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  1. Article ; Online: A Novel Humanized Model of NASH and Its Treatment With META4, A Potent Agonist of MET.

    Ma, Jihong / Tan, Xinping / Kwon, Yongkook / Delgado, Evan R / Zarnegar, Arman / DeFrances, Marie C / Duncan, Andrew W / Zarnegar, Reza

    Cellular and molecular gastroenterology and hepatology

    2021  Volume 13, Issue 2, Page(s) 565–582

    Abstract: Background & aims: Nonalcoholic fatty liver disease is a frequent cause of hepatic dysfunction and is now a global epidemic. This ailment can progress to an advanced form called nonalcoholic steatohepatitis (NASH) and end-stage liver disease. Currently, ...

    Abstract Background & aims: Nonalcoholic fatty liver disease is a frequent cause of hepatic dysfunction and is now a global epidemic. This ailment can progress to an advanced form called nonalcoholic steatohepatitis (NASH) and end-stage liver disease. Currently, the molecular basis of NASH pathogenesis is poorly understood, and no effective therapies exist to treat NASH. These shortcomings are due to the paucity of experimental NASH models directly relevant to humans.
    Methods: We used chimeric mice with humanized liver to investigate nonalcoholic fatty liver disease in a relevant model. We carried out histologic, biochemical, and molecular approaches including RNA-Seq. For comparison, we used side-by-side human NASH samples.
    Results: Herein, we describe a "humanized" model of NASH using transplantation of human hepatocytes into fumarylacetoacetate hydrolase-deficient mice. Once fed a high-fat diet, these mice develop NAFLD faithfully, recapitulating human NASH at the histologic, cellular, biochemical, and molecular levels. Our RNA-Seq analyses uncovered that a variety of important signaling pathways that govern liver homeostasis are profoundly deregulated in both humanized and human NASH livers. Notably, we made the novel discovery that hepatocyte growth factor (HGF) function is compromised in human and humanized NASH at several levels including a significant increase in the expression of the HGF antagonists known as NK1/NK2 and marked decrease in HGF activator. Based on these observations, we generated a potent, human-specific, and stable agonist of human MET that we have named META4 (Metaphor) and used it in the humanized NASH model to restore HGF function.
    Conclusions: Our studies revealed that the humanized NASH model recapitulates human NASH and uncovered that HGF-MET function is impaired in this disease. We show that restoring HGF-MET function by META4 therapy ameliorates NASH and reinstates normal liver function in the humanized NASH model. Our results show that the HGF-MET signaling pathway is a dominant regulator of hepatic homeostasis.
    MeSH term(s) Animals ; Diet, High-Fat ; Hepatocytes/metabolism ; Mice ; Non-alcoholic Fatty Liver Disease/pathology
    Language English
    Publishing date 2021-10-29
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2819778-1
    ISSN 2352-345X ; 2352-345X
    ISSN (online) 2352-345X
    ISSN 2352-345X
    DOI 10.1016/j.jcmgh.2021.10.007
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Genomic instability causes HGF gene activation in colon cancer cells, promoting their resistance to necroptosis.

    Seneviratne, Danushka / Ma, Jihong / Tan, Xinping / Kwon, Yong-Kook / Muhammad, Eman / Melhem, Mona / DeFrances, Marie C / Zarnegar, Reza

    Gastroenterology

    2014  Volume 148, Issue 1, Page(s) 181–191.e17

    Abstract: Background & aims: Genomic instability promotes colon carcinogenesis by inducing genetic mutations, but not all genes affected by this process have been identified. We investigated whether genomic instability in human colorectal cancer (CRC) cells ... ...

