bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract A22: Combined simvastatin and anti-IGF-1R therapy of prostate cancer cells in co-culture with bone
Authors: Nordstrand Annika , Lundholm Marie , Larsson Andreas , Lerner Ulf , Widmark Anders , Wikström. Pernilla 
Published: May 2013

Abstract
Prostate cancer frequently metastasizes to the bone. Bone metastases show weak responses to the conventional therapies given today, and patients with metastases cannot be cured. Bone matrix is rich in stored growth factors, with IGF-1 being one of the most abundant. IGF-1 acts as a survival factor for tumor cells and we speculate that bone-derived IGF-1 weakens the effects of therapies aimed to target bone metastases and, furthermore, that effects of apoptosis inducing therapies could be enhanced if given in combination with therapies inhibiting the IGF-1 receptor (IGF-1R). Simvastatin inhibits the mevalonate pathway and have been found to induce apoptosis of prostate cancer cells. The aims of this study were to confirm stimulating effects of bone-derived IGF-1 on prostate cancer cell growth and to test if IGF-1R inhibition could enhance simvastatin therapy effects on prostate cancer cells in a bone environment. Prostate cancer PC-3 and 22Rv1 cells were co-cultured with mice calvarias for 72 h and showed significantly increased cell numbers compared to when cultured alone. A phospho-RTK array confirmed activation of the IGF-1R on PC-3 and 22Rv1 cells by calvaria-conditioned media, and neutralization of bone-derived IGF-1 abolished the calvaria-induced increase of PC-3 cell growth. Treatments of PC-3 and 22Rv1 cells with simvastatin and the IGF-1R inhibitor NVP-AEW541 reduced tumor cell numbers and cell viability, and induced apoptosis, as assessed by flow cytometry analysis of Annexin-V. Combined s imvastatin and NVP-AEW541 treatments resulted in enhanced growth inhibitory effects compared to either therapy given alone. Expression analysis by RT-PCR and Western blot indicated that the therapeutic effects of simvastatin involved down-regulation of the IGF-1R in PC-3 cells and of the constitutively active androgen receptor AR-V7 variant in 22Rv1 cells. In conclusion, we believe that a combination of IGF-1R inhibition with simvastatin, and possibly other apoptosis inducing therapies, can provide novel and improved treatment regimes for prostate cancer bone metastases.
Citation Format: Annika Nordstrand, Marie Lundholm, Andreas Larsson, Ulf Lerner,Anders Widmark, Pernilla Wikström. Combined simvastatin and anti-IGF-1R therapy of prostate cancer cells in co-culture with bone [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A22.
Abstract A24: Epigenetic silencing of ID4 (inhibitor of DNA binding 4) is associated with prostate cancer
Authors: Sharma Pankaj , Chinaranagari Swathi , Patel Divya , Chaudhary Jaideep 
Published: May 2013

Abstract
Introduction: Inhibitor of DNA binding/differentiation protein 4 (Id4) is dominant negative regulator of basic helix loop helix (bHLH) family of transcription factors. Id4 shares the homology of HLH domain with other Ids and lack the basic DNA binding region. Previous studies from our lab had shown that unlike Id1, Id2 and Id3, Id4 acts as a tumor suppressor in prostate cancer by attenuating cell proliferation and promote apoptosis. Consistent with these observations Id4 is epigenetically silenced in Du145 prostate cancer cell line. In this study we investigated whether Id4 is also epigenetically silenced in prostate cancer. We also examined association between Id4 promoter hypermethylation and its expression in prostate cancer cell lines.
Experimental procedures: Id4 protein expression was analyzed on human prostate adenocarcinoma samples by Immunhistochemistry. Id4 promoter methylation pattern on prostate cancer cell lines (C33, C81, DU145, LNCaP, DU145+ID4, and PC3) was examined. In addition, we performed Laser capture microdisection (LCMD) on the human prostate tissues and methylation specific PCR to correlate our cell line studies with clinical studies.
