG1 also inhibited the formation of focal adhesions as well as cell migration and cell-collagen adhesion. Incubation of cells with novel thiosemicarbazones, namely di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone and di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone, that upregulate NDRG1 also resulted in decreased phosphorylation of FAK and paxillin. The ability of these thiosemicarbazones to inhibit cell migration and metastasis could be mediated, at least in part, through the FAK/paxillin pathway. PMID:26895766

  14. Down-regulation of integrin β1 and focal adhesion kinase in renal glomeruli under various hemodynamic conditions.

    Xiaoli Yuan

    Full Text Available Given that integrin β1 is an important component of the connection to maintain glomerular structural integrity, by binding with multiple extracellular matrix proteins and mediating intracellular signaling. Focal adhesion kinase (FAK is the most essential intracellular integrator in the integrin β1-FAK signalling pathway. Here, we investigated the changes of the two molecules and visualized the possible interaction between them under various hemodynamic conditions in podocytes. Mice kidney tissues were prepared using in vivo cryotechnique (IVCT and then were stained and observed using light microscopy, confocal laser scanning microscopy and immunoelectron microscopy. The expression of these molecules were examined by western blot. Under the normal condition, integrin β1 stained continually and evenly at the membrane, and FAK was located in the cytoplasm and nuclei of the podocytes. There were significant colocalized plaques of two molecules. But under acute hypertensive and cardiac arrest conditions, integrin β1 decreased and stained intermittently. Similarly, FAK decreased and appeared uneven. Additionally, FAK translocated to the nuclei of the podocytes. As a result, the colocalization of integrin β1 and FAK reduced obviously under these conditions. Western blot assay showed a consistent result with the immunostaining. Collectively, the abnormal redistribution and decreased expressions of integrin β1 and FAK are important molecular events in regulating the functions of podocytes under abnormal hemodynamic conditions. IVCT could offer considerable advantages for morphological analysis when researching renal diseases.

  15. Laminin α2-mediated focal adhesion kinase activation triggers Alport glomerular pathogenesis.

    Duane Delimont

    Full Text Available It has been known for some time that laminins containing α1 and α2 chains, which are normally restricted to the mesangial matrix, accumulate in the glomerular basement membranes (GBM of Alport mice, dogs, and humans. We show that laminins containing the α2 chain, but not those containing the α1 chain activates focal adhesion kinase (FAK on glomerular podocytes in vitro and in vivo. CD151-null mice, which have weakened podocyte adhesion to the GBM rendering these mice more susceptible to biomechanical strain in the glomerulus, also show progressive accumulation of α2 laminins in the GBM, and podocyte FAK activation. Analysis of glomerular mRNA from both models demonstrates significant induction of MMP-9, MMP-10, MMP-12, MMPs linked to GBM destruction in Alport disease models, as well as the pro-inflammatory cytokine IL-6. SiRNA knockdown of FAK in cultured podocytes significantly reduced expression of MMP-9, MMP-10 and IL-6, but not MMP-12. Treatment of Alport mice with TAE226, a small molecule inhibitor of FAK activation, ameliorated fibrosis and glomerulosclerosis, significantly reduced proteinuria and blood urea nitrogen levels, and partially restored GBM ultrastructure. Glomerular expression of MMP-9, MMP-10 and MMP-12 mRNAs was significantly reduced in TAE226 treated animals. Collectively, this work identifies laminin α2-mediated FAK activation in podocytes as an important early event in Alport glomerular pathogenesis and suggests that FAK inhibitors, if safe formulations can be developed, might be employed as a novel therapeutic approach for treating Alport renal disease in its early stages.

  16. Targeting FAK in human cancer: from finding to first clinical trials.

    Golubovskaya, Vita M

    2014-01-01

    It is twenty years since Focal Adhesion Kinase (FAK) was found to be overexpressed in many types of human cancer. FAK plays an important role in adhesion, spreading, motility, invasion, metastasis, survival, angiogenesis, and recently has been found to play an important role as well in epithelial to mesenchymal transition (EMT), cancer stem cells and tumor microenvironment. FAK has kinase-dependent and kinase independent scaffolding, cytoplasmic and nuclear functions. Several years ago FAK was proposed as a potential therapeutic target; the first clinical trials were just reported, and they supported further studies of FAK as a promising therapeutic target. This review discusses the main functions of FAK in cancer, and specifically focuses on recent novel findings on the role of FAK in cancer stem cells, microenvironment, epithelial-to-mesenchymal transition, invasion, metastasis, and also highlight new approaches of targeting FAK and critically discuss challenges that lie ahead for its targeted therapeutics. The review provides a summary of translational approaches of FAK-targeted and combination therapies and outline perspectives and future directions of FAK research. PMID:24389213

  17. Role of Titanium Surface Topography and Surface Wettability on Focal Adhesion Kinase Mediated Signaling in Fibroblasts

    Douglas W. Hamilton

    2011-05-01

    Full Text Available Changes of titanium surface roughness and surface free energy may influence protein absorption that increases cell differentiation through activation of focal adhesion kinase related pathways. However, the influence of titanium surface roughness and hydrophilicity on fibroblast behavior is not well understood. The aim of this study was to investigate the influence of topography and hydrophilicity on fibroblast attachment, spreading, morphology, intracellular signaling, proliferation, and collagen I mRNA levels. Using a cellular FAK knockout (FAK−/− model and wild-type (WT controls, we also investigated the contribution of adhesion in fibroblasts cultured on smooth (PT, sand-blasted, large grit, acid-etched (SLA and hydrophilic SLA topographies. Loss of FAK did not significantly affect fibroblast attachment to any surface, but SLA and hydrophilic SLA surface attenuated spreading of WT cells significantly more than FAK−/− fibroblasts. Both FAK−/− and WT cells formed numerous focal adhesions on PT surfaces, but significantly less on SLA and hydrophilic SLA surfaces. In WT cells, phosphorylation levels of FAK were lower on SLA and hydrophilic SLA in comparison with PT 24 h post seeding. Labeling of cells with antibodies to cortactin showed that FAK−/−cells contained significantly more cortactin-rich focal adhesion in comparison with WT cells on PT surfaces, but not on SLA or hydrophilic SLA. ERK 1/2 phosphorylation was highest in WT cells on all surfaces which correlated with collagen I expression levels. We conclude that fibroblasts are sensitive to changes in surface roughness and hydrophilicity, with adhesive interactions mediated through FAK, an important modulator of fibroblast response.

  18. Disruption of focal adhesion kinase and p53 interaction with small molecule compound R2 reactivated p53 and blocked tumor growth

    Focal Adhesion Kinase (FAK) is a 125 kDa non-receptor kinase that plays a major role in cancer cell survival and metastasis. We performed computer modeling of the p53 peptide containing the site of interaction with FAK, predicted the peptide structure and docked it into the three-dimensional structure of the N-terminal domain of FAK involved in the complex with p53. We screened small molecule compounds that targeted the site of the FAK-p53 interaction and identified compounds (called Roslins, or R compounds) docked in silico to this site. By different assays in isogenic HCT116p53+/+ and HCT116 p53-/- cells we identified a small molecule compound called Roslin 2 (R2) that bound FAK, disrupted the binding of FAK and p53 and decreased cancer cell viability and clonogenicity in a p53-dependent manner. In addition, dual-luciferase assays demonstrated that the R2 compound increased p53 transcriptional activity that was inhibited by FAK using p21, Mdm-2, and Bax-promoter targets. R2 also caused increased expression of p53 targets: p21, Mdm-2 and Bax proteins. Furthermore, R2 significantly decreased tumor growth, disrupted the complex of FAK and p53, and up-regulated p21 in HCT116 p53+/+ but not in HCT116 p53-/- xenografts in vivo. In addition, R2 sensitized HCT116p53+/+ cells to doxorubicin and 5-fluorouracil. Thus, disruption of the FAK and p53 interaction with a novel small molecule reactivated p53 in cancer cells in vitro and in vivo and can be effectively used for development of FAK-p53 targeted cancer therapy approaches

  19. Homozygous mutation of focal adhesion kinase in embryonic stem cell derived neurons: normal electrophysiological and morphological properties in vitro

    Komiyama NH

    2006-06-01

    Full Text Available Abstract Background Genetically manipulated embryonic stem (ES cell derived neurons (ESNs provide a powerful system with which to study the consequences of gene manipulation in mature, synaptically connected neurons in vitro. Here we report a study of focal adhesion kinase (FAK, which has been implicated in synapse formation and regulation of ion channels, using the ESN system to circumvent the embryonic lethality of homozygous FAK mutant mice. Results Mouse ES cells carrying homozygous null mutations (FAK-/- were generated and differentiated in vitro into neurons. FAK-/- ESNs extended axons and dendrites and formed morphologically and electrophysiologically intact synapses. A detailed study of NMDA receptor gated currents and voltage sensitive calcium currents revealed no difference in their magnitude, or modulation by tyrosine kinases. Conclusion FAK does not have an obligatory role in neuronal differentiation, synapse formation or the expression of NMDA receptor or voltage-gated calcium currents under the conditions used in this study. The use of genetically modified ESNs has great potential for rapidly and effectively examining the consequences of neuronal gene manipulation and is complementary to mouse studies.

  20. Focal adhesion kinase: predictor of tumour response and risk factor for recurrence after neoadjuvant chemoradiation in rectal cancer.

    Gómez Del Pulgar, Teresa; Cebrián, Arancha; Fernández-Aceñero, Maria Jesús; Borrero-Palacios, Aurea; Del Puerto-Nevado, Laura; Martínez-Useros, Javier; Marín-Arango, Juan Pablo; Caramés, Cristina; Vega-Bravo, Ricardo; Rodríguez-Remírez, María; Cruz-Ramos, Marlid; Manzarbeitia, Félix; García-Foncillas, Jesús

    2016-09-01

    Rectal cancer represents about 30% of colorectal cancers, being around 50% locally advanced at presentation. Chemoradiation (CRT) followed by total mesorectal excision is the standard of care for these locally advanced stages. However, it is not free of adverse effects and toxicity and the complete pathologic response rate is between 10% and 30%. This makes it extremely important to define factors that can predict response to this therapy. Focal adhesion kinase (FAK) expression has been correlated with worse prognosis in several tumours and its possible involvement in cancer radio- and chemosensitivity has been suggested; however, its role in rectal cancer has not been analysed yet. To analyse the association of FAK expression with tumour response to CRT in locally advanced rectal cancer. This study includes 73 patients with locally advanced rectal cancer receiving standard neoadjuvant CRT followed by total mesorectal excision. Focal adhesion kinase protein levels were immunohistochemically analysed in the pre-treatment biopsies of these patients and correlated with tumour response to CRT and patients survival. Low FAK expression was significantly correlated with local and distant recurrence (P = 0.013). Low FAK expression was found to be a predictive marker of tumour response to neoadjuvant therapy (P = 0.007) and patients whose tumours did not express FAK showed a strong association with lower disease-free survival (P = 0.01). Focal adhesion kinase expression predicts neoadjuvant CRT response in rectal cancer patients and it is a clinically relevant risk factor for local and distant recurrence. PMID:27171907

  1. Specific shRNA targeting of FAK influenced collagen metabolism in rat hepatic stellate cells

    Robert; Barrett

    2010-01-01

    AIM:To investigate the effects and mechanism of disruption of focal adhesion kinase(FAK) expression on collagen metabolism in rat hepatic stellate cells(HSC).METHODS:The plasmids expressing FAK short hairpin RNA(shRNA) were transfected into HSC-T6 cells,and the level of FAK expression was determined by both real-time quantitative polymerase chain reaction(QPCR) and Western blotting analysis.The production of type collagen and type collagen in FAK-disrupted cells was analyzed by real-time Q-PCR.The level of ...

  2. Therapeutic effects of tyroservatide on metastasis of lung cancer and its mechanism affecting integrin–focal adhesion kinase signal transduction

    Huang YT

    2016-03-01

    Full Text Available Yu-ting Huang,1,* Lan Zhao,1,* Zheng Fu,1 Meng Zhao,1 Xiao-meng Song,1 Jing Jia,1 Song Wang,1 Jin-ping Li,1 Zhi-feng Zhu,1 Gang Lin,1,2 Rong Lu,1,2 Zhi Yao1,3 1Department of Immunology, Tianjin Medical University, Tianjin, 2Shenzhen Kangzhe Pharmaceutical Co., Ltd., Shenzhen, 3Key Laboratory of Immuno Microenvironment and Disease of the Educational Ministry of China, Tianjin Medical University, Tianjin, People’s Republic of China *These authors contributed equally to this paper Abstract: Tyroservatide (YSV can inhibit the growth and metastasis of mouse lung cancer significantly. This study investigated the therapeutic effects of tripeptide YSV on metastasis of human lung cancer cells and explored its possible mechanism that affects integrin–focal adhesion kinase (FAK signal transduction in tumor cells. YSV significantly inhibited the adhesion and the invasion of highly metastatic human lung cancer cell lines 95D, A549, and NCI-H1299. In addition, YSV significantly inhibited phosphorylation of FAK Tyr397 and FAK Tyr576/577 in the 95D, A549, and NCI-H1299 human lung cancer cells in vitro. And the mRNA level and protein expression of FAK in these human lung cancer cells decreased at the same time. YSV also significantly inhibited mRNA and protein levels of integrin ß1 and integrin ß3 in the 95D, A549, and NCI-H1299 human lung cancer cells. Our research showed that YSV inhibited adhesion and invasion of human lung cancer cells and exhibited therapeutic effects on metastasis of lung cancer. Keywords: tyroservatide, integrin, focal adhesion kinase, FAK, MMP-2, MMP-9

  3. Somatic mutational analysis of FAK in breast cancer: A novel gain-of-function mutation due to deletion of exon 33

    Highlights: •A novel FAK splicing mutation identified in breast tumor. •FAK-Del33 mutation promotes cell migration and invasion. •FAK-Del33 mutation regulates FAK/Src signal pathway. -- Abstract: Focal adhesion kinase (FAK) regulates cell adhesion, migration, proliferation, and survival. We identified a novel splicing mutant, FAK-Del33 (exon 33 deletion, KF437463), in both breast and thyroid cancers through colony sequencing. Considering the low proportion of mutant transcripts in samples, this mutation was detected by TaqMan-MGB probes based qPCR. In total, three in 21 paired breast tissues were identified with the FAK-Del33 mutation, and no mutations were found in the corresponding normal tissues. When introduced into a breast cell line through lentivirus infection, FAK-Del33 regulated cell motility and migration based on a wound healing assay. We demonstrated that the expression of Tyr397 (main auto-phosphorylation of FAK) was strongly increased in FAK-Del33 overexpressed breast tumor cells compared to wild-type following FAK/Src RTK signaling activation. These results suggest a novel and unique role of the FAK-Del33 mutation in FAK/Src signaling in breast cancer with significant implications for metastatic potential

  4. Somatic mutational analysis of FAK in breast cancer: A novel gain-of-function mutation due to deletion of exon 33

    Fang, Xu-Qian [Department of Clinical Laboratory, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai (China); Liu, Xiang-Fan [Faculty of Medical Laboratory Science, Shanghai JiaoTong University School of Medicine, Shanghai (China); Yao, Ling [Department of Biochemistry and Molecular Biology, Shanghai JiaoTong University School of Medicine, Shanghai (China); Chen, Chang-Qiang; Gu, Zhi-Dong [Department of Clinical Laboratory, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai (China); Ni, Pei-Hua [Faculty of Medical Laboratory Science, Shanghai JiaoTong University School of Medicine, Shanghai (China); Zheng, Xin-Min [Department of Biochemistry and Molecular Biology, Shanghai JiaoTong University School of Medicine, Shanghai (China); Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY (United States); Fan, Qi-Shi, E-mail: qishifan@126.com [Department of Clinical Laboratory, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai (China)

    2014-01-10

    Highlights: •A novel FAK splicing mutation identified in breast tumor. •FAK-Del33 mutation promotes cell migration and invasion. •FAK-Del33 mutation regulates FAK/Src signal pathway. -- Abstract: Focal adhesion kinase (FAK) regulates cell adhesion, migration, proliferation, and survival. We identified a novel splicing mutant, FAK-Del33 (exon 33 deletion, KF437463), in both breast and thyroid cancers through colony sequencing. Considering the low proportion of mutant transcripts in samples, this mutation was detected by TaqMan-MGB probes based qPCR. In total, three in 21 paired breast tissues were identified with the FAK-Del33 mutation, and no mutations were found in the corresponding normal tissues. When introduced into a breast cell line through lentivirus infection, FAK-Del33 regulated cell motility and migration based on a wound healing assay. We demonstrated that the expression of Tyr397 (main auto-phosphorylation of FAK) was strongly increased in FAK-Del33 overexpressed breast tumor cells compared to wild-type following FAK/Src RTK signaling activation. These results suggest a novel and unique role of the FAK-Del33 mutation in FAK/Src signaling in breast cancer with significant implications for metastatic potential.

  5. PKCθ signaling is required for myoblast fusion by regulating the expression of caveolin-3 and β1D integrin upstream focal adhesion kinase

    Madaro, Luca; Marrocco, Valeria; Fiore, Piera; Aulino, Paola; Smeriglio, Piera; Adamo, Sergio; Molinaro, Mario; Bouché, Marina

    2011-01-01

    Fusion of mononucleated myoblasts to form multinucleated myofibers is an essential phase of skeletal myogenesis, which occurs during muscle development as well as during postnatal life for muscle growth, turnover, and regeneration. Many cell adhesion proteins, including integrins, have been shown to be important for myoblast fusion in vertebrates, and recently focal adhesion kinase (FAK), has been proposed as a key mediator of myoblast fusion. Here we focused on the possible role of PKCθ, the...

  6. Effect of focal adhesion kinase on cytoskeletal arrangement of HepG2 cells induced by hypoxia%黏着斑激酶在缺氧促进肝癌细胞细胞骨架重组中的作用研究

    Wei Yan; Yu Fu; Jiazhi Liao; Limin Xia; Min Luo; Oian Zhu; Dean Tian

    2009-01-01

    Objective: To study focal adhesion kinase (FAK) expression in hypoxic HepG2 cells and the effect of FAK siRNA on cytoskeletal arrangement of HepG2 cells induced by hypoxia. Methods: HepG2 cells were cultured in 21% O2 and 1%O2. Morphological changes were observed after hypoxia treatment. Westem blot was used to measure FAK expression. The siRNA expression vector pshRNA-FAK targeting the mRNA of FAK and vector pGensil-2 (as a control) were constructed, and then transfected into HepG2 cells. Western blot was used to detect FAK. The cytoskeletal arrangement of HepG2 cells trans fected with pshRNA-FAK induced by hypoxia was analyzed by phalloidin. The migratory ability of HepG2 cells transfected with pshRNA-FAK induced by hypoxia was analyzed by cell migration assay. Results: Hypoxia-treated cells displayed a more elongated shape with a large degree of cell detachment. FAK expression increased in hypoxic HepG2 cells. FAK protein level was decreased by 75.64% ± 3.12% (P < 0.01) after the pshRNA-FAK transfection. Hypoxia induced cytoskeletal arrangement of HepG2 cells. However, cytoskeletal arrangement of HepG2 cells transfected with pshRNA-FAK induced by hypoxia was inhibited in 1% O2. As cell migration assay showed, the migrating number of HepG cells transfected with pshRNA-FAK was significantly lower than that of control (P < 0.05). Conclusion: The expression of FAK in hypoxic HCC might have a close relationship to the cytoskeletal arrangement of HepG2 cells induced by hypoxia. Up-regulation of FAK expression may be one of mechanisms of cytoskeletal arrangement and invasion of hepatocellular carcinoma induced by hypoxia.

  7. FAK overexpression and p53 mutations are highly correlated in human breast cancer

    Golubovskaya, Vita M; Conway, Kathleen; Edmiston, Sharon N; Tse, Chiu-Kit; Lark, Amy L.; Livasy, Chad A.; Moore, Dominic; Millikan, Robert C.; Cance, William G

    2009-01-01

    Focal Adhesion Kinase (FAK) is overexpressed in a number of tumors, including breast cancer. Another marker of breast cancer tumorigenesis is the tumor suppressor gene p53 that is frequently mutated in breast cancer. In the present study, our aim was to find a correlation between FAK overexpression, p53 expression and mutation status in a population-based series of invasive breast cancer tumors from the Carolina Breast Cancer Study. Immunohistochemical analyses of 622 breast cancer tumors rev...

  8. Osthole Suppresses the Migratory Ability of Human Glioblastoma Multiforme Cells via Inhibition of Focal Adhesion Kinase-Mediated Matrix Metalloproteinase-13 Expression

    Cheng-Fang Tsai

    2014-03-01

    Full Text Available Glioblastoma multiforme (GBM is the most common type of primary and malignant tumor occurring in the adult central nervous system. GBM often invades surrounding regions of the brain during its early stages, making successful treatment difficult. Osthole, an active constituent isolated from the dried C. monnieri fruit, has been shown to suppress tumor migration and invasion. However, the effects of osthole in human GBM are largely unknown. Focal adhesion kinase (FAK is important for the metastasis of cancer cells. Results from this study show that osthole can not only induce cell death but also inhibit phosphorylation of FAK in human GBM cells. Results from this study show that incubating GBM cells with osthole reduces matrix metalloproteinase (MMP-13 expression and cell motility, as assessed by cell transwell and wound healing assays. This study also provides evidence supporting the potential of osthole in reducing FAK activation, MMP-13 expression, and cell motility in human GBM cells.

  9. Snail1 controls epithelial–mesenchymal lineage commitment in focal adhesion kinase–null embryonic cells

    Li, Xiao-Yan; Zhou, Xiaoming; Rowe, R. Grant; Hu, Yuexian; Schlaepfer, David D.; Ilić, Dusko; Dressler, Gregory; Park, Ann; Guan, Jun-Lin; Weiss, Stephen J.

    2011-01-01

    Mouse embryonic cells isolated from focal adhesion kinase (FAK)–null animals at embryonic day 7.5 display multiple defects in focal adhesion remodeling, microtubule dynamics, mechanotransduction, proliferation, directional motility, and invasion. To date, the ability of FAK to modulate cell function has been ascribed largely to its control of posttranscriptional signaling cascades in this embryonic cell population. In this paper, we demonstrate that FAK unexpectedly exerts control over an epi...

  10. Protocadherin clusters and cell adhesion kinase regulate dendrite complexity through Rho GTPase

    Lun Suo; Huinan Lu; Guoxin Ying; Mario R. Capecchi; Qiang Wu

    2012-01-01

    Dendritic patterning and spine morphogenesis are crucial for the assembly of neuronal circuitry to ensure normal brain development and synaptic connectivity as well as for understanding underlying mechanisms of neuropsychiatric diseases and cognitive impairments.The Rho GTPase family is essential for neuronal morphogenesis and synaptic plasticity by modulating and reorganizing the cytoskeleton.Here,we report that protocadherin (Pcdh) clusters and cell adhesion kinases (CAKs) play important roles in dendritic development and spine elaboration.The knockout of the entire Pcdhα cluster results in the dendritic simplification and spine loss in CA1 pyramidal neurons in vivo and in cultured primary hippocampal neurons in vitro.The knockdown of the whole Pcdhγ cluster or in combination with the Pcdhα knockout results in similar dendritic and spine defects in vitro.The overexpression of proline-rich tyrosine kinase 2 (Pyk2,also known as CAKβ,RAFTK,FAK2,and CADTK) recapitulates these defects and its knockdown rescues the phenotype.Moreover,the genetic deletion of the Pcdhα cluster results in phosphorylation and activation of Pyk2 and focal adhesion kinase (Fak) and the inhibition of Rho GTPases in vivo.Finally,the overexpression of PyK2 leads to inactivation of Rac1 and,conversely,the constitutive active Rac1 rescues the dendritic and spine morphogenesis defects caused by the knockout of the Pcdhα cluster and the knockdown of the Pcdhγ cluster.Thus,the involvement of the Pcdh-CAK-Rho GTPase pathway in the dendritic development and spine morphogenesis has interesting implications for proper assembly of neuronal connections in the brain.

  11. Cooperation between c-Met and focal adhesion kinase family members in medulloblastoma and implications for therapy

    Guessous, Fadila; Yang, Yanzhi; Johnson, Elizabeth; Marcinkiewicz, Lukasz; Smith, Matthew; Zhang, Ying; Kofman, Alexander; Schiff, David; Christensen, James; Abounader, Roger

    2011-01-01

    We previously demonstrated the involvement of the tyrosine kinase receptor c-Met in medulloblastoma malignancy. The nonreceptor tyrosine kinases FAK and Pyk2, are key players in the progression of different cancers. However, their role in medulloblastoma malignancy is not well understood. In this study, using a protein array approach, we found that c-Met phosphorylates FAK and Pyk2 in medulloblastoma cells. We therefore studied the interactions between c-Met and FAK/Pyk2 and their implication...

  12. 3D cell cultures of human head and neck squamous cell carcinoma cells are radiosensitized by the focal adhesion kinase inhibitor TAE226

    Background and purpose: Focal adhesion kinase (FAK), a main player in integrin signaling and survival, is frequently overexpressed in human cancers and therefore postulated as potential target in cancer therapy. The aim of this study was to evaluate the radiosensitizing potential of the FAK inhibitor TAE226 in three-dimensional (3D) tumor cell cultures. Materials and methods: Head and neck squamous cell carcinoma (HNSCC) cells (FaDu, UT-SCC15, UT-SCC45), lung cancer cells (A549), colorectal carcinoma cells (DLD-1, HCT-116) and pancreatic tumor cells (MiaPaCa2, Panc1) were treated with different concentrations of TAE226 (0-1 μm; 1 or 24 h) without or in combination with irradiation (0-6 Gy, X-ray, single dose). Subsequently, 3D clonogenic survival assays (laminin-rich extracellular matrix) and Western blotting (expression/phosphorylation, e.g. FAK, Akt, ERK1/2) were performed. Results: All investigated 3D cell cultures showed a dose-dependent reduction in clonogenic survival by TAE226. Intriguingly, TAE226 only significantly radiosensitized 3D HNSCC cell cultures accompanied by a pronounced dephosphorylation of FAK, Akt and ERK1/2. Conclusions: Our data demonstrate TAE226 as potent FAK inhibitor that enhances the cellular radiosensitivity particularly of HNSCC cells grown in a 3D cell culture model. Future in vitro and in vivo investigations will clarify, to which extent this approach might be clinically relevant for radiotherapy of HNSCC.

  13. Antroquinonol Targets FAK-Signaling Pathway Suppressed Cell Migration, Invasion, and Tumor Growth of C6 Glioma

    Varadharajan Thiyagarajan; May-Jywan Tsai; Ching-Feng Weng

    2015-01-01

    Focal adhesion kinase (FAK) is a non-receptor protein tyrosine that is overexpressed in many types of tumors and plays a pivotal role in multiple cell signaling pathways involved in cell survival, migration, and proliferation. This study attempts to determine the effect of synthesized antroquinonol on the modulation of FAK signaling pathways and explore their underlying mechanisms. Antroquinonol significantly inhibits cell viability with an MTT assay in both N18 neuroblastoma and C6 glioma ce...

  14. Protein kinase C involvement in focal adhesion formation

    Woods, A; Couchman, J R

    1992-01-01

    still to be elucidated. We show here that the kinase inhibitors H7 and HA1004 reduce focal adhesion and stress fiber formation in response to fibronectin in a dose-dependent manner, and that activators of protein kinase C can promote their formation under conditions where they do not normally form...... then treated with kinase inhibitors H7 and HA1004 for 2h, IRM indicated a reduction in focal adhesion formation at concentrations where protein kinase C (PKC) should be inhibited. In contrast, focal adhesions formed normally at concentrations of these inhibitors where cyclic AMP- or cyclic GMP......-dependent kinases should be inactivated. Inhibition of PKC, but not that of cyclic AMP- or cyclic GMP-dependent kinases, also prevented the formation of stress fibers and induced a dispersal of talin and vinculin, but not integrin beta 1 subunits, from small condensations present at 1h. Consistent with the...

  15. Knockdown of FAK inhibits the invasion and metastasis of Tca‑8113 cells in vitro.

    Xiao, Wenbo; Jiang, Mingxin; Li, Hongdan; Li, Chunshan; Su, Rongjian; Huang, Keqiang

    2013-08-01

    Tongue cancer originating on the surface of the tongue is most commonly squamous cell carcinoma, which has a higher invasive ability and a lower survival rate compared with other forms of tongue cancer. Notably, tongue squamous cell carcinomas metastasize into lymph nodes at early stages. Focal adhesion kinase (FAK) is an important protein tyrosine kinase involved in invasion and metastasis of cancer cells. In the present study, the role of FAK in the invasion and metastasis of tongue cancer was evaluated and the underlying mechanisms involved in this process were explored. FAK knockdown was performed using shRNA in the tongue cancer cell line, Tca‑8113, and the invasion and metastasis potentials were analyzed using wound healing and transwell assays, respectively. Cytoskeletal arrangement was detected by fluorescence using TRITC‑conjugated phalloidin staining. The activity of matrix metalloproteinase (MMP)‑2 and ‑9 was examined by gelatin zymography. Paxillin distribution was observed by immunofluorescence. The levels of E‑cadherin, N‑cadherin, MMP‑2 and ‑9, and c‑Jun N‑terminal kinase (JNK) was detected by western blot analysis. Wound healing and transwell assays demonstrated that FAK knockdown inhibited the invasion and metastasis of Tca‑8113 cells. Further analysis revealed that FAK knockdown caused the rearrangement of the cytoskeleton and decreased the activity of MMP‑2 and ‑9. Immunofluorescence analysis revealed that downregulation of FAK induced the relocalization of paxillin. Paxillin accumulated as dots and patches at the cell membrane in control cells. By contrast, in FAK knockdown cells, paxillin was distributed homogeneously in the cytoplasm. Western blot analysis revealed that FAK knockdown inhibited epithelial-mesenchymal transition (EMT) and decreased levels of MMP‑2 and ‑9, and p‑JNK. Knockdown of FAK inhibits the invasion and metastasis of Tca‑8113 by decreasing MMP‑2 and ‑9 activities and led to the

  16. PKCθ signaling is required for myoblast fusion by regulating the expression of caveolin-3 and β1D integrin upstream focal adhesion kinase

    Madaro, Luca; Marrocco, Valeria; Fiore, Piera; Aulino, Paola; Smeriglio, Piera; Adamo, Sergio; Molinaro, Mario; Bouché, Marina

    2011-01-01

    Fusion of mononucleated myoblasts to form multinucleated myofibers is an essential phase of skeletal myogenesis, which occurs during muscle development as well as during postnatal life for muscle growth, turnover, and regeneration. Many cell adhesion proteins, including integrins, have been shown to be important for myoblast fusion in vertebrates, and recently focal adhesion kinase (FAK), has been proposed as a key mediator of myoblast fusion. Here we focused on the possible role of PKCθ, the PKC isoform predominantly expressed in skeletal muscle, in myoblast fusion. We found that the expression of PKCθ is strongly up-regulated following freeze injury–induced muscle regeneration, as well as during in vitro differentiation of satellite cells (SCs; the muscle stem cells). Using both PKCθ knockout and muscle-specific PKCθ dominant-negative mutant mouse models, we observed delayed body and muscle fiber growth during the first weeks of postnatal life, when compared with wild-type (WT) mice. We also found that myofiber formation, during muscle regeneration after freeze injury, was markedly impaired in PKCθ mutant mice, as compared with WT. This phenotype was associated with reduced expression of the myogenic differentiation program executor, myogenin, but not with that of the SC marker Pax7. Indeed in vitro differentiation of primary muscle-derived SCs from PKCθ mutants resulted in the formation of thinner myotubes with reduced numbers of myonuclei and reduced fusion rate, when compared with WT cells. These effects were associated to reduced expression of the profusion genes caveolin-3 and β1D integrin and to reduced activation/phosphorylation of their up-stream regulator FAK. Indeed the exogenous expression of a constitutively active mutant form of PKCθ in muscle cells induced FAK phosphorylation. Moreover pharmacologically mediated full inhibition of FAK activity led to similar fusion defects in both WT and PKCθ-null myoblasts. We thus propose that PKC

  17. FAK activation is required for IGF1R-mediated regulation of EMT, migration, and invasion in mesenchymal triple negative breast cancer cells

    Taliaferro-Smith, LaTonia; Oberlick, Elaine; Liu, Tongrui; McGlothen, Tanisha; Alcaide, Tiffanie; Tobin, Rachel; Donnelly, Siobhan; Commander, Rachel; Kline, Erik; Nagaraju, Ganji Purnachandra; Havel, Lauren; Marcus, Adam; Nahta, Rita; O'Regan, Ruth

    2015-01-01

    Triple negative breast cancer (TNBC) is a highly metastatic disease that currently lacks effective prevention and treatment strategies. The insulin-like growth factor 1 receptor (IGF1R) and focal adhesion kinase (FAK) signaling pathways function in numerous developmental processes, and alterations in both are linked with a number of common pathological diseases. Overexpression of IGF1R and FAK are closely associated with metastatic breast tumors. The present study investigated the interrelati...

  18. Surface wettability of plasma SiOx:H nanocoating-induced endothelial cells' migration and the associated FAK-Rho GTPases signalling pathways.

    Shen, Yang; Wang, Guixue; Huang, Xianliang; Zhang, Qin; Wu, Jiang; Tang, Chaojun; Yu, Qingsong; Liu, Xiaoheng

    2012-02-01

    Vascular endothelial cell (EC) adhesion and migration are essential processes in re-endothelialization of implanted biomaterials. There is no clear relationship and mechanism between EC adhesion and migration behaviour on surfaces with varying wettabilities. As model substrates, plasma SiO(x):H nanocoatings with well-controlled surface wettability (with water contact angles in the range of 98.5 ± 2.3° to 26.3 ± 4.0°) were used in this study to investigate the effects of surface wettability on cell adhesion/migration and associated protein expressions in FAK-Rho GTPases signalling pathways. It was found that EC adhesion/migration showed opposite behaviour on the hydrophilic and hydrophobic surfaces (i.e. hydrophobic surfaces promoted EC migration but were anti-adhesions). The number of adherent ECs showed a maximum on hydrophilic surfaces, while cells adhered to hydrophobic surfaces exhibited a tendency for cell migration. The focal adhesion kinase (FAK) inhibitor targeting the Y-397 site of FAK could significantly inhibit cell adhesion/migration, suggesting that EC adhesion and migration on surfaces with different wettabilities involve (p)FAK and its downstream signalling pathways. Western blot results suggested that the FAK-Rho GTPases signalling pathways were correlative to EC migration on hydrophobic plasma SiO(x):H surfaces, but uncertain to hydrophilic surfaces. This work demonstrated that surface wettability could induce cellular behaviours that were associated with different cellular signalling events. PMID:21715399

  19. Oral administration of FAK inhibitor TAE226 inhibits the progression of peritoneal dissemination of colorectal cancer

    Highlights: ► A novel FAK inhibitor TAE226 suppressed FAK activity in HCT116 colon cancer cells. ► TAE226 suppressed proliferation and migration, with a modest effect on adhesion. ► Silencing of FAK by siRNA made no obvious difference on cancer cell attachment. ► TAE226 treatment suppressed the progression of peritoneal dissemination. ► Oral administration of TAE226 prolonged the survival of tumor-bearing mice. -- Abstract: Peritoneal dissemination is one of the most terrible types of colorectal cancer progression. Focal adhesion kinase (FAK) plays a crucial role in the biological processes of cancer, such as cell attachment, migration, proliferation and survival, all of which are essential for the progression of peritoneal dissemination. Since we and other groups have reported that the inhibition of FAK activity exhibited a potent anticancer effect in several cancer models, we hypothesized that TAE226, a novel ATP-competitive tyrosine kinase inhibitor designed to target FAK, can prevent the occurrence and progression of peritoneal dissemination. In vitro, TAE226 greatly inhibited the proliferation and migration of HCT116 colon cancer cells, while their adhesion on the matrix surface was minimally inhibited when FAK activity and expression was suppressed by TAE226 and siRNA. In vivo, when HCT116 cells were intraperitoneally inoculated in mice, the cells could attach to the peritoneum and begin to grow within 24 h regardless of the pretreatment of cells with TAE226 or FAK-siRNA, suggesting that FAK is not essential, at least for the initial integrin-matrix contact. Interestingly, the treatment of mice before and after inoculation significantly suppressed cell attachment to the peritoneum. Furthermore, oral administration of TAE226 greatly reduced the size of disseminated tumors and prolonged survival in tumor-bearing mice. Taken together, a possible strategy for inhibiting peritoneal dissemination by targeting FAK with TAE226 appears to be applicable

  20. Oral administration of FAK inhibitor TAE226 inhibits the progression of peritoneal dissemination of colorectal cancer

    Hao, Hui-fang [Department of Gastroenterological Surgery, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558 (Japan); Takaoka, Munenori [Department of General Surgery, Kawasaki Medical School, 2-1-80 Nakasange, Kita-ku, Okayama 700-8505 (Japan); Bao, Xiao-hong [Department of Gastroenterological Surgery, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558 (Japan); Wang, Zhi-gang [College of Life Science, Inner Mongolia University, The Key Laboratory of Mammal Reproductive Biology and Biotechnology, Ministry of Education, Hohhot 010021 (China); Tomono, Yasuko [Division of Molecular and Cell Biology, Shigei Medical Research Institute, 2117 Yamada, Okayama 700-0202 (Japan); Sakurama, Kazufumi; Ohara, Toshiaki [Department of Gastroenterological Surgery, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558 (Japan); Fukazawa, Takuya; Yamatsuji, Tomoki [Department of General Surgery, Kawasaki Medical School, 2-1-80 Nakasange, Kita-ku, Okayama 700-8505 (Japan); Fujiwara, Toshiyoshi [Department of Gastroenterological Surgery, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikatacho, Kita-ku, Okayama 700-8558 (Japan); Naomoto, Yoshio, E-mail: ynaomoto@med.kawasaki-m.ac.jp [Department of General Surgery, Kawasaki Medical School, 2-1-80 Nakasange, Kita-ku, Okayama 700-8505 (Japan)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer A novel FAK inhibitor TAE226 suppressed FAK activity in HCT116 colon cancer cells. Black-Right-Pointing-Pointer TAE226 suppressed proliferation and migration, with a modest effect on adhesion. Black-Right-Pointing-Pointer Silencing of FAK by siRNA made no obvious difference on cancer cell attachment. Black-Right-Pointing-Pointer TAE226 treatment suppressed the progression of peritoneal dissemination. Black-Right-Pointing-Pointer Oral administration of TAE226 prolonged the survival of tumor-bearing mice. -- Abstract: Peritoneal dissemination is one of the most terrible types of colorectal cancer progression. Focal adhesion kinase (FAK) plays a crucial role in the biological processes of cancer, such as cell attachment, migration, proliferation and survival, all of which are essential for the progression of peritoneal dissemination. Since we and other groups have reported that the inhibition of FAK activity exhibited a potent anticancer effect in several cancer models, we hypothesized that TAE226, a novel ATP-competitive tyrosine kinase inhibitor designed to target FAK, can prevent the occurrence and progression of peritoneal dissemination. In vitro, TAE226 greatly inhibited the proliferation and migration of HCT116 colon cancer cells, while their adhesion on the matrix surface was minimally inhibited when FAK activity and expression was suppressed by TAE226 and siRNA. In vivo, when HCT116 cells were intraperitoneally inoculated in mice, the cells could attach to the peritoneum and begin to grow within 24 h regardless of the pretreatment of cells with TAE226 or FAK-siRNA, suggesting that FAK is not essential, at least for the initial integrin-matrix contact. Interestingly, the treatment of mice before and after inoculation significantly suppressed cell attachment to the peritoneum. Furthermore, oral administration of TAE226 greatly reduced the size of disseminated tumors and prolonged survival in tumor-bearing mice. Taken

  1. β Integrins Mediate FAK Y397 Autophosphorylation of Resistance Arteries during Eutrophic Inward Remodeling in Hypertension

    Heerkens, Egidius H.J; Quinn, Lisa; Withers, Sarah B.; Heagerty, Anthony M

    2014-01-01

    Human essential hypertension is characterized by eutrophic inward remodeling of the resistance arteries with little evidence of hypertrophy. Upregulation of αVβ3 integrin is crucial during this process. In order to investigate the role of focal adhesion kinase (FAK) activation in this process, the level of FAK Y397 autophosphorylation was studied in small blood vessels from young TGR(mRen2)27 animals as blood pressure rose and eutrophic inward remodeling took place. Between weeks 4 and 5, thi...

  2. Downregulation of Focal Adhesion Kinase (FAK) by cord blood stem cells inhibits angiogenesis in glioblastoma

    Dasari, Venkata Ramesh; Kaur, Kiranpreet; Velpula, Kiran Kumar; Dinh, Dzung H.; Andrew J Tsung; Mohanam, Sanjeeva; Rao, Jasti S.

    2010-01-01

    Angiogenesis involves the formation of new blood vessels by rerouting or remodeling existing ones and is believed to be the primary method of vessel formation in gliomas. To study the mechanisms by which angiogenesis of glioma cells can be inhibited by human umbilical cord blood stem cells (hUCBSC), we studied two glioma cell lines (SNB19, U251) and a glioma xenograft cell line (5310) alone and in co-culture with hUCBSC. Conditioned media from co-cultures of glioma cells with hUCBSC showed re...

  3. Extracellular matrix protein ITGBL1 promotes ovarian cancer cell migration and adhesion through Wnt/PCP signaling and FAK/SRC pathway.

    Sun, Li; Wang, Defeng; Li, Xiaotian; Zhang, Lingling; Zhang, Hui; Zhang, Yingjie

    2016-07-01

    Despite the advances in cancer treatment and the progresses in tumor biological, ovarian cancer remains a bad situation. In current study, we found a novel extracellular matrix protein, ITGBL1, which is highly expressed in ovarian cancer tissues by immunohistochemistry examination. The expression pattern of ITGBL1 in malignant tissues inspired us to investigate its role in ovarian cancer progression. Both loss- and gain-function assays revealed that ITGBL1 could promote ovarian cancer cell migration and adhesion. As it's a secreted protein, we further used recombinant ITGBL1 protein treated cancer cells and found that ITGBL1 promotes cell migration and adhesion in a concentration dependent manner. Furthermore, we found that ITGBL1 not only influences the activity of Wnt/PCP signaling but also affects FAK/src pathway in vitro. Taken together, our results suggest that highly expressed ITGBL1 could promotes cancer cell migration and adhesion in ovarian cancer and as a secreted protein, ITGBL1 might be a novel biomarker for ovarian cancer diagnosis. PMID:27261588

  4. Preliminary crystallographic characterization of the Grb2 SH2 domain in complex with a FAK-derived phosphotyrosyl peptide

    Crystals of the Grb2 SH2 domain in complex with a phosphotyrosyl peptide corresponding to residues 921–930 of focal adhesion kinase (FAK) have been obtained using the sitting-drop vapour-diffusion technique. Data have been collected to 2.49 Å resolution. Growth factor receptor-bound protein 2 (Grb2) is an adaptor protein with a single SH2 domain that specifically binds to focal adhesion kinase (FAK) when residue Tyr925 of FAK is phosphorylated. The Grb2–FAK interaction is associated with cellular integrin-activated signal transduction events leading to the activation of the Ras-MAPK pathway. Crystals of the Grb2 SH2 domain in complex with a phosphopeptide corresponding to residues 921–930 of FAK have been obtained using the sitting-drop vapour-diffusion technique. The crystals belonged to space group P3121, with unit-cell parameters a = b = 102.7, c = 127.6 Å, α = β = 90.0, γ = 120.0°. A diffraction data set was collected from a flash-cooled crystal at 100 K to 2.49 Å resolution using synchrotron radiation. Structure determination by molecular replacement and analysis of the detailed structure of the complex are currently in progress

  5. Tumour-associated endothelial-FAK correlated with molecular sub-type and prognostic factors in invasive breast cancer

    Breast cancer is a heterogeneous disease that can be classified into one of 4 main molecular sub-types: luminal A, luminal B, Her2 over-expressing and basal-like (BL). These tumour sub-types require different treatments and have different risks of disease progression. BL cancers can be considered a sub-group of Triple negative (TN) cancers since they lack estrogen (ER), progesterone (PR) and Her2 expression. No targeted treatment currently exists for TN/BL cancers. Thus it is important to identify potential therapeutic targets and describe their relationship with established prognostic factors. Focal adhesion kinase (FAK) is upregulated in several human cancers and also plays a functional role in tumour angiogenesis. However, the association between breast cancer sub-types and tumour endothelial-FAK expression is unknown. Using immunofluorescence, we quantified FAK expression in tumour endothelial and tumour cell compartments in 149 invasive breast carcinomas and correlated expression with clinical, pathological and molecular parameters. Low endothelial-FAK expression was independently associated with luminal A tumours at univariate (p < 0.001) and multivariate (p = 0.001) analysis. There was a positive correlation between FAK expression in the vascular and tumour cell compartments (Spearman’s correlation co-efficient = 0.394, p < 0.001). Additionally, endothelial and tumour cell FAK expression were significantly increased in TN tumours (p = 0.043 and p = 0.033 respectively), in tumours with negative ER and PR status, and in high grade tumours at univariate analysis. Our findings establish a relationship between endothelial-FAK expression levels and the molecular sub-type of invasive breast cancer, and suggest that endothelial-FAK expression is potentially more clinically relevant than tumour cell FAK expression in breast cancer

  6. Green Tea Epigallocatechin Gallate Exhibits Anticancer Effect in Human Pancreatic Carcinoma Cells via the Inhibition of Both Focal Adhesion Kinase and Insulin-Like Growth Factor-I Receptor

    Hoang Anh Vu

    2010-01-01

    Full Text Available The exact molecular mechanism by which epigallocatechin gallate (EGCG suppresses human pancreatic cancer cell proliferation is unclear. We show here that EGCG-treated pancreatic cancer cells AsPC-1 and BxPC-3 decrease cell adhesion ability on micro-pattern dots, accompanied by dephosphorylations of both focal adhesion kinase (FAK and insulin-like growth factor-1 receptor (IGF-1R whereas retained the activations of mitogen-activated protein kinase and mammalian target of rapamycin. The growth of AsPC-1 and BxPC-3 cells can be significantly suppressed by EGCG treatment alone in a dose-dependent manner. At a dose of 100 μM which completely abolishes activations of FAK and IGF-1R, EGCG suppresses more than 50% of cell proliferation without evidence of apoptosis analyzed by PARP cleavage. Finally, the MEK1/2 inhibitor U0126 enhances growth-suppressive effect of EGCG. Our data suggests that blocking FAK and IGF-1R by EGCG could prove valuable for targeted therapy, which can be used in combination with other therapies, for pancreatic cancer.

  7. FAK regulates platelet extravasation and tumor growth after antiangiogenic therapy withdrawal.

    Haemmerle, Monika; Bottsford-Miller, Justin; Pradeep, Sunila; Taylor, Morgan L; Choi, Hyun-Jin; Hansen, Jean M; Dalton, Heather J; Stone, Rebecca L; Cho, Min Soon; Nick, Alpa M; Nagaraja, Archana S; Gutschner, Tony; Gharpure, Kshipra M; Mangala, Lingegowda S; Rupaimoole, Rajesha; Han, Hee Dong; Zand, Behrouz; Armaiz-Pena, Guillermo N; Wu, Sherry Y; Pecot, Chad V; Burns, Alan R; Lopez-Berestein, Gabriel; Afshar-Kharghan, Vahid; Sood, Anil K

    2016-05-01

    Recent studies in patients with ovarian cancer suggest that tumor growth may be accelerated following cessation of antiangiogenesis therapy; however, the underlying mechanisms are not well understood. In this study, we aimed to compare the effects of therapy withdrawal to those of continuous treatment with various antiangiogenic agents. Cessation of therapy with pazopanib, bevacizumab, and the human and murine anti-VEGF antibody B20 was associated with substantial tumor growth in mouse models of ovarian cancer. Increased tumor growth was accompanied by tumor hypoxia, increased tumor angiogenesis, and vascular leakage. Moreover, we found hypoxia-induced ADP production and platelet infiltration into tumors after withdrawal of antiangiogenic therapy, and lowering platelet counts markedly inhibited tumor rebound after withdrawal of antiangiogenic therapy. Focal adhesion kinase (FAK) in platelets regulated their migration into the tumor microenvironment, and FAK-deficient platelets completely prevented the rebound tumor growth. Additionally, combined therapy with a FAK inhibitor and the antiangiogenic agents pazopanib and bevacizumab reduced tumor growth and inhibited negative effects following withdrawal of antiangiogenic therapy. In summary, these results suggest that FAK may be a unique target in situations in which antiangiogenic agents are withdrawn, and dual targeting of FAK and VEGF could have therapeutic implications for ovarian cancer management. PMID:27064283

  8. Focal Adhesion Kinase Inhibitors in Combination with Erlotinib Demonstrate Enhanced Anti-Tumor Activity in Non-Small Cell Lung Cancer.

    Grant A Howe

    Full Text Available Blockade of epidermal growth factor receptor (EGFR activity has been a primary therapeutic target for non-small cell lung cancers (NSCLC. As patients with wild-type EGFR have demonstrated only modest benefit from EGFR tyrosine kinase inhibitors (TKIs, there is a need for additional therapeutic approaches in patients with wild-type EGFR. As a key component of downstream integrin signalling and known receptor cross-talk with EGFR, we hypothesized that targeting focal adhesion kinase (FAK activity, which has also been shown to correlate with aggressive stage in NSCLC, would lead to enhanced activity of EGFR TKIs. As such, EGFR TKI-resistant NSCLC cells (A549, H1299, H1975 were treated with the EGFR TKI erlotinib and FAK inhibitors (PF-573,228 or PF-562,271 both as single agents and in combination. We determined cell viability, apoptosis and 3-dimensional growth in vitro and assessed tumor growth in vivo. Treatment of EGFR TKI-resistant NSCLC cells with FAK inhibitor alone effectively inhibited cell viability in all cell lines tested; however, its use in combination with the EGFR TKI erlotinib was more effective at reducing cell viability than either treatment alone when tested in both 2- and 3-dimensional assays in vitro, with enhanced benefit seen in A549 cells. This increased efficacy may be due in part to the observed inhibition of Akt phosphorylation when the drugs were used in combination, where again A549 cells demonstrated the most inhibition following treatment with the drug combination. Combining erlotinib with FAK inhibitor was also potent in vivo as evidenced by reduced tumor growth in the A549 mouse xenograft model. We further ascertained that the enhanced sensitivity was irrespective of the LKB1 mutational status. In summary, we demonstrate the effectiveness of combining erlotinib and FAK inhibitors for use in known EGFR wild-type, EGFR TKI resistant cells, with the potential that a subset of cell types, which includes A549, could be

  9. Antroquinonol Targets FAK-Signaling Pathway Suppressed Cell Migration, Invasion, and Tumor Growth of C6 Glioma.

    Thiyagarajan, Varadharajan; Tsai, May-Jywan; Weng, Ching-Feng

    2015-01-01

    Focal adhesion kinase (FAK) is a non-receptor protein tyrosine that is overexpressed in many types of tumors and plays a pivotal role in multiple cell signaling pathways involved in cell survival, migration, and proliferation. This study attempts to determine the effect of synthesized antroquinonol on the modulation of FAK signaling pathways and explore their underlying mechanisms. Antroquinonol significantly inhibits cell viability with an MTT assay in both N18 neuroblastoma and C6 glioma cell lines, which exhibits sub G1 phase cell cycle, and further induction of apoptosis is confirmed by a TUNEL assay. Antroquinonol decreases anti-apoptotic proteins, whereas it increases p53 and pro-apoptotic proteins. Alterations of cell morphology are observed after treatment by atomic force microscopy. Molecular docking results reveal that antroquinonol has an H-bond with the Arg 86 residue of FAK. The protein levels of Src, pSrc, FAK, pFAK, Rac1, and cdc42 are decreased after antroquinonol treatment. Additionally, antroquinonol also regulates the expression of epithelial to mesenchymal transition (EMT) proteins. Furthermore, antroquinonol suppresses the C6 glioma growth in xenograft studies. Together, these results suggest that antroquinonol is a potential anti-tumorigenesis and anti-metastasis inhibitor of FAK. PMID:26517117

  10. Antroquinonol Targets FAK-Signaling Pathway Suppressed Cell Migration, Invasion, and Tumor Growth of C6 Glioma.

    Varadharajan Thiyagarajan

    Full Text Available Focal adhesion kinase (FAK is a non-receptor protein tyrosine that is overexpressed in many types of tumors and plays a pivotal role in multiple cell signaling pathways involved in cell survival, migration, and proliferation. This study attempts to determine the effect of synthesized antroquinonol on the modulation of FAK signaling pathways and explore their underlying mechanisms. Antroquinonol significantly inhibits cell viability with an MTT assay in both N18 neuroblastoma and C6 glioma cell lines, which exhibits sub G1 phase cell cycle, and further induction of apoptosis is confirmed by a TUNEL assay. Antroquinonol decreases anti-apoptotic proteins, whereas it increases p53 and pro-apoptotic proteins. Alterations of cell morphology are observed after treatment by atomic force microscopy. Molecular docking results reveal that antroquinonol has an H-bond with the Arg 86 residue of FAK. The protein levels of Src, pSrc, FAK, pFAK, Rac1, and cdc42 are decreased after antroquinonol treatment. Additionally, antroquinonol also regulates the expression of epithelial to mesenchymal transition (EMT proteins. Furthermore, antroquinonol suppresses the C6 glioma growth in xenograft studies. Together, these results suggest that antroquinonol is a potential anti-tumorigenesis and anti-metastasis inhibitor of FAK.

  11. FAK activation is required for IGF1R-mediated regulation of EMT, migration, and invasion in mesenchymal triple negative breast cancer cells.

    Taliaferro-Smith, LaTonia; Oberlick, Elaine; Liu, Tongrui; McGlothen, Tanisha; Alcaide, Tiffanie; Tobin, Rachel; Donnelly, Siobhan; Commander, Rachel; Kline, Erik; Nagaraju, Ganji Purnachandra; Havel, Lauren; Marcus, Adam; Nahta, Rita; O'Regan, Ruth

    2015-03-10

    Triple negative breast cancer (TNBC) is a highly metastatic disease that currently lacks effective prevention and treatment strategies. The insulin-like growth factor 1 receptor (IGF1R) and focal adhesion kinase (FAK) signaling pathways function in numerous developmental processes, and alterations in both are linked with a number of common pathological diseases. Overexpression of IGF1R and FAK are closely associated with metastatic breast tumors. The present study investigated the interrelationship between IGF1R and FAK signaling in regulating the malignant properties of TNBC cells. Using small hairpin RNA (shRNA)-mediated IGF1R silencing methods, we showed that IGF1R is essential for sustaining mesenchymal morphologies of TNBC cells and modulates the expression of EMT-related markers. We further showed that IGF1R overexpression promotes migratory and invasive behaviors of TNBC cell lines. Most importantly, IGF1R-driven migration and invasion is predominantly mediated by FAK activation and can be suppressed using pharmacological inhibitors of FAK. Our findings in TNBC cells demonstrate a novel role of the IGF1R/FAK signaling pathway in regulating critical processes involved in the metastatic cascade. These results may improve the current understanding of the basic molecular mechanisms of TNBC metastasis and provide a strong rationale for co-targeting of IGF1R and FAK as therapy for mesenchymal TNBCs. PMID:25749031

  12. Cordycepin suppresses integrin/FAK signaling and epithelial-mesenchymal transition in hepatocellular carcinoma.

    Yao, Wen-Ling; Ko, Bor-Sheng; Liu, Tzu-An; Liang, Shu-Man; Liu, Chia-Chia; Lu, Yi-Jhu; Tzean, Shean-Shong; Shen, Tang-Long; Liou, Jun-Yang

    2014-01-01

    Cordycepin, also known as 3-deoxyadenosine, is an analogue of adenosine extracted from the traditional Chinese medicine "Dong Chong Xia Cao". Cordycepin is an active small molecular weight compound and is implicated in modulating multiple physiological functions including immune activation, anti-aging and anti-tumor effects. Several studies have indicated that cordycepin suppresses tumor progression. However, the signaling pathways involved in cordycepin regulating cancer cell motility, invasiveness and epithelial-mesenchymal transition (EMT) remain unclear. In this study, we found that cordycepin inhibits hepatocellular carcinoma (HCC) cell proliferation and migration/invasion. Treatment of cordycepin results in the increasing expression of epithelial marker, Ecadherin while no significant effect was found on N-cadherin α-catenin and β-catenin. Furthermore, although the expression of focal adhesion kinase (FAK) was slightly reduced, the level of phosphorylated FAK was significantly reduced by the treatment of cordycepin. In addition, cordycepin significantly suppresses the expression of integrin α3, integrin α6 and integrin β1 which are crucial interacting partners of FAK in regulating the focal adhesion complex. These results suggest cordycepin may contribute to EMT, antimigration/ invasion and growth inhibitory effects of HCC by suppressing E-cadherin and integrin/FAK signaling. Thus, cordycepin is a potential therapeutic or supplementary agent for preventing HCC tumor progression. PMID:23855336

  13. Regulation of Stat5 by FAK and PAK1 in Oncogenic FLT3- and KIT-Driven Leukemogenesis

    Anindya Chatterjee

    2014-11-01

    Full Text Available Oncogenic mutations of FLT3 and KIT receptors are associated with poor survival in patients with acute myeloid leukemia (AML and myeloproliferative neoplasms (MPNs, and currently available drugs are largely ineffective. Although Stat5 has been implicated in regulating several myeloid and lymphoid malignancies, how precisely Stat5 regulates leukemogenesis, including its nuclear translocation to induce gene transcription, is poorly understood. In leukemic cells, we show constitutive activation of focal adhesion kinase (FAK whose inhibition represses leukemogenesis. Downstream of FAK, activation of Rac1 is regulated by RacGEF Tiam1, whose inhibition prolongs the survival of leukemic mice. Inhibition of the Rac1 effector PAK1 prolongs the survival of leukemic mice in part by inhibiting the nuclear translocation of Stat5. These results reveal a leukemic pathway involving FAK/Tiam1/Rac1/PAK1 and demonstrate an essential role for these signaling molecules in regulating the nuclear translocation of Stat5 in leukemogenesis.

  14. Gene Expression Profiling Identifies Important Genes Affected by R2 Compound Disrupting FAK and P53 Complex

    Focal Adhesion Kinase (FAK) is a non-receptor kinase that plays an important role in many cellular processes: adhesion, proliferation, invasion, angiogenesis, metastasis and survival. Recently, we have shown that Roslin 2 or R2 (1-benzyl-15,3,5,7-tetraazatricyclo[3.3.1.1~3,7~]decane) compound disrupts FAK and p53 proteins, activates p53 transcriptional activity, and blocks tumor growth. In this report we performed a microarray gene expression analysis of R2-treated HCT116 p53+/+ and p53−/− cells and detected 1484 genes that were significantly up- or down-regulated (p < 0.05) in HCT116 p53+/+ cells but not in p53−/− cells. Among up-regulated genes in HCT p53+/+ cells we detected critical p53 targets: Mdm-2, Noxa-1, and RIP1. Among down-regulated genes, Met, PLK2, KIF14, BIRC2 and other genes were identified. In addition, a combination of R2 compound with M13 compound that disrupts FAK and Mmd-2 complex or R2 and Nutlin-1 that disrupts Mdm-2 and p53 decreased clonogenicity of HCT116 p53+/+ colon cancer cells more significantly than each agent alone in a p53-dependent manner. Thus, the report detects gene expression profile in response to R2 treatment and demonstrates that the combination of drugs targeting FAK, Mdm-2, and p53 can be a novel therapy approach

  15. N-Cadherin Induction by ECM Stiffness and FAK Overrides the Spreading Requirement for Proliferation of Vascular Smooth Muscle Cells

    Keeley L. Mui

    2015-03-01

    Full Text Available In contrast to the accepted pro-proliferative effect of cell-matrix adhesion, the proliferative effect of cadherin-mediated cell-cell adhesion remains unresolved. Here, we studied the effect of N-cadherin on cell proliferation in the vasculature. We show that N-cadherin is induced in smooth muscle cells (SMCs in response to vascular injury, an in vivo model of tissue stiffening and proliferation. Complementary experiments performed with deformable substrata demonstrated that stiffness-mediated activation of a focal adhesion kinase (FAK-p130Cas-Rac signaling pathway induces N-cadherin. Additionally, by culturing paired and unpaired SMCs on microfabricated adhesive islands of different areas, we found that N-cadherin relaxes the spreading requirement for SMC proliferation. In vivo SMC deletion of N-cadherin strongly reduced injury-induced cycling. Finally, SMC-specific deletion of FAK inhibited proliferation after vascular injury, and this was accompanied by reduced induction of N-cadherin. Thus, a stiffness- and FAK-dependent induction of N-cadherin connects cell-matrix to cell-cell adhesion and regulates the degree of cell spreading needed for cycling.

  16. Doxycycline reduces the migration of tuberous sclerosis complex-2 null cells - effects on RhoA-GTPase and focal adhesion kinase.

