title: Divergent Ewing's sarcoma EWS/ETS fusions confer a common tumorigenic phenotype on NIH3T3 cells.
abstract: Ewing's sarcomas express chimeric transcription factors resulting from a fusion of the amino terminus of the EWS gene to the carboxyl terminus of one of five ETS proteins. While the majority of tumors express EWS/FLI1 fusions, some Ewing's tumors contain variant chimeras such as EWS/ETV1 that have divergent ETS DNA-binding domains. In spite of their structural differences, both EWS/ETS fusions up regulate EAT-2, a previously described EWS/FLI1 target gene. In contrast to EWS/FLI1, NIH3T3 cells expressing EWS/ETV1 cannot form colonies in soft agar though coexpression of a dominant negative truncated ETV1 construct attenuates EWS/FLI1 mediated anchorage independent growth. When EWS/ETV1 or EWS/FLI1 expressing NIH3T3 cells are injected into SCID mice, tumors form more often and faster than with NIH-3T3 cells with empty vector controls. The tumorigenic potency of each EWS/ETS fusion is linked to its C-terminal structure, with the FLI1 C-terminus confering a greater tumorigenic potential than the corresponding ETV1 domain. The resulting EWS/ETV1 and EWS/FLI1 tumors closely resemble each other at both a macroscopic and a microscopic level. These tumors differ greatly from tumors formed by NIH3T3 cells expressing activated RAS. These data indicate that in spite of their structural differences, EWS/ETV1 and EWS/FLI1 promote oncogenesis via similar biologic pathways.
authors.affiliation: Molecular Biology Institute, Gwynne Hazen Cherry Memorial Labs, University of California at Los Angeles, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Thompson
authors.forename: M A
authors.initials: MA
authors.lastname: Teitell
authors.forename: A
authors.initials: A
authors.lastname: Arvand
authors.forename: C T
authors.initials: CT
authors.lastname: Denny
mesh_terms: D016475:3T3 Cells / Q000473:pathology / Q000637:transplantation; D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001859:Bone Neoplasms / Q000235:genetics*; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D012512:Sarcoma, Ewing / Q000235:genetics*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C122140:EWS-ETV1 fusion protein, human; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; C103572:SH2D1B protein, human; C491225:Sh2d1b1 protein, mouse; D014157:Transcription Factors