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PubMed2001

Posttraining androgens' enhancement of cognitive performance is temporally distinct from androgens' increases in affective behavior.

Steroid hormone-induced variations in spatial learning and memory tasks have been reported. In this study, androgens' effects in various cognitive and affective tasks were investigated in order to determine whether any observed differences in cognitive performance could be due to affective changes produced by the hormones. Ovariectomized rats (N = 72) received 0.0, 3.0, or 7.5 mg/kg subcutaneously, of testosterone (T), dihydrotestosterone (DHT), or 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-Diol) suspended in 10% ethanol/sesame oil v/v. For the cognitive tasks (Y maze, inhibitory avoidance, and object recognition), subjects were injected after training trials. For the affective tasks (open field, elevated plus maze, and tailflick), subjects were injected 1 or 24 h before testing. Posttraining injections that produced physiological concentrations of androgens--T, DHT, and 3 alpha-Diol--1 h later increased the percentage of correct choices in the Y maze, the latencies to cross to the shock-associated side of the inhibitory avoidance chamber, and percentage of time exploring novel objects 24 h later, when androgen levels were no longer increased. Administration of T, DHT, and 3 alpha-Diol also increased the number of entries into the center squares of a brightly lit open field, open-arm time in the elevated plus maze, and tailflick latencies 1 but not 24 h following administration. These findings suggest that these androgens, when administered following training, can enhance cognitive performance in the tasks investigated 24 h later when androgen levels nadir, but overt changes in the affective behaviors examined occurred at the time of physiological concentrations 1 h but not 24 h following androgen administration. These findings suggest posttraining androgens can enhance consolidation and cognitive performance, independent of their anxiolytic actions.

Affect↗
PubMed2000

Inhibition of prostate specific antigen expression by genistein in prostate cancer cells.

Recent studies have provided convincing evidence for the role of soy-isoflavones, particularly genistein, in the inhibition of prostate cancer cell growth. Prostate specific antigen (PSA) is a biological marker used to detect and monitor the treatment of prostate cancer patients. Previous studies have documented that isoflavones can inhibit the secretion of PSA in the androgen-dependent prostate cancer cell line, LNCaP, however, the effects of genistein on androgen-independent PSA expression has not been explored. In this study, we have utilized a prostate cancer cell line, VeCaP, which expresses PSA in an androgen-independent manner, to determine the effects of genistein on cell proliferation and PSA expression. Here we show that genistein inhibits cell growth similarly in both the LNCaP and VeCaP cell lines, but has differential effects on PSA expression. We demonstrate using concentrations of genistein that have been detected in the serum of humans consuming a soy-rich diet, that genistein decreases PSA mRNA, protein expression and secretion. Conversely, only high concentrations of genistein inhibited PSA expression in VeCaP cells. Additionally, we have demonstrated that genistein inhibits cell proliferation independent of PSA signaling pathways, providing further evidence to support the role of genistein as a chemopreventive/therapeutic agent for prostate cancer irrespective of androgen responsiveness.

Antineoplastic Agents↗
PubMed2000

Anabolic-androgenic steroids: medical assessment of present, past and potential users.

OBJECTIVE: To document adverse effects of anabolic-androgenic steroid (AAS) use in community-based users attending a medical clinic. DESIGN AND SETTING: Prospective recruitment, questionnaire-based interview, physical examination and investigations, with follow-up, of people who attended, anonymously, an inner-city hospital clinic established specifically to examine AAS use. PARTICIPANTS: 58 men, comprising 27 past AAS users, 14 present users and 17 potential users (who formed the control group). MAIN OUTCOME MEASURE: Clinical adverse effects and abnormal laboratory findings. RESULTS: Cyclical use of oral and intramuscular, human and veterinary AASs were reported. The most commonly reported source of AASs was friends (59%), gymnasiums (25%) and doctors (14%). The most common reported adverse effects were alterations in libido (61%), changes in mood (48%), reduced testis volume (46%) and acne (43%). Although mean systolic and diastolic blood pressure was not significantly different between groups, five present (29%), 10 past (37%) and one potential user (8%) were hypertensive. Gynaecomastia was found in 10 past users (37%; P<0.01 v. potential users), two present users (12%) and no potential users. Mean testis volume was significantly smaller in present users (18 mL; P<0.02) than in the other groups. Twenty past users (83%), eight present users (62%) and five potential users (71%) had abnormal liver function test results (P=0.5). After discussion of test results, only 11 participants (19%) reported they would not use AASs in the future. CONCLUSIONS: Adverse effects were reported by or detected in most of the AAS users who attended the clinic. Despite awareness of adverse consequences, most participants planned future use of AASs.

