Project description:Expression data from DHT stimulation vs. control in LNCaP cells LNCaP cells were maintained in phenol red-free RPMI supplemented with 10% charcoal/dextran stripped FCS for three days before stimulation with 100 nM dihydrotestosterone (DHT) for 48 hours
Project description:Microarray experiments were carried out to ascertain whether TOP2β is required for DHT induced androgen receptor target gene expression. We investigated the effect of pharmacological inhibition or RNA interference-mediated depletion of TOP2β on gene expression in androgen-dependent LNCaP prostate cancer cells. Analysis of gene expression in LNCaP cells under various conditions including serum starvation, DHT treatment, and DHT treatment combined with TOPO2B pharmacological inhibitors (Merbarone and Etoposide) and TOPO2B-shRNA knockdown.
Project description:Microarray experiments were carried out to ascertain whether TOP2β is required for DHT induced androgen receptor target gene expression. We investigated the effect of pharmacological inhibition or RNA interference-mediated depletion of TOP2β on gene expression in androgen-dependent LNCaP prostate cancer cells.
Project description:Enzalutamide (formerly MDV3100 and available commercially as Xtandi), a novel androgen receptor (AR) signaling inhibitor, blocks the growth of castration-resistant prostate cancer (CRPC) in cellular model systems and was shown in a clinical study to increase survival in patients with metastatic CRPC. Enzalutamide inhibits multiple steps of AR signaling: (1) binding of androgens to AR, (2) AR nuclear translocation, and (3) association of AR with DNA. Here we used Affymetrix human genome microarray technology to investigate the global programme of gene expression of LNCaP cells in response to enzalutamide alone and in the context of DHT-stimulated androgen receptor gene expression. LNCaP cells were grown in RPMI 1640 supplemented with 5% hormone depleted FBS and treated with vehicle (control sample) , DHT (100 nM), enzalutamide (1 or 10 M-BM-5M) or DHT (100 nM) plus enzalutamide (1 or 10 M-BM-5M)for 16 hours for RNA extraction and hybridization. Each condition 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)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:ABSTRACT The effects of DHEA were compared with those of DHT using gene expression array profiles in human LNCaP prostate cancer cells. LNCaP cells were exposed to DHEA (300 nM), DHT (300 nM), or vehicle for 48 hrs, and mRNA was isolated. mRNA expression was measured using Affymetrix HU-95 gene chips in 3 experiments performed on different dates. Gene expression values for the two treatment groups and control were sorted in ascending order on the p-values corresponding to a variance stabilized Hotelling test, which measured the extent of differential RNA expression between control and either hormone treatment. The top four genes with significant differential expression were S100 calcium binding protein, neurotensin, 24-dehydrocholesterol reductase, and anterior-gradient 2 homologue. Corresponding per comparison p-values were less than 3 x 10 -5. Nested tests of differential expression between DHEA and DHT treatment revealed significant differences (p < 0.01) for two of the four genes: the S100 calcium binding protein and neurotensin. The microarray findings were confirmed by quantitative RT-PCR. The top 83 genes found to exhibit differential expression were used in a pathway analysis. In general, DHT decreased expression of more genes involved in intercellular communication, signal transduction, nucleic acid binding and transport, and in structural components, such as myosin and golgin, than did DHEA. These data reveal consistent, measurable differences in gene expression patterns following treatment of LNCaP prostate cancer cells with DHEA versus DHT. The mechanisms underlying these observations, and the possible pathophysiological significance of these differences, remain to be determined. Keywords: differential gene expression between DHT and DHEA
Project description:Enzalutamide (formerly MDV3100 and available commercially as Xtandi), a novel androgen receptor (AR) signaling inhibitor, blocks the growth of castration-resistant prostate cancer (CRPC) in cellular model systems and was shown in a clinical study to increase survival in patients with metastatic CRPC. Enzalutamide inhibits multiple steps of AR signaling: (1) binding of androgens to AR, (2) AR nuclear translocation, and (3) association of AR with DNA. Here we used Affymetrix human genome microarray technology to investigate the global programme of gene expression of LNCaP cells in response to enzalutamide alone and in the context of DHT-stimulated androgen receptor gene expression.
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:Androgen receptor (AR) is a ligand-dependent transcription factor that plays a key role in the onset and progression of prostate cancer. We investigated AR-induced gene expression in prostate cancer cells LNCaP and abl by transfecting siAR / siControl or treating cells with androgen (DHT) over a time course. Keywords: siRNA transfection and androgen stimulation time course