    Abstract Background & aims: Genomic instability promotes colon carcinogenesis by inducing genetic mutations, but not all genes affected by this process have been identified. We investigated whether genomic instability in human colorectal cancer (CRC) cells produces mutations in the hepatocyte growth factor (HGF) gene.
    Methods: We genotyped human colon tumor tissues and adjacent nontumor tissues collected from 78 patients University of Pittsburgh Health Sciences and Veterans Hospital, along with 40 human CRC and adjacent nontumor tissues in a commercial microarray. We used cellular, biochemical, and molecular biological techniques to investigate the factors that alter HGF signaling in colon cancer cells and its effects on cell proliferation and survival.
    Results: All tested human CRC tissues and cell lines that had microsatellite instability contained truncations in the regulatory deoxyadenosine tract element (DATE) of the HGF gene promoter. The DATE was unstable in 14% (11 of 78) of CRC samples; DATE truncation was also polymorphic and detected in 18% (13 of 78) of CRC tissues without microsatellite instability. In CRC cell lines, truncation of DATE activated expression of HGF, resulting in its autocrine signaling via MET. This promoted cell proliferation and resistance to necroptosis. HGF signaling via MET reduced levels of the receptor-interacting serine-threonine kinase 1, a mediator of necroptosis, in CRC cells. High levels of HGF protein in tumor tissues correlated with lower levels of receptor-interacting serine-threonine kinase 1 and shorter survival times of patients.
    Conclusions: Thirty-one percent of CRC samples contain alterations in the DATE of the HGF promoter. Disruption of the DATE increased HGF signaling via MET and reduced levels of receptor-interacting serine-threonine kinase 1 and CRC cell necroptosis. DATE alteration might be used as a prognostic factor or to select patients for therapies that target HGF-MET signaling.
    MeSH term(s) Adenocarcinoma/genetics ; Adenocarcinoma/metabolism ; Adenocarcinoma/mortality ; Adenocarcinoma/pathology ; Aged ; Aged, 80 and over ; Apoptosis ; Autocrine Communication ; Cell Proliferation ; Cell Survival ; Colonic Neoplasms/genetics ; Colonic Neoplasms/metabolism ; Colonic Neoplasms/mortality ; Colonic Neoplasms/pathology ; DNA Mismatch Repair ; Female ; Gene Expression Profiling/methods ; Gene Expression Regulation, Neoplastic ; Genetic Predisposition to Disease ; Genomic Instability ; HCT116 Cells ; HT29 Cells ; Hepatocyte Growth Factor/genetics ; Hepatocyte Growth Factor/metabolism ; Humans ; Male ; Microsatellite Instability ; Middle Aged ; Necrosis ; Oligonucleotide Array Sequence Analysis ; Phenotype ; Prognosis ; Promoter Regions, Genetic ; Proto-Oncogene Proteins c-met/metabolism ; Receptor-Interacting Protein Serine-Threonine Kinases/metabolism ; Signal Transduction ; Time Factors ; Transcriptional Activation ; Transfection
    Chemical Substances HGF protein, human ; Hepatocyte Growth Factor (67256-21-7) ; MET protein, human (EC 2.7.10.1) ; Proto-Oncogene Proteins c-met (EC 2.7.10.1) ; RIPK1 protein, human (EC 2.7.11.1) ; Receptor-Interacting Protein Serine-Threonine Kinases (EC 2.7.11.1)
    Language English
    Publishing date 2014-09-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 80112-4
    ISSN 1528-0012 ; 0016-5085
    ISSN (online) 1528-0012
    ISSN 0016-5085
    DOI 10.1053/j.gastro.2014.09.019
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: beta-Catenin and met deregulation in childhood Hepatoblastomas.

    Ranganathan, Sarangarajan / Tan, Xinping / Monga, Satdarshan P S

    Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society

    2005  Volume 8, Issue 4, Page(s) 435–447

    Abstract: Activation of the Wnt/beta-catenin and hepatocyte growth factor/Met signaling has been implicated in various tumors. Owing to the cross-talk between these pathways and aberrant redistribution of beta-catenin in hepatoblastomas, we examined their status ... ...