    Ng, Ho Yin; Oliver, Brian Gregory George; Burgess, Janette Kay; Krymskaya, Vera P; Black, Judith Lee; Moir, Lyn M

    2015-11-01

    Lymphangioleiomyomatosis (LAM) is associated with dysfunction of the tuberous sclerosis complex (TSC) leading to enhanced cell proliferation and migration. This study aims to examine whether doxycycline, a tetracycline antibiotic, can inhibit the enhanced migration of TSC2-deficient cells, identify signalling pathways through which doxycycline works and to assess the effectiveness of combining doxycycline with rapamycin (mammalian target of rapamycin complex 1 inhibitor) in controlling cell migration, proliferation and wound closure. TSC2-positive and TSC2-negative mouse embryonic fibroblasts (MEF), 323-TSC2-positive and 323-TSC2-null MEF and Eker rat uterine leiomyoma (ELT3) cells were treated with doxycycline or rapamycin alone, or in combination. Migration, wound closure and proliferation were assessed using a transwell migration assay, time-lapse microscopy and manual cell counts respectively. RhoA-GTPase activity, phosphorylation of p70S6 kinase (p70S6K) and focal adhesion kinase (FAK) in TSC2-negative MEF treated with doxycycline were examined using ELISA and immunoblotting techniques. The enhanced migration of TSC2-null cells was reduced by doxycycline at concentrations as low as 20 pM, while the rate of wound closure was reduced at 2-59 μM. Doxycycline decreased RhoA-GTPase activity and phosphorylation of FAK in these cells but had no effect on the phosphorylation of p70S6K, ERK1/2 or AKT. Combining doxycycline with rapamycin significantly reduced the rate of wound closure at lower concentrations than achieved with either drug alone. This study shows that doxycycline inhibits TSC2-null cell migration. Thus doxycycline has potential as an anti-migratory agent in the treatment of diseases with TSC2 dysfunction. PMID:26282580

  17. Anti-tumor effect in human breast cancer by TAE226, a dual inhibitor for FAK and IGF-IR in vitro and in vivo

    Kurio, Naito [Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8525 (Japan); Shimo, Tsuyoshi, E-mail: shimotsu@md.okayama-u.ac.jp [Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8525 (Japan); Fukazawa, Takuya; Takaoka, Munenori [Department of General Surgery, Kawasaki Medical School, Okayama, 700-0821 (Japan); Okui, Tatsuo; Hassan, Nur Mohammad Monsur; Honami, Tatsuki [Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8525 (Japan); Hatakeyama, Shinji [Novartis Institutes for BioMedical Research, Basel (Switzerland); Ikeda, Masahiko [Department of Surgery, Fukuyama City Hospital, Fukuyama, 720-8511 (Japan); Naomoto, Yoshio [Department of General Surgery, Kawasaki Medical School, Okayama, 700-0821 (Japan); Sasaki, Akira [Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, 700-8525 (Japan)

    2011-05-01

    Focal adhesion kinase (FAK) is a 125-kDa non-receptor type tyrosine kinase that localizes to focal adhesions. FAK overexpression is frequently found in invasive and metastatic cancers of the breast, colon, thyroid, and prostate, but its role in osteolytic metastasis is not well understood. In this study, we have analyzed anti-tumor effects of the novel FAK Tyr{sup 397} inhibitor TAE226 against bone metastasis in breast cancer by using TAE226. Oral administration of TAE226 in mice significantly decreased bone metastasis and osteoclasts involved which were induced by MDA-MB-231 breast cancer cells and increased the survival rate of the mouse models of bone metastasis. TAE226 also suppressed the growth of subcutaneous tumors in vivo and the proliferation and migration of MDA-MB-231 cells in vitro. Significantly, TAE226 inhibited the osteoclast formation in murine pre-osteoclastic RAW264.7 cells, and actin ring and pit formation in mature osteoclasts. Moreover, TAE226 inhibited the receptor activator for nuclear factor {kappa} B Ligand (RANKL) gene expression induced by parathyroid hormone-related protein (PTHrP) in bone stromal ST2 cells and blood free calcium concentration induced by PTHrP administration in vivo. These findings suggest that FAK was critically involved in osteolytic metastasis and activated in tumors, pre-osteoclasts, mature osteoclasts, and bone stromal cells and TAE226 can be effectively used for the treatment of cancer induced bone metastasis and other bone diseases.

  18. Anti-tumor effect in human breast cancer by TAE226, a dual inhibitor for FAK and IGF-IR in vitro and in vivo

    Focal adhesion kinase (FAK) is a 125-kDa non-receptor type tyrosine kinase that localizes to focal adhesions. FAK overexpression is frequently found in invasive and metastatic cancers of the breast, colon, thyroid, and prostate, but its role in osteolytic metastasis is not well understood. In this study, we have analyzed anti-tumor effects of the novel FAK Tyr397 inhibitor TAE226 against bone metastasis in breast cancer by using TAE226. Oral administration of TAE226 in mice significantly decreased bone metastasis and osteoclasts involved which were induced by MDA-MB-231 breast cancer cells and increased the survival rate of the mouse models of bone metastasis. TAE226 also suppressed the growth of subcutaneous tumors in vivo and the proliferation and migration of MDA-MB-231 cells in vitro. Significantly, TAE226 inhibited the osteoclast formation in murine pre-osteoclastic RAW264.7 cells, and actin ring and pit formation in mature osteoclasts. Moreover, TAE226 inhibited the receptor activator for nuclear factor κ B Ligand (RANKL) gene expression induced by parathyroid hormone-related protein (PTHrP) in bone stromal ST2 cells and blood free calcium concentration induced by PTHrP administration in vivo. These findings suggest that FAK was critically involved in osteolytic metastasis and activated in tumors, pre-osteoclasts, mature osteoclasts, and bone stromal cells and TAE226 can be effectively used for the treatment of cancer induced bone metastasis and other bone diseases.

  19. Inhibition of tumor vasculogenic mimicry and prolongation of host survival in highly aggressive gallbladder cancers by norcantharidin via blocking the ephrin type a receptor 2/focal adhesion kinase/paxillin signaling pathway.

    Hui Wang

    Full Text Available Vasculogenic mimicry (VM is a newly-defined tumor microcirculation pattern in highly aggressive malignant tumors. We recently reported tumor growth and VM formation of gallbladder cancers through the contribution of the ephrin type a receptor 2 (EphA2/focal adhesion kinase (FAK/Paxillin signaling pathways. In this study, we further investigated the anti-VM activity of norcantharidin (NCTD as a VM inhibitor for gallbladder cancers and the underlying mechanisms. In vivo and in vitro experiments to determine the effects of NCTD on tumor growth, host survival, VM formation of GBC-SD nude mouse xenografts, and vasculogenic-like networks, malignant phenotypes i.e., proliferation, apoptosis, invasion and migration of GBC-SD cells. Expression of VM signaling-related markers EphA2, FAK and Paxillin in vivo and in vitro were examined by immunofluorescence, western blotting and real-time polymerase chain reaction (RT-PCR, respectively. The results showed that after treatment with NCTD, GBC-SD cells were unable to form VM structures when injecting into nude mouse, growth of the xenograft was inhibited and these observations were confirmed by facts that VM formation by three-dimensional (3-D matrix, proliferation, apoptosis, invasion, migration of GBC-SD cells were affected; and survival time of the xenograft mice was prolonged. Furthermore, expression of EphA2, FAK and Paxillin proteins/mRNAs of the xenografts was downregulated. Thus, we concluded that NCTD has potential anti-VM activity against human gallbladder cancers; one of the underlying mechanisms may be via blocking the EphA2/FAK/Paxillin signaling pathway.

  20. Mycosporine-Like Amino Acids Promote Wound Healing through Focal Adhesion Kinase (FAK) and Mitogen-Activated Protein Kinases (MAP Kinases) Signaling Pathway in Keratinocytes

    Yun-Hee Choi; Dong Joo Yang; Atul Kulkarni; Sang Hyun Moh; Ki Woo Kim

    2015-01-01

    Mycosporine-like amino acids (MAAs) are secondary metabolites found in diverse marine, freshwater, and terrestrial organisms. Evidence suggests that MAAs have several beneficial effects on skin homeostasis such as protection against UV radiation and reactive oxygen species (ROS). In addition, MAAs are also involved in the modulation of skin fibroblasts proliferation. However, the regulatory function of MAAs on wound repair in human skin is not yet clearly elucidated. To investigate the roles ...

  1. MicroRNA-379-5p inhibits tumor invasion and metastasis by targeting FAK/AKT signaling in hepatocellular carcinoma.

    Chen, Jing-Song; Li, Hua-Shu; Huang, Jiong-Qiang; Dong, Shi-Hao; Huang, Zhi-Jie; Yi, Wei; Zhan, Gao-Fang; Feng, Ju-Tao; Sun, Jian-Cong; Huang, Xiao-Hui

    2016-05-28

    Some microRNAs (miRNAs) have been implicated in hepatocellular carcinoma (HCC) development and progression. However, the roles and mechanisms of several miRNAs in HCC remain poorly understood. Here, we report that miR-379-5p, which is down-regulated in HCC tissues and cell lines, is associated with advanced TNM stage and metastasis in HCC. The ectopic overexpression of miR-379-5p inhibited HCC cell migration, invasion, epithelial-to-mesenchymal transition (EMT) and metastasis both in vitro and in vivo. Conversely, miR-379 knockdown increased migration, invasion and EMT in HCC cells. Moreover, miR-379-5p exerted this function by directly targeting focal adhesion kinase (FAK) 3'-UTR and repressing FAK expression, thus leading to suppression of AKT signaling. Furthermore, the tumor suppressive effects of miR-379-5p in HCC cells were reversed by activating AKT signaling or restoring FAK expression. In clinical samples of HCC, miR-379-5p negatively correlated with FAK, which was up-regulated in HCC. Taken together, our findings highlight the important role of miR-379-5p in regulating the EMT and metastasis of HCC by targeting FAK/AKT signaling, suggesting that miR-379-5p may represent a novel potential therapeutic target and prognostic marker for HCC. PMID:26944318

  2. Simultaneous deactivation of FAK and Src improves the pathology of hypertrophic scar.

    Su, Linlin; Li, Xiaodong; Wu, Xue; Hui, Bo; Han, Shichao; Gao, Jianxin; Li, Yan; Shi, Jihong; Zhu, Huayu; Zhao, Bin; Hu, Dahai

    2016-01-01

    Hypertrophic scar (HS) is a serious fibrotic skin condition with currently no satisfactory therapy due to undefined molecular mechanism. FAK and Src are two important non-receptor tyrosine kinases that have been indicated in HS pathogenesis. Here we found both FAK and Src were activated in HS vs. normal skin (NS), NS fibroblasts treated with TGF-β1 also exhibited FAK/Src activation. Co-immunoprecipitation and dual-labelled immunofluorescence revealed an enhanced FAK-Src association and co-localization in HS vs. NS. To examine effects of FAK/Src activation and their interplay on HS pathogenesis, site-directed mutagenesis followed by gene overexpression was conducted. Results showed only simultaneous overexpression of non-phosphorylatable mutant FAK Y407F and phosphomimetic mutant Src Y529E remarkably down-regulated the expression of Col I, Col III and α-SMA in cultured HS fibroblasts, alleviated extracellular matrix deposition and made collagen fibers more orderly in HS tissue vs. the effect from single transfection with wild-type or mutational FAK/Src. Glabridin, a chemical found to block FAK-Src complex formation in cancers, exhibited therapeutic effects on HS pathology probably through co-deactivation of FAK/Src which further resulted in FAK-Src de-association. This study suggests FAK-Src complex could serve as a potential molecular target, and FAK/Src double deactivation might be a novel strategy for HS therapy. PMID:27181267

  3. 1-o-acetylbritannilactone (ABL) inhibits angiogenesis and lung cancer cell growth through regulating VEGF-Src-FAK signaling

    The search for safe, effective and affordable therapeutics against non-small cell lung cancer (NSCLC) and other lung cancers is important. Here we explored the potential effect of 1-o-acetylbritannilactone (ABL), a novel extract from Inula britannica-F, on angiogenesis and lung cancer cell growth. We demonstrated that ABL dose-dependently inhibited vascular endothelial growth factor (VEGF)-induced proliferation, migration, and capillary structure formation of cultured human umbilical vascular endothelial cells (HUVECs). In vivo, ABL administration suppressed VEGF-induced new vasculature formation in Matrigel plugs. For the mechanism investigations, we found that ABL largely inhibited VEGF-mediated activation of Src kinase and focal adhesion kinase (FAK) in HUVECs. Furthermore, treatment of A549 NSCLC cells with ABL resulted in cell growth inhibition and Src-FAK in-activation. Significantly, administration of a single dose of ABL (12 mg/kg/day) remarkably suppressed growth of A549 xenografts in nude mice. In vivo microvessels formation and Src activation were also significantly inhibited in ABL-treated xenograft tumors. Taken together, our findings suggest that ABL suppresses angiogenesis and lung cancer cell growth possibly via regulating the VEGFR-Src-FAK signaling. - Highlights: • 1-o-acetylbritannilactone (ABL) inhibits VEGF-induced angiogenesis in vivo. • ABL inhibits VEGF-induced HUVEC migration, proliferation, capillary tube formation. • ABL inhibits VEGF-mediated activation of Src and FAK in HUVECs. • ABL inhibits growth and Src-FAK activation in A549 cells. • ABL administration inhibits A549 tumor angiogenesis and growth in nude mice

  4. 1-o-acetylbritannilactone (ABL) inhibits angiogenesis and lung cancer cell growth through regulating VEGF-Src-FAK signaling

    Zhengfu, He; Hu, Zhang; Huiwen, Miao; Zhijun, Li [Department of Thoracic Surgery, Sir Run Run Shaw Hospital of Zhejiang University School of Medicine, Hangzhou (China); Jiaojie, Zhou [Zhejiang University School of Medicine, Hangzhou (China); Xiaoyi, Yan, E-mail: xiaoyiyan163@163.com [Zhejiang University School of Medicine, Hangzhou (China); Xiujun, Cai, E-mail: xiujuncaomaj@163.com [Sir Run Run Shaw Hospital of Zhejiang University School of Medicine, Hangzhou (China)

    2015-08-21

    The search for safe, effective and affordable therapeutics against non-small cell lung cancer (NSCLC) and other lung cancers is important. Here we explored the potential effect of 1-o-acetylbritannilactone (ABL), a novel extract from Inula britannica-F, on angiogenesis and lung cancer cell growth. We demonstrated that ABL dose-dependently inhibited vascular endothelial growth factor (VEGF)-induced proliferation, migration, and capillary structure formation of cultured human umbilical vascular endothelial cells (HUVECs). In vivo, ABL administration suppressed VEGF-induced new vasculature formation in Matrigel plugs. For the mechanism investigations, we found that ABL largely inhibited VEGF-mediated activation of Src kinase and focal adhesion kinase (FAK) in HUVECs. Furthermore, treatment of A549 NSCLC cells with ABL resulted in cell growth inhibition and Src-FAK in-activation. Significantly, administration of a single dose of ABL (12 mg/kg/day) remarkably suppressed growth of A549 xenografts in nude mice. In vivo microvessels formation and Src activation were also significantly inhibited in ABL-treated xenograft tumors. Taken together, our findings suggest that ABL suppresses angiogenesis and lung cancer cell growth possibly via regulating the VEGFR-Src-FAK signaling. - Highlights: • 1-o-acetylbritannilactone (ABL) inhibits VEGF-induced angiogenesis in vivo. • ABL inhibits VEGF-induced HUVEC migration, proliferation, capillary tube formation. • ABL inhibits VEGF-mediated activation of Src and FAK in HUVECs. • ABL inhibits growth and Src-FAK activation in A549 cells. • ABL administration inhibits A549 tumor angiogenesis and growth in nude mice.

  5. Role of cell adhesion signal molecules in hepatocellular carcinoma cell apoptosis

    Jian-Min Su; Li-Ying Wang; Yu-Long Liang; Xi-Liang Zha

    2005-01-01

    AIM: Cell adhesion molecules and their signal molecules play a very important role in carcinogenesis. The aim of this study is to elucidate the role of these molecules and the signal molecules of integrins and E-cadherins, such as (focal adhesion kinase) FAK, (integrin linked kinase)ILK, and β-catenin in hepatocellular carcinoma cell apoptosis.METHODS: We first synthesized the small molecular compound, S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and identified it, by element analysis and 1H NMR. To establish the apoptosis model of the SMMC-7721 hepatocellular carcinoma cell, we treated cells with DCVC in EBSS for different concentrations or for various length times in the presence of 20 μmol/L N,N-diphenyl-p-phenylenediamine,which blocks necrotic cell death and identified this model by flow cytometry and DNA ladder. Then we studied the changes of FAK, ILK, β-catenin, and PKB in this apoptotic model by Western blot.RESULTS: We found that the loss or decrease of cell adhesion signal molecules is an important reason in apoptosis of SMMC-7721 hepatocellular carcinoma cell and the apoptosis of SMMC-7721 cell was preceded by the loss or decrease of FAK, ILK, PKB, and β-catenin or the damage of cell-matrix and cell-cell adhesion.CONCLUSION: Our results suggested that the decrease of adhesion signal molecules, FAK, ILK, PKB, and β-catenin,could induce hepatocellular carcinoma cell apoptosis.

  6. Signaling via ITGB1/FAK and microfilament rearrangement mediates the internalization of Leptospira interrogans in mouse J774A.1 macrophages

    Zhao Xin

    2015-01-01

    Full Text Available Leptospirosis caused by pathogenic Leptospira species is a worldwide zoonotic 2 infectious disease, but the mechanisms of leptospiral internalization remain poorly understood. Here, we report that mouse J774A.1 macrophages expressed integrin-subfamily proteins (ITGB1, ITGB2 and ITGB3. Antibody blockage and siRNA-based knockdown of ITGB1 decreased the internalization of leptospires into mouse J774A.1 macrophage cells. The internalization required focal adhesion kinase (FAK activation in J774A.1 cells rather than phosphoinositide-3-kinase (PI3K, and microfilament rather than microtubule aggregation during infection. The data indicated that the ITGB1/FAK/microfilament signaling pathway is responsible for leptospiral internalization in mouse macrophages.

  7. Gene Expression Profiling Identifies Important Genes Affected by R2 Compound Disrupting FAK and P53 Complex

    Golubovskaya, Vita M., E-mail: Vita.Golubovskaya@roswellpark.org; Ho, Baotran [Department of Surgical Oncology, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Conroy, Jeffrey [Genomics Shared Resource, Center for Personalized Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Liu, Song; Wang, Dan [Bioinformatics Core Facility, Biostatistics, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States); Cance, William G. [Department of Surgical Oncology, Roswell Park Cancer Institute, Buffalo, NY 14263 (United States)

    2014-01-21

    Focal Adhesion Kinase (FAK) is a non-receptor kinase that plays an important role in many cellular processes: adhesion, proliferation, invasion, angiogenesis, metastasis and survival. Recently, we have shown that Roslin 2 or R2 (1-benzyl-15,3,5,7-tetraazatricyclo[3.3.1.1~3,7~]decane) compound disrupts FAK and p53 proteins, activates p53 transcriptional activity, and blocks tumor growth. In this report we performed a microarray gene expression analysis of R2-treated HCT116 p53{sup +/+} and p53{sup −/−} cells and detected 1484 genes that were significantly up- or down-regulated (p < 0.05) in HCT116 p53{sup +/+} cells but not in p53{sup −/−} cells. Among up-regulated genes in HCT p53{sup +/+} cells we detected critical p53 targets: Mdm-2, Noxa-1, and RIP1. Among down-regulated genes, Met, PLK2, KIF14, BIRC2 and other genes were identified. In addition, a combination of R2 compound with M13 compound that disrupts FAK and Mmd-2 complex or R2 and Nutlin-1 that disrupts Mdm-2 and p53 decreased clonogenicity of HCT116 p53{sup +/+} colon cancer cells more significantly than each agent alone in a p53-dependent manner. Thus, the report detects gene expression profile in response to R2 treatment and demonstrates that the combination of drugs targeting FAK, Mdm-2, and p53 can be a novel therapy approach.

  8. Twist induces epithelial-mesenchymal transition and cell motility in breast cancer via ITGB1-FAK/ILK signaling axis and its associated downstream network.

    Yang, Jiajia; Hou, Yixuan; Zhou, Mingli; Wen, Siyang; Zhou, Jian; Xu, Liyun; Tang, Xi; Du, Yan-e; Hu, Ping; Liu, Manran

    2016-02-01

    Twist, a highly conserved basic Helix-Loop-Helix transcription factor, functions as a major regulator of epithelial-mesenchymal transition (EMT) and tumor metastasis. In different cell models, signaling pathways such as TGF-β, MAPK/ERK, WNT, AKT, JAK/STAT, Notch, and P53 have also been shown to play key roles in the EMT process, yet little is known about the signaling pathways regulated by Twist in tumor cells. Using iTRAQ-labeling combined with 2D LC-MS/MS analysis, we identified 194 proteins with significant changes of expression in MCF10A-Twist cells. These proteins reportedly play roles in EMT, cell junction organization, cell adhesion, and cell migration and invasion. ECM-receptor interaction, MAPK, PI3K/AKT, P53 and WNT signaling were found to be aberrantly activated in MCF10A-Twist cells. Ingenuity Pathways Analysis showed that integrin β1 (ITGB1) acts as a core regulator in linking integrin-linked kinase (ILK), Focal-adhesion kinase (FAK), MAPK/ERK, PI3K/AKT, and WNT signaling. Increased Twist and ITGB1 are associated with breast tumor progression. Twist transcriptionally regulates ITGB1 expression. Over-expression of ITGB1 or Twist in MCF10A led to EMT, activation of FAK/ILK, MAPK/ERK, PI3K/AKT, and WNT signaling. Knockdown of Twist or ITGB1 in BT549 and Hs578T cells decreased activity of FAK, ILK, and their downstream signaling, thus specifically impeding EMT and cell invasion. Knocking down ILK or inhibiting FAK, MAPK/ERK, or PI3K/AKT signaling also suppressed Twist-driven EMT and cell invasion. Thus, the Twist-ITGB1-FAK/ILK pathway and their downstream signaling network dictate the Twist-induced EMT process in human mammary epithelial cells and breast cancer cells. PMID:26693891

  9. Therapeutic targeting of the focal adhesion complex prevents oncogenic TGF-β signaling and metastasis

    Wendt, Michael K.; William P. Schiemann

    2009-01-01

    Introduction Mammary tumorigenesis is associated with the increased expression of several proteins in the focal adhesion complex, including focal adhesion kinase (FAK) and various integrins. Aberrant expression of these molecules occurs concomitant with the conversion of TGF-β function from a tumor suppressor to a tumor promoter. We previously showed that interaction between β3 integrin and TβR-II facilitates TGF-β-mediated oncogenic signaling, epithelial-mesenchymal transition (EMT), and met...

  10. Involvement of the Tyrosine Kinase Fer in Cell Adhesion

    Rosato, Roberto; Veltmaat, Jacqueline M.; Groffen, John; Heisterkamp, Nora

    1998-01-01

    The Fer protein belongs to the fes/fps family of nontransmembrane receptor tyrosine kinases. Lack of success in attempts to establish a permanent cell line overexpressing it at significant levels suggested a strong negative selection against too much Fer protein and pointed to a critical cellular function for Fer. Using a tetracycline-regulatable expression system, overexpression of Fer in embryonic fibroblasts was shown to evoke a massive rounding up, and the subsequent detachment of the cel...

  11. Identification of novel FAK and S6K1 dual inhibitors from natural compounds via ADMET screening and molecular docking.

    Thiyagarajan, Varadharajan; Lin, Shin-Hung; Chang, Yu-Chuan; Weng, Ching-Feng

    2016-05-01

    Focal adhesion kinase (FAK) and human p70 ribosomal S6 kinase (S6K1) are non-receptor protein tyrosine plays a vital role in cell signaling pathways, such as cell proliferation, survival, and migration. In this study, the 3D structure of FAK (PDB ID: 2AL6) and S6K1 (3A60) were chosen for docking 60 natural compounds attempted to identify novel and specific inhibitors from them. The 30 selected molecules with high scores were further analyzed using DSSTox tools and DS 3.5 ADMET software. Based on a high docking score and energy interaction, 3 of the 9 candidate compounds, neferine B, neferine A, and antroquinonol D, were identified and the inhibitory activity of these compounds were subsequently validated in the C6 glioma cell line. All three selected compounds show potential effects on cell viability by MTT assay. Neferine B, neferine A, and antroquinonol D showed an IC50 value of 10-, 12-, and 16-μM, respectively. Moreover, these compounds decreased the p-FAk and p-S6k1 proteins in a dose-dependent manner. The results of best docked neferine B, neferine A, and antroquinonol D have the potential for further development as a supplement to treat tumorigenesis and metastasis. PMID:27133039

  12. 1-o-acetylbritannilactone (ABL) inhibits angiogenesis and lung cancer cell growth through regulating VEGF-Src-FAK signaling.

    Zhengfu, He; Hu, Zhang; Huiwen, Miao; Zhijun, Li; Jiaojie, Zhou; Xiaoyi, Yan; Xiujun, Cai

    2015-08-21

    The search for safe, effective and affordable therapeutics against non-small cell lung cancer (NSCLC) and other lung cancers is important. Here we explored the potential effect of 1-o-acetylbritannilactone (ABL), a novel extract from Inula britannica-F, on angiogenesis and lung cancer cell growth. We demonstrated that ABL dose-dependently inhibited vascular endothelial growth factor (VEGF)-induced proliferation, migration, and capillary structure formation of cultured human umbilical vascular endothelial cells (HUVECs). In vivo, ABL administration suppressed VEGF-induced new vasculature formation in Matrigel plugs. For the mechanism investigations, we found that ABL largely inhibited VEGF-mediated activation of Src kinase and focal adhesion kinase (FAK) in HUVECs. Furthermore, treatment of A549 NSCLC cells with ABL resulted in cell growth inhibition and Src-FAK in-activation. Significantly, administration of a single dose of ABL (12 mg/kg/day) remarkably suppressed growth of A549 xenografts in nude mice. In vivo microvessels formation and Src activation were also significantly inhibited in ABL-treated xenograft tumors. Taken together, our findings suggest that ABL suppresses angiogenesis and lung cancer cell growth possibly via regulating the VEGFR-Src-FAK signaling. PMID:26102035

  13. Effects of protein tyrosine kinase inhibitors on cytokine-induced adhesion molecule expression by human umbilical vein endothelial cells.

    May, M. J.; Wheeler-Jones, C. P.; Pearson, J. D.

    1996-01-01

    1. Endothelial cells can be stimulated by the pro-inflammatory cytokines interleukin (IL)-1 alpha and tumour necrosis factor (TNF) alpha to express the leukocyte adhesion molecules E-selectin, vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1 but the intracellular signalling mechanisms leading to this expression are incompletely understood. We have investigated the role of protein tyrosine kinases (PTK) in adhesion molecule expression by cytokine-activated ...

  14. Targeting Protein Kinase C Downstream of Growth Factor and Adhesion Signalling

    Dowling, Catríona M., E-mail: Catriona.Dowling@ul.ie; Kiely, Patrick A., E-mail: Catriona.Dowling@ul.ie [Department of Life Sciences, Materials and Surface Science Institute and Stokes Institute, University of Limerick, Limerick 78666 (Ireland); Health Research Institute (HRI), University of Limerick, Limerick 78666 (Ireland)

    2015-07-15

    The signaling outputs of Receptor Tyrosine Kinases, G-protein coupled receptors and integrins converge to mediate key cell process such as cell adhesion, cell migration, cell invasion and cell proliferation. Once activated by their ligands, these cell surface proteins recruit and direct a diverse range of proteins to disseminate the appropriate response downstream of the specific environmental cues. One of the key groups of proteins required to regulate these activities is the family of serine/threonine intracellular kinases called Protein Kinase Cs. The activity and subcellular location of PKCs are mediated by a series of tightly regulated events and is dependent on several posttranslational modifications and the availability of second messengers. Protein Kinase Cs exhibit both pro- and anti-tumorigenic effects making them an interesting target for anti-cancer treatment.

  15. Influence of focal adhesion kinase on epithelial-mesenchymal transition of human renal proximal tubular epithelial cells induced by transforming growth factor β1%黏着斑激酶在转化生长因子β1诱导的人肾小管上皮细胞转分化中的作用

    邓冰清; 朱忠华; 张春; 杨晓; 刘建社

    2009-01-01

    目的 观察转化生长因子(TGF)β1诱导的正常人近端肾小管上皮细胞(HK-2)转分化(EMT)过程中黏着斑激酶(FAK)的表达及下调FAK的表达后对TGF-β1诱导的HK-2细胞转分化进程的影响.方法 应用TGF-β1(10 μg/L)刺激HK-2细胞,采用RT-PCR、Western印迹和免疫荧光方法分别检测E钙黏蛋白(E-cadherin)、α平滑肌肌动蛋白(α-SMA)、FAK mRNA和蛋白的表达及磷酸化(p)-FAK(Tyr397)的蛋白表达.应用Lipofectmine2000将FAK siRNA转染HK-2细胞,采用Western印迹观察下调表达FAK对上述指标的影响.结果 TGF-β1刺激后,HK-2细胞α-SMA蛋白和mRNA水平上调,E-cadherin蛋白和mRNA表达下调.FAK蛋白和mRNA随时间的延长表达逐渐增多,48 h达到高峰.p-FAK(Tyr397)蛋白表达趋势与FAK相同.脂质体转染siRNA后FAK的mRNA和蛋白分别下调了50%和41%,下调表达FAK后可以显著抑制TGF-β1诱导的HK-2细胞α-SMA蛋白的上调表达,逆转E-cadherin蛋白的下调表达.结论 在TGF-β1诱导的HK-2细胞转分化进程FAK蛋白表达上调,敲低FAK蛋白表达后可以部分减轻EMT的程度,提示FAK在TGF-β1诱导的肾小管上皮细胞转分化和肾脏纤维化中发挥一定的作用.%Objective To investigate the expression of focal adhesion kinase(FAK)in epithelial-mesenchymal transition(EMT)of TGF-β1-stimulated HK-2 cells and the effect of FAK knockdown by small interfering RNA on EMT.Methods HK-2 cells were grown in DMEM-F12 medium supplemented by 10% fetal bovine serum(FBS).HK-2 cells were cultured in free serum medium for 24 h,then were stimulated by TGF-β1(10 μg/L).The expression of E-cadherin,α-SMA,FAK mRNA and protein were detected by RT-PCR,Western blot and immunofluorescence,respectively.The expression level of phosphorylated FAK-Tyr397 was detected by Western blot.HK-2 cells were transfected with 200 nmol/L FAK-siRNA or negative control siRNA using Lipofectamine 2000.Then the expression of E-cadherin,α-SMA,FAK protein was detected by

  16. Activation of AMP-activated protein kinase attenuates hepatocellular carcinoma cell adhesion stimulated by adipokine resistin

    Resistin, adipocyte-secreting adipokine, may play critical role in modulating cancer pathogenesis. The aim of this study was to investigate the effects of resistin on HCC adhesion to the endothelium, and the mechanism underlying these resistin effects. Human SK-Hep1 cells were used to study the effect of resistin on intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expressions as well as NF-κB activation, and hence cell adhesion to human umbilical vein endothelial cells (HUVECs). 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR), an AMP-activated protein kinase (AMPK) activator, was used to determine the regulatory role of AMPK on HCC adhesion to the endothelium in regard to the resistin effects. Treatment with resistin increased the adhesion of SK-Hep1 cells to HUVECs and concomitantly induced NF-κB activation, as well as ICAM-1 and VCAM-1 expressions in SK-Hep1 cells. Using specific blocking antibodies and siRNAs, we found that resistin-induced SK-Hep1 cell adhesion to HUVECs was through NF-κB-regulated ICAM-1 and VCAM-1 expressions. Moreover, treatment with AICAR demonstrated that AMPK activation in SK-Hep1 cells significantly attenuates the resistin effect on SK-Hep1 cell adhesion to HUVECs. These results clarify the role of resistin in inducing HCC adhesion to the endothelium and demonstrate the inhibitory effect of AMPK activation under the resistin stimulation. Our findings provide a notion that resistin play an important role to promote HCC metastasis and implicate AMPK may be a therapeutic target to against HCC metastasis

  17. The role of adhesion strength in human mesenchymal stem cell osteoblastic differentiation on biodegradable polymers

    Krizan, Sylva Jana

    Human mesenchymal stem cells (hMSC) are promising candidates for promoting bone growth on biodegradable polymer scaffolds however little is known about early hMSC-polymer interactions. Adhesion is highly dynamic and during adhesive reinforcement, numerous proteins form adhesion plaques linking the cell's cytoskeleton with the extracellular environment. These proteins are known to affect cellular function but their role in hMSC differentiation is less clear. Adhesion plaques are associated with adhesive force, still a detachment force of hMSC on polycaprolactone (PCL), poly-lactide-co-glycolide (PLGA) or alginate has never been described or shown to affect downstream function. We demonstrate that hMSC attached to PCL, PLGA and alginate exhibit different adhesion strengths (tau50) as determined by both fluid shear and spinning disk systems, with PLGA demonstrating the greatest tau 50. Elastic modulus and hydrophobicity were characterized for these surfaces and correlated positively with tau50 to an optimum. Attachment studies of hMSC showed that adhesion plateau timespans were independent of cell line and surface but both morphology and focal adhesion expression varied by polymer type. Differentiation studies of hMSC on PLGA and PCL showed a strong association between markers of differentiation (alkaline phosphatase activity and mineral content) and tau50 within polymer groups, but a poor relationship was found between tau50 and differentiation across polymer groups, suggesting that other polymer properties may be important for differentiation. Subsequently, we examined the role of focal adhesion kinase (FAK) and Rho-GTPase (RhoA) on hMSC adhesion and differentiation when plated onto PLGA. hMSC were retrovirally transduced with mutant constructs of FAK and RhoA cDNA. Alternatively, hMSC were treated with Rho-kinase inhibitor, Y27632. Both cells transduced with mutant RhoA or FAK constructs, or those treated with Y27632 displayed aberrant cell morphology and changes

  18. Identification of Fer Tyrosine Kinase Localized on Microtubules as a Platelet Endothelial Cell Adhesion Molecule-1 Phosphorylating Kinase in Vascular Endothelial CellsV⃞

    Kogata, Naoko; Masuda, Michitaka; Kamioka, Yuji; Yamagishi, Akiko; Endo, Akira; Okada, Masato; Mochizuki, Naoki

    2003-01-01

    Platelet endothelial adhesion molecule-1 (PECAM-1) is a part of intercellular junctions and triggers intracellular signaling cascades upon homophilic binding. The intracellular domain of PECAM-1 is tyrosine phosphorylated upon homophilic engagement. However, it remains unclear which tyrosine kinase phosphorylates PECAM-1. We sought to isolate tyrosine kinases responsible for PECAM-1 phosphorylation and identified Fer as a candidate, based on expression cloning. Fer kinase specifically phospho...

  19. Cell adhesion-dependent inactivation of a soluble protein kinase during fertilization in Chlamydomonas.

    Zhang, Y.; Luo, Y.; Emmett, K; Snell, W J

    1996-01-01

    Within seconds after the flagella of mt+ and mt- Chlamydomonas gametes adhere during fertilization, their flagellar adenylyl cyclase is activated several fold and preparation for cell fusion is initiated. Our previous studies indicated that early events in this pathway, including control of adenylyl cyclase, are regulated by phosphorylation and dephosphorylation. Here, we describe a soluble, flagellar protein kinase activity that is regulated by flagellar adhesion. A 48-kDa, soluble flagellar...

  20. Decreased cell adhesion promotes angiogenesis in a Pyk2-dependent manner

    Angiogenesis is regulated by both soluble growth factors and cellular interactions with the extracellular matrix (ECM). While cell adhesion via integrins has been shown to be required for angiogenesis, the effects of quantitative changes in cell adhesion and spreading against the ECM remain less clear. Here, we show that angiogenic sprouting in natural and engineered three-dimensional matrices exhibited a biphasic response, with peak sprouting when adhesion to the matrix was limited to intermediate levels. Examining changes in global gene expression to determine a genetic basis for this response, we demonstrate a vascular endothelial growth factor (VEGF)-induced upregulation of genes associated with vascular invasion and remodeling when cell adhesion was limited, whereas cells on highly adhesive surfaces upregulated genes associated with proliferation. To explore a mechanistic basis for this effect, we turned to focal adhesion kinase (FAK), a central player in adhesion signaling previously implicated in angiogenesis, and its homologue, proline-rich tyrosine kinase 2 (Pyk2). While FAK signaling had some impact, our results suggested that Pyk2 can regulate both gene expression and endothelial sprouting through its enhanced activation by VEGF in limited adhesion contexts. We also demonstrate decreased sprouting of tissue explants from Pyk2-null mice as compared to wild type mice as further confirmation of the role of Pyk2 in angiogenic sprouting. These results suggest a surprising finding that limited cell adhesion can enhance endothelial responsiveness to VEGF and demonstrate a novel role for Pyk2 in the adhesive regulation of angiogenesis.

  1. EFFECTS OF INTEGRIN ALPHA ⅡbR995A MUTATION ON RECEPTOR AFFINITY AND pp 125 (FAK) PHOSPHORYLATION

    Xue-yuan Tang; Zai-fu Jian; Guo-ping Wang; Hong-hui Yang; Wei Liu

    2004-01-01

    Objective To investigate the role of cytoplasmic domain of integrin alpha Ⅱb in platelet signal transduction.Methods Binding capacity of integrin alpha ⅡbR995Ato antibody platelet activation complex-1 (PAC-1) and pp125focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting.Results Without activation, wild-type alpha Ⅱ bbeta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alpha ⅡbR995Aeta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK)in wild-type alpha Ⅱbbeta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions.Conclusion The mutation in integrin alpha ⅡbR995Aalters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.

  2. Phosphorylation of the beta-subunit of CD11/CD18 integrins by protein kinase C correlates with leukocyte adhesion.

    Valmu, L; Autero, M; Siljander, P; Patarroyo, M; Gahmberg, C G

    1991-11-01

    Adhesion of activated leukocytes to cells is of critical functional importance. The adhesion is known to be mediated mainly by the CD11/CD18 integrins, also known as leukocytic cell adhesion molecules, or Leu-CAM. We have now studied the phosphorylation of Leu-CAM by protein kinase C and the correlation of phosphorylation with the generation of the adhesive phenotype among human peripheral blood mononuclear leukocytes during cell activation. We here show that a good correlation exists between the phosphorylation of the beta subunit of Leu-CAM (CD18), and the extent of cell-to-cell adhesion. The phosphorylated CD18 subunit was associated with both CD11a and CD11b. Purified protein kinase C was able to phosphorylate the beta subunit of isolated Leu-CAM in vitro. The phosphorylation occurred mainly on serine residues. PMID:1682156

  3. Role of Cbl-associated protein/ponsin in receptor tyrosine kinase signaling and cell adhesion

    Ritva Tikkanen

    2012-10-01

    Full Text Available The Cbl-associated protein/ponsin (CAP is an adaptor protein that contains a so-called Sorbin homology (SoHo domain and three Src homology 3 (SH3 domains which are engaged in diverse protein-protein interactions. CAP has been shown to function in the regulation of the actin cytoskeleton and cell adhesion and to be involved in the differentiation of muscle cells and adipocytes. In addition, it participates in signaling pathways through several receptor tyrosine kinases such as insulin and neurotrophin receptors. In the last couple of years, several studies have shed light on the details of these processes and identified novel interaction partners of CAP. In this review, we summarize these recent findings and provide an overview on the function of CAP especially in cell adhesion and membrane receptor signaling.

  4. Integrins and focal adhesion kinase in the malignant behavior of gliomas

    Efstathia Giannopoulou

    2015-03-01

    Full Text Available Glioblastoma multiforme (GBM is the most common type of glioma and is associated with a very poor prognosis. The standard treatment includes radiotherapy concurrent with temozolomide, however recently the Food and Drug Administration approved bevacizumab for use in patients with progressive glioblastoma following prior therapy. The limited number of treatment options points to the need for novel effective therapeutic approaches. A promising approach is the use of tyrosine kinase inhibitors (TKIs in GBM treatment. However, the results from the majority of clinical trials using TKIs are not very encouraging. One growing area is the development of tumor-homing peptides that resemble the integrin recognition sequence RGD. In this article, the role of integrins and focal adhesion kinase in malignant glioma is reviewed, and an experimental study is proposed that will apply a strategy for peptide-mediated delivery of compounds deep into tumor parenchyma using tumor-homing peptides.

  5. Epithelial membrane protein-2 promotes endometrial tumor formation through activation of FAK and Src.

    Maoyong Fu

    Full Text Available Endometrial cancer is the most common gynecologic malignancy diagnosed among women in developed countries. One recent biomarker strongly associated with disease progression and survival is epithelial membrane protein-2 (EMP2, a tetraspan protein known to associate with and modify surface expression of certain integrin isoforms. In this study, we show using a xenograft model system that EMP2 expression is necessary for efficient endometrial tumor formation, and we have started to characterize the mechanism by which EMP2 contributes to this malignant phenotype. In endometrial cancer cells, the focal adhesion kinase (FAK/Src pathway appears to regulate migration as measured through wound healing assays. Manipulation of EMP2 levels in endometrial cancer cells regulates the phosphorylation of FAK and Src, and promotes their distribution into lipid raft domains. Notably, cells with low levels of EMP2 fail to migrate and poorly form tumors in vivo. These findings reveal the pivotal role of EMP2 in endometrial cancer carcinogenesis, and suggest that the association of elevated EMP2 levels with endometrial cancer prognosis may be causally linked to its effect on integrin-mediated signaling.

  6. Curcumin Suppresses Metastasis via Sp-1, FAK Inhibition, and E-Cadherin Upregulation in Colorectal Cancer

    Chun-Chieh Chen

    2013-01-01

    Full Text Available Colorectal cancer (CRC is a serious public health problem that results due to changes of diet and various environmental stress factors in the world. Curcumin is a traditional medicine used for treatment of a wide variety of tumors. However, antimetastasis mechanism of curcumin on CRC has not yet been completely investigated. Here, we explored the underlying molecular mechanisms of curcumin on metastasis of CRC cells in vitro and in vivo. Curcumin significantly inhibits cell migration, invasion, and colony formation in vitro and reduces tumor growth and liver metastasis in vivo. We found that curcumin suppresses Sp-1 transcriptional activity and Sp-1 regulated genes including ADEM10, calmodulin, EPHB2, HDAC4, and SEPP1 in CRC cells. Curcumin inhibits focal adhesion kinase (FAK phosphorylation and enhances the expressions of several extracellular matrix components which play a critical role in invasion and metastasis. Curcumin reduces CD24 expression in a dose-dependent manner in CRC cells. Moreover, E-cadherin expression is upregulated by curcumin and serves as an inhibitor of EMT. These results suggest that curcumin executes its antimetastasis function through downregulation of Sp-1, FAK, and CD24 and by promoting E-cadherin expression in CRC cells.

  7. Curcumin Suppresses Metastasis via Sp-1, FAK Inhibition, and E-Cadherin Upregulation in Colorectal Cancer.

    Chen, Chun-Chieh; Sureshbabul, Munisamy; Chen, Huei-Wen; Lin, Yu-Shuang; Lee, Jen-Yi; Hong, Qi-Sheng; Yang, Ya-Chien; Yu, Sung-Liang

    2013-01-01

    Colorectal cancer (CRC) is a serious public health problem that results due to changes of diet and various environmental stress factors in the world. Curcumin is a traditional medicine used for treatment of a wide variety of tumors. However, antimetastasis mechanism of curcumin on CRC has not yet been completely investigated. Here, we explored the underlying molecular mechanisms of curcumin on metastasis of CRC cells in vitro and in vivo. Curcumin significantly inhibits cell migration, invasion, and colony formation in vitro and reduces tumor growth and liver metastasis in vivo. We found that curcumin suppresses Sp-1 transcriptional activity and Sp-1 regulated genes including ADEM10, calmodulin, EPHB2, HDAC4, and SEPP1 in CRC cells. Curcumin inhibits focal adhesion kinase (FAK) phosphorylation and enhances the expressions of several extracellular matrix components which play a critical role in invasion and metastasis. Curcumin reduces CD24 expression in a dose-dependent manner in CRC cells. Moreover, E-cadherin expression is upregulated by curcumin and serves as an inhibitor of EMT. These results suggest that curcumin executes its antimetastasis function through downregulation of Sp-1, FAK, and CD24 and by promoting E-cadherin expression in CRC cells. PMID:23970932

  8. Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization

    Datla, Srinivasa Raju; McGrail, Daniel J.; Vukelic, Sasa; Huff, Lauren P.; Lyle, Alicia N.; Pounkova, Lily; Lee, Minyoung; Seidel-Rogol, Bonnie; Khalil, Mazen K.; Hilenski, Lula L.; Terada, Lance S.; Dawson, Michelle R.; Lassègue, Bernard

    2014-01-01

    Polymerase-δ-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner. PMID:25063792

  9. RACK1 Targets the Extracellular Signal-Regulated Kinase/Mitogen-Activated Protein Kinase Pathway To Link Integrin Engagement with Focal Adhesion Disassembly and Cell Motility

    Vomastek, Tomáš; Iwanicki, M. P.; Schaeffer, J.; J.; Tarcsafalvi, A.; Parsons, J. T.; Weber, M. J.

    2007-01-01

    Roč. 27, č. 23 (2007), s. 8296-8305. ISSN 0270-7306 R&D Projects: GA AV ČR IAA500200716 Institutional research plan: CEZ:AV0Z50200510 Keywords : protein kinase * adhesion * cell Subject RIV: EE - Microbiology, Virology Impact factor: 6.420, year: 2007

  10. Degradation of adhesion molecules of G361 melanoma cells by a non-thermal atmospheric pressure microplasma

    Increased expression of integrins and focal adhesion kinase (FAK) is important for the survival, growth and metastasis of melanoma cells. Based on this well-established observation in oncology, we propose to use degradation of integrin and FAK proteins as a potential strategy for melanoma cancer therapy. A low-temperature radio-frequency atmospheric microplasma jet is used to study their effects on the adhesion molecules of G361 melanoma cells. Microplasma treatment is shown to (1) cause significant cell detachment from the bottom of microtiter plates coated with collagen, (2) induce the death of human melanoma cells, (3) inhibit the expression of integrin α2, integrin α4 and FAK on the cell surface and finally (4) change well-stretched actin filaments to a diffuse pattern. These results suggest that cold atmospheric pressure plasmas can strongly inhibit the adhesion of melanoma cells by reducing the activities of adhesion proteins such as integrins and FAK, key biomolecules that are known to be important in malignant transformation and acquisition of metastatic phenotypes.

  11. Degradation of adhesion molecules of G361 melanoma cells by a non-thermal atmospheric pressure microplasma

    Lee, H J [Department of Electrical Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Shon, C H [Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of); Kim, Y S; Kim, S [Department of Pediatric Dentistry, Pusan National University, Busan 602-739 (Korea, Republic of); Kim, G C [Department of Oral Anatomy, Pusan National University, Busan 602-739 (Korea, Republic of); Kong, M G [Department of Electronics and Electrical Engineering, Loughborough University, Leics LE11 3TU (United Kingdom)], E-mail: ki9100m@pusan.ac.kr, E-mail: m.g.kong@lboro.ac.uk

    2009-11-15

    Increased expression of integrins and focal adhesion kinase (FAK) is important for the survival, growth and metastasis of melanoma cells. Based on this well-established observation in oncology, we propose to use degradation of integrin and FAK proteins as a potential strategy for melanoma cancer therapy. A low-temperature radio-frequency atmospheric microplasma jet is used to study their effects on the adhesion molecules of G361 melanoma cells. Microplasma treatment is shown to (1) cause significant cell detachment from the bottom of microtiter plates coated with collagen, (2) induce the death of human melanoma cells, (3) inhibit the expression of integrin {alpha}{sub 2}, integrin {alpha}{sub 4} and FAK on the cell surface and finally (4) change well-stretched actin filaments to a diffuse pattern. These results suggest that cold atmospheric pressure plasmas can strongly inhibit the adhesion of melanoma cells by reducing the activities of adhesion proteins such as integrins and FAK, key biomolecules that are known to be important in malignant transformation and acquisition of metastatic phenotypes.

  12. αvβ5 Integrin/FAK/PGC-1α Pathway Confers Protective Effects on Retinal Pigment Epithelium.

    Murilo F Roggia

    Full Text Available To elucidate the mechanism of the induction of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α by photoreceptor outer segments (POS and its effects on retinal pigment epithelium (RPE.PGC-1α upregulation by POS was confirmed in ARPE-19 cells and in RPE ex vivo. To elucidate the mechanism, siRNAs against β5 integrin, CD36, Mer tyrosine kinase (MerTK, and Atg5, blocking antibodies against CD36 and MerTK, and a specific inhibitor for focal adhesion kinase (FAK were used. We examined the effect of POS-induced PGC-1α upregulation on the levels of reactive oxygen species (ROS, mitochondrial biogenesis, senescence-associated β-galactosidase (SA-β-gal after H2O2 treatment, and lysosomal activity. Lysosomal activity was evaluated through transcriptional factor EB and its target genes, and the activity of cathepsin D. Lipid metabolism after POS treatment was assessed using Oil Red O and BODIPY C11. RPE phenotypes of PGC-1α-deficient mice were examined.POS-induced PGC-1α upregulation was suppressed by siRNA against β5 integrin and a FAK inhibitor. siRNAs and blocking antibodies against CD36 and MerTK enhanced the effect of POS on PGC-1α. The upregulation of PGC-1α increased the levels of mRNA for antioxidant enzymes and stimulated mitochondrial biogenesis, decreased ROS levels, and reduced SA-β-gal staining in H2O2-treated ARPE-19 cells. PGC-1α was critical for lysosomal activity and lipid metabolism after POS treatment. PGC-1α-deficient mice demonstrated an accumulation of type 2 lysosomes in RPE, thickening of Bruch's membrane, and poor choriocapillaris vasculature.The binding, but not the internalization of POS confers protective effects on RPE cells through the αvβ5 integrin/FAK/PGC-1α pathway.

  13. Glycogen synthase kinase 3β sustains invasion of glioblastoma via the focal adhesion kinase, Rac1, and c-Jun N-terminal kinase-mediated pathway.

    Chikano, Yuri; Domoto, Takahiro; Furuta, Takuya; Sabit, Hemragul; Kitano-Tamura, Ayako; Pyko, Ilya V; Takino, Takahisa; Sai, Yoshimichi; Hayashi, Yutaka; Sato, Hiroshi; Miyamoto, Ken-ichi; Nakada, Mitsutoshi; Minamoto, Toshinari

    2015-02-01

    The failure of current treatment options for glioblastoma stems from their inability to control tumor cell proliferation and invasion. Biologically targeted therapies offer great hope and one promising target is glycogen synthase kinase-3β (GSK3β), implicated in various diseases, including cancer. We previously reported that inhibition of GSK3β compromises the survival and proliferation of glioblastoma cells, induces their apoptosis, and sensitizes them to temozolomide and radiation. Here, we explore whether GSK3β also contributes to the highly invasive nature of glioblastoma. The effects of GSK3β inhibition on migration and invasion of glioblastoma cells were examined by wound-healing and Transwell assays, as well as in a mouse model of glioblastoma. We also investigated changes in cellular microarchitectures, cytoskeletal components, and proteins responsible for cell motility and invasion. Inhibition of GSK3β attenuated the migration and invasion of glioblastoma cells in vitro and that of tumor cells in a mouse model of glioblastoma. These effects were associated with suppression of the molecular axis involving focal adhesion kinase, guanine nucleotide exchange factors/Rac1 and c-Jun N-terminal kinase. Changes in cellular phenotypes responsible for cell motility and invasion were also observed, including decreased formation of lamellipodia and invadopodium-like microstructures and alterations in the subcellular localization, and activity of Rac1 and F-actin. These changes coincided with decreased expression of matrix metalloproteinases. Our results confirm the potential of GSK3β as an attractive therapeutic target against glioblastoma invasion, thus highlighting a second role in this tumor type in addition to its involvement in chemo- and radioresistance. PMID:25504636

  14. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the

  15. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    Zhang, Bingyu [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Luo, Qing, E-mail: qing.luo@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Mao, Xinjian [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Xu, Baiyao [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Yang, Li [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Ju, Yang [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Song, Guanbin, E-mail: song@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2014-03-10

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the

  16. Amygdalin influences bladder cancer cell adhesion and invasion in vitro.

    Jasmina Makarević

    Full Text Available The cyanogenic diglucoside amygdalin, derived from Rosaceae kernels, is employed by many patients as an alternative anti-cancer treatment. However, whether amygdalin indeed acts as an anti-tumor agent is not clear. Metastasis blocking properties of amygdalin on bladder cancer cell lines was, therefore, investigated. Amygdalin (10 mg/ml was applied to UMUC-3, TCCSUP or RT112 bladder cancer cells for 24 h or for 2 weeks. Tumor cell adhesion to vascular endothelium or to immobilized collagen as well as tumor cell migration was examined. Effects of drug treatment on integrin α and β subtypes, on integrin-linked kinase (ILK and total and activated focal adhesion kinase (FAK were also determined. Integrin knock-down was carried out to evaluate integrin influence on migration and adhesion. A 24 h or 2 week amygdalin application distinctly reduced tumor cell adhesion and migration of UMUC-3 and RT112 cells. TCCSUP adhesion was also reduced, but migration was elevated under amygdalin. Integrin subtype expression was significantly and specifically altered by amygdalin depending on the cell line. ILK was moderately, and activated FAK strongly, lost in all tumor cell lines in the presence of amygdalin. Knock down of β1 integrin caused a significant decrease in both adhesion and migration of UMUC-3 cells, but a significant increase in TCCSUP adhesion. Knock down of β4 integrin caused a significant decrease in migration of RT112 cells. Since the different actions of amygdalin on the different cell lines was mirrored by β1 or β4 knock down, it is postulated that amygdalin influences adhesion and migratory properties of bladder cancer cells by modulating β1 or β4 integrin expression. The amygdalin induced increase in TCCSUP migratory behavior indicates that any anti-tumor benefits from amygdalin (seen with the other two cell lines may depend upon the cancer cell type.

  17. Anandamide inhibits adhesion and migration of breast cancer cells

    The endocannabinoid system regulates cell proliferation in human breast cancer cells. We reasoned that stimulation of cannabinoid CB1 receptors could induce a non-invasive phenotype in breast mtastatic cells. In a model of metastatic spreading in vivo, the metabolically stable anandamide analogue, 2-methyl-2'-F-anandamide (Met-F-AEA), significantly reduced the number and dimension of metastatic nodes, this effect being antagonized by the selective CB1 antagonist SR141716A. In MDA-MB-231 cells, a highly invasive human breast cancer cell line, and in TSA-E1 cells, a murine breast cancer cell line, Met-F-AEA inhibited adhesion and migration on type IV collagen in vitro without modifying integrin expression: both these effects were antagonized by SR141716A. In order to understand the molecular mechanism involved in these processes, we analyzed the phosphorylation of FAK and Src, two tyrosine kinases involved in migration and adhesion. In Met-F-AEA-treated cells, we observed a decreased tyrosine phosphorylation of both FAK and Src, this effect being attenuated by SR141716A. We propose that CB1 receptor agonists inhibit tumor cell invasion and metastasis by modulating FAK phosphorylation, and that CB1 receptor activation might represent a novel therapeutic strategy to slow down the growth of breast carcinoma and to inhibit its metastatic diffusion in vivo

  18. Heparan sulfate proteoglycans mediate interstitial flow mechanotransduction regulating MMP-13 expression and cell motility via FAK-ERK in 3D collagen.

    Zhong-Dong Shi

    Full Text Available BACKGROUND: Interstitial flow directly affects cells that reside in tissues and regulates tissue physiology and pathology by modulating important cellular processes including proliferation, differentiation, and migration. However, the structures that cells utilize to sense interstitial flow in a 3-dimensional (3D environment have not yet been elucidated. Previously, we have shown that interstitial flow upregulates matrix metalloproteinase (MMP expression in rat vascular smooth muscle cells (SMCs and fibroblasts/myofibroblasts via activation of an ERK1/2-c-Jun pathway, which in turn promotes cell migration in collagen. Herein, we focused on uncovering the flow-induced mechanotransduction mechanism in 3D. METHODOLOGY/PRINCIPAL FINDINGS: Cleavage of rat vascular SMC surface glycocalyx heparan sulfate (HS chains from proteoglycan (PG core proteins by heparinase or disruption of HS biosynthesis by silencing N-deacetylase/N-sulfotransferase 1 (NDST1 suppressed interstitial flow-induced ERK1/2 activation, interstitial collagenase (MMP-13 expression, and SMC motility in 3D collagen. Inhibition or knockdown of focal adhesion kinase (FAK also attenuated or blocked flow-induced ERK1/2 activation, MMP-13 expression, and cell motility. Interstitial flow induced FAK phosphorylation at Tyr925, and this activation was blocked when heparan sulfate proteoglycans (HSPGs were disrupted. These data suggest that HSPGs mediate interstitial flow-induced mechanotransduction through FAK-ERK. In addition, we show that integrins are crucial for mechanotransduction through HSPGs as they mediate cell spreading and maintain cytoskeletal rigidity. CONCLUSIONS/SIGNIFICANCE: We propose a conceptual mechanotransduction model wherein cell surface glycocalyx HSPGs, in the presence of integrin-mediated cell-matrix adhesions and cytoskeleton organization, sense interstitial flow and activate the FAK-ERK signaling axis, leading to upregulation of MMP expression and cell motility in 3D

  19. Antiproliferative effects of EGFR tyrosine kinase inhibition and radiation-induced genotoxic injury are attenuated by adhesion to fibronectin

    Background and purpose: Integrin-linked kinase (ILK) functions in cooperative integrin-growth factor receptor-mediated signaling to control cell survival and proliferation. The effect of tyrosine kinase (tk) inhibition of the epidermal growth factor receptor (EGFR) on radiation survival and growth was evaluated in human FaDu squamous cell carcinoma cells expressing different forms of ILK. Material and methods: ILK-wild-type (wk) and -hyperactive kinase (hk) transfected cells were grown on fibronectin (Fn) under serum presence or depletion, irradiated (0-6 Gy) and/or treated with the EGFR-tk inhibitor BIBX1382BS. Results: ILK-wk and -hk transfectants showed significant radiosensitization compared to vector control cells. Antisurvival and antiproliferative effects of EGFR-tk inhibition plus/minus irradiation were counteracted by adhesion to Fn relative to the control substratum, poly-L-lysine. Similar to vector controls, ILK transfectants exhibited a strong decrease in cell proliferation but no enhanced radiation sensitivity after EGFR-tk inhibition. This decrease was accompanied by changes in cyclin D1 and phosphorylated MAPK persisting to day 10 following transient drug exposure. Conclusions: Our data demonstrate a prosurvival role of adhesion and an antisurvival role of ILK upon irradiation. Inhibition of EGFR-tk using BIBX1382BS does not affect the intrinsic cellular radiosensitivity of cells grown on fibronectin. Thus, simultaneous targeting of adhesion and growth factor receptor-mediated signaling might potently improve anticancer strategies

  20. FAK Mediates a Compensatory Survival Signal Parallel to PI3K-AKT in PTEN-Null T-ALL Cells

    Dewen You

    2015-03-01

    Full Text Available Mutations and inactivation of phosphatase and tensin homolog deleted from chromosome 10 (PTEN are observed in 15%–25% of cases of human T cell acute lymphoblastic leukemia (T-ALL. Pten deletion induces myeloproliferative disorders (MPDs, acute myeloid leukemia (AML, and/or T-ALL in mice. Previous studies attributed Pten-loss-related hematopoietic defects and leukemogenesis to excessive activation of phosphatidylinositol 3-kinase (PI3K/AKT/mTOR signaling. Although inhibition of this signal dramatically suppresses the growth of PTEN-null T-ALL cells in vitro, treatment with inhibitors of this pathway does not cause a complete remission in vivo. Here, we report that focal adhesion kinase (Fak, a protein substrate of Pten, also contributes to T-ALL development in Pten-null mice. Inactivation of the FAK signaling pathway by either genetic or pharmacologic methods significantly sensitizes both murine and human PTEN-null T-ALL cells to PI3K/AKT/mTOR inhibition when cultured in vitro on feeder layer cells or a matrix and in vivo.

  1. FAK mediates a compensatory survival signal parallel to PI3K-AKT in PTEN-null T-ALL cells.

    You, Dewen; Xin, Junping; Volk, Andrew; Wei, Wei; Schmidt, Rachel; Scurti, Gina; Nand, Sucha; Breuer, Eun-Kyoung; Kuo, Paul C; Breslin, Peter; Kini, Ameet R; Nishimura, Michael I; Zeleznik-Le, Nancy J; Zhang, Jiwang

    2015-03-31

    Mutations and inactivation of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) are observed in 15%-25% of cases of human T cell acute lymphoblastic leukemia (T-ALL). Pten deletion induces myeloproliferative disorders (MPDs), acute myeloid leukemia (AML), and/or T-ALL in mice. Previous studies attributed Pten-loss-related hematopoietic defects and leukemogenesis to excessive activation of phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR signaling. Although inhibition of this signal dramatically suppresses the growth of PTEN-null T-ALL cells in vitro, treatment with inhibitors of this pathway does not cause a complete remission in vivo. Here, we report that focal adhesion kinase (Fak), a protein substrate of Pten, also contributes to T-ALL development in Pten-null mice. Inactivation of the FAK signaling pathway by either genetic or pharmacologic methods significantly sensitizes both murine and human PTEN-null T-ALL cells to PI3K/AKT/mTOR inhibition when cultured in vitro on feeder layer cells or a matrix and in vivo. PMID:25801032

  2. Direct binding of syndecan-4 cytoplasmic domain to the catalytic domain of protein kinase C alpha (PKC alpha) increases focal adhesion localization of PKC alpha

    Lim, Ssang-Taek; Longley, Robert L; Couchman, John R; Woods, Anne

    2003-01-01

    Syndecan-4 is a transmembrane heparan sulfate proteoglycan that acts as a coreceptor with integrins in focal adhesion formation. The central region of syndecan-4 cytoplasmic domain (4V; LGKKPIYKK) binds phosphatidylinositol 4,5-bisphosphate, and together they regulate protein kinase C alpha (PKC......, overexpression of syndecan-4 in rat embryo fibroblast cells, but not expression of the YF mutant, increased PKC alpha localization to focal adhesions. The data support a mechanism where syndecan-4 binds PKC alpha and localizes it to focal adhesions, whose assembly may be regulated by the kinase....

  3. Adhesion-related kinase induction of migration requires phosphatidylinositol-3-kinase and ras stimulation of rac activity in immortalized gonadotropin-releasing hormone neuronal cells.

    Nielsen-Preiss, Sheila M; Allen, Melissa P; Xu, Mei; Linseman, Daniel A; Pawlowski, John E; Bouchard, R J; Varnum, Brian C; Heidenreich, Kim A; Wierman, Margaret E

    2007-06-01

    GnRH neurons migrate into the hypothalamus during development. Although migratory defects may result in disordered activation of the reproductive axis and lead to delayed or absent sexual maturation, specific factors regulating GnRH neuronal migration remain largely unknown. The receptor tyrosine kinase, adhesion-related kinase (Ark) (also known as Axl, UFO, and Tyro7), has been implicated in the migration of GnRH neuronal cells. Binding of its ligand, growth arrest-specific gene 6 (Gas6), promotes cytoskeletal remodeling and migration of NLT GnRH neuronal cells via Rac and p38 MAPK. Here, we examined the Axl effectors proximal to Rac in the signaling pathway. Gas6/Axl-induced lamellipodia formation and migration were blocked after phosphatidylinositol-3-kinase (PI3K) inhibition in GnRH neuronal cells. The p85 subunit of PI3K coimmunoprecipitated with Axl and was phosphorylated in a Gas6-sensitive manner. In addition, PI3K inhibition in GnRH neuronal cells diminished Gas6-induced Rac activation. Exogenous expression of a dominant-negative form of Ras also decreased GnRH neuronal lamellipodia formation, migration, and Rac activation. PI3K inhibition blocked Ras in addition to Rac activation and migration. In contrast, pharmacological blockade of the phospholipase C gamma effectors, protein kinase C or calcium/calmodulin protein kinase II, had no effect on Gas6/Axl signaling to promote Rac activation or stimulate cytoskeletal reorganization and migration. Together, these data show that the PI3K-Ras pathway is a major mediator of Axl actions upstream of Rac to induce GnRH neuronal cell migration. PMID:17332061

  4. Activation of AMP-activated protein kinase attenuates hepatocellular carcinoma cell adhesion stimulated by adipokine resistin

    Yang, Chen-Chieh; Chang, Shun-Fu; Chao, Jian-Kang; Lai, Yi-Liang; Chang, Wei-En; Hsu, Wen-Hsiu; Kuo, Wu-Hsien

    2014-01-01

    Background Resistin, adipocyte-secreting adipokine, may play critical role in modulating cancer pathogenesis. The aim of this study was to investigate the effects of resistin on HCC adhesion to the endothelium, and the mechanism underlying these resistin effects. Methods Human SK-Hep1 cells were used to study the effect of resistin on intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expressions as well as NF-κB activation, and hence cell adhesion to hu...

