title: Deregulation of DNA-dependent protein kinase catalytic subunit contributes to human hepatocarcinogenesis development and has a putative prognostic value.
abstract: BACKGROUND
  The DNA-repair gene DNA-dependent kinase catalytic subunit (DNA-PKcs) favours or inhibits carcinogenesis, depending on the cancer type. Its role in human hepatocellular carcinoma (HCC) is unknown.
  
  
  METHODS
  DNA-dependent protein kinase catalytic subunit, H2A histone family member X (H2AFX) and heat shock transcription factor-1 (HSF1) levels were assessed by immunohistochemistry and/or immunoblotting and qRT-PCR in a collection of human HCC. Rates of proliferation, apoptosis, microvessel density and genomic instability were also determined. Heat shock factor-1 cDNA or DNA-PKcs-specific siRNA were used to explore the role of both genes in HCC. Activator protein 1 (AP-1) binding to DNA-PKcs promoter was evaluated by chromatin immunoprecipitation. Kaplan-Meier curves and multivariate Cox model were used to study the impact on clinical outcome.
  
  
  RESULTS
  Total and phosphorylated DNA-PKcs and H2AFX were upregulated in HCC. Activated DNA-PKcs positively correlated with HCC proliferation, genomic instability and microvessel density, and negatively with apoptosis and patient's survival. Proliferation decline and massive apoptosis followed DNA-PKcs silencing in HCC cell lines. Total and phosphorylated HSF1 protein, mRNA and activity were upregulated in HCC. Mechanistically, we demonstrated that HSF1 induces DNA-PKcs upregulation through the activation of the MAPK/JNK/AP-1 axis.
  
  
  CONCLUSIONS
  DNA-dependent protein kinase catalytic subunit transduces HSF1 effects in HCC cells, and might represent a novel target and prognostic factor in human HCC.
authors.affiliation: Institut für Pathologie, Universitätsmedizin Greifswald, Greifswald, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Evert
authors.forename: M
authors.initials: M
authors.lastname: Frau
authors.forename: M L
authors.initials: ML
authors.lastname: Tomasi
authors.forename: G
authors.initials: G
authors.lastname: Latte
authors.forename: M M
authors.initials: MM
authors.lastname: Simile
authors.forename: M A
authors.initials: MA
authors.lastname: Seddaiu
authors.forename: A
authors.initials: A
authors.lastname: Zimmermann
authors.forename: S
authors.initials: S
authors.lastname: Ladu
authors.forename: T
authors.initials: T
authors.lastname: Staniscia
authors.forename: S
authors.initials: S
authors.lastname: Brozzetti
authors.forename: G
authors.initials: G
authors.lastname: Solinas
authors.forename: F
authors.initials: F
authors.lastname: Dombrowski
authors.forename: F
authors.initials: F
authors.lastname: Feo
authors.forename: R M
authors.initials: RM
authors.lastname: Pascale
authors.forename: D F
authors.initials: DF
authors.lastname: Calvisi
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D063646:Carcinogenesis / Q000235:genetics*; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics; D051747:DNA-Activated Protein Kinase / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D000076249:Heat Shock Transcription Factors; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000473:pathology*; D009687:Nuclear Proteins / Q000235:genetics*; D011237:Predictive Value of Tests; D011379:Prognosis; D014157:Transcription Factors / Q000502:physiology
chemical_list: D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D000076249:Heat Shock Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human