PKC mediates 12(S)-HETE-induced cytoskeletal rearrangement in B16a melanoma cells

• Published in: Cell motility and the cytoskeleton Vol. 26; no. 1; p. 49
• Main Authors: Timar, J, Tang, D, Bazaz, R, Haddad, M M, Kimler, V A, Taylor, J D, Honn, K V
• Format: Journal Article
• Language: English
• Published: United States 1993
• Subjects: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Actin Cytoskeleton - chemistry; Actin Cytoskeleton - drug effects; Actin Cytoskeleton - ultrastructure; Actins - analysis; Animals; Calcium - pharmacology; Cell Movement - physiology; Cytoskeletal Proteins - metabolism; Cytoskeletal Proteins - physiology; Cytoskeleton - chemistry; Cytoskeleton - drug effects; Cytoskeleton - ultrastructure; Dose-Response Relationship, Drug; Fibronectins - analysis; Fluorescent Antibody Technique; Hydroxyeicosatetraenoic Acids - pharmacology; Immunohistochemistry; Intermediate Filaments - chemistry; Intermediate Filaments - drug effects; Intermediate Filaments - ultrastructure; Melanoma, Experimental - chemistry; Melanoma, Experimental - pathology; Melanoma, Experimental - ultrastructure; Mice; Myosins - analysis; Organelles - physiology; Organelles - ultrastructure; Phospholipids - pharmacology; Phosphorylation; Protein Kinases - pharmacology; Protein Kinases - physiology; Skin Neoplasms - chemistry; Skin Neoplasms - pathology; Skin Neoplasms - ultrastructure; Tumor Cells, Cultured; Vimentin - analysis; Vinculin - analysis
• ISSN: 0886-1544
• DOI: 10.1002/cm.970260106

The fatty acid 12(S)-HETE may be a new second messenger capable of activating PKC. In tumor cells 12(S)-HETE stimulates cytoskeleton-dependent cellular responses such as adhesion and spreading. Analysis of 12(S)-HETE effects on B16a melanoma cell cytoskeleton revealed reversible rearrangement of microtubules, microfilaments, the actin-binding proteins, vinculin, myosin heavy (MHC) and light chains (MLC), as well as bundling of vimentin intermediate filaments. The alterations in microfilaments and intermediate filaments occurred very rapidly, i.e., 5 min after exposure of tumor cells to 12(S)-HETE. The 12(S)-HETE-induced cytoskeletal alterations were accompanied by centrifugal organelle-translocation. Interestingly, MLC exhibited clear association with the cytoplasmic organelles. Biochemical analysis of the 12(S)-HETE effect indicated a PKC-mediated reversible hyperphosphorylation of MLC, vimentin, and a 130 kD cytoskeletal-associated protein. Optimal effects were obtained after 5 min treatment with 12(S)-HETE at 0.1 microM concentration. 12(S)-HETE pretreatment induced tumor cell spreading on a fibronectin matrix which required the intactness of all three major cytoskeletal components. The spreading process was dependent upon the activity of PKC. Our data suggest that 12(S)-HETE is a physiological stimulant of PKC. Further, it induces rearrangement of the cytoskeleton of tumor cells in interphase resulting in the stimulation of cytoskeleton-dependent cell activity such as spreading.