Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Androgen is essential for the physiological maintenance of the integrity of prostatic epithelial cells, and castration causes the cells to undergo apoptosis. To study the molecular mechanism of androgen-dependent cell growth, we showed that androgen up-regulates the expression of the cyclin-dependent kinase inhibitor p21 (WAF1, CIP1, SDI1, CAP20) gene at both the mRNA and protein levels. Nuclear run-on assays demonstrated that androgen stimulates endogenous p21 gene expression at the transcriptional level. Transient transfection experiments showed that androgen can enhance the activity of a 2.4-kb promoter of the p21 gene linked to a luciferase reporter. These results suggested that a putative androgen response element (ARE), which mediates androgen response to enhance the p21 transcription, is included in the 2.4-kb promoter fragment. Deletion analysis of the promoter revealed a functional ARE (AGCACGCGAGGTTCC) located at -200 bp of the p21 gene proximal to the promoter region. Electrophoretic mobility shift assay further demonstrated that the androgen receptor specifically binds to this element. Wild-type ARE, but not mutant ARE, confers androgen responsiveness to a heterologous promoter. The up-regulation of p21 gene expression by androgen suggests that p21 may have an antiapoptotic function in prostatic epithelial cells. However, this hypothesis will need to be tested in future experiments.
Mol Endocrinol 1999 Mar
PMID:Androgen regulation of the cyclin-dependent kinase inhibitor p21 gene through an androgen response element in the proximal promoter. 1007 95

Androgen excess is one of the most common reproductive endocrinologic abnormalities of women. Excluding specific etiologies such as androgen-secreting neoplasms and non-classic adrenal hyperplasia, the majority of androgen excess is functional in nature. It is clear that studies concerned with the heritability of this disorder greatly depend on how it is defined. Patients with the PolyCystic Ovary Syndrome (PCOS) are clearly included. However, we argue that ovulatory women with hirsutism and hyperandrogenemia should also be considered as affected which, together with PCOS, comprise the population of women we define as having Functional Androgen Excess (FAE). Our data, and that of others, suggests that FAE/PCOS is a familial disorder, with a single autosomal dominant gene effect and a variable phenotype. Inheritance appears to be equally probable from the maternal as from the paternal side of the family. Nonetheless, our data also suggests that the affection rate among mothers is less than expected, which may be due to decreased fertility of affected mothers, or to our inability to detect the disorder in older, menopausal or hormonally treated individuals. Finally, it appears that a woman's risk for developing PCOS is approximately 40% if her sister is affected. While considering FAE/PCOS to be a dominant genetic disorder with a high degree of expressivity, its highly variable phenotype suggests that besides a single genetic mutation other factors must be contributing to the development and expression of the disorder. These factors may include environmental influences (such as fat and carbohydrate consumption) exercise level, peripubertal stress and/or hormonal exposure; and additional genetic defects, such as those that regulate insulin secretion or determine body type.
J Steroid Biochem Mol Biol
PMID:Heritability and the risk of developing androgen excess. 1041

Androgens play a crucial role in several stages of male development and in the maintenance of the male phenotype. Androgens act in their target cells via an interaction with the androgen receptor, resulting in direct regulation of gene expression. The androgen receptor is a phosphoprotein and modulation of the phosphorylation status of the receptor influences ligand-binding and consequently transcription activation of androgen responsive genes. Androgen binding induces a conformational change in the ligand-binding domain, accompanied by additional receptor phosphorylation. Subsequently the liganded androgen receptor interacts with specific androgen response elements in the regulatory regions of androgen target genes, resulting in stimulation of gene expression. Anti-androgens induce a different conformational change of the ligand-binding domain, which does not or only partially result in stimulation of transactivation. Interestingly, different anti-androgens can induce different inactive conformations of the androgen receptor ligand-binding domain. Recent evidence strongly supports a ligand dependent functional interaction between the ligand-binding domain and the NH2-terminal transactivating domain of the androgen receptor. Two regions in the NH2-terminal domain are involved in this interaction, whereas in the ligand-binding domain the AF-2 AD core region is involved.
J Steroid Biochem Mol Biol
PMID:Mechanisms of androgen receptor activation and function. 1041 7

Beta-glucuronidase (GUS) is a lysosomal enzyme that, in mouse kidney, is subject to control by multiple hormones: androgen, which increases GUS transcription; estrogen, which antagonizes androgen-mediated stimulation of GUS; and growth hormone (GH), which appears to be necessary for the full androgen effect. Neither estrogen nor GH affects GUS in the absence of androgen. In hypophysectomized or pituitary dwarf mice the reduced androgen stimulation of GUS can be partially restored with GH treatment. Androgen-induced GUS mRNA increased significantly with intermittent GH, compared to no GH or continuous GH. Intact mice subjected to continuous infusion of GH showed a depressed androgen effect on GUS similar to that seen in GH-deficient mice. Thus, pulsatile GH is required for the full androgen response. Insulin-like growth factor-I (IGF-I) also restored GUS induction by androgen in GH-deficient mice. We conclude that GH enhances the effect of androgen on the GUS gene via IGF-I. Using transgenic mice, we have also identified a genetic variant of the GUS gene that is insensitive to GH enhancement of the androgen effect.
Mol Cell Endocrinol 1999 Jul 20
PMID:Growth hormone and insulin-like growth factor-I enhance beta-glucuronidase gene activation by androgen in mouse kidney. 1045 53

