| 1. |
- Braegelmann, Johannes, et al.
(författare)
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Pan-Cancer Analysis of the Mediator Complex Transcriptome Identifies CDK19 and CDK8 as Therapeutic Targets in Advanced Prostate Cancer
- 2017
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Ingår i: Clinical Cancer Research. - : American Association for Cancer Research Inc.. - 1078-0432 .- 1557-3265. ; 23:7, s. 1829-1840
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The Mediator complex is a multiprotein assembly, which serves as a hub for diverse signaling pathways to regulate gene expression. Because gene expression is frequently altered in cancer, a systematic understanding of the Mediator complex in malignancies could foster the development of novel targeted therapeutic approaches.Experimental Design: We performed a systematic deconvolution of the Mediator subunit expression profiles across 23 cancer entities (n = 8,568) using data from The Cancer Genome Atlas (TCGA). Prostate cancer-specific findings were validated in two publicly available gene expression cohorts and a large cohort of primary and advanced prostate cancer (n = 622) stained by immunohistochemistry. The role of CDK19 and CDK8 was evaluated by siRNA-mediated gene knockdown and inhibitor treatment in prostate cancer cell lines with functional assays and gene expression analysis by RNAseq.Results: Cluster analysis of TCGA expression data segregated tumor entities, indicating tumor-type-specific Mediator complex compositions. Only prostate cancerwasmarked by high expression of CDK19. In primary prostate cancer, CDK19 was associated with increased aggressiveness and shorter disease-free survival. During cancer progression, highest levels of CDK19 and of its paralog CDK8were present inmetastases. In vitro, inhibition ofCDK19 and CDK8 by knockdown or treatment with a selective CDK8/ CDK19 inhibitor significantly decreased migration and invasion.Conclusions: Our analysis revealed distinct transcriptional expression profiles of the Mediator complex across cancer entities indicating differential modes of transcriptional regulation. Moreover, it identified CDK19 and CDK8 to be specifically overexpressed during prostate cancer progression, highlighting their potential as novel therapeutic targets in advanced prostate cancer.
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| 2. |
- Merz, Constanze, et al.
(författare)
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IL-6 Overexpression in ERG-Positive Prostate Cancer Is Mediated by Prostaglandin Receptor EP2
- 2016
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Ingår i: American Journal of Pathology. - New York, USA : Elsevier. - 0002-9440 .- 1525-2191. ; 186:4, s. 974-984
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Tidskriftsartikel (refereegranskat)abstract
- Prostate cancer is the most diagnosed cancer in men and multiple risk factors and genetic alterations have been described. The TMPRSS2-ERG fusion event and the overexpression of the transcription factor ERG are present in approximately 50% of all prostate cancer patients, however, the clinical outcome is still controversial. Prostate tumors produce various soluble factors, including the pleiotropic cytokine IL-6, regulating cellular processes such as proliferation and metastatic segregation. Here, we used prostatectomy samples in a tissue microarray format and analyzed the co-expression and the clinicopathologic data of ERG and IL-6 using immunohistochemical double staining and correlated the read-out with clinicopathologic data. Expression of ERG and IL-6 correlated strongly in prostate tissue samples. Forced expression of ERG in prostate tumor cell lines resulted in significantly increased secretion of IL-6, whereas the down-regulation of ERG decreased IL-6 secretion. By dissecting the underlying mechanism in prostate tumor cell lines we show the ERG-mediated up-regulation of the prostanoid receptors EP2 and EP3. The prostanoid receptor EP2 was overexpressed in human prostate cancer tissue. Furthermore, the proliferation rate and IL-6 secretion in DU145 cells was reduced after treatment with EP2-receptor antagonist. Collectively, our study shows that the expression of ERG in prostate cancer is linked to the expression of IL-6 mediated by the prostanoid receptor EP2.
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| 3. |
- Offermann, Anne, et al.