  5. Paxillin, a novel controller in the signaling of estrogen to FAK/N-WASP/Arp2/3 complex in breast cancer cells.

    Shortrede, Jorge Eduardo; Uzair, Ivonne Denise; Neira, Flavia Judith; Flamini, Marina Inés; Sanchez, Angel Matías

    2016-07-15

    Breast cancer is the major cause of cancer-related death in women. Its treatment is particularly difficult when metastasis occurs. The ability of cancer cells to move and invade the surrounding environment is the basis of local and distant metastasis. Cancer cells are able to remodel the actin cytoskeleton, which requires the recruitment of numerous structural and regulatory proteins that modulate actin filaments dynamics, including Paxillin or the Neural Wiskott-Aldrich Syndrome Protein (N-WASP). We show that 17-β estradiol (E2) induces phosphorylation of Paxillin and its translocation toward membrane sites where focal adhesion complexes are assembled. This cascade is triggered by a Gαi1/Gβ protein-dependent signaling of estrogen receptor α (ERα) to c-Src, focal adhesion kinase (FAK) and Paxillin. Within this complex, activated Paxillin recruits the small GTPase Cdc42, which triggers N-WASP phosphorylation. This results in the redistribution of Arp2/3 complexes at sites where membrane structures related to cell movement are formed. Recruitment of Paxillin, Cdc42 and N-WASP is necessary for cell adhesion, migration and invasion induced by E2 in breast cancer cells. In parallel, we investigated whether Raloxifene (RAL), a selective estrogen receptor modulator (SERMs), could inhibit or revert the effects of E2 in breast cancer cell movement. We found that, in the presence of E2, RAL acts as an ER antagonist and displays an inhibitory effect on estrogen-promoted cell adhesion and migration via FAK/Paxillin/N-WASP. Our findings identify an original mechanism through which estrogen regulates breast cancer cell motility and invasion via Paxillin. These results may have clinical relevance for the development of new therapeutic strategies for cancer treatment. PMID:27095481

  6. Zoledronate blocks geranylgeranylation not farnesylation to suppress human osteosarcoma U2OS cells metastasis by EMT via Rho A activation and FAK-inhibited JNK and p38 pathways

    Cheng, Hsin-Lin; Lin, Chiao-Wen; Yang, Jia-Sin; Hsieh, Ming-Ju; Yang, Shun-Fa; Lu, Ko-Hsiu

    2016-01-01

    Zoledronate is a standard treatment for preventing skeletal complications of osteoporosis and some types of cancer associated with bone metastases, but we little know whether the effect of zoledronate on metastasis of osteosarcoma. Here, we investigated the inhibitory effects of zoledronate on cell viability, motility, migration and invasion of 4 osteosarcoma cell lines (Saos2, MG-63, HOS and U2OS) by affecting cell morphology, epithelial-mesenchymal transition (EMT) and cytoskeletal organization as well as induction of E-cadherin and reduction of N-cadherin with activation of transcription factors Slug and Twist, especially in U2OS cells. Zoledronate decreased JNK and p38 phosphorylation and upper streams of focal adhesion kinase (FAK) and Src to suppress the motility, invasiveness and migration of U2OS cells. In addition to zoledronate-inhibited Rho A and Cdc42 membrane translocation and GTPγS activities, the anti-metastatic effects in U2OS cells including inhibition of adhesion were reversed by geranylgeraniol, but not farnesol. In conclusion, Zoledronate blocks geranylgeranylation not farnesylation to suppress human osteosarcoma U2OS cell-matrix and cell-cell interactions, migration potential, the invasive activity, and the adhesive ability by EMT via Rho A activation and FAK-inhibited JNK and p38 pathways. PMID:26848867

  7. Zoledronate blocks geranylgeranylation not farnesylation to suppress human osteosarcoma U2OS cells metastasis by EMT via Rho A activation and FAK-inhibited JNK and p38 pathways.

    Cheng, Hsin-Lin; Lin, Chiao-Wen; Yang, Jia-Sin; Hsieh, Ming-Ju; Yang, Shun-Fa; Lu, Ko-Hsiu

    2016-03-01

    Zoledronate is a standard treatment for preventing skeletal complications of osteoporosis and some types of cancer associated with bone metastases, but we little know whether the effect of zoledronate on metastasis of osteosarcoma. Here, we investigated the inhibitory effects of zoledronate on cell viability, motility, migration and invasion of 4 osteosarcoma cell lines (Saos2, MG-63, HOS and U2OS) by affecting cell morphology, epithelial-mesenchymal transition (EMT) and cytoskeletal organization as well as induction of E-cadherin and reduction of N-cadherin with activation of transcription factors Slug and Twist, especially in U2OS cells. Zoledronate decreased JNK and p38 phosphorylation and upper streams of focal adhesion kinase (FAK) and Src to suppress the motility, invasiveness and migration of U2OS cells. In addition to zoledronate-inhibited Rho A and Cdc42 membrane translocation and GTPγS activities, the anti-metastatic effects in U2OS cells including inhibition of adhesion were reversed by geranylgeraniol, but not farnesol. In conclusion, Zoledronate blocks geranylgeranylation not farnesylation to suppress human osteosarcoma U2OS cell-matrix and cell-cell interactions, migration potential, the invasive activity, and the adhesive ability by EMT via Rho A activation and FAK-inhibited JNK and p38 pathways. PMID:26848867

  8. USP22 promotes epithelial-mesenchymal transition via the FAK pathway in pancreatic cancer cells.

    Ning, Zhen; Wang, Aman; Liang, Jinxiao; Xie, Yunpeng; Liu, Jiwei; Yan, Qiu; Wang, Zhongyu

    2014-10-01

    Epithelial-mesenchymal transition (EMT) contributes to the occurrence and development of tumors, particularly to the promotion of tumor invasion and metastasis. As a newly discovered ubiquitin hydrolase family member, USP22 plays a key role in the malignant transformation of tumors and the regulation of the cell cycle. However, recent studies on USP22 have primarily focused on its role in cell cycle regulation, and the potential mechanism underlying the promotion of tumor invasion and metastasis by abnormal USP22 expression has not been reported. Our studies revealed that the overexpression of USP22 in PANC-1 cells promoted Ezrin redistribution and phosphorylation and cytoskeletal remodeling, upregulated expression of the transcription factors Snail and ZEB1 to promote EMT, and increased cellular invasion and migration. In contrast, blockade of USP22 expression resulted in the opposite effects. In addition, the focal adhesion kinase (FAK) signaling pathway was shown to play a key role in the process of EMT induction in PANC-1 cells by USP22. Thus, the present study suggests that USP22 acts as a regulatory protein for EMT in pancreatic cancer, which may provide a new approach for the targeted therapy of pancreatic cancer. PMID:25070659

  9. Protein kinase C, focal adhesions and the regulation of cell migration

    Fogh, Betina S; Multhaupt, Hinke A B; Couchman, John Robert

    2014-01-01

    Cell adhesion to extracellular matrix is a complex process involving protrusive activity driven by the actin cytoskeleton, engagement of specific receptors, followed by signaling and cytoskeletal organization. Thereafter, contractile and endocytic/recycling activities may facilitate migration and...

  10. Focal Adhesion Assembly Induces Phenotypic Changes and Dedifferentiation in Chondrocytes.

    Shin, Hyunjun; Lee, Mi Nam; Choung, Jin Seung; Kim, Sanghee; Choi, Byung Hyune; Noh, Minsoo; Shin, Jennifer H

    2016-08-01

    The expansion of autologous chondrocytes in vitro is used to generate sufficient populations for cell-based therapies. However, during monolayer culture, chondrocytes lose inherent characteristics and shift to fibroblast-like cells as passage number increase. Here, we investigated passage-dependent changes in cellular physiology, including cellular morphology, motility, and gene and protein expression, as well as the role of focal adhesion and cytoskeletal regulation in the dedifferentiation process. We found that the gene and protein expression levels of both the focal adhesion complex and small Rho GTPases are upregulated with increasing passage number and are closely linked to chondrocyte dedifferentiation. The inhibition of focal adhesion kinase (FAK) but not small Rho GTPases induced the loss of fibroblastic traits and the recovery of collagen type II, aggrecan, and SOX9 expression levels in dedifferentiated chondrocytes. Based on these findings, we propose a strategy to suppress chondrogenic dedifferentiation by inhibiting the identified FAK or Src pathways while maintaining the expansion capability of chondrocytes in a 2D environment. These results highlight a potential therapeutic target for the treatment of skeletal diseases and the generation of cartilage in tissue-engineering approaches. J. Cell. Physiol. 231: 1822-1831, 2016. © 2015 Wiley Periodicals, Inc. PMID:26661891

  11. D-pinitol Inhibits Prostate Cancer Metastasis through Inhibition of αVβ3 Integrin by Modulating FAK, c-Src and NF-κB Pathways

    Chih-Hsin Tang

    2013-05-01

    Full Text Available Prostate cancer is the most commonly diagnosed malignancy in men and shows a predilection for metastasis to the bone. D-pinitol, a 3-methoxy analogue of d-chiro-inositol, was identified as an active principle in soy foods and legumes, and it has been proven to induce tumor apoptosis and metastasis of cancer cells. In this study, we investigated the anti-metastasis effects of D-pinitol in human prostate cancer cells. We found that D-pinitol reduced the migration and the invasion of prostate cancer cells (PC3 and DU145 at noncytotoxic concentrations. Integrins are the major adhesive molecules in mammalian cells and have been associated with the metastasis of cancer cells. Treatment of prostate cancer cells with D-pinitol reduced mRNA and cell surface expression of αvβ3 integrin. In addition, D-pinitol exerted its inhibitory effects by reducing focal adhesion kinase (FAK phosphorylation, c-Src kinase activity and NF-kB activation. Thus, D-pinitol may be a novel anti-metastasis agent for the treatment of prostate cancer metastasis.

  12. Caveolin-1 Up-regulation during Epithelial to Mesenchymal Transition Is Mediated by Focal Adhesion Kinase*

    Bailey, Kelly M.; Liu, Jun

    2008-01-01

    Emerging evidence has shown that caveolin-1 is up-regulated in a number of metastatic cancers and can influence various aspects of cell migration. However, in general, the role of caveolin-1 in cancer progression is poorly understood. In the present study, we examined alterations in caveolin-1 expression during epithelial-to-mesenchymal transition (EMT) and the ability of caveolin-1 to alter cancer cell adhesion, an aspect of cell motility. We employed two EMT cell models, the human embryonic...

  13. Involvement of Focal Adhesion Kinase in Escherichia coli Invasion of Human Brain Microvascular Endothelial Cells

    Reddy, Marpadga A; Wass, Carol A.; Kim, Kwang Sik; Schlaepfer, David D.; Prasadarao, Nemani V.

    2000-01-01

    Escherichia coli K1 traversal across the blood-brain barrier is an essential step in the pathogenesis of neonatal meningitis. We have previously shown that invasive E. coli promotes the actin rearrangement of brain microvascular endothelial cells (BMEC), which constitute a lining of the blood-brain barrier, for invasion. However, signal transduction mechanisms involved in E. coli invasion are not defined. In this report we show that tyrosine kinases play a major role in E. coli invasion of hu...

  14. The Src homology 2 protein Shb promotes cell cycle progression in murine hematopoietic stem cells by regulation of focal adhesion kinase activity

    Gustafsson, Karin [Department of Medical Cell Biology, Uppsala University, Uppsala 751 23 (Sweden); Heffner, Garrett; Wenzel, Pamela L.; Curran, Matthew [HHMI, Children' s Hospital Boston, Harvard Medical School, Boston, 02115 MA (United States); Grawé, Jan [Department of Genetics and Pathology, Uppsala University, Uppsala 75185 (Sweden); McKinney-Freeman, Shannon L. [Department of Hematology, St. Jude Children' s Research Hospital, Memphis, TN 38105 (United States); Daley, George Q. [HHMI, Children' s Hospital Boston, Harvard Medical School, Boston, 02115 MA (United States); Welsh, Michael, E-mail: michael.welsh@mcb.uu.se [Department of Medical Cell Biology, Uppsala University, Uppsala 751 23 (Sweden)

    2013-07-15

    The widely expressed adaptor protein Shb has previously been reported to contribute to T cell function due to its association with the T cell receptor and furthermore, several of Shb's known interaction partners are established regulators of blood cell development and function. In addition, Shb deficient embryonic stem cells displayed reduced blood cell colony formation upon differentiation in vitro. The aim of the current study was therefore to explore hematopoietic stem and progenitor cell function in the Shb knockout mouse. Shb deficient bone marrow contained reduced relative numbers of long-term hematopoietic stem cells (LT-HSCs) that exhibited lower proliferation rates. Despite this, Shb knockout LT-HSCs responded promptly by entering the cell cycle in response to genotoxic stress by 5-fluorouracil treatment. In competitive LT-HSC transplantations, Shb null cells initially engrafted as well as the wild-type cells but provided less myeloid expansion over time. Moreover, Shb knockout bone marrow cells exhibited elevated basal activities of focal adhesion kinase/Rac1/p21-activated kinase signaling and reduced responsiveness to Stem Cell Factor stimulation. Consequently, treatment with a focal adhesion kinase inhibitor increased Shb knockout LT-HSC proliferation. The altered signaling characteristics thus provide a plausible mechanistic explanation for the changes in LT-HSC proliferation since these signaling intermediates have all been shown to participate in LT-HSC cell cycle control. In summary, the loss of Shb dependent signaling in bone marrow cells, resulting in elevated focal adhesion kinase activity and reduced proliferative responses in LT-HSCs under steady state hematopoiesis, confers a disadvantage to the maintenance of LT-HSCs over time. -- Highlights: • Shb is an adaptor protein operating downstream of tyrosine kinase receptors. • Shb deficiency reduces hematopoietic stem cell proliferation. • The proliferative effect of Shb occurs via

  15. The Src homology 2 protein Shb promotes cell cycle progression in murine hematopoietic stem cells by regulation of focal adhesion kinase activity

    The widely expressed adaptor protein Shb has previously been reported to contribute to T cell function due to its association with the T cell receptor and furthermore, several of Shb's known interaction partners are established regulators of blood cell development and function. In addition, Shb deficient embryonic stem cells displayed reduced blood cell colony formation upon differentiation in vitro. The aim of the current study was therefore to explore hematopoietic stem and progenitor cell function in the Shb knockout mouse. Shb deficient bone marrow contained reduced relative numbers of long-term hematopoietic stem cells (LT-HSCs) that exhibited lower proliferation rates. Despite this, Shb knockout LT-HSCs responded promptly by entering the cell cycle in response to genotoxic stress by 5-fluorouracil treatment. In competitive LT-HSC transplantations, Shb null cells initially engrafted as well as the wild-type cells but provided less myeloid expansion over time. Moreover, Shb knockout bone marrow cells exhibited elevated basal activities of focal adhesion kinase/Rac1/p21-activated kinase signaling and reduced responsiveness to Stem Cell Factor stimulation. Consequently, treatment with a focal adhesion kinase inhibitor increased Shb knockout LT-HSC proliferation. The altered signaling characteristics thus provide a plausible mechanistic explanation for the changes in LT-HSC proliferation since these signaling intermediates have all been shown to participate in LT-HSC cell cycle control. In summary, the loss of Shb dependent signaling in bone marrow cells, resulting in elevated focal adhesion kinase activity and reduced proliferative responses in LT-HSCs under steady state hematopoiesis, confers a disadvantage to the maintenance of LT-HSCs over time. -- Highlights: • Shb is an adaptor protein operating downstream of tyrosine kinase receptors. • Shb deficiency reduces hematopoietic stem cell proliferation. • The proliferative effect of Shb occurs via increased

  16. Receptor protein tyrosine phosphatase alpha activates Src-family kinases and controls integrin-mediated responses in fibroblasts

    Su, J; Muranjan, M; Sap, J

    1999-01-01

    RPTPalpha-/- mice had impaired tyrosine kinase activity of both c-Src and Fyn, and this was accompanied by a concomitant increase in c-Src Tyr527 phosphorylation. RPTPalpha-/- fibroblasts also showed a reduction in the rate of spreading on fibronectin substrates, a trait that is a phenocopy of the effect of...... tyrosine kinases, the activity of which is tightly controlled by inhibitory phosphorylation of a carboxyterminal tyrosine residue (Tyr527 in chicken c-Src); this phosphorylation induces the kinases to form an inactive conformation. Whereas the identity of such inhibitory Tyr527 kinases has been well...... inactivation of the c-src gene. In response to adhesion on a fibronectin substrate, RPTPalpha-/- fibroblasts also exhibited characteristic deficiencies in integrin-mediated signalling responses, such as decreased tyrosine phosphorylation of the c-Src substrates Fak and p 130(cas), and reduced activation of...

  17. Focal Adhesion Kinase Signaling Mediated the Enhancement of Osteogenesis of Human Mesenchymal Stem Cells Induced by Extracorporeal Shockwave

    Hu, Jun; Liao, Haojie; Ma, Zebin; Chen, Hongjiang; Huang, Zhonglian; Zhang, Yuantao; Yu, Menglei; Chen, Youbin; Xu, Jiankun

    2016-02-01

    Extracorporeal shockwave (ESW) has been shown of great potential in promoting the osteogenesis of bone marrow mesenchymal stem cells (BMSCs), but it is unknown whether this osteogenic promotion effect can also be achieved in other MSCs (i.e., tendon-derived stem cells (TDSCs) and adipose-derived stem cells (ADSCs)). In the current study, we aimed not only to compare the osteogenic effects of BMSCs induced by ESW to those of TDSCs and ADSCs; but also to investigate the underlying mechanisms. We show here that ESW (0.16 mj/mm2) significantly promoted the osteogenic differentiation in all the tested types of MSCs, accompanied with the downregulation of miR-138, but the activation of FAK, ERK1/2, and RUNX2. The enhancement of osteogenesis in these MSCs was consistently abolished when the cells were pretreated with one of the following conditions: overexpression of miR-138, FAK knockdown using specific siRNA, and U0126, implying that all of these elements are indispensable for mediating the effect of ESW. Moreover, our study provides converging genetic and molecular evidence that the miR-138-FAK-ERK1/2-RUNX2 machinery can be generally activated in ESW-preconditioned MSCs, suggesting that ESW may be a promising therapeutic strategy for the enhancement of osteogenesis of MSCs, regardless of their origins.

  18. Prostaglandins in Cancer Cell Adhesion, Migration, and Invasion

    David G. Menter

    2012-01-01

    Full Text Available Prostaglandins exert a profound influence over the adhesive, migratory, and invasive behavior of cells during the development and progression of cancer. Cyclooxygenase-2 (COX-2 and microsomal prostaglandin E2 synthase-1 (mPGES-1 are upregulated in inflammation and cancer. This results in the production of prostaglandin E2 (PGE2, which binds to and activates G-protein-coupled prostaglandin E1-4 receptors (EP1-4. Selectively targeting the COX-2/mPGES-1/PGE2/EP1-4 axis of the prostaglandin pathway can reduce the adhesion, migration, invasion, and angiogenesis. Once stimulated by prostaglandins, cadherin adhesive connections between epithelial or endothelial cells are lost. This enables cells to invade through the underlying basement membrane and extracellular matrix (ECM. Interactions with the ECM are mediated by cell surface integrins by “outside-in signaling” through Src and focal adhesion kinase (FAK and/or “inside-out signaling” through talins and kindlins. Combining the use of COX-2/mPGES-1/PGE2/EP1-4 axis-targeted molecules with those targeting cell surface adhesion receptors or their downstream signaling molecules may enhance cancer therapy.

  19. Multiple myeloma is affected by multiple and heterogeneous somatic mutations in adhesion- and receptor tyrosine kinase signaling molecules

    Multiple myeloma (MM) is a largely incurable plasma cell malignancy with a poorly understood and heterogeneous clinical course. To identify potential, functionally relevant somatic mutations in MM, we performed whole-exome sequencing of five primary MM, corresponding germline DNA and six MM cell lines, and developed a bioinformatics strategy that also integrated published mutational data of 38 MM patients. Our analysis confirms that identical, recurrent mutations of single genes are infrequent in MM, but highlights that mutations cluster in important cellular pathways. Specifically, we show enrichment of mutations in adhesion molecules of MM cells, emphasizing the important role for the interaction of the MM cells with their microenvironment. We describe an increased rate of mutations in receptor tyrosine kinases (RTKs) and associated signaling effectors, for example, in EGFR, ERBB3, KRAS and MAP2K2, pointing to a role of aberrant RTK signaling in the development or progression of MM. The diversity of mutations affecting different nodes of a particular signaling network appears to be an intrinsic feature of individual MM samples, and the elucidation of intra- as well as interindividual redundancy in mutations that affect survival pathways will help to better tailor targeted therapeutic strategies to the specific needs of the MM patient

  20. Soluble fms-like tyrosine kinase-1 and endothelial adhesion molecules (intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1) as predictive markers for blood pressure reduction after renal sympathetic denervation.

    Dörr, Oliver; Liebetrau, Christoph; Möllmann, Helge; Gaede, Luise; Troidl, Christian; Rixe, Johannes; Hamm, Christian; Nef, Holger

    2014-05-01

    Renal sympathetic denervation (RSD) is a treatment option for patients with resistant arterial hypertension, but in some patients it is not successful. Predictive parameters on the success of RSD remain unknown. The angiogenic factors soluble fms-like tyrosine kinase-1 (sFLT-1), intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) are known to be associated with endothelial dysfunction, vascular remodeling, and hypertension. We evaluated whether sFLT-1, ICAM-1, and VCAM-1 are predictive markers for blood pressure reduction after RSD. Consecutive patients (n=55) undergoing renal denervation were included. Venous serum samples for measurement of sFlt-1, ICAM-1, and VCAM-1 were collected before and 6 months after RSD. A therapeutic response was defined as an office systolic blood pressure reduction of >10 mm Hg 6 months after RSD. A significant mean office systolic blood pressure reduction of 31.2 mm Hg was observed in 46 patients 6 months after RSD. Nine patients were classified as nonresponders, with a mean systolic blood pressure reduction of 4.6 mm Hg. At baseline, sFLT-1 levels were significantly higher in responders than in nonresponders (P<0.001) as were ICAM-1 (P<0.001) and VCAM-1 levels (P<0.01). The areas under the curve for sFLT-1, ICAM-1, and VCAM-1 were 0.82 (interquartile range, 0.718-0.921; P<0.001), 0.754 (0.654-0.854; P<0.001), and 0.684 (0.564-804; P=0.01), respectively, demonstrating prediction of an RSD response. Responders showed significantly higher serum levels of sFLT-1, ICAM-1, and VCAM-1 at baseline compared with nonresponders. Thus, this study identified for the first time potential biomarkers with a predictive value indicating a responder or nonresponder before renal denervation. PMID:24470464

  1. Overcoming EMT-associated resistance to anti-cancer drugs via Src/FAK pathway inhibition.

    Wilson, Catherine; Nicholes, Katrina; Bustos, Daisy; Lin, Eva; Song, Qinghua; Stephan, Jean-Philippe; Kirkpatrick, Donald S; Settleman, Jeff

    2014-09-15

    Epithelial to mesenchymal transition (EMT) is a key process in embryonic development and has been associated with cancer metastasis and drug resistance. For example, in EGFR mutated non-small cell lung cancers (NSCLC), EMT has been associated with acquired resistance to the EGFR inhibitor erlotinib. Moreover, "EGFR-addicted" cancer cell lines induced to undergo EMT become erlotinib-resistant in vitro. To identify potential therapeutic vulnerabilities specifically within these mesenchymal, erlotinib-resistant cells, we performed a small molecule screen of ~200 established anti-cancer agents using the EGFR mutant NSCLC HCC827 cell line and a corresponding mesenchymal derivative line. The mesenchymal cells were more resistant to most tested agents; however, a small number of agents showed selective growth inhibitory activity against the mesenchymal cells, with the most potent being the Abl/Src inhibitor, dasatinib. Analysis of the tyrosine phospho-proteome revealed several Src/FAK pathway kinases that were differentially phosphorylated in the mesenchymal cells, and RNAi depletion of the core Src/FAK pathway components in these mesenchymal cells caused apoptosis. These findings reveal a novel role for Src/FAK pathway kinases in drug resistance and identify dasatinib as a potential therapeutic for treatment of erlotinib resistance associated with EMT. PMID:25193862

  2. Effects of SphK1 and FAK on epithelial-mesenchymal transition in colon cancer HCT116 cells%SphK1和 FAK 对人结肠癌 HCT116细胞上皮间质转化的影响

    诸葛春凤; 刘诗权; 谭林; 覃蒙斌; 梁梦紫; 黄杰安

    2016-01-01

    [ ABSTRACT] AIM:To investigate the effects of sphingosine kinase l ( SphK1) and focal adhesion kinase ( FAK) on the epithelial-mesenchymal transition ( EMT) of human colon cancer HCT 116 cells.METHODS:Human colon cancer HCT116 cells were divided into 3 groups.N, N-dimethylsphingosine (DMS) was used to suppress the activity of SphK1. PF573228 was used to suppress the activation of FAK .The cells treated with equal volume of culture medium severed as control group.The cell viability was measured by MTT assay .The protein expression of SphK1, FAK and the EMT relative protein E-cadherin, N-cadherin, vimentin and matrix metalloproteinase (MMP) 2 was analyzed by Western blot.The mR-NA expression of SphK1, sphingosine-1-phosphate (S1P), FAK, E-cadherin and vimentin was detected by real-time PCR. The ability of tumor cell migration was measured by wound-healing assay.RESULTS:The cell viability of HCT116 cells was suppressed by DMS and PF 573228 in dose and time dependent manners .DMS significantly suppressed the expression of SphK1, FAK, N-cadherin, vimentin and MMP2, meanwhile enhanced the expression of E-cadherin.PF573228 reduced the expression of FAK , SphK1, N-cadherin, vimentin and MMP2, meanwhile increased the expression of E-cadherin (P<0.01).In addition, the migration ability of HCT116 cells was significantly decreased by treating with DMS and PF573228 (P<0.01).Compared with control group , the mRNA expression of FAK, SphK1, S1P and vimentin was de-creased, while the expression of E-cadherin was increased significantly in PF573228 group and DMS group (P<0.05). CONCLUSION:SphK1 and FAK signaling pathways may play an important role in the occurrence of EMT in the colon cancer HCT116 cells.%目的:研究鞘氨醇激酶1(sphingosine kinase l,SphK1)和黏着斑激酶(focal adhesion kinase,FAK)对人结肠癌HCT116细胞上皮间质转化( epithelial-mesenchymal transition ,EMT)的影响。方法:将人结肠癌HCT116细胞分成3组:采用SphK1

  3. Platelet adhesion enhances the glycoprotein VI-dependent procoagulant response: Involvement of p38 MAP kinase and calpain.

    Siljander, P; Farndale, R W; Feijge, M A; Comfurius, P; Kos, S; Bevers, E M; Heemskerk, J W

    2001-04-01

    In the final stages of activation, platelets express coagulation-promoting activity by 2 simultaneous processes: exposure of aminophospholipids, eg, phosphatidylserine (PS), at the platelet surface, and formation of membrane blebs, which may be shed as microvesicles. Contact with collagen triggers both processes via platelet glycoprotein VI (GPVI). Here, we studied the capacity of 2 GPVI ligands, collagen-related peptide (CRP) and the snake venom protein convulxin (CVX), to elicit the procoagulant platelet response. In platelets in suspension, either ligand induced full aggregation and high Ca(2+) signals but little microvesiculation or PS exposure. However, most of the platelets adhering to immobilized CRP or CVX had exposed PS and formed membrane blebs after a prolonged increase in cytosolic [Ca(2+)](i). Platelets adhering to fibrinogen responded similarly but only when exposed to soluble CRP or CVX. By scanning electron microscopic analysis, the bleb-forming platelets were detected as either round, spongelike structures with associated microparticles or as arrays of vesicular cell fragments. The phosphorylation of p38 mitogen-activated protein kinase (MAPK) elicited by CRP and CVX was enhanced in fibrinogen-adherent platelets compared with that in platelets in suspension. The p38 inhibitor SB203580 and the calpain protease inhibitor calpeptin reduced only the procoagulant bleb formation, having no effect on PS exposure. Inhibition of p38 also downregulated calpain activity. We conclude that the procoagulant response evoked by GPVI stimulation is potentiated by platelet adhesion. The sequential activation of p38 MAPK and calpain appears to regulate procoagulant membrane blebbing but not PS exposure. PMID:11304481

  4. The role of phosphatidylinositol 3-kinase in neural cell adhesion molecule-mediated neuronal differentiation and survival

    Ditlevsen, Dorte K; Køhler, Lene B; Pedersen, Martin Volmer;

    2003-01-01

    phosphatidylinositol 3-kinase (PI3K) is required for NCAM-mediated neurite outgrowth from PC12-E2 cells and from cerebellar and dopaminergic neurones in primary culture, and that the thr/ser kinase Akt/protein kinase B (PKB) is phosphorylated downstream of PI3K after stimulation with C3. Moreover, we present data...

  5. Inhibition of STAT3, FAK and Src mediated signaling reduces cancer stem cell load, tumorigenic potential and metastasis in breast cancer.

    Thakur, Ravi; Trivedi, Rachana; Rastogi, Namrata; Singh, Manisha; Mishra, Durga Prasad

    2015-01-01

    Cancer stem cells (CSCs) are responsible for aggressive tumor growth, metastasis and therapy resistance. In this study, we evaluated the effects of Shikonin (Shk) on breast cancer and found its anti-CSC potential. Shk treatment decreased the expression of various epithelial to mesenchymal transition (EMT) and CSC associated markers. Kinase profiling array and western blot analysis indicated that Shk inhibits STAT3, FAK and Src activation. Inhibition of these signaling proteins using standard inhibitors revealed that STAT3 inhibition affected CSCs properties more significantly than FAK or Src inhibition. We observed a significant decrease in cell migration upon FAK and Src inhibition and decrease in invasion upon inhibition of STAT3, FAK and Src. Combined inhibition of STAT3 with Src or FAK reduced the mammosphere formation, migration and invasion more significantly than the individual inhibitions. These observations indicated that the anti-breast cancer properties of Shk are due to its potential to inhibit multiple signaling proteins. Shk also reduced the activation and expression of STAT3, FAK and Src in vivo and reduced tumorigenicity, growth and metastasis of 4T1 cells. Collectively, this study underscores the translational relevance of using a single inhibitor (Shk) for compromising multiple tumor-associated signaling pathways to check cancer metastasis and stem cell load. PMID:25973915

  6. Ling Zhi-8 reduces lung cancer mobility and metastasis through disruption of focal adhesion and induction of MDM2-mediated Slug degradation.

    Lin, Tung-Yi; Hsu, Hsien-Yeh

    2016-06-01

    We recently reported that recombinant Ling Zhi-8 (rLZ-8), a medicinal mushroom Ganoderma lucidum recombinant protein, effectively prevents lung cancer cells proliferation in vivo mice model. In our current study, we demonstrated that rLZ-8 suppressed tumor metastasis and increased the survival rate in Lewis lung carcinoma cell-bearing mice. The epithelial to mesenchymal transition (EMT) process is regarded as the critical event in tumor metastasis. Herein, we showed that rLZ-8 effectively induced changes in EMT by interfering with cell adhesion and focal adhesion kinase (FAK) functions in lung cancer cells. Slug, a transcription factor, represses E-cadherin transcription and is regarded as a critical event in EMT and tumor metastasis. Functional studies revealed that downregulation of Slug as a result of rLZ-8-induced FAK inactivation enhanced E-cadherin expression and repressed cancer cell mobility. Moreover, we found that rLZ-8 enhanced the ubiquitination proteasome pathway (UPP)-mediated degradation of Slug in CL1-5 cells. Mechanistically, we demonstrated that rLZ-8 promoted the interaction between MDM2 and Slug, resulting in Slug degradation; however, MDM2-shRNA abolished rLZ-8-enhanced Slug degradation. This study is the first to determine anti-metastatic activity of rLZ-8 and its potential mechanism, with how the regulation of EMT and cell mobility is via the negative modulation of FAK, and thereby leading to the ubiquitination and degradation of Slug. Our findings suggest that the targets of FAK play a key role in metastasis. Moreover, rLZ-8 may be useful as a chemotherapeutic agent for treating lung cancer. PMID:26992741

  7. Aplysia cell adhesion molecule and a novel protein kinase C activity in the postsynaptic neuron are required for presynaptic growth and initial formation of specific synapses

    Hu, Jiang-Yuan; Chen, Yang; Bougie, Joanna K; Sossin, Wayne S.; Schacher, Samuel

    2010-01-01

    To explore the role of both Aplysia cell adhesion molecule (ApCAM) and activity of specific protein kinase C (PKC) isoforms in the initial formation of sensory neuron synapses with specific postsynaptic targets (L7 but not L11), we examined presynaptic growth, initial synapse formation, and the expression of the presynaptic neuropeptide sensorin following cell-specific reduction of ApCAM or of a novel PKC activity. Synapse formation between sensory neurons and L7 begins by 3 h after plating a...

  8. Non-small-cell lung cancer cells combat epidermal growth factor receptor tyrosine kinase inhibition through immediate adhesion-related responses

    Wang HY

    2016-05-01

    Full Text Available Hsian-Yu Wang,1,2 Min-Kung Hsu,3,4 Kai-Hsuan Wang,1 Ching-Ping Tseng,2,4 Feng-Chi Chen,3,4 John T-A Hsu1,4 1Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes (NHRI, Zhunan, Miaoli County, 2Institute of Molecular Medicine and Bioengineering, National Chiao Tung University (NCTU, Hsinchu, 3Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes (NHRI, Zhunan, Miaoli County, 4Department of Biological Science and Technology, National Chiao Tung University (NCTU, Hsinchu, Taiwan, Republic of China Background: Epidermal growth factor receptor (EGFR tyrosine kinase inhibitors (TKIs, such as gefitinib, erlotinib, and afatinib, have greatly improved treatment efficacy in non-small cell lung cancer (NSCLC patients with drug-sensitive EGFR mutations. However, in some TKI responders, the benefits of such targeted therapies are limited by the rapid development of resistance, and strategies to overcome this resistance are urgently needed. Studies of drug resistance in cancer cells typically involve long term in vitro induction to obtain stably acquired drug-resistant cells followed by elucidation of resistance mechanisms, but the immediate responses of cancer cells upon drug treatment have been ignored. The aim of this study was to investigate the immediate responses of NSCLC cells upon treatment with EGFR TKIs.Results: Both NSCLC cells, ie, PC9 and H1975, showed immediate enhanced adhesion-related responses as an apoptosis-countering mechanism upon first-time TKI treatment. By gene expression and pathway analysis, adhesion-related pathways were enriched in gefitinib-treated PC9 cells. Pathway inhibition by small-hairpin RNAs or small-molecule drugs revealed that within hours of EGFR TKI treatment, NSCLC cells used adhesion-related responses to combat the drugs. Importantly, we show here that the Src family inhibitor, dasatinib, dramatically inhibits

  9. N-terminal and C-terminal heparin-binding domain polypeptides derived from fibronectin reduce adhesion and invasion of liver cancer cells

    Fibronectin (FN) is known to be a large multifunction glycoprotein with binding sites for many substances, including N-terminal and C-terminal heparin-binding domains. We investigated the effects of highly purified rhFNHN29 and rhFNHC36 polypeptides originally cloned from the two heparin-binding domains on the adhesion and invasion of highly metastatic human hepatocellular carcinoma cells (MHCC97H) and analyzed the underlying mechanism involved. The MHCC97H cells that adhered to FN in the presence of various concentrations of rhFNHN29 and rhFNHC36 polypeptides were stained with crystal violet and measured, and the effects of rhFNHN29 and rhFNHC36 on the invasion of the MHCC97H cells were then detected using the Matrigel invasion assay as well as a lung-metastasis mouse model. The expression level of integrins and focal adhesion kinase (FAK) phosphotyrosyl protein was examined by Western blot, and the activity of matrix metalloproteinases (MMPs) and activator protein 1 (AP-1) was analyzed by gelatin zymography and the electrophoretic mobility band-shift assay (EMSA), respectively. Both of the polypeptides rhFNHN29 and rhFNHC36 inhibited adhesion and invasion of MHCC97H cells; however, rhFNHC36 exhibited inhibition at a lower dose than rhFNHN29. These inhibitory effects were mediated by integrin αvβ3 and reversed by a protein tyrosine phosphatase inhibitor. Polypeptides rhFNHN29 and rhFNHC36 abrogated the tyrosine phosphorylation of focal adhesion kinase (p-FAK) and activation of activator protein 1 (AP-1), resulting in the decrease of integrin αv, β3 and β1 expression as well as the reduction of MMP-9 activity. Polypeptides rhFNHN29 and rhFNHC36 could potentially be applicable to human liver cancer as anti-adhesive and anti-invasive agents

  10. How actin/myosin crosstalks guide the adhesion, locomotion and polarization of cells.

    Sackmann, Erich

    2015-11-01

    Cell-tissue-tissue interaction is determined by specific short range forces between cell adhesion molecules (CAMs) and ligands of the tissue, long range repulsion forces mediated by cell surface grafted macromolecules and adhesion-induced elastic stresses in the cell envelope. This interplay of forces triggers the rapid random clustering of tightly coupled linkers. By coupling of actin gel patches to the intracellular domains of the CAMs, these clusters can grow in a secondary process resulting in the formation of functional adhesion microdomains (ADs). The ADs can act as biochemical steering centers by recruiting and activating functional proteins, such as GTPases and associated regulating proteins, through electrostatic-hydrophobic forces with cationic lipid domains that act as attractive centers. First, I summarize physical concepts of cell adhesion revealed by studies of biomimetic systems. Then I describe the role of the adhesion domains as biochemical signaling platforms and force transmission centers promoting cellular protrusions, in terms of a shell string model of cells. Protrusion forces are generated by actin gelation triggered by molecular machines (focal adhesion kinase (FAK), Src-kinases and associated adaptors) which assemble around newly formed integrin clusters. They recruit and activate the GTPases Rac-1 and actin gelation promoters to charged membrane domains via electrostatic-hydrophobic forces. The cell front is pushed forward in a cyclic and stepwise manner and the step-width is determined by the dynamics antagonistic interplay between Rac-1 and RhoA. The global cell polarization in the direction of motion is mediated by the actin-microtubule (MT) crosstalk at adhesion domains. Supramolecular actin-MT assemblies at the front help to promote actin polymerization. At the rear they regulate the dismantling of the ADs through the Ca(++)-mediated activation of the protease calpain and trigger their disruption by RhoA mediated contraction via

  11. Marine bromophenol bis (2,3-dibromo-4,5-dihydroxy-phenyl)-methane inhibits the proliferation, migration, and invasion of hepatocellular carcinoma cells via modulating β1-integrin/FAK signaling.

    Wu, Ning; Luo, Jiao; Jiang, Bo; Wang, Lijun; Wang, Shuaiyu; Wang, Changhui; Fu, Changqing; Li, Jian; Shi, Dayong

    2015-02-01

    Bis (2,3-dibromo-4,5-dihydroxy-phenyl)-methane (BDDPM) is a natural bromophenol compound derived from marine algae. Previous reports have shown that BDDPM possesses antimicrobial activity. In the present study, we found that BDDPM has cytotoxic activity on a wide range of tumor cells, including BEL-7402 cells (IC50 = 8.7 μg/mL). Further studies have shown that prior to the onset of apoptosis, the BDDPM induces BEL-7402 cell detachment by decreasing the adherence of cells to the extracellular matrix (ECM). Detachment experiments have shown that the treatment of BEL-7402 cells with low concentrations of BDDPM (5.0 μg/mL) significantly inhibits cell adhesion to fibronectin and collagen IV as well as cell migration and invasion. High doses of BDDPM (10.0 μg/mL) completely inhibit the migration of BEL-7402 cells, and the expression level of MMPs (MMP-2 and MMP-9) is significantly decreased. Moreover, the expression of β1-integrin and focal adhesion kinase (FAK) is found to be down-regulated by BDDPM. This study suggests that BDDPM has a potential to be developed as a novel anticancer therapeutic agent due to its anti-metastatic activity and also indicates that BDDPM, which has a unique chemical structure, could serve as a lead compound for rational drug design and for future development of anticancer agents. PMID:25689564

  12. Marine Bromophenol Bis (2,3-Dibromo-4,5-dihydroxy-phenyl-methane Inhibits the Proliferation, Migration, and Invasion of Hepatocellular Carcinoma Cells via Modulating β1-Integrin/FAK Signaling

    Ning Wu

    2015-02-01

    Full Text Available Bis (2,3-dibromo-4,5-dihydroxy-phenyl-methane (BDDPM is a natural bromophenol compound derived from marine algae. Previous reports have shown that BDDPM possesses antimicrobial activity. In the present study, we found that BDDPM has cytotoxic activity on a wide range of tumor cells, including BEL-7402 cells (IC50 = 8.7 μg/mL. Further studies have shown that prior to the onset of apoptosis, the BDDPM induces BEL-7402 cell detachment by decreasing the adherence of cells to the extracellular matrix (ECM. Detachment experiments have shown that the treatment of BEL-7402 cells with low concentrations of BDDPM (5.0 μg/mL significantly inhibits cell adhesion to fibronectin and collagen IV as well as cell migration and invasion. High doses of BDDPM (10.0 μg/mL completely inhibit the migration of BEL-7402 cells, and the expression level of MMPs (MMP-2 and MMP-9 is significantly decreased. Moreover, the expression of β1-integrin and focal adhesion kinase (FAK is found to be down-regulated by BDDPM. This study suggests that BDDPM has a potential to be developed as a novel anticancer therapeutic agent due to its anti-metastatic activity and also indicates that BDDPM, which has a unique chemical structure, could serve as a lead compound for rational drug design and for future development of anticancer agents.

  13. SchA-p85-FAK complex dictates isoform-specific activation of Akt2 and subsequent PCBP1-mediated post-transcriptional regulation of TGFβ-mediated epithelial to mesenchymal transition in human lung cancer cell line A549.

    Xue, Xinying; Wang, Xin; Liu, Yuxia; Teng, Guigen; Wang, Yong; Zang, Xuefeng; Wang, Kaifei; Zhang, Jinghui; Xu, Yali; Wang, Jianxin; Pan, Lei

    2014-08-01

    A post-transcriptional pathway by which TGF-β modulates expression of specific proteins, Disabled-2 (Dab2) and Interleukin-like EMT Inducer (ILEI), inherent to epithelial to mesenchymal transition (EMT) in murine epithelial cells through Akt2-mediated phosphorylation of poly r(C) binding protein (PCBP1), has been previously elucidated. The aims of the current study were to determine if the same mechanism is operative in the non-small cell lung cancer (NSCLC) cell line, A549, and to delineate the underlying mechanism. Steady-state transcript and protein expression levels of Dab2 and ILEI were examined in A549 cells treated with TGF-β for up to 48 h. Induction of translational de-repression in this model was quantified by polysomal fractionation followed by qRT-PCR. The underlying mechanism of isoform-specific activation of Akt2 was elucidated through a combination of co-immunoprecipitation studies. TGF-β induced EMT in A549 cells concomitant with translational upregulation of Dab2 and ILEI proteins through isoform-specific activation of Akt2 followed by phosphorylation of PCBP1 at serine-43. Our experiments further elucidated that the adaptor protein SchA is phosphorylated at tyrosine residues following TGF-β treatment, which initiated a signaling cascade resulting in the sequential recruitment of p85 subunit of PI3K and focal adhesion kinase (FAK). The SchA-FAK-p85 complex subsequently selectively recruited and activated Akt2, not Akt1. Inhibition of the p85 subunit through phosphorylated 1257 peptide completely attenuated EMT in these cells. We have defined the underlying mechanism responsible for isoform-specific recruitment and activation of Akt2, not Akt1, during TGF-β-mediated EMT in A549 cells. Inhibition of the formation of this complex thus represents an important and novel therapeutic target in metastatic lung carcinoma. PMID:24819169

  14. CCR9-CCL25 interactions promote cisplatin resistance in breast cancer cell through Akt activation in a PI3K-dependent and FAK-independent fashion

    Lillard James W

    2011-05-01

    Full Text Available Abstract Background Chemotherapy heavily relies on apoptosis to kill breast cancer (BrCa cells. Many breast tumors respond to chemotherapy, but cells that survive this initial response gain resistance to subsequent treatments. This leads to aggressive cell variants with an enhanced ability to migrate, invade and survive at secondary sites. Metastasis and chemoresistance are responsible for most cancer-related deaths; hence, therapies designed to minimize both are greatly needed. We have recently shown that CCR9-CCL25 interactions promote BrCa cell migration and invasion, while others have shown that this axis play important role in T cell survival. In this study we have shown potential role of CCR9-CCL25 axis in breast cancer cell survival and therapeutic efficacy of cisplatin. Methods Bromodeoxyuridine (BrdU incorporation, Vybrant apoptosis and TUNEL assays were performed to ascertain the role of CCR9-CCL25 axis in cisplatin-induced apoptosis of BrCa cells. Fast Activated Cell-based ELISA (FACE assay was used to quantify In situ activation of PI3Kp85, AktSer473, GSK-3βSer9 and FKHRThr24 in breast cancer cells with or without cisplatin treatment in presence or absence of CCL25. Results CCR9-CCL25 axis provides survival advantage to BrCa cells and inhibits cisplatin-induced apoptosis in a PI3K-dependent and focal adhesion kinase (FAK-independent fashion. Furthermore, CCR9-CCL25 axis activates cell-survival signals through Akt and subsequent glycogen synthase kinase-3 beta (GSK-3β and forkhead in human rhabdomyosarcoma (FKHR inactivation. These results show that CCR9-CCL25 axis play important role in BrCa cell survival and low chemotherapeutic efficacy of cisplatin primarily through PI3K/Akt dependent fashion.

  15. Focal adhesions control cleavage furrow shape and spindle tilt during mitosis

    Taneja, Nilay; Fenix, Aidan M.; Rathbun, Lindsay; Millis, Bryan A.; Tyska, Matthew J.; Hehnly, Heidi; Burnette, Dylan T.

    2016-01-01

    The geometry of the cleavage furrow during mitosis is often asymmetric in vivo and plays a critical role in stem cell differentiation and the relative positioning of daughter cells during development. Early observations of adhesive cell lines revealed asymmetry in the shape of the cleavage furrow, where the bottom (i.e., substrate attached side) of the cleavage furrow ingressed less than the top (i.e., unattached side). This data suggested substrate attachment could be regulating furrow ingression. Here we report a population of mitotic focal adhesions (FAs) controls the symmetry of the cleavage furrow. In single HeLa cells, stronger adhesion to the substrate directed less ingression from the bottom of the cell through a pathway including paxillin, focal adhesion kinase (FAK) and vinculin. Cell-cell contacts also direct ingression of the cleavage furrow in coordination with FAs in epithelial cells—MDCK—within monolayers and polarized cysts. In addition, mitotic FAs established 3D orientation of the mitotic spindle and the relative positioning of mother and daughter centrosomes. Therefore, our data reveals mitotic FAs as a key link between mitotic cell shape and spindle orientation, and may have important implications in our understanding stem cell homeostasis and tumorigenesis. PMID:27432211

  16. 黏着斑激酶相关非激酶在瘢痕疙瘩组织中的表达及意义%Expression and significance of mRNA and protein of FAK related non kinase in keloid

    王朝阳; 吴文艺; 朱世泽; 杨维群; 蔡玉梅; 潘明孟; 周仙颖; 林新恭

    2016-01-01

    Objective To investigate the facol adhesion kinase-ralated nonkinase (FRNK) expression and significance in keloid tissue. Methods Using Western blotting and RT-PCR to test the expression of FRNK protein and mRNA in 10 cases of keloid tissues and 10 cases of normal skin, and conducte the statistic analysis. Results The expression of FRNK protein in the keloid tissue was significantly lower than that in normal skin (0.12±0.06 vs 0.32±0.04), and the difference was statistically significant (P<0.01). The expression of FRNK mRNAin the keloid tissue was significantly lower than that in normal skin(0.27±0.03 vs 1.10±0.05), and the difference was statistically significant (P<0.01). Conclusions FRNK protein and mRNA has a lower expressionin keloid tissue, inhibits the fiberblasts apoptosis, and may play an important roleon the formation of keloid. Regulating the expression of FRNK in keloid,could be a new therapeutic target.%目的:探讨黏着斑激酶相关非激酶(facol adhesion kinase-ralated nonkinase,FRNK)在瘢痕疙瘩组织中的表达及意义。方法:利用Western-blot及反转录聚合酶链式反应(reverse transcription-PCR,RT-PCR)检测10例瘢痕疙瘩及10例相应周围正常皮肤组织中FRNK蛋白及mRNA表达水平并进行统计学分析。结果:瘢痕疙瘩组织中的FRNK蛋白表达明显低于正常皮肤(0.12±0.06比0.32±0.04),差异有统计学意义(P<0.01);瘢痕疙瘩组织中FRNK mRNA表达明显低于正常皮肤(0.27±0.03比1.10±0.05),差异有统计学意义(P<0.01)。结论:FRNK蛋白及mRNA在瘢痕疙瘩组织中低表达,导致其对成纤维细胞凋亡作用减弱,对瘢痕疙瘩的形成可能起重要作用,通过调节FRNK的表达,有望为瘢痕的治疗提供新的靶点。

  17. The role of phosphatidylinositol 3-kinase in neural cell adhesion molecule-mediated neuronal differentiation and survival

    Ditlevsen, Dorte K; Køhler, Lene B; Pedersen, Martin V;

    2003-01-01

    kinase (MAPK) pathway and an increase in intracellular Ca2+ levels. Stimulation of neurones with the synthetic NCAM-ligand, C3, induces neurite outgrowth through signalling pathways similar to the pathways activated through physiological, homophilic NCAM-stimulation. We present here data indicating that...... indicating a survival-promoting effect of NCAM-stimulation by C3 on cerebellar and dopaminergic neurones induced to undergo apoptosis. This protective effect of C3 included an inhibition of both DNA-fragmentation and caspase-3 activation. The survival-promoting effect of NCAM-stimulation was also shown to be...

  18. Hypotonic shock mediation by p38 MAPK, JNK, PKC, FAK, OSR1 and SPAK in osmosensing chloride secreting cells of killifish opercular epithelium

    Marshall, W. S.; Ossum, Carlo Gunnar; Hoffmann, Else Kay

    2005-01-01

    at the basolateral membrane. The protein tyrosine kinase inhibitor genistein (100 µmol l-1) inhibited Cl- secretion that was high, increased Cl- secretion that was low and reduced immunocytochemical staining for phosphorylated FAK. We present a model for rapid control of CFTR and NKCC in chloride...... cells that includes: (1) activation of NKCC and CFTR via cAMP/PKA, (2) activation of NKCC by PKC, myosin light chain kinase (MLCK), p38, OSR1 and SPAK, (3) deactivation of NKCC by hypotonic cell swelling, Ca2+ and an as yet unidentified protein phosphatase and (4) involvement of protein tyrosine kinase...

  19. Extracellular Membrane-proximal Domain of HAb18G/CD147 Binds to Metal Ion-dependent Adhesion Site (MIDAS) Motif of Integrin β1 to Modulate Malignant Properties of Hepatoma Cells*

    Li, Yong; Wu, Jiao; Song, Fei; Tang, Juan; Wang, Shi-Jie; Yu, Xiao-Ling; Chen, Zhi-Nan; Jiang, Jian-Li

    2012-01-01

    Several lines of evidence suggest that HAb18G/CD147 interacts with the integrin variants α3β1 and α6β1. However, the mechanism of the interaction remains largely unknown. In this study, mammalian protein-protein interaction trap (MAPPIT), a mammalian two-hybrid method, was used to study the CD147-integrin β1 subunit interaction. CD147 in human hepatocellular carcinoma (HCC) cells was interfered with by small hairpin RNA. Nude mouse xenograft model and metastatic model of HCC were used to detect the role of CD147 in carcinogenesis and metastasis. We found that the extracellular membrane-proximal domain of HAb18G/CD147 (I-type domain) binds at the metal ion-dependent adhesion site in the βA domain of the integrin β1 subunit, and Asp179 in the I-type domain of HAb18G/CD147 plays an important role in the interaction. The levels of the proteins that act downstream of integrin, including focal adhesion kinase (FAK) and phospho-FAK, were decreased, and the cytoskeletal structures of HCC cells were rearranged bearing the HAb18G/CD147 deletion. Simultaneously, the migration and invasion capacities, secretion of matrix metalloproteinases, colony formation rate in vitro, and tumor growth and metastatic potential in vivo were decreased. These results indicate that the interaction of HAb18G/CD147 extracellular I-type domain with the integrin β1 metal ion-dependent adhesion site motif activates the downstream FAK signaling pathway, subsequently enhancing the malignant properties of HCC cells. PMID:22130661

  20. Extracellular membrane-proximal domain of HAb18G/CD147 binds to metal ion-dependent adhesion site (MIDAS) motif of integrin β1 to modulate malignant properties of hepatoma cells.

    Li, Yong; Wu, Jiao; Song, Fei; Tang, Juan; Wang, Shi-Jie; Yu, Xiao-Ling; Chen, Zhi-Nan; Jiang, Jian-Li

    2012-02-10

    Several lines of evidence suggest that HAb18G/CD147 interacts with the integrin variants α3β1 and α6β1. However, the mechanism of the interaction remains largely unknown. In this study, mammalian protein-protein interaction trap (MAPPIT), a mammalian two-hybrid method, was used to study the CD147-integrin β1 subunit interaction. CD147 in human hepatocellular carcinoma (HCC) cells was interfered with by small hairpin RNA. Nude mouse xenograft model and metastatic model of HCC were used to detect the role of CD147 in carcinogenesis and metastasis. We found that the extracellular membrane-proximal domain of HAb18G/CD147 (I-type domain) binds at the metal ion-dependent adhesion site in the βA domain of the integrin β1 subunit, and Asp(179) in the I-type domain of HAb18G/CD147 plays an important role in the interaction. The levels of the proteins that act downstream of integrin, including focal adhesion kinase (FAK) and phospho-FAK, were decreased, and the cytoskeletal structures of HCC cells were rearranged bearing the HAb18G/CD147 deletion. Simultaneously, the migration and invasion capacities, secretion of matrix metalloproteinases, colony formation rate in vitro, and tumor growth and metastatic potential in vivo were decreased. These results indicate that the interaction of HAb18G/CD147 extracellular I-type domain with the integrin β1 metal ion-dependent adhesion site motif activates the downstream FAK signaling pathway, subsequently enhancing the malignant properties of HCC cells. PMID:22130661

  1. A synthetic isoflavone, DCMF, promotes human keratinocyte migration by activating Src/FAK signaling pathway.

    Sophors, Phorl; Kim, Young Mee; Seo, Ga Young; Huh, Jung-Sik; Lim, Yoongho; Koh, Dong Soo; Cho, Moonjae

    2016-04-01

    Flavonoids are plant secondary compounds with various pharmacological properties. We previously showed that one flavonoid, trimethoxyisoflavone (TMF), could promote wound healing by inducing keratinocyte migration. Here, we screened TMF derivatives for enhanced activity and identified one compound, 2',6 Dichloro-7-methoxyisoflavone (DCMF), as most effective at promoting migration in a scratch wound assay. Using the HaCaT keratinocyte cell line, we found DCMF treatment induced phosphorylation of both FAK and Src, and increased keratinocyte migration. DCMF-induced Src kinase could promote activation of ERK, AKT, and p38 signaling pathways, and DCMF-induced secretion of matrix metalloproteinase (MMP)-2 and MMP-9 and partial epithelial-mesenchymal transition (EMT), whereas Src inhibition abolished DCMF-induced EMT. Using an in vivo excisional wound model, we observed improved wound closure and re-epithelialization in DCMF-treated mice, as compared to controls. Collectively, our data demonstrate that DCMF induces cell migration and promotes wound healing through activation of Src/FAK, ERK, AKT, and p38 MAPK signaling. PMID:26923073

  2. Inhibition of STAT3, FAK and Src mediated signaling reduces cancer stem cell load, tumorigenic potential and metastasis in breast cancer

    Thakur, Ravi; Trivedi, Rachana; Rastogi, Namrata; Singh, Manisha; Mishra, Durga Prasad

    2015-01-01

    Cancer stem cells (CSCs) are responsible for aggressive tumor growth, metastasis and therapy resistance. In this study, we evaluated the effects of Shikonin (Shk) on breast cancer and found its anti-CSC potential. Shk treatment decreased the expression of various epithelial to mesenchymal transition (EMT) and CSC associated markers. Kinase profiling array and western blot analysis indicated that Shk inhibits STAT3, FAK and Src activation. Inhibition of these signaling proteins using standard ...

  3. Resveratrol and Estradiol Exert Disparate Effects on Cell Migration, Cell Surface Actin Structures, and Focal Adhesion Assembly in MDA-MB-231 Human Breast Cancer Cells

    Nicolas G. Azios

    2005-02-01

    Full Text Available Resveratrol, a grape polyphenol, is thought to be a cancer preventive, yet its effects on metastatic breast cancer are relatively unknown. Since cancer cell invasion is dependent on cell migration, the chemotactic response of MDA-MB-231 metastatic human breast cancer cells to resveratrol, estradiol (E2, or epidermal growth factor (EGF was investigated. Resveratrol decreased while E2 and EGF increased directed cell migration. Resveratrol may inhibit cell migration by altering the cytoskeleton. Resveratrol induced a rapid global array of filopodia and decreased focal adhesions and focal adhesion kinase (FAK activity. E2 or EGF treatment did not affect filopodia extension but increased lamellipodia and associated focal adhesions that are integral for cell migration. Combined resveratrol and E2 treatment resulted in a filopodia and focal adhesion response similar to resveratrol alone. Combined resveratrol and EGF resulted in a lamellipodia and focal adhesion response similar to EGF alone. E2 and to a lesser extent resveratrol increased EGFR activity. The cytoskeletal changes and EGFR activity in response to E2 were blocked by EGFR1 inhibitor indicating that E2 may increase cell migration via crosstalk with EGFR signaling. These data suggest a promotional role for E2 in breast cancer cell migration but an antiestrogenic, preventative role for resveratrol.

  4. Reduced Mechanical Stretch Induces Enhanced Endothelin B Receptor-mediated Contractility via Activation of Focal Adhesion Kinase and Extra Cellular-regulated Kinase 1/2 in Cerebral Arteries from Rat

    Rasmussen, Marianne N P; Spray, Stine; Skovsted, Gry F;

    2016-01-01

    Cerebral ischaemia results in enhanced endothelin B (ETB ) receptor-mediated contraction and receptor protein expression in the affected cerebrovascular smooth muscle cells (SMC). Organ culture of cerebral arteries is a method to induce similar alterations in ETB receptor expression. We hypothesize......-mediated contractility via triggering of an early mechanosensitive signalling pathway involving ERK1/2 and FAK signalling. A mechanism likely to be an initiating factor for the increased ETB receptor-mediated contractility found after cerebral ischaemia. This article is protected by copyright. All rights reserved....

  5. Estrogen and pure antiestrogen fulvestrant (ICI 182 780) augment cell–matrigel adhesion of MCF-7 breast cancer cells through a novel G protein coupled estrogen receptor (GPR30)-to-calpain signaling axis

    Fulvestrant (ICI 182 780, ICI) has been used in treating patients with hormone-sensitive breast cancer, yet initial or acquired resistance to endocrine therapies frequently arises and, in particular, cancer recurs as metastasis. We demonstrate here that both 17-beta-estradiol (E2) and ICI enhance cell adhesion to matrigel in MCF-7 breast cancer cells, with increased autolysis of calpain 1 (large subunit) and proteolysis of focal adhesion kinase (FAK), indicating calpain activation. Additionally, either E2 or ICI induced down-regulation of estrogen receptor α without affecting G protein coupled estrogen receptor 30 (GPR30) expression. Interestingly, GPR30 agonist G1 triggered calpain 1 autolysis but not calpain 2, whereas ER agonist diethylstilbestrol caused no apparent calpain autolysis. Furthermore, the actions of E2 and ICI on calpain and cell adhesion were tremendously suppressed by G15, or knockdown of GPR30. E2 and ICI also induced phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 phosphorylation by U0126 profoundly impeded calpain activation triggered by estrogenic and antiestrogenic stimulations indicating implication of ERK1/2 in the GPR30-mediated action. Lastly, the E2- or ICI-induced cell adhesion was dramatically impaired by calpain-specific inhibitors, ALLN or calpeptin, suggesting requirement of calpain in the GPR30-associated action. These data show that enhanced cell adhesion by E2 and ICI occurs via a novel GPR30-ERK1/2-calpain pathway. Our results indicate that targeting the GPR30 signaling may be a potential strategy to reduce metastasis and improve the efficacy of antiestrogens in treatment of advanced breast cancer. - Highlights: • Estrogen and ICI augment adhesion to matrigel with calpain activation in MCF-7 cells. • GPR30 mediates cell–matrigel adhesion and calpain activation via ERK1/2. • Calpain is required in the cell–matrigel adhesion induced by E2 and ICI

  6. Estrogen and pure antiestrogen fulvestrant (ICI 182 780) augment cell–matrigel adhesion of MCF-7 breast cancer cells through a novel G protein coupled estrogen receptor (GPR30)-to-calpain signaling axis

    Chen, Yan; Li, Zheng; He, Yan; Shang, Dandan; Pan, Jigang; Wang, Hongmei; Chen, Huamei; Zhu, Zhuxia [Department of Physiology/Cancer Research Group, Guiyang Medical University School of Basic Medicine, 9 Beijing Road, Guiyang 550004, Guizhou (China); Wan, Lei [Department of Pharmacology, Guiyang Medical University School of Basic Medicine, 9 Beijing Road, Guiyang 550004, Guizhou (China); Wang, Xudong, E-mail: xdwang@gmc.edu.cn [Department of Physiology/Cancer Research Group, Guiyang Medical University School of Basic Medicine, 9 Beijing Road, Guiyang 550004, Guizhou (China)

    2014-03-01

    Fulvestrant (ICI 182 780, ICI) has been used in treating patients with hormone-sensitive breast cancer, yet initial or acquired resistance to endocrine therapies frequently arises and, in particular, cancer recurs as metastasis. We demonstrate here that both 17-beta-estradiol (E2) and ICI enhance cell adhesion to matrigel in MCF-7 breast cancer cells, with increased autolysis of calpain 1 (large subunit) and proteolysis of focal adhesion kinase (FAK), indicating calpain activation. Additionally, either E2 or ICI induced down-regulation of estrogen receptor α without affecting G protein coupled estrogen receptor 30 (GPR30) expression. Interestingly, GPR30 agonist G1 triggered calpain 1 autolysis but not calpain 2, whereas ER agonist diethylstilbestrol caused no apparent calpain autolysis. Furthermore, the actions of E2 and ICI on calpain and cell adhesion were tremendously suppressed by G15, or knockdown of GPR30. E2 and ICI also induced phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 phosphorylation by U0126 profoundly impeded calpain activation triggered by estrogenic and antiestrogenic stimulations indicating implication of ERK1/2 in the GPR30-mediated action. Lastly, the E2- or ICI-induced cell adhesion was dramatically impaired by calpain-specific inhibitors, ALLN or calpeptin, suggesting requirement of calpain in the GPR30-associated action. These data show that enhanced cell adhesion by E2 and ICI occurs via a novel GPR30-ERK1/2-calpain pathway. Our results indicate that targeting the GPR30 signaling may be a potential strategy to reduce metastasis and improve the efficacy of antiestrogens in treatment of advanced breast cancer. - Highlights: • Estrogen and ICI augment adhesion to matrigel with calpain activation in MCF-7 cells. • GPR30 mediates cell–matrigel adhesion and calpain activation via ERK1/2. • Calpain is required in the cell–matrigel adhesion induced by E2 and ICI.

