title: Differential sensitivity of MCF-7 and LCC2 cells, to multiple growth inhibitory agents: possible relation to high bcl-2/bax ratio?
abstract: Comparison of LCC2, the E(2)-independent, tamoxifen-resistant subline of the MCF-7 human breast cancer cell line with its parent line, disclosed that it is more resistant to growth inhibition and apoptosis induction by a variety of agents acting by diverse mechanisms. Thus, LCC2 cells can serve as a useful in-vitro model for the study of the molecular mechanisms of this resistance. It was found that bcl-2 protein and mRNA were elevated and that bax protein and mRNA were reduced in LCC2 compared with MCF-7 cells. Incubation of both lines in the presence of bcl-2 antisense caused growth inhibition and reduced bcl-2 protein levels only in MCF-7 cells, suggesting the involvement of bcl-2 in the regulation of normal growth of breast cancer cells. Increased bcl-2 expression in breast cancer cells may correlate with their resistance to growth inhibitory agents. Bcl-2 is a useful target for enhancing the effects of growth inhibitory agents.
authors.affiliation: The Department of Medicine 'C', The Laboratory of Experimental Cancer Chemotherapy and Cell Biology, The Chaim Sheba Medical Center, 52621, Tel Hashomer, Israel.
authors.forename: G
authors.initials: G
authors.lastname: Lilling
authors.forename: H
authors.initials: H
authors.lastname: Hacohen
authors.forename: J
authors.initials: J
authors.lastname: Nordenberg
authors.forename: T
authors.initials: T
authors.lastname: Livnat
authors.forename: V
authors.initials: V
authors.lastname: Rotter
authors.forename: Y
authors.initials: Y
authors.lastname: Sidi
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D004958:Estradiol / Q000494:pharmacology* / Q000502:physiology; D020847:Estrogen Receptor Modulators / Q000494:pharmacology; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D013629:Tamoxifen / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein
chemical_list: D000970:Antineoplastic Agents; C494826:BAX protein, human; D020847:Estrogen Receptor Modulators; D006131:Growth Inhibitors; D016376:Oligonucleotides, Antisense; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D013629:Tamoxifen; D004958:Estradiol