Androgen-sensitive spermine-binding protein of rat ventral prostate. Purification of the protein and characterization of the hormonal effect.
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ABSTRACT:
SUBMITTER: Mezzetti G
PROVIDER: S-EPMC1161779 | biostudies-other | 1979 Nov
REPOSITORIES: biostudies-other
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Project description:A solid-phase radioimmunoassay was developed to measure the level of the androgen-dependent spermine-binding protein (SBP) in the cytosol fraction of the rat ventral prostate during endocrine manipulation. The concentration of SBP and immunologically cross-reacting material (CRM) in the ventral prostate was at least 5000 times higher than the level of CRM detected in rat serum or cytosol from other rat tissues. Cytosol from the ventral prostate of intact rats was separated by DEAE-cellulose chromatography into three major fractions of CRM. One of these fractions corresponded to the elution position of SBP. Cytosol prepared from rats 48 h after castration lacked SBP and one of the two other fractions of CRM. This loss coincided with an increase in CRM in the remaining fraction. No significant difference was detected in the total level of CRM when intact and 48 h-castrated rats were compared. Injection of rats with 5 alpha-dihydrotestosterone (DHT) immediately after castration prevented these changes in the profile of CRM. Several proteins cross-reacting with antibodies to purified SBP were detected in cytosol by using an immunoblot procedure. The highest-Mr band corresponded to SBP. The effect of short- and long-term castration and subsequent DHT treatment on CRM was studied by using the immunoblot technique. Short-term castration (2 days) led to the disappearance of CRM coinciding with SBP (Mr 35 000-38 000) and an increase in smaller forms of CRM (Mr 24 000 and 22 000). Injection of rats with DHT 2 days after castration led to the reappearance of CRM corresponding to SBP, which returned to normal levels within 4 to 5 days of treatment. Long-term castration (up to 14 days) led to a gradual disappearance of all CRM; subsequent DHT treatment led to the reappearance of all forms of CRM and normal levels were attained within 5 days. We have identified SBP and the various forms of CRM as a secretory product of the rat ventral prostate by immunohistochemical staining and by DEAE-cellulose fractionation of prostatic fluid. Prostatic fluid is rich in proteolytic activity and these proteinases may be responsible for processing SBP to small forms of CRM.
| S-EPMC1153373 | biostudies-other
Project description:Aberrant androgen receptor (AR)-mediated transcription is a critical driver in progression of human prostate cancer. It's known that different doses of androgens can elicit differential transcriptional and proliferative responses in prostate-tumor cells. Here, we set out to examine the androgenic regulation of glycoprotein expression in the membrane fraction of prostate-tumor cells that could serve as mediators or markers of androgen-induced proliferative responses observed in prostate-tumor cells. A bioanalytical workflow involving lectin-affinity chromatography and label-free quantitative mass spectrometry was used to identify androgen-sensitive glycomembrane protein expression associated with androgen-mediated proliferation. This study would facilitate the identification of surface membrane proteins involved in androgen-mediated proliferation and provide potential therapeutic targets in the detection treatment of proliferation prostate-tumors.
2022-03-01 | PXD002913 | Pride
Project description:The androgen receptor (AR) pathway is critical for prostate cancer carcinogenesis and development; however, after 18-24 months of AR blocking therapy, patients invariably progress to castration-resistant prostate cancer (CRPC), which remains an urgent problem to be solved. Therefore, finding key molecules that interact with AR as novel strategies to treat prostate cancer and even CRPC is desperately needed. In the current study, we focused on the regulation of RNA-binding proteins (RBPs) associated with AR and determined that the mRNA and protein levels of AR were highly correlated with Musashi2 (MSI2) levels. MSI2 was upregulated in prostate cancer specimens and significantly correlated with advanced tumor grades. Downregulation of MSI2 in both androgen sensitive and insensitive prostate cancer cells inhibited tumor formation in vivo and decreased cell growth in vitro, which could be reversed by AR overexpression. Mechanistically, MSI2 directly bound to the 3'-untranslated region (UTR) of AR mRNA to increase its stability and, thus, enhanced its transcriptional activity. Our findings illustrate a previously unknown regulatory mechanism in prostate cancer cell proliferation regulated by the MSI2-AR axis and provide novel evidence towards a strategy against prostate cancer.