  7. The signaling pathway of Campylobacter jejuni-induced Cdc42 activation: Role of fibronectin, integrin beta1, tyrosine kinases and guanine exchange factor Vav2

    Krause-Gruszczynska, Malgorzata

    2011-12-28

    Abstract Background Host cell invasion by the foodborne pathogen Campylobacter jejuni is considered as one of the primary reasons of gut tissue damage, however, mechanisms and key factors involved in this process are widely unclear. It was reported that small Rho GTPases, including Cdc42, are activated and play a role during invasion, but the involved signaling cascades remained unknown. Here we utilised knockout cell lines derived from fibronectin-\\/-, integrin-beta1-\\/-, focal adhesion kinase (FAK)-\\/- and Src\\/Yes\\/Fyn-\\/- deficient mice, and wild-type control cells, to investigate C. jejuni-induced mechanisms leading to Cdc42 activation and bacterial uptake. Results Using high-resolution scanning electron microscopy, GTPase pulldowns, G-Lisa and gentamicin protection assays we found that each studied host factor is necessary for induction of Cdc42-GTP and efficient invasion. Interestingly, filopodia formation and associated membrane dynamics linked to invasion were only seen during infection of wild-type but not in knockout cells. Infection of cells stably expressing integrin-beta1 variants with well-known defects in fibronectin fibril formation or FAK signaling also exhibited severe deficiencies in Cdc42 activation and bacterial invasion. We further demonstrated that infection of wild-type cells induces increasing amounts of phosphorylated FAK and growth factor receptors (EGFR and PDGFR) during the course of infection, correlating with accumulating Cdc42-GTP levels and C. jejuni invasion over time. In studies using pharmacological inhibitors, silencing RNA (siRNA) and dominant-negative expression constructs, EGFR, PDGFR and PI3-kinase appeared to represent other crucial components upstream of Cdc42 and invasion. siRNA and the use of Vav1\\/2-\\/- knockout cells further showed that the guanine exchange factor Vav2 is required for Cdc42 activation and maximal bacterial invasion. Overexpression of certain mutant constructs indicated that Vav2 is a linker

  8. Reduction of lung metastasis, cell invasion, and adhesion in mouse melanoma by statin-induced blockade of the Rho/Rho-associated coiled-coil-containing protein kinase pathway

    Isozaki Misako

    2010-09-01

    Full Text Available Abstract Background Melanomas are highly malignant and have high metastatic potential; hence, there is a need for new therapeutic strategies to prevent cell metastasis. In the present study, we investigated whether statins inhibit tumor cell migration, invasion, adhesion, and metastasis in the B16BL6 mouse melanoma cell line. Methods The cytotoxicity of statins toward the B16BL6 cells were evaluated using a cell viability assay. As an experimental model, B16BL6 cells were intravenously injected into C57BL/6 mice. Cell migration and invasion were assessed using Boyden chamber assays. Cell adhesion analysis was performed using type I collagen-, type IV collagen-, fibronectin-, and laminin-coated plates. The mRNA levels, enzyme activities and protein levels of matrix metalloproteinases (MMPs were determined using RT-PCR, activity assay kits, and Western blot analysis, respectively; the mRNA and protein levels of vary late antigens (VLAs were also determined. The effects of statins on signal transduction molecules were determined by western blot analyses. Results We found that statins significantly inhibited lung metastasis, cell migration, invasion, and adhesion at concentrations that did not have cytotoxic effects on B16BL6 cells. Statins also inhibited the mRNA expressions and enzymatic activities of matrix metalloproteinases (MMPs. Moreover, they suppressed the mRNA and protein expressions of integrin α2, integrin α4, and integrin α5 and decreased the membrane localization of Rho, and phosphorylated LIM kinase (LIMK and myosin light chain (MLC. Conclusions The results indicated that statins suppressed the Rho/Rho-associated coiled-coil-containing protein kinase (ROCK pathways, thereby inhibiting B16BL6 cell migration, invasion, adhesion, and metastasis. Furthermore, they markedly inhibited clinically evident metastasis. Thus, these findings suggest that statins have potential clinical applications for the treatment of tumor cell metastasis.

  9. Signal transduction in endothelial cells by the angiogenesis inhibitor histidine-rich glycoprotein targets focal adhesions

    Histidine-rich glycoprotein (HRGP) is an abundant heparin-binding plasma protein. We have shown that a fragment released from the central histidine/proline-rich (His/Pro-rich) domain of HRGP blocks endothelial cell migration in vitro and vascularization and growth of murine fibrosarcoma in vivo. The minimal active HRGP domain exerting the anti-angiogenic effect was recently narrowed down to a 35 amino acid peptide, HRGP330, derived from the His/Pro-rich domain of HRGP. By use of a signal transduction antibody array representing 400 different signal transduction molecules, we now show that HRGP and the synthetic peptide HRGP330 specifically induce tyrosine phosphorylation of focal adhesion kinase and its downstream substrate paxillin in endothelial cells. HRGP/HRGP330 treatment of endothelial cells induced disruption of actin stress fibers, a process reversed by treatment of cells with the FAK inhibitor geldanamycin. In addition, VEGF-mediated endothelial cell tubular morphogenesis in a three-dimensional collagen matrix was inhibited by HRGP and HRGP330. In contrast, VEGF-induced proliferation was not affected by HRGP or HRGP330, demonstrating the central role of cell migration during tube formation. In conclusion, our data show that HRGP targets focal adhesions in endothelial cells, thereby disrupting the cytoskeletal organization and the ability of endothelial cells to assemble into vessel structures

  10. Molecular targeting of prostate cancer cells by a triple drug combination down-regulates integrin driven adhesion processes, delays cell cycle progression and interferes with the cdk-cyclin axis

    Single drug use has not achieved satisfactory results in the treatment of prostate cancer, despite application of increasingly widespread targeted therapeutics. In the present study, the combined impact of the mammalian target of rapamycin (mTOR)-inhibitor RAD001, the dual EGFr and VGEFr tyrosine kinase inhibitor AEE788 and the histone deacetylase (HDAC)-inhibitor valproic acid (VPA) on prostate cancer growth and adhesion in vitro was investigated. PC-3, DU-145 and LNCaP cells were treated with RAD001, AEE788 or VPA or with a RAD-AEE-VPA combination. Tumor cell growth, cell cycle progression and cell cycle regulating proteins were then investigated by MTT-assay, flow cytometry and western blotting, respectively. Furthermore, tumor cell adhesion to vascular endothelium or to immobilized extracellular matrix proteins as well as migratory properties of the cells was evaluated, and integrin α and β subtypes were analyzed. Finally, effects of drug treatment on cell signaling pathways were determined. All drugs, separately applied, reduced tumor cell adhesion, migration and growth. A much stronger anti-cancer effect was evoked by the triple drug combination. Particularly, cdk1, 2 and 4 and cyclin B were reduced, whereas p27 was elevated. In addition, simultaneous application of RAD001, AEE788 and VPA altered the membranous, cytoplasmic and gene expression pattern of various integrin α and β subtypes, reduced integrin-linked kinase (ILK) and deactivated focal adhesion kinase (FAK). Signaling analysis revealed that EGFr and the downstream target Akt, as well as p70S6k was distinctly modified in the presence of the drug combination. Simultaneous targeting of several key proteins in prostate cancer cells provides an advantage over targeting a single pathway. Since strong anti-tumor properties became evident with respect to cell growth and adhesion dynamics, the triple drug combination might provide progress in the treatment of advanced prostate cancer

  11. Activation of the FAK/PI3K pathway is crucial for AURKA-induced epithelial-mesenchymal transition in laryngeal cancer.

    Yang, Liyun; Zhou, Quan; Chen, Xuehua; Su, Liping; Liu, Bingya; Zhang, Hao

    2016-08-01

    Laryngeal squamous cell carcinoma (LSCC) is one of the most common malignant tumors, and the main cause of death is metastasis. Overexpression of aurora kinase A (AURKA) plays an important role in the metastasis of LSCC. However, the mechanism by which AURKA promotes the metastasis of LSCC is poorly understood. Recent accumulating evidence indicates that epithelial-mesenchymal transition (EMT) may be one of the mechanisms of tumor metastasis. In the present study, we studied whether AURKA may induce EMT to promote the metastasis of LSCC. CCK-8 and plate colony-formation assays were carried out to show that AURKA significantly promoted the proliferation of Hep2 cells. Immunofluorescence staining and western blotting showed that EMT-related proteins changed in a time-dependent manner along with the alteration of AURKA, with decreased expression of N-cadherin, vimentin and slug and increased expression of E-cadherin. Additionally, downregulation of the expression of AURKA inhibited FAK/PI3K pathway activity. Inhibition of the FAK/PI3K pathway caused less mesenchymal-like characteristics and reduced the mobility, migration and invasion of Hep2 cells. In conclusion, AURKA may induce EMT to promote metastasis via activation of the FAK/PI3K pathway in LSCC. Those regulatory factors may present new diagnostic biomarkers and potential therapeutic targets for LSCC. PMID:27373675

  12. Bcl-w, a Radio-resistant Protein, Promotes the Gastric Cancer Cell Migration by inducing the phosphorylation of Focal Adhesion Kinase

    Gastric cancer is one of the leading malignancies in many countries and lethal for the high incidence of recurrence even after drastic surgical resection. Because local invasion and subsequent metastasis contributes to the failure of anticancer treatments of gastric cancer, a better understanding of the mechanisms involved in tumor invasiveness within the stomach seems to be essential for the control of this disease. Bcl-w is a prosurvival member of the Bcl-2 protein family, and thus protects cells from γ-irradiation. Recent reports suggest that Bcl-w can be upregulated in gastric cancer cells in a manner associated with the infiltrative (diffuse) types of the tumor. An analysis of Bcl-w function consistently revealed that Bcl-w can also promote the migratory and invasive potentials of gastric cancer cells. While it was shown that Bcl-w increases the invasiveness of cancer cells by sequentially inducing PI3K, Akt, SP1, and MMP-2, cellular components involved in Bcl-w-induced cell migration remain to be determined. This was the reason why we undertook the present study, which shows that FAK is a critical mediator of the cell migration induced by Bcl-w

  13. P-Selectin Cross-Links PSGL-1 and Enhances Neutrophil Adhesion to Fibrinogen and ICAM-1 in a Src Kinase-Dependent, but GPCR-Independent Mechanism

    Xu, Tao; Zhang, Lei; Geng, Zhen H; Wang, Hai-Bo; Wang, Jin-Tao; Chen, Ming; Geng, Jian-Guo

    2007-01-01

    Endothelial and platelet P-selectin (CD62P) and leukocyte integrin αMβ2 (CD11bCD18, Mac-1) are cell adhesion molecules essential for host defense and innate immunity. Upon inflammatory challenges, P-selectin binds to PSGL-1 (P-selectin glycoprotein ligand-1, CD162) to mediate neutrophil rolling, during which integrins become activated by extracellular stimuli for their firm adhesion in a G-protein coupled receptor (GPCR)-dependent mechanism. Here we show that cross-linking of PSGL-1 by dimeri...

  14. Molecular characterization of c-Abl/c-Src kinase inhibitors targeted against murine tumour progenitor cells that express stem cell markers.

    Thomas Kruewel

    Full Text Available BACKGROUND: The non-receptor tyrosine kinases c-Abl and c-Src are overexpressed in various solid human tumours. Inhibition of their hyperactivity represents a molecular rationale in the combat of cancerous diseases. Here we examined the effects of a new family of pyrazolo [3,4-d] pyrimidines on a panel of 11 different murine lung tumour progenitor cell lines, that express stem cell markers, as well as on the human lung adenocarcinoma cell line A549, the human hepatoma cell line HepG2 and the human colon cancer cell line CaCo2 to obtain insight into the mode of action of these experimental drugs. METHODOLOGY/PRINCIPAL FINDINGS: Treatment with the dual kinase inhibitors blocked c-Abl and c-Src kinase activity efficiently in the nanomolar range, induced apoptosis, reduced cell viability and caused cell cycle arrest predominantly at G0/G1 phase while western blot analysis confirmed repressed protein expression of c-Abl and c-Src as well as the interacting partners p38 mitogen activated protein kinase, heterogenous ribonucleoprotein K, cyclin dependent kinase 1 and further proteins that are crucial for tumour progression. Importantly, a significant repression of the epidermal growth factor receptor was observed while whole genome gene expression analysis evidenced regulation of many cell cycle regulated genes as well integrin and focal adhesion kinase (FAK signalling to impact cytoskeleton dynamics, migration, invasion and metastasis. CONCLUSIONS/SIGNIFICANCE: Our experiments and recently published in vivo engraftment studies with various tumour cell lines revealed the dual kinase inhibitors to be efficient in their antitumour activity.

  15. Abdominal Adhesions

    ... adhesions? Abdominal adhesions can cause intestinal obstruction and female infertility—the inability to become pregnant after a year of trying. Abdominal adhesions can lead to female infertility by preventing fertilized eggs from reaching the uterus, ...

  16. Dystrophin Dp71f associates with the beta1-integrin adhesion complex to modulate PC12 cell adhesion

    Cerna, Joel; Cerecedo, Doris; Ortega, Arturo; García-Sierra, Francisco; Centeno, Federico; Garrido, Efrain; Mornet, Dominique; Cisneros, Bulmaro

    2006-01-01

    Dystrophin Dp71 is the main product of the Duchenne muscular dystrophy gene in the brain; however, its function is unknown. To study the role of Dp71 in neuronal cells, we previously generated by antisense treatment PC12 neuronal cell clones with decreased Dp71 expression (antisense-Dp71 cells). PC12 cells express two different splicing isoforms of Dp71, a cytoplasmic variant called Dp71f and a nuclear isoform called Dp71d. We previously reported that antisense-Dp71 cells display deficient adhesion to substrate and reduced immunostaining of β1-integrin in the cell area contacting the substrate. In this study, we isolated additional antisenseDp71 clones to analyze in detail the potential involvement of Dp71f isoform with the β1-integrin adhesion system of PC12 cells. Immunofluorescence analyses as well as immunoprecipitation assays demonstrated that the PC12 cell β1-integrin adhesion complex is composed of β1-integrin, talin, paxillin, α-actinin, FAK and actin. In addition, our results showed that Dp71f associates with most of the β1-integrin complex components (β1-integrin, FAK, α-actinin, talin and actin). In the antisense-Dp71 cells, the deficiency of Dp71 provokes a significant reduction of the β1-integrin adhesion complex and, consequently, the deficient adhesion of these cells to laminin. In vitro binding experiments confirmed the interaction of Dp71f with FAK and β1-integrin. Our data indicate that Dp71f is a structural component of the β1-integrin adhesion complex of PC12 cells that modulates PC12 cell adhesion by conferring proper complex assembly and/or maintenance. PMID:16935300

  17. Serine34 phosphorylation of RHO guanine dissociation inhibitor (RHOGDI{alpha}) links signaling from conventional protein kinase C to RHO GTPase in cell adhesion

    Dovas, Athanassios; Choi, Youngsil; Yoneda, Atsuko;

    2010-01-01

    . Phosphospecific antibodies reveal endogenous phosphorylation in several cell types that is sensitive to adhesion events triggered, for example, by hepatocyte growth factor. Phosphorylation is also sensitive to PKC inhibition. Together with FRET microscopy sensing GTP-RhoA levels, the data reveal a common pathway......, resulting in a specific decrease in affinity for RhoA, but not Rac1 or cdc42. The mechanism of RhoGDIalpha phosphorylation is distinct, requiring PKCalpha and phosphatidylinositol 4,5 bisphosphate, consistent with recent evidence that the inositide can activate, localize and orient PKCalpha in membranes...

  18. Adhesive Categories

    Lack, Stephen; Sobocinski, Pawel

    2003-01-01

    We introduce adhesive categories, which are categories with structure ensuring that pushouts along monomorphisms are well-behaved. Many types of graphical structures used in computer science are shown to be examples of adhesive categories. Double-pushout graph rewriting generalises well to...... rewriting on arbitrary adhesive categories....

  19. Adhesive Categories

    Lack, Stephen; Sobocinski, Pawel

    2004-01-01

    We introduce adhesive categories, which are categories with structure ensuring that pushouts along monomorphisms are well-behaved. Many types of graphical structures used in computer science are shown to be examples of adhesive categories. Double-pushout graph rewriting generalises well to...... rewriting on arbitrary adhesive categories....

  20. Adhesion of ZAP-70+ chronic lymphocytic leukemia cells to stromal cells is enhanced by cytokines and blocked by inhibitors of the PI3-kinase pathway.

    Lafarge, Sandrine T; Johnston, James B; Gibson, Spencer B; Marshall, Aaron J

    2014-01-01

    CLL cell survival and proliferation is enhanced through direct contact with supporting cells present in lymphoid tissues. PI3Ks are critical signal transduction enzymes controlling B cell survival and activation. PI3K inhibitors have entered clinical trials and show promising therapeutic activity; however, it is unclear whether PI3K inhibitor drugs differentially affect ZAP-70 positive versus negative CLL cells or target specific microenvironmental interactions. Here we provide evidence that CD40L+IL-4, IL-8 or IL-6 enhance adhesion to stromal cells, with IL-6 showing a selective effect on ZAP-70 positive cells. Stimulatory effects of IL-8 or IL-6 are fully reversed by PI3K inhibition, while the effects of CD40L+IL-4 are partially reversed. While CD40L+IL-4 is the only stimulation increasing CLL cell survival for all patient groups, IL-6 protects ZAP-70 positive cells from cell death induced by PI3K inhibition. Altogether, our results indicate that targeting the PI3K pathway can reverse protective CLL-microenvironment interactions in both ZAP-70 positive and negative CLL despite their differences in cytokine responsiveness. PMID:23981382

  1. Protein kinase C delta-mediated cytoskeleton remodeling is involved in aloe-emodin-induced photokilling of human lung cancer cells.

    Chang, Wen-Te; You, Bang-Jau; Yang, Wen-Hui; Wu, Chi-Yu; Bau, Da-Tian; Lee, Hong-Zin

    2012-09-01

    Photodynamic therapy is becoming a widely accepted form of cancer treatment using a photosensitizing agent and light. Our previous study has demonstrated that photoactivated aloe-emodin induced anoikis and changes in cell morphology, which were in part mediated through its effect on cytoskeleton in lung carcinoma H460 cells. However, the molecular mechanisms of these photoactivated aloe-emodin-induced changes remain unknown. The present study demonstrated that the expression of protein kinase Cδ (PKCδ) was triggered by aloe-emodin and irradiation in H460 cells. Furthermore, the photoactivated aloe-emodin-induced cell death and translocation of PKCδ from the cytosol to the nucleus was found to be significantly inhibited by rottlerin, a PKCδ-selective inhibitor. Western blot analysis demonstrated that rottlerin also reversed the decrease in protein expression of cytoskeleton-related proteins, such as rat sarcoma (RAS), ras homolog gene family member A (RHO), p38, heat shock protein 27 (HSP27), focal adhesion kinase (FAK), α-actinin and tubulin, induced by photoactivated aloe-emodin. Our findings suggest that the regulation of cytoskeleton-related proteins mediated by PKCδ may be the mechanisms for the protective effects of rottlerin against the photoactivated aloe-emodin induced H460 cell death. PMID:22993309

  2. 慢病毒介导Vimentin基因沉默抑制胰腺癌细胞侵袭和粘附的机制%Lentivirus-mediated Vimentin Gene Silencing Inhibits Invasion and Adhesion of Pancreatic Carcinoma Cells

    李旭; 江建新; 王敏; 朱峰; 田锐; 申铭; 秦仁义

    2013-01-01

    Objective To study the effect of vimentin down-regulation by lentivirus-mediated RNA interference (RNAi) on invasion and adhesion of human pancreatic carcinoma cells. Methods Vimentin expression in human pancreatic carcinoma Panc-1 cells was silenced by Lv-VIM-GFP-shRNA infection. The expression of vimentin in the cells was detected by qRT -PCR ,Western blot and immunofluorescence staining. Transwell and Scratch-wound assays were used to measure the invasive and migratory capability of cells. The adhesion ability of infected Panc-1 cells was evaluated by cell adhesion assay. The expression of tumor adhesion-related factors was detected by qRT -PCR and Western blot. The expression of F-actin and focal adhesion kinase(FAK ) was detected by immunofluorescence staining. Results Vimentin was constitutively expressed in Panc-1 cells. Vimentin expression was silenced by Lv-VIM-GFP-shRNA infection (P0. 05 ) ,but the expression of F-actin was decreased and immunofluorescence staining showed FAK rearrangement in Lv-VIM-GFP-shRNA group. Conclusion Suppression of vimentin expression may inhibit the invasion and adhesion of pancreatic cancer cells invitro by reducing the adhesion of tumor cells to the extracellular matrix and their migration via depolymer -ization of F-actin cytoskeleton and rearrangement of FAK.%目的 应用慢病毒介导的shRNA基因沉默技术,有效沉默人胰腺癌细胞株Panc-1中Vimentin表达,并探讨下调Vimentin后对Panc-1细胞侵袭运动及粘附能力的影响及其机制.方法 Lv-VIM-GFP-shRNA慢病毒转染人胰腺癌细胞株Panc-1,Real-time PCR、Western blot和免疫荧光法检测慢病毒转染后Vimentin的沉默效率;Transwell小室体外运动侵袭实验及划痕实验比较细胞运动侵袭能力变化,细胞粘附实验检测细胞粘附能力的变化;Real-time PCR 和Western blot检测肿瘤侵袭和粘附相关因子的表达,免疫荧光法观察转染前后细胞骨架蛋白F-actin和

  3. The Marine-Derived Sipholenol A-4-O-3′,4′-Dichlorobenzoate Inhibits Breast Cancer Growth and Motility in Vitro and in Vivo through the Suppression of Brk and FAK Signaling

    Mohamed R. Akl

    2014-04-01

    Full Text Available Sipholenol A is a natural sipholane triterpenoid isolated from the Red Sea sponge, Callyspongia siphonella. Previous studies showed the antimigratory and antiproliferative activities of the semisynthetic sipholenol A esters against breast cancer cell lines. This study investigated the effects of sipholenol A-4-O-3′,4′-dichlorobenzoate (SPA on the growth, migration and invasion of diverse human breast cancer cells. Results showed that SPA inhibited the growth of the human breast cancer cells, MDA-MB-231, MCF-7, BT-474 and T-47D, in a dose-dependent manner. Immunofluorescent analysis showed that SPA significantly reduced Ki-67-positive cells in MDA-MB-231 cells. Flow cytometry and Western blot analyses revealed that SPA treatment suppressed MDA-MB-231 cell growth by inducing cell cycle arrest at the G1 phase. In addition, SPA suppressed breast cancer cell migration, invasion and decreased Brk and FAK activation in a dose-dependent manner. Molecular docking study suggested a perfect fitting at the FAK’s FERM domain, inhibiting the main autophosphorylation site, Y397, which was further confirmed by Western blot analysis. Most known small molecule FAK inhibitors target the kinase domain, creating several off-target side effects. The in vivo studies showed that SPA treatment suppressed breast tumor growth and Ki-67, CD31, p-Brk and p-FAK expression in orthotopic breast cancer in nude mice. In conclusion, SPA inhibited the growth, invasion and migration of breast cancer cells possibly via deactivating Brk and FAK signaling, suggesting good potential for therapeutic use to control invasive breast cancer.

  4. Surgical adhesives

    I. A. THOMAZINI-SANTOS

    2001-12-01

    Full Text Available The authors have performed a literature review of surgical adhesives, such as cyanoacrylate, collagen gelatin, and fibrin glue. They have included different types of commercial and non-commercial fibrin sealants and have reported on the different components in these adhesives, such as fibrinogen, cryoprecipitate, bovine thrombin, and thrombin-like fraction of snake venom.

  5. Effects of the nanotopographic surface structure of commercially pure titanium following anodization–hydrothermal treatment on gene expression and adhesion in gingival epithelial cells

    The long-term stability and maintenance of endosseous implants with anodized–hydrothermally treated commercially pure titanium surfaces and a nanotopographic structure (SA-treated c.p.Ti) depend on the barrier function provided by the interface between the transmucosal portion of the implant surface and the peri-implant epithelium. This study investigated the effects of extracellular and intracellular gene expression in adherent gingival epithelial cells cultured for 1–7 days on SA-treated c.p.Ti implant surfaces compared to anodic oxide (AO) c.p.Ti and c.p.Ti disks. Scanning electron microscopy (SEM) showed filopodium-like extensions bound closely to the nanotopographic structure of SA-treated c.p.Ti at day 7 of culture. Gene expressions of focal adhesion kinase, integrin-α6β4, and laminin-5 (α3, β3, γ2) were significantly higher on SA-treated c.p.Ti than on c.p.Ti or AO c.p.Ti after 7 days (P < 0.05). Our results confirmed that gingival epithelial cells adhere to SA-treated c.p.Ti as the transmucosal portion of an implant, and that this interaction markedly improves expression of focal adhesion molecules and enhances the epithelial cell phenotype. The cellular gene expression responses driving extracellular and intracellular molecular interactions thus play an important role in maintenance at the interface between SA-treated c.p.Ti implant surfaces and the gingival epithelial cells. - Highlights: • SA-treated Ti provides a nanotopographic structure for clinical oral implants. • This could regulate integrin-mediated epithelial cell adhesion and gene expression. • FAK mRNA was significantly higher on SA-treated Ti. • Integrin-α6β4 and laminin-5 mRNA were significantly higher on SA-treated Ti. • Extracellular/intracellular molecular interactions play a key role on SA-treated Ti

  6. Resveratrol suppresses human colon cancer cell proliferation and induces apoptosis via targeting the pentose phosphate and the talin-FAK signaling pathways-A proteomic approach

    Reddivari Lavanya

    2011-08-01

    Full Text Available Abstract Background We and others have previously reported that resveratrol (RSV suppresses colon cancer cell proliferation and elevates apoptosis in vitro and/or in vivo, however molecular mechanisms are not fully elucidated. Particularly, little information is available on RSV's effects on metabolic pathways and the cell-extra cellular matrix (ECM communication that are critical for cancer cell growth. To identify important targets of RSV, we analyzed whole protein fractions from HT-29 advanced human colon cancer cell line treated with solvent control, IGF-1 (10 nM and RSV (150 μM using LC/MS/MS-Mud PIT (Multidimensional Protein Identification Technology. Results Pentose phosphate pathway (PPP, a vital metabolic pathway for cell cycle progression, was elevated and suppressed by IGF-1 and RSV, respectively in the HT-29 cell line. Enzymatic assays confirmed RSV suppression of glucose-6 phosphate dehydrogenase (rate limiting and transketolase, key enzymes of the PPP. RSV (150 μM suppressed, whereas IGF-1 (10 nM elevated focal adhesion complex (FAC proteins, talin and pFAK, critical for the cell-ECM communication. Western blotting analyses confirmed the suppression or elevation of these proteins in HT-29 cancer cells treated with RSV or IGF-1, respectively. Conclusions Proteomic analysis enabled us to establish PPP and the talin-pFAK as targets of RSV which suppress cancer cell proliferation and induce apoptosis in the colon cancer cell line HT-29. RSV (150 μM suppressed these pathways in the presence and absence of IGF-1, suggesting its role as a chemo-preventive agent even in obese condition.

  7. Proline-rich tyrosine kinase 2 (Pyk2 promotes cell motility of hepatocellular carcinoma through induction of epithelial to mesenchymal transition.

    Chris K Sun

    Full Text Available AIMS: Proline-rich tyrosine kinase 2 (Pyk2, a non-receptor tyrosine kinase of the focal adhesion kinase (FAK family, is up-regulated in more than 60% of the tumors of hepatocellular carcinoma (HCC patients. Forced overexpression of Pyk2 can promote the proliferation and invasion of HCC cells. In this study, we aimed to explore the underlying molecular mechanism of Pyk2-mediated cell migration of HCC cells. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that Pyk2 transformed the epithelial HCC cell line Hep3B into a mesenchymal phenotype via the induction of epithelial to mesenchymal transition (EMT, signified by the up-regulation of membrane ruffle formation, activation of Rac/Rho GTPases, down-regulation of epithelial genes E-cadherin and cytokeratin as well as promotion of cell motility in presence of lysophosphatidic acid (LPA. Suppression of Pyk2 by overexpression of dominant negative PRNK domain in the metastatic HCC cell line MHCC97L transformed its fibroblastoid phenotype to an epithelial phenotype with up-regulation of epithelial genes, down-regulation of mesenchymal genes N-cadherin and STAT5b, and reduction of LPA-induced membrane ruffle formation and cell motility. Moreover, overexpression of Pyk2 in Hep3B cells promoted the phosphorylation and localization of mesenchymal gene Hic-5 onto cell membrane while suppression of Pyk2 in MHCC97L cells attenuated its phosphorylation and localization. CONCLUSION: These data provided new evidence of the underlying mechanism of Pyk2 in controlling cell motility of HCC cells through regulation of genes associated with EMT.

  8. Phosphoproteomic analysis of adhesion receptor signalling

    Robertson, Joseph

    2014-01-01

    The binding of integrin adhesion receptors to their extracellular matrix (ECM) ligands activates intracellular signalling pathways that control diverse and fundamental aspects of cell behaviour. While it is clear that protein kinases and phosphatases play an integral role in such adhesion-mediated signalling, current knowledge of the phosphorylation events regulated downstream of integrin ligation is limited and prohibits a systems-level understanding of the molecular mechanisms through which...

  9. Bacterial Adhesion & Blocking Bacterial Adhesion

    Vejborg, Rebecca Munk

    2008-01-01

    parameters, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion is...... the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental...

  10. Modulation of Intracellular Calcium Levels by Calcium Lactate Affects Colon Cancer Cell Motility through Calcium-Dependent Calpain

    Pasupathi Sundaramoorthy; Jae Jun Sim; Yeong-Su Jang; Siddhartha Kumar Mishra; Keun-Yeong Jeong; Poonam Mander; Oh Byung Chul; Won-Sik Shim; Seung Hyun Oh; Ky-Youb Nam; Hwan Mook Kim

    2015-01-01

    Cancer cell motility is a key phenomenon regulating invasion and metastasis. Focal adhesion kinase (FAK) plays a major role in cellular adhesion and metastasis of various cancers. The relationship between dietary supplementation of calcium and colon cancer has been extensively investigated. However, the effect of calcium (Ca2+) supplementation on calpain-FAK-motility is not clearly understood. We sought to identify the mechanism of FAK cleavage through Ca2+ bound lactate (CaLa), its downstrea...

  11. Syndecan-4 and integrins: combinatorial signaling in cell adhesion

    Couchman, J R; Woods, A

    site for protein kinase C(&agr;) and phosphatidylinositol 4, 5-bisphosphate acts as a dominant negative inhibitor of focal adhesion formation. Focal adhesion induction does not require interaction between heparan sulfate glycosaminoglycan and ligand but can occur when non-glycanated core protein is...

  12. A focal adhesion kinase inhibitor 16-hydroxy-cleroda-3,13-dien-16,15-olide incorporated into enteric-coated nanoparticles for controlled anti-glioma drug delivery.

    Thiyagarajan, Varadharajan; Lin, Shi-Xiang; Lee, Chia-Hung; Weng, Ching-Feng

    2016-05-01

    16-Hydroxy-cleroda-3,13-dien-16,15-olide (HCD) which is extracted from a medicinal plant, Polyalthia longifolia, was shown to exhibit anticancer activity through apoptosis and FAK inhibition in our previous study. To improve its solubility and efficacy, a novel HCD delivery system using copper-substituted mesoporous silica nanoparticles (MSNs) was designed as a delivery vehicle, and the outer surfaces of MSNs were further coated with enteric polymers to prevent the drug from leaching in the stomach acid. All the data regarding synthesis and physical characterization, including Zeta potential, FT-IR spectra, N2 adsorption-desorption isotherms (BET), drug loading, powder X-ray diffraction, Thermo gravimetric analysis (TGA), Transmission electron microscopy (TEM), and Scanning electron microscopy (SEM) were well characterized. The non-coated MSN-HCD exposed to acidic pH (1.2) showed a rapid degradation of the drug, whereas the enteric-coated samples presented a sustained release profile in the gastrointestinal pHs. Cell cytotoxicity was further confirmed by the MTT-C6 Glioma cell line, in vitro. When compared with the control and pure HCD, the MSN-HCD revealed a potential anti-proliferation effect via the synergistic effect of the drug and the MSN vehicle. Additionally, this MSN-HCD had the effect of increasing the reactive oxygen species (ROS) levels and altered the Mitochondria membrane potential (MMP) in C6 cell line. The in vivo anti-tumor efficacy of enteric-coated MSN-HCD was evaluated by C6 Glioma bearing xenograft nude mice, and enteric-coated MSN-HCD clearly exhibited the greatest anti-glioma activity, as compared to the pure HCD and the untreated control. In terms of the effective treatment of brain glioma, this study provides conclusive evidence of the successful development of the anti-cancer agent HCD conjugated with enteric-coated MSN as a delivery control mechanism with enhanced dissolution characteristics. PMID:26851441

  13. FTY720 and two novel butterfly derivatives exert a general anti-inflammatory potential by reducing immune cell adhesion to endothelial cells through activation of S1P(3) and phosphoinositide 3-kinase.

    Imeri, Faik; Blanchard, Olivier; Jenni, Aurelio; Schwalm, Stephanie; Wünsche, Christin; Zivkovic, Aleksandra; Stark, Holger; Pfeilschifter, Josef; Huwiler, Andrea

    2015-12-01

    Sphingosine-1-phosphate (S1P) is a key lipid regulator of a variety of cellular responses including cell proliferation and survival, cell migration, and inflammatory reactions. Here, we investigated the effect of S1P receptor activation on immune cell adhesion to endothelial cells under inflammatory conditions. We show that S1P reduces both tumor necrosis factor (TNF)-α- and lipopolysaccharide (LPS)-stimulated adhesion of Jurkat and U937 cells to an endothelial monolayer. The reducing effect of S1P was reversed by the S1P1+3 antagonist VPC23019 but not by the S1P1 antagonist W146. Additionally, knockdown of S1P3, but not S1P1, by short hairpin RNA (shRNA) abolished the reducing effect of S1P, suggesting the involvement of S1P3. A suppression of immune cell adhesion was also seen with the immunomodulatory drug FTY720 and two novel butterfly derivatives ST-968 and ST-1071. On the molecular level, S1P and all FTY720 derivatives reduced the mRNA expression of LPS- and TNF-α-induced adhesion molecules including ICAM-1, VCAM-1, E-selectin, and CD44 which was reversed by the PI3K inhibitor LY294002, but not by the MEK inhibitor U0126.In summary, our data demonstrate a novel molecular mechanism by which S1P, FTY720, and two novel butterfly derivatives acted anti-inflammatory that is by suppressing gene transcription of various endothelial adhesion molecules and thereby preventing adhesion of immune cells to endothelial cells and subsequent extravasation. PMID:26267293

  14. Adhesion and Cohesion

    J. Anthony von Fraunhofer

    2012-01-01

    Full Text Available The phenomena of adhesion and cohesion are reviewed and discussed with particular reference to dentistry. This review considers the forces involved in cohesion and adhesion together with the mechanisms of adhesion and the underlying molecular processes involved in bonding of dissimilar materials. The forces involved in surface tension, surface wetting, chemical adhesion, dispersive adhesion, diffusive adhesion, and mechanical adhesion are reviewed in detail and examples relevant to adhesive dentistry and bonding are given. Substrate surface chemistry and its influence on adhesion, together with the properties of adhesive materials, are evaluated. The underlying mechanisms involved in adhesion failure are covered. The relevance of the adhesion zone and its importance with regard to adhesive dentistry and bonding to enamel and dentin is discussed.

  15. Parthenolide induces apoptosis by activating the mitochondrial and death receptor pathways and inhibits FAK-mediated cell invasion.

    Kwak, Sang Won; Park, Eon Sub; Lee, Chung Soo

    2014-01-01

    The natural product parthenolide induces apoptosis in cancer cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to parthenolide is not clear. In addition, it is unclear whether parthenolide-induced apoptosis is mediated by the formation of reactive oxygen species and the depletion of GSH contents, and the effect of parthenolide on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of parthenolide exposure on apoptosis, cell adhesion, and migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that parthenolide may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of parthenolide appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Parthenolide inhibited fetal bovine serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase-dependent activation of cytoskeletal-associated components. Therefore, parthenolide might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy. PMID:24065392

  16. In Vitro and In Vivo Anti-Melanoma Effects of Pituranthos tortuosus Essential Oil Via Inhibition of FAK and Src Activities.

    Krifa, Mounira; Meshri, Salah Edin El; Bentouati, Nawel; Pizzi, Antonio; Sick, Emilie; Chekir-Ghedira, Leila; Rondé, Philippe

    2016-05-01

    A large number of plants used in traditional medicines have been shown to possess antitumor activities. The aims of this study were to evaluate any anticancer effect of the essential oil (EO) extracted from P. tortuosus against B16F10 melanoma cancer cells in vitro as well as in vivo. In vitro, EO was shown to induce apoptosis and to inhibit migration and invasion processes. Further investigation revealed that EO decreased focal adhesion and invadopodia formation which was accompanied by a drastic downregulation of FAK, Src, ERK, p130Cas and paxillin. Moreover, EO treatment decreased the expression level of p190RhoGAP, and Grb2, which impair cell migration and actin assembly. Mice bearing the melanoma cells were used to confirm any in vivo effectiveness of the EO as an anti-tumor promoting agent. In mice dosed with 100 mg EO/kg/d (for 27 days), tumor weight was inhibited by 98% compared to that in mice that did not receive the product. In conclusion, these data suggested to us that an EO of P. tortuosus could evolve to be a potential medicinal resource for use in the treatment of cancers. J. Cell. Biochem. 117: 1167-1175, 2016. © 2015 Wiley Periodicals, Inc. PMID:26477879

  17. The microRNA-200/Zeb1 axis regulates ECM-dependent β1-integrin/FAK signaling, cancer cell invasion and metastasis through CRKL.

    Ungewiss, Christin; Rizvi, Zain H; Roybal, Jonathon D; Peng, David H; Gold, Kathryn A; Shin, Dong-Hoon; Creighton, Chad J; Gibbons, Don L

    2016-01-01

    Tumor cell metastasis is a complex process that has been mechanistically linked to the epithelial-mesenchymal transition (EMT). The double-negative feedback loop between the microRNA-200 family and the Zeb1 transcriptional repressor is a master EMT regulator, but there is incomplete understanding of how miR-200 suppresses invasion. Our recent efforts have focused on the tumor cell-matrix interactions essential to tumor cell activation. Herein we utilized both our Kras/p53 mutant mouse model and human lung cancer cell lines to demonstrate that upon miR-200 loss integrin β1-collagen I interactions drive 3D in vitro migration/invasion and in vivo metastases. Zeb1-dependent EMT enhances tumor cell responsiveness to the ECM composition and activates FAK/Src pathway signaling by de-repression of the direct miR-200 target, CRKL. We demonstrate that CRKL serves as an adaptor molecule to facilitate focal adhesion formation, mediates outside-in signaling through Itgβ1 to drive cell invasion, and inside-out signaling that maintains tumor cell-matrix contacts required for cell invasion. Importantly, CRKL levels in pan-cancer TCGA analyses were predictive of survival and CRKL knockdown suppressed experimental metastases in vivo without affecting primary tumor growth. Our findings highlight the critical ECM-tumor cell interactions regulated by miR-200/Zeb1-dependent EMT that activate intracellular signaling pathways responsible for tumor cell invasion and metastasis. PMID:26728244

  18. SRPX2 promotes cell migration and invasion via FAK dependent pathway in pancreatic cancer.

    Gao, Zhenyuan; Zhang, Jingjing; Bi, Minghong; Han, Xiao; Han, Zhengquan; Wang, Hongya; Ou, Yimei

    2015-01-01

    Sushi repeat-containing protein, X-linked 2, abbreviated as SRPX2, is a candidate downstream target protein for E2A-HLF and involved in disorders of language cortex and cognition. Recent studies have demonstrated that elevated SRPX2 exhibits crucial roles in gastric cancer, however, underlying clinical significance and biological function of SRPX2 in pancreatic ductal adenocarcinoma (PDAC), remains unclear. Data from Oncomine database showed that higher SRPX2 expression is more commonly observed in PDAC compared with normal pancreatic duct, similar results were also found in 12 matched PDAC tissue samples, 7 PDAC cell lines and a tissue microarray containing 81 PDAC specimens as demonstrated by real-time quantitative PCR and immunohistochemistry, respectively. Besides, higher SRPX2 expression was closely correlated with advanced TNM stage. Silencing of endogenous SRPX2 expression reduced abilities of cell migration and invasion of PDAC cells. Further studies revealed that SRPX2 expression in PDAC tissues significantly correlated with the phosphorylation levels of FAK, indicating that FAK dependent pathway may be account for the effect of SRPX2 on cell migration and invasion in PDAC. Collectively, this study reveals that frequently elevated SRPX2 contributes to cell migration and invasion in PDAC and SRPX2-related pathways might be a potential therapeutic target for PDAC. PMID:26191169

  19. Advanced adhesives in electronics

    Bailey, C

    2011-01-01

    Adhesives are widely used in the manufacture of electronic devices to act as passive and active components. Recently there has been considerable interest in the use of conductive adhesives. This book reviews key types of conductive adhesives, processing methods, properties and the way they can be modelled as well as potential applications.$bAdhesives for electronic applications serve important functional and structural purposes in electronic components and packaging, and have developed significantly over the last few decades. Advanced adhesives in electronics reviews recent developments in adhesive joining technology, processing and properties. The book opens with an introduction to adhesive joining technology for electronics. Part one goes on to cover different types of adhesive used in electronic systems, including thermally conductive adhesives, isotropic and anisotropic conductive adhesives and underfill adhesives for flip-chip applications. Part two focuses on the properties and processing of electronic ...

  20. Effect of Cigarette Smoke Extract on the Proliferation of Human Airway Epithelial Cells and Expression and Activation of FAK

    XU Li; ZHANG Zhenxiang; XU Yongjian

    2005-01-01

    Summary: The effect of cigarette smoke extract (CSE) on the proliferation of human airway epithelial cells and the possible mechanism was studied. After airway epithelial cells were treated with different concentrations of CSE for 24 h, the cell proliferation was measured by MTT and the distribution of different cell cycles by flow cytometry. The FAK expression level was detected by Western blot and the degree of tyrosine phosphorylation by immunoprecipitation. The results showed that CSE could inhibit the proliferation of human airway epithelial cells, arrest the epithelial cells in G1 phase of cell cycle, dramatically decrease the number of epithelial cells in S and G2 phases; Meanwhile CSE could decrease the expression level of FAK and the degree of its tyrosine phosphorylation. The above effects of CSE were concentration-dependent. The expression of FAK and the degree of its phosphorylation was positively correlated to the increased number of epithelial cells in G1 phase, and negatively to the number of epithelial cells in S and G2 phases. It was concluded that the mechanism by which CSE could inhibit the proliferation of human epithelial cells was contributed to the increased expression and activation of FAK.

  1. Adhesion in microelectronics

    Mittal, K L

    2014-01-01

    This comprehensive book will provide both fundamental and applied aspects of adhesion pertaining to microelectronics in a single and easily accessible source. Among the topics to be covered include; Various theories or mechanisms of adhesionSurface (physical or chemical) characterization of materials as it pertains to adhesionSurface cleaning as it pertains to adhesionWays to improve adhesionUnraveling of interfacial interactions using an array of pertinent techniquesCharacterization of interfaces / interphasesPolymer-polymer adhesionMetal-polymer adhesion  (metallized polymers)Polymer adhesi

  2. Thermal Characterization of Adhesive

    Spomer, Ken A.

    1999-01-01

    The current Space Shuttle Reusable Solid Rocket Motor (RSRM) nozzle adhesive bond system is being replaced due to obsolescence. Down-selection and performance testing of the structural adhesives resulted in the selection of two candidate replacement adhesives, Resin Technology Group's Tiga 321 and 3M's EC2615XLW. This paper describes rocket motor testing of these two adhesives. Four forty-pound charge motors were fabricated in configurations that would allow side by side comparison testing of the candidate replacement adhesives and the current RSRM adhesives. The motors provided an environment where the thermal performance of adhesives in flame surface bondlines was compared. Results of the FPC testing show that: 1) The phenolic char depths on radial bond lines is approximately the same and vary depending on the position in the blast tube regardless of which adhesive was used; 2) The adhesive char depth of the candidate replacement adhesives is less than the char depth of the current adhesives; 3) The heat-affected depth of the candidate replacement adhesives is less than the heat-affected depth of the current adhesives; and 4) The ablation rates for both replacement adhesives are slower than that of the current adhesives.

  3. Dynamic monitoring of changes in endothelial cell-substrate adhesiveness during leukocyte adhesion by microelectrical impedance assay

    Yakun Ge; Tongle Deng; Xiaoxiang Zheng

    2009-01-01

    Adhesion of leukocytes to endothelial cells in inflammation processes leads to changes of endothelial cell-substrate adhesiveness, and understanding of such changes will provide us with important information of inflammation processes. In this study, we used a non-invasive biosensor system referred to as real-time cell electronic sensor (RT-CES) system to monitor the changes in endothelial cell-substrate adhesiveness induced by human monoblastic cell line U937 cell adhesion in a dynamic and quantitative manner. This assay, which is based on cell-substrate impedance readout, is able to monitor transient changes in cell-substrate adhesiveness as a result of U937 cell adhesion. The U937 cell adhesion to endothelial cells was induced by lipopolysaccharide (LPS) in a dose-dependent manner. Although the number of adherent U937 cells to the endothelial cells was verified by a standard assay, the adhesiveness of endothelial cells after addition of U937 cells was monitored by the RT-CES system. Furthermore, focal adhesion kinase protein decrease and F-actin rearrangement in endothelial cells were observed after addition of U937 cells. Our results indicated that the adhesion of U937 cells to LPS-treated endothelial cells reduced the cell adhesiveness to the substrate, and such reduction might facilitate infiltration of leukocytes.

  4. Casein kinases

    Issinger, O G

    1993-01-01

    subunits are highly conserved during evolution. The relationship between CK-2 alpha from humans and plants is still 73%. Similar relationships are reported for the beta-subunit. Chromosomal assignment of CK-2 alpha shows two gene loci, one of which is a pseudogene. They are located on different chromosomes...... genetic changes are necessarily involved; the observed changes may be entirely due to a signal transduction pathway where CK-2 could be phosphorylated by another kinase(s). CK-2 cDNAs from various organisms have been isolated and characterized. From the deduced amino acid sequence it turns out that CK-2...

  5. Signaling transduction pathways involved in basophil adhesion and histamine release

    2006-01-01

    Background Little is known about basophil with respect to the different signaling transduction pathways involved in spontaneous, cytokine or anti-IgE induced adhesion and how this compares to IgE-dependent and IgE-independent mediator secretion. The purpose of the present study was to investigate the roles of β1 andβ2 integrins in basophil adhesion as well as hosphatidylinositol 3-kinase (PI3K), src-kinases and extracellular signal regulated kinase (ERK)1/2 in basophil adhesion and histamine release (HR). Methods Basophils (purity of 10%-50%) were preincubated with anti-CD29 or anti-CD18 blocking antibodies before used for adhesion study. Basophils were preincubated with the pharmacological inhibitors wortmannin, PP1, PD98059 before used for adhesion and HR study. Cell adherence to bovine serum albumin (BSA) or fibronectin (Fn) was monitored using cell associated histamine as a basophil marker and the histamine was measured by the glass fiber assay.Results Basophil spontaneous adhesion to Fn was inhibited by anti-CD29. Interleukin (IL)-3, granulocyte/macrophage colony stimulating factor (GM-CSF) induced adhesion to BSA was inhibited by anti-CD18. Wortmannin at 1 μmol/L and PP1 at 20 μmol/L strongly interfered with, whereas PD98059 at 50 μmol/L weakly inhibited basophil spontaneous adhesion to Fn. One μmol/L wortmannin strongly inhibited IL-3, IL-5, GM-CSF and anti-IgE induced adhesion to BSA. PP1 at 20 μmol/L partly inhibited anti-IgE induced adhesion. Fifty μmol/L PD98059 marginally inhibited IL-5, weakly inhibited anti-IgE, partly inhibited GM-CSF induced adhesion. Wortmannin, PP1 and PD98059 inhibited anti-IgE (1:100 or 1:1000) induced basophil HR in a dose dependent manner. They inhibited calcium ionophore A23187 (10 μmol/L, 5 μmol/L) induced basophil HR in a dose dependent manner, but to different extend with PP1 being the most efficient.Conclusions Basophil spontaneous adhesion to Fn is mediated by β1-integrins whereas cytokine induced adhesion

  6. A novel aminothiazole KY-05009 with potential to inhibit Traf2- and Nck-interacting kinase (TNIK) attenuates TGF-β1-mediated epithelial-to-mesenchymal transition in human lung adenocarcinoma A549 cells.

    Kim, Jiyeon; Moon, Seong-Hee; Kim, Bum Tae; Chae, Chong Hak; Lee, Joo Yun; Kim, Seong Hwan

    2014-01-01

    Transforming growth factor (TGF)-β triggers the epithelial-to-mesenchymal transition (EMT) of cancer cells via well-orchestrated crosstalk between Smad and non-Smad signaling pathways, including Wnt/β-catenin. Since EMT-induced motility and invasion play a critical role in cancer metastasis, EMT-related molecules are emerging as novel targets of anti-cancer therapies. Traf2- and Nck-interacting kinase (TNIK) has recently been considered as a first-in-class anti-cancer target molecule to regulate Wnt signaling pathway, but pharmacologic inhibition of its EMT activity has not yet been studied. Here, using 5-(4-methylbenzamido)-2-(phenylamino)thiazole-4-carboxamide (KY-05009) with TNIK-inhibitory activity, its efficacy to inhibit EMT in cancer cells was validated. The molecular docking/binding study revealed the binding of KY-05009 in the hinge region of TNIK, and the inhibitory activity of KY-05009 against TNIK was confirmed by an ATP competition assay (Ki, 100 nM). In A549 cells, KY-05009 significantly and strongly inhibited the TGF-β-activated EMT through the attenuation of Smad and non-Smad signaling pathways, including the Wnt, NF-κB, FAK-Src-paxillin-related focal adhesion, and MAP kinases (ERK and JNK) signaling pathways. Continuing efforts to identify and validate potential therapeutic targets associated with EMT, such as TNIK, provide new and improved therapies for treating and/or preventing EMT-based disorders, such as cancer metastasis and fibrosis. PMID:25337707

  7. A novel aminothiazole KY-05009 with potential to inhibit Traf2- and Nck-interacting kinase (TNIK attenuates TGF-β1-mediated epithelial-to-mesenchymal transition in human lung adenocarcinoma A549 cells.

    Jiyeon Kim

    Full Text Available Transforming growth factor (TGF-β triggers the epithelial-to-mesenchymal transition (EMT of cancer cells via well-orchestrated crosstalk between Smad and non-Smad signaling pathways, including Wnt/β-catenin. Since EMT-induced motility and invasion play a critical role in cancer metastasis, EMT-related molecules are emerging as novel targets of anti-cancer therapies. Traf2- and Nck-interacting kinase (TNIK has recently been considered as a first-in-class anti-cancer target molecule to regulate Wnt signaling pathway, but pharmacologic inhibition of its EMT activity has not yet been studied. Here, using 5-(4-methylbenzamido-2-(phenylaminothiazole-4-carboxamide (KY-05009 with TNIK-inhibitory activity, its efficacy to inhibit EMT in cancer cells was validated. The molecular docking/binding study revealed the binding of KY-05009 in the hinge region of TNIK, and the inhibitory activity of KY-05009 against TNIK was confirmed by an ATP competition assay (Ki, 100 nM. In A549 cells, KY-05009 significantly and strongly inhibited the TGF-β-activated EMT through the attenuation of Smad and non-Smad signaling pathways, including the Wnt, NF-κB, FAK-Src-paxillin-related focal adhesion, and MAP kinases (ERK and JNK signaling pathways. Continuing efforts to identify and validate potential therapeutic targets associated with EMT, such as TNIK, provide new and improved therapies for treating and/or preventing EMT-based disorders, such as cancer metastasis and fibrosis.

  8. Understanding Marine Mussel Adhesion

    H. G. Silverman; F. F. Roberto

    2007-12-01

    In addition to identifying the proteins that have a role in underwater adhesion by marine mussels, research efforts have focused on identifying the genes responsible for the adhesive proteins, environmental factors that may influence protein production, and strategies for producing natural adhesives similar to the native mussel adhesive proteins. The production-scale availability of recombinant mussel adhesive proteins will enable researchers to formulate adhesives that are waterimpervious and ecologically safe and can bind materials ranging from glass, plastics, metals, and wood to materials, such as bone or teeth, biological organisms, and other chemicals or molecules. Unfortunately, as of yet scientists have been unable to duplicate the processes that marine mussels use to create adhesive structures. This study provides a background on adhesive proteins identified in the blue mussel, Mytilus edulis, and introduces our research interests and discusses the future for continued research related to mussel adhesion.

  9. Understanding marine mussel adhesion.

    Silverman, Heather G; Roberto, Francisco F

    2007-01-01

    In addition to identifying the proteins that have a role in underwater adhesion by marine mussels, research efforts have focused on identifying the genes responsible for the adhesive proteins, environmental factors that may influence protein production, and strategies for producing natural adhesives similar to the native mussel adhesive proteins. The production-scale availability of recombinant mussel adhesive proteins will enable researchers to formulate adhesives that are water-impervious and ecologically safe and can bind materials ranging from glass, plastics, metals, and wood to materials, such as bone or teeth, biological organisms, and other chemicals or molecules. Unfortunately, as of yet scientists have been unable to duplicate the processes that marine mussels use to create adhesive structures. This study provides a background on adhesive proteins identified in the blue mussel, Mytilus edulis, and introduces our research interests and discusses the future for continued research related to mussel adhesion. PMID:17990038

  10. Anti-EMP2 diabody blocks Epithelial Membrane Protein 2 (EMP2) and FAK mediated collagen gel contraction in ARPE-19 cells

    Morales, Shawn A.; Telander, David G.; Mareninov, Sergey; Nagy, Agnes; Wadehra, Madhuri; Braun, Jonathan; Gordon, Lynn K.

    2012-01-01

    Epithelial membrane protein 2 (EMP2) regulates collagen gel contraction by the retinal pigment epithelium cell line ARPE-19 by modulating FAK activation. Collagen gel contraction is one in vitro model for an aberrant wound healing response, proliferative vitreoretinopathy (PVR), which occurs as a complication of severe ocular trauma. The purpose of this study is to investigate whether EMP2 specific recombinant diabody decreases activation of FAK and collagen gel contraction in ARPE-19. Anti-E...

  11. PH dependent adhesive peptides

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  12. Cucurbitacin B inhibits breast cancer metastasis and angiogenesis through VEGF-mediated suppression of FAK/MMP-9 signaling axis.

    Sinha, Sonam; Khan, Sajid; Shukla, Samriddhi; Lakra, Amar Deep; Kumar, Sudhir; Das, Gunjan; Maurya, Rakesh; Meeran, Syed Musthapa

    2016-08-01

    Available breast cancer therapeutic strategies largely target the primary tumor but are ineffective against tumor metastasis and angiogenesis. In our current study, we determined the effect of Cucurbitacin B (CuB), a plant triterpenoid, on the metastatic and angiogenic potential of breast cancer cells. CuB was found to inhibit cellular proliferation and induce apoptosis in breast cancer cells in a time- and dose-dependent manner. Further, CuB-treatment significantly inhibited the migratory and invasive potential of highly metastatic breast cancer MDA-MB-231 and 4T1 cells at sub-IC50 concentrations, where no significant apoptosis was observed. CuB was also found to inhibit migratory, invasive and tube-forming capacities of HUVECs in vitro. In addition, inhibition of pre-existing vasculature in chick embryo chorioallantoic membrane ex vivo further supports the anti-angiogenic effect of CuB. CuB-mediated anti-metastatic and anti-angiogenic effects were associated with the downregulation of VEGF/FAK/MMP-9 signaling, which has been validated by using FAK-inhibitor (FI-14). CuB-treatment resulted in a significant inhibition of VEGF-induced phosphorylation of FAK and MMP-9 expressions similar to the action of FI-14. CuB was also found to decrease the micro-vessel density as evidenced by the decreased expression of CD31, a marker for neovasculature. Further, CuB-treatment inhibited tumor growth, lung metastasis and angiogenesis in a highly metastatic 4T1-syngeneic mouse mammary cancer. Collectively, our findings suggest that CuB inhibited breast cancer metastasis and angiogenesis, at least in part, through the downregulation of VEGF/FAK/MMP-9 signaling. PMID:27210504

  13. Neuregulin facilitates nerve regeneration by speeding Schwann cell migration via ErbB2/3-dependent FAK pathway.

    Hung-Ming Chang

    Full Text Available BACKGROUND: Adequate migration of Schwann cells (Sc is crucial for axon-guidance in the regenerative process after peripheral nerve injury (PNI. Considering neuregulin-erbB-FAK signaling is an essential pathway participating in the regulation of Sc migration during development, the present study is aimed to examine whether neuregulin would exert its beneficial effects on adult following PNI and further determine the potential changes of downstream pathway engaged in neuro-regeneration by both in vitro and in vivo approaches. METHODOLOGY AND PRINCIPAL FINDINGS: Cultured RSC96 cells treated with neuregulin were processed for erbB2/3 immunofluorescence and FAK immunoblotings. The potential effects of neuregulin on Sc were assessed by cell adherence, spreading, and migration assays. In order to evaluate the functional significance of neuregulin on neuro-regeneration, the in vivo model of PNI was performed by chronic end-to-side neurorrhaphy (ESN. In vitro studies indicated that after neuregulin incubation, erbB2/3 were not only expressed in cell membranes, but also distributed throughout the cytoplasm and nucleus of RSC96 cells. Activation of erbB2/3 was positively correlated with FAK phosphorylation. Neuregulin also increases Sc adherence, spreading, and migration by 127.2 ± 5.0%, 336.8 ± 3.0%, and 80.0 ± 5.7%, respectively. As for in vivo study, neuregulin significantly accelerates the speed of Sc migration and increases Sc expression in the distal stump of injured nerves. Retrograde labeling and compound muscle action potential recordings (CMAP also showed that neuregulin successfully facilitates nerve regeneration by eliciting noticeably larger CMAP and promoting quick re-innervation of target muscles. CONCLUSIONS: As neuregulin successfully improves axo-glial interaction by speeding Sc migration via the erbB2/3-FAK pathway, therapeutic use of neuregulin may thus serve as a promising strategy to facilitate the progress of nerve regeneration

  14. Hydrogen Sulfide Recruits Macrophage Migration by Integrin β1-Src-FAK/Pyk2-Rac Pathway in Myocardial Infarction

    Miao, Lei; Xin, Xiaoming; Xin, Hong; Shen, Xiaoyan; Zhu, Yi-Zhun

    2016-03-01

    Myocardial infarction (MI) triggers an inflammatory reaction, in which macrophages are of key importance for tissue repairing. Infiltration and/or migration of macrophages into the infarct area early after MI is critical for infarct healing, vascularization, and cardiac function. Hydrogen sulfide (H2S) has been demonstrated to possess cardioprotective effects post MI and during the progress of cardiac remodeling. However, the specific molecular and cellular mechanisms involved in macrophage recruitment by H2S remain to be identified. In this study, the NaHS (exogenous sources of H2S) treatment exerted an increased infiltration of macrophages into the infarcted myocardium at early stage of MI cardiac tissues in both wild type (WT) and cystathionine-γ-lyase-knockout (CSE-KO) mice. And NaHS accelerated the migration of macrophage cells in vitro. While, the inhibitors not only significantly diminished the migratory ability in response to NaHS, but also blocked the activation of phospho-Src, -Pyk2, -FAK397, and -FAK925. Furthermore, NaHS induced the internalization of integrin β1 on macrophage surface, but, integrin β1 silencing inhibited macrophage migration and Src signaling activation. These results indicate that H2S may have the potential as an anti-infarct of MI by governing macrophage migration, which was achieved by accelerating internalization of integrin β1 and activating downstream Src-FAK/Pyk2-Rac pathway.

  15. The influence of Pyk2 on the mechanical properties in fibroblasts

    The cell surface receptor integrin is involved in signaling mechanical stresses via the focal adhesion complex (FAC) into the cell. Within FAC, the focal adhesion kinase (FAK) and Pyk2 are believed to act as important scaffolding proteins. Based on the knowledge that many signal transducing molecules are transiently immobilized within FAC connecting the cytoskeleton with integrins, we applied magnetic tweezer and atomic force microscopic measurements to determine the influence of FAK and Pyk2 in cells mechanically. Using mouse embryonic fibroblasts (MEF; FAK+/+, FAK-/-, and siRNA-Pyk2 treated FAK-/- cells) provided a unique opportunity to describe the function of FAK and Pyk2 in more detail and to define their influence on FAC and actin distribution.

  16. Particle adhesion and removal

    Mittal, K L

    2015-01-01

    The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal.  The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments.  Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand  particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and  n

  17. Activation of the canonical Wnt/β-catenin pathway enhances monocyte adhesion to endothelial cells

    Monocyte adhesion to vascular endothelium has been reported to be one of the early processes in the development of atherosclerosis. In an attempt to develop strategies to prevent or delay atherosclerosis progression, we analyzed effects of the Wnt/β-catenin signaling pathway on monocyte adhesion to various human endothelial cells. Adhesion of fluorescein-labeled monocytes to various human endothelial cells was analyzed under a fluorescent microscope. Unlike sodium chloride, lithium chloride enhanced monocyte adhesion to endothelial cells in a dose-dependent manner. We further demonstrated that inhibitors for glycogen synthase kinase (GSK)-3β or proteosome enhanced monocyte-endothelial cell adhesion. Results of semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) indicated that activation of Wnt/β-catenin pathway did not change expression levels of mRNA for adhesion molecules. In conclusion, the canonical Wnt/β-catenin pathway enhanced monocyte-endothelial cell adhesion without changing expression levels of adhesion molecules

  18. Radiation-curable adhesives

    Radiation-curable adhesives may be classified into two broad categories. In the first category, adhesive bonding occurs as a direct result of irradiation. The second category includes pressure-sensitive and hot-melt adhesives, which are composed of linear or lightly cross-linked polymers prepared by a radiation-induced polymerization reaction. This chapter is mainly concerned with radiation-curable adhesives of the first category. The various adhesive types are discussed and adhesive performance is examined, particularly in relation to the chemistry and chemical technology which underlies the individual materials. A description of a limited number of representative applications is included as is an outline of recent developments of curing and dispensing equipment. 268 refs., 14 figs., 13 tabs

  19. Prevention of bacterial adhesion

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will...