Results: IHC demonstrated decreased Id4 protein expression in human prostate tissue samples whereas higher nuclear Id4 expression was found in normal prostate tissues.Id4 methylation specific PCR (MSP) on prostate cancer cell lines, showed Id4 methylation in DU145 cell and but not in LNCaP and C33 cells. In C81 and PC3 cells it showed partial methylation. C81 are derivatives of LNCaP cell lines and are Androgen independent and are more metastatic. Increased Id4 methylation in C81 as compared to LNCaP suggests its epigenetic silencing as cells acquire androgen independence. Tumors with Id4 promoter hypermethylation showed distinct loss of Id4 expression.
Conclusions: Id4 appears as a potential tumor suppressor gene that is epigenetically silenced during cancer development.Id4 promoter hypermethylation had been reported in breast, colorectal cancer and chronic lymphocytic leukemia Thus, loss of Id4 expression due to promoter hypermethylation. Id4 methylation status could serve as a prognostic biomarker in human prostate cancer.
Acknowledgement: The research was supported by NIH/NCI-RO1CA128914 and in part by NIH/NCRR/RCMI G12RR03062.
Citation Format: Pankaj Sharma, Swathi Chinaranagari, Divya Patel, Jaideep Chaudhary. Epigenetic silencing of ID4 (inhibitor of DNA binding 4) is associated with prostate cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A24.
Abstract A27: Comprehensive analysis of the TMPRSS2-ERG translocation during prostate cancer progression
Authors: Tan Shyh-Han , Sesterhenn I. , Srivastava S. , Bubendorf L. , Ruiz C. , Braun M. , Scheble V.J. , Zellweger T. , Rentsch C.A. , Bachmann A. , Dobi Albert , Perner S. 
Published: May 2013

Abstract
Introduction: Approximately half of the diagnosed prostate carcinomas (PC) are characterized by a chromosomal rearrangement fusing the androgen regulated gene TMPRSS2 to the oncogenic ETS transcription factor ERG. Aim of this study was to comprehensively analyze the impact of this translocation on the expression of the ERG gene in hormone-naïve (untreated) and castration-resistant prostate cancers and to define the influence of AR protein expression and genomic amplification in this context.
Methods: We constructed a tissue microarray (TMA) containing 915 tissue cores from 107 hormone-naïve PC and from 101 castration-resistant (CR) PC. In addition, we included 56 specimens from distant metastases. We analyzed the TMPRSS2-ERG translocation status by fluorescence in-situ hybridization and the expression profiles of ERG, AR and the proliferation marker Ki67 by immunohistochemistry.
Results: Nearly half of the analyzed PC tissue specimens (untreated: 38%, castration-resistant: 46%) harbored a TMPRSS2-ERG gene fusion. Untreated PC with positive translocation status showed increased tumor cell proliferation (p &lt; 0.05). As expected, TMPRSS2-ERG gene fusion was strongly associated with increased ERG protein expression in untreated, as well as in castration-resistant PC (both p &lt; 0.0001). However, we detected a subgroup (26%) of CR PCs with the gene fusion, but without detectable ERG protein expression. This subgroup showed significantly lower levels of AR protein expression and of the androgen regulated serum PSA (both p&gt;0.05).
Conclusions: This comprehensive study comparing the TMPRSS2-ERG gene and ERG protein expression status in a large cohort of hormone-naïve and CR PC, identifies a subgroup of translocated CR PCs without ERG protein expression. Our results suggest that this subgroup may represent CR PCs with a dispensed AR pathway. Further analyses may help to explain if these tumors represent a distinct subgroup of AR independent CR PCs.
Citation Format: Shyh-Han Tan, I. Sesterhenn, S. Srivastava, L. Bubendorf, C. Ruiz, M. Braun, V.J. Scheble, T. Zellweger, C.A. Rentsch, A. Bachmann, Albert Dobi, S. Perner. Comprehensive analysis of the TMPRSS2-ERG translocation during prostate cancer progression [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A27.
