title: Induction of apoptosis and chemosensitization of mesothelioma cells by Bcl-2 and Bcl-xL antisense treatment.
abstract: Our study was designed to investigate the role of the anti-apoptotic proteins Bcl-2 and Bcl-xL in the chemoresistance of cells derived from malignant pleural mesothelioma. First, we determined the basal expression levels of Bcl-2 and Bcl-xL in mesothelioma cells and examined the effect of their downregulation by antisense oligonucleotides. Bcl-xL mRNA and protein could be readily detected in mesothelioma cell lines, whereas only low levels of Bcl-2 mRNA and protein were found. Preferential downregulation of either Bcl-xL alone or of Bcl-xL and Bcl-2 simultaneously was achieved by treatment with antisense oligonucleotides 4259 and 4625, respectively, whereas the expression of other apoptosis-relevant genes remained unaffected. Treatment with oligonucleotides 4259 or 4625 lowered the apoptosis threshold in ZL34 mesothelioma cells, as indicated by an increase in cell death accompanied by increased caspase-3-like activity, a decrease of the mitochondrial transmembrane potential and the cleavage of procaspase-7 and ICAD. In addition to the direct induction of apoptosis, antisense treatment sensitized ZL34 cells to the cytostatic effect of cisplatin and gemcitabine, with the combination of 4625 and cisplatin being the most effective. Our results demonstrate that Bcl-2 and Bcl-xL antisense treatment facilitates apoptosis in mesothelioma cells and suggest the use of Bcl-2/Bcl-xL bispecific antisense treatment in combination with cisplatin or gemcitabine for therapy of malignant pleural mesothelioma.
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, University Hospital Zürich, Zürich, Switzerland. sally.donaldon@usz.ch
authors.forename: Sally
authors.initials: S
authors.lastname: Hopkins-Donaldson
authors.forename: Richard
authors.initials: R
authors.lastname: Cathomas
authors.forename: A Paula
authors.initials: AP
authors.lastname: Simões-Wüst
authors.forename: Stefanie
authors.initials: S
authors.lastname: Kurtz
authors.forename: Larisa
authors.initials: L
authors.lastname: Belyanskaya
authors.forename: Rolf A
authors.initials: RA
authors.lastname: Stahel
authors.forename: Uwe
authors.initials: U
authors.lastname: Zangemeister-Wittke
authors.forename: Larisa
authors.initials: L
authors.lastname: Belyanskya
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D003131:Combined Modality Therapy; D017931:DNA Primers / Q000737:chemistry; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015536:Down-Regulation / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D008564:Membrane Potentials / Q000187:drug effects; D008654:Mesothelioma / Q000235:genetics / Q000378:metabolism / Q000628:therapy*; D008928:Mitochondria / Q000187:drug effects; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D010997:Pleural Neoplasms / Q000235:genetics / Q000378:metabolism / Q000628:therapy*; D016133:Polymerase Chain Reaction; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors; D014407:Tumor Cells, Cultured; D051020:bcl-X Protein; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; D000970:Antineoplastic Agents; C494811:BCL2L1 protein, human; D017931:DNA Primers; D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein; D003841:Deoxycytidine; D012264:Ribonucleotide Reductases; D020169:Caspases; D002945:Cisplatin; D000093542:Gemcitabine