Project description:To find novel targets regulated by AR upon DHT stimaulation at 24 hours of time point Agilent two-color ChIP on chip experiment, Organism: Homo sapiens , Agilent 2X400K Human Promoter array (AMADID: G4874A_27954)
Project description:We previously encountered regulatory processes where dihydrotestosterone (DHT) exerted its inhibitory effect on parathyroid hormone-related protein (PTHrP) gene repression through the estrogen receptor (ER)M-NM-1, but not the androgen receptor (AR) in breast cancer MCF-7 cells. Here, we investigated whether such an aberrant ligand-nuclear receptor (NR) interaction is present in prostate cancer LNCaP cells. First, we confirmed that LNCaP cells expressed a functional AR and at negligible levels of ERM-NM-1, and progesterone receptors. Both suppression of PTHrP and activation of the PSA genes were observed after treatment of E2, DHT and R5020. Consistent with the previous notion that the AR in LNCaP cells lost the ligand specificity due to a mutation AR (Thr-Ala877), our study using siRNA targeting each NR revealed that the AR, but not the other NRs, monopolized the role as the mediator of shared hormone-dependent regulation. These results were invariably associated with nuclear translocation of this mutant AR. Microarray of the genes regulated by either DHT, E2 or R5020 downstream of the AR (Thr-Ala877) revealed that more than half genes overlapped in LNCaP cells. Noticeably, AR (wild-type, wt) and AR (Thr-Ala877) were equally responsible for the E2-AR interactions. Fluorescent microscopic experiments demonstrated that both EGFP-AR (wt) and EGFP-AR (Thr-Ala877) were exclusively localized within the nucleus after E2 or DHT treatment. Further, a promoter assay revealed that breast cancer MCF-7 and Rv22 cells also exhibited such an aberrant E2-AR (wt) signaling. We postulate entangled interactions between the AR (wt) and E2 in a certain hormone-sensitive cancer cells. Total RNAs from the LNCaP cells transfected with control siRNA (siCT) or siRNA for AR (siAR) transfected LNCaP cells before 24 hr followed by exposed to 10-7M of DHT, E2 or R5020 exposure for another 24 h, respectively, were used.
Project description:Although molecular apocrine and some triple negative breast cancer tumours express high levels of AR, how AR signalling impacts their proliferative rate remains an area of controversy. The precise molecular mechanisms by which the AR can induce divergent proliferative effects in estrogen receptor-negative breast cancers has not been described. The potent androgen, DHT, inhibits proliferation of the MFM-223 estrogen receptor-negative breast cancer cell line. In contrast, activation of the AR by DHT either stimulates, or has no effect, on MDA-MB-453 cell proliferation. The AR cistrome was examined in order to identify candidate factors which mediate oncogenic versus tumour suppressive AR activity in ER-negative breast cancer.
Project description:This experiment addressed the question of whether full length Androgen receptor and Androgen Receptor variant ARv567es have similar transciptional activities. The transcriptomes of R1-AD1, a AR full length expressing cell line, are compared in an AR on (1nM DHT) to an AR off (ethanol vehicle) state. R1-D567 was derived from R1-AD1 and modified with TALENs in such a way as to express only AR-V567es. The AR on and off states were induced with a control siRNA (AR on) or a siRNA targeting exon 1 (AR off). R-AD1 was cultured for 24 hours in either base RPMI media with 1nM DHT or ethanol vehichle and RNA extracted. R1-D567 cells were electroporated with control siRNA or siRNA targeting exon 1 of AR and allowed to recover 48 hours and then cultured in base media with 1nM DHT or ethanol for 24 hrs. Each conditon was done in triplicate.