Abstract A29: Distinguishing features of ERG oncoprotein expression among matched cohorts of African-American and Caucasian-American prostate cancer patients
Authors: Petrovics Gyorgy , Rosen Philip , Pfister David , Young Denise , Chen Yongmei , Dobi Albert , McLeod David , Srivastava Shiv , Sesterhenn Isabell 
Published: May 2013

Abstract
Introduction and Objective: The ETS-related gene (ERG) proto-oncogene is frequently overexpressed in prostate cancer (CaP) as a result of a genomic rearrangement that places ERG under the control of the androgendependent TMPRSS2 promoter. The initial report of quantitative ERG mRNA expression in micro-dissected prostate tumor cells showed significantly higher ERG expression in CaP of Caucasian-Americans (CA) patients vs. African-American (AA) patients (Petrovics et al, Oncogene, 2005). Recent studies (Magi-Galluzzi et al, Prostate, 2011; Elliott et al, USCAP Mtg., 2011) have also shown higher frequency of ERG rearrangement or ERG oncoprotein expression in CaP of CA patients. We evaluate the frequency and pattern of the ERG oncoprotein expression in prostate tumors of matched CA and AA CaP patients to better understand the biological basis for differences in prostate cancer between the two populations.
Methods: Ninety one AA and 91 CA CaP patients were matched for age, Gleason score and pathologic stage. All underwent radical prostatectomy between 1993 and 2010. Whole mount prostate specimens were used for the immunohistochemical detection of the ERG oncoprotein by a highly specific ERG monoclonal antibody (clone 9FY). Individual foci of tumors were reported as either positive or negative. ERG staining data was linked to clinico-pathologic data. Biochemical recurrence was defined as two serum PSA measurements of 0.2 ng/mL or higher at least 8 weeks from surgery.
Results: A higher percentage of CA (61.8%) than AA (28.2%) CaP patients had ERG positive index tumors and had at least one focus of tumor positive for ERG. A higher percentage of overall tumor foci were also positive for ERG in CA than AA CaP patients. There was high concordance of ERG positive prostatic intra-epitheilal neoplasia (PIN) and ERG positive CaP in both AA and CA patients.
Conclusions: ERG expression is more prevalent among CA than AA CaP patients in matched cohorts. Differences in the pattern of ERG expression in CaP and differing trends in biochemical recurrence between CA and AA patients with ERG (+) index tumors suggest a dominant clonal selection of ERG-positive tumors in CA patients. These differences in ERG expression have the potential to delineate biological distinctions of CaP in the two patient populations.
Citation Format: Gyorgy Petrovics, Philip Rosen, David Pfister, Denise Young, Yongmei Chen, Albert Dobi, David McLeod, Shiv Srivastava, Isabell Sesterhenn. Distinguishing features of ERG oncoprotein expression among matched cohorts of African-American and Caucasian-American prostate cancer patients [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A29.
Abstract A30: ERG protein expression and genomic rearrangement status in primary and metastatic prostate cancer a comparative study of two monoclonal antibodies.
Authors: Sreenath Taduru , Fend Falko , Wernert Nicolas , Kristiansen Glen , Perner Sven , Tan Shyh-Han , Braun Martin , Goltz Diane , Shaikibrahim Zaki , Vogel Wenzel , Boehm Diana , Scheble Veit , Dobi Albert 
Published: May 2013

Abstract
Introduction and Objective: Overexpression of the ERG protein is highly prevalent in prostate cancer (PCa) and most commonly results from gene fusions involving the ERG gene. Recently, an N-terminal epitope targeted mouse and a C-terminal epitope targeted rabbit monoclonal anti-ERG antibody have been introduced for the detection of the ERG protein. Independent studies reported that immunohistochemical (IHC) stains with both monoclonal anti-ERG antibodies (ERG-MAbs) highly correlate with the underlying ERG gene rearrangement status. However, a comparative study of both antibodies has not been provided so far. Here, we are the first to compare the mouse ERG-MAb to the rabbit ERG-MAb for their concordance on the same PCa cohort. Furthermore, we assessed if the ERG protein expression is conserved in lymph node and distant PCa metastases, of which a subset underwent decalcification.
Methods: We evaluated tissue microarrays of 278 specimens containing 265 localized PCa, 29 lymph node, 30 distant metastases, and 13 normal prostatic tissues. We correlated the ERG protein expression with the ERG rearrangement status using an ERG break-apart fluorescence in-situ hybridization (FISH) assay and IHC of both ERG antibodies.
