Expression of the atorvastatin (AS) uptake transporters Oatp1a4 and Oatp1b2 in mouse liver tumors. A. Diminished expression of OATP1A4 and OATP1B2 protein in tumor tissue, as detected by immunohistochemistry. For comparison, staining for glutamine synthetase (GS, not expressed in the tumors) and E-cadherin (EC, overexpressed in the tumors) is shown. B. Validation of protein expression results by Western blotting. Abbreviations: t, tumor; n, normal tissue. C. Diminished expression of Oatp1a4 (Slco1a4) and Oatp1b2 (Slco1b2) mRNAs in tumors (left diagrams). Mean + SD (n = 5-6) is shown. Statistical significance (p < 0.05) is indicated by asterisks. For comparison, expression of Cdh1 mRNA (encoding E-cadherin) is shown. Data from atorvastatin-treated livers are depicted; comparable results were obtained with untreated livers (not shown). D. Levels of atorvastatin and hydroxyatorvastatin in normal liver and liver tumors (n = 13-16).