Reconstitution of the ERG Gene Expression Network Reveals New Biomarkers and Therapeutic Targets in ERG Positive Prostate Tumors (original) (raw)
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Anticancer research, 2012
Shortcomings of current methods of prostate cancer detection call for improved biomarkers. The transmembrane protease, serine 2:ets-related gene (TMPRSS2:ERG) gene fusion leads to the overexpression of ERG, an E-twenty six (ETS) family transcription factor, and is the most prevalent genetic lesion in prostate cancer, but its clinical utility remains unclear. Two radical prostatectomy samples were analysed by next-generation whole-transcriptome sequencing. The chosen samples differed in fusion gene status, as previously determined by reverse transcription polymerase chain reaction (RT-PCR). Next-generation sequencing identified the involvement of novel and previously reported prostate cancer-related transcripts, the WNT signalling pathway, evasion of p53-mediated anti-proliferation and several ETS-regulated pathways in the prostate cancer cases examined. Overexpression of Rho GDP-dissociation inhibitor (RhoGDIB), a gene associated with fusion-positive prostate cancer, was found to el...
Systematic analysis reveals molecular characteristics of ERG-negative prostate cancer
Scientific reports, 2018
The TMPRSS2:ERG gene fusion is the most prevalent early driver gene activation in prostate cancers of European ancestry, while the fusion frequency is much lower in Africans and Asians. The genomic characteristics and mechanisms for patients lacking ERG fusion are still unclear. In this study, we systematically compared the characteristics of gene fusions, somatic mutations, copy number alterations and gene expression signatures between 201 ERG fusion positive and 296 ERG fusion negative prostate cancer samples. Both common and group-specific genomic alterations were observed, suggesting shared and different mechanisms of carcinogenesis in prostate cancer samples with or without ERG fusion. The genomic alteration patterns detected in ERG-negative group showed similarities with 77.5% of tumor samples of African American patients. These results emphasize that genomic and gene expression features of the ERG-negative group may provide a reference for populations with lower ERG fusion fr...
Oncogene, 2008
The high prevalence of TMPRSS2-ERG rearrangements (B60%) in prostate cancer (CaP) leads to androgenic induction of the ETS-related gene (ERG ) expression. However, the biological functions of ERG overexpression in CaP remain to be understood. ERG knockdown in TMPRSS2-ERG expressing CaP cells induced striking morphological changes and inhibited cell growth both in cell culture and SCID mice. Evaluation of the transcriptome and specific gene promoters in ERG siRNA-treated cells and investigation of gene expression signatures of human prostate tumors revealed ERG-mediated activation of C-MYC oncogene and the repression of prostate epithelial differentiation genes (PSA and SLC45A3/ Prostein). Taken together, these data combining cell culture and animal models and human prostate tumors reveal that ERG overexpression in prostate tumor cells may contribute to the neoplastic process by activating C-MYC and by abrogating prostate epithelial differentiation as indicated by prostate epithelial specific markers.
