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

Autoregulation of androgen receptor (AR) mRNA was investigated using Northern blot analysis with AR cDNA fragments as probes. The amount of AR mRNA increased 2- to 10-fold with androgen withdrawal and decreased below control levels after androgen stimulation in rat ventral prostate, coagulating gland, epididymis, seminal vesicle, kidney, and brain, and in a human prostate cancer cell line, LNCaP. In rat ventral prostate, AR mRNA increased 2- to 3-fold within 24 h after castration and remained elevated for 4 days. Treatment with testosterone propionate beginning 24 h after castration reduced ventral prostate AR mRNA 4-fold within 8 h of androgen replacement. Administration of estradiol 24 h after castration had no significant effect on prostatic AR mRNA. Androgens, including testosterone and the synthetic androgen methyltrienolone (R1881), or the antiandrogen cyproterone acetate down-regulated AR mRNA in vitro in LNCaP cells, whereas estradiol was without effect. Administration of testosterone propionate to rats with androgen insensitivity did not decrease AR mRNA. Down-regulation of AR mRNA by androgen is therefore a receptor-mediated process which occurs in vivo in rat tissues that differ in androgen responsiveness and in cultured human prostate cells.
 ...
PMID:Autologous down-regulation of androgen receptor messenger ribonucleic acid. 232 67

Two iodinated steroids, E-17 alpha-(2-iodovinyl)-5 alpha-dihydrotestosterone and Z-17 alpha-(2-iodovinyl)-5 alpha-dihydrotestosterone were synthesized in a search for a gamma-emitting androgen that binds with high affinity to the androgen receptor. Such compounds would be extremely useful research tools for studies of androgen responsive tissues and as in vivo probes of androgen responsive tumors such as prostate cancer. These 17 alpha-iodovinyl steroids were synthesized because many 17 alpha-substituents do not interfere markedly with binding to the androgen receptor and because similar analogs of other steroids, estrogens and progestins, have been shown to have the requisite properties for ligands to those receptors. Both of these potential ligands were tested for their ability to compete with [3H]R1881 for binding to the androgen receptor in cytosols from prostate, hypothalamus and pituitary. The relative binding affinities ranged between 5 and 20%, depending upon the tissue and steroid. In order to test the two ligands directly, they were both synthesized labelled with 125I and tested for binding to the androgen receptor in prostatic cytosol and in vivo for specific concentration in androgen responsive tissues. While there was considerable binding in the prostatic cytosol, it was not specific because 5 alpha-dihydrotestosterone did not compete. Likewise in the in vivo experiment there was no evidence for androgen receptor mediated concentration of the tracers. While on the basis of relative binding affinity, these 2 steroids appeared to be good candidates for androgen receptor ligands, neither were useful for this purpose. These results contribute new information which will be valuable in the design of other gamma-emitting androgens and emphasises that, in this process, other factors such as metabolism and nonspecific binding must be considered.
 ...
PMID:The synthesis and testing of E-17 alpha-(2-iodovinyl)-5 alpha-dihydrotestosterone and Z-17 alpha-(2-iodovinyl)-5 alpha-dihydrotestosterone as gamma-emitting ligands for the androgen receptor. 236 41

Androgens mediate their effects through an intracellular receptor that is a member of the steroid/thyroid hormone family of receptors. The expression of this protein is tightly regulated in different tissues and among cell types within a single tissue. To define the mechanisms controlling the expression of the androgen receptor, we have isolated and characterized the promoter of the androgen receptor gene in the human prostate cell line LNCaP. The major site of transcription initiation is approximately 1.1 kilobases upstream of the initiator methionine of the androgen receptor protein. The promoter region lacks typical "TATA" and "CAAT" sequence motifs but lies in a GC-rich region and contains a putative Sp1 binding site characteristic of a "housekeeping" promoter and a 44-base segment composed of alternating adenosine and guanosine residues. S1 nuclease protection analyses indicate that the same promoter is employed both in human tissues (prostate, testes), in genital skin fibroblasts, in T47D and MCF-7 breast cancer cells, and in LNCaP prostate cancer cells.
 ...
PMID:Expression of the human androgen receptor gene utilizes a common promoter in diverse human tissues and cell lines. 238 Jan 87

