ERG-positive Tumors Research Articles

Associations of prostate tumor immune landscape with vigorous physical activity and prostate cancer progression.

Vigorous physical activity has been associated with lower risk of fatal prostate cancer. However, mechanisms contributing to this relationship are not understood. We studied 117 men with prostate cancer in the University of North Carolina Cancer Survivorship Cohort (UNC CSC) who underwent radical prostatectomy, and 101 radiation-treated prostate cancer patients in FASTMAN. Structured questionnaires administered in UNC CSC assessed physical activity. In both studies, digital image analysis of H&E-stained tissues was applied to quantify Tumor Infiltrating Lymphocytes (TILs) in segmented regions. Nanostring gene expression profiling in UNC CSC and microarray in FASTMAN were performed on tumor tissue and a 50-gene signature utilized to predict immune cell types. Vigorous recreational activity, reported by 34 (29.1%) UNC men, was inversely associated with TILs abundance. Tumors of men reporting any vigorous activity versus none showed lower gene expression-predicted abundance of Th, exhausted CD4 T cells and macrophages. T cell subsets, including Treg, Th, Tfh, exhausted CD4 T cells, and macrophages were associated with increased risk of biochemical recurrence, only among men with ERG-positive tumors. Vigorous activity was associated with lower prostate tumor inflammation and immune microenvironment differences. Macrophages and T cell subsets, including those with immunosuppressive roles and those with lower abundance in men reporting vigorous exercise, were associated with worse outcomes in ERG-positive prostate cancer. Our novel findings contribute to our understanding of the role of the tumor immune microenvironment in prostate cancer progression, and may provide insight into how vigorous exercise could affect prostate tumor biology.

Abstract 3440: Etiology of prostate cancer with the TMPRSS2:ERG fusion: A systematic review of risk factors

Abstract Background: The TMPRSS2:ERG gene fusion is the most common somatic alteration in primary prostate cancer and an early event in carcinogenesis. There are emerging data highlighting etiologic differences in prostate cancer by TMPRSS2:ERG status. This systematic review synthesized evidence from epidemiologic studies on prostate cancer risk factors for tumors with and without the TMPRSS2:ERG fusion. Methods: A systematic literature search was performed in Ovid MEDLINE, EMBASE, and Web of Science without language restriction for studies published by September 27, 2022. Studies that assessed associations between epidemiologic and genetic factors and prostate cancer risk by tumor TMPRSS2:ERG (ERG) fusion status in human populations were included. Results: Of 3,071 records identified, 20 publications comprising prospective cohort and case-control studies from five study populations (published 2009-2022) were included. Risk factors included germline genetic variants, circulating hormones, diet, lifestyle factors, and medications. The included studies suggested that taller height and higher total and free circulating testosterone levels tended to be associated with higher risk of ERG-positive, but not ERG-negative prostate cancer. CAG repeat length in the androgen receptor (AR) gene, related inversely to transcriptional activity, appeared to be associated with a lower risk of ERG-positive, but not ERG-negative prostate cancer. There was statistical evidence for etiologic differences for several germline single nucleotide polymorphisms (SNPs) by ERG status. Excess body weight, greater vigorous physical activity, greater lycopene intake, and calcium channel blocker use appeared to specifically be associated with a lower risk of ERG-positive tumors. Associations of other potential etiologic factors, including diabetes mellitus, baldness, aspirin use, circulating antioxidant levels, and sex hormones other than testosterone, with ERG-positive prostate cancer were null or inconclusive. Most associations had low precision, and the results were based on few distinct study populations, highlighting a need for replication. Conclusions: Prostate cancer with the TMPRSS2:ERG fusion may be an etiologically distinct subtype impacted by certain modifiable and hormonally-acting risk factors that align with the established mechanistic role of this gene fusion in androgen, insulin, and growth factor pathways. The findings suggest a potentially distinct genetic predisposition to prostate cancer with or without the TMPRSS2:ERG fusion. More broadly, these findings suggest that considering molecular subtypes of prostate cancer, beyond TMPRSS2:ERG, may strengthen etiologic understanding of prostate cancer and evidence for prevention. Citation Format: Colleen B. McGrath, Alaina H. Shreves, Megan R. Shanahan, Hannah E. Guard, Manelisi V. Nhliziyo, Kathryn L. Penney, Tamara L. Lotan, Michelangelo Fiorentino, Konrad H. Stopsack, Lorelei A. Mucci. Etiology of prostate cancer with the TMPRSS2:ERG fusion: A systematic review of risk factors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3440.

Abstract 4868: Targeting of ERG positive prostate cancers with ERGi-USU-6 salt derivative

