Androgen dynamics in vitro in the human prostate gland. Effect of cyproterone and cyproterone acetate.
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ABSTRACT:
SUBMITTER: Giorgi EP
PROVIDER: S-EPMC1177610 | biostudies-other | 1973 Mar
REPOSITORIES: biostudies-other
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Project description:Normal, hyperplastic and adenocarcinomatous human prostatic tissue was perfused in vitro with radioactively labelled androstenedione, testosterone and 5alpha-dihydrotestosterone with and without added oestradiol-17beta. Various parameters of tissue-steroid relationship were measured at the steady state. When oestradiol (0.11 or 0.22mumol/l) was added to the perfusing medium, the entry of the steroids into the tissue and their metabolism was increased in the majority of the glands studied. The ;uptake' of all the steroids varied, in response to the addition of oestradiol, in both normal and adenocarcinomatous glands in a way differing from the response of hyperplastic glands. As a consequence, the tissue clearance of the steroids, particularly of androstenedione and testosterone, increased in normal and adenocarcinomatous glands in the presence of oestradiol, and decreased in the hyperplastic tissues. At a concentration 0.33mumol/l, oestradiol decreased the entry of the steroids in all the tissues studied, while the clearance of steroids tended to decrease. The significance of these findings in terms of the regulation of androgen dynamics in vivo in the normal and diseased human prostate, with particular regard to the response to oestrogen treatment, is discussed.
| S-EPMC1178356 | biostudies-other
Project description:The dynamics of uptake and metabolism in vitro of androgens by normal and hyperplastic human prostate glands was studied by means of a new experimental design proposed by Gurpide & Welch (1969). Prostate slices were perfused with a medium containing [(3)H]testosterone and [(14)C]androstenedione, or 5alpha-dihydro-[(3)H]testosterone and [(14)C]testosterone. The entry into the slices, the irreversible metabolism, the conversion between the compounds and the tissue retention or ;uptake' of the steroids were measured at the steady state. A similar portion of the three androgens entered the tissue and was irreversibly metabolized. Conversion of testosterone into 5alpha-dihydrotestosterone was much greater than the interconversion of testosterone and androstenedione. The prostate slices retained 5alpha-dihydrotestosterone at a concentration three times that in the medium, whereas testosterone and androstenedione were retained to a smaller extent. At a steroid concentration of 0.11mumol/l in the medium, the various parameters did not differ significantly in experiments performed with slices from normal and hyperplastic glands. When the steroid concentration in the medium was increased tenfold, however, a difference between normal and hyperplastic glands was evident. The normal glands increased the uptake and metabolism proportionally to the elevation of the steroid concentration in the medium. In the hyperplastic glands the entry and metabolism lagged behind the increase in steroid supply, whereas the tissue uptake became disproportionately high. The possible causes of this finding are discussed.
| S-EPMC1176898 | biostudies-other
Project description:Androgens regulate prostate physiology, and exert their effects through the androgen receptor. We hypothesized that androgen deprivation needs additional transcription factors to orchestrate the changes taking place in the gland after castration and for the adaptation of the epithelial cells to the androgen-deprived environment, ultimately contributing to the origin of castration-resistant prostate cancer. This study was undertaken to identify transcription factors that regulate gene expression after androgen deprivation by castration (Cas). For the sake of comparison, we extended the analysis to the effects of administration of a high dose of 17?-estradiol (E2) and a combination of both (Cas+E2). We approached this by (i) identifying gene expression profiles and enrichment terms, and by searching for transcription factors in the derived regulatory pathways; and (ii) by determining the density of putative transcription factor binding sites in the proximal promoter of the 10 most up- or down-regulated genes in each experimental group in comparison to the controls Gapdh and Tbp7. Filtering and validation confirmed the expression and localized EVI1 (Mecom), NFY, ELK1, GATA2, MYBL1, MYBL2, and NFkB family members (NFkB1, NFkB2, REL, RELA and RELB) in the epithelial and/or stromal cells. These transcription factors represent major regulators of epithelial cell survival and immaturity as well as an adaptation of the gland as an immune barrier in the absence of functional stimulation by androgens. Elk1 was expressed in smooth muscle cells and was up-regulated after day 4. Evi1 and Nfy genes are expressed in both epithelium and stroma, but were apparently not affected by androgen deprivation.
| S-EPMC4041569 | biostudies-literature
Project description:Abiraterone acetate is the first second-line hormonal agent proven to improve survival in metastatic castration-resistant prostate cancer. It selectively inhibits cytochrome P450 17 (CYP17) α-hydroxylase and cytochrome17,20 (C17,20)-lyase, which are enzymes critical for androgen synthesis. Abiraterone acetate was initially approved in the United States in 2011 after demonstrating a 4-month survival benefit in docetaxel-refractory metastatic prostate cancer. The FDA recently expanded its indication for use in the pre-chemotherapy setting after it elicited significant delays in disease progression and a strong trend for increased overall survival in phase III studies. Ongoing investigations of abiraterone are evaluating its efficacy in earlier disease states, exploring its synergy in combination with other therapeutic agents, and assessing the necessity for administration of concurrent steroids and gonadal suppression. The identification and development of predictive biomarkers will optimize the incorporation of abiraterone into the management of advanced prostate cancer.
