Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0007112 (prostatic adenocarcinoma)
 2,574 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunohistochemical localization of the androgen receptor (AR) was performed in reproductive tissues, submaxillary gland, pituitary, and brain of the rat and in human prostate. AR was visualized using either of two polyclonal antibodies raised against peptides with sequences derived from rat and human AR. Tissue sections of 6-8 microns, frozen in isopentane and fixed in paraformaldehyde, were stained using immunoglobulin G fractions of immune, preimmune, and peptide-adsorbed immune sera in the avidin-biotin peroxidase procedure. AR was prominent in nuclei of acinar epithelial cells of epididymis, ventral prostate, seminal vesicle, and ductus deferens from the intact rat. Androgen withdrawal, 3 days after castration, resulted in the loss of receptor immunostaining, which was restored within 15 min of androgen administration. Stromal cell staining was absent or weak in the ventral prostate of intact rats, but was more evident in the epididymis. AR was confined to nuclei of cells within and bordering the interstitial compartment of the testis, including Sertoli cells, peritubular myoid cells, and interstitial cells, and was undetectable in germ cells. Submaxillary gland epithelial cells and a population of rat anterior pituitary cells showed strong nuclear staining of AR. In rat brain, AR was present in the medial preoptic, arcurate, and ventromedial nuclei of the hypothalamus, the medial nucleus of the amygdala, the CA-1 hippocampus, and the cortex. AR was prominent in acinar epithelial cells in human benign prostatic hyperplasia and was also present in stroma of fibromuscular benign hyperplasia. Heterogeneous staining was observed in stromal and epithelial cells of prostatic adenocarcinoma. The results of these studies indicate that AR can be detected immunohistochemically in a variety of tissues and cell types using antipeptide polyclonal antibodies. The presence of AR in tissues correlated with their known androgen responsiveness.
 ...
PMID:Immunohistochemical localization of the androgen receptor in rat and human tissues. 170 Nov 37

The synthetic androgen 17 beta-hydroxy-17 alpha-[3H]methyl-4,9,11-estratrien-3-one (R1881) has been used as photoaffinity label to characterize androgen receptors in rat prostate, in a human transplantable prostatic adenocarcinoma (PC-82) and in calf uterus. Androgen receptors preparations were partially purified either via differential chromatography on 2',5'-ADP-Sepharose (rat prostate), via anion exchange fast protein liquid chromatography (rat prostate and PC-82) or via DNA-cellulose chromatography (calf uterus). Purification factors obtained with the three different methods were: 245, 75 and 40 respectively. Photolabelling of receptor preparations was performed via irradiation with a high pressure mercury lamp either before or after partial purification. Polyacrylamide gel electrophoresis under denaturing conditions showed that the DNA-binding form of the androgen receptor in calf uterus cytosol is a protein with a molecular mass of approx 95 kD. The covalent attachment of [3H]R1881 to the 95 kD protein could be completely suppressed by a 200-fold molar excess of dihydrotestosterone. In rat prostate cytosol an androgen receptor with a molecular mass of approx 50 kD could be photoaffinity labelled with R1881. A similar size was found for the androgen receptor in the human prostatic adenocarcinoma. Our results show that photoaffinity labelling of androgen receptors with [3H]R1881 as ligand can be applied for characterization of partial purified androgen receptor preparations.
 ...
PMID:Characterization of androgen receptors after photoaffinity labelling with [3H]methyltrienolone (R1881). 242 46

