Effect of imatinib on

MDR1-transduced AR230 cell line. (A) Flow cytometric analysis of Pgp expression on AR230 and AR230/MDR cells labeled with a PE-conjugated Pgp antibody or a PE-conjugated isotype control. (B) Cell viability of AR230 and AR230/MDR in the presence or absence of 1 μM imatinib and/or 5 μg/mL verapamil (VP): AR230 (♦); AR230/MDR (×); AR230/MDR + imatinib (∗); AR230 + imatinib (▪); AR230/MDR + imatinib + VP (●); AR230 + imatinib + VP (▵).