  20. Cell adhesion and EGFR activation regulate EphA2 expression in cancer

    Larsen, Alice Bjerregaard; Stockhausen, Marie-Thérése; Poulsen, Hans Skovgaard

    2010-01-01

    largely unknown. Here we show that the expression of EphA2 in in vitro cultured cells, is restricted to cells growing adherently and that adhesion-induced EphA2 expression is dependent upon activation of the epidermal growth factor receptor (EGFR), mitogen activated protein kinase kinase (MEK) and Src...... family kinases (SRC). Moreover, the results show that adhesion-induced EGFR activation and EphA2 expression is affected by interactions with extracellular matrix (ECM) proteins working as integrin ligands. Stimulation with the EphA2 ligand, ephrinA1 inhibited ERK phosphorylation and cancer cell viability....... These effects were however abolished by activation of the EGF-receptor ligand system favoring Ras/MAPK signaling and cell proliferation. Based on our results, we propose a regulatory mechanism where cell adhesion induces EGFR kinase activation and EphA2 expression; and where the effect of ephrinA1...

  1. Bile acids-mediated overexpression of MUC4 via FAK-dependent c-Jun activation in pancreatic cancer.

    Joshi, Suhasini; Cruz, Eric; Rachagani, Satyanarayana; Guha, Sushovan; Brand, Randall E; Ponnusamy, Moorthy P; Kumar, Sushil; Batra, Surinder K

    2016-08-01

    The majority of pancreatic cancer (PC) patients are clinically presented with obstructive jaundice with elevated levels of circulatory bilirubin and alkaline phosphatases. In the current study, we examined the implications of bile acids (BA), an important component of bile, on the pathophysiology of PC and investigated their mechanistic association in tumor-promoting functions. Integration of results from PC patient samples and autochthonous mouse models showed an elevated levels of BA (p < 0.05) in serum samples compared to healthy controls. Similarly, an elevated BA levels was observed in pancreatic juice derived from PC patients (p < 0.05) than non-pancreatic non-healthy (NPNH) controls, further establishing the clinical association of BA with the pathogenesis of PC. The tumor-promoting functions of BA were established by observed transcriptional upregulation of oncogenic MUC4 expression. Luciferase reporter assay revealed distal MUC4 promoter as the primary responsive site to BA. In silico analysis recognized two c-Jun binding sites at MUC4 distal promoter, which was biochemically established using ChIP assay. Interestingly, BA treatment led to an increased transcription and activation of c-Jun in a FAK-dependent manner. Additionally, BA receptor, namely FXR, which is also upregulated at transcriptional level in PC patient samples, was demonstrated as an upstream molecule in BA-mediated FAK activation, plausibly by regulating Src activation. Altogether, these results demonstrate that elevated levels of BA increase the tumorigenic potential of PC cells by inducing FXR/FAK/c-Jun axis to upregulate MUC4 expression, which is overexpressed in pancreatic tumors and is known to be associated with progression and metastasis of PC. PMID:27185392

  2. Silencing Fibronectin Extra Domain A Enhances Radiosensitivity in Nasopharyngeal Carcinomas Involving an FAK/Akt/JNK Pathway

    Purpose: Fibronectin extra domain A (EDA) is known to play important roles in angiogenesis, lymphangiogenesis, and metastasis in malignant tumors. The present study examined the effect of EDA on the radioresistance potential of nasopharyngeal carcinoma (NPC). Methods and Materials: EDA expression levels in blood samples and tumor tissues of NPC patients were tested by enzyme-linked immunosorbent assay and immunohistochemistry. Radiosensitivity was tested by colony survival assay. Apoptosis was determined by flow cytometry. The expressions of EDA, cleaved caspase 9, cleaved caspase 3, cleaved PARP, Bcl-2, and the levels of phosphorylated FAK, Akt, and JNK were measured by Western blot. Xenografts were used to confirm the effect of EDA on radiosensitivity in vivo. Results: EDA levels in blood samples of advanced NPC patients were much higher than those in early-stage patients. In tumor tissues, the positive expressions of EDA in NPC tumor tissues were shown to be correlated with the differentiation degrees of cancer cells and lymph node metastases. Additionally, the expression of EDA is positively correlated with the expression of antiapoptotic gene (Bcl2), but negatively correlated with the expressions of apoptotic genes (cleaved caspase-3, cleaved caspase-9, cleaved PARP). In vitro, EDA-silenced NPC cells CNE-2 shows substantially enhanced radiosensitivity with lower colony survival and more apoptosis in response to radiation. In vivo, EDA-silenced xenografts were more sensitive to radiation. At the molecular level, FAK/Akt/JNK signaling was demonstrated to be inactivated in EDA-silenced CNE-2 cells. Conclusions: EDA strongly affected the radiosensitivity of NPC cells. FAK/Akt/JNK signaling was found to be a potential signaling mediating EDA function.

  3. Tissue adhesives in otorhinolaryngology

    Schneider, Gerlind

    2009-01-01

    Full Text Available The development of medical tissue adhesives has a long history without finding an all-purpose tissue adhesive for clinical daily routine. This is caused by the specific demands which are made on a tissue adhesive, and the different areas of application. In otorhinolaryngology, on the one hand, this is the mucosal environment as well as the application on bones, cartilage and periphery nerves. On the other hand, there are stressed regions (skin, oral cavity, pharynx, oesophagus, trachea and unstressed regions (middle ear, nose and paranasal sinuses, cranial bones. But due to the facts that adhesives can have considerable advantages in assuring surgery results, prevention of complications and so reduction of medical costs/treatment expenses, the search for new adhesives for use in otorhinolaryngology will be continued intensively. In parallel, appropriate application systems have to be developed for microscopic and endoscopic use.

  4. Mitogen-activated protein kinases mediate Mycobacterium tuberculosis–induced CD44 surface expression in monocytes

    Natarajan Palaniappan; S Anbalagan; Sujatha Narayanan

    2012-03-01

    CD44, an adhesion molecule, has been reported to be a binding site for Mycobacterium tuberculosis (M. tuberculosis) in macrophages and it also mediates mycobacterial phagocytosis, macrophage recruitment and protective immunity against pulmonary tuberculosis in vivo. However, the signalling pathways that are involved in M. tuberculosis–induced CD44 surface expression in monocytic cells are currently unknown. Exposure of THP-1 human monocytes to M. tuberculosis H37Rv and H37Ra induced distinct, time-dependent, phosphorylation of mitogen-activated protein kinase kinase-1, extracellular signal regulated kinase 1/2, mitogen-activated protein kinase kinase 3/6, p38 mitogen-activated protein kinase and c-jun N-terminal kinases. The strains also differed in their usage of CD14 and human leukocyte antigen-DR (HLA-DR) receptors in mediating mitogen-activated protein kinase activation. M. tuberculosis H37Rv strain induced lower CD44 surface expression and tumour necrosis factor-alpha levels, whereas H37Ra the reverse. Using highly specific inhibitors of mitogen-activated protein kinase kinase-1, p38 mitogen-activated protein kinase and c-jun N-terminal kinase, we report that inhibition of extracellular signal regulated kinase 1/2 and c-jun N-terminal kinases increases, but that inhibition of p38 mitogen-activated protein kinase decreases M. tuberculosis–induced CD44 surface expression in THP-1 human monocytes.

  5. Handbook of adhesion

    Packham, D E

    2006-01-01

    This second edition of the successful Handbook of Adhesion provides concise and authoritative articles covering many aspects of the science and technology associated with adhesion and adhesives. It is intended to fill a gap between the necessarily simplified treatment of the student textbook and the full and thorough treatment of the research monograph and review article. The articles are structured in such a way, with internal cross-referencing and external literature references, that the reader can build up a broader and deeper understanding, as their needs require.This second edition includ

  6. Lactobacillus Adhesion to Mucus

    Maxwell L. Van Tassell

    2011-05-01

    Full Text Available Mucus provides protective functions in the gastrointestinal tract and plays an important role in the adhesion of microorganisms to host surfaces. Mucin glycoproteins polymerize, forming a framework to which certain microbial populations can adhere, including probiotic Lactobacillus species. Numerous mechanisms for adhesion to mucus have been discovered in lactobacilli, including partially characterized mucus binding proteins. These mechanisms vary in importance with the in vitro models studied, which could significantly affect the perceived probiotic potential of the organisms. Understanding the nature of mucus-microbe interactions could be the key to elucidating the mechanisms of probiotic adhesion within the host.

  7. Tivantinib (ARQ-197) exhibits anti-tumor activity with down-regulation of FAK in oral squamous cell carcinoma

    Xi, Wei-Hong [Department of Oral and Maxillofacial Surgery, First Affiliated Hospital, Nanchang University, Nanchang 330006 (China); Yang, Li-Yun [Department of Blood Transfusion, First Affiliated Hospital, Nanchang University, Nanchang 330006 (China); Cao, Zhong-Yi, E-mail: m18070383032@163.com [Department of Oral and Maxillofacial Surgery, First Affiliated Hospital, Nanchang University, Nanchang 330006 (China); Qian, Yong, E-mail: yfykqkqy@163.com [Department of Oral and Maxillofacial Surgery, First Affiliated Hospital, Nanchang University, Nanchang 330006 (China)

    2015-02-20

    Oral squamous cell carcinoma (OSCC) is one of the most common cancers worldwide and the 5 years survival rate of the patients is about 60% in the USA, due to acquired chemotherapeutic resistance and metastasis of the disease. In this study, we found that tivantinib, a selective MET inhibitor, suppresses OCSS cell proliferation and colony formation, however, anti-tumor activities induced by tivantinib are independent of the inhibition of MET signaling pathway. In addition, tivantinib cause G2/M cell cycle arrest and caspases-dependent apoptosis in OSCC cell lines. We also found that tivantinib dose-dependently suppressed the activation and expression of FAK. In all, these data suggested that tivantinib may be developed as a chemotherapeutic agent to effectively treat certain cancers including OSCC. - Highlights: • Tivantinib suppresses OSCC cell growth independent of the inhibition of HGF/MET signaling pathway. • Tivantinib blocks cell cycle and induces caspases-mediated apoptosis. • Tivantinib elicits its anti-tumor activity with the inhibition of FAK signaling pathway.

  8. Tivantinib (ARQ-197) exhibits anti-tumor activity with down-regulation of FAK in oral squamous cell carcinoma

    Oral squamous cell carcinoma (OSCC) is one of the most common cancers worldwide and the 5 years survival rate of the patients is about 60% in the USA, due to acquired chemotherapeutic resistance and metastasis of the disease. In this study, we found that tivantinib, a selective MET inhibitor, suppresses OCSS cell proliferation and colony formation, however, anti-tumor activities induced by tivantinib are independent of the inhibition of MET signaling pathway. In addition, tivantinib cause G2/M cell cycle arrest and caspases-dependent apoptosis in OSCC cell lines. We also found that tivantinib dose-dependently suppressed the activation and expression of FAK. In all, these data suggested that tivantinib may be developed as a chemotherapeutic agent to effectively treat certain cancers including OSCC. - Highlights: • Tivantinib suppresses OSCC cell growth independent of the inhibition of HGF/MET signaling pathway. • Tivantinib blocks cell cycle and induces caspases-mediated apoptosis. • Tivantinib elicits its anti-tumor activity with the inhibition of FAK signaling pathway

  9. Syndecan-4 binding to the high affinity heparin-binding domain of fibronectin drives focal adhesion formation in fibroblasts

    Woods, A; Longley, R L; Tumova, S;

    2000-01-01

    fibroblasts attach and spread following integrin ligation, but do not form focal adhesions unless treated with a heparin-binding fragment of fibronectin (HepII), a peptide from this domain, or phorbol esters to activate protein kinase C. Syndecan-4 heparan sulfate proteoglycan is a transmembrane component......Cell adhesion to extracellular matrix involves signaling mechanisms which control attachment, spreading and the formation of focal adhesions and stress fibers. Fibronectin can provide sufficient signals for all three processes, even when protein synthesis is prevented by cycloheximide. Primary...... present together with integrins in focal adhesions. Syndecan-4 binds and activates protein kinase Calpha, whose activity is needed for focal adhesion formation. We now report that the glycosaminoglycan chains of syndecan-4 bind recombinant HepII and it is incorporated into forming focal adhesions....

  10. Adhesion of Lunar Dust

    Walton, Otis R.

    2007-04-01

    This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and/or tribo-electric charging) are likely to be the major contributors to the transport of dust particles. If fine regolith particles are deposited on a surface, then surface energy-related (e.g., van der Walls) adhesion forces and static-electric-image forces are likely to be the strongest contributors to adhesion. Some measurement techniques are offered to quantify the strength of adhesion forces. And finally some dust removal techniques are discussed.

  11. Leukocyte Adhesion Deficiency (LAD)

    ... Content Marketing Share this: Main Content Area Leukocyte Adhesion Deficiency (LAD) LAD is an immune deficiency in ... are slow to heal also may have LAD. Treatment and Research Doctors prescribe antibiotics to prevent and ...

  12. Management of adhesive capsulitis

    Neviaser, Andrew

    2015-01-01

    Kristen L Stupay,1 Andrew S Neviaser2 1Tulane University School of Medicine, New Orleans, LA, USA; 2George Washington University Medical Faculty Associates, Washington, DC, USA Abstract: Adhesive capsulitis of the shoulder is a condition of capsular contracture that reduces both active and passive glenohumeral motion. The cause of adhesive capsulitis is not known but it is strongly associated with endocrine abnormalities such as diabetes. Diverse terminology and the absence of definitive cri...

  13. Genotypic and phenotypic characterization of garlic-fermenting lactic acid bacteria isolated from som-fak, a Thai low-salt fermented fish product

    Paludan-Müller, Christine; Valyasevi, R.; Huss, Hans Henrik;

    2002-01-01

    AIMS: To evaluate the importance of garlic for fermentation of a Thai fish product, and to differentiate among garlic-/inulin-fermenting lactic acid bacteria (LAB) at strain level. METHODS AND RESULTS: Som-fak was prepared by fermentation of a mixture of fish, salt, rice, sucrose and garlic. p...

  14. Modulation of intracellular calcium levels by calcium lactate affects colon cancer cell motility through calcium-dependent calpain.

    Pasupathi Sundaramoorthy

    Full Text Available Cancer cell motility is a key phenomenon regulating invasion and metastasis. Focal adhesion kinase (FAK plays a major role in cellular adhesion and metastasis of various cancers. The relationship between dietary supplementation of calcium and colon cancer has been extensively investigated. However, the effect of calcium (Ca2+ supplementation on calpain-FAK-motility is not clearly understood. We sought to identify the mechanism of FAK cleavage through Ca2+ bound lactate (CaLa, its downstream signaling and role in the motility of human colon cancer cells. We found that treating HCT116 and HT-29 cells with CaLa immediately increased the intracellular Ca2+ (iCa2+ levels for a prolonged period of time. Ca2+ influx induced cleavage of FAK into an N-terminal FAK (FERM domain in a dose-dependent manner. Phosphorylated FAK (p-FAK was also cleaved in to its p-N-terminal FAK. CaLa increased colon cancer cells motility. Calpeptin, a calpain inhibitor, reversed the effects of CaLa on FAK and pFAK cleavage in both cancer cell lines. The cleaved FAK translocates into the nucleus and modulates p53 stability through MDM2-associated ubiquitination. CaLa-induced Ca2+ influx increased the motility of colon cancer cells was mediated by calpain activity through FAK and pFAK protein destabilization. In conclusion, these results suggest that careful consideration may be given in deciding dietary Ca2+ supplementation to patient undergoing treatment for metastatic cancer.

  15. CK (Creatine Kinase) Test

    ... be limited. Home Visit Global Sites Search Help? Creatine Kinase Share this page: Was this page helpful? Also known as: CK; Total CK; Creatine Phosphokinase; CPK Formal name: Creatine Kinase Related tests: ...

  16. PI3Kγ activation by CXCL12 regulates tumor cell adhesion and invasion

    Tumor dissemination is a complex process, in which certain steps resemble those in leukocyte homing. Specific chemokine/chemokine receptor pairs have important roles in both processes. CXCL12/CXCR4 is the most commonly expressed chemokine/chemokine receptor pair in human cancers, in which it regulates cell adhesion, extravasation, metastatic colonization, angiogenesis, and proliferation. All of these processes require activation of signaling pathways that include G proteins, phosphatidylinositol-3 kinase (PI3K), JAK kinases, Rho GTPases, and focal adhesion-associated proteins. We analyzed these pathways in a human melanoma cell line in response to CXCL12 stimulation, and found that PI3Kγ regulates tumor cell adhesion through mechanisms different from those involved in cell invasion. Our data indicate that, following CXCR4 activation after CXCL12 binding, the invasion and adhesion processes are regulated differently by distinct downstream events in these signaling cascades.

  17. Syndecan 4 heparan sulfate proteoglycan is a selectively enriched and widespread focal adhesion component

    Woods, A; Couchman, J R

    1994-01-01

    Focal adhesion formation in fibroblasts results from complex transmembrane signaling processes initiated by extracellular matrix molecules. Although a role for integrins with attendant tyrosine kinases has been established, there is evidence that cell surface heparan sulfate proteoglycans (HSPGs......) are also involved with an associated role of protein kinase C. The identity of the proteoglycan has remained elusive, but we now report that syndecan 4 (ryudocan/amphiglycan) is present in focal adhesions of a number of cell types. Affinity-purified antibodies raised against a unique portion of the...... cytoplasmic domain of syndecan 4 core protein recognized an HSPG of similar characteristics to those of syndecan 4. These antibodies stained focal adhesions only after cell permeabilization and recognized differing mammalian species. Syndecan 4 was associated with focal adhesions that contained either beta 1...

  18. Quantitative multicolor compositional imaging resolves molecular domains in cell-matrix adhesions.

    Eli Zamir

    Full Text Available BACKGROUND: Cellular processes occur within dynamic and multi-molecular compartments whose characterization requires analysis at high spatio-temporal resolution. Notable examples for such complexes are cell-matrix adhesion sites, consisting of numerous cytoskeletal and signaling proteins. These adhesions are highly variable in their morphology, dynamics, and apparent function, yet their molecular diversity is poorly defined. METHODOLOGY/PRINCIPAL FINDINGS: We present here a compositional imaging approach for the analysis and display of multi-component compositions. This methodology is based on microscopy-acquired multicolor data, multi-dimensional clustering of pixels according to their composition similarity and display of the cellular distribution of these composition clusters. We apply this approach for resolving the molecular complexes associated with focal-adhesions, and the time-dependent effects of Rho-kinase inhibition. We show here compositional variations between adhesion sites, as well as ordered variations along the axis of individual focal-adhesions. The multicolor clustering approach also reveals distinct sensitivities of different focal-adhesion-associated complexes to Rho-kinase inhibition. CONCLUSIONS/SIGNIFICANCE: Multicolor compositional imaging resolves "molecular signatures" characteristic to focal-adhesions and related structures, as well as sub-domains within these adhesion sites. This analysis enhances the spatial information with additional "contents-resolved" dimensions. We propose that compositional imaging can serve as a powerful tool for studying complex multi-molecular assemblies in cells and for mapping their distribution at sub-micron resolution.

  19. Electrically Conductive Epoxy Adhesives

    Lan Bai

    2011-02-01

    Full Text Available Conductive adhesives are widely used in electronic packaging applications such as die attachment and solderless interconnections, component repair, display interconnections, and heat dissipation. The effects of film thickness as functions of filler volume fraction, conductive filler size, shape, as well as uncured adhesive matrix viscosity on the electrical conduction behavior of epoxy-based adhesives are presented in this work. For this purpose, epoxy-based adhesives were prepared using conductive fillers of different size, shape, and types, including Ni powder, flakes, and filaments, Ag powder, and Cu powder. The filaments were 20 μm in diameter, and 160 or 260 μm in length. HCl and H3PO4 acid solutions were used to etch and remove the surface oxide layers from the fillers. The plane resistance of filled adhesive films was measured using the four-point method. In all cases of conductive filler addition, the planar resistivity levels for the composite adhesive films increased when the film thickness was reduced. The shape of resistivity-thickness curves was negative exponential decaying type and was modeled using a mathematical relation. The relationships between the conductive film resistivities and the filler volume fractions were also derived mathematically based on the experimental data. Thus, the effects of surface treatment of filler particles, the type, size, shape of fillers, and the uncured epoxy viscosity could be included empirically by using these mathematical relations based on the experimental data. By utilizing the relations we proposed to model thickness-dependent and volume fraction-dependent conduction behaviors separately, we were able to describe the combined and coupled volume fraction-film thickness relationship mathematically based on our experimental data.

  20. GIT1 Utilizes a Focal Adhesion Targeting-Homology Domain to Bind Paxillin

    Schmalzigaug, Robert; Garron, Marie-Line; Tyler Roseman, J.; Xing, Yanghui; Davidson, Collin E.; Arold, Stefan T.; Premont, Richard T.

    2007-01-01

    The GIT proteins, GIT1 and GIT2, are GTPase-activating proteins for the ADP-ribosylation factor family of small GTP binding proteins, but also serve as adaptors to link signaling proteins to distinct cellular locations. One role for GIT proteins is to link the PIX family of Rho guanine nucleotide exchange factors and their binding partners, the p21-activated protein kinases, to remodeling focal adhesions by interacting with the focal adhesion adaptor protein paxillin. We here identified the C...

  1. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-11-01

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects. PMID:26457864

  2. Hakai reduces cell-substratum adhesion and increases epithelial cell invasion

    The dynamic regulation of cell-cell adhesions is crucial for developmental processes, including tissue formation, differentiation and motility. Adherens junctions are important components of the junctional complex between cells and are necessary for maintaining cell homeostasis and normal tissue architecture. E-cadherin is the prototype and best-characterized protein member of adherens junctions in mammalian epithelial cells. Regarded as a tumour suppressor, E-cadherin loss is associated with poor prognosis in carcinoma. The E3 ubiquitin-ligase Hakai was the first reported posttranslational regulator of the E-cadherin complex. Hakai specifically targetted E-cadherin for internalization and degradation and thereby lowered epithelial cell-cell contact. Hakai was also implicated in controlling proliferation, and promoted cancer-related gene expression by increasing the binding of RNA-binding protein PSF to RNAs encoding oncogenic proteins. We sought to investigate the possible implication of Hakai in cell-substratum adhesions and invasion in epithelial cells. Parental MDCK cells and MDCK cells stably overexpressing Hakai were used to analyse cell-substratum adhesion and invasion capabilities. Western blot and immunofluoresecence analyses were performed to assess the roles of Paxillin, FAK and Vinculin in cell-substratum adhesion. The role of the proteasome in controlling cell-substratum adhesion was studied using two proteasome inhibitors, lactacystin and MG132. To study the molecular mechanisms controlling Paxillin expression, MDCK cells expressing E-cadherin shRNA in a tetracycline-inducible manner was employed. Here, we present evidence that implicate Hakai in reducing cell-substratum adhesion and increasing epithelial cell invasion, two hallmark features of cancer progression and metastasis. Paxillin, an important protein component of the cell-matrix adhesion, was completely absent from focal adhesions and focal contacts in Hakai-overexpressing MDCK cells. The

  3. Wood Composite Adhesives

    Gomez-Bueso, Jose; Haupt, Robert

    The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

  4. Coating Reduces Ice Adhesion

    Smith, Trent; Prince, Michael; DwWeese, Charles; Curtis, Leslie

    2008-01-01

    The Shuttle Ice Liberation Coating (SILC) has been developed to reduce the adhesion of ice to surfaces on the space shuttle. SILC, when coated on a surface (foam, metal, epoxy primer, polymer surfaces), will reduce the adhesion of ice by as much as 90 percent as compared to the corresponding uncoated surface. This innovation is a durable coating that can withstand several cycles of ice growth and removal without loss of anti-adhesion properties. SILC is made of a binder composed of varying weight percents of siloxane(s), ethyl alcohol, ethyl sulfate, isopropyl alcohol, and of fine-particle polytetrafluoroethylene (PTFE). The combination of these components produces a coating with significantly improved weathering characteristics over the siloxane system alone. In some cases, the coating will delay ice formation and can reduce the amount of ice formed. SILC is not an ice prevention coating, but the very high water contact angle (greater than 140 ) causes water to readily run off the surface. This coating was designed for use at temperatures near -170 F (-112 C). Ice adhesion tests performed at temperatures from -170 to 20 F (-112 to -7 C) show that SILC is a very effective ice release coating. SILC can be left as applied (opaque) or buffed off until the surface appears clear. Energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) data show that the coating is still present after buffing to transparency. This means SILC can be used to prevent ice adhesion even when coating windows or other objects, or items that require transmission of optical light. Car windshields are kept cleaner and SILC effectively mitigates rain and snow under driving conditions.

  5. Pathogenesis of postoperative adhesion formation

    Hellebrekers, B.W.J.; Kooistra, T.

    2011-01-01

    Background: Current views on the pathogenesis of adhesion formation are based on the "classical concept of adhesion formation", namely that a reduction in peritoneal fibrinolytic activity following peritoneal trauma is of key importance in adhesion development. Methods: A non-systematic literature s

  6. Survival and growth of Salmonella and Vibrio in som-fak, a Thai low-salt garlic containing fermented fish product

    Bernbom, Nete; Ng, Yin; Paludan-Müller, Christine;

    2009-01-01

    and potential growth of Salmonella enterica serovar Weltevreden, S. enterica serovar Enteritidis, Vibrio cholerae and V. parahaemolyticus as influenced by the preservation parameters (sodium chloride, garlic and lactic acid) present in the Thai fermented fish product som-fak. The inhibitory effects of......Fermentation of raw fish is a common process in Asia for improvement of shelf life and safety, however, little is known about the survival of pathogenic bacteria in these products. Raw fish may be contaminated with Salmonella and Vibrio species. The purpose of this study was to determine survival...... sodium chloride (0–4%), garlic (0–10%) and lactic acid (pH levels as in som-fak) were measured in modified brain heart infusion (BHI) broth at 30 °C. All bacteria were inhibited by 8–10% sodium chloride. Salmonella grew in all concentrations of garlic whereas Vibrio spp. were inhibited by 1...

  7. Eğitim Fakültesi Öğrencilerinin Empatik Becerileri ve Benlik Saygısı Düzeylerinin İncelenmesi

    Karataş, Zeynep

    2012-01-01

    ÖzetBu araştırmada, eğitim fakültesi öğrencilerinin cinsiyet, devam edilen program ve sınıf düzeyleri açısından empatik beceri ve benlik saygısı puanlarının farklılaşıp farklılaşmadığı incelenmiştir. Araştırmanın çalışma grubunu Mehmet Akif Ersoy Üniversitesi Eğitim Fakültesine devam eden 174 kız (%52.4), 158 erkek (%47.6) toplam 332 öğrenci oluşturmaktadır. Çalışmada öğrencilerin empatik becerilerini belirlemek için Empatik ...

  8. Deletion of inositol hexakisphosphate kinase 1 (IP6K1) reduces cell migration and invasion, conferring protection from aerodigestive tract carcinoma in mice.

    Jadav, Rathan S; Kumar, Dharmika; Buwa, Natasha; Ganguli, Shubhra; Thampatty, Sitalakshmi R; Balasubramanian, Nagaraj; Bhandari, Rashna

    2016-08-01

    Inositol hexakisphosphate kinases (IP6Ks), a family of enzymes found in all eukaryotes, are responsible for the synthesis of 5-diphosphoinositol pentakisphosphate (5-IP7) from inositol hexakisphosphate (IP6). Three isoforms of IP6Ks are found in mammals, and gene deletions of each isoform lead to diverse, non-overlapping phenotypes in mice. Previous studies show a facilitatory role for IP6K2 in cell migration and invasion, properties that are essential for the early stages of tumorigenesis. However, IP6K2 also has an essential role in cancer cell apoptosis, and mice lacking this protein are more susceptible to the development of aerodigestive tract carcinoma upon treatment with the oral carcinogen 4-nitroquinoline-1-oxide (4NQO). Not much is known about the functions of the equally abundant and ubiquitously expressed IP6K1 isoform in cell migration, invasion and cancer progression. We conducted a gene expression analysis on mouse embryonic fibroblasts (MEFs) lacking IP6K1, revealing a role for this protein in cell receptor-extracellular matrix interactions that regulate actin cytoskeleton dynamics. Consequently, cells lacking IP6K1 manifest defects in adhesion-dependent signaling, evident by lower FAK and Paxillin activation, leading to reduced cell spreading and migration. Expression of active, but not inactive IP6K1 reverses migration defects in IP6K1 knockout MEFs, suggesting that 5-IP7 synthesis by IP6K1 promotes cell locomotion. Actin cytoskeleton remodeling and cell migration support the ability of cancer cells to achieve their complete oncogenic potential. Cancer cells with lower IP6K1 levels display reduced migration, invasion, and anchorage-independent growth. When fed an oral carcinogen, mice lacking IP6K1 show reduced progression from epithelial dysplasia to invasive carcinoma. Thus, our data reveal that like IP6K2, IP6K1 is also involved in early cytoskeleton remodeling events during cancer progression. However, unlike IP6K2, IP6K1 is essential for 4NQO

  9. Management of adhesive capsulitis

    Stupay KL

    2015-08-01

    Full Text Available Kristen L Stupay,1 Andrew S Neviaser2 1Tulane University School of Medicine, New Orleans, LA, USA; 2George Washington University Medical Faculty Associates, Washington, DC, USA Abstract: Adhesive capsulitis of the shoulder is a condition of capsular contracture that reduces both active and passive glenohumeral motion. The cause of adhesive capsulitis is not known but it is strongly associated with endocrine abnormalities such as diabetes. Diverse terminology and the absence of definitive criteria for diagnosis make evaluating treatment modalities difficult. Many treatment methods have been reported, most with some success, but few have been proved to alter the natural course of this disease. Most afflicted patients will achieve acceptable shoulder function without surgery. Those who remain debilitated after 8–12 months are reasonable candidates for invasive treatments. Here, the various treatment methods and the data to support their use are reviewed. Keywords: frozen shoulder, stiff shoulder, periarthritis, painful shoulder 

  10. Syndecans and cell adhesion

    Couchman, J R; Chen, L; Woods, A

    2001-01-01

    Now that transmembrane signaling through primary cell-matrix receptors, integrins, is being elucidated, attention is turning to how integrin-ligand interactions can be modulated. Syndecans are transmembrane proteoglycans implicated as coreceptors in a variety of physiological processes, including...... cell adhesion, migration, response to growth factors, development, and tumorigenesis. This review will describe this family of proteoglycans in terms of their structures and functions and their signaling in conjunction with integrins, and indicate areas for future research....

  11. Ceramic microstructure and adhesion

    Buckley, D. H.

    1985-01-01

    When a ceramic is brought into contact with a ceramic, a polymer, or a metal, strong bond forces can develop between the materials. The bonding forces will depend upon the state of the surfaces, cleanliness and the fundamental properties of the two solids, both surface and bulk. Adhesion between a ceramic and another solid are discussed from a theoretical consideration of the nature of the surfaces and experimentally by relating bond forces to interface resulting from solid state contact. Surface properties of ceramics correlated with adhesion include, orientation, reconstruction and diffusion as well as the chemistry of the surface specie. Where a ceramic is in contact with a metal their interactive chemistry and bond strength is considered. Bulk properties examined include elastic and plastic behavior in the surficial regions, cohesive binding energies, crystal structures and crystallographic orientation. Materials examined with respect to interfacial adhesive interactions include silicon carbide, nickel zinc ferrite, manganese zinc ferrite, and aluminum oxide. The surfaces of the contacting solids are studied both in the atomic or molecularly clean state and in the presence of selected surface contaminants.

  12. FES kinase participates in KIT-ligand induced chemotaxis

    Voisset, Edwige, E-mail: Edwige.Voisset@inserm.fr [INSERM U891, Centre de Recherche en Cancerologie de Marseille (CRCM) (France); Institut Paoli-Calmettes, Marseille (France); Universite de la Mediterranee, Aix-Marseille II (France); Lopez, Sophie, E-mail: Sophie.Lopez@inserm.fr [INSERM U891, Centre de Recherche en Cancerologie de Marseille (CRCM) (France); Institut Paoli-Calmettes, Marseille (France); Universite de la Mediterranee, Aix-Marseille II (France); Chaix, Amandine, E-mail: Amandine.Chaix@inserm.fr [INSERM U891, Centre de Recherche en Cancerologie de Marseille (CRCM) (France); Institut Paoli-Calmettes, Marseille (France); Universite de la Mediterranee, Aix-Marseille II (France); Vita, Marina, E-mail: Marina.Vita@inserm.fr [INSERM U891, Centre de Recherche en Cancerologie de Marseille (CRCM) (France); Institut Paoli-Calmettes, Marseille (France); Universite de la Mediterranee, Aix-Marseille II (France); George, Coralie, E-mail: Coralie.Georges@inserm.fr [INSERM U891, Centre de Recherche en Cancerologie de Marseille (CRCM) (France); Institut Paoli-Calmettes, Marseille (France); Universite de la Mediterranee, Aix-Marseille II (France); Dubreuil, Patrice, E-mail: Patrice.Dubreuil@inserm.fr [INSERM U891, Centre de Recherche en Cancerologie de Marseille (CRCM) (France); Institut Paoli-Calmettes, Marseille (France); Universite de la Mediterranee, Aix-Marseille II (France); De Sepulveda, Paulo, E-mail: Sepulveda@inserm.fr [INSERM U891, Centre de Recherche en Cancerologie de Marseille (CRCM) (France); Institut Paoli-Calmettes, Marseille (France); Universite de la Mediterranee, Aix-Marseille II (France)

    2010-02-26

    FES is a cytoplasmic tyrosine kinase activated by several membrane receptors, originally identified as a viral oncogene product. We have recently identified FES as a crucial effector of oncogenic KIT mutant receptor. However, FES implication in wild-type KIT receptor function was not addressed. We report here that FES interacts with KIT and is phosphorylated following activation by its ligand SCF. Unlike in the context of oncogenic KIT mutant, FES is not involved in wild-type KIT proliferation signal, or in cell adhesion. Instead, FES is required for SCF-induced chemotaxis. In conclusion, FES kinase is a mediator of wild-type KIT signalling implicated in cell migration.

  13. The PPFLMLLKGSTR motif in globular domain 3 of the human laminin-5 α3 chain is crucial for integrin α3β1 binding and cell adhesion

    Laminin-5 regulates various cellular functions, including cell adhesion, spreading, and motility. Here, we expressed the five human laminin α3 chain globular (LG) domains as monomeric, soluble fusion proteins, and examined their biological functions and signaling. Recombinant LG3 (rLG3) protein, unlike rLG1, rLG2, rLG4, and rLG5, played roles in cell adhesion, spreading, and integrin α3β1 binding. More significantly, we identified a novel motif (PPFLMLLKGSTR) in the LG3 domain that is crucial for these responses. Studies with the synthetic peptides delineated the PPFLMLLKGSTR peptide within LG3 domain as a major site for both integrin α3β1 binding and cell adhesion. Substitution mutation experiments suggest that the Arg residue is important for these activities. rLG3 protein- and PPFLMLLKGSTR peptide-induced keratinocyte adhesion triggered cell signaling through FAK phosphorylation at tyrosine-397 and -577. To our knowledge, this is the first report demonstrating that the PPFLMLLKGSTR peptide within the LG3 domain is a novel motif that is capable of supporting integrin α3β1-dependent cell adhesion and spreading

  14. Muscle phosphorylase kinase deficiency

    Preisler, N; Orngreen, M C; Echaniz-Laguna, A; Laforet, P; Lonsdorfer-Wolf, E; Doutreleau, S; Geny, B; Akman, H O; Dimauro, S; Vissing, J

    2012-01-01

    To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD).......To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD)....

  15. Characterization of adhesively bonded joints using bulk adhesive properties

    Kon, Haruhiko

    1991-01-01

    Though using bulk adhesive properties to predict adhesively bonded joint response has yet to be proven infallible, based upon the success of previous works, this effort attempts to shed some light on the stresses present in a typical automotive bonded joint. Adhesive material properties obtained in previous works were used in a finite element analysis of a simulated automotive joint to predict the stresses in that joint. The automotive joint analyzed was a simplified repr...

  16. PTTG promotes invasion in human breast cancer cell line by upregulating EMMPRIN via FAK/Akt/mTOR signaling.

    Gao, Hui; Zhong, Feng; Xie, Jing; Peng, Jianjun; Han, Zhiwu

    2016-01-01

    Pituitary tumor transforming gene (PTTG) is a novel oncogene that is expressed at higher level in most of the tumors. PTTG overexpression correlates with lymph node infiltration and a higher degree of tumor recurrence in breast cancer. However, the cellular functions and precise signals elicited by PTTG in breast cancer are not fully understood. Here, we established a breast cancer cell line which stably overexpressed PTTG. In vitro experiments showed that overexpression of PTTG in MCF-7 cells was associated with enhanced cell migration and invasion as well as EMT. Our results also demonstrated that PTTG overexpression correlated with elevated EMMPRIN level, which mediated the enhanced cell migration, invasion and EMT. Moreover, our findings suggested that PTTG enhances metastatic potential of breast cancer cells by inducing EMMPRIN through activating FAK/Akt/mTOR pathway. Our findings may lead to a better understanding of the biological effect of PTTG and provide mechanistic insights for developing potential therapeutic strategies for inhibiting the invasion and metastasis of breast cancer. PMID:27186413

  17. RP1 is a phosphorylation target of CK2 and is involved in cell adhesion.

    Frank Stenner

    Full Text Available RP1 (synonym: MAPRE2, EB2 is a member of the microtubule binding EB1 protein family, which interacts with APC, a key regulatory molecule in the Wnt signalling pathway. While the other EB1 proteins are well characterized the cellular function and regulation of RP1 remain speculative to date. However, recently RP1 has been implicated in pancreatic cancerogenesis. CK2 is a pleiotropic kinase involved in adhesion, proliferation and anti-apoptosis. Overexpression of protein kinase CK2 is a hallmark of many cancers and supports the malignant phenotype of tumor cells. In this study we investigate the interaction of protein kinase CK2 with RP1 and demonstrate that CK2 phosphorylates RP1 at Ser(236 in vitro. Stable RP1 expression in cell lines leads to a significant cleavage and down-regulation of N-cadherin and impaired adhesion. Cells expressing a Phospho-mimicking point mutant RP1-ASP(236 show a marked decrease of adhesion to endothelial cells under shear stress. Inversely, we found that the cells under shear stress downregulate endogenous RP1, most likely to improve cellular adhesion. Accordingly, when RP1 expression is suppressed by shRNA, cells lacking RP1 display significantly increased cell adherence to surfaces. In summary, RP1 phosphorylation at Ser(236 by CK2 seems to play a significant role in cell adhesion and might initiate new insights in the CK2 and EB1 family protein association.

  18. Adhesive tape exfoliation

    Bohr, Jakob

    2015-01-01

    Single-crystal graphite can be cleaved by the use of an adhesive tape. This was also the initial route for obtaining graphene, a one-layer thick graphite slab. In this letter a few simple and fun considerations are presented in an attempt to shed some light on why this procedure is successful. In...... particular on the nature of the surprisingly small number of repetitive steps that are needed in order to obtain a single-layer slab. Two frameworks for exfoliation are investigated: parallel exfoliation involving repetitive simultaneous cleaving, the other, serial exfoliation, which involves the repetitive...

  19. Polyurethane adhesive ingestion.

    Fitzgerald, Kevin T; Bronstein, Alvin C

    2013-02-01

    Polyurethane adhesives are found in a large number of household products in the United States and are used for a variety of purposes. Several brands of these expanding wood glues (those containing diphenylmethane diisocyanate [MDI]) have the potential to form gastrointestinal (GI) foreign bodies if ingested. The ingested adhesive forms an expanding ball of glue in the esophagus and gastric lumen. This expansion is caused by a polymerization reaction using the heat, water, and gastric acids of the stomach. A firm mass is created that can be 4-8 times its original volume. As little as 2 oz of glue have been reported to develop gastric foreign bodies. The obstructive mass is reported to form within minutes of ingestion of the adhesive. The foreign body can lead to esophageal impaction and obstruction, airway obstruction, gastric outflow obstruction, mucosal hemorrhage, ulceration, laceration, perforation of the esophageal and gastric linings, and death. Clinical signs following ingestion include anorexia, lethargy, vomiting, tachypnea, and abdominal distention and pain, and typically develop within 12 hours. Clinical signs may depend upon the size of the mass. If left untreated, perforation and rupture of the esophagus or stomach can occur. The glue mass does not stick to the GI mucosa and is not always detectable on abdominal palpation. Radiographs are recommended to confirm the presence of the "glue-ball" foreign body, and radiographic evidence of the obstruction may be seen as early as 4-6 hours following ingestion. Emesis is contraindicated owing to the risk of aspiration of the glue into the respiratory tree or the subsequent lodging of the expanding glue mass in the esophagus. Likewise, efforts to dilute the glue and prevent the formation of the foreign body through administration of liquids, activated charcoal, or bulk-forming products to push the foreign body through the GI tract have proven ineffective. Even endoscopy performed to remove the foreign body has

  20. Syndecan proteoglycans and cell adhesion

    Woods, A; Oh, E S; Couchman, J R

    1998-01-01

    It is now becoming clear that a family of transmembrane proteoglycans, the syndecans, have important roles in cell adhesion. They participate through binding of matrix ligand to their glycosaminoglycan chains, clustering, and the induction of signaling cascades to modify the internal microfilament...... organization. Syndecans can modulate the type of adhesive responses induced by other matrix ligand-receptor interactions, such as those involving the integrins, and so contribute to the control of cell morphology, adhesion and migration....

  1. The neural cell adhesion molecule

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  2. Lipid Raft is required for PSGL-1 ligation induced HL-60 cell adhesion on ICAM-1.

    Tingshuang Xu

    Full Text Available P-selectin glycoprotein ligand-1 (PSGL-1 and integrins are adhesion molecules that play critical roles in host defense and innate immunity. PSGL-1 mediates leukocyte rolling and primes leukocytes for integrin-mediated adhesion. However, the mechanism that PSGL-1 as a rolling receptor in regulating integrin activation has not been well characterized. Here, we investigate the function of lipid raft in regulating PSGL-1 induced β2 integrin-mediated HL-60 cells adhesion. PSGL-1 ligation with antibody enhances the β2 integrin activation and β2 integrin-dependent adhesion to ICAM-1. Importantly, with the treatment of methyl-β-cyclodextrin (MβCD, we confirm the role of lipid raft in regulating the activation of β2 integrin. Furthermore, we find that the protein level of PSGL-1 decreased in raft fractions in MβCD treated cells. PSGL-1 ligation induces the recruitment of spleen tyrosine kinase (Syk, a tyrosine kinase and Vav1 (the pivotal downstream effector of Syk signaling pathway involved in cytoskeleton regulation to lipid raft. Inhibition of Syk activity with pharmacologic inhibitor strongly reduces HL-60 cells adhesion, implicating Syk is crucial for PSGL-1 mediated β2 integrin activation. Taken together, we report that ligation of PSGL-1 on HL-60 cells activates β2 integrin, for which lipid raft integrity and Syk activation are responsible. These findings have shed new light on the mechanisms that connect leukocyte initial rolling with subsequent adhesion.

  3. Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

    Jeong, Hoon Eui

    2010-02-16

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

  4. Improved Adhesion and Compliancy of Hierarchical Fibrillar Adhesives.

    Li, Yasong; Gates, Byron D; Menon, Carlo

    2015-08-01

    The gecko relies on van der Waals forces to cling onto surfaces with a variety of topography and composition. The hierarchical fibrillar structures on their climbing feet, ranging from mesoscale to nanoscale, are hypothesized to be key elements for the animal to conquer both smooth and rough surfaces. An epoxy-based artificial hierarchical fibrillar adhesive was prepared to study the influence of the hierarchical structures on the properties of a dry adhesive. The presented experiments highlight the advantages of a hierarchical structure despite a reduction of overall density and aspect ratio of nanofibrils. In contrast to an adhesive containing only nanometer-size fibrils, the hierarchical fibrillar adhesives exhibited a higher adhesion force and better compliancy when tested on an identical substrate. PMID:26167951

  5. Effect of adhesive thickness on adhesively bonded T-joint

    The aim of this work is to analyze the effect of adhesive thickness on tensile strength of adhesively bonded stainless steel T-joint. Specimens were made from SUS 304 Stainless Steel plate and SUS 304 Stainless Steel perforated plate. Four T-joint specimens with different adhesive thicknesses (0.5, 1.0, 1.5 and 2.0 mm) were made. Experiment result shows T-joint specimen with adhesive thickness of 1.0 mm yield highest maximum load. Identical T-joint specimen jointed by spot welding was also tested. Tensile test shows welded T-Joint had eight times higher tensile load than adhesively bonded T-joint. However, in low pressure application such as urea granulator chamber, high tensile strength is not mandatory. This work is useful for designer in fertilizer industry and others who are searching for alternative to spot welding

  6. Pyruvate kinase blood test

    ... break down faster than normal, a condition called hemolytic anemia . This test helps diagnose pyruvate kinase deficiency (PKD) . ... Pa: Elsevier Saunders; 2011:chap 32. Gallagher PG. Hemolytic anemias: red cell membrane and metabolic defects In: Goldman ...

  7. Syndecans, signaling, and cell adhesion

    Couchman, J R; Woods, A

    1996-01-01

    structures within the heparan sulfate chains, leaving the roles of chondroitin sulfate chains and extracellular portion of the core proteins to be elucidated. Evidence that syndecans are a class of receptor involved in cell adhesion is mounting, and their small cytoplasmic domains may link with the...... transmembrane signaling from matrix to cytoskeleton, as proposed for other classes of adhesion receptors....

  8. FAK-related nonkinase attenuates hypertrophy induced by angiotensin-Ⅱ in cultured neonatal rat cardiac myocytes

    Jin QIN; Zheng-xiang LIU

    2006-01-01

    Aim: To examine the inhibitory effect of FAK-related nonkinase (FRNK) in cardiac hypertrophy in vitro and investigate the possible mechanisms. Methods: A functional fragment of FRNK cDNA was amplified by reverse transcription-polymerase chain reaction and cloned into the vector pcDNA3.1. Hypertrophy in neonatal rat cardiac myocytes was established with angiotensin-Ⅱ stimulation. The pcDNA3.1-FRNK or pcDNA3.1 was respectively transfected into cardiomyocytes by Lipofectamine 2000. The surface area and mRNA expression of atrial natriuretic peptide (ANP) of myocytes were employed to detect cardiac hypertrophy. NF-κB p65 protein in nuclear extracts, phosphorylation levels of ERK1/2 (p-ERK1/2) and AKT (p-AKT), as well as total ERK1/2, and AKT in variant treated cardiomyocytes were determined by Western blot. Results: Under the stimulation of angiotensin Ⅱ, the surface area of myocytes and levels of ANP mRNA were significantly increased. But transient transfection with pcDNA3.1-FRNK in advance may reduce the surface area and expression of ANP mRNA of hypertrophic myocytes. The protein levels of NF-κB p65 in nuclear extracts and p-ERK1/2, p-AKT in FRNK treated cardiomyocytes were significantly decreased compared with that in angiotensin-Ⅱ induced cardiomyocytes, while different treatments had little effect on total ERK1/2 and AKT. Conclusion: FRNK may inhibit angiotensin-Ⅱ-induced cardiomyocyte hypertrophy via decreasing phosphorylation levels at ERK1/2 and AKT, consequently downregulating nuclear translocation of NF-κB p65.

  9. Hyaluronan-mediated cellular adhesion

    Curtis, Jennifer

    2005-03-01

    Many cells surround themselves with a cushioning halo of polysaccharides that is further strengthened and organized by proteins. In fibroblasts and chrondrocytes, the primary component of this pericellular matrix is hyaluronan, a large linear polyanion. Hyaluronan production is linked to a variety of disease, developmental, and physiological processes. Cells manipulate the concentration of hyaluronan and hyaluronan receptors for numerous activities including modulation of cell adhesion, cell motility, and differentiation. Recent investigations by identify hyaluronan's role in mediating early-stage cell adhesion. An open question is how the cell removes the 0.5-10 micron thick pericellular matrix to allow for further mature adhesion events requiring nanometer scale separations. In this investigation, holographic optical tweezers are used to study the adhesion and viscoelastic properties of chondrocytes' pericellular matrix. Ultimately, we aim to shed further light on the spatial and temporal details of the dramatic transition from micron to nanometer gaps between the cell and its adhesive substrate.

  10. [Retention of adhesive bridges].

    Raes, F; De Boever, J

    1994-04-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rests, interocclusal clearance and cingulum stops is equally important. Including more teeth in the design does not necessarily lead to an improved retention. Besides the material and technical aspects, the whole clinical procedure needs much attention. The retention does not depend on one single factor, but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 80% can be obtained. PMID:11830965

  11. Effect of fibril shape on adhesive properties

    Soto, Daniel; Hill, Ginel; Parness, Aaron; Esparza, Noé; Cutkosky, Mark; Kenny, Tom

    2010-08-01

    Research into the gecko's adhesive system revealed a unique architecture for adhesives using tiny hairs. By using a stiff material (β-keratin) to create a highly structured adhesive, the gecko's system demonstrates properties not seen in traditional pressure-sensitive adhesives which use a soft, unstructured planar layer. In contrast to pressure sensitive adhesives, the gecko adhesive displays frictional adhesion, in which increased shear force allows it to withstand higher normal loads. Synthetic fibrillar adhesives have been fabricated but not all demonstrate this frictional adhesion property. Here we report the dual-axis force testing of single silicone rubber pillars from synthetic adhesive arrays. We find that the shape of the adhesive pillar dictates whether frictional adhesion or pressure-sensitive behavior is observed. This work suggests that both types of behavior can be achieved with structures much larger than gecko terminal structures. It also indicates that subtle differences in the shape of these pillars can significantly influence their properties.

  12. Impact of oils and coatings on adhesion of structural adhesives

    Hagström, Marcus

    2015-01-01

    This is a master thesis project conducted for Scania CV AB in collaboration with Swerea Kimab. The purpose is to examine how oils and coatings on the surface affect the adhesion of adhesives. Earlier work done by Scania indicate that the amount of oil applied may have an impact on the adhesion. Substrates tested are hot dipped galvanised steel, electro galvanised. AlSi and ZnMg. Oils used are Anticorit RP 3802 that is an anti-corrosive oil and Renoform 3802 that is a drawing oil. The two adhes...

  13. Genotypic and phenotypic characterization of garlic-fermenting lactic acid bacteria isolated from som-fak, a Thai low-salt fermented fish product

    Paludan-Müller, Christine; Valyasevi, R.; Huss, Hans Henrik; Gram, Lone

    2002-01-01

    AIMS: To evaluate the importance of garlic for fermentation of a Thai fish product, and to differentiate among garlic-/inulin-fermenting lactic acid bacteria (LAB) at strain level. METHODS AND RESULTS: Som-fak was prepared by fermentation of a mixture of fish, salt, rice, sucrose and garlic. pH d...... IMPACT OF THE STUDY: The present study indicates the role of fructans (garlic/inulin) as carbohydrate sources for LAB. Fructan fermenters may have several biotechnological applications, for example, as probiotics....

  14. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Neil J Shirtcliffe

    Full Text Available Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted, texture (smooth, rough or granular or wetting property (hydrophilic or hydrophobic via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  15. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    Shirtcliffe, Neil J.; McHale, Glen; Newton, Michael I.

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces. PMID:22693563

  16. Marine Bioinspired Underwater Contact Adhesion.

    Clancy, Sean K; Sodano, Antonio; Cunningham, Dylan J; Huang, Sharon S; Zalicki, Piotr J; Shin, Seunghan; Ahn, B Kollbe

    2016-05-01

    Marine mussels and barnacles are sessile biofouling organisms that adhere to a number of surfaces in wet environments and maintain remarkably strong bonds. Previous synthetic approaches to mimic biological wet adhesive properties have focused mainly on the catechol moiety, present in mussel foot proteins (mfps), and especially rich in the interfacial mfps, for example, mfp-3 and -5, found at the interface between the mussel plaque and substrate. Barnacles, however, do not use Dopa for their wet adhesion, but are instead rich in noncatecholic aromatic residues. Due to this anomaly, we were intrigued to study the initial contact adhesion properties of copolymerized acrylate films containing the key functionalities of barnacle cement proteins and interfacial mfps, for example, aromatic (catecholic or noncatecholic), cationic, anionic, and nonpolar residues. The initial wet contact adhesion of the copolymers was measured using a probe tack testing apparatus with a flat-punch contact geometry. The wet contact adhesion of an optimized, bioinspired copolymer film was ∼15.0 N/cm(2) in deionized water and ∼9.0 N/cm(2) in artificial seawater, up to 150 times greater than commercial pressure-sensitive adhesive (PSA) tapes (∼0.1 N/cm(2)). Furthermore, maximum wet contact adhesion was obtained at ∼pH 7, suggesting viability for biomedical applications. PMID:27046671

  17. Adhesion and multi-materials

    Adhesion is a multidisciplinary science relevant to many practical fields. The main application of adhesion is bonding by adhesives. This technique is widely used in the industrial world and more specifically in the advanced technical domains. Adhesion is also involved in multi-component materials such as coatings, multilayer materials, polymer blends, composite materials... The multidisciplinary aspect of adhesion is well demonstrated by considering the wide variety of concepts, models and theories proposed for its description. An example of the adhesion between a fiber and a matrix in a composite material will lead to a general model relating the molecular properties of the interface to its capacity of stress transfer and hence to the macroscopic mechanical properties of the composite. This relationship is valid whatever the fiber (glass, carbon, polymeric) or the polymer matrix (thermoplastics, thermosetting). Any deviation from this model can be attributed to the existence of an interfacial zone or interphase exhibiting properties, mainly mechanical properties, different from the bulk matrix. Two examples are examined: the first one deals with the creation of a trans crystalline interphase in a semi-crystalline thermoplastic matrix and the second one is concerned with the formation of a pseudo glassy interphase in an elastomer matrix. These examples stress the need for complementary approaches in the understanding of adhesion phenomena at different levels of knowledge, from molecular to macroscopic. They also show how important it is to understand the mechanisms of formation of inter phases in order to be able to master the performance of multicomponent materials. (Author)

  18. Xenopus paraxial protocadherin inhibits Wnt/β-catenin signalling via casein kinase

    Kietzmann, Anja; Wang, Yingqun; Weber, Dominik; Steinbeisser, Herbert

    2011-01-01

    Paraxial protocadherin (PAPC) is a known cell adhesion molecule that also activates the Wnt/PCP pathway. Steinbeisser and colleagues show here that PAPC not only activates the non-canonical Wnt/PCP pathway but, at the same time, also inhibits the canonical Wnt/beta-catenin pathway through interaction with casein kinase 2.

  19. Photovoltaic module with adhesion promoter

    Xavier, Grace

    2013-10-08

    Photovoltaic modules with adhesion promoters and methods for fabricating photovoltaic modules with adhesion promoters are described. A photovoltaic module includes a solar cell including a first surface and a second surface, the second surface including a plurality of interspaced back-side contacts. A first glass layer is coupled to the first surface by a first encapsulating layer. A second glass layer is coupled to the second surface by a second encapsulating layer. At least a portion of the second encapsulating layer is bonded directly to the plurality of interspaced back-side contacts by an adhesion promoter.

  20. Adhesives from modified soy protein

    Sun, Susan; Wang, Donghai; Zhong, Zhikai; Yang, Guang

    2008-08-26

    The, present invention provides useful adhesive compositions having similar adhesive properties to conventional UF and PPF resins. The compositions generally include a protein portion and modifying ingredient portion selected from the group consisting of carboxyl-containing compounds, aldehyde-containing compounds, epoxy group-containing compounds, and mixtures thereof. The composition is preferably prepared at a pH level at or near the isoelectric point of the protein. In other preferred forms, the adhesive composition includes a protein portion and a carboxyl-containing group portion.

  1. XIAP reverses various functional activities of FRNK in endothelial cells

    Highlights: ► FRNK domain is recruited into focal adhesion (FA), controlling endothelial cell adhesion. ► XIAP binds the FRNK domain of FAK. ► XIAP inhibits recruitment of FRNK into Fas and FRNK-promoted cell adhesion. ► XIAP plays a key role in vascular functions of FRNK or FRNK domain-mediated vascular functions of FAK. -- Abstract: In endothelial cells, focal adhesion kinase (FAK) regulates cell proliferation, migration, adhesion, and shear-stimulated activation of MAPK. We recently found that FAK is recruited into focal adhesion (FA) sites through interactions with XIAP (X-chromosome linked inhibitor of apoptosis protein) and activated by Src kinase in response to shear stress. In this study, we examined which domain(s) of FAK is(are) important for various vascular functions such as FA recruiting, XIAP-binding and shear stress-stimulated ERK activation. Through a series of experiments, we determined that the FRNK domain is recruited into FA sites and promotes endothelial cell adhesion. Interestingly, XIAP knockdown was shown to reduce FA recruitment of FRNK and the cell adhesive effect of FRNK. In addition, we found that XIAP interacts with FRNK, suggesting cross-talk between XIAP and FRNK. We also demonstrated that FRNK inhibits endothelial cell migration and shear-stimulated ERK activation. These inhibitory effects of FRNK were reversed by XIAP knockdown. Taken together, we can conclude that XIAP plays a key role in vascular functions of FRNK or FRNK domain-mediated vascular functions of FAK.

  2. From Phosphosites to Kinases

    Munk, Stephanie; Refsgaard, Jan C; Olsen, Jesper V;

    2016-01-01

    Kinases play a pivotal role in propagating the phosphorylation-mediated signaling networks in living cells. With the overwhelming quantities of phosphoproteomics data being generated, the number of identified phosphorylation sites (phosphosites) is ever increasing. Often, proteomics investigations...... sequence motifs, mostly based on large scale in vivo and in vitro experiments. The context of the kinase and the phosphorylated proteins in a biological system is equally important for predicting association between the enzymes and substrates, an aspect that is also being tackled with available...

  3. Syndecan-4 proteoglycan regulates the distribution and activity of protein kinase C

    Oh, E S; Woods, A; Couchman, J R

    1997-01-01

    During cell-matrix adhesion, both tyrosine and serine/threonine kinases are activated. Integrin ligation correlates with tyrosine phosphorylation, whereas the later stages of spreading and focal adhesion and stress fiber formation in primary fibroblasts requires interactions of cell surface...... proteoglycan with heparin-binding moieties. This correlates with protein kinase C (PKC) activation, and PKCalpha can become localized to focal adhesions in normal, but not transformed, cells. PKC activation has been thought to be downstream of initial receptor-ligand interactions. We now show, however, that...... syndecan-4 transmembrane heparan sulfate proteoglycan and PKC co-immunoprecipitate and co-patch in vivo. The core protein of syndecan-4 can directly bind the catalytic domain of PKCalpha and potentiate its activation by phospholipid mediators. It can also directly activate PKCalpha in the absence of other...

  4. Phosphatidylinositol kinase from rabbit reticulocytes

    Phosphatidylinositol (PI) kinase was isolated from the postribosomal supernatant of rabbit reticulocytes. This activity was identified by the formation of a product that comigrated with phosphatidylinositol-4-phosphate (PIP) when purified PI was phosphorylated in the presence of [32P]ATP and Mg2+. Three major peaks of PI kinase activity were resolved by chromatography on DEAE-cellulose. The first peak eluted at 50-100 mM NaCl together with several serine protein kinases, casein kinase (CK) I and protease activated kinase (PAK) I and II. The PI kinase was subsequently separated from the protein kinases by chromatography on phosphocellulose. The second peak eluted at 125-160 mM NaCl and contained another lipid kinase activity that produced a product which comigrated with phosphatidic acid on thin layer chromatography. The third peak, which eluted at 165-200 mM NaCl, partly comigrated with casein kinase (CK) II and an active protein kinase(s) which phosphorylated mixed histone and histone I. CK II and the histone kinase activities were also separated by chromatography on phosphocelluslose. The different forms of PI kinase were characterized and compared with respect to substrate and salt requirements

  5. Denture Adhesives - A Literature Review

    Sudhanshu Shekhar

    2016-06-01

    Full Text Available Successful complete denture treatment combines exemplary technique, effective patient rapport and education and familiarity with all possible management options to provide the highest degree of patient satisfaction. Dentists need to know about denture adhesives to be able to identify those patients who actually need them and to be able to educate them about the advantages, disadvantages and correct use of these products. Denture adhesives are commercially available nontoxic, soluble materials that when applied to the tissue surface of dentures enhance their retention, stability and performance. They were introduced in dentistry in the late 18th century. The first patent related to adhesives was issued in 1913, followed in the 1920’s and 1930’s. The purpose of the use of denture adhesives can be described as to subjectively benefit denture-wearers with improved stability, retention and comfort of their dentures, and with improved incisal force, masticatory ability, and confidence.

  6. Marsdenia tenacissima extract suppresses A549 cell migration through regulation of CCR5-CCL5 axis, Rho C, and phosphorylated FAK.

    Lin, Sen-Sen; Li, Fang-Fang; Sun, Li; Fan, Wei; Gu, Ming; Zhang, Lu-Yong; Qin, Song; Yuan, Sheng-Tao

    2016-03-01

    Marsdenia tenacissima, a traditional Chinese medicine, is long been used to treat various diseases including asthma, cancer, trachitis, tonsillitis, pharyngitis, cystitis, and pneumonia. Although Marsdenia tenacissima has been demonstrated to have strong anti-tumor effects against primary tumors, its effect on cancer metastasis remains to be defined, and the molecular mechanism underlying the anti-metastatic effect is unknown. In the present study, we investigated the effects of XAP (an extract of Marsdenia tenacissima) on A549 lung cancer cell migration and explored the role of CCR5-CCL5 axis in the anti-metastatic effects of XAP. Our resutls showed that XAP inhibited A549 lung cancer cell migration and invasion in a dose-dependent manner. The protein levels of CCR5, but not CCR9 and CXCR4, were decreased by XAP. The secretion of CCL5, the ligand of CCR5, was reduced by XAP. XAP down-regulated Rho C expression and FAK phosphorylation. In conclusion, XAP inhibited A549 cell migration and invasion through down-regulation of CCR5-CCL5 axis, Rho C, and FAK. PMID:27025367

  7. Laser surface modification and adhesion

    Mittal, K L

    2014-01-01

    The book provides a unique overview on laser techniques and applications for the purpose of improving adhesion by altering surface chemistry and topography/morphology of the substrate. It details laser surface modification techniques for a wide range of industrially relevant materials (plastics, metals, ceramics, composites) with the aim to improve and enhance their adhesion to other materials. The joining of different materials is of critical importance in the fabrication of many and varied products.