Abstract Introduction: Prostate cancer (PCa) is the second leading cause of cancer deaths among men in the United States. Approximately 50% of patients with PCa harbor an oncogenic TMPRRS2- ERG gene fusion in their primary tumor and 35% of patients with metastatic castration resistant prostate cancers have the gene fusion. We have identified a potent small molecule inhibitor, ERGi-USU-6 salt derivative 7b, that selectively inhibits the growth of ERG positive tumor. This small molecule inhibitor is also effective in inhibiting the growth of benign and cancerous mouse prostate organoids expressing TMPRSS2-ERG (ERG positive organoids). To gain insights into the cancer-selective properties of ERGi-USU-6 salt 7b we evaluated pathways associated in ERGi-USU induced inhibition. Methods: The biological activities of salt derivative 7b, were assessed in hormone- refractory metastatic tumor derived ERG positive prostate cancer cell line, VCaP along with organoids. We monitored the pathways associated in the mechanism of drug action through, cell cycle-regulator proteins by immunoblot assays, cell cycle and ferroptosis related analyses in response to 7b treatment. We also monitored the levels of the RIOK2 kinase, previously shown to bind the parental ERGi-USU compound. The normal primary endothelium derived HUVEC cells were used as normal control due to the normal endogenous expression of ERG in endothelial cells including HUVEC. Results: Cell growth and immunoblot analysis indicated the inhibition of ERG positive prostate organoid upon ERGi-USU treatments resulting in the downregulation of ERG and RIOK2 protein levels. The cell cycle analyses, pathway mapping by protein assessment and ferroptotic assays suggests that salt derivative 7b treatment inhibits the ERG positive prostate cancer through ferroptosis along with RIOK2 inhibition. Conclusions: Our results showed that the ferroptosis inducer ATF3 gene is involved in the cancer-selective activity of ERGi-USU-6 salt derivative 7b. Further, based on our observations we hypothesize that ferroptosis, the iron-dependent form of programmed cell-death, may be the mechanism of cancer selective activity of salt derivative 7b. Disclaimer: The contents of this publication are the sole responsibility of the author(s) and do not necessarily reflect the views, opinions or policies of Uniformed Services University of the Health Sciences (USUHS), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., the Department of Defense (DoD), the Departments of the Army, Navy, or Air Force. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Government. Citation Format: Binil Eldhose, Katherine Beck, Cyrus Eghtedari, Gartrell C. Bowling, Mallesh Pandrala, Sanjay V. Malhotra, Xiaofeng A. Su, Albert Dobi. Targeting of ERG positive prostate cancers with ERGi-USU-6 salt derivative. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4868.

ERG Status at the Margin Is Associated With Biochemical Recurrence After Radical Prostatectomy With Positive Surgical Margins

Positive surgical margins at radical prostatectomy are associated with an increased risk of biochemical recurrence (BCR). However, there is considerable variability in outcomes, suggesting that molecular biomarkers—when assessed specifically at the margin tumor tissue—may be useful to stratify prognosis in this group. We used a case-cohort design for the outcome of BCR, selecting 215 patients from a cohort of 813 patients undergoing prostatectomy treated at the Johns Hopkins from 2008 to 2017 with positive margins and available clinical data. Tissue microarrays were created from the tumor adjacent to the positive margin and stained for PTEN, ERG, and Ki-67. Cases were scored dichotomously (PTEN and ERG) or by the Ki-67 staining index using previously validated protocols. The analysis used Cox proportional hazards models weighted for the case-cohort design. Overall, 20% (37/185) of evaluable cases had PTEN loss and 38% (71/185) had ERG expression, and the median Ki-67 expression was 0.42%. In multivariable analysis adjusting for the CAPRA-S score, adjuvant radiation, and grade group at the positive margin, ERG-positive tumors were associated with a higher risk of BCR compared to those that were ERGnegative (hazard ratio [HR], 2.4; 95% CI, 1.2-4.9; P = .012) regardless of PTEN status at the margin, and adding ERG to clinicopathologic variables increased the concordance index from 0.827 to 0.847. PTEN loss was associated with an increased risk of BCR on univariable analysis (HR, 3.19; 95% CI, 1.72-5.92; P = .0002), but this association did not remain after adjusting for clinicopathologic variables (HR, 1.06; 95% CI, 0.49-2.29; P = .890). Thus, in the setting of prostate tumors with positive surgical margins after prostatectomy, ERG-positive tumors with or without PTEN loss at the positive margin are associated with a significantly higher risk of BCR after adjusting for clinicopathologic variables. If validated, ERG status may be helpful in decision-making surrounding adjuvant therapy after prostatectomy.

Abstract 1961: Discovery and validation of prostate cancer biomarkers of biochemical recurrence in low-risk prostate cancer patients

Abstract Introduction: Prostate cancer (CaP) is predominantly indolent disease with a small fraction of patients undergoing metastatic progression. Therefore, it is critical to identify prognostic markers for the early detection of an aggressive subtype. We hypothesized that tissue specimens from early-stage, low risk CaP may harbor predictive prognostic signatures for disease progression after radical prostatectomy. Previously, we had systematically evaluated and optimized the NanoString platform for CaP gene expression analysis in formalin fixed paraffin embedded (FFPE) whole mounted prostate specimens. The goal of the study is to validate the CPDR findings on the differential mRNA expression of candidate markers from patients with BCR (biochemical recurrence) and non-BCR in an independent cohort. Methods: This is a retrospective case cohort study based on 78 tumor-normal paired (N=156) archived whole mounted FFPE prostate samples received from biobank at UTHSCSA. We performed an optimized NanoString analysis of 203-CaP probe set to evaluate the association of markers with BCR outcome in a racially diverse patient population comprising of 21.6% AA and 78.38% CA men. The cohort comprised of 28 patients with BCR, and 50 patients with no BCR (based on a minimum of 5 years of follow-up). ERG gene expression was validated by immunohistochemistry (IHC) assay using CPDR ERG-MAb (9FY). Normalized nCounter gene expression data was analyzed using the NanoString nSolver (v 4.0) platform. Fisher exact and Wilcoxon-Mann-Whitney tests were used for categorical and continuous variables respectively. Results: We found 96.1% (73/76) concordance between ERG IHC and NanoString datasets, which provides strong QC and validation for NanoString data. ERG positive tumors had strong expression of both TMPRSS2-ERG fusion and several other ERG splice forms. Additionally, the prostate epithelial cell markers PSA, MSMB and PAP had the highest signals in all samples reflecting the prostate epithelial origin of the specimens. Differential gene expression analysis showed that a total of 37 genes were found to be significantly (P adj <0.05) different across tumors and normal. Established CaP genes like AMACR, PCA3, OR51E2, ERG, HOXC6, DLX1, CACNA1D and PSGR were most highly over-expressed in tumors compared to matched normal while GSTP1, CAV1, PAP and MSMB were significantly downregulated in tumors compared to adjacent normal prostate epithelia. Race stratified analysis in this randomly selected patient cohort showed that AA men were found to be significantly younger (median age: 56 years AA vs. 63 years CA; p 0.01) and had higher frequency of BCR events (p 0.004) than CA men. Data analysis for disease outcome across AA and CA men is ongoing. Conclusions: We confirmed that NanoString approach is useful for evaluation of prognostic biomarker candidates in prostate cancer using FFPE specimens. Citation Format: Indu Kohaar, Kaitlyn Bejar, Denise Young, Yingjie Song, Jiji Jiang, Jacob Kagan, Sudhir Srivastava, Javier Hernandez, Gregory Chesnut, Isabell A. Sesterhenn, Robin J. Leach, Gyorgy Petrovics. Discovery and validation of prostate cancer biomarkers of biochemical recurrence in low-risk prostate cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1961.