With a technique adapted for needle biopsies from human prostate, androgen receptors have been quantitated in normal, hyperplastic, and carcinomatous samples. An important improvement in the yield of cytosol specific binding sites was obtained when samples were pre-incubated with the mercurial reagent mersalyl, which dissociates endogenously bound hormone receptor complexes, before the binding assay with 3H-methyltrienolone (3H-R1881). Androgen receptors in normal prostate tissue were found to be highest (7.81 +/- 1.12 pmoles/g tissue), and significantly different from hyperplastic prostate (2.02 +/- 0.55 pmoles/g tissue, p less than 0.025), but not from carcinomatous samples (4.47 +/- 0.79 pmoles/g tissue). Mean values for hyperplastic and carcinoma were not statistically distinguishable (p less than 0.1). The clinical response to hormone therapy in 85% of 13 patients with prostatic adenocarcinoma reflected the prostatic androgen receptor content. Orchidectomy followed by estrogen administration for several months leads to a dramatic fall (8-fold) in total androgen receptors in carcinomatous prostate, while estrogen alone did not seem to produce a significant effect. These preliminary data suggest that androgen could directly regulate its binding sites, as demonstrated earlier for other animal target organs.
 ...
PMID:Increased recovery of androgen receptors from human prostate through the use of mersalyl: evidence for androgen regulation of the binding sites in carcinomatous prostate. 242 91

The best treatment for adenocarcinoma of the prostate depends on the patient's age, general medical condition, life expectancy, and willingness to accept such side effects as impotence. Radical prostatectomy or full-dose radiation therapy are usually curative when cancer is confined to the gland. The technique of prostatectomy has been improved and potency often can be preserved. Once the tumor extends beyond the gland, treatment alternatives are radiation or endocrine therapy. If lymph nodes are negative, radiation therapy may result in a long period without progression. If lymph nodes are positive, the expense and morbidity of radiation therapy may not be worthwhile because the likelihood of cure is low. Androgen deprivation, or endocrine manipulation, is preferred for metastatic disease. Response is varied and may depend on the patient's testosterone level when therapy is initiated. Survival is shorter in those with levels below normal.
 ...
PMID:Adenocarcinoma of the prostate. Stage-by-stage treatment alternatives. 305 50

Androgen-responsive cells: To determine if testosterone or dihydrotestosterone is the main trophic hormone of prostatic adenocarcinoma, we have treated Dunning R3327H prostatic adenocarcinoma-bearing rats with 6-methylene progesterone, which blocks conversion of testosterone to dihydrotestosterone. Copenhagen-Fisher rats were treated with steroid (20 mg/Kg daily) immediately following implantation of tumor and thereafter for 117 days. There was a 92% inhibition of growth of tumors and a lesser effect upon prostate and seminal vesicles. Tumor-free body weights remained unchanged. Both treated and untreated tumors had equivalent DNA content on a per weight basis. This result supports the thesis that prostatic adenocarcinoma requires dihydrotestosterone for growth. Androgen-insensitive cells: Advanced prostate cancer does not respond to endocrine therapy but is temporarily controlled by the cytotoxic steroid estramustine. The latter shows significant selective binding to prostatic protein. To develop chemotherapeutic agents that will control androgen-insensitive cells and possess improved selectivity for prostatic protein, we have studied a number of steroids for their ability to displace 3H-labeled estramustine from prostatic cytosolic proteins. Surprisingly, a carbamido substituent at the C17 position was found to confer significant binding affinity for prostatic estramustine-binding protein. Extension of this structural characteristic to the estramustine type of molecule is being studied.
 ...
PMID:Approaches to prostatic cancer chemotherapy using the Dunning R3327H prostatic adenocarcinoma. 397 75

Quantitative analyses of cytosolic steroid hormone receptors were performed on nine tumors from the transplantable rat prostatic adenocarcinoma R-3327H. Androgen receptors and estrogen receptors were found in eight of nine and five of six tumors, respectively. None of the tumours analyzed contained detectable progestin or glucocorticoid receptors (four and seven tumors, respectively). The apparent equilibrium dissociation constants for the androgen and estrogen receptors were 0.7-4.3 nM and 0.6-1.8 nM, respectively. The apparent equilibrium Bmax values (maximum number of binding sites) were 1,500-25,000 fmoles/gm tissue for the androgen receptor and 640 to 5,800 fmoles/gm tissue for the estrogen receptor. A comparison between the receptor contents of the R-3327H rat tumor and human benign prostatic hyperplasia and metastatic carcinoma of the prostate showed that the rat tumor was different from the human tissues in several respects. Hence, the search for an optimal animal model for prostatic carcinoma in man must be continued.
 ...
PMID:Comparison of the R-3327H rat prostatic adenocarcinoma to human benign prostatic hyperplasia and metastatic carcinoma of the prostate with regard to steroid hormone receptors. 616 71