Administration, Oral↗
PubMed1999

Differential effects of estrogen-androgen and estrogen-only therapy on vasomotor symptoms, gonadotropin secretion, and endogenous androgen bioavailability in postmenopausal women.

OBJECTIVE: To investigate somatic symptom relief, gonadotropin secretion, and endogenous androgen bioavailability (protein-bound and free) during 3 months of estrogen-androgen therapy or matched estrogen-only replacement therapy. DESIGN: Ninety-three naturally menopausal outpatients with 6 or more months of amenorrhea, who were experiencing mild-to-moderate vasomotor symptoms, were randomized to receive one of five treatments: oral esterified estrogens (0.625 mg or 1.25 mg), oral esterified estrogens combined with methyltestosterone (0.625 mg combined with 1.25 mg methyltestosterone or esterified estrogens 1.25 mg combined with 2.5 mg methyltestosterone), or placebo for 12 weeks. All treatments were preceded by a 4-week placebo lead-in period. RESULTS: Patients receiving the lower dose of estrogen-androgen therapy had fewer somatic menopausal symptoms than patients receiving the lower dose estrogen (0.625 mg), and they experienced somatic symptom relief similar to those patients receiving the higher dose of estrogen (1.25 mg). Significantly greater luteinizing hormone suppression (p < or = 0.03) occurred in estrogen-androgen groups compared to estrogen groups, suggesting that added androgen might mediate a more pronounced negative feedback on the hypothalamic-pituitary axis. Sex hormone-binding globulin increased significantly in both estrogen-treated groups (p < or = 0.01), whereas decreases occurred in both estrogen-androgen groups (p < or = 0.006). The higher dose estrogen-only preparation significantly reduced androstenedione (p < or = 0.01) and dehydroepiandrosterone sulfate (p < or = 0.005). CONCLUSION: The extent of relief with lower dose estrogen-androgen therapy was similar to higher dose estrogen-only treatment. The greater efficacy of combination therapy on somatic symptoms could be mediated by the same mechanism responsible for the suppressive effects of estrogen-androgen therapy on luteinizing hormone secretion. The marked differences in circulating levels of sex hormone building globulin, which were increased by estrogen and decreased by estrogen-androgen, and the resulting impact on bioavailable androgens and estrogens could also explain the differential somatic relief with both treatments. Endogenous adrenal androgens were lower in women treated with esterified estrogens 1.25 mg/day, suggesting that estrogen therapy can produce a significant hypoandrogenic state by inhibiting production or accelerating clearance of adrenal androgens.

Administration, Oral↗
PubMed1999

Androgen and epidermal growth factor down-regulate cyclin-dependent kinase inhibitor p27Kip1 and costimulate proliferation of MDA PCa 2a and MDA PCa 2b prostate cancer cells.

Low levels of p27Kip1 in primary prostate cancer specimens have been shown to be associated with higher rates of disease recurrence and poor rates of disease-free survival in patients with localized disease. In this study, we provide the first direct evidence showing that dihydrotestosterone (DHT), a major proliferation regulator of prostate cancer, can down-regulate p27Kip1 and stimulate cyclin-dependent kinase-2 (CDK2) activity in established prostate cancer cell lines. We investigated the cooperative effects of DHT and epidermal growth factor (EGF) on the proliferation of androgen-responsive MDA PCa 2a and MDA PCa 2b prostate cancer cells. DHT and EGF each stimulated proliferation of these cells, but exposure of the cells to DHT and EGF together stimulated greater proliferation. Stimulation of cell proliferation by DHT and/or EGF was associated with increased CDK2 activity and a decreased level of p27Kip1. There seems to be a positive feedback stimulation loop between androgen-induced gene transcription and EGF-stimulated signal transduction, as one could stimulate the synthesis of the receptors for the other. Dual blockade of androgen receptor function with the antiandrogen hydroxyflutamide and EGF receptor superfamily-mediated signal transduction with the anti-EGF receptor monoclonal antibody C225 and the anti-HER2 receptor monoclonal antibody Herceptin significantly enhanced growth inhibition of the MDA PCa 2a cells. Our results demonstrate the importance of counteracting both androgen receptors and EGF receptors in the development of novel therapies for prostate cancer.