Recently, various progresses have been made in the treatment of the genitourinary malignant tumors. Effectiveness of the intravesical instillation of anti-cancer agents and biological reaction modifiers has been proved in the treatment and prevention of the superficial bladder cancer. Among them, superiority of BCG is now attracting attention of all the urologists. For the invasive bladder cancer, the M-VAC therapy (the combination chemotherapy of methotrexate, vinblastine, actinomycin and cis-platinum) has been found to be extremely useful. The multidisciplinary approach for the down-staging of the advanced bladder cancer has been advocated around the world. As for the prostatic cancer, that of the high stage is the main concern of the Japanese urologists, since the mass screening of the prostatic cancer has not prevailed in Japan. The LHRH agonists or the blockers of the androgen receptor have been replacing the classic antiandrogenic treatment consisting of castration and estrogen administration to treat the advanced carcinoma. On the other hand, the nerve-sparing total prostatectomy has been recommended for the low stage cancer by Walsh and associates to preserve potency. The testicular cancer has been most effectively treated with the combined chemotherapy. The PVB and VAB therapy are well known in the world. Lately, VP-16 (etoposide) was found to be a useful salvage agent. The least advance has been made in the treatment of renal cell carcinoma, although interferon therapy or LAK cell adoptive immunotherapy appears attractive.
 ...
PMID:[Treatment of genitourinary malignancy--present concept and controversy]. 244 33

Androphilic protein in prostatic cancer was histochemically observed with dihydrotestosterone (DHT), R 1881, and mibolerone as ligands. Cancer cells were equally stained with fluorescent R 1881 and mibolerone, and this fluorescence seems to be made up of both the androgen receptor and progestin-binding protein. The staining with fluorescent DHT was weak. Sixty-two Stage D2 prostatic cancer patients were examined with histochemical androphilic protein, and they then received endocrine therapy. The presence of fluorescence of R 1881 was not correlated with grade, but a relationship between the presence of fluorescence and the response to endocrine therapy was noticed 6 months after the start of treatment. Moreover, fluorescence-positive patients showed better survival than fluorescence-negative patients. An examination with fluorescent DHT revealed a similar tendency to that of R 1881, but the frequency of positive fluorescence was lower, indicating that R 1881 is a suitable ligand in this type of study.
 ...
PMID:Androphilic protein studied histochemically in stage D2 prostatic cancer. 244 48

A series of compounds designed to block the action of androgens in target tissues, and called antiandrogens, have been developed for the treatment of androgen-sensitive diseases, especially prostate cancer, hirsutism, precocious puberty and deviant sexual behavior. In order to further assess the androgenic activity of these compounds, we have studied their effect on the growth of an androgen-sensitive clone of the mouse mammary carcinoma Shionogi SC-115 cells in culture. Hydroxy-flutamide did not affect the doubling time (7.40 +/- 0.09 vs 7.20 +/- 0.12 days) characteristic of these cells. However, all of the other compounds tested stimulated cell growth. Thus, in the presence of cyproterone acetate, cells had an accelerated growth rate and shorter generation time of 6.28 +/- 0.06 days (P less than 0.01). In the presence of 1 microM spironolactone, the generation time was 4.96 +/- 0.04 days (P less than 0.01). With chlormadinone acetate, the doubling time was reduced to 3.79 +/- 0.08 days while for megestrol acetate, the doubling time was 3.63 +/- 0.04 days (P less than 0.01). The synthetic progestin Medroxyprogesterone acetate had the most potent androgenic effect reducing the doubling time to 1.85 +/- 0.05 days (P less than 0.01). For comparison, dihydrotestosterone gave a doubling time of 1.76 +/- 0.07 days. When hydroxy-flutamide (5 microM) was added simultaneously with each "progestin", the ED50 value of action of all the compounds was increased in a competitive manner, thus indicating that the mitogenic effect on cell growth of all compounds is mediated by the androgen receptor. Of all the compounds used, only hydroxy-Flutamide was devoid of any androgenic activity and thus meets the criteria of a pure antiandrogen.
 ...
PMID:Androgenic activity of synthetic progestins and spironolactone in androgen-sensitive mouse mammary carcinoma (Shionogi) cells in culture. 246 35

A new microassay in which cryostat sections of prostate tissue were used to provide the source of soluble androgen receptor for biochemical assay, was devised using an isoelectric focusing method, with [3H]-mibolerone as the androgenic radioligand. Adjacent cryostat sections from the same tissue block were stained for diagnostic and quantitative histological assessment. The assay was used to illustrate variations in tissue androgen receptor concentration for correlation with epithelial cell content in benign prostate hyperplasia and prostatic cancer, and to show the effects of androgen receptor concentration of resection of prostatic tissue by electroresection. The results indicate that the heat in electroresection renders prostatic tissue unsuitable for androgen receptor assays, and suggest that knowledge of the cellular composition of carcinomatous prostates may be of importance in the full assessment of androgen receptor assay results. This method incorporates both a biochemical assay and histological assessment of the assayed tissue on near-facsimile sections, an advantage over conventional biochemical assays.
 ...
PMID:Microassay for prostatic androgen receptors correlated with quantitative histological assessment. 246 26

