Currently, metastatic castration-resistant prostate cancer (CRPC) is invariably and unfortunately a lethal disease. The vast majority of CRPC is dependent upon and driven by androgen receptor (AR) signaling. While recent advances have resulted in the development of second generation therapeutics targeting the androgen signaling axis (e.g. enzalutamide and abiraterone), the responses to these new agents are often not durable. Thus, there is a clear and urgent need to develop completely new therapeutic approaches directed against the AR axis. Recently, our team identified a novel strategy for targeting the AR signaling axis via inhibition of bromodomain containing 4 (BRD4), a conserved member of the bromodomain and extraterminal (BET) family of transcriptional co-activators (In Revision at Nature). We discovered that AR physically interacts with BRD4, and that treatment with the BET-bromodomain inhibitor JQl disrupts the AR-BRD4 interaction as well as AR recruitment to target gene loci. Compared to the direct AR antagonist enzalutamide, BET bromodomain inhibitors are much more effective in inhibition of AR-mediated gene transcription, including induction of AR targets such as TMPRSS2:ERG and PSA. Significantly, JQ1 was also more effective than enzalutamide in inhibiting the growth of CRPC xenografts. Based upon our findings, we hypothesize that BET bromodomain inhibition is a promising approach for targeting the AR axis and for treating advanced prostate cancer. Our goal in this SPORE project is to develop a potent BET-bromodomain small-molecule inhibitor (BET inhibitor) with optimized in vivo properties for the treatment of advanced prostate cancer through the following specific aims:
Aim 1 : Develop a highly potent and selective BET inhibitor with optimized in vivo properties Aim 2: Interrogate the AR-BRD4 signaling axis with novel BET inhibitors.
Aim 3 : Establish the efficacy of BET bromodomain inhibitors using in vivo and ex vivo tumor models, and develop biomarkers of response. Upon successful completion of the Aims, we expect to nominate promising candidate(s) that could be developed further for clinical use to treat metastatic CRPG. The ultimate goal of this project is introduce BET bromodomain inhibitors as a novel therapy for CRPC based on a unique understanding of its mechanism of action.
We showed that AR physically interacts with BET proteins, and that treatment with preclinical BET inhibitors disrupts this interaction as well as the ability of AR to turn on its target genes. In preclinical experiments, BET inhibition is more effective than conventional anti-androgen therapies in blocking prostate tumor growth. Based on these findings, we seek to further develop BET inhibition as a strategy for treating CRPC patients.
|Zhang, Yajia; Pitchiaya, Sethuramasundaram; Cie?lik, Marcin et al. (2018) Analysis of the androgen receptor-regulated lncRNA landscape identifies a role for ARLNC1 in prostate cancer progression. Nat Genet 50:814-824|
|Hussain, Maha; Daignault-Newton, Stephanie; Twardowski, Przemyslaw W et al. (2018) Targeting Androgen Receptor and DNA Repair in Metastatic Castration-Resistant Prostate Cancer: Results From NCI 9012. J Clin Oncol 36:991-999|
|Salami, Simpa S; Hovelson, Daniel H; Kaplan, Jeremy B et al. (2018) Transcriptomic heterogeneity in multifocal prostate cancer. JCI Insight 3:|
|Zhao, Shanshan; Leonardson, Amy; Geybels, Milan S et al. (2018) A five-CpG DNA methylation score to predict metastatic-lethal outcomes in men treated with radical prostatectomy for localized prostate cancer. Prostate :|
|Niknafs, Yashar S; Pandian, Balaji; Gajjar, Tilak et al. (2018) MiPanda: A Resource for Analyzing and Visualizing Next-Generation Sequencing Transcriptomics Data. Neoplasia 20:1144-1149|
|Xiao, Lanbo; Tien, Jean C; Vo, Josh et al. (2018) Epigenetic Reprogramming with Antisense Oligonucleotides Enhances the Effectiveness of Androgen Receptor Inhibition in Castration-Resistant Prostate Cancer. Cancer Res 78:5731-5740|
|Piert, Morand; Shankar, Prasad R; Montgomery, Jeffrey et al. (2018) Accuracy of tumor segmentation from multi-parametric prostate MRI and 18F-choline PET/CT for focal prostate cancer therapy applications. EJNMMI Res 8:23|
|Wu, Yi-Mi; Cie?lik, Marcin; Lonigro, Robert J et al. (2018) Inactivation of CDK12 Delineates a Distinct Immunogenic Class of Advanced Prostate Cancer. Cell 173:1770-1782.e14|
|Rice, John D; Tsodikov, Alex (2017) Semiparametric profile likelihood estimation for continuous outcomes with excess zeros in a random-threshold damage-resistance model. Stat Med 36:1924-1935|
|Shen, Rex; Luo, Lan; Jiang, Hui (2017) Identification of gene pairs through penalized regression subject to constraints. BMC Bioinformatics 18:466|
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