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Sample records for hgf receptor c-met

  1. The tyrosine kinase receptor c-met, its cognate ligand HGF and the tyrosine kinase receptor trasducers STAT3, PI3K and RHO in thyroid nodules associated with Hashimoto's thyroiditis: an immunohistochemical characterization

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    R. M. Ruggeri

    2010-06-01

    Full Text Available Hepatocyte growth factor (HGF exerts proliferative activities in thyrocytes upon binding to its tyrosine kinase receptor c-met and is also expressed in benign thyroid nodules as well as in Hashimoto’s thyroiditis (HT. The simultaneous expression of HGF/c-met and three trasducers of tyrosine kinase receptors (STAT3, PI3K, RHO in both the nodular and extranodular tissues were studied by immunohistochemistry in 50 benign thyroid nodules (NGs, 25 of which associated with HT. The ligand/tyrosine kinase receptor pair HGF/c-met and the two trasducers PI3K and RHO were expressed in NGs, regardless of association with HT, with a higher positive cases percentage in HT-associated NGs compared to not HT-associated NGs (25/25 or 100% vs 7/25 or 28%; P<0.001. HGF, PI3K and RHO expression was only stromal (fibroblasts and endothelial cells, in all 32 reactive NGs, while c-met localization was consistently epithelial (thyrocyes. Immu­noreactions for HGF, c-met, PI3K and RHO were also apparent in the extra-nodular tissue of HT specimens, where HGF and PI3K were expressed not only in stromal cells but also in thyrocyes along with the c-met. Finally, a positive correlation was observed between the proportion of HGF, c-met, PI3K follicular cells and the grade of lymphoid aggregates in HT. In conclusion, HGF, c-met, PI3K are much more frequently and highly expressed in HT compared to NGs, and among all NGs in those present in the context of HT. A paracrine effect of HFG/c-met on nodule development, based on the prevalent stromal expression, may be suggested along with a major role of HGF/c-met and PI3K in HT. Finally, the expression of such molecules in HT may be regulated by lymphoid infiltrate.

  2. Antifolate/folate-activated HGF/c-Met signalling pathways in mouse kidneys-the putative role of their downstream effectors in cross-talk with androgen receptor.

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    Dudkowska, Magdalena; Bajer, Seweryn; Jaworski, Tomasz; Zielińska, Joanna; Manteuffel-Cymborowska, Małgorzata; Grzelakowska-Sztabert, Barbara

    2009-03-01

    This in vivo study of mouse kidneys was focused on the identification of protein mediators involved in the cross-talk between two signalling pathways. One pathway was triggered by testosterone via an androgen receptor, AR, and the other induced by CB 3717/folate via HGF, and its membrane receptor c-Met. Sequential activation of these pathways leads to a drastic decrease of testosterone-induced ornithine decarboxylase, ODC, expression. We proved that CB 3717/folate-induced ODC expression is Akt-dependent. CB 3717/folate activates Akt and ERK1/2 kinases, PTEN phosphatase and also up-regulates cyclin D2 and PCNA, but decreases GSK3beta and cyclin D1 protein levels. Testosterone activation of AR induces GSK3beta and PTEN. Results of the sequential activation of the studied signalling pathways suggest that Akt, GSK3beta and possibly ERK1/2 kinases may participate in the negative cross-talk and attenuation of AR transactivity, while the involvement of PTEN and cyclin D1 seems to be doubtful.

  3. Cooperative interaction of MUC1 with the HGF/c-Met pathway during hepatocarcinogenesis

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    Bozkaya Giray

    2012-09-01

    Full Text Available Abstract Background Hepatocyte growth factor (HGF induced c-Met activation is known as the main stimulus for hepatocyte proliferation and is essential for liver development and regeneration. Activation of HGF/c-Met signaling has been correlated with aggressive phenotype and poor prognosis in hepatocellular carcinoma (HCC. MUC1 is a transmembrane mucin, whose over-expression is reported in most cancers. Many of the oncogenic effects of MUC1 are believed to occur through the interaction of MUC1 with signaling molecules. To clarify the role of MUC1 in HGF/c-Met signaling, we determined whether MUC1 and c-Met interact cooperatively and what their role(s is in hepatocarcinogenesis. Results MUC1 and c-Met over-expression levels were determined in highly motile and invasive, mesenchymal-like HCC cell lines, and in serial sections of cirrhotic and HCC tissues, and these levels were compared to those in normal liver tissues. Co-expression of both c-Met and MUC1 was found to be associated with the differentiation status of HCC. We further demonstrated an interaction between c-Met and MUC1 in HCC cells. HGF-induced c-Met phosphorylation decreased this interaction, and down-regulated MUC1 expression. Inhibition of c-Met activation restored HGF-mediated MUC1 down-regulation, and decreased the migratory and invasive abilities of HCC cells via inhibition of β-catenin activation and c-Myc expression. In contrast, siRNA silencing of MUC1 increased HGF-induced c-Met activation and HGF-induced cell motility and invasion. Conclusions These findings indicate that the crosstalk between MUC1 and c-Met in HCC could provide an advantage for invasion to HCC cells through the β-catenin/c-Myc pathway. Thus, MUC1 and c-Met could serve as potential therapeutic targets in HCC.

  4. SF/HGF-c-Met autocrine and paracrine promote metastasis of hepatocellular carcinoma

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    Qian Xie; Kang-Da Liu; Mei-Yu Hu; Kang Zhou

    2001-01-01

    AIM: To explore the role of SF/HGF-Met autocrine and parscrine in metastasis of hepatocellular carcinoma (HCC). METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B,SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. Sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve. RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HGF autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation ( P < 0.05) and mobility increased. Such bio-activity could he blocked by c-met antibody ( P< 0.05). CONCLUSION: The system of SF/HGF-c-met autocrine and paracrine played an important role in development and metastasis potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.

  5. Research Progress of HGF/c-MET Inhibitor in the Treatment 
of Non-small Cell Lung Cancer

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    Tao JIANG

    2015-04-01

    Full Text Available Molecular targeted therapy has become more and more important in the treatment of non-small cell lung cancer (NSCLC. HGF/c-MET plays the pivotal role in the growth, development and tolerance to epidermal growth factor receptor tyrosine kinase inhibitor of NSCLC. Moreover it has become another heat point in the molecular targeted therapy of NSCLC. c-MET amplification or high expression was deemed to another significant gene modification beyond EGFR and ALK. In the preclinical studies, HGF/c-MET inhibitors have showed the promising anti-tumor effect. Recently, some phase II/III clinical trials have proved that these inhibitors could improve the survival of patients with NSCLC. Hence we performed this review to elaborate the research progress of c-MET inhibitor in the treatment of NSCLC.

  6. Evaluation of c-Met, HGF, and HER-2 expressions in gastric carcinoma and their association with other clinicopathological factors

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    Yıldız Y

    2016-09-01

    Full Text Available Yetkin Yıldız,1 Cenk Sokmensuer,2 Suayib Yalcin1 1Department of Medical Oncology, 2Department of Pathology, Hacettepe University, Ankara, Turkey Background: Met and HER-2 are proto-oncogenes encoding receptor tyrosine kinase c-Met and HER-2, respectively. Hepatocyte growth factor (HGF is a ligand of c-Met. The frequency of c-Met, HGF, and HER-2 expressions in gastric cancer and their association with other clinicopathological factors have not been fully understood. Patients and methods: Patients with stage 1–4 disease were analyzed. Expressions of c-Met, HGF, and HER-2 were examined using immunohistochemistry. Results: A total of 143 patients, 97 males and 46 females, were included. C-Met scores were 3(+ in 31.5%, 2(+ in 27.3%, and 1(+ in 10.5% of the patients. There was no statistically significant difference in age, sex, tumor location, differentiation, Lauren classification, TNM staging, presence of distant metastasis, depth of tumor invasion (T, lymphovascular invasion, and survival between c-Met subgroups. Overall HGF positivity was 20.6%. HER-2 scores were 3(+ in 9.1%, 2(+ in 9.8%, and 1(+ in 16.1% of the patients. HER-2 overexpression was associated with better differentiation, intestinal subtype, and advanced stage. C-Met overexpressions were 84.6% in the HER-2-overexpression-positive group and 56.2% in the HER-2-overexpression-negative group. There were no statistically significant differences in survival between the high c-Met-expression-positive and -negative stage 3 and stage 4 patients and between the HGF-positive and -negative groups. The mean survival was 11.6±6.3 months in the HER-2-overexpression-positive stage 4 group and 11.9±6.8 months in the HER-2-overexpression-negative stage 4 group. There were no statistically significant differences in survival between the two groups. Conclusion: c-Met was not associated with any prognostic factors in gastric cancer. HER-2 was associated with better differentiation, intestinal

  7. Evaluation of c-Met, HGF, and HER-2 expressions in gastric carcinoma and their association with other clinicopathological factors

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    Yıldız, Yetkin; Sokmensuer, Cenk; Yalcin, Suayib

    2016-01-01

    Background Met and HER-2 are proto-oncogenes encoding receptor tyrosine kinase c-Met and HER-2, respectively. Hepatocyte growth factor (HGF) is a ligand of c-Met. The frequency of c-Met, HGF, and HER-2 expressions in gastric cancer and their association with other clinicopathological factors have not been fully understood. Patients and methods Patients with stage 1–4 disease were analyzed. Expressions of c-Met, HGF, and HER-2 were examined using immunohistochemistry. Results A total of 143 patients, 97 males and 46 females, were included. C-Met scores were 3(+) in 31.5%, 2(+) in 27.3%, and 1(+) in 10.5% of the patients. There was no statistically significant difference in age, sex, tumor location, differentiation, Lauren classification, TNM staging, presence of distant metastasis, depth of tumor invasion (T), lymphovascular invasion, and survival between c-Met subgroups. Overall HGF positivity was 20.6%. HER-2 scores were 3(+) in 9.1%, 2(+) in 9.8%, and 1(+) in 16.1% of the patients. HER-2 overexpression was associated with better differentiation, intestinal subtype, and advanced stage. C-Met overexpressions were 84.6% in the HER-2-overexpression-positive group and 56.2% in the HER-2-overexpression-negative group. There were no statistically significant differences in survival between the high c-Met-expression-positive and -negative stage 3 and stage 4 patients and between the HGF-positive and -negative groups. The mean survival was 11.6±6.3 months in the HER-2-overexpression-positive stage 4 group and 11.9±6.8 months in the HER-2-overexpression-negative stage 4 group. There were no statistically significant differences in survival between the two groups. Conclusion c-Met was not associated with any prognostic factors in gastric cancer. HER-2 was associated with better differentiation, intestinal subtype, advanced stage, and c-Met overexpression. PMID:27703380

  8. Signal transduction and downregulation of C-MET in HGF stimulated low and highly metastatic human osteosarcoma cells

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    Husmann, Knut, E-mail: khusmann@research.balgrist.ch [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland); Ducommun, Pascal [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland); Division of Plastic Surgery and Hand Surgery, Department of Surgery, University Hospital Zurich, Zurich (Switzerland); Sabile, Adam A.; Pedersen, Else-Marie; Born, Walter; Fuchs, Bruno [Laboratory for Orthopedic Research, Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich (Switzerland)

    2015-09-04

    The poor outcome of osteosarcoma (OS), particularly in patients with metastatic disease and a five-year survival rate of only 20%, asks for more effective therapeutic strategies targeting malignancy-promoting mechanisms. Dysregulation of C-MET, its ligand hepatocyte growth factor (HGF) and the fusion oncogene product TPR-MET, first identified in human MNNG-HOS OS cells, have been described as cancer-causing factors in human cancers. Here, the expression of these molecules at the mRNA and the protein level and of HGF-stimulated signaling and downregulation of C-MET was compared in the parental low metastatic HOS and MG63 cell lines and the respective highly metastatic MNNG-HOS and 143B and the MG63-M6 and MG63-M8 sublines. Interestingly, expression of TPR-MET was only observed in MNNG-HOS cells. HGF stimulated the phosphorylation of Akt and Erk1/2 in all cell lines investigated, but phospho-Stat3 remained at basal levels. Downregulation of HGF-stimulated Akt and Erk1/2 phosphorylation was much faster in the HGF expressing MG63-M8 cells than in HOS cells. Degradation of HGF-activated C-MET occurred predominantly through the proteasomal and to a lesser extent the lysosomal pathway in the cell lines investigated. Thus, HGF-stimulated Akt and Erk1/2 signaling as well as proteasomal degradation of HGF activated C-MET are potential therapeutic targets in OS. - Highlights: • Expression of TPR-MET was only observed in MNNG-HOS cells. • HGF stimulated the phosphorylation of Akt and Erk1/2 but not of Stat3 in osteosarcoma cell lines. • Degradation of HGF-activated C-MET occurred predominantly through the proteasomal pathway.

  9. Targeting HGF/c-MET induces cell cycle arrest, DNA damage, and apoptosis for primary effusion lymphoma.

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    Dai, Lu; Trillo-Tinoco, Jimena; Cao, Yueyu; Bonstaff, Karlie; Doyle, Lisa; Del Valle, Luis; Whitby, Denise; Parsons, Chris; Reiss, Krzysztof; Zabaleta, Jovanny; Qin, Zhiqiang

    2015-12-24

    Kaposi sarcoma-associated herpesvirus (KSHV) is a principal causative agent of primary effusion lymphoma (PEL) with a poor prognosis in immunocompromised patients. However, it still lacks effective treatment which urgently requires the identification of novel therapeutic targets for PEL. Here, we report that the hepatocyte growth factor (HGF)/c-MET pathway is highly activated by KSHV in vitro and in vivo. The selective c-MET inhibitor, PF-2341066, can induce PEL apoptosis through cell cycle arrest and DNA damage, and suppress tumor progression in a xenograft murine model. By using microarray analysis, we identify many novel genes that are potentially controlled by HGF/c-MET within PEL cells. One of the downstream candidates, ribonucleoside-diphosphate reductase subunit M2 (RRM2), also displays the promising therapeutic value for PEL treatment. Our findings provide the framework for development of HGF/c-MET-focused therapy and implementation of clinical trials for PEL patients.

  10. c-MET receptor tyrosine kinase as a molecular target in advanced hepatocellular carcinoma

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    Granito A

    2015-04-01

    Full Text Available Alessandro Granito,1 Elena Guidetti,1 Laura Gramantieri2,3 1Dipartimento di Scienze Mediche e Chirurgiche Università di Bologna, Bologna, Italy; 2Dipartimento dell'Apparato Digerente, Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 3Centro di Ricerca Biomedica Applicata (CRBA, Azienda Ospedaliero-Universitaria Policlinico S Orsola-Malpighi e Università di Bologna, Bologna, Italy Abstract: c-MET is the membrane receptor for hepatocyte growth factor (HGF, also known as scatter factor or tumor cytotoxic factor, a mitogenic growth factor for hepatocytes. HGF is mainly produced by cells of mesenchymal origin and it mainly acts on neighboring epidermal and endothelial cells, regulating epithelial growth and morphogenesis. HGF/MET signaling has been identified among the drivers of tumorigenesis in human cancers. As such, c-MET is a recognized druggable target, and against it, targeted agents are currently under clinical investigation. c-MET overexpression is a common event in a wide range of human malignancies, including gastric, lung, breast, ovary, colon, kidney, thyroid, and liver carcinomas. Despite c-MET overexpression being reported by a large majority of studies, no evidence for a c-MET oncogenic addiction exists in hepatocellular carcinoma (HCC. In particular, c-MET amplification is a rare event, accounting for 4%–5% of cases while no mutation has been identified in c-MET oncogene in HCC. Thus, the selection of patient subgroups more likely to benefit from c-MET inhibition is challenging. Notwithstanding, c-MET overexpression was reported to be associated with increased metastatic potential and poor prognosis in patients with HCC, providing a rationale for its therapeutic inhibition. Here we summarize the role of activated HGF/MET signaling in HCC, its prognostic relevance, and the implications for therapeutic approaches in HCC. Keywords: hepatocellular carcinoma, c-MET, clinical trials

  11. Loss of HGF/c-Met signaling in pancreatic β-cells leads to incomplete maternal β-cell adaptation and gestational diabetes mellitus.

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    Demirci, Cem; Ernst, Sara; Alvarez-Perez, Juan C; Rosa, Taylor; Valle, Shelley; Shridhar, Varsha; Casinelli, Gabriella P; Alonso, Laura C; Vasavada, Rupangi C; García-Ocana, Adolfo

    2012-05-01

    Hepatocyte growth factor (HGF) is a mitogen and insulinotropic agent for the β-cell. However, whether HGF/c-Met has a role in maternal β-cell adaptation during pregnancy is unknown. To address this issue, we characterized glucose and β-cell homeostasis in pregnant mice lacking c-Met in the pancreas (PancMet KO mice). Circulating HGF and islet c-Met and HGF expression were increased in pregnant mice. Importantly, PancMet KO mice displayed decreased β-cell replication and increased β-cell apoptosis at gestational day (GD)15. The decreased β-cell replication was associated with reductions in islet prolactin receptor levels, STAT5 nuclear localization and forkhead box M1 mRNA, and upregulation of p27. Furthermore, PancMet KO mouse β-cells were more sensitive to dexamethasone-induced cytotoxicity, whereas HGF protected human β-cells against dexamethasone in vitro. These detrimental alterations in β-cell proliferation and death led to incomplete maternal β-cell mass expansion in PancMet KO mice at GD19 and early postpartum periods. The decreased β-cell mass was accompanied by increased blood glucose, decreased plasma insulin, and impaired glucose tolerance. PancMet KO mouse islets failed to upregulate GLUT2 and pancreatic duodenal homeobox-1 mRNA, insulin content, and glucose-stimulated insulin secretion during gestation. These studies indicate that HGF/c-Met signaling is essential for maternal β-cell adaptation during pregnancy and that its absence/attenuation leads to gestational diabetes mellitus.

  12. Expression of hepatocyte growth factor and the proto-oncogenic receptor c-Met in canine osteosarcoma

    NARCIS (Netherlands)

    Fieten, H|info:eu-repo/dai/nl/314112596; Spee, B|info:eu-repo/dai/nl/304830925; Ijzer, J|info:eu-repo/dai/nl/304839663; Kik, M J|info:eu-repo/dai/nl/080432565; Penning, L C|info:eu-repo/dai/nl/110369181; Kirpensteijn, J|info:eu-repo/dai/nl/189846992

    Hepatocyte growth factor (HGF) and the proto-oncogenic receptor c-Met are implicated in growth, invasion, and metastasis in human cancer. Little information is available on the expression and role of both gene products in canine osteosarcoma. We hypothesized that the expression of c-Met is

  13. Weight loss reversed obesity-induced HGF/c-Met pathway and basal-like breast cancer progression

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    Sneha eSundaram

    2014-07-01

    Full Text Available Epidemiologic studies demonstrate that obesity is associated with an aggressive subtype of breast cancer called basal-like breast cancer (BBC. Using the C3(1-TAg murine model of BBC, we previously demonstrated that mice displayed an early onset of tumors when fed obesogenic diets in the adult window of susceptibility. Obesity was also shown to elevate mammary gland expression and activation of hepatocyte growth factor (HGF/c-Met compared to lean controls, a pro-tumorigenic pathway associated with BBC in patients. Epidemiologic studies estimate that weight loss could prevent a large proportion of BBC. We sought to investigate whether weight loss in adulthood prior to tumor onset would protect mice from accelerated tumorigenesis observed in obese mice. Using a life-long model of obesity, C3(1-TAg mice were weaned onto and maintained on an obesogenic high fat diet. Obese mice displayed significant elevations in tumor progression, but not latency or burden. Tumor progression was significantly reversed when obese mice were induced to lose weight by switching to a control low fat diet prior to tumor onset compared to mice maintained on obesogenic diet. It is likely that other factors regulated tumor progression, hence we investigated the HGF/c-Met pathway known to regulate tumorigenesis. Importantly, HGF/c-Met expression in normal mammary glands and c-Met in tumors was elevated with obesity and was significantly reversed with weight loss. Changes in tumor growth could not be explained by measures of HGF action including phospho-AKT or phospho-S6. Other mediators associated with oncogenesis such as hyperinsulinemia and a high leptin/adiponectin ratio were elevated by obesity and reduced with weight loss. In sum, weight loss significantly blunted the obesity-responsive pro-tumorigenic HGF/c-Met pathway and improved several metabolic risk factors associated with BBC, which together may have contributed to the dramatic reversal of obesity-driven tumor

  14. A novel antagonist anti-cMet antibody with antitumor activities targeting both ligand-dependent and ligand-independent c-Met receptors.

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    Gonzalez, Alexandra; Broussas, Matthieu; Beau-Larvor, Charlotte; Haeuw, Jean-François; Boute, Nicolas; Robert, Alain; Champion, Thierry; Beck, Alain; Bailly, Christian; Corvaïa, Nathalie; Goetsch, Liliane

    2016-10-15

    c-Met is a prototypic member of a sub-family of RTKs. Inappropriate c-Met activation plays a crucial role in tumor formation, proliferation and metastasis. Using a key c-Met dimerization assay, a set of 12 murine whole IgG1 monoclonal antibodies was selected and a lead candidate, m224G11, was humanized by CDR-grafting and engineered to generate a divalent full antagonist humanized IgG1 antibody, hz224G11. Neither m224G11 nor hz224G11 bind to the murine c-Met receptor. Their antitumor activity was investigated in vitro in a set of experiments consistent with the reported pleiotropic effects mediated by c-Met and, in vivo, using several human tumor xenograft models. Both m224G11 and hz224G11 exhibited nanomolar affinities for the receptor and inhibited HGF binding, c-Met phosphorylation, and receptor dimerization in a similar fashion, resulting in a profound inhibition of all c-Met functions in vitro. These effects were presumably responsible for the inhibition of c-Met's major functions including cell proliferation, migration, invasion scattering, morphogenesis and angiogenesis. In addition to these in vitro properties, hz224G11 dramatically inhibits the growth of autocrine, partially autophosphorylated and c-Met amplified cell lines in vivo. Pharmacological studies performed on Hs746T gastric cancer xenografts demonstrate that hz224G11 strongly downregulates c-Met expression and phosphorylation. It also decreases the tumor mitotic index (Ki67) and induces apoptosis. Taken together, the in vitro and in vivo data suggest that hz224G11 is a promising candidate for the treatment of tumors. This antibody, now known as ABT-700 and currently in Phase I clinical trials, may provide a novel therapeutic approach to c-Met-expressing cancers.

  15. TGF-β Negatively Regulates CXCL1 Chemokine Expression in Mammary Fibroblasts through Enhancement of Smad2/3 and Suppression of HGF/c-Met Signaling Mechanisms.

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    Wei Bin Fang

    Full Text Available Fibroblasts are major cellular components of the breast cancer stroma, and influence the growth, survival and invasion of epithelial cells. Compared to normal tissue fibroblasts, carcinoma associated fibroblasts (CAFs show increased expression of numerous soluble factors including growth factors and cytokines. However, the mechanisms regulating expression of these factors remain poorly understood. Recent studies have shown that breast CAFs overexpress the chemokine CXCL1, a key regulator of tumor invasion and chemo-resistance. Increased expression of CXCL1 in CAFs correlated with poor patient prognosis, and was associated with decreased expression of TGF-β signaling components. The goal of these studies was to understand the role of TGF-β in regulating CXCL1 expression in CAFs, using cell culture and biochemical approaches. We found that TGF-β treatment decreased CXCL1 expression in CAFs, through Smad2/3 dependent mechanisms. Chromatin immunoprecipitation and site-directed mutagenesis assays revealed two new binding sites in the CXCL1 promoter important for Smad2/3 modulation of CXCL1 expression. Smad2/3 proteins also negatively regulated expression of Hepatocyte Growth Factor (HGF, which was found to positively regulate CXCL1 expression in CAFs through c-Met receptor dependent mechanisms. HGF/c-Met signaling in CAFs was required for activity of NF-κB, a transcriptional activator of CXCL1 expression. These studies indicate that TGF-β negatively regulates CXCL1 expression in CAFs through Smad2/3 binding to the promoter, and through suppression of HGF/c-Met autocrine signaling. These studies reveal novel insight into how TGF-β and HGF, key tumor promoting factors modulate CXCL1 chemokine expression in CAFs.

  16. Blood vessel endothelium-directed tumor cell streaming in breast tumors requires the HGF/C-Met signaling pathway.

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    Leung, E; Xue, A; Wang, Y; Rougerie, P; Sharma, V P; Eddy, R; Cox, D; Condeelis, J

    2016-11-28

    During metastasis to distant sites, tumor cells migrate to blood vessels. In vivo, breast tumor cells utilize a specialized mode of migration known as streaming, where a linear assembly of tumor cells migrate directionally towards blood vessels on fibronectin-collagen I-containing extracellular matrix (ECM) fibers in response to chemotactic signals. We have successfully reconstructed tumor cell streaming in vitro by co-plating tumors cells, macrophages and endothelial cells on 2.5 μm thick ECM-coated micro-patterned substrates. We found that tumor cells and macrophages, when plated together on the micro-patterned substrates, do not demonstrate sustained directional migration in only one direction (sustained directionality) but show random bi-directional walking. Sustained directionality of tumor cells as seen in vivo was established in vitro when beads coated with human umbilical vein endothelial cells were placed at one end of the micro-patterned 'ECM fibers' within the assay. We demonstrated that these endothelial cells supply the hepatocyte growth factor (HGF) required for the chemotactic gradient responsible for sustained directionality. Using this in vitro reconstituted streaming system, we found that directional streaming is dependent on, and most effectively blocked, by inhibiting the HGF/C-Met signaling pathway between endothelial cells and tumor cells. Key observations made with the in vitro reconstituted system implicating C-Met signaling were confirmed in vivo in mammary tumors using the in vivo invasion assay and intravital multiphoton imaging of tumor cell streaming. These results establish HGF/C-Met as a central organizing signal in blood vessel-directed tumor cell migration in vivo and highlight a promising role for C-Met inhibitors in blocking tumor cell streaming and metastasis in vivo, and for use in human trials.Oncogene advance online publication, 28 November 2016; doi:10.1038/onc.2016.421.

  17. Correlations of microvascular blood flow of contrast-enhanced ultrasound and HGF/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma

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    Zhuang, Peng-Hui; Xu, Lei; Gao, Lu; Lu, Wei; Ruan, Li-Tao; Yang, Jin

    2017-01-01

    The study is designed to explore the correlations of microvascular blood flow of contrast-enhanced ultrasound (CEUS) and hepatocyte growth factor (HGF)/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma (HCC). One hundred and eighteen patients pathologically diagnosed as primary HCC were selected. All HCC patients underwent CEUS examination before operation. HCC tissues and adjacent normal tissue specimens were obtained to detect the protein rates of HGF and c-Met expressions by immunohistochemistry. The mRNA expressions of HGF and c-Met were detected by quantitative real-time polymerase chase reaction assay. The microvessel density (MVD) was tested by CD34 immunohistochemistry. Compared with liver parenchyma, the HCC lesions had higher MVD, preoperative peak intensity (PI), area under the curve (AUC), lower preoperative time to peak (TTP), and washout time (WOT). Compared with adjacent normal tissues, the protein and mRNA expressions of HGF were reduced in HCC tissues, but the protein and mRNA expressions of c-Met and MVD were increased. The protein expressions of HGF and c-Met exhibited evident correlations with TNM stage, tumor size, vascular invasion, liver cirrhosis, and hepatitis B virus and hepatitis C virus infection of HCC patients. The tumor size and number, vascular invasion, the protein expressions of HGF and c-Met, and MVD were associated with the TTP, PI, WOT, and AUC of CEUS in HCC patients. The protein expressions of HGF and c-Met, MVD and preoperative PI revealed negative associations with the prognosis of HCC patients. In conclusion, quantitative parameters of CEUS and HGF/c-Met signaling pathway-related proteins may be helpful for early diagnosis and prognosis prediction of HCC patients.

  18. Obesity-mediated regulation of HGF/c-Met is associated with reduced basal-like breast cancer latency in parous mice.

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    Sneha Sundaram

    Full Text Available It is widely thought that pregnancy reduces breast cancer risk, but this lacks consideration of breast cancer subtypes. While a full term pregnancy reduces risk for estrogen receptor positive (ER+ and luminal breast cancers, parity is associated with increased risk of basal-like breast cancer (BBC subtype. Basal-like subtypes represent less than 10% of breast cancers and are highly aggressive, affecting primarily young, African American women. Our previous work demonstrated that high fat diet-induced obesity in nulliparous mice significantly blunted latency in C3(1-TAg mice, a model of BBC, potentially through the hepatocyte growth factor (HGF/c-Met oncogenic pathway. Experimental studies have examined parity and obesity individually, but to date, the joint effects of parity and obesity have not been studied. We investigated the role of obesity in parous mice on BBC. Parity alone dramatically blunted tumor latency compared to nulliparous controls with no effects on tumor number or growth, while obesity had only a minor role in further reducing latency. Obesity-associated metabolic mediators and hormones such as insulin, estrogen, and progesterone were not significantly regulated by obesity. Plasma IL-6 was also significantly elevated by obesity in parous mice. We have previously reported a potential role for stromal-derived hepatocyte growth factor (HGF via its cognate receptor c-Met in the etiology of obesity-induced BBC tumor onset and in both human and murine primary coculture models of BBC-aggressiveness. Obesity-associated c-Met concentrations were 2.5-fold greater in normal mammary glands of parous mice. Taken together, our studies demonstrate that, parity in C3(1-TAg mice dramatically reduced BBC latency compared to nulliparous mice. In parous mice, c-Met is regulated by obesity in unaffected mammary gland and is associated with tumor onset. C3(1-TAg mice recapitulate epidemiologic findings such that parity drives increased BBC risk and

  19. Obesity-Mediated Regulation of HGF/c-Met Is Associated with Reduced Basal-Like Breast Cancer Latency in Parous Mice

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    Sundaram, Sneha; Freemerman, Alex J.; Galanko, Joseph A.; McNaughton, Kirk K.; Bendt, Katharine M.; Darr, David B.; Troester, Melissa A.; Makowski, Liza

    2014-01-01

    It is widely thought that pregnancy reduces breast cancer risk, but this lacks consideration of breast cancer subtypes. While a full term pregnancy reduces risk for estrogen receptor positive (ER+) and luminal breast cancers, parity is associated with increased risk of basal-like breast cancer (BBC) subtype. Basal-like subtypes represent less than 10% of breast cancers and are highly aggressive, affecting primarily young, African American women. Our previous work demonstrated that high fat diet-induced obesity in nulliparous mice significantly blunted latency in C3(1)-TAg mice, a model of BBC, potentially through the hepatocyte growth factor (HGF)/c-Met oncogenic pathway. Experimental studies have examined parity and obesity individually, but to date, the joint effects of parity and obesity have not been studied. We investigated the role of obesity in parous mice on BBC. Parity alone dramatically blunted tumor latency compared to nulliparous controls with no effects on tumor number or growth, while obesity had only a minor role in further reducing latency. Obesity-associated metabolic mediators and hormones such as insulin, estrogen, and progesterone were not significantly regulated by obesity. Plasma IL-6 was also significantly elevated by obesity in parous mice. We have previously reported a potential role for stromal-derived hepatocyte growth factor (HGF) via its cognate receptor c-Met in the etiology of obesity-induced BBC tumor onset and in both human and murine primary coculture models of BBC-aggressiveness. Obesity-associated c-Met concentrations were 2.5-fold greater in normal mammary glands of parous mice. Taken together, our studies demonstrate that, parity in C3(1)-TAg mice dramatically reduced BBC latency compared to nulliparous mice. In parous mice, c-Met is regulated by obesity in unaffected mammary gland and is associated with tumor onset. C3(1)-TAg mice recapitulate epidemiologic findings such that parity drives increased BBC risk and potential

  20. Obesity-mediated regulation of HGF/c-Met is associated with reduced basal-like breast cancer latency in parous mice.

    Science.gov (United States)

    Sundaram, Sneha; Freemerman, Alex J; Galanko, Joseph A; McNaughton, Kirk K; Bendt, Katharine M; Darr, David B; Troester, Melissa A; Makowski, Liza

    2014-01-01

    It is widely thought that pregnancy reduces breast cancer risk, but this lacks consideration of breast cancer subtypes. While a full term pregnancy reduces risk for estrogen receptor positive (ER+) and luminal breast cancers, parity is associated with increased risk of basal-like breast cancer (BBC) subtype. Basal-like subtypes represent less than 10% of breast cancers and are highly aggressive, affecting primarily young, African American women. Our previous work demonstrated that high fat diet-induced obesity in nulliparous mice significantly blunted latency in C3(1)-TAg mice, a model of BBC, potentially through the hepatocyte growth factor (HGF)/c-Met oncogenic pathway. Experimental studies have examined parity and obesity individually, but to date, the joint effects of parity and obesity have not been studied. We investigated the role of obesity in parous mice on BBC. Parity alone dramatically blunted tumor latency compared to nulliparous controls with no effects on tumor number or growth, while obesity had only a minor role in further reducing latency. Obesity-associated metabolic mediators and hormones such as insulin, estrogen, and progesterone were not significantly regulated by obesity. Plasma IL-6 was also significantly elevated by obesity in parous mice. We have previously reported a potential role for stromal-derived hepatocyte growth factor (HGF) via its cognate receptor c-Met in the etiology of obesity-induced BBC tumor onset and in both human and murine primary coculture models of BBC-aggressiveness. Obesity-associated c-Met concentrations were 2.5-fold greater in normal mammary glands of parous mice. Taken together, our studies demonstrate that, parity in C3(1)-TAg mice dramatically reduced BBC latency compared to nulliparous mice. In parous mice, c-Met is regulated by obesity in unaffected mammary gland and is associated with tumor onset. C3(1)-TAg mice recapitulate epidemiologic findings such that parity drives increased BBC risk and potential

  1. Expression of hepatocyte growth factor and its receptor c-Met in lens-induced myopia in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-juan; YANG Xiao-peng; WAN Guang-ming; WANG Yu-ying; ZHANG Jin-song

    2013-01-01

    Background Myopia is a common disorder and the incidence has increased yearly,but its pathogenesis remains unclear.The aim of this study was to investigate the possible role of hepatocyte growth factor (HGF) and its receptor c-Met in the development of lens-induced myopia in guinea pigs.Methods Sixty one-week-old guinea pigs were chosen.The right eyes were treated with-10.0 diopters (D) lenses as the lens-induced myopia group; the left eyes remained untreated as the control group.Six weeks later,refractive status and axial length were determined by streak retinoscopy and A-scan ultrasonography,respectively.The guinea pigs were killed and both eyes collected.Morphological changes were observed by hematoxylin and eosin staining.The expression levels of HGF,c-Met,and matrix metalloproteinase 2 (MMP-2) mRNA and protein in the posterior sclera were analyzed by RT-PCR and Western blotting,respectively.Results The lens-induced myopia group became myopic with a significant increase in axial length and a significant decrease in refraction.Compared with the control group,the posterior retina and sclera were thinner in the lens-induced myopia group.The expression levels of HGF and MMP-2 mRNA and protein and of phosphorylated c-Met protein were significantly higher in the posterior sclera of the lens-induced myopia group than in the control group (all P <0.05).In the lens-induced myopia group,the expression level of MMP-2 in the posterior sclera positively correlated with the expression level of HGF (r=0.902,P <0.05) and phosphorylated c-Met (r=0.885,P <0.05).Conclusion HGF/c-Met might play a role in the development of lens-induced myopia in guinea pigs by upregulating the expression of MMP-2.

  2. Curcumin inhibited HGF-induced EMT and angiogenesis through regulating c-Met dependent PI3K/Akt/mTOR signaling pathways in lung cancer

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    Demin Jiao

    2016-01-01

    Full Text Available The epithelial-mesenchymal transition (EMT and angiogenesis have emerged as two pivotal events in cancer progression. Curcumin has been extensively studied in preclinical models and clinical trials of cancer prevention due to its favorable toxicity profile. However, the possible involvement of curcumin in the EMT and angiogenesis in lung cancer remains unclear. This study found that curcumin inhibited hepatocyte growth factor (HGF-induced migration and EMT-related morphological changes in A549 and PC-9 cells. Moreover, pretreatment with curcumin blocked HGF-induced c-Met phosphorylation and downstream activation of Akt, mTOR, and S6. These effects mimicked that of c-Met inhibitor SU11274 or PI3 kinase inhibitor LY294002 or mTOR inhibitor rapamycin treatment. c-Met gene overexpression analysis further demonstrated that curcumin suppressed lung cancer cell EMT by inhibiting c-Met/Akt/mTOR signaling pathways. In human umbilical vein endothelial cells (HUVECs, we found that curcumin also significantly inhibited PI3K/Akt/mTOR signaling and induced apoptosis and reduced migration and tube formation of HGF-treated HUVEC. Finally, in the experimental mouse model, we showed that curcumin inhibited HGF-stimulated tumor growth and induced an increase in E-cadherin expression and a decrease in vimentin, CD34, and vascular endothelial growth factor (VEGF expression. Collectively, these findings indicated that curcumin could inhibit HGF-promoted EMT and angiogenesis by targeting c-Met and blocking PI3K/Akt/mTOR pathways.

  3. HGF/C-Met在舌部鳞状细胞癌的表达及其临床意义%Expression of Hepatocyte Growth Factor (HGF) and c-Met in Squamous Cell Carcinoma of the Oral Tongue(SCCOT)

    Institute of Scientific and Technical Information of China (English)

    陈仲伟; 徐冬贵; 朱李军; 王启朋; 冯航; 江穗

    2013-01-01

    目的:探讨肝细胞生长因子及其受体C-Met蛋白在舌鳞癌中的表达与其临床病理特征之间的关系.方法:通过免疫组化法检测10例正常舌组织、14例舌癌前病变及63例舌鳞癌中肝细胞生长因子、C-Met的表达,数据通过SPSS13.0统计软件非参数秩和检验统计.结果:肝细胞生长因子和C-Met在舌癌、舌癌前病变及正常舌组织的阳性表达率分别为84.1%、57.1%、40.0%和76.2%、35.7%、20.0%,其表达差异均具有统计学意义(P<0.05).在中、低分化组(90.3%)及有淋巴结转移组(100%)舌鳞癌中肝细胞生长因子的阳性表达率显著高于高分化组(78.1%)及无转移淋巴结组(76.7%);在Ⅲ、Ⅳ期(82.1%)及有淋巴结转移组(85.0%)的舌鳞癌中C-Met阳性表达率显著高于Ⅰ、Ⅱ期(71.4%)及无转移淋巴结组(72.1%),表达差异均具有统计学意义(p<0.05);63例舌癌组织切片中46例HGF及C-Met都有阳性表达,其在舌鳞状细胞癌中的表达显著正相关(P<0.01).结论:过度表达的HGF/C-Met可作为判断舌鳞状细胞癌生物学行为、恶性潜能和预测淋巴结转移趋势的参考指标.%Objective: To evaluate the relationship of the expression of hepatocyte growth factor (HGF)/c-Met and clinical and pathologic characteristics of patients with squamous cell carcinoma of the oral tongue(SCCOT). Methods; Tumors from 63 patients with SCCOT, precancerous lesions of tongue from 14 patients and normal tissues of the tongue from 10 patients were evaluated for the expression of HGF and c -Met by immunohistochemis-try. Results: The positive rates of HGF and c-Met immunostaining in SCCOT were 84. 1% and 76. 2% respectively, which was significantly higher than that of the precancerous and normal groups (57. 1 % ,35. 7% and 40. 0% ,20. 0%). The HGF/c-Met staining was significantly correlated with lymph node metastasis(P<0. 05), tumor classification P<0. 05) and TNM pathologic stages. There was a

  4. Aptamers Binding to c-Met Inhibiting Tumor Cell Migration.

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    Birgit Piater

    Full Text Available The human receptor tyrosine kinase c-Met plays an important role in the control of critical cellular processes. Since c-Met is frequently over expressed or deregulated in human malignancies, blocking its activation is of special interest for therapy. In normal conditions, the c-Met receptor is activated by its bivalent ligand hepatocyte growth factor (HGF. Also bivalent antibodies can activate the receptor by cross linking, limiting therapeutic applications. We report the generation of the RNA aptamer CLN64 containing 2'-fluoro pyrimidine modifications by systematic evolution of ligands by exponential enrichment (SELEX. CLN64 and a previously described single-stranded DNA (ssDNA aptamer CLN3 exhibited high specificities and affinities to recombinant and cellular expressed c-Met. Both aptamers effectively inhibited HGF-dependent c-Met activation, signaling and cell migration. We showed that these aptamers did not induce c-Met activation, revealing an advantage over bivalent therapeutic molecules. Both aptamers were shown to bind overlapping epitopes but only CLN3 competed with HGF binding to cMet. In addition to their therapeutic and diagnostic potential, CLN3 and CLN64 aptamers exhibit valuable tools to further understand the structural and functional basis for c-Met activation or inhibition by synthetic ligands and their interplay with HGF binding.

  5. 6-Phosphogluconate dehydrogenase regulates tumor cell migration in vitro by regulating receptor tyrosine kinase c-Met

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    Chan, Barden, E-mail: cchan@bidmc.harvard.edu [Division of Interdisciplinary Medicine and Biotechnology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 (United States); VanderLaan, Paul A. [Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 (United States); Sukhatme, Vikas P. [Division of Interdisciplinary Medicine and Biotechnology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 (United States)

    2013-09-20

    Highlights: •Expression of 6PGD positively correlates with advancing stage of lung carcinoma. •Knockdown of 6PGD by shRNA potently inhibits c-Met tyrosine phosphorylation. •Exogenous HGF fails to restore c-Met phosphorylation in cells with 6PGD knocked down. •6PGD knockdown results in inhibition of cell migration in vitro. •Constitutively active TPR-cMet significantly restores migration of cells without 6PGD. -- Abstract: 6-Phosphogluconate dehydrogenase (6PGD) is the third enzyme in the oxidative pentose phosphate pathway (PPP). Recently, we reported that knockdown of 6PGD inhibited lung tumor growth in vitro and in a xenograft model in mice. In this study, we continued to examine the functional role of 6PGD in cancer. We show that 6PGD expression positively correlates with advancing stage of lung carcinoma. In search of functional signals related to 6PGD, we discovered that knockdown of 6PGD significantly inhibited phosphorylation of c-Met at tyrosine residues known to be critical for activity. This downregulation of c-Met phosphorylation correlated with inhibition of cell migration in vitro. Overexpression of a constitutively active c-Met specifically rescued the migration but not proliferation phenotype of 6PGD knockdown. Therefore, 6PGD appears to be required for efficient c-Met signaling and migration of tumor cells in vitro.

  6. The c-Met receptor tyrosine kinase inhibitor MP470 radiosensitizes glioblastoma cells

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    Bearss David

    2009-12-01

    Full Text Available Abstract Purpose Glioblastoma multiforme (GBM is resistant to current cytotoxic therapies, in part because of enhanced DNA repair. Activation of the receptor tyrosine kinase c-Met has been shown to protect cancer cells from DNA damage. We hypothesized that inhibiting c-Met would decrease this protection and thus sensitize resistant tumor cells to the effects of radiation therapy. Materials and methods Eight human GBM cell lines were screened for radiosensitivity to the small-molecule c-Met inhibitor MP470 with colony-count assays. Double-strand (ds DNA breaks was quantified by using antibodies to gamma H2AX. Western blotting demonstrate expression of RAD51, glycogen synthase kinase (GSK-3β, and other proteins. A murine xenograft tumor flank model was used for in vivo radiosensitization studies. Results MP470 reduced c-Met phosphorylation and enhanced radiation-induced cell kill by 0.4 logs in SF767 cells. Cells pretreated with MP470 had more ds DNA damage than cells treated with radiation alone. Mechanistically, MP470 was shown to inhibit dsDNA break repair and increase apoptosis. MP470 influences various survival and DNA repair related proteins such as pAKT, RAD51 and GSK3β. In vivo, the addition of MP470 to radiation resulted in a tumor-growth-delay enhancement ratio of 2.9 over radiation alone and extended survival time. Conclusions GBM is a disease site where radiation is often used to address both macroscopic and microscopic disease. Despite attempts at dose escalation outcomes remain poor. MP470, a potent small-molecule tyrosine kinase inhibitor of c-Met, radiosensitized several GBM cell lines both in vitro and in vivo, and may help to improve outcomes for patients with GBM.

  7. Inhibition of c-Met as a Therapeutic Strategy for Esophageal Adenocarcinoma

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    Gregory A. Watson

    2006-11-01

    Full Text Available The hepatocyte growth factor (HGF receptor c-Met is a tyrosine kinase receptor with established oncogenic properties. We have previously shown that c-Met is usually overexpressed in esophageal adenocarcinoma (EA, yet the implications of c-Met inhibition in EA remain unknown. Three c-Met-overexpressiog EA cell lines (Seg-1, Bic-1, Flo-1 were used to examine the effects of a c-Met-specific small molecule inhibitor (PHA665752 on cell viability, apoptosis, motility, invasion, downstream signaling pathways. PHA665752 demonstrated dose-dependent inhibition of constitutive and/or HGF-induced phosphorylation of c-Met, which correlated with reduced cell viability and inhibition of extracellular regulated kinase 1/2 phosphorylation in all three EA cell lines. In contrast, PHA665752 induced apoptosis and reduced motility and invasion in only one EA cell line, Flo-1. Interestingly, Flo-1 was the only cell line in which phosphatidylinositol 3-kinase (PI3K/Akt was induced following HGF stimulation. The PI3K inhibitor LY294002 produced effects equivalent to those of PHA665752 in these cells. We conclude that inhibition of c-Met may be a useful therapeutic strategy for EA. Factors other than receptor overexpression, such as c-Met-dependent PI3K/Akt signaling, may be predictive of an individual tumor's response to c-Met inhibition.

  8. Expressions of estrogen receptor subtypes and c-met proto-oncogene in endometrial carcinoma and their correlation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Objective To investigate the expressions of estrogen receptor(ER)subtypes and c-met proto-oncogene in human endometrial carcinomas and to assess the clinical significance of ER and c-met in this carcinoma.Methods Reverse transcription PCR(RT-PCR)was used to detect the expressions of ERα,ERβ and c-met proto-oncogene mRNA in 30 samples of endometrial carcinoma and 11 samples of normal endometrium.Results The expression of ERα in endometrial carcinoma(0.70±0.40)was significantly reduced in comparison to that i...

  9. Hepatocyte growth factor/cMET pathway activation enhances cancer hallmarks in adrenocortical carcinoma

    Science.gov (United States)

    Phan, Liem M.; Fuentes-Mattei, Enrique; Wu, Weixin; Velazquez-Torres, Guermarie; Sircar, Kanishka; Wood, Christopher G.; Hai, Tao; Jimenez, Camilo; Cote, Gilbert J.; Ozsari, Levent; Hofmann, Marie-Claude; Zheng, Siyuan; Verhaak, Roeland; Pagliaro, Lance; Cortez, Maria Angelica; Lee, Mong-Hong; Yeung, Sai-Ching J.; Habra, Mouhammed Amir

    2015-01-01

    Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis and limited response to chemotherapy. Hepatocyte growth factor (HGF) and its receptor cMET augment cancer growth and resistance to chemotherapy, but their role in ACC has not been examined. In this study, we investigated the association between HGF/cMET expression and cancer hallmarks of ACC. Transcriptomic and immunohistochemical analyses indicated that increased HGF/cMET expression in human ACC samples was positively associated with cancer-related biological processes including proliferation and angiogenesis, and negatively correlated with apoptosis. Accordingly, treatment of ACC cells with exogenous HCG resulted in increased cell proliferation in vitro and in vivo while short hairpin RNA-mediated knockdown or pharmacological inhibition of cMET suppressed cell proliferation and tumor growth. Moreover, exposure of cells to mitotane, cisplatin, or radiation rapidly induced pro-cMET expression and was associated with an enrichment of genes (e.g., CYP450 family) related to therapy resistance further implicating cMET in the anticancer drug response. Together, these data suggest an important role for HGF/cMET signaling in ACC growth and resistance to commonly used treatments. Targeting cMET, alone or in combination with other drugs, could provide a breakthrough in the management of this aggressive cancer. PMID:26282167

  10. The EGFR/ErbB3 Pathway Acts as a Compensatory Survival Mechanism upon c-Met Inhibition in Human c-Met+ Hepatocellular Carcinoma.

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    Steven N Steinway

    Full Text Available c-Met, a high-affinity receptor for Hepatocyte Growth Factor (HGF, plays a critical role in tumor growth, invasion, and metastasis. Hepatocellular carcinoma (HCC patients with activated HGF/c-Met signaling have a significantly worse prognosis. Targeted therapies using c-Met tyrosine kinase inhibitors are currently in clinical trials for HCC, although receptor tyrosine kinase inhibition in other cancers has demonstrated early success. Unfortunately, therapeutic effect is frequently not durable due to acquired resistance.We utilized the human MHCC97-H c-Met positive (c-Met+ HCC cell line to explore the compensatory survival mechanisms that are acquired after c-Met inhibition. MHCC97-H cells with stable c-Met knockdown (MHCC97-H c-Met KD cells were generated using a c-Met shRNA vector with puromycin selection and stably transfected scrambled shRNA as a control. Gene expression profiling was conducted, and protein expression was analyzed to characterize MHCC97-H cells after blockade of the c-Met oncogene. A high-throughput siRNA screen was performed to find putative compensatory survival proteins, which could drive HCC growth in the absence of c-Met. Findings from this screen were validated through subsequent analyses.We have previously demonstrated that treatment of MHCC97-H cells with a c-Met inhibitor, PHA665752, results in stasis of tumor growth in vivo. MHCC97-H c-Met KD cells demonstrate slower growth kinetics, similar to c-Met inhibitor treated tumors. Using gene expression profiling and siRNA screening against 873 kinases and phosphatases, we identified ErbB3 and TGF-α as compensatory survival factors that are upregulated after c-Met inhibition. Suppressing these factors in c-Met KD MHCC97-H cells suppresses tumor growth in vitro. In addition, we found that the PI3K/Akt signaling pathway serves as a negative feedback signal responsible for the ErbB3 upregulation after c-Met inhibition. Furthermore, in vitro studies demonstrate that

  11. Efficacy of c-Met inhibitor for advanced prostate cancer

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    Christensen James G

    2010-10-01

    Full Text Available Abstract Background Aberrant expression of HGF/SF and its receptor, c-Met, often correlates with advanced prostate cancer. Our previous study showed that expression of c-Met in prostate cancer cells was increased after attenuation of androgen receptor (AR signalling. This suggested that current androgen ablation therapy for prostate cancer activates c-Met expression and may contribute to development of more aggressive, castration resistant prostate cancer (CRPC. Therefore, we directly assessed the efficacy of c-Met inhibition during androgen ablation on the growth and progression of prostate cancer. Methods We tested two c-Met small molecule inhibitors, PHA-665752 and PF-2341066, for anti-proliferative activity by MTS assay and cell proliferation assay on human prostate cancer cell lines with different levels of androgen sensitivity. We also used renal subcapsular and castrated orthotopic xenograft mouse models to assess the effect of the inhibitors on prostate tumor formation and progression. Results We demonstrated a dose-dependent inhibitory effect of PHA-665752 and PF-2341066 on the proliferation of human prostate cancer cells and the phosphorylation of c-Met. The effect on cell proliferation was stronger in androgen insensitive cells. The c-Met inhibitor, PF-2341066, significantly reduced growth of prostate tumor cells in the renal subcapsular mouse model and the castrated orthotopic mouse model. The effect on cell proliferation was greater following castration. Conclusions The c-Met inhibitors demonstrated anti-proliferative efficacy when combined with androgen ablation therapy for advanced prostate cancer.

  12. The c-Met Inhibitor MSC2156119J Effectively Inhibits Tumor Growth in Liver Cancer Models

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    Bladt, Friedhelm, E-mail: Friedhelm.Bladt@merckgroup.com; Friese-Hamim, Manja; Ihling, Christian; Wilm, Claudia; Blaukat, Andree [EMD Serono, and Merck Serono Research and Development, Merck KGaA, Darmstadt 64293 (Germany)

    2014-08-19

    The mesenchymal-epithelial transition factor (c-Met) is a receptor tyrosine kinase with hepatocyte growth factor (HGF) as its only high-affinity ligand. Aberrant activation of c-Met is associated with many human malignancies, including hepatocellular carcinoma (HCC). We investigated the in vivo antitumor and antimetastatic efficacy of the c-Met inhibitor MSC2156119J (EMD 1214063) in patient-derived tumor explants. BALB/c nude mice were inoculated with MHCC97H cells or with tumor fragments of 10 patient-derived primary liver cancer explants selected according to c-Met/HGF expression levels. MSC2156119J (10, 30, and 100 mg/kg) and sorafenib (50 mg/kg) were administered orally as single-agent treatment or in combination, with vehicle as control. Tumor response, metastases formation, and alpha fetoprotein (AFP) levels were measured. MSC2156119J inhibited tumor growth and induced complete regression in mice bearing subcutaneous and orthotopic MHCC97H tumors. AFP levels were undetectable after 5 weeks of MSC2156119J treatment, and the number of metastatic lung foci was reduced. Primary liver explant models with strong c-Met/HGF activation showed increased responsiveness to MSC2156119J, with MSC2156119J showing similar or superior activity to sorafenib. Tumors characterized by low c-Met expression were less sensitive to MSC2156119J. MSC2156119J was better tolerated than sorafenib, and combination therapy did not improve efficacy. These findings indicate that selective c-Met/HGF inhibition with MSC2156119J is associated with marked regression of c-Met high-expressing tumors, supporting its clinical development as an antitumor treatment for HCC patients with active c-Met signaling.

  13. The clinical and functional significance of c-Met in breast cancer: a review.

    Science.gov (United States)

    Ho-Yen, Colan M; Jones, J Louise; Kermorgant, Stephanie

    2015-04-08

    c-Met is a receptor tyrosine kinase that upon binding of its ligand, hepatocyte growth factor (HGF), activates downstream pathways with diverse cellular functions that are important in organ development and cancer progression. Anomalous c-Met signalling has been described in a variety of cancer types, and the receptor is regarded as a novel therapeutic target. In breast cancer there is a need to develop new treatments, particularly for the aggressive subtypes such as triple-negative and basal-like cancer, which currently lack targeted therapy. Over the last two decades, much has been learnt about the functional role of c-Met signalling in different models of breast development and cancer. This work has been complemented by clinical studies, establishing the prognostic significance of c-Met in tissue samples of breast cancer. While the clinical trials of anti-c-Met therapy in advanced breast cancer progress, there is a need to review the existing evidence so that the potential of these treatments can be better appreciated. The aim of this article is to examine the role of HGF/c-Met signalling in in vitro and in vivo models of breast cancer, to describe the mechanisms of aberrant c-Met signalling in human tissues, and to give a brief overview of the anti-c-Met therapies currently being evaluated in breast cancer patients. We will show that the HGF/c-Met pathway is associated with breast cancer progression and suggest that there is a firm basis for continued development of anti-c-Met treatment, particularly for patients with basal-like and triple-negative breast cancer.

  14. Impact of Cell-surface Antigen Expression on Target Engagement and Function of an Epidermal Growth Factor Receptor × c-MET Bispecific Antibody*

    Science.gov (United States)

    Jarantow, Stephen W.; Bushey, Barbara S.; Pardinas, Jose R.; Boakye, Ken; Lacy, Eilyn R.; Sanders, Renouard; Sepulveda, Manuel A.; Moores, Sheri L.; Chiu, Mark L.

    2015-01-01

    The efficacy of engaging multiple drug targets using bispecific antibodies (BsAbs) is affected by the relative cell-surface protein levels of the respective targets. In this work, the receptor density values were correlated to the in vitro activity of a BsAb (JNJ-61186372) targeting epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (c-MET). Simultaneous binding of the BsAb to both receptors was confirmed in vitro. By using controlled Fab-arm exchange, a set of BsAbs targeting EGFR and c-MET was generated to establish an accurate receptor quantitation of a panel of lung and gastric cancer cell lines expressing heterogeneous levels of EGFR and c-MET. EGFR and c-MET receptor density levels were correlated to the respective gene expression levels as well as to the respective receptor phosphorylation inhibition values. We observed a bias in BsAb binding toward the more highly expressed of the two receptors, EGFR or c-MET, which resulted in the enhanced in vitro potency of JNJ-61186372 against the less highly expressed target. On the basis of these observations, we propose an avidity model of how JNJ-61186372 engages EGFR and c-MET with potentially broad implications for bispecific drug efficacy and design. PMID:26260789

  15. Impact of Cell-surface Antigen Expression on Target Engagement and Function of an Epidermal Growth Factor Receptor × c-MET Bispecific Antibody.

    Science.gov (United States)

    Jarantow, Stephen W; Bushey, Barbara S; Pardinas, Jose R; Boakye, Ken; Lacy, Eilyn R; Sanders, Renouard; Sepulveda, Manuel A; Moores, Sheri L; Chiu, Mark L

    2015-10-09

    The efficacy of engaging multiple drug targets using bispecific antibodies (BsAbs) is affected by the relative cell-surface protein levels of the respective targets. In this work, the receptor density values were correlated to the in vitro activity of a BsAb (JNJ-61186372) targeting epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (c-MET). Simultaneous binding of the BsAb to both receptors was confirmed in vitro. By using controlled Fab-arm exchange, a set of BsAbs targeting EGFR and c-MET was generated to establish an accurate receptor quantitation of a panel of lung and gastric cancer cell lines expressing heterogeneous levels of EGFR and c-MET. EGFR and c-MET receptor density levels were correlated to the respective gene expression levels as well as to the respective receptor phosphorylation inhibition values. We observed a bias in BsAb binding toward the more highly expressed of the two receptors, EGFR or c-MET, which resulted in the enhanced in vitro potency of JNJ-61186372 against the less highly expressed target. On the basis of these observations, we propose an avidity model of how JNJ-61186372 engages EGFR and c-MET with potentially broad implications for bispecific drug efficacy and design.

  16. Biochemical and pharmacological characterization of human c-Met neutralizing monoclonal antibody CE-355621

    Science.gov (United States)

    Michaud, Neil R.; Jani, Jitesh P.; Hillerman, Stephen; Tsaparikos, Konstantinos E.; Barbacci-Tobin, Elsa G.; Knauth, Elisabeth; Putz Jr., Henry; Campbell, Mary; Karam, George A.; Chrunyk, Boris; Gebhard, David F.; Green, Larry L.; Xu, Jinghai J.; Dunn, Margaret C.; Coskran, Tim M.; Lapointe, Jean-Martin; Cohen, Bruce D.; Coleman, Kevin G.; Bedian, Vahe; Vincent, Patrick; Kajiji, Shama; Steyn, Stefan J.; Borzillo, Gary V.; Los, Gerrit

    2012-01-01

    The c-Met proto-oncogene is a multifunctional receptor tyrosine kinase that is stimulated by its ligand, hepatocyte growth factor (HGF), to induce cell growth, motility and morphogenesis. Dysregulation of c-Met function, through mutational activation or overexpression, has been observed in many types of cancer and is thought to contribute to tumor growth and metastasis by affecting mitogenesis, invasion, and angiogenesis. We identified human monoclonal antibodies that bind to the extracellular domain of c-Met and inhibit tumor growth by interfering with ligand-dependent c-Met activation. We identified antibodies representing four independent epitope classes that inhibited both ligand binding and ligand-dependent activation of c-Met in A549 cells. In cells, the antibodies antagonized c-Met function by blocking receptor activation and by subsequently inducing downregulation of the receptor, translating to phenotypic effects in soft agar growth and tubular morphogenesis assays. Further characterization of the antibodies in vivo revealed significant inhibition of c-Met activity (≥ 80% lasting for 72–96 h) in excised tumors corresponded to tumor growth inhibition in multiple xenograft tumor models. Several of the antibodies identified inhibited the growth of tumors engineered to overexpress human HGF and human c-Met (S114 NIH 3T3) when grown subcutaneously in athymic mice. Furthermore, lead candidate antibody CE-355621 inhibited the growth of U87MG human glioblastoma and GTL-16 gastric xenografts by up to 98%. The findings support published pre-clinical and clinical data indicating that targeting c-Met with human monoclonal antibodies is a promising therapeutic approach for the treatment of cancer. PMID:23007574

  17. Activation of c-MET induces a stem-like phenotype in human prostate cancer.

    Directory of Open Access Journals (Sweden)

    Geert J L H van Leenders

    Full Text Available Prostate cancer consists of secretory cells and a population of immature cells. The function of immature cells and their mutual relation with secretory cells are still poorly understood. Immature cells either have a hierarchical relation to secretory cells (stem cell model or represent an inducible population emerging upon appropriate stimulation of differentiated cells. Hepatocyte Growth Factor (HGF receptor c-MET is specifically expressed in immature prostate cells. Our objective is to determine the role of immature cells in prostate cancer by analysis of the HGF/c-MET pathway.Gene-expression profiling of DU145 prostate cancer cells stimulated with HGF revealed induction of a molecular signature associated with stem cells, characterized by up-regulation of CD49b, CD49f, CD44 and SOX9, and down-regulation of CD24 ('stem-like signature'. We confirmed the acquisition of a stem-like phenotype by quantitative PCR, FACS analysis and Western blotting. Further, HGF led to activation of the stem cell related Notch pathway by up-regulation of its ligands Jagged-1 and Delta-like 4. Small molecules SU11274 and PHA665752 targeting c-MET activity were both able to block the molecular and biologic effects of HGF. Knock-down of c-MET by shRNA infection resulted in significant reduction and delay of orthotopic tumour-formation in male NMRI mice. Immunohistochemical analysis in prostatectomies revealed significant enrichment of c-MET positive cells at the invasive front, and demonstrated co-expression of c-MET with stem-like markers CD49b and CD49f.In conclusion, activation of c-MET in prostate cancer cells induced a stem-like phenotype, indicating a dynamic relation between differentiated and stem-like cells in this malignancy. Its mediation of efficient tumour-formation in vivo and predominant receptor expression at the invasive front implicate that c-MET regulates tumour infiltration in surrounding tissues putatively by acquisition of a stem-like phenotype.

  18. Inhibition of c-Met activation sensitizes osteosarcoma cells to cisplatin via suppression of the PI3K-Akt signaling.

    Science.gov (United States)

    Wang, Kelai; Zhuang, Yan; Liu, Chunlan; Li, Yang

    2012-10-01

    Osteosarcoma is a common malignant bone tumor. Cisplatin (CDDP) achieves a high response rate in osteosarcoma. However, osteosarcoma usually exhibits cisplatin resistance. Many members of receptor tyrosine kinases (RTKs)(1) have been demonstrated to be overexpressed and constitutively activated in various tumors including osteosarcoma, resulting in malignant progression and insensitivity to chemotherapy. Hepatocyte growth factor receptor (HGFR/c-Met) also appears overexpressed and activated in osteosarcoma cells. Nevertheless, which role of c-Met activation in cisplatin efficacy against osteosarcoma cells remains still elusive. This study found that inhibition of c-Met activity by PHA-665752 or blockade of the interaction of autocrined HGF with c-Met with neutralizing anti-HGF antibody promoted cisplatin efficacy in osteosarcoma cells, while addition of recombinant human HGF (rh-HGF) counteracts cisplatin cytotoxicity. Specifically, we demonstrated that inhibition of c-Met activity led to suppression of the PI3K-Akt pathway, thus enhancing cisplatin chemosensitivity. Our study clearly suggests that inhibition of c-Met activity can effectively sensitize osteosarcoma cells to cisplatin via suppression of the PI3K-Akt signaling.

  19. ExpressionofEzrin,HGF,C-metinpancreatic cancerandnon-cancerouspancreatic tissuesofrats

    Institute of Scientific and Technical Information of China (English)

    Xing-Guo Tan; Zhu-Lin Yang

    2010-01-01

    BACKGROUND: Recent studies have conifrmed that the expression of Ezrin, hepatocyte growth factor (HGF) and its receptor (C-met) is related to the genesis, progress, invasion and metastasis of some malignant tumors. Researches have also found that the biological function of Ezrin is closely related to HGF/C-met in malignant tumors. However, there is no report on the expression levels of Ezrin, HGF and C-met in rat pancreatic cancer induced by dimethylbenzanthracene (DMBA). This study aimed to detect the expression of Ezrin, HGF and C-met in rat pancreatic cancer and non-cancerous pancreatic tissues, and assess its effect in cancer induction by DMBA. METHODS: Ninety Sprague-Dawley rats were divided into 3 groups randomly: 40 in a pancreatic cancer model group (group A), 40 in a trichostatin A (TSA) intervention group (group B), and 10 in a control group (group C). DMBA was directly implanted into the parenchyma of rat pancreas in group A+group B. The rats of group B were treated with 1 ml of TSA saline solution (1μg/ml) via intraperitoneal injection weekly. The carcinogenesis of rats executed within 3-5 months in groups A and B was observed by macrograph and microscopy. Meanwhile, the rats in group C were executed within 5 months. The EnVisionTM immunohistochemistry for detecting the expression levels of Ezrin, HGF and C-met was used in parafifn-embedded sections of the pancreatic specimens. RESULTS: The incidence of pancreatic cancer in group A was 48.6%and in group B 33.3%. The maximal diameter of tumor mass was signiifcantly larger in group A than that in group B (P in the pancreas of group C and other main organs of groups A and B. The positive rates of Ezrin, HGF and C-met were signiifcantly higher in ductal adenocarcinoma than in non-cancerous pancreatic tissues of groups A and B (P0.05). The positive rates of Ezrin, HGF and C-met in non-cancerous pancreatic tissues proved mild to severe atypical hyperplasia of the ductal epithelia. The pancreas of group

  20. Isolation and characterization of anti c-met single chain fragment variable (scFv) antibodies.

    Science.gov (United States)

    Qamsari, Elmira Safaie; Sharifzadeh, Zahra; Bagheri, Salman; Riazi-Rad, Farhad; Younesi, Vahid; Abolhassani, Mohsen; Ghaderi, Sepideh Safaei; Baradaran, Behzad; Somi, Mohammad Hossein; Yousefi, Mehdi

    2017-12-01

    The receptor tyrosine kinase (RTK) Met is the cell surface receptor for hepatocyte growth factor (HGF) involved in invasive growth programs during embryogenesis and tumorgenesis. There is compelling evidence suggesting important roles for c-Met in colorectal cancer proliferation, migration, invasion, angiogenesis, and survival. Hence, a molecular inhibitor of an extracellular domain of c-Met receptor that blocks c-Met-cell surface interactions could be of great thera-peutic importance. In an attempt to develop molecular inhibitors of c-Met, single chain variable fragment (scFv) phage display libraries Tomlinson I + J against a specific synthetic oligopeptide from the extracellular domain of c-Met receptor were screened; selected scFv were then characterized using various immune techniques. Three c-Met specific scFv (ES1, ES2, and ES3) were selected following five rounds of panning procedures. The scFv showed specific binding to c-Met receptor, and significantly inhibited proliferation responses of a human colorectal carcinoma cell line (HCT-116). Moreover, anti- apoptotic effects of selected scFv antibodies on the HCT-116 cell line were also evaluated using Annexin V/PI assays. The results demonstrated rates of apoptotic cell death of 46.0, 25.5, and 37.8% among these cells were induced by use of ES1, ES2, and ES3, respectively. The results demonstrated ability to successfully isolate/char-acterize specific c-Met scFv that could ultimately have a great therapeutic potential in immuno-therapies against (colorectal) cancers.

  1. cMET in NSCLC: Can We Cut off the Head of the Hydra? From the Pathway to the Resistance

    Directory of Open Access Journals (Sweden)

    Nele Van Der Steen

    2015-03-01

    Full Text Available In the last decade, the tyrosine kinase receptor cMET, together with its ligand hepatocyte growth factor (HGF, has become a target in non-small cell lung cancer (NSCLC. Signalization via cMET stimulates several oncological processes amongst which are cell motility, invasion and metastasis. It also confers resistance against several currently used targeted therapies, e.g., epidermal growth factor receptor (EGFR inhibitors. In this review, we will discuss the basic structure of cMET and the most important signaling pathways. We will also look into aberrations in the signaling and the effects thereof in cancer growth, with the focus on NSCLC. Finally, we will discuss the role of cMET as resistance mechanism.

  2. cMET in NSCLC: Can We Cut off the Head of the Hydra? From the Pathway to the Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Steen, Nele [Center for Oncological Research Antwerp, University of Antwerp, Universiteitsplein 1, Wilrijk 2610 (Belgium); Pauwels, Patrick [Center for Oncological Research Antwerp, University of Antwerp, Universiteitsplein 1, Wilrijk 2610 (Belgium); Molecular Pathology Unit, Pathology Department, Antwerp University Hospital, Wilrijkstraat 10, Edegem 2650 (Belgium); Gil-Bazo, Ignacio [Department of Oncology, Clínica Universidad de Navarra, Pamplona 31008 (Spain); Castañon, Eduardo [Department of Oncology, Clínica Universidad de Navarra, Pamplona 31008 (Spain); Phase I-Early Clinical Trials Unit, Oncology Department, Antwerp University Hospital, Wilrijkstraat 10, Edegem 2650 (Belgium); Raez, Luis [Thoracic Oncology Program, Memorial Cancer Institute, Memorial Health Care System, Pembroke Pines, FL 33024 (United States); Cappuzzo, Federico [4Thoracic Oncology Program, Memorial Cancer Institute, Memorial Health Care System, Pembroke Pines, FL 33024 (United States); Rolfo, Christian, E-mail: Christian.Rolfo@uza.be [Center for Oncological Research Antwerp, University of Antwerp, Universiteitsplein 1, Wilrijk 2610 (Belgium); Phase I-Early Clinical Trials Unit, Oncology Department, Antwerp University Hospital, Wilrijkstraat 10, Edegem 2650 (Belgium)

    2015-03-25

    In the last decade, the tyrosine kinase receptor cMET, together with its ligand hepatocyte growth factor (HGF), has become a target in non-small cell lung cancer (NSCLC). Signalization via cMET stimulates several oncological processes amongst which are cell motility, invasion and metastasis. It also confers resistance against several currently used targeted therapies, e.g., epidermal growth factor receptor (EGFR) inhibitors. In this review, we will discuss the basic structure of cMET and the most important signaling pathways. We will also look into aberrations in the signaling and the effects thereof in cancer growth, with the focus on NSCLC. Finally, we will discuss the role of cMET as resistance mechanism.

  3. Lysophosphatidic acid transactivates both c-Met and epidermal growth factor receptor, and induces cyclooxygenase-2 expression in human colon cancer LoVo cells

    Institute of Scientific and Technical Information of China (English)

    Dai Shida; Joji Kitayama; Hironori Yamaguchi; Hiroharu Yamashita; Ken Mori; Toshiaki Watanabe; Hirokazu Nagawa

    2005-01-01

    AIM: To examine whether lysophosphatidic acid (LPA)induces phosphorylation of c-Met and epidermal growth factor receptor (EGFR), both of which have been proposed as prognostic markers of colorectal cancer, and whether LPA induces cyclooxygenase-2 (COX-2) expression in human colon cancer cells.METHODS: Using a human colon cancer cell line, LoVo cells, we performed immunoprecipitation analysis,followed by Western blot analysis. We also examined whether LPA induced COX-2 expression, by Western blot analysis.RESULTS: Immunoprecipitation analysis revealed that 10 μmol/L LPA induced tyrosine phosphorylation of c-Met and EGFR in LoVo cells within a few minutes. We found that c-Met tyrosine phosphorylation induced by LPA was not attenuated by pertussis toxin or a matrix metalloproteinase inhibitor, in marked contrast to the results for EGFR. In addition, 0.2-40 μmol/L LPA induced COX-2 expression in a dose-dependent manner.CONCLUSION: Our results suggest that LPA acts upstream of various receptor tyrosine kinases (RTKs) and COX-2,and thus may act as a potent stimulator of colorectal cancer.

  4. Cellular and molecular mechanisms of HGF/Met in the cardiovascular system.

    Science.gov (United States)

    Gallo, Simona; Sala, Valentina; Gatti, Stefano; Crepaldi, Tiziana

    2015-12-01

    Met tyrosine kinase receptor, also known as c-Met, is the HGF (hepatocyte growth factor) receptor. The HGF/Met pathway has a prominent role in cardiovascular remodelling after tissue injury. The present review provides a synopsis of the cellular and molecular mechanisms underlying the effects of HGF/Met in the heart and blood vessels. In vivo, HGF/Met function is particularly important for the protection of the heart in response to both acute and chronic insults, including ischaemic injury and doxorubicin-induced cardiotoxicity. Accordingly, conditional deletion of Met in cardiomyocytes results in impaired organ defence against oxidative stress. After ischaemic injury, activation of Met provides strong anti-apoptotic stimuli for cardiomyocytes through PI3K (phosphoinositide 3-kinase)/Akt and MAPK (mitogen-activated protein kinase) cascades. Recently, we found that HGF/Met is also important for autophagy regulation in cardiomyocytes via the mTOR (mammalian target of rapamycin) pathway. HGF/Met induces proliferation and migration of endothelial cells through Rac1 (Ras-related C3 botulinum toxin substrate 1) activation. In fibroblasts, HGF/Met antagonizes the actions of TGFβ1 (transforming growth factor β1) and AngII (angiotensin II), thus preventing fibrosis. Moreover, HGF/Met influences the inflammatory response of macrophages and the immune response of dendritic cells, indicating its protective function against atherosclerotic and autoimmune diseases. The HGF/Met axis also plays an important role in regulating self-renewal and myocardial regeneration through the enhancement of cardiac progenitor cells. HGF/Met has beneficial effects against myocardial infarction and endothelial dysfunction: the cellular and molecular mechanisms underlying repair function in the heart and blood vessels are common and include pro-angiogenic, anti-inflammatory and anti-fibrotic actions. Thus administration of HGF or HGF mimetics may represent a promising therapeutic agent for the

  5. MicroRNA-181b-5p, ETS1, and the c-Met pathway exacerbate the prognosis of pancreatic ductal adenocarcinoma after radiation therapy.

    Science.gov (United States)

    Tomihara, Hideo; Yamada, Daisaku; Eguchi, Hidetoshi; Iwagami, Yoshifumi; Noda, Takehiro; Asaoka, Tadafumi; Wada, Hiroshi; Kawamoto, Koichi; Gotoh, Kunihito; Takeda, Yutaka; Tanemura, Masahiro; Mori, Masaki; Doki, Yuichiro

    2017-03-01

    Preoperative chemoradiation therapy (CRT) for pancreatic ductal adenocarcinoma (PDAC) has emerged as a reasonable strategy that shows good prognostic impact. However, after preoperative CRT, resected specimens show remnant tumor cells, which indicate that some tumor cells had acquired or were selected for resistance to CRT. Recently, two oncological mechanisms, the EMT and the presence of CSCs, were reported to be associated with resistance in various cancers. Previous reports showed that HGF could induce EMT in PDAC cells; moreover, the HGF receptor, c-Met, was identified as a dominant pancreatic CSC marker. However, the clinical significance of c-Met expression remains unclear. So, we hypothesized that remnant PDAC tissue after CRT might harbor cells with high c-Met expression, and these cells may exacerbate patients' prognosis. In the immunohistochemical analysis, we showed that preoperative CRT was significantly associated with high c-Met expression; moreover, high c-Met expression was a significant marker of a dismal prognosis. Next, we investigated mechanisms of c-Met upregulation in PDAC cells. We established GEM-resistant and radioresistant PDAC cells to analyze the transcriptome involved in c-Met expression. The microarray data for the established radiation-resistant PDAC cells indicated miR-181b-5p downregulation, which targets ETS1, one of the transcription factors for c-Met, and it was shown that radiation exposure induced c-Met expression through ETS1 increase by the suppression of miR-181b-5p. These results suggested that targeting these mechanisms may promote the development of a novel multidisciplinary treatment strategy for improving preoperative CRT efficiency.