(författare)
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TRIM24 as an independent prognostic biomarker for prostate cancer
- 2019
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Ingår i: Urologic Oncology. - : Elsevier. - 1078-1439 .- 1873-2496. ; 37:9
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Simply applicable biomarkers for prostate cancer patients predicting the clinical course are urgently needed. Recently, TRIM24 has been identified to promote androgen receptor signaling and to correlate with an aggressive prostate cancer phenotype. Based on these data, we proofed TRIM24 as a prognostic biomarker for risk stratification.Materials and Methods: We performed TRIM24 immunohistochemistry on 2 independent cohorts including a total of 806 primary tumors, 26 locally advanced/recurrent tumors, 30 lymph node metastases, 30 distant metastases, and 129 benign prostatic samples from 497 patients as well as on 246 prostate needle biopsies. Expression data were correlated with clinic-pathological data including biochemical recurrence-free survival (bRFS) as endpoint.Results: Benign samples show no or low TRIM24 expression in 94%, while tumor tissues demonstrate significant higher levels. Strongest expression is observed in advanced and metastatic tumors. In multivariate analyses, TRIM24 up-regulation on radical prostatectomy specimens correlates with shorter bRFS independent of other prognostic parameters. 5-(10-) year bRFS rates for TRIM24 negative, low, medium and high expressing tumors are 93.1(93.1)%, 75.4(68.5)%, 54.9(47.5)% and 43.1(32.3)%, respectively. Of interest, tumors diagnosed as indolent disease, TRIM24 expression stratifies patients into specific risk groups. Increased TRIM24 expression associates with higher grade group, positive nodal status and extraprostatic tumor growth. TRIM24 assessment on prostate needle biopsies taken prior to treatment decision at time of initial diagnosis significantly correlates with recurrence after surgery.Conclusion: Using 2 large independent radical prostatectomy specimen cohorts, we found that TRIM24 expression predicts patients' risk to develop disease recurrence with high accuracy and independent from other established biomarkers. Further, this is the first study exploring TRIM24 expression on prostate needle biopsies which represents the clinically relevant tissue type on which biomarkers guide treatment decisions. Thus, we strongly suggest introducing TRIM24 evaluation in prostate needle biopsies in clinical routine as an inexpensive and simple immunohistochemical test.
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| 4. |
- Offermann, Anne, et al.
(författare)
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TRIM24 as Independent Prognostic Marker in Prostate Cancer
- 2018
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Ingår i: Modern Pathology. - : Nature Publishing Group. - 0893-3952 .- 1530-0285. ; 31:Suppl. 2, s. 372-373
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Simply applicable biomarkers for prostate cancer (PCa) predicting the clinical course are urgently needed. Recently, TRIM24 has been identified to promote androgen-receptor signaling and to correlate with poor outcome. Based on these data, we validated TRIM24 as a prognostic biomarker for PCa.Design: We performed TRIM24 immunohistochemistry on two independent cohorts including a total of 806 primary tumors, 26 locally advanced/recurrent tumors, 30 lymph node metastases, 30 distant metastases and 129 benign prostatic samples from 497 patients. Expression data were correlated with clinic-pathological data including biochemical recurrence free survival (bRFS) as endpoint.Results: Benign samples show no/low TRIM24 expression in 94%, while tumors demonstrate significantly higher levels. Strongest expression is observed in metastatic tumors. In multivariate analyses, TRIM24 up-regulation correlates with shorter bRFS independent of other prognostic parameters. 5-(10-) year bRFS rates for TRIM24 negative, low, medium and high expressing tumors are 93.1(93.1)%, 75.4(68.5)%, 54.9(47.5)% and 43.1(32.3)%, respectively. Of interest, tumors diagnosed as indolent disease, TRIM24 expression stratifies patients into specific risk groups. Increased TRIM24 expression associates with higher Grade Group, positive nodal status and extraprostatic tumor growth.Conclusions: Using two large independent cohorts, we found that TRIM24 expression predicts patients’ risk to develop disease recurrence with high accuracy and independently from other established prognostic markers. To our knowledge, TRIM24 is the first prognostic biomarker to be independent, accurate and reproducible on three different primary PCa cohorts. Thus, we strongly suggest introducing TRIM24 in clinical routine as a simple immunohistochemical test.
