Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Estrogens have an important role in the growth of breast and other hormone-sensitive cancers. We have shown that 4-hydroxyandrostenedione (4-OHA) selectively blocks estrogen synthesis by inhibiting aromatase activity in ovarian and peripheral tissues and reduces plasma estrogen levels in rat and non-human primate species. In postmenopausal men and women, estrogens are mainly of peripheral origin. When postmenopausal breast cancer patients were administered either by daily oral or parenteral weekly treatment with 4-OHA, plasma estrogen concentrations were significantly reduced. Complete or partial response to treatment occurred in 34% of 100 patients with advanced breast cancer, while the disease was stabilized in 12%. We recently studied the effects of 4-OHA and other aromatase inhibitors, 10-propargylestr-4-ene-3,17-dione (PED) and imidazo[1,5-alpha]3,4,5,6-tetrahydropyrin-6-yl-(4-benzonitrile) (CGS 16949A) as well as 5 alpha-reductase inhibitors, N,N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carboxyamide (4-MA) and 17 beta-hydroxy-4-aza-4-methyl-19norandrost-5-en-3-one (L651190) in prostatic tissue from 11 patients with prostatic cancer and six patients with benign prostatic hypertrophy (BPH), and from normal men at autopsy. We attempted to measure aromatase activity in tissue incubation by quantitating 3H2O released during aromatization of androstenedione or testosterone labeled at the C-1 position. The amount of 3H2O released from all samples was at least twice that of the heat inactivated tissue samples. The 3H2O release was significantly inhibited by 4-OHA and 4-MA, but not by the other aromatase inhibitors. However, when HPLC and TLC were used to isolate steroid products, no estrone or estradiol was detected in the incubates. Furthermore, no aromatase mRNA was detected following amplification by PCR. The 4-OHA was found to inhibit 5 alpha-reductase in both BPH and cancer tissue, although to a lesser extent than 4-MA. The other aromatase inhibitors were without effect. Although a mechanism involving intraprostatic aromatase is not likely, inhibitors may act to reduce peripherally-formed estrogens. In postmenopausal breast cancer, the results indicate that 4-OHA is of significant benefit.
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PMID:Aromatase and other inhibitors in breast and prostatic cancer. 228 80

Prostatic tissue removed at the time of cystoprostatectomy was separated into periurethral and peripheral zones. Homogenized tissue was incubated with [1,2,6,7(3)H] androstenedione in the presence or absence of an aromatase inhibitor, 4-hydroxyandrostenedione (4-OHAD) and a 5 alpha-reductase inhibitor 4-MA (N,N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane 17 beta-carboxamide). Estrogen formation was determined by reverse isotope dilution of [3H] estrone and [3H] estradiol and crystallization to constant specific activity. Control incubations were carried out in parallel utilizing heated prostatic tissue. Total estrogens produced in the periurethral zone in patients with benign prostatic hyperplasia (BPH) was 223 fmol/mg protein/hr (SE +/- 57) compared to 102 fmol (SE +/- 17) in patients without BPH. Estrogen formation in the peripheral zone was 175 fmol (SE +/- 69) and 105 fmol (SE +/- 26) in patients with and without BPH, respectively. The prostatic aromatase exhibits Michaelis-Menton kinetics with an apparent Km of 90 nM. 4-OHAD inhibited aromatization in the prostatic tissue by 57-93%. Aromatization was also strongly inhibited by 4-MA, indicating that 4-MA is a potent aromatase as well as a 5 alpha-reductase inhibitor in this tissue. These results suggest that aromatization of androgens to estrogens in the human prostate proceeds at a substantial rate and that local estrogen formation could preexist and be a factor in the etiology of BPH and prostatic cancer.
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PMID:Estrogen formation in human prostatic tissue from patients with and without benign prostatic hyperplasia. 243 1

The effects of 4-hydroxyandrostenedione (4-OHA) and other aromatase inhibitors, 10-propargylestr-4-ene-3,17-dione and imidazo[1,5-alpha]-3,4,5,6-tetrahydropyrin-6-yl-(4-benzonitrile), as well as 5 alpha-reductase inhibitors N,N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carboxyamide and 4-methyl-3-oxo-4-aza-androsta-5-ene-17-ol were investigated in prostatic tissue from six patients with benign prostatic hypertrophy and seven patients with prostatic cancer, and from normal men at autopsy. We attempted to measure aromatase activity in the tissue incubations by quantitating 3H2O released from androstenedione or testosterone labeled at the C-1 position. High performance liquid chromatography and thin layer chromatography were used to isolate steroid products. Although the amount of 3H2O released was at least twice that of the heat-inactivated tissue samples, no estrone or estradiol was detected on high performance liquid chromatography. The 3H2O release was significantly inhibited by 4-OHA and N,N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carboxyamide, but not by the other aromatase inhibitors. 4-OHA also inhibited 5 alpha-reductase in both benign prostatic hypertrophy and cancer tissue, although to a lesser extent than N,N-diethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carboxyamide. The other aromatase inhibitors were without effect on 5 alpha-reductase. Our results indicate that 3H2O released from [1 beta-3H]androstenedione and [1,2,6,7-3H]androstenedione does not correlate with estrogen formation and may be the result of other metabolic reactions. Although it appears that the prostate lacks aromatase, 4-OHA may be of benefit in patients with benign prostatic hypertrophy or prostatic cancer by inhibiting this enzyme in peripheral tissue.
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PMID:Lack of evidence for aromatase in human prostatic tissues: effects of 4-hydroxyandrostenedione and other inhibitors on androgen metabolism. 247 64

