title: CG5/Dx human breast cancer cell line: characterization of a new doxorubicin-resistant variant.
abstract: By continuous exposure of CG5 human breast cancer cell line to increasing doxorubicin (Dx) concentrations, a multidrug-resistant (MDR) subline (CG5/Dx) was obtained. The resistant variant showed P-glycoprotein (P-gp) expression and a lower intracellular doxorubicin level than the parental cells. CG5/Dx cells were 19.4 fold more resistant to Dx than CG5 cells and showed a cross-resistance to some structurally related and unrelated compounds. Differences in kinetics, biological and ultrastructural features between the two cell lines were investigated. The CG5/Dx cells grew more slowly, produced higher CEA levels and showed a reduced progesterone receptor (PgR) content than the parental cells. Ultrastructural studies revealed differences involving, polyribosomes, rough endoplasmic reticulum, [mitochondria] and cytoskeleton.
authors.affiliation: Divisione di Oncologia Medica, Università degli Studi, Pavia, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Gibelli
authors.forename: C
authors.initials: C
authors.lastname: Zibera
authors.forename: A
authors.initials: A
authors.lastname: Asti
authors.forename: L
authors.initials: L
authors.lastname: Maestri
authors.forename: L
authors.initials: L
authors.lastname: Bacchella
authors.forename: P
authors.initials: P
authors.lastname: Pedrazzoli
authors.forename: A
authors.initials: A
authors.lastname: Calligaro
authors.forename: G
authors.initials: G
authors.lastname: Robustelli della Cuna
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis*; D000903:Antibiotics, Antineoplastic / Q000378:metabolism / Q000633:toxicity*; D001943:Breast Neoplasms; D002455:Cell Division; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D004317:Doxorubicin / Q000378:metabolism / Q000633:toxicity*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D018870:Endoplasmic Reticulum, Rough / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D015870:Gene Expression; D014644:Genetic Variation; D006801:Humans; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D011132:Polyribosomes / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000903:Antibiotics, Antineoplastic; D004317:Doxorubicin