    Abstract Activation of the Wnt/beta-catenin and hepatocyte growth factor/Met signaling has been implicated in various tumors. Owing to the cross-talk between these pathways and aberrant redistribution of beta-catenin in hepatoblastomas, we examined their status in this tumor. This study examined changes in beta-catenin and Met in paired pretreatment and post-treatment hepatoblastoma tissues in relation to their effects on proliferation and target genes such as c-myc and cyclin-D1. In this study we compared proliferation indices, beta-catenin staining and its known molecular targets, c-myc and cyclin-D1, and Met, a tyrosine kinase receptor for hepatocyte growth factor in pretreatment and post-treatment specimens. Pretreatment and post-treatment sections from 13 children, ages 11 weeks to 9 years, were analyzed for these markers by immunohistochemistry. All tumors (13 of 13) displayed increased proliferation and beta-catenin (cytoplasmic and nuclear) staining in pretreatment biopsies that remained relatively unaffected after treatment. Aberrant Met staining (cytoplasmic) was observed in all pretreatment samples that decreased considerably after treatment in 11 of 13 patients. A significant subset of these tumors showed increased c-myc and cyclin-D1 staining in pretreatment biopsies that decreased after chemotherapy in most cases. beta-Catenin redistribution in tumor cells corresponds to proliferation in hepatoblastomas. However, beta-catenin nuclear localization remains unaffected in viable hepatoblastoma tissue after chemotherapy. In contrast, Met undergoes a prominent decrease after treatment and thus might be important in pathogenesis of hepatoblastoma.
    MeSH term(s) Biomarkers, Tumor/metabolism ; Cell Nucleus/drug effects ; Cell Nucleus/metabolism ; Cell Nucleus/pathology ; Cell Proliferation ; Chemotherapy, Adjuvant ; Child ; Child, Preschool ; Cytoplasm/drug effects ; Cytoplasm/metabolism ; Cytoplasm/pathology ; Female ; Hepatectomy ; Hepatoblastoma/drug therapy ; Hepatoblastoma/metabolism ; Hepatoblastoma/pathology ; Humans ; Infant ; Liver Neoplasms/drug therapy ; Liver Neoplasms/metabolism ; Liver Neoplasms/pathology ; Male ; Proto-Oncogene Proteins c-met/metabolism ; Retrospective Studies ; Signal Transduction ; Wnt Proteins/metabolism ; beta Catenin/metabolism
    Chemical Substances Biomarkers, Tumor ; Wnt Proteins ; beta Catenin ; Proto-Oncogene Proteins c-met (EC 2.7.10.1)
    Language English
    Publishing date 2005-07
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.
    ZDB-ID 1463498-3
    ISSN 1615-5742 ; 1093-5266
    ISSN (online) 1615-5742
    ISSN 1093-5266
    DOI 10.1007/s10024-005-0028-5
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: β-Catenin Regulates Vitamin C Biosynthesis and Cell Survival in Murine Liver

    Nejak-Bowen, Kari N / Zeng, Gang / Tan, Xinping / Cieply, Benjamin / Monga, Satdarshan P

    Journal of biological chemistry. 2009 Oct. 9, v. 284, no. 41

    2009  

    Abstract: Because the Wnt/β-catenin pathway plays multiple roles in liver pathobiology, it is critical to identify gene targets that mediate such diverse effects. Here we report a novel role of β-catenin in controlling ascorbic acid biosynthesis in murine liver ... ...