| S-EPMC7004550 | biostudies-literature
Project description:BackgroundAccumulating evidence suggests androgen receptor splice variant 7 (AR-V7) may be associated with the prognosis of castration-resistant prostate cancer (CRPC) received novel hormonal therapy while its characteristic and prognosis value in hormonal sensitive prostate cancer is unclear.MethodsWe aimed to evaluate the prognostic role of AR-V7 by progression free survival (PFS) and overall survival (OS) in hormonal sensitive prostate cancer (HSPC), and the AR-V7-positive-proportion difference in HSPC and CRPC. A search of PubMed, Embase, and the Web of Science was performed using the keywords prostate cancer, prostate tumor, prostate neoplasm, prostate carcinoma; AR-V7, AR3, androgen receptor splicing variant-7, or androgen receptor-3. Seventeen trials published due December 2019 were enrolled.ResultsAR-V7-positive proportion in CRPC was significantly larger than newly diagnosed prostate cancer (PCa) (odds ratio [OR] 7.06, 95% confidence interval [CI] 2.52-19.83, P < 0.001). Subgroup analyses indicated significantly higher AR-V7-positive proportion in CRPC derived from RNA in situ hybridization (OR 65.23, 95% CI 1.34-3171.43, P = 0.04), exosome RNA (OR 3.88, 95% CI 0.98-15.39, P = 0.05) and tissue RNA (OR 10.89, 95% CI 4.13-28.73, P < 0.001). AR-V7-positive patients had a significantly shorter PFS than those who were AR-V7-negative treated with first-line hormonal therapy (hazard ratio [HR] 3.63, 95% CI 1.85-7.10, P < 0.001) and prostatectomy (HR 2.49, 95% CI 1.33-4.64, P = 0.004). OS (HR 5.59, 95% CI 2.89-10.80, P < 0.001) were better in AR-V7-negative than AR-V7-positive HSPC patients treated with first-line hormonal therapy. The limitations of our meta-analysis were differences in study sample size and design, AR-V7 detection assay, and disease characteristics.ConclusionAR-V7-positive proportion was significantly higher in CRPC than that in newly diagnosed PCa. AR-V7 positive HSPC patients portend worse prognosis of first-line hormonal therapy and prostatectomy. Additional studies are warranted to confirm these findings.
| S-EPMC7201592 | biostudies-literature
Project description:BackgroundMonoamine oxidase A (MAOA) is best known for its role in neuro-transmitter regulation. Monoamine oxidase inhibitors are used to treat atypical depression. MAOA is highly expressed in high grade prostate cancer and modulates tumorigenesis and progression in prostate cancer. Here, we investigated the potential role of MAOA inhibitors (MAOAIs) in relation to the androgen receptor (AR) pathway and resistance to antiandrogen treatment in prostate cancer.MethodsWe examined MAOA expression and the effect of MAOI treatment in relation to AR-targeted treatments using the LNCaP, C4-2B, and 22Rv1 human prostate cancer cell lines. MAOA, AR-full length (AR-FL), AR splice variant 7 (AR-V7), and PSA expression was evaluated in the presence of MAOAIs (clorgyline, phenelzine), androgenic ligand (R1881), and antiandrogen (enzalutamide) treatments. An enzalutamide resistance cell line was generated to test the effect of MAOAI treatment in this model.ResultsWe observed that MAOAIs, particularly clorgyline and phenelzine, were effective at decreasing MAOA activity in human prostate cancer cells. MAOAIs significantly decreased growth of LNCaP, C4-2B, and 22Rv1 cells and produced additive growth inhibitory effects when combined with enzalutamide. Clorgyline decreased expression of AR-FL and AR-V7 in 22Rv1 cells and was effective at decreasing growth of an enzalutamide-resistant C4-2B cell line with increased AR-V7 expression.ConclusionsMAOAIs decrease growth and proliferation of androgen-sensitive and castration-resistant prostate cancer cells. Clorgyline, in particular, decreases expression of AR-FL and AR-V7 expression and decreases growth of an enzalutamide-resistant cell line. These findings provide preclinical validation of MAOA inhibitors either alone or in combination with antiandrogens for therapeutic intent in patients with advanced forms of prostate cancer.
