Project description:To investigate the mechanisms of drug resistance and castration resistance in prostate cancer, we performed proteomic sequencing on androgen-dependent prostate cancer cells (LNCaP) and androgen-independent cells (AI) treated with enzalutamide.
Project description:The Wnt/β-catenin-signaling pathway is modulated by androgen ablation therapy for advanced clinical prostate cancer and contributes to androgen independent cell growth
Project description:Prostate epithelial cells depend on androgens for survival and function. In early prostate cancer, besides survival, androgens also regulated tumor growth, which is exploited by androgen ablation/ blockade therapies in metastatic disease. The aim of the present study was to characterize the role of the androgen receptor pathway in prostate cancer progression and to identify potential disease markers. Microarray analysis was used to establish the androgen-regulated gene expression profile, upon stimulation with the synthetic androgen R1881 or the antiandrogen hydroxyflutamide, of the androgen-responsive PC346C cell line and its derivative castration-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A mutated AR)
Project description:Prostate epithelial cells depend on androgens for survival and function. In early prostate cancer, besides survival, androgens also regulated tumor growth, which is exploited by androgen ablation/ blockade therapies in metastatic disease. The aim of the present study was to characterize the role of the androgen receptor pathway in prostate cancer progression and to identify potential disease markers. Microarray analysis was used to establish the androgen-regulated gene expression profile, upon stimulation with the synthetic androgen R1881 or the antiandrogen hydroxyflutamide, of the androgen-responsive PC346C cell line and its derivative castration-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A mutated AR) PC346C, PC346DCC, PC346Flu1 and PC346Flu2 were stimulated with 1 nM R1881, 1uM hydroxyflutamide or vehicle control, following a 4, 8 and 16h time-course. Each condition was performed in dye-swap, using biological duplicates. PC346DCC was only stimulated with R1881, not hydroxyflutamide.
Project description:In castration-resistant prostate cancer (CRPC), clinical response to androgen receptor (AR) antagonists is limited mainly due to AR-variants expression and restored AR signaling. The metabolite spermine is most abundant in prostate and it decreases as prostate cancer progresses, but its functions remain poorly understood. Here, we show spermine inhibits full-length androgen receptor (AR-FL) and androgen receptor splice variant 7 (AR-V7) signaling and suppresses CRPC cell proliferation by directly binding and inhibiting protein arginine methyltransferase PRMT1. Spermine reduces H4R3me2a modification at the AR locus and suppresses AR binding as well as H3K27ac modification levels at AR target genes. Spermine supplementation restrains CRPC growth in vivo. PRMT1 inhibition also suppresses AR-FL and AR-V7 signaling and reduces CRPC growth. Collectively, we demonstrate spermine as an anticancer metabolite by inhibiting PRMT1 to transcriptionally inhibit AR-FL and AR-V7 signaling in CRPC, and we indicate spermine and PRMT1 inhibition as powerful strategies overcoming limitations of current AR-based therapies in CRPC.
Project description:Androgen receptor (AR) is the major therapeutic target in aggressive prostate cancer. However, targeting AR alone can result in drug resistance and disease recurrence. Therefore, simultaneous targeting of multiple pathways could in principle be an effective new approach to treating prostate cancer. Here we provide proof-of-concept that a small molecule inhibitor of nuclear β-catenin activity (called C3) can inhibit both the AR and β-catenin signaling pathways that are often misregulated in prostate cancer. Treatment with C3 ablated prostate cancer cell growth by disruption of both β-catenin/TCF and β-catenin/AR protein interaction, reflecting the fact that TCF and AR have overlapping binding sites on β-catenin. Given that AR interacts with, and is transcriptionally regulated by β-catenin, C3 treatment also resulted in decreased occupancy of β-catenin on the AR promoter and diminished AR and AR/β-catenin target gene expression. Interestingly, C3 treatment resulted in decreased AR binding to target genes accompanied by decreased recruitment of an AR and β-catenin cofactor, CARM1, providing new insight into the unrecognized function of β-catenin in prostate cancer. Importantly, C3 inhibited tumor growth in an in vivo xenograft model, and blocked renewal of bicalutamide-resistant sphere forming cells, indicating the therapeutic potential of this approach. Compare and contrast the expression profile of prostate cancer cells treated with a Wnt inhibitor (C3) with respect to β-catenin and AR knockdown (all samples in duplicates).