title: Potential downstream target genes of aberrant ETS transcription factors are differentially affected in Ewing's sarcoma and prostate carcinoma.
abstract: FLI1 and ERG, the major ETS transcription factors involved in rearrangements in the Ewing's sarcoma family of tumors (ESFT) and in prostate carcinomas (PCa), respectively, belong to the same subfamily, having 98% sequence identity in the DNA binding domain. We therefore decided to investigate whether the aberrant transcription factors in both malignancies have some common downstream targets. We crossed a publicly available list of all putative EWSR1-FLI1 target genes in ESFT with our microarray expression data on 24 PCa and 6 non-malignant prostate tissues (NPT) and choose four genes among the top-most differentially expressed between PCa with (PCa ERG+) and without (PCa ETS-) ETS fusion genes (HIST1H4L, KCNN2, ECRG4 and LDOC1), as well as four well-validated direct targets of the EWSR1-FLI1 chimeric protein in ESFT (NR0B1, CAV1, IGFBP3 and TGFBR2). Using quantitative expression analysis in 16 ESFT and seven alveolar rhabdomyosarcomas (ARMS), we were able to validate the four genes previously described as direct targets of the EWSR1-FLI1 oncoprotein, showing overexpression of CAV1 and NR0B1 and underexpression of IGFBP3 and TGFBR2 in ESFT as compared to ARMS. Although none of these four genes showed significant expression differences between PCa ERG+ and PCa ETS-, CAV1, IGFBP3 and TGFBR2 were less expressed in PCa in an independent series of 56 PCa and 15 NPT, as also observed for ECRG4 and LDOC1, suggesting a role in prostate carcinogenesis in general. On the other hand, we demonstrate for the first time that both HIST1H4L and KCNN2 are significantly overexpressed in PCa ERG+ and that ERG binds to the promoter of these genes. Conversely, KCNN2 was found underexpressed in ESFT relative to ARMS, suggesting that the EWSR1-ETS oncoprotein may have the opposite effect of ERG rearrangements in PCa. We conclude that aberrant ETS transcription factors modulate target genes differently in ESFT and PCa.
authors.affiliation: Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Camões
authors.forename: Paula
authors.initials: P
authors.lastname: Paulo
authors.forename: Franclim R
authors.initials: FR
authors.lastname: Ribeiro
authors.forename: João D
authors.initials: JD
authors.lastname: Barros-Silva
authors.forename: Mafalda
authors.initials: M
authors.lastname: Almeida
authors.forename: Vera L
authors.initials: VL
authors.lastname: Costa
authors.forename: Nuno
authors.initials: N
authors.lastname: Cerveira
authors.forename: Rolf I
authors.initials: RI
authors.lastname: Skotheim
authors.forename: Ragnhild A
authors.initials: RA
authors.lastname: Lothe
authors.forename: Rui
authors.initials: R
authors.lastname: Henrique
authors.forename: Carmen
authors.initials: C
authors.lastname: Jerónimo
authors.forename: Manuel R
authors.initials: MR
authors.lastname: Teixeira
mesh_terms: D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D057137:DAX-1 Orphan Nuclear Receptor / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics / Q000378:metabolism; D008297:Male; D046228:Microarray Analysis; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D051789:Proto-Oncogene Protein c-fli-1 / Q000235:genetics / Q000378:metabolism; D050783:Proto-Oncogene Proteins c-ets / Q000235:genetics / Q000378:metabolism; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D012512:Sarcoma, Ewing / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D000071230:Transcriptional Regulator ERG
chemical_list: C495540:CAV1 protein, human; D051242:Caveolin 1; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; C072312:ERG protein, human; C078433:FLI1 protein, human; C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; C539965:NR0B1 protein, human; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D050783:Proto-Oncogene Proteins c-ets; D018125:Receptors, Transforming Growth Factor beta; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II