title: Tumor cell-derived Timp-1 is necessary for maintaining metastasis-promoting Met-signaling via inhibition of Adam-10.
abstract: In many different tumor entities, increased expression of tissue inhibitor of metalloproteinases-1 (Timp-1) is associated with poor prognosis. We previously reported in mouse models that elevated systemic levels of Timp-1 induce a gene expression signature in the liver microenvironment increasing the susceptibility of this organ to tumor cells. This host effect was dependent on increased activity of the hepatocyte growth factor (Hgf)/hepatocyte growth factor receptor (Met) signaling pathway. In a recent study we showed that Met signaling is regulated by Timp-1 as it inhibits the Met sheddase A disintegrin and metalloproteinase-10 (Adam-10). The aim of the present study was to elucidate whether the metastatic potential of tumor cells benefits from autocrine Timp-1 as well and involves Adam-10 and Met signaling. In a syngeneic murine model of experimental liver metastasis Timp-1 expression and Met signaling were localized within metastatic colonies and expressed by tumor cells. Knock down of tumor cell Timp-1 suppressed Met signaling in metastases and inhibited metastasis formation and tumor cell-scattering in the liver. In vitro, knock down of tumor cell Timp-1 prevented Hgf-induced Met phosphorylation. Consequently, knock down of Met sheddase Adam-10 triggered auto-phosphorylation and responsiveness to Hgf. Accordingly, Adam-10 knock down increased Met phosphorylation in metastatic foci and induced tumor cell scattering into the surrounding liver parenchyma. In conclusion, these findings show that tumor cell-derived Timp-1 acts as a positive regulator of the metastatic potential and support the concept that proteases and their natural inhibitors, as members of the protease web, are major players of signaling during normal homeostasis and disease.
authors.affiliation: Institut für Experimentelle Onkologie und Therapieforschung des Klinikums rechts der Isar, Technische Universität München, Ismaninger Straße 22, 81675 Munich, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Schelter
authors.forename: Martina
authors.initials: M
authors.lastname: Grandl
authors.forename: Bastian
authors.initials: B
authors.lastname: Seubert
authors.forename: Susanne
authors.initials: S
authors.lastname: Schaten
authors.forename: Stephanie
authors.initials: S
authors.lastname: Hauser
authors.forename: Michael
authors.initials: M
authors.lastname: Gerg
authors.forename: Carla
authors.initials: C
authors.lastname: Boccaccio
authors.forename: Paolo
authors.initials: P
authors.lastname: Comoglio
authors.forename: Achim
authors.initials: A
authors.lastname: Krüger
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation; D002478:Cells, Cultured; D015972:Gene Expression Regulation, Neoplastic; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D008565:Membrane Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008811:Mice, Inbred DBA; D010766:Phosphorylation / Q000187:drug effects; D019859:Proto-Oncogene Proteins c-met / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D015996:Survival Rate; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D059016:Tumor Microenvironment
chemical_list: D008565:Membrane Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C560825:Timp1 protein, mouse; D019715:Tissue Inhibitor of Metalloproteinase-1; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met; D053829:Amyloid Precursor Protein Secretases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491234:Adam10 protein, mouse