Intraductal prostate cancer: An aggressive subset of prostate cancers? Immunophenotypic evaluation.

Introduction:The presence of intraductal prostate cancer in a sample is often associated with large tumor volume, an advanced stage of the disease, a high Gleason score and an increased risk of recurrence, and resistance to androgen suppression and chemotherapy, which are also correlated with reduced progression-free survival and with postoperative, biochemical relapse.Methods:The aim of our study was to investigate whether carbonic anhydrase IX (CA IX) is upregulated in prostate cancer and to investigate ERG and EZH2 as potential markers for cancer aggression in aggressive acinar disease with intraductal component prostate cancer. The series consisted of 79 cases of prostate cancer. Immunohistochemical staining was performed for EZH2 ERG and CA IX.Results:The results of this study underline the fact that EZH2 protein expression is a powerful predictor of PSA relapse in prostate cancer and that this effect is stronger in ERG-positive cancers than in ERG-negative cancers. Evident EZH2 nuclear expression was found in prostatic tumor, proposing increased EZH2 expression important for the spread of prostate cancer.Conclusions:The relationship to tumor phenotype and prognosis was more considerable in ERG-positive tumors than in ERG-negative tumors. EZH2 has gained great interest as a target for epigenetic cancer therapy. Although prostate cancer is a hypoxic tumor, it does not express CA IX and cannot be used as an endogenous marker for hypoxia.

Abstract 2565: Detection of ETV1 expression in human prostate tissue specimens using a novel and highly specific rabbit monoclonal antibody

Abstract Introduction: ETV1 is frequently involved in genomic fusions and translocation events that lead to its overexpression in multiple cancers. These events occur in approximately 5% of prostate cancers, which are mutually exclusive from tumors harboring TMPRSS2-ERG fusion or PTEN deletion. Studies suggest a correlation between strong ETV1 protein expression and poor outcome in prostate cancer. ETV1 has been reported to synergistically cooperate with KIT as a lineage survival factor in gastrointestinal stromal tumors. The expression of ETV1 in a subset of sarcomas that harbor CICrearrangements or CIC-DUX4 gene fusions presents a reliable molecular signature for the diagnosis of this cancer. Our understanding of the role that ETV1 plays in the activation of prostate cancer has been limited by the lack of ETV1 specific antibodies. Methods: A novel ETV1 monoclonal antibody (MAb) was raised by immunization of ETV1 peptides in rabbit followed by screening of hybridomas by ELISA and immunoblot assays. Further screening using exogenously expressed ETV1, ETV4, ETV5, ERG, SPDEF, and FLI1 proteins identified the clone with the most reactive MAb. Purified MAb was used to evaluate ETV1 expression on a tissue micro-array (TMA) constructed from radical prostatectomies of 50 African American (AA) and 50 Caucasian American (CA) patients by immunohistochemistry (IHC). Key residues required for Mab binding were mapped by ELISA using overlapping peptides and alanine scanning. Results: IHC evaluation using the ETV1 specific rabbit Mab on a prostate cancer TMA derived from 100 patients identified five ETV1 positive cases, of whom four were CA. The index tumors for these five ETV1 cases were ERG negative. One patient harbored both ERG positive and ERG negative tumor foci, and as expected, the ETV1 positive tumor focus was ERG negative, and vice versa. Conclusions: We developed a novel rabbit monoclonal ETV1 antibody that is suitable for IHC assay in human prostate tissue. An evaluation of prostate cancer specimens confirmed the reported frequency of ETV1 alteration. Further evaluation using tissue specimens from larger cohorts to establish the sensitivity and specificity of this antibody and validate the utility of ETV1 detection in improving the diagnosis and stratification of prostate and other cancers are in progress. Citation Format: Shyh-Han Tan, Denise Young, Sally Elsamanoudi, Jacob Kagan, Sudhir Srivastava, Albert Dobi, Gyorgy Petrovics, Isabell A. Sesterhenn, Gregory T. Chesnut. Detection of ETV1 expression in human prostate tissue specimens using a novel and highly specific rabbit monoclonal antibody [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2565.