  6. HGF/c-MET Pathway in AIDS-Related Lymphoma

    Science.gov (United States)

    2016-09-01

    Morrow RA, Corey L, Kiviat N, Wald A. HIV infection and human herpesvirus-8 oral shedding among men who have sex with men. J Acquir Immune Defic...progression, membrane trafficking , and stage differentiation in Giardia lamblia. J Lipid Res 2010; 519:2527-2545. 28. Abe A, Wu D, Shayman JA and Radin NS

  7. Host-pathogen systems biology: logical modelling of hepatocyte growth factor and Helicobacter pylori induced c-Met signal transduction

    Directory of Open Access Journals (Sweden)

    Kähne Thilo

    2008-01-01

    Full Text Available Abstract Background The hepatocyte growth factor (HGF stimulates mitogenesis, motogenesis, and morphogenesis in a wide range of tissues, including epithelial cells, on binding to the receptor tyrosine kinase c-Met. Abnormal c-Met signalling contributes to tumour genesis, in particular to the development of invasive and metastatic phenotypes. The human microbial pathogen Helicobacter pylori can induce chronic gastritis, peptic ulceration and more rarely, gastric adenocarcinoma. The H. pylori effector protein cytotoxin associated gene A (CagA, which is translocated via a type IV secretion system (T4SS into epithelial cells, intracellularly modulates the c-Met receptor and promotes cellular processes leading to cell scattering, which could contribute to the invasiveness of tumour cells. Using a logical modelling framework, the presented work aims at analysing the c-Met signal transduction network and how it is interfered by H. pylori infection, which might be of importance for tumour development. Results A logical model of HGF and H. pylori induced c-Met signal transduction is presented in this work. The formalism of logical interaction hypergraphs (LIH was used to construct the network model. The molecular interactions included in the model were all assembled manually based on a careful meta-analysis of published experimental results. Our model reveals the differences and commonalities of the response of the network upon HGF and H. pylori induced c-Met signalling. As another important result, using the formalism of minimal intervention sets, phospholipase Cγ1 (PLCγ1 was identified as knockout target for repressing the activation of the extracellular signal regulated kinase 1/2 (ERK1/2, a signalling molecule directly linked to cell scattering in H. pylori infected cells. The model predicted only an effect on ERK1/2 for the H. pylori stimulus, but not for HGF treatment. This result could be confirmed experimentally in MDCK cells using a specific

  8. Decorin is down-regulated in multiple myeloma and MGUS bone marrow plasma and inhibits HGF-induced myeloma plasma cell viability and migration

    DEFF Research Database (Denmark)

    Kristensen, Ida Bruun; Pedersen, Lise Mariager; Rø, Torstein Baade;

    2013-01-01

    OBJECTIVES: Decorin is a stromal-produced small leucine-rich proteoglycan known to attenuate tumour pro-survival, migration, proliferation and angiogenic signalling pathways. Recent studies have shown that decorin interacts with the hepatocyte growth factor (HGF) receptor c-Met, a potential key p...... of decorin to inhibit HGF-induced effects on MM cell lines were analysed in vitro using cell viability and Transwell migration assays. RESULTS: We found that decorin concentrations were significantly higher (p...

  9. EGFR is dispensable for c-Met-mediated proliferation and survival activities in mouse adult liver oval cells.

    Science.gov (United States)

    Martínez-Palacián, A; del Castillo, G; Herrera, B; Fernández, M; Roncero, C; Fabregat, I; Sánchez, A

    2012-02-01

    Liver progenitor cells rise as potential critical players in hepatic regeneration but also carcinogenesis. It is therefore mandatory to define the signals controlling their activation and expansion. Recently, by using a novel in vitro model of oval cell lines expressing a mutant tyrosine kinase-inactive form of c-Met we demonstrated that autocrine c-Met signalling plays an essential role in promoting oval cell survival. Here, we investigated the significance of the epidermal growth factor receptor (EGFR) signalling in oval cell proliferation and survival, as well as a potential functional crosstalk between the c-Met and the EGFR pathways. We found an autocrine activation of the EGFR-triggered pathway in Met(flx/flx) and Met(-/-) oval cells as judged by constitutive expression of the EGFR ligands, transforming growth factor-alpha (TGF-α) and heparin-binding EGF like growth factor (HB-EGF), and activation of EGFR. On the other hand, treatment with AG1478, a specific inhibitor of EGFR, effectively blocked endogenous and EGF-induced proliferation, while increased serum withdrawal and transforming growth factor-beta (TGF-β)-induced apoptosis. These results suggest that constitutively activated EGFR might promote oval cell proliferation and survival. We found that hepatocyte growth factor (HGF) does not transactivate EGFR nor EGF transactivates c-Met. Furthermore, treatment with AG1478 or EGFR gene silencing did not interfere with HGF-mediated activation of target signals, such as protein kinase B (AKT/PKB), and extracellular signal-regulated kinases 1/2 (ERK 1/2), nor did it have any effect on HGF-induced proliferative and antiapoptotic activities in Met(flx/flx) cells, showing that HGF does not require EGFR activation to mediate such responses. EGF induced proliferation and survival equally in Met(flx/flx) and Met(-/-) oval cells, proving that EGFR signalling does not depend on c-Met tyrosine kinase activity. Together, our results provide strong evidence that in

  10. Role of HGF in obesity-associated tumorigenesis: C3(1)-TAg mice as a model for human basal-like breast cancer

    Science.gov (United States)

    Sundaram, Sneha; Freemerman, Alex J.; Johnson, Amy R.; Milner, J. Justin; McNaughton, Kirk K.; Galanko, Joseph A.; Bendt, Katharine M.; Darr, David B.; Perou, Charles M.; Troester, Melissa A.; Makowski, Liza

    2013-01-01

    Obesity is associated with basal-like breast cancer (BBC), an aggressive breast cancer subtype. The objective of this study was to determine whether obesity promotes BBC onset in adulthood and to evaluate the role of stromal-epithelial interactions in obesity-associated tumorigenesis. We hypothesized that hepatocyte growth factor (HGF) plays a promoting role in BBC, which express the HGF receptor, c-Met. In C3(1)-Tag mice, a murine model of BBC, we demonstrated that obesity leads to a significant increase in HGF secretion and an associated decrease in tumor latency. By immunohistochemical analysis, normal mammary gland exhibited obesity-induced HGF, c-Met and phospho-c-Met, indicating that activation of the cascade was obesity-driven. HGF secretion was also increased from primary mammary fibroblasts isolated from normal mammary glands and tumors of obese mice compared to lean. These results demonstrate that obesity-induced elevation of HGF expression is a stable phenotype, maintained after several passages, and after removal of dietary stimulation. Conditioned media from primary tumor fibroblasts from obese mice drove tumor cell proliferation. In co-culture, neutralization of secreted HGF blunted tumor cell migration, further linking obesity-mediated HGF-dependent effects to in vitro measures of tumor aggressiveness. In sum, these results demonstrate that HGF/c-Met plays an important role in obesity-associated carcinogenesis. Understanding the effects of obesity on risk and progression is important given that epidemiologic studies imply a portion of BBC could be eliminated by reducing obesity. PMID:24218051

  11. Role of HGF in obesity-associated tumorigenesis: C3(1)-TAg mice as a model for human basal-like breast cancer.

    Science.gov (United States)

    Sundaram, Sneha; Freemerman, Alex J; Johnson, Amy R; Milner, J Justin; McNaughton, Kirk K; Galanko, Joseph A; Bendt, Katharine M; Darr, David B; Perou, Charles M; Troester, Melissa A; Makowski, Liza

    2013-12-01

    Obesity is associated with basal-like breast cancer (BBC), an aggressive breast cancer subtype. The objective of this study was to determine whether obesity promotes BBC onset in adulthood and to evaluate the role of stromal-epithelial interactions in obesity-associated tumorigenesis. We hypothesized that hepatocyte growth factor (HGF) plays a promoting role in BBC, which express the HGF receptor, c-Met. In C3(1)-T(Ag) mice, a murine model of BBC, we demonstrated that obesity leads to a significant increase in HGF secretion and an associated decrease in tumor latency. By immunohistochemical analysis, normal mammary gland exhibited obesity-induced HGF, c-Met and phospho-c-Met, indicating that the activation of the cascade was obesity-driven. HGF secretion was also increased from primary mammary fibroblasts isolated from normal mammary glands and tumors of obese mice compared to lean. These results demonstrate that obesity-induced elevation of HGF expression is a stable phenotype, maintained after several passages, and after removal of dietary stimulation. Conditioned media from primary tumor fibroblasts from obese mice drove tumor cell proliferation. In co-culture, neutralization of secreted HGF blunted tumor cell migration, further linking obesity-mediated HGF-dependent effects to in vitro measures of tumor aggressiveness. In sum, these results demonstrate that HGF/c-Met plays an important role in obesity-associated carcinogenesis. Understanding the effects of obesity on risk and progression is important given that epidemiologic studies imply a portion of BBC could be eliminated by reducing obesity.

  12. A phase-I study of lapatinib in combination with foretinib, a c-MET, AXL and vascular endothelial growth factor receptor inhibitor, in human epidermal growth factor receptor 2 (HER-2)-positive metastatic breast cancer.

    Science.gov (United States)

    Chia, Stephen K; Ellard, Susan L; Mates, Mihaela; Welch, Stephen; Mihalcioiu, Catalin; Miller, Wilson H; Gelmon, Karen; Lohrisch, Caroline; Kumar, Vikaash; Taylor, Sara; Hagerman, Linda; Goodwin, Rachel; Wang, Tao; Sakashita, Shingo; Tsao, Ming S; Eisenhauer, Elizabeth; Bradbury, Penelope

    2017-05-02

    The mechanisms of resistance to anti-human epidermal growth factor receptor 2 (HER 2) therapies are unclear but may include the tyrosine-protein kinase Met (c-Met), vascular endothelial growth factor (VEGF) and AXL pathways. Foretinib is an inhibitor of c-Met, VEGF receptor 2 (VEGFR-2), platelet-derived growth factor receptor beta (PDGFRB), AXL, Fms-like tyrosine kinase 3 (FLT3), angiopoiten receptor (TIE-2), RET and RON kinases. This phase Ib study sought to establish the associated toxicities, pharmacokinetics (PK) and recommended phase II doses (RP2D) of foretinib and lapatinib in a cohort of HER-2-positive patients with metastatic breast cancer (MBC). Women with HER-2 positive MBC, Performance status (PS 0-2), and no limit on number of prior chemotherapies or lines of anti-HER-2 therapies were enrolled. A 3 + 3 dose escalation design was utilized. Four dose levels were intended with starting doses of foretinib 30 mg and lapatinib 750 mg orally once a day (OD) on a 4-weekly cycle. Assessment of c-MET status from the primary archival tissue was performed. We enrolled 19 patients, all evaluable for toxicity assessment and for response evaluation. Median age was 60 years (34-86 years), 95% were PS 0-1, 53% were estrogen receptor-positive and 95% had at least one prior anti-HER-2-based regimen. The fourth dose level was reached (foretinib 45 mg/lapatinib 1250 mg) with dose-limiting toxicities of grade-3 diarrhea and fatigue. There was only one grade-4 non-hematological toxicity across all dose levels. There were no PK interactions between the agents. A median of two cycles was delivered across the dose levels (range 1-20) with associated progression-free survival of 3.2 months (95% CI 1.61-4.34 months). By immunohistochemical assessment with a specified cutoff, none of the 17 samples tested were classified as positive for c-Met. The RP2D of the combined foretinib and lapatinib is 45 mg and 1000 mg PO OD, respectively. Limited activity was seen with this

  13. Chronic lymphocytic leukemia nurse-like cells express hepatocyte growth factor receptor (c-MET) and indoleamine 2,3-dioxygenase and display features of immunosuppressive type 2 skewed macrophages

    Science.gov (United States)

    Giannoni, Paolo; Pietra, Gabriella; Travaini, Giorgia; Quarto, Rodolfo; Shyti, Genti; Benelli, Roberto; Ottaggio, Laura; Mingari, Maria Cristina; Zupo, Simona; Cutrona, Giovanna; Pierri, Ivana; Balleari, Enrico; Pattarozzi, Alessandra; Calvaruso, Marco; Tripodo, Claudio; Ferrarini, Manlio; de Totero, Daniela

    2014-01-01

    Hepatocyte growth factor, produced by stromal and follicular dendritic cells, and present at high concentrations in the sera of patients with chronic lymphocytic leukemia, prolongs the survival of leukemic B cells by interacting with their receptor, c-MET. It is, however, unknown whether hepatocyte growth factor influences microenvironmental cells, such as nurse-like cells, which deliver survival signals to the leukemic clone. We evaluated the expression of c-MET on nurse-like cells and monocytes from patients with chronic lymphocytic leukemia and searched for phenotypic/functional features supposed to be influenced by the hepatocyte growth factor/c-MET interaction. c-MET is expressed at high levels on nurse-like cells and at significantly higher levels than normal on monocytes from patients. Moreover, the hepatocyte growth factor/c-MET interaction activates STAT3TYR705 phosphorylation in nurse-like cells. Indoleamine 2,3-dioxygenase, an enzyme modulating T-cell proliferation and induced on normal monocytes after hepatocyte growth factor treatment, was detected together with interleukin-10 on nurse-like cells, and on freshly-prepared patients’ monocytes. Immunohistochemical/immunostaining analyses demonstrated the presence of c-MET+ and indoleamine 2,3-dioxygenase+ cells in lymph node biopsies, co-expressed with CD68 and vimentin. Furthermore nurse-like cells and chronic lymphocytic monocytes significantly inhibited T-cell proliferation, prevented by anti-transforming growth factor beta and interleukin-10 antibodies and indoleamine 2,3-dioxygenase inhibitors, and supported CD4+CD25high+/FOXP3+ T regulatory cell expansion. We suggest that nurse-like cells display features of immunosuppressive type 2 macrophages: higher hepatocyte growth factor levels, produced by leukemic or other microenvironmental surrounding cells, may cooperate to induce M2 polarization. Hepatocyte growth factor may thus have a dual pathophysiological role: directly through enhancement of

  14. The DNA replication licensing factor miniature chromosome maintenance 7 is essential for RNA splicing of epidermal growth factor receptor, c-Met, and platelet-derived growth factor receptor.

    Science.gov (United States)

    Chen, Zhang-Hui; Yu, Yan P; Michalopoulos, George; Nelson, Joel; Luo, Jian-Hua

    2015-01-16

    Miniature chromosome maintenance 7 (MCM7) is an essential component of DNA replication licensing complex. Recent studies indicate that MCM7 is amplified and overexpressed in a variety of human malignancies. In this report, we show that MCM7 binds SF3B3. The binding motif is located in the N terminus (amino acids 221-248) of MCM7. Knockdown of MCM7 or SF3B3 significantly increased unspliced RNA of epidermal growth factor receptor, platelet-derived growth factor receptor, and c-Met. A dramatic drop of reporter gene expression of the oxytocin exon 1-intron-exon 2-EGFP construct was also identified in SF3B3 and MCM7 knockdown PC3 and DU145 cells. The MCM7 or SF3B3 depleted cell extract failed to splice reporter RNA in in vitro RNA splicing analyses. Knockdown of SF3B3 and MCM7 leads to an increase of cell death of both PC3 and DU145 cells. Such cell death induction is partially rescued by expressing spliced c-Met. To our knowledge, this is the first report suggesting that MCM7 is a critical RNA splicing factor, thus giving significant new insight into the oncogenic activity of this protein.

  15. The role of cMet in non-small cell lung cancer resistant to EGFR-inhibitors: did we really find the target?

    Science.gov (United States)

    Passiglia, Francesco; Van Der Steen, Nele; Raez, Luis; Pauwels, Patrick; Gil-Bazo, Ignacio; Santos, Edgardo; Santini, Daniele; Tesoriere, Giovanni; Russo, Antonio; Bronte, Giuseppe; Zwaenepoel, Karen; Cappuzzo, Federico; Rolfo, Christian

    2014-01-01

    The advent of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) represented the most important innovation in NSCLC treatment over the last years. However, despite a great initial activity, secondary mutations in the same target, or different alterations in other molecular pathways, inevitably occur, leading to the emergence of acquired resistance, in median within the first year of treatment. In this scenario, the mesenchymal-epidermal transition (cMET) tyrosine kinase receptor and its natural ligand, the hepatocyte growth factor (HGF), seem to play an important role. Indeed either the overexpression or the amplification of cMET, as well as the overexpression of the HGF, have been reported in a substantial subgroup of NSCLC patients resistant to EGFR-TKIs. Several cMET-inhibitors have been developed as potential therapeutic candidates, and are currently under investigation in clinical trials. These compounds include both monoclonal antibodies and TKIs, and most of them have been investigated as dual combinations including an anti-EGFR TKI, to improve the efficacy of the available treatments, and ultimately overcome acquired resistance to EGFR-inhibitors.

  16. C-Met as a potential target for the treatment of gastrointestinal cancer: Current status and future perspectives.

    Science.gov (United States)

    Bahrami, Afsane; Shahidsales, Soodabeh; Khazaei, Majid; Ghayour-Mobarhan, Majid; Maftouh, Mina; Hassanian, Seyed Mahdi; Avan, Amir

    2017-10-01

    Aberrant activation of the HGF/c-Met signalling pathways is shown to be related with cell proliferation, progression, metastasis, and worse prognosis in several tumor types, including gastrointestinal cancers, suggesting its value as a stimulating-target for cancer-therapy. Several approaches have been developed for targeting HGF and/or c-Met, and one of them, crizotinib (dual c-Met/ALK inhibitor), is recently been approved by FDA for lung-cancers with ALK-rearrangement. The main aim of current review is to give an overview on the role of c-Met/HGF pathway in gastrointestinal cancer, in preclinical and clinical trials. Although several important matters is still remained to be elucidated on the molecular pathways underlying the antitumor effects of this therapy in gastrointestinal-cancers. Further investigations are warranted to recognize the main determinants of the activity of c-Met inhibitors, for parallel targeting signalling pathway associated/activated via MET/HGF pathway or in response to the cell resistance to anti-c-Met agents. Additionally, identification of patients that might benefit from therapy could help to increase the selectivity and efficacy of the therapy. © 2017 Wiley Periodicals, Inc.

  17. Fatty Acid Synthase Activity as a Target for c-Met Driven Prostate Cancer

    Science.gov (United States)

    2013-07-01

    Sharma, and H.E. Bazan , Association of protein tyrosine phosphatases (PTPs)-1B with c-Met receptor and modulation of corneal epithelial wound healing...Luteolin Post-Transcriptionally Downregulates c-Met Expression Independent of Proteosomal/Lysosomal Degradation. Mol. Cancer. Ther. 2009 Jan 1; 8(1

  18. The indole alkaloid meleagrin, from the olive tree endophytic fungus Penicillium chrysogenum, as a novel lead for the control of c-Met-dependent breast cancer proliferation, migration and invasion.

    Science.gov (United States)

    Mady, Mohamed S; Mohyeldin, Mohamed M; Ebrahim, Hassan Y; Elsayed, Heba E; Houssen, Wael E; Haggag, Eman G; Soliman, Randa F; El Sayed, Khalid A

    2016-01-15

    Fungi of the genus Penicillium produce unique and chemically diverse biologically active secondary metabolites, including indole alkaloids. The role of dysregulated hepatocyte growth factor (HGF) and its receptor, c-Met, in the development and progression of breast carcinoma is documented. The goal of this work is to explore the chemistry and bioactivity of the secondary metabolites of the endophytic Penicillium chrysogenum cultured from the leaf of the olive tree Olea europea, collected in its natural habitat in Egypt. This fungal extract showed good inhibitory activities against the proliferation and migration of several human breast cancer lines. The CH2Cl2 extract of P. chrysogenum mycelia was subjected to bioguided chromatographic separation to afford three known indole alkaloids; meleagrin (1), roquefortine C (2) and DHTD (3). Meleagrin inhibited the growth of the human breast cancer cell lines MDA-MB-231, MDA-468, BT-474, SK BR-3, MCF7 and MCF7-dox, while similar treatment doses were found to have no effect on the growth and viability of the non-tumorigenic human mammary epithelial cells MCF10A. Meleagrin also showed excellent ATP competitive c-Met inhibitory activity in Z-Lyte assay, which was further confirmed via molecular docking studies and Western blot analysis. In addition, meleagrin treatment caused a dose-dependent inhibition of HGF-induced cell migration, and invasion of breast cancer cell lines. Meleagrin treatment potently suppressed the invasive triple negative breast tumor cell growth in an orthotopic athymic nude mice model, promoting this unique natural product from hit to a lead rank. The indole alkaloid meleagrin is a novel lead c-Met inhibitory entity useful for the control of c-Met-dependent metastatic and invasive breast malignancies.

  19. The motogenic and mitogenic responses to HGF are amplified by the Shc adaptor protein

    DEFF Research Database (Denmark)

    Pelicci, G; Giordano, S; Zhen, Z

    1995-01-01

    The receptor of Hepatocyte Growth Factor-Scatter Factor (HGF) is a tyrosine kinase which regulates cell motility and growth. After ligand-induced tyrosine phosphorylation, the HGF receptor associates with the Shc adaptor, via the SH2 domain. Site-directed mutagenesis of the HGF receptor indicates...

  20. Indazoles as potential c-Met inhibitors: design, synthesis and molecular docking studies.

    Science.gov (United States)

    Ye, Lianbao; Ou, Xiaomin; Tian, Yuanxin; Yu, Bangwei; Luo, Yan; Feng, Binghong; Lin, Hansen; Zhang, Jiajie; Wu, Shuguang

    2013-07-01

    Deregulation of the receptor tyrosine kinase c-Met has been implicated in several human cancers and is considered as an attractive target for small molecule drug discovery. In this study, a series of indazoles were designed, synthesized and evaluated as novel c-Met inhibitors. The results showed that the majority of the compounds exhibited significant inhibition on c-Met and compound 4d showed highest activity against c-Met with IC50 value of 0.17 μM in TR-FRET-based assay and IC50 value of 5.45 μM in cell-based assay as compared to other tested compounds. Molecular docking experiments verified the results and explained the molecular mechanism of pretty activities to c-Met.

  1. c-Met in chromophobe renal cell carcinoma.

    Science.gov (United States)

    Erlmeier, Franziska; Ivanyi, Philipp; Hartmann, Arndt; Autenrieth, Michael; Wiedemann, Max; Weichert, Wilko; Steffens, Sandra

    2017-02-01

    c-Met plays a role as a prognostic marker in clear cell renal cell carcinoma. In addition, recently the tyrosine kinase inhibitor cabozantinib targeting c-Met was approved for the treatment of advanced renal cell carcinoma (RCC). In contrast to clear cell RCC, little is known about c-Met expression patterns in rarer RCC subtypes. The aim of this study was to evaluate the prevalence, distribution and prognostic impact of c-Met expression on chromophobe (ch)RCC. Patients who underwent renal surgery due to chRCC were retrospectively evaluated. Tumor specimens were analyzed for c-Met expression by immunohistochemistry. Expression data were associated with clinicopathological parameters including patient survival. Eighty-one chRCC patients were eligible for analysis. Twenty-four (29.6%) patients showed a high c-Met expression (c-Met(high), staining intensity higher than median). Our results showed an association between c-Met(high) expression and the existence of lymph node metastasis (p = 0.007). No further significant clinicopathological associations with c-Met were identified, also regarding c-Met expression and overall survival. In conclusion, to our knowledge this is the first study evaluating the prognostic impact of c-Met in a considerably large cohort of chRCC. High c-Met expression is associated with the occurrence of lymph node metastasis. This indicates that c-Met might be implicated into metastatic progression in chRCC.

  2. Co-cultivation of pancreatic cancer cells with orthotopic tumor-derived fibroblasts: fibroblasts stimulate tumor cell invasion via HGF secretion whereas cancer cells exert a minor regulative effect on fibroblasts HGF production.

    Science.gov (United States)

    Qian, Li-Wu; Mizumoto, Kazuhiro; Maehara, Naoki; Ohuchida, Kenoki; Inadome, Naoki; Saimura, Michiyo; Nagai, Eishi; Matsumoto, Kunio; Nakamura, Toshikazu; Tanaka, Masao

    2003-02-10

    The intensive stromal reaction is one of characteristics of pancreatic exocrine carcinoma. The mutual interaction between pancreatic cancer cells and orthotopic tumor-derived fibroblasts have not been clarified yet. In this study, we sought to elucidate the mechanism underlying the tumor-stromal interaction with an in vitro coculture experimental system. Considerable strong c-Met expression was detected in seven out ten lines of human pancreatic carcinoma cells, as determined by Western blotting. For hepatocyte growth factor (HGF)-production, however, none or only trace amounts of HGF could be detected in those ten cell lines. Of the two lots of tumor-derived fibroblasts obtained from two pancreatic cancer patients, the fibroblasts capable to produce HGF could initiate an apparent invasion-stimulating response in strong c-Met-expressed Suit-2 and Panc-1 cells but not in faint expressed Mia PaCa-2 and BxPC-3 cells. A specialized HGF antagonist, NK4 would effectively inhibit the fibroblast-mediated invasive growth, thus proving the key role of the paracrine-fashioned HGF/c-Met pathway in the tumor-stromal interaction. On the other hand, the regulative action of cancer cells on HGF expression of fibroblasts was also investigated using direct or indirect coculture systems. For the fibroblasts that originally did not produce HGF, cancer cells failed to show any HGF-inductive effect. For the HGF-producing fibroblasts, despite of somewhat upregulation or downregulation in fibroblast HGF expression, the feedback regulation by studied pancreatic cancer cells in both coculture modes were relatively limited. This in vitro study sketched out the interaction between cancerous and stromal compartments with an emphasis on HGF/c-Met signal pathway, thus possibly helping to unveil the more complicated mutual modulation in vivo between pancreatic cancer and host mesenchymal tissues.

  3. Establishment of Multiple Myeloma Cell lines with Hepatocyte growth factor (HGF) overexpression and knockdown

    OpenAIRE

    Qadir, Fouzia

    2013-01-01

    Multiple myeloma is the malignancy of plasma cells which causes 0.9 % of all cancer related deaths. These malignant plasma cells acquire chromosomal abnormalities and complex genetic instability. Hepatocyte growth factor (HGF) is a multifunctional cytokine promoting cell proliferation, survival, motility, scattering, differentiation and morphogenesis. HGF/c-MET pathway plays an important role in multiple myeloma pathogenesis and in extravasation and homing of myeloma cells to bone marrow micr...

  4. The Plasticity of Oncogene Addiction: Implications for Targeted Therapies Directed to Receptor Tyrosine Kinases

    Directory of Open Access Journals (Sweden)

    Vinochani Pillay

    2009-05-01

    Full Text Available A common mutation of the epidermal growth factor receptor (EGFR in glioblastoma multiforme (GBM is an extracellular truncation known as the de2-7 EGFR (or EGFRvIII. Hepatocyte growth factor (HGF is the ligand for the receptor tyrosine kinase (RTK c-Met, and this signaling axis is often active in GBM. The expression of the HGF/c-Met axis or de2-7 EGFR independently enhances GBMgrowth and invasiveness, particularly through the phosphatidylinositol-3 kinase/pAkt pathway. Using RTK arrays, we show that expression of de2-7 EGFR in U87MG GBM cells leads to the coactivation of several RTKs, including platelet-derived growth factor receptor β and c-Met. A neutralizing antibody to HGF (AMG102 did not inhibit de2-7 EGFR-mediated activation of c-Met, demonstrating that it is ligand-independent. Therapy for parental U87MG xenografts with AMG 102 resulted in significant inhibition of tumor growth, whereas U87MG.Δ2-7 xenografts were profoundly resistant. Treatment of U87MG.Δ2-7 xenografts with panitumumab, an anti-EGFR antibody, only partially inhibited tumor growth as xenografts rapidly reverted to the HGF/c-Met signaling pathway. Cotreatment with panitumumab and AMG 102 prevented this escape leading to significant tumor inhibition through an apoptotic mechanism, consistent with the induction of oncogenic shock. This observation provides a rationale for using panitumumab and AMG 102 in combination for the treatment of GBM patients. These results illustrate that GBM cells can rapidly change the RTK driving their oncogene addiction if the alternate RTK signals through the same downstream pathway. Consequently, inhibition of a dominant oncogene by targeted therapy can alter the hierarchy of RTKs resulting in rapid therapeutic resistance.

  5. Cancer-Associated Fibroblasts Regulate Tumor-Initiating Cell Plasticity in Hepatocellular Carcinoma through c-Met/FRA1/HEY1 Signaling

    Directory of Open Access Journals (Sweden)

    Eunice Yuen Ting Lau

    2016-05-01

    Full Text Available Like normal stem cells, tumor-initiating cells (T-ICs are regulated extrinsically within the tumor microenvironment. Because HCC develops primarily in the context of cirrhosis, in which there is an enrichment of activated fibroblasts, we hypothesized that cancer-associated fibroblasts (CAFs would regulate liver T-ICs. We found that the presence of α-SMA(+ CAFs correlates with poor clinical outcome. CAF-derived HGF regulates liver T-ICs via activation of FRA1 in an Erk1,2-dependent manner. Further functional analysis identifies HEY1 as a direct downstream effector of FRA1. Using the STAM NASH-HCC mouse model, we find that HGF-induced FRA1 activation is associated with the fibrosis-dependent development of HCC. Thus, targeting the CAF-derived, HGF-mediated c-Met/FRA1/HEY1 cascade may be a therapeutic strategy for the treatment of HCC.

  6. c-Met in pancreatic cancer stem cells: Therapeutic implications

    Institute of Scientific and Technical Information of China (English)

    Marta Herreros-Villanueva; Aizpea Zubia-Olascoaga; Luis Bujanda

    2012-01-01

    Pancreatic cancer is the deadliest solid cancer and currently the fourth most frequent cause of cancer-related deaths.Emerging evidence suggests that cancer stem cells (CSCs) play a crucial role in the development and progression of this disease.The identification of CSC markers could lead to the development of new therapeutic targets.In this study,the authors explore the functional role of c-Met in pancreatic CSCs,by analyzing self-renewal with sphere assays and tumorigenicity capacity in NOD SCID mice.They concluded that c-Met is a novel marker for identifying pancreatic CSCs and c-Methigh in a higher tumorigenic cancer cell population.Inhibition of c-Met with XL184 blocks self-renewal capacity in pancreatic CSCs.In pancreatic tumors established in NOD SCID mice,c-Met inhibition slowed tumor growth and reduced the population of CSCs,along with preventing the development of metastases.

  7. Microtubule dynamics control HGF-induced lung endothelial barrier enhancement.

    Directory of Open Access Journals (Sweden)

    Xinyong Tian

    Full Text Available Microtubules (MT play a vital role in many cellular functions, but their role in peripheral actin cytoskeletal dynamics which is essential for control of endothelial barrier and monolayer integrity is less understood. We have previously described the enhancement of lung endothelial cell (EC barrier by hepatocyte growth factor (HGF which was associated with Rac1-mediated remodeling of actin cytoskeleton. This study investigated involvement of MT-dependent mechanisms in the HGF-induced enhancement of EC barrier. HGF-induced Rac1 activation was accompanied by phosphorylation of stathmin, a regulator of MT dynamics. HGF also stimulated MT peripheral growth monitored by time lapse imaging and tracking analysis of EB-1-decorated MT growing tips, and increased the pool of acetylated tubulin. These effects were abolished by EC pretreatment with HGF receptor inhibitor, downregulation of Rac1 pathway, or by expression of a stathmin-S63A phosphorylation deficient mutant. Expression of stathmin-S63A abolished the HGF protective effects against thrombin-induced activation of RhoA cascade, permeability increase, and EC barrier dysfunction. These results demonstrate a novel MT-dependent mechanism of HGF-induced EC barrier regulation via Rac1/PAK1/stathmin-dependent control of MT dynamics.

  8. Fc-mediated activity of EGFR x c-Met bispecific antibody JNJ-61186372 enhanced killing of lung cancer cells.

    Science.gov (United States)

    Grugan, Katharine D; Dorn, Keri; Jarantow, Stephen W; Bushey, Barbara S; Pardinas, Jose R; Laquerre, Sylvie; Moores, Sheri L; Chiu, Mark L

    2017-01-01

    Epidermal growth factor receptor (EGFR) mutant non-small cell lung cancers acquire resistance to EGFR tyrosine kinase inhibitors through multiple mechanisms including c-Met receptor pathway activation. We generated a bispecific antibody targeting EGFR and c-Met (JNJ-61186372) demonstrating anti-tumor activity in wild-type and mutant EGFR settings with c-Met pathway activation. JNJ-61186372 was engineered with low fucosylation (<10 %), resulting in enhanced antibody-dependent cell-mediated cytotoxicity and FcγRIIIa binding. In vitro and in vivo studies with the single-arm EGFR or c-Met versions of JNJ-61186372 identified that the Fc-activity of JNJ-61186372 is mediated by binding of the anti-EGFR arm and required for inhibition of EGFR-driven tumor cells. In a tumor model driven by both EGFR and c-Met, treatment with Fc-silent JNJ-61186372 or with c-Met single-arm antibody reduced tumor growth inhibition compared to treatment with JNJ-61186372, suggesting that the Fc function of JNJ-61186372 is essential for maximal tumor inhibition. Moreover in this same model, downregulation of both EGFR and c-Met receptors was observed upon treatment with Fc-competent JNJ-61186372, suggesting that the Fc interactions are necessary for down-modulation of the receptors in vivo and for efficacy. These Fc-mediated activities, in combination with inhibition of both the EGFR and c-Met signaling pathways, highlight the multiple mechanisms by which JNJ-61186372 combats therapeutic resistance in EGFR mutant patients.

  9. Cross-arm binding efficiency of an EGFR x c-Met bispecific antibody.

    Science.gov (United States)

    Zheng, Songmao; Moores, Sheri; Jarantow, Stephen; Pardinas, Jose; Chiu, Mark; Zhou, Honghui; Wang, Weirong

    2016-01-01

    Multispecific proteins, such as bispecific antibodies (BsAbs), that bind to two different ligands are becoming increasingly important therapeutic agents. Such BsAbs can exhibit markedly increased target binding and target residence time when both pharmacophores bind simultaneously to their targets. The cross-arm binding efficiency (χ) describes an increase in apparent affinity when a BsAb binds to the second target or receptor (R2) following its binding to the first target or receptor (R1) on the same cell. χ is an intrinsic characteristic of a BsAb mostly related to the binding epitopes on R1 and R2. χ can have significant impacts on the binding to R2 for BsAbs targeting two receptors on the same cell. JNJ-61186372, a BsAb that targets epidermal growth factor receptor (EGFR) and c-Met, was used as the model compound for establishing a method to characterize χ. The χ for JNJ-61186372 was successfully determined via fitting of in vitro cell binding data to a ligand binding model that incorporated χ. The model-derived χ value was used to predict the binding of JNJ-61186372 to individual EGFR and c-Met receptors on tumor cell lines, and the results agreed well with the observed IC50 for EGFR and c-Met phosphorylation inhibition by JNJ-61186372. Consistent with the model, JNJ-61186372 was shown to be more effective than the combination therapy of anti-EGFR and anti-c-Met monovalent antibodies at the same dose level in a mouse xenograft model. Our results showed that χ is an important characteristic of BsAbs, and should be considered for rationale design of BsAbs targeting two membrane bound targets on the same cell.

  10. Prognostic Value of MACC1 and c-met Expressions in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Xingsheng HU

    2012-07-01

    Full Text Available Background and objective It has been proven that metastasis-associated in colon cancer 1 (MACC1 is a new gene that is related to the invasion and metastasis of tumors. MACC1 also regulates c-met expression. The aim of this study is to explore the expressions of MACC1 and hepatocyte growth factor receptor (c-met, and its relationship with invasion, metastasis, and prognosis of non-small cell lung cancer (NSCLC. Methods MACC1 and c-met expressions were detected in 103 cases of NSCLC and 40 cases of neighboring normal lung cancer tissue using immunohistochemistry. Results MACC1 and c-met expressions were significantly higher in lung cancer tissues than that in neighboring normal tissue (P<0.001. MACC1 and c-met expressions were associated with poor differentiation, advanced T stages, lymph node metastasis, and advanced TNM stages (P<0.05 of NSCLC, but not with sex, age, smoking, and histological classification (P>0.05. In addition, a positive correlation between MACC1 and c-met expressions was observed (r=0.403, P<0.001. The result from the Kaplan-Meier survival analysis showed that the five-year survival rate in patients with positive MACC1 and c-met expressions was remarkanly lower than that in patients with negative expressions (P<0.05. The result from the Cox regression analysis showed that MACC1 expression was an independent prognostic factor for NSCLC (P=0.026. Conclusion MACC1 and c-met have an important function in the differentiation, invasion, and metastasis of NSCLC. MACC1 and c-met have poor prognosis in patients with NSCLC. Moreover, MACC1 expression is an independent prognostic factor for NSCLC.

  11. NK3 and NK4 of HGF enhance filamin production via STAT pathway, but not NK1 and NK2 in human breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Ya-ling LIN; Hsiu-ling CHEN; Hsiu-maan KUO; Shi-ping HE

    2008-01-01

    Aim: The purpose of this study was to reveal the effects of hepatocyte growth factor (HGF) variants on human breast cancer cells and the differential signaling pathways of the variants in controlling cell proliferation and invasion. Methods: Four HGF variants (NK1, NK2, NK3, and NK4) were created by gene engineering, and the variant DNA fragments were cloned into pGEM-T for DNA sequencing and then transferred to a pTrcHis-A plasmid for expression. Recombinant pro-teins were purified from Escherichia coll, and a series of assays, including cell proliferation and invasion were carried out. Phosphorylated components in the HGF-c-Met and STAT (signal transducers and activators of transcription) path-ways were detected by immunoprecipitation-Western blots. Results: All the HGF variants inhibited the vigorous growth of the cancer cells differently and dose-dependently, but the effect of NK3 or NK4 was 7.5-fold higher than NK 1 or NK2. In addition, the assays for the phosphorylation of the components in the HGF-c-Met pathway showed that NK3 and NK4 inhibited invasion via the STAT pathway, whereas NK1 and NK2 were via the HGF--c-Met pathway. Conclusion: The engineered HGF variants inhibited the proliferation of human breast cancer cells via different signaling pathways, NK1 and NK2 via the HGF-c-Met pathways, and NK3 and NK4 via the STAT pathway, the latter being a possible key route for the inhibition of cell invasion. All of the HGF variants have the potential to become pharmaceutical drugs in the treatment of human cancer.

  12. Damnacanthal, a noni anthraquinone, inhibits c-Met and is a potent antitumor compound against Hep G2 human hepatocellular carcinoma cells.

    Science.gov (United States)

    García-Vilas, Javier A; Quesada, Ana R; Medina, Miguel A

    2015-01-26

    Damnacanthal, an anthraquinone present in noni plants, targets several tyrosine kinases and has antitumoral effects. This study aims at getting additional insight on the potential of damnacanthal as a natural antitumor compound. The direct effect of damnacanthal on c-Met was tested by in vitro activity assays. Additionally, Western blots of c-Met phosphorylation in human hepatocellular carcinoma Hep G2 cells were performed. The antitumor effects of damnacanthal were tested by using cell growth, soft agar clonogenic, migration and invasion assays. Their mechanisms were studied by Western blot, and cell cycle, apoptosis and zymographic assays. Results show that damnacanthal targets c-Met both in vitro and in cell culture. On the other hand, damnacanthal also decreases the phosphorylation levels of Akt and targets matrix metalloproteinase-2 secretion in Hep G2 cells. These molecular effects are accompanied by inhibition of the growth and clonogenic potential of Hep G2 hepatocellular carcinoma cells, as well as induction of Hep G2 apoptosis. Since c-Met has been identified as a new potential therapeutical target for personalized treatment of hepatocellular carcinoma, damnacanthal and noni extract supplements containing it could be potentially interesting for the treatment and/or chemoprevention of hepatocellular carcinoma through its inhibitory effects on the HGF/c-Met axis.

  13. Recent Progress and Advances in HGF/MET-Targeted Therapeutic Agents for Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Yilong Zhang

    2015-03-01

    Full Text Available The hepatocyte growth factor (HGF: MET axis is a ligand-mediated receptor tyrosine kinase pathway that is involved in multiple cellular functions, including proliferation, survival, motility, and morphogenesis. Aberrancy in the HGF/MET pathway has been reported in multiple tumor types and is associated with tumor stage and prognosis. Thus, targeting the HGF/MET pathway has become a potential therapeutic strategy in oncology development in the last two decades. A number of novel therapeutic agents—either as therapeutic proteins or small molecules that target the HGF/MET pathway—have been tested in patients with different tumor types in clinical studies. In this review, recent progress in HGF/MET pathway-targeted therapy for cancer treatment, the therapeutic potential of HGF/MET-targeted agents, and challenges in the development of such agents will be discussed.

  14. Absence of tpr-met and expression of c-met in human gastric mucosa and carcinoma.

    Science.gov (United States)

    Heideman, D A; Snijders, P J; Bloemena, E; Meijer, C J; Offerhaus, G J; Meuwissen, S G; Gerritsen, W R; Craanen, M E

    2001-08-01

    The c-met proto-oncogene, encoding the hepatocyte growth factor receptor, can be activated by various mechanisms. These include, among others, gene amplification with concomitant overexpression and the tpr-met oncogenic rearrangement. In the case of gastric cancer, contradictory results on the presence of the tpr-met oncogenic rearrangement have been published. The current study aimed therefore to assess the prevalence of tpr-met expression in Caucasian gastric adenocarcinomas, to evaluate the importance of this oncogene in their carcinogenesis. In addition, the level of c-met expression was determined, to evaluate the role of this alternative mode of activation of the proto-oncogene. A series of Caucasian gastric adenocarcinomas (n=43) and normal gastric mucosal samples (n=14) was analysed for tpr-met and c-met expression. Expression of tpr-met mRNA in the samples was performed by two reverse transcriptase polymerase chain reaction (RT-PCR) assays, with excellent correlation. The specificity of both methods was confirmed by direct sequencing of the PCR products of the MNNG-HOS cell line, which is known to contain the rearrangement. The level of c-met expression was assessed using semi-quantitative RT-PCR assays and immunohistochemistry (IHC). None of the normal gastric mucosal or gastric adenocarcinoma samples expressed tpr-met mRNA, as determined by both RT-PCR assays. Seventy per cent of the adenocarcinomas showed overexpression of c-met, according to elevated c-met mRNA levels, compared with the expression level of normal gastric mucosa. A significant correlation was found between the level of c-met mRNA and protein expression. In conclusion, these results strongly suggest that tpr-met activation does not play a role in Caucasian gastric carcinogenesis, while overexpression of the c-met gene occurs in the majority of Caucasian gastric adenocarcinomas.

  15. C. elegans as a model organism for in vivo screening in cancer: effects of human c-Met in lung cancer affect C. elegans vulva phenotypes.

    Science.gov (United States)

    Siddiqui, Shahid S; Loganathan, Sivakumar; Krishnaswamy, Soundararajan; Faoro, Leonardo; Jagadeeswaran, Ramasamy; Salgia, Ravi

    2008-06-01

    Cancers typically harbour several mutant forms of key cellular genes that contribute to its complex phenotype. Our lab has previously identified gain-of-function mutations in some of the receptor tyrosine kinases such as c-Met in lung cancer. In order to investigate the mutant gene in the context of a whole organism, the current choice of in vivo model is limited to the mouse. To rapidly screen the functional aspects of mutant forms of c-Met detected in lung cancer, we used the nematode C. elegans as the model organism. Transgenic worms were generated that harbour wild type or the frequently seen mutant forms of c-Met in lung cancer (c-MetR988C and c-MetT1010I). Expression of the mutant human c-Met forms in C. elegans consistently resulted in significantly low fecundity and abnormal vulval development characterized by hyperplasia. Interestingly, exposure of c-Met mutant transgenic worms to nicotine resulted in enhanced abnormal vulval development, fecundity and locomotion. Our studies provide first evidence that human c-Met mutations can be studied in C. elegans, and that carcinogens can enhance mutant c-Met function expressed in C. elegans transgenic animals. We therefore propose the use of C. elegans as a model to rapidly assess the role of cancer specific gene mutations in the context of a whole organism.

  16. Development of antibody-based c-Met inhibitors for targeted cancer therapy

    Directory of Open Access Journals (Sweden)

    Lee D

    2015-02-01

    Full Text Available Dongheon Lee, Eun-Sil Sung, Jin-Hyung Ahn, Sungwon An, Jiwon Huh, Weon-Kyoo You Hanwha Chemical R&D Center, Biologics Business Unit, Daejeon, Republic of Korea Abstract: Signaling pathways mediated by receptor tyrosine kinases (RTKs and their ligands play important roles in the development and progression of human cancers, which makes RTK-mediated signaling pathways promising therapeutic targets in the treatment of cancer. Compared with small-molecule compounds, antibody-based therapeutics can more specifically recognize and bind to ligands and RTKs. Several antibody inhibitors of RTK-mediated signaling pathways, such as human epidermal growth factor receptor 2, vascular endothelial growth factor, epidermal growth factor receptor or vascular endothelial growth factor receptor 2, have been developed and are widely used to treat cancer patients. However, since the therapeutic options are still limited in terms of therapeutic efficacy and types of cancers that can be treated, efforts are being made to identify and evaluate novel RTK-mediated signaling pathways as targets for more efficacious cancer treatment. The hepatocyte growth factor/c-Met signaling pathway has come into the spotlight as a promising target for development of potent cancer therapeutic agents. Multiple antibody-based therapeutics targeting hepatocyte growth factor or c-Met are currently in preclinical or clinical development. This review focuses on the development of inhibitors of the hepatocyte growth factor/c-Met signaling pathway for cancer treatment, including critical issues in clinical development and future perspectives for antibody-based therapeutics. Keywords: hepatocyte growth factor, ligands, receptor tyrosine kinase, signaling pathway, therapeutic agent

  17. Expression of the proto-oncogenes c-met and c-kit and their ligands, hepatocyte growth factor/scatter factor and stem cell factor, in SCLC cell lines and xenografts

    DEFF Research Database (Denmark)

    Rygaard, K; Nakamura, T; Spang-Thomsen, M

    1993-01-01

    We examined a panel of 25 small cell lung cancer (SCLC) cell lines and nude mouse xenografts for expression of the proto-oncogenes c-met and c-kit, and for expression of the corresponding ligands, hepatocyte growth factor (HGF) (also known as scatter factor (SF)), and stem cell factor (SCF......), respectively. Expression of mRNA was detected by Northern blotting, and c-met and c-kit protein expression was detected by Western blotting and immunocytochemistry. c-met and c-kit mRNA was expressed in 22 of the examined cell lines or xenografts, and coexpression of the two proto-oncogenes was observed in 20...... tumours. Expression of c-met and c-kit protein paralleled in the mRNA expression. HGF/SF mRNA was expressed in two of the examined tumours, and only one of these also expressed the c-met proto-oncogene. SCF mRNA was expressed in 19 of the examined tumours, and in 18 of these coexpression of c-kit and SCF...

  18. HGF Modulates Actin Cytoskeleton Remodeling and Contraction in Testicular Myoid Cells

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    Angela Catizone

    2015-01-01

    Full Text Available The presence of the HGF/Met system in the testicular myoid cells was first discovered by our group. However, the physiological role of this pathway remains poorly understood. We previously reported that HGF increases uPA secretion and TGF-β activation in cultured tubular fragments and that HGF is maximally expressed at Stages VII–VIII of the seminiferous epithelium cycle, when myoid cell contraction occurs. It is well known that the HGF/Met pathway is involved in cytoskeletal remodeling; moreover, the interaction of uPA with its receptor, uPAR, as well as the activation of TGF-β have been reported to be related to the actin cytoskeleton contractility of smooth muscle cells. Herein, we report that HGF induces actin cytoskeleton remodeling in vitro in isolated myoid cells and myoid cell contraction in cultured seminiferous tubules. To better understand these phenomena, we evaluated: (1 the regulation of the uPA machinery in isolated myoid cells after HGF administration; and (2 the effect of uPA or Met inhibition on HGF-treated tubular fragments. Because uPA activates latent TGF-β, the secretion of this factor was also evaluated. We found that both uPA and TGF-β activation increase after HGF administration. In testicular tubular fragments, HGF-induced TGF-β activation and myoid cell contraction are abrogated by uPA or Met inhibitor administration.

  19. The c-Met tyrosine kinase inhibitor JNJ-38877605 causes renal toxicity through species-specific insoluble metabolite formation

    NARCIS (Netherlands)

    M.P. Lolkema (Martijn); H.H. Bohets (Hilde H.); H.-T. Arkenau (H.); A. Lampo (Ann); E. Barale (Erio); M.J.A. de Jonge (Maja); L. van Doorn (Leni); P. Hellemans (Peter); J.S. de Bono (Johann); F.A.L.M. Eskens (Ferry)

    2015-01-01

    textabstractPurpose: The receptor tyrosine kinase c-Met plays an important role in tumorigenesis and is a novel target for anticancer treatment. This phase I, first-in-human trial, explored safety, pharmacokinetics, pharmacodynamics, and initial antitumor activity of JNJ-38877605, a potent and

  20. c-Met Expression Is a Marker of Poor Prognosis in Patients With Locally Advanced Head and Neck Squamous Cell Carcinoma Treated With Chemoradiation

    Energy Technology Data Exchange (ETDEWEB)

    Baschnagel, Andrew M. [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Williams, Lindsay [Department of Pathology, William Beaumont Hospital, Royal Oak, Michigan (United States); Hanna, Alaa; Chen, Peter Y.; Krauss, Daniel J. [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Pruetz, Barbara L. [Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States); Akervall, Jan [Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States); Department of Otolaryngology, William Beaumont Hospital, Royal Oak, Michigan (United States); Wilson, George D., E-mail: George.Wilson@Beaumont.edu [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan (United States); Beaumont BioBank, William Beaumont Hospital, Royal Oak, Michigan (United States)

    2014-03-01

    Purpose: To examine the prognostic significance of c-Met expression in relation to p16 and epidermal growth factor receptor (EGFR) in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) treated with definitive concurrent chemoradiation. Methods and Materials: Archival tissue from 107 HNSCC patients treated with chemoradiation was retrieved, and a tissue microarray was assembled. Immunohistochemical staining of c-Met, p16, and EGFR was performed. c-Met expression was correlated with p16, EGFR, clinical characteristics, and clinical endpoints including locoregional control (LRC), distant metastasis (DM), disease-free survival (DFS), and overall survival (OS). Results: Fifty-one percent of patients were positive for p16, and 53% were positive for EGFR. Both p16-negative (P≤.001) and EGFR-positive (P=.019) status predicted for worse DFS. Ninety-three percent of patients stained positive for c-Met. Patients were divided into low (0, 1, or 2+ intensity) or high (3+ intensity) c-Met expression. On univariate analysis, high c-Met expression predicted for worse LRC (hazard ratio [HR] 2.27; 95% CI, 1.08-4.77; P=.031), DM (HR 4.41; 95% CI, 1.56-12.45; P=.005), DFS (HR 3.00; 95% CI, 1.68-5.38; P<.001), and OS (HR 4.35; 95% CI, 2.13-8.88; P<.001). On multivariate analysis, after adjustment for site, T stage, smoking history, and EGFR status, only high c-Met expression (P=.011) and negative p16 status (P=.003) predicted for worse DFS. High c-Met expression was predictive of worse DFS in both EGFR-positive (P=.032) and -negative (P=.008) patients. In the p16-negative patients, those with high c-Met expression had worse DFS (P=.036) than did those with low c-Met expression. c-Met expression was not associated with any outcome in the p16-positive patients. Conclusions: c-Met is expressed in the majority of locally advanced HNSCC cases, and high c-Met expression predicts for worse clinical outcomes. High c-Met expression predicted for worse DFS in p16

  1. Delivery of an engineered HGF fragment in an extracellular matrix-derived hydrogel prevents negative LV remodeling post-myocardial infarction.

    Science.gov (United States)

    Sonnenberg, Sonya B; Rane, Aboli A; Liu, Cassie J; Rao, Nikhil; Agmon, Gillie; Suarez, Sophia; Wang, Raymond; Munoz, Adam; Bajaj, Vaibhav; Zhang, Shirley; Braden, Rebecca; Schup-Magoffin, Pamela J; Kwan, Oi Ling; DeMaria, Anthony N; Cochran, Jennifer R; Christman, Karen L

    2015-03-01

    Hepatocyte growth factor (HGF) has been shown to have anti-fibrotic, pro-angiogenic, and cardioprotective effects; however, it is highly unstable and expensive to manufacture, hindering its clinical translation. Recently, a HGF fragment (HGF-f), an alternative c-MET agonist, was engineered to possess increased stability and recombinant expression yields. In this study, we assessed the potential of HGF-f, delivered in an extracellular matrix (ECM)-derived hydrogel, as a potential treatment for myocardial infarction (MI). HGF-f protected cardiomyocytes from serum-starvation and induced down-regulation of fibrotic markers in whole cardiac cell isolate compared to the untreated control. The ECM hydrogel prolonged release of HGF-f compared to collagen gels, and in vivo delivery of HGF-f from ECM hydrogels mitigated negative left ventricular (LV) remodeling, improved fractional area change (FAC), and increased arteriole density in a rat myocardial infarction model. These results indicate that HGF-f may be a viable alternative to using recombinant HGF, and that an ECM hydrogel can be employed to increase growth factor retention and efficacy.

  2. LoVo colon cancer cells resistant to oxaliplatin overexpress c-MET and VEGFR-1 and respond to VEGF with dephosphorylation of c-MET.

    Science.gov (United States)

    Mezquita, Belén; Pineda, Estela; Mezquita, Jovita; Mezquita, Pau; Pau, Montserrat; Codony-Servat, Jordi; Martínez-Balibrea, Eva; Mora, Conchi; Maurel, Joan; Mezquita, Cristóbal

    2016-05-01

    Oxaliplatin-resistant LoVo colon cancer cells overexpressing c-MET and VEGFR-1 were selected to study several signaling pathways involved in chemoresistance, as well as the effect of increasing amounts of VEGF in the regulation of c-MET. In comparison with chemosensitive LoVo colon cancer cells, oxaliplatin-resistant cells (LoVoR) overexpress and phosphorylate c-MET, upregulate the expression of transmembrane and soluble VEGFR-1 and, unexpectedly, downregulate VEGF. In addition, LoVoR cells activate other transduction pathways involved in chemoresistance such as Akt, β-catenin-TCF4 and E-cadherin. While c-MET is phosphorylated in LoVoR cells expressing low levels of VEGF, c-MET phosphorylation decreases when recombinant VEGF is added into the culture medium. Inhibition of c-MET by VEGF is mediated by VEGFR-1, since phosphorylation of c-MET in the presence of VEGF is restored after silencing VEGFR-1. Dephosphorylation of c-MET by VEGF suggests that tumors coexpressing VEGFR-1 and c-MET may activate c-MET as a result of anti-VEGF therapy. © 2015 Wiley Periodicals, Inc.

  3. Recent Developments of c-Met as a Therapeutic Target in Hepatocellular Carcinoma.

    Science.gov (United States)

    Bouattour, Mohamed; Raymond, Eric; Qin, Shukui; Cheng, Ann-Lii; Stammberger, Uz; Locatelli, Giuseppe; Faivre, Sandrine

    2017-09-01

    Aberrant c-Met activity is implicated in the development of hepatocellular carcinoma (HCC), suggesting that c-Met inhibition may have therapeutic potential. However, clinical trials of nonselective kinase inhibitors with c-Met activity (tivantinib, cabozantinib, foretinib, and golvatinib) in patients with HCC have failed so far to demonstrate significant efficacy. This is likely due to several factors, including trial design, lack of patient selection according to tumor c-Met status, and the prevalent off-target activity of these agents, which may mean that c-Met inhibition is incomplete. In contrast, selective c-Met inhibitors (tepotinib, capmatinib) can be dosed at a level predicted to achieve a complete inhibition of tumor c-Met activity. Moreover, results from early trials can be used to optimize the design of clinical trials of these agents. Preliminary results suggest that selective c-Met inhibitors have antitumor activity in HCC, with acceptable safety and tolerability in patients with Child-Pugh A liver function. Ongoing trials have been designed to assess the efficacy and safety of selective c-Met inhibition compared with standard therapy in patients with HCC selected based on tumor c-Met status. Thus, c-Met inhibition continues to be an active area of research in HCC, with well-designed trials in progress to investigate the benefit of selective c-Met inhibitors. This article is protected by copyright. All rights reserved. © 2017 by the American Association for the Study of Liver Diseases.

  4. Overview of multilayer ceramic actuator program at C-MET

    Science.gov (United States)

    Raghu, N.; Kumar, V.; Dayas, K. R.; Rao, I. C.

    2003-10-01

    One of the major programs being undertaken in our unit is, development of actuator materials and conversion of these materials into multilayer actuator devices. In order to achieve this objective, development of piezoelectric and electrostrictive materials are also being attempted. A simple and novel chemical precipitation route has been adopted for the synthesis of nano-actuator materials. Lead Zirconate Titanate (PZT) powder, free of agglomerates, phase pure, good chemical homogeneity and of 50 - 75 nm size has been synthesized. Synthesis of nano Ba(Sn,Ti)O3 which shows linear, nearly hysteresis free strain curve is also discussed. Phase pure electrostrictive Lead Magnesium Niobate-Lead Titanate (PMN-PT) powder with a dielectric constant of 25,000 and a Tc of 38°C was prepared through double-step process. C-MET has state of the art facility for multilayer (ML) ceramic processing. These Nano-PZT powders have been converted into 50 micron green tapes through tape casting technique. Characteristics of these synthesized materials and the fabrication of ML actuators there from are presented.

  5. A Novel SND1-BRAF Fusion Confers Resistance to c-Met Inhibitor PF-04217903 in GTL16 Cells though MAPK Activation

    Science.gov (United States)

    Lee, Nathan V.; Lira, Maruja E.; Pavlicek, Adam; Ye, Jingjing; Buckman, Dana; Bagrodia, Shubha; Srinivasa, Sreesha P.; Zhao, Yongjun; Aparicio, Samuel; Rejto, Paul A.; Christensen, James G.; Ching, Keith A.

    2012-01-01

    Targeting cancers with amplified or abnormally activated c-Met (hepatocyte growth factor receptor) may have therapeutic benefit based on nonclinical and emerging clinical findings. However, the eventual emergence of drug resistant tumors motivates the pre-emptive identification of potential mechanisms of clinical resistance. We rendered a MET amplified gastric cancer cell line, GTL16, resistant to c-Met inhibition with prolonged exposure to a c-Met inhibitor, PF-04217903 (METi). Characterization of surviving cells identified an amplified chromosomal rearrangement between 7q32 and 7q34 which overexpresses a constitutively active SND1-BRAF fusion protein. In the resistant clones, hyperactivation of the downstream MAPK pathway via SND1-BRAF conferred resistance to c-Met receptor tyrosine kinase inhibition. Combination treatment with METi and a RAF inhibitor, PF-04880594 (RAFi) inhibited ERK activation and circumvented resistance to either single agent. Alternatively, treatment with a MEK inhibitor, PD-0325901 (MEKi) alone effectively blocked ERK phosphorylation and inhibited cell growth. Our results suggest that combination of a c-Met tyrosine kinase inhibitor with a BRAF or a MEK inhibitor may be effective in treating resistant tumors that use activated BRAF to escape suppression of c-Met signaling. PMID:22745804

  6. HGF induces EMT in non-small-cell lung cancer through the hBVR pathway.

    Science.gov (United States)

    Liu, Fang; Song, Shasha; Yi, Zhi; Zhang, Min; Li, Jiali; Yang, Fang; Yin, Hongtao; Yu, Xiufeng; Guan, Chao; Liu, Ying; Liu, Zizhen; Wang, Jing; Zhu, Daling

    2017-09-15

    The epithelial-to-mesenchymal transition (EMT) is a crucial event during non-small-cell lung cancer (NSCLC) invasion and metastasis. However, the mechanisms involved in NSCLC EMT have not been fully clarified. Hepatocyte growth factor (HGF) and human biliverdin reductase (hBVR) are reported to contribute to EMT in several diseases. Here, we show that compared with transforming growth factor beta (TGF-β), fibroblast growth factor (FGF), and epidermal growth factor (EGF), HGF is an important cell factor for EMT in NSCLC cell lines A549 and H460. Met protein, HGF receptors, and hBVR were found to be highly expressed and positively correlated with EMT in NSCLC tissue sections. In addition, HGF and hBVR induced a decrease in epithelial protein marker expression and an increase in mesenchymal protein marker expression as well as increased cellular migration and invasion, indicating that both HGF and hBVR mediate EMT in A549 and H460 cell lines. Furthermore, HGF-induced EMT and migration and invasion in both cell lines was inhibited by si-hBVR. Taken together, our data show that HGF induces EMT in NSCLC through the hBVR pathway. Copyright © 2017. Published by Elsevier B.V.

  7. Dynamic expression and localization of c-MET isoforms in the developing rat pancreas.

    Science.gov (United States)

    Wu, Yulong; Cheng, Mei; Shi, Zhen; Feng, Zhenqing; Guan, Xiaohong

    2014-01-01

    Pancreata from Sprague Dawley rats of different developmental stages were studied to determine the expression and cellular localization of different c-MET isoforms in the developing rat pancreas. Pancreatic mRNA and protein expression levels of c-MET at different developmental stages from embryo to adult were detected by reverse transcription-polymerase chain reaction and by western blotting. To identify the cellular localization of c-MET protein in the developing rat pancreas, double immunofluorescent staining was performed using antibodies for cell type-specific markers and for c-MET. The expression of two isoforms of c-MET (190 kDa and 170 kDa) coincided with the development of the pancreas. The 190 kDa isoform of c-MET is expressed during embryonic stages, and its expression is replaced by the expression of the 170 kDa isoform as the pancreas develops. Only the 170 kDa isoform is expressed in the adult rat pancreas. Throughout all stages of pancreatic development, c-MET is expressed by vimentin-positive cells. In contrast, c-MET staining was stronger in rat pancreata from newborn to adult stages and overlapped with insulin-positive beta-cells. The dynamic expression and localization of different c-MET isoforms in the rat pancreas during different developmental stages indicates that distinct c-MET isoform might be involved in different aspects of pancreatic development.

  8. Activation of c-Met and upregulation of CD44 expression are associated with the metastatic phenotype in the colorectal cancer liver metastasis model.

    Directory of Open Access Journals (Sweden)

    Victoria A Elliott

    Full Text Available BACKGROUND: Liver metastasis is the most common cause of death in patients with colorectal cancer. Despite extensive research into the biology of cancer progression, the molecular mechanisms that drive colorectal cancer metastasis are not well characterized. METHODS: HT29 LM1, HT29 LM2, HT29 LM3 cell lines were derived from the human colorectal cancer cell line HT29 following multiple rounds of in vivo selection in immunodeficient mice. RESULTS: CD44 expression, a transmembrane glycoprotein involved in cell-cell and cell-matrix adhesions, and cancer cells adhesion to endothelial cells was increased in all in vivo selected cell lines, with maximum CD44 expression and cancer cells adhesion to endothelial cells in the highly metastatic HT29 LM3 cell line. Activation of c-Met upon hepatocyte growth factor (HGF stimulation in the in vivo selected cell lines is CD44 independent. In vitro separation of CD44 high and low expression cells from HT29 LM3 cell line with FACS sorting confirmed that c-Met activation is CD44 independent upon hepatocyte growth factor stimulation. Furthermore, in vivo evaluation of CD44 low and high expressing HT29 LM3 cells demonstrated no difference in liver metastasis penetrance. CONCLUSIONS: Taken together, our findings indicate that the aggressive metastatic phenotype of in vivo selected cell lines is associated with overexpression of CD44 and activation of c-MET. We demonstrate that c-Met activation is CD44 independent upon hepatocyte growth factor stimulation and confirm that CD44 expression in HT29 LM3 cell line is not responsible for the increase in metastatic penetrance in HT29 LM3 cell line.

  9. Genetic Nrf2 Overactivation Inhibits the Deleterious Effects Induced by Hepatocyte-Specific c-met Deletion during the Progression of NASH

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    Pierluigi Ramadori

    2017-01-01

    Full Text Available We have recently shown that hepatocyte-specific c-met deficiency accelerates the progression of nonalcoholic steatohepatitis in experimental murine models resulting in augmented production of reactive oxygen species and accelerated development of fibrosis. The aim of this study focuses on the elucidation of the underlying cellular mechanisms driven by Nrf2 overactivation in hepatocytes lacking c-met receptor characterized by a severe unbalance between pro-oxidant and antioxidant functions. Control mice (c-metfx/fx, single c-met knockouts (c-metΔhepa, and double c-met/Keap1 knockouts (met/Keap1Δhepa were then fed a chow or a methionine-choline-deficient (MCD diet, respectively, for 4 weeks to reproduce the features of nonalcoholic steatohepatitis. Upon MCD feeding, met/Keap1Δhepa mice displayed increased liver mass albeit decreased triglyceride accumulation. The marked increase of oxidative stress observed in c-metΔhepa was restored in the double mutants as assessed by 4-HNE immunostaining and by the expression of genes responsible for the generation of free radicals. Moreover, double knockout mice presented a reduced amount of liver-infiltrating cells and the exacerbation of fibrosis progression observed in c-metΔhepa livers was significantly inhibited in met/Keap1Δhepa. Therefore, genetic activation of the antioxidant transcription factor Nrf2 improves liver damage and repair in hepatocyte-specific c-met-deficient mice mainly through restoring a balance in the cellular redox homeostasis.

  10. Human adult chondrocytes express hepatocyte growth factor (HGF) isoforms but not HgF: potential implication of osteoblasts on the presence of HGF in cartilage.

    Science.gov (United States)

    Guévremont, Melanie; Martel-Pelletier, Johanne; Massicotte, Frédéric; Tardif, Ginette; Pelletier, Jean-Pierre; Ranger, Pierre; Lajeunesse, Daniel; Reboul, Pascal

    2003-06-01

    HGF is increased in human OA cartilage, possibly from Ob's. RT-PCR shows HGF isoforms are differently regulated between chondrocytes and Ob. A paracrine cross-talk between subchondral bone and cartilage may occur during OA. Recently, hepatocyte growth factor (HGF) has been identified by immunohistochemistry in cartilage and more particularly in the deep zone of human osteoarthritic (OA) cartilage. By investigating HGF expression in cartilage, we found that chondrocytes did not express HGF; however, they expressed the two truncated isoforms, namely HGF/NK1 and HGF/NK2. Because the only other cells localized near the deep zone are osteoblasts from the subchondral bone plate, we hypothesized that they were expressing HGF. Indeed, we found that HGF was synthesized by osteoblasts from the subchondral bone plate. Moreover, OA osteoblasts produced five times more HGF than normal osteoblasts and almost no HGF/NK1, unlike normal osteoblasts. Because prostaglandin E2 (PGE2) and pro-inflammatory cytokines such as interleukin (IL)-1 and IL-6 are involved in OA progression, we investigated whether these factors impact HGF produced by normal osteoblasts. PGE2 was the only factor tested that was able to stimulate HGF synthesis. However, the addition of NS398, a selective inhibitor of cyclo-oxygenase-2 (COX-2) had no effect on HGF produced by OA osteoblasts. HGF/NK2 had a moderate stimulating effect on HGF production by normal osteoblasts, whereas osteocalcin was not modulated by either HGF or HGF/NK2. When investigating signaling routes that might be implicated in OA osteoblast-produced HGF, we found that protein kinase A was at least partially involved. In summary, this study raises the hypothesis that the HGF found in articular cartilage is produced by osteoblasts, diffuses into the cartilage, and may be implicated in the OA process.

  11. Transcriptional activation of the Axl and PDGFR-α by c-Met through a ras- and Src-independent mechanism in human bladder cancer

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    Tseng Vincent S

    2011-04-01

    Full Text Available Abstract Background A cross-talk between different receptor tyrosine kinases (RTKs plays an important role in the pathogenesis of human cancers. Methods Both NIH-Met5 and T24-Met3 cell lines harboring an inducible human c-Met gene were established. C-Met-related RTKs were screened by RTK microarray analysis. The cross-talk of RTKs was demonstrated by Western blotting and confirmed by small interfering RNA (siRNA silencing, followed by elucidation of the underlying mechanism. The impact of this cross-talk on biological function was demonstrated by Trans-well migration assay. Finally, the potential clinical importance was examined in a cohort of 65 cases of locally advanced and metastatic bladder cancer patients. Results A positive association of Axl or platelet-derived growth factor receptor-alpha (PDGFR-α with c-Met expression was demonstrated at translational level, and confirmed by specific siRNA knock-down. The transactivation of c-Met on Axl or PDGFR-α in vitro was through a ras- and Src-independent activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK pathway. In human bladder cancer, co-expression of these RTKs was associated with poor patient survival (p p Conclusions In addition to c-Met, the cross-talk with Axl and/or PDGFR-α also contributes to the progression of human bladder cancer. Evaluation of Axl and PDGFR-α expression status may identify a subset of c-Met-positive bladder cancer patients who may require co-targeting therapy.

  12. HGF/Met Signaling Is a Key Player in Malignant Mesothelioma Carcinogenesis

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    Giovanni Gaudino

    2014-11-01

    Full Text Available Malignant mesothelioma (MM is a highly aggressive cancer related to asbestos or erionite exposure and resistant to current therapies. Hepatocyte Growth Factor (HGF and its tyrosine kinase receptor Met regulate cell growth, survival, motility/migration, and invasion. HGF and Met are expressed in MM cells, suggesting that the HGF/Met signaling plays a role in development and progression of this tumor, by autocrine and/or paracrine mechanisms. Upregulation and ligand-independent activation of Met, which is under suppressive control of miR-34 family members, correlate with enhanced invasion, migration and metastatic potential in several cancers, including MM. Moreover, Simian Virus 40 (SV40 Tag expression also induces a HGF autocrine circuit in an Rb-dependent manner in human mesothelial cells (HM and possibly other cell types, enhancing cell adhesion, invasion and angiogenesis. The resulting activation of Met causes HM transformation and cell cycle progression, and contributes to virus particle assembling and infection of adjacent cells. The constitutive activation of Met, frequently occurring in MM, has been successfully targeted in preclinical models of MM. In conclusion, Met expression, activation state, subcellular localization and also HGF co-receptors expression, such as CD44, have clinical relevance for novel targeted therapies in a cancer for which no effective treatment is currently available.

  13. Deguelin action involves c-Met and EGFR signaling pathways in triple negative breast cancer cells.

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    Rajeshwari Mehta

    Full Text Available BACKGROUND: Treatment of breast cancer patients with antiestrogens and aromatase inhibitor(s or Herceptin have shown significant success in steroid receptor positive or Her-2+ breast cancers respectively. However, choice of treatments for breast cancer patients with negative status for estrogen, progesterone receptors and HER2/neu is limited. As a result, search for appropriate therapy regimen for these triple negative breast cancers (TNBC has become a major focus of investigations for many laboratories. Recently, Deguelin, a natural product isolated from African plant Mundulea sericea (Leguminossae has shown both antiproliferative actions in various cancers including breast as well as chemoprenventive activity against carcinogen induced experimental cancers. In this report we evaluated efficacy and mechanism of action of Deguelin in triple negative breast cancer cell lines. METHODS/FINDINGS: In vitro, Deguelin in a dose and time dependent manner inhibited the growth of MDA-MB-231, MDA-MB-468, BT-549 and BT-20 cells. Deguelin (2 or 4 mg/kg body weight, when injected intraperitoneally, reduced the in vivo tumor growth of MDA-MB-231 cells transplanted subcutaneously in athymic mice. Moreover it was nontoxic as evident from daily observations on mobility, food and water consumption and comparison of bodyweight and other visceral organ weights with those in control animals at the termination of the study. The western blot analyses and immunostaining studies indicated that the deguelin effects may be mediated through EGFR-PAKT/c-Met p-ERK and NF-κB by down regulating their downstream targets such as p-STAT3, c-Myc, Survivin. CONCLUSION/SIGNIFICANCE: These results suggest that Deguelin may have a significant therapeutic value for the treatment of TNBC patients.

  14. The Hepatocyte Growth Factor (HGF)/Met Axis: A Neglected Target in the Treatment of Chronic Myeloproliferative Neoplasms?

    Energy Technology Data Exchange (ETDEWEB)

    Boissinot, Marjorie [Translational Neuro-Oncology Group, Leeds Institute of Cancer and Pathology, University of Leeds, Level 5 Wellcome Trust Brenner Building, St James’s Hospital, Leeds LS9 7TF (United Kingdom); Vilaine, Mathias [Institute of Research on Cancer and Aging (IRCAN), CNRS-Inserm-UNS UMR 7284, U 1081, Centre A. Lacassagne, 33 Avenue Valombrose, Nice 06189 (France); Hermouet, Sylvie, E-mail: sylvie.hermouet@univ-nantes.fr [Centre Hospitalier Universitaire (CHU), Place Alexis Ricordeau, Nantes 44093 (France); Inserm UMR892, Centre de Recherche en Cancérologie Nantes-Angers, Institut de Recherche en Santé, Université de Nantes, 8 quai Moncousu, Nantes cedex 44007 (France)

    2014-08-12

    Met is the receptor of hepatocyte growth factor (HGF), a cytoprotective cytokine. Disturbing the equilibrium between Met and its ligand may lead to inappropriate cell survival, accumulation of genetic abnormalities and eventually, malignancy. Abnormal activation of the HGF/Met axis is established in solid tumours and in chronic haematological malignancies, including myeloma, acute myeloid leukaemia, chronic myelogenous leukaemia (CML), and myeloproliferative neoplasms (MPNs). The molecular mechanisms potentially responsible for the abnormal activation of HGF/Met pathways are described and discussed. Importantly, inCML and in MPNs, the production of HGF is independent of Bcr-Abl and JAK2V617F, the main molecular markers of these diseases. In vitro studies showed that blocking HGF/Met function with neutralizing antibodies or Met inhibitors significantly impairs the growth of JAK2V617F-mutated cells. With personalised medicine and curative treatment in view, blocking activation of HGF/Met could be a useful addition in the treatment of CML and MPNs for those patients with high HGF/MET expression not controlled by current treatments (Bcr-Abl inhibitors in CML; phlebotomy, hydroxurea, JAK inhibitors in MPNs)

  15. The HGF/c-MET Axis as a Critical Driver of Resistance to Androgen Suppression in Metastatic Castrate-Resistant Prostate Cancer

    Science.gov (United States)

    2015-10-01

    aspirates from 5 patients. We have obtained 6 blood samples for CTC analyses from 4 patients on abiraterone and 3 blood samples from 2 patients on...bone marrow aspirates has been slower than anticipated. We have addressed this in a number of ways, including pre- screening clinics for eligible...a graphene oxide based microfluidic device (GO Chip) to prostate cancer circulating tumor cell capture and analysis, AACR, 2015. *Patnaik, A

  16. The HGF/c-MET Axis as a Critical Driver of Resistance to Androgen Suppression in Metastatic Castrate-Resistant Prostate Cancer

    Science.gov (United States)

    2016-10-01

    resistant prostate cancer PRINCIPAL INVESTIGATOR: Todd M. Morgan CONTRACTING ORGANIZATION: University of Michigan Ann Arbor, MI REPORT DATE: October...NAME(S) AND ADDRESS(ES) University of Michigan Ann Arbor, MI 8. PERFORMING ORGANIZATION REPORT NUMBER University of Michigan Ann Arbor, Michigan...efficacious than either inhibitor alone . These data support the concept that the MET pathway may be an key mechanism of resistance in men with CRPC

  17. Rhodocetin-αβ-induced neuropilin-1-cMet association triggers restructuring of matrix contacts in endothelial cells.

    Science.gov (United States)

    Niland, Stephan; Ditkowski, Bartosz; Parrandier, Désirée; Roth, Lise; Augustin, Hellmut; Eble, Johannes A

    2013-03-01

    The snake venom component rhodocetin-αβ (RCαβ) stimulates endothelial cell motility in an α2β1 integrin-independent manner. We aimed to elucidate its cellular and molecular mechanisms. We identified neuropilin-1 (Nrp1) as a novel target of RCαβ by protein-chemical methods. RCαβ and vascular endothelial growth factor (VEGF)-A avidly bind to Nrp1. Instead of acting as VEGF receptor 2 coreceptor, Nrp1 associates upon RCαβ treatment with cMet. Furthermore, cell-based ELISAs and kinase inhibitor studies showed that RCαβ induces phosphorylation of tyrosines 1234/1235 [corrected] and thus activation of cMet. Consequently, paxillin is phosphorylated at Y31, which is redistributed from streak-like focal adhesions to spot-like focal contacts at the cell perimeter, along with α2β1 integrin, thereby regulating cell-matrix interactions. Cortactin is abundant in the cell perimeter, where it is involved in the branching of the cortical actin network of lamellipodia, whereas tensile force-bearing actin stress fibers radiating from focal adhesions disappear together with zyxin, a focal adhesion marker, on RCαβ treatment. Our data demonstrate that (1) Nrp1 is a novel target for venom components, such as RCαβ; (2) Nrp1 coupled to cMet regulates the type of cell-matrix interactions in a manner involving paxillin phosphorylation; and (3) altered cell-matrix interactions determine endothelial cell migration and cellular force management.

  18. Anti-c-Met antibody bioconjugated with hollow gold nanospheres as a novel nanomaterial for targeted radiation ablation of human cervical cancer cell.

