The SH2-containing inositol 5-phosphatase (SHIP)-1 is implicated in the control of cell-cell junction and induces dissociation and dispersion of MDCK cells.
Hepatocyte growth factor (HGF) induces the breakdown of cell junction and the dispersion of colonies of epithelial cells, providing a model system for the investigation of the molecular mechanisms of one of the important aspects of tumorogenesis. We have previously reported that the SH2-domain-containing inositol 5'phosphatase (SHIP)-1 binds to c-Met, and potentiated HGF-mediated branching tubulogenesis. In this study, we describe the establishment of MDCK cell lines which express MycHis-tagged SHIP-1 at different levels. Expression of SHIP-1 in MDCK cells at a high level resulted in cell morphology characteristic of an epithelial-mesenchymal like transition; cells lost cortical actin, developed actin stress fibers and gained spontaneous motility without treatment of HGF. When the level of MycHis-tagged SHIP-expression was relatively low, transfectants partially lost cortical actin and phalloidin stained puncta appeared at cell-cell junctions even in the absence of HGF. The treatment of MAP kinase inhibitor, PD98059, did not influence SHIP-1 mediated alteration of adherens-junction of MDCK cells, while, phosphatidylinositol 3 (PI 3)- kinase inhibitor, LY294002, drastically reduced SHIP-1 mediated phenotype. Furthermore, expression of a mutant SHIP-1 lacking catalytic activity in MDCK cells did not alter the cortical actin distribution and HGF-mediated MAP and Akt kinase-phosphorylation, but suppressed HGF induced cell dispersion, suggesting that phosphatase activity is important for cytoskeleton rearrangement and cell dispersion.
Mancini
Annalisa
A
Institut für Biochemie, OE 4310, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30623 Hannover, Germany.
Koch
Alexandra
A
Wilms
Regina
R
Tamura
Teruko
T
D022005:Adherens Junctions / Q000201:enzymology* / Q000378:metabolism / Q000648:ultrastructure; D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D002867:Chromones / Q000494:pharmacology; D004285:Dogs; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure*; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009154:Mutation; D010590:Phalloidine / Q000737:chemistry; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D022502:Stress Fibers / Q000648:ultrastructure; D014162:Transfection; D018909:src Homology Domains
D002867:Chromones; D004791:Enzyme Inhibitors; D009025:Morpholines; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010590:Phalloidine; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D017228:Hepatocyte Growth Factor; D020928:Mitogen-Activated Protein Kinases; D010744:Phosphoric Monoester Hydrolases; C098706:INPPL1 protein, human; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases