title: Quercetin potentiates the effect of adriamycin in a multidrug-resistant MCF-7 human breast-cancer cell line: P-glycoprotein as a possible target.
abstract: This study demonstrates that the flavonoid quercetin (Q), a plant-derived compound with low toxicity in vivo, greatly potentiates the growth-inhibitory activity of Adriamycin (ADR) on MCF-7 ADR-resistant human breast cancer cells. The effect of Q was dose-dependent at concentrations ranging between 1 and 10 microM. Since ADR resistance in these cells is associated with the expression of high levels of P-glycoprotein (Pgp), we evaluated the effect of Q and related flavonoids of Pgp activity in cytofluorographic efflux experiments with the fluorescent dye rhodamine 123 (Rh 123). Our results indicate that Q and 3-OMe Q (3',4',7-trimethoxyquercetin) but not the 3-rhamnosylglucoside of Q (rutin) inhibit the Pgp pump-efflux activity in a dose-related manner. Moreover, 10 microM Q reduces the expression of the immunoreactive Pgp in MCF-7 ADR-resistant cells as evaluated by cytofluorimetric assay. In conclusion, these findings provide a further biological basis for the potential therapeutic application of Q as an anti-cancer drug either alone or in combination with ADR in multidrug-resistant breast tumor cells.
authors.affiliation: Department of Gynecology, Catholic University, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Scambia
authors.forename: F O
authors.initials: FO
authors.lastname: Ranelletti
authors.forename: P B
authors.initials: PB
authors.lastname: Panici
authors.forename: R
authors.initials: R
authors.lastname: De Vincenzo
authors.forename: G
authors.initials: G
authors.lastname: Bonanno
authors.forename: G
authors.initials: G
authors.lastname: Ferrandina
authors.forename: M
authors.initials: M
authors.lastname: Piantelli
authors.forename: S
authors.initials: S
authors.lastname: Bussa
authors.forename: C
authors.initials: C
authors.lastname: Rumi
authors.forename: M
authors.initials: M
authors.lastname: Cianfriglia
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy*; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D004357:Drug Synergism; D005434:Flow Cytometry; D006801:Humans; D011794:Quercetin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D004317:Doxorubicin; D011794:Quercetin