    Science.gov (United States)

    Liang, Ying; Liu, Jiao; Liu, Ting; Yang, Xingsheng

    2017-08-01

    Radiotherapy is preferred to chemotherapy as an adjuvant therapy for postoperative cervical cancer owing to its convenience and minimal effects on various non-targeted systems. The present study sought to investigate whether the utilization of anti-MET proto-oncogene, receptor tyrosine kinase (c-Met) antibodies conjugated to hollow gold nanospheres (anti-c-Met/HGNs) may enhance the efficiency of radiation therapy for cervical cancer. Anti-c-Met/HGNs were synthesized and confirmed to target c-Met, which was overexpressed on the cell membrane of multiple malignancies. The successful synthesis of HGNs was observed using transmission electron microscopy (TEM). Overrepresentation of c-Met in the human cervical cancer cell line CaSki was verified by immunofluorescence. The cellular uptake of HGNs was assessed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). To assess the toxicity of functionalized gold nanospheres, a cell proliferation and toxicity assay was used and flow cytometry, with staining by propidium iodide (PI), was performed to study the cell cycle changes. Each experiment was conducted on three groups: Control, HGNs alone and anti-c-Met/HGNs, with each group also assessed with or without X-rays. The variation of apoptotic rate was observed by flow cytometry using a dual-staining Annexin V-fluorescein isothiocyanate/PI kit. Expression of apoptosis-associated proteins was examined by western blot analysis. TEM revealed a number of hollow spheres with cells with an average diameter of 56.25 nm and a mean wall thickness of 6.56 nm. CaSki cells were detected by inverted fluorescence microscopy via a layer of fluorescent green marker, and ICP-AES confirmed the distinct uptake of anti-c-Met/HGNs by each CaSki cell. Anti-c-Met/HGNs induced 38.7% of cells to stay in the G2/M phase, whereas the equivalent proportion in the control group was 19.8%. Compared with other groups, CaSki cells treated with anti-c-Met/HGNs and 5 Gy X-ray radiation

  19. Interaction of apoptotic cells with macrophages upregulates COX-2/PGE2 and HGF expression via a positive feedback loop.

    Science.gov (United States)

    Byun, Ji Yeon; Youn, Young-So; Lee, Ye-Ji; Choi, Youn-Hee; Woo, So-Yeon; Kang, Jihee Lee

    2014-01-01

    Recognition of apoptotic cells by macrophages is crucial for resolution of inflammation, immune tolerance, and tissue repair. Cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and hepatocyte growth factor (HGF) play important roles in the tissue repair process. We investigated the characteristics of macrophage COX-2 and PGE2 expression mediated by apoptotic cells and then determined how macrophages exposed to apoptotic cells in vitro and in vivo orchestrate the interaction between COX-2/PGE2 and HGF signaling pathways. Exposure of RAW 264.7 cells and primary peritoneal macrophages to apoptotic cells resulted in induction of COX-2 and PGE2. The COX-2 inhibitor NS-398 suppressed apoptotic cell-induced PGE2 production. Both NS-398 and COX-2-siRNA, as well as the PGE2 receptor EP2 antagonist, blocked HGF expression in response to apoptotic cells. In addition, the HGF receptor antagonist suppressed increases in COX-2 and PGE2 induction. The in vivo relevance of the interaction between the COX-2/PGE2 and HGF pathways through a positive feedback loop was shown in cultured alveolar macrophages following in vivo exposure of bleomycin-stimulated lungs to apoptotic cells. Our results demonstrate that upregulation of the COX-2/PGE2 and HGF in macrophages following exposure to apoptotic cells represents a mechanism for mediating the anti-inflammatory and antifibrotic consequences of apoptotic cell recognition.

  20. Interaction of Apoptotic Cells with Macrophages Upregulates COX-2/PGE2 and HGF Expression via a Positive Feedback Loop

    Directory of Open Access Journals (Sweden)

    Ji Yeon Byun

    2014-01-01

    Full Text Available Recognition of apoptotic cells by macrophages is crucial for resolution of inflammation, immune tolerance, and tissue repair. Cyclooxygenase-2 (COX-2/prostaglandin E2 (PGE2 and hepatocyte growth factor (HGF play important roles in the tissue repair process. We investigated the characteristics of macrophage COX-2 and PGE2 expression mediated by apoptotic cells and then determined how macrophages exposed to apoptotic cells in vitro and in vivo orchestrate the interaction between COX-2/PGE2 and HGF signaling pathways. Exposure of RAW 264.7 cells and primary peritoneal macrophages to apoptotic cells resulted in induction of COX-2 and PGE2. The COX-2 inhibitor NS-398 suppressed apoptotic cell-induced PGE2 production. Both NS-398 and COX-2-siRNA, as well as the PGE2 receptor EP2 antagonist, blocked HGF expression in response to apoptotic cells. In addition, the HGF receptor antagonist suppressed increases in COX-2 and PGE2 induction. The in vivo relevance of the interaction between the COX-2/PGE2 and HGF pathways through a positive feedback loop was shown in cultured alveolar macrophages following in vivo exposure of bleomycin-stimulated lungs to apoptotic cells. Our results demonstrate that upregulation of the COX-2/PGE2 and HGF in macrophages following exposure to apoptotic cells represents a mechanism for mediating the anti-inflammatory and antifibrotic consequences of apoptotic cell recognition.

  1. High levels of c-Met is associated with poor prognosis in glioblastoma

    DEFF Research Database (Denmark)

    Petterson, Stine Asferg; Dahlrot, Rikke Hedegaard; Hermansen, Simon Kjær;

    2015-01-01

    . Measurements of high c-Met intensity correlated with high WHO grade (p = 0.006) but no association with survival was observed in patients with WHO grade II (p = 0.09) or III (p = 0.17) tumors. High expression of c-Met was associated with shorter overall survival in patients with glioblastoma multiforme (p = 0.......03). However the prognostic effect of c-Met in glioblastomas was time-dependent and only observed in patients who survived more than 8.5 months, and not within the first 8.5 months after diagnosis. This was significant in multivariate analysis (HR 1.99, 95 % CI 1.29-3.08, p = 0.002) adjusted for treatment...... and the clinical variables age (HR 1.01, 95 % CI 0.99-1.03, p = 0.30), performance status (HR 1.34, 95 % CI 1.17-1.53, p glioblastomas....

  2. UniProt search blastx result: AK287970 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Eulemur macaco macaco (Black lemur) 3.00E-20 ...

  3. UniProt search blastx result: AK287484 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Eulemur macaco macaco (Black lemur) 3.00E-16 ...

  4. UniProt search blastx result: AK288291 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Eulemur macaco macaco (Black lemur) 1.00E-13 ...

  5. UniProt search blastx result: AK287692 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Eulemur macaco macaco (Black lemur) 1.00E-15 ...

  6. UniProt search blastx result: AK288206 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Eulemur macaco macaco (Black lemur) 3.00E-21 ...

  7. UniProt search blastx result: AK288287 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Eulemur macaco macaco (Black lemur) 7.00E-18 ...

  8. UniProt search blastx result: AK289170 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Eulemur macaco macaco (Black lemur) 8.00E-19 ...

  9. UniProt search blastx result: AK287970 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 3.00E-20 ...

  10. UniProt search blastx result: AK287484 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 3.00E-16 ...

  11. UniProt search blastx result: AK288291 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 6.00E-14 ...

  12. UniProt search blastx result: AK289170 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 1.00E-18 ...

  13. UniProt search blastx result: AK288287 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 3.00E-18 ...

  14. UniProt search blastx result: AK288206 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 4.00E-21 ...

  15. UniProt search blastx result: AK288291 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Callithrix jacchus (Common marmoset) 1.00E-13 ...

  16. UniProt search blastx result: AK288287 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Callithrix jacchus (Common marmoset) 7.00E-18 ...

  17. UniProt search blastx result: AK287970 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Callithrix jacchus (Common marmoset) 3.00E-20 ...

  18. UniProt search blastx result: AK288206 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Callithrix jacchus (Common marmoset) 3.00E-21 ...

  19. UniProt search blastx result: AK287692 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Callithrix jacchus (Common marmoset) 1.00E-15 ...

  20. UniProt search blastx result: AK287484 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Callithrix jacchus (Common marmoset) 3.00E-16 ...

  1. UniProt search blastx result: AK289170 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Callithrix jacchus (Common marmoset) 8.00E-19 ...

  2. UniProt search blastx result: AK287970 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Gorilla gorilla gorilla (Lowland gorilla) 3.00E-20 ...

  3. UniProt search blastx result: AK287692 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Gorilla gorilla gorilla (Lowland gorilla) 1.00E-15 ...

  4. UniProt search blastx result: AK288206 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Gorilla gorilla gorilla (Lowland gorilla) 3.00E-21 ...

  5. UniProt search blastx result: AK288291 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Gorilla gorilla gorilla (Lowland gorilla) 1.00E-13 ...

  6. UniProt search blastx result: AK287484 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Gorilla gorilla gorilla (Lowland gorilla) 3.00E-16 ...

  7. UniProt search blastx result: AK288287 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Loxodonta africana (African elephant) 3.00E-18 ...

  8. UniProt search blastx result: AK287970 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Loxodonta africana (African elephant) 3.00E-20 ...

  9. UniProt search blastx result: AK287484 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Loxodonta africana (African elephant) 3.00E-16 ...

  10. UniProt search blastx result: AK289170 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Loxodonta africana (African elephant) 3.00E-18 ...

  11. UniProt search blastx result: AK288291 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Loxodonta africana (African elephant) 5.00E-14 ...

  12. UniProt search blastx result: AK288206 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Loxodonta africana (African elephant) 3.00E-21 ...

  13. TEC protein tyrosine kinase is involved in the Erk signaling pathway induced by HGF

    Energy Technology Data Exchange (ETDEWEB)

    Li, Feifei; Jiang, Yinan [Department of Pathophysiology, Anhui Medical University, Hefei 230032 (China); Zheng, Qiping [Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, IL 60612 (United States); Yang, Xiaoming [Institute of Radiation Medicine, Academy of Military Medical Sciences, Beijing 100850 (China); Wang, Siying, E-mail: sywang@ahmu.edu.cn [Department of Pathophysiology, Anhui Medical University, Hefei 230032 (China)

    2011-01-07

    Research highlights: {yields} TEC is rapidly tyrosine-phosphorylated and activated by HGF-stimulation in vivo or after partial hepatectomy in mice. {yields} TEC enhances the activity of Elk and serum response element (SRE) in HGF signaling pathway in hepatocyte. {yields} TEC promotes hepatocyte proliferation through the Erk-MAPK pathway. -- Abstract: Background/aims: TEC, a member of the TEC family of non-receptor type protein tyrosine kinases, has recently been suggested to play a role in hepatocyte proliferation and liver regeneration. This study aims to investigate the putative mechanisms of TEC kinase regulation of hepatocyte differentiation, i.e. to explore which signaling pathway TEC is involved in, and how TEC is activated in hepatocyte after hepatectomy and hepatocyte growth factor (HGF) stimulation. Methods: We performed immunoprecipitation (IP) and immunoblotting (IB) to examine TEC tyrosine phosphorylation after partial hepatectomy in mice and HGF stimulation in WB F-344 hepatic cells. The TEC kinase activity was determined by in vitro kinase assay. Reporter gene assay, antisense oligonucleotide and TEC dominant negative mutant (TEC{sup KM}) were used to examine the possible signaling pathways in which TEC is involved. The cell proliferation rate was evaluated by {sup 3}H-TdR incorporation. Results: TEC phosphorylation and kinase activity were increased in 1 h after hepatectomy or HGF treatment. TEC enhanced the activity of Elk and serum response element (SRE). Inhibition of MEK1 suppressed TEC phosphorylation. Blocking TEC activity dramatically decreased the activation of Erk. Reduced TEC kinase activity also suppressed the proliferation of WB F-344 cells. These results suggest TEC is involved in the Ras-MAPK pathway and acts between MEK1 and Erk. Conclusions: TEC promotes hepatocyte proliferation and regeneration and is involved in HGF-induced Erk signaling pathway.

  14. E-cadherin and c-Met expression in actinic cheilits and lip squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    A Martínez

    2011-12-01

    Full Text Available Objective: The aim of this study was to assess epithelial expression of E-cadherin and c-Met in normal lip, in actinic cheilitis and lip squamous cell carcinoma. Study Design: Biopsies of normal lip vermillion (NL, n=18, actinic cheilitis (AC, n=37, and lip SCC (n=22 were processed for E-cadherin and c-Met immunodetection. Epithelial and tumor cell expression was scored for each sample considering staining intensity and percentage. Results: E-cadherin expression was significantly reduced in AC and lip SCC as compared to normal lip (P<0.05, with a significant reduction in lip SCC as compared to AC (P=0.003. Expression of c-Met was significantly higher in AC and lip SCC as compared to NL (P<0.05, with a significant increase in lip SCC as compared to AC (P<0.0001. Conclusion: The results showed that epithelial E-cadherin expression is reduced and c-Met expression is increased as lip carcinogenesis progresses, suggesting that these proteins may be useful markers of malignant transformation.

  15. Sequence-defined cMET/HGFR-targeted Polymers as Gene Delivery Vehicles for the Theranostic Sodium Iodide Symporter (NIS) Gene.

    Science.gov (United States)

    Urnauer, Sarah; Morys, Stephan; Krhac Levacic, Ana; Müller, Andrea M; Schug, Christina; Schmohl, Kathrin A; Schwenk, Nathalie; Zach, Christian; Carlsen, Janette; Bartenstein, Peter; Wagner, Ernst; Spitzweg, Christine

    2016-08-01

    The sodium iodide symporter (NIS) as well-characterized theranostic gene represents an outstanding tool to target different cancer types allowing noninvasive imaging of functional NIS expression and therapeutic radioiodide application. Based on its overexpression on the surface of most cancer types, the cMET/hepatocyte growth factor receptor serves as ideal target for tumor-selective gene delivery. Sequence-defined polymers as nonviral gene delivery vehicles comprising polyethylene glycol (PEG) and cationic (oligoethanoamino) amide cores coupled with a cMET-binding peptide (cMBP2) were complexed with NIS-DNA and tested for receptor-specificity, transduction efficiency, and therapeutic efficacy in hepatocellular cancer cells HuH7. In vitro iodide uptake studies demonstrated high transduction efficiency and cMET-specificity of NIS-encoding polyplexes (cMBP2-PEG-Stp/NIS) compared to polyplexes without targeting ligand (Ala-PEG-Stp/NIS) and without coding DNA (cMBP2-PEG-Stp/Antisense-NIS). Tumor recruitment and vector biodistribution were investigated in vivo in a subcutaneous xenograft mouse model showing high tumor-selective iodide accumulation in cMBP2-PEG-Stp/NIS-treated mice (6.6 ± 1.6% ID/g (123)I, biological half-life 3 hours) by (123)I-scintigraphy. Therapy studies with three cycles of polyplexes and (131)I application resulted in significant delay in tumor growth and prolonged survival. These data demonstrate the enormous potential of cMET-targeted sequence-defined polymers combined with the unique theranostic function of NIS allowing for optimized transfection efficiency while eliminating toxicity.

  16. Novel germline c-MET mutation in a family with hereditary papillary renal carcinoma

    DEFF Research Database (Denmark)

    Wadt, Karin; Gerdes, Anne-Marie; Hansen, Thomas V O;

    2012-01-01

    Hereditary papillary renal carcinoma (HPRC) is a highly penetrant hereditary renal cancer syndrome caused by germline missense mutations in the c-MET proto-oncogene. HPRC is clinically characterized by multiple bilateral papillary renal-cell carcinomas. Here we report a family with a novel missense...... mutation in c-MET. The original pathology report of four primary kidney cancers (1988-1997) revealed renal-cell carcinoma. A revised report described multiple adenomas and papillary renal-cell carcinomas with focal clear cells and a mixture of type 1 and type 2 pattern, emphasizing the importance...... of revised pathology examinations in possible hereditary renal-cell carcinomas especially when described before 1997....

  17. A novel activating role of SRC and STAT3 on HGF transcription in human breast cancer cells

    Directory of Open Access Journals (Sweden)

    Elliott Bruce E

    2007-10-01

    Full Text Available Abstract We have previously determined that the HGF promoter can be transactivated by a combination of activated Src and wild-type Stat3 in the mouse breast cell lines HC11 and SP1. To determine if this pathway is of relevance for the human disease, a series of human breast and other human cells lines were examined, and the status of key proteins in these cells determined. All of the human breast cell lines exhibited strong transactivation by a combination of activated Src and Stat3. This activation was dependent on a Stat3 recognition element present at nt-95. The exception was the ErbB2 over-expressing cell line SK-BR-3 where Stat3 alone could transactivate HGF though Src augmented this effect. Increased phosphorylation of Stat3 tyrosine 705 was also observed in this line. Analysis of three ovarian cell lines revealed that Src/Stat3 expression was not able to activate the HGF promoter in two of these lines (SKOV3 and IOSE-80PC. Src/Stat3 expression did activate HGF transcription in OVCAR3 cells, but this effect was not mediated by the Stat3 site at nt-95. Stat3 phosphorylation at tyrosine 705 was observed in IOSE-80PC cells, but was insufficient to allow for activation of the HGF promoter. Human kidney (HEK293 and cervical carcinoma (HeLa cells were also not Src/Stat3 permissive, despite high levels of Stat3 phospho-Y705. These results suggest that human breast cells are a uniquely permissive environment for HGF transactivation by Src/Stat3 which may allow for the inappropriate activation of HGF transcription during the early stages of breast transformation. This could lead to paracrine or autocrine activation of the Met receptor in breast carcinoma cells.

  18. Exogenous HGF Bypasses the Effects of ErbB Inhibition on Tumor Cell Viability in Medulloblastoma Cell Lines

    NARCIS (Netherlands)

    Zomerman, Waldrik W; Plasschaert, Sabine L. A.; Diks, Sander H.; Lourens, Harm-Jan; Meeuwsen-de Boer, Tiny; Hoving, Eelco W.; den Dunnen, Wilfred F. A.; de Bont, Eveline S. J. M.

    2015-01-01

    Recent clinical trials investigating receptor tyrosine kinase (RTK) inhibitors showed a limited clinical response in medulloblastoma. The present study investigated the role of micro-environmental growth factors expressed in the brain, such as HGF and EGF, in relation to the effects of hepatocyte gr

  19. Glomerular ultrafiltration and apical tubular action of IGF-I, TGF-beta, and HGF in nephrotic syndrome.

    Science.gov (United States)

    Wang, S N; Lapage, J; Hirschberg, R

    1999-10-01

    In nephrotic glomerulopathies, there is ultrafiltration of high molecular weight forms of insulin-like growth factor-I (IGF-I), hepatocyte growth factor (HGF), and transforming growth factor-beta (TGF-beta), which are bioactive in tubular fluid and act through apical tubular receptors. Experimental evidence indicates that ultrafiltered IGF-I, HGF, and TGF-beta may contribute to increased tubular phosphate and sodium absorption, synthesis of extracellular matrix proteins, and secretion of chemokines such as monocyte chemoattractant protein-1 (MCP-1). Through these mechanisms, glomerular proteinuria may contribute to tubulointerstitial pathobiology in nephrotic syndrome.

  20. Low c-Met expression levels are prognostic for and predict the benefits of temozolomide chemotherapy in malignant gliomas

    Science.gov (United States)

    Li, Ming-Yang; Yang, Pei; Liu, Yan-Wei; Zhang, Chuan-Bao; Wang, Kuan-Yu; Wang, Yin-Yan; Yao, Kun; Zhang, Wei; Qiu, Xiao-Guang; Li, Wen-Bin; Peng, Xiao-Xia; Wang, Yong-Zhi; Jiang, Tao

    2016-01-01

    Aberrant c-Met has been implicated in the development of many cancers. The objective of this study was to identify an unfavorable prognostic marker that might guide decisions regarding clinical treatment strategies for high-grade gliomas. C-Met expression was measured using immunohistochemistry in 783 gliomas, and we further analyzed c-Met mRNA levels using the Agilent Whole Genome mRNA Microarray in 286 frozen samples. In vitro, we performed cell migration and invasion assays. Cell sensitivity to temozolomide (TMZ) chemotherapy was determined using MTT assays. Both mRNA and protein levels of c-Met were significantly associated with tumor grade progression and inversely correlated with overall and progression-free survival in high-grade gliomas (all P < 0.0001). These findings were nearly consistent at the mRNA level across 3 independent cohorts. Multivariable analysis indicated that c-Met was an independent prognostic marker after adjusting for age, preoperative Karnofsky Performance Status (KPS) score, the extent of resection, radiotherapy, TMZ chemotherapy, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status. Further analysis in vitro revealed that downregulating the expression of c-Met dramatically inhibited cell migration and invasion capacities, enhanced sensitivity to TMZ chemotherapy in H4 and U87 glioma cells. Our results suggest that c-Met may serve as a potential predictive maker for clinical decision making. PMID:26879272

  1. c-Met inhibitor SU11274 enhances the response of the prostate cancer cell line DU145 to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hongliang; Li, Xiaoying; Sun, Shaoqian [Department of Radiation Oncology, Peking University First Hospital, Peking University, Beijing (China); Gao, Xianshu, E-mail: xsgao777@hotmail.com [Department of Radiation Oncology, Peking University First Hospital, Peking University, Beijing (China); Zhou, Demin, E-mail: deminzhou@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing (China)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer c-Met inhibition could significantly enhance the radiosensitivity of DU145 cells. Black-Right-Pointing-Pointer The mechanisms of the radiosensitization effect of c-Met inhibition on DU145 cells were also presented in this paper. Black-Right-Pointing-Pointer This is the first study demonstrating the effectiveness of c-Met inhibition on treating HRPC cells with radiotherapy. -- Abstract: Hormone-refractory prostate cancer shows substantial resistance to most conventional therapies including radiotherapy, constitutes a key impediment to curing patients with the disease. c-Met overexpression plays a key role in prostate cancer tumorigenesis and disease progression. Here, we demonstrate that c-Met inhibition by SU11274 could significantly suppress cell survival and proliferation as well as enhance the radiosensitivity of DU145 cells. The underlying mechanisms of the effects of SU11274 on DU145 cells may include the inhibition of c-Met signaling, depolarization of the mitochondrial membrane potential, impairment of DNA repair function, abrogation of cell cycle arrest, and enhancement of cell death. Our study is the first to show the effectiveness of combining c-Met inhibition with ionizing radiation to cure hormone-refractory prostate cancer.

  2. RhoA/phosphatidylinositol 3-kinase/protein kinase B/mitogen-activated protein kinase signaling after growth arrest-specific protein 6/mer receptor tyrosine kinase engagement promotes epithelial cell growth and wound repair via upregulation of hepatocyte growth factor in macrophages.

    Science.gov (United States)

    Lee, Ye-Ji; Park, Hyun-Jung; Woo, So-Youn; Park, Eun-Mi; Kang, Jihee Lee

    2014-09-01

    Growth arrest-specific protein 6 (Gas6)/Mer receptor tyrosine kinase (Mer) signaling modulates cytokine secretion and helps to regulate the immune response and apoptotic cell clearance. Signaling pathways that activate an epithelial growth program in macrophages are still poorly defined. We report that Gas6/Mer/RhoA signaling can induce the production of epithelial growth factor hepatic growth factor (HGF) in macrophages, which ultimately promotes epithelial cell proliferation and wound repair. The RhoA/protein kinase B (Akt)/mitogen-activated protein (MAP) kinases, including p38 MAP kinase, extracellular signal-regulated protein kinase, and Jun NH2-terminal kinase axis in RAW 264.7 cells, was identified as Gas6/Mer downstream signaling pathway for the upregulation of HGF mRNA and protein. Conditioned medium from RAW 264.7 cells that had been exposed to Gas6 or apoptotic cells enhanced epithelial cell proliferation of the epithelial cell line LA-4 and wound closure. Cotreatment with an HGF receptor-blocking antibody or c-Met antagonist downregulated this enhancement. Inhibition of Mer with small interfering RNA (siRNA) or the RhoA/Rho kinase pathway by RhoA siRNA or Rho kinase pharmacologic inhibitor suppressed Gas6-induced HGF mRNA and protein expression in macrophages and blocked epithelial cell proliferation and wound closure induced by the conditioned medium. Our data provide evidence that macrophages can be reprogrammed by Gas6 to promote epithelial proliferation and wound repair via HGF, which is induced by the Mer/RhoA/Akt/MAP kinase pathway. Thus, defects in Gas6/Mer/RhoA signaling in macrophages may delay tissue repair after injury to the alveolar epithelium.

  3. Structure Based Drug Design of Crizotinib (PF-02341066), a Potent and Selective Dual Inhibitor of Mesenchymal-Epithelial Transition Factor (c-MET) Kinase and Anaplastic Lymphoma Kinase (ALK)

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J Jean; Tran-Dube,; #769; Michelle,; Shen, Hong; Nambu, Mitchell; Kung, Pei-Pei; Pairish, Mason; Jia, Lei; Meng, Jerry; Funk, Lee; Botrous, Iriny; McTigue, Michele; Grodsky, Neil; Ryan, Kevin; Padrique, Ellen; Alton, Gordon; Timofeevski, Sergei; Yamazaki, Shinji; Li, Qiuhua; Zou, Helen; Christensen, James; Mroczkowski, Barbara; Bender, Steve; Kania, Robert S; Edwards, Martin P [Pfizer

    2011-08-03

    Because of the critical roles of aberrant signaling in cancer, both c-MET and ALK receptor tyrosine kinases are attractive oncology targets for therapeutic intervention. The cocrystal structure of 3 (PHA-665752), bound to c-MET kinase domain, revealed a novel ATP site environment, which served as the target to guide parallel, multiattribute drug design. A novel 2-amino-5-aryl-3-benzyloxypyridine series was created to more effectively make the key interactions achieved with 3. In the novel series, the 2-aminopyridine core allowed a 3-benzyloxy group to reach into the same pocket as the 2,6-dichlorophenyl group of 3 via a more direct vector and thus with a better ligand efficiency (LE). Further optimization of the lead series generated the clinical candidate crizotinib (PF-02341066), which demonstrated potent in vitro and in vivo c-MET kinase and ALK inhibition, effective tumor growth inhibition, and good pharmaceutical properties.

  4. Stroke Induces Mesenchymal Stem Cell Migration to Infarcted Brain Areas Via CXCR4 and C-Met Signaling.

    Science.gov (United States)

    Bang, Oh Young; Moon, Gyeong Joon; Kim, Dong Hee; Lee, Ji Hyun; Kim, Sooyoon; Son, Jeong Pyo; Cho, Yeon Hee; Chang, Won Hyuk; Kim, Yun-Hee

    2017-05-25

    Mesenchymal stem cells circulate between organs to repair and maintain tissues. Mesenchymal stem cells cultured with fetal bovine serum have therapeutic effects when intravenously administered after stroke. However, only a small number of mesenchymal stem cells reach the brain. We hypothesized that the serum from stroke patients increases mesenchymal stem cells trophism toward the infarcted brain area. Mesenchymal stem cells were grown in fetal bovine serum, normal serum from normal rats, or stroke serum from ischemic stroke rats. Compared to the fetal bovine serum group, the stroke serum group but not the normal serum group showed significantly greater migration toward the infarcted brain area in the in vitro and in vivo models (p stroke serum group than the others. The enhanced mesenchymal stem cells migration of the stroke serum group was abolished by inhibition of signaling. Serum levels of chemokines, cytokines, matrix metalloproteinase, and growth factors were higher in stroke serum than in normal serum. Behavioral tests showed a significant improvement in the recovery after stroke in the stroke serum group than the others. Stroke induces mesenchymal stem cells migration to the infarcted brain area via C-X-C chemokine receptor type 4 and c-Met signaling. Culture expansion using the serum from stroke patients could constitute a novel preconditioning method to enhance the therapeutic efficiency of mesenchymal stem cells.

  5. mTOR inhibitors control the growth of EGFR mutant lung cancer even after acquiring resistance by HGF.

    Directory of Open Access Journals (Sweden)

    Daisuke Ishikawa

    Full Text Available Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs, gefitinib and erlotinib, is a critical problem in the treatment of EGFR mutant lung cancer. Several mechanisms, including bypass signaling by hepatocyte growth factor (HGF-triggered Met activation, are implicated as mediators of resistance. The mammalian target of rapamycin (mTOR, is a downstream conduit of EGFR and MET signaling, and is thus considered a therapeutically attractive target in the treatment of various types of cancers. The purpose of this study was to examine whether 2 clinically approved mTOR inhibitors, temsirolimus and everolimus, overcome HGF-dependent resistance to EGFR-TKIs in EGFR mutant lung cancer cells. Both temsirolimus and everolimus inhibited the phosphorylation of p70S6K and 4E-BP1, which are downstream targets of the mTOR pathway, and reduced the viability of EGFR mutant lung cancer cells, PC-9, and HCC827, even in the presence of HGF in vitro. In a xenograft model, temsirolimus suppressed the growth of PC-9 cells overexpressing the HGF-gene; this was associated with suppression of the mTOR signaling pathway and tumor angiogenesis. In contrast, erlotinib did not suppress this signaling pathway or tumor growth. Multiple mechanisms, including the inhibition of vascular endothelial growth factor production by tumor cells and suppression of endothelial cell viability, contribute to the anti-angiogenic effect of temsirolimus. These findings indicate that mTOR inhibitors may be useful for controlling HGF-triggered EGFR-TKI resistance in EGFR mutant lung cancer, and they provide the rationale for clinical trials of mTOR inhibitors in patients stratified by EGFR mutation and HGF expression status.

  6. Association between Hepatocyte Growth Factor (HGF) Gene Polymorphisms and Serum HGF Levels in Patients with Rheumatoid Arthritis.

    Science.gov (United States)

    Kara, Fatih; Yildirim, Abdulkadir; Gumusdere, Musa; Karatay, Saliha; Yildirim, Kadir; Bakan, Ebubekir

    2014-10-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by proliferation and insufficient apoptosis of synovial cell, inflammatory cell infiltration, angiogenesis, and destruction of joints. Hepatocyte growth factor (HGF) has many functions, such as regulation of inflammation, angiogenesis, and inhibition of apoptosis. The purpose of this study was to investigate the association between intron 13 C/A and intron 14 T/C HGF gene polymorphisms and serum HGF levels in patients with RA. 100 patients with RA and 123 healthy controls were included in this study. Serum HGF concentrations were measured using ELISA kit. Gene polymorphisms were determined by allelic discrimination analysis using the real-time PCR method. HGF levels, frequency of AA genotype and A allele for intron 13 C/A polymorphism and frequency of CC genotype and C allele for intron 14 T/C polymorphism were increased in patients with RA compared to healthy controls. There was no overall associations between genotypes and serum HGF concentrations in both patient and control groups. Our results indicate that HGF protein and gene may play an important role in the etiopathogenesis of RA. However, further studies are required for a better understanding of mechanisms related to the disease process.

  7. Molecular modeling studies and synthesis of novel quinoxaline derivatives with potential anticancer activity as inhibitors of c-Met kinase.

    Science.gov (United States)

    Abbas, Hebat-Allah S; Al-Marhabi, Aisha R; Eissa, Sally I; Ammar, Yousry A

    2015-10-15

    In an effort to develop potent anti-cancer agents, we have synthesized some substituted quinoxaline derivatives. Reaction of 6-bromo-3-methylquinoxalin-2(1H)-one 1 with aromatic aldehydes furnished the styryl derivatives 2a-e. Alkylation of 1 with ethyl chloroacetate produced the N-alkyl derivatives 3. Hydrazinolysis of the ester derivative 3 with hydrazine hydrate afforded the hydrazide derivative 4. In addition, chlorination of 1 with phosphorus oxychloride afforded the 2-chloro derivative 5 which was used as a key intermediate for the synthesis of substituted quinoxaline derivatives 6-8, N-pyrazole derivative 9, tetrazolo[1,5-a]quinoxaline derivative 10 and Schiff base derivatives 13, 15 via reaction with several nucleophiles reagents. Docking methodologies were used to predict their binding conformation to explain the differences of their tested biological activities. All the tested compounds were screened in vitro for their cytotoxic effect on three tumor cell lines. Some new quinoxaline derivatives were studied as inhibitors of c-Met kinase, a receptor associated with high tumor grade and poor prognosis in a number of human cancers. Compounds 2e, 4, 7a, 12a, 12b and 13 showed the highest binding affinity with CDOCKER energy score, while showed the lowest IC50 values against three types of cancer cell lines. It is worth to mention that, compounds 2e, 7a, 12b and 13 showed comparable inhibition activity to the reference drug, while compounds 4 and 12a showed a more potent inhibition activity than Doxorubicin.

  8. FAK kinase activity is required for the progression of c-Met/β-catenin-driven HCC

    Science.gov (United States)

    Shang, Na; Arteaga, Maribel; Zaidi, Ali; Cotler, Scott J.; Breslin, Peter; Ding, Xianzhong; Kuo, Paul; Nishimura, Michael; Zhang, Jiwang; Qiu, Wei

    2016-01-01

    Background & Aims There is an urgent need to develop new and more effective therapeutic strategies and agents to treat hepatocellular carcinoma (HCC). We have recently found that deletion of Fak in hepatocytes before tumors form inhibits tumor development and prolongs survival of animals in a c-Met (MET)/β-catenin (CAT)-driven HCC mouse model. However, it has yet to be determined whether FAK expression in hepatocytes promotes MET/CAT-induced HCC progression after tumor initiation. In addition, it remains unclear whether FAK promotes HCC development through its kinase activity. Methods We generated hepatocyte-specific inducible Fak-deficient mice (Alb-creERT2; Fakflox/flox) to examine the role of FAK in HCC progression. We re-expressed wild-type and mutant FAK in Fak-deficient mice to determine FAK’s kinase activity in HCC development. We also examined the efficacy of a FAK kinase inhibitor PF-562271 on HCC inhibition. Results We found that deletion of Fak after tumors form significantly repressed MET/CAT-induced tumor progression. Ectopic FAK expression restored HCC formation in hepatocyte-specific Fak-deficient mice. However, overexpression of a FAK kinase-dead mutant led to reduced tumor load compared to mice which express wild-type FAK. Furthermore, PF-562271 significantly suppressed progression of MET/CAT-induced HCC. Conclusion Fak kinase activity is important for MET/CAT-induced HCC progression. Inhibiting FAK kinase activity provides a potential therapeutic strategy to treat HCC. PMID:27142958

  9. Discovery and optimization of novel 4-phenoxy-6,7-disubstituted quinolines possessing semicarbazones as c-Met kinase inhibitors.

    Science.gov (United States)

    Qi, Baohui; Mi, Bin; Zhai, Xin; Xu, Ziyi; Zhang, Xiaolong; Tian, Zeru; Gong, Ping

    2013-09-01

    A novel series of N(1)-(3-fluoro-4-(6,7-disubstituted-quinolin-4-yloxy)phenyl)-N(4)-arylidenesemicarbazide derivatives were synthesized and evaluated for their c-Met kinase inhibition and cytotoxicity against A549, HT-29, MKN-45 and MDA-MB-231 cancer cell lines in vitro. Several potent compounds were further evaluated against three other cancer cell lines (U87MG, NCI-H460 and SMMC7721). Most of compounds tested exhibited moderate to excellent activity. The studies of SARs identified the most promising compound 28 (c-Met IC50=1.4nM) as a c-Met kinase inhibitor. In this study, a promising compound 28 was identified, which displayed 2.1-, 3.3-, 48.4- and 3.6-fold increase against A549, HT-29, U87MG and NCI-H460 cell lines, respectively, compared with that of Foretinib.

  10. Discovery of quinazolin-4-amines bearing benzimidazole fragments as dual inhibitors of c-Met and VEGFR-2.

    Science.gov (United States)

    Shi, Lei; Wu, Ting-Ting; Wang, Zhi; Xue, Jia-Yu; Xu, Yun-Gen

    2014-09-01

    Both c-Met and VEGFR-2 are important targets for the treatment of cancers. In this study, a series of N-(2-phenyl-1H-benzo[d]imidazol-5-yl)quinazolin-4-amine derivatives were designed and identified as dual c-Met and VEGFR-2 inhibitors. Among these compounds bearing quinazoline and benzimidazole fragments, compound 7j exhibited the most potent inhibitory activity against c-Met and VEGFR-2 with IC50 of 0.05μM and 0.02μM, respectively. It also showed the highest anticancer activity against the tested cancer cell lines with IC50 of 1.5μM against MCF-7 and 8.7μM against Hep-G2. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction at the ATP-binding site of c-Met and VEGFR-2, which demonstrates that compound 7j is a potential agent for cancer therapy deserving further researching.

  11. Inhibition of tubular cell proliferation by neutralizing endogenous HGF leads to renal hypoxia and bone marrow-derived cell engraftment in acute renal failure.

    Science.gov (United States)

    Ohnishi, Hiroyuki; Mizuno, Shinya; Nakamura, Toshikazu

    2008-02-01

    During the progression of acute renal failure (ARF), the renal tubular S3 segment is sensitive to ischemic stresses. For reversing tubular damage, resident tubular cells proliferate, and bone marrow-derived cells (BMDC) can be engrafted into injured tubules. However, how resident epithelium or BMDC are involved in tubular repair remains unknown. Using a mouse model of ARF, we examined whether hepatocyte growth factor (HGF) regulates a balance of resident cell proliferation and BMDC recruitment. Within 48 h post-renal ischemia, tubular destruction became evident, followed by two-waved regenerative events: 1) tubular cell proliferation between 2 and 4 days, along with an increase in blood HGF; and 2) appearance of BMDC in the tubules from 6 days postischemia. When anti-HGF IgG was injected in the earlier stage, tubular cell proliferation was inhibited, leading to an increase in BMDC in renal tubules. Under the HGF-neutralized state, stromal cell-derived factor-1 (SDF1) levels increased in renal tubules, associated with the enhanced hypoxia. Administrations of anti-SDF1 receptor IgG into ARF mice reduced the number of BMDC in interstitium and tubules. Thus possible cascades include 1) inhibition of tubular cell proliferation by neutralizing HGF leads to renal hypoxia and SDF1 upregulation; and 2) BMDC are eventually engrafted in tubules through SDF1-mediated chemotaxis. Inversely, administration of recombinant HGF suppressed the renal hypoxia, SDF1 upregulation, and BMDC engraftment in ARF mice by enhancing resident tubular cell proliferation. Thus we conclude that HGF is a positive regulator for eliciting resident tubular cell proliferation, and SDF1 for BMDC engraftment during the repair process of ARF.

  12. Telmisartan prevents angiotensin II-induced endothelial dysfunction in rabbit aorta via activating HGF/Met system and PPARγ pathway.

    Science.gov (United States)

    Hu, Ze-Ping; Fang, Xiao-Ling; Qian, Hai-Yan; Fang, Nan; Wang, Bang-Ning; Wang, Yuan

    2014-10-01

    Telmisartan with partial activation of peroxisome proliferator-activated receptor γ (PPARγ) powerfully reduces blood pressure, improves endothelial function and lipid metabolism. Hepatocyte growth factor/mesenchymal-epithelial transition factor (HGF/Met) system in the local vasculature plays a pivotal role in maintaining normal endothelial function. This study is aimed to evaluate whether telmisartan directly prevents angiotensin II (Ang II)-induced endothelial dysfunction (ED) via activating HGF/Met system and/or PPARγ pathway. The isolated aortic rings of rabbits were incubated with Ang II (0.01-1 μM), telmisartan (0.1-10 μM), SU11274 (5 μM) as a specific Met inhibitor, GW9662 (10 μM) as a PPARγ antagonist alone or a combination for 6 h. Ang II obviously inhibited the mRNA and protein expression of HGF, Met and PPARγ, and the accumulative concentration-relaxation of the aortic rings to acetylcholine, among which the inhibitory effect of 1 μM Ang II was most significant. By contrast, telmisartan significantly increased the mRNA and protein expression of HGF, Met, and PPARγ, thus preventing Ang II-induced ED in a dose-dependent pattern. However, SU11274, GW9662 or a combination of both partially abolished the protective effects derived from telmisartan, with the effect of SU11274 exceeding that of GW9662. These results demonstrate that Ang II-induced ED in rabbit aortic rings in vitro can be prevented by telmisartan through selective PPARγ-modulating pathway. Moreover, this study indicates for the first time that activating HGF/Met system in the local vasculature is involved in the protective mechanism of telmisartan. © 2013 Société Française de Pharmacologie et de Thérapeutique. Published by John Wiley & Sons Ltd.

  13. Immunohistochemical expressions of fatty acid synthase and phosphorylated c-Met in thyroid carcinomas of follicular origin.

    Science.gov (United States)

    Liu, Jing; Brown, Robert E

    2011-01-01

    Thyroid carcinoma is the most common endocrine malignancy and the first cause of death among endocrine cancers. Fatty acid synthase (FASN) and c-Met are overexpressed in many types of human cancers. Recent studies have suggested a functional interaction between FASN and c-Met. However, their roles in thyroid carcinomas have not been fully investigated. In this study, we evaluated the expressions of FASN and phosphorylated (p)-c-Met by using immunohistochemistry in thyroid carcinomas of follicular origin, from 32 patients. The adjacent non-neoplastic thyroid tissue was also evaluated for comparison. Immunoreactive intensity and extensiveness were semi-quantified. The overexpression of FASN was observed in a subset of papillary thyroid carcinomas (PTC) including the classical type and tall cell, follicular, trabecular/insular and diffuse sclerosing variants, a subset of follicular thyroid carcinomas (FTC), and the PTC and FTC components in anaplastic thyroid carcinomas (ATC). No overexpression was observed in the ATCs per se and the columnar cell, solid, and cribriform variants of PTCs. All Hürthle cell variant FTCs and non-neoplastic Hürthle cells demonstrated positive staining for FASN while the non-neoplastic follicular cells without Hürthle cell change were negative. An association in overexpression between FASN and p-c-Met was observed in the majority of carcinomas as well as in the non-neoplastic Hürthle cells. In conclusion, overexpressions of FASN and p-c-Met were observed in a subset of thyroid carcinomas of follicular origin, which may be of values for targeted therapy and predicting prognosis while the positive immunostaining for these immunomarkers may be nonspecific for Hürthle cell thyroid carcinomas.

  14. Necroptosis Induced by Ad-HGF Activates Endogenous C-Kit+ Cardiac Stem Cells and Promotes Cardiomyocyte Proliferation and Angiogenesis in the Infarcted Aged Heart

    Directory of Open Access Journals (Sweden)

    Jiabao Liu

    2016-12-01

    Full Text Available Background/Aims: The discovery of c-kit+ cardiac stem cells (CSCs provided us with new therapeutic targets to repair the damaged heart. However, the precise mechanisms regulating CSC proliferation and differentiation in the aged heart remained elusive. Necroptosis, a type of regulated cell death, has recently been shown to occur following myocardial infarction (MI; however, its effect on c-kit+ CSCs remains unknown. We investigated the effects of hepatocyte growth factor (HGF and necroptosis on the proliferation and differentiation of endogenous c-kit+ CSCs in aged rat hearts following MI. Methods: The c-kit+ CSCs and HGF/p-Met expression levels in neonatal, adult and aged rats were compared using immunofluorescence and Western blotting. Immediately after MI, adenovirus carrying the HGF gene (Ad-HGF was injected into the left ventricular wall surrounding the infarct areas of the aged rat heart. The proliferation and differentiation of the endogenous c-kit+ CSCs were studied using immunofluorescence. The signalling pathways were analysed via Western blotting and ELISA. Results: HGF/p-Met expression levels and c-kit+ CSC abundance gradually decreased with age. Ad-HGF promoted c-kit+ CSC differentiation into precursor cells of cardiomyocyte, endothelial and smooth muscle cell lineages and enhanced cardiomyocyte proliferation and angiogenesis in aged rats; these effects were reversed by the inhibition of necroptosis. Ad-HGF administration induced necroptosis by increasing the expression of receptor interacting protein kinase (RIP 1 and receptor interacting protein kinase (RIP 3 proteins in the infarcted heart. Moreover, Ad-HGF-induced necroptosis increased high-mobility group box 1 protein (HMGB1 levels and enhanced the abundance of c-kit+ cells in the bone marrow, which may partly account for the beneficial effect of necroptosis on the c-kit+ CSCs. Conclusion: Ad-HGF-induced necroptosis facilitated aged heart repair after MI by promoting c-kit+ CSC

  15. HGF is released from buccal fibroblasts after smokeless tobacco stimulation

    DEFF Research Database (Denmark)

    Dabelsteen, S; Christensen, S; Gron, B

    2005-01-01

    To investigate the effect of smokeless tobacco (ST) on (1) HGF, KGF and GM-CSF expression by buccal fibroblasts and (2) on keratinocyte and fibroblast proliferation. Buccal fibroblasts were stimulated with different concentrations of ST extracts in a double dilution from 0.50% w/v to 0.03% w...... on exposure time and on concentration of the tobacco extract. High concentration increased production of HGF 4-fold. KGF production was doubled when high concentration of tobacco was used, low concentration did not stimulate cells. GM-CSF production was low in both stimulated and non-stimulated cells...

  16. Mechanism of c-Met and EGFR tyrosine kinase inhibitor resistance through epithelial mesenchymal transition in non-small cell lung cancer

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    Rastogi, Ichwaku; Rajanna, Supriya; Webb, Andrew; Chhabra, Gagan; Foster, Brad [Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Illinois (United States); Webb, Brian [Thermo Fisher Scientific, Rockford, Illinois (United States); Puri, Neelu, E-mail: neelupur@uic.edu [Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Illinois (United States)

    2016-09-02

    According to currently available estimates from Cancer Research UK, 14.1 million new lung cancer cases were diagnosed and a staggering 8.2 million people worldwide died from lung cancer in 2012. EGFR and c-Met are two tyrosine kinase receptors most commonly overexpressed or mutated in Non-small Cell Lung Cancer (NSCLC) resulting in increased proliferation and survival of lung cancer cells. Tyrosine kinase inhibitors (TKIs), such as erlotinib, approved by the FDA as first/second line therapy for NSCLC patients have limited clinical efficacy due to acquired resistance. In this manuscript, we investigate and discuss the role of epithelial mesenchymal transition (EMT) in the development of resistance against EGFR and c-Met TKIs in NSCLC. Our findings show that Zeb-1, a transcriptional repressor of E-Cadherin, is upregulated in TKI-resistant cells causing EMT. We observed that TKI-resistant cells have increased gene and protein expression of EMT related proteins such as Vimentin, N-Cadherin, β-Catenin and Zeb-1, while expression of E-Cadherin, an important cell adhesion molecule, was suppressed. We also confirmed that TKI-resistant cells display mesenchymal cell type morphology, and have upregulation of β-Catenin which may regulate expression of Zeb-1, a transcriptional repressor of E-Cadherin in TKI-resistant NSCLC cells. Finally, we show that down-regulating Zeb-1 by inducing miR-200a or β-Catenin siRNA can increase drug sensitivity of TKI-resistant cells. - Highlights: • Resistance to TKIs in NSCLC cells is mediated via modulation in EMT related proteins. • EMT may induce c-Met mediated TKI resistance, similar to EGFR TKI resistance. • Role of β-catenin and cadherins in TKI resistance was validated by FACS and qPCR. • Knockdown of β-catenin or Zeb-1 can increase TKI sensitivity in TKI-resistant cells. • Targeting key EMT related proteins may overcome TKI resistance in NSCLC.

  17. Increased NQO1 but Not c-MET and Survivin Expression in Non-Small Cell Lung Carcinoma with KRAS Mutations

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    Ahmet Yilmaz

    2014-09-01

    Full Text Available Cigarette smoking is one of the most significant public health issues and the most common environmental cause of preventable cancer deaths worldwide. EGFR (Epidermal Growth Factor Receptor-targeted therapy has been used in the treatment of LC (lung cancer, mainly caused by the carcinogens in cigarette smoke, with variable success. Presence of mutations in the KRAS (Kirsten rat sarcoma viral oncogene homolog driver oncogene may confer worse prognosis and resistance to treatment for reasons not fully understood. NQO1 (NAD(PH:quinone oxidoreductase, also known as DT-diaphorase, is a major regulator of oxidative stress and activator of mitomycins, compounds that have been targeted in over 600 pre-clinical trials for treatment of LC. We sequenced KRAS and investigated expression of NQO1 and five clinically relevant proteins (DNMT1, DNMT3a, ERK1/2, c-MET, and survivin in 108 patients with non-small cell lung carcinoma (NSCLC. NQO1, ERK1/2, DNMT1, and DNMT3a but not c-MET and survivin expression was significantly more frequent in patients with KRAS mutations than those without, suggesting the following: (1 oxidative stress may play an important role in the pathogenesis, worse prognosis, and resistance to treatment reported in NSCLC patients with KRAS mutations, (2 selecting patients based on their KRAS mutational status for future clinical trials may increase success rate, and (3 since oxidation of nucleotides also specifically induces transversion mutations, the high rate of KRAS transversions in lung cancer patients may partly be due to the increased oxidative stress in addition to the known carcinogens in cigarette smoke.

  18. Ochratoxin A activates opposing c-MET/PI3K/Akt and MAPK/ERK 1-2 pathways in human proximal tubule HK-2 cells.

    Science.gov (United States)

    Özcan, Zeynep; Gül, Gizem; Yaman, Ibrahim

    2015-08-01

    Ochratoxin A (OTA) is a mycotoxin produced as a secondary metabolite by filamentous fungi, such as Aspergillus and Penicillium. Because OTA is a common contaminant of food and feeds, humans and animals are frequently exposed to OTA in daily life. It has been classified as a carcinogen in rodents and a possible carcinogen in humans. OTA has been shown to deregulate a variety of different signal transduction pathways in a cell type- and dosage-depending manner resulting in contrasting physiological effects, such as survival or cell death. While the ERK1-2 and JNK/SAPK MAPK pathways are major targets, knowledge about their role in OTA-mediated cell survival and death is fragmented. Similarly, the contribution of the PI3K/Akt pathway to the carcinogenic effect of OTA in proximal tubule cells has not been elucidated in detail. In this study, we demonstrated that OTA induced sustained activation of the PI3K/Akt and MEK/ERK1-2 signaling pathways in a dose- and time-dependent manner in HK-2 cells. Chemical inhibition of ERK1-2 activation or overexpression of dominant-negative and kinase-dead MEK1 leads to increased cell viability and decreased apoptosis in OTA-treated cells. Blockage of PI3K/Akt with Wortmannin aggravated the negative effect of OTA on cell viability and increased the levels of apoptosis. Moreover, we identified the c-MET proto-oncogene as an upstream receptor tyrosine kinase responsible for OTA-induced activation of PI3K/Akt signaling in HK-2 cells. Our data suggest that OTA may potentiate carcinogenesis by sustained activation of c-MET/PI3K/Akt signaling through suppression of apoptosis induced by MEK/ERK1-2 activation in damaged renal proximal tubule epithelial cells.

  19. Response assessment of bevacizumab therapy in GBM with integrated 11C-MET-PET/MRI: a feasibility study.

    Science.gov (United States)

    Deuschl, Cornelius; Moenninghoff, Christoph; Goericke, Sophia; Kirchner, Julian; Köppen, Susanne; Binse, Ina; Poeppel, Thorsten D; Quick, Harald H; Forsting, Michael; Umutlu, Lale; Herrmann, Ken; Hense, Joerg; Schlamann, Marc

    2017-08-01

    The objective of this study was to evaluate the potential of integrated 11C-MET PET/MR for response assessment of relapsed glioblastoma (GBM) receiving bevacizumab treatment. Eleven consecutive patients with relapsed GBM were enrolled for an integrated 11C-MET PET/MRI at baseline and at follow-up. Treatment response for MRI was evaluated according to Response Assessment in Neuro-oncology (RANO) criteria and integrated 11C-MET PET was assessed by the T/N ratio. MRI showed no patient with complete response (CR), six of 11 patients with PR, four of 11 patients with SD, and one of 11 patients with progressive disease (PD). PET revealed metabolic response in five of the six patients with partial response (PR) and in two of the four patients with stable disease (SD), whereas metabolic non-response was detected in one of the six patients with PR, in two of the four patients with SD, and in the one patient with PD. Morphological imaging was predictive for PFS and OS when response was defined as CR, PR, SD, and non-response as PD. Metabolic imaging was predictive when using T/N ratio reduction of >25 as discriminator. Based on the morphologic and metabolic findings of this study a proposal for applying integrated PET/MRI for treatment response in relapsed GBM was developed, which was significantly predictive for PFS and OS (P = 0.010 respectively 0,029, log). This study demonstrates the potential of integrated 11C-MET-PET/MRI for response assessment of GBM and the utility of combined assessment of morphologic and metabolic information with the proposal for assessing relapsed GBM.

  20. Expression and migratory analysis of 5 human uveal melanoma cell lines for CXCL12, CXCL8, CXCL1, and HGF

    Directory of Open Access Journals (Sweden)

    Di Cesare Sebastian

    2007-01-01

    Full Text Available Abstract Background The aim of this study was to characterize the presence and roles of CXCL12, CXCL8, CXCL1, and HGF in five human uveal melanoma cell lines, using different methods, in order to ascertain their significance in this disease. Methods Five human uveal melanoma cell lines (92.1, SP6.5, MKT-BR, OCM-1, and UW-1 of known proliferative, invasive, and metastatic potential were used in this experiment. A migration assay was used in order to assess the responsiveness of each cell line towards the four chosen chemotactic factors. Immunohistochemistry was then performed for all five cell lines (cytospins using antibodies directed toward CXCL1, CXCL8 and their receptors CXCR2 and CXCR1 respectively. Quantitative real-time PCR was then performed on all five cell lines in order to establish the presence of these four chemotactic factors. Results All five human uveal melanoma cell lines migrated towards the four chosen chemotactic factors at a level greater than that of the negative control. Chemokines CXCL1 and CXCL8 resulted in the greatest number of migrating cells in all five of our cell lines. Immunohistochemistry confirmed the expression of CXCL1, CXCL8, and their receptors CXCR2 and CXCR1 in all five of the cell lines. Quantitative real-time PCR results established expression of CXCL8, CXCL1, and HGF in all 5 cell lines tested. CXCL1 and CXCL8 are highly expressed in SP6.5 and UW-1. None of the five cell lines expressed any detectable levels of CXCL12. Conclusion The migratory ability of the 5 human uveal melanoma cell lines was positively influenced by the four chemotactic factors tested, namely CXCL12, CXCL8, CXCL1, and HGF. Self-expression of chemotactic factors CXCL8, CXCL1, and HGF may indicate an autocrine system, which perhaps contributes to the cells' metastatic ability in vivo.

  1. The sonic hedgehog signaling pathway stimulates anaplastic thyroid cancer cell motility and invasiveness by activating Akt and c-Met.

    Science.gov (United States)

    Williamson, Ashley J; Doscas, Michelle E; Ye, Jin; Heiden, Katherine B; Xing, Mingzhao; Li, Yi; Prinz, Richard A; Xu, Xiulong

    2016-03-01

    The sonic hedgehog (Shh) pathway is highly activated in thyroid neoplasms and promotes thyroid cancer stem-like cell phenotype, but whether the Shh pathway regulates thyroid tumor cell motility and invasiveness remains unknown. Here, we report that the motility and invasiveness of two anaplastic thyroid tumor cell lines, KAT-18 and SW1736, were inhibited by two inhibitors of the Shh pathway (cyclopamine and GANT61). Consistently, the cell motility and invasiveness was decreased by Shh and Gli1 knockdown, and was increased by Gli1 overexpression in KAT-18 cells. Mechanistic studies revealed that Akt and c-Met phosphorylation was decreased by a Gli1 inhibitor and by Shh and Gli1 knockdown, but was increased by Gli1 overexpression. LY294002, a PI-3 kinase inhibitor, and a c-Met inhibitor inhibited the motility and invasiveness of Gli1-transfected KAT-18 cells more effectively than the vector-transfected cells. Knockdown of Snail, a transcription factor regulated by the Shh pathway, led to decreased cell motility and invasiveness in KAT-18 and SW1736 cells. However, key epithelial-to-mesenchymal transition (EMT) markers including E-cadherin and vimentin as well as Slug were not affected by cyclopamine and GANT61 in either SW1736 or WRO82, a well differentiated follicular thyroid carcinoma cell line. Our data suggest that the Shh pathway-stimulated thyroid tumor cell motility and invasiveness is largely mediated by AKT and c-Met activation with little involvement of EMT.

  2. Comparison of the c-MET gene amplification between primary tumor and metastatic lymph nodes in non-small cell lung cancer.

    Science.gov (United States)

    Xu, Chun-Wei; Wang, Wen-Xian; Wu, Mei-Juan; Zhu, You-Cai; Zhuang, Wu; Lin, Gen; Du, Kai-Qi; Huang, Yun-Jian; Chen, Yan-Ping; Chen, Gang; Fang, Mei-Yu

    2017-09-01

    c-MET has recently been identified as a promising novel target in non-small cell lung cancer (NSCLC). We detected the consistency of c-MET gene amplification in metastatic lymph nodes and tumor tissues of NSCLC patients and discuss the clinical application value of c-MET gene amplification in metastatic lymph nodes. Real-time fluorescent quantitative PCR was used to test tumor tissues in 368 NSCLC patients and 178 paired metastatic lymph node samples. The amplification consistency in metastatic lymph nodes and tissue samples were compared and the correlation between c-MET gene amplification and the clinical characteristics of patients was analyzed. The c-MET gene amplification rate was 8.97% (33/368) in tumor tissues. Of the 178 paired cases, c-MET gene amplification was positive in 7.95% (15/178) of cancerous tissues and 18.54% (33/178) of metastatic lymph nodes. c-MET gene amplification was detected more frequently in metastatic lymph nodes than in primary cancerous tissue. When metastatic lymph nodes were used as surrogate samples of primary cancerous tissues, the sensitivity was 86.67% (13/15) and the specificity was 87.69% (143/163). Screening for c-MET gene amplification in lymph node metastases could determine which patients are eligible for tyrosine kinase inhibitor therapy. Lymph node metastasis can predict c-MET gene amplification in a primary tumor and guide the clinical use of c-MET gene targeted drugs. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  3. The role of c-Met in prognosis and clinicopathology of renal cell carcinoma: Results from a single-centre study and systematic review.

    Science.gov (United States)

    Chen, Shouzhen; Zhu, Yaofeng; Cui, Jianfeng; Wang, Yong; Xia, Yangyang; Song, Jing; Cheng, Shanshan; Zhou, Changkuo; Zhang, Dongqing; Zhang, Bing; Shi, Benkang

    2017-08-01

    The c-Met proto-oncogene pathway plays an important role in the progression of various cancers. However, the effect of the c-Met pathway on renal cell carcinoma (RCC) remains controversial. We decided to clarify the role of c-Met in prognosis and clinicopathology of RCC. A total of 10 pairs of tumour and adjacent tissues were obtained from patients with primary RCC between 2013 and 2014 and tissue microarrays to assess c-Met expression in tumour tissues from 90 patients with RCC by Western blot and immunohistochemical staining. We also presented a meta-analysis to explore the correlation between c-Met and pathological grade and stage of RCC. The two-tailed Pearson's χ(2) and Fischer exact tests were used to compare categorical variables. Multivariate analysis was performed using the multivariate Cox proportional hazards model. C-Met protein levels were increased in 8 of 10 RCC tissue samples compared with their adjacent normal tissue and c-Met expression levels were positively associated with a high nuclear grade (P = 0.008) and pT stage (P = 0.002). Multivariate analysis showed that a high expression of c-Met was an independent predictor of disease-specific survival (P = 0.017). A meta-analysis found that increased c-Met expression in RCC tissues was closely correlated with high tumour grade (Pc-Met expression was significantly correlated with disease-specific survival (Pc-Met is strongly associated with pathological grade, stage and disease-specific survival, c-Met levels may have potential to predict patient prognosis and to guide clinical diagnosis and treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Influence of adenovirus vector-mediated RNAi on expression of c-Met in SK-BR-3 cells%腺病毒载体介导的RNAi对SK-BR-3细胞c-Met表达的影响

    Institute of Scientific and Technical Information of China (English)

    赵慧; 陈东; 袁振华; 王忠山; 吴小兵

    2006-01-01

    目的:通过腺病毒载体介导的RNA干扰技术抑制乳腺癌细胞HGF受体c-Met的表达,抑制乳腺癌细胞增殖、诱导细胞凋亡.方法:PCR法获得人U6启动子及带有c-Met反向互补靶序列的片段HU6shmet;利用腺病毒载体将其传递至SK-BR-3细胞;RNA狭缝杂交检测SK-BR-3细胞c-Met mRNA水平,Western印迹检测c-Met蛋白水平.结果:获得了带有人U6启动子及c-Met反向互补靶序列的重组腺病毒载体rAdUshmet1和rAdUshmet2.转导了重组腺病毒的SK-BR-3细胞的c-Met mRNA和蛋白相对表达量均有所下降.结论:腺病毒载体rAdUshmet通过抑制HGF受体c-Met表达,能在一定程度上阻断HGF-c-Met信号转导通路,有可能成为对乳腺癌进行基因治疗的有效载体.

  5. Overexpression of c-met in the early stage of pancreatic carcinogenesis; altered expression is not sufficient for progression from chronic pancreatitis to pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Jun Yu; Eishi Nagai; Masao Tanaka; Kenoki Ohuchida; Kazuhiro Mizumoto; Nami Ishikawa; Yasuhiro Ogura; Daisuke Yamada; Takuya Egami; Hayato Fujita; Seiji Ohashi

    2006-01-01

    AIM: To investigate c-met expression during early pancreatic carcinogenesis.METHODS: We used 46 bulk tissues and 36 microdissected samples, including normal pancreas, chronic pancreatitis, and pancreatic cancer, for quantitative real time reverse transcription-polymerase chain reaction.RESULTS: In bulk tissue analyses, pancreatic cancer tissues expressed significantly higher levels of c-met than did chronic pancreatitis and normal pancreas tissues.c-met levels did not differ between chronic pancreatitis and normal pancreas tissues. In microdissection-based analyses, c-met was expressed at higher levels in microdissected pancreatic cancer cells and pancreatitisaffected epithelial cells than in normal ductal epithelial cells (both, P < 0.01). Interestingly, pancreatitis-affected epithelial cells expressed levels of c-met similar to those of pancreatic cancer cells.CONCLUSION: Overexpression of c-met occurs during the early stage of pancreatic carcinogenesis, and a single alteration of c-met expression is not sufficient for progression of chronic pancreatitis-affected epithelial cells to pancreatic cancer cells.

  6. Target identification, lead optimization and antitumor evaluation of some new 1,2,4-triazines as c-Met kinase inhibitors.

    Science.gov (United States)

    El-Wakil, Marwa H; Ashour, Hayam M; Saudi, Manal N; Hassan, Ahmed M; Labouta, Ibrahim M

    2017-08-01

    In silico target fishing approach using PharmMapper server identified c-Met kinase as the selective target for our previously synthesized compound NCI 748494/1. This approach was validated by in vitro kinase assay which showed that NCI 748494/1 possessed promising inhibitory activity against c-Met kinase (IC50=31.70μM). Assessment of ADMET profiling, drug-likeness, drug score as well as docking simulation for the binding pose of that compound in the active site of c-Met kinase domain revealed that NCI 748494/1 could be considered as a promising drug lead. Based on target identification and validation, it was observed that there is structure similarity between NCI 748494/1 and the reported type II c-Met kinase inhibitor BMS-777607. Optimization of our lead NCI 748494/1 furnished newly synthesized 1,2,4-triazine derivatives based on well-established structure-activity relationships, whereas three compounds namely; 4d, 7a and 8c displayed excellent in vitro cytotoxicity against three c-Met addicted cancer cell lines; A549 (lung adenocarcinoma), HT-29 (colon cancer) and MKN-45 (gastric carcinoma); with IC50 values in the range 0.01-1.86µM. In vitro c-Met kinase assay showed 8c to possess the highest c-Met kinase inhibition profile (IC50=4.31µM). Docking of the active compounds in c-Met kinase active site revealed strong binding interactions comparable to the lead NCI 748494/1 and BMS-777607, suggesting that c-Met inhibition is very likely to be the mechanism of the antitumor effect of these derivatives. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Therapeutic angiogenesis induced by human hepatocyte growth factor (HGF) gene in rat myocardial ischemia models

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In order to investigate the feasibility of myocardial ischemia gene therapy, we cloned human hepatocyte growth factor gene from human placenta cDNA library by the RT-PCR method. Recombination adenovirus Ad-HGF was constructed by the method of co-transfection and homologous recombination of plasmids in 293 cells. Ad-HGF was amplified in 293 cells and purified through CsCl density gradient centrifugation. Ad-HGF could be expressed in rat primary myocardial cells and HGF secreted into the culture media, which was tested by ELISA. The distribution and persistence of adenovirus in rat were investigated by green fluorescence protein as a report gene. In vivo we found that intramyocardial administration of Ad-HGF could induce angiogenesis in rat myocardium after ligation of coronary artery. The results suggested that Ad-HGF was effective in vitro and in vivo, and the data for designing human trial of gene therapy-- mediated cardiac angiogenesis were provided.

  8. Bufalin Reverses HGF-Induced Resistance to EGFR-TKIs in EGFR Mutant Lung Cancer Cells via Blockage of Met/PI3k/Akt Pathway and Induction of Apoptosis

    Directory of Open Access Journals (Sweden)

    Xiao-Hong Kang

    2013-01-01

    Full Text Available The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs, such as gefitinib and erlotinib, have shown promising therapeutic efficacy in nonsmall cell lung cancer (NSCLC patients harboring epidermal growth factor receptor- (EGFR- activating mutation. However, the inevitable recurrence resulting from acquired resistance has limited the clinical improvement in therapy outcomes. Many studies demonstrate that hepatocyte growth factor- (HGF- Met axis plays an important role in tumor progression and drug sensitivity. HGF may induce resistance to EGFR-TKIs in EGFR mutant lung cancer cells by Met/PI3K/Akt signaling. The purpose of this study was to determine whether bufalin, a major bioactive component of Venenum Bufonis, could reverse HGF-induced resistance to reversible and irreversible EGFR-TKIs in mutant lung cancer cells PC-9, HCC827, and H1975. Our studies showed that bufalin could reverse resistance to reversible and irreversible EGFR-TKIs induced by exogenous HGF in EGFR mutant lung cancer cells by inhibiting the Met/PI3K/Akt pathway and inducing death signaling. These results suggested that bufalin might have a potential to overcome HGF-induced resistance to molecular-targeted drugs for lung cancer.

  9. Exogenous HGF Prevents Cardiomyocytes from Apoptosis after Hypoxia via Up-Regulating Cell Autophagy

    Directory of Open Access Journals (Sweden)

    Yunle Wang

    2016-06-01

    Full Text Available Background: Hepatocyte growth factor (HGF is widely known as a protective factor in ischemic myocardium, however HGF sensitive cellular mechanism remained ill-defined. Autophagy at early stage of hypoxia has been demonstrated to play a role in protecting myocardium both in vivo and vitro. We performed this study to investigate the association between the protective effect of HGF and autophagy. Methods: Ventricular myocytes were isolated from neonatal rat heart (NRVMs. We evaluated cardiomyocytes apoptosis by Hoechst staining and flow cytometry. Autophagy was assessed by transmission electron microscope and mRFP-GFP-LC3 adenovirus infection. Mitochondrial membrane potential was estimated by JC-1 staining. Western blotting and ELISA assay were used to quantify protein concentrations. Results: We found that autophagy in NRVMs increased at early stage after hypoxia and HGF release was consistent with the change of autophagy. Exogenous HGF enhanced autophagy and decreased apoptosis, while neutralizing HGF yielded opposite effects. Besides, inhibition of autophagy increased apoptosis of myocytes. Furthermore, exogenous HGF induced Parkin, the marker of mitochondrial autophagy, indicating increased clearance of injured mitochondria. Conclusions: Our results revealed a potential mechanism in which exogenous HGF prevented NRVMs from apoptosis after hypoxia. Upregulation of Parkin through administration of exogenous HGF may be a potential therapeutic strategy ptotecting myocytes during ischemia.

  10. Characterization of HGF/Met Signaling in Cell Lines Derived From Urothelial Carcinoma of the Bladder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young H. [Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Apolo, Andrea B. [Genitourinary Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Agarwal, Piyush K.; Bottaro, Donald P., E-mail: dbottaro@helix.nih.gov [Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2014-11-25

    There is mounting evidence of oncogenic hepatocyte growth factor (HGF)/Met signaling in urothelial carcinoma (UC) of the bladder. The effects of three kinase inhibitors, cabozantinib, crizotinib and EMD1214063, on HGF-driven signaling and cell growth, invasion and tumorigenicity were analyzed in cultured UC cell lines. SW780 xenograft growth in SCID and human HGF knock-in SCID (hHGF/SCID) mice treated with cabozantinib or vehicle, as well as tumor levels of Met and pMet, were also determined. Met content was robust in most UC-derived cell lines. Basal pMet content and effector activation state in quiescent cells were low, but significantly enhanced by added HGF, as were cell invasion, proliferation and anchorage independent growth. These HGF-driven effects were reversed by Met inhibitor treatment. Tumor xenograft growth was significantly higher in hHGF/SCID mice vs. SCID mice and significantly inhibited by cabozantinib, as was tumor phospho-Met content. These studies indicate the prevalence and functionality of the HGF/Met signaling pathway in UC cells, suggest that paracrine HGF may contribute to UC tumor growth and progression, and that support further preclinical investigation of Met inhibitors for the treatment of UC is warranted.

  11. Characterization of HGF/Met Signaling in Cell Lines Derived From Urothelial Carcinoma of the Bladder

    Directory of Open Access Journals (Sweden)

    Young H. Lee

    2014-11-01

    Full Text Available There is mounting evidence of oncogenic hepatocyte growth factor (HGF/Met signaling in urothelial carcinoma (UC of the bladder. The effects of three kinase inhibitors, cabozantinib, crizotinib and EMD1214063, on HGF-driven signaling and cell growth, invasion and tumorigenicity were analyzed in cultured UC cell lines. SW780 xenograft growth in SCID and human HGF knock-in SCID (hHGF/SCID mice treated with cabozantinib or vehicle, as well as tumor levels of Met and pMet, were also determined. Met content was robust in most UC-derived cell lines. Basal pMet content and effector activation state in quiescent cells were low, but significantly enhanced by added HGF, as were cell invasion, proliferation and anchorage independent growth. These HGF-driven effects were reversed by Met inhibitor treatment. Tumor xenograft growth was significantly higher in hHGF/SCID mice vs. SCID mice and significantly inhibited by cabozantinib, as was tumor phospho-Met content. These studies indicate the prevalence and functionality of the HGF/Met signaling pathway in UC cells, suggest that paracrine HGF may contribute to UC tumor growth and progression, and that support further preclinical investigation of Met inhibitors for the treatment of UC is warranted.

  12. Characterization of HGF/Met Signaling in Cell Lines Derived From Urothelial Carcinoma of the Bladder.

    Science.gov (United States)

    Lee, Young H; Apolo, Andrea B; Agarwal, Piyush K; Bottaro, Donald P

    2014-11-25

    There is mounting evidence of oncogenic hepatocyte growth factor (HGF)/Met signaling in urothelial carcinoma (UC) of the bladder. The effects of three kinase inhibitors, cabozantinib, crizotinib and EMD1214063, on HGF-driven signaling and cell growth, invasion and tumorigenicity were analyzed in cultured UC cell lines. SW780 xenograft growth in SCID and human HGF knock-in SCID (hHGF/SCID) mice treated with cabozantinib or vehicle, as well as tumor levels of Met and pMet, were also determined. Met content was robust in most UC-derived cell lines. Basal pMet content and effector activation state in quiescent cells were low, but significantly enhanced by added HGF, as were cell invasion, proliferation and anchorage independent growth. These HGF-driven effects were reversed by Met inhibitor treatment. Tumor xenograft growth was significantly higher in hHGF/SCID mice vs. SCID mice and significantly inhibited by cabozantinib, as was tumor phospho-Met content. These studies indicate the prevalence and functionality of the HGF/Met signaling pathway in UC cells, suggest that paracrine HGF may contribute to UC tumor growth and progression, and that support further preclinical investigation of Met inhibitors for the treatment of UC is warranted.

  13. Gene signatures derived from a c-MET-driven liver cancer mouse model predict survival of patients with hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Irena Ivanovska

    Full Text Available Biomarkers derived from gene expression profiling data may have a high false-positive rate and must be rigorously validated using independent clinical data sets, which are not always available. Although animal model systems could provide alternative data sets to formulate hypotheses and limit the number of signatures to be tested in clinical samples, the predictive power of such an approach is not yet proven. The present study aims to analyze the molecular signatures of liver cancer in a c-MET-transgenic mouse model and investigate its prognostic relevance to human hepatocellular carcinoma (HCC. Tissue samples were obtained from tumor (TU, adjacent non-tumor (AN and distant normal (DN liver in Tet-operator regulated (TRE human c-MET transgenic mice (n = 21 as well as from a Chinese cohort of 272 HBV- and 9 HCV-associated HCC patients. Whole genome microarray expression profiling was conducted in Affymetrix gene expression chips, and prognostic significances of gene expression signatures were evaluated across the two species. Our data revealed parallels between mouse and human liver tumors, including down-regulation of metabolic pathways and up-regulation of cell cycle processes. The mouse tumors were most similar to a subset of patient samples characterized by activation of the Wnt pathway, but distinctive in the p53 pathway signals. Of potential clinical utility, we identified a set of genes that were down regulated in both mouse tumors and human HCC having significant predictive power on overall and disease-free survival, which were highly enriched for metabolic functions. In conclusions, this study provides evidence that a disease model can serve as a possible platform for generating hypotheses to be tested in human tissues and highlights an efficient method for generating biomarker signatures before extensive clinical trials have been initiated.

  14. hHGF overexpression in myoblast sheets enhances their angiogenic potential in rat chronic heart failure.

    Directory of Open Access Journals (Sweden)

    Antti Siltanen

    Full Text Available After severe myocardial infarction (MI, heart failure results from ischemia, fibrosis, and remodeling. A promising therapy to enhance cardiac function and induce therapeutic angiogenesis via a paracrine mechanism in MI is myoblast sheet transplantation. We hypothesized that in a rat model of MI-induced chronic heart failure, this therapy could be further improved by overexpression of the antiapoptotic, antifibrotic, and proangiogenic hepatocyte growth factor (HGF in the myoblast sheets. We studied the ability of wild type (L6-WT and human HGF-expressing (L6-HGF L6 myoblast sheet-derived paracrine factors to stimulate cardiomyocyte, endothelial cell, or smooth muscle cell migration in culture. Further, we studied the autocrine effect of hHGF-expression on myoblast gene expression profiles by use of microarray analysis. We induced MI in Wistar rats by left anterior descending coronary artery (LAD ligation and allowed heart failure to develop for 4 weeks. Thereafter, we administered L6-WT (n = 15 or L6-HGF (n = 16 myoblast sheet therapy. Control rats (n = 13 underwent LAD ligation and rethoracotomy without therapy, and five rats underwent a sham operation in both surgeries. We evaluated cardiac function with echocardiography at 2 and 4 weeks after therapy, and analyzed cardiac angiogenesis and left ventricular architecture from histological sections at 4 weeks. Paracrine mediators from L6-HGF myoblast sheets effectively induced migration of cardiac endothelial and smooth muscle cells but not cardiomyocytes. Microarray data revealed that hHGF-expression modulated myoblast gene expression. In vivo, L6-HGF sheet therapy effectively stimulated angiogenesis in the infarcted and non-infarcted areas. Both L6-WT and L6-HGF therapies enhanced cardiac function and inhibited remodeling in a similar fashion. In conclusion, L6-HGF therapy effectively induced angiogenesis in the chronically failing heart. Cardiac function, however, was not further

  15. The angiogenic growth factors HGF and VEGF in serum and plasma from neuroblastoma patients.

    Science.gov (United States)

    Sköldenberg, Erik G; Larsson, Anders; Jakobson, Ake; Hedborg, Fredrik; Kogner, Per; Christofferson, Rolf H; Azarbayjani, Faranak

    2009-08-01

    To determine whether concentrations of the angiogenic growth factors hepatocyte growth factor (HGF) and vascular endothelial growth factor A (VEGF-A) correlate with clinical and genetic markers in samples taken at diagnosis in children with neuroblastoma (NB). Heparin plasma (P-) and serum (S-) samples of healthy controls (n=73, mean age +/- SD 3.5+/-2.1; females/males: 23/50) and patients with NB (n=62; 2.2+/-1.8; 26/36) were collected between 1988 and 1999. Clinical data included age at diagnosis, gender, stage, outcome, amplification of the oncogene MYCN, loss of heterozygosity at the short arm of chromosome 1 (1p LOH) and ploidy. HGF and S-VEGF-A were elevated in NB as compared to controls (38/62 patients, p<0.0001 and p<0.05, Mann-Whitney U test). HGF concentrations were higher in high-stage (stage 3-4) as compared to low-stage (stage 1-2) disease (p<0.01). P-HGF was elevated in patients with 1p LOH (p<0.01), MYCN amplification (p<0.001) and di- or tetraploidy (p<0.001). S-HGF concentration was elevated in patients MYCN-amplified tumors only. Plasma and S-HGF concentrations were higher in the deceased group (p<0.05), but not P or S-VEGF-A. This study showed that concentrations of HGF and S-VEGF-A are elevated in patients with NB. Furthermore, HGF and S-VEGF-A concentrations correlate to higher stage disease and HGF correlates to genetic markers known to indicate a poor outcome. These observations imply that HGF and VEGF-A have biological roles in NB and suggest the possibility of interference with HGF or VEGF-A signaling as a therapeutic strategy.

