title: IDH1 R132H Mutation Enhances Cell Migration by Activating AKT-mTOR Signaling Pathway, but Sensitizes Cells to 5-FU Treatment as NADPH and GSH Are Reduced.
abstract: OBJECTIVE
  Mutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) gene were recently discovered in vast majority of World Health Organization (WHO) grade II/III gliomas. This study is to understand the effects of IDH1 R132H mutation in gliomagenesis and to develop new strategies to treat glioma with IDH1 R132H mutation.
  
  
  METHODS
  Over expression of IDH1 R132H in U87MG cells was done by transfecting cells with IDH1 R132H plasmid. MTT assay, scratch repair assay and western blot were performed to study effects of IDH1 R132H mutation on cell proliferation, migration, regulating AKT-mTOR signaling pathway and cell death respectively. NADP+/NADPH and GSH quantification assays were performed to evaluate effects of IDH1 R132H mutation on the production of antioxidant NADPH and GSH.
  
  
  RESULTS
  We found that over expression of IDH1 R132H mutation decreased cell proliferation consistent with previous reports; however, it increased cell migration and enhanced AKT-mTOR signaling pathway activation. Mutations in isocitrate dehydrogenase (IDH) 1 also change the function of the enzymes and cause them to produce 2-hydroxyglutarate and not produce NADPH. We tested the level of NADPH and GSH and demonstrated that IDH1 R132H mutant stable cells had significantly low NADPH and GSH level compared to control or IDH1 wild type stable cells. The reduced antioxidants (NADPH and GSH) sensitized U87MG cells with IDH R132H mutant to 5-FU treatment.
  
  
  CONCLUSIONS
  Our study highlights the important role of IHD1 R132H mutant in up- regulating AKT-mTOR signaling pathway and enhancing cell migration. Furthermore, we demonstrate that IDH1 R132H mutation affects cellular redox status and sensitizes gliomas cells with IDH1 R132H mutation to 5FU treatment.
authors.affiliation: Soochow University, Soochow, Jiangsu, China.|Medical College, Nantong University, Nantong, Jiangsu, China.
authors.forename: Huixia
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Soochow University, Soochow, Jiangsu, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Chinese medicine hospital, Wuxi, Jiangsu, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Medical College, Nantong University, Nantong, Jiangsu, China.
authors.forename: Jiangdong
authors.initials: J
authors.lastname: Qiu
authors.affiliation: Medical College, Nantong University, Nantong, Jiangsu, China.
authors.forename: Keting
authors.initials: K
authors.lastname: Huang
authors.affiliation: Medical College, Nantong University, Nantong, Jiangsu, China.
authors.forename: Mindan
authors.initials: M
authors.lastname: Wu
authors.affiliation: Soochow University, Soochow, Jiangsu, China.
authors.forename: Chunlin
authors.initials: C
authors.lastname: Xia
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D015153:Blotting, Western; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation; D005472:Fluorouracil / Q000494:pharmacology; D005910:Glioma / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009249:NADP / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D009249:NADP; D007521:Isocitrate Dehydrogenase; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; D058570:TOR Serine-Threonine Kinases; D005978:Glutathione; D005472:Fluorouracil