title: Identification of PAX3-FKHR-regulated genes differentially expressed between alveolar and embryonal rhabdomyosarcoma: focus on MYCN as a biologically relevant target.
abstract: Rhabdomyosarcoma is a family of myogenic soft tissue tumors subdivided into two main subtypes: alveolar (ARMS) and embryonal (ERMS). ARMS is characterized by a frequent 2;13 chromosomal translocation that creates a PAX3-FKHR fusion transcription factor. To identify downstream targets of PAX3-FKHR, we introduced an inducible form of PAX3-FKHR into human RD ERMS cells. Microarray analysis identified 39 genes (29 upregulated and 10 downregulated) that are modulated by PAX3-FKHR in RD cells and differentially expressed between ERMS and PAX3-FKHR-positive ARMS tumors. Functional annotation demonstrated that genes involved in regulation of transcription and development, particularly neurogenesis, are represented in this group. MYCN was one notable neural-related transcription factor-encoding gene identified in this set, and its regulation by PAX3-FKHR was further confirmed at the RNA and protein levels. The findings of cycloheximide inhibition and time-course studies are consistent with the hypothesis that the PAX3-FKHR protein acts directly on the MYCN gene at the transcriptional level. Functional studies established that MYCN cooperates with PAX3-FKHR to enhance oncogenic activity. In conclusion, we identified a selected set of biologically relevant genes modulated by PAX3-FKHR, and demonstrated that PAX3-FKHR contributes to the expression of MYCN and in turn MYCN collaborates with PAX3-FKHR in tumorigenesis.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
authors.forename: Gabriela E
authors.initials: GE
authors.lastname: Mercado
authors.forename: Shujuan J
authors.initials: SJ
authors.lastname: Xia
authors.forename: Chune
authors.initials: C
authors.lastname: Zhang
authors.forename: Eun Hyun
authors.initials: EH
authors.lastname: Ahn
authors.forename: Donna M
authors.initials: DM
authors.lastname: Gustafson
authors.forename: Marick
authors.initials: M
authors.lastname: Laé
authors.forename: Marc
authors.initials: M
authors.lastname: Ladanyi
authors.forename: Frederic G
authors.initials: FG
authors.lastname: Barr
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D002648:Child; D003513:Cycloheximide / Q000494:pharmacology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051379:Mice; D000071447:N-Myc Proto-Oncogene Protein; D041681:NIH 3T3 Cells / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D009687:Nuclear Proteins / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D015513:Oncogene Proteins / Q000502:physiology*; D015514:Oncogene Proteins, Fusion / Q000502:physiology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000502:physiology; D018232:Rhabdomyosarcoma, Alveolar / Q000235:genetics* / Q000378:metabolism; D018233:Rhabdomyosarcoma, Embryonal / Q000235:genetics* / Q000378:metabolism; D012983:Soft Tissue Neoplasms / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D015514:Oncogene Proteins, Fusion; C523321:PAX3-FKHR fusion protein, human; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011993:Recombinant Fusion Proteins; D003513:Cycloheximide