Comprehensive metabolomics analysis of prostate cancer tissue in relation to tumor aggressiveness and TMPRSS2-ERG fusion status

BackgroundProstate cancer (PC) can display very heterogeneous phenotypes ranging from indolent asymptomatic to aggressive lethal forms. Understanding how these PC subtypes vary in their striving for energy and anabolic molecules is of fundamental importance for developing more effective therapies and diagnostics. Here, we carried out an extensive analysis of prostate tissue samples to reveal metabolic alterations during PC development and disease progression and furthermore between TMPRSS2-ERG rearrangement-positive and -negative PC subclasses.MethodsComprehensive metabolomics analysis of prostate tissue samples was performed by non-destructive high-resolution magic angle spinning nuclear magnetic resonance (1H HR MAS NMR). Subsequently, samples underwent moderate extraction, leaving tissue morphology intact for histopathological characterization. Metabolites in tissue extracts were identified by 1H/31P NMR and liquid chromatography-mass spectrometry (LC-MS). These metabolomics profiles were analyzed by chemometric tools and the outcome was further validated using proteomic data from a separate sample cohort.ResultsThe obtained metabolite patterns significantly differed between PC and benign tissue and between samples with high and low Gleason score (GS). Five key metabolites (phosphocholine, glutamate, hypoxanthine, arginine and α-glucose) were identified, who were sufficient to differentiate between cancer and benign tissue and between high to low GS. In ERG-positive PC, the analysis revealed several acylcarnitines among the increased metabolites together with decreased levels of proteins involved in β-oxidation; indicating decreased acyl-CoAs oxidation in ERG-positive tumors. The ERG-positive group also showed increased levels of metabolites and proteins involved in purine catabolism; a potential sign of increased DNA damage and oxidative stress.ConclusionsOur comprehensive metabolomic analysis strongly indicates that ERG-positive PC and ERG-negative PC should be considered as different subtypes of PC; a fact requiring different, sub-type specific treatment strategies for affected patients.

Neuropilin-2 is an independent prognostic factor for shorter cancer-specific survival in patients with acinar adenocarcinoma of the prostate.

Neuropilin-2 (NRP2) is a member of the neuropilin receptor family and known to regulate autophagy and mTORC2 signaling in prostate cancer (PCa). Our study investigated the association of immunohistochemical NRP2 expression with clinicopathological data in PCa patients. For this purpose, we generated a tissue microarray with prostate tissue specimens from 400 PCa patients treated by radical prostatectomy. We focused on patients with high-risk factors such as extraprostatic extension (pT ≥ 3), Gleason score ≥8 and/or the presence of regional lymph node metastases (pN1). Protein levels of NRP2, the vascular endothelial growth factor C (VEGFC) and oncogenic v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) gene as an indicator for TMPRSS2-ERG fusion was assessed in relation to the patients' outcome. NRP2 emerged as an independent prognostic factor for cancer-specific survival (CSS) (hazard ratio 2.360, 95% confidence interval = 1.2-4.8; p = 0.016). Moreover, the association between NRP2 expression and shorter CSS was also especially pronounced in patients at high risk for progression (log-rank test: p = 0.010). We evaluated the association between NRP2 and the TMPRSS2-ERG gene fusion status assessed by immunohistochemical nuclear ERG staining. However, ERG staining alone did not show any prognostic significance. NRP2 immunostaining is significantly associated with shorter CSS in ERG-negative tumors (log-rank test: p = 0.012). No prognostic impact of NRP2 expression on CSS was observed in ERG-positive tumors (log-rank test: p = 0.153). Our study identifies NRP2 as an important prognostic marker for a worse clinical outcome especially in patients with a high-risk PCa and in patients with ERG-negative PCa.

PTEN Loss with ERG Negative Status is Associated with Lethal Disease after Radical Prostatectomy.

Few groups have investigated the combined effects of PTEN loss and ERG expression on the outcomes of metastasis of or death from prostate cancer in surgically treated patients. We examined the association of PTEN/ERG status with lethal prostate cancer in patients treated with radical prostatectomy. Included in analysis were 791 patients with clinically localized prostate cancer treated with radical prostatectomy at a single institution. Genetically validated immunohistochemistry assays for PTEN and ERG were performed on tissue microarrays. Multivariable Cox proportional hazard models were used to assess the association of PTEN/ERG status with lethal prostate cancer (defined as metastasis or prostate cancer specific death), adjusting for patient age, race, pathological grade and stage, and surgical margin status. Median followup in the cohort was 12.8 years. Of 791 cases 203 (25%) demonstrated PTEN loss and 330 of 776 (43%) were ERG positive. On multivariable analysis PTEN loss (HR 1.9, 95% CI 1.2-3.0, p=0.012) but not ERG expression (HR 0.6, 95% CI 0.4-1.1, p=0.11) was associated with an increased risk of lethal prostate cancer. The association of PTEN loss with lethal disease only remained among men with ERG negative tumors (HR 2.3, 95% CI 1.3-4.1, p=0.005) and not ERG positive tumors (HR 1.1, 95% CI 0.6-2.1, p=0.81). PTEN loss is associated with an increased risk of lethal prostate cancer after radical prostatectomy and this risk is most pronounced in the subgroup of patients with ERG negative tumors. This work corroborates the use of PTEN and ERG status for risk stratification in surgically treated patients.

Novel Genomic Biomarker Panel Predictive of Aggressive Disease in African American Men with Prostate Cancer

