IGF-1 elevation led to the accumulation of FOXO3A in the cytosol of prostate tumor cells and downregulation of its target gene Bim, which resulted in the apoptosis inhibition and prostate cancer overgrowth.
To identify HOXB13 transcriptional targets in metastatic PCs, we performed integrative bioinformatics analysis of differentially expressed genes (DEGs) in the proximity of the human prostate tumor-specific AR binding sites.
As second-generation androgen receptor antagonists have been increasingly used for treatment of castration-resistant stage metastatic prostate cancer, new onset of symptomatic epidural lipomatosis should be considered as a possible differential diagnosis, especially because the urinary symptoms of cauda equina compression may be improperly attributed to the primary prostate neoplasm.
Here, we identified and characterized an AR circular RNA, called circAR3, that is widely expressed in PCa cell models and prostate tumors. circAR3 can be secreted into culture media of PCa cell lines and is detectable in the serum from mice bearing PCa xenografts.
Our early detection efforts led to the identification of elevated levels of antiapoptotic protein, c-FLIP and its upstream regulatory factors such as androgen receptor (AR), recepteur d'origine nantais (RON), a receptor tyrosine kinase in human prostate tumors.
These results identify HoxB13 as a pivotal upstream regulator of AR-V7-driven transcriptomes that are often cell context-dependent in CRPC, suggesting that HoxB13 may serve as a therapeutic target for AR-V7-driven prostate tumors.
Our study links AR expression heterogeneity to distinct castration/enzalutamide responses and has important implications in understanding the cellular basis of prostate tumor responses to AR-targeting therapies and in facilitating development of novel therapeutics to target AR<sup>-/lo</sup> PCa cells/clones.
High intracellular ROS levels selectively sensitize cells displaying hyperactive Akt to ROS-induced cell death enabling a therapeutic strategy combining a ROS inducer and rapamycin in PTEN-deficient prostate tumors in mouse models.
Furthermore, ADT combined with vaccination, specifically a DNA vaccine encoding the ligand-binding domain of the AR, led to improved antitumor responses as measured by tumor volumes and delays in the emergence of castrate-resistant prostate tumors in two murine prostate cancer models (Myc-CaP and prostate-specific PTEN-deficient mice).