| S-EPMC7462252 | biostudies-literature
Project description:BackgroundProstate epithelial cells depend on androgens for survival and function. In (early) prostate cancer (PCa) androgens also regulate tumor growth, which is exploited by hormonal therapies in metastatic disease. The aim of the present study was to characterize the androgen receptor (AR) response in hormonal therapy-resistant PC346 cells and identify potential disease markers.Methodology/principal findingsHuman 19K oligoarrays were used to establish the androgen-regulated expression profile of androgen-responsive PC346C cells and its derivative therapy-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A AR mutation). In total, 107 transcripts were differentially-expressed in PC346C and derivatives after R1881 or hydroxyflutamide stimulations. The AR-regulated expression profiles reflected the AR modifications of respective therapy-resistant sublines: AR overexpression resulted in stronger and broader transcriptional response to R1881 stimulation, AR down-regulation correlated with deficient response of AR-target genes and the T877A mutation resulted in transcriptional response to both R1881 and hydroxyflutamide. This AR-target signature was linked to multiple publicly available cell line and tumor derived PCa databases, revealing that distinct functional clusters were differentially modulated during PCa progression. Differentiation and secretory functions were up-regulated in primary PCa but repressed in metastasis, whereas proliferation, cytoskeletal remodeling and adhesion were overexpressed in metastasis. Finally, the androgen-regulated genes ENDOD1, MCCC2 and ACSL3 were selected as potential disease markers for RT-PCR quantification in a distinct set of human prostate specimens. ENDOD1 and ACSL3 showed down-regulation in high-grade and metastatic PCa, while MCCC2 was overexpressed in low-grade PCa.Conclusions/significanceAR modifications altered the transcriptional response to (anti)androgens in therapy-resistant cells. Furthermore, selective down-regulation of genes involved in differentiation and up-regulation of genes promoting proliferation and invasion suggest a disturbed balance between the growth and differentiation functions of the AR pathway during PCa progression. These findings may have implications in the current treatment and development of novel therapeutical approaches for metastatic PCa.
| S-EPMC3150397 | biostudies-literature
Project description:Promoter DNA methylation of CpG islands is an important epigenetic mechanism in cancer development. We have characterized the promoter methylation profile of 82 genes in three prostate cancer cell lines (LNCaP, PC3, and DU145) and two normal prostate cell lines (RWPE1 and RWPE2). The methylation pattern was analyzed using a Panomics gene array system that consists of immobilized probes of known gene promoters on a nitrocellulose membrane. Methylation binding protein-purified methylated DNA was hybridized on the membrane and detected by the chemiluminescence method. We analyzed methylation profile in normal (RWPE1) versus cancerous cells and androgen receptor (AR)-sensitive (LNCaP) versus AR-negative cells (DU145 and PC3). Our study shows that >50% of the genes were hypermethylated in prostate cancer cells compared with 13% in normal cell lines. Among these were the tumor suppressor (RB, TMS1, DAPK, RBL1, PAX6, and FHIT), cell cycle (p27KIP1 and CDKN2A), transporters (MDR1, MLC1, and IGRP), and transcription factor (STAT1, CIITA, MYOD, and NPAT) genes. Relative methylation pattern shows that most of these genes were methylated from 5-fold to >10-fold compared with the normal prostate cells. In addition, promoter methylation was detected for the first time in target genes such as RIOK3, STAT5, CASP8, SRBC, GAGE1, and NPAT. A significant difference in methylation pattern was observed between AR-sensitive versus AR-negative cancer cells for the following genes: CASP8, GPC3, CD14, MGMT, IGRP, MDR1, CDKN2A, GATA3, and IFN. In summary, our study identified candidate genes that are methylated in prostate cancer.
| S-EPMC2806502 | biostudies-literature
Project description:Although the vital role of the androgen receptor (AR) has been well demonstrated in primary prostate cancers, its role in the androgen-insensitive prostate cancers still remains unclear. Here, we used a small hairpin RNA approach to directly assess AR activity in prostate cancer cells. Reduction of AR expression in the two androgen-sensitive prostate cancer cell lines, LNCaP and LAPC4, significantly decreased AR-mediated transcription and cell growth. Intriguingly, in two androgen-insensitive prostate cell lines, LNCaP-C42B4 and CWR22Rv1, knockdown of AR expression showed a more pronounced effect on AR-induced transcription and cell growth than androgen depletion. Using cDNA microarrays, we also compared the transcriptional profiles induced by either androgen depletion or AR knockdown. Although a significant number of transcripts appear to be regulated by both androgen depletion and AR knockdown, we observed a subset of transcripts affected only by androgen depletion but not by AR knockdown, and vice versa. Finally, we demonstrated a direct role for AR in promoting tumor formation and growth in a xenograft model. Taken together, our results elucidate an important role for the AR in androgen-insensitive prostate cancer cells, and suggest that AR can be used as a therapeutic target for androgen-insensitive prostate cancers.