Mutations in the E26 transforming specific (ETS) transcription factors occur early in the oncogenic process of prostate cancer. These mutations behave in a race dependent manner with the majority of European American (EA) men possessing ERG positive (ERG+) tumors while ≥75% of African American (AA) men have ERG negative (ERG-) tumors. In order to establish clinically relevant biomarkers in AA men, we studied ETS gene expression differences among AA men and EA men and identified race specific ETS negative (ETS-) genes that predict for clinically relevant outcomes. Previously published datasets from the Decipher Genomic Resource Information Database (GRID) were used to obtain microarray data. The validated microarray-based ETS positive (ETS+) (ERG or ETV1/4/5) over expression was used to determine ETS+ status in the GRID database. Samples with overexpression of ERG, ETV1-5, and FLI1 were categorized as ETS+. Chi square (X2)/Fisher Exact method was used to assess the race differences in clinico-pathologic endpoints such as extraprostatic extension, seminal vesicle invasion, pathologic Gleason Score, and the post-surgical Cancer of the Prostate Risk Assessment Score (CAPRA-S) . Logistic regression model was used to analyze the association between aforementioned clinico-pathologic endpoints and ETS status. Genes that showed differential expression were evaluated. On multivariable logistic regression analysis, race was found to be the strongest predictor of ETS- status. Analysis showed that AA men were four times more likely to be ETS- than EA men (p<0.001). Using a q value ≤0.05 and an expression fold change level of 0.05, we identified 3047 genes (6.6%) that were differentially expressed based on ETS status. Of these, 248 were found to be differentially expressed in a race-specific manner. Using a false-discovery rate q<0.1 we identified 143 genes that predicted for one or more clinical endpoint. In order to determine which of these race specific ETS- genes are significantly overexpressed in tumors we selected genes that met all three of the following criteria; significantly overexpressed in ETS- compared to ETS+ tumors, preferentially overexpressed in AA and not in EA, and predictive for one or more adverse outcome in a race-specific manner. Using this criteria, we have identified a 19-gene panel that includes ADAMTS1, AFF3, ANKRD20, ANPEP, CCL3, CYP4F35, FAR2P1, INPP4B, MAP1LC3, MIPEP, NPIPB7, NPNT, OPHN1, OR4K7P, PCGEM1, RLN2, SCIN, SPINK1, and TTN. In an effort to elucidate biologic features associated with aggressiveness of prostate cancer in AA men, we have identified ETS- biomarkers that predict for one or more adverse clinical outcome in AA men. Our investigation found 19 ETS- genes that are both overexpressed in AA men and predictive of clinical outcomes thus representing ideal candidates for prognostic biomarkers.

High concordance of TMPRSS-ERG fusion between primary prostate cancer and its lymph node metastases.

Approximately 50% of prostate cancer types harbor the transmembrane protease, serine 2: Erythroblast transformation-specific-related gene (ERG) fusion, resulting in oncogenic expression of the ERG transcription factor. ERG represents an attractive target for potential future anticancer therapy in advanced and metastatic prostate cancer. To better understand whether the analysis of the primary cancer is sufficient to estimate the ERG expression status of the lymph node metastases, the present study examined patterns of immunohistochemical ERG expression in a tissue microarray created from multiple primary and metastatic sites of 77 prostate cancer tissues. Among the identified tumor types, 80% were either entirely ERG-positive (38%) or ERG-negative (42%) across all (at least 9) analyzed different tumor sites. The results were heterogeneous in 20% of the tumor types and typically resulted from small ERG-negative areas within otherwise ERG-positive tumor types. Comparison of the ERG expression status in 51 primary cancer types with at least three interpretable lymph node metastases revealed an entirely identical ERG status in all tumor sites in 75% of the cases, including 16 ERG-positive and 22 ERG-negative cancer types. The remaining 13 cancer types exhibited ERG heterogeneity within the primary tumor, while all metastases had an identical (12 positive and 1 negative) ERG status. The results of the present study revealed a high degree of concordance of the ERG expression status between primary prostate cancer types and their lymph node metastases. Therefore, potential anti-ERG therapy may also be effective against lymph node metastases in the majority of cases of ERG-positive metastatic prostate cancer.

Systematic analysis reveals molecular characteristics of ERG-negative prostate cancer

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 frequency. While the overall expression patterns were comparable between ERG-negative and ERG-positive tumors, we found that genomic alterations could affect the same pathway through distinct genes in the same pathway in both groups of tumor types. Altogether, the genomic and molecular characteristics revealed in our study may provide new opportunities for molecular stratification of ERG-negative prostate cancers.

Expression of IGF/insulin receptor in prostate cancer tissue and progression to lethal disease.

Circulating insulin-like growth factor-1 (IGF-1) is consistently associated with prostate cancer risk. IGF-1 binds to IGF-1 receptor (IGF1R) and insulin receptor (IR), activating cancer hallmark pathways. Experimental evidence suggests that TMPRSS2:ERG may interact with IGF/insulin signaling to influence progression. We investigated IGF1R and IR expression and its association with lethal prostate cancer among 769 men. Protein expression of IGF1R, IR and ERG (i.e. a surrogate of ERG fusion genes) were assayed by immunohistochemistry. Cox models estimated hazard ratios (HR) and 95% confidence intervals (CI) adjusted for clinical characteristics. Among patients, 29% had strong tumor IGF1R expression and 10% had strong IR expression. During a mean follow-up of 13.2 years through 2012, 80 men (11%) developed lethal disease. Tumors with strong IGF1R or IR expression showed increased cell proliferation, decreased apoptosis and a higher prevalence of ERG. In multivariable models, strong IGF1R was associated with a borderline increased risk of lethal prostate cancer (HR 1.7; 95% CI 0.9-3.1). The association appeared greater in ERG-positive tumors (HR 2.8; 95% CI 0.9-8.4) than in ERG-negative tumors (HR 1.3; 95% CI 0.6-3.0, p-heterogeneity 0.08). There was no association between IR and lethal prostate cancer (HR 0.8; 95% CI 0.4-1.9). These results suggest that tumor IGF1R expression may play a role in prostate cancer progression to a lethal phenotype and that ERG-positive tumors may be more sensitive to IGF signaling. These data may improve our understanding of IGF signaling in prostate cancer and suggest therapeutic options for disease subtypes.

13q deletion is linked to an adverse phenotype and poor prognosis in prostate cancer.

