title: Comparison between anthracyclines and rhodamine-123 accumulation in chronic lymphoid leukemia: effect of cyclosporin A and verapamil.
abstract: Multidrug resistance in leukemic cells is associated with decreased drug accumulation. A resistant cell line and cells from 11 patients with chronic lymphoid leukemia B were used for the evaluation of intracellular accumulation of daunorubicin (DNR), idarubicin (IDA), epirubicin (EPI) and rhodamine-123 (Rh-123). Cyclosporin A (CSA) and verapamil were used to test their modulatory effects on anthracyclines and the fluorescent dye. In leukemic samples there was a tendency for a lower accumulation index in samples tested with Rh-123 as compared to anthracyclines. IDA was a poorer substrate to P-glycoprotein (Pgp) than two of its analogues, e.g. DNR and EPI. A good correlation (80%) was found between Rh-123 accumulation and Pgp expression by phosphatase-anti-alkaline phosphatase. A strict correlation (100%) was found between modulation by CSA of Rh-123 accumulation and immunoreactivity to Pgp. Two discordant results were seen suggesting that other mechanisms of resistance could be present. The Rh-123 accumulation test seems to give a better indication than anthracyclines, however, it is not selective and may allow the detection of other drug-transport pumps.
authors.affiliation: Serviço de Hematologia, Instituto Nacional de Câncer, Rio de Janeiro, Brazil.
authors.forename: R C
authors.initials: RC
authors.lastname: Maia
authors.forename: F C
authors.initials: FC
authors.lastname: Vasconcelos
authors.forename: R C
authors.initials: RC
authors.lastname: Harab
authors.forename: A M
authors.initials: AM
authors.lastname: Coelho
authors.forename: J A
authors.initials: JA
authors.lastname: Dobbin
authors.forename: V M
authors.initials: VM
authors.lastname: Rumjanek
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000903:Antibiotics, Antineoplastic / Q000378:metabolism*; D016572:Cyclosporine / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D005260:Female; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020112:Rhodamine 123; D012235:Rhodamines / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D014700:Verapamil / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D005456:Fluorescent Dyes; D012235:Rhodamines; D020112:Rhodamine 123; D016572:Cyclosporine; D014700:Verapamil