  8. Notch-Mediated Cell Adhesion

    Akihiko Murata; Shin-Ichi Hayashi

    2016-01-01

    Notch family members are generally recognized as signaling molecules that control various cellular responses in metazoan organisms. Early fly studies and our mammalian studies demonstrated that Notch family members are also cell adhesion molecules; however, information on the physiological roles of this function and its origin is limited. In this review, we discuss the potential present and ancestral roles of Notch-mediated cell adhesion in order to explore its origin and the initial roles of...

  9. Adhesive capsulitis: a case report

    Kazemi, Mohsen

    2000-01-01

    Adhesive capsulitis or frozen shoulder is an uncommon entity in athletes. However, it is a common cause of shoulder pain and disability in the general population. Although it is a self limiting ailment, its rather long, restrictive and painful course forces the affected person to seek treatment. Conservative management remains the mainstay treatment of adhesive capsulitis. This includes chiropractic manipulation of the shoulder, therapeutic modalities, mobilization, exercise, soft tissue ther...

  10. Neuron Membrane Trafficking and Protein Kinases Involved in Autism and ADHD

    Yasuko Kitagishi

    2015-01-01

    Full Text Available A brain-enriched multi-domain scaffolding protein, neurobeachin has been identified as a candidate gene for autism patients. Mutations in the synaptic adhesion protein cell adhesion molecule 1 (CADM1 are also associated with autism spectrum disorder, a neurodevelopmental disorder of uncertain molecular origin. Potential roles of neurobeachin and CADM1 have been suggested to a function of vesicle transport in endosomal trafficking. It seems that protein kinase B (AKT and cyclic adenosine monophosphate (cAMP-dependent protein kinase A (PKA have key roles in the neuron membrane trafficking involved in the pathogenesis of autism. Attention deficit hyperactivity disorder (ADHD is documented to dopaminergic insufficiencies, which is attributed to synaptic dysfunction of dopamine transporter (DAT. AKT is also essential for the DAT cell-surface redistribution. In the present paper, we summarize and discuss the importance of several protein kinases that regulate the membrane trafficking involved in autism and ADHD, suggesting new targets for therapeutic intervention.

  11. DDRs: receptors that mediate adhesion, migration and invasion in breast cancer cells

    Emmanuel Reyes-Uribe

    2015-08-01

    Full Text Available Discoidin domain receptors (DDRs are receptor tyrosine kinases that are activated by native collagens and have an important role during cell adhesion, development, differentiation, proliferation, and migration. DDR deregulation is associated with progression of several different cancers. However, there is limited information about the role of DDRs in the progression of breast cancer. In this review we attempt to collect the most relevant information about DDR signaling and their role in various cancer-related processes such as adhesion, epithelial to mesenchymal transition, migration, invasion, and survival, with a focus on breast cancer.

  12. Kinase Inhibitors from Marine Sponges

    Ana Zivanovic

    2011-10-01

    Full Text Available Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included.

  13. Integrin-linked kinase regulates interphase and mitotic microtubule dynamics.

    Simin Lim

    Full Text Available Integrin-linked kinase (ILK localizes to both focal adhesions and centrosomes in distinct multiprotein complexes. Its dual function as a kinase and scaffolding protein has been well characterized at focal adhesions, where it regulates integrin-mediated cell adhesion, spreading, migration and signaling. At the centrosomes, ILK regulates mitotic spindle organization and centrosome clustering. Our previous study showed various spindle defects after ILK knockdown or inhibition that suggested alteration in microtubule dynamics. Since ILK expression is frequently elevated in many cancer types, we investigated the effects of ILK overexpression on microtubule dynamics. We show here that overexpressing ILK in HeLa cells was associated with a shorter duration of mitosis and decreased sensitivity to paclitaxel, a chemotherapeutic agent that suppresses microtubule dynamics. Measurement of interphase microtubule dynamics revealed that ILK overexpression favored microtubule depolymerization, suggesting that microtubule destabilization could be the mechanism behind the decreased sensitivity to paclitaxel, which is known to stabilize microtubules. Conversely, the use of a small molecule inhibitor selective against ILK, QLT-0267, resulted in suppressed microtubule dynamics, demonstrating a new mechanism of action for this compound. We further show that treatment of HeLa cells with QLT-0267 resulted in higher inter-centromere tension in aligned chromosomes during mitosis, slower microtubule regrowth after cold depolymerization and the presence of a more stable population of spindle microtubules. These results demonstrate that ILK regulates microtubule dynamics in both interphase and mitotic cells.

  14. Plasma polymerization for cell adhesive/anti-adhesive implant coating

    Meichsner, Juergen; Testrich, Holger; Rebl, Henrike; Nebe, Barbara

    2015-09-01

    Plasma polymerization of ethylenediamine (C2H8N2, EDA) and perfluoropropane (C3F8, PFP) with admixture of argon and hydrogen, respectively, was studied using an asymmetric 13.56 MHz CCP. The analysis of the plasma chemical gas phase processes for stable molecules revealed consecutive reactions: C2H8N2 consumption, intermediate product NH3, and main final product HCN. In C3F8- H2 plasma the precursor molecule C3F8 and molecular hydrogen are consumed and HF as well as CF4 and C2F6 are found as main gaseous reaction products. The deposited plasma polymer films on the powered electrode are strongly cross-linked due to ion bombardment. The stable plasma polymerized films from EDA are characterized by high content of nitrogen with N/C ratio of about 0.35. The plasma polymerized fluorocarbon film exhibit a reduced F/C ratio of about 1.2. Adhesion tests with human osteoblast cell line MG-63 on coated Ti6Al4V samples (polished) compared with uncoated reference sample yielded both, the enhanced cell adhesion for plasma polymerized EDA and significantly reduced cell adhesion for fluorocarbon coating, respectively. Aging of the plasma polymerized EDA film, in particular due to the reactions with oxygen from air, showed no significant change in the cell adhesion. The fluorocarbon coating with low cell adhesion is of interest for temporary implants. Funded by the Campus PlasmaMed.

  15. Overexpressed GRP78 affects EMT and cell-matrix adhesion via autocrine TGF-β/Smad2/3 signaling.

    Zhang, Lichao; Li, Zongwei; Fan, Yongsheng; Li, Hanqing; Li, Zhouyu; Li, Yaoping

    2015-07-01

    Glucose-regulated protein of 78kD (GRP78) is a multifunctional protein belonging to the heat shock protein 70 family. Overexpression of GRP78 triggered by environmental and physiological stresses is positively correlated with the occurrence and progression of various tumors, but the molecular mechanisms have not been well established. The present study indicated that overexpression of GRP78 in colon cancer cells could promote cell-matrix adhesion through the upregulation of fibronectin, integrin-β1 and phosphorylated FAK. Meanwhile, it resulted in a visible epithelial-mesenchymal transition in DLD1 cells, and the Snail-2 played the key role during the process. More importantly, the data indicated that GRP78 overexpression facilitated the expression and secretion of TGF-β1, which further activated the downstream Smad2/3 signaling module to effectuate the cell-matrix adhesion and epithelial-mesenchymal transition. Taken together, this study provides a novel molecular mechanism involving in the effects of GRP78 on colon cancer metastasis. PMID:25934251

  16. The first EGF domain of coagulation factor IX attenuates cell adhesion and induces apoptosis.

    Ishikawa, Tomomi; Kitano, Hisataka; Mamiya, Atsushi; Kokubun, Shinichiro; Hidai, Chiaki

    2016-07-01

    Coagulation factor IX (FIX) is an essential plasma protein for blood coagulation. The first epidermal growth factor (EGF) motif of FIX (EGF-F9) has been reported to attenuate cell adhesion to the extracellular matrix (ECM). The purpose of the present study was to determine the effects of this motif on cell adhesion and apoptosis. Treatment with a recombinant EGF-F9 attenuated cell adhesion to the ECM within 10 min. De-adhesion assays with native FIX recombinant FIX deletion mutant proteins suggested that the de-adhesion activity of EGF-F9 requires the same process of FIX activation as that which occurs for coagulation activity. The recombinant EGF-F9 increased lactate dehydrogenase (LDH) activity release into the medium and increased the number of cells stained with annexin V and activated caspase-3, by 8.8- and 2.7-fold respectively, indicating that EGF-F9 induced apoptosis. Activated caspase-3 increased very rapidly after only 5 min of administration of recombinant EGF-F9. Treatment with EGF-F9 increased the level of phosphorylated p38 mitogen-activated protein kinase (MAPK), but not that of phosphorylated MAPK 44/42 or c-Jun N-terminal kinase (JNK). Inhibitors of caspase-3 suppressed the release of LDH. Caspase-3 inhibitors also suppressed the attenuation of cell adhesion and phosphorylation of p38 MAPK by EGF-F9. Our data indicated that EGF-F9 activated signals for apoptosis and induced de-adhesion in a caspase-3 dependent manner. PMID:27129300

  17. Regulation of the formation of osteoclastic actin rings by proline-rich tyrosine kinase 2 interacting with gelsolin

    Wang, Qiang; Xie, Yi; Du, Quan-Sheng; Wu, Xiao-Jun; FENG, XU; Mei, Lin; McDonald, Jay M.; Xiong, Wen-Cheng

    2003-01-01

    Osteoclast activation is important for bone remodeling and is altered in multiple bone disorders. This process requires cell adhesion and extensive actin cytoskeletal reorganization. Proline-rich tyrosine kinase 2 (PYK2), a major cell adhesion–activated tyrosine kinase in osteoclasts, plays an important role in regulating this event. The mechanisms by which PYK2 regulates actin cytoskeletal organization and osteoclastic activation remain largely unknown. In this paper, we provide evidence tha...

  18. Innovative Electrostatic Adhesion Technologies

    Bryan, Tom; Macleod, Todd; Gagliano, Larry; Williams, Scott; McCoy, Brian

    2015-01-01

    Developing specialized Electro-Static grippers (commercially used in Semiconductor Manufacturing and in package handling) will allow gentle and secure Capture, Soft Docking, and Handling of a wide variety of materials and shapes (such as upper-stages, satellites, arrays, and possibly asteroids) without requiring physical features or cavities for a pincher or probe or using harpoons or nets. Combined with new rigid boom mechanisms or small agile chaser vehicles, flexible, high speed Electro-Static Grippers can enable compliant capture of spinning objects starting from a safe stand-off distance. Electroadhesion (EA) can enable lightweight, ultra-low-power, compliant attachment in space by using an electrostatic force to adhere similar and dissimilar surfaces. A typical EA enabled device is composed of compliant space-rated materials, such as copper-clad polyimide encapsulated by polymers. Attachment is induced by strong electrostatic forces between any substrate material, such as an exterior satellite panel and a compliant EA gripper pad surface. When alternate positive and negative charges are induced in adjacent planar electrodes in an EA surface, the electric fields set up opposite charges on the substrate and cause an electrostatic adhesion between the electrodes and the induced charges on the substrate. Since the electrodes and the polymer are compliant and can conform to uneven or rough surfaces, the electrodes can remain intimately close to the entire surface, enabling high clamping pressures. Clamping pressures of more than 3 N/cm2 in shear can be achieved on a variety of substrates with ultra-low holding power consumption (measured values are less than 20 microW/Newton weight held). A single EA surface geometry can be used to clamp both dielectric and conductive substrates, with slightly different physical mechanisms. Furthermore EA clamping requires no normal force be placed on the substrate, as conventional docking requires. Internally funded research and

  19. Elastocapilllarity in insect adhesion: the case of beetle adhesive hair

    Gernay, Sophie; Gilet, Tristan; Lambert, Pierre; Federle, Walter

    2014-11-01

    The feet of many insects are covered with dense arrays of hair-like structures called setae. Liquid capillary bridges at the tip of these micrometric structures are responsible for the controlled adhesion of the insect on a large variety of substrates. The resulting adhesion force can exceed several times the body weight of the insect. The high aspect-ratio of setae suggests that flexibility is a key ingredient in this capillary-based adhesion mechanism. There is indeed a strong coupling between their elastic deformation and the shape of the liquid meniscus. In this experimental work, we observe and quantify the local deflection of dock beetle seta tips under perpendicular loading using interference microscopy. Our results are then interpreted in the light of an analytic model of elastocapillarity. This research has been funded by the FRIA/FNRS and the Interuniversity Attraction Poles Programme (IAP 7/38 MicroMAST) initiated by the Belgian Science Policy Office.

  20. Tyrosine kinases in rheumatoid arthritis

    Kobayashi Akiko

    2011-08-01

    Full Text Available Abstract Rheumatoid arthritis (RA is an inflammatory, polyarticular joint disease. A number of cellular responses are involved in the pathogenesis of rheumatoid arthritis, including activation of inflammatory cells and cytokine expression. The cellular responses involved in each of these processes depends on the specific signaling pathways that are activated; many of which include protein tyrosine kinases. These pathways include the mitogen-activated protein kinase pathway, Janus kinases/signal transducers and activators transcription pathway, spleen tyrosine kinase signaling, and the nuclear factor κ-light-chain-enhancer of activated B cells pathway. Many drugs are in development to target tyrosine kinases for the treatment of RA. Based on the number of recently published studies, this manuscript reviews the role of tyrosine kinases in the pathogenesis of RA and the potential role of kinase inhibitors as new therapeutic strategies of RA.

  1. Oncoprotein protein kinase

    Karin, Michael (San Diego, CA); Hibi, Masahiko (San Diego, CA); Lin, Anning (La Jolla, CA); Davis, Roger (Princeton, MA); Derijard, Benoit (Shrewsbury, MA)

    2003-02-04

    An isolated polypeptide (JNK) characterized by having a molecular weight of 46kD as determined by reducing SDS-PAGE, having serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

  2. Kinase-Catalyzed Biotinylation

    Senevirathne, Chamara; Green, Keith D.; Pflum, Mary Kay H.

    2012-01-01

    Kinase-catalyzed protein phosphorylation plays an essential role in a variety of biological processes. Methods to detect phosphoproteins and phosphopeptides in cellular mixtures will aid in cell biological and signaling research. Our laboratory recently discovered the utility of γ-modified ATP analogues as tools for studying phosphorylation. Specifically, ATP-biotin can be used for labeling and visualizing phosphoproteins from cell lysates. Because the biotin tag is suitable for protein detec...

  3. Lignin-Furfural Based Adhesives

    Prajakta Dongre

    2015-07-01

    Full Text Available Lignin recovered from the hot-water extract of sugar maple (Acer saccharum is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC. The effect of pH (0.3, 0.65 and 1, ex situ furfural, and curing conditions on the tensile properties of adhesive reinforced glass fibers is determined and compared to the reinforcement level of commercially available PF resin. The adhesive blend prepared at pH = 0.65 with no added furfural exhibits the highest tensile properties and meets 90% of the PF tensile strength.

  4. Inhibition of Rac and ROCK Signalling Influence Osteoblast Adhesion, Differentiation and Mineralization on Titanium Topographies

    Paul D H Prowse; Elliott, Christopher G.; Jeff Hutter; Hamilton, Douglas W.

    2013-01-01

    Reducing the time required for initial integration of bone-contacting implants with host tissues would be of great clinical significance. Changes in osteoblast adhesion formation and reorganization of the F-actin cytoskeleton in response to altered topography are known to be upstream of osteoblast differentiation, and these processes are regulated by the Rho GTPases. Rac and RhoA (through Rho Kinase (ROCK)). Using pharmacological inhibitors, we tested how inhibition of Rac and ROCK influenced...

  5. Tyrosine Phosphorylation of CD13 Regulates Inflammatory Cell-Cell Adhesion and Monocyte Trafficking

    Subramani, Jaganathan; Ghosh, Mallika; Rahman, M. Mamunur; Caromile, Leslie A.; Gerber, Claire; Rezaul, Karim; David K. Han; Shapiro, Linda H.

    2013-01-01

    CD13 is a large cell surface peptidase expressed on the monocytes and activated endothelial cells important for homing to and resolving the damaged tissue at sites of injury. We have previously shown that crosslinking of human monocytic CD13 with activating antibodies induces strong adhesion to endothelial cells in a tyrosine kinase- and microtubule-dependent manner. In the current study we examined the molecular mechanisms underlying these observations in vitro and in vivo. We found that cro...

  6. Cell adhesion property affected by cyclooxygenase and lipoxygenase: Opto-electric approach.

    Choi, Chang Kyoung; Sukhthankar, Mugdha; Kim, Chul-Ho; Lee, Seong-Ho; English, Anthony; Kihm, Kenneth D; Baek, Seung Joon

    2010-01-15

    Expression of cyclooxygenases (COX) and lipoxygenases (LOX) has been linked to many pathophysiological phenotypes, including cell adhesion. However, many current approaches to measure cellular changes are performed only in a fixed-time point. Since cells dynamically move in conjunction with the cell matrix, there is a pressing need for dynamic or time-dependent methods for the investigation of cell properties. In the presented study, we used stable human colorectal cancer cell lines ectopically expressing COX-1, COX-2, and 15LOX-1, to investigate whether expression of COX-1, COX-2, or 15LOX-1 would affect cell adhesion using our opto-electric methodology. In a fixed-time point experiment, only COX-1- and COX-2-expressing cells enhanced phosphorylation of focal adhesion kinase, but all the transfected cells showed invasion activity. However, in a real-time experiment using opto-electric approaches, transmitted cellular morphology was much different with tight adhesion being shown in COX-2 expressing cells, as imaged by differential interference contrast microscopy (DICM) and interference reflection contrast microscopy (IRCM). Furthermore, micro-impedance measurements showed a continued increase in both resistance and reactance of COX- and LOX-transfected cells, consistent with the imaging data. Our data indicate that both COX- and LOX-expressing cells have strong cell-to-cell and cell-to-substrate adhesions, and that cell imaging analysis with cell impedance data generates fully reliable results on cell adhesion measurement. PMID:20026301

  7. Aqueous Extraction of Citrus unshiu Peel Induces Proangiogenic Effects Through the FAK and ERK1/2 Signaling Pathway in Human Umbilical Vein Endothelial Cells.

    Lee, Jungwhoi; Yang, Dong-Shik; Han, Song-I; Yun, Jeong Hun; Kim, Il-Woong; Kim, Seung Jun; Kim, Jae Hoon

    2016-06-01

    Citrus unshiu peel has been used empirically as a traditional medicine to improve bronchial asthma and blood circulation in northeast Asian nations, including Korea, Japan, and China. In this study, we report the proangiogenic effects of the aqueous extract of Citrus unshiu peel (AECUP). In human umbilical vein endothelial cells, AECUP significantly induced cellular migration and capillary tube formation. We also demonstrated that AECUP markedly increased the phosphorylation of FAK and ERK1/2 through the integrin signaling pathway. Additionally, we identified that narirutin and hesperidin were major constituents of AECUP and both showed proangiogenic effects, but at different levels. Collectively, these results suggest that the AECUP may have potential as a therapeutic agent for improving angiogenic functions with reduced harmful side effects. PMID:27266341

  8. CDH1 and IL1-beta expression dictates FAK and MAPKK-dependent cross-talk between cancer cells and human mesenchymal stem cells

    Al-toub, Mashael; Vishnubalaji, Radhakrishnan; Hamam, Rimi;

    2015-01-01

    : (MCF7, BT-20, BT-474, MDA-MB-468, T-47D, SK-BR-3, MDA-MB-231, PC-3, HT-29, MDA-MB-435s, and FaDu) and changes in their morphology were assessed using fluorescent microscopy. For cellular tracking, cells were labeled with Vybrant DiO, DiL, and DiD lipophilic dyes. Time-lapse microscopy was conducted...... signaling pathways related to bone formation, FAK and MAPKK signaling. Co-culturing hMSCs with MCF7 cells increased their growth evidenced by increase in Ki67 and PCNA staining in tumor cells in direct contact with hMSCs niche. On the other hand, co-culturing hMSCs with FaDu, HT-29 or MDA-MB-231 cells led...

  9. Regulation of Autophagy by Kinases

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets

  10. Artemisinin inhibits monocyte adhesion to HUVECs through the NF-κB and MAPK pathways in vitro.

    Wang, Yue; Cao, Jiatian; Fan, Yuqi; Xie, Yushui; Xu, Zuojun; Yin, Zhaofang; Gao, Lin; Wang, Changqian

    2016-06-01

    The adhesion of monocytes to human umbilical vein endothelial cells (HUVECs) plays a crucial role in the initiation of atherosclerosis. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) are two important molecules involved in the adhesion of monocytes to HUVECs. Previous studies have suggested that artemisinin, apart from an anti-malarial agent, also has other effects. In the present study, we found that artemisinin significantly decreased the adhesion of monocytes to tumor necrosis factor-α (TNF-α)-stimulated HUVECs in a dose-dependent manner and suppressed the mRNA and protein level of ICAM-1 and VCAM-1 in the TNF-α-stimulated HUVECs. In addition, the nuclear factor-κB (NF-κB) inhibitor, Bay 11-7082, and mitogen-activated protein kinase (MAPK) inhibitors (SB203580 and U0126) respectively reduced the adhesion of monocytes to TNF-α-stimulated HUVECs, and suppressed ICAM-1 and VCAM-1 expression in TNF-α stimulated HUVECs. Moreover, artemisinin impeded the activation of the NF-κB and MAPK signaling pathways. Furthermore, Bay 11-7082 significantly decreased the phosphorylation of levels extracellular signal-regulated protein kinase (ERK)1/2, p38 and c-Jun N-terminal kinase (JNK). Taken together, the findings of our study indicated that artemisinin blocked monocyte adhesion to TNF-α-stimulated to HUVECs by downregulating ICAM-1 and VCAM-1 expression in the TNF-α-stimulated HUVECs. Artemisinin may thus have potential for use in the protection against the early development of atherosclerotic lesions. PMID:27122190

  11. Discoidin domain receptor 1 (DDR1) kinase as target for structure-based drug discovery.

    Kothiwale, Sandeepkumar; Borza, Corina M; Lowe, Edward W; Pozzi, Ambra; Meiler, Jens

    2015-02-01

    Discoidin domain receptor (DDR) 1 and 2 are transmembrane receptors that belong to the family of receptor tyrosine kinases (RTK). Upon collagen binding, DDRs transduce cellular signaling involved in various cell functions, including cell adhesion, proliferation, differentiation, migration, and matrix homeostasis. Altered DDR function resulting from either mutations or overexpression has been implicated in several types of disease, including atherosclerosis, inflammation, cancer, and tissue fibrosis. Several established inhibitors, such as imatinib, dasatinib, and nilotinib, originally developed as Abelson murine leukemia (Abl) kinase inhibitors, have been found to inhibit DDR kinase activity. As we review here, recent discoveries of novel inhibitors and their co-crystal structure with the DDR1 kinase domain have made structure-based drug discovery for DDR1 amenable. PMID:25284748

  12. p38 signaling and receptor recycling events in a microfluidic endothelial cell adhesion assay.

    Dwayne A L Vickers

    Full Text Available Adhesion-based microfluidic cell separation has proven to be very useful in applications ranging from cancer diagnostics to tissue engineering. This process involves functionalizing microchannel surfaces with a capture molecule. High specificity and purity capture can be achieved using this method. Despite these advances, little is known about the mechanisms that govern cell capture within these devices and their relationships to basic process parameters such as fluid shear stress and the presence of soluble factors. This work examines how the adhesion of human endothelial cells (ECs is influenced by a soluble tetrapeptide, Arg-Glu-Asp-Val (REDV and fluidic shear stress. The ability of these ECs to bind within microchannels coated with REDV is shown to be governed by shear- and soluble-factor mediated changes in p38 mitogen-activated protein kinase expression together with recycling of adhesion receptors from the endosome.

  13. Mice Devoid of Fer Protein-Tyrosine Kinase Activity Are Viable and Fertile but Display Reduced Cortactin Phosphorylation

    Craig, Andrew W. B.; Zirngibl, Ralph; Williams, Karen; Cole, Lesley-Ann; Greer, Peter A.

    2001-01-01

    The ubiquitous Fer protein-tyrosine kinase has been proposed to regulate diverse processes such as cell growth, cell adhesion, and neurite outgrowth. To gain insight into the biological function of Fer, we have targeted the fer locus with a kinase-inactivating missense mutation (ferD743R). Mice homozygous for this mutation develop normally, have no overt phenotypic differences from wild-type mice, and are fertile. Since these mice lack both Fer and the testis-specific FerT kinase activities, ...

  14. Computational Chemistry of Adhesive Bonds

    Phillips, Donald H.

    1999-01-01

    This investigation is intended to determine the electrical mechanical, and chemical properties of adhesive bonds at the molecular level. The initial determinations will be followed by investigations of the effects of environmental effects on the chemistry and properties of the bond layer.

  15. Adhesion of biocompatible and biodegradable micropatterned surfaces

    Kaiser, J.S.; Kamperman, M.M.G.; Souza, E.J.; Schick, B.; Arzt, E.

    2011-01-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PL

  16. Bacterial Protein-Tyrosine Kinases

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten;

    2010-01-01

    Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... enzymes that are unique in exploiting the ATP/GTP-binding Walker motif to catalyze phosphorylation of protein tyrosine residues. Characterized for the first time only a decade ago, BY-kinases have now come to the fore. Important regulatory roles have been linked with these enzymes, via their involvement...... in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by...

  17. MEK inhibitors, novel anti-adhesive molecules, reduce sickle red blood cell adhesion in vitro and in vivo, and vasoocclusion in vivo.

    Rahima Zennadi

    Full Text Available In sickle cell disease, sickle erythrocyte (SSRBC interacts with endothelial cells, leukocytes, and platelets, and activates coagulation and inflammation, promoting vessel obstruction, which leads to serious life-threatening complications, including acute painful crises and irreversible damage to multiple organs. The mitogen-activated protein kinase, ERK1/2, is abnormally activated in SSRBCs. However, the therapeutic potential of SSRBC ERK1/2 inactivation has never been investigated. I tested four different inhibitors of MEK1/2 (MEK, the kinase that activates ERK1/2, in a model of human SSRBC adhesion to TNFα-activated endothelial cells (ECs. SSRBC MEK inhibition abrogated adhesion to non-activated and TNFα-activated ECs to levels below baseline SSRBC adhesion to non-activated ECs in vitro. SSRBC MEK inhibition also prevented SSRBCs from activating naïve neutrophils to adhere to endothelium. To determine the effect of MEK inhibitors on SSRBC adherence in vivo, sham-treated or MEK inhibitor-treated SSRBCs were infused to nude mice previously treated with TNFα. Sham-treated SSRBCs displayed marked adhesion and occlusion of enflamed vessels, both small and large. However, SSRBC treatment with MEK inhibitors ex vivo showed poor SSRBC adhesion to enflamed vessels with no visible vasoocclusion in vivo. In addition, MEK inhibitor treatment of SSRBCs reduced SSRBC organ trapping and increased the number of SSRBCs circulating in bloodstream. Thus, these data suggest that SSRBC ERK1/2 plays potentially a critical role in sickle pathogenesis, and that MEK inhibitors may represent a valuable intervention for acute sickle cell crises.

  18. Laminin isoform-specific promotion of adhesion and migration of human bone marrow progenitor cells.

    Gu, Yu-Chen; Kortesmaa, Jarkko; Tryggvason, Karl; Persson, Jenny; Ekblom, Peter; Jacobsen, Sten-Eirik; Ekblom, Marja

    2003-02-01

    Laminins are alphabetagamma heterotrimeric extracellular proteins that regulate cellular functions by adhesion to integrin and nonintegrin receptors. Laminins containing alpha4 and alpha5 chains are expressed in bone marrow, but their interactions with hematopoietic progenitors are unknown. We studied human bone marrow cell adhesion to laminin-10/11 (alpha5beta1gamma1/alpha5beta2gamma1), laminin-8 (alpha4beta1gamma1), laminin-1 (alpha1beta1gamma1), and fibronectin. About 35% to 40% of CD34(+) and CD34(+)CD38(-) stem and progenitor cells adhered to laminin-10/11, and 45% to 50% adhered to fibronectin, whereas they adhered less to laminin-8 and laminin-1. Adhesion of CD34(+)CD38(-) cells to laminin-10/11 was maximal without integrin activation, whereas adhesion to other proteins was dependent on protein kinase C activation by 12-tetradecanoyl phorbol-13-acetate (TPA). Fluorescence-activated cell-sorting (FACS) analysis showed expression of integrin alpha6 chain on most CD34(+) and CD34(+)CD38(-) cells. Integrin alpha6 and beta1 chains were involved in binding of both cell fractions to laminin-10/11 and laminin-8. Laminin-10/11 was highly adhesive to lineage-committed myelomonocytic and erythroid progenitor cells and most lymphoid and myeloid cell lines studied, whereas laminin-8 was less adhesive. In functional assays, both laminin-8 and laminin-10/11 facilitated stromal-derived factor-1alpha (SDF-1alpha)-stimulated transmigration of CD34(+) cells, by an integrin alpha6 receptor-mediated mechanism. In conclusion, we demonstrate laminin isoform-specific adhesive interactions with human bone marrow stem, progenitor, and more differentiated cells. The cell-adhesive laminins affected migration of hematopoietic progenitors, suggesting a physiologic role for laminins during hematopoiesis. PMID:12393739

  19. Therapeutic targeting of Janus kinases

    Pesu, Marko; Laurence, Arian; Kishore, Nandini; Zwillich, Sam; Chan, Gary; O’Shea, John J.

    2008-01-01

    Cytokines play pivotal roles in immunity and inflammation, and targeting cytokines and their receptors is an effective means of treating such disorders. Type I and II cytokine receptors associate with Janus family kinases (JAKs) to effect intracellular signaling. These structurally unique protein kinases play essential and specific roles in immune cell development and function. One JAK, JAK3, has particularly selective functions. Mutations of this kinase underlie severe combined immunodeficie...

  20. Visualizing autophosphorylation in histidine kinases

    Casino, Patricia; Miguel-Romero, Laura; Marina, Alberto

    2014-01-01

    Reversible protein phosphorylation is the most widespread regulatory mechanism in signal transduction. Autophosphorylation in a dimeric sensor histidine kinase is the first step in two-component signalling, the predominant signal-transduction device in bacteria. Despite being the most abundant sensor kinases in nature, the molecular bases of the histidine kinase autophosphorylation mechanism are still unknown. Furthermore, it has been demonstrated that autophosphorylation can occur in two dir...

  1. Tau-tubulin kinase

    Seiko Ikezu

    2014-04-01

    Full Text Available Tau-tubulin kinase (TTBK belongs to casein kinase superfamily and can phosphorylate microtubule-associated protein tau and tubulin. TTBK has two isoforms, TTBK1 and TTBK2, which contain highly homologous catalytic domains but their non-catalytic domains are distinctly different. TTBK1 is expressed specifically in the central nervous system and is involved in phosphorylation and aggregation of tau. TTBK2 is ubiquitously expressed in multiple tissues and genetically linked to spinocerebellar ataxia type 11. TTBK1 directly phosphorylates tau protein, especially at Ser422, and also activates cycline-dependent kinase 5 in a unique mechanism. TTBK1 protein expression is significantly elevated in Alzheimer’s disease brains, and genetic variations of the TTBK1 gene are associated with late-onset Alzheimer’s disease in two cohorts of Chinese and Spanish populations. TTBK1 transgenic mice harboring the entire 55-kilobase genomic sequence of human TTBK1 show progression of tau accumulation, neuroinflammation, and neurodegeneration when crossed with tau mutant mice. Our recent study shows that there is a striking switch in mononuclear phagocyte and activation phenotypes in the anterior horn of the spinal cord from alternatively activated (M2-skewed microglia to pro-inflammatory (M1-skewed infiltrating peripheral monocytes in P301L tau mutant mice by crossing with TTBK1 transgenic mice. TTBK1 is responsible for mediating M1-activated microglia-induced neurotoxicity, and its overexpression induces axonal degeneration in vitro. These studies suggest that TTBK1 is an important molecule for the inflammatory axonal degeneration, which may be relevant to the pathobiology of tauopathy including Alzheimer’s disease.

  2. Phosphatidylinositol 3-kinase in myogenesis.

    Kaliman, P; Zorzano, A

    1997-08-01

    Phosphatidylinositol 3-kinase (PI 3-kinase) has been cloned and characterized in a wide range of organisms. PI 3-kinases are activated by a diversity of extracellular stimuli and are involved in multiple cell processes such as cell proliferation, protein trafficking, cell motility, differentiation, regulation of cytoskeletal structure, and apoptosis. It has recently been shown that PI 3-kinase is a crucial second messenger in the signaling of myogenesis. Two structurally unrelated highly specific inhibitors of PI 3-kinase-wortmannin and LY294002-block the morphological and biochemical differentiation program of different skeletal-muscle cell models. Moreover, L6E9 myoblasts overexpressing a dominant-negative mutant of PI 3-kinase p85 regulatory subunit (Δp85) are unable to differentiate. Furthermore, PI 3-kinase is specifically involved in the insulinlike growth factor (IGF)-dependent myogenic pathway. Indeed, the ability of IGF-I, des-1,3-IGF-I, and IGF-II to promote cell fusion and muscle-specific protein expression is impaired after treatment with PI 3-kinase inhibitors or in cells overexpressing Δp85. The identification of additional key downstream elements of the IGF/PI 3-kinase myogenic cascade is crucial to a detailed understanding of the process of muscle differentiation and may generate new tools for skeletal and cardiac muscle regeneration therapies. (Trends Cardiovasc Med 1997;7:198-202). © 1997, Elsevier Science Inc. PMID:21235885

  3. Film adhesion in amorphous silicon solar cells

    A R M Yusoff; M N Syahrul; K Henkel

    2007-08-01

    A major issue encountered during fabrication of triple junction -Si solar cells on polyimide substrates is the adhesion of the solar cell thin films to the substrates. Here, we present our study of film adhesion in amorphous silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and Gouldflex), and the effect of tie coats on film adhesion.

  4. Nonwoven glass fiber mat reinforces polyurethane adhesive

    Roseland, L. M.

    1967-01-01

    Nonwoven glass fiber mat reinforces the adhesive properties of a polyurethane adhesive that fastens hardware to exterior surfaces of aluminum tanks. The mat is embedded in the uncured adhesive. It ensures good control of the bond line and increases the peel strength.

  5. The calcium-sensing receptor-dependent regulation of cell-cell adhesion and keratinocyte differentiation requires Rho and Filamin A

    Tu, Chia-Ling; Chang, Wenhan; Bikle, Daniel D.

    2011-01-01

    Extracellular Ca2+ (Ca2+o) acting through the calcium-sensing receptor (CaR) induces E-cadherin mediated cell-cell adhesion and cellular signals mediating cell differentiation in epidermal keratinocytes. Previous studies indicate that the CaR regulates cell-cell adhesion through the Fyn/Src tyrosine kinases. Here we investigate whether Rho GTPase is a part of the CaR-mediated signaling cascade regulating cell adhesion and differentiation. Suppressing endogenous Rho A expression by small inter...

  6. Mechanical strength of adhesive-bonding

    In order to meet the prospective application of a GFRP dewar for energy storage system using a large superconducting magnet, the dewar with a complex structure together with a large size are desired to be made. It is difficult to manufacture such a type of the dewars in one united body. These dewars can be manufactured by the adhesive-bonding method. In the present study, the mechanical strength of adhesive-bonding is studied from this point of view. The mechanical strength of the adhesive-bonding has been investigated by the static tensile method and the impact loading method using small test samples. From the static tensile tests, the following results have been obtained. For the sample adhesive-bonded with insertion structure, the mechanical strength of the adhesive-bonding is found to depend on the adhesives used and on the difference of the thermal contraction between the materials which are adhesive-bonded each other. Using a soft adhesive as Araldite 106, the mechanical strength of the adhesive-bonding is small at room temperature, but it remarkably increases at cryogenic temperatures. For a hard adhesive as Araldite 103 and Stycast 2850 FT, it is large at room temperature, and it further increases at cryogenic temperatures. The dewar has to be strong enough not only at cryogenic temperatures but also at room temperature. A soft adhesive is not suitable for constructing the dewar. For the sample adhesive-bonded with screwing structure, the mechanical strength of the adhesive-bonding depends on the shear strength of GFRP itself. The mechanical strength of the adhesive-bonded part increases with the decreasing temperature. Therefore, this screwing method is advantageous for the construction of the dewar. According to the impact loading tests, it is found that the adhesive-bonding of screwing structure is not brittle at cryogenic temperature. This is due to inherent property of GFRP. (J.P.N.)

  7. Propofol protects against high glucose-induced endothelial adhesion molecules expression in human umbilical vein endothelial cells

    Zhu Minmin

    2013-01-01

    Full Text Available Abstract Background Hyperglycemia could induce oxidative stress, activate transcription factor nuclear factor kappa B (NF-κB, up-regulate expression of endothelial adhesion molecules, and lead to endothelial injury. Studies have indicated that propofol could attenuate oxidative stress and suppress NF-κB activation in some situations. In the present study, we examined whether and how propofol improved high glucose-induced up-regulation of endothelial adhesion molecules in human umbilical vein endothelial cells (HUVECs. Methods Protein expression of endothelial adhesion molecules, NF-κB, inhibitory subunit of NF-κBα (IκBα, protein kinase Cβ2 (PKCβ2, and phosphorylation of PKCβ2 (Ser660 were measured by Western blot. NF-κB activity was measured by electrophoretic mobility shift assay. PKC activity was measured with SignaTECT PKC assay system. Superoxide anion (O2.- accumulation was measured with the reduction of ferricytochrome c assay. Human peripheral mononuclear cells were prepared with Histopaque-1077 solution. Results High glucose induced the expression of endothelial selectin (E-selectin, intercellular adhesion molecule 1 (ICAM-1, vascular cell adhesion molecule 1 (VCAM-1, and increased mononuclear-endothelial adhesion. High glucose induced O2.- accumulation, PKCβ2 phosphorylation and PKC activation. Further, high glucose decreased IκBα expression in cytoplasm, increased the translocation of NF-κB from cytoplasm to nuclear, and induced NF-κB activation. Importantly, we found these high glucose-mediated effects were attenuated by propofol pretreatment. Moreover, CGP53353, a selective PKCβ2 inhibitor, decreased high glucose-induced NF-κB activation, adhesion molecules expression, and mononuclear-endothelial adhesion. Conclusion Propofol, via decreasing O2.- accumulation, down-regulating PKCβ2 Ser660 phosphorylation and PKC as well as NF-κB activity, attenuated high glucose-induced endothelial adhesion molecules expression

  8. Gecko adhesion pad: a smart surface?

    Pesika, Noshir S.; Zeng, Hongbo; Kristiansen, Kai; Zhao, Boxin; Tian, Yu; Autumn, Kellar; Israelachvili, Jacob

    2009-11-01

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  9. Gecko adhesion pad: a smart surface?

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  10. Gecko adhesion pad: a smart surface?

    Pesika, Noshir S [Chemical and Biomolecular Engineering Department, Tulane University, New Orleans, LA 70118 (United States); Zeng Hongbo [Chemical and Materials Engineering Department, University of Alberta, Edmonton, AB, T6G 2V4 (Canada); Kristiansen, Kai; Israelachvili, Jacob [Chemical Engineering Department, University of California, Santa Barbara, CA 93117 (United States); Zhao, Boxin [Chemical Engineering Department and Waterloo Institute of Nanotechnology, University of Waterloo, Ontario, N2L 3G1 (Canada); Tian Yu [State Key Laboratory of Tribology, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Autumn, Kellar, E-mail: npesika@tulane.ed [Department of Biology, Lewis and Clark College, Portland, OR 97219 (United States)

    2009-11-18

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  11. Identification of a novel agrin-dependent pathway in cell signaling and adhesion within the erythroid niche.

    Anselmo, A; Lauranzano, E; Soldani, C; Ploia, C; Angioni, R; D'amico, G; Sarukhan, A; Mazzon, C; Viola, A

    2016-08-01

    Establishment of cell-cell adhesion is crucial in embryonic development as well as within the stem cell niches of an adult. Adhesion between macrophages and erythroblasts is required for the formation of erythroblastic islands, specialized niches where erythroblasts proliferate and differentiate to produce red blood cells throughout life. The Eph family is the largest known family of receptor tyrosine kinases (RTKs) and controls cell adhesion, migration, invasion and morphology by modulating integrin and adhesion molecule activity and by modifying the actin cytoskeleton. Here, we identify the proteoglycan agrin as a novel regulator of Eph receptor signaling and characterize a novel mechanism controlling cell-cell adhesion and red cell development within the erythroid niche. We demonstrate that agrin induces clustering and activation of EphB1 receptors on developing erythroblasts, leading to the activation of α5β1 integrins. In agreement, agrin knockout mice display severe anemia owing to defective adhesion to macrophages and impaired maturation of erythroid cells. These results position agrin-EphB1 as a novel key signaling couple regulating cell adhesion and erythropoiesis. PMID:26990660

  12. Adhesive mechanisms in cephalopods: a review.

    von Byern, Janek; Klepal, Waltraud

    2006-01-01

    Several genera of cephalopods (Nautilus, Sepia, Euprymna and Idiosepius) produce adhesive secretions, which are used for attachment to the substratum, for mating and to capture prey. These adhesive structures are located in different parts of the body, viz. in the digital tentacles (Nautilus), in the ventral surface of the mantle and fourth arm pair (Sepia), in the dorsal epidermis (Euprymna), or in the dorsal mantle side and partly on the fins (Idiosepius). Adhesion in Sepia is induced by suction of dermal structures on the mantle, while for Nautilus, Euprymna and Idiosepius adhesion is probably achieved by chemical substances. Histochemical studies indicate that in Nautilus and Idiosepius secretory cells that appear to be involved in adhesion stain for carbohydrates and protein, whilst in Euprymna only carbohydrates are detectable. De-adhesion is either achieved by muscle contraction of the tentacles and mantle (Nautilus and Sepia) or by secretion of substances (Euprymna). The de-adhesive mechanism used by Idiosepius remains unknown. PMID:17110356

  13. Bacterial adhesion and biofilms on surfaces

    Trevor Roger Garrett; Manmohan Bhakoo; Zhibing Zhang

    2008-01-01

    Bacterial adhesion has become a significant problem in industry and in the domicile,and much research has been done for deeper understanding of the processes involved.A generic biological model of bacterial adhesion and population growth called the bacterial biofilm growth cycle,has been described and modified many times.The biofilm growth cycle encompasses bacterial adhesion at all levels,starting with the initial physical attraction of bacteria to a substrate,and ending with the eventual liberation of cell dusters from the biofilm matrix.When describing bacterial adhesion one is simply describing one or more stages of biofilm development,neglecting the fact that the population may not reach maturity.This article provides an overview of bacterial adhesion.cites examples of how bac-terial adhesion affects industry and summarises methods and instrumentation used to improve our understanding of the adhesive prop-erties of bacteria.

  14. Host Selection of Microbiota via Differential Adhesion.

    McLoughlin, Kirstie; Schluter, Jonas; Rakoff-Nahoum, Seth; Smith, Adrian L; Foster, Kevin R

    2016-04-13

    The host epithelium is the critical interface with microbial communities, but the mechanisms by which the host regulates these communities are poorly understood. Here we develop the hypothesis that hosts use differential adhesion to select for and against particular members of their microbiota. We use an established computational, individual-based model to study the impact of host factors that regulate adhesion at the epithelial surface. Our simulations predict that host-mediated adhesion can increase the competitive advantage of microbes and create ecological refugia for slow-growing species. We show how positive selection via adhesion can be transformed into negative selection if the host secretes large quantities of a matrix such as mucus. Our work predicts that adhesion is a powerful mechanism for both positive and negative selection within the microbiota. We discuss molecules-mucus glycans and IgA-that affect microbe adhesion and identify testable predictions of the adhesion-as-selection model. PMID:27053168

  15. Electrochemical Corrosion of Adhesive Joints

    Vondrák, Jiří

    Vol. 2. Brno: Akademické nakladatelství CERM, 2000 - (Vondrák, J.; Sedlaříková, M.), s. 10.1-10.2 ISBN 80-214-1615-7. [Advanced Batteries and Accumulators /1./. Brno (CZ), 28.08.2000-01.09.2000] Institutional research plan: CEZ:AV0Z4032918 Keywords : adhesive * joints * corrosion Subject RIV: CG - Electrochemistry

  16. Underwater adhesion: The barnacle way

    Khandeparker, L.; Anil, A.C.

    surrounded by calcium carbonate (calcite). It has been suggested that the anionic groups on the matric proteins may serve as sites for nucleation during calcification [47]. The disruption in such interactions can thus bring about hindrance during... of bones, nerves and blood vessels in an aqueous environment and dental filling without the need for drilling [83]. It has been suggested that with the advances in biomimetics, future dentin adhesive monomers may contain domains derived from...

  17. Genistein inhibits human TNF-α-induced porcine endothelial cell adhesiveness for human monocytes and natural killer cells

    2002-01-01

    Cellular immune response is a major barrier to xenotransplantation. Human tumor necrosis factor-α (hTNF-α) possesses cross-species activity and directly amplifies the immune rejection via the upregulation of adhesion molecules on porcine endothelium. We investigated the role of protein tyrosine phosphorylation in the induction of expression of E-sclectin and vascular cell adhesion molecule-1 (VCAM-1), and the augmentation of adhesion of human peripheral blood monocytes (PBMo) and natural killer cells (PBNK), after rhTNF-α-stimulation of porcine aortic endothelial cells (PAEC) in vitro, rhTNF-α-increased adhesiveness of PAEC for both PBMo and PBNK was dose-dependently reduced by pretreatment of PAEC with the selective protein tyrosine kinase (PTK) inhibitor genistein. The inhibitory effect occurred at the early time of PAEC activation triggered by rhTNF-α, and was completely reversible. PTK activity assay indicated that genistein also suppressed rhTNF-α stimulated activation of protein tyrosine kinases (PTKs) in PAEC in a dose-dependent manner. Flow cytometric analysis showed that genistein inhibited the upregulation of E-selectin and VCAM-1 by rhTNF-α. These results suggest that PTKs may regulate the expression of E-selectin and VCAM-1 on PAEC and the adherence of PBMo and PBNK induced by rhTNF-α. Moreover, dietary genistein, used as an adhesion antagonist, may contribute to managing the cell-mediated rejection in the clinical application.

  18. Culinary Medicine-Jalebi Adhesions.

    Kapoor, Vinay K

    2016-02-01

    Culinary terms have been used to describe anatomy (bean-shaped kidneys), pathology (strawberry gall bladder), clinical signs (café-au-lait spots), radiological images (sausage-shaped pancreas), etc. While Indian cuisine is popular all over the world, no Indian dish finds mention in medical terminology. In intra-abdominal adhesions, sometimes, the intestinal loops are so densely adherent that it is difficult to make out proximal from distal and it is impossible to separate them without injuring the bowel resulting in spill of contents-resection is the only option (Fig. 1). Jalebi, an Indian dessert, has a single long tubular strip of fried batter filled with sugary syrup so intertwined that it is impossible to discern its ends; if broken, the syrup spills out-the best way to relish it is to chew the whole piece (Fig. 2). Because of these similarities between them, I propose to name dense intra-abdominal adhesions as 'jalebi adhesions.' PMID:27186047

  19. [Adhesion to the antiretroviral treatment].

    Carballo, M

    2004-12-01

    The objective of the therapy antiretroviral is to improve the quality of life and the survival of the persons affected by the VIH through the suppression of the viral replication. Nevertheless one of the present problems is the resistant apparition of stumps to the new medicines caused by an incorrect management of the therapeutic plan; by an incorrect adhesion of the personal processing. Since the therapeutic success will depend, among others factors, and of important form of the degree of implication and commitment of the person affected, is a matter of identifying prematurely the possible situations concomitants (personal factors and of addiction, psycho-social, related to the processing and its possible secondary effects, associated factors to the own illness or even to the relation professional-patient) that can interfere in a correct adhesion. For it is necessary of the interaction multidisciplinary of the welfare team, and fundamental the work of nursing at the moment of to detect the possible determinant factors and the intervention definition of strategies arrived at by consensus with the own person, that they promote it or it improve. The quantification of the degree of adhesion (measure in %) values through various direct and indirect methods and should keep in mind in it takes of therapeutic decisions being able to come to be advised the suspension of the processing until obtaining to conscience to the person affected of the importance of a correct therapeutic compliance. PMID:15672996

  20. Crosstalk between EGFR and integrin affects invasion and proliferation of gastric cancer cell line, SGC7901

    Dan L

    2012-10-01

    Full Text Available Li Dan,1,* Ding Jian,2,* Lin Na,1 Wang Xiaozhong,1 1Digestive Department, the Union Hospital of Fujian Medical University, Fujian, People’s Republic of China; 2Digestive Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, People’s Republic of China*These authors contributed equally to this workBackground/objective: To investigate the crosstalk between epidermal growth factor receptor (EGFR and integrin-mediated signal transduction pathways in human gastric adenocarcinoma cells.Methods: EGF was used as a ligand of EGFR to stimulate the gastric adenocarcinoma cell, SGC7901. Signal molecules downstream of the integrin, FAK(Y397 and p130cas(Y410 phosphorylation, were measured by immunoprecipitation and western blot. Fibronectin (Fn was used as a ligand of integrin to stimulate the same cell line. Signal molecules downstream of EGFR and extracellular signal-regulated kinase (ERK general phosphorylation were also measured. Focal adhesion kinase (FAK small-interfering RNA was designed and transfected into SGC7901 cells to decrease the expression of FAK. Modified Boyden chambers and MTT assay were used to examine the effect of FAK inhibition on the invasiveness and proliferation of SGC7901.Results: EGF activated FAK(Y397 and p130cas(Y410 phosphorylation, while Fn activated ERK general phosphorylation. Inhibition of FAK expression decreased p130cas(Y410 phosphorylation activated by EGF and ERK general phosphorylation activated by Fn, also decreased the invasiveness and proliferation of SGC7901 cells activated by EGF or Fn.Conclusion: There is crosstalk between EGFR and integrin signal transduction. FAK may be a key cross point of the two signal pathways and acts as a potential target for human gastric cancer therapy.Keywords: gastric adenocarcinoma, epidermal growth factor receptor, integrin, focal adhesion kinase, crosstalk

  1. 上皮-钙粘素和粘着斑激酶在星形细胞瘤中的表达及意义%Expressions and significances of E-cadherin and FAK in human astrocytoma

    尹志明; 张贺; 王健

    2009-01-01

    Objective To explore the expressions and significances of E-cadherin and FAK in human astrocytoma.Methods The expressions of E-cadherin and FAK in 48 cases of astrocytoma tissues and 12 cases of normal brain tissues were detected by immunohistochemical S-P technique.Results The positive expressions rates of E-cadherin and FAK in human astrocytoma of grades Ⅰ-Ⅱ were significantly higher than those in normal brain tissue (P<0.05),The positive expression rate of E- cadherin was decreased with the elevated levels of astrocytoma,and The positive expression rate of FAK was rised with the elevated levels of astrocytoma,and the expression of E- cadherin was negatively correlated with the expressions of FAK (r=-0.354,P<0.01).Conclusion The over expressions of FAK and the low expression of E- cadherin may play an important role in the invasion and malignant progress of human astrocytoma,The expressions of E- cadherin and FAK were closely related with the prognoses of the patients with astrocytomas,and may act as valuable indicators of the malignant degree of astrocytoma and the prognosis in the patients with astrocytomas.%目的 探讨上皮-钙粘素(E-cadherin)和粘着斑激酶(FAK)在星形瘤中的表达及临床意义.方法 采用S-P免疫组化方法检测E-cadherin、FAK在48例不同级别星形细胞瘤及12例正常脑组织中的表达.结果 E-cadherin和FAK在正常脑组织与星形细胞瘤之间及星形细胞瘤高低级别组之间差异有统计学意义(P<0.05),E-cadherin的表达随着星形细胞瘤级别的升高而降低,FAK的表达随着星形细胞瘤级别的升高而升高,且二者在星形细胞瘤中的表达呈负相关(r=-0.354,P<0.01).结论 FAK的过度表达和E-cadherin的表达下调在星形细胞瘤的侵袭及恶性进展中起着重要作用,两者的表达可能与星形细胞瘤患者的预后密切相关,提示可作为反映星形细胞瘤恶性程度及预后的指标.

  2. Novel pharmacologic targeting of tight junctions and focal adhesions in prostate cancer cells.

    Patrick J Hensley

    Full Text Available Cancer cell resistance to anoikis driven by aberrant signaling sustained by the tumor microenvironment confers high invasive potential and therapeutic resistance. We recently generated a novel lead quinazoline-based Doxazosin® derivative, DZ-50, which impairs tumor growth and metastasis via anoikis. Genome-wide analysis in the human prostate cancer cell line DU-145 identified primary downregulated targets of DZ-50, including genes involved in focal adhesion integrity (fibronectin, integrin-α6 and talin, tight junction formation (claudin-11 as well as insulin growth factor binding protein 3 (IGFBP-3 and the angiogenesis modulator thrombospondin 1 (TSP-1. Confocal microscopy demonstrated structural disruption of both focal adhesions and tight junctions by the downregulation of these gene targets, resulting in decreased cell survival, migration and adhesion to extracellular matrix (ECM components in two androgen-independent human prostate cancer cell lines, PC-3 and DU-145. Stabilization of cell-ECM interactions by overexpression of talin-1 and/or exposing cells to a fibronectin-rich environment mitigated the effect of DZ-50. Loss of expression of the intracellular focal adhesion signaling effectors talin-1 and integrin linked kinase (ILK sensitized human prostate cancer to anoikis. Our findings suggest that DZ-50 exerts its antitumor effect by targeting the key functional intercellular interactions, focal adhesions and tight junctions, supporting the therapeutic significance of this agent for the treatment of advanced prostate cancer.

  3. Interplay of cadherin-mediated cell adhesion and canonical Wnt signaling.

    Heuberger, Julian; Birchmeier, Walter

    2010-02-01

    The epithelial-mesenchymal transition is essential in both embryonic development and the progression of carcinomas. Wnt signaling and cadherin-mediated adhesion have been implicated in both processes; clarifying their role will depend on linking them to rearrangements of cellular structure and behavior. beta-Catenin is an essential molecule both in cadherin-mediated cell adhesion and in canonical Wnt signaling. Numerous experiments have shown that the loss of cadherin-mediated cell adhesion can promote beta-catenin release and signaling; this is accomplished by proteases, protein kinases and other molecules. Cadherin loss can also signal to several other regulatory pathways. Additionally, many target genes of Wnt signaling influence cadherin adhesion. The most conspicuous of these Wnt target genes encode the transcription factors Twist and Slug, which directly inhibit the E-cadherin gene promoter. Other Wnt/beta-catenin target genes encode metalloproteases or the cell adhesion molecule L1, which favor the degradation of E-cadherin. These factors provide a mechanism whereby cadherin loss and increased Wnt signaling induce epithelial-mesenchymal transition in both carcinomas and development. PMID:20182623

  4. MET Receptor Tyrosine Kinase

    Faoro, Leonardo; Cervantes, Gustavo M.; El-Hashani, Essam; Salgia, Ravi

    2010-01-01

    MET receptor tyrosine kinase (RTK) and its ligand hepatocyte growth factor (HGF) have become important therapeutic target in oncology, especially lung cancer. MET RTK is involved in cancer cell growth/survival, motility/migration, invasion/metastasis, and in angiogenesis. MET can be overexpressed in lung cancer, sometimes mutated, and sometimes amplified. Not only can MET be overexpressed, there are subsets of lung cancer tumors that have HGF overexpression. The mutations of MET can occur in the semaphorin and/or juxtamembrane domain in a majority of times. Amplification of MET can occur de novo in primary/metastatic tumors, as well arise in the context of therapeutic inhibition. There are a number of clinical inhibitors that have been developed against MET/HGF. Small molecule inhibitors such as XL184 and PF02341066 have come to clinical fruition, as well as antibodies against MET (such as MetMAb). These inhibitors will be discussed. PMID:19861919

  5. Inhibitory Effect of Doxycycline on the Adhesion of Melanoma Cells and Its MolecularMechanisms%多西环素抑制黑色素瘤细胞黏附的分子机制研究

    董恒磊; 孙保存; 孙涛; 赵楠; 董学易; 车娜; 赵秀兰

    2011-01-01

    Objective: To investigate the inhibitory effect of Doxycycline on the adhesion of melanoma cells and its mechanism.Methods: Melanoma B16F110, WM351 and WM451 cell lines were treated with Doxycycline at different doses and through different administration methods.MMT, cell adhesion experiment and Western blot were used to observe the effect of different treatment.A total of 20 C57/BL mice were transplanted with melanoma through injection of B16F10 cells and were divided into two groups.One group was treated with Doxycycline, and the other NaCl solution.Carcinoma tissues were obtained and underwentWestern blot and gelatin zymography.Results: MTT analysis showed that the inhibition ratio was significantly higher in the group receiving treatment before cell adhesion than in the group receiving treatment after cell adhesion ( P < 0.05 ).Cell adhesion experiment showed that Doxycycline had an inhibitory effect on the adhesion of B16F110, WM351 and WM451 cells, with a statistical significance ( P < 0.05 ).Western blot revealed that FAK expression in the three cell lines was decreased at 12 h after Doxycycline treatment.Observations from the mice melanoma model suggested obvious changes in FAK expression and its phosphorylation level ( P < 0.05 ).Conclusion: Doxycycline can interfere the adhesion of melanoma cells, possibly through inhibiting FAK expression and its phosphorylation.%目的:研究多西环素对黑色素瘤细胞黏附的抑制作用及分子机制.方法:对黑色素瘤细胞系B16F10、WM351、WM451分别以不同给药方式和给药浓度进行处理,利用MTT实验、细胞黏附实验和Western blot技术检测比较其差异.C57/BL小鼠20只进行黑色素瘤动物实验,接种B16F10后随机分为2组,分别给予多西环素和NaCl溶液处理,取瘤组织进行Western blot和明胶酶谱检测.结果:MTT实验显示"贴壁前"给药组的细胞抑制率显著高于"贴壁后"给药组且差异具有统计学意义(P<0.05).细胞黏附实

  6. Alpha9beta1 integrin in melanoma cells can signal different adhesion states for migration and anchorage

    Lydolph, Magnus C; Morgan-Fisher, Marie; Høye, Anette M;

    2009-01-01

    Cell surface integrins are the primary receptors for cell migration on extracellular matrix, and exist in several activation states regulated in part by ectodomain conformation. The alpha9 integrin subunit, which pairs only with beta1, has specific roles in the immune system and may regulate cell......beta1 integrin- and Rho kinase-dependent focal adhesion and stress fibre formation, suggesting that the activation status of alpha9beta1 integrin was altered. The effect of manganese ions in promoting focal adhesion formation was reproduced by beta1 integrin activating antibody. The alpha9beta1...

  7. Investigating the role of Integrin Linked Kinase in mammary epithelial cell differentiation

    Rooney, Nicholas

    2014-01-01

    Epithelial cell adhesion to the surrounding extracellular matrix (ECM) is necessary for their proper behaviour and function. During pregnancy and lactation mammary epithelial cells (MECs) require signals imparted by specific β1 integrin-laminin interactions for their functional differentiation in response to Prolactin (Prl) and for the correct formation of polarised secretory acini. Downstream of β1 integrin (β1Itg), the scaffold protein Integrin Linked Kinase (ILK) has been identified as the...

  8. The SYK tyrosine kinase: a crucial player in diverse biological functions

    Mócsai, Attila; Ruland, Jürgen; Tybulewicz, Victor L.J.

    2010-01-01

    Spleen tyrosine kinase (SYK) has been known to relay adaptive immune receptor signalling. However, recent reports indicate that SYK also mediates other, unexpectedly diverse biological functions including cellular adhesion, innate immune recognition, osteoclast maturation, platelet activation and vascular development. SYK is activated by C-type lectins and integrins, and activates novel targets including the CARD9/CARMA1–BCL10–MALT1 pathway and the NLRP3 inflammasome. Drosophila studies indic...

  9. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    Shirtcliffe, Neil; McHale, Glen; Newton, Michael

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and th...

  10. MAP Kinases in Immune Responses

    Yongliang Zhang; Chen Dong

    2005-01-01

    MAP kinases are evolutionarily conserved signaling regulators from budding yeast to mammals and play essential roles in both innate and adaptive immune responses. There are three main families of MAPKs in mammals. Each of them has its own activators, inactivators, substrates and scaffolds, which altogether form a fine signaling network in response to different extracellular or intracellular stimulation. In this review, we summarize recent advances in understanding of the regulation of MAP kinases and the roles of MAP kinases in innate and adaptive immune responses.

  11. C-terminal Src kinase-mediated EPIYA phosphorylation of Pragmin creates a feed-forward C-terminal Src kinase activation loop that promotes cell motility.