    Abstract Because the Wnt/β-catenin pathway plays multiple roles in liver pathobiology, it is critical to identify gene targets that mediate such diverse effects. Here we report a novel role of β-catenin in controlling ascorbic acid biosynthesis in murine liver through regulation of expression of regucalcin or senescence marker protein 30 and L-gulonolactone oxidase. Reverse transcription-PCR, Western blotting, and immunohistochemistry demonstrate decreased regucalcin expression in β-catenin-null livers and greater expression in β-catenin overexpressing transgenic livers, HepG2 hepatoma cells (contain constitutively active β-catenin), regenerating livers, and in hepatocellular cancer tissues that exhibit β-catenin activation. Interestingly, coprecipitation and immunofluorescence studies also demonstrate an association of β-catenin and regucalcin. Luciferase reporter and chromatin immunoprecipitation assays verified a functional TCF-4-binding site located between -163 and -157 (CTTTGCA) on the regucalcin promoter to be critical for regulation by β-catenin. Significantly lower serum ascorbate levels were observed in β-catenin knock-out mice secondary to decreased expression of regucalcin and also of L-gulonolactone oxidase, the penultimate and last (also rate-limiting) steps in the synthesis of ascorbic acid, respectively. These mice also show enhanced basal hepatocyte apoptosis. To test if ascorbate deficiency secondary to β-catenin loss and regucalcin decrease was contributing to apoptosis, β-catenin-null hepatocytes or regucalcin small interfering RNA-transfected HepG2 cells were cultured, which exhibited significant apoptosis that was alleviated by the addition of ascorbic acid. Thus, through regucalcin and L-gulonolactone oxidase expression, β-catenin regulates vitamin C biosynthesis in murine liver, which in turn may be one of the mechanisms contributing to the role of β-catenin in cell survival.
    Language English
    Dates of publication 2009-1009
    Size p. 28115-28127.
    Publishing place American Society for Biochemistry and Molecular Biology
    Document type Article
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Beta-catenin regulates vitamin C biosynthesis and cell survival in murine liver.

    Nejak-Bowen, Kari N / Zeng, Gang / Tan, Xinping / Cieply, Benjamin / Monga, Satdarshan P

    The Journal of biological chemistry

    2009  Volume 284, Issue 41, Page(s) 28115–28127

    Abstract: Because the Wnt/beta-catenin pathway plays multiple roles in liver pathobiology, it is critical to identify gene targets that mediate such diverse effects. Here we report a novel role of beta-catenin in controlling ascorbic acid biosynthesis in murine ... ...

    Abstract Because the Wnt/beta-catenin pathway plays multiple roles in liver pathobiology, it is critical to identify gene targets that mediate such diverse effects. Here we report a novel role of beta-catenin in controlling ascorbic acid biosynthesis in murine liver through regulation of expression of regucalcin or senescence marker protein 30 and L-gulonolactone oxidase. Reverse transcription-PCR, Western blotting, and immunohistochemistry demonstrate decreased regucalcin expression in beta-catenin-null livers and greater expression in beta-catenin overexpressing transgenic livers, HepG2 hepatoma cells (contain constitutively active beta-catenin), regenerating livers, and in hepatocellular cancer tissues that exhibit beta-catenin activation. Interestingly, coprecipitation and immunofluorescence studies also demonstrate an association of beta-catenin and regucalcin. Luciferase reporter and chromatin immunoprecipitation assays verified a functional TCF-4-binding site located between -163 and -157 (CTTTGCA) on the regucalcin promoter to be critical for regulation by beta-catenin. Significantly lower serum ascorbate levels were observed in beta-catenin knock-out mice secondary to decreased expression of regucalcin and also of L-gulonolactone oxidase, the penultimate and last (also rate-limiting) steps in the synthesis of ascorbic acid, respectively. These mice also show enhanced basal hepatocyte apoptosis. To test if ascorbate deficiency secondary to beta-catenin loss and regucalcin decrease was contributing to apoptosis, beta-catenin-null hepatocytes or regucalcin small interfering RNA-transfected HepG2 cells were cultured, which exhibited significant apoptosis that was alleviated by the addition of ascorbic acid. Thus, through regucalcin and L-gulonolactone oxidase expression, beta-catenin regulates vitamin C biosynthesis in murine liver, which in turn may be one of the mechanisms contributing to the role of beta-catenin in cell survival.
    MeSH term(s) Animals ; Antioxidants/metabolism ; Ascorbic Acid/biosynthesis ; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ; Calcium-Binding Proteins/genetics ; Calcium-Binding Proteins/metabolism ; Carcinoma, Hepatocellular/genetics ; Carcinoma, Hepatocellular/metabolism ; Cell Line, Tumor ; Cell Survival/physiology ; DNA-Binding Proteins/genetics ; DNA-Binding Proteins/metabolism ; Gene Expression Regulation ; Hepatocytes/cytology ; Hepatocytes/metabolism ; Humans ; Intracellular Signaling Peptides and Proteins/genetics ; Intracellular Signaling Peptides and Proteins/metabolism ; L-Gulonolactone Oxidase/genetics ; L-Gulonolactone Oxidase/metabolism ; Liver/cytology ; Liver/metabolism ; Liver Neoplasms/genetics ; Liver Neoplasms/metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mice, Transgenic ; Promoter Regions, Genetic ; RNA, Small Interfering/genetics ; RNA, Small Interfering/metabolism ; Transcription Factor 4 ; Transcription Factors/genetics ; Transcription Factors/metabolism ; beta Catenin/genetics ; beta Catenin/metabolism
    Chemical Substances Antioxidants ; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors ; Calcium-Binding Proteins ; DNA-Binding Proteins ; Intracellular Signaling Peptides and Proteins ; RGN protein, human ; RNA, Small Interfering ; Rgn protein, mouse ; TCF4 protein, human ; Transcription Factor 4 ; Transcription Factors ; beta Catenin ; L-Gulonolactone Oxidase (EC 1.1.3.8) ; Ascorbic Acid (PQ6CK8PD0R)
    Language English
    Publishing date 2009-08-18
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1074/jbc.M109.047258
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Mesenchymal stem cells enhance survival and bacterial clearance in murine Escherichia coli pneumonia.