The levels of plasma dehydroepiandrosterone (DHEA), androst-5-ene-3 beta,17 beta-diol (delta 5-diol), testosterone (T), dihydrostestosterone (DHT), androstane-3 alpha,17 beta-diol (3 alpha-diol), androsterone (ADT), and the related glucuronide (G) derivatives were determined in intact and castrated men with prostatic cancer. The plasma concentrations of DHEA and DHEA-G were not significantly different in intact and castrated men while delta 5-diol as well as delta 5-diol-G were 50% lowered in castrated men. As expected, T and DHT concentrations were markedly lower in castrated men. These low plasma levels of T and DHT were accompanied by a decrease of 3 alpha-diol, ADT, T-G, 3 alpha-diol-G, and ADT-G levels. There was, in unoperated men, a positive correlation between the levels of DHEA and ADT-G as well as DHEA and DHEA-G, while T values were highly correlated with ADT-G and 3 alpha-diol-G levels. Furthermore, a significant relationship was found between DHEA and ADT-G as well as 3 alpha-diol-G in castrated men. Our data clearly demonstrate that ADT-G and 3 alpha-diol-G levels are more affected by castration than are the corresponding unconjugated steroids and suggest that these steroid glucuronides should be good markers of androgen metabolism. Moreover, the significant relationship between DHEA, ADT-G, and 3 alpha-diol-G in castrated men also suggests that approximately 30% of C-19 steroids from the adrenals are converted to T and DHT, which are further transformed into steroid glucuronides.
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PMID:Levels of plasma steroid glucuronides in intact and castrated men with prostatic cancer. 293 1

Plasma levels of androstane-3 alpha, 17 beta-diol glucuronide (3 alpha-diol-G) and androsterone glucuronide (ADT-G) have been found to be effective markers of C-19 steroid metabolism in periphery in man. The present study has been performed in order to study in castrated patients the effect of antiandrogen administered alone or in combination with aminoglutethimide (AG) on the metabolism of adrenal C-19 steroid. Ten castrated patients with prostatic cancer received flutamide (FLU) alone for 2 months and, afterwards, the combined therapy of FLU and AG for 2 months. Antiandrogen treatment alone reduces the levels of dehydroepiandrosterone sulfate (DHEA-S), dehydroepiandrosterone glucuronide (DHEA-G) and androstenedione (4-ene-dione) by 43, 34 and 38% (P less than or equal to 0.01) respectively while dehydroepiandrosterone (DHEA), androst-5-ene-3 beta,17 beta-diol (5-ene-diol) and androst-5-ene-3 beta,17 beta-diol-glucuronide (5-ene-diol-G) levels show a nonsignificant inhibition. In these patients, plasma 3 alpha-diol-G and ADT-G concentrations are nonsignificantly stimulated to 122 and 143%. Moreover, when patients were receiving the combined administration of FLU and AG, adrenal C-19 steroids were further inhibited while both 3 alpha-diol-G and ADT-G show a small but nonsignificant decrease. Our data indicate that the antiandrogen increases the formation and/or the metabolism of adrenal C-19 steroids into steroid glucuronides.
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PMID:Effects of flutamide and aminoglutethimide on plasma 5 alpha-reduced steroid glucuronide concentrations in castrated patients with cancer of the prostate. 296 45

Testicular tissue obtained from ten patients orchiectomized for prostatic cancer was incubated with [3H]5 alpha-dihydrotestosterone (DHT) in order to study the metabolic transformation into 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-diol) and 5 alpha-androstane-3 beta,17 beta-diol (3 beta-diol). Throughout 5 days before surgery four subjects were treated with cyproterone acetate (CA). To three patients flutamide (F) was administered for the same period of time. Three subjects remained untreated. Compared to the control group the administration of CA decreased the formation of 3 beta-diol whereas that of 3 alpha-diol increased. Treatment with F lead to an elevated formation of both diols. However, the 3 alpha/3 beta ratio did not change. As 3 beta-diol is considered to be an index of tubular function in the human testis it is concluded that CA has a direct inhibitory effect upon this testicular compartment whereas F has none.
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PMID:The effect of short term treatment with cyproterone acetate or flutamide on the metabolism of 5 alpha-dihydrotestosterone in human testicular tissue. 297