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| 5. |
- Schulte, Johannes H, et al.
(författare)
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Lysine-Specific Demethylase 1 Is Strongly Expressed in Poorly Differentiated Neuroblastoma: Implications for Therapy.
- 2009
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Ingår i: Cancer Research. - 1538-7445. ; 69, s. 2065-2071
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Tidskriftsartikel (refereegranskat)abstract
- Aberrant epigenetic changes in DNA methylation and histone acetylation are hallmarks of most cancers, whereas histone methylation was previously considered to be irreversible and less versatile. Recently, several histone demethylases were identified catalyzing the removal of methyl groups from histone H3 lysine residues and thereby influencing gene expression. Neuroblastomas continue to remain a clinical challenge despite advances in multimodal therapy. Here, we address the functional significance of the chromatin-modifying enzyme lysine-specific demethylase 1 (LSD1) in neuroblastoma. LSD1 expression correlated with adverse outcome and was inversely correlated with differentiation in neuroblastic tumors. Differentiation of neuroblastoma cells resulted in down-regulation of LSD1. Small interfering RNA-mediated knockdown of LSD1 decreased cellular growth, induced expression of differentiation-associated genes, and increased target gene-specific H3K4 methylation. Moreover, LSD1 inhibition using monoamine oxidase inhibitors resulted in an increase of global H3K4 methylation and growth inhibition of neuroblastoma cells in vitro. Finally, targeting LSD1 reduced neuroblastoma xenograft growth in vivo. Here, we provide the first evidence that a histone demethylase, LSD1, is involved in maintaining the undifferentiated, malignant phenotype of neuroblastoma cells. We show that inhibition of LSD1 reprograms the transcriptome of neuroblastoma cells and inhibits neuroblastoma xenograft growth. Our results suggest that targeting histone demethylases may provide a novel option for cancer therapy. [Cancer Res 2009;69(5):2065-71].
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| 6. |
- Schulte, Johannes H., et al.
(författare)
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The low-affinity neurotrophin receptor, p75, is upregulated in ganglioneuroblastoma/ganglioneuroma and reduces tumorigenicity of neuroblastoma cells in vivo
- 2009
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 124:10, s. 2488-2494
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma, the most common extracranial tumor of childhood, is derived from neural crest progenitor cells that fail to differentiate along their predefined route to sympathetic neurons or sympatho-adrenergic adrenal cells. Although expression of the high-affinity neurotrophin receptors, TrkA and TrkB, is of major importance in neuroblastoma, the significance of the expression of the low-affinity neurotrophin receptor, p75, is unclear. Here, we analyzed immunohistochemically expression of p75 on a tissue microarray of 93 primary neuroblastic tumors and assessed the functional consequences of p75 expression in neuroblastoma cell lines. We found the p75 receptor protein to be expressed in neuroblastic cells of ganglioneuromas/ganglioneuroblastomas as well as differentiating neuroblastomas, but not in poorly differentiated neuroblastomas. In an unrelated cohort of 110 neuroblastic tumors, p75 mRNA expression levels correlated with differentiation, and patients with tumors that expressed p75 at high levels had an increased event-free and overall survival. In addition, we did not detect p75 expression in 8 established neuroblastoma cell lines examined with FACS analysis. These cell lines exhibited an undifferentiated morphology, and were all derived from aggressive, high-stage neuroblastomas. Ectopic p75 expression in the SH-SY5Y neuroblastoma cell line significantly reduced proliferation, increased the fraction of apoptotic cells in vitro and resulted in a loss of tumorigenicity in nude mice. Taken together, our data suggest that expression of the p75 low-affinity neurotrophin receptor is correlated with a reduced level of tumorigenicity, and that induction of p75 expression may be an option to revert features of an aggressive tumor phenotype. (C) 2008 Wiley-Liss, Inc.
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| 7. |
- Shaikhibrahim, Zaki, et al.