    Gupta, Naveen / Krasnodembskaya, Anna / Kapetanaki, Maria / Mouded, Majd / Tan, Xinping / Serikov, Vladimir / Matthay, Michael A

    Thorax

    2012  Volume 67, Issue 6, Page(s) 533–539

    Abstract: Rationale: Bacterial pneumonia is the most common infectious cause of death worldwide and treatment is increasingly hampered by antibiotic resistance. Mesenchymal stem cells (MSCs) have been demonstrated to provide protection against acute inflammatory ... ...

    Abstract Rationale: Bacterial pneumonia is the most common infectious cause of death worldwide and treatment is increasingly hampered by antibiotic resistance. Mesenchymal stem cells (MSCs) have been demonstrated to provide protection against acute inflammatory lung injury; however, their potential therapeutic role in the setting of bacterial pneumonia has not been well studied.
    Objective: This study focused on testing the therapeutic and mechanistic effects of MSCs in a mouse model of Gram-negative pneumonia.
    Methods and results: Syngeneic MSCs from wild-type mice were isolated and administered via the intratracheal route to mice 4 h after the mice were infected with Escherichia coli. 3T3 fibroblasts and phosphate-buffered saline (PBS) were used as controls for all in vivo experiments. Survival, lung injury, bacterial counts and indices of inflammation were measured in each treatment group. Treatment with wild-type MSCs improved 48 h survival (MSC, 55%; 3T3, 8%; PBS, 0%; p<0.05 for MSC vs 3T3 and PBS groups) and lung injury compared with control mice. In addition, wild-type MSCs enhanced bacterial clearance from the alveolar space as early as 4 h after administration, an effect that was not observed with the other treatment groups. The antibacterial effect with MSCs was due, in part, to their upregulation of the antibacterial protein lipocalin 2.
    Conclusions: Treatment with MSCs enhanced survival and bacterial clearance in a mouse model of Gram-negative pneumonia. The bacterial clearance effect was due, in part, to the upregulation of lipocalin 2 production by MSCs.
    MeSH term(s) Acute-Phase Proteins/biosynthesis ; Acute-Phase Proteins/metabolism ; Animals ; Disease Models, Animal ; Escherichia coli/pathogenicity ; Escherichia coli Infections/complications ; Escherichia coli Infections/surgery ; Lipocalin-2 ; Lipocalins/biosynthesis ; Lipocalins/metabolism ; Mesenchymal Stem Cell Transplantation/methods ; Mice ; Mice, Inbred C57BL ; Oncogene Proteins/biosynthesis ; Oncogene Proteins/metabolism ; Pneumonia, Bacterial/microbiology ; Pneumonia, Bacterial/surgery ; Survival Analysis ; Trachea ; Treatment Outcome ; Up-Regulation
    Chemical Substances Acute-Phase Proteins ; Lipocalin-2 ; Lipocalins ; Oncogene Proteins ; Lcn2 protein, mouse (126469-30-5)
    Language English
    Publishing date 2012-01-16
    Publishing country England
    Document type Comparative Study ; Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 204353-1
    ISSN 1468-3296 ; 0040-6376
    ISSN (online) 1468-3296
    ISSN 0040-6376
    DOI 10.1136/thoraxjnl-2011-201176
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: A hepatocyte growth factor receptor (Met)-insulin receptor hybrid governs hepatic glucose metabolism.