Results: ERG protein expression and ERG rearrangement status were highly concordant regardless of whether the mouse or rabbit ERG-MAb was used (97.8% versus 98.6%, respectively). Of interest, both ERG antibodies reliably detected the ERG expression in lymph node and distant PCa metastases, of which a subset underwent decalcification. If an ERG protein expression was present in localized PCa, we observed the same pattern in the corresponding lymph node metastases.
Conclusions: This is the first study to comprehensively compare the two available ERG-MAbs. By demonstrating a broad applicability of IHC to study ERG protein expression using either antibody, this study adds an important step towards a facilitated routine clinical application. Further, we demonstrate that the clonal nature of the ERG rearrangement is not restricted to the genomic level, but proceeds in the proteome. Together, our results simplify future efforts to further elucidate the biological role of ERG in PCa.
Citation Format: Taduru Sreenath, Falko Fend, Nicolas Wernert, Glen Kristiansen, Sven Perner, Shyh-Han Tan, Sr., Martin Braun, Diane Goltz, Zaki Shaikibrahim, Wenzel Vogel, Diana Boehm, Veit Scheble, Albert Dobi. ERG protein expression and genomic rearrangement status in primary and metastatic prostate cancer a comparative study of two monoclonal antibodies [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A30.
Abstract A31: ERG-mediated alterations in chromatin conformation
Authors: Rickman David S. , Melnick Ari , Elemento Olivier , Rubin Mark , Soong T. David , Moss Benjamin , Mosquera Juan Miguel , Dlabal Jan , Terry Stephane , MacDonald Theresa , Bunting Karen , Demichelis Francesca 
Published: May 2013

Abstract
Emerging evidence suggests that chromatin adopts a non-random three dimensional (3D) topology and that the organization of genes into structural hubs and domains affects their transcriptional status. How chromatin conformation changes in diseases such as cancer is poorly understood. Moreover, how oncogenic transcription factors, which bind to thousands of sites across the genome, influence gene regulation by globally altering the topology of chromatin requires further elucidation. To address these questions, we performed unbiased high-resolution mapping of intra- and inter-chromosome interactions upon over-expression of ERG, an oncogenic transcription factor frequently over-expressed in prostate cancer as a result of a gene fusion. By integrating data from genome-wide chromosome conformation capture (Hi-C), ERG binding (ChIP-seq), gene expression (RNA-seq) and spectral karytopying, we demonstrate for the first time that the oncogenic transcription factor ERG can induce global, reproducible and functionally coherent changes in chromatin organization that are associated with gene expression differences and genomic alterations. The results presented here have broader implications, as many driving genetic lesions in other cancer types involve altered levels of transcription factors due to genomic alterations (e.g. EWS-FLI1, c-Myc, n-Myc, PML-RARα).
Citation Format: David S. Rickman, Ari Melnick, Olivier Elemento, Mark Rubin, T. David Soong, Benjamin Moss, Juan Miguel Mosquera, Jan Dlabal, Stephane Terry, Theresa MacDonald, Karen Bunting, Francesca Demichelis. ERG-mediated alterations in chromatin conformation [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A31.
Abstract A33: Characterization of signaling pathways associated with docetaxel resistance in prostate cancer
Authors: Lee Brian Yong , Hochgrafe Falko , Raftery Mark , Horvath Lisa G. , Daly Roger J. 
Published: May 2013

Abstract
Docetaxel (DTX) is the only treatment option for patients diagnosed with metastatic castration-refractory prostate cancer (CRPC). However, approximately 50% of patients do not respond to DTX, but are exposed to significant toxicity without direct benefit. This study aims to use mass spectrometry (MS) based techniques to characterize the perturbed intracellular signaling, particularly tyrosine phosphorylation, which contributes to the chemoresistant phenotype in CRPC patients, and thereby identify novel therapeutic targets.
Two DTX-resistant prostate cancer cell lines (DU145-Rx & PC3-Rx) were established from their parental DTX-sensitive cell lines, DU145 & PC3, respectively, by a dose-escalation protocol. Phosphotyrosine profiling was performed by immunoaffinity coupled LC-MS/MS in combination with stable isotope labeling with amino acid in cell culture (SILAC). The chemosensitive and resistant cells were cultured in “light” and “heavy” SILAC media, respectively, and their isotopic labels were switched in a replicate experiment. Phosphotyrosine peptides were analysed on the state-of-the-art High Performance Liquid Chromatography MS/MS (Orbitrap Velos ETD). Raw MS spectra were quantified using MaxQuant software.
