African American CaP Research Articles

PD65-12 GERMLINE MUTATION LANDSCAPE OF DNA REPAIR GENES IN AFRICAN AMERICAN PROSTATE CANCER PATIENTS HIGHLIGHT POTENTIALLY TARGETABLE RAD GENES

PD65-12 GERMLINE MUTATION LANDSCAPE OF DNA REPAIR GENES IN AFRICAN AMERICAN PROSTATE CANCER PATIENTS HIGHLIGHT POTENTIALLY TARGETABLE <i>RAD</i> GENES

Abstract 2074: Germline mutation landscape of all DNA repair genes in African American prostate cancer patients

Abstract Introduction: DNA damage repair genes (DDRGs) play a critical role in genomic stability and their dysfunction contributes to mutagenesis in several cancer types. In prostate cancer (CaP) emerging data provide potential roles of DDR pathways in aggressive disease. However, the association with disease progression and therapeutic stratification based on inherited mutations of DDRGs remains to be defined in African American (AA) CaP patients. Our objective was to genomically profile all known annotated DDRGs in AA and Caucasian American (CA) CaP patient to determine whether DDRG germline variation status can refine patient stratification for targeted therapeutic options. Methods: Germline mutations in all DDRGs (N=276) was evaluated by whole genome sequence (WGS) analysis of archived blood DNA samples from 600 CaP patients (300 AA and 300 CA) who underwent primary treatment at Walter Reed National Military Medical Center. The WGS mean coverage exceeded 37x. Principal Component Analysis (PCA) was used infer axes of genetic variation within AA men and examine individual and population clustering to predict ancestry of each sample using the Peddy program. Variant frequencies in CPDR CaP patients were compared to variant frequencies available from the Exome Aggregation Consortium (ExAC) control cases with no CaP by Fisher's Exact Test, using false discovery rate adjusted p-values. Results: Interrogation of the complete known DDRG set of 276 genes revealed several known and novel mutations in this cohort. The Pathogenic/likely pathogenic (P/LP) variant carrier rate was higher than reported before (23.5%) in both AA and CA patients. However, the analysis revealed that more than 2/3 of the identified 47 DDRGs with P/LP mutation were different between AA and CA patients. Unlike in CA patients, several RAD family genes (RAD51, RAD54L, RAD54B), PMS2, and BRCA1 were among the most frequently mutated DDRGs in AA patients, but not in CA patients. The most frequent (over 1% carrier frequency) and potentially targetable type of mutations were independently validated by ddPCR. These genes are part of targetable DDRG pathways (homologous recombination and mismatch repair), suggesting that targeted therapy could potentially benefit AA patients. AA men harbor more potentially targetable DDRG germline mutations (over 10%) than CA men which may contribute to addressing CaP disparity. Germline mutations in any of the DDRG genes was associated with shorter time to BCR (Kaplan-Meier analysis, log rank p value 0.044) in AA patients, but not in CA patients. Conclusion: Our findings highlight distinct racial differences in DDRGs and addresses the clinical utility by targeted therapy across AA and CA men. The percentage of patients with DDRG germline variation is of suitable threshold (23%) to consider early genetic testing for them in both AA and CA patients. Citation Format: Indu Kohaar, Xijun Zhang, Shyh-Han Tan, Darryl Nousome, Kevin Babcock, Lakshmi Ravindranath, Gauthaman Sukumar, Elisa Mcgrath-Martinez, John Rosenberger, Camille Alba, Amina Ali, Denise Young, Yongmei Chen, Jennifer Cullen, Inger Rosner, Isabella Sesterhenn, Albert Dobi, Gregory Chesnut, Clesson Turner, Clifton Dalgard, Matthew Wilkerson, Shiv Srivastava, Gyorgy Petrovics. Germline mutation landscape of all DNA repair genes in African American prostate cancer patients [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 2074.

Abstract A111: Urine-based gene expression panels with focus on prostate cancer in African Americans

Abstract Introduction: Prostate cancer (CaP) affects 1 in 7 men in their lifetime. African American (AA) men have significantly higher incidence and mortality from CaP compared to Caucasian American (CA) men. We and others have also noted that the genes commonly overexpressed in CaP (e.g., ERG) and currently used as diagnostic markers exhibit much lower frequency and more heterogeneity in AA men. The goals of this study are to develop CaP diagnostic/prognostic marker panels that takes into account race-associated differences in molecular alterations. Here we evaluated a panel of CaP associated genes using regular (non-DRE) urine from AA and CA CaP for discriminating between high-grade (Gleason score [GS], 7-10) and low-grade disease (GS, 6) and cancer negative biopsy. Methods: The quantitative expression assay protocols have been developed for noninvasive detection of candidate genes in exosomal RNAs from regular urine. The selected genes were reverse transcribed in a single reaction using gene-specific primer pool (GSP) followed by preamplification and PCR-based assay of all target genes. Results: Regular urine exosomal RNA-based assays were developed and optimized for PSGR, DLX1, HOXC4, NKX2-3, COL10A1, HOXC6, PCA3, PCGEM1, PCAT1, CTBP1, SChLAP1, ERG and SPDEF. All markers have been evaluated in a pilot study of 72 subjects undergoing diagnostic biopsies. For AA patients a sensitivity of 88.2%, specificity of 83.3%, and AUC of 0.81 were achieved for the panel (PCA3, PCGEM1, HOXC6 and SChLAP1). Consistent with numerous studies, ERG and PCA3 panel was optimal for CA patients. Preliminary analysis showed that 3 markers were found to be associated with improved discrimination between GS7 or greater and GS6 (AUC 0.78 for ERG; AUC 0.72 for PSGR and AUC 0.72 for SChLaP1) in AA CaP. In CA patients, PCA3 gave an AUC of 0.76 for predicting high-grade from low-grade disease. Analysis of an additional 100 patients is in progress. Conclusions: Given the genomic difference of prostate cancer among different race/ethnicity, this study highlights the potential for developing CaP biomarker panels in the context of race for enhancing precision medicine through improved CaP diagnosis/prognosis Citation Format: Indu Kohaar, Sreedatta Banerjee, Yongmei Chen, Amina Ali, Jacob Kagan, Sudhir Srivastava, Jennifer Cullen, Inger Rosner, Shiv Srivastava, Gyorgy Petrovics. Urine-based gene expression panels with focus on prostate cancer in African Americans [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A111.

Abstract B075: Defining germline mutations of DNA damage repair genes in African American prostate cancer patients