    Fafalios, Arlee / Ma, Jihong / Tan, Xinping / Stoops, John / Luo, Jianhua / Defrances, Marie C / Zarnegar, Reza

    Nature medicine

    2011  Volume 17, Issue 12, Page(s) 1577–1584

    Abstract: Met is the transmembrane tyrosine kinase cell surface receptor for hepatocyte growth factor (HGF) and is structurally related to the insulin receptor (INSR) tyrosine kinase. Here we report that the HGF-Met axis regulates metabolism by stimulating hepatic ...

    Abstract Met is the transmembrane tyrosine kinase cell surface receptor for hepatocyte growth factor (HGF) and is structurally related to the insulin receptor (INSR) tyrosine kinase. Here we report that the HGF-Met axis regulates metabolism by stimulating hepatic glucose uptake and suppressing hepatic glucose output. We show that Met is essential for an optimal hepatic insulin response by directly engaging INSR to form a Met-INSR hybrid complex, which culminates in a robust signal output. We also found that the HGF-Met system restores insulin responsiveness in a mouse model of insulin refractoriness. These results provide new insights into the molecular basis of hepatic insulin resistance and suggest that HGF may have therapeutic potential for type 2 diabetes in the clinical setting.
    MeSH term(s) Animals ; Blood Glucose ; Diabetes Mellitus, Type 2/therapy ; Down-Regulation ; Female ; Glucose/metabolism ; Hep G2 Cells ; Hepatocyte Growth Factor/metabolism ; Humans ; Insulin/metabolism ; Liver/metabolism ; Male ; Mice ; Mice, Transgenic ; Models, Animal ; Phosphorylation ; Proto-Oncogene Proteins c-met/metabolism ; RNA, Small Interfering/metabolism ; Receptor Cross-Talk ; Receptor, Insulin/metabolism ; Signal Transduction
    Chemical Substances Blood Glucose ; Insulin ; RNA, Small Interfering ; Hepatocyte Growth Factor (67256-21-7) ; Proto-Oncogene Proteins c-met (EC 2.7.10.1) ; Receptor, Insulin (EC 2.7.10.1) ; Glucose (IY9XDZ35W2)
    Language English
    Publishing date 2011-11-13
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1220066-9
    ISSN 1546-170X ; 1078-8956
    ISSN (online) 1546-170X
    ISSN 1078-8956
    DOI 10.1038/nm.2531
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Platelet-derived growth factor receptor-alpha: a novel therapeutic target in human hepatocellular cancer.

    Stock, Peggy / Monga, Dulabh / Tan, Xinping / Micsenyi, Amanda / Loizos, Nick / Monga, Satdarshan P S

    Molecular cancer therapeutics

    2007  Volume 6, Issue 7, Page(s) 1932–1941

    Abstract: Hepatocellular cancer (HCC) is a disease of poor prognosis. Identifying novel molecular aberrations might present opportunities to identify new therapeutic targets. Due to the similarities between the processes of development and cancer, we used early ... ...