  16. Relationship between pathological characteristics of prostate cancer and MACC1, c-Met, Apaf-1 as well as Caspase-9 expression in tumor tissue

    Institute of Scientific and Technical Information of China (English)

    Hang-Yu Ai; Xue-De Qiu

    2016-01-01

    Objective:To study the MACC1, c-Met, Apaf-1 and Caspase-9 expression in prostate cancer tissue and their relationship with the pathological characteristics of tumor.Methods:Prostate cancer and benign prostatic hyperplasia patients who received surgical treatment in our hospital from May 2015 to March 2016 were selected as the research subjects, prostate cancer tissue and benign prostatic hyperplasia tissue were collected during surgery to determine MACC1, c-Met, Apaf-1 and Caspase-9 expression, and serum specimens were collected to determine miR-let7i, -32, -128, -196a and -218 expression levels.Results: mRNA content of MACC1 and c-Met in prostate cancer tissue were significantly higher than those in benign prostatic hyperplasia tissue while mRNA content of Apaf-1 and Caspase-9 were significantly lower than those in benign prostatic hyperplasia tissue, and the higher the Gleason grading and the higher the Whitmore-Prout staging, the higher the mRNA content of MACC1 and c-Met in prostate cancer tissue and the lower the mRNA content of Apaf-1 and Caspase-9; serum miR-32, miR-128 and miR-196a expression levels in prostate cancer patients were significantly higher than those in patients with benign prostatic hyperplasia and negatively correlated with the mRNA content of Apaf-1 and Caspase-9, and the expression levels of miR-let7i and miR-218 were significantly lower than those in patients with benign prostatic hyperplasia and negatively correlated with MACC1 and c-Met.Conclusion: High MACC1 and c-Met expression and low Caspase-9 and Apaf-1 expression are related to the occurrence and progression of prostate cancer, and the MACC1, c-Met, Apaf-1 and Caspase-9 expression in prostate cancer tissue are regulated by miRNAs.

  17. 大肠癌细胞增殖中HGF/SF作用的观察%The function of HGF/SF in the proliferation of colorectal cancer cells

    Institute of Scientific and Technical Information of China (English)

    李宏武; 张趣; 梁健

    2006-01-01

    目的研究肝细胞生长因子/离散因子(HGF/SF)在诱导大肠癌细胞增殖中的作用.方法采用Western Blot方法,检测HGF的受体c-met在受检大肠癌细胞株Caco-2,Colo320中的表达;观察Caco-2,Colo320中HGF/SF活化p42/p44 MAPK和p3 8 MAPK的动态变化;应用[3H]-TdR,MTT方法观察p42/p44MAPK和p38MAPK传导通路阻滞剂PD98059和SB2035 80对HGF/SF诱导的大肠癌细胞增殖的抑制作用.结果(1)c-met在Caco-2和Colo320中有表达.(2)HGF/SF激活p42/p44MAPK,p3 8 MAPK:20ng/mL的HGF/SF处理细胞,p42/p44 MAPK磷酸化在10min达高峰(2.28±0.01);p3 8 MAPK变化与之相似(2.25±0.01).(3)HGF/SF诱导大肠癌细胞的DNA合成增加依赖于p42/p44MAPK的激活,在24h时点分别以20ng/mlHGF/SF,不同浓度(1μmol/L,5 μmol/L,1 0μmol/L)的PD98059和SB203 5 80处理细胞,HGF/SF使胸腺啶吸收增加(P<0.01);PD98059以浓度依赖性抑制胸腺啶的吸收(P<0.01).(4)HGF促进Caco-2细胞的增殖,而PD98059对这种增殖有抑制作用.结论HGF激活大肠癌细胞Caco-2和Colo320中p42/p44MAPK和p3 8MAPK:p42/p44MAPK参与HGF/SF诱导的大肠癌细胞Caco-2有丝分裂;HGF促进大肠癌细胞Caco-2增殖;HGF/SF和p42/p44MAPK在大肠癌细胞中发挥作用可能有细胞选择性.

  18. Design and synthesis of novel benzo[d]oxazol-2(3H)-one derivatives bearing 7-substituted-4-enthoxyquinoline moieties as c-Met kinase inhibitors.

    Science.gov (United States)

    Lu, Dong; Shen, Aijun; Liu, Yang; Peng, Xia; Xing, Weiqiang; Ai, Jing; Geng, Meiyu; Hu, Youhong

    2016-06-10

    Analysis of the results of studies of docking 1 and 7a with c-Met kinase led to the identification of benzo[d]oxazol-2(3H)-one-quinolone derivatives as potential inhibitors of this enzyme. A molecular hybrid strategy, using a 4-ethoxy-7-substituted-quinoline core and a benzo[d]oxazol-2(3H)-one scaffold, was employed to design members of this family for study as inhibitors of the kinase and proliferation of EBC-1 cells. Most of the substances were found to display good to excellent c-Met kinase inhibitory activities. The results of a structure-activity relationship (SAR) study led to the discovery of benzo[d]oxazol-2(3H)-one-quinolone 13, which has IC50 values of 1 nM against c-Met kinase and 5 nM against proliferation of the EBC-1 cell line.

  19. Fibulin-3 negatively regulates ALDH1 via c-MET suppression and increases γ-radiation-induced sensitivity in some pancreatic cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In-Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology (UST), 989-111 Daedeok-daero, Yusong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Jae-Ha [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology (UST), 989-111 Daedeok-daero, Yusong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Seo-Yoen; Kim, Jeong-Yul [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Cho, Eun-Wie [Epigenomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)

    2014-11-21

    Highlights: • FBLN-3 gene was poorly expressed in some pancreatic cancer lines. • FBLN-3 promoter region was highly methylated in some pancreatic cancer cell lines. • FBLN-3 inhibited c-MET activation and expression and reduced cellular level of ALDH1. • FBLN-3/c-Met/ALDH1 axis modulates stemness and EMT in pancreatic cancer cells. - Abstract: Fibulin-3 (FBLN-3) has been postulated to be either a tumor suppressor or promoter depending on the cell type, and hypermethylation of the FBLN-3 promoter is often associated with human disease, especially cancer. We report that the promoter region of the FBLN-3 was significantly methylated (>95%) in some pancreatic cancer cell lines and thus FBLN-3 was poorly expressed in pancreatic cancer cell lines such as AsPC-1 and MiaPaCa-2. FBLN-3 overexpression significantly down-regulated the cellular level of c-MET and inhibited hepatocyte growth factor-induced c-MET activation, which were closely associated with γ-radiation resistance of cancer cells. Moreover, we also showed that c-MET suppression or inactivation decreased the cellular level of ALDH1 isozymes (ALDH1A1 or ALDH1A3), which serve as cancer stem cell markers, and subsequently induced inhibition of cell growth in pancreatic cancer cells. Therefore, forced overexpression of FBLN-3 sensitized cells to cytotoxic agents such as γ-radiation and strongly inhibited the stemness and epithelial to mesenchymal transition (EMT) property of pancreatic cancer cells. On the other hand, if FBLN3 was suppressed in FBLN-3-expressing BxPC3 cells, the results were opposite. This study provides the first demonstration that the FBLN-3/c-MET/ALDH1 axis in pancreatic cancer cells partially modulates stemness and EMT as well as sensitization of cells to the detrimental effects of γ-radiation.

  20. Analysis of receptor tyrosine kinase internalization using flow cytometry.

    Science.gov (United States)

    Li, Ning; Hill, Kristen S; Elferink, Lisa A

    2008-01-01

    The internalization of activated receptor tyrosine kinases (RTKs) by endocytosis and their subsequent down regulation in lysosomes plays a critical role in regulating the duration and intensity of downstream signaling events. Uncoupling of the RTK cMet from ligand-induced degradation was recently shown to correlate with sustained receptor signaling and increased cell tumorigenicity, suggesting that the corruption of these endocytic mechanisms could contribute to increased cMet signaling in metastatic cancers. To understand how cMet signaling for normal cell growth is controlled by endocytosis and how these mechanisms are dysregulated in metastatic cancers, we developed flow cytometry-based assays to examine cMet internalization.

  1. Met and its ligand HGF are associated with clinical outcome in breast cancer

    Science.gov (United States)

    Veenstra, Cynthia; Pérez-Tenorio, Gizeh; Stelling, Anna; Karlsson, Elin; Mirwani, Sanam Mirwani; Nordensköljd, Bo; Fornander, Tommy; Stål, Olle

    2016-01-01

    Few biomarkers exist to predict radiotherapy response in breast cancer. In vitro studies suggest a role for Met and its ligand HGF. To study this suggested role, MET and HGF gene copy numbers were determined by droplet digital PCR in tumours from 205 pre-menopausal and 184 post-menopausal patients, both cohorts randomised to receive either chemo- or radiotherapy. MET amplification was found in 8% of the patients in both cohorts and HGF amplification in 7% and 6% of the patients in the pre- and post-menopausal cohort, respectively. Met, phosphorylated Met (pMet), and HGF protein expression was determined by immunohistochemistry in the pre-menopausal cohort. Met, pMet, and HGF was expressed in 33%, 53%, and 49% of the tumours, respectively. MET amplification was associated with increased risk of distant recurrence for patients receiving chemotherapy. For the pre-menopausal patients, expression of cytoplasmic pMet and HGF significantly predicted benefit from radiotherapy in terms of loco-regional recurrence. Similar trends were seen for MET and HGF copy gain. In the post-menopausal cohort, no significant association of benefit from radiotherapy with neither genes nor proteins was found. The present results do not support that inhibition of Met prior to radiotherapy would be favourable for pre-menopausal breast cancer, as previously suggested. PMID:27175600

  2. Human hepatocyte growth factor (hHGF-modified hepatic oval cells improve liver transplant survival.

    Directory of Open Access Journals (Sweden)

    Zhu Li

    Full Text Available Despite progress in the field of immunosuppression, acute rejection is still a common postoperative complication following liver transplantation. This study aims to investigate the capacity of the human hepatocyte growth factor (hHGF in modifying hepatic oval cells (HOCs administered simultaneously with orthotopic liver transplantation as a means of improving graft survival. HOCs were activated and isolated using a modified 2-acetylaminofluorene/partial hepatectomy (2-AAF/PH model in male Lewis rats. A HOC line stably expressing the HGF gene was established following stable transfection of the pBLAST2-hHGF plasmid. Our results demonstrated that hHGF-modified HOCs could efficiently differentiate into hepatocytes and bile duct epithelial cells in vitro. Administration of HOCs at the time of liver transplantation induced a wider distribution of SRY-positive donor cells in liver tissues. Administration of hHGF-HOC at the time of transplantation remarkably prolonged the median survival time and improved liver function for recipients compared to these parameters in the other treatment groups (P<0.05. Moreover, hHGF-HOC administration at the time of liver transplantation significantly suppressed elevation of interleukin-2 (IL-2, tumor necrosis factor-α (TNF-α and interferon-γ (IFN-γ levels while increasing the production of IL-10 and TGF-β1 (P<0.05. HOC or hHGF-HOC administration promoted cell proliferation, reduced cell apoptosis, and decreased liver allograft rejection rates. Furthermore, hHGF-modified HOCs more efficiently reduced acute allograft rejection (P<0.05 versus HOC transplantation only. Our results indicate that the combination of hHGF-modified HOCs with liver transplantation decreased host anti-graft immune responses resulting in a reduction of allograft rejection rates and prolonging graft survival in recipient rats. This suggests that HOC-based cell transplantation therapies can be developed as a means of treating severe liver

  3. A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yanlan; Chen, Yicheng; Ding, Guoqing; Wang, Mingchao; Wu, Haiyang; Xu, Liwei; Rui, Xuefang; Zhang, Zhigen, E-mail: srrshurology@163.com

    2015-08-14

    The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice.

  4. 肝细胞生长因子研究进展%Progress of research on HGF/SF

    Institute of Scientific and Technical Information of China (English)

    张武; 陈文杰

    2001-01-01

    查阅近二十年国外有关HGF/SF文献,基本弄清了HGF/SF的分子结构及组织分布,说明了HGF/SF的调节和cmet受体及两者的关系,揭示了HGF/SF的生物活性、HGF/SF和肿瘤扩散以及与肝再生的关系.因此,HGF/SF在肝再生中起主要作用;是肾再生的关键因子;可促进伤口愈合;通过增加恶性细胞的侵袭性,HGF/SF可能作为肿瘤转移的重要因素之一.

  5. Decreased Serum Hepatocyte Growth Factor (HGF) in Autistic Children with Severe Gastrointestinal Disease

    OpenAIRE

    Russo, A.J.; Krigsman, A; Jepson, B; Wakefield, Andrew

    2009-01-01

    Aim: To assess serum Hepatocyte Growth Factor (HGF) levels in autistic children with severe gastrointestinal (GI) disease and to test the hypothesis that there is a relationship between GI pathology and HGF concentration. Subjects and Methods: Serum from 29 autistic children with chronic digestive disease (symptoms for a minimum of 6–12 months), most with ileo-colonic lymphoid nodular hyperplasia (LNH—markedly enlarged lymphoid nodules) and inflammation of the colorectum, small bowel and/or s...

  6. Perioperative hepatocyte growth factor (HGF) infusions improve hepatic regeneration following portal branch ligation (PBL) in rodents.

    Science.gov (United States)

    Mangieri, Christopher W; McCartt, Jason C; Strode, Matthew A; Lowry, John E; Balakrishna, Prasad M

    2017-07-01

    As hepatic surgery has become safer and more commonly performed, the extent of hepatic resections has increased. When there is not enough expected hepatic reserve to facilitate primary resection of hepatic tumors, a clinical adjunct to facilitating primary resection is portal vein embolization (PVE). PVE allows the hepatic remnant to increase to an appropriate size prior to resection via hepatocyte regeneration; however, PVE is not always successful in facilitating adequate regeneration. One of the strongest trophic factors for hepatocyte regeneration is hepatocyte growth factor (HGF). The purpose of this study was to improve hepatic regeneration with perioperative HGF infusions in an animal model that mimics PVE. Portal branch ligation (PBL) in rodents is equivalent to PVE in humans. We performed left-sided PBL in Sprague-Dawley rodents with the experimental group receiving perioperative HGF infusions. Baseline and postoperative liver volumetrics were obtained with CT scanning methods as performed in clinical practice. Baseline and postoperative liver functions were assessed via indocyanine green (ICG) elimination testing. HGF infused rodents had statistically significant increase in all postoperative liver volumetrics. Most clinically relevant were increased right liver volumes (RLV), 14.10 versus 7.85 cm(3) (p value 0.0001), and increased degree of hypertrophy (DH %), 159.23 versus 47.11 % (p value 0.0079). HGF infused rodents also had a quick return to baseline liver function, 2.38 days compared to 6.13 days (p value 0.0001). Perioperative HGF infusions significantly increase hepatic regeneration following PBL in rodents. Perioperative HGF infusions following PVE are a possible adjunct to increase the amount of patients able to successfully undergo primary resection for hepatic tumors. Further basic science is warranted in examining the use of HGF infusions to increase hepatic regeneration and translating that basic science work to clinical practice.

  7. Studies on Platelet-Derived Growth Factor Beta-Receptor and Hepatocyte Growth Factor Receptor c-met in Paracrine Interactions in Human Breast Cancer

    Science.gov (United States)

    1996-09-01

    matrix. B.E. Elliott, R. Saulnier, B. Bhardwaj, R. Lall, D. Leopold, N. Rahimi, and L. Maxwell. UCLA Symposium on Breast and Prostate Cancer, Taos...adipocytes. N. Rahimi, R. Lall, R. Saulnier and B.E. Elliott. UCLA Symposium on Breast and Prostate Cancer, Taos, New Mexico, February, 1994. 34...seen throughout the stroma of eight nonmalig- taxis (16), and fibronectin matrix assembly (17) in connective nant breast tissues as well as of

  8. Design, Synthesis, and Biological Evaluation of 4-Phenoxyquinoline Derivatives Containing Benzo[d]thiazole-2-yl Urea as c-Met Kinase Inhibitors.

    Science.gov (United States)

    Lei, Hongrui; Hu, Gang; Wang, Yu; Han, Pei; Liu, Zijian; Zhao, Yanfang; Gong, Ping

    2016-08-01

    A series of novel 4-phenoxyquinoline derivatives containing the benzo[d]thiazole-2-yl urea moiety were synthesized and evaluated for their cytotoxicity against the HT-29, MKN-45, and H460 cell lines. The structures of the target compounds were confirmed by (1) H NMR and MS spectra. Most of them showed moderate to excellent potency against the three tested cell lines. Especially, compound 23 was identified a promising agent (c-Met IC50  = 17.6 nM), showing the most potent anticancer activities with IC50 values of 0.18, 0.06, and 0.01 µM against the HT-29, MKN-45, and H460 cell lines, respectively. The docking results of 23 with the c-Met kinase model 3LQ8 showed a specific binding mode between the ligand and the target protein.

  9. The afatinib resistance of in vivo generated H1975 lung cancer cell clones is mediated by SRC/ERBB3/c-KIT/c-MET compensatory survival signaling.

    Science.gov (United States)

    Booth, Laurence; Roberts, Jane L; Tavallai, Mehrad; Webb, Timothy; Leon, Daniel; Chen, Jesse; McGuire, William P; Poklepovic, Andrew; Dent, Paul

    2016-04-12

    We generated afatinib resistant clones of H1975 lung cancer cells by transient exposure of established tumors to the drug and collected the re-grown tumors. Afatinib resistant H1975 clones did not exhibit any additional mutations in proto-oncogenes when compared to control clones. Afatinib resistant H1975 tumor clones expressed less PTEN than control clones and in afatinib resistant clones this correlated with increased basal SRC Y416, ERBB3 Y1289, AKT T308 and mTOR S2448 phosphorylation, decreased expression of ERBB1, ERBB2 and ERBB3 and increased total expression of c-MET, c-KIT and PDGFRβ. Afatinib resistant clones were selectively killed by knock down of [ERBB3 + c-MET + c-KIT] but not by the individual or doublet knock down combinations. The combination of the ERBB1/2/4 inhibitor afatinib with the SRC family inhibitor dasatinib killed afatinib resistant H1975 cells in a greater than additive fashion; other drugs used in combination with dasatinib such as sunitinib, crizotinib and amufatinib were less effective. [Afatinib + dasatinib] treatment profoundly inactivated ERBB3, AKT and mTOR in the H1975 afatinib resistant clones and increased ATG13 S318 phosphorylation. Knock down of ATG13, Beclin1 or eIF2α strong suppressed killing by [ERBB3 + c-MET + c-KIT] knock down, but were only modestly protective against [afatinib + dasatinib] lethality. Thus afatinib resistant H1975 NSCLC cells rely on ERBB1- and SRC-dependent hyper-activation of residual ERBB3 and elevated signaling, due to elevated protein expression, from wild type c-MET and c-KIT to remain alive. Inhibition of ERBB3 signaling via both blockade of SRC and ERBB1 results in tumor cell death.

  10. Synthesis and biological evaluation of 4-phenoxy-6,7-disubstituted quinolines possessing semicarbazone scaffolds as selective c-Met inhibitors.

    Science.gov (United States)

    Qi, Baohui; Tao, Haiyan; Wu, Di; Bai, Jinying; Shi, Yandan; Gong, Ping

    2013-08-01

    Novel quinoline derivatives bearing acyclic semicarbazones were prepared and their chemical structures as well as the relative stereochemistry were confirmed. All the synthesized compounds were evaluated for their c-Met kinase inhibitory activity and their cytotoxicity against the cell lines HT-29, MKN-45, and MDA-MB-231 in vitro. Several potent compounds were further evaluated against A549 cells. Most compounds displayed moderate to excellent activity, and the structure-activity relationship studies identified the most promising compound 35 as a selective c-Met kinase inhibitor (IC50  = 4.3 nM). Compound 35 showed a 3.5- and 18.8-fold increase in cytotoxicity in vitro against HT-29 and A549 cells, respectively, compared to that of foretinib. Poor off-target effects of compound 35 were further confirmed by the antiproliferative activity against the c-Met inhibition less sensitive MDA-MB-231 cell line (IC50  = 0.77 µM).

  11. The HgF2 Ionic Switch: A Triumph of Electrostatics against Relativistic Odds.

    Science.gov (United States)

    Donald, Kelling J; Kretz, William J; Omorodion, Oluwarotimi

    2015-11-16

    A remarkable transition in the chemical bonding in (HgF2)n clusters as a function of n is identified and characterized. HgF2 is a fascinating material. Certain significant consequences of relativistic effects on the structure of the HgF2 molecule, dimer, and trimer disappear in the extended solid. Relativistic effects in Hg ensure that HgX2 molecules (X≡F, Cl, Br, and I) are linear, rigid, and form weakly bound dimers and trimers held together by weak electrostatic and van der Waals-type forces (unlike ZnX2 and CdX2 systems in which the intermonomer contacts are strong polar covalent bonds). For HgF2, the location and nature of an apparent transition from weak interactions in the smallest (HgF2)n clusters to ionic bonding in the (fluorite) HgF2 extended solid has remained a mystery. Computational evidence obtained at the M06-2X, B97D3, and MP2 levels of theory and reported herein indicate that polar covalent bonding in (HgF2)n begins as early as n=5. For n=2 through to n=13, the transition or switch from weak (primarily dipole-dipole-type) intermonomer interactions to a preference for polar covalent bonding occurs within the range 5

  12. Integrin-linked kinase (ILK) modulates wound healing through regulation of hepatocyte growth factor (HGF)

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, Isabel; Diez-Marques, Maria L.; Rodriguez-Puyol, Manuel [Department of Physiology, University of Alcala, Alcala de Henares, Madrid (Spain); Red de Investigacion Renal Cooperativa (RedinRen) (Spain); Instituto Reina Sofia de Investigacion Nefrologica (Spain); Herrero-Fresneda, Inmaculada [Nephrology Unit, IDIBELL, Hospital de Bellvitge, Barcelona (Spain); Red de Investigacion Renal Cooperativa (RedinRen) (Spain); Garcia del Moral, Raimundo [Department of Pathology, University of Granada (Spain); Red de Investigacion Renal Cooperativa (RedinRen) (Spain); Dedhar, Shoukat [Department of Integrative Oncology, BC Cancer Research Center, Vancouver, BC (Canada); Ruiz-Torres, Maria P., E-mail: mpiedad.ruiz@uah.es [Department of Physiology, University of Alcala, Alcala de Henares, Madrid (Spain); Red de Investigacion Renal Cooperativa (RedinRen) (Spain); Instituto Reina Sofia de Investigacion Nefrologica (Spain); Rodriguez-Puyol, Diego [Nephrology Unit, Hospital Universitario Principe de Asturias, Alcala de Henares, Madrid (Spain); Red de Investigacion Renal Cooperativa (RedinRen) (Spain); Instituto Reina Sofia de Investigacion Nefrologica (Spain)

    2012-11-15

    Integrin-linked kinase (ILK) is an intracellular effector of cell-matrix interactions and regulates many cellular processes, including growth, proliferation, survival, differentiation, migration, invasion and angiogenesis. The present work analyzes the role of ILK in wound healing in adult animals using a conditional knock-out of the ILK gene generated with the tamoxifen-inducible Cre-lox system (CRE-LOX mice). Results show that ILK deficiency leads to retarded wound closure in skin. Intracellular mechanisms involved in this process were analyzed in cultured mouse embryonic fibroblast (MEF) isolated from CRE-LOX mice and revealed that wounding promotes rapid activation of phosphatidylinositol 3-kinase (PI3K) and ILK. Knockdown of ILK resulted in a retarded wound closure due to a decrease in cellular proliferation and loss of HGF protein expression during the healing process, in vitro and in vivo. Alterations in cell proliferation and wound closure in ILK-deficient MEF or mice could be rescued by exogenous administration of human HGF. These data demonstrate, for the first time, that the activation of PI3K and ILK after skin wounding are critical for HGF-dependent tissue repair and wound healing. -- Highlights: Black-Right-Pointing-Pointer ILK deletion results in decreased HGF expression and delayed scratch wound repair. Black-Right-Pointing-Pointer PI3K/ILK/AKT pathway signals through HGF to regulate wound healing. Black-Right-Pointing-Pointer An ILK-dependent increase in HGF expression is responsible for wound healing in vivo. Black-Right-Pointing-Pointer ILK-KO mice are used to confirm the requirement for ILK function in wound healing. Black-Right-Pointing-Pointer Human HGF treatment restores delayed wound closure in vitro and in vivo.

  13. Transcriptional gene expression profiles of HGF/SF-met signaling pathway in colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Xue-Nong Li; Yan-Qing Ding; Guo-Bing Liu

    2003-01-01

    AIM: To explore the transcriptional gene expression profiles of HGF/SF-met signaling pathway in colorectal carcinoma to understand mechanisms of the signaling pathway at so gene level.METHODS: Total RNA was isolated from human colorectal carcinoma cell line LoVo treated with HGF/SF (80 ng/L)for 48 h. Fluorescent probes were prepared from RNA labeled with cy3-dUTP for the control groups and with cy5-dUTP for the HGF/SF-treated groups through reversetranscription. The probes were mixed and hybridized on the microarray at 60 ℃ for 15-20 h, then the microarray was scanned by laser scanner (GenePix 4000B). The intensity of each spot and ratios of Cy5/Cy3 were analyzed and finally the differentially expressed genes were selected by GenePix Pro 3.0 software. 6 differential expression genes (3 up-regulated genes and 3 down-regulated genes) were selected randomly and analyzed by β-actin semiquantitative RT-PCR.RESULTS: The fluorescent intensities of built-in negative control spots were less than 200, and the fluorescent intensities of positive control spots were more than 5000.Of the 4004 human genes analyzed by microarray, 129 genes (holding 3.22 % of the investigated genes) revealed differential expression in HGF/SF-treated groups compared with the control groups, of which 61 genes were up-regulated (holding 1.52 % of the investigated genes) and 68 genes were down-regulated (holding 1.70 % of the investigated genes), which supplied abundant information about target genes of HGF/SF-met signaling.CONCLUSION: HGF/SF-met signaling may up-regulate oncogenes, signal transduction genes, apoptosis-related genes, metastasis related genes, and down-regulate a number of genes. The complexity of HGF/SF-met signaling to control the gene expression is revealed as a whole by the gene chip technology.

  14. Evaluation of serum HGF and CK18 levels in patients with esophageal cancer.

    Science.gov (United States)

    Kilic-Baygutalp, N; Ozturk, N; Orsal-Ibisoglu, E; Gündogdu, B; Ozgeris, F B; Bakan, N; Bakan, E; Kilic, A F

    2016-08-29

    Cytokeratins are thought to play a role in apoptosis. Cytokeratin 18 (CK18) is involved in the formation of intracellular cytoskeleton, and has been considered a promising apoptosis marker in gastrointestinal carcinomas. Growth factors, including hepatocyte growth factor (HGF), may provide a microenvironment for malignant cells. In this study, we aimed to compare serum HGF and CK18 levels between esophageal squamous cell carcinoma patients and healthy controls. The study included 41 adult patients (20 male, 21 female) diagnosed with esophageal squamous cell carcinoma, with a mean age of 63.54 ± 10.88 years (range, 41-82 years). We also recruited 39 age and gender-matched healthy control subjects. Venous blood samples were taken; serum HGF and CK18 concentrations were determined via ELISA. Results indicated that serum HGF levels were higher in patients (1.37 ± 0.63 ng/mL) as compared to the healthy subjects (0.41 ± 0.29 ng/mL). Similarly, serum CK18 levels were higher in the patient group (2.53 ± 1.33 ng/mL) than in the control group (0.34 ± 0.23 ng/mL) (P < 0.001). In addition, serum HGF and CK18 levels were positively correlated with metastasis stage, tumor stage, and disease stage of esophageal squamous cell carcinoma. To our knowledge, this is the first study to evaluate serum HGF and CK18 levels in patients with esophageal squamous cell carcinoma. The results suggest that serum CK18 and HGF levels may be used as prognostic and disease monitoring biomarkers of esophageal squamous cell carcinoma.

  15. Deregulation of ARID1A, CDH1, cMET and PIK3CA and target-related microRNA expression in gastric cancer

    Science.gov (United States)

    Ibarrola-Villava, Maider; Llorca-Cardeñosa, Marta J.; Tarazona, Noelia; Mongort, Cristina; Fleitas, Tania; Perez-Fidalgo, José Alejandro; Roselló, Susana; Navarro, Samuel; Ribas, Gloria; Cervantes, Andrés

    2015-01-01

    Genetic and epigenetic alterations play an important role in gastric cancer (GC) pathogenesis. Aberrations of the phosphatidylinositol-3-kinase signaling pathway are well described. However, emerging genes have been described such as, the chromatin remodeling gene ARID1A. Our aim was to determine the expression levels of four GC-related genes, ARID1A, CDH1, cMET and PIK3CA, and 14 target-related microRNAs (miRNAs). We compared mRNA and miRNA expression levels among 66 gastric tumor and normal adjacent mucosa samples using quantitative real-time reverse transcription PCR. Moreover, ARID1A, cMET and PIK3CA protein levels were assessed by immunohistochemistry (IHC). Finally, gene and miRNAs associations with clinical characteristics and outcome were also evaluated. An increased cMET and PIK3CA mRNA expression was found in 78.0% (P = 2.20 × 10−5) and 73.8% (P = 1.00 × 10−3) of the tumors, respectively. Moreover, IHC revealed that cMET and PIK3CA expression was positive in 63.6% and 87.8% of the tumors, respectively. Six miRNAs had significantly different expression between paired-samples, finding five up-regulated [miR-223-3p (P = 1.65 × 10−6), miR-19a-3p (P = 1.23 × 10−4), miR-128-3p (P = 3.49 × 10−4), miR-130b-3p (P = 1.00 × 10−3) and miR-34a-5p (P = 4.00 × 10−3)] and one down-regulated [miR-124-3p (P = 0.03)]. Our data suggest that cMET, PIK3CA and target-related miRNAs play an important role in GC and may serve as potential targets for therapy. PMID:26334097

  16. The role of the microtubular system in the cell response to HGF/SF.

    Science.gov (United States)

    Dugina, V B; Alexandrova, A Y; Lane, K; Bulanova, E; Vasiliev, J M

    1995-04-01

    The effects of the microtubular drugs colcemid and taxol on the morphological changes induced by hepatocyte growth factor/scatter factor (HGF/SF) in MDCK cells were studied. Dynamic changes in the area and shape of individual cells were assessed by morphometric methods whereas alterations of the cytoskeleton were assessed by immunomorphological methods. The results suggest that there are two components in the response to HGF/SF: (a) activation of the extension of lamellae leading to cell spreading; and (b) reorganization of microtubules leading to polarization of cell shape. The latter response is highly sensitive to microtubular drugs, especially taxol. HGF/SF induced spreading in taxol-treated MDCK cells but these cells retained a non-polarized discoid shape and a pattern of actin microfilament bundles characteristic of the untreated cells. Colcemid and taxol did not prevent HGF/SF-induced migration of cells in Boyden chambers but completely inhibited the outgrowth of multicellular strands and tubules from cell aggregates in collagen gels. These results show that enhanced lamella formation in response to HGF/SF without polarization of cell shape is sufficient to induce cell motility. In contrast, microtubule-dependent polarization is essential for complex morphogenetic responses such as tubulogenesis in collagen gels.

  17. Pre-Osteoblasts Stimulate Migration of Breast Cancer Cells via the HGF/MET Pathway.

    Directory of Open Access Journals (Sweden)

    Sonia Vallet

    Full Text Available The occurrence of skeletal metastases in cancer, e.g. breast cancer (BC, deteriorates patient life expectancy and quality-of-life. Current treatment options against tumor-associated bone disease are limited to anti-resorptive therapies and aimed towards palliation. There remains a lack of therapeutic approaches, which reverse or even prevent the development of bone metastases. Recent studies demonstrate that not only osteoclasts (OCs, but also osteoblasts (OBs play a central role in the pathogenesis of skeletal metastases, partly by producing hepatocyte growth factor (HGF, which promotes tumor cell migration and seeding into the bone. OBs consist of a heterogeneous cell pool with respect to their maturation stage and function. Recent studies highlight the critical role of pre-OBs in hematopoiesis. Whether the development of bone metastases can be attributed to a particular OB maturation stage is currently unknown.Pre-OBs were generated from healthy donor (HD-derived bone marrow stromal cells (BMSC as well as the BMSC line KM105 and defined as ALPlow OPNlow RUNX2high OSX high CD166high. Conditioned media (CM of pre-OBs, but not of undifferentiated cells or mature OBs, enhanced migration of metastatic BC cells. Importantly, HGF mRNA was significantly up-regulated in pre-OBs versus mature OBs, and CM of pre-OBs activated the MET signaling pathway. Highlighting a key role for HGF, CM from HGF-negative pre-OBs derived from the BMSC line HS27A did not support migration of BC cells. Genetically (siMET or pharmacologically (INCB28060 targeting MET inhibited both HGF- and pre-OB CM- mediated BC cell migration.Our data demonstrate for the first time a role for pre-OBs in mediating HGF/MET- dependent migration of BC cells and strongly support the clinical evaluation of INCB28060 and other MET inhibitors to limit and/or prevent BC-associated bone metastases.

  18. HGF Gene Modification in Mesenchymal Stem Cells Reduces Radiation-Induced Intestinal Injury by Modulating Immunity.

    Directory of Open Access Journals (Sweden)

    Hua Wang

    Full Text Available Effective therapeutic strategies to address intestinal complications after radiation exposure are currently lacking. Mesenchymal stem cells (MSCs, which display the ability to repair the injured intestine, have been considered as delivery vehicles for repair genes. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF-gene-modified MSCs on radiation-induced intestinal injury (RIII.Female 6- to 8-week-old mice were radiated locally at the abdomen with a single 13-Gy dose of radiation and then treated with saline control, Ad-HGF or Ad-Null-modified MSCs therapy. The transient engraftment of human MSCs was detected via real-time PCR and immunostaining. The therapeutic effects of non- and HGF-modified MSCs were evaluated via FACS to determine the lymphocyte immunophenotypes; via ELISA to measure cytokine expression; via immunostaining to determine tight junction protein expression; via PCNA staining to examine intestinal epithelial cell proliferation; and via TUNEL staining to detect intestinal epithelial cell apoptosis.The histopathological recovery of the radiation-injured intestine was significantly enhanced following non- or HGF-modified MSCs treatment. Importantly, the radiation-induced immunophenotypic disorders of the mesenteric lymph nodes and Peyer's patches were attenuated in both MSCs-treated groups. Treatment with HGF-modified MSCs reduced the expression and secretion of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α and interferon-gamma (IFN-γ, increased the expression of the anti-inflammatory cytokine IL-10 and the tight junction protein ZO-1, and promoted the proliferation and reduced the apoptosis of intestinal epithelial cells.Treatment of RIII with HGF-gene-modified MSCs reduces local inflammation and promotes the recovery of small intestinal histopathology in a mouse model. These findings might provide an effective therapeutic strategy for RIII.

  19. Correlation of Epstein-Barr virus and its encoded proteins with Helicobacter pylori and expression of c-met and c-myc in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Bing Luo; Yun Wang; Xiao-Feng Wang; Yu Gao; Bao-Hua Huang; Peng Zhao

    2006-01-01

    AIM: To investigate the interrelationship of Epstein-Barr virus (EBV) and EBV- encoded proteins with Helicobacter pylori (H pylori) infection and the expression of c-met and c-myc oncogene proteins in gastric carcinoma, and to explore their role in gastric carcinogenesis.METHODS: One hundred and eighty-five gastric carcinoma tissues were detected by polymerase chain reaction (PCR)-Southern blot for EBV genome and in situ hybridization (ISH) for EBV-encoded small RNA 1 (EBER1). Gastric carcinoma with positive EBER1 signals was confirmed EBV-associated gastric carcinoma (EBVaGC). The status of H pylori infection in 185 gastric carcinomas was assessed by rapid urease test and PCR.The samples with positive PCR and urease test were defined as H pylori infection. The expression of c-met and c-myc oncogene proteins in tissues of EBVaGC and matched EBV-negative gastric carcinoma (EBVnGC) were examined by immunohistochemistry. RT-PCR and Southern hybridization were used to detect the expression of nuclear antigens (EBNAs) 1 and 2, latent membrane protein (LMP) 1, early genes BARF1 and BHRF1 in EBVaGC cases.RESULTS: The positive rate of H pylori and EBV in 185 gastric carcinomas was 59.45% (110/L85) and 7.03% (13/185) respectively. No difference was found in sex, age, pathological differentiation, clinical stages and lymph node metastasis between H pylori-positive and H pylori-negative gastric carcinomas. However, the positive rate of H pylori infection in the antrum gastric carcinomas was higher than that of cardia and body gastric carcinomas. In our series, age, pathological differentiation, clinical stages, lymph node metastasis and location of cancer were not different between EBVnGC and EBVaGC, while the positive rate of EBV in male patients was significantly higher than that of female patients. The positivity of Hpyloriin EBV-associated and EBV-negative gastric carcinomas was 46.15% (6/13) and 81.40%(104/172) respectively. There was no significant correlation between

  20. Mecp2-mediated Epigenetic Silencing of miR-137 Contributes to Colorectal Adenoma-Carcinoma Sequence and Tumor Progression via Relieving the Suppression of c-Met

    Science.gov (United States)

    Chen, Tao; Cai, Shi-Lun; Li, Jian; Qi, Zhi-Peng; Li, Xu-Quan; Ye, Le-Chi; Xie, Xiao-Feng; Hou, Ying-Yong; Yao, Li-Qing; Xu, Mei-Dong; Zhou, Ping-Hong; Xu, Jian-Min; Zhong, Yun-Shi

    2017-01-01

    The molecular mechanisms underlying colorectal cancer (CRC) development remain elusive. In this study, we examined the miRNA and mRNA expressions in the adenoma-carcinoma sequence (ACS), a critical neoplastic progression in CRC development. We found that miR-137 was down-regulated in all adenoma and carcinoma tissues. Low miR-137 levels were correlated negatively with tumor progression and metastasis. Then we identified the inhibition effect of the miR-137 in CRC development, both in CRC cell lines and mouse models. MiR-137 was shown to control CRC cell proliferation, colony formation, migration and invasion and to control tumor growth and metastasis. We further confirmed the negative association between miR-137 and c-Met expression and thus validated this important oncogene as the target of miR-137 in CRC. In addition, we found a DNA methyl-CpG-binding protein, Mecp2, was up-regulated in ACS tissues via mRNA sequencing. Further experiment showed that miR-137 expression in CRC was subjected to epigenetic regulation mediated by Mecp2. We also confirmed c-Met expression can be up-regulated by silencing of miR-137 and suppressed by coexpression of Mecp2 and miR-137. These findings highlight the critical role of miR-137-c-Met nexus in CRC development and reveal Mecp2-regulated epigenetic silence causes the downregulation of miR-137 in colorectal adenoma and carcinoma. PMID:28291253

  1. Monitoring of TNFR1, IL-2Rα, HGF, CCL8, IL-8 and IL-12p70 following HSCT and their role as GVHD biomarkers in paediatric patients.

    Science.gov (United States)

    Berger, M; Signorino, E; Muraro, M; Quarello, P; Biasin, E; Nesi, F; Vassallo, E; Fagioli, F

    2013-09-01

    No predictive factors are currently available to establish patient-specific GVHD risk. A panel of six serum cytokines (TNF receptor 1, IL-2 receptor alfa (IL-2Rα), hepatocyte growth factor (HGF), monocyte chemo-attractant protein-2, IL-8, IL-12p70) were monitored at established time points (days -1, +1, +7, +14, +21, +28 and +60) in 170 paediatric hematopoietic SCT (HSCT) recipients. We found that higher concentrations of IL-2Rα on days +14 and +21 together with HGF on days +14 and +21 were significantly associated at a higher probability of both grade II-IV GVHD (on day +14 it was: 60% vs 28%, P=0.007) and grade III-IV (on day +14 it was: 40% vs 15%, P=0.001). The higher IL-8 serum concentration on day +28 was associated with a lower probability of chronic GVHD being 4% vs 29% (P=0.01) for patients with higher vs lower IL-8 serum concentration. These findings were confirmed when the analysis was restricted to the the matched unrelated donor group. In conclusion, even if the serum cytokine levels were related to several variables associated with HSCT, we identified two cytokines as predictors of GVHD II-IV and III-IV, translating into a higher TRM risk (17% vs 3%, P=0.004).

  2. HGF/SF increases number of skin melanocytes but does not alter quality or quantity of follicular melanogenesis.

    Directory of Open Access Journals (Sweden)

    Agnieszka Wolnicka-Glubisz

    Full Text Available Melanins are an important factor determining the vulnerability of mammalian skin to UV radiation and thus to UV-induced skin cancers. Transgenic mice overexpressing hepatocyte growth factor/scatter factor (HGF/SF have extra-follicular dermal melanocytes, notably in the papillary upper dermis, and are susceptible to UV-induced melanoma. Pigmented HGF/SF neonatal mice are more susceptible than albino HGF/SF animals to UVA -induced melanoma, indicating an involvement of melanin in melanoma formation. This raises the question of the effect of transgenic HGF/SF on melanization. We developed a methodology to accurately quantitate both the production of melanin and the efficiency of melanogenesis in normal, and HGF/SF transgenic mice in vivo. Skin and hair shafts of 5 day old and adult (3 week old C57BL/6-HGF/SF and corresponding C57BL/6 wild type mice were investigated by electron paramagnetic resonance spectroscopy (EPR to quantitate melanin, by transmission electron microscopy (TEM for the presence of melanosomes, and by standard histology and by Western blotting and zymography to determine the expression and activity of melanogenesis-related proteins. Eumelanin but no phaeomelanin was detected in transgenic C57BL/6-HGF and C57BL/6 wild type mice. Transgenic HGF/SF overexpression did not change the type of melanin produced in the skin or hair, did not affect the terminal content of melanin production in standard samples of hair and did not influence hair cycle/morphogenesis-related changes in skin thickness. No melanocytes were found in the epidermis and no melanosomes were found in epidermal keratinocytes. HGF/SF transgenic mice thus lack the epidermal melanin UV-protection found in constitutively dark human skin. We conclude that melanocytes in the HGF/SF transgenic mouse, particularly in the papillary dermis, are vulnerable to UVA which interacts with eumelanin but not phaeomelanin to induce melanoma.

  3. MicroRNA-449a is downregulated in non-small cell lung cancer and inhibits migration and invasion by targeting c-Met.

    Directory of Open Access Journals (Sweden)

    Wenting Luo

    Full Text Available MicroRNA-449a is expressed at a low level in several tumors and cancer cell lines, and induces G1 arrest, apoptosis, and senescence. To identify the function of miR-449a in non-small cell lung cancer (NSCLC, we discussed the potential relevance of miR-449a to clinicopathological characteristics and prognosis in NSCLC. We also investigated the impact of miR-449a on migration and invasion in NSCLC cells. The expression of miR-449a in NSCLC tissues and cell lines was detected using RT-qPCR. In vitro, gain-of-function, loss-of-function experiments, and fluorescence assays were performed to identify the potential target of miR-449a and the function of miR-449a in NSCLC cells. MiR-449a was downregulated in both NSCLC tissues and cell lines. Moreover, a low expression level of miR-449a appeared to be correlated with lymph node metastasis and poor survival. In vitro, miR-449 regulated cell migration and invasion in NSCLC cells as a potential tumor suppressor, at least in part by targeting c-Met. Furthermore, reciprocal expression of miR-449a and c-Met was shown in NSCLC tissue samples. This study indicates that miR-449a might be associated with NSCLC progression, and suggests a crucial role for miR-449a in NSCLC.

  4. Stimulatory effect of HGF-overexpressing adipose tissue-derived mesenchymal stem cells on thymus regeneration in a rat thymus involution model.

    Science.gov (United States)

    Jung, Woo-Sung; Han, Sei-Myoung; Kim, Sung-Min; Kim, Mi-Eun; Lee, Jun-Sik; Seo, Kyoung-Won; Youn, Hwa-Young; Lee, Hee-Woo

    2014-10-01

    The thymus is the central lymphoid organ providing a unique and essential microenvironment for T-cell precursor development into mature functionally competent T-lymphocytes. Thus, it is important to develop the strategies for enhancing thymic regeneration from involution induced by a variety of clinical treatments and conditions. Hepatocyte growth factor (HGF) promotes proliferation in a variety of cell types. We have used stem cell-based HGF gene therapy to enhance regeneration from acute thymic involution. HGF-overexpressing human adipose tissue-derived mesenchymal stem cells (HGF-hATMSCs) were generated by liposomal transfection with the pMEX expression vector, constructed by inserting the HGF gene. Significantly increased HGF expression in these cells was confirmed by reverse transcription-polymerase chain reaction and an enzyme-linked immunosorbent assay. HGF produced by HGF-hATMSCs enhanced the proliferation of a mouse thymic epithelial cell line and the expression of interleukin-7 in vitro. We also examined the effect of HGF-hATMSCs on thymic regeneration in rats with acute thymic involution. Significant increases in thymus size and weight, as well as the number of thymocytes (especially, early thymocyte progenitors), were seen in the HGF-hATMSCs-treated rats compared to saline-treated control animals. A stimulatory effect of HGF-hATMSCs on thymic regeneration has therefore been shown, highlighting the clinical value of HGF-hATMSCs for treating thymic involution.

  5. Quantitative analysis of HGF and EGF-dependent phosphotyrosine signaling networks

    DEFF Research Database (Denmark)

    Hammond, Dean E; Hyde, Russell; Kratchmarova, Irina;

    2010-01-01

    549 lung adenocarcinoma cells with EGF or HGF. In total, we obtained quantitative information for 274 proteins, which respond to either or both stimuli by >1.5 fold changes in enrichment, following immuno-precipitation with antiphosphotyrosine antibodies. The data reveal a high degree of overlap...

  6. Oral fibroblasts produce more HGF and KGF than skin fibroblasts in response to co-culture with keratinocytes

    DEFF Research Database (Denmark)

    Grøn, Birgitte; Stoltze, Kaj; Andersson, Anders

    2002-01-01

    The production of hepatocyte growth factor (HGF) and keratinocyte growth factor (KGF) in subepithelial fibroblasts from buccal mucosa, periodontal ligament, and skin was determined after co-culture with keratinocytes. The purpose was to detect differences between the fibroblast subpopulations...... that could explain regional variation in epithelial growth and wound healing. Normal human fibroblasts were cultured on polystyrene or maintained in collagen matrix and stimulated with keratinocytes cultured on membranes. The amount of HGF and KGF protein in the culture medium was determined every 24 h for 5...... days by ELISA. When cultured on polystyrene, the constitutive level of KGF and HGF in periodontal fibroblasts was higher than the level in buccal and skin fibroblasts. In the presence of keratinocytes, all three types of fibroblasts in general increased their HGF and KGF production 2-3 times. When...

  7. Ad-HGF improves the cardiac remodeling of rat following myocardial infarction by upregulating autophagy and necroptosis and inhibiting apoptosis

    Science.gov (United States)

    Liu, Jiabao; Wu, Peng; Wang, Yunle; Du, Yingqiang; A, Nan; Liu, Shuiyuan; Zhang, Yiming; Zhou, Ningtian; Xu, Zhihui; Yang, Zhijian

    2016-01-01

    Cell death in MI is the most critical determinant of subsequent left ventricular remodeling and heart failure. Besides apoptosis, autophagy and necroptosis have been recently found to be another two regulated cell death styles. HGF has been reported to have a protective role in MI, but its impact on the three death styles remains unclear. Thus, our study was performed to investigate the distribution of autophagy, apoptosis and necroptosis in cardiac tissues after MI and explore the role and mechanism of Ad-HGF on cardiac remodeling by regulating the three death styles. We firstly showed the distribution of autophagy, apoptosis and necroptosis differs in temporal and spatial context after MI using immunofluorescence. Notably, Ad-HGF treatment improves the cardiac remodeling of SD rats following MI by preserving the heart function, reducing the scar size and aggresomes. Further mechanism study reveals Ad-HGF promotes autophagy and necroptosis and inhibits apoptosis in vivo and in vitro. Co-immunoprecipitation assays showed Ad-HGF treatment significantly decreased the binding of Bcl-2 to Beclin1 but enhanced Bcl-2 binding to Bax in H9c2 cells under hypoxia. Moreover, HGF-induced sequestration of Bax by Bcl-2 allows Bax to become inactive, thereby inhibiting apoptosis. In addition, Ad-HGF markedly increased the formation of Beclin1-Vps34-Atg14L complex, which accounted for promoting autophagy. Both the western blot and activity assay showed Ad-HGF significantly decreased the caspase 8 protein and activity levels, which obligated the cell to undergo necroptosis under hypoxia and block apoptosis. Thus, our findings offer new evidence and strategies for the treatment of MI and post-MI cardiac remodeling. PMID:27904666

  8. CONSTRUCTION OF RECOMBINANT PLASMID PIRES-BAX-HGF%pIRES-Bax-HGF重组质粒的构建

    Institute of Scientific and Technical Information of China (English)

    黄涛; 常青; 徐平

    2011-01-01

    Objective To construct the plasmid vector of pIRES-Bax-HGF. Methods The Bax gene sequence was cloned from ovarian cancer samples, and HGF gene sequence from pBluescript Ⅱ SK+HGF plasmid derived from ATCC. Bax and HGF coding sequence were inserted into pIRES plasmid by step double enzyme digestion. Results Enzyme digestion and sequencing indicated that the construction of recombinant pIRES-Bax-HGF plasmid was successful. Conclusion Obtaining the coding genes of both Bax and HGF, and successfully creating the plasmid vector of plRES-Bax-HGF establish a foundation for further study of the effects of HGF and Bax on vascular endothelial cells, smooth muscle cells, and fibrocytes, which steps out an important step to treat post-CABG restenosis at gene level.%目的 构建pIRES-Bax-HGF质粒载体.方法 采用RT-PCR方法从卵巢癌标本中克隆Bax的基因序列,从ATCC来源的pBlueseriptⅡ SK+HGF质粒中克隆HGF的基因序列.分步双酶切插入到plRES载体质粒中.结果 酶切鉴定及测序表明,重组pIRES-Bax-HGF质粒构建成功.结论 获取HGF及Bax编码基因并成功构建重组pIRES-Bax-HGF质粒载体,为进一步研究HGF及Bax对血管内皮细胞、平滑肌细胞、纤维细胞等的影响奠定了基础,也向基因水平干预冠状动脉旁路移植术术后再狭窄的形成迈出了重要一步.

  9. Expression of c-Met in Endemic Kaposi's Sarcoma and AIDS-related Kaposi's Sarcoma%c-Met蛋白和c-Met mRNA在地方性及艾滋病相关性Kaposi肉瘤中的表达

    Institute of Scientific and Technical Information of China (English)

    张树华; 阮幼冰; 武忠弼; J.N Kitinya; 马云; 朱玉红; 吕增华

    2003-01-01

    目的探讨c-Met原癌基因蛋白和c-Met mRNA在地方性及艾滋病相关性Kaposi肉瘤不同期的表达.方法对源自坦桑尼亚首都Muhimbili医疗中心病理科的30份标本,用免疫组化、原位杂交方法进行了研究.结果根据Kaposi肉瘤组织中血管成分和梭形细胞的比例分为早期血管瘤样型(11个病灶)、晚期梭形细胞型(14个病灶)和中期混合型(13个病灶).c-Met蛋白在早期表达弱,晚期表达强,中期介于两者之间,相互间差异有非常显著性(P<0.01);c-Met mRNA在不同期的表达与c-Met蛋白的表达类似.c-Met蛋白和c-Met mRNA在地方性和艾滋病相关性Kaposi肉瘤的表达差异无显著性(P>0.05).结论c-Met表达的改变在地方性和艾滋病相关性Kaposi肉瘤的发生发展过程中起了作用.

  10. Structure-based design, synthesis, and evaluation of 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine derivatives as novel c-Met inhibitors.

    Science.gov (United States)

    Zhang, Li; Zhang, Beichen; Zhao, Jingyun; Zhi, Yanle; Wang, Lu; Lu, Tao; Chen, Yadong

    2017-09-29

    c-Met was emerging as an attractive target for cancer-targeted therapy because deregulation of c-Met has been observed in multiple tumor types. A series of 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine derivatives were designed, synthesized and evaluated for their enzymatic inhibitory activity against c-Met kinase and cellular potency against MKN45, EBC-1 and PC-3 cell lines. Nine of them showed better activity than lead compound 1 which was found via computer-aided drug design. Among them, compound 8c showed inhibitory activity of 68 nM against c-Met and low micromole cellular potency against MKN45 and EBC-1 cell lines. Moreover, 8c demonstrated more than 50-fold selectivity against other tyrosine kinases tested. The result of western blot indicated that compound 8c was capable of inhibiting the phosphorylation of c-Met kinase in MKN45 cell line in a dose-dependent manner. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Effects of HGF gene polymorphisms and protein expression on transhepatic arterial chemotherapeutic embolism efficacy and prognosis in patients with primary liver cancer

    Science.gov (United States)

    Chen, Hai-Yong; Chen, Yao-Min; Wu, Jian; Yang, Fu-Chun; Lv, Zhen; Qian, Yi-Gang; Zheng, Shu-Sen

    2017-01-01

    Objective To investigate the correlations of two hepatocyte growth factor (HGF) gene polymorphisms (rs5745652 and rs2074725) and their protein expression levels with the efficacy of transhepatic arterial chemotherapeutic embolism (TACE) and prognosis in patients with primary liver cancer (PLC). Methods From March 2011 to June 2012, 109 PLC patients (the case group) who chose TACE as primary treatment and 80 healthy people (the control group) who had undergone physical examination in The First Affiliated Hospital, Zhejiang University were selected during the same period. Gene polymorphisms of HGF rs5745652 and HGF rs2074725 were detected. Serum HGF level, treating efficacy, survival quality, and 3-year survival rate for PLC patients who received TACE were observed. Results There were significant differences in genotype and allele frequencies of HGF rs5745652 and HGF rs2074725, between the case and control groups (all PCancer stage were independent prognostic factors for PLC (Pprognosis after TACE treatment.

  12. Hepatocyte growth factor activates several transduction pathways in rat pancreatic acini.

    Science.gov (United States)

    Aparicio, I M; Garcia-Marin, L J; Andreolotti, A G; Bodega, G; Jensen, R T; Bragado, M J

    2003-12-07

    The receptor of hepatocyte growth factor (HGF), c-met induces different physiological responses in several cell types. Little is known about the role of HGF in exocrine pancreas. However, abnormal HGF signaling has been strongly implicated in pancreatic tumorigenesis and association of HGF with pancreatitis has been demonstrated. We have studied the presence of c-met and activation of their intracellular pathways associated in rat pancreatic acini in comparison with cholecystokinin (CCK) and epidermal growth factor (EGF). C-met expression in rat exocrine pancreas was identified by immunohistochemistry and immunoprecipitation followed by Western analysis. Tyrosine phosphorylation of c-met is strongly stimulated as well as kinase pathways leading to ERK1/2 cascade. HGF, but not CCK or EGF, selectively caused a consistent increase in the amount of p85 regulatory subunit of PI3-K present in anti-phosphotyrosine immunoprecipitates. Downstream of PI3-K, HGF increased Ser473 phosphorylation of Akt selectively, as CCK or EGF did not affect it. HGF selectively stimulated tyrosine phosphorylation of phosphatase PTP1D. HGF failed to promote the well-known CCK effects in pancreatic acini such as amylase secretion and intracellular calcium mobilization. Although HGF shares activation of ERK1/2 with CCK, we demonstrate that it promotes the selective activation of intracellular pathways not regulated by CCK or EGF. Our results suggest that HGF is an in vivo stimulus of pancreatic acini and provide novel insight into the transduction pathways and effects of c-met/HGF in normal pancreatic acinar cells.

  13. Effects of HGF gene polymorphisms and protein expression on transhepatic arterial chemotherapeutic embolism efficacy and prognosis in patients with primary liver cancer

    Directory of Open Access Journals (Sweden)

    Chen HY

    2017-02-01

    Full Text Available Hai-Yong Chen,1,2 Yao-Min Chen,3 Jian Wu,1,2 Fu-Chun Yang,1,2 Zhen Lv,1,2 Yi-Gang Qian,1,2 Shu-Sen Zheng1,2 1Department of Surgery, Division of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University, 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 3Department of Breast Surgery, The First Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of China Objective: To investigate the correlations of two hepatocyte growth factor (HGF gene polymorphisms (rs5745652 and rs2074725 and their protein expression levels with the efficacy of transhepatic arterial chemotherapeutic embolism (TACE and prognosis in patients with primary liver cancer (PLC. Methods: From March 2011 to June 2012, 109 PLC patients (the case group who chose TACE as primary treatment and 80 healthy people (the control group who had undergone physical examination in The First Affiliated Hospital, Zhejiang University were selected during the same period. Gene polymorphisms of HGF rs5745652 and HGF rs2074725 were detected. Serum HGF level, treating efficacy, survival quality, and 3-year survival rate for PLC patients who received TACE were observed. Results: There were significant differences in genotype and allele frequencies of HGF rs5745652 and HGF rs2074725, between the case and control groups (all P<0.05. Compared with CT+TT genotype of HGF rs5745652, patients carrying CC genotype had lower serum HGF levels, higher efficacy, better survival quality, and prolonged 3-year survival rate (all P<0.05. In rs2074725, patients carrying CA+AA genotype had lower serum HGF levels, higher efficacy, better survival quality, and prolonged 3-year survival rate compared with patients carrying rs2074725 CC genotype (all P<0.05. Gene polymorphisms of HGF rs5745652 and HGF rs2074725, tumor size, and Barcelona Clinic Liver Cancer stage were independent prognostic factors for PLC (P<0.05. Conclusion: Our

  14. Expression of Factors in the Hepatocyte Growth Factor (HGF) Pathway in Whole Bone Marrow Biopsies in Association to the Osteolytic Bone Disease of Multiple Myeloma

    DEFF Research Database (Denmark)

    Kristensen, Ida Bruun; Christensen, Jacob Haaber; Lyng, Maria Bibi

    Expression of Factors in the Hepatocyte Growth Factor (HGF) Pathway in Whole Bone Marrow Biopsies in Association to the Osteolytic Bone Disease of Multiple Myeloma......Expression of Factors in the Hepatocyte Growth Factor (HGF) Pathway in Whole Bone Marrow Biopsies in Association to the Osteolytic Bone Disease of Multiple Myeloma...

  15. Gene expression alterations during HGF-induced dedifferentiation of a renal tubular epithelial cell line (MDCK) using a novel canine DNA microarray.

    Science.gov (United States)

    Balkovetz, Daniel F; Gerrard, Edward R; Li, Shixiong; Johnson, David; Lee, James; Tobias, John W; Rogers, Katherine K; Snyder, Richard W; Lipschutz, Joshua H

    2004-04-01

    Hepatocyte growth factor (HGF) elicits a broad spectrum of biological activities, including epithelial cell dedifferentiation. One of the most widely used and best-studied polarized epithelial cell lines is the Madin-Darby canine kidney (MDCK) cell line. Here, we describe and validate the early response of polarized monolayers of MDCK cells stimulated with recombinant HGF using a novel canine DNA microarray designed to query 12,473 gene sequences. In our survey, eight genes previously implicated in the HGF signaling pathway were differentially regulated, demonstrating that the system was responsive to HGF. Also identified were 117 genes not previously known to be involved in the HGF pathway. The results were confirmed by real-time PCR or Western blot analysis for 38 genes. Of particular interest were the large number of differentially regulated genes encoding small GTPases, proteins involved in endoplasmic reticulum translation, proteins involved in the cytoskeleton, the extracellular matrix, and the hematopoietic and prostaglandin systems.

  16. Dynamic soluble changes in sVEGFR1, HGF, and VEGF promote chemotherapy and bevacizumab resistance: A prospective translational study in the BECOX (GEMCAD 09-01) trial.

    Science.gov (United States)

    Pineda, Estela; Salud, A; Vila-Navarro, E; Safont, M J; Llorente, Beatriz; Aparicio, J; Vera, R; Escudero, P; Casado, E; Bosch, C; Bohn, U; Pérez-Carrión, R; Carmona, A; Ayuso, J R; Ripollés, T; Bouzas, R; Gironella, M; García-Albéniz, X; Feliu, J; Maurel, J

    2017-06-01

    Despite initial responsiveness, acquired resistance to both bevacizumab and chemotherapy in metastatic colorectal cancer is universal. We have recently published that in vitro, chronically oxaliplatin resistance upregulates soluble vascular endothelial growth factor receptor 1, downregulates vascular endothelial growth factor, and also promotes c-MET, b-catenin/transcription factor 4, and AKT activation. We tested whether variation in three serum biomarkers such as the natural c-MET ligand (hepatocyte growth factor), soluble vascular endothelial growth factor receptor 1, and vascular endothelial growth factor-A was associated with efficacy in metastatic colorectal cancer patients treated in the prospective BECOX study. Serum levels of vascular endothelial growth factor-A165, soluble vascular endothelial growth factor receptor 1, and hepatocyte growth factor were assessed by enzyme-linked immunosorbent assay method basally and every 3 cycles (at the time of computed tomography evaluation) in a preplanned translational study in the first-line BECOX trial in metastatic colorectal cancer patients treated with CAPOX plus bevacizumab. Response was evaluated by routine contrast-enhanced computed tomography by RECIST 1.1 by investigator assessment and by three blinded independent radiologists. Ratios between soluble vascular endothelial growth factor receptor 1/vascular endothelial growth factor-A and hepatocyte growth factor/vascular endothelial growth factor-A were established and variations through time were related to RECIST 1.1 by investigator assessment and independent radiologist. The BECOX trial included 68 patients, and 27 patients were analyzed in the translational trial. A total of 80 RECIST 1.1 evaluations were done by investigator assessment and 56 by independent radiologist. We found that a 3.22-fold increase in soluble vascular endothelial growth factor receptor 1/vascular endothelial growth factor-A by investigator assessment and a 3.06-fold increase in

  17. MET receptor variant R970C favors calpain-dependent generation of a fragment promoting epithelial cell scattering.

    Science.gov (United States)

    Montagne, Rémi; Baranzelli, Anne; Muharram, Ghaffar; Catherine, Leroy; Lesaffre, Marie; Vinchent, Audrey; Kherrouche, Zoulika; Werkmeister, Elisabeth; Cortot, Alexis B; Tulasne, David

    2017-01-04

    The receptor tyrosine kinase MET and its ligand, the hepatocyte growth factor, are essential to embryonic development, whereas deregulation of MET signaling is associated with tumorigenesis leading to various cancers, including lung carcinoma. Mutations in the MET kinase domain lead to constitutive kinase activity and are associated with tumorigenesis. In lung cancer, however, some mutations are found in the juxtamembrane domain, and their functional consequences are unknown. Because the juxtamembrane domain of MET is targeted by several proteolytic cleavages, involved in its degradation during cell death or under steady-state conditions, we evaluated the influence of these mutations on the MET proteolytic cleavages. In stably transfected epithelial cells expressing MET, the juxtamembrane mutations R970C, P991S, and T992I were found not to modify the known caspase or presenilin-dependent regulated intramembrane proteolysis. Yet when overexpressed, the R970C variant caused generation of an as yet undescribed 45-kDa fragment (p45 MET). This fragment was found in the confluent lung cancer cell line NCI-H1437 carrying the R970C mutation and at a lesser extent in cell lines expressing WT MET, suggesting that R970C mutation favors this cleavage. Generation of p45 MET required the activity of the calpain proteases, confirming the involvement of proteolysis. Ectopic expression of reconstituted p45 MET in epithelial cell lines favored cell scattering and invasion indicating active role of this fragment in HGF/SF induced responses. Hence, although the juxtamembrane mutations of MET do not affect its known proteolytic cleavages, the R970C MET variant favors calpain dependent proteolytic cleavage in lung cancer cells.

  18. Design, synthesis and biological evaluation of 1H-pyrrolo[2,3-b]pyridine and 1H-pyrazolo[3,4-b]pyridine derivatives as c-Met inhibitors.

    Science.gov (United States)

    Liu, Na; Wang, Yanfen; Huang, Gongchao; Ji, Conghui; Fan, Wei; Li, Haitao; Cheng, Ying; Tian, Hongqi

    2016-04-01

    Five novel 1H-pyrrolo[2,3-b]pyridine or 1H-pyrazolo[3,4-b]pyridine derivatives, with a methylene, sulfur, sulfoxide or cyclopropyl group as a linker, were designed, synthesized and biologically evaluated against c-Met and ALK. The development of these methods of compound synthesis may provide an important reference for the construction of novel 7-azaindole and 7-azaindazole derivatives with a single atom linker. The enzyme assay and cell assay in vitro showed that compound 9 displayed strong c-Met kinase inhibition with IC50 of 22.8nM, moderate ALK kinase inhibition, and strong cell inhibition with MKN-45 IC50 of 329nM and EBC-1 IC50 of 479nM. In order to find the better candidate compounds, compounds 8, 9 and 10 have been selected as tool compounds for further optimization.

  19. Hepatocyte Growth Factor Effects on Mesenchymal Stem Cells Derived from Human Arteries: A Novel Strategy to Accelerate Vascular Ulcer Wound Healing

    Directory of Open Access Journals (Sweden)

    Sabrina Valente

    2016-01-01

    Full Text Available Vascular ulcers are a serious complication of peripheral vascular disease, especially in diabetics. Several approaches to treat the wounds are proposed but they show poor outcomes and require long healing times. Hepatocyte Growth Factor/Scatter Factor (HGF/SF is a pleiotropic cytokine exerting many biological activities through the c-Met receptor. This study was aimed at verifying whether HGF/SF influences proliferation, migration, and angiogenesis on mesenchymal stem cells isolated from human arteries (hVW-MSCs. hVW-MSCs were exposed to NIBSC HGF/SF (2.5, 5, 10, and 70 ng/mL from 6 hrs to 7 days. HGF and c-MET mRNA and protein expression, cell proliferation (Alamar Blue and Ki–67 assay, migration (scratch and transwell assays, and angiogenesis (Matrigel were investigated. hVW-MSCs displayed stemness features and expressed HGF and c-MET. HGF/SF did not increase hVW-MSC proliferation, whereas it enhanced the cell migration, the formation of capillary-like structures, and the expression of angiogenic markers (vWF, CD31, and KDR. The HGF/SF effects on hVW-MSC migration and angiogenic potential are of great interest to accelerate wound healing process. Local delivery of HGF/SF could therefore improve the healing of unresponsive vascular ulcers.

  20. Hepatocyte Growth Factor Effects on Mesenchymal Stem Cells Derived from Human Arteries: A Novel Strategy to Accelerate Vascular Ulcer Wound Healing.

    Science.gov (United States)

    Valente, Sabrina; Ciavarella, Carmen; Pasanisi, Emanuela; Ricci, Francesca; Stella, Andrea; Pasquinelli, Gianandrea

    2016-01-01

    Vascular ulcers are a serious complication of peripheral vascular disease, especially in diabetics. Several approaches to treat the wounds are proposed but they show poor outcomes and require long healing times. Hepatocyte Growth Factor/Scatter Factor (HGF/SF) is a pleiotropic cytokine exerting many biological activities through the c-Met receptor. This study was aimed at verifying whether HGF/SF influences proliferation, migration, and angiogenesis on mesenchymal stem cells isolated from human arteries (hVW-MSCs). hVW-MSCs were exposed to NIBSC HGF/SF (2.5, 5, 10, and 70 ng/mL) from 6 hrs to 7 days. HGF and c-MET mRNA and protein expression, cell proliferation (Alamar Blue and Ki-67 assay), migration (scratch and transwell assays), and angiogenesis (Matrigel) were investigated. hVW-MSCs displayed stemness features and expressed HGF and c-MET. HGF/SF did not increase hVW-MSC proliferation, whereas it enhanced the cell migration, the formation of capillary-like structures, and the expression of angiogenic markers (vWF, CD31, and KDR). The HGF/SF effects on hVW-MSC migration and angiogenic potential are of great interest to accelerate wound healing process. Local delivery of HGF/SF could therefore improve the healing of unresponsive vascular ulcers.

  1. The Impact of Chain Length and Flexibility in the Interaction between Sulfated Alginates and HGF and FGF-2.

    Science.gov (United States)

    Arlov, Øystein; Aachmann, Finn L; Feyzi, Emadoldin; Sundan, Anders; Skjåk-Bræk, Gudmund

    2015-11-09

    Alginate is a promising polysaccharide for use in biomaterials as it is biologically inert. One way to functionalize alginate is by chemical sulfation to emulate sulfated glycosaminoglycans, which interact with a variety of proteins critical for tissue development and homeostasis. In the present work we studied the impact of chain length and flexibility of sulfated alginates for interactions with FGF-2 and HGF. Both growth factors interact with defined sequences of heparan sulfate (HS) at the cell surface or in the extracellular matrix. Whereas FGF-2 interacts with a pentasaccharide sequence containing a critical 2-O-sulfated iduronic acid, HGF has been suggested to require a highly sulfated HS/heparin octasaccharide. Here, oligosaccharides of alternating mannuronic and guluronic acid (MG) were sulfated and assessed by their relative efficacy at releasing growth factor bound to the surface of myeloma cells. 8-mers of sulfated MG (SMG) alginate showed significant HGF release compared to shorter fragments, while the maximum efficacy was achieved at a chain length average of 14 monosaccharides. FGF-2 release required a higher concentration of the SMG fragments, and the 14-mer was less potent compared to an equally sulfated high-molecular weight SMG. Sulfated mannuronan (SM) was subjected to periodate oxidation to increase chain flexibility. To assess the change in flexibility, the persistence length was estimated by SEC-MALLS analysis and the Bohdanecky approach to the worm-like chain model. A high degree of oxidation of SM resulted in approximately twice as potent HGF release compared to the nonoxidized SM alginate. The release of FGF-2 also increased with the degree of oxidation, but to a lower degree compared to that of HGF. It was found that the SM alginates were more efficient at releasing FGF-2 than the SMG alginates, indicating a greater dependence on monosaccharide identity and charge orientation over chain flexibility and charge density.

  2. Hepatocyte growth factor in renal failure: promise and reality.

    Science.gov (United States)

    Vargas, G A; Hoeflich, A; Jehle, P M

    2000-04-01

    Can science discover some secrets of Greek mythology? In the case of Prometheus, we can now suppose that his amazing hepatic regeneration was caused by a peptide growth factor called hepatocyte growth factor (HGF). Increasing evidence indicates that HGF acts as a multifunctional cytokine on different cell types. This review addresses the molecular mechanisms that are responsible for the pleiotropic effects of HGF. HGF binds with high affinity to its specific tyrosine kinase receptor c-met, thereby stimulating not only cell proliferation and differentiation, but also cell migration and tumorigenesis. The three fundamental principles of medicine-prevention, diagnosis, and therapy-may be benefited by the rational use of HGF. In renal tubular cells, HGF induces mitogenic and morphogenetic responses. In animal models of toxic or ischemic acute renal failure, HGF acts in a renotropic and nephroprotective manner. HGF expression is rapidly up-regulated in the remnant kidney of nephrectomized rats, inducing compensatory growth. In a mouse model of chronic renal disease, HGF inhibits the progression of tubulointerstitial fibrosis and kidney dysfunction. Increased HGF mRNA transcripts were detected in mesenchymal and tubular epithelial cells of rejecting kidney. In transplanted patients, elevated HGF levels may indicate renal rejection. When HGF is considered as a therapeutic agent in human medicine, for example, to stimulate kidney regeneration after acute injury, strategies need to be developed to stimulate cell regeneration and differentiation without an induction of tumorigenesis.

  3. Enhanced antioxidant capacity of dental pulp-derived iPSC-differentiated hepatocytes and liver regeneration by injectable HGF-releasing hydrogel in fulminant hepatic failure.

    Science.gov (United States)

    Chiang, Chih-Hung; Wu, Wai-Wah; Li, Hsin-Yang; Chien, Yueh; Sun, Cho-Chin; Peng, Chi-Hsien; Lin, Alex Tong-Long; Huang, Chi-Shuan; Lai, Ying-Hsiu; Chiou, Shih-Hwa; Hung, Shuen-Iu; Chang, Yuh-Lih; Lan, Yuan-Tzu; Liu, Dean-Mo; Chien, Chian-Shiu; Huo, Teh-Ia; Lee, Shou-Dong; Wang, Chien-Ying

    2015-01-01

    Acute hepatic failure (AHF) is a severe liver injury leading to sustained damage and complications. Induced pluripotent stem cells (iPSCs) may be an alternative option for the treatment of AHF. In this study, we reprogrammed human dental pulp-derived fibroblasts into iPSCs, which exhibited pluripotency and the capacity to differentiate into tridermal lineages, including hepatocyte-like cells (iPSC-Heps). These iPSC-Heps resembled human embryonic stem cell-derived hepatocyte-like cells in gene signature and hepatic markers/functions. To improve iPSC-Heps engraftment, we next developed an injectable carboxymethyl-hexanoyl chitosan hydrogel (CHC) with sustained hepatocyte growth factor (HGF) release (HGF-CHC) and investigated the hepatoprotective activity of HGF-CHC-delivered iPSC-Heps in vitro and in an immunocompromised AHF mouse model induced by thioacetamide (TAA). Intrahepatic delivery of HGF-CHC-iPSC-Heps reduced the TAA-induced hepatic necrotic area and rescued liver function and recipient viability. Compared with PBS-delivered iPSC-Heps, the HGF-CHC-delivered iPSC-Heps exhibited higher antioxidant and antiapoptotic activities that reduced hepatic necrotic area. Importantly, these HGF-CHC-mediated responses could be abolished by administering anti-HGF neutralizing antibodies. In conclusion, our findings demonstrated that HGF mediated the enhancement of iPSC-Hep antioxidant/antiapoptotic capacities and hepatoprotection and that HGF-CHC is as an excellent vehicle for iPSC-Hep engraftment in iPSC-based therapy against AHF.

  4. Expression of CCR5 and c-Met in Breast Cancer and Its Significance%乳腺癌中CCR5和c-Met的表达及意义

    Institute of Scientific and Technical Information of China (English)

    张玉文; 王丹; 刘亚

    2014-01-01

    Objective To study the signiifcance of CCR5 and c-Met expression in breast cancer.Methods The expression of CCR5 and c-Met in 45 cases of breast cancer was analyzed by using immunohistochemisty. Results CCR5 was expressed in 55.6% of cancerous breast tissue (25/45), whereas it was only expressed in 8.9% of normal breast tissue (4/45). Signiifcant difference was noted between the expression levels (P<0.01). c-Met was expressed in 51% of cancerous breast tissue (23/45), but only 6.6% (3/45) of normal tissue. The observed difference in expression level of c-Met was also statistically signiifcant (P<0.01). On the other hand, 44.4% (20/45) of breast cancer patients with lymph node metastasis showed co-expression of both c-Met and CCR5, compared to 22.2% (10/45) in the normal breast tissue. Our ifndings demonstrate signiifcant associations between the expression of c-Met, CCR5 and lymph node metastasis in breast cancer patients. Conclusion CCR5 and c-Met expression was associated with poor prognosis of breast cancer patients, which could be predict the prognosis of breast cancer.%目的:探讨乳腺癌组织中CCR5和c-Met的表达及其意义。方法采用免疫组化SP法检测45例乳腺癌中CCR5和c-Met的表达。结果乳腺癌组织CCR5阳性率55.6%(25/45),正常乳腺组织中CCR5表达率8.9%(4/45),两种组织阳性表达率差异显著(P<0.01),c-Met的阳性表达率为51%(23/45),正常乳腺组织中c-Met表达率6.6%(3/45),两种组织阳性表达率差异显著(P<0.01)。在伴有淋巴结转移的乳腺癌中c-Met和CCR5的共同阳性率44.4%(20/45),无淋巴结转移的乳腺癌中阳性表达率为22.2%(10/45)。CCR5和c-Met的表达和乳腺癌的淋巴结转移成正相关。结论CCR5和c-Met与提示乳腺癌的转移预后因素有关,可作为预测乳腺癌转移的参考指标之一。

  5. 抑制脂筏对肝细胞生长因子受体介导的信号跨膜转导作用的影响%Effects of lipid rafts on signal transmembrane transduction mediated by c-Met

    Institute of Scientific and Technical Information of China (English)

    王蕾; 赵玉峰; 李亚丽; 徐跃飞; 夏泉; 马克里

    2008-01-01

    Objective To study the effects of lipid rafts on cell signal transmembrane transduction mediated by c-Met. Methods After HepG2Cells were treated with MβCD to disrupt the lipid rafts and were treated with artificial recombination hepatocyte growth factor to activate c-Met, the activities of PLCγ1/PKC, P13K/Akt and MAPK signaling pathways in HepG2 cells were analyzed using Western blot. Results (1) After disruption of lipid rafts with MβCD, phosphorylation of PLCγ1 decreased by 35% (P=0.022); the content of PLCγ in the cytoplasm increased by 1.75 fold (P=0.017); PLCγ1 conjugated with membrane decreased by 30% (P=0.037). (2) The content of PKB in the cytosol decreased by 38% (P=0.028), and the phosphorylation level of PKB conjugated with membrane decreased by 14% (P=0.041). At the same time, PDK translocation from cytosol to the plasma membrane and its activation were inhibited by treatment with MβCD. (3) Treatment with MβCD had no significant effect on ErK/MAPK, p38/MAPK and JNK/MAPK signaling pathways. Conclusion Disruption of lipid rafts with MβCD inhibits the activation of PLCγ1/PKC and PI3K/PKB signaling pathways by HGF/cMet, but has no effect on MAPK signaling pathway.%目的 探讨脂筏在肝细胞生长因子受体介导的信号跨膜转导中的作用.方法 采用甲基-β-环糊精(MβCD)处理HepG2细胞,以干扰脂筏的形成,然后加入人工重组肝细胞生长因子以活化其受体.采用Western blot技术及计算机扫描定量分析分别检测MβCD处理组和对照组细胞磷脂酶Cγ1(PLCγ1)/二脂酰甘油/蛋白激酶C信号通路、磷脂酰肌醇-3-激酶/磷脂酰肌醇依赖的蛋白激酶/蛋白激酶B信号通路和有丝分裂原激活的蛋白激酶(MAPK)信号通路活性的变化.结果 (1)用MβCD处理细胞后,细胞PLCγ1磷酸化程度降低,为对照组的65%(P=0.022);胞浆中PLCγ1含量增加,为对照组的1.75倍(P=0.017);膜结合的PLCγ1减少,为对照组的70%(P=0.037).(2)用MβCD处理细胞

  6. Mesenchymal stem cells and myoblast differentiation under HGF and IGF-1 stimulation for 3D skeletal muscle tissue engineering.