DU145-Rx & PC3-Rx displayed 44 and 35-fold higher IC50 values, respectively, and significantly greater colony forming ability, in the presence of DTX, compared to the parental lines. Phosphotyrosine profiling of these cell lines identified a total of 365 phosphosites in the chemoresistant lines, corresponding to 227 proteins. 3 kinases and 3 cytoskeletal proteins showed a significant increase in tyrosine phosphorylation in both DTX-resistant models.
These candidate proteins will be further characterized by gain- and loss-of-function approaches, both in vitro and in xenograft models, to elucidate the intracellular mechanism of chemoresistance, and to design therapeutic strategies to reverse the chemoresistant phenotype in CRPC.
Citation Format: Brian Yong Lee, Falko Hochgrafe, Mark Raftery, Lisa G. Horvath, Roger J. Daly. Characterization of signaling pathways associated with docetaxel resistance in prostate cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A33.
Abstract A4: Androgen receptor (AR) degradation is controlled by the co-operation of PMEPA1 and the E3 ubiquitin ligase NEDD4-1
Authors: Li Hua , Dobi Albert , Srivastava Shiv 
Published: May 2013

Abstract
Introduction and Objective: Androgen receptor (AR) plays critical roles in prostate growth and differentiation and prostate tumorigenesis. Our recent investigations have discovered a novel mechanism of AR degradation in CaP cells involving PMEPA1 and NEDD4-1 which is independent of MDM2. Previously we have shown that PMEPA1 is a highly androgen-inducible gene in CaP cells that recruits the NEDD4-1, an E3 ubiquitin ligase, to degrade AR. In an independent study NEDD4-1 has been identified as an E3 ligase controlling the levels of PTEN. We hypothesize that decreased or loss of PMPEA1 expression that is frequently observed in human prostate tumor cells may lead to enhanced AR functions. Elevated AR levels may increase NEDD4-1 and in turn destabilize PTEN in prostate cancer cells. Here, we further investigate the co-operation between PMEPA1 and NEDD4-1 to alter AR and PTEN protein levels.
Methods: PMEPA1 and NEDD4-1 were ectopically expressed in androgen responsive LNCaP and VCaP cells by pCMV-XL4 and pcDNA3.1 vectors, respectively. AR, PMEPA1, NEDD4-1, MDM2 and PTEN were silenced by using specific siRNAs. Cell growth was monitored in response modulation of PMEPA1, NEDD4 and AR. Protein levels of AR, PMEPA1, NEDD4-1, PTEN and PSA were assessed by immunoblot assays.
Results: Decreases in AR protein levels, inhibited AR signaling and cell growth in response to heterologous expression of NEDD4-1. Consistent with this observation, inhibition of NEDD4-1 by siRNA resulted in elevated AR protein levels, AR signaling and increased cell growth. Reduced cell growth by AR knock-down or by heterologous expression of NEDD4-, were rescued by the knockdown of PMEPA1. It was also shown that AR up-regulates the expression of NEDD4-1 in hormone responsive CaP cells. In VCaP cells, overexpression of NEDD4-1 resulted in decreased PTEN protein levels. Remarkably, PMEPA1 knockdown resulted in elevated AR and NEDD4-1 levels and the downregulation of PTEN protein.
Conclusions: NEDD4-1 mediated AR degradation in hormone responsive CaP cells requires PMEPA1. The frequently observed decreased expression of PMEPA1 results in elevated AR protein levels and may facilitate NEDD4-1 mediated degradation of PTEN in CaP. Our findings revealed a complex interplay of the AR, PMEPA1, NEDD4 and PTEN underscoring the impact of the loss of PMEPA1 to increased AR and decreased PTEN, both proteins critical in prostate tumorigenesis.
Citation Format: Hua Li, Albert Dobi, Shiv Srivastava. Androgen receptor (AR)degradation is controlled by the cooperation of PMEPA1 and the E3 ubiquitin ligase NEDD4-1 [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A4.