Effects of a new steroidal antiandrogen, TZP-4238 (17 alpha-acetoxy-6-chloro-2-oxa-4, 6-pregnadiene-3, 20-dione), on spontaneously developed canine benign prostatic hyperplasia

PAQR6 Upregulation Is Associated with AR Signaling and Unfavorite Prognosis in Prostate Cancers

Progesterone-induced rapid non-genomic signaling events have been confirmed through several membrane progesterone receptors (mPR). Some mPRs were reported to correlate with cancer progression and patient prognosis. In this study, we conducted a comprehensive analysis of all progesterone receptor (PGR)-related genes in prostate cancer tissues and examined the correlations of their expression levels with disease progression and patient survival outcomes. We utilized multiple RNA-seq and cDNA microarray datasets to analyze gene expression profiles and performed logistics aggression and Kaplan-Meier survival analysis after stratifying patients based on tumor stages and Gleason scores. We also used NCBI GEO datasets to examine gene expression patterns in individual cell types of the prostate gland and to determine the androgen-induced alteration of gene expression. Spearman coefficient analysis was conducted to access the correlation of target gene expression with treatment responses and disease progression status. The classic PGR was mainly expressed in stromal cells and progestin and adipoQ receptor (PAQR) genes were the predominant genes in prostate epithelial cells. Progesterone receptor membrane component-1 (PGRMC1) was significantly higher than PGRMC2 in all prostate cell types. In prostate cancer tissues, PAQR6 expression was significantly upregulated, while all other genes were largely downregulated compared to normal prostate tissues. Although both PAQR6 upregulation and PAQR5 downregulation were significantly correlated with tumor pathological stages, only PAQR6 upregulation was associated with Gleason score, free-prostate-specific antigen (fPSA)/total-PSA (tPSA) ratio, and patient overall survival outcomes. In addition, PAQR6 upregulation and PGR/PGRMC1 downregulation were significantly associated with a quick relapse. Conversely, in neuroendocrinal prostate cancer (NEPC) tissues, PAQR6 expression was significantly lower, but PAQR7/8 expression was higher than castration-resistant prostate cancer (CRPC) tissues. PAQR8 expression was positively correlated with androgen receptor (AR) score and AR-V7 expression levels but inversely correlated with NEPC score in metastatic CRPC tumors. This study provides detailed expression profiles of membrane progesterone receptor genes in primary cancer, CRPC, and NEPC tissues. PAQR6 upregulation in primary cancer tissues is a novel prognostic biomarker for disease progression, overall, and progression-free survival in prostate cancers. PAQR8 expression in CRPC tissues is a biomarker for AR activation.

Progesterone: the forgotten hormone in men?

'Classical' genomic progesterone receptors appear relatively late in phylogenesis, i.e. it is only in birds and mammals that they are detectable. In the different species, they mediate manifold effects regarding the differentiation of target organ functions, mainly in the reproductive system. Surprisingly, we know little about the physiology, endocrinology, and pharmacology of progesterone and progestins in male gender or men respectively, despite the fact that, as to progesterone secretion and serum progesterone levels, there are no great quantitative differences between men and women (at least outside the luteal phase). In a prospective cohort study of 1026 men with and without cardiovascular disease, we were not able to demonstrate any age-dependent change in serum progesterone concentrations. Progesterone influences spermiogenesis, sperm capacitation/acrosome reaction and testosterone biosynthesis in the Leydig cells. Other progesterone effects in men include those on the central nervous system (CNS) (mainly mediated by 5alpha-reduced progesterone metabolites as so-called neurosteroids), including blocking of gonadotropin secretion, sleep improvement, and effects on tumors in the CNS (meningioma, fibroma), as well as effects on the immune system, cardiovascular system, kidney function, adipose tissue, behavior, and respiratory system. A progestin may stimulate weight gain and appetite in men as well as in women. The detection of progesterone receptor isoforms would have a highly diagnostic value in prostate pathology (benign prostatic hypertrophy and prostate cancer). The modulation of progesterone effects on typical male targets is connected with a great pharmacodynamic variability. The reason for this is that, in men, some important effects of progesterone are mediated non-genomically through different molecular biological modes of action. Therefore, the precise therapeutic manipulation of progesterone actions in the male requires completely new endocrine-pharmacological approaches.

