Project description:More effective therapeutic approaches for castration-resistant prostate cancer (CRPC) are urgently needed, thus reinforcing the need to understand how prostate tumors progress to castration resistance. We have established a novel mouse xenograft model of prostate cancer, KUCaP-2, which expresses the wild-type androgen receptor (AR) and which produces the prostate-specific antigen (PSA). In this model, tumors regress soon after castration, but then reproducibly restore their ability to proliferate after 1 to 2 months without AR mutation, mimicking the clinical behavior of CRPC. In the present study, we used this model to identify novel therapeutic targets for CRPC. Evaluating tumor tissues at various stages by gene expression profiling, we discovered that the prostaglandin E receptor EP4 subtype (EP4) was significantly upregulated during progression to castration resistance. Immunohistochemical results of human prostate cancer tissues confirmed that EP4 expression was higher in CRPC compared with hormone-naïve prostate cancer. Ectopic overexpression of EP4 in LNCaP cells (LNCaP-EP4 cells) drove proliferation and PSA production in the absence of androgen supplementation in vitro and in vivo. Androgen-independent proliferation of LNCaP-EP4 cells was suppressed when AR expression was attenuated by RNA interference. Treatment of LNCaP-EP4 cells with a specific EP4 antagonist, ONO-AE3-208, decreased intracellular cyclic AMP levels, suppressed PSA production in vitro, and inhibited castration-resistant growth of LNCaP-EP4 or KUCaP-2 tumors in vivo. Our findings reveal that EP4 overexpression, via AR activation, supports an important mechanism for castration-resistant progression of prostate cancer. Furthermore, they prompt further evaluation of EP4 antagonists as a novel therapeutic modality to treat CRPC. 4 samples in each group: androgen-dependent growth (AD), castration-induced regression nadir (ND), and castration-resistant regrowth (CR) stages
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. Androgen-deprivation therapy is the first-line treatment strategy for advanced prostate cancer. However, many tumors develop to castration-resistant prostate cancer (CRPC) and relapse. Thus, analyzing key factors for development of CRPC is important. We found PSF functions as RNA binding protein and transcription factor to promote castration-resistant tumor growth. High expression of PSF in metastatic prostate cancer tissue indicates the clinical relevance. In order to investigate the PSF function in CRPC cells, we performed gene expression in CRPC model cells derived from AR-positive prostate cancer cell lines after siPSF treatment.
Project description:The purpose of the study was to characterize the properties of human prostate cancer VCaP tumors pre- and post-castration. The main focus was on androgen signaling, androgen metabolism and steroid synthesis. Results provide valuable information about how castration-resistant tumors (CRPC) are able grow in absence of gonadal androgens. One million VCaP cells were inoculated orthotopically into the dorsolateral prostate of nude mice through an abdominal incision. Tumor growth was followed by serum PSA measurements. Intact mice were sacrificed and tumors were collected 3-14 weeks after inoculation (Intact 1, Intact 2). Mice in the remaining three groups (GNX, CRPC 1, CRPC 2) were castrated by removing the testes. Mice were sacrificed and tumors were collected one day after castration (GNX) or 3-14 weeks after castration (CRPC 1, CRPC 2) in castration-resistant stage. 4 tumors were selected from each study group, totally 20 tumors.
Project description:Castration-resistant prostate cancer (CRPC) that arise after the failure of androgen deprivation therapy is a leading cause of deaths in prostate cancer patients.However, its underlying mechanism is not fully understood. Long noncoding RNAs (lncRNAs) act as crucial regulators in a lot of human cancers, yet their potential roles and molecular mechanisms in CRPC are poorly understood.The goal of this study is to identify the differentially expressed lncRNAs in LNCaP cells and its two castration resistant sublines. Our study reveals that deregulation of lncRNAs is involved in the initiation and progression of CRPC.
Project description:Prostate cancer is the most common cancer in men and androgen receptor (AR) downstream signalings promote prostate cancer progression. Although androgen deprivation therapy is effective for treating prostate cancer, most of tumors relapsed as castration-resistant prostate cancer (CRPC). We performed ChIP-seq analysis to investigate the role of AR-associated factors and histone modifications using CRPC model cells, 22Rv1.
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:We generate transcription factor, histone modification and ATAC cistromes in castration-resistant prostate cancer (CRPC) and treatment-induced neuroendocrine prostate cancer (tNEPC) specimens.
Project description:Prostate cancer is the most common cancer in men and androgen receptor (AR) downstream signalings promote prostate cancer progression. Although androgen deprivation therapy is effective for treating prostate cancer, most tumors relapsed as castration-resistant prostate cancer (CRPC). We performed ChIP-seq analysis to investigate the role of important transcription factors and histone modifications using AR positive prostate cancer cells, LNCaP, CRPC model cells, 22Rv1 and DU145 cells.
Project description:EZH2 is frequently over-expressed in aggressive and metastatic solid tumors, including castration resistant prostate cancer (CRPC). We sought to determine EZH2-dependent gene expression programmes in prostate cancer progression, and found an intriguing functional switch of EZH2 from a repressor to an activator during CRPC development. We used microarrays to detail the global profiling of gene expression that are differentially regulated upon EZH2 depletion in two different prostate cancer cell lines. The androgen-dependent prostate cancer cell line LNCaP and the LNCaP-derived androgen-independent cell line LNCaP-abl (abl) were used for this study, as their transcription profiles strongly resemble that of clinical androgen-dependent and castration resistant prostate tumors, respectively. EZH2 was silenced by specific siRNAs in both cell lines, and total RNA was extracted and hybridized on Affymetrix microarrays.
Project description:To investigate if there is a difference of N6-methyladenosine(m6A) modification between castration-resistant prostate cancer (CRPC) and castration-sensitive prostate cancer (CSPC), we collected 30 specimens, including 15 CRPC and 15 CSPC, to perform RNA-seq and MeRIP-seq. All specimens were postoperative tissues and each 5 CRPC or CSPC specimens were mixed into 1 sample to meet the RNA dosage of RNA-seq and MeRIP-seq.