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Smiraglia, D. J.

Publications and source records attributed to Smiraglia, D. J..

3 recordsLinked to original sources

Racial differences in androgen metabolism and receptor signaling in prostate cancer

Dihydrotestosterone (DHT) and testosterone (T) mediated androgen receptor (AR) nuclear translocation initiates transcription of AR target genes that are pivotal for prostate cancer (PrCa) development and progression. Here we provide data indicating that in contrast to European American (EA) men, African American (AA) men with localized PrCa can exploit an alternative progesterone-androsterone-5-androstanedione pathway for DHT biosynthesis. Enzymes that are involved in alternate pathways of DHT biosynthesis are elevated in PrCa tissues from AA men, compared to EA men, and also correlated with increased serum DHT levels. In addition, higher serum DHT levels reflect increased RNA expression of AR target genes in PrCa tissues from AA men. Interestingly, serum T but not DHT levels are significantly lower in AA men compared to EA men with PrCa. Furthermore, serum progesterone and related intermediate metabolites levels that are produced during alternate pathways of DHT biosynthesis are significantly lower in AA men with PrCa and associated with a shorter time to disease progression. These data highlight that androgen biosynthesis is altered in therapy naive localized PrCa in AA men, and can potentially serve as prognostic indicators of disease progression. SignificanceOur work provides a rationale to examine potential pharmacological interventions that target androgen biosynthesis and AR signaling earlier in the disease continuum in AA men with PrCa. Additionally, our study lays the groundwork for developing serum measurements of intermediate androgen metabolites as PrCa prognostic biomarkers. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=147 SRC="FIGDIR/small/437727v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@932dd0org.highwire.dtl.DTLVardef@a4cca0org.highwire.dtl.DTLVardef@1764be4org.highwire.dtl.DTLVardef@1708a63_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Pan-cancer analysis of transcriptional metabolic dysregulation using The Cancer Genome Atlas

Understanding the levels of metabolic dysregulation in different disease settings is vital for the safe and effective incorporation of metabolism-targeted therapeutics in the clinic. Using transcriptomic data from 10,704 tumor and normal samples from The Cancer Genome Atlas, across 26 disease sites, we developed a novel bioinformatics pipeline that distinguishes tumor from normal tissues, based on differential gene expression for 114 metabolic pathways. This pathway dysregulation was confirmed in separate patient populations, further demonstrating the robustness of this approach. A bootstrapping simulation was then applied to assess whether these alterations were biologically meaningful, rather than expected by chance. We provide distinct examples of the types of analysis that can be accomplished with this tool to understand cancer specific metabolic dysregulation, highlighting novel pathways of interest in both common and rare disease sites. Utilizing a pathway mapping approach to understand patterns of metabolic flux, differential drug sensitivity, can accurately be predicted. Further, the identification of Master Metabolic Transcriptional Regulators, whose expression was highly correlated with pathway gene expression, explains why metabolic differences exist in different disease sites. We demonstrate these also have the ability to segregate patient populations and predict responders to different metabolism-targeted therapeutics.

bioinformatics↗

The miR-96/RARγ signaling axis governs androgen signaling and PCa progression

Expression levels of retinoic acid receptor gamma (NR1B3/RARG, encodes RAR{gamma}), are commonly reduced in prostate cancer (PCa). Therefore we sought to establish the cellular and gene regulatory consequences of reduced RAR{gamma} expression, and determine RAR{gamma} regulatory mechanisms. RARG shRNA approaches in non-malignant (RWPE-1 and HPr1-AR) and malignant (LNCaP) prostate models revealed that reducing RAR{gamma} levels, rather than adding exogenous retinoid ligand, had the greatest impact on prostate cell viability and gene expression. ChIP-Seq defined the RAR{gamma} cistrome which was significantly enriched at active enhancers associated with AR binding sites. Reflecting a significant genomic role for RAR{gamma} to regulate androgen signaling, RAR{gamma} knockdown in HPr1-AR cells significantly regulated the magnitude of the AR transcriptome. RAR{gamma} down-regulation was explained by increased miR-96 in PCa cell and mouse models, and TCGA PCa cohorts. Biochemical approaches confirmed that miR-96 directly regulated RAR{gamma} expression and function Capture of the miR-96 targetome by biotin-miR96 identified that RAR{gamma} and a number of RAR{gamma} interacting co-factors including TACC1 were all targeted by miR-96, and expression of these genes were prominently altered, positively and negatively, in the TCGA-PRAD cohort. Differential gene expression analyses between tumors in the TCGA-PRAD cohort with lower quartile expression levels of RARG and TACC1 and upper quartile miR-96, compared to the reverse, identified a gene network including several RAR{gamma} target genes (e.g. SOX15) that significantly associated with worse disease free survival (hazard ratio 2.23, 95% CI 1.58 to 2.88, p=0.015). In summary, miR-96 targets a RAR{gamma} network to govern AR signaling, PCa progression and disease outcome.\n\nConflict of interestThe authors certify that they have NO affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.\n\nFUNDINGLESC acknowledges support, in part, of Roswell Park Comprehensive Cancer Center-University of Pittsburg Cancer Institute Ovarian Cancer Specialized Program of Research Excellence National Institutes of Health [P50CA159981-01A1].\n\nMDL acknowledges support of Molecular Pharmacology and Experimental Therapeutics NRSA T32 program [T32CA009072] held at Roswell Park Comprehensive Cancer Center.\n\nMJC and DJS acknowledges support in part from the Prostate program of the Department of Defense Congressionally Directed Medical Research Programs [W81XWH-14-1-0608, W81XWH-11-2-0033] and the National Cancer Institute (NCI) grant P30CA016056 involving the use of Roswell Park Comprehensive Cancer Centers Genomic Shared Resource.\n\nMJC, GL, AR, HW and PvdB acknowledges support from the European Union-United States Atlantis Program [P116J090011].\n\nMJC and LESC acknowledge support from the National Cancer Institute (NCI) grant P30CA016056 involving the use of OSUCCC The James, CCSG P30CA016058

cancer biology↗