    Abstract Hepatocellular cancer (HCC) is a disease of poor prognosis. Identifying novel molecular aberrations might present opportunities to identify new therapeutic targets. Due to the similarities between the processes of development and cancer, we used early developing livers to identify genes that might play a primary role in HCC. Platelet-derived growth factor receptor-alpha (PDGFRalpha) was identified from microarray using early developing mouse livers. Expression of PDGFRalpha and its upstream effectors, PDGF-AA and PDGF-CC, were examined in HCC tissues (n = 43) by Western blot, real-time PCR, and immunohistochemistry. Finally, effect of anti-PDGFRalpha antibody (mAb 3G3, ImClone Systems, Inc.) was examined on human hepatoma cells. A high expression of PDGFRalpha was observed during early liver development. HCCs (17 of 21) revealed cytoplasmic PDGFRalpha and activated PDGFRalpha (phospho-Tyr(754)) by immunohistochemistry. Additional HCCs (14 of 22) showed elevated PDGFRalpha levels when compared with the adjacent normal livers by Western blots. Of these 14 patients, 3 showed increased PDGFRalpha gene expression, 3 showed elevated PDGF-AA, and 4 had higher PDGF-CC levels in the tumors compared with adjacent livers. Multiple hepatoma cell lines, when treated with mAb 3G3, showed significant decreases in cell proliferation and survival (P < 0.05). In conclusion, approximately 70% of HCC tissues had elevated PDGFRalpha levels due to diverse mechanisms. PDGFRalpha inhibition in hepatoma cells led to diminution of tumor cell survival and proliferation and thus might be of therapeutic significance.
    MeSH term(s) Animals ; Antibodies, Monoclonal/pharmacology ; Apoptosis/drug effects ; Carcinoma, Hepatocellular/genetics ; Carcinoma, Hepatocellular/metabolism ; Carcinoma, Hepatocellular/pathology ; Carcinoma, Hepatocellular/therapy ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Cell Survival/drug effects ; Gene Expression Regulation, Neoplastic/drug effects ; Humans ; Ligands ; Liver/drug effects ; Liver/growth & development ; Liver Neoplasms/genetics ; Liver Neoplasms/metabolism ; Liver Neoplasms/pathology ; Liver Neoplasms/therapy ; Mice ; Receptor, Platelet-Derived Growth Factor alpha/antagonists & inhibitors ; Receptor, Platelet-Derived Growth Factor alpha/genetics ; Receptor, Platelet-Derived Growth Factor alpha/metabolism ; Up-Regulation/drug effects
    Chemical Substances Antibodies, Monoclonal ; Ligands ; Receptor, Platelet-Derived Growth Factor alpha (EC 2.7.10.1)
    Language English
    Publishing date 2007-06-29
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2063563-1
    ISSN 1538-8514 ; 1535-7163
    ISSN (online) 1538-8514
    ISSN 1535-7163
    DOI 10.1158/1535-7163.MCT-06-0720
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: [Clinical analysis of binocular anisei konia after laser in situ keratomileusis on myopic patients].

    Liu, Shuangzhen / Zhang, Ping / Wu, Xiaoying / Hu, Shengfa / Tan, Xinping

    Yan ke xue bao = Eye science

    2003  Volume 19, Issue 2, Page(s) 107–109

    Abstract: Purpose: To explore the effect produced by laser in situ keratomileusis (LASIK) on binocular aniseikonia(BA) and steropsis of myopic patients.: Methods: Sixty-four cases who received LASIK were divided into 4 groups by different binoeular diopter ... ...

    Abstract Purpose: To explore the effect produced by laser in situ keratomileusis (LASIK) on binocular aniseikonia(BA) and steropsis of myopic patients.
    Methods: Sixty-four cases who received LASIK were divided into 4 groups by different binoeular diopter with the binocular aniserkonia (BA) designed by Liugeping and BA. The patients were tested on 6 months before and after the operation respectively for studing the relationship between the post-operative BA and steropsis.
    Results: When the binocular diopter difference was < or = 2.5 D, there was no significant difference between the preoperative and postoperative BA. When the diopter difference was > 2.50 D, the incongruons images of simultaneous perception and stereoscopic vision after operation had significant divergence compared with those before the operation. The postoperative stereopsis was closely related to binocular vision.
    Conclusion: LASIK can not only reduce the BA of high myopic anisome tropia patients to a range that can be endured, but also be helpful to restore the stereopsis. Moreover, the better the postoperative binocular vision, the patients have the finer the stereopsis will be.
    MeSH term(s) Adult ; Aniseikonia/etiology ; Aniseikonia/surgery ; Depth Perception ; Female ; Humans ; Keratomileusis, Laser In Situ ; Male ; Middle Aged ; Myopia/complications ; Myopia/surgery ; Vision, Binocular ; Visual Acuity
    Language Chinese
    Publishing date 2003-06
    Publishing country China
    Document type English Abstract ; Journal Article
    ZDB-ID 2013110-0
    ISSN 1000-4432
    ISSN 1000-4432
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Novel Death Defying Domain in Met entraps the active site of caspase-3 and blocks apoptosis in hepatocytes.

