title: Isolation of retinoic acid-resistant clones from human breast cancer cell line MCF-7 with altered activity of cellular retinoic acid-binding protein.
abstract: After ethyl methane sulfonate mutagenesis of the mammary carcinoma cell line, MCF-7, we have isolated three clones, U-2, U-3, and U-9, resistant to retinoic acid. These three clones showed more than a 1000-fold higher level of resistance to retinoic acid than the parental MCF-7 cells when assayed by colony formation in monolayer culture system or by growth curves. The three resistant clones showed a 200-fold higher resistance to 13-cis-retinoic acid, about 10-fold higher resistance to retinol, and about 2-fold higher resistance to retinyl acetate, respectively, than MCF-7. Binding of [3H]retinoic acid or [3H]-retinol to a cellular fraction in situ showed apparent decrease of the specific binding of retinoic acid in U-2, but there was no such specific fraction bound to retinol in U-2 and MCF-7. Sucrose gradient analysis with cytoplasmic fraction showed little, if any, cellular retinoic acid-binding protein in U-2, but a significant amount of the cellular retinoic acid-binding protein could be found in MCF-7. By contrast, there was no activity of cellular retinol-binding protein in both MCF-7 and U-2. The sensitivity or resistance of mammalian cells in culture to retinoic acid is discussed in relation with cellular binding activity for vitamin A.
authors.forename: H
authors.initials: H
authors.lastname: Ueda
authors.forename: M
authors.initials: M
authors.lastname: Ono
authors.forename: Y
authors.initials: Y
authors.lastname: Hagino
authors.forename: M
authors.initials: M
authors.lastname: Kuwano
mesh_terms: D001943:Breast Neoplasms / Q000032:analysis* / Q000188:drug therapy / Q000473:pathology; D002352:Carrier Proteins / Q000032:analysis*; D002460:Cell Line; D002999:Clone Cells; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007621:Karyotyping; D009154:Mutation; D018168:Receptors, Retinoic Acid; D014212:Tretinoin / Q000494:pharmacology*; D014801:Vitamin A / Q000378:metabolism / Q000494:pharmacology
chemical_list: D002352:Carrier Proteins; D018168:Receptors, Retinoic Acid; D014801:Vitamin A; D014212:Tretinoin