A 36-gene Signature Predicts Clinical Progression in a Subgroup of ERG-positive Prostate Cancers
European Urology, 2013
Background: The molecular basis of the clinical heterogeneity of prostate cancer (PCa) is not well understood. Objective: The purpose of our study was to identify and characterize genes in a clinically relevant gene expression signature in a subgroup of primary PCa positive for transmembrane protease, serine 2 (TMPRSS2)-v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG). Design, setting, and participants: We studied gene expression profiles by unsupervised hierarchical clustering in 48 primary PCas from patients with a long clinical follow-up. Results were correlated with clinical outcome and validated in an independent patient cohort. Selected genes from a defined classifier were tested in vitro for biologic properties. Intervention: Initial treatment of primary tumors was radical prostatectomy. Outcome measurements and statistical analysis: Associations between clinical and histopathologic variables were evaluated by the Pearson x 2 test, Mann-Whitney U test, or Kruskal-Wallis test, where appropriate. The log-rank test or Breslow method was used for statistical analysis of Kaplan-Meier survival curves. Results and limitations: Most tumors that overexpressed ERG clustered separately from other primary PCas. No differences in any clinical end points between ERG-positive and ERG-negative cancers were detected. Importantly, within the ERG-positive samples, two subgroups were identified, which differed significantly in prostate-specific antigen recurrence-free survival, and cancer-specific and overall survival. From our findings, we defined a gene expression classifier of 36 genes. In a second, completely independent tumor set, the classifier also distinguished ERG-positive subgroups with different clinical outcome. In both patient cohorts, the classifier was not predictive in ERG-negative tumors. Biologic processes regulated by genes in the classifier included cell adhesion and bone remodeling. Tumor growth factor-b signaling was indicated as the main differing signaling pathway between the two ERG subgroups. In vitro biologic assays of two selected genes from the classifier (inhibin, beta A [INHBA] and cadherin 11, type 2, OBcadherin (osteoblast) [CDH11]) supported a functional role in PCa progression. Possible multifocality and limited number of PCa samples can be limitations of the study. Conclusions: The classifier identified can contribute to prediction of tumor progression in ERG-positive primary prostate tumors and might be instrumental in therapy decisions.
Journal of Cancer Science & Therapy, 2012
TMPRSS2-Ets gene fusions were identified in prostate cancers where the promoter of transmembrane protease, serine 2 (TMPRSS2) fused with coding sequence of the erythroblastosis virus E26 (Ets) gene family members. TMPRSS2 is an androgen responsive transmembrane serine protease. Ets family members are oncogenic transcription factors that contain a highly conserved Ets DNA binding domain and an N-terminal regulatory domain. Fusion of these gene results in androgen dependent transcription of Ets factor in prostate tumor cells. The ERG is the most common fusion partner with TMPRSS2 promoter in prostate cancer patients. The high prevalence of these gene fusions, in particular TMPRSS2-ERG, makes them attractive as potential diagnostic and prognostic indicators, as well as making them a potential target for tailored therapies. This review focuses on the clinical and biological significance of TMPRSS2-ERG fusions and their role in PC development and progression.
Evaluation of ERG responsive proteome in prostate cancer
The Prostate, 2013
BACKGROUND. Gene fusion between TMPRSS2 promoter and the ERG proto-oncogene is a major genomic alteration found in over half of prostate cancers (CaP), which leads to aberrant androgen dependent ERG expression. Despite extensive analysis for the biological functions of ERG in CaP, there is no systematic evaluation of the ERG responsive proteome (ERP). ERP has the potential to define new biomarkers and therapeutic targets for prostate tumors stratified by ERG expression. METHODS. Global proteome analysis was performed by using ERG (þ) and ERG (À) CaP cells isolated by ERG immunohistochemistry defined laser capture microdissection and by using TMPRSS2-ERG positive VCaP cells treated with ERG and control siRNA. RESULTS. We identified 1,196 and 2,190 unique proteins stratified by ERG status from prostate tumors and VCaP cells, respectively. Comparative analysis of these two proteomes identified 330 concordantly regulated proteins characterizing enrichment of pathways modulating cytoskeletal and actin reorganization, cell migration, protein biosynthesis, and proteasome and ER-associated protein degradation. ERPs unique for ERG (þ) tumors reveal enrichment for cell growth and survival pathways while proteasome and redox function pathways were enriched in ERPs unique for ERG (À) tumors. Meta-analysis of ERPs against CaP gene expression data revealed that Myosin VI and Monoamine oxidase A were positively and negatively correlated to ERG expression, respectively. CONCLUSIONS. This study delineates the global proteome for prostate tumors stratified by ERG expression status. The ERP data confirm the functions of ERG in inhibiting cell differentiation and activating cell growth, and identify potentially novel biomarkers and therapeutic targets.