Pharmacokinetics and biliary excretion of osaterone acetate, a new steroidal antiandrogen, in dogs

The pharmacokinetics and biliary excretion of osaterone acetate (17alpha-acetoxy-6-chloro-2-oxa-4,6-pregnadiene-3,20-dione; OA), a new steroidal antiandrogen, were investigated in intact dogs and biliary fistula dogs after bolus intravenous administration of (14)C-labeled drug. In intact dogs, OA exhibited a biexponential disposition with a very long half-life of 197.9 +/- 109.9 h. OA accounted for almost all the plasma radioactivity. The major route of excretion was in feces via the bile. One-third of the radioactivity in the bile was due to OA. The major biliary metabolite was identified as a glucuronide of 17alpha-acetoxy-6-chloro-21-hydroxy-2-oxa-4,6-pregnadiene-3,20-dione. A significant amount of biliary recycling occurs in dogs.

The effects of chlormadinone acetate (CMA), antiandrogen, on the pituitary, testis, prostate and adrenal gland of the dog with spontaneous benign prostatic hyperplasia

The effect of chlormadinone acetate (CMA), a synthetic steroidal antiandrogen, on spontaneous benign prostatic hyperplasia (BPH) in dogs was investigated. Male beagle dogs (5-8 years old) were divided into four experimental group. Group 1 consisted of untreated controls. Groups 2 and 3 received CMA 0.03 and 0.1 mg/kg/day, p.o., respectively, for 6 months. In group 1, glandular hyperplasia of the prostate was clearly detected. The glandular epithelial cells showed uniformly intense nuclear staining for androgen receptor (AR). AR was also localized in the nuclei of the fibro-muscular stromal cells. In groups 2 and 3, CMA produced marked atrophy of the glandular epithelium. The interacinar fibro-muscular stroma was prominent. The nuclear staining for AR in both epithelial and stromal cells was remarkably decreased. In addition, a histopathological study showed that CMA medication for 6 months exerted no effect on the testes and adrenal glands or on immunoreactive positive cells to LH- and ACTH-antibody (pituitary LH- and ACTH-cells). Therefore, it is concluded that CMA (0.03 and 0.1 mg/kg) causes regression of spontaneous canine BPH without any histopathological effects on the testes, adrenal glands or pituitary LH- and ACTH-cells.

Effect of osaterone acetate administration on prostatic regression rate, peripheral blood hormone levels and semen quality in dogs with benign prostatic hypertrophy

The effects of osaterone acetate (OSA), which is an anti-androgen agent being developed as a therapeutic drug for benign prostatic hypertrophy (BPH) in dogs, on the degree of prostatic regression and semen qualities were investigated. Prostatic regression was compared between dogs with and without orchidectomy. Five male beagles aged 5-9 years were used in the experiment. OSA was orally administered at doses of 0.2 mg/kg and 0.5 mg/kg for one week. The prostatic regression rate one week after the end of administration was 62.6% on average. In the orchidectomized group, the mean regression rate one week after orchidectomy was 60.1%. However, the prostate became enlarged 6 months after administration, compared to the size prior to administration. The above findings suggested that OSA is clinically applicable as a therapeutic drug for BPH in dogs, and inhibits prostatic hypertrophy during the early phase.

Regression of prostatic hypertrophy by osaterone acetate in dogs

The prostatic regression effect of oral administration of a new steroidal anti-androgen, osaterone acetate, was investigated in dogs with prostatic hypertrophy. To dogs with prostatic hypertrophy, 0.1-1.0 mg/kg of osaterone acetate was orally administered for one week, and the regression rate was observed. It was shown that administration of osaterone acetate at 0.2 mg/kg or higher, sharply regressed prostatic hypertrophy during the early stage. Therefore, this agent may be clinically applicable as a therapeutic agent for benign prostatic hypertrophy.