Abstract Background: DNA damage repair genes (DDRGs) play a critical role in protecting genome integrity and have been implicated in several cancer types. In the context of prostate cancer (CaP) emerging data provide potential role of this pathway in aggressive disease. It has also been recently demonstrated that PARP inhibitors can extend overall survival in metastatic patients with DDRG mutations. However, the association and therapeutic stratification based on inherited mutations of DDRGs remains to be defined in African American (AA) CaP patients. Our objective was to assess the frequency and association with disease aggressiveness of all known DDRGs in blood derived genomic DNAs of AA and Caucasian American (CA) CaP patients archived at the DOD Center for Prostate Disease Research and assess how this information can refine patient stratification for specific targeted therapeutic options. Method: Germline mutations in all DDRGs was evaluated by whole genome sequence (WGS) analysis of archived blood DNA samples from 600 CaP patients (300 AA and 300 CA) who underwent primary treatment at Walter Reed National Military Medical Center (WRNMMC) over the past 20 years. These patients had equal access Department of Defense healthcare system with up to 20 years of follow-up time. Following quality control steps to assess DNA quantity by Qubit assay and DNA quality by Bioanalyzer assay, DNA samples were used to generate PCR-free libraries for WGS using the NovaSeq (Illumina) platform. Out of the 600 libraries we generated, 14 dropped out, achieving a success rate of 97.6%. The successful libraries had an excellent quality based on DNA library metrics (yield and fragment length). Whole genome sequencing depth of the samples exceeded 37x on average and about 4 million SNPs were identified in the samples. Patient genotypes were projected onto principal components from reference populations. Sample ancestries were predicted by using the “Peddy” program, which uses a machine learning model trained on individuals of diverse ancestries from the 1000 Genomes Project reference panel. Due to mismatched ancestry, 33 samples were excluded from further analyses. An additional 17 samples were excluded due to higher than minimal noise level based on analyses using “ContEst” tool from Broad GATK package and Illumina noise percent values. Results: Interrogation of an inclusive DDRG set of 180 genes predicted to have non-silent effects on the protein sequence (e.g. missense, nonsense, frameshift) for germline mutations in this cohort revealed several known and novel mutations. The analysis has not been finalized yet. Mutation data will be assessed for association with the extensive available clinical and pathological data, including disease progression (metastasis), family history and African ancestry. Novel mutations, anticipated especially in the understudied AA context, will be analyzed for functional impact. Citation Format: Kevin Babcock, Xijun Zhang, Matthew Wilkerson, Clifton L. Dalgard, Shyh-Han Tan, Lakshmi Ravindranath, Yongmei Chen, Jennifer Cullen, Shiv Srivastava, Inger L. Rosner, Gyorgy Petrovics. Defining germline mutations of DNA damage repair genes in African American prostate cancer patients [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B075.

Abstract B084: Dysregulation of the AR-Nrdp1-ErbB3 axis occurs in African American prostate cancer patients and is associated with worse outcomes

Abstract Background: We previously showed that Nrdp1, an E3 ubiquitin ligase, is transcriptionally regulated by the androgen receptor (AR) in prostate cancer (CaP) cells and that Nrdp1 can post-translationally regulate ErbB3 (an EGFR family member) levels via ubiquitination and subsequent proteasomal degradation. Increased levels of ErbB3 are associated with worse CaP patient outcome. The goal of the current study was to determine whether dysregulation of the AR-Nrdp1-ErbB3 axis contributes to prostate cancer health disparities for African American (AA) men, and to identify the underlying mechanisms involved. Methods: Expression levels and localization of AR, Nrdp1, and ErbB3 were assessed in a total of 208 CaP patient samples (50 African American (AA) and 158 Caucasian (CA) CaP patients) and two cell lines (LNCaP (CA) and MDAPCa2b (AA)). Expression levels and localization of these molecules were determined by immunohistochemistry (IHC) and subcellular fractionation and western blot. A combination of knockdown (siRNA), forced overexpression (Nrdp1-FLAG construct), and treatment with enzalutamide or synthetic androgen (R1881) experiments were employed to investigate the relationship between AR, Nrdp1, and ErbB3 expression levels and localization and to identify differences in AA and CA cell lines. Immunoprecipitation allowed for investigation of the mechanisms which facilitate nuclear transport of Nrdp1. Results: A statistically significant negative association between cytoplasmic levels of AR (AR C) and nuclear Nrdp1 (Nrdp1 N) exists in both Caucasian (CA) and African American (AA) prostate cancer (CaP) patients, but this association was stronger in AA patients compared to CA patients (Spearman correlation coefficient of -0.62 for AA patients, and -0.36 for CA patients). Increased nuclear Nrdp1 expression levels were associated with increased 5-year survival rates, and reduced nuclear Nrdp1 expression levels predicted biochemical recurrence (AUC 0.63). Dysregulation of the AR-Nrdp1-ErbB3 axis in AA CaP cells was also observed in cell line studies; AA CaP cells expressed significantly lower levels of both total and nuclear Nrdp1 compared to their CA CaP counterparts. Manipulation of AR expression levels and localization via knockdown and inhibition with enzalutamide had a lesser impact on Nrdp1 expression levels and localization in AA versus CA CaP cells. Immunoprecipitation studies demonstrated that Nrdp1 can bind to AR in CA CaP cells but not AA CaP cells. Conclusions: Our combined data indicate that dysregulation of the AR-Nrdp1-ErbB3 axis occurs to a larger extent in AA than CA CaP cells and that this can contribute to worse patient outcomes. Our data also indicate that lack of binding between AR and Nrdp1 in AA CaP cells may account for the lower levels of nuclear Nrdp1 observed in AA CaP cells. Further understanding of the mechanisms which regulate Nrdp1 levels and localization may allow for the development of treatments which help abrogate cancer health disparities. Note: This abstract was not presented at the conference. Citation Format: Anhao Sam, Elizabeth Browning, Shawna Evans, Thomas Steele, Paramita Ghosh, Ruth Vinall. Dysregulation of the AR-Nrdp1-ErbB3 axis occurs in African American prostate cancer patients and is associated with worse outcomes [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B084.

Abstract B083: Dysregulation of the AR-Nrdp1-ErbB3 axis occurs in African American prostate cancer patients and is associated with worse outcomes

Abstract Background: We previously showed that Nrdp1, an E3 ubiquitin ligase, is transcriptionally regulated by the androgen receptor (AR) in prostate cancer (CaP) cells and that Nrdp1 can post-translationally regulate ErbB3 (an EGFR family member) levels via ubiquitination and subsequent proteasomal degradation. Increased levels of ErbB3 are associated with worse CaP patient outcome. The goal of the current study was to determine whether dysregulation of the AR-Nrdp1-ErbB3 axis contributes to prostate cancer health disparities for African American (AA) men, and to identify the underlying mechanisms involved. Methods: Expression levels and localization of AR, Nrdp1, and ErbB3 were assessed in a total of 208 CaP patient samples (50 African American (AA) and 158 Caucasian (CA) CaP patients) and two cell lines (LNCaP (CA) and MDAPCa2b (AA)). Expression levels and localization of these molecules were determined by immunohistochemistry (IHC) and subcellular fractionation and western blot. A combination of knockdown (siRNA), forced overexpression (Nrdp1-FLAG construct), and treatment with enzalutamide or synthetic androgen (R1881) experiments were employed to investigate the relationship between AR, Nrdp1, and ErbB3 expression levels and localization and to identify differences in AA and CA cell lines. Immunoprecipitation allowed for investigation of the mechanisms which facilitate nuclear transport of Nrdp1. Results: A statistically significant negative association between cytoplasmic levels of AR (AR C) and nuclear Nrdp1 (Nrdp1 N) exists in both Caucasian (CA) and African American (AA) prostate cancer (CaP) patients, but this association was stronger in AA patients compared to CA patients (Spearman correlation coefficient of -0.62 for AA patients, and -0.36 for CA patients). Increased nuclear Nrdp1 expression levels were associated with increased 5-year survival rates, and reduced nuclear Nrdp1 expression levels predicted biochemical recurrence (AUC 0.63). Dysregulation of the AR-Nrdp1-ErbB3 axis in AA CaP cells was also observed in cell line studies; AA CaP cells expressed significantly lower levels of both total and nuclear Nrdp1 compared to their CA CaP counterparts. Manipulation of AR expression levels and localization via knockdown and inhibition with enzalutamide had a lesser impact on Nrdp1 expression levels and localization in AA versus CA CaP cells. Immunoprecipitation studies demonstrated that Nrdp1 can bind to AR in CA CaP cells but not AA CaP cells. Conclusions: Our combined data indicate that dysregulation of the AR-Nrdp1-ErbB3 axis occurs to a larger extent in AA than CA CaP cells and that this can contribute to worse patient outcomes. Our data also indicate that lack of binding between AR and Nrdp1 in AA CaP cells may account for the lower levels of nuclear Nrdp1 observed in AA CaP cells. Further understanding of the mechanisms which regulate Nrdp1 levels and localization may allow for the development of treatments which help abrogate cancer health disparities. Citation Format: Anhao Sam, Shawna Evans, Elizabeth Browning, Sheryl Krig, Neelu Batra, Thomas Steele, Salma Siddqui, Paramita Ghosh, Ruth Vinall. Dysregulation of the AR-Nrdp1-ErbB3 axis occurs in African American prostate cancer patients and is associated with worse outcomes [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B083.