Hybrid cell lines were prepared by the fusion of BALB/c myeloma NS-1 cells with the lymphocytes of BALB/c mice that were immunized with partially purified androgen receptor (AR) from human prostates. One of the clones, 5F4, was chosen for detailed specificity analysis. The avidin-biotin-peroxidase complex (ABC) procedure was used for immunohistochemical staining of the 5F4 monoclonal antibody. In human benign prostatic hypertrophy (BPH) tissues, cytoplasm and nuclei were stained. Of 16 prostatic cancer tissues, 2 were composed of AR-positive cells exclusively, 7 were composed of AR-negative cells, and 7 contained both AR-positive cells and AR-negative cells (mixed). Of nine cases that were AR-positive or mixed, seven cases responded to the hormone therapy, and two were not determined for responsiveness because the patients died early of other diseases. Of seven AR-negative cases, all but one inestimable case had no response to the hormone therapy. Immunohistochemical analysis of AR by using the monoclonal antibody 5F4, was a useful tool for determining androgen dependency of prostatic cancers.
 ...
PMID:Establishment of monoclonal antibody to human androgen receptor and its clinical application for prostatic cancers. 246 71

The nuclear and crude nuclear 5 alpha-dihydrotestosterone (DHT) levels were measured in patients with benign prostatic hypertrophy (BPH) and prostatic cancer (PC). In the fundamental study using BPH tissues, nuclear DHT levels were not influenced by the treatment for nuclear purification such as DTT, Triton X-100 or DNase I. The correlation between DHT levels and androgen receptor contents was found in only the crude nuclear salt extractable fractions (r = 0.748, p less than 0.01). In the relation of DHT levels to prostatic cancer patients, crude nuclear salt extractable and salt resistant DHT in both the low grade and in early stage group were significantly higher than those in the high grade and in advanced stage. Moreover, DHT levels in the both crude nuclear salt extractable and salt resistant fractions were below 5 pg/mg protein in all of clinical non-responders to endocrine therapy, and the total crude nuclear DHT, the sum of the crude extractable and salt resistant DHT, was below 10 pg/mg protein in all of the non-responders to endocrine therapy. When the relation between the total crude nuclear DHT level and the clinical course of 34 prostatic cancer patients followed for over 12 months was studied, the elevated DHT group (over 20 pg/ml protein) responded to endocrine therapy and experienced long-term remissions, but the low DHT group (below 10 pg/ml protein) did not respond to endocrine therapy. Therefore, it is suggested that the total crude nuclear DHT levels were appropriate biochemical indicators for androgen dependency in prostatic cancer patients.
 ...
PMID:[A study on usefulness of the crude nuclear DHT measurement in prostatic cancer patients]. 248 Apr 69

Win 49596 is a new orally active, steroidal androgen receptor antagonist. Win 49596 inhibited ventral prostate, seminal vesicle and levator ani weight gain in either 5 alpha-dihydrotestosterone (DHT) or testosterone propionate-treated castrated, immature male rats. In intact, adult male rats, Win 49596 significantly inhibited weight gain by the ventral prostate, dorsal lateral prostate and seminal vesicles, but not the testes at doses as low as 50 mg/kg/day x 14 p.o. However, daily oral administration of equivalent antiandrogenic doses of either Win 49596, ICI 176,334, or flutamide for 14 days to mature, intact male rats resulted in elevations of circulating testosterone of approximately 3-, 2-, and 10-fold, respectively. At doses as high as 400 mg/kg p.o., Win 49596 did not have androgenic, progestational, estrogenic or antiestrogenic activity in rat or rabbit models. However, in the Clauberg assay, Win 49596 did have weak antiprogestational activity at doses of 25-400 mg/kg/day p.o. These data indicate that Win 49596 is a peripherally selective antiandrogen that has minimal effects on circulating testosterone levels and is devoid of hormone agonist activity. Thus, Win 49596 may be useful for the treatment of androgen dependent conditions such as benign prostatic hyperplasia and prostatic cancer.
 ...
PMID:Endocrine profile of Win 49596 in the rat: a novel androgen receptor antagonist. 261 57


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>