title: Promyelocytic leukemia protein (PML) regulates endothelial cell network formation and migration in response to tumor necrosis factor α (TNFα) and interferon α (IFNα).
abstract: Promyelocytic leukemia protein (PML) is a tumor suppressor that is highly expressed in vascular endothelium and inflamed tissues, yet its role in inflammation-associated cytokine-regulated angiogenesis and underlying mechanism remains largely unclear. We show that tumor necrosis factor α (TNFα) and interferon α (IFNα) stimulate PML expression while suppressing EC network formation and migration, two key events during angiogenesis. By a knockdown approach, we demonstrate that PML is indispensable for TNFα- and IFNα-mediated inhibition of EC network formation. We further demonstrate that signal transducer and activator of transcription 1 (STAT1) binds PML promoter and that is an important regulator of PML expression. Knockdown of STAT1 reduces endogenous PML and blocks TNFα- and IFNα-induced PML accumulation and relieves TNFα- and IFNα-mediated inhibition of EC network formation. Our data also indicate that PML regulates EC migration, in part, by modulating expression of downstream genes, such as negatively regulating integrin β1 (ITGB1). In addition, knockdown of STAT1 or PML alleviates TNFα- and IFNα-mediated inhibition of ITGB1 expression. Antibody blockade demonstrates that ITGB1 is functionally important for PML- and STAT1-regulated EC migration. Taken together, our data provide novel mechanistic insights that PML functions as a negative regulator in EC network formation and migration.
authors.affiliation: Department of Biochemistry, School of Medicine, Case Western Reserve University and the Comprehensive Cancer Center of CWRU and University Hospital of Cleveland, Cleveland, Ohio 44106, USA.
authors.forename: Xiwen
authors.initials: X
authors.lastname: Cheng
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Hao
authors.initials: H
authors.lastname: Chu
authors.forename: Hung-Ying
authors.initials: HY
authors.lastname: Kao
mesh_terms: D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D020869:Gene Expression Profiling; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism; D016898:Interferon-alpha / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D000071156:Promyelocytic Leukemia Protein; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050794:STAT1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D019012:Integrin beta1; D016898:Interferon-alpha; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D050794:STAT1 Transcription Factor; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D025521:Tumor Suppressor Proteins; C070576:PML protein, human