| S-EPMC3778906 | biostudies-literature
Project description:BackgroundWe analyzed the potential of abiraterone acetate (henceforth abiraterone) to reduce androgen levels below lower limits of quantification (LLOQ) and explored the association with changes in PSA decline in metastatic castration-resistant prostate cancer (mCRPC) patients.MethodsCOU-AA-301 is a 2:1 randomized, double-blind, placebo-controlled study comparing abiraterone (1000 mg q.d.) plus low-dose prednisone (5 mg b.i.d.) with placebo plus prednisone in mCRPC patients post docetaxel. Serum testosterone, androstenedione and dehydroepiandrosterone sulfate from baseline to week 12 were measured by novel ultrasensitive two-dimensional liquid chromatography coupled to tandem mass spectrometry assays in a subset of subjects in each arm (abiraterone plus prednisone, n=80; prednisone, n=38). The association between PSA response (< or =50% baseline) and undetectable androgens (week 12 androgen level below LLOQ) was analyzed using logistic regression.ResultsA significantly greater reduction in serum androgens was observed with abiraterone plus prednisone versus prednisone (all P < or = 0.0003), reaching undetectable levels for testosterone (47.2% versus 0%, respectively). A positive association was observed between achieving undetectable serum androgens and PSA decline (testosterone: odds ratio=1.54; 95% confidence interval: 0.546-4.347). Reduction of androgens to undetectable levels did not occur in all patients achieving a PSA response, and a PSA response did not occur in all patients achieving undetectable androgen levels.ConclusionsAbiraterone plus prednisone significantly reduced serum androgens, as measured by ultrasensitive assays and was generally associated with PSA response. However, androgen decline did not uniformly predict PSA decline suggesting ligand-independent or other mechanisms for mCRPC progression.
| S-EPMC4020277 | biostudies-literature
Project description:The management of hormone-refractory prostate cancer represents a major challenge in the therapy of this tumor, and identification of novel androgen receptor antagonists is needed to render treatment more effective. We analyzed the activity of two novel androgen receptor antagonists, (S)-11 and (R)-9, in in vitro and in vivo experimental models of hormone-sensitive or castration-resistant prostate cancer (CRPC). In vitro experiments were performed on LNCaP, LNCaP-AR, LNCaP-Rbic and VCaP human prostate cancer cells. Cytotoxic activity was assessed by SRB and BrdU uptake, AR transactivation by luciferase reporter assay and PSA levels by Real Time RT-PCR and ELISA assays. Cell cycle progression-related markers were evaluated by western blot. In vivo experiments were performed on SCID mice xenografted with cells with different sensitivity to hormonal treatment. In hormone-sensitive LNCaP and LNCaP-AR cells, the latter expressing high androgen receptor levels, (R)-9 and (S)-11 exhibited a higher cytotoxic effect compared to that of the reference compound ((R)-bicalutamide), also in the presence of the synthetic androgen R1881. Furthermore, the cytotoxic effect produced by (R)-9 was higher than that of (S)-11 in the two hormone-resistant LNCaP-AR and VCaP cells. A significant reduction in PSA levels was observed after exposure to both molecules. Moreover, (S)-11 and (R)-9 inhibited DNA synthesis by blocking the androgen-induced increase in cyclin D1 protein levels. In vivo studies on the toxicological profile of (R)-9 did not reveal the presence of adverse events. Furthermore, (R)-9 inhibited tumor growth in various in vivo models, especially LNCaP-Rbic xenografts, representative of recurrent disease. Our in vitro results highlight the antitumor activity of the two novel molecules (R)-9 and (S)-11, making them a potentially attractive option for the treatment of CRPC.