    Senda, Yoshie; Murata-Kamiya, Naoko; Hatakeyama, Masanori

    2016-07-01

    Pragmin is one of the few mammalian proteins containing the Glu-Pro-Ile-Tyr-Ala (EPIYA) tyrosine-phosphorylation motif that was originally discovered in the Helicobacter pylori CagA oncoprotein. Following delivery into gastric epithelial cells by type IV secretion and subsequent tyrosine phosphorylation at the EPIYA motifs, CagA serves as an oncogenic scaffold/adaptor that promiscuously interacts with SH2 domain-containing mammalian proteins such as the Src homology 2 (SH2) domain-containing protein tyrosine phosphatase-2 (SHP2) and the C-terminal Src kinase (Csk), a negative regulator of Src family kinases. Like CagA, Pragmin also forms a physical complex with Csk. In the present study, we found that Pragmin directly binds to Csk by the tyrosine-phosphorylated EPIYA motif. The complex formation potentiates kinase activity of Csk, which in turn phosphorylates Pragmin on tyrosine-238 (Y238), Y343, and Y391. As Y391 of Pragmin comprises the EPIYA motif, Pragmin-Csk interaction creates a feed-forward regulatory loop of Csk activation. Together with the finding that Pragmin and Csk are colocalized to focal adhesions, these observations indicate that the Pragmin-Csk interaction, triggered by Pragmin EPIYA phosphorylation, robustly stimulates the kinase activity of Csk at focal adhesions, which direct cell-matrix adhesion that regulates cell morphology and cell motility. As a consequence, expression of Pragmin and/or Csk in epithelial cells induces an elongated cell shape with elevated cell scattering in a manner that is mutually dependent on Pragmin and Csk. Deregulation of the Pragmin-Csk axis may therefore induce aberrant cell migration that contributes to tumor invasion and metastasis. PMID:27116701

  12. Experimental Investigation of Optimal Adhesion of Mushroomlike Elastomer Microfibrillar Adhesives.

    Marvi, Hamidreza; Song, Sukho; Sitti, Metin

    2015-09-22

    Optimal fiber designs for the maximal pull-off force have been indispensable for increasing the attachment performance of recently introduced gecko-inspired reversible micro/nanofibrillar adhesives. There are several theoretical studies on such optimal designs; however, due to the lack of three-dimensional (3D) fabrication techniques that can fabricate such optimal designs in 3D, there have not been many experimental investigations on this challenge. In this study, we benefitted from recent advances in two-photon lithography techniques to fabricate mushroomlike polyurethane elastomer fibers with different aspect ratios of tip to stalk diameter (β) and tip wedge angles (θ) to investigate the effect of these two parameters on the pull-off force. We found similar trends to those predicted theoretically. We found that β has an impact on the slope of the force-displacement curve while both β and θ play a role in the stress distribution and crack propagation. We found that these effects are coupled and the optimal set of parameters also depends on the fiber material. This is the first experimental verification of such optimal designs proposed for mushroomlike microfibers. This experimental approach could be used to evaluate a wide range of complex microstructured adhesive designs suggested in the literature and optimize them. PMID:26322396

  13. Synaptic Cell Adhesion Molecules in Alzheimer's Disease

    Leshchyns'ka, Iryna

    2016-01-01

    Alzheimer's disease (AD) is a neurodegenerative brain disorder associated with the loss of synapses between neurons in the brain. Synaptic cell adhesion molecules are cell surface glycoproteins which are expressed at the synaptic plasma membranes of neurons. These proteins play key roles in formation and maintenance of synapses and regulation of synaptic plasticity. Genetic studies and biochemical analysis of the human brain tissue, cerebrospinal fluid, and sera from AD patients indicate that levels and function of synaptic cell adhesion molecules are affected in AD. Synaptic cell adhesion molecules interact with Aβ, a peptide accumulating in AD brains, which affects their expression and synaptic localization. Synaptic cell adhesion molecules also regulate the production of Aβ via interaction with the key enzymes involved in Aβ formation. Aβ-dependent changes in synaptic adhesion affect the function and integrity of synapses suggesting that alterations in synaptic adhesion play key roles in the disruption of neuronal networks in AD. PMID:27242933

  14. The Rheological Property of Potato Starch Adhesives

    Junjun Liu

    2014-02-01

    Full Text Available The main goal of this study was to use potato starch in the production of environmentally sound adhesives. ‘Three-formaldehyde glue’ pollutes the environment and harms to human health strongly, which widely used for wood-based panels preparation. Environment-friendly potato starch adhesives were prepared using method of oxidation-gelatinization, insteading of the three formaldehyde glue. The effects of the quality ratio of starch and water, temperature and shear rate on the apparent viscosity of the adhesive were studied. The rheological eigenvalue of apparent viscosity was studied through nonlinear regression. The results showed that the apparent viscosity of potato starch adhesives decreased with the increasing of temperature; the apparent viscosity decreased slowly with the increasing of rotor speed; the phenomenon of shear thinning appeared within potato starch adhesives which was pseudo-plastic fluids. Potato starch adhesives with characteristics of non-toxic, no smell and pollution could be applied in interior and upscale packaging.

  15. Lignin-Furfural Based Adhesives

    Prajakta Dongre; Mark Driscoll; Thomas Amidon; Biljana Bujanovic

    2015-01-01

    Lignin recovered from the hot-water extract of sugar maple (Acer saccharum) is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF) resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR) analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC). The effect of pH (0.3, 0.65 and 1), ex situ furfural, and curing conditions on the tensile properties of a...

  16. Lignin-Furfural Based Adhesives

    Prajakta Dongre; Mark Driscoll; Thomas Amidon; Biljana Bujanovic

    2015-01-01

    Lignin recovered from the hot-water extract of sugar maple ( Acer saccharum ) is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF) resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR) analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC). The effect of pH (0.3, 0.65 and 1), ex situ furfural, and curing conditions on the tensile properties of...

  17. Syndecan-4 and focal adhesion function

    Woods, A; Couchman, J R

    2001-01-01

    Two groups have now reported the viability of mice that lack syndecan-4. These mice have wound healing/angiogenesis problems, and fibroblasts from these animals differ in adhesion and migration from normal. This is consistent with recent in vitro data indicating a need for signaling via syndecan-4...... for focal adhesion formation, and reports that overexpression of proteins that bind syndecan-4 can modify cell adhesion and migration....

  18. Tuning the kinetics of cadherin adhesion

    Sivasankar, Sanjeevi

    2013-01-01

    Cadherins are Ca2+ dependent cell-cell adhesion proteins that maintain the structural integrity of the epidermis; their principle function is to resist mechanical force. This review summarizes the biophysical mechanisms by which classical cadherins tune adhesion and withstand mechanical stress. We first relate the structure of classical cadherins to their equilibrium binding properties. We then review the role of mechanical perturbations in tuning the kinetics of cadherin adhesion. In particu...

  19. Factors influencing bacterial adhesion to contact lenses

    Dutta, Debarun; Cole, Nerida; Willcox, Mark

    2012-01-01

    The process of any contact lens related keratitis generally starts with the adhesion of opportunistic pathogens to contact lens surface. This article focuses on identifying the factors which have been reported to affect bacterial adhesion to contact lenses. Adhesion to lenses differs between various genera/species/strains of bacteria. Pseudomonas aeruginosa, which is the predominant causative organism, adheres in the highest numbers to both hydrogel and silicone hydrogel lenses in vitro. The ...

  20. Dancing with the dead: Eph receptors and their kinase-null partners.

    Truitt, Luke; Freywald, Andrew

    2011-04-01

    Eph receptor tyrosine kinases and their ligands, ephrins, are membrane proteins coordinating a wide range of biological functions both in developing embryos and in adult multicellular organisms. Numerous studies have implicated Eph receptors in the induction of opposing responses, including cell adhesion or repulsion, support or inhibition of cell proliferation and cell migration, and progression or suppression of multiple malignancies. Similar to other receptor tyrosine kinases, Eph receptors rely on their ability to catalyze tyrosine phosphorylation for signal transduction. Interestingly, however, Eph receptors also actively utilize three kinase-deficient receptor tyrosine kinases, EphB6, EphA10, and Ryk, in their signaling network. The accumulating evidence suggests that the unusual flexibility of the Eph family, allowing it to initiate antagonistic responses, might be partially explained by the influence of the kinase-dead participants and that the exact outcome of an Eph-mediated action is likely to be defined by the balance between the signaling of catalytically potent and catalytically null receptors. We discuss in this minireview the emerging functions of the kinase-dead EphB6, EphA10, and Ryk receptors both in normal biological responses and in malignancy, and analyze currently available information related to the molecular mechanisms of their action in the context of the Eph family. PMID:21455264

  1. Improving controllable adhesion on both rough and smooth surfaces with a hybrid electrostatic/gecko-like adhesive

    Ruffatto, Donald; Parness, Aaron; Spenko, Matthew

    2014-01-01

    This paper describes a novel, controllable adhesive that combines the benefits of electrostatic adhesives with gecko-like directional dry adhesives. When working in combination, the two technologies create a positive feedback cycle whose adhesion, depending on the surface type, is often greater than the sum of its parts. The directional dry adhesive brings the electrostatic adhesive closer to the surface, increasing its effect. Similarly, the electrostatic adhesion helps engage more of the di...

  2. Isolation of chloroplastic phosphoglycerate kinase

    Macioszek, J.; Anderson, L.E. (Univ. of Illinois, Chicago (USA)); Anderson, J.B. (Pennsylvania State Univ., University Park (USA))

    1990-09-01

    We report here a method for the isolation of high specific activity phosphoglycerate kinase (EC 2.7.2.3) from chloroplasts. The enzyme has been purified over 200-fold from pea (Pisum sativum L.) stromal extracts to apparent homogeneity with 23% recovery. Negative cooperativity is observed with the two enzyme phosphoglycerate kinase/glyceraldehyde-3-P dehydrogenase (EC 1.2.1.13) couple restored from the purified enzymes when NADPH is the reducing pyridine nucleotide, consistent with earlier results obtained with crude chloroplastic extracts. Michaelis Menten kinetics are observed when 3-phosphoglycerate is held constant and phosphoglycerate kinase is varied, which suggests that phosphoglycerate kinase-bound 1,3-bisphosphoglycerate may be the preferred substrate for glyceraldehyde-3-P dehydrogenase in the chloroplast.

  3. Protein Crystals of Raf Kinase

    1995-01-01

    This image shows crystals of the protein raf kinase grown on Earth (photo a) and on USML-2 (photo b). The space-grown crystals are an order of magnitude larger. Principal Investigator: Dan Carter of New Century Pharmaceuticals

  4. Nucleation and growth of cadherin adhesions

    Cell-cell contact formation relies on the recruitment of cadherin molecules and their anchoring to actin. However, the precise chronology of events from initial cadherin trans-interactions to adhesion strengthening is unclear, in part due to the lack of access to the distribution of cadherins within adhesion zones. Using N-cadherin expressing cells interacting with N-cadherin coated surfaces, we characterized the formation of cadherin adhesions at the ventral cell surface. TIRF and RIC microscopies revealed streak-like accumulations of cadherin along actin fibers. FRAP analysis indicated that engaged cadherins display a slow turnover at equilibrium, compatible with a continuous addition and removal of cadherin molecules within the adhesive contact. Association of cadherin cytoplasmic tail to actin as well as actin cables and myosin II activity are required for the formation and maintenance of cadherin adhesions. Using time lapse microscopy we deciphered how cadherin adhesions form and grow. As lamellipodia protrude, cadherin foci stochastically formed a few microns away from the cell margin. Neo-formed foci coalesced aligned and coalesced with preformed foci either by rearward sliding or gap filling to form cadherin adhesions. Foci experienced collapse at the rear of cadherin adhesions. Based on these results, we present a model for the nucleation, directional growth and shrinkage of cadherin adhesions

  5. GIT2 represses Crk- and Rac1-regulated cell spreading and Cdc42-mediated focal adhesion turnover

    Frank, Scott R.; Adelstein, Molly R; Hansen, Steen H.

    2006-01-01

    G protein-coupled receptor kinase interactors (GITs) regulate focal adhesion (FA) turnover, cell spreading, and motility through direct interaction with paxillin and the Rac-exchange factor Pak-interacting exchange factor β (βPIX). However, it is not clear whether GITs function to activate or repress motility or if the predominant GIT forms, GIT1 and GIT2, serve distinct or redundant roles. Here we demonstrate an obligatory role for endogenous GIT2 in repression of lamellipodial extension and...

  6. Design and fabrication of polymer based dry adhesives inspired by the gecko adhesive system

    Jin, Kejia

    There has been significant interest in developing dry adhesives mimicking the gecko adhesive system, which offers several advantages compared to conventional pressure sensitive adhesives. Specifically, gecko adhesive pads have anisotropic adhesion properties: the adhesive pads (spatulae) stick strongly when sheared in one direction but are non-adherent when sheared in the opposite direction. This anisotropy property is attributed to the complex topography of the array of fine tilted and curved columnar structures (setae) that bear the spatulae. In this thesis, easy, scalable methods, relying on conventional and unconventional techniques are presented to incorporate tilt in the fabrication of synthetic polymer-based dry adhesives mimicking the gecko adhesive system, which provide anisotropic adhesion properties. In the first part of the study, the anisotropic adhesion and friction properties of samples with various tilt angles to test the validity of a nanoscale tape-peeling model of spatular function are measured. Consistent with the Peel Zone model, samples with lower tilt angles yielded larger adhesion forces. Contact mechanics of the synthetic array were highly anisotropic, consistent with the frictional adhesion model and gecko-like. Based on the original design, a new design of gecko-like dry adhesives was developed which showed superior tribological properties and furthermore showed anisotropic adhesive properties without the need for tilt in the structures. These adhesives can be used to reversibly suspend weights from vertical surfaces (e.g., walls) and, for the first time to our knowledge, horizontal surfaces (e.g., ceilings) by simultaneously and judiciously activating anisotropic friction and adhesion forces. Furthermore, adhesion properties between artificial gecko-inspired dry adhesives and rough substrates with varying roughness are studied. The results suggest that both adhesion and friction forces on a rough substrate depends significantly on the

  7. Metaphorical perceptions of pre-service teachers in related to faculty of education: Asample of Kocaeli University Faculty of EducationÖğretmen adaylarının eğitim fakültesine ilişkin metaforik algıları: Kocaeli Üniversitesi Eğitim Fakültesi örneği

    Tuğba Konaklı

    2013-07-01

    Disappointment and sadness” and “Reserving diversity”. Also ıt has been determined that there is a significant difference between metaphors according to class level and preservice teachers’ departments. According to the study results, creating educational environments for preservice teachers to express themselves freely, guidance studies to support their self efficiency and to reduce exam anxiety can be suggested. ÖzetBu araştırmada öğretmen adaylarının öğrenim görmekte oldukları eğitim fakültesine ilişkin sahip oldukları metaforların belirlenmesi amaçlanmıştır. Bu genel amaç çerçevesinde eğitim fakültesine ilişkin metaforlardan oluşturulan kavramsal kategorilerim, öğretmen adaylarının sınıf düzeylerine ve öğrenim gördükleri bölüme göre farklılık gösterip göstermediği incelenmiştir. Olgubilim deseninde tasarlanan araştırmanın çalışma grubunu, 2011-2012 öğretim yılı Bahar döneminde I. öğretimde öğrenim görmekte olan 420 1. ve 4. sınıf öğretmen adayı oluşturmuştur. Çalışma grubuna Kocaeli Üniversitesi Eğitim Fakültesi, Fen Bilgisi Öğretmenliği, Matematik Öğretmenliği, Sınıf Öğretmenliği, Okul Öncesi Öğretmenliği, İngilizce Öğretmenliği, Türkçe Öğretmenliği, Rehberlik ve Psikolojik Danışmanlık Bölümü öğrencileri dahil edilmiştir. Öğretmen adaylarının eğitim fakültesine ilişkin metaforlarını saptamak amacıyla “Öğrenim görmekte olduğum eğitim fakültesi……....gibidir; çünkü,……” cümlesinin yazılı olduğu formlar dağıtılmıştır. Elde edilen metaforların analizi ve yorumlanması sürecinde adlandırma, tasnif etme, örnek metafor derleme ve kategori oluşturma aşamaları takip edilmiştir. Verilerin analizinde SPSS ve Nvivo nitel veri analizi programından yararlanılmıştır. Çalışma grubunu oluşturan 420 öğretmen adayından 55 öğretmen adayının formları bu aşamalara dayalı olarak elenmiştir. 365 öğretmen aday

  8. Quantal concept of T-cell activation: adhesion domains as immunological synapses

    Sackmann, Erich

    2011-06-01

    Adhesion micro-domains (ADs) formed during encounters of lymphocytes with antigen-presenting cells (APC) mediate the genetic expression of quanta of cytokines interleukin-2 (IL-2). The IL-2-induced activation of IL-2 receptors promotes the stepwise progression of the T-cells through the cell cycle, hence their name, immunological synapses. The ADs form short-lived reaction centres controlling the recruitment of activators of the biochemical pathway (the kinases Lck and ZAP) while preventing the access of inhibitors (phosphatase CD45) through steric repulsion forces. CD45 acts as the generator of adhesion domains and, through its role as a spacer protein, also as the promoter of the reaction. In a second phase of T-cell-APC encounters, long-lived global reaction spaces (called supramolecular activation complexes (SMAC)) form by talin-mediated binding of the T-cell integrin (LFA-1) to the counter-receptor ICAM-1, resulting in the formation of ring-like tight adhesion zones (peripheral SMAC). The ADs move to the centre of the intercellular adhesion zone forming the central SMAC, which serve in the recycling of the AD. We propose that cell stimulation is triggered by integrating the effect evoked by the short-lived adhesion domains. Similar global reaction platforms are formed by killer cells to destruct APC. We present a testable mechanical model showing that global reaction spaces (SMAC or dome-like contacts between cytotoxic cells and APC) form by self-organization through delayed activation of the integrin-binding affinity and stabilization of the adhesion zones by F-actin recruitment. The mechanical stability and the polarization of the adhering T-cells are mediated by microtubule-actin cross-talk.

  9. Quantal concept of T-cell activation: adhesion domains as immunological synapses

    Sackmann, Erich, E-mail: sackmann@ph.tum.de [Physics Department E22, Technical University Munich, D-85748 Garching (Germany)

    2011-06-15

    Adhesion micro-domains (ADs) formed during encounters of lymphocytes with antigen-presenting cells (APC) mediate the genetic expression of quanta of cytokines interleukin-2 (IL-2). The IL-2-induced activation of IL-2 receptors promotes the stepwise progression of the T-cells through the cell cycle, hence their name, immunological synapses. The ADs form short-lived reaction centres controlling the recruitment of activators of the biochemical pathway (the kinases Lck and ZAP) while preventing the access of inhibitors (phosphatase CD45) through steric repulsion forces. CD45 acts as the generator of adhesion domains and, through its role as a spacer protein, also as the promoter of the reaction. In a second phase of T-cell-APC encounters, long-lived global reaction spaces (called supramolecular activation complexes (SMAC)) form by talin-mediated binding of the T-cell integrin (LFA-1) to the counter-receptor ICAM-1, resulting in the formation of ring-like tight adhesion zones (peripheral SMAC). The ADs move to the centre of the intercellular adhesion zone forming the central SMAC, which serve in the recycling of the AD. We propose that cell stimulation is triggered by integrating the effect evoked by the short-lived adhesion domains. Similar global reaction platforms are formed by killer cells to destruct APC. We present a testable mechanical model showing that global reaction spaces (SMAC or dome-like contacts between cytotoxic cells and APC) form by self-organization through delayed activation of the integrin-binding affinity and stabilization of the adhesion zones by F-actin recruitment. The mechanical stability and the polarization of the adhering T-cells are mediated by microtubule-actin cross-talk.

  10. Focal adhesions and cell-matrix interactions

    Woods, A; Couchman, J R

    1988-01-01

    Focal adhesions are areas of cell surfaces where specializations of cytoskeletal, membrane and extracellular components combine to produce stable cell-matrix interactions. The morphology of these adhesions and the components identified in them are discussed together with possible mechanisms of...

  11. Synthesis of melamine-glucose resin adhesive

    CHEN; Shuanhu; ZHANG; Lei

    2005-01-01

    The synthesis of a novel melamine-glucose adhesive that is similar to urea-formaldehyde adhesive is reported in this paper. The conditions of synthesis, such as the initial pH, the quantity of catalyst, the temperature of reaction, the percentage of each reactant and the time of reaction, were optimized by using the orthogonal experimental method.

  12. Adhesion force studies of nanofibers and nanoparticles.

    Xing, Malcolm; Zhong, Wen; Xu, Xiuling; Thomson, Douglas

    2010-07-20

    Surface adhesion between nanofibers and nanoparticles has attracted attention for potential biomedical applications, but the measurement has not been reported. Adhesion forces were measured using a polystyrene (PS) nanoparticle attached to an atomic force microscopy (AFM) tip/probe. Electrospun PS nanofibers of different diameters were tapped with the probe to study the effect of fiber diameters on adhesion force. Both AFM experiments and numerical models suggest that the adhesion force increases with increased fiber diameters. Numerical models further demonstrated that local deformation of the fiber surface, including the flattening of surface asperities and the nanofiber wrapping around the particle during contact, may have a significant impact on the adhesion force. The adhesion forces are in the order of 100 nN, much smaller than the adhesion forces of the gecko foot hair, but much larger than that of the receptor-ligand pair, antibody-antigen pair, and single-stranded DNA from a substrate. Adhesion forces of nanofibers with roughness were predicted by numerical analysis. This study is expected to provide approaches and information useful in the design of nanomedicine and scaffold based on nanofibers for tissue engineering and regenerative medicine. PMID:20552953

  13. Adhesion Between Poly(dimethylsiloxane) Layers

    Yu, Liyun; Daugaard, Anders Egede; Skov, Anne Ladegaard

    Different adhesion methods of poly(dimethylsiloxane) (PDMS) layers were studied with respect to adhesional force and the resulting rheology of the two-layered PDMS films were investigated. The role of adhesion between PDMS layers on the performances of two-layer structures was studied with peel...

  14. Mechanisms of temporary adhesion in benthic animals

    Dodou, D.; Breedveld, P.; Winter, J.C.F.; Dankelman, J.; Leeuwen, van J.L.

    2011-01-01

    Adhesive systems are ubiquitous in benthic animals and play a key role in diverse functions such as locomotion, food capture, mating, burrow building, and defence. For benthic animals that release adhesives, surface and material properties and external morphology have received little attention compa

  15. Evaluation of progestogens for postoperative adhesion prevention.

    Beauchamp, P J; Quigley, M M; Held, B

    1984-10-01

    Progesterone (P) has been shown to have potent antiinflammatory and immunosuppressive properties. Previous reports have suggested that the use of P decreases postoperative adhesion formation. To further evaluate the role of pharmacologic doses of progestogens in adhesion prevention, 42 mature New Zealand White rabbits underwent standardized injuries to the uterine horns, fimbriae, and pelvic peritoneum and received one of six treatments. Group S had intraperitoneal placement of normal saline (0.9%); group H received intraperitoneal placement of 32% dextran 70; group IM-P received intramuscular P-in-oil 10 days before and after laparotomy in addition to intraperitoneal saline; group IP-P had intraperitoneal placement of an aqueous P suspension; group DP received medroxyprogesterone acetate intraperitoneally; and group C received no intramuscular or intraperitoneal adhesion-prevention agents. The animals were sacrificed 6 weeks after laparotomy, and the adhesions were scored. Intraperitoneal saline (group S) significantly reduced the amount of adhesions when compared with the control group (C) (P less than 0.05). No significant difference was observed when group S was compared with group H. Intramuscular P added to saline (group IM-P) did not cause further reduction in adhesions when compared with group S. Both group IP-P and group DP had more adhesions than did group S (P less than 0.01). These data fail to support previous claims regarding adhesion prevention by the use of locally or parenterally administered progestogens. PMID:6237937

  16. Recurrent spinal adhesive arachnoiditis: a case report

    James Pitágoras de Mattos

    1988-03-01

    Full Text Available Spinal adhesive arachnoiditis is not an uncommon disease, usually having a monophasic course. We studied an atypical patient with recurrent spinal adhesive arachnoiditis nine years after intrathecal anesthesia and the first attack of the disease. Also noteworthy was the favorable evolution after surgery.

  17. Syndecans: synergistic activators of cell adhesion

    Woods, A; Couchman, J R

    1998-01-01

    Cell-surface proteoglycans participate in cell adhesion, growth-factor signalling, lipase activity and anticoagulation. Until recently, only the roles of the glycosaminoglycan chains were investigated. Now, with molecular characterization of several core proteins, the roles of each individual...... molecules modulating integrin-based adhesion....

  18. Adhesion mechanism of a gecko-inspired oblique structure with an adhesive tip for asymmetric detachment

    Sekiguchi, Yu; Takahashi, Kunio; Sato, Chiaki

    2015-12-01

    An adhesion model of an oblique structure with an adhesive tip is proposed by considering a limiting stress for adhesion to describe the detachment mechanism of gecko foot hairs. When a force is applied to the root of the oblique structure, normal and shear stresses are generated at contact and the adhesive tip is detached from the surface when reaching the limiting stress. An adhesion criterion that considers both the normal and shear stresses is introduced, and the asymmetric detachment of the oblique structure is theoretically investigated. In addition, oblique beam array structures are manufactured, and an inclination effect of the structure on the asymmetric detachment is experimentally verified.

  19. Heparan sulfate chain valency controls syndecan-4 function in cell adhesion

    Gopal, Sandeep; Bober, Adam; Whiteford, James R; Multhaupt, Hinke A B; Yoneda, Atsuko; Couchman, John R

    2010-01-01

    , clustering of one-chain syndecan-4 forms with antibodies overcame the block, indicating that valency of interactions with ligands is a key component of syndecan-4 function. Measurements of focal contact/adhesion size and focal adhesion kinase phosphorylation correlated with syndecan-4 status and alpha...... the core protein cytoplasmic domain, though not interactions with PDZ proteins. A second key requirement is multiple heparan sulfate chains. Mutant syndecan-4 with no chains, or only one chain, failed to restore the wild type phenotype, while those expressing two or three were competent. However......-smooth muscle actin organization, being reduced where syndecan-4 function was compromised by a lack of multiple heparan sulfate chains....

  20. Critical length scale controls adhesive wear mechanisms

    Aghababaei, Ramin; Warner, Derek H.; Molinari, Jean-Francois

    2016-06-01

    The adhesive wear process remains one of the least understood areas of mechanics. While it has long been established that adhesive wear is a direct result of contacting surface asperities, an agreed upon understanding of how contacting asperities lead to wear debris particle has remained elusive. This has restricted adhesive wear prediction to empirical models with limited transferability. Here we show that discrepant observations and predictions of two distinct adhesive wear mechanisms can be reconciled into a unified framework. Using atomistic simulations with model interatomic potentials, we reveal a transition in the asperity wear mechanism when contact junctions fall below a critical length scale. A simple analytic model is formulated to predict the transition in both the simulation results and experiments. This new understanding may help expand use of computer modelling to explore adhesive wear processes and to advance physics-based wear laws without empirical coefficients.

  1. Coating to enhance metal-polymer adhesion

    Parthasarathi, A.; Mahulikar, D. [Olin Metals Research Laboratories, New Haven, CT (United States)

    1996-12-31

    An ultra-thin electroplated coating has been developed to enhance adhesion of metals to polymers. The coating was developed for microelectronic packaging applications where it greatly improves adhesion of metal leadframes to plastic molding compounds. Recent tests show that the coating enhances adhesion of different metals to other types of adhesives as well and may thus have wider applicability. Results of adhesion tests with this coating, as well as its other characteristics such as corrosion resistance, are discussed. The coating is a very thin transparent electroplated coating containing zinc and chromium. It has been found to be effective on a variety of metal surfaces including copper alloys, Fe-Ni alloys, Al alloys, stainless steel, silver, nickel, Pd/Ni and Ni-Sn. Contact resistance measurements show that the coating has little or no effect on electrical resistivity.

  2. Dynamic analysis of two adhesively bonded rods

    Kenneth L. Kuttler

    2009-07-01

    Full Text Available This work presents two models for the dynamic analysis of two rods that are adhesively bonded. The first model assumes that the adhesive is an elasto-plastic material and that complete debonding occurs when the stress reaches the yield limit. In the second model the degradation of the adhesive is described by the introduction of material damage. Failure occurs when the material is completely damaged, or the damage reaches a critical floor value. Both models are analyzed and the existence of a weak solution is established for the model with damage. In the quasistatic case, a new condition for adhesion is found as the limit of the adhesive thickness tends to zero.

  3. Adhesives for orthodontic bracket bonding

    Déborah Daniella Diniz Fonseca

    2010-04-01

    Full Text Available The advent of acid etching, introduced by Buonocore in 1955, brought the possibility of bonding between the bracket base and enamel, contributing to more esthetic and conservative orthodontics. This direct bracket bonding technique has brought benefits such as reduced cost and time in performing the treatment, as well as making it easier to perform oral hygiene. The aim of this study was to conduct a survey of published studies on orthodontic bracket bonding to dental enamel. It was verified that resin composites and glass ionomer are the most studied and researched materials for this purpose. Resin-modified glass ionomer, with its biocompatibility, capacity of releasing fluoride and no need for acid etching on the tooth structure, has become increasingly popular among dentists. However, due to the esthetic and mechanical properties of light polymerizable resin composite, it continues to be one of the adhesives of choice in the bracket bonding technique and its use is widely disseminated.

  4. Multibody simulation of adhesion pili

    Zakrisson, Johan; Servin, Martin; Axner, Ove; Lacoursiere, Claude; Andersson, Magnus

    2014-01-01

    We present a coarse grained rigid multibody model of a subunit assembled helix-like polymer, e.g., adhesion pili expressed by bacteria, that is capable of describing the polymers force-extension response. With building blocks representing individual subunits the model appropriately describes the complex behavior of pili expressed by the gram-negative uropathogenic Escherichia coli bacteria under the action of an external force. Numerical simulations show that the dynamics of the model, which include both the effects of unwinding and rewinding, are in good quantitative agreement with the characteristic force-extension response as observed experimentally for type 1 and P pili. By tuning the model, it is also possible to reproduce the force-extension response in the presence of anti-shaft antibodies, which dramatically changes the mechanical properties. Thus, the model and the results in this work give enhanced understanding of how a pilus unwinds under action of external forces and provide new perspective of th...

  5. Surface tension driven shaping of adhesive microfluidic channel walls

    Janting, Jakob; Storm, Elisabeth K.; Geschke, Oliver

    2005-01-01

    The feasibility of making microfluidic channels with different wall geometries using adjacent lines of dispensed adhesive between substrates has been studied. Important parameters for the geometry have been identified to be: surface tension (adhesive / substrates), adhesive viscosity / thixotropy...

  6. Videography supported adhesion, and proliferation behavior of MG-63 osteoblastic cells on 2.5D titania nanotube matrices.

    Manurung, Robeth Viktoria; Fu, Pei-Wen; Chu, Yeh-Shiu; Lo, Chun-Min; Chattopadhyay, Surojit

    2016-04-01

    Human osteosarcoma cells MG-63 were cultured on anodically etched titania nanotubes (TiO2 NT), with diameters ranging from 40-100 nm, to study the correlations between cell proliferation and adhesion on the 2.5 dimensional (2.5D) extracellular matrix (ECM). Unlike other reports, mostly based on mouse stem cells, and 2D cell culture, our studies indicate that the 2.5D NT promote higher proliferation and activity, but less 2D adhesion. Proliferation of the MG-63 cells was significantly higher in the NTs, the best being the 70 nm diameter sample, compared to planar titania (control). This is consistent with previous studies. However, cellular adhesion was stronger on TiO2 NT with increasing diameter, and highest on the control as obtained from shear stress measurement, paxilin imaging, and western blot measurements probing focal adhesion kinase, p130 CAS, and extracellular-regulated kinase, in addition to cell morphology imaging by fluorescence microscopy. We provide direct videography of cell migration, and cell speed data indicating faster filopodial activity on the TiO2 NT surfaces having lower adhesion. This evidence was not available previously. The NT matrices promote cells with smaller surface area, because of less 2D stretching. In contrast, on comparatively planar 2D-like surfaces uniaxial stretching of the cell body with strong anchoring of the filopodia, resulted in larger cell surface area, and demonstrated stronger adhesion. The difference in the results, with those previously published, may be generally attributed to, among others, the use of mouse stem cells (human osteosarcoma used here), and unannealed as-grown TiO2 NTs used previously (annealed ECMs used here). © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 842-852, 2016. PMID:26650774

  7. Loss of Cell-Substrate Adhesion Leads to Periodic Shape Oscillations in Fibroblasts

    Pullarkat, P A

    2006-01-01

    We report the phenomenon of periodic shape oscillations occurring in 3T3 fibroblasts merely as a consequence of a loss of cell-substrate adhesion. The oscillatory behavior can last many hours at a constant frequency, and can be switched off and on using chemical agents. This robustness allows for the extraction of quantitative data using single cells. We demonstrate that the frequency of oscillations increases with increasing actomyosin contractility. Both the Myosin Light Chain Kinase as well as the Rho Kinase pathways are shown to operate during this process. Further, we reveal significant similarities between the oscillatory dynamics and the commonly observed phenomenon of blebbing. We show that both these processes ceases when extracellular calcium is depleted or when stretch activated calcium channels are blocked. This, along with the fact that these dynamical processes require actomyosin contactility points towards strong similarities in the respective mechanisms. Finally, we speculate on a possible mec...

  8. CCR9 interactions support ovarian cancer cell survival and resistance to cisplatin-induced apoptosis in a PI3K-dependent and FAK-independent fashion

    Johnson Erica L

    2010-06-01

    Full Text Available Abstract Background Cisplatin is more often used to treat ovarian cancer (OvCa, which provides modest survival advantage primarily due to chemo-resistance and up regulated anti-apoptotic machineries in OvCa cells. Therefore, targeting the mechanisms responsible for cisplatin resistance in OvCa cell may improve therapeutic outcomes. We have shown that ovarian cancer cells express CC chemokine receptor-9 (CCR9. Others have also shown that CCL25, the only natural ligand for CCR9, up regulates anti-apoptotic proteins in immature T lymphocytes. Hence, it is plausible that CCR9-mediated cell signals might be involved in OvCa cell survival and inhibition of cisplatin-induced apoptosis. In this study, we investigated the potential role and molecular mechanisms of CCR9-mediated inhibition of cisplatin-induced apoptosis in OvCa cells. Methods Cell proliferation, vibrant apoptosis, and TUNEL assays were performed with or without cisplatin treatment in presence or absence of CCL25 to determine the role of the CCR9-CCL25 axis in cisplatin resistance. In situ Fast Activated cell-based ELISA (FACE assays were performed to determine anti-apoptotic signaling molecules responsible for CCL25-CCR9 mediated survival. Results Our results show interactions between CCR9 and CCL25 increased anti-apoptotic signaling cascades in OvCa cells, which rescued cells from cisplatin-induced cell death. Specifically, CCL25-CCR9 interactions mediated Akt, activation as well as GSK-3β and FKHR phosphorylation in a PI3K-dependent and FAK-independent fashion. Conclusions Our results suggest the CCR9-CCL25 axis plays an important role in reducing cisplatin-induced apoptosis of OvCa cells.

  9. Surface wettability of plasma SiOx:H nanocoating-induced endothelial cells' migration and the associated FAK-Rho GTPases signalling pathways

    Shen, Yang; Wang, Guixue; Huang, Xianliang; Zhang, Qin; Wu, Jiang; Tang, Chaojun; Yu, Qingsong; Liu, Xiaoheng

    2011-01-01

    Vascular endothelial cell (EC) adhesion and migration are essential processes in re-endothelialization of implanted biomaterials. There is no clear relationship and mechanism between EC adhesion and migration behaviour on surfaces with varying wettabilities. As model substrates, plasma SiOx:H nanocoatings with well-controlled surface wettability (with water contact angles in the range of 98.5 ± 2.3° to 26.3 ± 4.0°) were used in this study to investigate the effects of surface wettability on c...

  10. Adhesion in ceramics and magnetic media

    Miyoshi, Kazuhisa

    1989-01-01

    When a ceramic is brought into contact with a metal or a polymeric material such as a magnetic medium, strong bonds form between the materials. For ceramic-to-metal contacts, adhesion and friction are strongly dependent on the ductility of the metals. Hardness of metals plays a much more important role in adhesion and friction than does the surface energy of metals. Adhesion, friction, surface energy, and hardness of a metal are all related to its Young's modulus and shear modulus, which have a marked dependence on the electron configuration of the metal. An increase in shear modulus results in a decrease in area of contact that is greater than the corresponding increase in surface energy (the fond energy) with shear modulus. Consequently, the adhesion and friction decrease with increasing shear modulus. For ceramics in contact with polymeric magnetic tapes, environment is extremely important. For example, a nitrogen environment reduces adhesion and friction when ferrite contacts polymeric tape, whereas a vacuum environment strengthens the ferrite-to-tape adhesion and increases friction. Adhesion and friction are strongly dependent on the particle loading of the tape. An increase in magnetic particle concentration increases the complex modulus of the tape, and a lower real area of contact and lower friction result.

  11. Dangling chain elastomers as repeatable fibrillar adhesives.

    Sitti, Metin; Cusick, Brian; Aksak, Burak; Nese, Alper; Lee, Hyung-il; Dong, Hongchen; Kowalewski, Tomasz; Matyjaszewski, Krzysztof

    2009-10-01

    This work reports on repeatable adhesive materials prepared by controlled grafting of dangling hetero chains from polymer elastomers. The dangling chain elastomer system was prepared by grafting poly(n-butyl acrylate) (PBA) chains from prefunctionalized polydimethylsiloxane (PDMS) elastomer networks using atom transfer radical polymerization. To study the effects of chain growth and network strain as they relate to network adhesion mechanics, various lengths of PBA chains with degree of polymerizations (DP) of 65, 281, 508, and 1200 were incorporated into the PDMS matrix. PBA chains with a DP value of 281 grafted from a flat PDMS substrate showed the highest (approximately 3.5-fold) enhancement of nano- and macroscale adhesion relative to a flat raw (ungrafted and not prefunctionalized) PDMS substrate. Moreover, to study the effect of PBA dangling chains on adhesion in fibrillar elastomer structures inspired by gecko foot hairs, a dip-transfer fabrication method was used to graft PBA chains with a DP value of 296 from the tip endings of mushroom-shaped PDMS micropillars. A PBA chain covered micropillar array showed macroscale adhesion enhancement up to approximately 7 times relative to the flat ungrafted prefunctionalized PDMS control substrate, showing additional nonoptimized approximately 2-fold adhesion enhancement due to fibrillar structuring and mushroom-shaped tip ending. These dangling hetero chains on elastomer micro-/nanofibrillar structures may provide a novel fabrication platform for multilength scale, repeatable, and high-strength fibrillar adhesives inspired by gecko foot hairs. PMID:20355863

  12. Adhesion property of epoxidized natural rubber (ENR-based adhesives containing calcium carbonate

    2008-06-01

    Full Text Available The adhesion property (i.e. viscosity, loop tack and peel strength of epoxidized natural rubber (ENR 25 and ENR 50 grade-based pressure-sensitive adhesive was studied in the presence of calcium carbonate. The range of calcium carbonate loaded was from 10 to 50 parts per hundred parts of rubber (phr. Coumarone-indene resin was used as the tackifier and its concentration was fixed at 80 phr. Toluene was chosen as the solvent throughout the investigation. The substrates (PET film/paper were coated with the adhesive using a SHEEN hand coater at a coating thickness of 60 µm. Viscosity of the adhesive was measured by a HAAKE Rotary Viscometer whereas loop tack and peel strength were determined by a Llyod Adhesion Tester operating at 30 cm/min. Results show that viscosity of ENR-based adhesives increases gradually with increase in calcium carbonate loading due to the concentration effect of the filler. However, for loop tack and peel strength, it passes through a maximum at 30 phr calcium carbonate, an observation which is attributed to the optimum wettability of adhesive on the substrate at this adhesive composition. ENR 25-based adhesive consistently exhibits higher adhesion property than ENR 50 for all calcium carbonate loadings studied.

  13. Adhesion of Dental Materials to Tooth Structure

    Mitra, Sumita B.

    2000-03-01

    The understanding and proper application of the principles of adhesion has brought forth a new paradigm in the realm of esthetic dentistry. Modern restorative tooth procedures can now conserve the remaining tooth-structure and also provide for the strengthening of the tooth. Adhesive restorative techniques call for the application and curing of the dental adhesive at the interface between the tooth tissue and the filling material. Hence the success of the restoration depends largely on the integrity of this interface. The mechanism of adhesion of the bonding materials to the dental hard tissue will be discussed in this paper. There are four main steps that occur during the application of the dental adhesive to the oral hard tissues: 1) The first step is the creation of a microstructure in the tooth enamel or dentin by means of an acidic material. This can be through the application of a separate etchant or can be accomplished in situ by the adhesive/primer. This agent has to be effective in removing or modifying the proteinaceous “smear” layer, which would otherwise act as a weak boundary layer on the surface to be bonded. 2) The primer/adhesive must then be able to wet and penetrate the microstructure created in the tooth. Since the surface energies of etched enamel and that of etched dentin are different finding one material to prime both types of dental tissues can be quite challenging. 3) The ionomer types of materials, particularly those that are carboxylate ion-containing, can chemically bond with the calcium ions of the hydroxyapatite mineral. 4) Polymerization in situ allows for micromechanical interlocking of the adhesive. The importance of having the right mechanical properties of the cured adhesive layer and its role in absorbing and dissipating stresses encountered by a restored tooth will also be discussed.

  14. Adhesion of actinomyces isolates to experimental pellicles.

    Steinberg, D; Kopec, L K; Bowen, W H

    1993-06-01

    The ability of oral bacteria to adhere to surfaces is associated with their pathogenicity. Actinomyces can adhere to pellicle and cells through extracellular fimbriae. Research on adhesion of actinomyces has been conducted with use of hydroxyapatite (HA) coated with mammalian-derived salivary constituents, whereas the bacterial-derived components of the acquired pellicle have been largely ignored. The influence of the cell-free bacterial enzyme, glucosyltransferase (GTF), on adhesion of human and rodent isolates of Actinomyces viscosus was examined. Cell-free GTF was adsorbed onto parotid saliva-coated hydroxyapatite (sHA). Next, A. viscosus was exposed to the pellicle following the synthesis of glucan formed in situ by GTF. Glucans formed on the pellicle served as binding sites for adhesion of a rodent strain of A. viscosus. Conversely, the presence of in situ glucans on sHA reduced the adhesion of human isolates of A. viscosus compared with their adhesion to sHA. Adhesion of the rodent strains may be facilitated through a dextran-binding protein, since the rodent strains aggregated in the presence of dextrans and mutan. The human isolates were not aggregated by dextran or mutan. Pellicle harboring A. viscosus rodent strains interfered with the subsequent adhesion of Streptococcus mutans to the bacterial-coated pellicle. In contrast, the adhesion of S. mutans to pellicle was not decreased when the pellicle was pre-exposed to a human isolate of A. viscosus. The experimental data suggest that human and the rodent isolates of A. viscosus have distinct glucan adhesion properties.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8496474

  15. Improving controllable adhesion on both rough and smooth surfaces with a hybrid electrostatic/gecko-like adhesive.

    Ruffatto, Donald; Parness, Aaron; Spenko, Matthew

    2014-04-01

    This paper describes a novel, controllable adhesive that combines the benefits of electrostatic adhesives with gecko-like directional dry adhesives. When working in combination, the two technologies create a positive feedback cycle whose adhesion, depending on the surface type, is often greater than the sum of its parts. The directional dry adhesive brings the electrostatic adhesive closer to the surface, increasing its effect. Similarly, the electrostatic adhesion helps engage more of the directional dry adhesive fibrillar structures, particularly on rough surfaces. This paper presents the new hybrid adhesive's manufacturing process and compares its performance to three other adhesive technologies manufactured using a similar process: reinforced PDMS, electrostatic and directional dry adhesion. Tests were performed on a set of ceramic tiles with varying roughness to quantify its effect on shear adhesive force. The relative effectiveness of the hybrid adhesive increases as the surface roughness is increased. Experimental data are also presented for different substrate materials to demonstrate the enhanced performance achieved with the hybrid adhesive. Results show that the hybrid adhesive provides up to 5.1× greater adhesion than the electrostatic adhesive or directional dry adhesive technologies alone. PMID:24451392

  16. The role of Src kinase in the biology and pathogenesis of Acanthamoeba castellanii

    Siddiqui Ruqaiyyah

    2012-06-01

    Full Text Available Abstract Background Acanthamoeba species are the causative agents of fatal granulomatous encephalitis in humans. Haematogenous spread is thought to be a primary step, followed by blood–brain barrier penetration, in the transmission of Acanthmaoeba into the central nervous system, but the associated molecular mechanisms remain unclear. Here, we evaluated the role of Src, a non-receptor protein tyrosine kinase in the biology and pathogenesis of Acanthamoeba. Methods Amoebistatic and amoebicidal assays were performed by incubating amoeba in the presence of Src kinase-selective inhibitor, PP2 (4-amino-5-(4-chlorophenyl-7-(t-butylpyrazolo[3,4-d]pyrimidine and its inactive analog, PP3 (4-amino-7-phenylpyrazolo[3,4-d]pyrimidine. Using this inhibitor, the role of Src kinase in A. castellanii interactions with Escherichia coli was determined. Zymographic assays were performed to study effects of Src kinase on extracellular proteolytic activities of A. castellanii. The human brain microvascular endothelial cells were used to determine the effects of Src kinase on A. castellanii adhesion to and cytotoxicity of host cells. Results Inhibition of Src kinase using a specific inhibitor, PP2 (4-amino-5-(4 chlorophenyl-7-(t-butylpyrazolo [3,4-d] pyrimidine but not its inactive analog, PP3 (4-amino-7-phenylpyrazolo[3,4-d] pyrimidine, had detrimental effects on the growth of A. castellanii (keratitis isolate, belonging to the T4 genotype. Interestingly, inhibition of Src kinase hampered the phagocytic ability of A. castellanii, as measured by the uptake of non-invasive bacteria, but, on the contrary, invasion by pathogenic bacteria was enhanced. Zymographic assays revealed that inhibition of Src kinases reduced extracellular protease activities of A. castellanii. Src kinase inhibition had no significant effect on A. castellanii binding to and cytotoxicity of primary human brain microvascular endothelial cells, which constitute the blood–brain barrier

  17. Mesalamine modulates intercellular adhesion through inhibition of p-21 activated kinase-1

    Khare, Vineeta; Lyakhovich, Alex; Dammann, Kyle; Lang, Michaela; Borgmann, Melanie; Tichy, Boris; Pospisilova, Sarka; Luciani, Gloria; Campregher, Christoph; Evstatiev, Rayko; Pflueger, Maren; Hundsberger, Harald; Gasche, Christoph

    2013-01-01

    Mesalamine (5-ASA) is widely used for the treatment of ulcerative colitis, a remitting condition characterized by chronic inflammation of the colon. Knowledge about the molecular and cellular targets of 5-ASA is limited and a clear understanding of its activity in intestinal homeostasis and interference with neoplastic progression is lacking. We sought to identify molecular pathways interfered by 5-ASA, using CRC cell lines with different genetic background. Microarray was performed for gene ...

  18. Oxidative and adhesive responses of human neutrophils to nitrovasodilators in vitro: the role of protein kinases

    Magdalena Klink

    2003-01-01

    Full Text Available Background: Sodium nitroprusside (SNP and molsidomine are used in the treatment of coronary heart disease. Since the neutrophils play a pathological role in ischaemic heart disease, it is important to understand the direct action of nitrovasodilators on their function.

  19. Phosphorylation of calcium/calmodulin-stimulated protein kinase II at T286 enhances invasion and migration of human breast cancer cells.

    Chi, Mengna; Evans, Hamish; Gilchrist, Jackson; Mayhew, Jack; Hoffman, Alexander; Pearsall, Elizabeth Ann; Jankowski, Helen; Brzozowski, Joshua Stephen; Skelding, Kathryn Anne

    2016-01-01

    Calcium/calmodulin-stimulated protein kinase II (CaMKII) is a multi-functional kinase that controls a range of cellular functions, including proliferation, differentiation and apoptosis. The biological properties of CaMKII are regulated by multi-site phosphorylation. However, the role that CaMKII phosphorylation plays in cancer cell metastasis has not been examined. We demonstrate herein that CaMKII expression and phosphorylation at T286 is increased in breast cancer when compared to normal breast tissue, and that increased CAMK2 mRNA is associated with poor breast cancer patient prognosis (worse overall and distant metastasis free survival). Additionally, we show that overexpression of WT, T286D and T286V forms of CaMKII in MDA-MB-231 and MCF-7 breast cancer cells increases invasion, migration and anchorage independent growth, and that overexpression of the T286D phosphomimic leads to a further increase in the invasive, migratory and anchorage independent growth capacity of these cells. Pharmacological inhibition of CaMKII decreases MDA-MB-231 migration and invasion. Furthermore, we demonstrate that overexpression of T286D, but not WT or T286V-CaMKII, leads to phosphorylation of FAK, STAT5a, and Akt. These results demonstrate a novel function for phosphorylation of CaMKII at T286 in the control of breast cancer metastasis, offering a promising target for the development of therapeutics to prevent breast cancer metastasis. PMID:27605043

  20. Protein kinase CK2 in human diseases

    Guerra, Barbara; Issinger, Olaf-Georg

    2008-01-01

    Protein kinase CK2 (formerly referred to as casein kinase II) is an evolutionary conserved, ubiquitous protein kinase. There are two paralog catalytic subunits, i.e. alpha (A1) and alpha' (A2). The alpha and alpha' subunits are linked to two beta subunits to produce a heterotetrameric structure....... The catalytic alpha subunits are distantly related to the CMGC subfamily of kinases, such as the Cdk kinases. There are some peculiarities associated with protein kinase CK2, which are not found with most other protein kinases: (i) the enzyme is constitutively active, (ii) it can use ATP and GTP and...... specifically target this protein kinase [10]. Since not all the aspects of what has been published on CK2 can be covered in this review, we would like to recommend the following reviews; (i) for general information on CK2 [11-18] and (ii) with a focus on aberrant CK2 [19-22]....

  1. Degradation of Activated Protein Kinases by Ubiquitination

    Lu, Zhimin; Hunter, Tony

    2009-01-01

    Protein kinases are important regulators of intracellular signal transduction pathways and play critical roles in diverse cellular functions. Once a protein kinase is activated, its activity is subsequently downregulated through a variety of mechanisms. Accumulating evidence indicates that the activation of protein kinases commonly initiates their downregulation via the ubiquitin/proteasome pathway. Failure to regulate protein kinase activity or expression levels can cause human diseases.

  2. Determinants of homodimerization specificity in histidine kinases

    Ashenberg, Orr; Rozen-Gagnon, Kathryn; Laub, Michael T; Keating, Amy E.

    2011-01-01

    Two-component signal transduction pathways consisting of a histidine kinase and a response regulator are used by prokaryotes to respond to diverse environmental and intracellular stimuli. Most species encode numerous paralogous histidine kinases that exhibit significant structural similarity. Yet in almost all known examples, histidine kinases are thought to function as homodimers. We investigated the molecular basis of dimerization specificity, focusing on the model histidine kinase EnvZ and...

  3. Puerarin activates endothelial nitric oxide synthase through estrogen receptor-dependent PI3-kinase and calcium-dependent AMP-activated protein kinase

    The cardioprotective properties of puerarin, a natural product, have been attributed to the endothelial nitric oxide synthase (eNOS)-mediated production of nitric oxide (NO) in EA.hy926 endothelial cells. However, the mechanism by which puerarin activates eNOS remains unclear. In this study, we sought to identify the intracellular pathways underlying eNOS activation by puerarin. Puerarin induced the activating phosphorylation of eNOS on Ser1177 and the production of NO in EA.hy926 cells. Puerarin-induced eNOS phosphorylation required estrogen receptor (ER)-mediated phosphatidylinositol 3-kinase (PI3K)/Akt signaling and was reversed by AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent kinase II (CaMKII) inhibition. Importantly, puerarin inhibited the adhesion of tumor necrosis factor (TNF)-α-stimulated monocytes to endothelial cells and suppressed the TNF-α induced expression of intercellular cell adhesion molecule-1. Puerarin also inhibited the TNF-α-induced nuclear factor-κB activation, which was attenuated by pretreatment with NG-nitro-L-arginine methyl ester, a NOS inhibitor. These results indicate that puerarin stimulates eNOS phosphorylation and NO production via activation of an estrogen receptor-mediated PI3K/Akt- and CaMKII/AMPK-dependent pathway. Puerarin may be useful for the treatment or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease. -- Highlights: ► Puerarin induced the phosphorylation of eNOS and the production of NO. ► Puerarin activated eNOS through ER-dependent PI3-kinase and Ca2+-dependent AMPK. ► Puerarin-induced NO was involved in the inhibition of NF-kB activation. ► Puerarin may help for prevention of vascular dysfunction and diabetes.

  4. Annexin A6 contributes to the invasiveness of breast carcinoma cells by influencing the organization and localization of functional focal adhesions

    The interaction of annexin A6 (AnxA6) with membrane phospholipids and either specific extracellular matrix (ECM) components or F-actin suggests that it may influence cellular processes associated with rapid plasma membrane reorganization such as cell adhesion and motility. Here, we examined the putative roles of AnxA6 in adhesion-related cellular processes that contribute to breast cancer progression. We show that breast cancer cells secrete annexins via the exosomal pathway and that the secreted annexins are predominantly cell surface-associated. Depletion of AnxA6 in the invasive BT-549 breast cancer cells is accompanied by enhanced anchorage-independent cell growth but cell-cell cohesion, cell adhesion/spreading onto collagen type IV or fetuin-A, cell motility and invasiveness were strongly inhibited. To explain the loss in adhesion/motility, we show that vinculin-based focal adhesions in the AnxA6-depleted BT-549 cells are elongated and randomly distributed. These focal contacts are also functionally defective because the activation of focal adhesion kinase and the phosphoinositide-3 kinase/Akt pathway were strongly inhibited while the MAP kinase pathway remained constitutively active. Compared with normal human breast tissues, reduced AnxA6 expression in breast carcinoma tissues correlates with enhanced cell proliferation. Together this suggests that reduced AnxA6 expression contributes to breast cancer progression by promoting the loss of functional cell-cell and/or cell-ECM contacts and anchorage-independent cell proliferation.

  5. Controllable and switchable capillary adhesion mechanism for bio-adhesive pads: Effect of micro patterns

    ZHANG XiangJun; LIU Yuan; LIU YongHe; AHMED S.I.-U.

    2009-01-01

    Some insects and animals, such as bugs, grasshoppers and tree frogs, realize their efficient adhesion mechanism to glass surface, wall and ceiling by injecting a wetting liquid thin film into the pad-substrate contact area. Their ability to control adhesion (attaching or detaching from a surface) is in many cases connected to the contact geometry and surface patterns of their attachment pads. This paper focuses on the dependence of the capillary adhesion (wet adhesion) on the micro patterns of the bio-adhesive pads. The objective is to reveal the possible mechanism for a bio-adhesive pad to control capillary force through adjusting its micro-scale surface pattern and topography. A capillary adhesion force model is built up taking account of the combined role of micro-dimple geometry as well as the wetting behavior of the confined liquid thin film. Calculated results of the apparent contact angle on the regularly micro-dimpled surfaces are compared with and in good agreement with the experimental measurements. Simulation of the capillary adhesion force reveals that it is controllable in a large mag-nitude by adjusting a dimensionless surface pattern parameter k defined as a/(a+b), where a is the dia-meter of micro dimple, and (a+b) is the side length of one pattern cell. When adjusting the parameter k more than 0.75, the capillary adhesion force could be switchable from attractive to repulsive. This effect of micro patterns on the interfacial capillary force is proved to be dominant when the pad-substrate clearance decreases to the nano/micrometer scale. These results indicate that a controllable and switchable capillary adhesive mechanism might be utilized by a living insect or animal to realize its stable adhesion and quick releasing movement through adjusting the micro-pattern topography of its bio-adhesive pad.

  6. A randomized control clinical trial of fissure sealant retention: Self etch adhesive versus total etch adhesive

    Nadia Aman; Farhan Raza Khan; Aisha Salim; Huma Farid

    2015-01-01

    Context: There are limited studies on comparison of Total etch (TE) and Self etch (SE) adhesive for placement of sealants. Aims: The aim of the study was to compare the retention of fissure sealants placed using TE adhesive to those sealants placed using SE (seventh generation) adhesive. Settings and Design: The study was conducted in the dental section, Aga Khan University Hospital. This study was a randomized single blinded trial with a split mouth design. Materials and Methods:...

  7. Embedded adhesive connection for laminated glass plates

    Hansen, Jens Zangenberg; Poulsen, S.H.; Bagger, A.; Stang, Henrik; Olesen, John Forbes

    2012-01-01

    The structural behavior of a new connection design, the embedded adhesive connection, used for laminated glass plates is investigated. The connection consists of an aluminum plate encapsulated in-between two adjacent triple layered laminated glass plates. Fastening between glass and aluminum is...... ensured using a structural adhesive. At first, the elastic and viscoelastic material properties of the adhesive are identified where the influence of load-rate and failure properties are also examined. Through an inverse analysis using the finite element method, the experimental observations are...... replicated to identify a material model of the adhesive. The material model consists of an elastic and linear viscoelastic formulation suitable for a numerical implementation of the material. Based on two relevant load cases, out-of-plane bending and in-plane shear, the connection performance is investigated...

  8. ENHANCING ADHESION OF TETRAHEDRAL AMORPHOUS CARBON FILMS

    Zhao Yuqing; Lin Yi; Wang Xiaoyan; Wang Yanwu; Wei Xinyu

    2005-01-01

    Objective The high energy ion bombardment technique is applied to enhancing the adhesion of the tetrahedral amorphous carbon (TAC) films deposited by the filtered cathode vacuum arc (FCVA). Methods The abrasion method, scratch method, heating and shaking method as well as boiling salt solution method is used to test the adhesion of the TAC films on various material substrates. Results The test results show that the adhesion is increased as the ion bombardment energy increases. However, if the bombardment energy were over the corresponding optimum value, the adhesion would be enhanced very slowly for the harder material substrates and drops quickly, for the softer ones. Conclusion The optimum values of the ion bombardment energy are larger for the harder materials than that for the softer ones.

  9. Micropatterning cell adhesion on polyacrylamide hydrogels.

    Zhang, Jian; Guo, Wei-Hui; Rape, Andrew; Wang, Yu-Li

    2013-01-01

    Cell shape and substrate rigidity play critical roles in regulating cell behaviors and fate. Controlling cell shape on elastic adhesive materials holds great promise for creating a physiologically relevant culture environment for basic and translational research and clinical applications. However, it has been technically challenging to create high-quality adhesive patterns on compliant substrates. We have developed an efficient and economical method to create precise micron-scaled adhesive patterns on the surface of a hydrogel (Rape et al., Biomaterials 32:2043-2051, 2011). This method will facilitate the research on traction force generation, cellular mechanotransduction, and tissue engineering, where precise controls of both materials rigidity and adhesive patterns are important. PMID:23955741

  10. Recent advances in nanostructured biomimetic dry adhesives

    CarloMenon

    2013-12-01

    Full Text Available The relatively large size of the gecko and its ability to climb a multitude of structures with ease has often been cited as the inspiration upon which the field of dry adhesives is based. Since 2010, there have been many advances in the field of dry adhesives with much of the new research focusing on developing nanoscale and hierarchical features in a concentrated effort to develop synthetic gecko-like dry adhesives which are strong, durable and self-cleaning. A brief overview of the geckos and the hairs which it uses to adhere to many different surfaces is provided before delving into the current methods and materials used to fabricate synthetic gecko hairs. A summary of the recently published literature on bio-inspired, nanostructured dry adhesives is presented with an emphasis being placed on fabrication techniques.

  11. Nano-clustering of ligands on surrogate antigen presenting cells modulates T cell membrane adhesion and organization.

    Dillard, Pierre; Pi, Fuwei; Lellouch, Annemarie C; Limozin, Laurent; Sengupta, Kheya

    2016-03-14

    We investigate the adhesion and molecular organization of the plasma membrane of T lymphocytes interacting with a surrogate antigen presenting cell comprising glass supported ordered arrays of antibody (α-CD3) nano-dots dispersed in a non-adhesive matrix of polyethylene glycol (PEG). The local membrane adhesion and topography, as well as the distribution of the T cell receptors (TCRs) and the kinase ZAP-70, are influenced by dot-geometry, whereas the cell spreading area is determined by the overall average density of the ligands rather than specific characteristics of the dots. TCR clusters are recruited preferentially to the nano-dots and the TCR cluster size distribution has a weak dot-size dependence. On the patterns, the clusters are larger, more numerous, and more enriched in TCRs, as compared to the homogeneously distributed ligands at comparable concentrations. These observations support the idea that non-ligated TCRs residing in the non-adhered parts of the proximal membrane are able to diffuse and enrich the existing clusters at the ligand dots. However, long distance transport is impaired and cluster centralization in the form of a central supramolecular cluster (cSMAC) is not observed. Time-lapse imaging of early cell-surface contacts indicates that the ZAP-70 microclusters are directly recruited to the site of the antibody dots and this process is concomitant with membrane adhesion. These results together point to a complex interplay of adhesion, molecular organization and activation in response to spatially modulated stimulation. PMID:26887857

  12. Adhesion between Polydimethylsiloxane Layers by Crosslinking

    Yu, Liyun; Daugaard, Anders Egede; Skov, Anne Ladegaard

    2013-01-01

    Adhesion between two surfaces may be strongly improved by chemical crosslinking of the interfaces. Polydimethylsiloxane (PDMS) is a widely used polymer that has received considerable attention due to its unique properties, such as relatively low price, biocompatibility, flexibility, high thermal...... investigated by rheology and microscopy. The objective of this work was to create adhesion of two layers without destroying the original viscoelastic properties of the PDMS films....

  13. Hierarchical Nanopatterns for Cell Adhesion Studies

    Schwieder, Marco

    2008-01-01

    Hierarchical nanopatterned interfaces are an intriguing tool to study clustering processes of proteins like for example integrins that mediate cell adhesion. The aim of this work is the development of innovative methods for the fabrication of hierarchical micro-nanopatterned surfaces and the use of such systems as platforms to study cell adhesion. In the first part of this work different approaches are presented which are suitable for preparing micro-nanopatterned interfaces at a large scale ...

  14. Effectiveness of cyanoacrylate adhesive in rabbit aortorrhaphy

    Marcus Vinicius Henriques de Carvalho; Evaldo Marchi; Mario Pantaroto

    2015-01-01

    BACKGROUND: Even when properly performed, arterial sutures are not always absolutely hemostatic. Tissue sealants and adhesives have become available that can be used to complete sutures, preventing hemorrhage problems.OBJECTIVES: To evaluate the effectiveness of cyanoacrylate adhesive for sealing aortotomies in rabbits in a coagulopathic state, by analyzing survival of the animals and the time taken to achieve hemostasis.METHODS: Ten-mm long aortotomies were performed on the infrarenal aortas...

  15. Relationships between water wettability and ice adhesion.

    Meuler, Adam J; Smith, J David; Varanasi, Kripa K; Mabry, Joseph M; McKinley, Gareth H; Cohen, Robert E

    2010-11-01

    Ice formation and accretion may hinder the operation of many systems critical to national infrastructure, including airplanes, power lines, windmills, ships, and telecommunications equipment. Yet despite the pervasiveness of the icing problem, the fundamentals of ice adhesion have received relatively little attention in the scientific literature and it is not widely understood which attributes must be tuned to systematically design "icephobic" surfaces that are resistant to icing. Here we probe the relationships between advancing/receding water contact angles and the strength of ice adhesion to bare steel and twenty-one different test coatings (∼200-300 nm thick) applied to the nominally smooth steel discs. Contact angles are measured using a commercially available goniometer, whereas the average strengths of ice adhesion are evaluated with a custom-built laboratory-scale adhesion apparatus. The coatings investigated comprise commercially available polymers and fluorinated polyhedral oligomeric silsesquioxane (fluorodecyl POSS), a low-surface-energy additive known to enhance liquid repellency. Ice adhesion strength correlates strongly with the practical work of adhesion required to remove a liquid water drop from each test surface (i.e., with the quantity [1 + cos θ(rec)]), and the average strength of ice adhesion was reduced by as much as a factor of 4.2 when bare steel discs were coated with fluorodecyl POSS-containing materials. We argue that any further appreciable reduction in ice adhesion strength will require textured surfaces, as no known materials exhibit receding water contact angles on smooth/flat surfaces that are significantly above those reported here (i.e., the values of [1 + cos θ(rec)] reported here have essentially reached a minimum for known materials). PMID:20949900

  16. The adhesive revolution of restorative dentistry

    Barnes, IE; Newsome, PRH

    1996-01-01

    In many countries, the incidence of dental decay in the young is decreasing, and Hong Kong is no exception. However, there remains in the region, a number of restorative dental problems of some significance. These are tooth discolouration, fracture, and root surface decay. This article discusses these problems and the way in which their treatment is increasingly being undertaken by means of minimalԸ?intervention adhesive techniques. The formulation of dental adhesive systems that are effectiv...

