title: Anaplastic Lymphoma Kinase (ALK) regulates initiation of transcription of MYCN in neuroblastoma cells.
abstract: Neuroblastoma is a neural crest-derived embryonal tumour of the postganglionic sympathetic nervous system and a disease with several different chromosomal gains and losses, which include MYCN-amplified neuroblastoma on chromosome 2, deletions of parts of the chromosomes 1p and 11q, gain of parts of 17q and triploidy. Recently, activating mutations of the ALK (Anaplastic Lymphoma Kinase) RTK (Receptor Tyrosine Kinase) gene have been described in neuroblastoma. A meta-analysis of neuroblastoma cases revealed that ALK mutations (49 of 709 cases) in relation to genomic subtype were most frequently observed in MYCN amplified tumours (8.9%), correlating with a poor clinical outcome. MYCN proteins target proliferation and apoptotic pathways, and have an important role in the progression of neuroblastoma. Here, we show that both wild-type and gain-of-function mutants in ALK are able to stimulate transcription at the MYCN promoter and initiate mRNA transcription of the MYCN gene in both neuronal and neuroblastoma cell lines. Further, this stimulation of MYCN gene transcription and de novo MYCN protein expression is abrogated by specific ALK inhibitors, such as crizotinib (PF-2341066), NVP-TAE684, and by small interfering RNA to ALK resulting in a decrease in proliferation rate. Finally, co-transfection of ALK gain-of-function mutations together with MYCN leads to an increase in transformation potential. Taken together, our results indicate that ALK signalling regulates initiation of transcription of the MYCN gene providing a possible explanation for the poor clinical outcome observed when MYCN is amplified together with activated ALK.
authors.affiliation: Department of Molecular Biology, Umeå University, Umeå, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Schönherr
authors.forename: K
authors.initials: K
authors.lastname: Ruuth
authors.forename: S
authors.initials: S
authors.lastname: Kamaraj
authors.forename: C-L
authors.initials: CL
authors.lastname: Wang
authors.forename: H-L
authors.initials: HL
authors.lastname: Yang
authors.forename: V
authors.initials: V
authors.lastname: Combaret
authors.forename: A
authors.initials: A
authors.lastname: Djos
authors.forename: T
authors.initials: T
authors.lastname: Martinsson
authors.forename: J G
authors.initials: JG
authors.lastname: Christensen
authors.forename: R H
authors.initials: RH
authors.lastname: Palmer
authors.forename: B
authors.initials: B
authors.lastname: Hallberg
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D051379:Mice; D009154:Mutation / Q000235:genetics; D000071447:N-Myc Proto-Oncogene Protein; D041681:NIH 3T3 Cells; D009447:Neuroblastoma / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D015513:Oncogene Proteins / Q000235:genetics* / Q000378:metabolism*; D016716:PC12 Cells; D011401:Promoter Regions, Genetic / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D012333:RNA, Messenger; D003513:Cycloheximide; C000626173:ALK protein, human; C000626174:Alk protein, mouse; C000626175:Alk protein, rat; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases