title: Atorvastatin attenuation of ABCB1 expression is mediated by microRNA miR-491-3p in Caco-2 cells.
abstract: OBJECTIVE
  Atorvastatin, a HMG-CoA reductase inhibitor, used in the treatment of hypercholesterolemia, has been previously shown to regulate ABCB1 expression in vivo and in vitro. We hypothesized that the statin could regulate gene expression of ABCB1 transporter via microRNAs.
  
  
  METHODS
  Expression of microRNAs and ABCB1 mRNA was examined in atorvastatin-treated and control cells using real-time PCR. miR-491-3P mimic and inhibitor were transfected in Caco-2 and ABCB1 expression was monitored by western blot and real-time PCR.
  
  
  RESULTS
  In HepG2 cells, none of the microRNAs predicted to target ABCB1 3'UTR was regulated by atorvastatin treatment. In agreement with this, ABCB1 3'UTR activity was not modulated in HepG-2 cells after 48h-treatment as measured by luciferase assay. In Caco-2 cells, atorvastatin treatment provoked a decrease in luciferase activity and, accordingly, miR-491-3p was upregulated about 2.7 times after 48h-statin treatment. Luciferase analysis of miR-491-3p with a mimetic or inhibitor of miR-491-3p revealed that this microRNA could target ABCB1 3'UTR, as after miR-491-3p inhibition, ABCB1 levels were increased by two-fold, and miR-491-3p superexpression decreased ABCB1 3'UTR activity. Finally, functional analysis revealed that treatment with miR-491-3p inhibitor could reverses atorvastatin attenuation of ABCB1 (Pg-p) protein levels.
  
  
  CONCLUSIONS
  Our results suggest atorvastatin control ABCB1 expression via miR-491-3p in Caco-2 cells. This finding may be an important mechanism of statin drug-drug interaction, since common concomitant drugs used in the prevention of cardiovascular diseases are ABCB1 substrates.
authors: Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil. Electronic address: alice-rodrigues@usp.br.
authors: Alice C
authors: AC
authors: Rodrigues
authors: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
authors: Elida Adalgisa
authors: EA
authors: Neri
authors: Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
authors: Sidney
authors: S
authors: Veríssimo-Filho
authors: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
authors: Nancy Amaral
authors: NA
authors: Rebouças
authors: Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
authors: Rosario D C
authors: RD
authors: Hirata
authors: Department of Biochemistry and Molecular Medicine, School of Medicine, University of California-Davis, Sacramento, CA, United States.
authors: Ai-Ming
authors: AM
authors: Yu
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000069059:Atorvastatin / Q000494:pharmacology*; D045744:Cell Line, Tumor; D015536:Down-Regulation; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology; D035683:MicroRNAs / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; C551410:MIRN491 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D000069059:Atorvastatin
keywords: ABCB1; Efflux drug transporters; HMG-CoA inhibitors; MicroRNAs