title: Influence of Bcl-2 family members on the cellular response of small-cell lung cancer cell lines to ABT-737.
abstract: ABT-737 is a novel and potent Bcl-2 antagonist with single-agent activity against small-cell lung cancer (SCLC) cell lines. Here, we evaluated the contribution of Bcl-2 family members to the in vitro cellular response of several SCLC cell lines to ABT-737. Relatively higher levels of Bcl-2, Bcl-X(L), Bim and Noxa, and lower levels of Mcl-1 characterized naïve SCLC cell lines that were sensitive to ABT-737. Conversely, a progressive decrease in the relative levels of Bcl-2 and Noxa and a progressive increase in Mcl-1 levels characterized the increased resistance of H146 cells following chronic exposure to ABT-737. Knockdown of Mcl-1 with small interfering RNA sensitized two resistant SCLC cell lines H196 and DMS114 to ABT-737 by enhancing the induction of apoptosis. Likewise, up-regulation of Noxa sensitized H196 cells to ABT-737. Combination treatment with DNA-damaging agents was extremely synergistic with ABT-737 and was associated with the down-regulation of Mcl-1 and the up-regulation of Noxa, Puma, and Bim in H196 cells. Thus, SCLC cells sensitive to ABT-737 expressed the target proteins Bcl-2 and Bcl-X(L), whereas Mcl-1 and factors regulating Mcl-1 function seem to contribute to the overall resistance of SCLC cells to ABT-737. Overall, these observations provide further insight as to the mechanistic bases for ABT-737 efficacy in SCLC and will be helpful for profiling patients and aiding in the rational design of combination therapies.
authors.affiliation: Global Pharmaceutical Product Research Division, Abbott Laboratories, Abbott Park Road, Abbott Park, IL 60064, USA. stephen.k.tahir@abbott.com
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Tahir
authors.forename: Xiufen
authors.initials: X
authors.lastname: Yang
authors.forename: Mark G
authors.initials: MG
authors.lastname: Anderson
authors.forename: Susan E
authors.initials: SE
authors.lastname: Morgan-Lappe
authors.forename: Aparna V
authors.initials: AV
authors.lastname: Sarthy
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Robert B
authors.initials: RB
authors.lastname: Warner
authors.forename: Shi-Chung
authors.initials: SC
authors.lastname: Ng
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Fesik
authors.forename: Steve W
authors.initials: SW
authors.lastname: Elmore
authors.forename: Saul H
authors.initials: SH
authors.lastname: Rosenberg
authors.forename: Christin
authors.initials: C
authors.lastname: Tse
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis / Q000235:genetics; D000072224:Bcl-2-Like Protein 11; D001713:Biphenyl Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D016190:Carboplatin / Q000008:administration & dosage; D018288:Carcinoma, Small Cell / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D015536:Down-Regulation; D004357:Drug Synergism; D005047:Etoposide / Q000008:administration & dosage; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics; D009596:Nitrophenols / Q000008:administration & dosage / Q000494:pharmacology*; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology*; D014162:Transfection; D015854:Up-Regulation
chemical_list: C501332:ABT-737; D051017:Apoptosis Regulatory Proteins; C438378:BBC3 protein, human; C000606775:BCL2L11 protein, human; D000072224:Bcl-2-Like Protein 11; D001713:Biphenyl Compounds; D008565:Membrane Proteins; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D009596:Nitrophenols; C498702:PMAIP1 protein, human; D010879:Piperazines; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering; D013449:Sulfonamides; D005047:Etoposide; D016190:Carboplatin