title: Modulation of Sonic hedgehog signaling and WW domain containing oxidoreductase WOX1 expression enhances radiosensitivity of human glioblastoma cells.
abstract: WW domain containing oxidoreductase, designated WWOX, FOR or WOX1, is a known pro-apoptotic factor when ectopically expressed in various types of cancer cells, including glioblastoma multiforme (GBM). The activation of sonic hedgehog (Shh) signaling, especially paracrine Shh secretion in response to radiation, is associated with impairing the effective irradiation of cancer cells. Here, we examined the role of Shh signaling and WOX1 overexpression in the radiosensitivity of human GBM cells. Our results showed that ionizing irradiation (IR) increased the cytoplasmic Shh and nuclear Gli-1 content in GBM U373MG and U87MG cells. GBM cells with exogenous Shh treatment exhibited similar results. Pretreatment with Shh peptides protected U373MG and U87MG cells against IR in a dose-dependent manner. Cyclopamine, a Hedgehog/Smoothened (SMO) inhibitor, reversed the protective effect of Shh in U87MG cells. Cyclopamine increased Shh plus IR-induced H2AX, a marker of DNA double-strand breaks, in these cells. To verify the role of Shh signaling in the radiosensitivity of GBM cells, we tested the effect of the Gli family zinc finger 1 (Gli-1) inhibitor zerumbone and found that it could sensitize GBM cells to IR. We next examined the role of WOX1 in radiosensitivity. Overexpression of WOX1 enhanced the radiosensitivity of U87MG (possessing wild type p53 or WTp53) but not U373MG (harboring mutant p53 or MTp53) cells. Pretreatment with Shh peptides protected both WOX1-overexpressed U373MG and U87MG cells against IR and increased the cytoplasmic Shh and nuclear Gli-1 content. Zerumbone enhanced the radiosensitivity of WOX1-overexpressed U373MG and U87MG cells. In conclusion, overexpression of WOX1 preferentially sensitized human GBM cells possessing wild type p53 to radiation therapy. Blocking of Shh signaling may enhance radiosensitivity independently of the expression of p53 and WOX1. The crosstalk between Shh signaling and WOX1 expression in human glioblastoma warrants further investigation.
authors.affiliation: Department of Neurosurgery, MacKay Memorial Hospital, Taipei 104, Taiwan Graduate Institute of Injury Prevention and Control, Taipei Medical University, Taipei 110, Taiwan.
authors.forename: Ming-Fu
authors.initials: MF
authors.lastname: Chiang
authors.affiliation: Department of Medical Research, MacKay Memorial Hospital, Taipei 104, Taiwan.
authors.forename: Hsin-Hong
authors.initials: HH
authors.lastname: Chen
authors.affiliation: Department of Medical Research, MacKay Memorial Hospital, Taipei 104, Taiwan.
authors.forename: Chih-Wen
authors.initials: CW
authors.lastname: Chi
authors.affiliation: Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chun-I
authors.initials: CI
authors.lastname: Sze
authors.affiliation: Department of Medical Research, MacKay Memorial Hospital, Taipei 104, Taiwan.
authors.forename: Ming-Ling
authors.initials: ML
authors.lastname: Hsu
authors.affiliation: Department of Medical Research, MacKay Memorial Hospital, Taipei 104, Taiwan.
authors.forename: Hui-Ru
authors.initials: HR
authors.lastname: Shieh
authors.affiliation: Department of Medical Research, MacKay Memorial Hospital, Taipei 104, Taiwan.
authors.forename: Chin-Ping
authors.initials: CP
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan.
authors.forename: Jo-Ting
authors.initials: JT
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Pharmacology, Taipei Medical University, Taipei 110, Taiwan Department of Radiation Oncology, MacKay Memorial Hospital, Taipei 104, Taiwan chenmdphd@gmail.com kitty4024@gmail.com.
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D001932:Brain Neoplasms / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005909:Glioblastoma / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D053823:Hedgehog Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D006657:Histones / Q000378:metabolism; D006801:Humans; D010088:Oxidoreductases / Q000378:metabolism*; D011836:Radiation Tolerance / Q000502:physiology*; D011839:Radiation, Ionizing; D012717:Sesquiterpenes / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology; D014704:Veratrum Alkaloids / Q000494:pharmacology; D000074584:WW Domain-Containing Oxidoreductase; D000071676:Zinc Finger Protein GLI1
chemical_list: C400551:GLI1 protein, human; C468783:H2AX protein, human; D053823:Hedgehog Proteins; D006657:Histones; D012717:Sesquiterpenes; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D014704:Veratrum Alkaloids; D000071676:Zinc Finger Protein GLI1; C403304:zerumbone; D010088:Oxidoreductases; D000074584:WW Domain-Containing Oxidoreductase; C486071:WWOX protein, human; C000541:cyclopamine
keywords: Sonic hedgehog; WOX1; glioblastoma; p53; radiosensitivity