Project description:Background: Most forms of castration-resistant prostate cancer (CRPC) are dependent on the androgen receptor (AR) for survival. While, enzalutamide provides a substantial survival benefit, it is not curative and many patients develop resistance to therapy. Although not yet fully understood, resistance can develop through a number of mechanisms, such as AR copy number gain, the generation of splice variants such as AR-V7 and mutations within the ligand binding domain (LBD) of the AR. Circular RNAs (circRNAs) are a novel type of non-coding RNA, which can regulate the function of miRNA, and may play a key role in the development of drug resistance. CircRNAs are highly resistant to degradation, are detectable in plasma and, therefore may serve a role as clinical biomarkers. Methods: AR-V7 expression was assessed in an isogenic model of enzalutamide resistance. The model consisted of age matched control cells and two sub-lines displaying varied resistance to enzalutamide. circRNA profiling was performed on the panel using a high throughout microarray assay. Bioinformatic analysis identified a number of differentially expressed circRNAs and predicted five miRNA binding sites for each circRNA. miRNAs were stratified based on known associations with prostate cancer, and targets were validated using qPCR. Results: Overall, circRNAs were more often down regulated in resistant cell lines compared with control (588 vs. 278). Of particular interest was hsa_circ_0004870 (Probe ID ASCRP3009662), which was down-regulated in enzalutamide resistant cells (p≤0.05, vs. sensitive cells), decreased in AR positive cells (p≤0.01, vs. AR negative), and in malignant cells (p≤0.01, vs. benign). The associated parental gene was identified as RBM39, a member of the U2AF65 family of proteins. Both genes were down-regulated in resistant cells (p<0.05, vs. sensitive cells). Conclusion: This is one of the first studies to profile and demonstrate discrete circRNA expression patterns in an enzalutamide resistant cell line model of prostate cancer. Our data suggests that hsa_circ_0004870, through RBM39, may play a critical role in the development of enzalutamide resistance in CRPC.
Project description:Prostate cancer is one of the major cancers that seriously affect men's health. It has high morbidity and high mortality, but there is still no ideal molecular markers for the diagnosis and prognosis of prostate cancer. Castration-resistant prostate cancer is associated with wide variations in survival. To determine whether differentially expressed circRNAs in plasma exosomes can be used as a novel biomarker for castration-resistant prostate cancer prognosis, we performed high-throughput circRNA sequencing on 15 pairs of plasma exosomes from 30 metastatic castration-resistant prostate cancer patients, with or without early progression, to screen differentially expressed circRNAs.
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. To investigate the AR signaling, we performed ChIP sequence analysis in AR-positive prostate cancer cell lines, LNCaP and VCaP. In addition, we also examined the effect of PI polyamide specificly inhibit Oct1 binding to AR occupied-regions. ChIP sequence analysis of AR binding sites and epigenetic condition in two prostate cancer cells
Project description:Prostate cancer cell lines DU145 and LNCaP were purchased from the American Type Culture Collection. Radioresistant (RR) sublines were generated form these original parental radiosensitive (RS) cell lines. aCGH profiles of radiosensitive (RS) and radioresistant (RR) prostate cancer cell lines were measured and compared to normal DNA.
Project description:We report the high-throughput profiling of AR binding in prostate cancer cells. Examination of AR binding in prostate cancer cell lines VCaP and VCS2