(författare)
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MED12 overexpression is a frequent event in castration-resistant prostate cancer
- 2014
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Ingår i: Endocrine-Related Cancer. - : Bioscientifica. - 1351-0088 .- 1479-6821. ; 21:4, s. 663-675
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Tidskriftsartikel (refereegranskat)abstract
- In a recent effort to unravel the molecular basis of prostate cancer (PCa), Barbieri and colleagues using whole-exome sequencing identified a novel recurrently mutated gene, MED12, in 5.4% of primary PCa. MED12, encoding a subunit of the Mediator complex, is a transducer of Wnt/beta-catenin signaling, linked to modulation of hedgehog signaling and to the regulation of transforming growth factor beta (TGF beta)-receptor signaling. Therefore, these studies prompted us to investigate the relevance of MED12 in PCa. Expression of MED12, SMAD3 phosphorylation, and proliferation markers was assessed by immunohistochemistry on tissue microarrays from 633 patients. siRNA-mediated knockdown of MED12 was carried out on PCa cell lines followed by cellular proliferation assays, cell cycle analysis, apoptosis assays, and treatments with recombinant TGF beta 3. We found nuclear overexpression of MED12 in 40% (28/70) of distant metastatic castration-resistant prostate cancer (CRPCMET) and 21% (19/90) of local-recurrent CRPC (CRPCLOC) in comparison with frequencies of less than 11% in androgen-sensitive PCa, and no overexpression in benign prostatic tissues. MED12 expression was significantly correlated with high proliferative activity in PCa tissues, whereas knockdown of MED12 decreased proliferation, reduced G1-to S-phase transition, and increased the expression of the cell cycle inhibitor p27. TGF beta signaling activation associates with MED12 nuclear overexpression in tissues and results in a strong increase in MED12 nuclear expression in cell lines. Furthermore, MED12 knockdown reduced the expression of the TGF beta target gene vimentin. Our findings show that MED12 nuclear overexpression is a frequent event in CRPC in comparison with androgen-sensitive PCa and is directly implicated in TGF beta signaling.
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| 8. |
- Shaikhibrahim, Zaki, et al.
(författare)
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MED15, encoding a subunit of the mediator complex, is overexpressed at high frequency in castration-resistant prostate cancer
- 2014
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Ingår i: International Journal of Cancer. - Hoboken : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 135:1, s. 19-26
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Tidskriftsartikel (refereegranskat)abstract
- The mediator complex is an evolutionary conserved key regulator of transcription of protein-coding genes and an integrative hub for diverse signaling pathways. In this study, we investigated whether the mediator subunit MED15 is implicated in castration-resistant prostate cancer (CRPC). MED15 expression and copy number/rearrangement status were assessed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively on 718 prostate cancer (PCa) specimens and sequenced by Sanger on a subset. Furthermore, SMAD3 phosphorylation, androgen receptor (AR) and proliferation markers were evaluated by IHC. In PCa cells, siRNA/shRNA knockdown of MED15 was followed by proliferation assays with/without dihydrotestosterone (DHT), and treatments with recombinant TGF-beta 3. Our results show that MED15 is overexpressed in 76% of distant metastatic CRPC (CRPCMET) and 70% of local-recurrent CRPC (CRPCLOC), in contrast to low frequencies in androgen-sensitive PCa, and no expression in benign prostatic tissue. Furthermore, MED15 overexpression correlates with worse clinical outcome thus defining a highly lethal phenotype. Moreover, TGF-beta signaling activation associates with MED15 overexpression in PCa tissues, and leads to increased expression of MED15 in PCa cells. MED15 knockdown effects phosphorylation and shuttling of p-SMAD3 to the nucleus as well as TGF-beta-enhanced proliferation. In PCa tissues, MED15 overexpression associates with AR overexpression/amplification and correlates with high proliferative activity. MED15 knockdown decreases both androgen-dependent and -independent proliferation in PCa cells. Taken together, these findings implicate MED15 in CRPC, and as MED15 is evolutionary conserved, it is likely to emerge as a lethal phenotype in other therapeutic-resistant diseases, and not restricted to our disease model.
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