    Science.gov (United States)

    Witt, R; Weigand, A; Boos, A M; Cai, A; Dippold, D; Boccaccini, A R; Schubert, D W; Hardt, M; Lange, C; Arkudas, A; Horch, R E; Beier, J P

    2017-02-28

    Volumetric muscle loss caused by trauma or after tumour surgery exceeds the natural regeneration capacity of skeletal muscle. Hence, the future goal of tissue engineering (TE) is the replacement and repair of lost muscle tissue by newly generating skeletal muscle combining different cell sources, such as myoblasts and mesenchymal stem cells (MSCs), within a three-dimensional matrix. Latest research showed that seeding skeletal muscle cells on aligned constructs enhance the formation of myotubes as well as cell alignment and may provide a further step towards the clinical application of engineered skeletal muscle. In this study the myogenic differentiation potential of MSCs upon co-cultivation with myoblasts and under stimulation with hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) was evaluated. We further analysed the behaviour of MSC-myoblast co-cultures in different 3D matrices. Primary rat myoblasts and rat MSCs were mono- and co-cultivated for 2, 7 or 14 days. The effect of different concentrations of HGF and IGF-1 alone, as well as in combination, on myogenic differentiation was analysed using microscopy, multicolour flow cytometry and real-time PCR. Furthermore, the influence of different three-dimensional culture models, such as fibrin, fibrin-collagen-I gels and parallel aligned electrospun poly-ε-caprolacton collagen-I nanofibers, on myogenic differentiation was analysed. MSCs could be successfully differentiated into the myogenic lineage both in mono- and in co-cultures independent of HGF and IGF-1 stimulation by expressing desmin, myocyte enhancer factor 2, myosin heavy chain 2 and alpha-sarcomeric actinin. An increased expression of different myogenic key markers could be observed under HGF and IGF-1 stimulation. Even though, stimulation with HGF/IGF-1 does not seem essential for sufficient myogenic differentiation. Three-dimensional cultivation in fibrin-collagen-I gels induced higher levels of myogenic differentiation

  7. KAI1 inhibits HGF-induced invasion of pancreatic cancer by sphingosine kinase activity

    Institute of Scientific and Technical Information of China (English)

    Xu Liu; Xiao-Zhong Guo; Wei-Wei Zhang; Zhuo-Zhuang Lu; Qun-Wei Zhang; Hai-Feng Duan; d Li-Sheng Wang

    2011-01-01

    BACKGROUND: KAI1/CD82 has been reported to attenuate the process of metastases in a variety of tumors; however, its mechanism of action in invasion has not been fully elucidated. The present study aimed to investigate the importance of KAI1 in invasion and its correlation with activation of sphingosine kinase (SPK) in human pancreatic cancer PANC1 and Miapaca-2 cell lines. METHODS: The expression of KAI1 in PANC1 and Miapaca-2 cells,whichwasmediatedbyrecombinantadenovirus(Ad-KAI1), was assessed by a flow cytometer and Western blotting. After successful infection was established, in vitro growth curve and invasive ability in Boyden Chamber assay were studied. The presence of KAI1 correlating with c-Met and SPK was detected by co-immunoprecipitationand[γ-32P]ATPincorporation. RESULTS: KAI1 genes had no significant effects on the curve representing cell growth. After infection with the KAI1 gene, decreased invasive ability in the Boyden Chamber assay was observed in PANC1 and Miapaca-2 cells that were induced by hepatocyte growth factor. Over-expression of KAI1 in the cells led to the deactivation of SPK and a decreased level of intracellular sphingosine-1-phosphate. No correlation was observed between c-Met and KAI1 during co-immunoprecipitation. CONCLUSION: The results of this study for the first time demonstrated a regulatory role for KAI1 in SPK activation, which leads to decreased invasive ability in disease progression of human pancreatic cancer.

  8. Phase II study evaluating 2 dosing schedules of oral foretinib (GSK1363089, cMET/VEGFR2 inhibitor, in patients with metastatic gastric cancer.

    Directory of Open Access Journals (Sweden)

    Manish A Shah

    Full Text Available PURPOSE: The receptors for hepatocyte and vascular endothelial cell growth factors (MET and VEGFR2, respectively are critical oncogenic mediators in gastric adenocarcinoma. The purpose is to examine the safety and efficacy of foretinib, an oral multikinase inhibitor targeting MET, RON, AXL, TIE-2, and VEGFR2 receptors, for the treatment of metastatic gastric adenocarcinoma. PATIENTS AND METHODS: Foretinib safety and tolerability, and objective response rate (ORR were evaluated in patients using intermittent (240 mg/day, for 5 days every 2 weeks or daily (80 mg/day dosing schedules. Thirty evaluable patients were required to achieve alpha = 0.10 and beta = 0.2 to test the alternative hypothesis that single-agent foretinib would result in an ORR of ≥ 25%. Up to 10 additional patients could be enrolled to ensure at least eight with MET amplification. Correlative studies included tumor MET amplification, MET signaling, pharmacokinetics and plasma biomarkers of foretinib activity. RESULTS: From March 2007 until October 2009, 74 patients were enrolled; 74% male; median age, 61 years (range, 25-88; 93% had received prior therapy. Best response was stable disease (SD in 10 (23% patients receiving intermittent dosing and five (20% receiving daily dosing; SD duration was 1.9-7.2 months (median 3.2 months. Of 67 patients with tumor samples, 3 had MET amplification, one of whom had SD. Treatment-related adverse events occurred in 91% of patients. Rates of hypertension (35% vs. 15% and elevated aspartate aminotransferase (23% vs. 8% were higher with intermittent dosing. In both patients with high baseline tumor phospho-MET (pMET, the pMET:total MET protein ratio decreased with foretinib treatment. CONCLUSION: These results indicate that few gastric carcinomas are driven solely by MET and VEGFR2, and underscore the diverse molecular oncogenesis of this disease. Despite evidence of MET inhibition by foretinib, single-agent foretinib lacked efficacy in

  9. Astragalus mongholicus ameliorates renal fibrosis by modulating HGF and TGF-β in rats with unilateral ureteral obstruction

    Institute of Scientific and Technical Information of China (English)

    Chuan ZUO; Xi-sheng XIE; Hong-yu QIU; Yao DENG; Da ZHU; Jun-ming FAN

    2009-01-01

    Astragalus mongholicus (AM) derived from the dry root of Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao is a widely used traditional Chinese medicine. The present study investigated the potential role of AM on renal fibrosis on a rat model of unilateral ureteral obstruction (UUO). We divided 48 Sprague-Dawley rats randomly into 4 groups: sham-operated group (Sham), untreated UUO group, AM-treated (10 g/(kg.d)) UUO group, and losartan-treated (20 mg/(kg.d)) UUO group as positive control. Haematoxylin & eosin (HE) and Masson staining were used to study the dynamic histological changes of the kidneys 7 and 14 d after operation. The expressions of fibronectin (FN), type I collagen (coII), hepatocyte growth factor (HGF), transforming growth factor-pi (TGF-βl), and a-smooth muscle actin (a-SMA) were analyzed by real-time polymerase chain reaction (PCR), immunohistochemistry staining, and Western blot. Results show that, similar to losartan, AM alleviated the renal damage and decreased the deposition of FN and colI from UUO by reducing the expressions of TGF-pi and a-SMA (P<0.05), whereas HGF increased greatly with AM treatment (P<0.05). Our findings reveal that AM could retard the progression of renal fibrosis. The renoprotective effect of AM might be related to inhibition of myofibroblast activation, inducing of HGF and reducing of TGF-β1 expression.

  10. Hepatocyte growth factor/scatter factor modulates cell motility, proliferation, and proteoglycan synthesis of chondrocytes.

    Science.gov (United States)

    Takebayashi, T; Iwamoto, M; Jikko, A; Matsumura, T; Enomoto-Iwamoto, M; Myoukai, F; Koyama, E; Yamaai, T; Matsumoto, K; Nakamura, T

    1995-06-01

    Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional growth factor that promotes proliferation, motility, and morphogenesis in epithelial cells. Recently the HGF receptor, c-met protooncogene product, has been shown to be expressed in developing limb buds (Sonnenberg, E., D. Meyer, M. Weidner, and C. Birchmeiyer, 1993. J. Cell Biol. 123: 223-235), suggesting that some populations of mesenchymal cells in limb buds respond to HGF/SF. To test the possibility that HGF/SF is involved in regulation of cartilage development, we isolated chondrocytes from knee joints and costal cartilages of 23-d embryonic and 4-wk-old rabbits, and analyzed the effects of HGF/SF on migration and proliferation of these cells. We found that HGF/SF stimulated migration of cultured articular chondrocytes but did not scatter limb mesenchymal fibroblasts or synovial fibroblasts in culture. HGF/SF also stimulated proliferation of chondrocytes; a maximum three-fold stimulation in DNA synthesis was observed at the concentration of 3 ng/ml of HGF/SF. Moreover, HGF/SF had the ability to enhance proteoglycan synthesis in chondrocytes. The responsiveness of chondrocytes to HGF/SF was also supported by the observation that they expressed the HGF/SF receptor. Addition of the neutralizing antibody to rat HGF/SF affected neither DNA synthesis nor proteoglycan synthesis in rat chondrocytes, suggesting a paracine mechanism of action of HGF/SF on these cells. In situ hybridization analysis showed that HGF/SF mRNA was restrictively expressed in the areas of future joint regions in developing limb buds and in the intercostal spaces of developing costal cartilages. These findings suggest that HGF/SF plays important roles in cartilage development through its multiple activities.

  11. Hepatocyte growth factor/scatter factor modulates cell motility, proliferation, and proteoglycan synthesis of chondrocytes

    Science.gov (United States)

    1995-01-01

    Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional growth factor that promotes proliferation, motility, and morphogenesis in epithelial cells. Recently the HGF receptor, c-met protooncogene product, has been shown to be expressed in developing limb buds (Sonnenberg, E., D. Meyer, M. Weidner, and C. Birchmeiyer, 1993. J. Cell Biol. 123: 223-235), suggesting that some populations of mesenchymal cells in limb buds respond to HGF/SF. To test the possibility that HGF/SF is involved in regulation of cartilage development, we isolated chondrocytes from knee joints and costal cartilages of 23-d embryonic and 4-wk-old rabbits, and analyzed the effects of HGF/SF on migration and proliferation of these cells. We found that HGF/SF stimulated migration of cultured articular chondrocytes but did not scatter limb mesenchymal fibroblasts or synovial fibroblasts in culture. HGF/SF also stimulated proliferation of chondrocytes; a maximum three-fold stimulation in DNA synthesis was observed at the concentration of 3 ng/ml of HGF/SF. Moreover, HGF/SF had the ability to enhance proteoglycan synthesis in chondrocytes. The responsiveness of chondrocytes to HGF/SF was also supported by the observation that they expressed the HGF/SF receptor. Addition of the neutralizing antibody to rat HGF/SF affected neither DNA synthesis nor proteoglycan synthesis in rat chondrocytes, suggesting a paracine mechanism of action of HGF/SF on these cells. In situ hybridization analysis showed that HGF/SF mRNA was restrictively expressed in the areas of future joint regions in developing limb buds and in the intercostal spaces of developing costal cartilages. These findings suggest that HGF/SF plays important roles in cartilage development through its multiple activities. PMID:7775584

  12. Hepatocyte growth factor and alternative splice variants - expression, regulation and implications in osteogenesis and bone health and repair.

    Science.gov (United States)

    Frisch, Rachel N; Curtis, Kevin M; Aenlle, Kristina K; Howard, Guy A

    2016-09-01

    Bone marrow-derived mesenchymal stem cells (MSCs) can differentiate into multiple cell types, including osteoblasts, chondrocytes, and adipocytes. These pluripotent cells secrete hepatocyte growth factor (HGF), which regulates cell growth, survival, motility, migration, mitogenesis and is important for tissue development/regeneration. HGF has four splice variants, NK1, NK2, NK3, and NK4 which have varying functions and affinities for the HGF receptor, cMET. HGF promotes osteoblastic differentiation of MSCs into bone forming cells, playing a role in bone development, health and repair. This review will focus on the effects of HGF in osteogenesis, bone repair and bone health, including structural and functional insights into the role of HGF in the body. Approximately 6.2 million Americans experience a fracture annually, with 5-10% being mal- or non-union fractures. HGF is important in priming MSCs for osteogenic differentiation in vitro and is currently being studied to assess its role during bone repair in vivo. Due to the high turnover rate of systemic HGF, non-classic modes of HGF-treatment, including naked-plasmid HGF delivery and the use of HGF splice variants (NK1 & NK2) are being studied to find safe and efficacious treatments for bone disorders, such as mal- or non-union fractures.

  13. Targeting hepatocyte growth factor receptor (Met) positive tumor cells using internalizing nanobody-decorated albumin nanoparticles

    NARCIS (Netherlands)

    Heukers, Raimond|info:eu-repo/dai/nl/325788103; Altintas, Isil|info:eu-repo/dai/nl/341537160; Raghoenath, Smiriti; De Zan, Erica; Pepermans, Richard; Roovers, Rob C.|info:eu-repo/dai/nl/205435599; Haselberg, Rob|info:eu-repo/dai/nl/304822647; Hennink, Wim E.|info:eu-repo/dai/nl/070880409; Schiffelers, Raymond M.|info:eu-repo/dai/nl/212909509; Kok, Robbert J.|info:eu-repo/dai/nl/170678326; Van Bergen en Henegouwen, Paul M P|info:eu-repo/dai/nl/071919481

    2014-01-01

    The hepatocyte growth factor receptor (HGFR, c-Met or Met) is a receptor tyrosine kinase that is involved in embryogenesis, tissue regeneration and wound healing. Abnormal activation of this proto-oncogene product is implicated in the development, progression and metastasis of many cancers. Current

  14. Gene expression of hepatocyte growth factor and its receptor in HCC and nontumorous liver tissues

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    AIM To study the changes of gene expression of hepatocyte growth factor (HGF) and hepatocyte growth factor receptor (HGFr) in hepatocellular carcinoma (HCC) tissue and nontumorous liver tissue and the relationship between these changes and the biological behavior of the tumor.METHODS Gene expression of HGF and HGFr in 26 cases of HCC tissue and their adjacent nontumorous liver tissues was determined with digoxigenin-labeled DNA probes.RESULTS Positive expression of HGF in HCC tissue was similar to that in the adjacent nontumorous liver tissue, but positive rate of HGF expression was lower than HGFr gene expression. However, HGFr expression was higher in the metastatic cases than in those without metastasis. It was found that HGFr was overexpressed in HCC tissue as well as in the adjacent nontumorous liver tissue.CONCLUSION There seems to be a close relationship between overexpression of HGFr gene and tumor metastasis, and the HGF and HGFr system plays an important role in regulating tumor growth and metastasis.

  15. Comment on "Effect of transferred NK4 gene on proliferation,migration, invasion, and apoptosis of human prostate cancer DU145 cells" by Dan Yue et al. in Asian Journal of Andrology

    Institute of Scientific and Technical Information of China (English)

    Shahriar Koochekpour

    2010-01-01

    @@ Hepatocyte growth factor/scatter factor (HGF/SF) interacting with its cell surface receptor tyrosine kinase (RTK) c-met proto-oncogene drives downstream signaling pathways which lead to cell proliferation, migration,invasion, apoptotic cell-death protection, angiogenesis during embryogenesis, repair and regeneration, and neoplastic growth and metastatic progression [1-6].

  16. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  17. Determination of a novel anticancer c-Met inhibitor LS-177 in rat plasma and tissues with a validated UPLC-MS/MS method: application to pharmacokinetics and tissue distribution study.

    Science.gov (United States)

    Ju, Ping; Liu, Zhenzhen; Jiang, Yu; Zhao, Simin; Zhang, Lunhui; Zhang, Yuanyuan; Gu, Liqiang; Tang, Xing; Bi, Kaishun; Chen, Xiaohui

    2015-07-01

    LS-177 is a novel small-molecule kinase inhibitor employed to interrupt the c-Met signaling pathway. A rapid and sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of LS-177 in rat plasma and tissues. The biosamples were extracted by liquid-liquid extraction with methyl tert-butyl ether and separated on a C18 column (50 × 4.6 mm, 2.6 µm) using a gradient elution mobile phase consisting of acetonitrile-0.1% formic acid water. Under the optimal conditions, the selectivity of the method was satisfactory with no endogenous interference. The intraday and interday precisions (relative standard deviation) were LS-177 was stable during the preparation and analytical processes. The UPLC-MS/MS method was successfully applied to pharmacokinetic and tissue distribution studies. The results indicated that there was no significant drug accumulation after multiple-dose oral administration of LS-177. The tissue distribution study exhibited significant higher uptakes of LS-177 in stomach, intestine, lung and liver among all of the tissues. The results in pharmacokinetics and tissue distribution may provide a meaningful basis for clinical application.

  18. Comparative study of effects of bone marrow cell vs. Ad5-HGF administration via non infarct-related artery injection in myocardial infarction in swine

    Institute of Scientific and Technical Information of China (English)

    Liansheng Wang; Jun Huang; Zhijian Yang; Wei Wang; Dongchao Ma; Shunlin Xu; Yuqing Zhang; Fang Zhou; Bo Chen; Kejiang Cao

    2007-01-01

    Objective: To evaluate the effect of transplanting bone marrow-derived mesenchymal stem cells (BM-MSCs) or adenovirus5-hepatocyte growth factor(Ad5-HGF) via non-infarct-related artery injection in swine myocardial infarction models. Methods :BMMSCs were obtained from swine bone marrow and expanded in vitro to a purity of >50%. A myocardial infarction(MI) was created by ligating the distal left anterior descending artery in swine. Either BM-MSCs (5 × 106/ml) or Ad5-HGF (4 × 109 pfu) were transfused via the right coronary artery (non-infarcted artery) four weeks after MI. Gate-controled cardiac perfusion imaging was performed at the end of four and seven weeks after LAD ligation, to evaluate heart function and cardiac perfusion. Morphologic and histologic characteristics of the hearts were also studied. Results: (1)The gate-controlled cardiac perfusion imaging showed that the improvement in LVEF was greater in both treatment groups than in control group at the 4th weeks. (2)In both treatment groups, capillary density was significantly higher than that of control group (P < 0.05). Conclusion:BM-MSCs or Ad5-HGF transplantation via non-infarcted artery administration can stimulate angiogenesis and improve heart function, but there was no difference in therapeutic efficacy between BM-MSCs and Ad5-HGF.

  19. Mutant MMP-9 and HGF gene transfer enhance resolution of CCl4-induced liver fibrosis in rats: role of ASH1 and EZH2 methyltransferases repression.

    Directory of Open Access Journals (Sweden)

    Hussein Atta

    Full Text Available Hepatocyte growth factor (HGF gene transfer inhibits liver fibrosis by regulating aberrant cellular functions, while mutant matrix metalloproteinase-9 (mMMP-9 enhances matrix degradation by neutralizing the elevated tissue inhibitor of metalloproteinase-1 (TIMP-1. It was shown that ASH1 and EZH2 methyltransferases are involved in development of liver fibrosis; however, their role in the resolution phase of liver fibrosis has not been investigated. This study evaluated the role of ASH1 and EZH2 in two mechanistically different therapeutic modalities, HGF and mMMP-9 gene transfer in CCl4 induced rat liver fibrosis. Liver fibrosis was induced in rats with twice a week intraperitoneal injection of CCl4 for 8 weeks. Adenovirus vectors encoding mMMP-9 or HGF genes were injected through tail vein at weeks six and seven and were sacrificed one week after the second injection. A healthy animal group was likewise injected with saline to serve as a negative control. Rats treated with mMMP-9 showed significantly lower fibrosis score, less Sirius red stained collagen area, reduced hydroxyproline and ALT concentration, decreased transforming growth factor beta 1 (TGF-β1 mRNA and lower labeling indices of α smooth muscle actin (α-SMA and proliferating cell nuclear antigen (PCNA stained cells compared with HGF- or saline-treated rats. Furthermore, TIMP-1 protein expression in mMMP-9 group was markedly reduced compared with all fibrotic groups. ASH1 and EZH2 protein expression was significantly elevated in fibrotic liver and significantly decreased in mMMP-9- and HGF-treated compared to saline-treated fibrotic livers with further reduction in the mMMP-9 group.Gene transfer of mMMP-9 and HGF reduced liver fibrosis in rats. ASH1 and EZH2 methyltransferases are significantly reduced in mMMP-9 and HGF treated rats which underlines the central role of these enzymes during fibrogenesis. Future studies should evaluate the role of selective pharmacologic inhibitors

  20. 非肝硬变性胆道梗阻大鼠肝脏部分切除术后肝内促肝细胞生长因子及其受体mRNA 的表达变化%Expression of HGF/Met mRNA and TGF-α/EGFR mRNA in the liver/hepatocyte after partial hepatectomy in noncirrhotic obstructive rats

    Institute of Scientific and Technical Information of China (English)

    徐明清; 韩本立; 薛兰; 龚建平; 董家鸿; 王曙光

    2001-01-01

    Objective To investigate the expression of HGF and TGF-α and their receptor, Met (HGF receptor) and EGFR (TGF-αreceptor) mRNA, in the regenerative liver/hepatocytes after 70% partial hepatectomy (70% PH) in noncirrhotic biliary obstruction rats. Methods Wistar rats were divided randomly into N-PH group, BDO-RBF-PH group and BDO-RBF group. The expression of HGF/Met mRNA and TGF-α/EGFR mRNA was measured by RT-PCR in the liver/hepatocytes at the time point of 0, 6, 12, 24, 48 and 72 h after 70% PH or RBF. Results In N-PH group, the expression of HGF/Met mRNA increased sharply and peaked at 6 h, and maintained at a high level until 24 h after 70% PH. In BDO-RBF-PH group however, the expression of HGF/Met mRNA increased slowly and peaked at 12 h after 70% PH. The peak level was lower in BDO-RBF-PH group than in N-PH one. The expression of TGF-α/EGFR mRNA increased sharply and peaked at 24 h after 70% PH in N-PH group. However, the expression of TGF-α/EGFR mRNA elevated slowly and peaked at 48 h after 70% PH in BDO-RBF-PH group with a lower peak level than that in N-PH group. Conclusion The expression of HGF/Met mRNA and TGF-α/EGFR mRNA in the regenerative liver/hepatocytes after 70% PH decreases significantly in noncirrhotic biliary duct obstruction rats. There is a tendency that the expression of HGF mRNA and TGF-α mRNA is less than Met mRNA and EGFR mRNA.%目的 检测非肝硬变性胆道梗阻肝脏部分切除(PH)术后肝内促肝细胞生长的肝细胞生长因子(HGF)与转化生长因子-α(TGF-α)及其受体Met基因(HGF受体)、表皮生长因子受体EGFR(亦是TGF-α受体)mRNA的表达变化。方法 Wistar大鼠随机分为正常70%肝部分切除组(N-PH)、胆道梗阻(BDO)胆流再通(RBF)70%PH组(BDO-RBF-PH)、及胆道梗阻胆流再通组(BDO-RBF)。观察时相点为术后0、6、12、24、48及72 h。RT-PCR法检测肝内HGF mRNA、TGF-α mRNA及肝细胞Met mRNA与EGFR m

  1. Evidence for an LKB1/AMPK/eNOS Cascade Regulated by HGF, S-Adenosylmethionine and NO in Hepatocyte Proliferation

    Science.gov (United States)

    Vázquez, Mercedes; Ariz, Usue; Varela-Rey, Marta; Embade, Nieves; Martínez, Nuria; Fernández, David; Gómez, Laura; Lamas, Santiago; Lu, Shelly C; Martínez-Chantar, M Luz; Mato, José M

    2008-01-01

    S-Adenosylmethionine (SAMe) is involved in numerous complex hepatic processes such as hepatocyte proliferation, death, inflammatory responses, and anti-oxidant defense. One of the most relevant actions of SAMe is the inhibition of hepatocyte proliferation during liver regeneration. In hepatocytes, SAMe regulates the levels of cytoplasmic HuR, an RNA-binding protein that increases the half-life of target mRNA such as cyclin D1 and A2, via inhibition of HGF-mediated AMP-activated protein kinase (AMPK) phosphorylation. Because AMPK is activated by the tumor suppressor kinase LKB1, and AMPK activates endothelial nitric oxide (NO) synthase (eNOS), and NO synthesis is of great importance for hepatocyte proliferation, we hypothesized that in hepatocytes HGF may induce the phosphorylation of LKB1, AMPK and eNOS through a process regulated by SAMe, and that this cascade might be crucial for hepatocyte growth. Here we demonstrate that the proliferative response of hepatocytes involves eNOS phosphorylation via HGF-mediated LKB1 and AMPK phosphorylation, and that this process is regulated by SAMe and NO. We also show that knockdown of LKB1, AMPK, or eNOS with specific iRNA inhibits HGF-mediated hepatocyte proliferation. Finally, we found that the LKB1/AMPK/eNOS cascade is activated during liver regeneration after partial hepatectomy and that this process is impaired in mice treated with SAMe before hepatectomy, in knockout mice deficient in hepatic SAMe, and in eNOS knockout mice. Conclusion We have identified an LKB1/AMPK/eNOS cascade regulated by HGF, SAMe and NO that functions as a critical determinant of hepatocyte proliferation during liver regeneration after partial hepatectomy. PMID:19177591

  2. The (PrS/HGF-pDNA) multilayer films for gene-eluting stent coating: Gene-protecting, anticoagulation, antibacterial properties, and in vivo antirestenosis evaluation.

    Science.gov (United States)

    Chang, Hao; Ren, Ke-feng; Zhang, He; Wang, Jin-lei; Wang, Bai-liang; Ji, Jian

    2015-02-01

    Vascular gene-eluting stents (GES) is a promising strategy for treatment of cardiovascular disease. Very recently, we have proved that the (protamine sulfate/plasmid DNA encoding hepatocyte growth factor) (PrS/HGF-pDNA) multilayer can serve as a powerful tool for enhancing competitiveness of endothelial cell over smooth muscle cell, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy. However, before the gene multilayer films could be used in vascular stents for real clinical application, the preservation of gene bioactivity during the industrial sterilization and the hemocompatibility of film should be taken into account. Actually, both are long been ignored issues in the field of gene coating for GES. In this study, we demonstrate that the (PrS/HGF-pDNA) multilayer film exhibits the good gene-protecting abilities, which is confirmed by using the industrial sterilizations (gamma irradiation and ethylene oxide) and a routine storage condition (dry state at 4°C for 30 days). Furthermore, hemocompatible measurements (such as platelet adhesion and whole blood coagulation) and antibacterial assays (bacteria adhesion and growth inhibition) indicate the good anticoagulation and antibacterial properties of the (PrS/HGF-pDNA) multilayer film. The in vivo preliminary data of angiography and histological analysis suggest that the (PrS/HGF-pDNA) multilayer coated stent can reduce the in-stent restenosis. This work reveals that the (PrS/HGF-pDNA) multilayer film could be a promising candidate as coating for GES, which is of great potential in future clinic application.

  3. HGF, MET, and matrix-related proteases in hepatocellular carcinoma, fibrolamellar variant, cirrhotic and normal liver.

    Science.gov (United States)

    Schoedel, Karen E; Tyner, Valerie Zajac; Kim, Tae-Hyoung; Michalopoulos, George K; Mars, Wendy M

    2003-01-01

    Fibrolamellar variant is an uncommon subcategory of hepatocellular carcinoma with a better prognostic outcome. Proteinases and growth factors that are involved in the remodeling of extracellular matrix may influence the behavior of cancers. To determine whether these factors contribute to the distinct etiologies of fibrolamellar hepatocellular carcinoma and traditional hepatocellular carcinoma, we assayed hepatocyte growth factor, the hepatocyte growth factor receptor, and two hepatocyte growth factor activators, hepatocyte growth factor activator and urokinase-type plasminogen activator, in hepatocellular carcinoma, fibrolamellar hepatocellular carcinoma, cirrhotic liver and normal liver. In addition, we examined the urokinase-type plasminogen activator receptor, the type 1 plasminogen activator inhibitor, plasmin, fibrinogen, and the type IV matrix metalloproteinases. Eighteen hepatocellular carcinomas and 11 fibrolamellar hepatocellular carcinomas were obtained as paraffin embedded sections from the University of Pittsburgh Department of Pathology. Frozen tissues from a subset of cases (9 hepatocellular carcinomas, 4 fibrolamellar hepatocellular carcinomas, 12 cirrhotic livers and 2 normal livers) were also available for analysis. Antibodies against urokinase-type plasminogen activator, urokinase-type plasminogen activator receptor, hepatocyte growth factor and hepatocyte growth factor receptor were used to analyze immunoperoxidase stained slides from the paraffin blocks. Western blot analyses using antibodies against hepatocyte growth factor, hepatocyte growth factor receptor, phosphotyrosine, hepatocyte growth factor activator, urokinase-type plasminogen activator receptor, urokinase-type plasminogen activator, plasminogen activator inhibitor-1, fibrinogen and plasmin were performed on membrane-enriched fractions from the frozen tissue, as was collagen zymography for matrix metalloproteinase-2 and matrix metalloproteinase-9. The most notable findings are as

  4. Construction of human naive Fab library, screening and identification of phage antibody against c-Met%人源天然Fab噬菌体抗体库的构建及抗c-Met抗体的筛选、鉴定

    Institute of Scientific and Technical Information of China (English)

    万佳艺; 孙慧; 焦永军; 朱晓娟; 朱进; 刘政; 冯振卿

    2008-01-01

    目的:构建大容量人源天然Fab噬菌体抗体库,筛选抗c-Met特异性抗体并进行初步鉴定.方法:采集20位健康成人的骨髓淋巴细胞.用PCR扩增人Fab片断抗体基因,插入载体pComb3XSS内,构建人源天然Fab抗体库.以固相化的抗原对抗体库进行6轮筛选后,随机挑选60个克隆用Phage ELISA、BstO I酶切片断分析进行检测,阳性克隆作可溶性表达和鉴定.结果:构建的Fab噬菌体抗体库的库容为1.2×109,从中筛选到1株与c-Met特异性结合的人源抗体克隆,命名为AM2-26.DNA序列分析证明为人免疫球蛋白可变区基因,Western blot证实为人源抗c-Met Fab抗体片段,ELISA特异性鉴定阳性.结论:构建了大容量人源天然Fab抗体库,从中获得1株抗c-Met人源Fab抗体片段,有望为抗肿瘤药物的研制提供新的候选分子.

  5. Hepatocyte Growth Factor Suppresses Transforming Growth Factor-Beta-1 and Type III Collagen in Human Primary Renal Fibroblasts

    Directory of Open Access Journals (Sweden)

    Shan Mou

    2009-11-01

    Full Text Available Tubulointerstitial changes in the diabetic kidney correlate closely with renal fibrosis, and transforming growth factor-beta-1 (TGF-β1 is thought to play a key role in this process. In contrast, hepatocyte growth factor (HGF has shown therapeutic effects on injured renal tubules in animal models. This study was undertaken to test the hypothesis that the preventive effects of HGF may result from interventions in TGF-β1-mediated signaling and collagen III secretion. We examined the expression of HGF/HGF receptor (c-Met and TGF-β1 in renal fibroblasts at multiple time points. The effects of recombinant human HGF on TGF-β1 expression were studied by RT-PCR and Western blotting, and the levels of collagen III were measured by ELISA. In the high-glucose condition, the expression of HGF and c-Met in renal fibroblasts was detected as early as 6 hours following cell culture while the level of TGF-β1 peaked at 96 hours. The addition of recombinant human HGF to the culture media dose-dependently inhibited TGF-β1 mRNA expression and reduced collagen III secretion by 34%. These results indicate that, during hyperglycemia, HGF inhibits TGF-β1 signaling and type III collagen activation in interstitial fibroblasts. Furthermore, we should recognize that changes in the balance between HGF and TGF-β1 might be decisive in the pathogenesis of chronic renal fibrosis. Therefore, administration of HGF to restore this balance may offer a novel therapeutic intervention in managing renal fibrogenesis in diabetic nephropathy.

  6. Agonist antibodies activating the Met receptor protect cardiomyoblasts from cobalt chloride-induced apoptosis and autophagy

    Science.gov (United States)

    Gallo, S; Gatti, S; Sala, V; Albano, R; Costelli, P; Casanova, E; Comoglio, P M; Crepaldi, T

    2014-01-01

    Met, the tyrosine kinase receptor for hepatocyte growth factor (HGF), mainly activates prosurvival pathways, including protection from apoptosis. In this work, we investigated the cardioprotective mechanisms of Met activation by agonist monoclonal antibodies (mAbs). Cobalt chloride (CoCl2), a chemical mimetic of hypoxia, was used to induce cardiac damage in H9c2 cardiomyoblasts, which resulted in reduction of cell viability by (i) caspase-dependent apoptosis and (ii) – surprisingly – autophagy. Blocking either apoptosis with the caspase inhibitor benzyloxycarbonyl-VAD-fluoromethylketone or autophagosome formation with 3-methyladenine prevented loss of cell viability, which suggests that both processes contribute to cardiomyoblast injury. Concomitant treatment with Met-activating antibodies or HGF prevented apoptosis and autophagy. Pro-autophagic Redd1, Bnip3 and phospho-AMPK proteins, which are known to promote autophagy through inactivation of the mTOR pathway, were induced by CoCl2. Mechanistically, Met agonist antibodies or HGF prevented the inhibition of mTOR and reduced the flux of autophagosome formation. Accordingly, their anti-autophagic function was completely blunted by Temsirolimus, a specific mTOR inhibitor. Targeted Met activation was successful also in the setting of low oxygen conditions, in which Met agonist antibodies or HGF demonstrated anti-apoptotic and anti-autophagic effects. Activation of the Met pathway is thus a promising novel therapeutic tool for ischaemic injury. PMID:24743740

  7. LINE-1 ORF-1p functions as a novel HGF/ETS-1 signaling pathway co-activator and promotes the growth of MDA-MB-231 cell.

    Science.gov (United States)

    Yang, Qian; Feng, Fan; Zhang, Fan; Wang, Chunping; Lu, Yinying; Gao, Xudong; Zhu, Yunfeng; Yang, Yongping

    2013-12-01

    Long interspersed nucleotide element (LINE)-1 ORF-1p is encoded by the human pro-oncogene LINE-1. It is involved in the development and progression of several human carcinomas, such as hepatocellular carcinoma and lung and breast cancers. The hepatocyte growth factor (HGF)/ETS-1 signaling pathway is involved in regulation of cancer cell proliferation, metastasis and invasion. The biological function of the interaction between LINE-1 ORF-1p and the HGF/ETS-1 signaling pathway in regulation of human breast cancer proliferation remains largely unknown. Here, we showed that LINE-1 ORF-1p enhanced ETS-1 transcriptional activity and increased expression of downstream genes of ETS-1. Interaction between ETS-1 and LINE-1 ORF-1p was identified by immunoprecipitation assays. LINE-1 ORF-1p modulated ETS-1 activity through cytoplasm/nucleus translocation and recruitment to the ETS-1 binding element in the MMP1 gene promoter. We also showed that LINE-1 ORF-1p promoted proliferation and anchorage-independent growth of MDA-MB-231 breast cancer cells. By investigating a novel role of the LINE-1 ORF-1p in the HGF/ETS-1 signaling pathway and MDA-MB-231 cells, we demonstrated that LINE-1 ORF-1p may be a novel ETS-1 coactivator and molecular target for therapy of human triple negative breast cancer. © 2013.

  8. The role of FGF-2/HGF and fibronectin matrix on pleomorphic adenoma myoepithelial cell morphology and immunophenotype: an in vitro study.

    Science.gov (United States)

    Silva, Carolina Amália Barcellos; Nardello, Laura Cristina Leite; Garcia, Frederico Windlin; Araújo, Ney Soares de; Montalli, Victor Angelo; Araújo, Vera Cavalcanti de; Martinez, Elizabeth Ferreira

    2015-02-01

    Myoepithelial cells play a central role in glandular tumors, regulating the progression of in situ to invasive neoplasias, with the tumor microenvironment being shown to be involved in both initiation and progression. This study aimed to analyze the in vitro effects of fibroblast growth factor-2 (FGF-2) and hepatocyte growth factor (HGF) in myoepithelial cells under the influence of the fibronectin matrix extracellular protein. Benign myoepithelial cells were obtained from pleomorphic adenoma and cultured on a fibronectin substratum. FGF-2 and HGF were supplemented at different concentrations and time intervals, in order to evaluate cell proliferation, morphology and immunophenotype. Individually, FGF-2 and HGF supplementation did not alter myoepithelial cell proliferation, morphology or immunophenotype. The fibronectin substratum provoked an increase in cell proliferation and immunopositivity for α-smooth muscle actin and FGF-2. The myoepithelial cell morphology changed when the fibronectin substratum and FGF-2 acted together, highlighting the importance of the fibronectin extracellular matrix protein on the behavior of these cells.

  9. Hepatocyte Growth Factor from a Clinical Perspective: A Pancreatic Cancer Challenge

    Energy Technology Data Exchange (ETDEWEB)

    Rizwani, Wasia [Department of Biochemistry, Osmania University, Hyderabad, Telangana 500007 (India); Allen, Amanda E.; Trevino, Jose G., E-mail: Jose.Trevino@surgery.ufl.edu [Department of Surgery, University of Florida, 1600 SW Archer Rd, Rm 6175, P.O. Box 100109, Gainesville, FL 32610 (United States)

    2015-09-03

    Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States and incidence rates are rising. Both detection and treatment options for pancreatic cancer are limited, providing a less than 5% five-year survival advantage. The need for new biomarkers for early detection and treatment of pancreatic cancer demands the efficient translation of bench knowledge to provide clinical benefit. One source of therapeutic resistance is the pancreatic tumor microenvironment, which is characterized by desmoplasia and hypoxia making it less conducive to current therapies. A major factor regulating desmoplasia and subsequently promoting chemoresistance in pancreatic cancer is hepatocyte growth factor (HGF), the sole ligand for c-MET (mesenchymal-epithelial transition), an epithelial tyrosine kinase receptor. Binding of HGF to c-MET leads to receptor dimerization and autophosphorylation resulting in the activation of multiple cellular processes that support cancer progression. Inhibiting activation of c-MET in cancer cells, in combination with other approaches for reducing desmoplasia in the tumor microenvironment, might significantly improve the success of chemotherapy. Therefore, HGF makes a potent novel target for developing therapeutic strategies in combination with existing drugs for treating pancreatic adenocarcinoma. This review provides a comprehensive analysis of HGF and its promising potential as a chemotherapeutic target for pancreatic cancer.

  10. 第3~5周人胚肝的细胞特征和生长因子及其受体表达%Morphologic characteristics of human hepatic cells and expressions of growth factors and their receptors

    Institute of Scientific and Technical Information of China (English)

    蒋吉英; 李爱冬; 姜红心; 羊惠君; 魏志新; 李磊; 王箐; 于树娜

    2006-01-01

    overnight at 4 ℃ with polyclonal antibodies against hepatocyte growth factor (HGF),c-Met, insulin-like growth factor (IGF-Ⅰ), IGF-Ⅰ receptor (IGF-IR), transforming growth factor (TGFβ1), TGFβR1, TGFβR2 or monoclonal antibodies against proliferating cell nuclear antigen (PCNA), AFP and CK19.The following day, the sections were incubated for 2 hours at room temperature with biotinylated anti-mouse or anti-rabbit IgG and SABC liquid respectively, and then diaminobenzidine (DAB) was used to color them. The negative control was conducted with the phosphate buffer, then the sections were observed and photographed under light microscope.MAIN OUTCOME MEASUERS: ①the morphologic characteristic of human hepatic stem cells and immunohistochemical staining of markers②the expression of HGF, IGF-Ⅰ, TGFβ1 and their receptors on human embryonic livers of 3-5 weeks, primitive cardiac cells and septum transversum mesenchyme.RESULTS: ①The morphologic characteristic of human hepatic stem cells and immunohistochemical staining of markers: The hepatic bud formed at the end of 3rd week and migrated into the septum transversum mesenchyme to form the hepatic cords at the 4th week. The cells structuring the hepatic cords displayed the typical characteristic of immature cells. At the 5th week, the number of cells within the hepatic cords, the size of cell body,the cytoplasmic acidophilia all increased, whereas the basophilia of nuclei decreased. However the cellular forms were still homogeneous and displayed the typical characteristic of immature cells. The cells of hepatic cords were negative for PCNA response during 3rd-4th week but began to express positive at the 5th week, mainly in the nucleus and minority cellular cytoplasm showed weak positive. Most hepatic cells during 3rd-5th weeks were positive for AFP, c-Met and negative for CK19. The immunologic reaction depositors of AFP positive cells were located in the nuclei, cytoplasm and membrane of the hepatocytes, and c-Met

  11. The Expression and Significance of HGF and MMP-9 in Lichen Planus%HGF和MMP-9在扁平苔藓皮损中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    何肖; 白莉

    2011-01-01

    目的 检测扁平苔藓皮损中肝细胞生长因子(HGF)和基质金属蛋白酶-9(MMP-9)的表达情况,探讨其在扁平苔藓发病中的意义.方法 应用免疫组化法和RT-PCR法测定30例扁平苔藓及30例正常皮肤组织中HGF和MMP-9的表达水平.结果 扁平苔藓组中HGF和MMP-9的表达率均高于正常对照组(P<0.01),且二者在扁平苔藓皮损中的表达呈正相关(r1=0.391,P1=0.032;r2=0.375,P2=0.041).结论 HGF和MMP-9的高表达可能参与了扁平苔藓的发病.%Objective To explore the expression of hepatocyte growth factor( HGF ) and metalloproteinase - 9( MMP - 9 ) in lichen planus,and investigate the function in pathogenesis of lichen planus.Methods The expression of HGF and MMP - 9 was assayed by RT - PCR and immunohistochemistry in 30 LP lesions and 30 normal skins.Results The expression of HGF and MMP - 9 in LP lesions was stronger than that in normal skins( P <0.01 ),and HGF was positively related to the expression of MMP -9 in LP lesions ( r1 =0.391 ,P1 = 0.032; r2 = 0.375, P2 = 0.041 ).Conclusion The increased expression of HGF and MMP -9 may contribute to the formation and progression of lichen planus.

  12. HGF-transgenic MSCs can improve the effects of tissue self-repair in a rabbit model of traumatic osteonecrosis of the femoral head.

    Directory of Open Access Journals (Sweden)

    Qian Wen

    Full Text Available BACKGROUND: Osteonecrosis of the femoral head (ONFH is generally characterized as an irreversible disease and tends to cause permanent disability. Therefore, understanding the pathogenesis and molecular mechanisms of ONFH and developing effective therapeutic methods is critical for slowing the progress of the disease. METHODOLOGY/PRINCIPAL FINDINGS: In this study, an experimental rabbit model of early stage traumatic ONFH was established, validated, and used for an evaluation of therapy. Computed tomography (CT and magnetic resonance (MR imaging confirmed that this model represents clinical Association Research Circulation Osseous (ARCO phase I or II ONFH, which was also confirmed by the presence of significant tissue damage in osseous tissue and vasculature. Pathological examination detected obvious self-repair of bone tissue up to 2 weeks after trauma, as indicated by revascularization (marked by CD105 and expression of collagen type I (Col I, osteocalcin, and proliferating cell nuclear antigen. Transplantation of hepatocyte growth factor (HGF-transgenic mesenchymal stem cells (MSCs 1 week after trauma promoted recovery from ONFH, as evidenced by a reversed pattern of Col I expression compared with animals receiving no therapeutic treatment, as well as increased expression of vascular endothelial growth factor. CONCLUSIONS/SIGNIFICANCE: These results indicate that the transplantation of HGF-transgenic MSCs is a promising method for the treatment for ONFH and suggest that appropriate interference therapy during the tissue self-repair stage contributes to the positive outcomes. This study also provides a model for the further study of the ONFH etiology and therapeutic interventions.

  13. THE PROGNOSTIC RESEARCH AND RELATIONSHIP BETWEEN HELICOBACTER PYLORI AND EXPRESSION OF C-MET ONCOGENE IN GASTRIC CARCINOMAS%胃癌中幽门螺杆菌感染与原癌基因c-met表达及预后研究

    Institute of Scientific and Technical Information of China (English)

    庄小强; 孙桂华; 林三仁; 郑杰; 李燕; 王立新

    2001-01-01

    Aim To determine whether there is a relationship betweenHelicobacter pylori(Hp) and expression of c-met oncogene in gastric mucosal lesions,and prognostic significance of gastric carcinomas(GC).Methods Hp and expression of c-met were investigated in 145 gastric mucosal lesions by using immunohistochemistry,and Hp was examined by Warthin-starry method.Results For chronic superficial gastritis (CSG),chronic atrophic gastritis and intestinal mataplasia (CAG+IM),dysplasia(DYS),early GC and advanced GC,the expression rates of c-met were 25.53%,51.28%,61.54%,66.67% and 68.42%.The positive rates were higher in CAG+IM,DYS and GC than in CSG(P<0.05).Expressions of c-met of Hp positive were higher than Hp negative in intestinal GC(P<0.05).Expressions of c-met were correlated significantly with Hp positive in CAG+IM,DYS and GC.The survival rate of patients with Hp non-infection.Conclusions Hp infection and expression of c-met may be associated with in proliferation and malignant transformation of gastric mucosa.Hp infection is associated with prognosis of gastric carcinoma.%目的 研究幽门螺杆菌(Hp)感染的胃癌(GC)组织中c-met表达及(Hp)感染对胃癌预后的影响。方法 经病理证实,不同病变胃粘膜145例以免疫组化检测c-met基因表达,以W-S法及快速尿素酶试验检测(Hp)感染。结果 在浅表性胃炎(CSG)、萎缩肠化生胃炎(CAG+IM)、异型增生(DYS)、早期GC和进展期GC中,c-met基因表达率分别为25.53%,51.28%,61.54%,66.67%和68.42%,CAG+IM、DYS、GC均显著高于CSG(P<0.05)。肠型胃癌c-met阳性表达与(Hp)感染密切相关。CAG+IM,DYS和GC组c-met阳性表达(Hp)感染者明显高于阴性组。(Hp)阳性者5年生存期显著短于(Hp)阴性者。结论 (Hp)感染和c-met表达与胃粘膜增殖和恶化有关,前者也与胃癌预后有关。

  14. The Serum Levels and Clinical Significance of HGF and KL-6 in Patients of Interstitial Lung Disease with Reumatoid Arthritis%HGF 与 KL-6在 RA-ILD 患者血清中的表达水平及意义

    Institute of Scientific and Technical Information of China (English)

    王树刚; 王晓东; 慈春增; 于杰; 李向东

    2015-01-01

    目的:通过检测肝细胞生长因子( HGF)和人Ⅱ型肺泡细胞表面抗原( KL-6)在类风湿关节炎合并肺间质病变( RA-ILD)患者血清中的表达水平,探讨其在RA-ILD中的意义。方法采用ELISA法检测60例RA(包括28例RA-ILD)和20例健康体检者血清HGF,KL-6的表达水平。结果 RA-ILD组中HGF的含量明显低于单纯RA组及对照组,差异有统计学意义(P<0.05);RA-ILD组中KL-6的含量明显高于单纯RA组及对照组,差异有统计学意义(P<0.05);且HGF与KL-6呈负相关关系;在RA-ILD组,HGF与疾病活动性指标DAS28评分呈负相关关系,KL-6与疾病活动性指标DAS28评分呈正相关关系。结论 HGF和KL-6可能参与RA-ILD的发生发展过程,HGF和KL-6可作为判断RA-ILD活动的指标。%Objective To analyze the hepatocyte growth factor( HGF) and human typeⅡalveolar cell sur-face antigen( KL-6 ) serum levels and their clinical significance in the patients of interstitial lung disease with rheumatoid arthritis( RA-ILD) .Methods The serum levels of HGF and KL-6 were detected in 60 patients with rheumatoid arthritis ( including 28 patients with interstitial lung disease) and 20 healthy individuals by means of enzyme linked immunosor-bent assay( ELISA) .Results In patients of RA-ILD,the serum levels of HGF was lower than simple RA group and the control group,and the serum levels of KL-6 was higher than simple RA group and the control group,there were signifi-cantly statistical difference(P<0.05).The levels of HGF and KL-6 were negatively related;In group RA-ILD,HGF was negatively correlated with disease activity index DAS28 score,KL-6 was positively correlated with disease activity index DAS28 score.Conclusion The cytokines of HGF and KL-6 may play important roles in the development of RA-ILD;perhaps they can be seen as indexes of RA-ILD activities.

  15. NK4 with Anti-tumor Activity: A Competitive Antagonist against HGF%肝细胞生长因子抑制剂——NK4的抗肿瘤作用

    Institute of Scientific and Technical Information of China (English)

    蔡超; 侯玲玲; 胡红刚

    2014-01-01

    肝细胞生长因子(hepatocyte growth factor,HGF)是一种多功能的细胞因子,其生物学活性由c-Met蛋白所介导.HGF/c-Met信号通路在肿瘤生成、侵袭、转移以及肿瘤新生血管生成方面起重要促进作用.因此,HGF/c-Met信号转导通路可以作为抗肿瘤药物设计的靶点.其中,HGF α链N端447个氨基酸组成的NK4蛋白是HGF的特异性拮抗剂,它不仅通过抑制HGF/c-Met系统的信号转导发挥抗肿瘤效应;而且可以通过拮抗HGF和其它血管生成因子如成纤维细胞生长因子(fibroblast growth factors,FGF)、血管内皮生长因子(vascular endothelial growth factor,VEGF)的活性,进而抑制肿瘤新生血管生成,最终导致肿瘤细胞的凋亡.NK4的这种双重抗肿瘤功能使其成为一类很有前景的新型抗肿瘤药物.本文就NK4对肿瘤的抑制作用及其机制的研究进展进行综述.

  16. Ezrin ubiquitylation by the E3 ubiquitin ligase, WWP1, and consequent regulation of hepatocyte growth factor receptor activity.

    Directory of Open Access Journals (Sweden)

    Rania F Zaarour

    Full Text Available The membrane cytoskeleton linker ezrin participates in several functions downstream of the receptor Met in response to Hepatocyte Growth Factor (HGF stimulation. Here we report a novel interaction of ezrin with a HECT E3 ubiquitin ligase, WWP1/Aip5/Tiul1, a potential oncogene that undergoes genomic amplification and overexpression in human breast and prostate cancers. We show that ezrin binds to the WW domains of WWP1 via the consensus motif PPVY(477 present in ezrin's C-terminus. This association results in the ubiquitylation of ezrin, a process that requires an intact PPVY(477 motif. Interestingly ezrin ubiquitylation does not target the protein for degradation by the proteasome. We find that ezrin ubiquitylation by WWP1 in epithelial cells leads to the upregulation of Met level in absence of HGF stimulation and increases the response of Met to HGF stimulation as measured by the ability of the cells to heal a wound. Interestingly this effect requires ubiquitylated ezrin since it can be rescued, after depletion of endogenous ezrin, by wild type ezrin but not by a mutant of ezrin that cannot be ubiquitylated. Taken together our data reveal a new role for ezrin in Met receptor stability and activity through its association with the E3 ubiquitin ligase WWP1. Given the role of Met in cell proliferation and tumorigenesis, our results may provide a mechanistic basis for understanding the role of ezrin in tumor progression.

  17. The scatter factor signaling pathways as therapeutic associated target in cancer treatment.

    Science.gov (United States)

    Accornero, P; Pavone, L M; Baratta, M

    2010-01-01

    Receptor tyrosine kinases (RTKs) are key regulators of critical cellular processes such as proliferation, differentiation, neo-vascularization, and tissue repair. In addition to their importance in the regulation of normal physiology, aberrant expression of certain RTKs has also been associated to the development and progression of many types of cancer. c-Met and RON are two RTKs with closely related sequences, structural homology, and similar functional properties. Both these receptors, once activated by their respective ligands, the Hepatocyte Growth Factor/Scatter Factor (HGF/SF1) and the Macrophage Stimulating Protein/Scatter Factor 2 (MSP/SF2), can induce cell migration, invasion and proliferation. Soon after its discovery in the mid-1980s, c-Met attracted a great interest because of its role in modulating cell motility. Moreover, the causal role for c-Met activating mutations in human cancer propelled an intensive drug discovery effort throughout academic institutions and pharmaceutical companies. While c-Met is now a well-accepted target for anticancer drug design, less is known about the role of RON in cancer and less has been done to target this receptor. In this review we will discuss the biological relevance of c-Met and RON, their deregulation in human cancers and the progress, so far, in identifying c-Met and RON signaling inhibitors. Finally, we will focus on the development of therapeutic strategies and drug efficacy studies based on interfering the scatter factor signaling pathways.

  18. Tumor microenvironment elicits primary resistance to afatinib through HGF secretion%肿瘤微环境中肝细胞生长因子介导H1975肺癌细胞对afatinib产生原发耐药

    Institute of Scientific and Technical Information of China (English)

    康小红; 王立芳; 曹飞; 范方田; 徐振晔

    2013-01-01

    Objective To observe the effects of hepatocyte growth factor (HGF) derived from tumor microenvironment and/or afatinib on the growth of human lung adenocarcinoma H1975 cells and explore the potential mechanisms by which HGF induces primary resistance to afatinib.Methods The effects of HGF,TGF-α and afatinib on the growth of H1975 cells were evaluated by MTT assay.The HGF concentrations of normal human fetal lung fibroblasts MRC-5 cells and human lung adenocarcinoma H1975 cells co-cultured or separately cultured were determined by ELISA assay.Western blot was used to detect the expressions of EGFR and Met signal pathway-related proteins and epithelial-mesenchymal transition (EMT) markers in H1975 cells treated with HGF and/or afatinib.Results The MTT assay showed that H1975 cells were hyposensitive to afatinib in the presence of HGF.The ELISA assay showed that HGF production by H1975 cells was less than 0.1 ng/2.0 × 106 cells,but HGF production by MRC-5 cells was (151.37 ± 2.07) ng/2.0 × 106 cells incubated for 48 h.When H1975 cells and MRC-5 cells were co-cultured for 72 h,the concentration of HGF in the culture supematant was (61.13 ± 16.21) ng/ml.In the presence of HGF,the expression of p-Met,p-Akt and p-ERK proteins in the H1975 cells was markedly up-regulated.afatinib inhibited p-EGFR,but did not affect the expression of p-Met,p-Akt and p-ERK proteins.In the presence of afatinib,HGF up-regulated the expression of vimentin and down-regulated the expression of E-cadherin.Conclusions HGF secreted by stromal cells in the tumor micro-environment may confer resistance to afatinib in H1975 cells by activation of the Met/PI3K/Akt and Met/MAPK/ERK signaling pathways,and is involved in the epithelial-mesenchymal transition process.%目的 观察肿瘤微环境中肝细胞生长因子(HGF)和afatinib对H1975肺癌细胞增殖的影响,探讨肿瘤微环境中HGF介导afatinib耐药的机制.方法 采用四甲基偶氮唑蓝(MTT)法检测肿瘤微环境中HGF、

  19. Efficacy of HGF carried by ultrasound microbubble-cationic nano-liposomes complex for treating hepatic fibrosis in a bile duct ligation rat model, and its relationship with the diffusion-weighted MRI parameters.

    Science.gov (United States)

    Zhang, Shou-hong; Wen, Kun-ming; Wu, Wei; Li, Wen-yan; Zhao, Jian-nong

    2013-12-01

    Hepatic fibrosis is a major consequence of liver aggression. Finding novel ways for counteracting this damaging process, and for evaluating fibrosis with a non-invasive imaging approach, represent important therapeutic and diagnostic challenges. Hepatocyte growth factor (HGF) is an anti-fibrosis cell growth factor that induces apoptosis in activated hepatic stellate cells, reduces excessive collagen deposition, and stimulates hepatocyte regeneration. Thus, using HGF in gene therapy against liver fibrosis is an attractive approach. The aims of the present study were: (i) to explore the efficacy of treating liver fibrosis using HGF expression vector carried by a novel ultrasound microbubble delivery system; (ii) to explore the diagnostic interest of diffusion-weighted MRI (DWI-MRI) in evaluating liver fibrosis. We established a rat model of hepatic fibrosis. The rats were administered HGF linked to novel ultrasound micro-bubbles. Progression of hepatic fibrosis was evaluated by histopathology, hydroxyproline content, and DWI-MRI to determine the apparent diffusion coefficient (ADC). Our targeted gene therapy produced a significant anti-fibrosis effect, as shown by liver histology and significant reduction of hydroxyproline content. Moreover, using DWI-MRI, the b value (diffusion gradient factor) was equal to 300s/mm(2), and the ADC values significantly decreased as the severity of hepatic fibrosis increased. Using this methodology, F0-F2 could be distinguished from F3 and F4 (Pmicrobubble-cationic nano-liposome complex for gene delivery. The data indicate that, this approach is efficient to counteract the fibrosis process. DWI-MRI appears a promising imaging technique for evaluating liver fibrosis.

  20. Development of a 3D Tissue Culture-Based High-Content Screening Platform That Uses Phenotypic Profiling to Discriminate Selective Inhibitors of Receptor Tyrosine Kinases.

    Science.gov (United States)

    Booij, Tijmen H; Klop, Maarten J D; Yan, Kuan; Szántai-Kis, Csaba; Szokol, Balint; Orfi, Laszlo; van de Water, Bob; Keri, Gyorgy; Price, Leo S

    2016-10-01

    3D tissue cultures provide a more physiologically relevant context for the screening of compounds, compared with 2D cell cultures. Cells cultured in 3D hydrogels also show complex phenotypes, increasing the scope for phenotypic profiling. Here we describe a high-content screening platform that uses invasive human prostate cancer cells cultured in 3D in standard 384-well assay plates to study the activity of potential therapeutic small molecules and antibody biologics. Image analysis tools were developed to process 3D image data to measure over 800 phenotypic parameters. Multiparametric analysis was used to evaluate the effect of compounds on tissue morphology. We applied this screening platform to measure the activity and selectivity of inhibitors of the c-Met and epidermal growth factor (EGF) receptor (EGFR) tyrosine kinases in 3D cultured prostate carcinoma cells. c-Met and EGFR activity was quantified based on the phenotypic profiles induced by their respective ligands, hepatocyte growth factor and EGF. The screening method was applied to a novel collection of 80 putative inhibitors of c-Met and EGFR. Compounds were identified that induced phenotypic profiles indicative of selective inhibition of c-Met, EGFR, or bispecific inhibition of both targets. In conclusion, we describe a fully scalable high-content screening platform that uses phenotypic profiling to discriminate selective and nonselective (off-target) inhibitors in a physiologically relevant 3D cell culture setting.

  1. 外源性HGF基因转染对肺动脉高压兔肺血流灌注及肺动脉压力的影响%Effect of exogenous HGF gene transfection on pulmonary perfusion and pressure in pulmonary artery hypertension in rabbits

    Institute of Scientific and Technical Information of China (English)

    王伟; 张芳; 谢悦; 张宜乾; 吴树明

    2011-01-01

    AIM: To investigate the feasibility of exogenous hepatocyte growth factor (HGF) gene transfection to promote pulmonary collateral angiogenesis, improve pulmonary perfusion and reduce pulmonary artery pressure in the rabbit model of pulmonary artery hypertension (PAH). METHODS: The model rabbits of PAH were randomly divided into control group, empty vector group and HGF gene transfection group. The rabbits in HGF gene transfection group were transfected with Ad - HGF via intratracheal instillation. Pulmonary hemodynamic indicators were monitored in the 4th week after HGF gene transfection. Density of pulmonary vessels was examined with double - labeling immunofluorescence (endo-thelial cells were labeled with anti - FVK and vascular smooth muscle cells were marked with anti - a - SMA). Double - labeling immunofluorescence of FTTC - lectin and anti - a - SMA was also performed to evaluate the pulmonary blood perfusion. RESULTS: Four weeks after transfection, the density of pulmonary arterioles of the rabbits in HGF gene transfection group was higher than that in control group and empty vector group ( P < 0.05 ) , which was confirmed by double - labeling immunofluorescence. Pulmonary blood perfusion in HGF group was significantly increased compared with that in the other two groups, in which pulmonary arterial stenosis and occlusion were observed. The mean pulmonary artery pressure in HGF transfection group was much lower than that in control group and empty vector group (P <0.05). CONCLUSION: Four weeks after intratracheal adenoviral - mediated HGF gene transfection, pulmonary collateral vessels and pulmonary perfusion increase, and the pulmonary artery pressure is effectively reduced.%目的:探讨外源性肝细胞生长因子(HGF)基因转染高动力性肺动脉高压家兔后促进侧支肺血管生成、改善肺血流灌注、降低肺动脉压力的可行性.方法:将肺动脉高压兔随机分为对照组、空病毒组和HGF基因转染组;HGF基因转染

  2. 小眼畸形转录因子和c-Met及组织蛋白酶-K在黑色素病变中的表达及意义%Expressions and significances of microphthalmia transcription factor, c-Met and cathepsin-K in malignant melanoma and nevi

    Institute of Scientific and Technical Information of China (English)

    李良; 张正祥; 吴波; 缪国良; 饶秋

    2014-01-01

    目的 探讨小眼畸形转录因子(microphthalmia transcription factor,MITF)、e-Met和组织蛋白酶-K (cathepsin-K)在恶性黑色素瘤、痣和非典型性痣中的表达及意义.方法 32例恶性黑色素瘤(恶黑组)、13例普通痣患者(普通痣组)和6例非典型性痣患者(非典型痣组)的组织标本,采用免疫组织化学法检测3组组织中MITF、c-Met和cathepsin-K的表达情况.结果 MITF、c-Met表达于黑色素细胞的细胞核和细胞质,cathepsin-K表达于细胞质和细胞膜;MITF、c-Met和cathepsin-K阳性表达率恶黑组分别为93.8%、90.6%和93.8%,普通痣组分别为92.3%、92.3%和100.0%,非典型痣组分别为100.0%、100.0%和100.0%,3组间比较差异均无统计学意义(P>0.05);恶黑组MITF((卅))、c-Met((卅))及cathepsin-K((卅))阳性率高于普通痣组和非典型痣组(P<0.05);恶黑组转移者MITF、c-Met及cathepsin-K阳性率明显高于非转移者(P<0.05),结节性恶性黑色素瘤者MITF、c-Met及cathepsin-K阳性率高于表浅扩散性恶性黑色素瘤者(P<0.05);恶黑组转移者MITF、c-Met及cathepsin-K阳性率均为100%,高于HMB-45阳性率(75.0%)(P<0.05).结论 MITF、c-Met及cathepsin-K对恶性黑色素瘤的诊断及评估其进展和生物学行为有重要价值.

  3. Stimulation of oral fibroblast chemokine receptors identifies CCR3 and CCR4 as potential wound healing targets.

    Science.gov (United States)

    Buskermolen, Jeroen K; Roffel, Sanne; Gibbs, Susan

    2017-11-01

    The focus of this study was to determine which chemokine receptors are present on oral fibroblasts and whether these receptors influence proliferation, migration, and/or the release of wound healing mediators. This information may provide insight into the superior wound healing characteristics of the oral mucosa. The gingiva fibroblasts expressed 12 different chemokine receptors (CCR3, CCR4, CCR6, CCR9, CCR10, CXCR1, CXCR2, CXCR4, CXCR5, CXCR7, CX3CR1, and XCR1), as analyzed by flow cytometry. Fourteen corresponding chemokines (CCL5, CCL15, CCL20, CCL22, CCL25, CCL27, CCL28, CXCL1, CXCL8, CXCL11, CXCL12, CXCL13, CX3CL1, and XCL1) were used to study the activation of these receptors on gingiva fibroblasts. Twelve of these fourteen chemokines stimulated gingiva fibroblast migration (all except for CXCL8 and CXCL12). Five of the chemokines stimulated proliferation (CCL5/CCR3, CCL15/CCR3, CCL22/CCR4, CCL28/CCR3/CCR10, and XCL1/XCR1). Furthermore, CCL28/CCR3/CCR10 and CCL22/CCR4 stimulation increased IL-6 secretion and CCL28/CCR3/CCR10 together with CCL27/CCR10 upregulated HGF secretion. Moreover, TIMP-1 secretion was reduced by CCL15/CCR3. In conclusion, this in-vitro study identifies chemokine receptor-ligand pairs which may be used in future targeted wound healing strategies. In particular, we identified the chemokine receptors CCR3 and CCR4, and the mucosa specific chemokine CCL28, as having an predominant role in oral wound healing by increasing human gingiva fibroblast proliferation, migration, and the secretion of IL-6 and HGF and reducing the secretion of TIMP-1. © 2017 The Authors. Journal of Cellular Physiology Published by wiley periodicals, Inc.

  4. 猎隼肾脏的组织学观察及HGF在肾脏中的表达%Histological Observation and Expression of HGF of Falco Cherrug Kidney

    Institute of Scientific and Technical Information of China (English)

    王昱

    2015-01-01

    应用组织学方法观察了猎隼肾脏的组织结构,利用免疫组织化学方法检测了肝细胞生长因子(hepatocyte growth factor,HGF)在肾脏中的表达。结果表明:与大多数鸟类的肾脏结构相似,猎隼的肾脏主要由许多肾单位、集合管和少量结缔组织构成,但猎隼的肾脏皮质与髓质分界较明显。肾单位由肾小体和与之相连的上皮样肾小管构成。肾小体由一团蟠曲的毛细血管构成。近曲小管由单层立方上皮细胞组成,上皮细胞游离面有刷状缘。远曲小管和集合管管腔较大,腔面无刷状缘。肾小管和集合管上皮细胞都呈HGF免疫反应阳性。表明HGF可能参与调节正常组织细胞的生命活动。%To provide basic data for the study on zoology, physiology and zootomy, the structural features of the kidney of Falco cherrug were studied by microscopy and expression of HGF was measured by immunohistochem-ical method. The result shows that similar to most birds’ kidney, the kidney of Falco cherrug consisted mainly of nephrons, collecting ducts and a little connective tissue, but the verge of cortex and medulla in kidney was clear. The nephron comprised renal corpuscle and a renal tubule. The structure of glomerular capillary was made from convoluted capillaries. The proximal convoluted tubule was lined with a well-developed brush border. The lumen diameters of both distal convoluted tubule and collecting duct were large, and their cell apex had no a bush border. HGF appeared to be expressed in the epithelial cells of the renal tubular and collecting duct. The evidence indicates that HGF might be involved in the regulation of the normal histiocyte life activities.

  5. Three-dimensional lung tumor microenvironment modulates therapeutic compound responsiveness in vitro--implication for drug development.

    Directory of Open Access Journals (Sweden)

    Jason E Ekert

    Full Text Available Three-dimensional (3D cell culture is gaining acceptance in response to the need for cellular models that better mimic physiologic tissues. Spheroids are one such 3D model where clusters of cells will undergo self-assembly to form viable, 3D tumor-like structures. However, to date little is known about how spheroid biology compares to that of the more traditional and widely utilized 2D monolayer cultures. Therefore, the goal of this study was to characterize the phenotypic and functional differences between lung tumor cells grown as 2D monolayer cultures, versus cells grown as 3D spheroids. Eight lung tumor cell lines, displaying varying levels of epidermal growth factor receptor (EGFR and cMET protein expression, were used to develop a 3D spheroid cell culture model using low attachment U-bottom plates. The 3D spheroids were compared with cells grown in monolayer for 1 EGFR and cMET receptor expression, as determined by flow cytometry, 2 EGFR and cMET phosphorylation by MSD assay, and 3 cell proliferation in response to epidermal growth factor (EGF and hepatocyte growth factor (HGF. In addition, drug responsiveness to EGFR and cMET inhibitors (Erlotinib, Crizotinib, Cetuximab [Erbitux] and Onartuzumab [MetMab] was evaluated by measuring the extent of cell proliferation and migration. Data showed that EGFR and cMET expression is reduced at day four of untreated spheroid culture compared to monolayer. Basal phosphorylation of EGFR and cMET was higher in spheroids compared to monolayer cultures. Spheroids showed reduced EGFR and cMET phosphorylation when stimulated with ligand compared to 2D cultures. Spheroids showed an altered cell proliferation response to HGF, as well as to EGFR and cMET inhibitors, compared to monolayer cultures. Finally, spheroid cultures showed exceptional utility in a cell migration assay. Overall, the 3D spheroid culture changed the cellular response to drugs and growth factors and may more accurately mimic the natural

  6. Three-dimensional lung tumor microenvironment modulates therapeutic compound responsiveness in vitro--implication for drug development.

    Science.gov (United States)

    Ekert, Jason E; Johnson, Kjell; Strake, Brandy; Pardinas, Jose; Jarantow, Stephen; Perkinson, Robert; Colter, David C

    2014-01-01

    Three-dimensional (3D) cell culture is gaining acceptance in response to the need for cellular models that better mimic physiologic tissues. Spheroids are one such 3D model where clusters of cells will undergo self-assembly to form viable, 3D tumor-like structures. However, to date little is known about how spheroid biology compares to that of the more traditional and widely utilized 2D monolayer cultures. Therefore, the goal of this study was to characterize the phenotypic and functional differences between lung tumor cells grown as 2D monolayer cultures, versus cells grown as 3D spheroids. Eight lung tumor cell lines, displaying varying levels of epidermal growth factor receptor (EGFR) and cMET protein expression, were used to develop a 3D spheroid cell culture model using low attachment U-bottom plates. The 3D spheroids were compared with cells grown in monolayer for 1) EGFR and cMET receptor expression, as determined by flow cytometry, 2) EGFR and cMET phosphorylation by MSD assay, and 3) cell proliferation in response to epidermal growth factor (EGF) and hepatocyte growth factor (HGF). In addition, drug responsiveness to EGFR and cMET inhibitors (Erlotinib, Crizotinib, Cetuximab [Erbitux] and Onartuzumab [MetMab]) was evaluated by measuring the extent of cell proliferation and migration. Data showed that EGFR and cMET expression is reduced at day four of untreated spheroid culture compared to monolayer. Basal phosphorylation of EGFR and cMET was higher in spheroids compared to monolayer cultures. Spheroids showed reduced EGFR and cMET phosphorylation when stimulated with ligand compared to 2D cultures. Spheroids showed an altered cell proliferation response to HGF, as well as to EGFR and cMET inhibitors, compared to monolayer cultures. Finally, spheroid cultures showed exceptional utility in a cell migration assay. Overall, the 3D spheroid culture changed the cellular response to drugs and growth factors and may more accurately mimic the natural tumor

  7. Three-Dimensional Lung Tumor Microenvironment Modulates Therapeutic Compound Responsiveness In Vitro – Implication for Drug Development

    Science.gov (United States)

    Ekert, Jason E.; Johnson, Kjell; Strake, Brandy; Pardinas, Jose; Jarantow, Stephen; Perkinson, Robert; Colter, David C.

    2014-01-01

    Three-dimensional (3D) cell culture is gaining acceptance in response to the need for cellular models that better mimic physiologic tissues. Spheroids are one such 3D model where clusters of cells will undergo self-assembly to form viable, 3D tumor-like structures. However, to date little is known about how spheroid biology compares to that of the more traditional and widely utilized 2D monolayer cultures. Therefore, the goal of this study was to characterize the phenotypic and functional differences between lung tumor cells grown as 2D monolayer cultures, versus cells grown as 3D spheroids. Eight lung tumor cell lines, displaying varying levels of epidermal growth factor receptor (EGFR) and cMET protein expression, were used to develop a 3D spheroid cell culture model using low attachment U-bottom plates. The 3D spheroids were compared with cells grown in monolayer for 1) EGFR and cMET receptor expression, as determined by flow cytometry, 2) EGFR and cMET phosphorylation by MSD assay, and 3) cell proliferation in response to epidermal growth factor (EGF) and hepatocyte growth factor (HGF). In addition, drug responsiveness to EGFR and cMET inhibitors (Erlotinib, Crizotinib, Cetuximab [Erbitux] and Onartuzumab [MetMab]) was evaluated by measuring the extent of cell proliferation and migration. Data showed that EGFR and cMET expression is reduced at day four of untreated spheroid culture compared to monolayer. Basal phosphorylation of EGFR and cMET was higher in spheroids compared to monolayer cultures. Spheroids showed reduced EGFR and cMET phosphorylation when stimulated with ligand compared to 2D cultures. Spheroids showed an altered cell proliferation response to HGF, as well as to EGFR and cMET inhibitors, compared to monolayer cultures. Finally, spheroid cultures showed exceptional utility in a cell migration assay. Overall, the 3D spheroid culture changed the cellular response to drugs and growth factors and may more accurately mimic the natural tumor

  8. Clinical Significance of Measurement on the Changes of Plasma Leptin and Serum VEGF, HGF Levels After Hemodialysis in Patients with Chronic Renal Failure%慢性肾功能衰竭患者血透前后血浆leptin和血清VEGF、HGF检测的临床意义

    Institute of Scientific and Technical Information of China (English)

    顾涛

    2012-01-01

    Objective To explor the clinical significance of changes on plasma leptin and serum VEGF,HGF levels after hemodi-alysis in patients with chronic renal failure. Methods Plasma leptin (with RIA) , serum VEGF, HGF(with ELISA) levels were measured in 32 patients with chronic renal failure both before and after hemodialysis as well as in 35 normal healthy controls. Results Before hemodialysis plasma leptin and serum VEGF,HGF levels were significantiy higher in the patients than those in controls (P < 0.05). Conclusion The levels of leptin, VEGF and HGF were significantly increased in patients with chronic renal failure. Hemodialysis could increase the clearance rate of leptin, VEGF and HGF and might be useful for clinical assessment.%目的:探讨了慢性肾功能衰竭(CRF)患者血透前后血浆leptin和血清VEGF、HGF水平的变化及意义.方法:应用放射免疫分析和酶联法对32例CRF患者进行了血透前后血浆leptin和血清VEGF、HGF检测,并与35名正常健康人作比较.结果:CRF在血透前血浆leptin和血清VEGF、HGF水平非常显著地高于正常人组(P<0.01).结论:CRF患者存在高leptin、VEGF、HGF血症.血透可增加leptin、VEGF和HGF的清除率,具有重要的临床价值.

  9. Tumors initiated by constitutive Cdk2 activation exhibit transforming growth factor beta resistance and acquire paracrine mitogenic stimulation during progression

    DEFF Research Database (Denmark)

    Corsino, P.; Davis, B.; Law, M.;

    2007-01-01

    mediate some of the transforming effects that result from cyclin D1 overexpression in human breast cancers. MMTV-DIK2 cancer cells express the hepatocyte growth factor (HGF) receptor, c-Met. MMTV-D1K2 cancer cells also secrete transforming growth factor beta (TGF beta), but are relatively resistant to TGF......Cyclin D1/cyclin-dependent kinase 2 (Cdk2) complexes are present at high frequency in human breast cancer cell lines, but the significance of this observation is unknown. This report shows that expression of a cyclin D1-Cdk2 fusion protein under the control of the mouse mammary tumor virus (MMITV...... beta antiproliferative effects. Fibroblasts derived from MMTV-DIK2 tumors secrete factors that stimulate the proliferation of MMTV-D1K2 cancer cells, stimulate c-Met tyrosine phosphorylation, and stimulate the phosphorylation of the downstream signaling intermediates p70(s6k) and Akt on activating...

