title: The Na+/K+-ATPase is the Achilles heel of multi-drug-resistant cancer cells.
abstract: We recently reported that over-expressed Na(+)/K(+)-ATPase alpha subunits are new important anti-cancer targets. Cardiotonic steroids are the natural ligands of Na(+)/K(+)-ATPase and thus potentially potent anti-cancer agents with a novel mechanism of action. We report here that the hemi-synthetic cardenolide 19-hydroxy-2''oxovoruscharin is impressively active in cancer cells expressing diverse forms of multi-drug resistance (MDR) either conferred by the over-expression of selected drug-transporter proteins or induced by a range of chemotherapeutic agents. Together with the inability of tumor cells to acquire resistance to 19-hydroxy-2''oxovoruscharin, our data suggest that this novel compound could be especially applicable to notoriously drug-resistant cancers.
authors.affiliation: Unibioscreen SA, Brussels, Belgium.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Mijatovic
authors.forename: Ute
authors.initials: U
authors.lastname: Jungwirth
authors.forename: Petra
authors.initials: P
authors.lastname: Heffeter
authors.forename: Mir Ali Reza
authors.initials: MA
authors.lastname: Hoda
authors.forename: Rita
authors.initials: R
authors.lastname: Dornetshuber
authors.forename: Robert
authors.initials: R
authors.lastname: Kiss
authors.forename: Walter
authors.initials: W
authors.lastname: Berger