This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dumont, J. A. Articles by Bitonti, A. J. Search for Related Content PubMed PubMed Citation Articles by Dumont, J. A. Articles by Bitonti, A. J.

Inhibition of Experimental Metastasis and Cell Adhesion of B16F1 Melanoma Cells by Inhibitors of Protein Kinase C

Marion Merrell Dow Research Institute, Cincinnati, Ohio 45215

Phorbol esters which activate protein kinase C (PKC) have been shown to enhance experimental lung metastasis. Therefore, it was reasoned that inhibitors of PKC might also modulate metastasis. We have investigated this possibility using a PKC inhibitor, MDL 27,032 [4-propyl-5(4-pyridinyl)-2(3H)-oxazolone], as well as staurosporine and H-7. Treatment of B16F1 murine melanoma cells with MDL 27,032 for 24 h in culture and subsequent i.v. injection of the cells into mice resulted in >90% inhibition of lung metastasis. Inhibition of metastasis was time dependent, with 90% of maximum inhibition occurring by 8 h of incubation. The 50% inhibitory concentration (IC₅₀) for inhibition of metastasis with MDL 27,032 was 7 µM, a value similar to that for the inhibition of B16F1 membrane-associated PKC (IC₅₀ = 13 µM) but not cytosolic PKC (IC₅₀ = 54 µM). B16F1 cells treated with MDL 27,032 for 24 h were less adherent than untreated cells to extracellular matrix/basement membrane proteins. Adhesion to fibrinogen and collagen IV was inhibited (IC₅₀ = 6 µM and 48 µM, respectively) by MDL 27,032, whereas adherence to laminin and fibronectin was not affected, indicating that the drug affects specific adhesion molecules. MDL 27,032-treated cells were also found to be less adherent than untreated cells to human umbilical vein endothelial cells. The phosphorylation of an 80-kDa B16F1 cell plasma membrane protein was stimulated under conditions known to stimulate PKC activity, and MDL 27,032 inhibited this phosphorylation in a dose-dependent manner. MDL 27,032 was more potent than H-7 for the inhibition of metastasis but was significantly less potent than staurosporine. These results support the hypothesis that there is a critical role for PKC-mediated phosphorylation of cell surface adhesion receptors in metastasis.

¹ To whom requests for reprints should be addressed, at Marion Merrell Dow Research Institute, 2110 E. Galbraith Road, Cincinnati, OH 45215.

Received 7/24/91. Accepted 12/16/91.

This article has been cited by other articles:

				E. Sanz-Navares, N. Fernandez, M. G. Kazanietz, and S. A. Rotenberg Atypical Protein Kinase C{zeta} Suppresses Migration of Mouse Melanoma Cells Cell Growth Differ., October 1, 2001; 12(10): 517 - 524. [Abstract] [Full Text] [PDF]

				R. Palmantier, M. D. George, S. K. Akiyama, F. M. Wolber, K. Olden, and J. D. Roberts cis-Polyunsaturated Fatty Acids Stimulate {beta}1 Integrin-mediated Adhesion ofHuman Breast Carcinoma Cells to Type IV Collagen by Activating ProteinKinases C-{{epsilon}} and -{micro} Cancer Res., March 1, 2001; 61(6): 2445 - 2452. [Abstract] [Full Text]

				J. Szalay, P. Bruno, R. Bhati, J. Adjodha, D. Schueler, V. Summerville, and R. Vazeos Associations of PKC Isoforms with the Cytoskeleton of B16F10 Melanoma Cells J. Histochem. Cytochem., January 1, 2001; 49(1): 49 - 66. [Abstract] [Full Text]

				R. M. Sullivan, M. Stone, J. F. Marshall, F. Uberall, and S. A. Rotenberg Photo-Induced Inactivation of Protein Kinase Calpha by Dequalinium Inhibits Motility of Murine Melanoma Cells Mol. Pharmacol., October 1, 2000; 58(4): 729 - 737. [Abstract] [Full Text]

				M. Kobayashi, H. Kobayashi, R. B. Pollard, and F. Suzuki A Pathogenic Role of Th2 Cells and Their Cytokine Products on the Pulmonary Metastasis of Murine B16 Melanoma J. Immunol., June 15, 1998; 160(12): 5869 - 5873. [Abstract] [Full Text] [PDF]

				X. Ouyang, T. Gulliford, H. Zhang, G. C. Huang, and R. Epstein Human Cancer Cells Exhibit Protein Kinase C-dependent c-erbB-2 Transmodulation That Correlates with Phosphatase Sensitivity and Kinase Activity J. Biol. Chem., September 6, 1996; 271(36): 21786 - 21792. [Abstract] [Full Text] [PDF]

				K. Tsuchida, Y. Aoyagi, S. Odani, T. Mita, and M. Isemura Isolation of a Novel Collagen-binding Protein from the Mushroom, Hypsizigus marmoreus, Which Inhibits the Lewis Lung Carcinoma Cell Adhesion to Type IV Collagen J. Biol. Chem., January 27, 1995; 270(4): 1481 - 1484. [Abstract] [Full Text] [PDF]