5
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Activation of G-proteins with AIF-4 induces LFA-1-mediated adhesion of T-cell hybridoma cells to ICAM-1 by signal pathways that differ from phorbol ester- and manganese-induced adhesion.

      Experimental Cell Research
      Aluminum Compounds, pharmacology, Androstadienes, Animals, Cell Adhesion, drug effects, Enzyme Activation, Enzyme Inhibitors, Estrenes, Fluorides, GTP-Binding Proteins, metabolism, Genistein, Humans, Hybridomas, Indoles, Intercellular Adhesion Molecule-1, Isoflavones, Lymphocyte Function-Associated Antigen-1, Maleimides, Manganese, Mice, Neoplasm Invasiveness, Neoplasm Proteins, antagonists & inhibitors, physiology, Phosphatidylinositol 3-Kinases, Phosphatidylinositol 4,5-Diphosphate, Phosphatidylinositol Diacylglycerol-Lyase, Phosphodiesterase Inhibitors, Phosphoric Diester Hydrolases, Phosphotransferases (Alcohol Group Acceptor), Protein Kinase C, Protein-Tyrosine Kinases, Pyrrolidinones, Signal Transduction, T-Lymphocytes, Tetradecanoylphorbol Acetate

      Read this article at

      ScienceOpenPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          T-cell hybridomas metastasize widely, and the extent of dissemination correlates with invasiveness in fibroblast cultures. Previously, we provided evidence that both metastasis and in vitro invasion require activation of LFA-1, induced by G-protein-transduced signals triggered by as yet unidentified factors. We show here that LFA-1-mediated adhesion of TAM2D2 T-cell hybridoma cells to ICAM-1 can in fact be induced by direct activation of G-proteins using AIF-4, to the same extent as by using PMA or Mn2+. We assessed effects of protein kinase C (PKC), tyrosine kinase (TK), PI3-kinase (PI3K), and phospholipase C (PLC) inhibitors. Both AIF-4-induced adhesion and invasion were completely blocked by the TK inhibitor genistein and partially blocked by the PI3K inhibitor wortmannin, but not influenced by PKC inhibitor GF109203X. Downregulation of PKC did not affect invasion or adhesion induced by AIF-4 either. In contrast, GF109203X and PKC downregulation blocked PMA-induced adhesion, but genistein and wortmannin had no effect. Invasion and both AIF-4- and PMA-induced adhesion were completely blocked by the PLC inhibitor U73122. Mn(2+)-induced adhesion, which was not or was only partially blocked by the other inhibitors, was delayed by U73122, and spreading of Mn(2+)-treated cells was completely prevented by U73122. However, PLC activity during adhesion was not detected. We conclude that signals required for invasion and G-protein-induced adhesion are similar and are distinct from PKC-induced adhesion, and that in all cases PLC is likely to be activated, but is probably too local and/or transient to be detected.

          Related collections

          Author and article information

          Comments

          Comment on this article