title: Extracellular signal-regulated kinase 5 and cyclic AMP response element binding protein are novel pathways inhibited by vandetanib (ZD6474) and doxorubicin in mesotheliomas.
abstract: Malignant mesothelioma (MM), lung cancers, and asbestosis are hyperproliferative diseases associated with exposures to asbestos. All have a poor prognosis; thus, the need to develop novel and effective therapies is urgent. Vandetanib (Van) (ZD6474, ZACTIMA) is a tyrosine kinase inhibitor that has shown equivocal results in clinical trials for advanced non-small cell lung cancer. However, tyrosine kinase inhibitors alone have shown no significant clinical activity in phase II trials of patients with unresectable MM. Using epithelioid (HMESO) and sarcomatoid (H2373) human MM lines, the efficacy of tumor cell killing and signaling pathways modulated by Van with and without doxorubicin (Dox) was examined. Van alone reduced total cell numbers in HMESO MM and synergistically increased the toxicity of Dox in HMESO and H2373 cells. Most importantly, we identified two novel cell survival/resistance pathways, ERK5 and cyclic AMP response element binding protein (CREB), that were inhibited by Van and Dox. After silencing of either ERK5 or CREB, significant decreases in cell numbers in the Dox-resistant sarcomatoid H2373 line were observed. Results suggest that a plethora of cell signaling pathways associated with cell survival are induced by Dox but inhibited by the addition of Van in MM. Data from our study support the combined efficacy of Van and Dox as a novel approach in the treatment of MM that is further enhanced by blocking ERK5 or CREB signaling cascades.
authors.affiliation: Department of Pathology, University of Vermont College of Medicine, Burlington, Vermont.
authors.forename: Mutlay
authors.initials: M
authors.lastname: Sayan
authors.forename: Arti
authors.initials: A
authors.lastname: Shukla
authors.forename: Maximilian B
authors.initials: MB
authors.lastname: MacPherson
authors.forename: Sherrill L
authors.initials: SL
authors.lastname: Macura
authors.forename: Jedd M
authors.initials: JM
authors.lastname: Hillegass
authors.forename: Timothy N
authors.initials: TN
authors.lastname: Perkins
authors.forename: Joyce K
authors.initials: JK
authors.lastname: Thompson
authors.forename: Stacie L
authors.initials: SL
authors.lastname: Beuschel
authors.forename: Jill M
authors.initials: JM
authors.lastname: Miller
authors.forename: Brooke T
authors.initials: BT
authors.lastname: Mossman
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology / Q000633:toxicity; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D004317:Doxorubicin / Q000494:pharmacology* / Q000633:toxicity; D004357:Drug Synergism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D008654:Mesothelioma / Q000188:drug therapy* / Q000378:metabolism; D048054:Mitogen-Activated Protein Kinase 7 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009372:Neoplasms, Connective Tissue / Q000188:drug therapy / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D010880:Piperidines / Q000494:pharmacology* / Q000633:toxicity; D011799:Quinazolines / Q000494:pharmacology* / Q000633:toxicity; D034741:RNA, Small Interfering / Q000235:genetics; D012509:Sarcoma / Q000188:drug therapy / Q000378:metabolism
chemical_list: D000903:Antibiotics, Antineoplastic; D017362:Cyclic AMP Response Element-Binding Protein; D010880:Piperidines; D011799:Quinazolines; D034741:RNA, Small Interfering; D004317:Doxorubicin; C481581:MAPK7 protein, human; D048054:Mitogen-Activated Protein Kinase 7; C452423:vandetanib
keywords: doxorubicin; extracellular signal-regulated kinases; malignant mesothelioma; tyrosine kinases; vandetanib