  17. Particle diameter influences adhesion under flow.

    Shinde Patil, V R; Campbell, C. J.; Yun, Y.H.; Slack, S M; Goetz, D J

    2001-01-01

    The diameter of circulating cells that may adhere to the vascular endothelium spans an order of magnitude from approximately 2 microm (e.g., platelets) to approximately 20 microm (e.g., a metastatic cell). Although mathematical models indicate that the adhesion exhibited by a cell will be a function of cell diameter, there have been few experimental investigations into the role of cell diameter in adhesion. Thus, in this study, we coated 5-, 10-, 15-, and 20-microm-diameter microspheres with ...

  18. Shear adhesion strength of aligned electrospun nanofibers.

    Najem, Johnny F; Wong, Shing-Chung; Ji, Guang

    2014-09-01

    Inspiration from nature such as insects' foot hairs motivates scientists to fabricate nanoscale cylindrical solids that allow tens of millions of contact points per unit area with material substrates. In this paper, we present a simple yet robust method for fabricating directionally sensitive shear adhesive laminates. By using aligned electrospun nylon-6, we create dry adhesives, as a succession of our previous work on measuring adhesion energies between two single free-standing electrospun polymer fibers in cross-cylinder geometry, randomly oriented membranes and substrate, and peel forces between aligned fibers and substrate. The synthetic aligned cylindrical solids in this study are electrically insulating and show a maximal Mode II shear adhesion strength of 27 N/cm(2) on a glass slide. This measured value, for the purpose of comparison, is 270% of that reported from gecko feet. The Mode II shear adhesion strength, based on a commonly known "dead-weight" test, is 97-fold greater than the Mode I (normal) adhesion strength of the same. The data indicate a strong shear binding on and easy normal lifting off. Anisotropic adhesion (Mode II/Mode I) is pronounced. The size and surface boundary effects, crystallinity, and bending stiffness of fibers are used to understand these electrospun nanofibers, which vastly differ from otherwise known adhesive technologies. The anisotropic strength distribution is attributed to a decreasing fiber diameter and an optimized laminate thickness, which, in turn, influences the bending stiffness and solid-state "wettability" of points of contact between nanofibers and surface asperities. PMID:25105533

  19. Synthesis and Characterization of Mussel Adhesive Peptides

    Deshmukh Manjeet Vinayakrao

    2005-01-01

    Mussels, marine organisms, attach to underwater surfaces by making a byssus, which is an extra-corporeal bundle of tiny tendons attached distally to a foreign surface and proximally by insertion of the root into the byssal retractor muscles. The interaction exterior of byssus and marine surface is an adhesive plaque that contains different proportion of five mytilus edulis adhesive proteins (mefp-1 to 5). Relatively high contains ...

  20. Pyk2 Controls Integrin-Dependent CTL Migration through Regulation of De-Adhesion.

    Cheung, Samuel M S; Ostergaard, Hanne L

    2016-09-01

    Protein tyrosine kinase 2 (Pyk2) is required for T cell adhesion to ICAM-1; however, the mechanism by which it regulates adhesion remains unexplored. Pyk2 function in murine CTL clones and activated ex vivo CD8(+) T cells was disrupted by pharmacological inhibition, knockdown of expression with small interfering RNA, or expression of the dominant-negative C-terminal domain. We found that Pyk2 is not absolutely required for adhesion of CTL to ICAM-1, but rather delays the initial adhesion. Disruption of Pyk2 function caused cells to display an unusual elongated appearance after 1 h on ICAM-1, consistent with abnormally strong adhesion. Furthermore, the random mobility of CTL on ICAM-1 was severely compromised using all three methods of disrupting Pyk2 function. Live-cell imaging studies revealed that the decreased migration is the result of a defect in the detachment from ICAM-1 at the trailing edge when Pyk2 function is inhibited. Examination of Pyk2 tyrosine phosphorylation in normal polarized cells demonstrated that Pyk2 phosphorylated at Y579 and Y580 preferentially localizes to the leading edge, whereas Y881-phosphorylated Pyk2 is enriched at the trailing edge, suggesting that the tyrosine phosphorylation of Pyk2 is spatially regulated in migrating CTL. Additionally, inhibition of Pyk2 caused cells to form multiple LFA-1-rich tails at the trailing edge, most likely resulting from a defect in LFA-1 release required for forward movement. Our results show that Pyk2 contributes to CTL migration by regulating detachment of CTL at the trailing edge, which could explain why Pyk2 is important for chemotactic and migratory responses. PMID:27456486

  1. Elimination of the reactivation process in the adhesion of chlorinated SBS rubber with polychloroprene adhesives

    2007-04-01

    Full Text Available Chlorination treatment of a thermoplastic styrene-butadiene-styrene rubber (SBS with a 3 wt% solution of trichloroisocyanuric acid (TCI in methyl ethyl ketone (MEK introduces chlorinated and oxidized moieties on the rubber surface which increase its surface energy and produces surface microroughness. Consequently adhesion properties, evaluated by T-peel strength measurements in chlorinated SBS/solvent based-polyurethane adhesive/leather joints, are enhanced. In this study, two solvent-based polychloroprene adhesives (PCP0 and PCP30R have been considered as an alternative to the commonly used solvent-based polyurethane adhesive (PU. A thermoreactive phenolic resin was added to one of the polychloroprene adhesive formulations (PCP30R. This tackifier resin favors chlorination of the adhesive and reinforces the interface between the chlorinated adhesive and the chlorinated rubber surface. Besides, PCP30R adhesive does not need adhesive reactivation and considerable high T-peel strength value (5.7±0.3 kN/m was obtained. Elimination of the reactivation process implies a considerable improvement of the manufacturing process in the footwear industry.

  2. 21 CFR 878.3750 - External prosthesis adhesive.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External prosthesis adhesive. 878.3750 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3750 External prosthesis adhesive. (a) Identification. An external prosthesis adhesive is a silicone-type adhesive intended to...

  3. Controlled Adhesion of Silicone Elastomer Surfaces

    Owen, Michael

    2000-03-01

    Opportunities exist for controllably enhancing the adhesion of silicone surfaces, ranging from modest enhancement of release force levels of pressure-sensitive adhesive (PSA) release liners by incorporation of adhesion promoters known as high release additives (HRA), to permanent bonding of silicone elastomers using surface modification techniques such as plasma or corona treatment. Although only a part of the complex interaction of factors contributing to adhesion, surface properties such as wettability are a critical component in the understanding and control of release and adhesion phenomena. Surface characterization studies of low-surface-energy silicones before and after various adhesion modification strategies are reviewed. The silicones include polydimethylsiloxane (PDMS) and fluorosiloxane elastomers and coatings. Techniques used include contact angle, the Johnson, Kendall and Roberts (JKR) contact mechanics approach, scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). Topics addressed are: use of HRA in PDMS release liners, the interaction of PDMS PSAs with polytetrafluoroethylene (PTFE), and the effect of plasma treatment on PDMS and fluorosiloxane surfaces.

  4. Preparation and Properties of Cornstarch Adhesives

    Li Yang

    2013-08-01

    Full Text Available The main goal of this study was to use cornstarch in the production of environmentally sound adhesives. ‘Three-formaldehyde glue’ pollutes the environment and harms to human health strongly, which widely used for wood-based panels preparation. Environment-friendly cornstarch adhesives were prepared using method of oxidation-gelatinization, insteading of the three formaldehyde glue. The effects of the quality ratio of starch and water, temperature and shear rate on the apparent viscosity of the adhesive were studied. The rheological eigenvalue of apparent viscosity was studied through nonlinear regression. The results showed that the apparent viscosity of cornstarch adhesives increased and then decreased with the increasing of temperature and the maximum value was obtained at 10oC; the apparent viscosity decreased slowly with the increasing of rotor speed; the phenomenon of shear thinning appeared wither cornstarch adhesives which was pseudo-plastic fluids. Cornstarch adhesives with characteristics of non-toxic, no smell and pollution could be applied in interior and upscale packaging.

  5. FINITE ELEMENT ANALYSIS OF WOOD ADHESIVE JOINTS

    Thomas GEREKE

    2016-03-01

    Full Text Available Engineered wood products such as glulam or cross-laminated timber are widely established in the construction industry. Their structural behaviour and reliability clearly bases on the adhesive bonding. In order to understand and improve the performance of glued wood members a finite element modelling of standard single lap shear samples was carried out. A three-dimensional model of a longitudinal tensile-shear specimen with quasi-centric load application was developed. The main influences of wood and adhesive parameters on structural performance were identified. Therefore, variations of the elasticity, the annual ring angle, fibre angle, and the interface zone and their effect on the occurring stresses in the adhesive bond line were investigated numerically. The adhesive bond line is most significantly sensitive to the Young´s modulus of the adhesive itself. A variation of the fibre angle of the glued members in the standard test is an essential criterion and to be considered when preparing lap shear specimens. A model with representation of early- and latewood gives a more detailed insight into wooden adhesive joints.

  6. Heterophyllin B inhibits the adhesion and invasion of ECA-109 human esophageal carcinoma cells by targeting PI3K/AKT/β-catenin signaling

    Tantai, Ji-Cheng; Zhang, Yao; Zhao, Heng

    2015-01-01

    The present study aimed to measure the effect of heterophyllin B (HB) on the adhesion and invasion of ECA-109 human esophageal carcinoma cells, and examine the possible mechanism involved. A Cell Counting kit 8 assay was performed to determine the cell viability. Cell adhesion and invasion were determined following treatment of the ECA-109 cells with HB (0, 10, 25 and 50 µM) for 24 h. The levels of phosphorylated (p-)ATK and p-phosphoinositide 3-kinase (PI3K), and the protein levels of β-cate...

  7. Neuritogenic and survival-promoting effects of the P2 peptide derived from a homophilic binding site in the neural cell adhesion molecule

    Pedersen, Martin V; Køhler, Lene B; Ditlevsen, Dorte K;

    2004-01-01

    The neural cell adhesion molecule (NCAM) plays a pivotal role in neural development, regeneration, and plasticity. NCAM mediates adhesion and subsequent signal transduction through NCAM-NCAM binding. Recently, a peptide ligand termed P2 corresponding to a 12-amino-acid sequence in the FG loop of...... fragmentation were lowered by P2. Finally, treatment of neurons with P2 resulted in phosphorylation of the ser/thr kinase Akt. Thus, a small peptide mimicking homophilic NCAM interaction is capable of inducing differentiation as reflected by neurite outgrowth in several neuronal cell types and inhibiting...

  8. Enhanced adhesion of diamond coatings

    Zheng, Zhido

    potential layers identified: TiN and TiC. Crystalline diamond coatings are subsequently deposited on these layers by hot filament CVD. A large grained TiC coating with a relatively rough surface was found to provide the best adhesion to the diamond layer. As judged qualitatively by the extent of spallation adjacent to hardness indentation, this intermediate layer performs better than similar TiC layers reported in the literature. The residual stresses in the diamond coatings are analysed using Raman microprobe spectroscopy, and compared with the predictions of the analytical model. The adhesion of the diamond coatings on various substrates with and without an intermediate layer of TiC is quantitatively evaluated by measuring the length of the delamination crack surrounding through-thickness holes in the coating and comparing with the relationship derived between crack length and strain energy release rate. The measured adherence on WC-Co substrates, as characterised by the critical strain energy release rate for growth of the delamination crack, was found to be significantly higher in the presence of the TiC intermediate layer developed during the course of this work.

  9. Advances in modeling and design of adhesively bonded systems

    Kumar, S

    2013-01-01

    The book comprehensively charts a way for industry to employ adhesively bonded joints to make systems more efficient and cost-effective Adhesively bonded systems have found applications in a wide spectrum of industries (e.g., aerospace, electronics, construction, ship building, biomedical, etc.) for a variety of purposes. Emerging adhesive materials with improved mechanical properties have allowed adhesion strength approaching that of the bonded materials themselves. Due to advances in adhesive materials and the many potential merits that adhesive bonding offers, adhesive bonding has replac

  10. Application of the Blister Test in Study of Epoxy Adhesive

    Fei Xiong; Ingegerd Annergren

    2000-01-01

    Shaft-loaded blister test technique is used as an effective quantitative tool to measure adhesion strength. Investigation on conductive adhesive was done by modified blister test. It is found that shaftloaded blister test can be a good solution for the debonding of thin film adhesion. The intrinsic stable interface debonding process has been proved an attractive alternative to the conventional adhesion measurement techniques. In our study, epoxy matrix adhesive was studied using blister test technique in comparison with the traditional test-lap shear test. Adhesion strength was studied as a function of surface treatment and the metallization of substrate. It was found that surface conditions of substrate have significant impact on adhesion behaviour. The oxidation of surface is responsible for the poor adhesion. Activating chemical treatment and Plasma cleaning on substrate surface has been found to be a way of dreamatically improving adhesion strength of electronic conductive adhesive.

  11. Decipher the dynamic coordination between enzymatic activity and structural modulation at focal adhesions in living cells

    Lu, Shaoying; Seong, Jihye; Wang, Yi; Chang, Shiou-Chi; Eichorst, John Paul; Ouyang, Mingxing; Li, Julie Y.-S.; Chien, Shu; Wang, Yingxiao

    2014-07-01

    Focal adhesions (FAs) are dynamic subcellular structures crucial for cell adhesion, migration and differentiation. It remains an enigma how enzymatic activities in these local complexes regulate their structural remodeling in live cells. Utilizing biosensors based on fluorescence resonance energy transfer (FRET), we developed a correlative FRET imaging microscopy (CFIM) approach to quantitatively analyze the subcellular coordination between the enzymatic Src activation and the structural FA disassembly. CFIM reveals that the Src kinase activity only within the microdomain of lipid rafts at the plasma membrane is coupled with FA dynamics. FA disassembly at cell periphery was linearly dependent on this raft-localized Src activity, although cells displayed heterogeneous levels of response to stimulation. Within lipid rafts, the time delay between Src activation and FA disassembly was 1.2 min in cells seeded on low fibronectin concentration ([FN]) and 4.3 min in cells on high [FN]. CFIM further showed that the level of Src-FA coupling, as well as the time delay, was regulated by cell-matrix interactions, as a tight enzyme-structure coupling occurred in FA populations mediated by integrin αvβ3, but not in those by integrin α5β1. Therefore, different FA subpopulations have distinctive regulation mechanisms between their local kinase activity and structural FA dynamics.

  12. Pressure-sensitive adhesives for transdermal drug delivery systems.

    Tan; Pfister

    1999-02-01

    Adhesives are a critical component in transdermal drug delivery (TDD) devices. In addition to the usual requirements of functional adhesive properties, adhesives for TDD applications must have good biocompatibility with the skin, chemical compatibility with the drug, various components of the formulation, and provide consistent, effective delivery of the drug. This review discusses the three most commonly used adhesives (polyisobutylenes, polyacrylates and silicones) in TDD devices, and provides an update on recently introduced TDD products and recent developments of new adhesives. PMID:10234208

  13. Characteristics of the adhesive determinants of Lactobacillus fermentum 104.

    Henriksson, A; Szewzyk, R; Conway, P L

    1991-01-01

    The adhesion of Lactobacillus fermentum 104-R and the variant strain 104-S to porcine gastric squamous epithelium was investigated. An epithelium-specific adhesion was detected for strain 104-S; however, strain 104-R expressed enhanced adhesion capacity to the control surfaces of polystyrene and bovine serum albumin. To characterize the adhesive determinants, the bacterial cells were exposed to various treatments. The adhesion pattern of bacterial cells in buffers of pH values ranging from 2 ...

  14. Improved stress prediction in adhesive bonded optical components

    Vreugd, J. de; Voert, M.J.A. te; Nijenhuis, J.R.; Pijnenburg, J.A.C.M.; Tabak, E.

    2012-01-01

    Adhesives are widely used in optomechanical structures for bonding optical components to their mounts. The main advantage of using adhesives is the excellent strength to weight ratio. Adhesive bonding is seen as a desirable joining technique as it allows for greater flexibility in design. A disadvantage of adhesives however is the limited dimensional stability and loadability. To design stable optical mounts, accurate prediction of stresses and deformation is therefore needed. Adhesives show ...

  15. Molecular mechanisms of action and potential biomarkers of growth inhibition of dasatinib (BMS-354825) on hepatocellular carcinoma cells

    Molecular targeted therapy has emerged as a promising treatment of Hepatocellular carcinoma (HCC). One potential target is the Src family Kinase (SFK). C-Src, a non-receptor tyrosine kinase is a critical link of multiple signal pathways that regulate proliferation, invasion, survival, metastasis, and angiogenesis. In this study, we evaluated the effects of a novel SFK inhibitor, dasatinib (BMS-354825), on SFK/FAK/p130CAS, PI3K/PTEN/Akt/mTOR, Ras/Raf/MAPK and Stats pathways in 9 HCC cell lines. Growth inhibition was assessed by MTS assay. EGFR, Src and downstream proteins FAK, Akt, MAPK42/44, Stat3 expressions were measured by western blot. Cell adhesion, migration and invasion were performed with and without dasatinib treatment. The IC50 of 9 cell lines ranged from 0.7 μM ~ 14.2 μM. In general the growth inhibition by dasatinib was related to total Src (t-Src) and the ratio of activated Src (p-Src) to t-Src. There was good correlation of the sensitivity to dasatinib and the inhibition level of p-Src, p-FAK576/577 and p-Akt. No inhibition was found on Stat3 and MAPK42/44 in all cell lines. The inhibition of cell adhesion, migration and invasion were correlated with p-FAK inhibition. Dasatinib inhibits the proliferation, adhesion, migration and invasion of HCC cells in vitro via inhibiting of Src tyrosine kinase and affecting SFK/FAK and PI3K/PTEN/Akt, but not Ras/Raf/MEK/ERK and JAK/Stat pathways. T-Src and p-Src/t-Src may be useful biomarkers to select HCC patients for dasatinib treatment

  16. INTERLEUKIN 10 INHIBITS THE RAT VSMC PROLIFERATION AND COLLAGEN SECRETION STIMULATED BY ANGIOTENSIN Ⅱ

    夏春芳; 霍勇; 尹航; 朱国英; 唐朝枢

    2001-01-01

    Objective. To study the effect of interleukin 10 (IL-10) on the angiotensin Ⅱ(AngⅡ) stimulated rat VSMC proliferation and collagen secretion, and furthermore, explore its mechanism. Methods. On cultured VSMC of rat, 3H-thymine (3H-TdR) and 3H-proline incorporations were used to evaluate the DNA and collagen synthesis, respectively. Western blot and immunoprecipitation were applied to assay the expression and activity of focal adhesion kinase (FAK), respectively. Results. IL-10 (10-8 -10-10g/ml) inhibited the increase of 3H-TdR and 3H-proline incorporation as wellas FAK activity, which was induced by 10-Tmol/L AngⅡ (P 0.05). Conclusion. IL-10 antagonizes the VSMC proliferation and collagen synthesis by regulating FAK activity stimulated by AngⅡ.

  17. DMPD: Bruton's tyrosine kinase (Btk)-the critical tyrosine kinase in LPS signalling? [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15081522 Bruton's tyrosine kinase (Btk)-the critical tyrosine kinase in LPS signall...ruton's tyrosine kinase (Btk)-the critical tyrosine kinase in LPS signalling? PubmedID 15081522 Title Bruton...'s tyrosine kinase (Btk)-the critical tyrosine kinase in LPS signalling? Authors

  18. Surface Modifications in Adhesion and Wetting

    Longley, Jonathan

    Advances in surface modification are changing the world. Changing surface properties of bulk materials with nanometer scale coatings enables inventions ranging from the familiar non-stick frying pan to advanced composite aircraft. Nanometer or monolayer coatings used to modify a surface affect the macro-scale properties of a system; for example, composite adhesive joints between the fuselage and internal frame of Boeing's 787 Dreamliner play a vital role in the structural stability of the aircraft. This dissertation focuses on a collection of surface modification techniques that are used in the areas of adhesion and wetting. Adhesive joints are rapidly replacing the familiar bolt and rivet assemblies used by the aerospace and automotive industries. This transition is fueled by the incorporation of composite materials into aircraft and high performance road vehicles. Adhesive joints have several advantages over the traditional rivet, including, significant weight reduction and efficient stress transfer between bonded materials. As fuel costs continue to rise, the weight reduction is accelerating this transition. Traditional surface pretreatments designed to improve the adhesion of polymeric materials to metallic surfaces are extremely toxic. Replacement adhesive technologies must be compatible with the environment without sacrificing adhesive performance. Silane-coupling agents have emerged as ideal surface modifications for improving composite joint strength. As these coatings are generally applied as very thin layers (method to surface vibration for moving drops in microfluidic devices. The final surface modification considered is the application of a thin layer of rubber to a rigid surface. While this technique has many practical uses, such as easy release coatings in marine environments, it is applied herein to enable spontaneous healing between a rubber surface and a glass cover slip. Study of the diffusion controlled healing of a blister can be made by

  19. Nanorough titanium surfaces reduce adhesion of Escherichia coli and Staphylococcus aureus via nano adhesion points.

    Lüdecke, Claudia; Roth, Martin; Yu, Wenqi; Horn, Uwe; Bossert, Jörg; Jandt, Klaus D

    2016-09-01

    Microbial adhesion to natural and synthetic materials surfaces is a key issue e.g. in food industry, sewage treatment and most importantly in the biomedical field. The current development and progress in nanoscale structuring of materials surfaces to control microbial adhesion requires an advanced understanding of the microbe-material-interaction. This study aimed to investigate the nanostructure of the microbe-material-interface and link it to microbial adhesion kinetics as function of titanium surface nanoroughness to gain new insight into controlling microbial adhesion via materials' surface nanoroughness. Adhesion of Escherichia coli and Staphylococcus aureus was statistically significantly reduced (p≤0.05) by 55.6 % and 40.5 %, respectively, on physical vapor deposited titanium thin films with a nanoroughness of 6nm and the lowest surface peak density compared to 2nm with the highest surface peak density. Cross-sectioning of the microbial cells with a focused ion beam (FIB) and SEM imaging provided for the first time direct insight into the titanium-microbe-interface. High resolution SEM micrographs gave evidence that the surface peaks are the loci of initial contact between the microbial cells and the material's surface. In a qualitative model we propose that the initial microbial adhesion on nanorough surfaces is controlled by the titanium surface peak density via nano adhesion points. This new understanding will help towards the design of materials surfaces for controlling microbial adhesion. PMID:27288816

  20. RIP Kinases Initiate Programmed Necrosis

    Lorenzo Galluzzi; Oliver Kepp; Guido Kroemer

    2009-01-01

    Some lethal stimuli can induce either apoptosis or necrosis, depending on the cell type and/or experimental setting. Until recently,the molecular bases of this phenomenon were largely unknown. Now, two members of the receptor-interacting serine-threonine kinase (RIP) family, RIP1 and RIP3, have been demonstrated to control the switch between apoptotic and necrotic cell death.Some mechanistic details, however, remain controversial.

  1. Thymidine kinase diversity in bacteria

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.;

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The...... TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  2. Pantothenate Kinase-Associated Neurodegeneration

    Meitinger, Thomas; Prokisch, Holger; Hartig, Monika B.; Klopstock, Thomas

    2012-01-01

    Pantothenate kinase-associated neurodegeneration (PKAN) is a hereditary progressive disorder and the most frequent form of neurodegeneration with brain iron accumulation (NBIA). PKAN patients present with a progressive movement disorder, dysarthria, cognitive impairment and retinitis pigmentosa. In magnetic resonance imaging, PKAN patients exhibit the pathognonomic "eye of the tiger" sign in the globus pallidus which corresponds to iron accumulation and gliosis as shown in neuropathological e...

  3. Oncoprotein protein kinase antibody kit

    Karin, Michael; Hibi, Masahiko; Lin, Anning

    2008-12-23

    An isolated polypeptide (JNK) characterized by having a molecular weight of 46 kD as determined by reducing SDS-PAGE, having serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

  4. Thymidine kinase diversity in bacteria

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.; Piskur, Jure

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The...... TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  5. Regulation and function of TPL-2,an IκB kinase-regulated MAP kinase kinase kinase

    Thorsten Gantke; Srividya Sriskantharajah; Steven C Ley

    2011-01-01

    The IκB kinase(IKK)complex plays a well-documented role in innate and adaptive immunity.This function has been widely attributed to its role as the central activator of the NF-κB family of transcription factors.However,another important consequence of IKK activation is the regulation of TPL-2,a MEK kinase that is required for activation of ERK-1/2 MAP kinases in myeioid cells following Toll-like receptor and TNF receptor stimulation.In unstimulated cells,TPL-2 is stoichiometrically complexed with the NF-κB inhibitory protein NF-κB1 p105,which blocks TPL-2 access to its substrate MEK,and the ubiquitin-binding protein ABIN-2(A20-binding inhibitor of NF-κB 2),both of which are required to maintain TPL-2 protein stability.Following agonist stimulation,the IKK complex phosphorylates p105,triggering its K48-1inked ubiquitination and degradation by the proteasome.This releases TPL-2 from p105-mediated inhibition,facilitating activation of MEK,in addition to modulating NF-κB activation by liberating associated Rel subunits for translocation into the nucleus.IKK-induced proteolysis of 0105,therefore,can directly regulate both NF-κB and ERK MAP kinase activation via NF-κB1 p105.TPL-2 is critical for production of the proinflammatory cytokine TNF during inflammatory responses.Consequently,there has been considerable interest in the pharmaceutical industry to develop selective TPL-2 inhibitors as drugs for the treatment of TNF-dependent inflammatory,diseases,such as rheumatoid arthritis and inflammatory bowel disease.This review summarizes our current understanding of the regulation of TPL-2 signaling function,and also the complex positive and negative roles of TPL-2 in immune and inflammatory responses.

  6. A proteomic approach for comprehensively screening substrates of protein kinases such as Rho-kinase.

    Mutsuki Amano

    Full Text Available BACKGROUND: Protein kinases are major components of signal transduction pathways in multiple cellular processes. Kinases directly interact with and phosphorylate downstream substrates, thus modulating their functions. Despite the importance of identifying substrates in order to more fully understand the signaling network of respective kinases, efficient methods to search for substrates remain poorly explored. METHODOLOGY/PRINCIPAL FINDINGS: We combined mass spectrometry and affinity column chromatography of the catalytic domain of protein kinases to screen potential substrates. Using the active catalytic fragment of Rho-kinase/ROCK/ROK as the model bait, we obtained about 300 interacting proteins from the rat brain cytosol fraction, which included the proteins previously reported as Rho-kinase substrates. Several novel interacting proteins, including doublecortin, were phosphorylated by Rho-kinase both in vitro and in vivo. CONCLUSIONS/SIGNIFICANCE: This method would enable identification of novel specific substrates for kinases such as Rho-kinase with high sensitivity.

  7. Hyaluronan synthase 3 (HAS3) overexpression downregulates MV3 melanoma cell proliferation, migration and adhesion

    Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis. Nonetheless its role in melanomagenesis is not understood. In this study we produced a MV3 melanoma cell line with inducible expression of the hyaluronan synthase 3 (HAS3) and studied its effect on the behavior of the melanoma cells. HAS3 overexpression expanded the cell surface hyaluronan coat and decreased melanoma cell adhesion, migration and proliferation by cell cycle arrest at G1/G0. Melanoma cell migration was restored by removal of cell surface hyaluronan by Streptomyces hyaluronidase and by receptor blocking with hyaluronan oligosaccharides, while the effect on cell proliferation was receptor independent. Overexpression of HAS3 decreased ERK1/2 phosphorylation suggesting that inhibition of MAP-kinase signaling was responsible for these suppressive effects on the malignant phenotype of MV3 melanoma cells. - Highlights: • Inducible HAS3-MV3 melanoma cell line was generated using Lentiviral transduction. • HAS3 overexpression inhibits MV3 cell migration via hyaluronan–receptor interaction. • HAS3 overexpression decreases MV3 melanoma cell proliferation and adhesion. • ERK1/2 phosphorylation is downregulated by 50% in HAS3 overexpressing cells. • The results suggest that hyaluronan has anti-cancer like effects in melanoma

  8. Hyaluronan synthase 3 (HAS3) overexpression downregulates MV3 melanoma cell proliferation, migration and adhesion

    Takabe, Piia, E-mail: piia.takabe@uef.fi [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland); Bart, Geneviève [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland); Ropponen, Antti [University of Eastern Finland, Institute of Clinical Medicine, 70211 Kuopio (Finland); Rilla, Kirsi; Tammi, Markku; Tammi, Raija; Pasonen-Seppänen, Sanna [University of Eastern Finland, Institute of Biomedicine, 70211 Kuopio (Finland)

    2015-09-10

    Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis. Nonetheless its role in melanomagenesis is not understood. In this study we produced a MV3 melanoma cell line with inducible expression of the hyaluronan synthase 3 (HAS3) and studied its effect on the behavior of the melanoma cells. HAS3 overexpression expanded the cell surface hyaluronan coat and decreased melanoma cell adhesion, migration and proliferation by cell cycle arrest at G1/G0. Melanoma cell migration was restored by removal of cell surface hyaluronan by Streptomyces hyaluronidase and by receptor blocking with hyaluronan oligosaccharides, while the effect on cell proliferation was receptor independent. Overexpression of HAS3 decreased ERK1/2 phosphorylation suggesting that inhibition of MAP-kinase signaling was responsible for these suppressive effects on the malignant phenotype of MV3 melanoma cells. - Highlights: • Inducible HAS3-MV3 melanoma cell line was generated using Lentiviral transduction. • HAS3 overexpression inhibits MV3 cell migration via hyaluronan–receptor interaction. • HAS3 overexpression decreases MV3 melanoma cell proliferation and adhesion. • ERK1/2 phosphorylation is downregulated by 50% in HAS3 overexpressing cells. • The results suggest that hyaluronan has anti-cancer like effects in melanoma.

  9. Angiogenin enhances cell migration by regulating stress fiber assembly and focal adhesion dynamics.

    Saisai Wei

    Full Text Available Angiogenin (ANG acts on both vascular endothelial cells and cancer cells, but the underlying mechanism remains elusive. In this study, we carried out a co-immunoprecipitation assay in HeLa cells and identified 14 potential ANG-interacting proteins. Among these proteins, β-actin, α-actinin 4, and non-muscle myosin heavy chain 9 are stress fiber components and involved in cytoskeleton organization and movement, which prompted us to investigate the mechanism of action of ANG in cell migration. Upon confirmation of the interactions between ANG and the three proteins, further studies revealed that ANG co-localized with β-actin and α-actinin 4 at the leading edge of migrating cells. Down-regulation of ANG resulted in fewer but thicker stress fibers with less dynamics, which was associated with the enlargements of focal adhesions. The focal adhesion kinase activity and cell migration capacity were significantly decreased in ANG-deficient cells. Taken together, our data demonstrated that the existence of ANG in the cytoplasm optimizes stress fiber assembly and focal adhesion formation to accommodate cell migration. The finding that ANG promoted cancer cell migration might provide new clues for tumor metastasis research.

  10. Ultrasonic Nondestructive Characterization of Adhesive Bonds

    Qu, Jianmin

    1999-01-01

    Adhesives and adhesive joints are widely used in various industrial applications to reduce weight and costs, and to increase reliability. For example, advances in aerospace technology have been made possible, in part, through the use of lightweight materials and weight-saving structural designs. Joints, in particular, have been and continue to be areas in which weight can be trimmed from an airframe through the use of novel attachment techniques. In order to save weight over traditional riveted designs, to avoid the introduction of stress concentrations associated with rivet holes, and to take full advantage of advanced composite materials, engineers and designers have been specifying an ever-increasing number of adhesively bonded joints for use on airframes. Nondestructive characterization for quality control and remaining life prediction has been a key enabling technology for the effective use of adhesive joints. Conventional linear ultrasonic techniques generally can only detect flaws (delamination, cracks, voids, etc) in the joint assembly. However, more important to structural reliability is the bond strength. Although strength, in principle, cannot be measured nondestructively, a slight change in material nonlinearity may indicate the onset of failure. Furthermore, microstructural variations due to aging or under-curing may also cause changes in the third order elastic constants, which are related to the ultrasonic nonlinear parameter of the polymer adhesive. It is therefore reasonable to anticipate a correlation between changes in the ultrasonic nonlinear acoustic parameter and the remaining bond strength. It has been observed that higher harmonics of the fundamental frequency are generated when an ultrasonic wave passes through a nonlinear material. It seems that such nonlinearity can be effectively used to characterize bond strength. Several theories have been developed to model this nonlinear effect. Based on a microscopic description of the nonlinear

  11. The effect of midazolam on neutrophil mitogen-activated protein kinase.

    Ghori, Kamran

    2010-06-01

    Neutrophil p38 mitogen-activated protein kinase (MAPK) is a key enzyme in the intracellular signalling pathway that is responsible for many neutrophil functions, which are important in neutrophil-endothelial interaction. The imidazole compounds are inhibitors of this enzyme system. The objectives of this in-vitro investigation were to examine the effect of midazolam on neutrophil p38 MAPK activation (phosphorylation) following in-vitro ischaemia-reperfusion injury, and the expression of adhesion molecule CD11b\\/CD18.

  12. Immunochemical characterization of rat brain protein kinase

    Polyclonal antibodies against rat brain protein kinase C (the Ca2+/phospholipid-dependent enzyme) were raised in goat. These antibodies can neutralize completely the kinase activity in purified enzyme preparation as well as that in the crude homogenate. Immunoblot analysis of the purified and the crude protein kinase C preparations revealed a major immunoreactive band of 80 kDa. The antibodies also recognize the same enzyme from other rat tissues. Neuronal tissues (cerebral cortex, cerebellum, hypothalamus, and retina) and lymphoid organs (thymus and spleen) were found to be enriched in protein kinase C, whereas lung, kidney, liver, heart, and skeletal muscle contained relatively low amounts of this kinase. Limited proteolysis of the purified rat brain protein kinase C with trypsin results in an initial degradation of the kinase into two major fragments of 48 and 38 kDa. Both fragments are recognized by the antibodies. However, further digestion of the 48-kDa fragment to 45 kDa and the 38-kDa fragment to 33 kDa causes a loss of the immunoreactivity. Upon incubation of the cerebellar extract with Ca2+, the 48-kDa fragment was also identified as a major proteolytic product of protein kinase C. Proteolytic degradation of protein kinase C converts the Ca2+/phospholipid-dependent kinase to an independent form without causing a large impairment of the binding of [3H]phorbol 12,13-dibutyrate. The two major proteolytic fragments were separated by ion exchange chromatography and one of them (45-48 kDa) was identified as a protein kinase and the other (33-38 kDa) as a phorbol ester-binding protein. These results demonstrate that rat brain protein kinase C is composed of two functionally distinct units, namely, a protein kinase and a Ca2+-independent/phospholipid-dependent phorbol ester-binding protein

  13. Thermal Characterization of Epoxy Adhesive by Hotfire Testing

    Spomer, Ken A.; Haddock, M. Reed; McCool, Alex (Technical Monitor)

    2001-01-01

    This paper describes subscale solid-rocket motor hot-fire testing of epoxy adhesives in flame surface bondlines to evaluate heat-affected depth, char depth and ablation rate. Hot-fire testing is part of an adhesive down-selection program on the Space Shuttle Solid Rocket Motor Nozzle to provide additional confidence in the down-selected adhesives. The current nozzle structural adhesive bond system is being replaced due to obsolescence. Prior to hot-fire testing, adhesives were tested for chemical, physical and mechanical properties, which resulted in the selection of two potential replacement adhesives, Resin Technology Group's TIGA 321 and 3M's EC2615XLW. Hot-fire testing consisted of four forty-pound charge (FPC) motors fabricated in configurations that would allow side-by-side comparison testing of the candidate replacement adhesives with the current RSRM adhesives. Results of the FPC motor testing show that: 1) the phenolic char depths on radial bondlines is approximately the same and vary depending on the position in the blast tube regardless of which adhesive was used, 2) the replacement candidate adhesive char depths are equivalent to the char depths of the current adhesives, 3) the heat-affected depths of the candidate and current adhesives are equivalent, and 4) the ablation rates for both replacement adhesives were equivalent to the current adhesives.

  14. Pyk2 is essential for astrocytes mobility following brain lesion

    Giralt, Albert; Coura, Renata; Girault, Jean-Antoine

    2016-01-01

    Proline-rich tyrosine kinase 2 (Pyk2) is a calcium-dependent, non-receptor protein-tyrosine kinase of the focal adhesion kinase (FAK) family. Pyk2 is enriched in the brain, especially the forebrain. Pyk2 is highly expressed in neurons but is also present in astrocytes, where its role is not known. We used Pyk2 knockout mice (Pyk2−/−) developed in our laboratory to investigate the function of Pyk2 in astrocytes. Morphology and basic properties of astrocytes in vivo and in culture were not alte...

  15. Opportunities to Target Specific Contractile Abnormalities with Smooth Muscle Protein Kinase Inhibitors

    Annegret Ulke-Lemée

    2010-05-01

    Full Text Available Smooth muscle is a major component of most hollow organ systems (e.g., airways, vasculature, bladder and gut/gastrointestine; therefore, the coordinated regulation of contraction is a key property of smooth muscle. When smooth muscle functions normally, it contributes to general health and wellness, but its dysfunction is associated with morbidity and mortality. Rho-associated protein kinase (ROCK is central to calcium-independent, actomyosin-mediated contractile force generation in the vasculature, thereby playing a role in smooth muscle contraction, cell motility and adhesion. Recent evidence supports an important role for ROCK in the increased vasoconstriction and remodeling observed in various models of hypertension. This review will provide a commentary on the development of specific ROCK inhibitors and their clinical application. Fasudil will be discussed as an example of bench-to-bedside development of a clinical therapeutic that is used to treat conditions of vascular hypercontractility. Due to the wide spectrum of biological processes regulated by ROCK, many additional clinical indications might also benefit from ROCK inhibition. Apart from the importance of ROCK in smooth muscle contraction, a variety of other protein kinases are known to play similar roles in regulating contractile force. The zipper-interacting protein kinase (ZIPK and integrin-linked kinase (ILK are two well-described regulators of contraction. The relative contribution of each kinase to contraction depends on the muscle bed as well as hormonal and neuronal stimulation. Unfortunately, specific inhibitors for ZIPK and ILK are still in the development phase, but the success of fasudil suggests that inhibitors for these other kinases may also have valuable clinical applications. Notably, the directed inhibition of ZIPK with a pseudosubstrate molecule shows unexpected effects on the contractility of gastrointestinal smooth muscle.

  16. MAP kinase pathways and calcitonin influence CD44 alternate isoform expression in prostate cancer cells

    Dysregulated expression and splicing of cell adhesion marker CD44 is found in many types of cancer. In prostate cancer (PC) specifically, the standard isoform (CD44s) has been found to be downregulated compared with benign tissue whereas predominant variant isoform CD44v7-10 is upregulated. Mitogen-activated protein kinase pathways and paracrine calcitonin are two common factors linked to dysregulated expression and splicing of CD44 in cancer. Calcitonin has been found to increase proliferation and invasion in PC acting through the protein kinase A pathway. In androgen-independent PC with known high CD44v7-10 expression, CD44 total and CD44v7-10 RNA or protein were assessed in response to exogenous and endogenous calcitonin and to inhibitors of protein kinase A, MEK, JNK, or p38 kinase. Benign cells and calcitonin receptor-negative PC cells were also tested. MEK or p38 but not JNK reduced CD44 total RNA by 40%–65% in cancer and benign cells. Inhibition of protein kinase A reduced CD44 total and v7-10 protein expression. In calcitonin receptor-positive cells only, calcitonin increased CD44 variant RNA and protein by 3 h and persisting to 48 h, apparently dependent on an uninhibited p38 pathway. Cells with constitutive CT expression showed an increase in CD44v7-10 mRNA but a decrease in CD44 total RNA. The MEK pathway increases CD44 RNA, while calcitonin, acting through the protein kinase A and p38 pathway, facilitates variant splicing. These findings could be used in the formulation of therapeutic methods for PC targeting CD44 alternate splicing

  17. Apparatus for Removing Remaining Adhesives of Filter

    A Large amount of ventilation filter was used at radiation areas not only in nuclear power plants but also in nuclear facilities. These spent ventilation filters are generated as radioactive waste and composed of a steel frame, glass fiber media and aluminum separator. When treated, the spent filter is separated into filter media for air purification and frame. After separation, while the filter media is collected using steel drum for reducing internal exposure, the filter frame is treated further to remove adhesives for recycling the frame as many as possible in order to reduce waste and cost and improve working conditions. Usually, the adhesives are separated from the filter frame manually. As a result, a lot of time and labor is required. So, the objective of this study is to develop a motor-driven apparatus for removing adhesives efficiently

  18. Biologically Inspired Mushroom-Shaped Adhesive Microstructures

    Heepe, Lars; Gorb, Stanislav N.

    2014-07-01

    Adhesion is a fundamental phenomenon with great importance in technology, in our everyday life, and in nature. In this article, we review physical interactions that resist the separation of two solids in contact. By using examples of biological attachment systems, we summarize and categorize various principles that contribute to the so-called gecko effect. Emphasis is placed on the contact geometry and in particular on the mushroom-shaped geometry, which is observed in long-term biological adhesive systems. Furthermore, we report on artificial model systems with this bio-inspired geometry and demonstrate that surface microstructures with this geometry are promising candidates for technical applications, in which repeatable, reversible, and residue-free adhesion under different environmental conditions—such as air, fluid, and vacuum—is required. Various applications in robotic systems and in industrial pick-and-place processes are discussed.

  19. Laparoscopic Management of Adhesive Small Bowel Obstruction

    Konjic, Ferid; Idrizovic, Enes; Hasukic, Ismar; Jahic, Alen

    2016-01-01

    Introduction: Adhesions are the reason for bowel obstruction in 80% of the cases. In well selected patients the adhesive ileus laparoscopic treatment has multiple advantages which include the shorter hospitalization period, earlier food taking, and less postoperative morbidity rate. Case report: Here we have a patient in the age of 35 hospitalized at the clinic due to occlusive symptoms. Two years before an opened appendectomy had been performed on him. He underwent the treatment of exploration laparoscopy and laparoscopic adhesiolysis. Dilated small bowel loops connected with the anterior abdominal wall in the ileocecal region by adhesions were found intraoperatively and then resected harmonically with scalpel. One strangulation around which a small bowel loop was wrapped around was found and dissected. Postoperative course was normal. PMID:27041815

  20. Loss of MLCK leads to disruption of cell-cell adhesion and invasive behavior of breast epithelial cells via increased expression of EGFR and ERK/JNK signaling.

    Kim, D Y; Helfman, D M

    2016-08-25

    Myosin light chain kinase (MLCK) expression is downregulated in breast cancer, including invasive ductal carcinoma compared with ductal breast carcinoma in situ and metastatic breast tumors. However, little is known about how loss of MLCK expression contributes to tumor progression. MLCK is a component of the actin cytoskeleton and its known role is the phosphorylation of the regulatory light chain of myosin II. To gain insights into the role of MLCK in breast cancer, we perturbed its function using small interfering RNA (siRNA) or pharmacological inhibition in untransformed breast epithelial cells (MCF10A). Loss of MLCK by siRNAs led to increased cell migration and invasion, disruption of cell-cell adhesions and enhanced formation of focal adhesions at the leading edge of migratory cells. In addition, downregulation of MLCK cooperated with HER2 in MCF10A cells to promote cell migration and invasion and low levels of MLCK is associated with a poor prognosis in HER2-positive breast cancer patients. Associated with these altered migratory behaviors were increased expression of epidermal growth factor receptor and activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase signaling pathways in MLCK downregulated MCF10A cells. By contrast, inhibition of the kinase function of MLCK using pharmacological agents inhibited cell migration and invasion, and did not affect cellular adhesions. Our results show that loss of MLCK contributes to the migratory properties of epithelial cells resulting from changes in cell-cell and cell-matrix adhesions, and increased epidermal growth factor receptor signaling. These findings suggest that decreased expression of MLCK may have a critical role during tumor progression by facilitating the metastatic potential of tumor cells. PMID:26876209

  1. Inhibition of tumor necrosis factor-α-induced expression of adhesion molecules in human endothelial cells by the saponins derived from roots of Platycodon grandiflorum

    Adhesion molecules play an important role in the development of atherogenesis and are produced by endothelial cells after being stimulated with various inflammatory cytokines. This study examined the effect of saponins that were isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), on the cytokine-induced monocyte/human endothelial cell interaction, which is a crucial early event in atherogenesis. CKS significantly inhibited the TNFα-induced increase in monocyte adhesion to endothelial cells as well as decreased the protein and mRNA expression levels of vascular adhesion molecule-1 and intercellular cell adhesion molecule-1 on endothelial cells. Furthermore, CKS significantly inhibited the TNFα-induced production of intracellular reactive oxygen species (ROS) and activation of NF-κB by preventing IκB degradation and inhibiting IκB kinase activity. Overall, CKS has anti-atherosclerotic and anti-inflammatory activity, which is least in part the result of it reducing the cytokine-induced endothelial adhesion to monocytes by inhibiting intracellular ROS production, NF-κB activation, and cell adhesion molecule expression in endothelial cells

  2. High-Temperature Adhesive Strain Gage Developed

    Pereira, J. Michael; Roberts, Gary D.

    1997-01-01

    Researchers at the NASA Lewis Research Center have developed a unique strain gage and adhesive system for measuring the mechanical properties of polymers and polymer composites at elevated temperatures. This system overcomes some of the problems encountered in using commercial strain gages and adhesives. For example, typical commercial strain gage adhesives require a postcure at temperatures substantially higher than the maximum test temperature. The exposure of the specimen to this temperature may affect subsequent results, and in some cases may be higher than the glass-transition temperature of the polymer. In addition, although typical commercial strain gages can be used for short times at temperatures up to 370 C, their long-term use is limited to 230 C. This precludes their use for testing some high-temperature polyimides near their maximum temperature capability. Lewis' strain gage and adhesive system consists of a nonencapsulated, unbacked gage grid that is bonded directly to the polymer after the specimen has been cured but prior to the normal postcure cycle. The gage is applied with an adhesive specially formulated to cure under the specimen postcure conditions. Special handling, mounting, and electrical connection procedures were developed, and a fixture was designed to calibrate each strain gage after it was applied to a specimen. A variety of tests was conducted to determine the performance characteristics of the gages at elevated temperatures on PMR-15 neat resin and titanium specimens. For these tests, which included static tension, thermal exposure, and creep tests, the gage and adhesive system performed within normal strain gage specifications at 315 C. An example of the performance characteristics of the gage can be seen in the figure, which compares the strain gage measurement on a polyimide specimen at 315 C with an extensometer measurement.

  3. Mechanical Behaviour of Adhesive Joints in Cartonboard for Packaging

    Korin, Christer

    2009-01-01

    A cartonboard package is often sealed and closed with an adhesive – either a hot-melt adhesive (adhesives that are applied in a molten state on the cartonboard) or a dispersion adhesive (adhesives that are applied as water-based dispersions). This thesis focuses on the process of hot-melt gluing, and how material properties and process conditions affect the performance of the adhesive joint. Requirements vary depending on how the package is to be used. A package that is only supposed to prote...

  4. Surgical Adhesives in Facial Plastic Surgery.

    Toriumi, Dean M; Chung, Victor K; Cappelle, Quintin M

    2016-06-01

    In facial plastic surgery, attaining hemostasis may require adjuncts to traditional surgical techniques. Fibrin tissue adhesives have broad applications in surgery and are particularly useful when addressing the soft tissue encountered in facial plastic surgery. Beyond hemostasis, tissue adhesion and enhanced wound healing are reported benefits associated with a decrease in operating time, necessity for drains and pressure dressings, and incidence of wound healing complications. These products are clinically accessible to most physicians who perform facial plastic surgery, including skin grafts, flaps, rhytidectomy, and endoscopic forehead lift. PMID:27267012

  5. EFFECTIVENESS OF ADHESIVES IN SOYBEAN SEED INOCULATION

    Zlata Milaković

    2012-06-01

    Full Text Available Effectiveness of soybean seed inoculation can be improved by application of substances increasing adhesion of inoculant to the seed. Higher initial inoculum in the soil is ensured in this way, which increases formation of higher number and mass of nodules and consequently produces higher yield. In this research effects of different adhesives on nodulation capacity and components of soybean yield has been investigated. The best result of the investigated parameters was obtained by sugar and honey application, while carboximethyl cellulose did not show similar influence

  6. Coatings against corrosion and microbial adhesion

    Telegdi, J.; Szabo, T.; Al-Taher, F.; Pfeifer, E.; Kuzmann, E.; Vertes, A. [Chemical Research Center, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59/67 (Hungary)

    2010-12-15

    A systematic study on anti-corrosion and anti-fouling effect of hydrophobic Langmuir-Blodgett and self-assembled molecular layers deposited on metal surfaces, as well as anti-microbial adhesion properties of coatings with biocide is presented. Both types of efficiencies produced by LB films are enhanced by Fe{sup 3+} ions built in the molecular film. The quaternary ammonium type biocide embedded into the cross-linked gelatin decreased significantly the microbial adhesion, the biofilm formation. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Adhesion of PBO Fiber in Epoxy Composites

    2007-01-01

    The high mechanical and thermal performance of poly p-phenylene- 2, 6-benzobisoxazole ( PBO ) fiber provides great potential applications as reinforcement fibers for composites. A composite of PBO fiber and epoxy resin has excellent electrical insulation properties, therefore, it is considered to be the best choice for the reinforcement in high magnetic field coils for pulsed magnetic fields up to 100 T.However, poor adhesion between PBO fiber and matrix is found because of the chemically inactive and/or relatively smooth surface of the reinforcement fiber preventing efficient chemical bonding in the interface, which is a challenging issue to improve mechanical properties. Here, we report the surface modification of PBO fibers by ultraviolet (UV)irradiation, O2 and NH3 plasma, as well as acidic treatments. The interfacial adhesion strength values of all the treatments show the similar level as determined for aramid fibers by pull-out tests, a significant impact on fibermatrix-adhesion was not achieved. The surface free energy and roughness are increased for both sized and extracted fibers after plasma treatments together with maleic anhydride grafting. The sized fiber shows marginal improvement in adhesion strength and no change in fiber tensile strength because of the barrier effect of the finish.For the extracted fiber, different surface treatments either show no apparent effect or cause reduction in adhesion strength. Atomic force microscopy (AFM) topography analysis of the fracture surfaces proved adhesive failure at the fiber surface. The fiber surface roughness is increased and more surface flaws are induced, which could result in coarse interface structures when the treated fiber surface has no adequate wetting and functional groups. The adhesion failure is further confirmed by similar adhesion strength and compression shear strength values when the fiber was embedded in various epoxy resins with different temperature behavior. The tensile strength of fiber

  8. Regulation of the interaction between protein kinase C-related protein kinase 2 (PRK2) and its upstream kinase, 3-phosphoinositide-dependent protein kinase 1 (PDK1)

    Dettori, Rosalia; Sonzogni, Silvina; Meyer, Lucas;

    2009-01-01

    The members of the AGC kinase family frequently exhibit three conserved phosphorylation sites: the activation loop, the hydrophobic motif (HM), and the zipper (Z)/turn-motif (TM) phosphorylation site. 3-Phosphoinositide-dependent protein kinase 1 (PDK1) phosphorylates the activation loop of...... numerous AGC kinases, including the protein kinase C-related protein kinases (PRKs). Here we studied the docking interaction between PDK1 and PRK2 and analyzed the mechanisms that regulate this interaction. In vivo labeling of recombinant PRK2 by (32)P(i) revealed phosphorylation at two sites, the...... the mechanism that negatively regulates the docking interaction of PRK2 to the upstream kinase PDK1 is directly linked to the activation mechanism of PRK2 itself. Finally, our results indicate that the mechanisms underlying the regulation of the interaction between PRK2 and PDK1 are specific for PRK2...

  9. Reversible low adhesive to high adhesive superhydrophobicity transition on ZnO nanoparticle surfaces

    Li, Jian, E-mail: jianli83@126.com; Jing, Zhijiao; Yang, Yaoxia; Zha, Fei; Yan, Long; Lei, Ziqiang, E-mail: leizq@nwnu.edu.cn

    2014-01-15

    Superhydrophobic ZnO surfaces with water contact angle of 162° and sliding angle of 2° were fabricated successfully by spraying hydrophobic ZnO nanoparticle suspensions without limitations the shape and size of substrates. The as-prepared superhydrophobic ZnO surfaces are low adhesive and a water droplet easily rolls off with the surface slightly tilted. However, after being irradiated by UV light through a photomask, it becomes highly adhesive, on which a water droplet is firmly pinned without any movement. Further annealing the irradiated film, water droplets can roll off the surface again. Reversible transition between the low adhesive rolling state and high adhesive pinning state can be realized simply by UV illumination and heat treatment alternately. At the same time, the maximum adhesive force between the superhydrophobic ZnO surfaces and the water droplet changes from extreme low (∼5.1 μN) to very high (∼136.1 μN). When irradiated without a photomask, the surface became hydrophilic. Additionally, a water droplet can be transfered from the low adhesive superhydrophobic ZnO surfaces to the hydrophilic ZnO surfaces using the high adhesive superhydrophobic ZnO surfaces as a mechanical hand.

  10. Beetle adhesive hairs differ in stiffness and stickiness: in vivo adhesion measurements on individual setae

    Bullock, James M. R.; Federle, Walter

    2011-05-01

    Leaf beetles are able to climb on smooth and rough surfaces using arrays of micron-sized adhesive hairs (setae) of varying morphology. We report the first in vivo adhesive force measurements of individual setae in the beetle Gastrophysa viridula, using a smooth polystyrene substrate attached to a glass capillary micro-cantilever. The beetles possess three distinct adhesive pads on each leg which differ in function and setal morphology. Visualisation of pull-offs allowed forces to be measured for each tarsal hair type. Male discoidal hairs adhered with the highest forces (919 ± 104 nN, mean ± SE), followed by spatulate (582 ± 59 nN) and pointed (127 ± 19 nN) hairs. Discoidal hairs were stiffer in the normal direction (0.693 ± 0.111 N m-1) than spatulate (0.364 ± 0.039 N m-1) or pointed (0.192 ± 0.044 N m-1) hairs. The greater adhesion on smooth surfaces and the higher stability of discoidal hairs help male beetles to achieve strong adhesion on the elytra of females during copulation. A comparison of pull-off forces measured for single setae and whole pads (arrays) revealed comparable levels of adhesive stress. This suggests that beetles are able to achieve equal load sharing across their adhesive pads so that detachment through peeling is prevented.

  11. A randomized control clinical trial of fissure sealant retention: Self etch adhesive versus total etch adhesive

    Nadia Aman

    2015-01-01

    Full Text Available Context: There are limited studies on comparison of Total etch (TE and Self etch (SE adhesive for placement of sealants. Aims: The aim of the study was to compare the retention of fissure sealants placed using TE adhesive to those sealants placed using SE (seventh generation adhesive. Settings and Design: The study was conducted in the dental section, Aga Khan University Hospital. This study was a randomized single blinded trial with a split mouth design. Materials and Methods: The study included 37 patients, 101 teeth were included in both study groups. The intervention arm was treated with SE Adhesive (Adper Easy One, 3M ESPE, US. Control arm received TE adhesive (Adper Single Bond 2, 3M ESPE, US before sealant application. The patients were followed after 6 months for assessment of sealant retention. Statistical analysis used: Interexaminer agreement for outcome assessment was assessed by Kappa Statistics and outcome in intervention group was assessed by McNemar′s test. Results: Ninety-one pairs of molar (90% were reevaluated for sealant retention. Complete retention was 56% in TE arm and 28% in SE arm with an odds ratio (OR of 3.7. Conclusions: Sealants applied with TE adhesives show higher rate of complete sealant retention than SE adhesive.

  12. Galectin-1-mediated cell adhesion, invasion and cell death in human anaplastic large cell lymphoma: regulatory roles of cell surface glycans.

    Suzuki, Osamu; Abe, Masafumi

    2014-05-01

    steric hindrance. The adhesive capacity of H-ALCL cells is regulated by phosphatidylinositol 3 phosphate kinase (PI3K) and actin cytoskeleton, and the invasive capacity of H-ALCL cells is regulated by PI3K, mitogen-activated protein kinase (MAPK), Rho and actin cytoskeleton. Furthermore, galectin-1-induced cell death in H-ALCL cells was accompanied by inhibition of CD45 protein tyrosine phosphatase (PTP) activity. In conclusion, cell adhesion and invasion to galectin-1 appeared to be regulated by cell surface sialylation and N-glycosylation, and galectin-1 regulates cell death through inhibition of CD45 PTP activity of H-ALCL. PMID:24589677

  13. In vitro neutrophil migration requires protein kinase c-delta (δ-PKC) mediated MARCKS (Myristoylated Alanine Rich C-Kinase Substrate) phosphorylation

    Sung, Eui Jae; Adler, Kenneth B.; Jones, Samuel L.

    2015-01-01

    Dysregulated release of neutrophil reactive oxygen species and proteolytic enzymes contributes to both acute and chronic inflammatory diseases. Therefore, molecular regulators of these processes are potential targets for new anti-inflammatory therapies. We have shown previously that MARCKS (Myristoylated Alanine Rich C-Kinase Substrate), a well-known PKC substrate protein, is a key regulator of neutrophil functions. In the current study we investigate the role of PKC-mediated MARCKS phosphorylation in neutrophil migration and adhesion in vitro. We report that treatment of human neutrophils with the δ-PKC inhibitor rottlerin significantly attenuates fMLF induced MARCKS phosphorylation (IC50 = 5.709 μM), adhesion (IC50 = 8.4 uM) and migration (IC50 = 6.7 uM); while α-, β- and ζ-PKC inhibitors had no significant effect. We conclude that δ-PKC mediated MARCKS phosphorylation is essential for human neutrophil migration and adhesion in vitro. These results implicate δ-PKC mediated MARCKS phosphorylation as a key step in the inflammatory response of neutrophils. PMID:25515270

  14. Diacylglycerol Kinase Inhibition and Vascular Function

    Choi, Hyehun; Allahdadi, Kyan J.; Tostes, Rita C A; Webb, R. Clinton

    2009-01-01

    Diacylglycerol kinases (DGKs), a family of lipid kinases, convert diacylglycerol (DG) to phosphatidic acid (PA). Acting as a second messenger, DG activates protein kinase C (PKC). PA, a signaling lipid, regulates diverse functions involved in physiological responses. Since DGK modulates two lipid second messengers, DG and PA, regulation of DGK could induce related cellular responses. Currently, there are 10 mammalian isoforms of DGK that are categorized into five groups based on their structu...

  15. Polyphenols from Artemisia annua L Inhibit Adhesion and EMT of Highly Metastatic Breast Cancer Cells MDA-MB-231.

    Ko, Young Shin; Lee, Won Sup; Panchanathan, Radha; Joo, Young Nak; Choi, Yung Hyun; Kim, Gon Sup; Jung, Jin-Myung; Ryu, Chung Ho; Shin, Sung Chul; Kim, Hye Jung

    2016-07-01

    Recent evidence suggests that polyphenolic compounds from plants have anti-invasion and anti-metastasis capabilities. The Korean annual weed, Artemisia annua L., has been used as a folk medicine for treatment of various diseases. Here, we isolated and characterized polyphenols from Korean A. annua L (pKAL). We investigated anti-metastatic effects of pKAL on the highly metastatic MDA-MB-231 breast cancer cells especially focusing on cancer cell adhesion to the endothelial cell and epithelial-mesenchymal transition (EMT). Firstly, pKAL inhibited cell viability of MDA-MB-231 cells in a dose-dependent manner, but not that of human umbilical vein endothelial cells (ECs). Polyphenols from Korean A. annua L inhibited the adhesion of MDA-MB-231 cells to ECs through reducing vascular cell adhesion molecule-1 expression of MDA-MB-231 and ECs, but not intracellular adhesion molecule-1 at the concentrations where pKAL did not influence the cell viability of either MDA-MB-231 cells nor EC. Further, pKAL inhibited tumor necrosis factor-activated MDA-MB-231 breast cancer cell invasion through inhibition of matrix metalloproteinase-2 and matrix metalloproteinase-9 and EMT. Moreover, pKAL inhibited phosphorylation of Akt, but not that of protein kinase C. These results suggest that pKAL may serve as a therapeutic agent against cancer metastasis at least in part by inhibiting the cancer cell adhesion to ECs through suppression of vascular cell adhesion molecule-1 and invasion through suppression of EMT. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27151203

  16. Aluminum and steel adhesion with polyurethanes from castor oil adhesives submitted to gamma irradiation

    Polyurethanes adhesive from castor oil is used to join aluminum and steel pieces. The effect of gamma radiation on the resistance to tension tests is investigated. The aluminum and steel pieces after being glued with the adhesive were submitted to gamma irradiation in doses of 1 kGy, 25 kGy and 100 kGy. The rupture strength of the joints after irradiation have a slightly increase or remains practically unchanged indicating that the adhesive properties is not affected by the gamma radiation. (author)

  17. Adhesive thickness effects of a ductile adhesive by optical measurement techniques

    Campilho, Raul; Moura, D.C.; Banea, Mariana D.; Silva, L. F. M. da

    2015-01-01

    Adhesive bonding is an excellent alternative to traditional joining techniques such as welding, mechanical fastening or riveting. However, there are many factors that have to be accounted for during joint design to accurately predict the joint strength. One of these is the adhesive layer thickness (tA). Most of the results are for epoxy structural adhesives, tailored to perform best with small values of tA, and these show that the lap joint strength decreases with increase of tA (the optimum ...

  18. Allosteric small-molecule kinase inhibitors

    Wu, Peng; Clausen, Mads Hartvig; Nielsen, Thomas E.

    2015-01-01

    Small-molecule kinase inhibitors are invaluable targeted therapeutics for the treatment of various human diseases, especially cancers. While the majority of approved and developed preclinical small-molecule inhibitors are characterized as type I or type II inhibitors that target the ATP......-binding pocket of kinases, the remarkable sequential and structural similarity among ATP pockets renders the selective inhibition of kinases a daunting challenge. Therefore, targeting allosteric pockets of kinases outside the highly conversed ATP pocket has been proposed as a promising alternative to overcome...

  19. MST kinases in development and disease

    Thompson, Barry J.; Sahai, Erik

    2015-01-01

    The mammalian MST kinase family, which is related to the Hippo kinase in Drosophila melanogaster, includes five related proteins: MST1 (also called STK4), MST2 (also called STK3), MST3 (also called STK24), MST4, and YSK1 (also called STK25 or SOK1). MST kinases are emerging as key signaling molecules that influence cell proliferation, organ size, cell migration, and cell polarity. Here we review the regulation and function of these kinases in normal physiology and pathologies, including cance...

  20. Seeding Collaborations to Advance Kinase Science with the GSK Published Kinase Inhibitor Set (PKIS)

    Drewry, David H.; Willson, Timothy M.; Zuercher, William J

    2014-01-01

    To catalyze research on historically untargeted protein kinases, we created the PKIS, an annotated set of 367 small molecule kinase inhibitors. The set has been widely distributed to academic collaborators as an open access tool. It has been used to identify chemical starting points for development of chemical probes for orphan kinases and to investigate kinase signaling in high content phenotypic assays. Access to the set comes with few restrictions other than the requirement that assay resu...