Abstract A018: Distinct genomic alterations in prostate cancer of African American men

Abstract Background: In recent years remarkable ethnic/racial differences in the frequency of prostate cancer (CaP) driver gene alterations have emerged. Along the lines of ethnic differences in CaP genomes, oncogenic activation of ERG proto-oncogene and deletion of the PTEN tumor suppressor gene are most widely studied. These findings underscore distinct biology of prostate cancer in different ethnicities and races. We have reported the cumulative analyses of 435 patients (whole genome sequencing (WGS): 14, FISH evaluations: 101, SNP array: 320) comparing CaP genomes of African American (AA) and Caucasian American (CA) patients. An AA CaP genome-associated deletion was identified and mapped to the Limbic System-Associated Membrane Protein (LSAMP) gene locus. Further examination of the data indicated the AA CaP-genome associated deletion of the Chromodomain Helicase DNA Binding Protein 1(CHD1) gene. The goal of the current study is the comparative assessment of frequencies and prognostic associations of CaP genome alterations in the context of racial/ethnic differences. Methods: A prostate tumor tissue microarray (TMA) of benign and tumor foci (500+ cores) was generated by sampling 2-3 cores representing the range of cell morphology in matched cohort of 42 AA and 59 CA patients with up to 20 years of follow-up. Comparative evaluation of frequencies and prognostic associations of ERG oncoprotein by immunohistochemistry and the deletion of LSAMP, CHD1, and PTEN genes by FISH was performed. ERG frequencies were further assessed in index tumors of Chinese CaPs (N=100) and were compared to ERG frequencies in index tumors of patients from the United States equal-access military health-care system (N=336 AA and N=594 CA). Results: Higher frequencies of recurrent deletions of CHD1 (29% AA vs. 10% CA p=0.017) and LSAMP (26% AA vs. 7% CA, p=0.006) were identified in AA CaP compared to CA CaPs. These deletions were associated with significantly higher risk of rapid biochemical recurrence. In contrast, PTEN deletions (15% AA vs. 63% CA) and the frequency of ERG positive CaPs (26% AA vs. 64% CA) were more frequent among CA CaPs. Comparative evaluation of ERG frequencies in CaPs (N=1,292) underscores highest ERG frequency among CA patients (49.3%) followed by AA (23.2%) and Chinese (22%) men. Conclusions: In light of distinct biology of CaPs in ethnically/racially diverse CaP patient populations, there is a need for developing broadly applicable diagnostic, prognostic marker panels and therapeutic approaches. Higher frequency of CHD1 deletion in CaPs of AA patients may provide new therapeutic opportunities due to the sensitivity of CHD1 deletion harboring tumors to PARP inhibitors and platinum agents. Acknowledgments: This research was supported by the CPDR-USU program HU0001-10-2-0002, the National Cancer Institute R01CA162383 grant, the EDRN/NCI ACN12011-001-0 grant, the Snyder Medical Foundation, the Otto Mønsteds Foundation, the Mazzone Foundation, the Breast Cancer Research Foundation, the Novo Nordisk Foundation, and grants by MTA-TKI643/2012, KTIA_NAP_13-2014-0021. Citation Format: Albert Dobi, Gyorgy Petrovics, Hua Li, Denise Young, Shyh-Han Tan, Yongmei Chen, Qingyu Xiao, Yidi Sun, Hong Li, Yixue Li, Yuan Ji, Jun Hou, Wendy Wang, Jacob Kagan, Guo-Ping Zhao, Sudhir Srivastava, Reinhard Ebner, Inger L. Rosner, Jennifer Cullen, Matthew Freedman, Isabell Sesterhenn, Zoltan Szallasi, Shiv Srivastava. Distinct genomic alterations in prostate cancer of African American men [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A018.

Abstract 5352: Racial/ethnic differences in prostate cancer genomic alterations

Abstract Background: Distinct biology of prostate cancer (CaP) among men of different races and ethnicities have been recently highlighted. Along these lines higher frequencies of the most common CaP gene alterations, ERG proto-oncogene activation and deletion of the PTEN tumor suppressor, have been reported among Caucasian Americans (CA) when compared to other racial/ethnic groups. We have reported the cumulative analyses of CaPs from 435 patients (whole genome sequencing (WGS), FISH evaluations and SNP arrays) that highlighted the recurrent deletion and disease progression association of the Limbic System-Associated Membrane Protein (LSAMP) in CaP genomes of African American (AA) men. Further examination of these data indicated the AA CaP genome associated recurrent deletion of the Chromodomain Helicase DNA Binding Protein 1(CHD1) gene. Methods: Combined evaluation of frequencies and prognostic associations of ERG oncoprotein by immunohistochemistry and deletions of LSAMP, CHD1 and PTEN genes by FISH were performed using a multi-core TMA (42 AA and 59 CA patients) with longitudinal follow up data (median 16 years). CaP and matched blood genomic DNA samples (N=60) from AA patients were analyzed by WGS. ERG frequencies were further evaluated in index tumors of Chinese CaPs (N=100) and were compared to ERG frequencies in index tumors of AA (N=336) and CA (N=594) patients. Results: Frequent deletions of CHD1 (29% AA vs. 10% CA p=0.017) and LSAMP (26% AA vs. 7% CA, p=0.006) were found in AA CaPs by FISH assay. Both of these deletions were associated with rapid disease progression. Evaluation of CaPs by WGS further highlighted the recurrent deletion of CHD1 among AA men. Comparative evaluation of ERG (AA, N=336; CA, N=594, and Asian N=100) underscored highest ERG frequencies among CA patients (49.3%) followed by AA (23.2%) and Chinese (22%) men. Conclusions: In light of distinct biology of CaPs in ethnically/racially diverse CaP patient populations there is a need for developing broadly applicable diagnostic, prognostic marker panels and therapeutic approaches. Recurrent CHD1 deletion in CaPs of AA patients may provide new therapeutic opportunities in light of recent reports suggesting that CaP patients harboring CHD1 deletion may benefit from PARP inhibitor or platinum agents therapies. Funding: This study was supported by CPDR, USUHS, HU0001-10-2-0002 to I.L.R., the NCI/EDRN IAA ACN12011-001-0 to S.S. and by the NCI R01CA162383 to S.S. Citation Format: Albert Dobi, Gyorgy Petrovics, Shyh-Han Tan, Hua Li, Denise Young, Cara Schafer, Jesse Fox, Kevin Babcock, Heng-Cheng Hu, Gauthaman Sukumar, Yingjie Song, Lakshmi Ravindranath, Yongmei Chen, Joseph Cheng, Reinhard Ebner, Qingyu Xiao, Yidi Sun, Yixue Li, Yuan Ji, Jun Hou, Wendy Wang, Guo-Ping Zhao, Jacob Kagan, Sudhir Srivastava, Joel T. Moncur, Clifton L. Dalgard, Matthew Wilkerson, Inger L. Rosner, Jennifer Cullen, Matthew Freedman, Zoltan Szallasi, Isabell A. Sesterhenn, Shiv Srivastava. Racial/ethnic differences in prostate cancer genomic alterations [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 5352.