The androgen receptor (AR) gene is transcriptionally regulated by AR (autoregulation); however, the androgen response elements (AREs) required for this process have not been found in the AR promoter or in the 5'-flanking region. We previously showed that the AR cDNA contains AREs involved in AR mRNA autoregulation and that auto(up)regulation is reproduced in PC3 cells (a human prostate cancer cell line) expressing the human AR cDNA driven by a heterologous promoter. A 350-bp fragment of the AR cDNA contains the requisite AREs (ARE-1 and ARE-2) and, when linked upstream of a reporter gene, confers androgen inducibility in a cell-specific manner. Here we report that, although an AR cDNA harboring silent mutations of ARE-1 and ARE-2 produces a transcriptionally active AR, AR mRNA encoded by this mutant cDNA is not up-regulated in androgen-treated PC3 cells. Thus, ARE-1 and ARE-2 are essential for androgen-mediated up-regulation of AR mRNA in this model. Since ARE-1 and ARE-2 are located on separate exons (exons D and E) in the AR gene, we evaluated these AREs in their native context, a 6.5-kb AR genomic fragment. Androgen regulated the 6.5-kb AR genomic fragment and the 350-bp region of the AR cDNA at comparable levels, suggesting that sequences in exons D and E are likely to be involved in androgen-mediated up-regulation of the native AR gene. Furthermore, androgen regulated both responsive regions in U2OS cells, a human osteoblastic cell line that exhibits androgen-mediated up-regulation of native AR mRNA. DNAse I footprinting of the 350-bp region with recombinant AR (DNA- and ligand-binding domains) suggested the presence of additional AREs. Gel shift analyses and mutational studies showed that maximal androgen regulation and AR binding were dependent on the integrity of four AREs (ARE-1, ARE-1A, IVSARE, and ARE-2). While the presence of multiple, nonconsensus AREs is common among other androgen-regulated enhancers, the androgen-responsive region of the AR gene is unique because it contains exonic AREs. DNA binding studies with nuclear extracts were performed to determine whether non-AR transcription factors contribute to androgen regulation of the 350-bp region. These studies, in conjunction with mutational analysis and reporter gene assays with dominant negative Myc and Max expression vectors, showed that Myc and Max interaction with a Myc consensus site is required for androgen regulation of the 350-bp fragment. These results represent a novel interaction between AR and the Myc family of proteins and support a model of androgenic control of AR mRNA via AR and Myc family interaction with a unique internal androgen-responsive region harboring multiple exonic regulatory sequences.
Mol Endocrinol 1999 Nov
PMID:Multiple androgen response elements and a Myc consensus site in the androgen receptor (AR) coding region are involved in androgen-mediated up-regulation of AR messenger RNA. 1055 83

Androgen ablation therapy is a primary treatment for advanced prostate cancer, but tumors become refractive to therapy. Consequently, the role of the androgen receptors (ARs) and of mutations in the AR in prostate cancer has been a subject of much concern. In the course of analyzing tumors for mutations, we identified a somatic mutation that substitutes tyrosine for a cysteine at amino acid 619 (C619Y), which is near the cysteines that coordinate zinc in the DNA binding domain in the AR. The mutation was re-created in a wild-type expression vector and functional analyses carried out using transfection assays with androgen-responsive reporters. The mutant is transcriptionally inactive and unable to bind DNA. In response to ligand treatment, AR619Y localizes abnormally in numerous, well circumscribed predominantly nuclear aggregates in the nucleus and cytoplasm. Interestingly, these aggregates also contain the bulk of the coexpressed steroid receptor coactivator SRC-1, suggesting, in analogy to AR in spinal bulbar muscular atrophy, that this mutant may alter cellular physiology through sequestration of critical proteins. Although many inactivating mutations have been identified in androgen insensitivity syndrome patients, to our knowledge, this is the first characterization of an inactivating mutation identified in human prostate cancer.
Mol Endocrinol 1999 Dec
PMID:A C619Y mutation in the human androgen receptor causes inactivation and mislocalization of the receptor with concomitant sequestration of SRC-1 (steroid receptor coactivator 1) 1059 82

