title: Human neuroblastoma cells with MYCN amplification are selectively resistant to oxidative stress by transcriptionally up-regulating glutamate cysteine ligase.
abstract: Neuroblastoma is a sympathetic nervous system tumour whose degree of malignancy, prognosis and therapy resistance has been associated with the amplification of MYCN oncogene. However, the molecular pathway responsible for such resistance is unknown. To contribute addressing this issue, in this study, we have compared the vulnerability of four human neuroblastoma cell lines differentially amplifying MYCN, namely SK-N-BE-2 and IMR-32 (MYCN-amplified cells) and SH-SY5Y and SK-N-SH (MCYN-non-amplified cells), to H(2)O(2)-mediated apoptotic death. We found that the high resistance of the MYCN-amplified neuroblastoma cells against oxidative damage can be accounted for by their greater expression of both the mRNA and protein of the catalytic subunit of glutamate-cysteine ligase (GCL(cat)), the rate-limiting step in GSH biosynthesis. Furthermore, we found that MYCN directly binds to an E-box containing GCL(cat) promoter and that over-expression of MYCN in MYCN-non-amplified cells stimulated GCL(cat) expression and provided resistance to oxidative damage; whereas knock down of MYCN in MYCN-amplified cells decreased GCL(cat) expression and sensitized them to oxidative damage. Finally, GCL(cat) knock down enhanced the vulnerability of MYCN-amplified cells to oxidative damage. These results demonstrate that regulation of GCL(cat) by MYCN accounts for the survival of neuroblastoma cells against oxidative damage, and suggest that GCL should be considered a potential therapeutic target for the treatment of MYCN-amplified neuroblastoma.
authors.affiliation: Unidad de Investigacion, Hospital Universitario de Salamanca, Instituto de Estudios de Ciencias de la Salud de Castilla y Leon, Salamanca, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Veas-Perez de Tudela
authors.forename: María
authors.initials: M
authors.lastname: Delgado-Esteban
authors.forename: Julia
authors.initials: J
authors.lastname: Cuende
authors.forename: Juan P
authors.initials: JP
authors.lastname: Bolaños
authors.forename: Angeles
authors.initials: A
authors.lastname: Almeida
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D020134:Catalytic Domain / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D005721:Glutamate-Cysteine Ligase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D000071447:N-Myc Proto-Oncogene Protein; D009447:Neuroblastoma / Q000188:drug therapy / Q000201:enzymology* / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics*; D015513:Oncogene Proteins / Q000235:genetics*; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D015533:Transcriptional Activation / Q000502:physiology; D015854:Up-Regulation / Q000502:physiology
chemical_list: D000970:Antineoplastic Agents; C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D016877:Oxidants; D012333:RNA, Messenger; D006861:Hydrogen Peroxide; D005721:Glutamate-Cysteine Ligase