Deletions of chromosome arm 13q belong to the most frequent molecular alterations in prostate cancer. To better understand the role of 13q deletion in prostate cancer we took advantage of our large prostate cancer tissue microarray comprising more than 12 000 cancer samples with full pathological and clinical follow-up data. Fluorescence in situ hybridization with probes for ENOX1 (13q14.11) and the retinoblastoma gene (RB1, 13q14.2) was employed. A 13q deletion was found in 21% of 7375 analyzable cancers. Deletions were always heterozygous and associated with high Gleason grade (P < .0001), advanced tumor stage (P < .0001), high preoperative prostate-specific antigen (PSA) levels (P = .0125), lymph node metastasis (P = .0377), positive resection margin (P = .0064), and early biochemical recurrence (P < .0001). 13q deletions were marginally more frequent in prostate cancers with negative ERG status (22.9%) than in ERG-positive tumors (18.7%; P < .0001). Loss of 13q predicted patient prognosis independently from established prognostic parameters that are available at the time of biopsy (P = .0004), including preoperative PSA level, clinical tumor stage, and biopsy Gleason grade. In summary, the results of our study identify 13q deletion as a frequent event in prostate cancer, which is linked to an adverse phenotype and poor prognosis in this disease.

Abstract 3620: Histopathological associations with PTEN and ERG status in prostate biopsies from men treated with radiation

Abstract Loss of the PTEN tumor suppressor gene in prostate cancer, which usually occurs by genomic deletion, is associated with adverse outcome. Recent work (PMID:23888040) suggested that PTEN activity is also required for maintaining genomic integrity and its loss may be associated with resistance to DNA damaging agents, such as ionizing radiation. We assembled a series of patients with intermediate to high grade clinically localized prostate cancer who underwent external beam radiation as their primary treatment. We obtained and regraded all positive biopsy cores according the the new Grade Grouping system for Gleason scores (PMID: 26492179) and performed analytically and clinically validated IHC assays for PTEN (associated with PTEN genomic alterations) and ERG (associated with the TMPRSS2-ERG gene fusion) on all positive tissue cores from a given biopsy that were contained in up to 5 separate FFPE blocks (n=589 positive cores, n positive cores ranged from 1 to 13, with median of 2 and mean of 3) from 193 patients. PTEN and ERG status were correlated with the new Grade Groups as well as other histopathological features, including the presence of cribriform architecture and intraductal carcinoma. Patients were 66% White, and 27% African American, and median age was 68.5. Grade Group designations (taken as the highest Grade group in the case) were as follows (Group 1 = 27%, Group 2 = 30%, Group 3= 15%, Group 4 = 18%, Group 5 = 11%). Overall there was at least some PTEN loss in 36% of cases. The presence of any PTEN loss in a given case was strongly associated with Grade Group (P&amp;lt;0.001, chi square), in that 17% of patients with Grade Group 1 showed any PTEN loss and 77% of patients with Grade Group 5 showed any PTEN loss. As seen in prior studies, PTEN loss was frequently heterogeneous in that only 11% of cases overall showed complete loss of PTEN in all tumor tissue examined. Homogeneous PTEN loss was also significantly associated with Grade Groups since 3.8% of cases of Grade Group 1 showed such loss and 27% of cases of Grade Group 5 showed such loss (P=0.024, chi square). PTEN loss was also associated with cribriform morphology (P&amp;lt;0.001) and the presence of intraductal carcinoma of the prostate (P&amp;lt;0.001), both known independent prognostic factors. Having any PTEN loss was also associated with ERG gene fusions since 22% of cases showed PTEN loss that were negative for ERG and 52% of cases showed PTEN loss in cases positive for ERG (P&amp;lt;0.000). As also previously found, the rate of PTEN loss was higher in samples from White patients than African Americans (complete PTEN loss = 3.9% in African Americans and 14% in White patients). The presence of any ERG positive tumor was also higher in tissues from White patients (54%) compared to African Americans (29%) (P=0.003). Additional analyses are underway regarding associations between PTEN and ERG status and outcomes after radiation therapy. Citation Format: Onur Ertunc, Mark Markowski, Phuoc T. Tran, Amol Narang, Jessica Hicks, Daniel Song, Jiayun Lu, Elizabeth A. Platz, Theodore Deweese, Angelo M. De Marzo. Histopathological associations with PTEN and ERG status in prostate biopsies from men treated with radiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3620.

Abstract 2797: Synthesis and evaluation of derivatives of selective inhibitor ERGi USU, for ERG-positive prostate cancer cells

