Project description:Most prostate cancers depend on androgen and androgen receptor signaling for their proliferation and development, which underpins the efficacy of antiandrogens as powerful therapeutic agents for prostate cancers. On the other hand, interaction between AR and other nuclear hormone receptors (NRs) such as glucocorticoid receptor in the prostatic cancer or between AR and ER in breast cancers depicts the close association or “crosstalk” of AR with other NRs in terms of the new approach toward the management of hormone-resistant prostate/breast cancers. Along with this line, chemopreventive and antiproliferative action of 1,25(OH)2D3 (abbreviated as 1,25D3), an active metabolite of vitamin D3, during the management of prostate and/or breast cancers has been recently rigorously argued. We found that in its physiological concentration, 25(OH)D3 (abbreviated as 25D3), the precursor metabolite of 1,25D3 and widely-recognized as an inactive vitamin D because of its much weaker binding activity to vitamin D receptor (VDR) compared to 1,25D3, has a gene transcription profile similar to 1,25D3 in some prostate cancers. In this study, we investigated whole genome target gene profiles and intracellular behaviors of VDR after administration of 25D3 or 1,25D3 in prostate cancer LNCaP cells to elucidate the hormonal activity of 25D3. First, we confirmed that LNCaP cells possessed functional 25D3-VDR as well as 1,25D3-VDR signaling systems by qRT-PCR. By immunofluorescent examination of nuclear translocation, western blotting and most importantly, knockdown of CYP27B1 and/or VDR after the introduction of the respective siRNA into these cells, we found that, just like 1,25D3, 10-7 M of 25D3, which is within its uppermost physiological concentrations in the bloodstream, induced VDR nuclear import and robustly activated its target gene such as CYP24A1 in the virtual absence of CYP27B1 expression in LNCaP cells. These results indicate that the unconverted 25D3 alone behaved similarly to 1,25D3 in activating CYP24A1 mRNA expression. Our comprehensive microarray analyses verified the bioactivity of 25D3 and we found that 25D3 target gene profiles largely matched those of 1,25D3, while the presence a small subset of 25D3-, or 1,25D3-specific target genes were not excluded. The concentration of 1,25D3 in the culture media after 25D3 treatment with or without siRNA for CYP27B1 mRNA was below the lower limit of the sensitivity measured by ultrasensitive LC/MS/MS method. These results indicated that 25D3 shares bioactivity with 1,25D3 without conversion to the latter at least in some prostate cancer cells.
Project description:Recently, it has been reported that 25(OH)D3 (25D3) has physiological bioactivity in certain tissues derived from the Cyp27b1 knockout mice. To investigate 25D3 function in the kidney as an informational crossroad of various calciotropic substances, we employed CRISPR-Cas9 system to knock out the Cyp27b1 gene in the mouse renal tubular cell line, mDCT cells. Unlike the previously reported mice targeted to the Cyp27b1 gene systemically, Cyp27b1 knockout mDCT cells did not produce any measurable 1a,25(OH)2D3 (1,25D3) after 25D3 administration. As was seen in the treatment with 10-8 M and higher dose of 1,25D3, we found that 10-7 M of 25D3 could translocate VDR into the nucleus and promoted expression of the representative 1,25D3-responsive Cyp24a1 gene in the Cyp27b1 knockout mDCT cells. The exhaustive target gene profiles of 25D3 showed results closely mimicking those of 1,25D3. Subsequently, we confirmed that 25D3 induced the expression of a calcium reabsorption-related gene, Calbindin-D9K gene, in a similar way to 1,25D3. As another example among others, we found that both 1,25D3 and 25D3 induced the expression of Megalin gene. Our ChIP assay identified that two VDRE sites at the upstream region of the Megalin gene contributed to such gene activation. Together, we surmise that the ability to stimulate VDR target genes may provide a novel perspective with 25D3 contribution in certain tissues.
Project description:To investigate targets of miR-582-5p that which might participate in the transition to CRPC, we evaluated the gene expression profiles of LNCaP miR-582-5p cells and LNCaP EV cells using DNA microarray analysis.
Project description:To investigate targets of miR-582-5p that which might participate in the transition to CRPC, we evaluated the gene expression profiles of LNCaP miR-582-5p cells and LNCaP EV cells using DNA microarray analysis. We evaluated the gene expression profiles of LNCaP miR-582-5p cells and LNCaP EV cells using DNA microarray with GeneChipM-BM-. Human Gene 1.0 ST array.
Project description:Vitamin D (VD) exerts a wide variety of biological functions including calcemic activity. VD nutritional status is closely associated with the onset and development of chronic diseases. To develop a VD analog with the desired VD activity but without calcemic activity, we screened synthetic VDR antagonists. We identified DLAM-2b as a VDR ligand in a competitive VDR binding assay for 1α,25(OH)2 vitamin D3 (1,25D3), and DLAM-2b showed an antagonistic effect on 1,25D3-induced cell differentiation in HL60 cells. In a luciferase reporter assay in which human VDR was exogenously expressed in cultured COS1 cells, DLAM-2b acted as a transcriptional antagonist. Consistently, DLAM-2b had an antagonistic effect on the 1,25D3-induced expression of a known VD target gene (CYP24A1), and VDR-bound DLAM-2b was recruited to an endogenous VD response element in chromatin in human keratinocytes (HaCaT) and human colon cancer cells (HCT116) endogenously expressing VDR. In an ATAC-seq assay, the effects of 1,25D3 and DLAM-2b on chromatin reorganization were undetectable in HCT116 cells, while the effect of an androgen receptor (AR) antagonist (bicalutamide) was confirmed in prostate cancer cells (LNCaP) expressing endogenous AR. However, whole genome analysis using RNA-seq and ATAC-seq revealed differential gene expression profiles regulated by DLAM-2b versus 1,25D3. The upregulated and downregulated genes only partially overlapped between cells treated with 1,25D3 and those treated with DLAM-2b. Thus, the present findings illustrate a novel VDR ligand with gene regulatory activity differing from that of 1,25D3.
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: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. 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:The androgen receptor is considered as the key promoter of prostate cancer. It is a transcription factor that controls the transcription of hundreds of its target genes. In this project we focuses on how androgen receptor stimulation by the synthetic androgen R1881 can affect the proteome of peroxiosmes and the antioxidant enzymes in LNCaP cells.
Project description:We report the application of ChIP and RNA sequencing to identify the mechanism whereby stable overexpression of MED19 in androgen-dependent LNCaP cells promotes growth under conditions of androgen deprivation. We determined the MED19 and AR transcriptomes and cistromes in control and MED19 LNCaP cells. We also examined genome-wide H3K27 acetylation in both the absence and presence of androgens. We found that MED19 overexpression selectively alters AR occupancy, H3K27 acetylation, and gene expression. Under conditions of androgen deprivation, genes regulated by MED19 correspond to genes regulated by ELK1, a transcription factor that binds the AR N-terminus to induce select AR target gene expression and proliferation. This study provides important insight into the mechanisms of prostate cancer cell growth under low androgen, and underscores the importance of the MED19 in this process.