Abstract 4486: Reexpression of LSAMP, a gene frequently deleted in African American prostate cancers, alters adhesive qualities of prostate tumor cells and inhibits Akt, ERK1/2, and β-Catenin signaling axis

Abstract INTRODUCTION: Although African American (AA) men have the highest prostate cancer (CaP) incidence and mortality rates in the US, most studies of CaP genome have been performed using tumor specimens from Caucasian Americans (CA). To address the underrepresentation of AA CaP in these studies, we performed whole genome sequencing, IHC and FISH validation on tissue microarrays, and analysis of TCGA data, on a total of 438 CaPs. We noted less frequent alterations of two common CaP driver genes, PTEN and ERG, in CaP genomes of AA compared to CA men, confirming earlier observations by others and us. We reported a higher frequency of a genomic deletion of the Limbic System Associated Membrane Protein (LSAMP) gene, located on 3q13.31 locus in AA CaP, which was also associated with rapid biochemical recurrence. A recent study of CaP genome in a Chinese cohort detected LSAMP alterations at a frequency similar to that in our AA cases. LSAMP loss in other cancers have been associated with aggressive disease. We hypothesize that the loss of LSAMP contributes to CaP progression. Here, we report further biological evaluations of LSAMP modulation in CaP cells. METHODS: The copy number and expression of LSAMP in CaP cell lines were assessed. We established stable doxycycline inducible LSAMP expression in LNCaP and in MDA PCa 2b cells (AA patient derived cell line with monoallelic LSAMP deletion), and constitutive expression in DU145 cells. We assessed the effect of LSAMP expression on cell-cell adhesion by monitoring the binding of LSAMP expressing and control DU145 cells to mouse fibroblast (NIH-3T3), normal human prostate stroma (WPMY-1), human endothelial (HUVEC), and human bone marrow stroma (HS-5) cells. We analyzed LSAMP modulated signaling pathways in the inducible and constitutively LSAMP expressing cell lines by immunoblot and immunofluorescence assays. RESULTS: Overexpression of LSAMP resulted in attenuated cell proliferation and increased adhesion of cells to extracellular matrix proteins. LSAMP expression in DU145 cells increased their adhesion to fibroblast and prostate stroma cell lines, and concomitantly decreased their adhesion to endothelial, and bone marrow stroma cells. LSAMP expression resulted in decreased expression of FGFR2, FGFR4, and EphA3 receptor tyrosine kinases, and decreased phosphorylation of their downstream targets in Akt and ERK1/2 signaling pathways, leading to the inactivation of β-catenin. LSAMP expression also alters the levels of some Integrins. CONCLUSION: Cell biologic features of LSAMP reported here, along with observations of genomic inactivations of LSAMP in CaP support its role in CaP progression through altered cell adhesion. These data provide the first insight into LSAMP function in CaP, corroborating with studies that suggest bona fide tumor suppressor function for LSAMP in cancers. Citation Format: Kevin Babcock, Inger L. Rosner, Shiv Srivastava, Albert Dobi, Shyh-Han Tan. Reexpression of LSAMP, a gene frequently deleted in African American prostate cancers, alters adhesive qualities of prostate tumor cells and inhibits Akt, ERK1/2, and β-Catenin signaling axis [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 4486.

Abstract B42: Development of a urine exosome-based prostate cancer gene expression panel to address racial differences in prostate cancer

Abstract Introduction: Prostate cancer (CaP) is the most prevalent cancer and third leading cause of cancer death among men in United States, with an anticipated 161,360 newly diagnosed cases and approximately 26,730 deaths in 2017. It is estimated that 1 in 6 men of African ancestry will be diagnosed with prostate cancer in their lifetime in comparison with 1 in 8 men of Caucasian origin. One of the major risk factors for the development of CaP is race/ethnicity. African American (AA) men have significantly higher incidence and mortality from CaP compared to Caucasian American (CA) men. Emerging data, including ours, have described significantly lower frequencies of alterations in common CaP driver genes (ERG and PTEN) in AA men as compared to CA men. We have also noted that genes commonly overexpressed in CaP (ERG, AMACR, PCA3), and currently used as diagnostic markers, exhibit much lower frequency and more heterogeneity in AA men. The goal of this study was to define a CaP marker panel that is overexpressed equally well in AA and CA CaP. Methods: RNA-seq, NanoString, and qRT-PCR platforms were used for evaluation of CaP-associated gene expression in CA and AA patients (N=144). Candidate genes with robust tumor overexpression (over 4-fold) in CaP in paired normal and tumor specimens from AA and CA patients were selected from Nanostring and RNA-seq datasets for validation by TaqMan based qRT-PCR approach in laser microdissected (LCM) tumor and benign cells of frozen tissue sections (50 CA and 35 AA). An assay protocol based on gene-specific RT and preamplification followed by TaqMan PCR was developed for noninvasive early detection of candidate markers in regular patient urine (non-DRE) using urinary exosomal RNA. Results: Tumor transcriptomes of CA patients consistently revealed overexpression of PCA3 and AMACR. However, these genes had variable overexpression in AA cohort. The top genes that were similarly over expressed in tumors of AA and CA patients were further validated by qRT-PCR in LCM tumor and normal epithelial cells (N=85). At least one gene of a six-gene signature (DLX1, HOXC4, NKX2-3, COL10A1, HOXC6, and PSGR) was overexpressed in tumor cells of all AA and CA cases, providing a consistent ethnicity-informed tumor-expression signature, which was further validated in silico in TCGA RNA-seq data. Urinary exosome-based assay was developed and optimized for PSGR, DLX1, HOXC4, NKX2-3, as well as PCA3 and ERG. Sensitivity and specificity of the marker panel in a feasibility cohort (N=40) with optimal cutoff for the urine marker panel was 78% and 65%, respectively. Evaluation of the assay performance in CA and AA patients in a prospective independent cohort of 100 patients is ongoing. Conclusion: An ethnicity-informed CaP tissue-based gene expression marker panel has been defined with potential diagnostic utility for both CA and AA men in the context of urinary exosomes. Citation Format: Indu Kohaar, Sreedatta Banerjee, Lakshmi Ravindranath, Yongmei Chen, Amina Ali, Jacob Kagan, Sudhir Srivastava, Albert Dobi, David McLeod, Inger L. Rosner, Shiv Srivastava, Gyorgy Petrovics. Development of a urine exosome-based prostate cancer gene expression panel to address racial differences in prostate cancer [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr B42.