| S-EPMC1885678 | biostudies-literature
Project description:Androgens are required for prostate development, growth and physiology, by activating the androgen receptor (AR) upon activation by testosterone and dihydrotestosterone (DHT), the AR undergoes conformational changes, dimerizes and translocates to the cell nucleus regulation important genes releted to cell survival. Understanding the mechanisms of androgen regulation in the prostate gland is important, because the prostate is affected by several different diseases, in particular prostate cancer (PCa). Several ways exist to treat prostate cancer and promote epithelial cell death. Treatments involving androgen manipulation include surgical castration (bilateral orchiectomy), antiandrogens (usually AR antagonists), or substances that inhibit androgen synthesis (5 alpha-reductase inhibitors, gonadotrophin-releasing hormone blockers). 17 beta-estradiol exerts anti-androgen effects by blocking the hypothalamic production of gonadotropin-releasing hormone and thereby inhibiting the production of testosterone by the testes , but also acts locally via interactions with either of the estrogen receptors found in the gland. It is known that the kinetics of apoptosis are different in the rat ventral prostate (VP) of castrated rats (Cas group) and in rats subjected to 17 beta-estradiol high dose (group E2) or their combination (group Cas+E2), with an evident additive effect in the latter situation (Garcia-Florez et al, 2005). The microarray approach was done to figure out what genes are expressed and how the cells of ventral prostate gland responses when the androgen is not available comparing three diferent androgen deprivation methods (sirurgical castration, high dose of 17-beta estradiol and both treatment combined). Forty-eight 21-day-old male Wistar rats were obtained from the Multidisciplinary Center for Biological Research (CEMIB), University of Campinas. The animals were kept under normal light conditions (12-h light:dark cycle) and received filtered tap water and Purina rodent chow ad libitum. On the 90th day after birth, the rats were divided in four groups (n=3) and assigned to different treatment groups. To cause androgen deprivation, we utilized three different procedures with different effects on epithelial cell apoptosis. Animals in the first group were castrated (Cas) by orchiectomy via scrotal incision under ketamine (150 mg/Kg body weight) and xylazin (10 mg/kg body weight) anesthesia. Animals in the second group received a 25 mg/Kg body weight dose of 17β-estradiol diluted in corn oil (E2 group). The third group received a combination of both treatments (Cas+E2 group) (combined orchiectomy and 17β-estradiol). In the control group (Ct; normal androgen and estrogen), the animals received only the vehicle. Three days after the treatments, the rats were killed by anesthetic overdose, and the ventral prostate was dissected out for the microarray and immunohistochemistry analyses.
2015-03-28 | E-GEOD-56289 | biostudies-arrayexpress
Project description:Enzalutamide is the first second-generation nonsteroidal androgen receptor (AR) antagonist with a strong binding affinity to AR. Most significantly, enzalutamide can prolong not only overall survival time and metastatic free survival time for patients with lethal castration-resistant prostate cancer (CRPC), but also castration-resistant free survival time for patients with castration-sensitive prostate cancer (CSPC). Enzalutamide has thus been approved by the US Food and Drug Administration (FDA) for the treatment of both metastatic (in 2012) and non-metastatic (in 2018) CRPC, as well as CSPC (2019). This is an inspiring drug discovery story created by an amazing interdisciplinary collaboration. Equally important, the successful clinical use of enzalutamide proves the notion that the second-generation AR antagonists can serve as hormonal therapeutics for three forms of advanced prostate cancer. This has been further verified by the recent FDA approval of the other two second-generation AR antagonists, apalutamide and darolutamide, for the treatment of prostate cancer. This review focuses on the rational design and discovery of these three second-generation AR antagonists, and then highlights their syntheses, clinical studies, and use. Strategies to overcome the resistance to the second-generation AR antagonists are also reviewed.
| S-EPMC7287767 | biostudies-literature