  10. 聚束蛋白和肝细胞生长因子在鼻内翻性乳头状瘤中的表达及临床意义%Expression and significances of FSCN1 and HGF in nasal inverted papilloma

    Institute of Scientific and Technical Information of China (English)

    袁林林; 娄卫华; 桑建中

    2012-01-01

    Objective: To study the expressions of FSCN1 and HGF in nasal inverted papilloma(NIP)and explore their role in occurrence and development of this disease. Method: Immunohistochemical method was used to determine the expression of FSCN1 and HGF in 12 cases of chronic hypertrophic rhinitis. 40 cases of NIP and 14 cases of NIP with malignant transformation. Result:FSCN1 was expressed in 52. 5% of NIP, 78. 6% of NIP with malignant transformation and 8. 3% of inferior turbinate of chronic hypertrophic rhinitis. Expression of FSCN1 was significantly higher in NIP and NIP with malignant transformation than in inferior turbinate(P<0. 05). HGF was expressed in 85. 7% of NIP with malignant transformation and 8. 3% of inferior turbinate. Expression of HGF was significantly higher in NIP with malignant transformation than in inferior turbinate(P<0. 05). HGF was expressed in 40. 0% of NIP,which was higher than that of inferior turbinate. Expression of HGF was positively related to expression of FSCN1 in NIP and NIP with malignant transformation. Conclusion: The abnormal expression of FSCN1 and HGF may be closely correlated with NIP and its malignant process. Analysis of FSCN1 and HGF expression in NIP may be useful in predicting malignant transformation.%目的:探讨聚束蛋白(FSCN1)和肝细胞生长因子(HGF)在鼻内翻性乳头状瘤(NIP)中的表达及其在该病恶性转化中的临床意义.方法:应用免疫组织化学方法检测12例慢性肥厚性鼻炎下鼻甲黏膜组织(对照组)、40例NIP(NIP组)及14例NIP恶变(恶变组)中FSCN1和HGF的表达情况.结果:在NIP组和恶变组中FSCN1的阳性表达率分别为52.5%和78.6%,均明显高于对照组(8.3%),差异均有统计学意义(均P<0.05).恶变组中HGF的表达率为85.7%,显著高于对照组,差异有统计学意义(P<0.05).NIP组中HGF的阳性表达率为40.0%,高于对照组,但两者之间的差异无统计学意义(P>0.05).FSCN1/HGF在NIP组和恶变组

  11. Somatostatin receptors

    DEFF Research Database (Denmark)

    Møller, Lars Neisig; Stidsen, Carsten Enggaard; Hartmann, Bolette

    2003-01-01

    therefore been acknowledged to be a third endogenous ligand at SRIF receptors. This review goes through mechanisms of signal transduction, pharmacology, and anatomical distribution of SRIF receptors. Structurally, SRIF receptors belong to the superfamily of G protein-coupled (GPC) receptors, sharing....... The generation of knock-out (KO) mice, intended as a means to define the contributions made by individual receptor subtypes, necessarily marks but an approximation. Furthermore, we must now take into account the stunning complexity of receptor co-operation indicated by the observation of receptor homo......-peptides, receptor agonists and antagonists. Relatively long half lives, as compared to those of the endogenous ligands, have been paramount from the outset. Motivated by theoretical puzzles or the shortcomings of present-day diagnostics and therapy, investigators have also aimed to produce subtype...

  12. Loss of α1,6-fucosyltransferase suppressed liver regeneration: implication of core fucose in the regulation of growth factor receptor-mediated cellular signaling.

    Science.gov (United States)

    Wang, Yuqin; Fukuda, Tomohiko; Isaji, Tomoya; Lu, Jishun; Gu, Wei; Lee, Ho-Hsun; Ohkubo, Yasuhito; Kamada, Yoshihiro; Taniguchi, Naoyuki; Miyoshi, Eiji; Gu, Jianguo

    2015-02-05

    Core fucosylation is an important post-translational modification, which is catalyzed by α1,6-fucosyltransferase (Fut8). Increased expression of Fut8 has been shown in diverse carcinomas including hepatocarcinoma. In this study, we investigated the role of Fut8 expression in liver regeneration by using the 70% partial hepatectomy (PH) model, and found that Fut8 is also critical for the regeneration of liver. Interestingly, we show that the Fut8 activities were significantly increased in the beginning of PH (~4d), but returned to the basal level in the late stage of PH. Lacking Fut8 led to delayed liver recovery in mice. This retardation mainly resulted from suppressed hepatocyte proliferation, as supported not only by a decreased phosphorylation level of epidermal growth factor (EGF) receptor and hepatocyte growth factor (HGF) receptor in the liver of Fut8(-/-) mice in vivo, but by the reduced response to exogenous EGF and HGF of the primary hepatocytes isolated from the Fut8(-/-) mice. Furthermore, an administration of L-fucose, which can increase GDP-fucose synthesis through a salvage pathway, significantly rescued the delayed liver regeneration of Fut8(+/-) mice. Overall, our study provides the first direct evidence for the involvement of Fut8 in liver regeneration.

  13. 促肝细胞生长素对重度烧伤所致肝脏活性酶异常的疗效%Therapeutic effect of HGF on liver enzyme abnormalities in burned patients

    Institute of Scientific and Technical Information of China (English)

    卢强; 王淑娟; 张宏山; 王晓霞; 郑莉

    2011-01-01

    [Objective] To observe the therapeutic effect of HGF on liver enzyme abnormalities in burned patients. [Methods] 76 burned patients with liver enzyme abnormalities were randomly divided into two groups.38 patients were treated only by normal burned method and the other 38 patients were treated by normal burned method and HGFO. ALT, AST, 7 - GT and ALP were determined before injection of HGF. 5th day and 10th day during the treatment and analyzed. [Results] There were significant difference in these parameters in treat group(P 0.05). There were significant difference in these parameters between the two groups (P<0.05). [Conclusion] HGF may decline the level of liver enzymes and reduce the injury of hepatic cell in burned patients.%[目的]观察促肝细胞生长素对重度烧伤所致肝脏损伤引起的酶学异常的临床治疗效果.[方法]对76例重度烧伤合并肝脏酶学异常的患者随机分为治疗组和对照组,每组38人.治疗组给予常规烧伤治疗并静脉滴注加入促肝细胞生长素80mg的5%葡萄糖注射液250 ml,1次/d,连续治疗10d.对照组仅给予常规烧伤治疗.两组均于治疗前和治疗后第5、第10天抽取患者静脉血,检测血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、γ-谷氨酰转肽酶(γ- GT)、碱性磷酸酶(ALP)水平,并进行比较分析.[结果]治疗组用药前与治疗5、10d后ALT、AST、γ- GT、ALP检查结果比较,差异有统计学意义(P<0.05).对照组治疗前后检查结果比较差异无统计学意义(P>0.05).治疗组与对照组在治疗后5d、10d分别对检测结果进行比较,差异有统计学意义(P<0.05).[结论]应用促肝细胞生长素可降低烧伤后患者肝脏酶学的异常升高、减轻烧伤患者肝细胞损伤.

  14. Receptor tyrosine kinases as target for anti-cancer therapy.

    Science.gov (United States)

    Brunelleschi, S; Penengo, L; Santoro, M M; Gaudino, G

    2002-01-01

    Receptor tyrosine kinases (RTKs) are cell surface transmembrane proteins responsible for intracellular signal transduction. They are expressed in several cell types and, after activation by growth factor binding, trigger a series of intracellular pathways, leading to a wide variety of cell responses (e.g., differentiation, proliferation, migration and invasion, angiogenesis, survival). Over-expression and/or structural alteration of RTKs family members are often associated to human cancers and tumor cells are known to use RTK transduction pathways to achieve tumor growth, angiogenesis and metastasis. Therefore, RTKs represent pivotal target in approaches of cancer therapy. A number of small molecules acting as RTK inhibitors have been synthesized by pharmaceutical companies and are under clinical trials, are being analyzed in animal models or have been successfully marketed. Ligand-dependent downregulation of RTKs is a critical step for modulating their activity and the adaptor Cbl has been indicated as the key protein involved in negative regulation of RTKs, such as EGF and HGF receptors. These data suggest novel potential pharmacological targets for the treatment of human malignancies associated to oncogenic activation of RTKs.

  15. Ad-HGF基因修饰的胎盘间充质干细胞治疗兔肢体缺血的实验研究%Evaluation of therapeutic effect of Ad-HGF gene modified PMSCs on limb ischemia in rabbit model

    Institute of Scientific and Technical Information of China (English)

    肖凤君; 黄晓东; 王少霞; 王华; 杨月峰; 李沛雨; 王立生

    2016-01-01

    目的:研究重组腺病毒介导肝细胞生长因子( adenoviral vector mediated human hepatocyte growth factor,Ad-HGF)修饰的胎盘源间充质干细胞( placenta-derived mesenchymal stem cells,PMSC)在兔肢体缺血模型中促新生血管生成的作用。方法无菌取足月产妇胎盘胎儿面中心区域胎盘组织,胶原酶消化法分离干细胞,体外培养传代,感染Ad-HGF 48 h后收集细胞用于治疗兔肢体缺血实验。左侧治疗组后肢缺血肌肉组织内多点注射总细胞数5×106/ml Ad-HGF修饰的PMSC,右侧对照组后肢缺血肌肉组织内注射生理盐水。结果治疗后第14天腹主动脉穿刺行数字减影血管造影( digital subtraction angiography,DSA)检查,可见左侧肢体缺血治疗后微血管生成数明显多于未治疗右侧肢体,血管形成能力明显增强。苏木精伊红染色法( HE)后置光镜下观察显示,治疗组毛细血管密度明显大于未治疗组(P<0.05)。实时荧光定量聚合酶链反应(quantitative polymerase chain reaction,qPCR)检测后肢肌肉组织中血管内皮生长因子( vascular endothelial growth factor, VEGF)、碱性成纤维细胞生长因子( basic fibroblast growth factor,bFGF)、HGF的表达明显升高(P<0.05)。结论经Ad-HGF基因修饰的PMSC能明显促进血管新生,加快局部缺血组织血流循环的重建,是治疗肢体慢性缺血的有效手段。%Objective To evaluate the therapeutic effect of hepatocyte growth factor(HGF) gene modified placenta-derived mesenchymal stem cells( PMSCs) on limb ischemia in a rabbit model.Methods The placental tissue was digested with enzyme, cultured and passaged.The PMSCs were characterized by surface marker expression.These cells were infected with adenoviral( Ad)-HGF and intramuscular injected for treatment of limb ischemia in a rabbit model.The blood supply of the limb was detected by digital subtraction

  16. Therapeutic efficacy of antigen-specific vaccination and toll-like receptor stimulation against established transplanted and autochthonous melanoma in mice.

    Science.gov (United States)

    Tormo, Damia; Ferrer, Aleix; Bosch, Pilar; Gaffal, Evelyn; Basner-Tschakarjan, Etiena; Wenzel, Jörg; Tüting, Thomas

    2006-05-15

    Malignant melanoma is an attractive model disease for the development of antigen-specific immunotherapy because many antigens recognized by tumor-specific T cells have been identified. In C57BL/6 mice, genetic immunization with recombinant adenovirus encoding xenogeneic human tyrosinase-related protein 2 (Ad-hTRP2) induces protective but not therapeutic cellular immunity against growth of transplanted B16 melanoma cells. Here, we additionally applied CpG DNA and synthetic double-stranded RNA, which activate the innate immune system via Toll-like receptors (TLR). Both adenoviral vaccination and peritumoral injections of TLR ligands were required for rejection of established B16 melanoma in the skin. To more closely mimic the clinical situation in patients with melanoma, we evaluated this combined immunotherapeutic strategy in genetically modified mice, which overexpress hepatocyte growth factor (HGF) and carry an oncogenic mutation in the cyclin-dependent kinase 4 (CDK4)(R24C). HGF x CDK4(R24C) mice rapidly develop multiple invasive melanomas in the skin following neonatal carcinogen treatment, which spontaneously metastasize to lymph nodes and lungs. Vaccination with Ad-hTRP2 followed by injections of TLR ligands resulted in delayed growth of autochthonous primary melanomas in the skin and reduction in the number of spontaneous lung metastases but did not induce tumor regression. Carcinogen-treated HGF x CDK4(R24C) mice bearing multiple autochthonous melanomas did not reject transplanted B16 melanoma despite treatment with Ad-hTRP2 and TLR ligands, suggesting the development of tumor immunotolerance. Further investigations in our novel genetic melanoma model may help to better understand the role of the immune system in the pathogenesis and treatment of this life-threatening disease.

  17. Integrin-Mediated Signaling in Prostate Cancer: Role of KAI1/CD82 in Regulating Integrin and Androgen Receptor Function During Metastasis

    Science.gov (United States)

    2007-09-01

    recently been successful at generating two immortalized cell lines of PECs using E6 / E7 and hTert. These cells are now past the 100 doublings stage. As...KAI1/CD82 suppresses invasion by inhibiting integrin-dependent crosstalk with c-Met receptor and Src kinases. Oncogene , 25:2367–78. Knudsen, B.S...Zhang, X. A. (2005) J Biol Chem 280(5), 3346-3354 8. Sridhar, S. C., and Miranti, C. K. (2006) Oncogene 25(16), 2367-2378 9. Odintsova, E., Sugiura

  18. 生长激素、肝细胞生长因子和烟酰胺对人胎胰岛细胞的增殖作用%Effect of GH, HGF and NIC on proliferation of human fetal pancreatic islets pancreatic islets in tissue culture

    Institute of Scientific and Technical Information of China (English)

    陈永兵; 严律南; 吴泽建; 张阳德

    2004-01-01

    目的研究生长激素(GH),肝细胞生长因子(HGF)和烟酰胺(NIC)对体外培养的人胎胰岛细胞的增殖作用及其交互作用.方法采用L8(27)正交设计法在体外培养的人胎胰岛细胞的各组中分别加入不同浓度及组合的GH,HGF和NIC,培养48 h后,收集各孔细胞,DTZ染色,计数.结果GH,HGF和NIC均起主要作用,HGF和NIC的交互作用不可忽视,最佳的生长因子组合及适配浓度为GH(100ng/ml)HGF(25ng/ml)NIC(100mmol/L).结论GH,HGF和NIC均能促进体外培养的胰岛细胞的增殖,且组合GH(100ng/ml)HGF(25 ng/ml)NIC(100mmpol/L)的作用最大.

  19. Signal transduction of Helicobacter pylori during interaction with host cell protein receptors of epithelial and immune cells

    Science.gov (United States)

    Pachathundikandi, Suneesh Kumar; Tegtmeyer, Nicole; Backert, Steffen

    2013-01-01

    Helicobacter pylori infections can induce pathologies ranging from chronic gastritis, peptic ulceration to gastric cancer. Bacterial isolates harbor numerous well-known adhesins, vacuolating cytotoxin VacA, protease HtrA, urease, peptidoglycan, and type IV secretion systems (T4SS). It appears that H. pylori targets more than 40 known host protein receptors on epithelial or immune cells. A series of T4SS components such as CagL, CagI, CagY, and CagA can bind to the integrin α5β1 receptor. Other targeted membrane-based receptors include the integrins αvβ3, αvβ5, and β2 (CD18), RPTP-α/β, GP130, E-cadherin, fibronectin, laminin, CD46, CD74, ICAM1/LFA1, T-cell receptor, Toll-like receptors, and receptor tyrosine kinases EGFR, ErbB2, ErbB3, and c-Met. In addition, H. pylori is able to activate the intracellular receptors NOD1, NOD2, and NLRP3 with important roles in innate immunity. Here we review the interplay of various bacterial factors with host protein receptors. The contribution of these interactions to signal transduction and pathogenesis is discussed. PMID:24280762

  20. Hepatocyte growth factor protects endothelial cells against gamma ray irradiation-induced damage

    Institute of Scientific and Technical Information of China (English)

    Shun-ying HU; Hai-feng DUAN; Qing-fang LI; Yue-feng YANG; Jin-long CHEN; Li-sheng WANG; Hua WANG

    2009-01-01

    Aim:To investigate the effect of HGF on proliferation, apoptosis and migratory ability of human vascular endothelial cells against gamma ray irradiation.Methods: ECV304 cells derived from adult human umbilical vein endothelial cells (HUVEC) were irradiated with a single gamma ray dose of 20 Gy. Immunocytochemistry and Western blot analysis were used to detect c-Met protein expression and HGF/c-Met signal pathway. In the HGF-treated groups, ECV304 cells were incubated with HGF (20 or 40 ng/mL) 3 h prior to irradiation. At 48 h post-irradiation, the proliferation of ECV304 cells was measured by MTT assay, the apoptosis was assessed by flow cytometry, and the migratory ability of ECV304 cells was measured by transwell chamber assay.Results: c-Met protein is expressed in ECV304 cells and can be activated by HGF. Gamma ray irradiation inhibits proliferation and migration of ECV304 cells in a dose-dependent manner. HGF significantly promoted the proliferation of ECV304 cells, and flow cytom-etry revealed that HGF can inhibit apoptosis of ECV304 cells. Transwell chamber assay also showed that HGF increases migration activity of endothelial cells.Conclusion: HGF may afford protection to vascular endothelial cells against gamma ray irradiation-induced damage.

  1. Effects of GH,HGF and NIC on proliferation and function of human fetal pancreatic islets in culture%生长激素、肝细胞生长因子和烟酰胺对人胎胰岛细胞体外增殖的影响

    Institute of Scientific and Technical Information of China (English)

    陈永兵; 严律南; 彭珂; 刘立新; 周祥

    2003-01-01

    目的:探讨生长激素(GH),肝细胞生长因子(HGF)和烟酰胺(NIC)对体外培养人胎胰岛细胞增殖的影响.方法:胶原酶消化法制胰岛样细胞团(ICCs),接种于24孔培养板培养,在实验组中分别加入GH(100 μg/L),HGF(25 μg/L)和NIC(10 mmol/L)及其组合,同时设空白组为对照,间日调换培养液并测定胰岛素分泌量,于培养6 d末测定胰岛细胞内胰岛素含量,收集细胞计数,观察细胞有丝分裂相及胰岛细胞分布情况.结果:①在人胎胰岛细胞体外培养第2 d、第4 d、第6 d胰岛素分泌量各实验组均高于空白组(P<0.01),以GH+HGF+NIC组最高, GH+HGF+NIC组与GH+NIC组、GH+HGF组、HGF+NIC组相比,差异无统计学意义,但与GH组、HGF组、NIC组比较,差异有统计学意义(P<0.05).②各组胰岛细胞内胰岛素含量与胰岛样细胞团数均呈正相关,r均大于0.80(P<0.05).结论:GH、HGF、NIC均能显著促进体外培养的人胎胰岛细胞的增殖,胰岛素含量及分泌量增加,3者有协同作用.

  2. Clinical Significance of Determination of Serum Cystatin C (Cys C),Transforming Growth Factor (TGF-β) and Hepatocyte Growth Factor (HGF) Levels in Patients with DM2 Complicated with Nephropathy%DN患者血清Cys C、TGF-β1和HGF检测的临床意义

    Institute of Scientific and Technical Information of China (English)

    武幸福; 陈立侠

    2011-01-01

    目的:探讨了2型糖尿病并发肾病(DN)患者血清胱抑素C(Cys C)、转化生长因子(TGF-β1)和肝细胞因子(HGF)水平的变化及临床意义.方法:对102例2型糖尿病(DM2)患者(其中并发DN 33例,未并发DN 69例)应用酶联法和免疫比浊法进行了Cys C、TGF-β1和HGF水平测定,并与35名正常健康人作比较.结果:DN组血清CysC、TGF-β1水平非常显著地高于正常人组(P<0.01),而HGF水平又非常显著地低于正常人组(P<0.01).血清HGF水平与Cys C、TGF-β1水平呈负相关(r=-0.482、-0.450,P<0.01).结论:检测DM2患者血清Cys C,TGF-β1和HGF水平的变化对早期DN的发生和病情发展程度有重要的临床意义.%0bjective To study the clinical significance of determination of serum Cystatin C, transforming growth factor and hepatocyte growth factor levels in patients with DM2 complicated with nephropathy. Methods Serum TGF-β, HGF (with ELISA), Cys C (with immunoturbidimetry) levels were determined in 102 patients with type2 diabetis (33 with diabetic nephropathy and 69 without nephropathy) and 35controls. Results The serum levels of Cys C ,TGF-β contents in patients with nephropathy were significantly higher than those in the controls (P<0. 01), while the serum HGF levels were significantly lower than those in controls (P <0.01). Serum HGF levels were negativiely correlated with serum Cys C and TGF-β1 levels (r= -0.482, -0.450, P<0. 01). Conclusion Serum Cys C, TGF-β1 and HGF could be used as sensitive markers for early diagnosis of development of diabetic nephropathy.

  3. Small Molecule AngIV-based Analogs to Treat Alzheimers Disease

    Directory of Open Access Journals (Sweden)

    John W Wright

    2016-06-01

    Full Text Available Alzheimer’s disease (AD patients are presently without adequate treatment thus new therapeutic approaches are needed to slow and hopefully reverse disease progression. Neurotrophic agents such as nerve growth factor and brain-derived neurotrophic factor have received research attention concerning their potential to treat AD but have not progressed to clinical trials due to their large size, inability to penetrate the blood-brain barrier (BBB, and the high cost of synthesis. This review focuses on one over looked neurotrophin, hepatocyte growth factor (HGF that acts via the Type 1 tyrosine kinase receptor Met to mediate stem cell differentiation, synaptogenesis, neurogenesis, and protect against tissue insults in a wide range of cell types including neurons. We have determined that the brain angiotensin and HGF/c-Met systems interact in such a way that angiotensin IV (AngIV-based analogs including Nle1-AngIV, Norleual-AngIV, Dihexa, and others influence HGF dimerization which is a prerequisite to binding at the Met receptor. Several of these analogs have shown the ability to facilitate the formation of new functional synaptic connections in hippocampal slices, promote neurogenesis, and augment memory consolidation and retrieval in animal models of AD. This family of compounds represents a new class of drugs with lead candidates that are orally active, penetrate the BBB sufficiently to reach therapeutic concentrations, and reverse memory deficits seen in animal models of dementia.

  4. Lipoxin Receptors

    Directory of Open Access Journals (Sweden)

    Mario Romano

    2007-01-01

    Full Text Available Lipoxins (LXs represent a class of arachidonic acid (AA metabolites that carry potent immunoregulatory and anti-inflammatory properties, LXA4 and LXB4 being the main components of this series. LXs are generated by cooperation between 5-lipoxygenase (LO and 12- or 15-LO during cell-cell interactions or by single cell types. LX epimers at carbon 15, the 15-epi-LXs, are formed by aspirin-acetylated cyclooxygenase-2 (COX-2 in cooperation with 5-LO. 15-epi-LXA4 is also termed aspirin-triggered LX (ATL. In vivo studies with stable LX and ATL analogs have established that these eicosanoids possess potent anti-inflammatory activities. A LXA4 receptor has been cloned. It belongs to the family of chemotactic receptors and clusters with formyl peptide receptors on chromosome 19. Therefore, it was initially denominated formyl peptide receptor like 1 (FPRL1. This receptor binds with high affinity and stereoselectivity LXA4 and ATL. It also recognizes a variety of peptides, synthetic, endogenously generated, or disease associated, but with lower affinity compared to LXA4. For this reason, this receptor has been renamed ALX. This review summarizes the current knowledge on ALX expression, signaling, and potential pathophysiological role. The involvement of additional recognition sites in LX bioactions is also discussed.

  5. 肝细胞生长因子抗肾纤维化研究进展%Advances of Hepatocyte Growth Factor as an Anti-Fibrotic Regulator in Renal Disease

    Institute of Scientific and Technical Information of China (English)

    陈杏; 张庆林; 熊锡山; 王汉斌

    2011-01-01

    The renal function of patients suffered from chronic kidney disease shows a progressive decline over time.The pathogenesis of renal fibrosis is a progressive process, which is characterized by the progressive loss of renal parenchymal cells and an excessive accumulation of extracellular matrix, that ultimately leads to end-stage renal failure.Hepatocyte growth factor(HGF) and c-Met/HGF receptor play roles in kidney development and regeneration after acute renal injury.As to chronic renal failure and renal fibrosis, HGF also acts an nutritional and anti-fibrotic factor.The mini-review attempts to highlight the recent progress in our understanding of the cellular and molecular pathways by which HGF plays a role in anti-fibrosis, indicating the challenges and opportunities in developing therapeutic strategies.%慢性肾脏疾病患者的肾功能会随时间的推移而进行性恶化,肾实质细胞进行性丧失及细胞外基质蛋白过度沉积将导致肾纤维化形成,肾纤维化进行性发展将最终走向终末期肾衰竭.肝细胞生长因子(HGF)及其受体c-Met对肾发育和急性肾损伤后的肾脏再生修复具有重要作用,在慢性肾衰竭及肾纤维化时,HGF还具有营养肾脏及抗肾纤维化的作用.简要综述了HGF抑制肾纤维化形成的细胞分子机制的研究进展,提示HGF在治疗肾纤维化方面所具有的前景.

  6. Immunohistochemical Study of the Expression of HGF in Rat's Reparative Dentinogenesis%肝细胞生长因子在大鼠修复性牙本质形成过程中的表达研究

    Institute of Scientific and Technical Information of China (English)

    叶玲; 凌均棨; 彭栗; 谭红; 周学东

    2007-01-01

    目的 探讨肝细胞生长因子(HGF)在大鼠修复性牙本质形成过程中的作用.方法 以窝洞预备形成大鼠修复性牙本质模型,免疫组织化学染色法检测HGF在窝洞预备后3 d、15 d、30 d的大鼠牙髓组织中的表达,采用积分光密度值(IOD)定量修复性牙本质形成不同阶段HGF的表达.结论 窝洞预备后3 d,HGF在大鼠牙髓细胞及成牙本质细胞胞浆中呈强阳性表达(IOD为8.995±0.943);窝洞预备后15 d,HGF在两种细胞的表达仍呈阳性(IOD为5.624±0.951), 但弱于3 d组(P<0.01);30 d组(4.073±0.127)和正常对照组(4.279±0.348)大鼠牙髓细胞及成牙本质细胞胞浆中HGF均呈弱阳性表达,两者间差异无统计学意义.结论 HGF参与了牙髓损伤早期修复及修复性牙本质形成的过程.

  7. 子痫前期患者母胎循环肝细胞生长因子检测及其意义%Measurement of maternal and fetal circulating hepatocyte growth factor (HGF) in preeclampsia

    Institute of Scientific and Technical Information of China (English)

    符孜牧; 吕时铭

    2006-01-01

    目的 探讨子痫前期母胎循环肝细胞生长因子(HGF)对子痫前期发病的影响.方法 采用酶联免疫吸附法测定33例子痫前期孕妇(子痫前期组)和32例正常妊娠孕妇(对照组)外周血、脐静脉血清HGF水平.结果 子痫前期组孕妇外周血HGF水平为(142.9±87.64)pg/ml,明显低于对照组的(207.6±110.55)pg/ml(t=2.487,P<0.05);子痫前期组孕妇脐静脉血HGF水平为(13.2±6.28)pg/ml,与正常对照组(16.5±8.22)pg/ml比较差异无统计学意义(t=1.546,P>0.05).轻度和重度子痫前期孕妇外周血、脐静脉血HGF水平差异均无显著性意义(t=0.382、0.747,均P>0.05).结论 外周血HGF下降可能是子痫前期重要的发病机制之一.

  8. Increased DNA binding activity of NF-κB, STAT-3, SMAD3 and AP-1 in acutely damaged liver

    Institute of Scientific and Technical Information of China (English)

    Adriana Salazar-Montes; Luis Ruiz-Corro; Ana SandovaI-Rodriguez; Alberto Lopez-Reyes; Juan Armendariz-Borunda

    2006-01-01

    AIM: To investigate the role of genes and kinetics of specific transcription factors in liver regeneration, and to analyze the gene expression and the activity of some molecules crucially involved in hepatic regeneration.METHODS: USING gel-shift assay and RT-PCR,transcription factors, such as NF-κB, STAT-3, SMAD3and AP-1, and gene expression of inducible nitric oxide synthase (iNOS), hepatocyte growth factor (HGF) and c-met were analyzed in an animal model of chemically induced hepatectomy.RESULTS: Gene expression of HGF and its receptor c-met peaked at 3 h and 24 h after acute CCl4 intoxication. iNOS expression was only observed from 6 to 48 h.Transcriptional factor NF-κB had an early activation at 30min after acute liver damage. STAT-3 peaked 3 h postintoxication, while AP-1 displayed a peak of activation at 48 h. SMAD3 showed a high activity at all analyzed times.CONCLUSION: TNF-α and IL-6 play a central role in hepatic regeneration. These two molecules are responsible for triggering the cascade of events and switch-on of genes involved in cell proliferation, such as growth factors, kinases and cyclins which are direct participants of cell proliferation.

  9. Importance of the Brain Angiotensin System in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    John W. Wright

    2012-01-01

    Full Text Available Parkinson’s disease (PD has become a major health problem affecting 1.5% of the world’s population over 65 years of age. As life expectancy has increased so has the occurrence of PD. The primary direct consequence of this disease is the loss of dopaminergic (DA neurons in the substantia nigra and striatum. As the intensity of motor dysfunction increases, the symptomatic triad of bradykinesia, tremors-at-rest, and rigidity occur. Progressive neurodegeneration may also impact non-DA neurotransmitter systems including cholinergic, noradrenergic, and serotonergic, often leading to the development of depression, sleep disturbances, dementia, and autonomic nervous system failure. L-DOPA is the most efficacious oral delivery treatment for controlling motor symptoms; however, this approach is ineffective regarding nonmotor symptoms. New treatment strategies are needed designed to provide neuroprotection and encourage neurogenesis and synaptogenesis to slow or reverse this disease process. The hepatocyte growth factor (HGF/c-Met receptor system is a member of the growth factor family and has been shown to protect against degeneration of DA neurons in animal models. Recently, small angiotensin-based blood-brain barrier penetrant mimetics have been developed that activate this HGF/c-Met system. These compounds may offer a new and novel approach to the treatment of Parkinson’s disease.

  10. Importance of the brain Angiotensin system in Parkinson's disease.

    Science.gov (United States)

    Wright, John W; Harding, Joseph W

    2012-01-01

    Parkinson's disease (PD) has become a major health problem affecting 1.5% of the world's population over 65 years of age. As life expectancy has increased so has the occurrence of PD. The primary direct consequence of this disease is the loss of dopaminergic (DA) neurons in the substantia nigra and striatum. As the intensity of motor dysfunction increases, the symptomatic triad of bradykinesia, tremors-at-rest, and rigidity occur. Progressive neurodegeneration may also impact non-DA neurotransmitter systems including cholinergic, noradrenergic, and serotonergic, often leading to the development of depression, sleep disturbances, dementia, and autonomic nervous system failure. L-DOPA is the most efficacious oral delivery treatment for controlling motor symptoms; however, this approach is ineffective regarding nonmotor symptoms. New treatment strategies are needed designed to provide neuroprotection and encourage neurogenesis and synaptogenesis to slow or reverse this disease process. The hepatocyte growth factor (HGF)/c-Met receptor system is a member of the growth factor family and has been shown to protect against degeneration of DA neurons in animal models. Recently, small angiotensin-based blood-brain barrier penetrant mimetics have been developed that activate this HGF/c-Met system. These compounds may offer a new and novel approach to the treatment of Parkinson's disease.

  11. Matriptase is required for the active form of hepatocyte growth factor induced Met, focal adhesion kinase and protein kinase B activation on neural stem/progenitor cell motility.

    Science.gov (United States)

    Fang, Jung-Da; Lee, Sheau-Ling

    2014-07-01

    Hepatocyte growth factor (HGF) is a chemoattractant and inducer for neural stem/progenitor (NS/P) cell migration. Although the type II transmembrane serine protease, matriptase (MTP) is an activator of the latent HGF, MTP is indispensable on NS/P cell motility induced by the active form of HGF. This suggests that MTP's action on NS/P cell motility involves mechanisms other than proteolytic activation of HGF. In the present study, we investigate the role of MTP in HGF-stimulated signaling events. Using specific inhibitors of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt) or focal adhesion kinase (FAK), we demonstrated that in NS/P cells HGF-activated c-Met induces PI3k-Akt signaling which then leads to FAK activation. This signaling pathway ultimately induces MMP2 expression and NS/P cell motility. Knocking down of MTP in NS/P cells with specific siRNA impaired HGF-stimulation of c-Met, Akt and FAK activation, blocked HGF-induced production of MMP2 and inhibited HGF-stimulated NS/P cell motility. MTP-knockdown NS/P cells cultured in the presence of recombinant protein of MTP protease domain or transfected with the full-length wild-type but not the protease-defected MTP restored HGF-responsive events in NS/P cells. In addition to functioning as HGF activator, our data revealed novel function of MTP on HGF-stimulated c-Met signaling activation.

  12. Opioid Receptors.

    Science.gov (United States)

    Stein, Christoph

    2016-01-01

    Opioids are the oldest and most potent drugs for the treatment of severe pain. Their clinical application is undisputed in acute (e.g., postoperative) and cancer pain, but their long-term use in chronic pain has met increasing scrutiny. This article reviews mechanisms underlying opioid analgesia and other opioid actions. It discusses the structure, function, and plasticity of opioid receptors; the central and peripheral sites of analgesic actions and side effects; endogenous and exogenous opioid receptor ligands; and conventional and novel opioid compounds. Challenging clinical situations, such as the tension between chronic pain and addiction, are also illustrated.

  13. 雌激素对大鼠心肌缺血再灌注损伤过程中心肌HGF表达的影响%E2 upregulates HGF mRNA expression in rat heart during myocardial ischemia-reperfusion process

    Institute of Scientific and Technical Information of China (English)

    王彦; 王冬梅; 宫德正; 许莹平; 谢玲; 赵赫男

    2009-01-01

    目的 观察17β-雌二醇(E_2)在大鼠心肌缺血再灌注损伤(myocardial ischemia-reperfusion injury,MIRI)过程中对肝细胞生长因子(hepatocyte growth factor,HGF)mRNA的表达影响并探讨其与细胞凋亡的关系.方法 雄性SD大鼠40只,利用随机数字表将其分为缺血再灌注组(即对照组)、17β-雌二醇作用后的缺血再灌注组(即E_2作用组),每组20只.结扎大鼠冠状动脉左前降支20 min,再灌注30 min,造成心肌缺血再灌注损伤模型,观察17β-雌二醇对心肌HGF表达的影响,同时测定心肌细胞的凋亡.结果 心肌缺血20 min及再灌注30 min时,E_2作用组HGF mRNA表达均较对照组相应时点显著增高(P<0.05).TUNEL法检测E_2作用组再灌注30 min单位面积内心肌细胞凋亡较对照组明显减低(P<0.05);同时流式细胞仪检测结果显示,E_2作用组亦显著低于对照组(P<0.05).对照组再灌注30 min及E_2作用组再灌注30 min的HGF mRNA表达变化与相应时间点的心肌细胞凋亡变化成负相关.结论 17β-雌二醇在大鼠心肌缺血再灌注损伤(MIRI)过程中可提高HGF的表达,来发挥抗凋亡作用.%Objective To investigate the effect of 17β-estradiol (E_2) on the expression of hepatocyte growth factor (HGF) mRNA in the myocardial tissues in rats during myocardial ischemia-reperfusion (I/R) process, and explore the relationship between HGF mRNA expression and myocardial apoptosis. Methods U-sing the random number table, 40 male SD rats were divided into 2 groups (20 rats in each group) randomly, ischemia-reperfusion (control) group and E_2 treatment group. Myocardial I/R models of rats were duplicated by ligating the left anterior descending coronary artery for 20 min then reperfusion for 30 min. The expression of HGF and the apoptosis of myocardiocytes were observed with RT-PCR, TUNEL and flow cytometry. Results At the points of cardiac ischemia for 20 min and reperfusion for 30 min, in the E_2 treatment group, the

  14. Effects of Combination of passive Stretching and Resistance Exercise on HGF and MGF mRNA of Rat's Gastrocnemius%抗阻和被动拉伸联合训练对大鼠腓肠肌卫星细胞激活相关因子基因表达的影响∗

    Institute of Scientific and Technical Information of China (English)

    吴国梁; 李娜

    2016-01-01

    Objective:To investigate the effect of the combination of passive stretching and resistance exercise on the activation of skeletal muscle satellite cell, through examine the expression of HGF、MGF mRNA of rat's gastrocnemius. Methods:32 a-dult SD rats were randomly divided into 4 groups:control group(group C,n=8),nothing were done;stretch group (group S, n=8), animals right gastrocnemius muscle was stretched repetitively for 2 seconds/time,15 times/min, 15min daily and 4 times/week under anesthesia; resistance group (group R, n =8), animals underwent 10 weeks(3 times/set, 2sets/day, 3days/week) climbing ladder training with weights (as 200% of their body weights) attached to the rats tails ;combination group( group C, n=8 ) , animals underwent both stretching and resistance trains for 10 weeks. After training, animal 's the right gastrocnemius were token respectively. The protein HGF、MGF were detected by the ELISA, RT-PCR was applied to detect the expression of HGF mRNA and MGF mRNA in gastrocnemius muscle. Results: After the combination of passive stretching and resistance exercise ,the weight of gastrocnemius muscle, the expression of HGF,MGF and mRNA was higher in group S,R,C than the group N(P<0. 05). Compare to the group N, the expression of HGF,MGF and their mRNA was most in the group C (P<0. 01). Compare to group R, the expression of HGF mRNA, MGF mRNA and MGF was high significant differences(P<0. 05). But compare to the group S, the expression of HGF mRNA of the group C was not significant differ-ences; Compare to the group R, the expression of HGF,MGF and their mRNA was high significant differences in group S. Conclusion:Both passive stretching and resistance exercise can effectively improve the expression level of the HGF,MGF and their mRNA, and activate the satellite ecll into the cell cycle to differentiation and proliferation. And the effect of them can be accumulated.%目的::通过大鼠运动实验模型,观察抗阻和被动拉伸训练后

  15. Effect of eccentric contraction on satellite cell activation in human vastus lateralis muscle.

    Science.gov (United States)

    Imaoka, Yoko; Kawai, Minako; Mori, Futoshi; Miyata, Hirofumi

    2015-09-01

    We compared the time-course of satellite cell (SC) activation between eccentric and concentric contractions in the vastus lateralis (VL) muscle after step exercise. Young adults participated in a 30-min step up/down exercise which mainly involved concentric contractions with the right VL muscle and eccentric contractions with the left VL muscle. The concentric and eccentric contraction phases of the VL muscles were identified by changes in the electromyogram (EMG) and knee joint angle. Biopsy samples were taken from both VL muscles at three time periods: before the exercise and 2 and 5 days after the exercise. We found that the numbers of SCs were significantly increased in the type IIa fibers of the left VL at 2 and 5 days after the exercise. The expression of both hepatocyte growth factor (HGF) and myogenic differentiation 1 (MyoD) mRNA had significantly increased in the left VL at 2 and 5 days after the exercise and in the right VL at 5 days after the exercise. The expression of transient receptor potential canonical (TRPC) 1 mRNA also increased in the left VL at 2 days after exercise. These results indicate that eccentric contraction can effectively activate SC proliferation for up to 5 days after exercise. Similar changes in HGF, MyoD and TRPC1 mRNA expression suggest that HGF/c-Met signal activation through cation influx has a major impact on skeletal muscle SC activation in response to eccentric exercise.

  16. Activation of c-MET induces a Stem-Like phenotype in human prostate cancer

    NARCIS (Netherlands)

    G.J.H.L. Leenders (Geert); R. Sookhlall (Rajesh); W.J. Teubel (Wilma); C.M.A. Ridder (Corrina); S. Reneman (Suzanne); A. Sacchetti (Andrea); K.J. Vissers (Kees); W.M. van Weerden (Wytske); G.W. Jenster (Guido)

    2011-01-01

    textabstractProstate cancer consists of secretory cells and a population of immature cells. The function of immature cells and their mutual relation with secretory cells are still poorly understood. Immature cells either have a hierarchical relation to secretory cells (stem cell model) or represent

  17. Thromboxane A{sub 2} receptor signaling promotes liver tissue repair after toxic injury through the enhancement of macrophage recruitment

    Energy Technology Data Exchange (ETDEWEB)

    Minamino, Tsutomu [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ito, Yoshiya [Departments of Surgery, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ohkubo, Hirotoki [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Surgery, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Hosono, Kanako; Suzuki, Tatsunori [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Sato, Takehito [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Ae, Takako; Shibuya, Akitaka [Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Sakagami, Hiroyuki [Departments of Anatomy, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Narumiya, Shuh [Department of Pharmacology, Kyoto University School of Medicine, Kyoto, 606-8315 (Japan); Koizumi, Wasaburo [Departments of Gastroenterology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan); Majima, Masataka, E-mail: mmajima@med.kitasato-u.ac.jp [Departments of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374 (Japan)

    2012-02-15

    It is thought that thromboxane A{sub 2} (TxA{sub 2}) contributes to the progression of inflammation during acute hepatic injury; however, it is still unknown whether TxA{sub 2} is involved in liver repair. The objective of the present study was to examine the role of TxA{sub 2} receptor (TP) signaling in liver injury and repair in response to toxic injury. Carbon tetrachloride (CCl{sub 4}) was used to induce liver injury in TP knockout (TP{sup −/−}) mice and wild-type (WT) mice. In WT mice, serum levels of alanine aminotransferase (ALT) and the size of the necrotic area peaked at 24 and 48 h, respectively, and then declined. In TP{sup −/−} mice, the changes in ALT levels were similar to WT mice, but liver regeneration was impaired as evidenced by remained elevated levels of hepatic necrosis and by delayed hepatocyte proliferation, which was associated with the reduced expression of growth factors including interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and hepatocyte growth factor (HGF). In TP{sup −/−} mice, the accumulation of hepatic CD11b{sup +}/F4/80{sup +} macrophages in injured livers was attenuated, and the hepatic expression of monocyte chemoattractant protein-1 (MCP-1/CCL2) and its receptor, the C―C chemokine receptor (CCR2), was reduced compared to WT. Additionally, the application of the TP receptor agonist, U-46619, enhanced the expression of MCP-1/CCL2 and CCR2 in peritoneal macrophages, which was associated with increased levels of IL-6, TNFα and HGF. These results suggested that TP receptor signaling facilitates liver recovery following CCl{sub 4}-induced hepatotoxicity by affecting the expression of hepatotrophic growth factors, and through the recruitment of macrophages mediated by MCP-1/CCL2-CCR2 expression. -- Highlights: ► TP enhances liver regeneration by CCl{sub 4}. ► TP accumulates macrophages. ► TP up-regulates MCP-1.

  18. Effect of HGF on cerebral water content, activity of MPO, TNF-α and IL-10 in rats subjected to focal cerebral ischemia/reperfusion%HGF对局灶性脑缺血/再灌注大鼠脑含水量、MPO活性及TNF-α、IL-10的影响

    Institute of Scientific and Technical Information of China (English)

    贺芳; 孙小娅; 向敏; 李畅

    2012-01-01

    目的:观察HGF对脑缺血/再灌注(L/R)大鼠脑含水量、MPO活性及TNF-α、IL-10的影响.方法:SD大鼠随机分为5组:对照组;脑L/R组;实验Ⅰ、Ⅱ、Ⅲ组,分别用质量分数为15、30、60 μg/kg HGF处理.线栓法制备大鼠大脑中动脉闭塞模型,缺血1.5h再灌注24h后,测定脑含水量、MPO活性,检测TNF-α、IL-10含量及mRNA水平的表达.结果:I/R大鼠脑含水量增加,MPO活性升高,TNF-α、IL-10含量及mRNA表达上升.不同质量分数HGF处理均能减少I/R大鼠脑含水量,降低MPO活性,下调TNF-α含量和mRNA水平,上调IL-10含量及mRNA表达.结论:促进抗炎症因子IL-10的表达、抑制促炎症因子TNF-α的表达可能是HGF减轻缺血性脑损伤炎症反应的机制之一.%Aim:To investigate the effect of hepatocyte growth factor (HGF) on cerebral water con-tent, activity of MPO, levels of TNF-a and IL-10 in rate after to focal cerebral ischemia/reperfusion (1/ R). Methods; Sprague-Dawley rats were randomly divided into five groups as: control group; I/R group; experimental group Ⅰ , Ⅱ , Ⅲ, which were respectively treated with HGF of 15, 30, 60|xg/kg HGF. A model of middle cerebral artery occlusion ( MCAO) in rats was performed. After a transient MCAO of 1. 5 h followed by reperfusion of 24 h, cerebral water levels, activity of MPO and content of TNF-a, IL-10 were measured. RT-PCR was conducted to determine the level of TNF-a and IL-10 mR-NA. Results; I/R significantly increased cerebral water content, activity of MPO and content of TNF-a, IL-10 in brain tissue. The expression of TNF-a and IL-10 mRNA in brain tissue were remarkably in-creased. Treatment with HGF of different mass fraction decreased cerebral water content, activity of MPO, the mRNA level of TNF-a. While the mRNA level of IL-10 were increased. Conclusion: HGF canreduce the inflammatory response in focal cerebral ischemia/reperfusion injury. It may be related to pro-mote the expression of anti

  19. TetraMabs: simultaneous targeting of four oncogenic receptor tyrosine kinases for tumor growth inhibition in heterogeneous tumor cell populations

    Science.gov (United States)

    Castoldi, Raffaella; Schanzer, Jürgen; Panke, Christian; Jucknischke, Ute; Neubert, Natalie J.; Croasdale, Rebecca; Scheuer, Werner; Auer, Johannes; Klein, Christian; Niederfellner, Gerhard; Kobold, Sebastian; Sustmann, Claudio

    2016-01-01

    Monoclonal antibody-based targeted tumor therapy has greatly improved treatment options for patients. Antibodies against oncogenic receptor tyrosine kinases (RTKs), especially the ErbB receptor family, are prominent examples. However, long-term efficacy of such antibodies is limited by resistance mechanisms. Tumor evasion by a priori or acquired activation of other kinases is often causative for this phenomenon. These findings led to an increasing number of combination approaches either within a protein family, e.g. the ErbB family or by targeting RTKs of different phylogenetic origin like HER1 and cMet or HER1 and IGF1R. Progress in antibody engineering technology enabled generation of clinical grade bispecific antibodies (BsAbs) to design drugs inherently addressing such resistance mechanisms. Limited data are available on multi-specific antibodies targeting three or more RTKs. In the present study, we have evaluated the cloning, eukaryotic expression and purification of tetraspecific, tetravalent Fc-containing antibodies targeting HER3, cMet, HER1 and IGF1R. The antibodies are based on the combination of single-chain Fab and Fv fragments in an IgG1 antibody format enhanced by the knob-into-hole technology. They are non-agonistic and inhibit tumor cell growth comparable to the combination of four parental antibodies. Importantly, TetraMabs show improved apoptosis induction and tumor growth inhibition over individual monospecific or BsAbs in cellular assays. In addition, a mimicry assay to reflect heterogeneous expression of antigens in a tumor mass was established. With this novel in vitro assay, we can demonstrate the superiority of a tetraspecific antibody to bispecific tumor antigen-binding antibodies in early pre-clinical development. PMID:27578890

  20. 膀胱癌术后灌注化疗中检测尿HGF和NMP22含量的临床意义%Clinical significance of HGF and NMP22 of voided urine tests for post-operative bladder cancer

    Institute of Scientific and Technical Information of China (English)

    张延继; 于正刚; 朱广博; 侯瑞鹏; 李健; 冯起庆; 李昭夷; 张纪军; 苏彦慧; 王小波

    2012-01-01

    目的:探讨膀胱尿路上皮癌术后检测尿肝细胞生长因子(HGF)和核基质蛋白22(NMP22)表达水平在肿瘤复发监测中的临床价值.方法:2005年1月~2009年6月收治膀胱尿路上皮癌患者92例(接受TURBT或膀胱部分切除术者),术后2周开始规律性膀胱灌注化疗药物吡柔比星(THP).采用酶联免疫吸附法(ELISA)分别检测灌注前、灌注6周、6个月和12个月时尿中HGF和NMP22的含量;对照组为31例健康人.结果:92例膀胱癌患者术后12个月有11例复发,复发率12%.未复发者尿HGF和NMP22含量随膀胱灌注时间的延长呈下降趋势,肿瘤复发时却明显升高,与对照组比较,差异有统计学意义(P<0.05);尿HGF、NMP22含量和尿脱落细胞学检查(VUC)对膀胱尿路上皮癌术后复发诊断的敏感性分别为91%、73%和45%,特异性分别为58%、48%和98%,阳性预测值分别为100% 、80%和71.4%,阴性预测值分别为57% 、48%和93%.结论:检测尿HGF和NMP22含量可以作为膀胱尿路上皮癌术后肿瘤复发监测及早期诊断的有效指标,二者结合具有较高的敏感性和预测性.%Objective:To evaluate clinical significance of Hepatocyte Growth Factor(HGF) and Nuclear Matrix Protein 22CNMP22) of voided urine tests in detecting the relapse of post-operative bladder cancer. Method: A total of 92 patients (males 79, females 13) with bladder cancer and 31 healthy volunteers enrolled in this study were classified into two groups: post-operative patients with bladder cancer were used pirarubicin(THP) ; 31 heathly volunteers. The voided urine of all the patients in before, 6weeks, 6 months, 12 months post perfusion were recovered selectively. HGF and NMP22 kits were used to detect bladder cancer. Voided urine cytology(VUC) was used to compare the sensitivity and specificity of the screening test. Result:There were 11 cases who relapsed in 92 patients with perfusion in 12 months. The level of HGF and NMP22

  1. The androgen receptor and estrogen receptor

    NARCIS (Netherlands)

    Oosterkamp, H.M.; Bernards, R.A.

    2002-01-01

    The androgen receptor (AR) and the estrogen receptors (ER) are members of the nuclear receptor (NR) family. These NRs are distinguished from the other transcription factors by their ability to control gene expression upon ligand binding (steroids, retinoids, thyroid hormone, vitamin D, fatty acids,

  2. GLP-1 Receptor Agonists

    Science.gov (United States)

    ... in Balance › GLP-1 Receptor Agonists Fact Sheet GLP-1 Receptor Agonists May, 2012 Download PDFs English Espanol Editors Silvio ... are too high or too low. What are GLP-1 receptor agonist medicines? GLP-1 receptor agonist medicines, also called ...

  3. Hepatocyte growth factor promotes proliferation, invasion, and metastasis of myeloid leukemia cells through PI3K-AKT and MAPK/ERK signaling pathway

    Science.gov (United States)

    Guo, Jiang-Rui; Li, Wei; Wu, Yong; Wu, Lin-Qing; Li, Xin; Guo, Ya-Fei; Zheng, Xiao-Hui; Lian, Xiao-Lan; Huang, Hui-Fang; Chen, Yuan-Zhong

    2016-01-01

    This study aims to investigate effects of HGF expression on biological behaviors of Kasumi-1 and HL60. Expression of HGF and c-Met gene were detected using qRT-PCR. Short hairpin RNA (shRNA) was used to reduce HGF expression. Silencing effect of shRNA was verified by qRT-PCR and western blot. Cell reproductive capacity, cell clonality and cell cycle (apoptosis) were detected by CCK-8, clone formation, flow cytometry (FCM), respectively. Cell adhesion, cell invasion ability and cell proliferation were also examined. Changes of PI3K-AKT, MAPK/ERK signaling factors were detected by western blot. HGF and c-Met expression in first-vist AML group was significantly higher than in AML-relief and normal control group. HGF shRNA can inhibit cell proliferation, inhibit cloning ability. Compared with control group, apoptosis ratios of Kasumi-1 and HL60 cell in interference groups were significantly higher. After shRNA interference, the number of adherent cells and transmembrane cells were significantly decreased compared with control group. Meanwhile, shRNA also down-regulated Bad, Bcl-XL, Bcl-2, CDK1, Cyclin B, MMP2, MMP9, and up-regulated cleaved caspase9, cleaved caspase3, cleaved PARP, Bax, and P21. Moreover, phosphorylated c-Met, AKT, Erk, and mTOR were also reduced. In conclusion, HGF and c-Met gene highly expressed among first-visit AML patients, but decreased after relief treatment. HGF may promote proliferation, invasion, and metastasis of AML cells through PI3K-AKT and MAPK/ERK signaling pathway. Therefore, proliferation and invasion ability of AML cell can be inhibited by down-regulating HGF gene to retardate cell in G2/M stage. PMID:27725846

  4. [Thirty years of Met receptor research: from the discovery of an oncogene to the development of targeted therapies].

    Science.gov (United States)

    Montagne, Rémi; Furlan, Alessandro; Kherrouche, Zoulika; Tulasne, David

    2014-10-01

    In 1984, the Met receptor and its ligand, the HGF/SF, were discovered thanks to their ability to induce cell transformation and proliferation. Thirty years of research highlighted their crucial role in the development and homeostasis of various structures, including many epithelial organs. This period also allowed unraveling the structural basis of their interaction and their complex signaling network. In parallel, Met was shown to be deregulated and associated with a poor prognosis in many cancers. Met involvement in resistance to current therapies is also being deciphered. Based on these data, pharmaceutical companies developed a variety of Met inhibitors, some of which are evaluated in phase III clinical trials. In this review, we trace the exemplary track record of research on Met receptor, which allowed moving from bench to bedside through the development of therapies targeting its activity. Many questions still remain unanswered such as the involvement of Met in several processes of development, the mechanisms involving Met in resistance to current therapies or the likely emergence of resistances to Met-targeted therapies.

  5. Cardiotoxin III Inhibits Hepatocyte Growth Factor-Induced Epithelial-Mesenchymal Transition and Suppresses Invasion of MDA-MB-231 Cells.

    Science.gov (United States)

    Tsai, Pei-Chien; Fu, Yaw-Syan; Chang, Long-Sen; Lin, Shinne-Ren

    2016-01-01

    The epithelial-mesenchymal transition (EMT) is the first step required for breast cancer to initiate metastasis. In this study, hepatocyte growth factor (HGF) was used as a metastatic inducer of MDA-MB-231 cells. Cardiotoxin III (CTX III) inhibited HGF-induced morphological changes and upregulation of E-cadherin with the concomitant decrease in N-cadherin and Vimentin protein levels, resulting in inhibition of cell migration and invasion. CTX III-induced downregulation of transcription factors, Snail, Twist, and Slug, in MDA-MB-231 cells. CTX III suppressed c-Met phosphorylation and downstream activation of phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK)1/2. The c-Met specific inhibitor PHA665752 attenuated ERK1/2 and Akt phosphorylation, cell migration and invasion, as well as the expressional changes of EMT markers induced by HGF. Taken together, our data suggest that CTX III suppresses HGF/c-Met-induced cell migration and invasion by reversing EMT, which involves the inactivation of the HGF/c-Met-mediated ERK1/2 and PI3K/Akt pathways in MDA-MB-231 cells.

  6. Recruitment of stem cells by hepatocyte growth factor via intracoronary gene transfection in the postinfarction heart failure

    Institute of Scientific and Technical Information of China (English)

    YANG; ZhiJian; WANG; Wei; MA; DongChao; ZHANG; YouRong; WANG; LianSheng; ZHANG; YuQing; XU; ShunLin; CHEN; Bo; MIAO; DengShun; CAO; KeJiang

    2007-01-01

    We aim to study the amelioration effect of adenovirus5-mediated human hepatocyte growth factor gene transfer on postinfarction heart failure in swine model. Twelve Suzhong young swine were randomly divided into 2 groups of 6 pigs each: Ad5-HGF group and mock-vector Ad5 group. Four weeks after ligation of the left anterior descending coronary artery, Ad5-HGF was intracoronarily transferred into the myocardium. Simultaneously, gate cardiac perfusion imaging was performed to evaluate the heart function. Three weeks later, gate cardiac perfusion imaging was performed again, then the hearts were removed and sectioned for immunohistochemical examination to illustrate the effects of Ad5-HGF on infarcted myocardium. The expression of HGF was examined by ELISA. The results were: (1) compared with the mock-vector Ad5 group, high expression of human HGF was observed in the myocardium of Ad5-HGF group; (2) in the Ad5-HGF group, the number of CD117+ cells co-expressing c-Met per mm2 was significantly larger; (3) the improvement in LVEF was greater in the Ad5-HGF group than in the mock-vector Ad5 group. We concluded that: (1) high expression of human HGF was observed in the myocardium through intracoronary gene transfection; (2) HGF can improve the mobilization of CD117+/c-Met+ stem cells into ischemic myocardium. The amelioration effect of HGF on postinfarction heart failure could not be limited to stimulating angiogenesis, anti-apoptosis, anti-fibrosis, but was also involved in the recruitment of stem cells into myocardium.

  7. Acetylcholine receptor antibody

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003576.htm Acetylcholine receptor antibody To use the sharing features on this page, please enable JavaScript. Acetylcholine receptor antibody is a protein found in the blood ...

  8. Androgen receptor abnormalities

    NARCIS (Netherlands)

    A.O. Brinkmann (Albert); G.G.J.M. Kuiper (George); C. Ris-Stalpers (Carolyn); H.C.J. van Rooij (Henri); G. Romalo (G.); G. Trifiro (Gianluca); E. Mulder (Eppo); L. Pinsky (L.); H.U. Schweikert (H.); J. Trapman (Jan)

    1991-01-01

    markdownabstract__Abstract__ The human androgen receptor is a member of the superfamily of steroid hormone receptors. Proper functioning of this protein is a prerequisite for normal male sexual differentiation and development. The cloning of the human androgen receptor cDNA and the elucidation of t

  9. Mammalian Sweet Taste Receptors

    National Research Council Canada - National Science Library

    Nelson, Greg; Hoon, Mark A; Chandrashekar, Jayaram; Zhang, Yifeng; Ryba, Nicholas J.P; Zuker, Charles S

    2001-01-01

    ... and information coding, and have focused on the isolation and characterization of genes encoding sweet and bitter taste receptors. The identification of taste receptors generates powerful molecular tools to investigate not only the function of taste receptor cells, but also the logic of taste coding. For example, defining the size and diversity of the re...

  10. Listeria monocytogenes internalin B activates junctional endocytosis to accelerate intestinal invasion.

    Directory of Open Access Journals (Sweden)

    Mickey Pentecost

    2010-05-01

    Full Text Available Listeria monocytogenes (Lm uses InlA to invade the tips of the intestinal villi, a location at which cell extrusion generates a transient defect in epithelial polarity that exposes the receptor for InlA, E-cadherin, on the cell surface. As the dying cell is removed from the epithelium, the surrounding cells reorganize to form a multicellular junction (MCJ that Lm exploits to find its basolateral receptor and invade. By examining individual infected villi using 3D-confocal imaging, we uncovered a novel role for the second major invasin, InlB, during invasion of the intestine. We infected mice intragastrically with isogenic strains of Lm that express or lack InlB and that have a modified InlA capable of binding murine E-cadherin and found that Lm lacking InlB invade the same number of villi but have decreased numbers of bacteria within each infected villus tip. We studied the mechanism of InlB action at the MCJs of polarized MDCK monolayers and find that InlB does not act as an adhesin, but instead accelerates bacterial internalization after attachment. InlB locally activates its receptor, c-Met, and increases endocytosis of junctional components, including E-cadherin. We show that MCJs are naturally more endocytic than other sites of the apical membrane, that endocytosis and Lm invasion of MCJs depends on functional dynamin, and that c-Met activation by soluble InlB or hepatocyte growth factor (HGF increases MCJ endocytosis. Also, in vivo, InlB applied through the intestinal lumen increases endocytosis at the villus tips. Our findings demonstrate a two-step mechanism of synergy between Lm's invasins: InlA provides the specificity of Lm adhesion to MCJs at the villus tips and InlB locally activates c-Met to accelerate junctional endocytosis and bacterial invasion of the intestine.

  11. [Melatonin receptor agonist].

    Science.gov (United States)

    Uchiyama, Makoto

    2015-06-01

    Melatonin is a hormone secreted by the pineal gland and is involved in the regulation of human sleep-wake cycle and circadian rhythms. The melatonin MT1 and MT2 receptors located in the suprachiasmatic nucleus in the hypothalamus play a pivotal role in the sleep-wake regulation. Based on the fact that MT1 receptors are involved in human sleep onset process, melatonin receptor agonists have been developed to treat insomnia. In this article, we first reviewed functions of melatonin receptors with special reference to MT1 and MT2, and properties and clinical application of melatonin receptor agonists as hypnotics.

  12. Dopamine receptors and hypertension.

    Science.gov (United States)

    Banday, Anees Ahmad; Lokhandwala, Mustafa F

    2008-08-01

    Dopamine plays an important role in regulating renal function and blood pressure. Dopamine synthesis and dopamine receptor subtypes have been shown in the kidney. Dopamine acts via cell surface receptors coupled to G proteins; the receptors are classified via pharmacologic and molecular cloning studies into two families, D1-like and D2-like. Two D1-like receptors cloned in mammals, the D1 and D5 receptors (D1A and D1B in rodents), are linked to adenylyl cyclase stimulation. Three D2-like receptors (D2, D3, and D4) have been cloned and are linked mainly to adenylyl cyclase inhibition. Activation of D1-like receptors on the proximal tubules inhibits tubular sodium reabsorption by inhibiting Na/H-exchanger and Na/K-adenosine triphosphatase activity. Reports exist of defective renal dopamine production and/or dopamine receptor function in human primary hypertension and in genetic models of animal hypertension. In humans with essential hypertension, renal dopamine production in response to sodium loading is often impaired and may contribute to hypertension. A primary defect in D1-like receptors and an altered signaling system in proximal tubules may reduce dopamine-mediated effects on renal sodium excretion. The molecular basis for dopamine receptor dysfunction in hypertension is being investigated, and may involve an abnormal posttranslational modification of the dopamine receptor.

  13. GABA receptor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Doo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    GABA is primary an inhibitory neurotransmitter that is localized in inhibitory interneurons. GABA is released from presynaptic terminals and functions by binding to GABA receptors. There are two types of GABA receptors, GABA{sub A}-receptor that allows chloride to pass through a ligand gated ion channel and GABA{sub B}-receptor that uses G-proteins for signaling. The GABA{sub A}-receptor has a GABA binding site as well as a benzodiazepine binding sites, which modulate GABA{sub A}-receptor function. Benzodiazepine GABAA receptor imaging can be accomplished by radiolabeling derivates that activates benzodiazepine binding sites. There has been much research on flumazenil (FMZ) labeled with {sup 11}C-FMZ, a benzodiazepine derivate that is a selective, reversible antagonist to GABAA receptors. Recently, {sup 18}F-fluoroflumazenil (FFMZ) has been developed to overcome {sup 11}C's short half-life. {sup 18}F-FFMZ shows high selective affinity and good pharmacodynamics, and is a promising PET agent with better central benzodiazepine receptor imaging capabilities. In an epileptic focus, because the GABA/benzodiazepine receptor amount is decreased, using '1{sup 1}C-FMZ PET instead of {sup 18}F-FDG, PET, restrict the foci better and may also help find lesions better than high resolution MR. GABA{sub A} receptors are widely distributed in the cerebral cortex, and can be used as an viable neuronal marker. Therefore it can be used as a neuronal cell viability marker in cerebral ischemia. Also, GABA-receptors decrease in areas where neuronal plasticity develops, therefore, GABA imaging can be used to evaluate plasticity. Besides these usages, GABA receptors are related with psychological diseases, especially depression and schizophrenia as well as cerebral palsy, a motor-related disorder, so further in-depth studies are needed for these areas.

  14. 乳猪肝胶原水解物和促肝细胞生长素对裸小鼠肾包膜移植的人源性胰腺癌细胞的影响%Effects of porcine liver collagen hydrolyte and pHGF on human-pancreas cancer cell lines transplanted in renal capsule of BALB/C nude mice

    Institute of Scientific and Technical Information of China (English)

    曾平鲁; 黄文革; 邹晓军; 陈凤英; 黄冰; 陈系古; 孔祥平; 邹清雁

    2004-01-01

    目的:探讨乳猪肝胶原水解物(LCH)和促肝细胞生长素(pHGF)对裸小鼠肾包膜下移植人胰腺癌细胞(SW1990)的影响.方法:应用裸小鼠肾包膜下移植人胰腺癌细胞,瘤体积测量和组织细胞形态学观察.结果:高、中、低LCH剂量组和pHGF组的抑瘤率分别为58.22%,65.90%,55.23%和34.17%.而对胰腺癌细胞有丝分裂影响不明显.形态学观察表明,LCH和pHGF均能抑制肿瘤细胞生长,表现为细胞固缩,核染色质分叶固缩.结论:LCH和pHGF能抑制移植于裸小鼠肾包膜下的人源性胰腺癌细胞生长.

  15. Chicken NK cell receptors.

    Science.gov (United States)

    Straub, Christian; Neulen, Marie-Luise; Sperling, Beatrice; Windau, Katharina; Zechmann, Maria; Jansen, Christine A; Viertlboeck, Birgit C; Göbel, Thomas W

    2013-11-01

    Natural killer cells are innate immune cells that destroy virally infected or transformed cells. They recognize these altered cells by a plethora of diverse receptors and thereby differ from other lymphocytes that use clonally distributed antigen receptors. To date, several receptor families that play a role in either activating or inhibiting NK cells have been identified in mammals. In the chicken, NK cells have been functionally and morphologically defined, however, a conclusive analysis of receptors involved in NK cell mediated functions has not been available. This is partly due to the low frequencies of NK cells in blood or spleen that has hampered their intensive characterization. Here we will review recent progress regarding the diverse NK cell receptor families, with special emphasis on novel families identified in the chicken genome with potential as chicken NK cell receptors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Novel cannabinoid receptors

    OpenAIRE

    Brown, A J

    2007-01-01

    Cannabinoids have numerous physiological effects. In the years since the molecular identification of the G protein-coupled receptors CB1 and CB2, the ion channel TRPV1, and their corresponding endogenous ligand systems, many cannabinoid-evoked actions have been shown conclusively to be mediated by one of these specific receptor targets. However, there remain several examples where these classical cannabinoid receptors do not explain observed pharmacology. Studies using mice genetically delete...

  17. Therapeutic androgen receptor ligands

    OpenAIRE

    Allan, George F.; Sui, Zhihua

    2003-01-01

    In the past several years, the concept of tissue-selective nuclear receptor ligands has emerged. This concept has come to fruition with estrogens, with the successful marketing of drugs such as raloxifene. The discovery of raloxifene and other selective estrogen receptor modulators (SERMs) has raised the possibility of generating selective compounds for other pathways, including androgens (that is, selective androgen receptor modulators, or SARMs).

  18. AMPA receptor ligands

    DEFF Research Database (Denmark)

    Strømgaard, Kristian; Mellor, Ian

    2004-01-01

    Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPAR), subtype of the ionotropic glutamate receptors (IGRs), mediate fast synaptic transmission in the central nervous system (CNS), and are involved in many neurological disorders, as well as being a key player in the f......Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPAR), subtype of the ionotropic glutamate receptors (IGRs), mediate fast synaptic transmission in the central nervous system (CNS), and are involved in many neurological disorders, as well as being a key player...

  19. Differential requirement of the epidermal growth factor receptor for G protein-mediated activation of transcription factors by lysophosphatidic acid

    Directory of Open Access Journals (Sweden)

    Dent Paul

    2010-01-01

    Full Text Available Abstract Background The role of the epidermal growth factor receptor (EGFR and other receptor tyrosine kinases (RTKs in provoking biological actions of G protein-coupled receptors (GPCRs has been one of the most disputed subjects in the field of GPCR signal transduction. The purpose of the current study is to identify EGFR-mediated mechanisms involved in activation of G protein cascades and the downstream transcription factors by lysophosphatidic acid (LPA. Results In ovarian cancer cells highly responsive to LPA, activation of AP-1 by LPA was suppressed by inhibition of EGFR, an effect that could be reversed by co-stimulation of another receptor tyrosine kinase c-Met with hepatocyte growth factor, indicating that LPA-mediated activation of AP-1 requires activity of a RTK, not necessarily EGFR. Induction of AP-1 components by LPA lied downstream of Gi, G12/13, and Gq. Activation of the effectors of Gi, but not Gq or G12/13 was sensitive to inhibition of EGFR. In contrast, LPA stimulated another prominent transcription factor NF-κB via the Gq-PKC pathway in an EGFR-independent manner. Consistent with the importance of Gi-elicited signals in a plethora of biological processes, LPA-induced cytokine production, cell proliferation, migration and invasion require intact EGFR. Conclusions An RTK activity is required for activation of the AP-1 transcription factor and other Gi-dependent cellular responses to LPA. In contrast, activation of G12/13, Gq and Gq-elicited NF-κB by LPA is independent of such an input. These results provide a novel insight into the role of RTK in GPCR signal transduction and biological functions.

  20. [The LDL receptor family].

    Science.gov (United States)

    Meilinger, Melinda

    2002-12-29

    The members of the LDL receptor family are structurally related endocytic receptors. Our view on these receptors has considerably changed in recent years. Not only have new members of the family been identified, but also several interesting observations have been published concerning the biological function of these molecules. The LDL receptor family members are able to bind and internalize a plethora of ligands; as a consequence, they play important roles in diverse physiological processes. These receptors are key players in the lipoprotein metabolism, vitamin homeostasis, Ca2+ homeostasis, cell migration, and embryonic development. Until recently, LDL receptor family members were thought to be classic endocytic receptors that provide cells with metabolites on one hand, while regulating the concentration of their ligands in the extracellular fluids on the other hand. However, recent findings indicate that in addition to their cargo transport function, LDL receptor family members can act as signal transducers, playing important roles in the development of the central nervous system or the skeleton. Better understanding of physiological and pathophysiological functions of these molecules may open new avenues for the treatment or prevention of many disorders.

  1. Hepatocyte specific deletion of c-Met leads to the development of severe non-alcoholic steatohepatitis in mice

    NARCIS (Netherlands)

    Kroy, D.C.; Schumacher, F.; Ramadori, P.; Hatting, M.; Bergheim, I.; Gassler, N.; Boekschoten, M.V.; Müller, M.R.; Streetz, K.L.; Trautwein, C.

    2014-01-01

    Background & Aims Non-alcoholic-fatty-liver disease (NAFLD) is part of the metabolic syndrome. The spectrum of NAFLD includes NASH (non-alcoholic steatohepatitis), which is characterised by progressive inflammation associated with oxidative stress and apoptosis, finally triggering liver

  2. Glutamate receptor agonists

    DEFF Research Database (Denmark)

    Vogensen, Stine Byskov; Greenwood, Jeremy R; Bunch, Lennart;

    2011-01-01

    The neurotransmitter (S)-glutamate [(S)-Glu] is responsible for most of the excitatory neurotransmission in the central nervous system. The effect of (S)-Glu is mediated by both ionotropic and metabotropic receptors. Glutamate receptor agonists are generally a-amino acids with one or more...... stereogenic centers due to strict requirements in the agonist binding pocket of the activated state of the receptor. By contrast, there are many examples of achiral competitive antagonists. The present review addresses how stereochemistry affects the activity of glutamate receptor ligands. The review focuses...... mainly on agonists and discusses stereochemical and conformational considerations as well as biostructural knowledge of the agonist binding pockets, which is useful in the design of glutamate receptor agonists. Examples are chosen to demonstrate how stereochemistry not only determines how the agonist...

  3. Activated human neutrophils release hepatocyte growth factor/scatter factor.

    LENUS (Irish Health Repository)

    McCourt, M

    2012-02-03

    BACKGROUND: Hepatocyte growth factor or scatter factor (HGF\\/SF) is a pleiotropic cytokine that has potent angiogenic properties. We have previously demonstrated that neutrophils (PMN) are directly angiogenic by releasing vascular endothelial growth factor (VEGF). We hypothesized that the acute inflammatory response can stimulate PMN to release HGF. AIMS: To examine the effects of inflammatory mediators on PMN HGF release and the effect of recombinant human HGF (rhHGF) on PMN adhesion receptor expression and PMN VEGF release. METHODS: In the first experiment, PMN were isolated from healthy volunteers and stimulated with tumour necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), interleukin-8 (IL-8), and formyl methionyl-leucyl-phenylalanine (fMLP). Culture supernatants were assayed for HGF using ELISA. In the second experiment, PMN were lysed to measure total HGF release and HGF expression in the PMN was detected by Western immunoblotting. Finally, PMN were stimulated with rhHGF. PMN CD 11a, CD 11b, and CD 18 receptor expression and VEGF release was measured using flow cytometry and ELISA respectively. RESULTS: TNF-alpha, LPS and fMLP stimulation resulted in significantly increased release of PMN HGF (755+\\/-216, 484+\\/-221 and 565+\\/-278 pg\\/ml, respectively) compared to controls (118+\\/-42 pg\\/ml). IL-8 had no effect. Total HGF release following cell lysis and Western blot suggests that HGF is released from intracellular stores. Recombinant human HGF did not alter PMN adhesion receptor expression and had no effect on PMN VEGF release. CONCLUSIONS: This study demonstrates that pro-inflammatory mediators can stimulate HGF release from a PMN intracellular store and that activated PMN in addition to secreting VEGF have further angiogenic potential by releasing HGF.

  4. Opiate receptors: an introduction.

    Science.gov (United States)

    Carmody, J J

    1987-02-01

    Current status of opiate receptors and their agonists is reviewed--basic aspects of receptor theory, the importance of stereospecificity in drug-receptor interactions and the role of 'second messengers' in drug action. The three classes of endogenous opioids, originating from three distinct genes, are discussed: pro-opiomelanocortin, giving rise to beta-endorphin, ACTH and various MSHs; pro-enkephalin, giving methionine enkephalin and leucine enkephalin; and prodynorphin; their anatomical distribution and the main classes of receptors with which they interact, the mu-receptor, with a high affinity for met-enkephalin and beta-endorphin (as well as morphine and dynorphin A); the delta-receptor for which the primary ligand is leu-enkephalin; and the kappa-receptor which is the main target for the dynorphins. Functional roles for endogenous opioids are considered. Essentially they are inhibitory to target neurones, depressing motor reflexes, baroreflexes and nociception. They also have roles in the response to physical and psychological stress.

  5. Serotonin receptors in hippocampus.

    Science.gov (United States)

    Berumen, Laura Cristina; Rodríguez, Angelina; Miledi, Ricardo; García-Alcocer, Guadalupe

    2012-01-01

    Serotonin is an ancient molecular signal and a recognized neurotransmitter brainwide distributed with particular presence in hippocampus. Almost all serotonin receptor subtypes are expressed in hippocampus, which implicates an intricate modulating system, considering that they can be localized as autosynaptic, presynaptic, and postsynaptic receptors, even colocalized within the same cell and being target of homo- and heterodimerization. Neurons and glia, including immune cells, integrate a functional network that uses several serotonin receptors to regulate their roles in this particular part of the limbic system.

  6. Serotonin Receptors in Hippocampus

    Directory of Open Access Journals (Sweden)

    Laura Cristina Berumen

    2012-01-01

    Full Text Available Serotonin is an ancient molecular signal and a recognized neurotransmitter brainwide distributed with particular presence in hippocampus. Almost all serotonin receptor subtypes are expressed in hippocampus, which implicates an intricate modulating system, considering that they can be localized as autosynaptic, presynaptic, and postsynaptic receptors, even colocalized within the same cell and being target of homo- and heterodimerization. Neurons and glia, including immune cells, integrate a functional network that uses several serotonin receptors to regulate their roles in this particular part of the limbic system.

  7. Dopamine receptor and hypertension.

    Science.gov (United States)

    Zeng, Chunyu; Eisner, Gilbert M; Felder, Robin A; Jose, Pedro A

    2005-01-01

    Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport and reactive oxygen and by interacting with vasopressin, renin-angiotensin, and the sympathetic nervous system. Decreased renal dopamine production and/or impaired dopamine receptor function have been reported in hypertension. Disruption of any of the dopamine receptors (D(1), D(2), D(3), D(4), and D(5)) results in hypertension. In this paper, we review the mechanisms by which hypertension develops when dopamine receptor function is perturbed.