Abstract 4645: A serum multiomics signature for enhancing prostate cancer diagnosis and prognosis

Abstract Introduction and Objective: Diagnosis of prostate cancer (CaP) has relied on prostate specific antigen (PSA) level and digital rectal examination (DRE) followed by prostate biopsies. These modalities have the potential to yield false-positive and false-negative results for CaP. These challenges prompted efforts to develop more specific body fluid based assays including PCA3, TMPRSS2:ERG, K4csore and PHI tests. Further, emerging data on significant racial differences of common CaP driver genes, e.g., PTEN and ERG in CaP can lead to significant limitations in biomarker performance. Thus, the goal of our study was to discover CaP serum markers with equal performance among African American (AA) and Caucasian American (CA) men. We employed proteomics, signal- and structural lipidomics and metabolomics platforms to discover serum biomarkers and evaluate their utility for diagnosis and prognosis of CaP in AA and CA men. Methods: Sera from 700 individuals were analyzed, which included AA and CA CaP patients stratified for ERG oncoprotein expression by immunohistochemistry (N=495). Sera from age-matched healthy control men were also included (N=205) in this study. Quantitative global profiles of lipidome, proteome and metabolome were analyzed by high resolution MS-based technologies. Random forest and Interrogative Biology® analytical platforms were used to identify analytes differentiating healthy from CaP cases including clinical-pathologic data. Results: The unbiased global profiling and integration of the data and clinical-pathologic features have led to the identification of molecular fingerprints differentiating cancer patients from healthy controls. Specifically, three analytes in serum metabolome showed robust separation between both AA and CA CaP and control groups. Elevated levels of nicotinamide and eicosenoic acid and decreased levels of a decanoylcarnitate alone have indicated strong separation between cases and controls. Further inclusion of additional 9 analytes provided an optimal multi-omics panel for distinguishing the combined cohort of AA and CA cases vs. healthy controls. Conclusions: The findings presented here support that an integrated multiomics approach has the potential to define serum marker panels for diagnosis of CaP in the context of racial diversity and molecular annotation (e.g., ERG) of CaP. These promising data are undergoing validation in additional patient cohorts. Citation Format: Michael A. Kiebish, Jennifer Cullen, Albert Dobi, Amina Ali, Leonardo O. Rodrigues, Yezhou Sun, Aniruddha Pawar, Aditee Dalvi, Denise Young, Vivek K. Vishnudas, Jason Sedarsky, Gyorgy Petrovics, Emily Chen, Viatcheslav Akmaev, Inger L. Rosner, David McLeod, Isabell A. Sesterhenn, Rangaprasad Sarangarajan, Alagarsamy Srinivasan, Elder Grainger, Niven R. Narain, Shiv Srivastava. A serum multiomics signature for enhancing prostate cancer diagnosis and prognosis [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 4645. doi:10.1158/1538-7445.AM2017-4645

Abstract 4649: Development of an ethnicity informed gene expression panel with potential to improve prostate cancer diagnosis

Abstract Introduction and Objectives: Prostate cancer (CaP) affects 1 in 7 men throughout their life time. One of the major risk factors for the development of CaP is race/ethnicity. African American (AA) men have significantly higher incidence and mortality from CaP compared to Caucasian American (CA) men. Emerging data including ours have described significantly lower frequencies of alterations in the common CaP driver genes (ERG and PTEN) in AA men as compared to CA men. We have also noted that genes commonly overexpressed in CaP (ERG, AMACR and PCA3), and currently used as diagnostic markers, exhibit much lower frequency and more heterogeneity in AA men. The goal of this study was to define a broader CaP marker panel that is overexpressed equally well in AA and CA CaP. Methods: Three platforms (RNASeq, NanoString and QRT-PCR) were used for evaluation of CaP associated gene expression in CA and AA patients (N=144). Candidate genes with robust tumor overexpression (over 4-fold) in CaP in comparison of paired normal and tumor specimens from AA and CA patients were selected from the Nanostring and RNASeq data for validation by QRT-PCR (TaqMan) in laser microdissected (LCM) tumor and benign cells of frozen tissue sections (50 CA and 35 AA). An assay protocol (gene specific pooled RT and pre-amplification followed by TaqMan PCR) was set up for the noninvasive early detection of candidate genes in regular patient urine (non-DRE) using RNA derived from urinary exosomes. Results: As expected tumor transcriptomes of CA patients revealed consistently elevated expression of PCA3 and AMACR genes. However, these genes had variable overexpression in AA cohort. The top genes that were similarly over expressed in tumors of AA and CA patients were validated by real time QRT-PCR (TaqMan) analysis in LCM dissected tumor and normal epithelial cells (N=85). At least one gene of a six gene signature (DLX1, HOXC4, NKX2-3, COL10A1, HOXC6 and PSGR) was overexpressed in tumor cells of all AA and CA cases, providing a consistent ethnicity informed tumor expression signature, which was further validated in silico in TCGA RNASeq data. Urinary exosome based assay was developed and optimized for PSGR, DLX1, HOXC4, NKX2-3, as well as PCA3 and ERG. Sensitivity and specificity with optimal cutoff for the urine marker panel was 71% and 61% respectively (N=40). Evaluation of the assay performance in CA and AA patients in a prospective independent cohort of 100 patients addressing race specific performance is in progress. Conclusions: A CaP tissue based gene expression marker panel has been defined with potential diagnostic utility for both CA and AA men in the context of urinary exosomes. Citation Format: Indu Kohaar, Lakshmi Ravindranath, Sreedatta Banerjee, Yongmei Chen, Amina Ali, Yingjie Song, Jacob Kagan, Sudhir Srivastava, Albert Dobi, David McLeod, Inger L. Rosner, Shiv Srivastava, Gyorgy Petrovics. Development of an ethnicity informed gene expression panel with potential to improve prostate cancer diagnosis [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 4649. doi:10.1158/1538-7445.AM2017-4649

MP33-12 DEVELOPMENT OF A PROSTATE CANCER GENE EXPRESSION PANEL TO ADDRESS RACIAL DIFFERENCES OF MOLECULAR ALTERATIONS IN PROSTATE CANCER