Abstract Introduction and objectives: Prostate cancer is the most frequently diagnosed non-skin malignancy and third leading cause of cancer related deaths among men in the United States. Currently, early detected organ confined prostate cancer (CaP) is managed by active surveillance, surgery or radiation therapy. A significant subset of patients (20% to 40%) experience biochemical recurrence after definitive treatment. New AR axis inhibitors (abiraterone and enzalutamide) are leading to significant improvements in treatment of late stages of CaP. However, sustained therapeutic response remains a challenge due to high mutation load at late stages of the disease. Thus, there is an urgent need for evaluating new therapeutic targets for early stages of CaP. ERG oncoprotein and ERG dependent pathways are promising targets for early stage cancer therapy. Previously identified ERGi-USU from our laboratory, demonstrated remarkable exclusivity for inhibiting ERG protein and cell growth of ERG positive tumor cells in both in vitro and in vivo. With comprehensive structure activity relationship (SAR) studies, we generated new derivatives with substituents around the core structure to further enhance efficacy. Methods: Cell growth inhibition of small molecules was validated with established prostate cancer cell lines and normal prostate/endothelial derived cell panel. Preferential species-specific binding of ERGi-USU to human RIOK2 was confirmed by tryptophan fluorescence quenching assay. Result: Based on SAR of the parental ERGi-USU, 90 new ERGi-USU derivatives were designed using structure based predictions. Of these, 37 compounds were prioritized for chemical synthesis and biological evaluations using assays that were developed earlier in our laboratory. We completed primary screen of these compounds in cell culture models. Among these one compound (ERGi-USU-6) inhibited the growth of ERG positive prostate cancer cells with remarkable improvement IC50=70 nM. This value is in the range of current FDA approved drugs. The result also confirmed the high selectivity of ERGi-USU-6 for the inhibition of ERG positive cancer cell growth. Further, mechanistic studies revealed ERGi-USU binding and disruption of the atypical RIOK2 kinase basic function of ribosome biogenesis, due to initiation of ribosomal stress, cell cycle arrest and apoptosis in ERG positive VCaP cells. We also demonstarte preferential binding of ERGi-USU to human RIOK2 by tryptophan fluorescence quenching assay. Conclusion: The ERGi-USU-6, derivative of ERGi-USU showed improved efficacy in selectively inhibiting the growth of ERG positive cancer cells. Since ERG is a prostate cancer causing oncogene that affects approximately one third of CaP patients world-wide, early therapeutic intervention with ERGi-USU derivatives may prevent the development of late stage disease in prostate cancer patients. Citation Format: Charles Peter Xavier, Ahmed A. Mohamed, Nishat Seraj, Vineet Kumar, Taduru Sreenath, Inger L. Rosner, Gyorgy Petrovics, Meera Srivastava, Clifton L. Dalgard, Sanjay V. Malhotra, Nicole A. LaRonde, Albert Dobi, Shiv Srivastava. Synthesis and evaluation of derivatives of selective inhibitor ERGi USU, for ERG-positive prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2797.

PD60-12 PROGNOSTIC VALUE OF COMBINED ANALYSIS OF PRO-NPY AND ERG PROTEIN EXPRESSION IN PROSTATE CANCER

You have accessJournal of UrologyProstate Cancer: Markers III1 Apr 2018PD60-12 PROGNOSTIC VALUE OF COMBINED ANALYSIS OF PRO-NPY AND ERG PROTEIN EXPRESSION IN PROSTATE CANCER Gitte Kristensen, Martin Andreas Roeder, Kasper Drimer Berg, Johanna Elversang, Birgitte Groenkaer Toft, and Klaus Brasso Gitte KristensenGitte Kristensen More articles by this author , Martin Andreas RoederMartin Andreas Roeder More articles by this author , Kasper Drimer BergKasper Drimer Berg More articles by this author , Johanna ElversangJohanna Elversang More articles by this author , Birgitte Groenkaer ToftBirgitte Groenkaer Toft More articles by this author , and Klaus BrassoKlaus Brasso More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.2824AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Apart from PSA, only few biomarkers reflecting prostate cancer (PCa) biology are introduced. Discovery of new biomarkers could refine prognostication for patients at risk of biochemical failure (BF) following radical prostatectomy (RP). Neuropeptide Y (NPY) and its precursor pro-NPY may be important factors for mitogenic and angiogenic activity. High expression of pro-NPY in ERG positive tumors has previously shown to be associated with increased risk of PCa specific death in men on watchful-waiting. This study aimed to investigate if combined analysis of pro-NPY and ERG protein expression in tumor tissue were associated with BF for men undergoing RP. METHODS The study included 311 consecutive patients, who underwent RP from Jan. 1st 2002 to Dec. 31st 2005 at the Department of Urology, Rigshospitalet, Copenhagen, Denmark. Pro-NPY and ERG protein expression were analyzed using immunohistochemistry (IHC; anti-pro-NPY: HPA044572; anti-ERG: EPR3864) on tissue arrays with tumor tissue from the RP specimens. pro-NPY immunoreactivity (IR) was scored semiquantitative as low (IR negative or weak) or high (IR moderate or strong). ERG IR was scored as negative or positive. Assessment of the IHC staining was done blinded. Clinicopathological information were collected from the medical records. Risk of BF was analyzed using multiple cause-specific Cox regression and stratified cumulative incidences (Aalen-Johansen method) using competing risk assessment. Death without BF was treated as a competing event. RESULTS After median 11.6 years follow-up, 147 men experienced BF. In total, 266 patients (85.5%) had high and 45 (14.5%) had low pro-NPY IR whereas 195 (62.7%) were ERG positive and 116 (37.3%) were ERG negative. The 10-year cumulative incidence of BF was 48.7% (95% CI: 33.7-63.7) in the pro-NPY low group compared with 44.1% (95% CI: 37.9-50.4) in the pro-NPY high group. In the multiple cause-specific Cox regression analysis pro-NPY high was not found associated with BF (HR: 0.82; 95% CI 0.5-1.4; p=0.49). The 10-year cumulative incidence for BF was 48.6% (95% CI: 33.2-64.0) in the ERG negative pro-NPY low group compared with 41.8% (95% CI: 34.6-49.0) in the ERG positive pro-NPY high group. The combination of ERG positive and pro-NPY high was not associated with a risk of BF in the multiple cause-specific Cox regression analysis (HR: 1.02; 95% CI 0.6-1.7; p=0.94). CONCLUSIONS pro-NPY expression alone or combined with ERG status was not found associated with risk of BF following RP. Analyses of association with time to initiation of secondary treatments and death are ongoing. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e1151 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Gitte Kristensen More articles by this author Martin Andreas Roeder More articles by this author Kasper Drimer Berg More articles by this author Johanna Elversang More articles by this author Birgitte Groenkaer Toft More articles by this author Klaus Brasso More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Abstract 5324: ERG expression and PTEN loss by BMI and weight change in men with prostate cancer

