title: Motexafin gadolinium and zinc induce oxidative stress responses and apoptosis in B-cell lymphoma lines.
abstract: There is an emerging appreciation of the importance of zinc in regulating cancer cell growth and proliferation. Recently, we showed that the anticancer agent motexafin gadolinium (MGd) disrupted zinc metabolism in A549 lung cancer cells, leading, in the presence of exogenous zinc, to cell death. Here, we report the effect of MGd and exogenous zinc on intracellular levels of free zinc, oxidative stress, proliferation, and cell death in exponential phase human B-cell lymphoma and other hematologic cell lines. We find that increased levels of oxidative stress and intracellular free zinc precede and correlate with cell cycle arrest and apoptosis. To better understand the molecular basis of these cellular responses, gene expression profiling analyses were conducted on Ramos cell cultures treated with MGd and/or zinc acetate. Cultures treated with MGd or zinc acetate alone elicited transcriptional responses characterized by induction of metal response element-binding transcription factor-1 (MTF-1)-regulated and hypoxia-inducible transcription factor-1 (HIF-1)-regulated genes. Cultures cotreated with MGd and zinc acetate displayed further increases in the levels of MTF-1- and HIF-1-regulated transcripts as well as additional transcripts regulated by NF-E2-related transcription factor 2. These data provide insights into the molecular changes that accompany the disruption of intracellular zinc homeostasis and support a role for MGd in treatment of B-cell hematologic malignancies.
authors.affiliation: Pharmacyclics, Inc., Sunnyvale, CA 94085, USA.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Lecane
authors.forename: Mazen W
authors.initials: MW
authors.lastname: Karaman
authors.forename: Mint
authors.initials: M
authors.lastname: Sirisawad
authors.forename: Louie
authors.initials: L
authors.lastname: Naumovski
authors.forename: Richard A
authors.initials: RA
authors.lastname: Miller
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Hacia
authors.forename: Darren
authors.initials: D
authors.lastname: Magda
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D016393:Lymphoma, B-Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008665:Metalloporphyrins / Q000494:pharmacology*; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress / Q000187:drug effects*; D020218:Response Elements; D016196:S Phase / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D015032:Zinc / Q000378:metabolism*; D000097809:Transcription Factor MTF-1
chemical_list: D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008665:Metalloporphyrins; D051267:NF-E2-Related Factor 2; D014157:Transcription Factors; D015032:Zinc; D000097809:Transcription Factor MTF-1; C437683:motexafin gadolinium