You have accessJournal of UrologyProstate Cancer: Detection & Screening III1 Apr 2017MP33-12 DEVELOPMENT OF A PROSTATE CANCER GENE EXPRESSION PANEL TO ADDRESS RACIAL DIFFERENCES OF MOLECULAR ALTERATIONS IN PROSTATE CANCER Indu Kohaar, Lakshmi Ravindranath, Sreedatta Banerjee, Yongmei Chen, Amina Ali, Jacob Kagan, Sudhir Srivastava, Albert Dobi, David McLeod, Inger Rosner, Shiv Srivastava, and Gyorgy Petrovics Indu KohaarIndu Kohaar More articles by this author , Lakshmi RavindranathLakshmi Ravindranath More articles by this author , Sreedatta BanerjeeSreedatta Banerjee More articles by this author , Yongmei ChenYongmei Chen More articles by this author , Amina AliAmina Ali More articles by this author , Jacob KaganJacob Kagan More articles by this author , Sudhir SrivastavaSudhir Srivastava More articles by this author , Albert DobiAlbert Dobi More articles by this author , David McLeodDavid McLeod More articles by this author , Inger RosnerInger Rosner More articles by this author , Shiv SrivastavaShiv Srivastava More articles by this author , and Gyorgy PetrovicsGyorgy Petrovics More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1008AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Prostate cancer (CaP) affects 1 in 7 men in their life time. One of the major risk factors for the development of CaP is race/ethnicity. African American (AA) men have significantly higher incidence and mortality from CaP compared to Caucasian American (CA) men. Emerging data including ours have described significantly lower frequencies of alterations in common CaP driver genes (ERG and PTEN) in AA men as compared to CA men. We have also noted that genes commonly overexpressed in CaP (ERG, AMACR, PCA3), and currently used as diagnostic markers, exhibit much lower frequency and more heterogeneity in AA men. The goal of this study was to define a CaP marker panel that is overexpressed equally well in AA and CA CaP. METHODS Three platforms (RNASeq, NanoString and qRT-PCR) were used for evaluation of CaP associated gene expression in CA and AA patients (N=144). Candidate genes with robust tumor overexpression (over 4-fold) in CaP in paired normal and tumor specimens from AA and CA patients were selected from Nanostring and RNASeq data for validation by qRT-PCR (TaqMan) in laser microdissected (LCM) tumor and benign cells of frozen tissue sections (50 CA and 35 AA). An assay protocol (gene specific RT and pre-amplification followed by TaqMan PCR) was set up for noninvasive early detection of candidate genes in regular patient urine (non-DRE) using urinary exosomal RNA. RESULTS As expected tumor transcriptomes of CA patients consistently revealed elevated expression of PCA3 and AMACR. However, these genes had variable overexpression in AA cohort. The top genes that were similarly over expressed in tumors of AA and CA patients were validated by qRT-PCR in LCM tumor and normal epithelial cells (N=85). At least one gene of a six gene signature (DLX1, HOXC4, NKX2-3, COL10A1, HOXC6 and PSGR) was overexpressed in tumor cells of all AA and CA cases, providing a consistent ethnicity informed tumor expression signature, which was further validated in silico in TCGA RNASeq data. Urinary exosome based assay was developed and optimized for PSGR, DLX1, HOXC4, NKX2-3, as well as PCA3 and ERG. Sensitivity and specificity in a feasibility cohort (N=40) with optimal cutoff for the urine marker panel was 71% and 61%, respectively. Evaluation of the assay performance in CA and AA patients in a prospective independent cohort of 100 patients is in progress. CONCLUSIONS A CaP tissue based gene expression marker panel has been defined with potential diagnostic utility for both CA and AA men in the context of urinary exosomes. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e421-e422 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Indu Kohaar More articles by this author Lakshmi Ravindranath More articles by this author Sreedatta Banerjee More articles by this author Yongmei Chen More articles by this author Amina Ali More articles by this author Jacob Kagan More articles by this author Sudhir Srivastava More articles by this author Albert Dobi More articles by this author David McLeod More articles by this author Inger Rosner More articles by this author Shiv Srivastava More articles by this author Gyorgy Petrovics More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Predicting Prostate Cancer Progression as a Function of ETS-related Gene Status, Race, and Obesity in a Longitudinal Patient Cohort

BackgroundETS-related gene (ERG) oncogenic activation is the most common genomic alteration in prostate cancer (CaP) although it occurs less frequently in African American (AA) versus Caucasian (CA) patients, and the potential role of ERG as a prognostic marker has not been confirmed. ObjectiveThis study was conducted to confirm strong racial variation in the prevalence of ERG oncoprotein expression and to examine ERG oncoprotein expression, race, and body mass index as independent and joint predictors of CaP biochemical recurrence (BCR) following radical prostatectomy (RP). Design, setting, and participantsA retrospective cohort study of CA and AA CaP patients enrolled at Walter Reed National Military Medical Center, who donated clinically annotated, whole-mounted, prostatectomy specimens between 1994 and 2014 following RP, was conducted. Outcome measurements and statistical analysisKaplan–Meier (KM) estimation curves and multivariable Cox proportional hazards models were used to examine time to BCR as a function of ERG status, patient race, and obesity. Results and limitationsAmong 930 eligible patients (36.1% AA and 63.9% CA), with 155 (16.7%) BCR events and a median follow-up time of 5.1 yr, ERG oncoprotein expression was significantly less prevalent in index tumors of AA versus CA patients (23.2% vs 49.3%; p<0.0001). KM curves showed significantly poorer BCR-free survival for CA patients with ERG-negative index tumors but not for AA patients. Race-stratified multivariable analyses revealed a significant association between ERG-negative index tumors and poorer BCR-free survival among CA patients (hazards ratio=1.67, confidence interval=1.07, 2.61; p=0.024). Less heterogeneity in ERG expression among AA patients may reduce the ability to show its association with BCR. ConclusionsStriking racial variation in ERG oncoprotein expression was confirmed. A novel observation was the importance of index tumor ERG-negative status in predicting CaP progression for CA patients. Patient summaryETS-related gene (ERG) typing of tumors may be useful in prognosticating prostate cancer aggressiveness.

Autoantibodies against oncogenic ERG protein in prostate cancer: potential use in diagnosis and prognosis in a panel with C-MYC, AMACR and HERV-K Gag.

Overdiagnosis and overtreatment of prostate cancer (CaP) is attributable to widespread reliance on PSA screening in the US. This has prompted us and others to search for improved biomarkers for CaP, to facilitate early detection and disease stratification. In this regard, autoantibodies (AAbs) against tumor antigens could serve as potential candidates for diagnosis and prognosis of CaP. Towards this, our goals were: i) To investigate whether AAbs against ERG oncoprotein (overexpressed in 25-50% of Caucasian American and African American CaP) are present in the sera of CaP patients; ii) To evaluate an AAb panel to enhance CaP detection. The results using an enzyme-linked immunosorbent assay (ELISA) showed that anti-ERG AAbs are present in a significantly higher proportion in the sera of CaP patients compared to healthy controls (p = 0.0001). Furthermore, a panel of AAbs against ERG, AMACR and human endogenous retrovirus-K Gag successfully differentiated CaP patient sera from healthy controls (AUC = 0.791). These results demonstrate for the first time that anti-ERG AAbs are present in the sera of CaP patients. In addition, the data also suggest that AAbs against ERG together with AMACR and HERV-K Gag may be a useful panel of biomarkers for diagnosis and prognosis of CaP.

Abstract 140: LSAMP gene deletion is associated with rapid disease progression in prostate cancer of African American men

Abstract INTRODUCTION: Disproportionately higher rates of prostate cancer (CaP) incidence and mortality have been reported among African American (AA) men. Although oncogenic TMPRSS2-ERG gene fusion and deletion of the PTEN tumor suppressor gene are established cancer driver gene alterations in CaP, they are known to be more prevalent among men of European ancestry. By utilizing carefully annotated specimens, this study focused on the discovery of recurrent genomic alterations in CaP of AA men in comparison to Caucasian Americans (CA). METHODS: Genomic DNA from clinically localized primary prostate tumors (Gleason 6 or 7 with primary pattern 3) and matched peripheral blood lymphocytes of seven AA and seven CA patients, were analyzed by paired-end sequencing on Illumina Genome Analyzer IIx to a depth of 30x. Following alignment to reference genome, somatic alterations on tumor DNA that include single nucleotide variants (SNVs), insertion and deletions (Indels), structural variations, copy number variations, and inter- and intra-chromosomal translocations of tumor DNA sequence were identified. To confirm prevalent genomic deletions we performed FISH analysis on a tissue microarray constructed from 42 AA and 59 CA tumor and normal samples of an independent cohort. Frequently deleted loci were further validated by analysis of TCGA CaP SNP array data from 41 AA and 279 CA prostate tumors. RESULTS: A comparative evaluation of whole genome sequences of AA and CA CaP revealed a prevalent deletion of the LSAMP locus of chromosome 3q13.31 in AA CaP. These observations were confirmed by SNP array and FISH assays in independent cohorts of specimens. AA CaP patients with LSAMP deletion showed rapid disease progression. In contrast to higher frequency of LSAMP deletion, significantly lower frequencies of PTEN and ERG alterations were noted in CaP of AA men. Furthermore, CaP genomes of AA men displayed a higher rate of inter-chromosomal rearrangements than those from CA men. CONCLUSIONS: We highlight distinct features of AA and CA CaP genomes including common CaP driver genes (TMPRSS2- ERG, PTEN) and define a novel recurrent deletion of the LSAMP locus. This study underscores the need for careful evaluations of cancer genomes in underrepresented populations in the global context with implications for precision medicine strategies. Citation Format: Albert Dobi, Gyorgy Petrovics, Hua Li, Shyh-Han Tan, Tanja Stümpel, Denise Young, Shilpa Katta, Qiyuan Li, Kai Ying, Bernward Klocke, Lakshmi Ravindranath, Indu Kohaar, Yongmei Chen, Dezső Ribli, Korbinian Grote, Hau Zou, Joseph Cheng, Clifton L. Dalgard, Shimin Zhang, István Csabai, Jacob Kagan, David Takeda, Massimo Loda, Sudhir Srivastava, Matthias Scherf, Martin Seifert, Timo Gaiser, David G. McLeod, Zoltan Szallasi, Reinhard Ebner, Thomas Werner, Isabell A. Sesterhenn, Matthew Freedman, Shiv Srivastava. LSAMP gene deletion is associated with rapid disease progression in prostate cancer of African American men. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 140.