Abstract Background: Obesity and weight gain are associated with poor prostate cancer outcome; underlying mechanisms are unknown. Obesity has been more strongly associated with lethal disease in men positive for the TMPRSS2:ERG gene fusion than negative for this fusion. PTEN loss is associated with increased risk of lethal progression; its association with obesity has not been explored. We evaluated whether prevalence of ERG expression and PTEN loss in prostate tumors differs by BMI and weight change. Methods: From a retrospective cohort study of 1,337 men with clinically-localized prostate cancer who underwent prostatectomy at Johns Hopkins (1993-2006), we sampled 291 men by combination of BMI at 1 year after surgery (normal, overweight, obese) and weight change from 5 years before to 1 year after surgery (loss, maintenance, gain). Within each category, men were frequency-matched on age, Gleason sum, organ confinement, and surgery year. We used genetically validated immunohistochemistry assays to assess ERG positivity and heterogeneous PTEN loss. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association of BMI and weight change (adjusted for height, starting weight) with ERG positivity and heterogeneous PTEN loss. Results: Mean age was 56.1 years and mean Gleason sum was 6.2; 73% had organ-confined disease. Prevalence of ERG positivity did not statistically significantly differ by BMI or weight change. However, when jointly categorized by BMI and weight change, overweight/obese men who maintained (OR=2.5; 95%CI 1.1-5.7) or gained weight (OR=2.5; 95%CI 1.1-5.8), and normal weight men who gained weight (OR=4.7; 95%CI 1.4-15.2) were significantly more likely to have ERG positive tumors compared with normal weight men who maintained weight. Overweight/obese men were also significantly more likely (OR=2.4; 95%CI 1.3-4.7) to have PTEN loss compared with normal weight men. When stratified by ERG status, this association appeared to be stronger for men with ERG positive tumors (OR=2.9; 95%CI 1.3-6.8) than for men with ERG negative tumors (OR=1.6; 95%CI 0.6-4.9). Prevalence of PTEN loss did not differ by weight change. When jointly categorized by BMI and weight change, overweight/obese men who maintained (OR=2.0; 95%CI 0.8-5.3) or gained weight (OR=1.9; 95%CI 0.7-5.1) appeared to be more likely to have PTEN loss compared with normal weight men who maintained weight. Conclusions: Overweight/obese men who maintained or gained weight circa diagnosis and normal weight men who gained weight were more likely to have ERG positive tumors. Overweight/obese men were more likely to have tumors with PTEN loss; this association was stronger among overweight/obese men who also had ERG positive tumors. The TMPRSS2:ERG gene fusion and PTEN loss may contribute to the increased risk of poor prostate cancer outcomes among overweight/obese men. Funding: Prostate Cancer Foundation Citation Format: Janelle S. Ho, Ibrahim Kulac, Tamara L. Lotan, John R. Barber, Patrick C. Walsh, Misop Han, Angelo M. De Marzo, Elizabeth A. Platz, Corinne E. Joshu. ERG expression and PTEN loss by BMI and weight change in men with prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5324. doi:10.1158/1538-7445.AM2017-5324

Abstract 4236: Gene expression profiling of prostate tissue identifies biological pathways associated with TMPRSS2:ERG gene fusion

Abstract Background: TMPRSS2:ERG, a hormonally regulated gene fusion present in about half of prostate tumors, is the most common somatic event in prostate cancer. There is intriguing evidence to suggest that TMPRSS2:ERG-positive tumors may define a distinct subgroup of prostate cancer. In this study we compared gene expression profiles according to fusion status to identify genes and biological pathways differential expressed by TMPRSS2:ERG. Methods: The study included men with prostate cancer in the Health Professionals Follow-up Study and the Physicians’ Health Study diagnosed between 1982 and 2004 and followed through 2012. Tumor biomarker data was available for archival tumor tissue from 380 cases, 191 of whom also had gene expression data for adjacent normal tissue. Whole genome mRNA expression profiling (20,254 genes) was performed using the Affymetrix 1.0 ST array. TMPRSS2:ERG tumor status was assessed by a genetically validated IHC assay for ERG. To relate expression of individual genes to ERG we used linear regression. Gene Set Enrichment Analysis (GSEA) was used to identify pathways of genes associated with ERG in both tumor and adjacent normal tissue. Data from The Cancer Genome Atlas (TCGA) was used to validate these findings. Results: Among 380 cases, 186 (49%) of tumors were positive for the gene fusion. Genome-wide differential expression analysis identified 492 genes upregulated and 369 genes downregulated in tumor tissue comparing ERG+ to ERG- tumors (FDR p-value &amp;lt; 0.05). No genes were identified in the adjacent normal tissue at this significance level. 772 of the 861 genes (90%) identified in the HPFS/PHS dataset were confirmed in TCGA (448 upregulated and 324 downregulated). The top ten genes included ERG, WNK2, CACNA1D, HES1, SEPT9, PLA2G7, TDRD1, ANTXR2, SORBS2, and MYO6. Enrichment analysis identified a number of metabolic pathways associated with ERG tumor status including pathways involved in amino acid and fatty acid metabolism. Conclusions: We identified significant differences in gene expression profiles in prostate tumor tissue according to TMPRSS2:ERG status, providing supportive evidence of this fusion as a unique subtype. Citation Format: Ericka Ebot, Masis Isikbay, Travis Gerke, Thomas U. Ahearn, Rachel S. Kelly, Svitlana Tyekucheva, Andreas Pettersson, Kathryn L. Penney, Lorelei A. Mucci. Gene expression profiling of prostate tissue identifies biological pathways associated with TMPRSS2:ERG gene fusion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4236. doi:10.1158/1538-7445.AM2017-4236