To study the mechanisms by which androgens intervene in the regulation of growth and differentiation of human prostatic epithelial cells, cDNA clones encoding putative prostate-secreted proteins were characterized and tested as potential markers for androgen action. One of the isolated cDNAs expressed diazepam-binding inhibitor/acyl-CoA-binding protein (DBI/ACBP), suggesting that this polypeptide, that has been implicated in a large number of biochemical processes, is expressed and secreted by prostate cells. As demonstrated by Northern blot analysis, the mRNA encoding DBI/ACBP was expressed in prostate tissue and in the three human prostatic adenocarcinoma cell lines tested: LNCaP, PC-3 and DU-145. In androgen-sensitive LNCaP cells, the synthetic androgen R1881 stimulated the DBI/ACBP steady state mRNA levels with half maximal effects at a concentration of 0.2 nM. Increases were a maximal 12 h after addition of the synthetic hormone. DBI/ACBP mRNA levels could also be stimulated by the synthetic androgen mibolerone and by the natural androgens testosterone and dihydrotestosterone. In agreement with the altered steroid specificity of the androgen receptor in LNCaP cells, estradiol and progesterone also exerted a stimulatory effect. Cortisol and the synthetic glucocorticoid dexamethasone were without effect. Androgen stimulation of DBI/ACBP mRNA levels was abolished in the presence of the protein synthesis inhibitor cycloheximide, implying a role for labile or androgen-induced proteins in this androgen stimulation. This is in contrast to the androgen stimulation of the mRNA encoding prostate-specific antigen (PSA), suggesting that different mechanisms are involved in the androgen regulation of these two genes. Although further experiments are required to confirm that DBI/ACBP is secreted by prostatic epithelial cells, these data demonstrate that the mRNA encoding DBI/ACBP is expressed in prostate cells and is affected by androgens in androgen-responsive LNCaP cells.
 ...
PMID:Androgen regulation of the messenger RNA encoding diazepam-binding inhibitor/acyl-CoA-binding protein in the human prostatic adenocarcinoma cell line LNCaP. 752 52

The therapeutic benefit of chemotherapy in androgen independent prostate cancer is limited. 5-Fluorouracil has been reported to have modest antitumor activity in androgen independent prostate cancer. Although alpha-interferon is inactive as a single agent in prostate cancer, preclinical data indicate that it increases the in vitro cytotoxicity of 5-fluorouracil against a variety of malignant cells. We evaluated the relative antitumor activity and tolerance of 5-fluorouracil versus 5-fluorouracil plus alpha-interferon in 50 patients with histologically confirmed metastatic adenocarcinoma of the prostate. These patients had progressive disease in the presence of castrate levels of testosterone. A prospective randomized phase II open labeled trial was performed because of the difficulty in measuring responses in patients with metastatic prostate cancer. Of 23 patients treated with 5-fluorouracil alone and 28 treated with 5-fluorouracil plus alpha-interferon 17 and 23, respectively, were evaluable for response and toxicity, and 5 and 5, respectively, were evaluable for toxicity only. Only 2 of 17 (11.7%) and 4 of 23 (17%) patients, respectively, showed a greater than 50% decrease in serum prostate specific antigen (no significant difference). There was no difference in duration of response or duration of survival between the 2 groups (mean duration of response 8.64 and 6.17 weeks, respectively, and mean duration of survival 33.70 and 38.65 weeks, respectively). Both regimens caused significant morbidity (mucositis and neurotoxicity) and 3 treatment related deaths at the high 5-fluorouracil doses. 5-Fluorouracil alone and with alpha-interferon at the doses used have minimal antitumor activity against androgen independent prostate cancer and, therefore, should not be tested further in these patients. Androgen independent prostate cancer selected using our criteria is a rapidly progressive disease, and these patients are an ideal target population for phase II studies.
 ...
PMID:The results of a phase II randomized trial comparing 5-fluorouracil and 5-fluorouracil plus alpha-interferon: observations on the design of clinical trials for androgen-independent prostate cancer. 771 79