MP39-18 HIGHER FREQUENCY OF GERMLINE BRCA1 AND BRCA2 MUTATIONS IN AFRICAN AMERICAN PROSTATE CANCER

You have accessJournal of UrologyProstate Cancer: Detection & Screening V1 Apr 2016MP39-18 HIGHER FREQUENCY OF GERMLINE BRCA1 AND BRCA2 MUTATIONS IN AFRICAN AMERICAN PROSTATE CANCER Gyorgy Petrovics, Lakshmi Ravindranath, Yongmei Chen, Kai Ying, Amina Ali, Denise Young, David McLeod, Isabell Sesterhenn, Inger Rosner, William Dahut, Shiv Srivastava, and Michael Dean Gyorgy PetrovicsGyorgy Petrovics More articles by this author , Lakshmi RavindranathLakshmi Ravindranath More articles by this author , Yongmei ChenYongmei Chen More articles by this author , Kai YingKai Ying More articles by this author , Amina AliAmina Ali More articles by this author , Denise YoungDenise Young More articles by this author , David McLeodDavid McLeod More articles by this author , Isabell SesterhennIsabell Sesterhenn More articles by this author , Inger RosnerInger Rosner More articles by this author , William DahutWilliam Dahut More articles by this author , Shiv SrivastavaShiv Srivastava More articles by this author , and Michael DeanMichael Dean More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.143AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES BRCA1 and BRCA2 tumor suppressor proteins play a critical role in protecting genome integrity by participating in the repair of damaged DNA and have been implicated in breast, ovarian and other cancers. Mutations in BRCA2 have been linked to a higher risk of prostate cancer (CaP), and high frequency of BRCA2 and BRCA1 gene alterations were recently reported in metastatic castration resistant CaP specimens. Mutations in BRCA2 vary in racial and ethnic groups including African American (AA) and Caucasian American (CA) populations. The goal of this study was to assess the frequency and clinical correlation of BRCA1 and BRCA2 mutations in AA and CA CaP. METHODS BRCA1 and BRCA2 genes were sequenced (Ion AmpliSeq targeted sequencing) in archived blood DNA specimens (N=1139) collected from CaP patients undergoing radical prostatectomy treatment at WRNMMC. Evaluable sequences (N=1074) were analyzed for known and novel mutations in BRCA1 and BRCA2. Statistical analyses were performed (N=857 cases with complete associated data) to determine associations of the mutations with clinico-pathological parameters. RESULTS Mutations in the BRCA1 and BRCA2 genes were categorized as benign, likely benign, variant of unknown significance (VUS) and pathogenic. Pathogenic and VUS mutations in BRCA1 and BRCA2 (N=32) associated with African ancestry (7.3% in AA versus 2.2% in CA). A trend of increased metastasis frequency (9.4%) was noted in patients with pathogenic/VUS mutations compared to patients with no such mutations (2.4%). Time to metastasis was significantly shorter in patients with these mutations (Kaplan-Meier analysis, p=0.044). Analyses of BRCA2 mutations alone (N=30) showed similar association with African ancestry (7.4% in AA versus 2.1% in CA), but the shorter time to metastasis dropped to borderline significance (p=0.052). CONCLUSIONS Germline mutations in BRCA1 and BRCA2 were more frequent in AA than CA CaP patients. Patients carrying these mutations are more likely to progress to metastasis. Testing for BRCA1 and BRCA2 germline mutations, especially in AA patients, may provide useful information for treatment stratification and improving current nomograms. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e548 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Gyorgy Petrovics More articles by this author Lakshmi Ravindranath More articles by this author Yongmei Chen More articles by this author Kai Ying More articles by this author Amina Ali More articles by this author Denise Young More articles by this author David McLeod More articles by this author Isabell Sesterhenn More articles by this author Inger Rosner More articles by this author William Dahut More articles by this author Shiv Srivastava More articles by this author Michael Dean More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP90-14 DISTINCT BIOLOGICAL FEATURES OF PROSTATE TUMORS IN THE CONTEXT OF RACE/ETHNICITY AND ERG STATUS

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology IV1 Apr 2016MP90-14 DISTINCT BIOLOGICAL FEATURES OF PROSTATE TUMORS IN THE CONTEXT OF RACE/ETHNICITY AND ERG STATUS Jennifer Cullen, Denise Young, Yongmei Chen, Michael Degon, Wagner Baptist, James Farrell, Jason Sedarsky, Claire Huai-Ching Kuo, Jacob Kagan, Sudhir Srivastava, Inger Rosner, Gyorgy Petrovics, Albert Dobi, David McLeod, Shiv Srivastava, and Isabell Sesterhenn Jennifer CullenJennifer Cullen More articles by this author , Denise YoungDenise Young More articles by this author , Yongmei ChenYongmei Chen More articles by this author , Michael DegonMichael Degon More articles by this author , Wagner BaptistWagner Baptist More articles by this author , James FarrellJames Farrell More articles by this author , Jason SedarskyJason Sedarsky More articles by this author , Claire Huai-Ching KuoClaire Huai-Ching Kuo More articles by this author , Jacob KaganJacob Kagan More articles by this author , Sudhir SrivastavaSudhir Srivastava More articles by this author , Inger RosnerInger Rosner More articles by this author , Gyorgy PetrovicsGyorgy Petrovics More articles by this author , Albert DobiAlbert Dobi More articles by this author , David McLeodDavid McLeod More articles by this author , Shiv SrivastavaShiv Srivastava More articles by this author , and Isabell SesterhennIsabell Sesterhenn More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2558AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Oncogenic activation of the ERG in prostate cancer (CaP) results from tumor cell specific gene fusions (predominantly TMPRSS2-ERG) that encode truncated ERG oncoprotein. Despite the prevalence of ERG alterations in CaP, emerging reports have underscored remarkable differences in the frequency of ERG alterations among different racial/ethnic groups. In this study, ERG oncoprotein status is compared in a large cohort of African American (AA) and Caucasian American (CA) men within an equal-access military healthcare system and examined for its association with CaP progression. METHODS Representative sections of whole mounted prostatectomy specimens from AA (N=373) and CA (N=684) patients were evaluated for ERG oncoprotein status by previously established immuno-histochemistry assays that showed very high concordance between ERG oncoprotein expression and ERG genomic fusions. ERG positive or negative status of index prostate tumors was analyzed for associations with self reported race/ethnicity, BMI, tumor grade, stage, multi-focality, and biochemical recurrence (BCR) and distant metastasis. RESULTS Comparison of ERG frequencies in index tumors of AA and CA men confirmed the significantly lower rate of ERG alterations in this large cohort of AA CaP. Another striking finding was the significant association between negative ERG index tumor status with greater odds of BCR and metastasis over time for CA men, controlling for key clinical covariates. CONCLUSIONS Distinct biological behavior of ERG positive or negative tumors in the context of race was evident in this study. These data are consistent with some of the previous reports including ours. This large cohort study underscores that ERG negative index status in CA men is predictive of disease progression. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e1150 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Jennifer Cullen More articles by this author Denise Young More articles by this author Yongmei Chen More articles by this author Michael Degon More articles by this author Wagner Baptist More articles by this author James Farrell More articles by this author Jason Sedarsky More articles by this author Claire Huai-Ching Kuo More articles by this author Jacob Kagan More articles by this author Sudhir Srivastava More articles by this author Inger Rosner More articles by this author Gyorgy Petrovics More articles by this author Albert Dobi More articles by this author David McLeod More articles by this author Shiv Srivastava More articles by this author Isabell Sesterhenn More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Abstract A35: Increased expression of PCGEM1 lncRNA in prostate cancer of African American men