Rapid advances in positional cloning studies have identified most of the genes on the human Y chromosome, thereby providing resources for studying the expression of its genes in prostate cancer. Using a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) procedure, we had examined the expression of the Y chromosome genes in a panel of prostate samples diagnosed with benign prostatic hyperplasia (BPH), low and/or high grade carcinoma, and the prostatic cell line, LNCaP, stimulated by androgen treatment. Results from this expression analysis of 31 of the 33 genes, isolated so far from the Y chromosome, revealed three types of expression patterns: i) specific expression in other tissues (e.g., AMELY, BPY1, BPY2, CDY, and RBM); ii) ubiquitous expression among prostate and control testis samples, similar to those of house-keeping genes (e.g., ANT3, XE7,ASMTL, IL3RA, SYBL1, TRAMP, MIC2, DBY, RPS4Y, and SMCY); iii) differential expression in prostate and testis samples. The last group includes X-Y homologous (e.g., ZFY, PRKY, DFFRY, TB4Y, EIF1AY, and UTY) and Y-specific genes (e.g., SRY, TSPY, PRY, and XKRY). Androgen stimulation of the LNCaP cells resulted in up-regulation of PGPL, CSFR2A, IL3RA, TSPY, and IL9R and down regulation of SRY, ZFY, and DFFRY. The heterogeneous and differential expression patterns of the Y chromosome genes raise the possibility that some of these genes are either involved in or are affected by the oncogenic processes of the prostate. The up- and down-regulation of several Y chromosome genes by androgen suggest that they may play a role(s) in the hormonally stimulated proliferation of the responsive LNCaP cells.
Mol Carcinog 2000 Apr
PMID:Expression analysis of thirty one Y chromosome genes in human prostate cancer. 1074 95

Male hypogonadism is characterised by androgen deficiency and infertility. Hypogonadism can be caused by disorders at the hypothalamic or pituitary level (hypogonadotropic forms) or by testicular dysfunction (hypergonadotropic forms). Testosterone substitution is necessary in all hypogonadal patients, because androgen deficiency causes slight anemia, changes in coagulation parameters, decreased bone density, muscle atrophy, regression of sexual function and alterations in mood and cognitive abilities. Androgen replacement comprises injectable forms of testosterone as well as implants, transdermal systems, sublingual, buccal and oral preparations. Transdermal systems provide the pharmacokinetic modality closest to natural diurnal variations in testosterone levels. New injectable forms of testosterone are currently under clinical evaluation (testosterone undecanoate, testosterone buciclate), allowing extended injection intervals. If patients with hypogonadotropic hypogonadism wish to father a child, spermatogenesis can be initiated and maintained by gonadotropin therapy (conventionally in the form of human chorionic gonadotropin (hCG) and human menopausal gonadotropin (hMG) or, more recently, purified or recombinant follicle stimulating hormone (FSH)). Apart from this option, patients with disorders at the hypothalamic level can be stimulated with pulsatile gonadotropin-releasing hormone (GnRH). Both treatment modalities have to be administered on average for 7-10 months until pregnancy is achieved. In individual cases, treatment may be necessary for up to 46 months. Testosterone treatment is interrupted for the time of GnRH of gonadotropin therapy, but resumed after cessation of this therapy.
Mol Cell Endocrinol 2000 Mar 30
PMID:Hormone substitution in male hypogonadism. 1077 95

Androgen ablation therapy has been combined with permanent interstitial brachytherapy in order to downsize the gland prior to seed implantation. It also has been employed in an attempt to improve the effectiveness of therapy in patients with a poor prognosis. We report on 50 patients consecutively treated and prospectively followed. All received neoadjuvant hormonal therapy (NHT) and 45 Gy of external-beam therapy to a limited pelvic field, followed by permanent implantation of (125)I or (103)Pd seeds. The median follow-up is 42.1 months (range 9.0-90.8 months). The prostate specific antigen (PSA) progression-free survival rate (<1.0 ng/mL) was 76% at 5 years (Kaplan-Meier method). Local control was achieved in 100% of the patients and distant disease-free survival in 85%. High-risk patients treated contemporaneously with these patients, who received external-beam radiation and a seed boost without NHT, had a 62% rate of 5-year PSA progression-free survival. Although the modest improvement in PSA progression-free survival is not statistically significant at 5 years (P = 0.5), the patients treated with NHT in addition to combined radiotherapy presented with significantly higher serum PSA concentrations (mean 21.0 ng/mL; median 17.0 ng/mL) than those treated with combination radiotherapy alone (mean 15.6 ng/mL; median 10.6 ng/mL) and thus had a worse prognosis.
Mol Urol 1999
PMID:Neoadjuvant Androgen Ablation Combined with External-Beam Radiation Therapy and Permanent Interstitial Brachytherapy Boost in Localized Prostate Cancer. 1085 28

Androgen deprivation induces substantial changes in the phenotype of prostate cancer that are accompanied by alterations in protein expression. Immunohistochemical studies allow precise cellular localization of such expression, thereby providing an understanding of the biochemical alterations caused by therapy. Expression of proteins may be increased (e.g., multiple growth factors, heat shock protein), decreased (e.g., microvessel density, proliferation markers, certain integrins), or remain unchanged (e.g., prostate specific antigen, prostatic acid phosphatase, prostate-specific membrane antigen, and other secretory proteins). Variations in immunoreactivity may be of prognostic value in some patients. This report summarizes the existing literature regarding changes in tissue expression of proteins, as determined by immunohistochemistry, and the clinical implications of these changes.
Mol Urol 2000
PMID:Immunohistochemical changes in prostate cancer after androgen deprivation therapy. 1106 63


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