| S-EPMC3648536 | biostudies-literature
Project description:PurposeThe activity of androgen-deprivation therapy (ADT) in androgen receptor-positive (AR+) salivary gland carcinomas (SGCs) has been established in the past few years. Second-line treatment in castration-resistant patients is still unknown. We investigated the activity of abiraterone acetate as second-line treatment in ADT-resistant, AR+ patients with SGC.MethodsThis was a single-institution phase II trial. A two-stage Simon's design was applied. The primary end point was confirmed objective response rate. Secondary end points were disease control rate, safety, progression-free survival, and overall survival. Patients were eligible when the following criteria were met: histologic diagnosis of AR-overexpressing SGC, measurable disease according to RECIST 1.1, clinical and/or radiologic progression on ADT, suppressed serum testosterone, and no limits for the number of previous chemotherapy lines. All patients received abiraterone 1 g daily plus prednisone 10 mg and luteinizing hormone-releasing hormone agonist until progression or unacceptable toxicities.ResultsFrom 2015 to 2019, 24 AR+ patients with SGC (23 men; median age 65.8 years) were treated within the study. The overall response rate was 21% (5 partial responses), with a disease control rate of 62.5%. The median duration of response was 5.82 months. Median progression-free survival was 3.65 months (95% CI, 1.94 to 5.89), and median overall survival was 22.47 months (95% CI, 6.74 to not reached). Objective response to previous ADT did not correlate with the activity of abiraterone. Adverse events (AEs) were recorded in 22 cases (92%) with grade 3 AEs in six patients (25%): fatigue (two), flushing (one), supraventricular tachycardia (one), and two non-drug-related AEs. No drug-related grade 4 or 5 AEs were recorded.ConclusionAbiraterone plus luteinizing hormone-releasing hormone agonist is active and safe as a second-line option in AR-expressing, castration-resistant SGC.
| S-EPMC8677956 | biostudies-literature
Project description:PurposePersistent androgen signaling is implicated in castrate-resistant prostate cancer (CRPC) progression. This study aimed to evaluate androgen signaling in bone marrow-infiltrating cancer and testosterone in blood and bone marrow and to correlate with clinical observations.Patients and methodsThis was an open-label, observational study of 57 patients with bone-metastatic CRPC who underwent transiliac bone marrow biopsy between October 2007 and March 2010. Patients received oral abiraterone acetate (1 g) once daily and prednisone (5 mg) twice daily. Androgen receptor (AR) and CYP17 expression were assessed by immunohistochemistry, testosterone concentration by mass spectrometry, AR copy number by polymerase chain reaction, and TMPRSS2-ERG status by fluorescent in situ hybridization in available tissues.ResultsMedian overall survival was 555 days (95% CI, 440 to 965+ days). Maximal prostate-specific antigen decline ≥ 50% occurred in 28 (50%) of 56 patients. Homogeneous, intense nuclear expression of AR, combined with ≥ 10% CYP17 tumor expression, was correlated with longer time to treatment discontinuation (> 4 months) in 25 patients with tumor-infiltrated bone marrow samples. Pretreatment CYP17 tumor expression ≥ 10% was correlated with increased bone marrow aspirate testosterone. Blood and bone marrow aspirate testosterone concentrations declined to less than picograms-per-milliliter levels and remained suppressed at progression.ConclusionThe observed pretreatment androgen-signaling signature is consistent with persistent androgen signaling in CRPC bone metastases. This is the first evidence that abiraterone acetate achieves sustained suppression of testosterone in both blood and bone marrow aspirate to less than picograms-per-milliliter levels. Potential admixture of blood with bone marrow aspirate limits our ability to determine the origin of measured testosterone.
| S-EPMC3295561 | biostudies-literature
Project description:The treatment of castration-resistant (CR) prostate cancer (PCa) is limited. A sub-population of CR PCa tumors can synthesize androgens for intracrine androgen receptor (AR) activation, thus targeting androgen biosynthesis could be an effective therapeutic option for these patients. We determined that androgen biosynthesis inhibitors simvastatin, atorvastatin, and ketoconazole directly inhibit growth, migration, and colony formation of LNCaP C-81 cells, which exhibit de novo androgen biosynthesis, with simvastatin being the most effective. Importantly, in combination treatments, statins specifically enhanced growth suppression with added effects by anti-androgen abiraterone acetate on the CR PCa cells. Thus, statins can be used in conjunction with abiraterone acetate to enhance anti-androgen therapy for CR PCa.
| S-EPMC6641547 | biostudies-literature
Project description:Androgens are essential for the development of the prostate and prostate cancer. We examined androgen-regulated gene expression in the human prostate. Samples from benign and malignant prostate tissue and samples containing prostate tissue obtained from prostate cancer patients three days after surgical castration were further processed as probes for a GeneChip array. The comparison of gene expression profiles in castrated samples and in benign or malignant prostate tissue samples revealed androgen-regulated genes. We further evaluated the genes which were differentially expressed in benign and malignant prostate samples. The androgen-regulated expression of dual specificity phosphatase 1 (DUSP1) was confirmed in the LNCaP prostate cancer cell line, as the expression of DUSP1 increased with androgen treatment over the course of time. The expression of the genes CRISP3, PCA3, OR51E2, HOXC6, AGR3, AMACR and SLC14A1 was affected by castration in addition to differential expression in the benign and malignant prostate. These sample results require further investigation for the role of AGR3 and SLC14A1 in prostate cancer as these associations have not been reported previously.
| S-EPMC3493087 | biostudies-literature