Characterization of integrin expression and regulation on SW-480 human colon adenocarcinoma cells and the effect of rhodostomin on basal and upregulated tumor cell adhesion.

• Abstract: Integrins are a superfamily of cell surface glycoproteins that mediate cell-extracellular matrix (ECM) and cell-cell adhesion. Immunofluorescence microscopy and flow cytometric analysis using anti-integrin mAbs as the primary binding ligands demonstrated that the platelet integrin receptor alpha IIb beta 3, as well as alpha v beta 3, alpha 5 beta 1 and alpha 6 beta 1, are present on the surface of SW-480 human colon adenocarcinoma cells. Monoclonal antibodies (mAbs) against alpha IIb beta 3 and alpha 5 beta 1 inhibited unstimulated basal adhesion to fibronectin by approximately 30% and 40%, respectively. The surface immunoreactivity of tumor cells for alpha IIb beta 3 was enhanced by pretreatment (5 min) with a phorbol ester (12-O-tetradecanoylphorbol-13-acetate (TPA)) or a lipoxygenase metabolite of arachidonic acid, 12-hydroxyeicosatetraenoic acid (12-HETE) in a dose- and time-dependent manner. SW-480 cells possess a large intracellular pool of alpha IIb beta 3, from which the receptor complex translocates to the cell surface following pretreatment with TPA or 12(S)-HETE. This pretreatment enhances adhesion to fibronectin, which is mediated exclusively by alpha IIb beta 3 integrins. Staurosporine was found to block alpha IIb beta 3 up-regulation and enhanced-adhesion. TPA and 12(S)-HETE also facilitated the redistribution of alpha IIb beta 3 during the enhanced-spreading process. Rhodostomin, an Arg-Gly-Asp- (RGD) containing antiplatelet snake venom peptide, was about 400-times more potent than RGDS at inhibiting control, TPA- or 12(S)-HETE-enhanced adhesion of SW-480 cells to fibronectin. The binding of mAbs against alpha IIb beta 3, alpha v beta 3 and alpha 5 beta 1 was inhibited by pretreatment with rhodostomin, suggesting that rhodostomin binds via its RGD sequence to multiple integrin receptors (i.e., alpha IIb beta 3, alpha v beta 3, alpha 5 beta 1) expressed on the SW-480 cell surface, inhibiting cell adhesion to ECM.
• Authors: H S Chiang, H C Peng, T F Huang (Affiliation: Pharmacological Institute, College of Medicine, National Taiwan University, Taipei.)
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1224 Issue 3 Pg. 506-16 (Dec 30 1994) ISSN: 0006-3002 [Print] NETHERLANDS
• PMID: 7803510 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Binding Sites, Antibody
• Fibronectins
• Hydroxyeicosatetraenoic Acids
• Integrins
• Peptides
• Platelet Aggregation Inhibitors
• rhodostomin
• Tetradecanoylphorbol Acetate
• 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid

Topics

• 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
• Adenocarcinoma (metabolism, pathology)
• Antibodies, Monoclonal (immunology)
• Binding Sites, Antibody
• Cell Adhesion (drug effects)
• Colonic Neoplasms (metabolism, pathology)
• Extracellular Matrix (metabolism)
• Fibronectins (metabolism)
• Fluorescent Antibody Technique
• Humans
• Hydroxyeicosatetraenoic Acids (pharmacology)
• Integrins (immunology, metabolism)
• Peptides (pharmacology)
• Platelet Aggregation Inhibitors (pharmacology)
• Tetradecanoylphorbol Acetate (pharmacology)
• Tumor Cells, Cultured
• Up-Regulation