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.
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.
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: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:The molecular drivers for the AR signaling reprogramming in castration-resistant prostate cancer remain to be determined. In this study, we hypothesize that increased AR expression in conjunction with lower-level androgens, which is a typical condition in prostate cancer cells receiving androgen deprivation therapy, is a major driving force of the reprogramming. To test this, we used LNCaP model with inducible overexpression of AR to examine the acute effects of AR overexpression stimulated by low-dose DHT (0.1nM) on AR cistrome.
Project description:(1) Transcription profiling of MDA-PCa-2b cells comparing ARlnc1 knockdown treated cells with control cells. Two methods were used to knockdown ARlnc1: siRNA or ASO. (2) Transcription profiling of MDA-PCa-2b cells comparing dihydrotestosterone (DHT) stimulated cells with vehicle treated cells. The goal is to determine AR-regulated gene expression signature in MDA-PCa-2b cells.
Project description:The molecular drivers for the AR signaling reprogramming in castration-resistant prostate cancer remain to be determined. In this study, we hypothesize that increased AR expression in conjunction with lower-level androgens, which is a typical condition in prostate cancer cells receiving androgen deprivation therapy, is a major driving force of the reprogramming. To test this, we used LNCaP model with inducible overexpression of AR to examine the acute effects of AR overexpression stimulated by DHT on AR transcriptome.
Project description:Gene expression data from AML cell lines, MOLM-14, U937, THP-1 and HL-60, that were infected with a scrambled control hairpin (shControl), two shRNAs directed against GSK-3B (shGSK3B_1 and shGSK3B_2), or two shRNAs directed against GSK-3A (shGSK3A_5 and shGSK3A_6). Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults. Long-term survival of patients with AML has changed little over the past decade, necessitating the identification and validation of new AML targets. Integration of genomic approaches with small-molecule and genetic-based high-throughput screening holds the promise of improved discovery of candidate targets for cancer therapy. Here, we identified a role for glycogen synthase kinase 3A (GSK-3A) in AML by performing two independent small-molecule library screens and an shRNA screen for perturbations that induced a differentiation expression signature in AML cells. GSK-3 is a serine-threonine kinase involved in diverse cellular processes including differentiation, signal transduction, cell cycle regulation, and proliferation. We demonstrated that specific loss of GSK-3A induced differentiation in AML by multiple measurements, including induction of gene expression signatures, morphological changes, and cell surface markers consistent with myeloid maturation. GSK-3AM-bM-^@M-^Sspecific suppression also led to impaired growth and proliferation in vitro, induction of apoptosis, loss of colony formation in methylcellulose, and anti-AML activity in vivo. Although the role of GSK-3B has been well studied in cancer development, these studies support a role for GSK-3A in AML. The AML cell lines, MOLM-14, U937, THP-1 and HL-60, were infected with a scrambled control hairpin (shControl), two shRNAs directed against GSK-3B (shGSK3B_1 and shGSK3B_2), and two shRNAs directed against GSK-3A (shGSK3A_5 and shGSK3A_6).