    Ma, Jihong / Zou, Chunbin / Guo, Lida / Seneviratne, Danushka S / Tan, Xinping / Kwon, Yong-Kook / An, Jiyan / Bowser, Robert / DeFrances, Marie C / Zarnegar, Reza

    Hepatology (Baltimore, Md.)

    2014  Volume 59, Issue 5, Page(s) 2010–2021

    Abstract: Unlabelled: Met, the transmembrane tyrosine kinase receptor for hepatocyte growth factor (HGF), is known to function as a potent antiapoptotic mediator in normal and neoplastic cells. Herein we report that the intracellular cytoplasmic tail of Met has ... ...

    Abstract Unlabelled: Met, the transmembrane tyrosine kinase receptor for hepatocyte growth factor (HGF), is known to function as a potent antiapoptotic mediator in normal and neoplastic cells. Herein we report that the intracellular cytoplasmic tail of Met has evolved to harbor a tandem pair of caspase-3 cleavage sites, which bait, trap, and disable the active site of caspase-3, thereby blocking the execution of apoptosis. We call this caspase-3 cleavage motif the Death Defying Domain (DDD). This site consists of the following sequence: DNAD-DEVD-T (where the hyphens denote caspase cleavage sites). Through functional and mechanistic studies, we show that upon DDD cleavage by caspase-3 the resulting DEVD-T peptide acts as a competitive inhibitor and entraps the active site of caspase-3 akin to DEVD-CHO, which is a potent, synthetic inhibitor of caspase-3 activity. By gain- and loss-of-function studies using restoration of DDD expression in DDD-deficient hepatocytic cells, we found that both caspase-3 sites in DDD are necessary for inhibition of caspase-3 and promotion of cell survival. Employing mutagenesis studies, we show that DDD could operate independently of Met's enzymatic activity as determined by using kinase-dead human Met mutant constructs. Studies of both human liver cancer tissues and cell lines uncovered that DDD cleavage and entrapment of caspase-3 by DDD occur in vivo, further proving that this site has physiological and pathophysiological relevance.
    Conclusion: Met can directly inhibit caspase-3 by way of a novel mechanism and promote hepatocyte survival. The results presented here will further our understanding of the mechanisms that control not only normal tissue homeostasis but also abnormal tissue growth such as cancer and degenerative diseases in which apoptotic caspases are at play.
    MeSH term(s) Amino Acid Sequence ; Animals ; Apoptosis ; Binding Sites ; Caspase 3/chemistry ; Caspase 3/physiology ; Caspase Inhibitors/pharmacology ; Cytoprotection ; Hepatocytes/physiology ; Humans ; Mice ; Molecular Sequence Data ; Oligopeptides/pharmacology ; Protein Structure, Tertiary ; Proto-Oncogene Proteins c-met/chemistry ; Proto-Oncogene Proteins c-met/physiology
    Chemical Substances Caspase Inhibitors ; Oligopeptides ; aspartyl-glutamyl-valyl-aspartal ; MET protein, human (EC 2.7.10.1) ; Proto-Oncogene Proteins c-met (EC 2.7.10.1) ; Caspase 3 (EC 3.4.22.-)
    Language English
    Publishing date 2014-04-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 604603-4
    ISSN 1527-3350 ; 0270-9139
    ISSN (online) 1527-3350
    ISSN 0270-9139
    DOI 10.1002/hep.26769
    Database MEDical Literature Analysis and Retrieval System OnLINE

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