title: Synergistic antiproliferative effects of gamma-tocotrienol and statin treatment on mammary tumor cells.
abstract: Statins are potent inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMGCoA) reductase and display anticancer activity, but their clinical use is limited by their high-dose toxicity. Similarly, gamma-tocotrienol, an isoform of vitamin E, also reduces HMGCoA reductase activity and displays potent anticancer activity. Studies were conducted to determine if combined low dose treatment of gamma-tocotrienol with individual statins resulted in a synergistic antiproliferative effect on neoplastic mouse +SA mammary epithelial cells. Treatment with 3-4 microM gamma-tocotrienol or 2-8 microM simvastatin, lovastatin or mevastatin alone resulted in a significant decrease, whereas treatment with 10-100 microM pravastatin had no effect on +SA cell growth. However, combined treatment of subeffective doses (0.25 or 10 microM) of individual statins with 0.25-2.0 microM gamma-tocotrienol resulted in a dose-responsive synergistic inhibition in +SA cell proliferation. Additional studies showed that treatment with subeffective doses of individual statins or gamma-tocotrienol alone had no effect, whereas combined treatment of these compounds resulted in a relatively large decrease in intracellular levels of phosphorylated (activated) MAPK, JNK, p38, and Akt. These findings strongly suggest that combined low dose treatment of gamma-tocotrienol with individual statins may have potential value in the treatment of breast cancer without causing myotoxicity that is associated with high dose statin treatment.
authors: College of Pharmacy, University of Louisiana at Monroe, 700 University Ave., Monroe, LA 71209-0470, USA.
authors: Vikram B
authors: VB
authors: Wali
authors: Paul W
authors: PW
authors: Sylvester
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002839:Chromans / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D008148:Lovastatin / Q000031:analogs & derivatives / Q000494:pharmacology; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D015674:Mammary Neoplasms, Animal / Q000378:metabolism / Q000473:pathology; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D017035:Pravastatin / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D019821:Simvastatin / Q000494:pharmacology; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D002839:Chromans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D014810:Vitamin E; C012258:mevastatin; C013649:plastochromanol 8; D008148:Lovastatin; D019821:Simvastatin; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D017035:Pravastatin
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