Total tissue content and subcellular distribution of DHEA sulfate, DHEA, androst-5-ene-3 beta,17 beta-diol, androst-4-ene-3,17-dione, testosterone, 5 alpha-DHT, and 5 alpha-androstane-3 alpha,17 beta-diol as well as the activities of steroid sulfate-sulfatase, 17 beta-hydroxysteroid dehydrogenase, 5 alpha-reductase, 3 alpha/beta-hydroxysteroid dehydrogenase, and creatine kinase were quantified in 12 untreated primary tumors of prostatic cancer. Samples were obtained by radical prostatectomy and serial sections, and were alternately used for either biochemical or morphological evaluation. The results were compared with values determined in benign parts of the same prostates. Qualitatively, all enzymes and steroids found in the benign tissues could also be demonstrated in the cancers. Steroid patterns showed individual quantitative variation but no general differences between the carcinomas and the benign tissues. Enzymes showed a tendency to lower activities in the cancers, particularly when expressed per DNA. Substantial diminutions of creatine kinase and 5 alpha-reductase activity, the latter being often accompanied by an increased testosterone/DHT ratio, were the most striking differences seen in most of the cases between malignant and nonmalignant tissues. Some interesting individual parallels of morphological and biochemical aspects were seen, but there was no obvious general parallelism between the histological picture and endocrinological characteristics.
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PMID:Quantitative assessment of endogenous testicular and adrenal sex steroids and of steroid metabolizing enzymes in untreated human prostatic cancerous tissue. 316 31

The concentrations of testosterone and its tissular metabolites were determined in testicular and epididymal tissue obtained from eleven male subjects (aged 65-85 years) after orchiectomy for prostatic cancer. The steroids were measured in different tissular compartments, i.e. testis, caput, corpus and cauda epididymis. The values (mean +/- SD; ng/g wet weight) were: Testosterone 724.0 +/- 286.0, 32.08 +/- 2.56, 41.45 +/- 1.77 and 32.24 +/- 2.14; 5 alpha-dihydrotestosterone 6.95 +/- 1.99, 9.76 +/- 2.33, 16.87 +/- 0.21 and 15.79 +/- 2.67; 5 alpha-androstane-3 alpha, 17 beta-diol 6.07 +/- 2.33, 2.17 +/- 0.24, 1.93 +/- 0.02 and 1.17 +/- 0.20; 5 alpha-androstane-3 beta, 17 beta-diol 56.66 +/- 20.97, 3.55 +/- 0.19, 2.21 +/- 0.27 and 3.34 +/- 0.32; estradiol-17 beta 5.36 +/- 3.0, 1.08 +/- 0.014, 1.44 +/- 0.038 and 1.47 +/- 0.03, respectively. Incubation of human testicular tissue with [3H]androst-5-ene-3 beta, 17 beta-diol or [3H]dihydrotestosterone showed that both androstane-diols were exclusively formed from dihydrotestosterone. Since high concentrations of 5 alpha-androstane-3 beta, 17 beta-diol are found in testicular tissue it is suggested that this steroid may be an index of seminiferous tubular function.
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PMID:Concentrations of unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol and 5 alpha-androstane-3 beta, 17 beta-diol and their precursor in human testicular tissue. Comparison with testosterone, 5 alpha-dihydrotestosterone, estradiol-17 beta, and with steroid concentrations in human epididymis. 358 50

The concentrations of testosterone, 5 alpha-dihydrotestosterone, 5 alpha-androstan-3 alpha, 17 beta-diol, 5 alpha-androstane-3 beta, 17 beta-diol, estradiol-17 beta and testosterone-glucosiduronate were measured in the plasma of the testicular vein and artery simultaneously with the estimation in peripheral venous and arterial plasma 60 min after an infusion of 3000 micrograms dihydrotestosterone (DHT) or estradiol (E2), respectively, in patients undergoing orchiectomy for prostatic cancer. The results were as follows; following infusion of DHT or E2, both steroids were completely metabolized by the testes. After DHT the testicular secretion of E2 was significantly reduced. In peripheral plasma 3 alpha-diol concentration was increased. Following E2 a transient elevation of testosterone in the spermatic vein was observed, whereas a slight decrease of DHT and an increase especially of 3 beta-diol levels occurred. It is assumed that DHT as well as E2 plays a role as intratesticular regulator of steroid synthesis and metabolism.
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PMID:The effect of infusions of 5 alpha-dihydrotestosterone or estradiol-17 beta on the concentration of some steroids in the human testicular vein and artery. 404 9

Serum levels of testosterone (T), dihydrotestosterone (DHT), androsterone (A), 5 alpha-androstane-3 alpha, 17 beta-diol (5 alpha-diol) and estradiol-17 beta (E2) were measured by radioimmunoassay in the sera of 9 patients with untreated prostatic cancer and in 11 with benign prostatic hypertrophy (BPH). Basal levels and responses to hCG stimulation were investigated. Although no specific changes in steroid hormone levels in either disease group were found, response patterns of serum T, DHT, and E2 were shown to be those characteristic of male senescence, suggesting a relative predominance of estrogens over androgens. Neither 5 alpha-diol nor A exhibited appreciable responses to hCG stimulation in our study.
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PMID:Responses of serum levels of testicular steroid hormones to hCG stimulation in patients with prostatic cancer and benign prostatic hypertrophy. 617 80


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