Hly conserved, DNA binding domain (known as ETS domain), which displays sequence specific binding to purine-rich DNA sequences containing a 59-GGAA/T-39 core sequence [5?6]. The Ewing’s sarcoma family of tumors (ESFT) serves as a paradigm for the entire class of ETS-related tumors, since more than 99 of the cases harbor translocations involving ETS genes and EWSR1 [7]. In 85 of the cases, the ESFT harbors a t(11;22)(q24;q12) chromosomal translocation, resulting in a fusion of the amino terminus of the EWSR1 gene to the carboxylETS Fusion Targets in Cancerterminus (containing the DNA binding domain) of FLI1. Fusions between EWSR1 and other ETS genes, namely ERG (10 ) and ETV1, ETV4, or FEV (,5 ), are alternative pathogenetic mechanisms in ESFT [7]. Prostate cancer (PCa) is the most recent ETS-related neoplasia [8], with the TMPRSS2-ERG fusion gene being reported in about 50 of the cases [8?1]. Other, less common gene fusions (1?0 ), involve additional ETS family members, such as ETV1, ETV4, ETV5, and FLI1 [12?4]. In both ESFT and PCa these ETS Gracillin web chimeric genes function as aberrant transcription factors, having a pivotal role in promoting transformation and oncogenesis. This hypothesis is consistent with experiments showing that EWSR1-FLI1 
knockdown is correlated with decreased cell invasion and increased apoptosis [15?6] and with reports showing that overexpression of ERG and ETV1 in benign prostate cells induces a transcriptional program associated with invasion [17?8]. Identifying the target genes of the ETS fusion genes is crucial to understand the oncogenic pathways of the ETS-positive malignancies and some of them may turn out to be more amenable to targeted therapy than the chimeric/truncated transcription factors Tetracosactrin chemical information themselves. Whereas several target genes relevant for ESFT have been uncovered [19?0], the search for the downstream effectors of aberrant ETS transcription factors in PCa is still in its infancy [21?2]. The major ETS genes involved in rearrangements in ESFT and PCa, FLI1 and ERG, respectively, belong to the same subfamily, have 98 sequence identity in the DNA binding domain [23?4], and have been found rearranged in both neoplasias [7?,13]. In order to investigate whether these ETS fusion genes have some common downstream targets, we crossed a publicly available list of all putative EWSR1-FLI1 direct target genes in ESFT (obtained by chromatin immunoprecipitation coupled with DNA microarrays) [20] with our microarray expression data on PCa with and without ERG rearrangements [25] and validated the findings in an independent series of PCa and ESFT.included the two upregulated genes CAV1 [26] and NR0B1 [27] and the two downregulated genes IGFBP3 [16] and TGFBR2 [28].Prostate Cancer and Non-malignant Tissue SpecimensFifty-six PCa samples were selected from a pool of 200 patients with clinically localized prostate adenocarcinoma consecutively diagnosed and treated with radical prostatectomy at the Portuguese Oncology Institute ?Porto (IPO-Porto), Portugal [13]. These samples were chosen in order to represent different molecular subtypes of prostate cancer, as previously classified, and included: 24 samples with ERG rearrangements (PCa ERG+), 12 with other ETS rearrangements (PCa oETS+, which include rearrangements with ETS members of the PEA3 subfamily ?ETV1, ETV4 and ETV5 [24]) and 20 without ETS rearrangements (PCa ETS-). For control purposes, 15 NPT were collected from cystoprostatectomy specimens of bladder cancer patie.Hly conserved, DNA binding domain (known as ETS domain), which displays sequence specific binding to purine-rich DNA sequences containing a 59-GGAA/T-39 core sequence [5?6]. The Ewing’s sarcoma family of tumors (ESFT) serves as a paradigm for the entire class of ETS-related tumors, since more than 99 of the cases harbor translocations involving ETS genes and EWSR1 [7]. In 85 of the cases, the ESFT harbors a t(11;22)(q24;q12) chromosomal translocation, resulting in a fusion of the amino terminus of the EWSR1 gene to the carboxylETS Fusion Targets in Cancerterminus (containing the DNA binding domain) of FLI1. Fusions between EWSR1 and other ETS genes, namely ERG (10 ) and ETV1, ETV4, or FEV (,5 ), are alternative pathogenetic mechanisms in ESFT [7]. Prostate cancer (PCa) is the most recent ETS-related neoplasia [8], with the TMPRSS2-ERG fusion gene being reported in about 50 of the cases [8?1]. Other, less common gene fusions (1?0 ), involve additional ETS family members, such as ETV1, ETV4, ETV5, and FLI1 [12?4]. In both ESFT and PCa these ETS chimeric genes function as aberrant transcription factors, having a pivotal role in promoting transformation and oncogenesis. This hypothesis is consistent with experiments showing that EWSR1-FLI1 knockdown is correlated with decreased cell invasion and increased apoptosis [15?6] and with reports showing that overexpression of ERG and ETV1 in benign prostate cells induces a transcriptional program associated with invasion [17?8]. Identifying the target genes of the ETS fusion genes is crucial to understand the oncogenic pathways of the ETS-positive malignancies and some of them may turn out to be more amenable 
to targeted therapy than the chimeric/truncated transcription factors themselves. Whereas several target genes relevant for ESFT have been uncovered [19?0], the search for the downstream effectors of aberrant ETS transcription factors in PCa is still in its infancy [21?2]. The major ETS genes involved in rearrangements in ESFT and PCa, FLI1 and ERG, respectively, belong to the same subfamily, have 98 sequence identity in the DNA binding domain [23?4], and have been found rearranged in both neoplasias [7?,13]. In order to investigate whether these ETS fusion genes have some common downstream targets, we crossed a publicly available list of all putative EWSR1-FLI1 direct target genes in ESFT (obtained by chromatin immunoprecipitation coupled with DNA microarrays) [20] with our microarray expression data on PCa with and without ERG rearrangements [25] and validated the findings in an independent series of PCa and ESFT.included the two upregulated genes CAV1 [26] and NR0B1 [27] and the two downregulated genes IGFBP3 [16] and TGFBR2 [28].Prostate Cancer and Non-malignant Tissue SpecimensFifty-six PCa samples were selected from a pool of 200 patients with clinically localized prostate adenocarcinoma consecutively diagnosed and treated with radical prostatectomy at the Portuguese Oncology Institute ?Porto (IPO-Porto), Portugal [13]. These samples were chosen in order to represent different molecular subtypes of prostate cancer, as previously classified, and included: 24 samples with ERG rearrangements (PCa ERG+), 12 with other ETS rearrangements (PCa oETS+, which include rearrangements with ETS members of the PEA3 subfamily ?ETV1, ETV4 and ETV5 [24]) and 20 without ETS rearrangements (PCa ETS-). For control purposes, 15 NPT were collected from cystoprostatectomy specimens of bladder cancer patie.