  8. Serotonin Receptors in Hippocampus

    Science.gov (United States)

    Berumen, Laura Cristina; Rodríguez, Angelina; Miledi, Ricardo; García-Alcocer, Guadalupe

    2012-01-01

    Serotonin is an ancient molecular signal and a recognized neurotransmitter brainwide distributed with particular presence in hippocampus. Almost all serotonin receptor subtypes are expressed in hippocampus, which implicates an intricate modulating system, considering that they can be localized as autosynaptic, presynaptic, and postsynaptic receptors, even colocalized within the same cell and being target of homo- and heterodimerization. Neurons and glia, including immune cells, integrate a functional network that uses several serotonin receptors to regulate their roles in this particular part of the limbic system. PMID:22629209

  9. Recognition receptors in biosensors

    CERN Document Server

    Zourob, Mohammed

    2010-01-01

    This book presents a significant and up-to-date review of the various recognition receptors, their immobilization, and an overview of the used surface characterization techniques. It includes more than 150 illustrations that help explain the ideas presented.

  10. Somatostatin receptor skintigrafi

    DEFF Research Database (Denmark)

    Rasmussen, Karin; Nielsen, Jørn Theil; Rehling, Michael

    2005-01-01

    Somatostatin receptor scintigraphy (SRS) is a very valuable imaging technique for visualisation of a diversity of neuroendocrine tumours. The sensitivity for localisation of carcinoid tumours is high, but somewhat lower for other neuroendocrine tumours. The methodology, multiple clinical aspects...

  11. Update on Melatonin Receptors. IUPHAR Review. : Melatonin Receptors

    OpenAIRE

    Jockers, Ralf; Delagrange, Philippe; Dubocovich, Margarita ,; Markus, Regina ,; Renault, Nicolas; Tosini, Gianluca; Cecon, Erika; Zlotos, Darius Paul

    2016-01-01

    International audience; Melatonin receptors are seven transmembrane-spanning proteins belonging to the G protein-coupled receptor super-family. In mammals, two melatonin receptor subtypes exit MT1 and MT2 encoded by the MTNR1A and MTNR1B genes, respectively. The current review provides an update on melatonin receptors by the corresponding sub-committee of the International Union of Basic and Clinical Pharmacology. We will highlight recent developments of melatonin receptor ligands, including ...

  12. Serotonin Receptors in Hippocampus

    OpenAIRE

    Laura Cristina Berumen; Angelina Rodríguez; Ricardo Miledi; Guadalupe García-Alcocer

    2012-01-01

    Serotonin is an ancient molecular signal and a recognized neurotransmitter brainwide distributed with particular presence in hippocampus. Almost all serotonin receptor subtypes are expressed in hippocampus, which implicates an intricate modulating system, considering that they can be localized as autosynaptic, presynaptic, and postsynaptic receptors, even colocalized within the same cell and being target of homo- and heterodimerization. Neurons and glia, including immune cells, integrate a fu...

  13. Receptors for enterovirus 71

    OpenAIRE

    Yamayoshi, Seiya; Fujii, Ken; Koike, Satoshi

    2014-01-01

    Enterovirus 71 (EV71) is one of the major causative agents of hand, foot and mouth disease (HFMD). Occasionally, EV71 infection is associated with severe neurological diseases, such as acute encephalitis, acute flaccid paralysis and cardiopulmonary failure. Several molecules act as cell surface receptors that stimulate EV71 infection, including scavenger receptor B2 (SCARB2), P-selectin glycoprotein ligand-1 (PSGL-1), sialylated glycan, heparan sulfate and annexin II (Anx2). SCARB2 plays crit...

  14. Adenosine receptor neurobiology: overview.

    Science.gov (United States)

    Chen, Jiang-Fan; Lee, Chien-fei; Chern, Yijuang

    2014-01-01

    Adenosine is a naturally occurring nucleoside that is distributed ubiquitously throughout the body as a metabolic intermediary. In the brain, adenosine functions as an important upstream neuromodulator of a broad spectrum of neurotransmitters, receptors, and signaling pathways. By acting through four G-protein-coupled receptors, adenosine contributes critically to homeostasis and neuromodulatory control of a variety of normal and abnormal brain functions, ranging from synaptic plasticity, to cognition, to sleep, to motor activity to neuroinflammation, and cell death. This review begun with an overview of the gene and genome structure and the expression pattern of adenosine receptors (ARs). We feature several new developments over the past decade in our understanding of AR functions in the brain, with special focus on the identification and characterization of canonical and noncanonical signaling pathways of ARs. We provide an update on functional insights from complementary genetic-knockout and pharmacological studies on the AR control of various brain functions. We also highlight several novel and recent developments of AR neurobiology, including (i) recent breakthrough in high resolution of three-dimension structure of adenosine A2A receptors (A2ARs) in several functional status, (ii) receptor-receptor heterodimerization, (iii) AR function in glial cells, and (iv) the druggability of AR. We concluded the review with the contention that these new developments extend and strengthen the support for A1 and A2ARs in brain as therapeutic targets for neurologic and psychiatric diseases.

  15. Imidazoline receptors ligands

    Directory of Open Access Journals (Sweden)

    Agbaba Danica

    2012-01-01

    Full Text Available Extensive biochemical and pharmacological studies have determined three different subtypes of imidazoline receptors: I1-imidazoline receptors (I1-IR involved in central inhibition of sympathicus that produce hypotensive effect; I2-imidazoline receptors (I2-IR modulate monoamine oxidase B activity (MAO-B; I3-imidazoline receptors (I3-IR regulate insulin secretion from pancreatic β-cells. Therefore, the I1/I2/I3 imidazoline receptors are selected as new, interesting targets for drug design and discovery. Novel selective I1/I2/I3 agonists and antagonists have been recently developed. In the present review, we provide a brief update to the field of imidazoline research, highlighting some of the chemical diversity and progress made in the 2D-QSAR, 3D-QSAR and quantitative pharmacophore development studies of I1-IR and I2-IR imidazoline receptor ligands. Theoretical studies of I3-IR ligands are not yet performed because of insufficient number of synthesized I3-IR ligands.

  16. Cardiac concentric hypertrophy promoted by activated Met receptor is mitigated in vivo by inhibition of Erk1,2 signalling with Pimasertib.

    Science.gov (United States)

    Sala, Valentina; Gallo, Simona; Gatti, Stefano; Medico, Enzo; Vigna, Elisa; Cantarella, Daniela; Fontani, Lara; Natale, Massimo; Cimino, James; Morello, Mara; Comoglio, Paolo Maria; Ponzetto, Antonio; Crepaldi, Tiziana

    2016-04-01

    Cardiac hypertrophy is a major risk factor for heart failure. Hence, its attenuation represents an important clinical goal. Erk1,2 signalling is pivotal in the cardiac response to stress, suggesting that its inhibition may be a good strategy to revert heart hypertrophy. In this work, we unveiled the events associated with cardiac hypertrophy by means of a transgenic model expressing activated Met receptor. c-Met proto-oncogene encodes for the tyrosine kinase receptor of Hepatocyte growth factor and is a strong inducer of Ras-Raf-Mek-Erk1,2 pathway. We showed that three weeks after the induction of activated Met, the heart presents a remarkable concentric hypertrophy, with no signs of congestive failure and preserved contractility. Cardiac enlargement is accompanied by upregulation of growth-regulating transcription factors, natriuretic peptides, cytoskeletal proteins, and Extracellular Matrix remodelling factors (Timp1 and Pai1). At a later stage, cardiac hypertrophic remodelling results into heart failure with preserved systolic function. Prevention trial by suppressing activated Met showed that cardiac hypertrophy is reversible, and progression to heart failure is prevented. Notably, treatment with Pimasertib, Mek1 inhibitor, attenuates cardiac hypertrophy and remodelling. Our results suggest that modulation of Erk1.2 signalling may constitute a new therapeutic approach for treating cardiac hypertrophies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Paracrine Effects of Adipose-Derived Stem Cells on Matrix Stiffness-Induced Cardiac Myofibroblast Differentiation via Angiotensin II Type 1 Receptor and Smad7

    Science.gov (United States)

    Yong, Kar Wey; Li, Yuhui; Liu, Fusheng; Bin Gao; Lu, Tian Jian; Wan Abas, Wan Abu Bakar; Wan Safwani, Wan Kamarul Zaman; Pingguan-Murphy, Belinda; Ma, Yufei; Xu, Feng; Huang, Guoyou

    2016-01-01

    Human mesenchymal stem cells (hMSCs) hold great promise in cardiac fibrosis therapy, due to their potential ability of inhibiting cardiac myofibroblast differentiation (a hallmark of cardiac fibrosis). However, the mechanism involved in their effects remains elusive. To explore this, it is necessary to develop an in vitro cardiac fibrosis model that incorporates pore size and native tissue-mimicking matrix stiffness, which may regulate cardiac myofibroblast differentiation. In the present study, collagen coated polyacrylamide hydrogel substrates were fabricated, in which the pore size was adjusted without altering the matrix stiffness. Stiffness is shown to regulate cardiac myofibroblast differentiation independently of pore size. Substrate at a stiffness of 30 kPa, which mimics the stiffness of native fibrotic cardiac tissue, was found to induce cardiac myofibroblast differentiation to create in vitro cardiac fibrosis model. Conditioned medium of hMSCs was applied to the model to determine its role and inhibitory mechanism on cardiac myofibroblast differentiation. It was found that hMSCs secrete hepatocyte growth factor (HGF) to inhibit cardiac myofibroblast differentiation via downregulation of angiotensin II type 1 receptor (AT1R) and upregulation of Smad7. These findings would aid in establishment of the therapeutic use of hMSCs in cardiac fibrosis therapy in future. PMID:27703175

  18. Ionotropic crustacean olfactory receptors.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Corey

    Full Text Available The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs, the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs, as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling.

  19. Presynaptic P2 receptors?

    Science.gov (United States)

    Stone, T W; O'Kane, E M; Nikbakht, M R; Ross, F M

    2000-07-01

    Although the emphasis in ATP research has been on postjunctional receptors, there is also evidence for presynaptic receptors regulating transmitter release in the autonomic nervous system. Recent work has attempted to identify similar mechanisms in the central nervous system. Some of the existing results can be explained by the metabolism of nucleotides to adenosine or adenosine 5'-monophosphate (AMP). However, studies of presynaptic effects using sensitive electrophysiological tests such as paired-pulse interactions indicate that nucleotides can act at presynaptic sites, but that their effects may be mediated by a release of adenosine. Results are also described which indicate that, under some conditions, nucleotides can mediate phenomena such as long-term potentiation, which probably involves a significant presynaptic element. In part these effects may involve a nucleotide-induced release of adenosine and the simultaneous activation of P1 and P2 receptors.

  20. Human presynaptic receptors.

    Science.gov (United States)

    Schlicker, Eberhard; Feuerstein, Thomas

    2017-04-01

    Presynaptic receptors are sites at which transmitters, locally formed mediators or hormones inhibit or facilitate the release of a given transmitter from its axon terminals. The interest in the identification of presynaptic receptors has faded in recent years and it may therefore be justified to give an overview of their occurrence in the autonomic and central nervous system; this review will focus on presynaptic receptors in human tissues. Autoreceptors are presynaptic receptors at which a given transmitter restrains its further release, though in some instances may also increase its release. Inhibitory autoreceptors represent a typical example of a negative feedback; they are tonically activated by the respective endogenous transmitter and/or are constitutively active. Autoreceptors also play a role under pathophysiological conditions, e.g. by limiting the massive noradrenaline release occurring during congestive heart failure. They can be used for therapeutic purposes; e.g., the α2-adrenoceptor antagonist mirtazapine is used as an antidepressant and the inverse histamine H3 receptor agonist pitolisant has been marketed as a new drug for the treatment of narcolepsy in 2016. Heteroreceptors are presynaptic receptors at which transmitters from adjacent neurons, locally formed mediators (e.g. endocannabinoids) or hormones (e.g. adrenaline) can inhibit or facilitate transmitter release; they may be subject to an endogenous tone. The constipating effect of the sympathetic nervous system or of the antihypertensive drug clonidine is related to the activation of inhibitory α2-adrenoceptors on postganglionic parasympathetic neurons. Part of the stimulating effect of adrenaline on the sympathetic nervous system during stress is related to its facilitatory effect on noradrenaline release via β2-adrenoceptors.

  1. Biomimetic Receptors and Sensors

    Directory of Open Access Journals (Sweden)

    Franz L. Dickert

    2014-11-01

    Full Text Available In biomimetics, living systems are imitated to develop receptors for ions, molecules and bioparticles. The most pertinent idea is self-organization in analogy to evolution in nature, which created the key-lock principle. Today, modern science has been developing host-guest chemistry, a strategy of supramolecular chemistry for designing interactions of analytes with synthetic receptors. This can be realized, e.g., by self-assembled monolayers (SAMs or molecular imprinting. The strategies are used for solid phase extraction (SPE, but preferably in developing recognition layers of chemical sensors.

  2. Beyond the Receptor

    Institute of Scientific and Technical Information of China (English)

    Russell Jones

    2008-01-01

    @@ Had this Special Issue on plant hormones been published 5 years ago,it is likely that details about biosynthetic pathways would have taken center stage.As articles in this issue show,however,the field of plant hormone research has progressed rapidly and is now moving beyond the search for receptors.Progress in research on the mechanism of action of plant hormones has been rapid;receptors for the main classes of hormones have been identified;and the search is on for players downstream in signal-transduction chains.

  3. Assays for calcitonin receptors

    Energy Technology Data Exchange (ETDEWEB)

    Teitelbaum, A.P.; Nissenson, R.A.; Arnaud, C.D.

    1985-01-01

    The assays for calcitonin receptors described focus on their use in the study of the well-established target organs for calcitonin, bone and kidney. The radioligand used in virtually all calcitonin binding studies is /sup 125/I-labelled salmon calcitonin. The lack of methionine residues in this peptide permits the use of chloramine-T for the iodination reaction. Binding assays are described for intact bone, skeletal plasma membranes, renal plasma membranes, and primary kidney cell cultures of rats. Studies on calcitonin metabolism in laboratory animals and regulation of calcitonin receptors are reviewed.

  4. Chemokine Receptors and Transplantation

    Institute of Scientific and Technical Information of China (English)

    Jinquan Tan; Gang Zhou

    2005-01-01

    A complex process including both the innate and acquired immune responses results in allograft rejection. Some chemokine receptors and their ligands play essential roles not only for leukocyte migration into the graft but also in facilitating dendritic and T cell trafficking between lymph nodes and the transplant in the early and late stage of the allogeneic response. This review focuses on the impact of these chemoattractant proteins on transplant outcome and novel diagnostic and therapeutic approaches for antirejection therapy based on targeting of chemokine receptors and/or their ligands. Cellular & Molecular Immunology.

  5. Angiotensin type 2 receptor (AT2R) and receptor Mas

    DEFF Research Database (Denmark)

    Villela, Daniel; Leonhardt, Julia; Patel, Neal

    2015-01-01

    The angiotensin type 2 receptor (AT2R) and the receptor Mas are components of the protective arms of the renin-angiotensin system (RAS), i.e. they both mediate tissue protective and regenerative actions. The spectrum of actions of these two receptors and their signalling mechanisms display striking...

  6. Characterization of melanocortin receptors.

    Science.gov (United States)

    Goetz, Aaron S; Ignar, Diane M

    2003-11-01

    This unit describes a Scintillation Proximity Assay (SPA) for the measurement of ligand binding to melanocortin receptors (MCRs) using membranes prepared from cell lines stably expressing recombinant MCRs. It provides a facile method for determining the affinity of compounds at MC1R, MC3R, MC4R, or MC5R.

  7. P2-purinerge receptorer

    DEFF Research Database (Denmark)

    Solgaard, Marie; Jørgensen, Niklas Rye

    2005-01-01

    and by osteoclasts, and agonist binding affects cell proliferation, differentiation, activity and apoptosis. With increasing knowledge of the function and role of these receptors in bone biology, they will undoubtedly be a future target for the design of new drugs which can be used for treatment of metabolic bone...

  8. Meeting report: nuclear receptors

    DEFF Research Database (Denmark)

    Tuckermann, Jan; Bourguet, William; Mandrup, Susanne

    2010-01-01

    The biannual European Molecular Biology Organization (EMBO) conference on nuclear receptors was organized by Beatrice Desvergne and Laszlo Nagy and took place in Cavtat near Dubrovnik on the Adriatic coast of Croatia September 25-29, 2009. The meeting brought together researchers from all over...

  9. Glutamate receptor ligands

    DEFF Research Database (Denmark)

    Guldbrandt, Mette; Johansen, Tommy N; Frydenvang, Karla Andrea;

    2002-01-01

    Homologation and substitution on the carbon backbone of (S)-glutamic acid [(S)-Glu, 1], as well as absolute stereochemistry, are structural parameters of key importance for the pharmacological profile of (S)-Glu receptor ligands. We describe a series of methyl-substituted 2-aminoadipic acid (AA......-ray crystallographic analyses, chemical correlation, and CD spectral analyses. The effects of the individual stereoisomers at ionotropic and metabotropic (S)-Glu receptors (iGluRs and mGluRs) were characterized. Compounds with S-configuration at the alpha-carbon generally showed mGluR2 agonist activity of similar...... limited effect on pharmacology. Structure-activity relationships at iGluRs in the rat cortical wedge preparation showed a complex pattern, some compounds being NMDA receptor agonists [e.g., EC(50) =110 microM for (2S,5RS)-5-methyl-AA (6a,b)] and some compounds showing NMDA receptor antagonist effects [e...

  10. Ginkgolides and glycine receptors

    DEFF Research Database (Denmark)

    Jaracz, Stanislav; Nakanishi, Koji; Jensen, Anders A.

    2004-01-01

    Ginkgolides from the Ginkgo biloba tree are diterpenes with a cage structure consisting of six five-membered rings and a unique tBu group. They exert a variety of biological properties. In addition to being antagonists of the platelet activating factor receptor (PAFR), it has recently been shown...

  11. Androgen receptor mutations

    NARCIS (Netherlands)

    A.O. Brinkmann (Albert); G.W. Jenster (Guido); C. Ris-Stalpers (Carolyn); J.A.G.M. van der Korput (J. A G M); H.T. Brüggenwirth (Hennie); A.L.M. Boehmer (Annemie); J. Trapman (Jan)

    1995-01-01

    textabstractMale sexual differentiation and development proceed under direct control of androgens. Androgen action is mediated by the intracellular androgen receptor, which belongs to the superfamily of ligand-dependent transcription factors. At least three pathological situations are associated wit

  12. Metformin and insulin receptors

    Energy Technology Data Exchange (ETDEWEB)

    Vigneri, R.; Gullo, D.; Pezzino, V.

    The authors evaluated the effect of metformin (N,N-dimethylbiguanide), a biguanide known to be less toxic than phenformin, on insulin binding to its receptors, both in vitro and in vivo. Specific /sup 125/I-insulin binding to cultured IM-9 human lymphocytes and MCF-7 human breast cancer cells was determined after preincubation with metformin. Specific /sup 125/I-insulin binding to circulating monocytes was also evaluated in six controls, eight obese subjects, and six obese type II diabetic patients before and after a short-term treatment with metformin. Plasma insulin levels and blood glucose were also measured on both occasions. Metformin significantly increased insulin binding in vitro to both IM-9 lymphocytes and MCF-7 cells; the maximum increment was 47.1% and 38.0%, respectively. Metformin treatment significantly increased insulin binding in vivo to monocytes of obese subjects and diabetic patients. Scatchard analysis indicated that the increased binding was mainly due to an increase in receptor capacity. Insulin binding to monocytes of normal controls was unchanged after metformin as were insulin levels in all groups; blood glucose was significantly reduced after metformin only in diabetic patients. These data indicate that metformin increases insulin binding to its receptors in vitro and in vivo. The effect in vivo is observed in obese subjects and in obese type II diabetic patients, paralleling the clinical effectiveness of this antidiabetic agent, and is not due to receptor regulation by circulating insulin, since no variation in insulin levels was recorded.

  13. Quantitative analysis of individual hepatocyte growth factor receptor clusters in influenza A virus infected human epithelial cells using localization microscopy.

    Science.gov (United States)

    Wang, Qiaoyun; Dierkes, Rüdiger; Kaufmann, Rainer; Cremer, Christoph

    2014-04-01

    In this report, we applied a special localization microscopy technique (Spectral Precision Distance/Spatial Position Determination Microscopy/SPDM) to quantitatively analyze the effect of influenza A virus (IAV) infection on the spatial distribution of individual HGFR (Hepatocyte Growth Factor Receptor) proteins on the membrane of human epithelial cells at the single molecule resolution level. We applied this SPDM method to Alexa 488 labeled HGFR proteins with two different ligands. The ligands were either HGF (Hepatocyte Growth Factor), or IAV. In addition, the HGFR distribution in a control group of mock-incubated cells without any ligands was investigated. The spatial distribution of 1×10(6) individual HGFR proteins localized in large regions of interest on membranes of 240 cells was quantitatively analyzed and found to be highly non-random. Between 21% and 24% of the HGFR molecules were located in 44,304 small clusters with an average diameter of 54nm. The mean density of HGFR molecule signals per individual cluster was very similar in control cells, in cells with ligand only, and in IAV infected cells, independent of the incubation time. From the density of HGFR molecule signals in the clusters and the diameter of the clusters, the number of HGFR molecule signals per cluster was estimated to be in the range between 4 and 11 (means 5-6). This suggests that the membrane bound HGFR clusters form small molecular complexes with a maximum diameter of few tens of nm, composed of a relatively low number of HGFR molecules. This article is part of a Special Issue entitled: Viral Membrane Proteins - Channels for Cellular Networking. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Levamisole receptors: a second awakening

    Science.gov (United States)

    Martin, Richard J.; Robertson, Alan P.; Buxton, Samuel K.; Beech, Robin N.; Charvet, Claude L.; Neveu, Cedric

    2012-01-01

    Levamisole and pyrantel are old (1965) but useful anthelmintics that selectively activate nematode acetylcholine ion-channel receptors; they are used to treat roundworm infections in humans and animals. Interest in their actions has surged, giving rise to new knowledge and technical advances, including an ability to reconstitute receptors that reveal more details of modes of action/resistance. We now know that the receptors are plastic and may form diverse species-dependent subtypes of receptor with different sensitivities to individual cholinergic anthelmintics. Understanding the biology of the levamisole receptors is expected to inform other studies on anthelmintics (ivermectin and emodepside) that act on ion-channels. PMID:22607692

  15. Histamine H3-receptor isoforms.

    Science.gov (United States)

    Bakker, R A

    2004-10-01

    Increasing evidence supports a role for HA as a neurotransmitter and neuromodulator in various brain functions, including emotion, cognition, and feeding. The recent cloning of the histamine H3 receptor allowed for the subsequent cloning of a variety of H3 receptor isoforms from different species as well as the H4 receptor. As a result a wide variety of H3-receptor isoforms are now known that display differential brain expression patterns and signalling properties. These recent discoveries are discussed in view of the growing interest of the H3 receptor as a target for the development of potential therapeutics.

  16. Virally encoded 7TM receptors

    DEFF Research Database (Denmark)

    Rosenkilde, M M; Waldhoer, M; Lüttichau, H R

    2001-01-01

    A number of herpes- and poxviruses encode 7TM G-protein coupled receptors most of which clearly are derived from their host chemokine system as well as induce high expression of certain 7TM receptors in the infected cells. The receptors appear to be exploited by the virus for either immune evasion...... in various parts of the viral life cyclus. Most of the receptors encoded by human pathogenic virus are still orphan receptors, i.e. the endogenous ligand is unknown. In the few cases where it has been possible to characterize these receptors pharmacologically, they have been found to bind a broad spectrum...... expression of this single gene in certain lymphocyte cell lineages leads to the development of lesions which are remarkably similar to Kaposi's sarcoma, a human herpesvirus 8 associated disease. Thus, this and other virally encoded 7TM receptors appear to be attractive future drug targets....

  17. Receptor tyrosine kinases in carcinogenesis.

    Science.gov (United States)

    Zhang, Xiao-Ying; Zhang, Pei-Ying

    2016-11-01

    Receptor tyrosine kinases (RTKs) are cell surface glycoproteins with enzymatic activity involved in the regulation of various important functions. In all-important physiological functions including differentiation, cell-cell interactions, survival, proliferation, metabolism, migration and signaling these receptors are the key players of regulation. Additionally, mutations of RTKs or their overexpression have been described in many human cancers and are being explored as a novel avenue for a new therapeutic approach. Some of the deregulated RTKs observed to be significantly affected in cancers included vascular endothelial growth factor receptor, epidermal growth factor receptor, fibroblast growth factor receptor, RTK-like orphan receptor 1 (ROR1) and the platelet-derived growth factor receptor. These deregulated RTKs offer attractive possibilities for the new anticancer therapeutic approach involving specific targeting by monoclonal antibodies as well as kinase. The present review aimed to highlight recent perspectives of RTK ROR1 in cancer.

  18. TSH RECEPTOR AUTOANTIBODIES

    Science.gov (United States)

    Michalek, Krzysztof; Morshed, Syed A.; Latif, Rauf; Davies, Terry F.

    2009-01-01

    Thyrotropin receptor autoantibodies (TSHR-Abs) of the stimulating variety are the hallmark of Graves’ disease. The presence of immune defects leading to synthesis of TSHR-Abs causes hyperthyroidism and is associated with other extrathyroidal manifestations. Further characterization of these antibodies has now been made possible by the generation of monoclonal antibodies with this unique stimulating capacity as well as similar TSHR-Abs not associated with hyperthyroidism. Their present classification divides TSHR-Abs into stimulating, blocking (competing with TSH binding) and neutral (no signaling). Recent studies using monoclonal TSHR-Abs has revealed that stimulating and blocking antibodies bind to the receptor using mostly conformational epitopes, whilst neutral antibodies utilize exclusively linear peptides. Subtle differences in epitopes for stimulating and blocking antibodies account for the diversity of their biological actions. Recently non-classical signaling elicited by neutral antibodies has also been described, raising the need for a new classification of TSHR-Abs. PMID:19332151

  19. Ligand-Receptor Interactions

    CERN Document Server

    Bongrand, Pierre

    2008-01-01

    The formation and dissociation of specific noncovalent interactions between a variety of macromolecules play a crucial role in the function of biological systems. During the last few years, three main lines of research led to a dramatic improvement of our understanding of these important phenomena. First, combination of genetic engineering and X ray cristallography made available a simultaneous knowledg of the precise structure and affinity of series or related ligand-receptor systems differing by a few well-defined atoms. Second, improvement of computer power and simulation techniques allowed extended exploration of the interaction of realistic macromolecules. Third, simultaneous development of a variety of techniques based on atomic force microscopy, hydrodynamic flow, biomembrane probes, optical tweezers, magnetic fields or flexible transducers yielded direct experimental information of the behavior of single ligand receptor bonds. At the same time, investigation of well defined cellular models raised the ...

  20. The interleukin-4 receptor: signal transduction by a hematopoietin receptor.

    Science.gov (United States)

    Keegan, A D; Pierce, J H

    1994-02-01

    Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3'-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome.

  1. Functional EpoR pathway utilization is not detected in primary tumor cells isolated from human breast, non-small cell lung, colorectal, and ovarian tumor tissues.

    Directory of Open Access Journals (Sweden)

    Scott D Patterson

    Full Text Available Several clinical trials in oncology have reported increased mortality or disease progression associated with erythropoiesis-stimulating agents. One hypothesis proposes that erythropoiesis-stimulating agents directly stimulate tumor proliferation and/or survival through cell-surface receptors. To test this hypothesis and examine if human tumors utilize the erythropoietin receptor pathway, the response of tumor cells to human recombinant erythropoietin was investigated in disaggregated tumor cells obtained from 186 patients with colorectal, breast, lung, ovarian, head and neck, and other tumors. A cocktail of well characterized tumor growth factors (EGF, HGF, and IGF-1 were analyzed in parallel as a positive control to determine whether freshly-isolated tumor cells were able to respond to growth factor activation ex vivo. Exposing tumor cells to the growth factor cocktail resulted in stimulation of survival and proliferation pathways as measured by an increase in phosphorylation of the downstream signaling proteins AKT and ERK. In contrast, no activation by human recombinant erythropoietin was observed in isolated tumor cells. Though tumor samples exhibited a broad range of cell-surface expression of EGFR, c-Met, and IGF-1R, no cell-surface erythropoietin receptor was detected in tumor cells from the 186 tumors examined (by flow cytometry or Western blot. Erythropoiesis-stimulating agents did not act directly upon isolated tumor cells to stimulate pathways known to promote proliferation or survival of human tumor cells isolated from primary and metastatic tumor tissues.

  2. [Lipoprotein receptors. Old acquaintances and newcomers].

    Science.gov (United States)

    Ducobu, J

    1997-02-01

    Lipoprotein receptors are plasma membrane proteins of high affinity which interact with circulating lipoprotein particles. The well characterized LDL receptor continues to be analysed and some new findings on its intracellular mechanisms of action have emerged. New lipoprotein receptors have recently been described: the chylomicron remnant receptor or LDL-related protein (LRP), the lipolysis stimulated receptor (LSR), the very low density lipoprotein receptor (VLDLR), the HDL receptor (HDLR) and the scavenger receptor (SR). The molecular details of the receptors will facilitate the development of new therapeutic means to improve receptor-mediated clearance of lipoproteins.

  3. Similarity of Bovine Rotavirus Receptor and Human Rotavirus Receptor

    Institute of Scientific and Technical Information of China (English)

    苏琦华; 訾自强; 潘菊芬; 徐燕

    2004-01-01

    The monoclonal antibody against bovine rotavirus (BRV) receptor (BRV-R-mAb) was used to explore the similarity between the receptors of BRV and human rotavirus (HRV). ELISA, dot immunobinding assay, cell protection assay, solid-phase assay and immunohistochemistry method were applied. BRV-R-mAb bound both anti-BRV IgG and anti-HRV IgG respectively and could protect MA 104 cells against BRV and HRV challenges. Immunohistochemistry test showed that there were rotavirus receptors on the surfaces of foetal intestinal, tracheal mucosa and MA 104 cells membrane. We purified the rotavirus receptors on MA 104 ceils, which could bind both BRV and HRV in vitro. It is concluded that BRV receptor and HRV receptor are homogenous proteins and can be recognized by both BRV and HRV.

  4. Melatonin Receptor Genes in Vertebrates

    Directory of Open Access Journals (Sweden)

    Hua Dong Yin

    2013-05-01

    Full Text Available Melatonin receptors are members of the G protein-coupled receptor (GPCR family. Three genes for melatonin receptors have been cloned. The MT1 (or Mel1a or MTNR1A and MT2 (or Mel1b or MTNR1B receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype, Mel1c (or MTNR1C, has been identified in fish, amphibians and birds. Another melatonin related orphan receptor, GPR50, which does not bind melatonin, is found exclusively in mammals. The hormone melatonin is secreted primarily by the pineal gland, with highest levels occurring during the dark period of a circadian cycle. This hormone acts systemically in numerous organs. In the brain, it is involved in the regulation of various neural and endocrine processes, and it readjusts the circadian pacemaker, the suprachiasmatic nucleus. This article reviews recent studies of gene organization, expression, evolution and mutations of melatonin receptor genes of vertebrates. Gene polymorphisms reveal that numerous mutations are associated with diseases and disorders. The phylogenetic analysis of receptor genes indicates that GPR50 is an outgroup to all other melatonin receptor sequences. GPR50 may have separated from a melatonin receptor ancestor before the split between MTNR1C and the MTNR1A/B ancestor.

  5. Significant blockade of multiple receptor tyrosine kinases by MGCD516 (Sitravatinib), a novel small molecule inhibitor, shows potent anti-tumor activity in preclinical models of sarcoma.

    Science.gov (United States)

    Patwardhan, Parag P; Ivy, Kathryn S; Musi, Elgilda; de Stanchina, Elisa; Schwartz, Gary K

    2016-01-26

    Sarcomas are rare but highly aggressive mesenchymal tumors with a median survival of 10-18 months for metastatic disease. Mutation and/or overexpression of many receptor tyrosine kinases (RTKs) including c-Met, PDGFR, c-Kit and IGF1-R drive defective signaling pathways in sarcomas. MGCD516 (Sitravatinib) is a novel small molecule inhibitor targeting multiple RTKs involved in driving sarcoma cell growth. In the present study, we evaluated the efficacy of MGCD516 both in vitro and in mouse xenograft models in vivo. MGCD516 treatment resulted in significant blockade of phosphorylation of potential driver RTKs and induced potent anti-proliferative effects in vitro. Furthermore, MGCD516 treatment of tumor xenografts in vivo resulted in significant suppression of tumor growth. Efficacy of MGCD516 was superior to imatinib and crizotinib, two other well-studied multi-kinase inhibitors with overlapping target specificities, both in vitro and in vivo. This is the first report describing MGCD516 as a potent multi-kinase inhibitor in different models of sarcoma, superior to imatinib and crizotinib. Results from this study showing blockade of multiple driver signaling pathways provides a rationale for further clinical development of MGCD516 for the treatment of patients with soft-tissue sarcoma.

  6. Flavivirus Entry Receptors: An Update

    Directory of Open Access Journals (Sweden)

    Manuel Perera-Lecoin

    2013-12-01

    Full Text Available Flaviviruses enter host cells by endocytosis initiated when the virus particles interact with cell surface receptors. The current model suggests that flaviviruses use at least two different sets of molecules for infectious entry: attachment factors that concentrate and/or recruit viruses on the cell surface and primary receptor(s that bind to virions and direct them to the endocytic pathway. Here, we present the currently available knowledge regarding the flavivirus receptors described so far with specific attention to C-type lectin receptors and the phosphatidylserine receptors, T-cell immunoglobulin and mucin domain (TIM and TYRO3, AXL and MER (TAM. Their role in flavivirus attachment and entry as well as their implication in the virus biology will be discussed in depth.

  7. Angiotensin II receptors in testes

    Energy Technology Data Exchange (ETDEWEB)

    Millan, M.A.; Aguilera, G.

    1988-05-01

    Receptors for angiotensin II (AII) were identified and characterized in testes of rats and several primate species. Autoradiographic analysis of the binding of 125I-labeled (Sar1,Ile8)AII to rat, rhesus monkey, cebus monkey, and human testicular slide-mounted frozen sections indicated specific binding to Leydig cells in the interstitium. In rat collagenase-dispersed interstitial cells fractionated by Percoll gradient, AII receptor content was parallel to that of hCG receptors, confirming that the AII receptors are in the Leydig cells. In rat dispersed Leydig cells, binding was specific for AII and its analogs and of high affinity (Kd, 4.8 nM), with a receptor concentration of 15 fmol/10(6) cells. Studies of AII receptors in rat testes during development reveals the presence of high receptor density in newborn rats which decreases toward the adult age (4934 +/- 309, 1460 +/- 228, 772 +/- 169, and 82 +/- 12 fmol/mg protein at 5, 15, 20, and 30 days of age, respectively) with no change in affinity. At all ages receptors were located in the interstitium, and the decrease in binding was parallel to the decrease in the interstitial to tubular ratio observed with age. AII receptor properties in membrane-rich fractions from prepuberal testes were similar in the rat and rhesus monkey. Binding was time and temperature dependent, reaching a plateau at 60 min at 37 C, and was increased by divalent cations, EGTA, and dithiothreitol up to 0.5 mM. In membranes from prepuberal monkey testes, AII receptors were specific for AII analogs and of high affinity (Kd, 4.2 nM) with a receptor concentration of 7599 +/- 1342 fmol/mg protein. The presence of AII receptors in Leydig cells in rat and primate testes in conjunction with reports of the presence of other components of the renin-angiotensin system in the testes suggests that the peptide has a physiological role in testicular function.

  8. Uncompetitive antagonism of AMPA receptors

    DEFF Research Database (Denmark)

    Andersen, Trine F; Tikhonov, Denis B; Bølcho, Ulrik;

    2006-01-01

    Philanthotoxins are uncompetitive antagonists of Ca2+-permeable AMPA receptors presumed to bind to the pore-forming region, but a detailed molecular mechanism for this interaction is missing. Here a small library of novel philanthotoxins was designed and synthesized using a solid-phase strategy. ...... polyamine toxins antagonize the AMPA receptor ion channel and provide the basis for rational development of uncompetitive antagonists of AMPA receptors....

  9. GABAρ1/GABAAα1 receptor chimeras to study receptor desensitization

    Science.gov (United States)

    Martínez-Torres, Ataúlfo; Demuro, Angelo; Miledi, Ricardo

    2000-01-01

    γ-Aminobutyrate type C (GABAC) receptors are ligand-gated ion channels that are expressed preponderantly in the vertebrate retina and are characterized, among other things, by a very low rate of desensitization and resistance to the specific GABAA antagonist bicuculline. To examine which structural elements determine the nondesensitizing character of the human homomeric ρ1 receptor, we used a combination of gene chimeras and electrophysiology of receptors expressed in Xenopus oocytes. Two chimeric genes were constructed, made up of portions of the ρ1-subunit and of the α1-subunit of the GABAA receptor. When expressed in Xenopus oocytes, one chimeric gene (ρ1/α1) formed functional homooligomeric receptors that were fully resistant to bicuculline and were blocked by the specific GABAC antagonist (1,2,5,6-tetrahydropyridine-4-yl)methylphosphinic acid and by zinc. Moreover, these chimeric receptors had a fast-desensitizing component, even faster than that of heterooligomeric GABAA receptors, in striking contrast to the almost nil desensitization of wild-type ρ1 (wt ρ1) receptors. To see whether the fast-desensitizing characteristic of the chimera was determined by the amino acids forming the ion channels, we replaced the second transmembrane segment (TM2) of ρ1 by that of the α1-subunit of GABAA. Although the α1-subunit forms fast-desensitizing receptors when coexpressed with other GABAA subunits, the sole transfer of the α1TM2 segment to ρ1 was not sufficient to form desensitizing receptors. All this suggests that the slow-desensitizing trait of ρ1 receptors is determined by a combination of several interacting domains along the molecule. PMID:10725369

  10. Renal dopamine receptors and hypertension.

    Science.gov (United States)

    Hussain, Tahir; Lokhandwala, Mustafa F

    2003-02-01

    Dopamine has been recognized as an important modulator of central as well as peripheral physiologic functions in both humans and animals. Dopamine receptors have been identified in a number of organs and tissues, which include several regions within the central nervous system, sympathetic ganglia and postganglionic nerve terminals, various vascular beds, the heart, the gastrointestinal tract, and the kidney. The peripheral dopamine receptors influence cardiovascular and renal function by decreasing afterload and vascular resistance and promoting sodium excretion. Within the kidney, dopamine receptors are present along the nephron, with highest density on proximal tubule epithelial cells. It has been reported that there is a defective dopamine receptor, especially D(1) receptor function, in the proximal tubule of various animal models of hypertension as well as in humans with essential hypertension. Recent reports have revealed the site of and the molecular mechanisms responsible for the defect in D(1) receptors in hypertension. Moreover, recent studies have also demonstrated that the disruption of various dopamine receptor subtypes and their function produces hypertension in rodents. In this review, we present evidence that dopamine and dopamine receptors play an important role in regulating renal sodium excretion and that defective renal dopamine production and/or dopamine receptor function may contribute to the development of various forms of hypertension.

  11. 表皮生长因子受体和血管内皮细胞生长因子受体之外肺癌靶向治疗新进展%Targeted therapies for lung cancer beyond anti-epidermal growth factor receptors and anti-vascular endothelial cell growth factor receptors: exploring a new frontier

    Institute of Scientific and Technical Information of China (English)

    虞永峰; 陆舜

    2010-01-01

    目前肺癌的生物靶向治疗已进入临床治疗阶段,以吉非替尼、厄洛替尼和西妥昔单抗为代表的抗表皮生长因子受体(epidermal growth factor receptor, EGFR)通路的药物和以贝伐单抗为代表的抗血管内皮细胞生长因子受体(vascular endothelial cell growth factor receptor, VEGFR)通路的药物已成功地应用于肺癌临床治疗.然而,肺癌分子生物学机制十分复杂,以EGFR和VEGFR信号通路为靶点的治疗存在局限和不足.近年来,肺癌新的分子生物靶点逐渐受到关注,例如棘皮动物微管相关蛋白4/间变淋巴瘤激酶(echinoderm microtubule-associated protein-like 4/anaplastic lymphoma kinase, EML4-ALK)融合基因、哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin, mTOR)、胰岛素样生长因子Ⅰ型受体(insulin-like growth factor type Ⅰ receptor, IGF-1R)和间质上皮转变因子(mesenchymal-epithelial transition factor, c-MET)等.本文对上述分子生物学标志物在肺癌治疗中的作用及其相关临床研究进展进行综述.

  12. Leptin and its receptors.

    Science.gov (United States)

    Wada, Nobuhiro; Hirako, Satoshi; Takenoya, Fumiko; Kageyama, Haruaki; Okabe, Mai; Shioda, Seiji

    2014-11-01

    Leptin is mainly produced in the white adipose tissue before being secreted into the blood and transported across the blood-brain barrier. Leptin binds to a specific receptor (LepR) that has numerous subtypes (LepRa, LepRb, LepRc, LepRd, LepRe, and LepRf). LepRb, in particular, is expressed in several brain nuclei, including the arcuate nucleus, the paraventricular nucleus, and the dorsomedial, lateral and ventromedial regions of the hypothalamus. LepRb is also co-expressed with several neuropeptides, including proopiomelanocortin, neuropeptide Y, galanin, galanin-like peptide, gonadotropin-releasing hormone, tyrosine hydroxylase and neuropeptide W. Functionally, LepRb induces activation of the JAK2/ERK, /STAT3, /STAT5 and IRS/PI3 kinase signaling cascades, which are important for the regulation of energy homeostasis and appetite in mammals. In this review, we discuss the structure, genetics and distribution of the leptin receptors, and their role in cell signaling mechanisms.

  13. Axonal GABAA receptors.

    Science.gov (United States)

    Trigo, Federico F; Marty, Alain; Stell, Brandon M

    2008-09-01

    Type A GABA receptors (GABA(A)Rs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated showing that GABA(A)Rs are prevalent not only in the somatodendritic compartment of CNS neurons, but also in their axonal compartment. Evidence for axonal GABA(A)Rs includes new immunohistochemical and immunogold data: direct recording from single axonal terminals; and effects of local applications of GABA(A)R modulators on action potential generation, on axonal calcium signalling, and on neurotransmitter release. Strikingly, whereas presynaptic GABA(A)Rs have long been considered inhibitory, the new studies in the mammalian brain mostly indicate an excitatory action. Depending on the neuron that is under study, axonal GABA(A)Rs can be activated by ambient GABA, by GABA spillover, or by an autocrine action, to increase either action potential firing and/or transmitter release. In certain neurons, the excitatory effects of axonal GABA(A)Rs persist into adulthood. Altogether, axonal GABA(A)Rs appear as potent neuronal modulators of the mammalian CNS.

  14. Discoidin Domain Receptor 1

    Science.gov (United States)

    Song, Sunmi; Shackel, Nicholas A.; Wang, Xin M.; Ajami, Katerina; McCaughan, Geoffrey W.; Gorrell, Mark D.

    2011-01-01

    Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that binds and is activated by collagens. Transcriptional profiling of cirrhosis in human liver using a DNA array and quantitative PCR detected elevated mRNA expression of DDR1 compared with that in nondiseased liver. The present study characterized DDR1 expression in cirrhotic and nondiseased human liver and examined the cellular effects of DDR1 expression. mRNA expression of all five isoforms of DDR1 was detected in human liver, whereas DDR1a demonstrated differential expression in liver with hepatitis C virus and primary biliary cirrhosis compared with nondiseased liver. In addition, immunoblot analysis detected shed fragments of DDR1 more readily in cirrhotic liver than in nondiseased liver. Inasmuch as DDR1 is subject to protease-mediated cleavage after prolonged interaction with collagen, this differential expression may indicate more intense activation of DDR1 protein in cirrhotic compared with nondiseased liver. In situ hybridization and immunofluorescence localized intense DDR1 mRNA and protein expression to epithelial cells including hepatocytes at the portal-parenchymal interface and the luminal aspect of the biliary epithelium. Overexpression of DDR1a altered hepatocyte behavior including increased adhesion and less migration on extracelular matrix substrates. DDR1a regulated extracellular expression of matrix metalloproteinases 1 and 2. These data elucidate DDR1 function pertinent to cirrhosis and indicate the importance of epithelial cell–collagen interactions in chronic liver injury. PMID:21356365

  15. Trace amine-associated receptors are olfactory receptors in vertebrates.

    Science.gov (United States)

    Liberles, Stephen D

    2009-07-01

    The mammalian nose is a powerful chemosensor, capable of detecting and distinguishing a myriad of chemicals. Sensory neurons in the olfactory epithelium contain two types of chemosensory G protein-coupled receptors (GPCRs): odorant receptors (ORs), which are encoded by the largest gene family in mammals, and trace amine-associated receptors (TAARs), a smaller family of receptors distantly related to biogenic amine receptors. Do TAARs play a specialized role in olfaction distinct from that of ORs? Genes encoding TAARs are found in diverse vertebrates, from fish to mice to humans. Like OR genes, each Taar gene defines a unique population of canonical sensory neurons dispersed in a single zone of the olfactory epithelium. Ligands for mouse TAARs include a number of volatile amines, several of which are natural constituents of mouse urine, a rich source of rodent social cues. One chemical, 2-phenylethylamine, is reported to be enriched in the urine of stressed animals, and two others, trimethylamine and isoamylamine, are enriched in male versus female urine. Furthermore, isoamylamine has been proposed to be a pheromone that induces puberty acceleration in young female mice. These data raise the possibility that some TAARs are pheromone receptors in the nose, a hypothesis consistent with recent data suggesting that the olfactory epithelium contains dedicated pheromone receptors, separate from pheromone receptors in the vomeronasal organ. Future experiments will clarify the roles of TAARs in olfaction.

  16. GABAB receptors modulate NMDA receptor calcium signals in dendritic spines.

    Science.gov (United States)

    Chalifoux, Jason R; Carter, Adam G

    2010-04-15

    Metabotropic GABA(B) receptors play a fundamental role in modulating the excitability of neurons and circuits throughout the brain. These receptors influence synaptic transmission by inhibiting presynaptic release or activating postsynaptic potassium channels. However, their ability to directly influence different types of postsynaptic glutamate receptors remains unresolved. Here we examine GABA(B) receptor modulation in layer 2/3 pyramidal neurons from the mouse prefrontal cortex. We use two-photon laser-scanning microscopy to study synaptic modulation at individual dendritic spines. Using two-photon optical quantal analysis, we first demonstrate robust presynaptic modulation of multivesicular release at single synapses. Using two-photon glutamate uncaging, we then reveal that GABA(B) receptors strongly inhibit NMDA receptor calcium signals. This postsynaptic modulation occurs via the PKA pathway and does not affect synaptic currents mediated by AMPA or NMDA receptors. This form of GABA(B) receptor modulation has widespread implications for the control of calcium-dependent neuronal function.

  17. Possible Relevance of Receptor-Receptor Interactions between Viral- and Host-Coded Receptors for Viral-Induced Disease

    Directory of Open Access Journals (Sweden)

    Luigi F. Agnati

    2007-01-01

    Full Text Available It has been demonstrated that some viruses, such as the cytomegalovirus, code for G-protein coupled receptors not only to elude the immune system, but also to redirect cellular signaling in the receptor networks of the host cells. In view of the existence of receptor-receptor interactions, the hypothesis is introduced that these viral-coded receptors not only operate as constitutively active monomers, but also can affect other receptor function by interacting with receptors of the host cell. Furthermore, it is suggested that viruses could also insert not single receptors (monomers, but clusters of receptors (receptor mosaics, altering the cell metabolism in a profound way. The prevention of viral receptor-induced changes in host receptor networks may give rise to novel antiviral drugs that counteract viral-induced disease.

  18. The Mechanism of Gefitinib Resistance Induced by Hepatocyte Growth Factor 
in Sensitive Non-small Cell Lung Cancer Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Xianglan XUAN

    2013-01-01

    Full Text Available Background and objective Previous studies have reported that Met might be related to gefitinib resistance in non-small cell lung cancer (NSCLC. The present study aims to explore the mechanism of hepatocyte growth factor (HGF-induced gefitinib resistance in different gene types of sensitive NSCLC in vitro. Methods The PC-9 and H292 cell lines were chosen and induced by HGF. The cell survival was measured using MTT assay, the cell cycle distribution was measured using PI assay, and cell apoptosis with an Annexin V-PE assay, respectively. The c-Met and p-Met protein expression was determined via Western blot analysis. Results Gefitinib inhibited the growth of PC-9 and H292 cells in a dose-dependent manner. The concentration-survival curves of both cell lines shifted to the right when induced with HGF. HGF did not affect PC-9 and H292 cell proliferation. The cell also had a higher cell survival rate when treated with HGF and gefitinib compared with that under gefitinib alone (P<0.05. The apoptotic rate and cell cycle progression showed no significant difference between the HG and G group (P>0.05. HGF stimulated Met phosphorylation in the PC-9 and H292 cells. Gefitinib inhibited the HGF-induced Met phosphorylation in PC-9 cells, but not in H292 cells. Conclusion HGF induces gefitinib resistance in PC-9 and H292 cells. HGF-induced Met phosphorylation may be an important mechanism of gefitinib resistance in sensitive NSCLC.

  19. Hepatocyte growth factor, a determinant of airspace homeostasis in the murine lung.

    Directory of Open Access Journals (Sweden)

    Carla Calvi

    Full Text Available The alveolar compartment, the fundamental gas exchange unit in the lung, is critical for tissue oxygenation and viability. We explored hepatocyte growth factor (HGF, a pleiotrophic cytokine that promotes epithelial proliferation, morphogenesis, migration, and resistance to apoptosis, as a candidate mediator of alveolar formation and regeneration. Mice deficient in the expression of the HGF receptor Met in lung epithelial cells demonstrated impaired airspace formation marked by a reduction in alveolar epithelial cell abundance and survival, truncation of the pulmonary vascular bed, and enhanced oxidative stress. Administration of recombinant HGF to tight-skin mice, an established genetic emphysema model, attenuated airspace enlargement and reduced oxidative stress. Repair in the TSK/+ mouse was punctuated by enhanced akt and stat3 activation. HGF treatment of an alveolar epithelial cell line not only induced proliferation and scattering of the cells but also conferred protection against staurosporine-induced apoptosis, properties critical for alveolar septation. HGF promoted cell survival was attenuated by akt inhibition. Primary alveolar epithelial cells treated with HGF showed improved survival and enhanced antioxidant production. In conclusion, using both loss-of-function and gain-of-function maneuvers, we show that HGF signaling is necessary for alveolar homeostasis in the developing lung and that augmentation of HGF signaling can improve airspace morphology in murine emphysema. Our studies converge on prosurvival signaling and antioxidant protection as critical pathways in HGF-mediated airspace maintenance or repair. These findings support the exploration of HGF signaling enhancement for diseases of the airspace.

  20. Sensory receptors in monotremes.

    Science.gov (United States)

    Proske, U; Gregory, J E; Iggo, A

    1998-01-01

    This is a summary of the current knowledge of sensory receptors in skin of the bill of the platypus, Ornithorhynchus anatinus, and the snout of the echidna, Tachyglossus aculeatus. Brief mention is also made of the third living member of the monotremes, the long-nosed echidna, Zaglossus bruijnii. The monotremes are the only group of mammals known to have evolved electroreception. The structures in the skin responsible for the electric sense have been identified as sensory mucous glands with an expanded epidermal portion that is innervated by large-diameter nerve fibres. Afferent recordings have shown that in both platypuses and echidnas the receptors excited by cathodal (negative) pulses and inhibited by anodal (positive) pulses. Estimates give a total of 40,000 mucous sensory glands in the upper and lower bill of the platypus, whereas there are only about 100 in the tip of the echidna snout. Recording of electroreceptor-evoked activity from the brain of the platypus have shown that the largest area dedicated to somatosensory input from the bill, S1, shows alternating rows of mechanosensory and bimodal neurons. The bimodal neurons respond to both electrosensory and mechanical inputs. In skin of the platypus bill and echidna snout, apart from the electroreceptors, there are structures called push rods, which consist of a column of compacted cells that is able to move relatively independently of adjacent regions of skin. At the base of the column are Merkel cell complexes, known to be type I slowly adapting mechanoreceptors, and lamellated corpuscles, probably vibration receptors. It has been speculated that the platypus uses its electric sense to detect the electromyographic activity from moving prey in the water and for obstacle avoidance. Mechanoreceptors signal contact with the prey. For the echidna, a role for the electrosensory system has not yet been established during normal foraging behaviour, although it has been shown that it is able to detect the presence

  1. Coronavirus spike-receptor interactions

    NARCIS (Netherlands)

    Mou, H.

    2015-01-01

    Coronaviruses cause important diseases in humans and animals. Coronavirus infection starts with the virus binding with its spike proteins to molecules present on the surface of host cells that act as receptors. This spike-receptor interaction is highly specific and determines the virus’ cell, tissue

  2. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

    Steenbeek, F.G. van; Spee, B.; Penning, L.C.; Kummeling, A.; Gils, I.H.M.; Grinwis, G.C.M.; Leenen, D. van; Holstege, F.C.P.; Vos-Loohuis, M.; Rothuizen, J.; Leegwater, P.A.J.

    2013-01-01

    The aryl hydrocarbon receptor (AHR) mediates biological responses to toxic chemicals. An unexpected role for AHR in vascularization was suggested when mice lacking AHR displayed impaired closure of the ductus venosus after birth, as did knockout mice for aryl hydrocarbon receptor interacting protein

  3. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

    Steenbeek, F.G. van; Spee, B.; Penning, L.C.; Kummeling, A.; Gils, I.H.M.; Grinwis, G.C.M.; Leenen, D. van; Holstege, F.C.P.; Vos-Loohuis, M.; Rothuizen, J.; Leegwater, P.A.J.

    The aryl hydrocarbon receptor (AHR) mediates biological responses to toxic chemicals. An unexpected role for AHR in vascularization was suggested when mice lacking AHR displayed impaired closure of the ductus venosus after birth, as did knockout mice for aryl hydrocarbon receptor interacting

  4. Purinergic Receptors in Thrombosis and Inflammation

    National Research Council Canada - National Science Library

    Hechler, Béatrice; Gachet, Christian

    2015-01-01

    .... Beyond platelets, these 3 receptors, along with the P2Y2, P2Y6, and P2X7 receptors, constitute the main P2 receptors mediating the proinflammatory effects of nucleotides, which play important roles...

  5. Dopamine Receptors and Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Shin Hisahara

    2011-01-01

    Full Text Available Parkinson's disease (PD is a progressive extrapyramidal motor disorder. Pathologically, this disease is characterized by the selective dopaminergic (DAergic neuronal degeneration in the substantia nigra. Correcting the DA deficiency in PD with levodopa (L-dopa significantly attenuates the motor symptoms; however, its effectiveness often declines, and L-dopa-related adverse effects emerge after long-term treatment. Nowadays, DA receptor agonists are useful medication even regarded as first choice to delay the starting of L-dopa therapy. In advanced stage of PD, they are also used as adjunct therapy together with L-dopa. DA receptor agonists act by stimulation of presynaptic and postsynaptic DA receptors. Despite the usefulness, they could be causative drugs for valvulopathy and nonmotor complication such as DA dysregulation syndrome (DDS. In this paper, physiological characteristics of DA receptor familyare discussed. We also discuss the validity, benefits, and specific adverse effects of pharmaceutical DA receptor agonist.

  6. Opioids and their peripheral receptors

    Directory of Open Access Journals (Sweden)

    Francesco Amato

    2012-12-01

    Full Text Available The inflammation of peripheral tissues leads the primary afferent neurons, in particular at the cell bodies level located in the DRG (dorsal root ganglia, to an increased synthesis of opioid receptors: determining an “up-regulation”. After that opioid receptors are transported at the level of the nociceptive terminals, they are incorporated into the neuronal membrane becoming functional receptors. The above receptor proteins bind to opioid produced by immune cells or the exogenous ones. This leads to a direct or indirect suppression of the Ca2+ currents induced by TRPV1 or the currents of the Na+, resulting in neuronal reduced excitability and in transmitted signals decrease. The observation that the immune system is able to modulate the pain by ligands that interact with the opioid receptors located on sensory neurons, may have broad implications for the development of innovative and safer pain drugs.

  7. Ryanodine receptor channelopathies

    Science.gov (United States)

    Betzenhauser, Matthew J.

    2010-01-01

    Ryanodine receptors (RyR) are intracellular Ca2+-permeable channels that provide the sarcoplasmic reticulum Ca2+ release required for skeletal and cardiac muscle contractions. RyR1 underlies skeletal muscle contraction, and RyR2 fulfills this role in cardiac muscle. Over the past 20 years, numerous mutations in both RyR isoforms have been identified and linked to skeletal and cardiac diseases. Malignant hyperthermia, central core disease, and catecholaminergic polymorphic ventricular tachycardia have been genetically linked to mutations in either RyR1 or RyR2. Thus, RyR channelopathies are both of interest because they cause significant human diseases and provide model systems that can be studied to elucidate important structure–function relationships of these ion channels. PMID:20179962

  8. The evolution of vertebrate opioid receptors

    OpenAIRE

    Stevens, Craig W.

    2009-01-01

    The proteins that mediate the analgesic and other effects of opioid drugs and endogenous opioid peptides are known as opioid receptors. Opioid receptors consist of a family of four closely-related proteins belonging to the large superfamily of G-protein coupled receptors. The three types of opioid receptors shown unequivocally to mediate analgesia in animal models are the mu (MOR), delta (DOR), and kappa (KOR) opioid receptor proteins. The role of the fourth member of the opioid receptor fami...

  9. Estrogen-related receptor β (ERRβ) - renaissance receptor or receptor renaissance?

    Science.gov (United States)

    Divekar, Shailaja D; Tiek, Deanna M; Fernandez, Aileen; Riggins, Rebecca B

    2016-01-01

    Estrogen-related receptors (ERRs) are founding members of the orphan nuclear receptor (ONR) subgroup of the nuclear receptor superfamily. Twenty-seven years of study have yet to identify cognate ligands for the ERRs, though they have firmly placed ERRα and ERRγ at the intersection of cellular metabolism and oncogenesis. The pace of discovery for novel functions of ERRβ, however, has until recently been somewhat slower than that of its family members. ERRβ has also been largely ignored in summaries and perspectives of the ONR literature. Here, we provide an overview of established and emerging knowledge of ERRβ in mouse, man, and other species, highlighting unique aspects of ERRβ biology that set it apart from the other two estrogen-related receptors, with a focus on the impact of alternative splicing on the structure and function of this receptor.

  10. Stargazin Modulation of AMPA Receptors

    Directory of Open Access Journals (Sweden)

    Sana A. Shaikh

    2016-10-01

    Full Text Available Fast excitatory synaptic signaling in the mammalian brain is mediated by AMPA-type ionotropic glutamate receptors. In neurons, AMPA receptors co-assemble with auxiliary proteins, such as stargazin, which can markedly alter receptor trafficking and gating. Here, we used luminescence resonance energy transfer measurements to map distances between the full-length, functional AMPA receptor and stargazin expressed in HEK293 cells and to determine the ensemble structural changes in the receptor due to stargazin. In addition, we used single-molecule fluorescence resonance energy transfer to study the structural and conformational distribution of the receptor and how this distribution is affected by stargazin. Our nanopositioning data place stargazin below the AMPA receptor ligand-binding domain, where it is well poised to act as a scaffold to facilitate the long-range conformational selection observations seen in single-molecule experiments. These data support a model of stargazin acting to stabilize or select conformational states that favor activation.

  11. Cytokine receptors and hematopoietic differentiation.

    Science.gov (United States)

    Robb, L

    2007-10-15

    Colony-stimulating factors and other cytokines signal via their cognate receptors to regulate hematopoiesis. In many developmental systems, inductive signalling determines cell fate and, by analogy with this, it has been postulated that cytokines, signalling via their cognate receptors, may play an instructive role in lineage specification in hematopoiesis. An alternative to this instructive hypothesis is the stochastic or permissive hypothesis. The latter proposes that commitment to a particular hematopoietic lineage is an event that occurs independently of extrinsic signals. It predicts that the role of cytokines is to provide nonspecific survival and proliferation signals. In this review, we look at the role of cytokine receptor signalling in hematopoiesis and consider the evidence for both hypotheses. Data from experiments that genetically manipulate receptor gene expression in vitro or in vivo are reviewed. Experiments in which cytokine receptors were installed in multipotential cells showed that, in some cases, stimulation with the cognate ligand could lead to alterations in lineage output. The creation of genetically manipulated mouse strains demonstrated that cytokine receptors are required for expansion and survival of single lineages but did not reveal a role in lineage commitment. We conclude that hematopoietic differentiation involves mainly stochastic events, but that cytokine receptors also have some instructive role.

  12. Vascular dopamine-I receptors.

    Science.gov (United States)

    Yasunari, K; Kohno, M; Yokokawa, K; Horio, T; Kano, H; Takeda, T

    1995-06-01

    The modulation of dopamine DA1 receptors of cultured rat renal arterial smooth muscle cells by phorbol ester, glucocorticoid and sodium chloride was studied. The extent of [3H]Sch-23390 binding to phorbol ester-treated cell was increased without any change in the dissociation constant (Kd). At a concentration of 10 nmol/l, the synthetic glucocorticoid dexamethasone increased maximum receptor binding (Bmax) but had no effect on the Kd. 100 mmol/l sodium chloride did not change Bmax, but increased the Kd for DA1 receptor. The production of cAMP in response to DA1 receptor stimulation was enhanced without any change of the adenylate cyclase activity. The glucocorticoid effect on DA1 of arterial smooth muscle cells became apparent after hours of incubation in the presence of the steroid and was significantly inhibited by cycloheximide (10 micrograms/ml) and by the glucocorticoid receptor antagonist RU-38486, indicating that the effect required protein synthesis through glucocorticoid receptors. Treatment of cells with 1 mumol/l dexamethasone for 24 h increased basal and DA1-stimulated adenylate cyclase activity. Basal adenylate cyclase was decreased by sodium chloride in a dose-dependent manner. These results suggest differential control of DA1 receptors on vascular smooth muscle cells by protein kinase C, glucocorticoid or sodium chloride.

  13. Nuclear hormone receptors in podocytes

    Directory of Open Access Journals (Sweden)

    Khurana Simran

    2012-09-01

    Full Text Available Abstract Nuclear receptors are a family of ligand-activated, DNA sequence-specific transcription factors that regulate various aspects of animal development, cell proliferation, differentiation, and homeostasis. The physiological roles of nuclear receptors and their ligands have been intensively studied in cancer and metabolic syndrome. However, their role in kidney diseases is still evolving, despite their ligands being used clinically to treat renal diseases for decades. This review will discuss the progress of our understanding of the role of nuclear receptors and their ligands in kidney physiology with emphasis on their roles in treating glomerular disorders and podocyte injury repair responses.

  14. Innovative T Cell-Targeted Therapy for Ovarian Cancer

    Science.gov (United States)

    2013-10-01

    9. Yap TA, Sandhu SK, Alam SM, de Bono JS. HGF/c-MET targeted therapeutics: novel strategies for cancer medicine. Curr Drug Targets 2011; 12(14...transmembrane (TM) domain , (v) co-stimulation domain (either CD28 (yellow) or CD137 (blue)), and CD3-zeta T cell signaling domains . ROR1- specific CARs...2- oxoquinoline derivatives. Bioorg Med Chem. 2011;19:5698-707. 30. Rabinovich BA, Ye Y, Etto T, Chen JQ, Levitsky HI, Overwijk WW , et al

  15. Quantitative receptor radioautography in the study of receptor-receptor interactions in the nucleus tractus solitarii

    Directory of Open Access Journals (Sweden)

    Fior-Chadi D.R.

    1998-01-01

    Full Text Available The nucleus tractus solitarii (NTS in the dorsomedial medulla comprises a wide range of neuropeptides and biogenic amines. Several of them are related to mechanisms of central blood pressure control. Angiotensin II (Ang II, neuropeptide Y (NPY and noradrenaline (NA are found in the NTS cells, as well as their receptors. Based on this observation we have evaluated the modulatory effect of these peptide receptors on a2-adrenoceptors in the NTS. Using quantitative receptor radioautography, we observed that NPY and Ang II receptors decreased the affinity of a2-adrenoceptors for their agonists in the NTS of the rat. Cardiovascular experiments agreed with the in vitro data. Coinjection of a threshold dose of Ang II or of the NPY agonists together with an ED50 dose of adrenergic agonists such as NA, adrenaline and clonidine counteracted the depressor effect produced by the a2-agonist in the NTS. The results provide evidence for the existence of an antagonistic interaction between Ang II at1 receptors and NPY receptor subtypes with the a2-adrenoceptors in the NTS. This receptor interaction may reduce the transduction over the a2-adrenoceptors which can be important in central cardiovascular regulation and in the development of hypertension

  16. Autoimmune NMDA receptor encephalitis.

    Science.gov (United States)

    Lazar-Molnar, Eszter; Tebo, Anne E

    2015-01-01

    Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is a treatable autoimmune disease of the central nervous system (CNS) with prominent neurologic and psychiatric features at disease onset. The disease is associated with the production of autoantibodies to NMDAR, a protein involved in memory function and synaptic plasticity. Affected patients develop a multistage progressive illness with symptoms ranging from memory deficits, seizures and psychosis, to potentially lethal catatonia, and autonomic and breathing instability. The outcome can be much improved with accurate diagnosis and early treatment using adequate immunosuppressive therapy. However, since the neurological and psychiatric symptoms as well as the clinical examination results can be non-specific, the disease is probably under-recognized. Reliable and accurate clinical testing for the identification of NMDAR autoantibodies is crucial for diagnosis, timely treatment selection, and monitoring. Recently, a cell-based indirect immunofluorescent antibody test for the detection of IgG antibodies to NMDAR has become available for diagnostic use. This review highlights the progress and challenges of laboratory testing in the evaluation and management anti-NMDAR encephalitis, and perspectives for the future.

  17. Nuclear Receptor Signaling Atlas (NURSA)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Nuclear Receptor Signaling Atlas (NURSA) is designed to foster the development of a comprehensive understanding of the structure, function, and role in disease...

  18. Anthrax receptors position the spindle.

    Science.gov (United States)

    Minc, Nicolas; Piel, Matthieu

    2013-01-01

    Spindle orientation plays a pivotal role in tissue morphogenesis. An asymmetric anthrax receptor cap is revealed to promote activation of a formin to orient the spindle along the planar cell polarity (PCP) axis in zebrafish dorsal epiblast cells.

  19. [Nucleotide receptors and renal function].

    Science.gov (United States)

    Jankowski, Maciej

    2014-01-01

    Kidney plays a key role in homeostasis of human body. It has heterogenic structure and is characterized by complicated vascular beds and numbers of sympathetic nerves endings. Nucleotides receptors are involved in the regulation of blood flow, a fundamental process for renal function. Plasma is filtrated in renal glomerulus and activity of nucleotides receptors located on cells of glomerular filter modifies the physi- cochemical properties of filter and affects the filtration process. Electrolytes, water and low molecular weight molecules are reabsorbed from tubular fluid or secreted into fluid in proximal and distal tubules. Glomerular filtration rate and activity of tubular processes are regulated via nucleotides receptors by glomerulotubularbalance and tubuloglomerular feedback. Nucleotides receptors are involved in systemic regulation of blood pressure and carbohydrate metabolism.

  20. The lactate receptor, G-protein-coupled receptor 81/hydroxycarboxylic acid receptor 1

    DEFF Research Database (Denmark)

    Morland, Cecilie; Lauritzen, Knut Huso; Puchades, Maja;

    2015-01-01

    We have proposed that lactate is a “volume transmitter” in the brain and underpinned this by showing that the lactate receptor, G-protein-coupled receptor 81 (GPR81, also known as HCA1 or HCAR1), which promotes lipid storage in adipocytes, is also active in the mammalian brain. This includes...... anion channels activated by depolarization. In addition to locally produced lactate, lactate produced by exercising muscle as well as exogenous HCAR1 agonists, e.g., from fruits and berries, might activate the receptor on cerebral blood vessels and brain cells....

  1. An Update on GABAρ Receptors

    OpenAIRE

    Martínez-Delgado, Gustavo; Estrada-Mondragón, Argel; Miledi, Ricardo; Martínez-Torres, Ataúlfo

    2010-01-01

    The present review discusses the functional and molecular diversity of GABAρ receptors. These receptors were originally described in the mammalian retina, and their functional role in the visual pathway has been recently elucidated; however new studies on their distribution in the brain and spinal cord have revealed that they are more spread than originally thought, and thus it will be important to determine their physiological contribution to the GABAergic transmission in other areas of the ...

  2. Lysophospholipid receptors in drug discovery

    OpenAIRE

    Kihara, Yasuyuki; Mizuno, Hirotaka; Chun, Jerold

    2014-01-01

    Lysophospholipids (LPs), including lysophosphatidic acid (LPA), sphingosine 1-phospate (S1P), lysophosphatidylinositol (LPI), and lysophosphatidylserine (LysoPS), are bioactive lipids that transduce signals through their specific cell-surface G protein-coupled receptors, LPA1–6, S1P1–5, LPI1, and LysoPS1–3, respectively. These LPs and their receptors have been implicated in both physiological and pathophysiological processes such as autoimmune diseases, neurodegenerative diseases, fibrosis, p...

  3. Receptor antibodies as novel therapeutics for diabetes

    DEFF Research Database (Denmark)

    Ussar, Siegfried; Vienberg, Sara Gry; Kahn, C Ronald

    2011-01-01

    Antibodies to receptors can block or mimic hormone action. Taking advantage of receptor isoforms, co-receptors, and other receptor modulating proteins, antibodies and other designer ligands can enhance tissue specificity and provide new approaches to the therapy of diabetes and other diseases....

  4. Receptor-targeted metalloradiopharmaceuticals. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Green, Mark A.

    2000-03-22

    Copper (II) and platinum (II) coordination complexes were prepared and characterized. These complexes were designed to afford structural homology with steroidal and non-steroidal estrogens for possible use as receptor-targeted radiopharmaceuticals. While weak affinity for the estrogen receptor was detectable, none would appear to have sufficient receptor-affinity for estrogen-receptor-targeted imaging or therapy.

  5. A role for the brain RAS in Alzheimer's and Parkinson's diseases

    Directory of Open Access Journals (Sweden)

    John William Wright

    2013-10-01

    Full Text Available The brain renin-angiotensin system (RAS has available the necessary functional components to produce the active ligands angiotensins II, III, IV, angiotensin (1-7, and angiotensin (3-7. These ligands interact with several receptor proteins including AT1, AT2, AT4 and Mas distributed within the central and peripheral nervous systems as well as local RASs in several organs. This review first describes the enzymatic pathways in place to synthesize these ligands and the binding characteristics of these angiotensin receptor subtypes. We next discuss current hypotheses to explain the disorders of Alzheimer’s disease (AD and Parkinson’s disease (PD, as well as research efforts focused on the use of angiotensin converting enzyme (ACE inhibitors and angiotensin receptor blockers (ARBs, in their treatment. ACE inhibitors and ARBs are showing promise in the treatment of several neurodegenerative pathologies; however, there is a need for the development of analogues capable of penetrating the blood-brain barrier and acting as agonists or antagonists at these receptor sites. Angiotensins II (AngII and IV (Ang(IV have been shown to play opposing roles regarding memory acquisition and consolidation in animal models. We discuss the development of efficacious AngIV analogues in the treatment of animal models of AD and PD. These AngIV analogues act via the AT4 receptor subtype which may coincide with the hepatocyte growth factor (HGF/c-Met receptor system. Finally, future research directions are described concerning new approaches to the treatment of these two neurological diseases.

  6. Estrogen receptors in breast carcinoma.

    Science.gov (United States)

    Huaman, A

    1979-11-01

    On the basis of estrogen receptor assays, breast carcinomas are presently classified as estrogen-dependent tumors, which respond to endocrine therapy, and autonomous tumors, for which endocrine therapy is useless. This paper presents a short review of the biochemical principles of estrogen dependence, the procedures used to determine estrogen receptors, and the clinical applications of the findings of these assay procedures. Biobhemically, the estroogen dependence of normal breast cells is explained as a biochemical reaction occurring between the circulating estradiol and the breast cell, which occurs in 3 steps: 1) circulating estradiol penetrates the cellular membrane by passive diffusion, followed by 2) combining of estradiol with the estrogen-binding protein (estrophilin) and formation of an estrogen receptor complex which undergoes activation and translocation into the nucleus, to result in 3) the activated steroid receptor which combines with the nuclear charomatin and stimulates ribonucleic acid synthesis for the formation of estradiol binding proteins or estradiol receptors. The cytosol method of Wittliff et al. is described in brief and entails radioactive competitive analysis; the other available laboratory procedure is immunofluorescence of tumor sections. Quantification of estrogen receptor content can be used clinically to decide on ablative endocrine therapy, to determine the effectiveness of anti-estrogen administration, to determine the primary site of metastatic carcinoma, and as a screenng device.

  7. Nuclear Receptors, RXR, and the Big Bang.

    Science.gov (United States)

    Evans, Ronald M; Mangelsdorf, David J

    2014-03-27

    Isolation of genes encoding the receptors for steroids, retinoids, vitamin D, and thyroid hormone and their structural and functional analysis revealed an evolutionarily conserved template for nuclear hormone receptors. This discovery sparked identification of numerous genes encoding related proteins, termed orphan receptors. Characterization of these orphan receptors and, in particular, of the retinoid X receptor (RXR) positioned nuclear receptors at the epicenter of the "Big Bang" of molecular endocrinology. This Review provides a personal perspective on nuclear receptors and explores their integrated and coordinated signaling networks that are essential for multicellular life, highlighting the RXR heterodimer and its associated ligands and transcriptional mechanism.

  8. Prognostic Value of Estrogen Receptor alpha and Progesterone Receptor Conversion in Distant Breast Cancer Metastases

    NARCIS (Netherlands)

    Hoefnagel, Laurien D. C.; Moelans, Cathy B.; Meijer, S. L.; van Slooten, Henk-Jan; Wesseling, Pieter; Wesseling, Jelle; Westenend, Pieter J.; Bart, Joost; Seldenrijk, Cornelis A.; Nagtegaal, Iris D.; Oudejans, Joost; van der Valk, Paul; van Gils, Carla H.; van der Wall, Elsken; van Diest, Paul J.

    2012-01-01

    BACKGROUND: Changes in the receptor profile of primary breast cancers to their metastases (receptor conversion) have been described for the estrogen receptor alpha (ER alpha) and progesterone receptor (PR). The purpose of this study was to evaluate the impact of receptor conversion for ER alpha and

  9. Neurotrophins and their receptors in inflammation

    Institute of Scientific and Technical Information of China (English)

    NellyFROSSARD; CharlesADVENIER

    2004-01-01

    The neurotrophin family has recently been in volved ininflammatory and remodelling processes occurring in chronic inflammatory diseases, in particular in asthma. Nerve growth fac-tor (NGF) is a high molecular weight peptide that belongs to the neurotrophin family. It is synthesized by various structural and inflammatory cells and activates two types of receptors, the TrkA (tropomyosin-receptor kinase A) receptor and the p75NTR receptor, in the death receptor family. NGF was first studied for

  10. Toll-like receptors in neonatal sepsis.

    LENUS (Irish Health Repository)

    O'Hare, Fiona M

    2013-06-01

    Toll-like receptors are vital transmembrane receptors that initiate the innate immune response to many micro-organisms. The discovery of these receptors has improved our understanding of host-pathogen interactions, and these receptors play an important role in the pathogenesis of multiple neonatal conditions such as sepsis and brain injury. Toll-like receptors, especially TLRs 2 and 4, are associated with necrotizing enterocolitis, periventricular leukomalacia and sepsis.

  11. PAK4 interacts with p85 alpha: implications for pancreatic cancer cell migration

    Science.gov (United States)

    King, Helen; Thillai, Kiruthikah; Whale, Andrew; Arumugam, Prabhu; Eldaly, Hesham; Kocher, Hemant M.; Wells, Claire M.

    2017-01-01

    It has been reported that p21-activated kinase 4 (PAK4) is amplified in pancreatic cancer tissue. PAK4 is a member of the PAK family of serine/threonine kinases, which act as effectors for several small GTPases, and has been specifically identified to function downstream of HGF-mediated c-Met activation in a PI3K dependent manner. However, the functionality of PAK4 in pancreatic cancer and the contribution made by HGF signalling to pancreatic cancer cell motility remain to be elucidated. We now find that elevated PAK4 expression is coincident with increased expression levels of c-Met and the p85α subunit of PI3K. Furthermore, we demonstrate that pancreatic cancer cells have a specific motility response to HGF both in 2D and 3D physiomimetic organotypic assays; which can be suppressed by inhibition of PI3K. Significantly, we report a specific interaction between PAK4 and p85α and find that PAK4 deficient cells exhibit a reduction in Akt phosphorylation downstream of HGF signalling. These results implicate a novel role for PAK4 within the PI3K pathway via interaction with p85α. Thus, PAK4 could be an essential player in PDAC progression representing an interesting therapeutic opportunity. PMID:28205613

  12. Phenobarbital and Insulin Reciprocate Activation of the Nuclear Receptor Constitutive Androstane Receptor through the Insulin Receptor.