Estimation of canine prostatic volume: nomogram based on prostatic cubic volume

To estimate prostate volume in canines, we demonstrated the nomogram based on prostatic cubic volume. Transrectal ultrasonography (TRUS) was performed in twenty beagle dogs. Prostatic length (L) and height (H) were determined on sagittal image, and prostatic width (W) was determined on transaxial image. Data of one dog, which had asymmetrical shaped prostate, were excluded from the analysis. Prostate volume was estimated by the following nomogram: Gravimetric prostatic volume (g) = 0.642 x prostatic cubic volume (cm3) + 1.84 (prostatic cubic volume = L x H x W cm3, r = 0.997, p<0.001). By substituting the prostatic height to the average of height, prostatic volume of one dog showing asymmetrical shape was successfully estimated. We also showed technical points in evaluating morphology of canine prostate on TRUS. In conclusion, this nomogram is of great use for directly estimating prostatic volume.

Effect of dual inhibition of 5-alpha-reductase and aromatase on spontaneously developed canine prostatic hypertrophy

BACKGROUND

Our aim was to assess the effect of dual inhibition of 5-alpha-reductase and aromatase on prostate glands.

METHODS

We investigated the morphological changes in the prostate gland and the changes in the hormonal environment after administration of finasteride and arimidex to intact canine specimens. The study consisted of four groups: a 5-alpha-reductase only group (5RI only, n = 5); a 5RI plus aromatase-inhibitor combination group (5RI + ARI combination, n = 5); a BPH control group (n = 3); and a castration control group (n = 3). Finasteride (1 mg/kg/day) and the same dose of arimidex were orally administered for 80 days.

RESULTS

In the 5RI group, a significant decrease in the serum dihydrotestosterone (DHT) level was found, and prostatic volume was significantly decreased. However, significant increases in serum testosterone (T) and DHT levels were observed, with a concomitant increase in prostatic volume in the 5RI + ARI combination group. Morphometric analysis showed that histopathological findings in the 5RI + ARI combination group were similar to those in the BPH control group.

CONCLUSIONS

Dual inhibition of 5-alpha-reductase and aromatase resulted in a significant increase in prostate volume, accompanied by a 3-10-fold increase in serum testosterone levels and a significant increase in testicular volume.

Pharmacological profile of RU 58642, a potent systemic antiandrogen for the treatment of androgen-dependent disorders

The pharmacological profile of RU 58642, a new non-steroidal antiandrogen was investigated both in vitro and in vivo. In vitro, the compound displays a strong and specific affinity for androgen receptor. In vivo, its antiandrogenic activity was evaluated in castrated rat supplemented with testosterone propionate and in intact animals on prostate, seminal vesicles weight and serum levels of testosterone by oral and subcutaneous route. In castrated rats RU 58642 induced a significant decrease in prostate weight at a dose as low as 0.3 mg/kg whatever the route of administration. In intact rats its activity was compared to that of other non-steroidal antiandrogens such as flutamide, nilutamide and bicalutamide. RU 58642 proved to be significantly more potent than the reference compounds in reducing prostate weight: 3-30 times orally and 3-100 times subcutaneously, and thus the most potent antiandrogen to date to our knowledge. These results suggest that this compound may be very useful in the treatment of systemic androgen-dependent diseases.

Expression and degradation of rat androgen receptor following castration, testosterone replacement and antiandrogens administration: analysis by Western blot and immunohistochemistry

To elucidate the autoregulation of androgen receptor (AR) by androgen and antiandrogen, Western blot analysis and immunohistochemical study were performed. Castration reduced the immunodetected AR content, and nuclear staining was lost without cytoplasmic staining. Testosterone (T) supplement restored AR content. Quick response of AR content restoring following single administration of T was observed 48 hours after castration. The recovery of AR content detected by Western blot under each condition was accompanied by recovery of the reduced unclear staining intensities in the epithelia. Neither steroidal nor non-steroidal antiandrogens, chlormadinone acetate and flutamide, altered the AR content in normal rat ventral prostate 5, 12, 24 or 48 hours after single administration. Furthermore, neither of the drugs at various doses altered AR levels 12 hours after single administration. In summary, the rat AR is upregulated by androgen. Single administration of antiandrogens have no effect on immunodetected AR content.