title: Effects of two benzo[a]phenothiazines on multi-drug resistance (mdr) and tumor antigen expression.
abstract: Two benzo[a]phenothiazines 5H-benzo[a]phenothiazin-5-one (1), and its derivative 6-methyl-5H-benzo[a]phenothiazin-5-one (2) inhibited the proliferation of human and mouse tumor cell lines. The multi-drug resistant (mdr) subline was more sensitive than its parent cell line to 5H-benzo[a]phenothiazin-5-one (1), 6-methyl-5H-benzo[a]phenothiazin-5-one (2) was equally antiproliferative against the three cell lines tested. Rhodamine 123 efflux of mdr cells was more efficiently inhibited by 5H-benzo[a]phenothiazin-5-one (1) than by 6-methyl-5H-benzo[a]phenothiazin-5-one (2). The exposure of adenovirus infected cells to 5H-benzo[a]phenothiazin-5-one (1) resulted in a reduction of tumor-antigen expression, whereas 6-methyl-5H-benzo[a]phenothiazin-5-one (2) enhanced the T-antigen expression.
authors.affiliation: Faculty of Medicine, Institute of Microbiology, Albert Szent-Györgyi Medical University, Szeged, Hungary.
authors.forename: J
authors.initials: J
authors.lastname: Molnár
authors.forename: R
authors.initials: R
authors.lastname: Pusztai
authors.forename: A
authors.initials: A
authors.lastname: Hevér
authors.forename: S
authors.initials: S
authors.lastname: Nagy
authors.forename: N
authors.initials: N
authors.lastname: Motohashi
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D018432:Drug Resistance, Multiple; D006801:Humans; D051379:Mice; D010640:Phenothiazines / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D010640:Phenothiazines