Project description:We previously encountered regulatory processes where dihydrotestosterone (DHT) exerted its inhibitory effect on parathyroid hormone-related protein (PTHrP) gene repression through the estrogen receptor (ER)α, but not the androgen receptor (AR) in breast cancer MCF-7 cells. Here, we investigated whether such an aberrant ligand-nuclear receptor (NR) interaction is present in prostate cancer LNCaP cells. First, we confirmed that LNCaP cells expressed a functional AR and at negligible levels of ERα, and progesterone receptors. Both suppression of PTHrP and activation of the PSA genes were observed after treatment of E2, DHT and R5020. Consistent with the previous notion that the AR in LNCaP cells lost the ligand specificity due to a mutation AR (Thr-Ala877), our study using siRNA targeting each NR revealed that the AR, but not the other NRs, monopolized the role as the mediator of shared hormone-dependent regulation. These results were invariably associated with nuclear translocation of this mutant AR. Microarray of the genes regulated by either DHT, E2 or R5020 downstream of the AR (Thr-Ala877) revealed that more than half genes overlapped in LNCaP cells. Noticeably, AR (wild-type, wt) and AR (Thr-Ala877) were equally responsible for the E2-AR interactions. Fluorescent microscopic experiments demonstrated that both EGFP-AR (wt) and EGFP-AR (Thr-Ala877) were exclusively localized within the nucleus after E2 or DHT treatment. Further, a promoter assay revealed that breast cancer MCF-7 and Rv22 cells also exhibited such an aberrant E2-AR (wt) signaling. We postulate entangled interactions between the AR (wt) and E2 in a certain hormone-sensitive cancer cells.
Project description:Building on the observation that metastatic, castration-resistant prostate cancer (CRPC) correlates with activation of Src-family tyrosine kinases, we showed that the expression of activated Src renders LNCaP androgen-independent. Here, we report on RNA-seq and/or AR ChIP-seq analyses of LNCaP, LNCaP[Src], VCaP, 22Rv1 cells grown in the presence or absence of 10 nM DHT for 16h, or LuCaP35.1 tumors grown in androgen-supplemented vs. castrated mice (androgen-dependent vs. castration-resistant). We identify an 11-gene Src-induced signature found only in CRPC in response to DHT, and moreover, the differentail expression of a subset (DPP4, BCAT1, CNTNAP4, CDH3) correlates with earlier PC metastasis onset and poorer survival.
Project description:Building on the observation that metastatic, castration-resistant prostate cancer (CRPC) correlates with activation of Src-family tyrosine kinases, we showed that the expression of activated Src renders LNCaP androgen-independent. Here, we report on RNA-seq and/or AR ChIP-seq analyses of LNCaP, LNCaP[Src], VCaP, 22Rv1 cells grown in the presence or absence of 10 nM DHT for 16h, or LuCaP35.1 tumors grown in androgen-supplemented vs. castrated mice (androgen-dependent vs. castration-resistant). We identify an 11-gene Src-induced signature found only in CRPC in response to DHT, and moreover, the differentail expression of a subset (DPP4, BCAT1, CNTNAP4, CDH3) correlates with earlier PC metastasis onset and poorer survival.
Project description:Identifying the effect of the co-regulator Hic-5 (TGFB1I1) on global androgen receptor transcriptional activity in PShTert-AR prostate fibroblast cells with view to further elucidating the broader biological role of Hic-5 on fibroblast spceific androgen signaling. Knockdown of Hic5 for 48 hours in PShTert-AR cells significantly altered the androgen regulation of approximately 1347 genes. The effect of Hic-5 knockdown was to suppress androgen regulation of approximately 85% of those transcripts, by either reducing androgen mediated repression or activition of gene expression. PShTert-AR cells were transfected with 10nM non-specific control siRNA (NS) or with commercially avaliable Hic-5 specific siRNA (siHic5) for 24hrs. Cells were kept in 5% hormone stripped FBS RPMI for a further 24 hours and subsequently treated with either ethanol vehicle control or 10nM DHT for 16hr. Total RNA was extracted. Nine independent vehicle and 9 DHT siNS and siHic5 samples were pooled into three groups of vechicle and DHT treated siNS and siHic5 samples and hybrydised to Affymetrix Human Gene 1.0 ST array chips.
Project description:The major pioneer factor activity of FOXA1 in PCa is to facilitate AR recruitment to androgen-regulated enhancers. Therefore, we hypothesized that the decreased FOXA1 binding and enhancer availability by LSD1 inhibition may result in the impairment of subsequent AR recruitment to enhancers. To globally test this hypothesis, we performed AR ChIP-seq in LNCaP cells treated with an LSD1 inhibitors. Consistent with previous reports, DHT treatment can dramatically induce AR binding to chromatin. Significantly, LSD1 inhibitor treatment in presence of DHT stimulation markedly decreased the total number of AR binding peaks and their intensity. We further assessed the impact of LSD1 inhibition on overall AR transcriptional output using RNA-seq data.