title: Maximal killing of lymphoma cells by DNA damage-inducing therapy requires not only the p53 targets Puma and Noxa, but also Bim.
abstract: DNA-damaging chemotherapy is the backbone of cancer treatment, although it is not clear how such treatments kill tumor cells. In nontransformed lymphoid cells, the combined loss of 2 proapoptotic p53 target genes, Puma and Noxa, induces as much resistance to DNA damage as loss of p53 itself. In Eμ-Myc lymphomas, however, lack of both Puma and Noxa resulted in no greater drug resistance than lack of Puma alone. A third B-cell lymphoma-2 homology domain (BH)3-only gene, Bim, although not a direct p53 target, was up-regulated in Eμ-Myc lymphomas incurring DNA damage, and knockdown of Bim levels markedly increased the drug resistance of Eμ-Myc/Puma(-/-)Noxa(-/-) lymphomas both in vitro and in vivo. Remarkably, c-MYC-driven lymphoma cell lines from Noxa(-/-)Puma(-/-)Bim(-/-) mice were as resistant as those lacking p53. Thus, the combinatorial action of Puma, Noxa, and Bim is critical for optimal apoptotic responses of lymphoma cells to 2 commonly used DNA-damaging chemotherapeutic agents, identifying Bim as an additional biomarker for treatment outcome in the clinic.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.
authors.forename: Lina
authors.initials: L
authors.lastname: Happo
authors.forename: Mark S
authors.initials: MS
authors.lastname: Cragg
authors.forename: Belinda
authors.initials: B
authors.lastname: Phipson
authors.forename: Jon M
authors.initials: JM
authors.lastname: Haga
authors.forename: Elisa S
authors.initials: ES
authors.lastname: Jansen
authors.forename: Marco J
authors.initials: MJ
authors.lastname: Herold
authors.forename: Grant
authors.initials: G
authors.lastname: Dewson
authors.forename: Ewa M
authors.initials: EM
authors.lastname: Michalak
authors.forename: Cassandra J
authors.initials: CJ
authors.lastname: Vandenberg
authors.forename: Gordon K
authors.initials: GK
authors.lastname: Smyth
authors.forename: Andreas
authors.initials: A
authors.lastname: Strasser
authors.forename: Suzanne
authors.initials: S
authors.lastname: Cory
authors.forename: Clare L
authors.initials: CL
authors.lastname: Scott
mesh_terms: D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000502:physiology*; D000072224:Bcl-2-Like Protein 11; D003520:Cyclophosphamide / Q000494:pharmacology; D004249:DNA Damage; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005047:Etoposide / Q000494:pharmacology; D016393:Lymphoma, B-Cell / Q000188:drug therapy / Q000473:pathology*; D008565:Membrane Proteins / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000502:physiology; D025521:Tumor Suppressor Proteins / Q000502:physiology
chemical_list: D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; C000606776:Bcl2l11 protein, mouse; D008565:Membrane Proteins; C488588:PUMA protein, mouse; C408009:Pmaip1 protein, mouse; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D025521:Tumor Suppressor Proteins; D005047:Etoposide; D003520:Cyclophosphamide