Potent Suppression of Proliferation of A10 Vascular Smooth Muscle Cells by Combined Treatment with Lovastatin and 3-Allylfarnesol, an Inhibitor of Protein Farnesyltransferase
- 1Department of Pharmacology (R.R.M, R.E.M.), Wayne State University, Detroit, Michigan; 2Programs in Molecular Biology and Genetics (R.R.M.) and 3Proteases (J.J.R.), Barbara Ann Karmanos Cancer Institute, Detroit, Michigan; 4Department of Medicinal Chemistry and Molecular Pharmacology (R.A.G.), College of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, Indiana; and 5Institute of Environmental Health Sciences (J.J.R.), Wayne State University, Detroit, Michigan
- Raymond R. Mattingly, Department of Pharmacology, Wayne State University, 540 E. Canfield Ave., Detroit, MI 48201. E-mail: r.mattingly{at}wayne.edu
Abstract
Statins, which inhibit 3-hydroxy-3-methylglutaryl-CoA reductase and thus the synthesis of cholesterol, are remarkably effective in the treatment of cardiovascular disease. In addition to their favorable effect on lipid profile, these drugs may also prevent the proliferation of vascular smooth muscle that is characteristic of atherosclerosis. We hypothesize that statins prevent the post-translational prenylation, and thus inhibit the function, of critical small GTPases in vascular smooth muscle cells. We have therefore assayed the effect of lovastatin on both the growth of A10 vascular smooth muscle cells and the status of their Ras and RhoB proteins. We find that ≤1 μM lovastatin potently inhibits the proliferation of A10 cultures, and higher concentrations (≥3 μM) induce apoptosis. We have also tested the effect of 3-allylfarnesol (3-alFOH), an inhibitor of farnesyl transferase (FTI). The data show that although ≥10 μM 3-alFOH is required for a cytostatic effect, the action of 3 μM 3-alFOH can be greatly potentiated by even nanomolar levels of lovastatin. We also find that lovastatin and 3-alFOH exhibit synergism to cause the up-regulation and relocalization of RhoB from the membrane to cytosolic compartments. This relocalization of RhoB, which is presumed to reflect an inhibition of its prenylation, correlates with the proapoptotic activities of combined 3-alFOH and lovastatin treatment. These data suggest that RhoB may be a valuable pharmacological target in cardiovascular disease, and that combinations of statins and certain FTIs may be of value in treatment of disorders that are characterized by excess cell proliferation.
Footnotes
-
This work was supported by an Atorvastatin Research Award Award from Pfizer, Inc., Grant DAMD17-00-1-0544 from the Department of the Army, and a Faculty Development Award from the PhRMA Foundation (to R.R.M.), and by National Institutes of Health Grants CA-78819 (to R.A.G.) and ES-09392 (to J.J.R.). This work was aided by the Cell Imaging and Cytometry Facility Core, which is supported by Center Grants from the National Institute of Environmental Health Sciences (P30 ES06639) and National Cancer Institute (P30 CA22453). R.E.M. was supported in part by a Training Program in Cancer Biology (T32-CA09531-15). The content of the information does not necessarily reflect the position or policy of the U.S. Government, and no official endorsement should be inferred.
-
DOI: 10.1124/jpet.102.036061
- Abbreviations:
- . HMG
- 3-hydroxy-3-methylglutaryl
- FTI
- inhibitor of farnesyl transferase
- 3-alFOH
- 3-allylfarnesol
- DMSO
- dimethyl sulfoxide
- AMC
- 7-amino-4-methyl-coumarin
- DMEM
- Dulbecco's modified Eagle's medium
- PBS
- phosphate-buffered saline
- HLB
- hypotonic lysis buffer
- PAGE
- polyacrylamide gel electrophoresis
- HEK
- human embryonic kidney
- HA
- hemagglutinin
- ERK
- extracellular signal-regulated kinase
- FPP
- farnesyl pyrophosphate
-
- Received March 11, 2002.
- Accepted June 4, 2002.
- The American Society for Pharmacology and Experimental Therapeutics
