title: MYCN concurrence with SAHA-induced cell death in human neuroblastoma cells.
abstract: BACKGROUND
  In the past, the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) has been shown to induce apoptosis in several human tumor types, including neuroblastomas. Amplification and over-expression of the MYCN oncogene is a diagnostic hallmark and a poor prognostic indicator in high-risk neuroblastomas. Here, we studied the relationship between MYCN amplification and over-expression and the anti-tumor effect of SAHA to assess whether this drug may serve as a treatment option for high-risk neuroblastomas.
  
  
  METHODS
  Different human neuroblastoma cell lines, over-expressing or not over-expressing MYCN, were used in this study. Targeted knockdown and exogenous over-expression of MYCN were employed to examine correlations between MYCN expression levels and SAHA responses. After various time periods and concentration exposures to the drug, cell viability was measured by MTS assay, and variations in MYCN mRNA and protein levels were assessed by qPCR and Western blotting, respectively.
  
  
  RESULTS
  We found that SAHA decreased cell viability in all cell lines tested through apoptosis induction, and that SAHA had a stronger effect on cell lines carrying an amplified MYCN gene. A decrease in MYCN mRNA and protein levels was observed in the SAHA treated cell lines. Subsequent silencing and exogenous over-expression of MYCN changed the proliferation rate of the cells, but did not have any significant impact on the effect of SAHA on the viability of the cells. We also found that SAHA blocked the expression of MYCN and, by doing so, reduced the effects mediated by this protein.
  
  
  CONCLUSIONS
  Our results suggest that SAHA may be used as a single-drug treatment option for neuroblastomas with an amplified MYCN gene, and as an adjuvant treatment option for all neuroblastomas.
authors: Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, 08028, Barcelona, Catalunya, Spain.|Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, L'Hospitalet de Llobregat, Catalunya, 08907, Spain.
authors: Constanza
authors: C
authors: Cortés
authors: Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, L'Hospitalet de Llobregat, Catalunya, 08907, Spain.
authors: Sara C
authors: SC
authors: Kozma
authors: Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, 08028, Barcelona, Catalunya, Spain.|Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, L'Hospitalet de Llobregat, Catalunya, 08907, Spain.
authors: Albert
authors: A
authors: Tauler
authors: Unitat de Bioquímica, Dep. Ciències Fisiològiques II, Facultat de Medicina, Campus Universitari de Bellvitge - IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Catalunya, 08907, Spain. sambrosio@ub.edu.
authors: Santiago
authors: S
authors: Ambrosio
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects* / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D000071447:N-Myc Proto-Oncogene Protein; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D015513:Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D000077337:Vorinostat
chemical_list: D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D000077337:Vorinostat
keywords: MYCN; Neuroblastoma; SAHA