    Science.gov (United States)

    Yasujima, Tomoya; Saito, Kosuke; Moore, Rick; Negishi, Masahiko

    2016-05-01

    Phenobarbital (PB) antagonized insulin to inactivate the insulin receptor and attenuated the insulin receptor downstream protein kinase B (AKT)-forkhead box protein O1 and extracellular signal-regulated kinase 1/2 signals in mouse primary hepatocytes and HepG2 cells. Hepatic AKT began dephosphorylation in an early stage of PB treatment, and blood glucose levels transiently increased in both wild-type and constitutive androstane receptor (CAR) knockout (KO) mice. On the other hand, blood glucose levels increased in wild-type mice, but not KO mice, in later stages of PB treatment. As a result, PB, acting as an insulin receptor antagonist, elicited CAR-independent increases and CAR-dependent decreases of blood glucose levels at these different stages of treatment, respectively. Reciprocally, insulin activation of the insulin receptor repressed CAR activation and induction of its target CYP2B6 gene in HepG2 cells. Thus, PB and insulin cross-talk through the insulin receptor to regulate glucose and drug metabolism reciprocally.

  13. Met-Independent Hepatocyte Growth Factor-mediated regulation of cell adhesion in human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Davis Rodney

    2006-07-01

    Full Text Available Abstract Background Prostate cancer cells communicate reciprocally with the stromal cells surrounding them, inside the prostate, and after metastasis, within the bone. Each tissue secretes factors for interpretation by the other. One stromally-derived factor, Hepatocyte Growth Factor (HGF, was found twenty years ago to regulate invasion and growth of carcinoma cells. Working with the LNCaP prostate cancer progression model, we found that these cells could respond to HGF stimulation, even in the absence of Met, the only known HGF receptor. The new HGF binding partner we find on the cell surface may help to clarify conflicts in the past literature about Met expression and HGF response in cancer cells. Methods We searched for Met or any HGF binding partner on the cells of the PC3 and LNCaP prostate cancer cell models, using HGF immobilized on agarose beads. By using mass spectrometry analyses and sequencing we have identified nucleolin protein as a novel HGF binding partner. Antibodies against nucleolin (or HGF were able to ameliorate the stimulatory effects of HGF on met-negative prostate cancer cells. Western blots, RT-PCR, and immunohistochemistry were used to assess nucleolin levels during prostate cancer progression in both LNCaP and PC3 models. Results We have identified HGF as a major signaling component of prostate stromal-conditioned media (SCM and have implicated the protein nucleolin in HGF signal reception by the LNCaP model prostate cancer cells. Antibodies that silence either HGF (in SCM or nucleolin (on the cell surfaces eliminate the adhesion-stimulatory effects of the SCM. Likewise, addition of purified HGF to control media mimics the action of SCM. C4-2, an LNCaP lineage-derived, androgen-independent human prostate cancer cell line, responds to HGF in a concentration-dependent manner by increasing its adhesion and reducing its migration on laminin substratum. These HGF effects are not due to shifts in the expression levels of

  14. Purinergic Receptors in Ocular Inflammation

    Directory of Open Access Journals (Sweden)

    Ana Guzman-Aranguez

    2014-01-01

    Full Text Available Inflammation is a complex process that implies the interaction between cells and molecular mediators, which, when not properly “tuned,” can lead to disease. When inflammation affects the eye, it can produce severe disorders affecting the superficial and internal parts of the visual organ. The nucleoside adenosine and nucleotides including adenine mononucleotides like ADP and ATP and dinucleotides such as P1,P4-diadenosine tetraphosphate (Ap4A, and P1,P5-diadenosine pentaphosphate (Ap5A are present in different ocular locations and therefore they may contribute/modulate inflammatory processes. Adenosine receptors, in particular A2A adenosine receptors, present anti-inflammatory action in acute and chronic retinal inflammation. Regarding the A3 receptor, selective agonists like N6-(3-iodobenzyl-5′-N-methylcarboxamidoadenosine (CF101 have been used for the treatment of inflammatory ophthalmic diseases such as dry eye and uveoretinitis. Sideways, diverse stimuli (sensory stimulation, large intraocular pressure increases can produce a release of ATP from ocular sensory innervation or after injury to ocular tissues. Then, ATP will activate purinergic P2 receptors present in sensory nerve endings, the iris, the ciliary body, or other tissues surrounding the anterior chamber of the eye to produce uveitis/endophthalmitis. In summary, adenosine and nucleotides can activate receptors in ocular structures susceptible to suffer from inflammatory processes. This involvement suggests the possible use of purinergic agonists and antagonists as therapeutic targets for ocular inflammation.

  15. Ionotropic glutamate receptors & CNS disorders.

    Science.gov (United States)

    Bowie, Derek

    2008-04-01

    Disorders of the central nervous system (CNS) are complex disease states that represent a major challenge for modern medicine. Although aetilogy is often unknown, it is established that multiple factors such as defects in genetics and/or epigenetics, the environment as well as imbalance in neurotransmitter receptor systems are all at play in determining an individual's susceptibility to disease. Gene therapy is currently not available and therefore, most conditions are treated with pharmacological agents that modify neurotransmitter receptor signaling. Here, I provide a review of ionotropic glutamate receptors (iGluRs) and the roles they fulfill in numerous CNS disorders. Specifically, I argue that our understanding of iGluRs has reached a critical turning point to permit, for the first time, a comprehensive re-evaluation of their role in the cause of disease. I illustrate this by highlighting how defects in AMPA receptor (AMPAR) trafficking are important to fragile X mental retardation and ectopic expression of kainate receptor (KAR) synapses contributes to the pathology of temporal lobe epilepsy. Finally, I discuss how parallel advances in studies of other neurotransmitter systems may allow pharmacologists to work towards a cure for many CNS disorders rather than developing drugs to treat their symptoms.

  16. Brain CB₂ Receptors: Implications for Neuropsychiatric Disorders.

    Science.gov (United States)

    Roche, Michelle; Finn, David P

    2010-08-10

    Although previously thought of as the peripheral cannabinoid receptor, it is now accepted that the CB₂ receptor is expressed in the central nervous system on microglia, astrocytes and subpopulations of neurons. Expression of the CB₂ receptor in the brain is significantly lower than that of the CB₁ receptor. Conflicting findings have been reported on the neurological effects of pharmacological agents targeting the CB₂ receptor under normal conditions. Under inflammatory conditions, CB₂ receptor expression in the brain is enhanced and CB2 receptor agonists exhibit potent anti-inflammatory effects. These findings have prompted research into the CB₂ receptor as a possible target for the treatment of neuroinflammatory and neurodegenerative disorders. Neuroinflammatory alterations are also associated with neuropsychiatric disorders and polymorphisms in the CB₂ gene have been reported in depression, eating disorders and schizophrenia. This review will examine the evidence to date for a role of brain CB₂ receptors in neuropsychiatric disorders.

  17. Identification and mechanism of ABA receptor antagonism

    Energy Technology Data Exchange (ETDEWEB)

    Melcher, Karsten; Xu, Yong; Ng, Ley-Moy; Zhou, X. Edward; Soon, Fen-Fen; Chinnusamy, Viswanathan; Suino-Powell, Kelly M; Kovach, Amanda; Tham, Fook S.; Cutler, Sean R.; Li, Jun; Yong, Eu-Leong; Zhu, Jian-Kang; Xu, H. Eric (NU Sinapore); (Van Andel); (UCR)

    2010-11-11

    The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2 to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands.

  18. 胃癌相关基因c-met表达和凋亡的研究%Relationship between apoptosis and expression of c- met oncogene in gastric carcinomas

    Institute of Scientific and Technical Information of China (English)

    庄小强; 林三仁; 郑杰; 王立新; 孙桂华; 李燕

    2000-01-01

    目的研究c-met基因蛋白和细胞凋亡在胃黏膜病变演进的表达及关系,探讨c-met表达对胃癌(GC)预后的意义.方法145例经病理证实不同胃黏膜病变,采用免疫组织化学法检测c-met基因表达,采用原位末端标记法(TUNEL)检测细胞凋亡.用Long-rank法检测胃癌生存率.结果在浅表性胃炎(CSG)、萎缩肠化生胃炎(CAG+IM)、异型增生(DYS)、早期GC和进展期GC中,c-met基因表达率分别为24%,51%,62%,67%和68%,CAG+IM、DYS、GC均显著高于CSG(P<0.05).凋亡指数(AI)分别为(4.55±2.33)%,(6.43±5.60)%,(6.45±5.12)%,(6.55±4.80)%及(8.84±5.63)%,进展期GC显著高于CSG(P<0.05).胃黏膜凋亡指数与c-met表达强度有密切相关(P<0.05).c-met阳性表达与胃癌组织类型、浆膜浸润和淋巴结转移密切相关,而且BorrmannⅣ明显高于早期胃癌和Borrmann Ⅰ,Ⅱ(P<O.05).c-met阳性表达胃癌患者生存率显著差于阴性表达者.结论c-met基因表达与胃黏膜增殖和恶化有关,且与凋亡有相关性.c-met基因可能成为评估胃癌预后的一项新指标.

  19. Cannabinoids, cannabinoid receptors and tinnitus.

    Science.gov (United States)

    Smith, Paul F; Zheng, Yiwen

    2016-02-01

    One hypothesis suggests that tinnitus is a form of sensory epilepsy, arising partly from neuronal hyperactivity in auditory regions of the brain such as the cochlear nucleus and inferior colliculus. Although there is currently no effective drug treatment for tinnitus, anti-epileptic drugs are used in some cases as a potential treatment option. There is increasing evidence to suggest that cannabinoid drugs, i.e. cannabinoid receptor agonists, can also have anti-epileptic effects, at least in some cases and in some parts of the brain. It has been reported that cannabinoid CB1 receptors and the endogenous cannabinoid, 2-arachidonylglycerol (2-AG), are expressed in the cochlear nucleus and that they are involved in the regulation of plasticity. This review explores the question of whether cannabinoid receptor agonists are likely to be pro- or anti-epileptic in the cochlear nucleus and therefore whether cannabinoids and Cannabis itself are likely to make tinnitus better or worse.

  20. Are olfactory receptors really olfactive?

    DEFF Research Database (Denmark)

    Giorgi, Franco; Maggio, Roberto; Bruni, Luis Emilio

    2011-01-01

    Any living organism interacts with and responds specifically to environmental molecules by expressing specific olfactory receptors. This specificity will be first examined in causal terms with particular emphasis on the mechanisms controlling olfactory gene expression, cell-to-cell interactions...... and odor-decoding processes. However, this type of explanation does not entirely justify the role olfactory receptors have played during evolution, since they are also expressed ectopically in different organs and/or tissues. Homologous olfactory genes have in fact been found in such diverse cells and....../or organs as spermatozoa, testis and kidney where they are assumed to act as chemotactic sensors or renin modulators. To justify their functional diversity, homologous olfactory receptors are assumed to share the same basic role: that of conferring a self-identity to cells or tissues under varying...

  1. An Update on GABAρ Receptors

    Science.gov (United States)

    Martínez-Delgado, Gustavo; Estrada-Mondragón, Argel; Miledi, Ricardo; Martínez-Torres, Ataúlfo

    2010-01-01

    The present review discusses the functional and molecular diversity of GABAρ receptors. These receptors were originally described in the mammalian retina, and their functional role in the visual pathway has been recently elucidated; however new studies on their distribution in the brain and spinal cord have revealed that they are more spread than originally thought, and thus it will be important to determine their physiological contribution to the GABAergic transmission in other areas of the central nervous system. In addition, molecular modeling has revealed peculiar traits of these receptors that have impacted on the interpretations of the latest pharmacolgical and biophysical findings. Finally, sequencing of several vertebrate genomes has permitted a comparative analysis of the organization of the GABAρ genes. PMID:21629448

  2. Overexpression of NK2 inhibits liver regeneration after partial hepatectomy in mice

    Institute of Scientific and Technical Information of China (English)

    Toshiyuki Otsuka; Hitoshi Takagi; Glenn Merlino; Masatomo Mori; Norio Horiguchi; Daisuke Kanda; Takashi Kosone; Yuichi Yamazaki; Kazuhisa Yuasa; Naondo Sohara; Satoru Kakizaki; Ken Sato

    2005-01-01

    AIM: To investigate the in vivo effects of NK2 on liver regeneration after partial hepatectomy (PH). METHODS: Survival after PH was observed with 21 NK2 transgenic mice and 23 wild-type (WT) mice over 10 d. Liver regeneration was analyzed using histology and immunohistochemistry. Expressions of genes were analyzed using Northern blot analysis, immunoprecipitation and immunoblotting, and reverse transcriptase polymerase chain reaction assay. KaplanMeier method and the log-rank test were used for ahalyzing the survival after PH. Differences in the resultsof immunohistochemistry and percentage of liver regeneration was determined by the Student's t-test. RESULTS: More than half of NK2 transgenic mice died within 48 h after PH. After PH, increased deposition of small lipid droplets in hepatocytes was evident and hepatic proliferation was inhibited in NK2 transgenic mice. The hepatic expression and kinase activity of HGF receptor, c-Met, were unchanged among WT mice and NK2 transgenic mice after PH. The expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in liver tissues were prolonged in NK2 transgenic mice that died after PH.CONCLUSION: Our findings indicate that overexpression of NK2 inhibits liver regeneration after PH.

  3. Ionizing Radiation in Glioblastoma Initiating Cells

    Directory of Open Access Journals (Sweden)

    Maricruz eRivera

    2013-04-01

    Full Text Available Glioblastoma is the most common primary malignant brain tumor in adults with a median survival of 12-15 months with treatment consisting of surgical resection followed by ionizing radiation (IR and chemotherapy. Even aggressive treatment is often palliative due to near universal recurrence. Therapeutic resistance has been linked to a subpopulation of GBM cells with stem-cell like properties termed glioblastoma initiating cells (GICs. Recent efforts have focused on elucidating resistance mechanisms activated in GICs in response to IR. Among these, GICs preferentially activate the DNA damage response (DDR to result in a faster rate of double-strand break (DSB repair induced by IR as compared to the bulk tumor cells. IR also activates NOTCH and the hepatic growth factor (HGF receptor, c-MET, signaling cascades that play critical roles in promoting proliferation, invasion, and resistance to apoptosis. These pathways are preferentially activated in GICs and represent targets for pharmacologic intervention. While IR provides the benefit of improved survival, it paradoxically promotes selection of more malignant cellular phenotypes of glioblastoma. As reviewed here, finding effective combinations of radiation and molecular inhibitors to target GICs and non-GICs is essential for the development of more effective therapies.

  4. Cytokine-Leukotriene Receptor Interactions

    Directory of Open Access Journals (Sweden)

    Marek Rola-Pleszczynski

    2007-01-01

    Full Text Available Biochemical and pharmacological studies have identified the structure of leukotrienes, the pathways that lead to their synthesis, and the signaling events they trigger when they interact with their cognate receptors. A privileged interaction exists between these lipid mediators and another group of molecules essential for inflammation and immune modulation, namely, cytokines. Whereas leukotrienes can trigger the synthesis and release of selected cytokines in distinct cell populations, many cytokines can affect cellular responsiveness to leukotrienes by modulating leukotriene receptor expression. As we progressively begin to unravel these complex interactions, new areas of cell-cell communication and eventual therapeutic interventions will emerge.

  5. Nuclear receptors and nonalcoholic fatty liver disease.

    Science.gov (United States)

    Cave, Matthew C; Clair, Heather B; Hardesty, Josiah E; Falkner, K Cameron; Feng, Wenke; Clark, Barbara J; Sidey, Jennifer; Shi, Hongxue; Aqel, Bashar A; McClain, Craig J; Prough, Russell A

    2016-09-01

    Nuclear receptors are transcription factors which sense changing environmental or hormonal signals and effect transcriptional changes to regulate core life functions including growth, development, and reproduction. To support this function, following ligand-activation by xenobiotics, members of subfamily 1 nuclear receptors (NR1s) may heterodimerize with the retinoid X receptor (RXR) to regulate transcription of genes involved in energy and xenobiotic metabolism and inflammation. Several of these receptors including the peroxisome proliferator-activated receptors (PPARs), the pregnane and xenobiotic receptor (PXR), the constitutive androstane receptor (CAR), the liver X receptor (LXR) and the farnesoid X receptor (FXR) are key regulators of the gut:liver:adipose axis and serve to coordinate metabolic responses across organ systems between the fed and fasting states. Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease and may progress to cirrhosis and even hepatocellular carcinoma. NAFLD is associated with inappropriate nuclear receptor function and perturbations along the gut:liver:adipose axis including obesity, increased intestinal permeability with systemic inflammation, abnormal hepatic lipid metabolism, and insulin resistance. Environmental chemicals may compound the problem by directly interacting with nuclear receptors leading to metabolic confusion and the inability to differentiate fed from fasting conditions. This review focuses on the impact of nuclear receptors in the pathogenesis and treatment of NAFLD. Clinical trials including PIVENS and FLINT demonstrate that nuclear receptor targeted therapies may lead to the paradoxical dissociation of steatosis, inflammation, fibrosis, insulin resistance, dyslipidemia and obesity. Novel strategies currently under development (including tissue-specific ligands and dual receptor agonists) may be required to separate the beneficial effects of nuclear receptor activation from unwanted metabolic

  6. Slamf receptors : Modulators of Phagocyte Immune Responses

    NARCIS (Netherlands)

    Van Driel, Boaz Job

    2015-01-01

    Signaling Lymphocyte Activation Molecule family (Slamf) receptors can operate in three distinct modes. Slamf receptors can dictate the extent of immune responses, thereby maneuvering immunity to the optimal zone between immunopathology or autoimmunity and weak, ineffective immune responses. A second

  7. Mechanism for the activation of glutamate receptors

    Science.gov (United States)

    Scientists at the NIH have used a technique called cryo-electron microscopy to determine a molecular mechanism for the activation and desensitization of ionotropic glutamate receptors, a prominent class of neurotransmitter receptors in the brain and spina

  8. Cannabinoid receptor localization in brain

    Energy Technology Data Exchange (ETDEWEB)

    Herkenham, M.; Lynn, A.B.; Little, M.D.; Johnson, M.R.; Melvin, L.S.; de Costa, B.R.; Rice, K.C. (National Institute of Mental Health, Bethesda, MD (USA))

    1990-03-01

    (3H)CP 55,940, a radiolabeled synthetic cannabinoid, which is 10-100 times more potent in vivo than delta 9-tetrahydrocannabinol, was used to characterize and localize a specific cannabinoid receptor in brain sections. The potencies of a series of natural and synthetic cannabinoids as competitors of (3H)CP 55,940 binding correlated closely with their relative potencies in several biological assays, suggesting that the receptor characterized in our in vitro assay is the same receptor that mediates behavioral and pharmacological effects of cannabinoids, including human subjective experience. Autoradiography of cannabinoid receptors in brain sections from several mammalian species, including human, reveals a unique and conserved distribution; binding is most dense in outflow nuclei of the basal ganglia--the substantia nigra pars reticulata and globus pallidus--and in the hippocampus and cerebellum. Generally high densities in forebrain and cerebellum implicate roles for cannabinoids in cognition and movement. Sparse densities in lower brainstem areas controlling cardiovascular and respiratory functions may explain why high doses of delta 9-tetrahydrocannabinol are not lethal.

  9. Are olfactory receptors really olfactive?

    DEFF Research Database (Denmark)

    Giorgi, Franco; Maggio, Roberto; Bruni, Luis Emilio

    2011-01-01

    Any living organism interacts with and responds specifically to environmental molecules by expressing specific olfactory receptors. This specificity will be first examined in causal terms with particular emphasis on the mechanisms controlling olfactory gene expression, cell-to-cell interactions a...

  10. Hormone receptors in breast cancer

    NARCIS (Netherlands)

    Suijkerbuijk, K. P M; van der Wall, E.; van Diest, P. J.

    2016-01-01

    Steroid hormone receptors are critical for the growth and development of breast tissue as well as of breast cancer. The importance of the role estrogens in breast cancer has been delineated for more than 100 years. The analysis of its expression has been used not only to classify breast cancers but

  11. Dopamine Receptor Availability in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2002-01-01

    Full Text Available Striatal dopamine (D2 receptor availability was determined by iodobenzamide brain SPECT, before and 3 months after methylphenidate (MPH therapy, in 9 children (mean age, 9.8 years with attention deficit hyperactivity disorder (ADHD examined at Gazi University, Ankara, Turkey.

  12. Emerging GLP-1 receptor agonists

    DEFF Research Database (Denmark)

    Lund, Asger; Knop, Filip K; Vilsbøll, Tina

    2011-01-01

    Introduction: Recently, glucagon-like peptide-1 receptor (GLP-1R) agonists have become available for the treatment of type 2 diabetes. These agents exploit the physiological effects of GLP-1, which is able to address several of the pathophysiological features of type 2 diabetes. GLP-1R agonists...

  13. Serotonin receptors as cardiovascular targets

    NARCIS (Netherlands)

    C.M. Villalón (Carlos); P.A.M. de Vries (Peter); P.R. Saxena (Pramod Ranjan)

    1997-01-01

    textabstractSerotonin exerts complex effects in the cardiovascular system, including hypotension or hypertension, vasodilatation or vasoconstriction, and/or bradycardia or tachycardia; the eventual response depends primarily on the nature of the 5-HT receptors involved. In the light of current 5-HT

  14. Estrogen Receptor Driven Inhibitor Synthesis

    Science.gov (United States)

    2006-09-01

    Engstrom O, Ohman L, Greene GL, Gustaffson JA, Carlquist M. Molecular basis of agonism and antagonism in the oestrogen receptor. Nature 389, 753-758...oxidatively modified proteins in Bacillus subtilis, Mol. Microbiol. 58 (2005) 409–425. [7] K. Tyagarajan, E. Pretzer, J.E. Wiktorowicz, Thiol-reactive dyes

  15. NMDA receptors and memory encoding.

    Science.gov (United States)

    Morris, Richard G M

    2013-11-01

    It is humbling to think that 30 years have passed since the paper by Collingridge, Kehl and McLennan showing that one of Jeff Watkins most interesting compounds, R-2-amino-5-phosphonopentanoate (d-AP5), blocked the induction of long-term potentiation in vitro at synapses from area CA3 of the hippocampus to CA1 without apparent effect on baseline synaptic transmission (Collingridge et al., 1983). This dissociation was one of the key triggers for an explosion of interest in glutamate receptors, and much has been discovered since that collectively contributes to our contemporary understanding of glutamatergic synapses - their biophysics and subunit composition, of the agonists and antagonists acting on them, and their diverse functions in different networks of the brain and spinal cord. It can be fairly said that Collingridge et al.'s (1983) observation was the stimulus that has led, on the one hand, to structural biological work at the atomic scale describing the key features of NMDA receptors that enables their coincidence function to happen; and, on the other, to work with whole animals investigating the contributions that calcium signalling via this receptor can have on rhythmical activities controlled by spinal circuits, memory encoding in the hippocampus (the topic of this article), visual cortical plasticity, sensitization in pain, and other functions. In this article, I lay out how my then interest in long-term potentiation (LTP) as a model of memory enabled me to recognise the importance of Collingridge et al.'s discovery - and how I and my colleagues endeavoured to take things forward in the area of learning and memory. This is in some respects a personal story, and I tell it as such. The idea that NMDA receptor activation is essential for memory encoding, though not for storage, took time to develop and to be accepted. Along the way, there have been confusions, challenges, and surprises surrounding the idea that activation of NMDA receptors can

  16. Amide-based Fluorescent Macrocyclic Anion Receptors

    Institute of Scientific and Technical Information of China (English)

    ZENG, Zhen-Ya(曾振亚); XU, Kuo-Xi(徐括喜); HE, Yong-Bing(何永炳); LIU, Shun-Ying(刘顺英); WU, Jin-Long(吴进龙); WEI, Lan-Hua(隗兰华); MENG, Ling-Zhi(孟令芝)

    2004-01-01

    Two fluorescent anion receptors (1 and 2) based on amide macrocycle were synthesized and corresponding fluorescence quenching induced by anion complexation was observed in different degree. Receptors form 1: 1 complexes with anions by hydrogen bonding interactions. Receptor 1 bound anions in the order of F->Cl->H2PO4->CH3COO->>Br-, I- and receptor 2 showed high selectivity to F- over other anions.

  17. Endogenous ion channel complexes: the NMDA receptor.

    Science.gov (United States)

    Frank, René A W

    2011-06-01

    Ionotropic receptors, including the NMDAR (N-methyl-D-aspartate receptor) mediate fast neurotransmission, neurodevelopment, neuronal excitability and learning. In the present article, the structure and function of the NMDAR is reviewed with the aim to condense our current understanding and highlight frontiers where important questions regarding the biology of this receptor remain unanswered. In the second part of the present review, new biochemical and genetic approaches for the investigation of ion channel receptor complexes will be discussed.

  18. Neuroexcitatory Drug Receptors in Mammals and Invertebrates

    Science.gov (United States)

    1990-03-16

    several animal species investigated. We identified the codfish as having a single polypeptide/gene for CABA -A receptors, as compared to 10-15 different...through blocking of CABA receptor functions. The CABA receptor-chloride channel system is important in wide-spread regions of the mammalian nervous... CABA receptor distribution was quantitated and mapped (14). For this analysis, we employed an image analyzer purchased by Drs. Olsen and de Vellis under

  19. Benzodiazepine receptor antagonists for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Gluud, L L; Gluud, C

    2004-01-01

    Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy....

  20. Mannose receptor-targeted vaccines.

    Science.gov (United States)

    Keler, Tibor; Ramakrishna, Venky; Fanger, Michael W

    2004-12-01

    Targeting antigens to endocytic receptors on professional antigen-presenting cells (APCs) represents an attractive strategy to enhance the efficacy of vaccines. Such APC-targeted vaccines have an exceptional ability to guide exogenous protein antigens into vesicles that efficiently process the antigen for major histocompatibility complex class I and class II presentation. Efficient targeting not only requires high specificity for the receptor that is abundantly expressed on the surface of APCs, but also the ability to be rapidly internalised and loaded into compartments that contain elements of the antigen-processing machinery. The mannose receptor (MR) and related C-type lectin receptors are particularly designed to sample antigens (self and non-self), much like pattern recognition receptors, to integrate the innate with adaptive immune responses. In fact, a variety of approaches involving delivery of antigens to the MR have demonstrated effective induction of potent cellular and humoral immune responses. Yet, although several lines of evidence in diverse experimental systems attest to the efficacy of targeted vaccine strategies, it is becoming increasingly clear that additional signals, such as those afforded by adjuvants, may be critical to elicit sustained immunity. Therefore, MR-targeted vaccines are likely to be most efficacious in vivo when combined with agents that elicit complementary activation signals. Certainly, a better understanding of the mechanism associated with the induction of immune responses as a result of targeting antigens to the MR, will be important in exploiting MR-targeted vaccines not only for mounting immune defenses against cancer and infectious disease, but also for specific induction of tolerance in the treatment of autoimmune disease.

  1. Repeated blockade of mineralocorticoid receptors, but not of glucocorticoid receptors impairs food rewarded spatial learning

    NARCIS (Netherlands)

    Douma, BRK; Korte, SM; Buwalda, B; la Fleur, SE; Bohus, B; Luiten, PGM

    1998-01-01

    Corticosteroids from the adrenal cortex influence a variety of behaviours including cognition, learning and memory. These hormones act via two intracellular receptors, the mineralo-corticoid receptor (MR) and the glucocorticoid receptor (GR). These two receptor types display a high concentration and

  2. Repeated blockade of mineralocorticoid receptors, but not of glucocorticoid receptors impairs food rewarded spatial learning

    NARCIS (Netherlands)

    Douma, B.R.; Korte, S.M.; Buwalda, B.; Fleur, la S.E.; Bohus, B.; Luiten, P.G.

    1998-01-01

    Corticosteroids from the adrenal cortex influence a variety of behaviours including cognition, learning and memory. These hormones act via two intracellular receptors, the mineralo-corticoid receptor (MR) and the glucocorticoid receptor (GR). These two receptor types display a high concentration and

  3. The brain mineralocorticoid receptor and stress resilience

    NARCIS (Netherlands)

    ter Heegde, Freija; De Rijk, Roel H.; Vinkers, Christiaan H.

    2015-01-01

    Stress exposure activates the HPA-axis and results in the release of corticosteroids which bind to two receptor types in the brain: the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). While the role of the GR in stress reactivity has been extensively studied, the MR has receive

  4. The brain mineralocorticoid receptor and stress resilience

    NARCIS (Netherlands)

    ter Heegde, Freija; De Rijk, Roel H.; Vinkers, Christiaan H.

    Stress exposure activates the HPA-axis and results in the release of corticosteroids which bind to two receptor types in the brain: the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). While the role of the GR in stress reactivity has been extensively studied, the MR has

  5. Chapter 8. Activation mechanisms of chemokine receptors

    DEFF Research Database (Denmark)

    Jensen, Pia C; Rosenkilde, Mette M

    2009-01-01

    Chemokine receptors belong to the large family of 7-transmembrane (7TM) G-protein-coupled receptors. These receptors are targeted and activated by a variety of different ligands, indicating that activation is a result of similar molecular mechanisms but not necessarily similar modes of ligand bin...

  6. Imaging of receptors in clinical neurosciences

    NARCIS (Netherlands)

    Korf, J

    This article deals with the question why should one determine receptors in the brain with positron and single photon emission tomography (PET and SPECT, respectively). Radiopharmaceuticals for a wide variety of receptors are available now. Receptors studies with PET and SPECT have thus far focused

  7. A new family of insect tyramine receptors

    DEFF Research Database (Denmark)

    Cazzamali, Giuseppe; Klærke, Dan Arne; Grimmelikhuijzen, Cornelis J P

    2005-01-01

    in the genomic databases from the malaria mosquito Anopheles gambiae and the honeybee Apis mellifera. These four tyramine or tyramine-like receptors constitute a new receptor family that is phylogenetically distinct from the previously identified insect octopamine/tyramine receptors. The Drosophila tyramine...

  8. Estrogen receptors in human vaginal tissue

    NARCIS (Netherlands)

    Wiegerinck, M.A.H.M.; Poortman, J.; Agema, A.R.; Thijssen, J.H.H.

    1980-01-01

    The presence of specific estrogen receptors could be demonstrated in vaginal tissue, obtained during operation from 38 women, age 27–75 yr. In 23 premenopausal women the receptor concentration in the vaginal tissue varied between 12 and 91 fmol/mg protein, no significant difference in the receptor

  9. The Human Laminin Receptor is a Member of the Integrin Family of Cell Adhesion Receptors

    Science.gov (United States)

    Gehlsen, Kurt R.; Dillner, Lena; Engvall, Eva; Ruoslahti, Erkki

    1988-09-01

    A receptor for the adhesive basement membrane protein, laminin, was isolated from human glioblastoma cells by affinity chromatography on laminin. This receptor has a heterodimeric structure similar to that of receptors for other extracellular matrix proteins such as fibronectin and vitronectin. Incorporation of the laminin receptor into liposomal membranes makes it possible for liposomes to attach to surfaces coated with laminin. The receptor liposomes also attached to some extent to surfaces coated with fibronectin, but not with other matrix proteins. These properties identify the laminin receptor as a member of the integrin family of cell adhesion receptors.

  10. Activation of Neuropeptide FF Receptors by Kisspeptin Receptor Ligands.

    Science.gov (United States)

    Oishi, Shinya; Misu, Ryosuke; Tomita, Kenji; Setsuda, Shohei; Masuda, Ryo; Ohno, Hiroaki; Naniwa, Yousuke; Ieda, Nahoko; Inoue, Naoko; Ohkura, Satoshi; Uenoyama, Yoshihisa; Tsukamura, Hiroko; Maeda, Kei-Ichiro; Hirasawa, Akira; Tsujimoto, Gozoh; Fujii, Nobutaka

    2011-01-13

    Kisspeptin is a member of the RFamide neuropeptide family that is implicated in gonadotropin secretion. Because kisspeptin-GPR54 signaling is implicated in the neuroendocrine regulation of reproduction, GPR54 ligands represent promising therapeutic agents against endocrine secretion disorders. In the present study, the selectivity profiles of GPR54 agonist peptides were investigated for several GPCRs, including RFamide receptors. Kisspeptin-10 exhibited potent binding and activation of neuropeptide FF receptors (NPFFR1 and NPFFR2). In contrast, short peptide agonists bound with much lower affinity to NPFFRs while showing relatively high selectivity toward GPR54. The possible localization of secondary kisspeptin targets was also demonstrated by variation in the levels of GnRH release from the median eminence and the type of GPR54 agonists used. Negligible affinity of the reported NPFFR ligands to GPR54 was observed and indicates the unidirectional cross-reactivity between both ligands.

  11. Venus Kinase Receptors: prospects in signalling and biological functions of these invertebrate receptors

    OpenAIRE

    Colette eDissous; Marion eMorel; Mathieu eVanderstraete

    2014-01-01

    Venus Kinase Receptors (VKRs) form a family of invertebrate receptor tyrosine kinases (RTKs) initially discovered in the parasitic platyhelminth Schistosoma mansoni. VKRs are single transmembrane receptors which contain an extracellular Venus Flytrap (VFT) structure similar to the ligand binding domain of G Protein Coupled Receptors of class C, and an intracellular Tyrosine Kinase domain close to that of Insulin Receptors. VKRs are found in a large variety of invertebrates from cnidarians to ...

  12. Discoidin Domain Receptors Role in Human Diseases

    Directory of Open Access Journals (Sweden)

    Iker BADIOLA

    2011-11-01

    Full Text Available Discoidin Domain Receptor 1 and Discodin Domain Receptor 2 are the two only members of the DDR family. The DDR family is a Tyrosine Kinase Receptor (TKR family with some peculiarities compared with other Tyrosine Kinase Receptors such as their natural ligand; which in this case is the fibrillar collagen; or the slow phosphorylation pattern. These peculiarities confer a special role to the receptors present in many diseases development processes as cancer, cirrhosis or lung fibrosis. In this review it is described the overview of the DDRs structure and their role in the different disease development and the possibility to consider them as therapeutic targets.

  13. Novel receptors for bacterial protein toxins.

    Science.gov (United States)

    Schmidt, Gudula; Papatheodorou, Panagiotis; Aktories, Klaus

    2015-02-01

    While bacterial effectors are often directly introduced into eukaryotic target cells by various types of injection machines, toxins enter the cytosol of host cells from endosomal compartments or after retrograde transport via Golgi from the ER. A first crucial step of toxin-host interaction is receptor binding. Using optimized protocols and new methods novel toxin receptors have been identified, including metalloprotease ADAM 10 for Staphylococcus aureus α-toxin, laminin receptor Lu/BCAM for Escherichia coli cytotoxic necrotizing factor CNF1, lipolysis stimulated lipoprotein receptor (LSR) for Clostridium difficile transferase CDT and low-density lipoprotein receptor-related protein (LRP) 1 for Clostridium perfringens TpeL toxin.

  14. Evolutionary vignettes of natural killer cell receptors.

    Science.gov (United States)

    Sambrook, Jennifer G; Beck, Stephan

    2007-10-01

    The discovery of novel immune receptors has led to a recent renaissance of research into the innate immune system, following decades of intense research of the adaptive immune system. Of particular interest has been the discovery of the natural killer (NK) cell receptors which, depending on type, interact with classical or non-classical MHC class I antigens of the adaptive immune system, thus functioning at the interface of innate and adaptive immunity. Here, we review recent progress with respect to two such families of NK receptors, the killer immunoglobulin-like receptors (KIRs) and the killer cell lectin-like receptors (KLRs), and attempt to trace their evolution across vertebrates.

  15. Sugars, Sweet Taste Receptors, and Brain Responses.

    Science.gov (United States)

    Lee, Allen A; Owyang, Chung

    2017-06-24

    Sweet taste receptors are composed of a heterodimer of taste 1 receptor member 2 (T1R2) and taste 1 receptor member 3 (T1R3). Accumulating evidence shows that sweet taste receptors are ubiquitous throughout the body, including in the gastrointestinal tract as well as the hypothalamus. These sweet taste receptors are heavily involved in nutrient sensing, monitoring changes in energy stores, and triggering metabolic and behavioral responses to maintain energy balance. Not surprisingly, these pathways are heavily regulated by external and internal factors. Dysfunction in one or more of these pathways may be important in the pathogenesis of common diseases, such as obesity and type 2 diabetes mellitus.

  16. Differences in the interaction of acetylcholine receptor antibodies with receptor from normal, denervated and myasthenic human muscle.

    OpenAIRE

    Lefvert, A. K.

    1982-01-01

    The interaction of acetylcholine receptor antibodies with different kinds of human skeletal muscle receptor was investigated. The reaction of most receptor antibodies was strongest with receptor from a patient with myasthenia gravis and with receptor from denervated muscle. Results obtained with these receptors were well correlated. The binding of most receptor antibodies to receptor from functionally normal muscle was much weaker and also qualitatively different. In a few patients with moder...

  17. Receptor arrays optimized for natural odor statistics.

    Science.gov (United States)

    Zwicker, David; Murugan, Arvind; Brenner, Michael P

    2016-05-17

    Natural odors typically consist of many molecules at different concentrations. It is unclear how the numerous odorant molecules and their possible mixtures are discriminated by relatively few olfactory receptors. Using an information theoretic model, we show that a receptor array is optimal for this task if it achieves two possibly conflicting goals: (i) Each receptor should respond to half of all odors and (ii) the response of different receptors should be uncorrelated when averaged over odors presented with natural statistics. We use these design principles to predict statistics of the affinities between receptors and odorant molecules for a broad class of odor statistics. We also show that optimal receptor arrays can be tuned to either resolve concentrations well or distinguish mixtures reliably. Finally, we use our results to predict properties of experimentally measured receptor arrays. Our work can thus be used to better understand natural olfaction, and it also suggests ways to improve artificial sensor arrays.

  18. Targeting Nuclear Receptors with Marine Natural Products

    Directory of Open Access Journals (Sweden)

    Chunyan Yang

    2014-01-01

    Full Text Available Nuclear receptors (NRs are important pharmaceutical targets because they are key regulators of many metabolic and inflammatory diseases, including diabetes, dyslipidemia, cirrhosis, and fibrosis. As ligands play a pivotal role in modulating nuclear receptor activity, the discovery of novel ligands for nuclear receptors represents an interesting and promising therapeutic approach. The search for novel NR agonists and antagonists with enhanced selectivities prompted the exploration of the extraordinary chemical diversity associated with natural products. Recent studies involving nuclear receptors have disclosed a number of natural products as nuclear receptor ligands, serving to re-emphasize the translational possibilities of natural products in drug discovery. In this review, the natural ligands of nuclear receptors will be described with an emphasis on their mechanisms of action and their therapeutic potentials, as well as on strategies to determine potential marine natural products as nuclear receptor modulators.

  19. How calcium makes endocytic receptors attractive

    DEFF Research Database (Denmark)

    Andersen, Christian B F; Moestrup, Søren K

    2014-01-01

    Nutrients, biological waste-products, toxins, pathogens, and other ligands for endocytosis are typically captured by multidomain receptors with multiligand specificity. Upon internalization, the receptor-ligand complex segregates, followed by lysosomal degradation of the ligand and recycling...... of the receptor. Endosomal acidification and calcium efflux lead to the essential ligand-receptor affinity switch and separation. Recent data, including crystal structures of receptor-ligand complexes, now reveal how calcium, in different types of domain scaffolds, functions in a common way as a removable...... 'lynchpin' that stabilizes favorable positioning of ligand-attractive receptor residues. In addition to explaining how calcium depletion can cause ligand-receptor dissociation, the new data add further insight into how acidification contributes to dissociation through structural changes that affect...

  20. Receptor arrays optimized for natural odor statistics

    CERN Document Server

    Zwicker, David; Brenner, Michael P

    2016-01-01

    Natural odors typically consist of many molecules at different concentrations. It is unclear how the numerous odorant molecules and their possible mixtures are discriminated by relatively few olfactory receptors. Using an information-theoretic model, we show that a receptor array is optimal for this task if it achieves two possibly conflicting goals: (i) each receptor should respond to half of all odors and (ii) the response of different receptors should be uncorrelated when averaged over odors presented with natural statistics. We use these design principles to predict statistics of the affinities between receptors and odorant molecules for a broad class of odor statistics. We also show that optimal receptor arrays can be tuned to either resolve concentrations well or distinguish mixtures reliably. Finally, we use our results to predict properties of experimentally measured receptor arrays. Our work can thus be used to better understand natural olfaction and it also suggests ways to improve artificial sensor...

  1. Glutamate Receptor Aptamers and ALS

    Science.gov (United States)

    2009-01-01

    proposed, including oxidative stress, excitotoxicity, mitochondrial dysfunction, etc., the cause(s) of the disease, including the pathogenesis of the...GluR6-Selective Aptamers for Potential Autism Therapy This project is to develop RNA aptamers against a GluR6 kainate receptor mutant thought to be...involved in autism . Role: PI Department of Defense (PI: Niu) 4/1/09-3/30/14 Advanced Tech./Therapeutic Develop. Grant Developing Biostable

  2. The vanilloid receptor and hypertension

    Institute of Scientific and Technical Information of China (English)

    Donna H WANG

    2005-01-01

    Mammalian transient receptor potential (TRP) channels consist of six related protein sub-families that are involved in a variety of pathophysiological function, and disease development. The TRPV1 channel, a member of the TRPV sub-family, is identified by expression cloning using the "hot" pepper-derived vanilloid compound capsaicin as a ligand. Therefore, TRPV1 is also referred as the vanilloid receptor (VR1) or the capsaicin receptor. VR1 is mainly expressed in a subpopulation of primary afferent neurons that project to cardiovascular and renal tissues.These capsaicin-sensitive primary afferent neurons are not only involved in the perception of somatic and visceral pain, but also have a "sensory-effector" function.Regarding the latter, these neurons release stored neuropeptides through a calcium-dependent mechanism via the binding of capsaicin to VR1. The most studied sensory neuropeptides are calcitonin gene-related peptide (CGRP) and substance P (SP), which are potent vasodilators and natriuretic/diuretic factors. Recent evidence using the model of neonatal degeneration of capsaicin-sensitive sensory nerves revealed novel mechanisms that underlie increased salt sensitivity and several experimental models of hypertension. These mechanisms include insufficient suppression of plasma renin activity and plasma aldosterone levels subsequent to salt loading, enhancement of sympathoexcitatory response in the face of a salt challenge, activation of the endothelin- 1 receptor, and impaired natriuretic response to salt loading in capsaicin-pretreated rats. These data indicate that sensory nerves counterbalance the prohypertensive effects of several neurohormonal systems to maintain normal blood pressure when challenged with salt loading. The therapeutic utilities of vanilloid compounds, endogenous agonists,and sensory neuropeptides are also discussed.

  3. Endomorphins interact with tachykinin receptors.

    Science.gov (United States)

    Kosson, Piotr; Bonney, Iwona; Carr, Daniel B; Lipkowski, Andrzej W

    2005-09-01

    Soon after the discovery of endomorphins several studies indicated differences between pharmacological effects of endomorphins and other MOR selective ligands, as well as differences between the effects of endomorphin I and endomorphin II. We now propose that these differences are the result of an additional non-opioid property of endomorphins, namely, their weak antagonist properties with respect to tachykinin NK1 and NK1 receptors.

  4. The Laminins and their Receptors

    OpenAIRE

    Ferletta, Maria

    2002-01-01

    Basement membranes are thin extracellular sheets that surround muscle, fat and peripheral nerve cells and underlay epithelial and endothelial cells. Laminins are one of the main protein families of these matrices. Integrins and dystroglycan are receptors for laminins, connecting cells to basement membranes. Each laminin consists of three different chains, (α, β, γ). Laminin-1 (α1β1γ1) was the first laminin to be found and is the most frequently studied. Despite this, it was unclear where its ...

  5. Nitrosamines as nicotinic receptor ligands

    OpenAIRE

    Schuller, Hildegard M

    2007-01-01

    Nitrosamines are carcinogens formed in the mammalian organism from amine precursors contained in food, beverages, cosmetics and drugs. The potent carcinogen, NNK, and the weaker carcinogen, NNN, are nitrosamines formed from nicotine. Metabolites of the nitrosamines react with DNA to form adducts responsible for genotoxic effects. We have identified NNK as a high affinity agonist for the alpha7 nicotinic acetylcholine receptor (α7nAChR) whereas NNN bound with high affinity to epibatidine-sensi...

  6. CB receptor ligands from plants.

    Science.gov (United States)

    Woelkart, Karin; Salo-Ahen, Outi M H; Bauer, Rudolf

    2008-01-01

    Advances in understanding the physiology and pharmacology of the endogenous cannabinoid system have potentiated the interest of cannabinoid receptors as potential therapeutic targets. Cannabinoids have been shown to modulate a variety of immune cell functions and have therapeutic implications on central nervous system (CNS) inflammation, chronic inflammatory conditions such as arthritis, and may be therapeutically useful in treating autoimmune conditions such as multiple sclerosis. Many of these drug effects occur through cannabinoid receptor signalling mechanisms and the modulation of cytokines and other gene products. Further, endocannabinoids have been found to have many physiological and patho-physiological functions, including mood alteration and analgesia, control of energy balance, gut motility, motor and co-ordination activities, as well as alleviation of neurological, psychiatric and eating disorders. Plants offer a wide range of chemical diversity and have been a growing domain in the search for effective cannabinoid ligands. Cannabis sativa L. with the known plant cannabinoid, Delta(9-)tetrahydrocannabinol (THC) and Echinacea species with the cannabinoid (CB) receptor-binding lipophilic alkamides are the best known herbal cannabimimetics. This review focuses on the state of the art in CB ligands from plants, as well their possible therapeutic and immunomodulatory effects.

  7. Autophagy selectivity through receptor clustering

    Science.gov (United States)

    Rutenberg, Andrew; Brown, Aidan

    Substrate selectivity in autophagy requires an all-or-none cellular response. We focus on peroxisomes, for which autophagy receptor proteins NBR1 and p62 are well characterized. Using computational models, we explore the hypothesis that physical clustering of autophagy receptor proteins on the peroxisome surface provides an appropriate all-or-none response. We find that larger peroxisomes nucleate NBR1 clusters first, and lose them due to competitive coarsening last, resulting in significant size-selectivity. We then consider a secondary hypothesis that p62 inhibits NBR1 cluster formation. We find that p62 inhibition enhances size-selectivity enough that, even if there is no change of the pexophagy rate, the volume of remaining peroxisomes can significantly decrease. We find that enhanced ubiquitin levels suppress size-selectivity, and that this effect is more pronounced for individual peroxisomes. Sufficient ubiquitin allows receptor clusters to form on even the smallest peroxisomes. We conclude that NBR1 cluster formation provides a viable physical mechanism for all-or-none substrate selectivity in pexophagy. We predict that cluster formation is associated with significant size-selectivity. Now at Simon Fraser University.

  8. [Anti-NMDA-receptor encephalitis].

    Science.gov (United States)

    Engen, Kristine; Agartz, Ingrid

    2016-06-01

    BACKGROUND In 2007 a clinical disease caused by autoantibodies directed against the N-methyl-D-aspartate (NMDA) receptor was described for the first time. Anti-NMDA-receptor encephalitis is a subacute, autoimmune neurological disorder with psychiatric manifestations. The disease is a form of limbic encephalitis and is often paraneoplastic. The condition is also treatable. In this review article we examine the development of the disease, clinical practice, diagnostics and treatment.MATERIAL AND METHOD The article is based on references retrieved from searches in PubMed, and a discretionary selection of articles from the authors' own literature archive.RESULTS The disease most frequently affects young women. It may initially be perceived as a psychiatric condition, as it usually presents in the form of delusions, hallucinations or mania. The diagnosis should be suspected in patients who later develop neurological symptoms such as various movement disorders, epileptic seizures and autonomic instability. Examination of serum or cerebrospinal fluid for NMDA receptor antibodies should be included in the assessment of patients with suspected encephalitis. MRI, EEG and assessment for tumours are important tools in diagnosing the condition and any underlying malignancy.INTERPRETATION If treatment is initiated early, the prognosis is good. Altogether 75 % of patients will fully recover or experience significant improvement. Apart from surgical resection of a possible tumour, the treatment consists of immunotherapy. Because of good possibilities for treatment, it is important that clinicians, particularly those in acute psychiatry, are aware of and alert to this condition.

  9. Presynaptic inhibition by kainate receptors converges mechanistically with presynaptic inhibition by adenosine and GABAB receptors.

    Science.gov (United States)

    Partovi, Dara; Frerking, Matthew

    2006-11-01

    Kainate receptors are widely reported to regulate the release of neurotransmitter in the CNS, but the mechanisms involved remain controversial. Previous studies have found that the kainate receptor agonist ATPA, which selectively activates Glu(K5)-containing kainate receptors, depresses glutamate release at Schaffer-collateral synapses in the hippocampus. In the present study, we provide pharmacological evidence that this depressant effect is mediated by Glu(K5)-containing heteromers, but is distinct from a similar depressant effect engaged by the kainate receptor agonist domoate. The depressant effect of ATPA is insensitive to antagonists for GABA(A), GABA(B), and adenosine receptors, and is also unaffected by lowering the release probability by reducing extracellular calcium. However, the effect of ATPA is partly occluded by prior activation of GABA(B) receptors and completely occluded by prior activation of adenosine receptors, suggesting a mechanistic convergence of heteromeric Glu(K5) kainate receptor signaling with GABA(B) receptors and adenosine receptors. The effects of domoate are partially occluded by both adenosine and GABA(B) receptor agonists, indicating at least a partial convergence of Glu(K5)-lacking kainate receptor signaling with these other pathways. The depressant effect of ATPA is not blocked by inhibition of serine/threonine protein kinases. These results suggest that ATPA and domoate inhibit glutamate release through mechanisms that converge with those of classical metabotropic receptor agonists, although they do so through different receptors.

  10. Selected Reaction Monitoring (SRM Analysis of Epidermal Growth Factor Receptor (EGFR in Formalin Fixed Tumor Tissue

    Directory of Open Access Journals (Sweden)

    Hembrough Todd

    2012-05-01

    Full Text Available Abstract Background Analysis of key therapeutic targets such as epidermal growth factor receptor (EGFR in clinical tissue samples is typically done by immunohistochemistry (IHC and is only subjectively quantitative through a narrow dynamic range. The development of a standardized, highly-sensitive, linear, and quantitative assay for EGFR for use in patient tumor tissue carries high potential for identifying those patients most likely to benefit from EGFR-targeted therapies. Methods A mass spectrometry-based Selected Reaction Monitoring (SRM assay for the EGFR protein (EGFR-SRM was developed utilizing the Liquid Tissue®-SRM technology platform. Tissue culture cells (n = 4 were analyzed by enzyme-linked immunosorbent assay (ELISA to establish quantitative EGFR levels. Matching formalin fixed cultures were analyzed by the EGFR-SRM assay and benchmarked against immunoassay of the non-fixed cultured cells. Xenograft human tumor tissue (n = 10 of non-small cell lung cancer (NSCLC origin and NSCLC patient tumor tissue samples (n = 23 were microdissected and the EGFR-SRM assay performed on Liquid Tissue lysates prepared from microdissected tissue. Quantitative curves and linear regression curves for correlation between immunoassay and SRM methodology were developed in Excel. Results The assay was developed for quantitation of a single EGFR tryptic peptide for use in FFPE patient tissue with absolute specificity to uniquely distinguish EGFR from all other proteins including the receptor tyrosine kinases, IGF-1R, cMet, Her2, Her3, and Her4. The assay was analytically validated against a collection of tissue culture cell lines where SRM analysis of the formalin fixed cells accurately reflects EGFR protein levels in matching non-formalin fixed cultures as established by ELISA sandwich immunoassay (R2 = 0.9991. The SRM assay was applied to a collection of FFPE NSCLC xenograft tumors where SRM data range from 305amol/μg to 12,860amol/μg and

  11. Receptor response in Venus's fly-trap.

    Science.gov (United States)

    Jacobson, S L

    1965-09-01

    The insect-trapping movement of the plant Dionaea muscipula (Venus's fly-trap) is mediated by the stimulation of mechanosensory hairs located on the surface of the trap. It is known that stimulation of the hairs is followed by action potentials which are propagated over the surface of the trap. It has been reported that action potentials always precede trap closure. The occurrence of non-propagated receptor potentials is reported here. Receptor potentials always precede the action potentials. The receptor potential appears to couple the mechanical stimulation step to the action potential step of the preying sequence. Receptor potentials elicited by mechanical stimulation of a sensory hair were measured by using the hair as an integral part of the current-measuring path. The tip of the hair was cut off exposing the medullary tissue; this provided a natural extension of the measuring electrode into the receptor region at the base of the hair. A measuring pipette electrode was slipped over the cut tip of the hair. Positive and negative receptor potentials were measured. Evidence is presented which supports the hypothesis that the positive and negative receptor potentials originate from independent sources. An analysis is made of (a) the relation of the parameters of mechanical stimuli to the magnitude of the receptor potential, and (b) the relation of the receptor potentials to the action potential. The hypothesis that the positive receptor potential is the generator of the action potential is consistent with these data.

  12. Constitutive receptor systems for drug discovery.

    Science.gov (United States)

    Chen, G; Jayawickreme, C; Way, J; Armour, S; Queen, K; Watson, C; Ignar, D; Chen, W J; Kenakin, T

    1999-12-01

    This paper discusses the use of constitutively active G-protein-coupled receptor systems for drug discovery. Specifically, the ternary complex model is used to define the two major theoretical advantages of constitutive receptor screening-namely, the ability to detect antagonists as well as agonists directly and the fact that constitutive systems are more sensitive to agonists. In experimental studies, transient transfection of Chinese hamster ovary cyclic AMP response element (CRE) luciferase reporter cells with cDNA for human parathyroid hormone receptor, glucagon receptor, and glucagon-like peptide (GLP-1) receptor showed cDNA concentration-dependent constitutive activity with parathyroid hormone (PTH-1) and glucagon. In contrast, no constitutive activity was observed for GLP-1 receptor, yet responses to GLP-1 indicated that receptor expression had taken place. In another functional system, Xenopus laevi melanophores transfected with cDNA for human calcitonin receptor showed constitutive activity. Nine ligands for the calcitonin receptor either increased or decreased constitutive activity in this assay. The sensitivity of the system to human calcitonin increased with increasing constitutive activity. These data indicate that, for those receptors which naturally produce constitutive activity, screening in this mode could be advantageous over other methods.

  13. Protein Connectivity in Chemotaxis Receptor Complexes.

    Directory of Open Access Journals (Sweden)

    Stephan Eismann

    2015-12-01

    Full Text Available The chemotaxis sensory system allows bacteria such as Escherichia coli to swim towards nutrients and away from repellents. The underlying pathway is remarkably sensitive in detecting chemical gradients over a wide range of ambient concentrations. Interactions among receptors, which are predominantly clustered at the cell poles, are crucial to this sensitivity. Although it has been suggested that the kinase CheA and the adapter protein CheW are integral for receptor connectivity, the exact coupling mechanism remains unclear. Here, we present a statistical-mechanics approach to model the receptor linkage mechanism itself, building on nanodisc and electron cryotomography experiments. Specifically, we investigate how the sensing behavior of mixed receptor clusters is affected by variations in the expression levels of CheA and CheW at a constant receptor density in the membrane. Our model compares favorably with dose-response curves from in vivo Förster resonance energy transfer (FRET measurements, demonstrating that the receptor-methylation level has only minor effects on receptor cooperativity. Importantly, our model provides an explanation for the non-intuitive conclusion that the receptor cooperativity decreases with increasing levels of CheA, a core signaling protein associated with the receptors, whereas the receptor cooperativity increases with increasing levels of CheW, a key adapter protein. Finally, we propose an evolutionary advantage as explanation for the recently suggested CheW-only linker structures.

  14. Characterization of astrocytic and neuronal benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Bender, A.S.

    1988-01-01

    Primary cultures of astrocytes and neurons express benzodiazepine receptors. Neuronal benzodiazepine receptors were of high-affinity, K{sub D} values were 7.5-43 nM and the densities of receptors (B{sub max}) were 924-4131 fmol/mg protein. Astrocytes posses a high-affinity benzodiazepine receptor, K{sub D} values were 6.6-13 nM. The B{sub max} values were 6,033-12,000 fmol/mg protein. The pharmacological profile of the neuronal benzodiazepine receptor was that of the central-type benzodiazepine receptor, where clonazepam has a high-affinity and Ro 5-4864 (4{prime}-chlorodiazepam) has a low-affinity. Whereas astrocytic benzoidazepine receptor was characteristic of the so called peripheral-type benzodiazepine receptors, which shows a high-affinity towards Ro 5-4863, and a low-affinity towards clonazepam. The astrocytic benzodiazepine receptors was functionally correlated with voltage dependent calcium channels, since dihydropyridines and benzodiazepines interacted with ({sup 3}H) diazepam and ({sup 3}H) nitrendipine receptors with the same rank order of potency, showing a statistically significant correlation. No such correlation was observed in neurons.

  15. Assembly of PRR-containing receptors on scaffolds: a model for imidazoline I(1)-receptor action.

    Science.gov (United States)

    Musgrave, I F; Dehle, F C; Piletz, J

    2003-12-01

    IRAS, a putative clone of the I(1)-imidazoline receptor, possesses a proline-rich region (PRR) motif, which might interact with SH3 regions on tyrosine kinases, and an integrin-binding motif. Receptors with a PRR motif can generally assemble onto multi-element signaling complexes (eg., the beta(3)-receptor on the EGF receptor) and thereby modulate signal transduction. Integrins serve as scaffolds for multi-element signaling complexes, similar to that assembled with the EGF receptor. It is therefore possible that IRAS signals through a complex with other receptors.

  16. Subtype selective kainic acid receptor agonists

    DEFF Research Database (Denmark)

    Bunch, Lennart; Krogsgaard-Larsen, Povl

    2009-01-01

    (S)-Glutamic acid (Glu) is the major excitatory neurotransmitter in the mammalian central nervous system, activating the plethora of glutamate receptors (GluRs). In broad lines, the GluRs are divided into two major classes: the ionotropic Glu receptors (iGluRs) and the metabotropic Glu receptors (m......GluRs). Within the iGluRs, five subtypes (KA1, KA2, iGluR5-7) show high affinity and express full agonist activity upon binding of the naturally occurring amino acid kainic acid (KA). Thus these receptors have been named the KA receptors. This review describes all-to our knowledge-published KA receptor agonists...

  17. Mast Cell and Immune Inhibitory Receptors

    Institute of Scientific and Technical Information of China (English)

    LixinLi; ZhengbinYao

    2004-01-01

    Modulation by balancing activating and inhibitory receptors constitutes an important mechanism for regulating immune responses. Cells that are activated following ligation of receptors bearing immunoreceptor tyrosine-based activation motifs (ITAMs) can be negatively regulated by other receptors bearing immunoreceptor tyrosine-based inhibition motifs (ITIMs). Human mast cells (MCs) are the major effector cells of type I hypersensitivity and important participants in a number of disease processes. Antigen-mediated aggregation of IgE bound to its high-affinity receptor on MCs initiates a complex series of biochemical events leading to MC activation. With great detailed description and analysis of several inhibitory receptors on human MCs, a central paradigm of negative regulation of human MC activation by these receptors has emerged. Cellular & Molecular Immunology. 2004;1(6):408-415.

  18. The anatomy of mammalian sweet taste receptors.

    Science.gov (United States)

    Chéron, Jean-Baptiste; Golebiowski, Jérôme; Antonczak, Serge; Fiorucci, Sébastien

    2017-02-01

    All sweet-tasting compounds are detected by a single G-protein coupled receptor (GPCR), the heterodimer T1R2-T1R3, for which no experimental structure is available. The sweet taste receptor is a class C GPCR, and the recently published crystallographic structures of metabotropic glutamate receptor (mGluR) 1 and 5 provide a significant step forward for understanding structure-function relationships within this family. In this article, we recapitulate more than 600 single point site-directed mutations and available structural data to obtain a critical alignment of the sweet taste receptor sequences with respect to other class C GPCRs. Using this alignment, a homology 3D-model of the human sweet taste receptor is built and analyzed to dissect out the role of key residues involved in ligand binding and those responsible for receptor activation. Proteins 2017; 85:332-341. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. P2X receptors in epithelia

    DEFF Research Database (Denmark)

    Leipziger, Jens Georg

    2015-01-01

    pathways that inhibit epithelial absorption are currently not well understood. Epithelial P2X7 receptors show pronounced up-regulation during varies diseased states highlighting a role of purinergic signaling in epithelial pathophysiology. Importantly, functional effects of epithelial P2X receptors cover......P2X receptors are ubiquitously expressed in all epithelial tissues but their functional roles are less well studied. Here we review the current state of knowledge by focusing on functional effects of P2X receptor in secretory and in absorptive tissues. In glandular tissue like the parotid gland...... basolateral P2X receptors stimulate ion secretion via an increase of [Ca2+]i. In absorptive epithelia like the renal tubule P2X receptor stimulation mediates the inhibition of NaCl, Mg2+ and water transport in the thick ascending limb and the distal convoluted tubule, respectively. The underlying signaling...

  20. Nitrosamines as nicotinic receptor ligands.

    Science.gov (United States)

    Schuller, Hildegard M

    2007-05-30

    Nitrosamines are carcinogens formed in the mammalian organism from amine precursors contained in food, beverages, cosmetics and drugs. The potent carcinogen, NNK, and the weaker carcinogen, NNN, are nitrosamines formed from nicotine. Metabolites of the nitrosamines react with DNA to form adducts responsible for genotoxic effects. We have identified NNK as a high affinity agonist for the alpha7 nicotinic acetylcholine receptor (alpha7nAChR) whereas NNN bound with high affinity to epibatidine-sensitive nAChRs. Diethylnitrosamine (DEN) bound to both receptors but with lower affinity. High levels of the alpha7nAChR were expressed in human small cell lung cancer (SCLC) cell lines and in hamster pulmonary neuroendocrine cells (PNECs), which serve as a model for the cell of origin of human SCLC. Exposure of SCLC or PNECs to NNK or nicotine increased expression of the alpha7nAChR and caused influx of Ca(2+), activation of PKC, Raf-1, ERK1/2, and c-myc, resulting in the stimulation of cell proliferation. Signaling via the alpha7nAChR was enhanced when cells were maintained in an environment of 10-15% CO(2) similar to that in the diseased lung. Hamsters with hyperoxia-induced pulmonary fibrosis developed neuroendocrine lung carcinomas similar to human SCLC when treated with NNK, DEN, or nicotine. The development of the NNK-induced tumors was prevented by green tea or theophylline. The beta-adrenergic receptor agonist, isoproterenol or theophylline blocked NNK-induced cell proliferation in vitro. NNK and nicotine-induced hyperactivity of the alpha7nAChR/RAF/ERK1/2 pathway thus appears to play a crucial role in the development of SCLC in smokers and could be targeted for cancer prevention.

  1. Angiotensin II receptors in the gonads

    Energy Technology Data Exchange (ETDEWEB)

    Aguilera, G.; Millan, M.A.; Harwood, J.P.

    1989-05-01

    The presence of components of the renin-angiotensin system in ovaries and testes suggests that angiotensin II (AII) is involved in gonadal function, and thus we sought to characterize receptors for AII in rat and primate gonads. In the testes, autoradiographic studies showed receptors in the interstitium in all species. In rat interstitial cells fractionated by Percoll gradient, AII receptors coincided with hCG receptors indicating that AII receptors are located on the Leydig cells. In Leydig cells and membranes from rat and rhesus monkey prepuberal testes, AII receptors were specific for AII analogues and of high affinity (Kd=nM). During development, AII receptor content in rat testes decreases with age parallel to a fall in the ratio of interstitial to tubular tissue. In the ovary, the distribution of AII receptors was dependent on the stage of development, being high in the germinal epithelium and stromal tissue between five and 15 days, and becoming localized in secondary follicles in 20-and 40-day-old rats. No binding was found in primordial or primary follicles. In rhesus monkey ovary, AII receptors were higher in stromal tissue and lower in granulosa and luteal cells of the follicles. Characterization of the binding in rat and monkey ovarian membranes showed a single class of sites with a Kd in the nmol/L range and specificity similar to that of the adrenal glomerulosa and testicular AII receptors. Receptors for AII were also present in membrane fractions from PMSG/hCG primed rat ovaries. Infusion of AII (25 ng/min) or captopril (1.4 micrograms/min) during the PMSG/hCG induction period had no effect on ovarian weight or AII receptor concentration in the ovaries.

  2. Complex pharmacology of free fatty acid receptors

    OpenAIRE

    Milligan, Graeme; Shimpukade, Bharat; Ulven, Trond; Hudson, Brian D.

    2017-01-01

    G protein-coupled receptors (GPCRs) are historically the most successful family of drug targets. In recent times it has become clear that the pharmacology of these receptors is far more complex than previously imagined. Understanding of the pharmacological regulation of GPCRs now extends beyond simple competitive agonism or antagonism by ligands interacting with the orthosteric binding site of the receptor to incorporate concepts of allosteric agonism, allosteric modulation, signaling bias, c...

  3. Muscarinic Receptor Agonists and Antagonists

    Directory of Open Access Journals (Sweden)

    David R. Kelly

    2001-02-01

    Full Text Available A comprehensive review of pharmacological and medical aspects of the muscarinic class of acetylcholine agonists and antagonists is presented. The therapeutic benefits of achieving receptor subtype selectivity are outlined and applications in the treatment of Alzheimer’s disease are discussed. A selection of chemical routes are described, which illustrate contemporary methodology for the synthesis of chiral medicinal compounds (asymmetric synthesis, chiral pool, enzymes. Routes to bicyclic intrannular amines and intramolecular Diels-Alder reactions are highlighted.

  4. Emerging GLP-1 receptor agonists

    DEFF Research Database (Denmark)

    Lund, Asger; Knop, Filip K; Vilsbøll, Tina

    2011-01-01

    Introduction: Recently, glucagon-like peptide-1 receptor (GLP-1R) agonists have become available for the treatment of type 2 diabetes. These agents exploit the physiological effects of GLP-1, which is able to address several of the pathophysiological features of type 2 diabetes. GLP-1R agonists...... presently available are administered once or twice daily, but several once-weekly GLP-1R agonists are in late clinical development. Areas covered: The present review aims to give an overview of the clinical data on the currently available GLP-1R agonists used for treatment of type 2 diabetes, exenatide...

  5. New transmembrane AMPA receptor regulatory protein isoform, gamma-7, differentially regulates AMPA receptors

    National Research Council Canada - National Science Library

    Kato, Akihiko S; Zhou, Wei; Milstein, Aaron D; Knierman, Mike D; Siuda, Edward R; Dotzlaf, Joe E; Yu, Hong; Hale, John E; Nisenbaum, Eric S; Nicoll, Roger A; Bredt, David S

    2007-01-01

    AMPA-type glutamate receptors (GluRs) mediate most excitatory signaling in the brain and are composed of GluR principal subunits and transmembrane AMPA receptor regulatory protein (TARP) auxiliary subunits...

  6. The angiotensin Ⅱ type 1 receptor and receptor-associated proteins

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The mechanisms of regulation, activation and signal transduction of the angiotensin Ⅱ(Ang Ⅱ) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1receptor is a major component of the renin-angiotensin system (RAS). It mediates the classical biological actions of Ang Ⅱ. Among the structures required for regulation and activation of the receptor, its carboxylterminal region plays crucial roles in receptor internalization, desensitization and phosphorylation. The mechanisms involved in heterotrimeric G-protein coupling to the receptor, activation of the downstreamsignaling pathway by G proteins and the Ang Ⅱ signal transduction pathways leading to specific cellularresponses are discussed. In addition, recent work on the identification and characterization of novel proteinsassociated with carboxyl-terminus of the AT1 receptor is presented. These novel proteins will advance ourunderstanding of how the receptor is internalized and recycled as they provide molecular mechanisms for the activation and regulation of G-protein-coupled receptors.

  7. ABA Receptors: Past, Present and Future

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jianjun [Harvard University; Yang, Xiaohan [ORNL; Weston, David [ORNL; Chen, Jay [ORNL

    2011-01-01

    Abscisic acid (ABA) is the key plant stress hormone. Consistent with the earlier studies in support of the presence of both membrane- and cytoplasm-localized ABA receptors, recent studies have identified multiple ABA receptors located in various subcellular locations. These include a chloroplast envelope-localized receptor (the H subunit of Chloroplast Mg2+-chelatase/ABA Receptor), two plasma membrane-localized receptors (G-protein Coupled Receptor 2 and GPCR-type G proteins), and one cytosol/nucleus-localized Pyrabactin Resistant (PYR)/PYR-Like (PYL)/Regulatory Component of ABA Receptor 1 (RCAR). Although the downstream molecular events for most of the identified ABA receptors are currently unknown, one of them, PYR/PYL/RACR was found to directly bind and regulate the activity of a long-known central regulator of ABA signaling, the A-group protein phosphatase 2C (PP2C). Together with the Sucrose Non-fermentation Kinase Subfamily 2 (SnRK2s) protein kinases, a central signaling complex (ABA-PYR-PP2Cs-SnRK2s) that is responsible for ABA signal perception and transduction is supported by abundant genetic, physiological, biochemical and structural evidence. The identification of multiple ABA receptors has advanced our understanding of ABA signal perception and transduction while adding an extra layer of complexity.

  8. Challenges in imaging cell surface receptor clusters

    Science.gov (United States)

    Medda, Rebecca; Giske, Arnold; Cavalcanti-Adam, Elisabetta Ada

    2016-01-01

    Super-resolution microscopy offers unique tools for visualizing and resolving cellular structures at the molecular level. STED microscopy is a purely optical method where neither complex sample preparation nor mathematical post-processing is required. Here we present the use of STED microscopy for imaging receptor cluster composition. We use two-color STED to further determine the distribution of two different receptor subunits of the family of receptor serine/threonine kinases in the presence or absence of their ligands. The implications of receptor clustering on the downstream signaling are discussed, and future challenges are also presented.

  9. Neuropeptide Receptor Transcriptome Reveals Unidentified Neuroendocrine Pathways

    Science.gov (United States)

    Yamanaka, Naoki; Yamamoto, Sachie; Žitňan, Dušan; Watanabe, Ken; Kawada, Tsuyoshi; Satake, Honoo; Kaneko, Yu; Hiruma, Kiyoshi; Tanaka, Yoshiaki; Shinoda, Tetsuro; Kataoka, Hiroshi

    2008-01-01

    Neuropeptides are an important class of molecules involved in diverse aspects of metazoan development and homeostasis. Insects are ideal model systems to investigate neuropeptide functions, and the major focus of insect neuropeptide research in the last decade has been on the identification of their receptors. Despite these vigorous efforts, receptors for some key neuropeptides in insect development such as prothoracicotropic hormone, eclosion hormone and allatotropin (AT), remain undefined. In this paper, we report the comprehensive cloning of neuropeptide G protein-coupled receptors from the silkworm, Bombyx mori, and systematic analyses of their expression. Based on the expression patterns of orphan receptors, we identified the long-sought receptor for AT, which is thought to stimulate juvenile hormone biosynthesis in the corpora allata (CA). Surprisingly, however, the AT receptor was not highly expressed in the CA, but instead was predominantly transcribed in the corpora cardiaca (CC), an organ adjacent to the CA. Indeed, by using a reverse-physiological approach, we purified and characterized novel allatoregulatory peptides produced in AT receptor-expressing CC cells, which may indirectly mediate AT activity on the CA. All of the above findings confirm the effectiveness of a systematic analysis of the receptor transcriptome, not only in characterizing orphan receptors, but also in identifying novel players and hidden mechanisms in important biological processes. This work illustrates how using a combinatorial approach employing bioinformatic, molecular, biochemical and physiological methods can help solve recalcitrant problems in neuropeptide research. PMID:18725956

  10. Neuropeptide receptor transcriptome reveals unidentified neuroendocrine pathways.

    Directory of Open Access Journals (Sweden)

    Naoki Yamanaka

    Full Text Available Neuropeptides are an important class of molecules involved in diverse aspects of metazoan development and homeostasis. Insects are ideal model systems to investigate neuropeptide functions, and the major focus of insect neuropeptide research in the last decade has been on the identification of their receptors. Despite these vigorous efforts, receptors for some key neuropeptides in insect development such as prothoracicotropic hormone, eclosion hormone and allatotropin (AT, remain undefined. In this paper, we report the comprehensive cloning of neuropeptide G protein-coupled receptors from the silkworm, Bombyx mori, and systematic analyses of their expression. Based on the expression patterns of orphan receptors, we identified the long-sought receptor for AT, which is thought to stimulate juvenile hormone biosynthesis in the corpora allata (CA. Surprisingly, however, the AT receptor was not highly expressed in the CA, but instead was predominantly transcribed in the corpora cardiaca (CC, an organ adjacent to the CA. Indeed, by using a reverse-physiological approach, we purified and characterized novel allatoregulatory peptides produced in AT receptor-expressing CC cells, which may indirectly mediate AT activity on the CA. All of the above findings confirm the effectiveness of a systematic analysis of the receptor transcriptome, not only in characterizing orphan receptors, but also in identifying novel players and hidden mechanisms in important biological processes. This work illustrates how using a combinatorial approach employing bioinformatic, molecular, biochemical and physiological methods can help solve recalcitrant problems in neuropeptide research.

  11. Abscisic Acid Receptors: Past, Present and Future

    Institute of Scientific and Technical Information of China (English)

    Jianjun Guo; Xiaohan Yang; David J. Weston; Jin-Gui Chen

    2011-01-01

    Abscisic acid (ABA) is the key plant stress hormone. Consistent with the earlier studies in support of the presence of both membrane- and cytoplasm-localized ABA receptors, recent studies have identified multiple ABA receptors located in various subcellular locations. These include a chloroplast envelope-localized receptor (the H subunit of Chloroplast Mg2+-chelatase/ABA Receptor), two plasma membrane-localized receptors (G-protein Coupled Receptor 2 and GPCR-type G proteins),and one cytosol/nucleus-localized Pyrabactin Resistant (PYR)/PYR-Like (PYL)/Regulatory Component of ABA Receptor 1 (RCAR). Although the downstream molecular events for most of the identified ABA receptors are currently unknown, one of them, PYR/PYL/RCAR was found to directly bind and regulate the activity of a long-known central regulator of ABA signaling, the A-group protein phosphatase 2C (PP2C). Together with the Sucrose Non-fermentation Kinase Subfamily 2 (SnRK2s) protein kinases, a central signaling complex (ABA-PYR-PP2Cs-SnRK2s) that is responsible for ABA signal perception and transduction is supported by abundant genetic, physiological, biochemical and structural evidence. The identification of multiple ABA receptors has advanced our understanding of ABA signal perception and transduction while adding an extra layer of complexity.

  12. CERAPP: Collaborative Estrogen Receptor Activity Prediction Project

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data from a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project) demonstrating using predictive computational...

  13. Identification and mechanism of ABA receptor antagonism

    KAUST Repository

    Melcher, Karsten

    2010-08-22

    The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2 to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands. © 2010 Nature America, Inc. All rights reserved.

  14. Regulation of Estrogen Receptor Nuclear Export by Ligand-Induced and p38-Mediated Receptor Phosphorylation

    OpenAIRE

    Lee, Heehyoung; Bai, Wenlong

    2002-01-01

    Estrogen receptors are phosphoproteins which can be activated by ligands, kinase activators, or phosphatase inhibitors. Our previous study showed that p38 mitogen-activated protein kinase was involved in estrogen receptor activation by estrogens and MEKK1. Here, we report estrogen receptor-dependent p38 activation by estrogens in endometrial adenocarcinoma cells and in vitro and in vivo phosphorylation of the estrogen receptor α mediated through p38. The phosphorylation site was identified as...

  15. Studies on mu and delta opioid receptor selectivity utilizing chimeric and site-mutagenized receptors.

    Science.gov (United States)

    Wang, W W; Shahrestanifar, M; Jin, J; Howells, R D

    1995-01-01

    Opioid receptors are members of the guanine nucleotide binding protein (G protein)-coupled receptor family. Three types of opioid receptors have been cloned and characterized and are referred to as the delta, kappa and mu types. Analysis of receptor chimeras and site-directed mutant receptors has provided a great deal of information about functionally important amino acid side chains that constitute the ligand-binding domains and G-protein-coupling domains of G-protein-coupled receptors. We have constructed delta/mu opioid receptor chimeras that were express in human embryonic kidney 293 cells in order to define receptor domains that are responsible for receptor type selectivity. All chimeric receptors and wild-type delta and mu opioid receptors displayed high-affinity b