Abstract Introduction: Prostate cancer (CaP) affects 1 in 7 men throughout their life time. One of the major risk factors for the development of CaP is race/ethnicity. African American (AA) men have significantly higher incidence and mortality from CaP compared to Caucasian American (CA). Our laboratory and others have recently described that cancer driver genes, including ERG and PTEN, have significantly different frequencies in AA versus CA CaP. In recent years progress has been made in evaluating the expression and role of long noncoding RNAs (lncRNAs) in prostate tumorigenesis, but variations in lncRNAs expression across race/ethnicity (AA vs CA) remains poorly understood. The objective of this study is to compare the expression of CaP related lncRNAs among AA and CA men. Methods: Whole-mounted prostate sections from 30 patients, 15 AA and 15 CA matched for age, Gleason score and pathologic stage, were evaluated for the expression of lncRNAs that have been reported to be associated with CaP or other cancers. Probe sets were designed for the following 20 lncRNAs: CTBP1-AS, PCA3, PRNCR1, Hoxa11as, H19, HOTTIP, MEG3, PCGEM1, ST7OT1, SChLAP1, ANRIL/p15AS/CDK2BAS, HOTAIR, SRA-1/SRA, MALAT1/NEAT2, GAS5/SNHG2, PlncRNA-1/CBR3-AS1, Xist, hY1/RNY1, hY3/RNY3, PCAT-1. Tumor and benign epithelium was dissected under microscope from the slides, and the isolated RNA, passing BioAnalyzer quality control, was evaluated by using Nanostring platform. PCGEM1 expression analysis was updated in an existing QRT-PCR dataset of 88 patients (24 AA and 64 CA). Results: Copy numbers of each gene, normalized to ten housekeeping genes, was compared between tumor and matched normal prostate epithelium and across ethnic groups. We have identified a panel of lncRNAs (CTBP1-AS, PCA3, PCAT-1, PRNCR1) overexpressed in tumor versus matched normal samples in 95% of patients when combined. Three genes were significantly downregulated in CaP (MEG3, HOTTIP, H19). Most significantly, PCGEM1 had robust overexpression in prostate tumors (over 10-fold upregulation) only in AA patients (7 of 15) but not in CAs (0 of 15), which was in concordance with evaluation of PCGEM1 in existing dataset, underscoring selective overexpression in AA CaP. Conclusions: PCGEM1 was robustly overexpressed only in AA patients, whereas several lncRNAs were overexpressed (CTBP1-AS, PCA3, PCAT-1, PRNCR1) or downregulated (MEG3, HOTTIP, H19) in tumors of both AA and CA patients. Biomarker potential and biological functions of PCGEM1 are under further investigation. Citation Format: Jocelyn Lee, Muhammad Jamal, Wusheng Yan, Denise young, Yingjie Song, Yongmei Chen, Shilpa Katta, Lakshmi Ravindranath, Alagarsamy Srinivasan, Jennifer Cullen, Jacob Kagan, Sudhir Srivastava, Albert Dobi, Inger L. Rosner, David G. McLeod, Isabell A. Sesterhenn, Shiv Srivastava, Gyorgy Petrovics. Increased expression of PCGEM1 lncRNA in prostate cancer of African American men. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr A35.

Abstract 1859: Potential impact on the biology and biomarker utility of ERG-typing in the context of ethnic differences of prostate cancer

Abstract Introduction: In comparison to other ethnicities African American men have the highest incidence and mortality rates of prostate cancer (CaP). Recent reports on ethnic differences of ERG oncogenic activation, the most common CaP genomic alteration, provide new insights into the ERG based stratification of CaP in the context of the increasingly diverse ethnic patient populations in the United States. This rapidly advancing knowledge has potential to stratify CaP by ERG typing in a given patient population that may eventually lead to new targeted treatments. Methods: Whole-mounted prostate sections of 91 Caucasian American (CA) and 91 African American (AA) men matched for age, Gleason score and pathologic stage were analyzed for ERG oncoprotein expression. High grade tumors with a primary Gleason pattern of 4 or 5 or cumulative Gleason score of 8-10 from a total of 63 AA patients and 63 CA patients were also assessed for ERG. Hormone naïve AA CaP patients (n=306) with a minimum of two years of follow up after radical prostatectomy were evaluated for ERG frequencies in whole-mounted prostate specimens. Performance of PCA3, ERG and PSA biomarkers were evaluated in 306 post-DRE urine samples from CA and AA patients by the DTS® 400 system and by whole transcriptome analyses in selected CaP samples. The associations of biomarker scores with clinical parameters were assessed in matching biopsies and were stratified by ethnicity. Results: Remarkably higher frequencies of ERG expression was noted in the index tumors of CA (63.3%) compared to AA (28.6%) men. The observed difference was even more pronounced in higher grade disease AA (16%) and CA (49%), respectively. ERG positive tumors were more likely to be present in index tumors of younger AA men. Furthermore, ERG negative tumors were significantly associated with higher pathologic T stage. In urine assays the combination of ERG and PCA3 scores increased the AUC performance as compared to serum PSA alone (0.68 vs. 0.53, p = 0.0062) for predicting CaP in CA men. In contrast, the biomarker panel showed strikingly poor performance in AA men (AUC = 0.49). Conclusions: ERG-based stratification defines molecular subtypes and ethnic differences in the biology of CaP. Association of ERG negative status with high grade tumors and poor prognostic features in AA patients warrants the development of informative marker panels that includes ERG to aid in diagnostic, prognostic and targeted therapy settings. Citation Format: Albert Dobi, Yongmei Chen, Amina Ali, Denise Young, Philip Rosen, James Farrell, Michael Degon, Sudhir Srivastava, Jacob Kagan, Jocelyn Lee, Jennifer Cullen, Gyorgy Petrovics, David G. McLeod, Isabell A. Sesterhenn, Shiv Srivastava. Potential impact on the biology and biomarker utility of ERG-typing in the context of ethnic differences of prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1859. doi:10.1158/1538-7445.AM2014-1859