TMPRSS2:ERG gene fusion associated with lethal prostate cancer in a watchful waiting cohort
Oncogene, 2007
The identification of the TMPRSS2:ERG fusion in prostate cancer suggests that distinct molecular subtypes may define risk for disease progression. In surgical series, TMPRSS2:ERG fusion was identified in 50% of the tumors. Here, we report on a population-based cohort of men with localized prostate cancers followed by expectant (watchful waiting) therapy with 15% (17/111) TMPRSS2:ERG fusion. We identified a statistically significant association between TMPRSS2:ERG fusion and prostate cancer specific death (cumulative incidence ratio ¼ 2.7, Po0.01, 95% confidence interval ¼ 1.3-5.8). Quantitative reverse-transcription-polymerase chain reaction demonstrated high estrogen-regulated gene (ERG) expression to be associated with TMPRSS2:ERG fusion (Po0.005). These data suggest that TMPRSS2:ERG fusion prostate cancers may have a more aggressive phenotype, possibly mediated through increased ERG expression.
TMPRSS2:ERG fusion identifies a subgroup of prostate cancers with a favorable prognosis
Purpose: Our aim was to assess the frequency of ERG overexpression and TMPRSS2:ERG rearrangement in prostate cancer and their association with clinicopathologic variables and outcome. Experimental Design: The presence of theTMPRSS2:ERG rearrangement was studied by reverse transcription-PCR and fluorescence in situ hybridization in 19 prostate cancer xenografts and 7 prostate cancer cell lines.The expression of ERG was studied in the xenografts and cell lines and in 49 freshly frozen clinical prostate samples by quantitative reverse transcription-PCR. The frequency of the TMPRSS2:ERG fusion in clinical prostate cancer (n = 253) on tissue microarrays was assessed by three-color fluorescence in situ hybridization. Results: Seven of 19 (37%) of the xenografts overexpressed ERG and had TMPRSS2:ERG rearrangement. Two xenografts, representing small cell carcinomas, also contained the fusion but did not express ERG. In clinical tumor specimens, the overexpression of ERG was associated with the rearrangement (P = 0.0019). Fifty of 150 (33%) of the prostatectomy specimens and 28 of 76 (37%) of the hormone-refractory prostate cancers on the tissue microarrays carried the TMPRSS2:ERG rearrangement. It was associated with longer progression-free survival in patients treated by prostatectomy (P = 0.019), and according to multivariate analysis, it was an independent predictor of favorable outcome (relative risk, 0.54; 95% confidence interval, 0.30-0.98). The fusion was not associated with Gleason score, pT stage, diagnostic prostatespecific antigen, or cell proliferation activity in prostatectomy specimens nor with the AR gene amplification in hormone-refractory tumors. Conclusions: TheTMPRSS2:ERG rearrangement can be found in about one third of prostate cancers. A subgroup of prostate cancer patients with a good prognosis may be identified by the rearrangement.
Overexpression of truncated ERG from TMPRSS2-ERG fusion and prostate cancer development
Pathology and Laboratory Medicine International, 2009
In men, prostate cancer is one of the most common cancers worldwide and the second leading cause of death among all cancer types in Europe and North America, with the numbers of those affected continuing to increase. Recent studies have identified a recurrent fusion of TMPRSS2 with members of the ETS family of transcription factors in about 80% of prostate cancer tissues. Among them, the TMPRSS2-ERG fusion accounts for approximately 50% of these cases. TMPRSS2 is highly regulated by androgen receptor and the chromosomal rearrangement abnormally induces ERG production by androgen. To investigate the effects of ERG overexpression on its target genes expression and prostate cancer development, plasmids were first constructed by inserting the truncated ERG into an expression vector in the forward or reverse directions. A predicted three-dimensional model of the protein structure of the truncated ERG, along with immunofluorescence assays, suggest that the minor deletion on the N-terminus does not appear to affect the structure or function of ERG. Results from ERG target gene expression profile indicate that TMPRSS2-ERG fusion-induced aberrant ERG overexpression is likely involved in prostate cancer development by enhancing tumor angiogenesis.