title: Inhibition of Notch1 signaling overcomes resistance to the death ligand Trail by specificity protein 1-dependent upregulation of death receptor 5.
abstract: The Notch1 signaling pathway contributes to tumorigenesis by influencing differentiation, proliferation and apoptosis. Here, we demonstrate that inhibition of the Notch1 signaling pathway sensitizes glioblastoma cell lines and glioblastoma initiating cells to apoptosis induced by the death ligand TRAIL. This sensitization occurs through transcriptional upregulation of the death receptor 5 (DR5, TRAIL-R2). The increase in DR5 expression is abrogated by concomitant repression of the transcription factor Sp1, which directly binds to the DR5 promoter in the absence of Notch1 as revealed by chromatin immunoprecipitation. Consistent with these findings, Notch1 inhibition resulted in increased DR5 promoter activity, which was impaired by mutation of one out of two Sp1-binding sites within the proximal DR5 promoter. Moreover, we demonstrate that JNK signaling contributes to the regulation of DR5 expression by Notch1. Taken together, our results identify Notch1 as key driver for TRAIL resistance and suggest Notch1 as a promising target for anti-glioblastoma therapy.
authors.affiliation: Molecular Tumor Pathology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany, and Institute of Pathology, Im Neuenheimer Feld 224, 69120 Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Fassl
authors.affiliation: Molecular Tumor Pathology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany, and Institute of Pathology, Im Neuenheimer Feld 224, 69120 Heidelberg, Germany.
authors.forename: K E
authors.initials: KE
authors.lastname: Tagscherer
authors.affiliation: Molecular Tumor Pathology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany, and Institute of Pathology, Im Neuenheimer Feld 224, 69120 Heidelberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Richter
authors.affiliation: Division of Viral Transformation Mechanisms, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: De-Castro Arce
authors.affiliation: Division of Viral Transformation Mechanisms, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Savini
authors.affiliation: Division of Viral Transformation Mechanisms, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Rösl
authors.affiliation: Molecular Tumor Pathology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany, and Institute of Pathology, Im Neuenheimer Feld 224, 69120 Heidelberg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Roth
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053181:Caspase 8 / Q000378:metabolism; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D015870:Gene Expression / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006801:Humans; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: D000970:Antineoplastic Agents; C497761:NOTCH1 protein, human; D051881:Receptor, Notch1; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D016329:Sp1 Transcription Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; C505530:CASP8 protein, human; D053181:Caspase 8