Apoptosis in the androgen-sensitive Dunning R3327 PAP prostatic adenocarcinoma was studied during the post castration period of 14 days and compared with the ventral prostate. The mRNA expression of testosterone repressed prostatic message-2 and tissue-type plasminogen activator in the Dunning tumor and in the ventral prostate was analyzed by Northern blot experiments and immunohistochemical procedures. The degree of endonuclease-degraded genomic DNA was examined by gel electrophoresis. Apoptotic tumor epithelial cells were identified with in situ end labeling. Epithelial cells incorporating bromodeoxyuridine (BrdUrd) after castration in the ventral prostate and the Dunning tumors were localized with immunostaining. Androgen ablation resulted in an induction of testosterone repressed prostatic message-2 and tissue-type plasminogen activator transcripts in the normal prostate with a peak at approximately 2 to 5 days post castration. These transcript levels in the Dunning prostatic tumors did not show any induction during the same period. Immunohistochemical staining for sulfated glycoprotein-2 and tissue-type plasminogen activator confirmed this difference between the tumor tissue and the ventral prostate at the transcriptional level. The determination of DNA integrity showed similar results in that the degree of DNA fragmentation in the tumor was much lower than the initial and marked degradation of DNA in the ventral prostate. The number of in situ end-labeled epithelial tumor cells were not increased by castration. BrdUrd immunodetection showed that castration induced an initial increase in the number of BrdUrd-positive epithelial cells in the ventral prostate. In the tumors, castration resulted in a decrease in BrdUrd-positive epithelial cells. It was concluded that in the androgen-sensitive prostatic Dunning R3327 PAP adenocarcinoma, the biochemical cascade leading to apoptosis is not activated by androgen withdrawal, as in the ventral prostate.
 ...
PMID:Castration induces apoptosis in the ventral prostate but not in an androgen-sensitive prostatic adenocarcinoma in the rat. 801 87

Recent studies have demonstrated that retinoic acid (RA) can repress the growth of human prostatic epithelial cells. Since the proliferation of prostate cells is highly dependent on androgen stimulation, presumably via its cognate receptor, we investigated the effects of RA on the expression of the androgen receptor and other androgen-regulated genes in the human prostatic adenocarcinoma cell line LNCaP. Using a radioligand binding assay, we found that androgen-binding activity was reduced 30-40% in cells treated with 10(-5) M RA plus 6 nM dihydrotestosterone (DHT), as compared to cells with the androgen alone. Moreover, the reduction of the androgen receptor (AR) was not accompanied by alteration of the ligand-binding affinity. Concomitant changes in the function of AR were manifested by a dramatic reduction in AR-mediated transcription activity in a transfection experiment. Androgen-induced levels of both prostate-specific antigen (PSA) and human glandular kallikrein-1 (hKLK2) mRNAs were significantly repressed by RA in a dose- and time-dependent manner. Consistent with this finding, androgen induction of PSA glycoprotein was also repressed by RA, with maximal inhibition occurring at 10(-5) M. These data suggest that the suppression of proliferation and function of prostatic cells by RA may be via modulatory effects on the AR.
 ...
PMID:Antagonism of androgen action in prostate tumor cells by retinoic acid. 802 10


1 2 3 4 Next >>