Androgen Antagonists↗
PubMed2000

Androgen and taxol cause cell type-specific alterations of centrosome and DNA organization in androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cells.

We investigated the effects of androgen and taxol on the androgen-responsive LNCaP and androgen-independent DU145 prostate cancer cell lines. Cells were treated for 48 and 72 h with 0.05-1 nM of the synthetic androgen R1881 and with 100 nM taxol. Treatment of LNCaP cells with 0.05 nM R1881 led to increased cell proliferation, whereas treatment with 1 nM R1881 resulted in inhibited cell division, DNA cycle arrest, and altered centrosome organization. After treatment with 1 nM R1881, chromatin became clustered, nuclear envelopes convoluted, and mitochondria accumulated around the nucleus. Immunofluorescence microscopy with antibodies to centrosomes showed altered centrosome structure. Although centrosomes were closely associated with the nucleus in untreated cells, they dispersed into the cytoplasm after treatment with 1 nM R1881. Microtubules were only faintly detected in 1 nM R1881-treated LNCaP cells. The effects of taxol included microtubule bundling and altered mitochondria morphology, but not DNA organization. As expected, the androgen-independent prostate cancer cell line DU145 was not affected by R1881. Treatment with taxol resulted in bundling of microtubules in both cell lines. Additional taxol effects were seen in DU145 cells with micronucleation of DNA, an indication of apoptosis. Simultaneous treatment with R1881 and taxol had no additional effects on LNCaP or DU145 cells. These results suggest that LNCaP and DU145 prostate cancer cells show differences not only in androgen responsiveness but in sensitivity to taxol as well.

Androgens↗
PubMed1999

A two-year, double-blind comparison of estrogen-androgen and conjugated estrogens in surgically menopausal women. Effects on bone mineral density, symptoms and lipid profiles.

OBJECTIVE: To compare the effects of two doses of conjugated equine estrogen (CEE) and two of esterified estrogen plus methyltestosterone (E + A) in surgically menopausal women. STUDY DESIGN: A two-year, parallel-group, double-blind study of 311 women who were randomly assigned to one of four regimens: (1) CEE, 0.625 mg/d; (2) CEE, 1.25 mg/d; (3) esterified estrogens, 0.625 mg, + methyltestosterone, 1.25 mg/d; or (4) esterified estrogens, 1.25, + methyltestosterone, 2.5 mg/d. Study parameters were symptoms, lipids, bone mineral density, side effects and safety. RESULTS: All treatments prevented loss of bone in the spine and hip. The higher E + A dose increased spine and hip BMD more than other treatments (P < .002). All treatments improved menopausal symptoms, with non-significantly greater improvements in well-being and sexual interest in the E + A groups. Similar and significant decreases in low-density lipoprotein were observed in all groups, but high-density lipoprotein and triglycerides were increased only in the unopposed estrogen groups (P < .05). Hirsutism was uncommon and similar in all groups at two years. Discontinuation rates and reasons for withdrawal from the study were similar in both groups. No clinically significant side effects or laboratory test abnormalities were seen. CONCLUSION: As compared to estrogen alone, E + A significantly improved BMD and was well tolerated in surgically menopausal women.

Administration, Oral↗
PubMed2000

Expression profile of an androgen regulated prostate specific homeobox gene NKX3.1 in primary prostate cancer.

PURPOSE: NKX3.1, a member of the family of homeobox genes, exhibits prostate tissue specific expression and appears to play a role in mouse prostate development. Rapid induction of NKX3.1 gene expression in response to androgens has also been described. On the basis of the established role of androgens in prostatic growth and differentiation and studies showing an association of aberrant homeobox gene expression with the neoplastic process, we hypothesize that alterations of NKX3.1 gene expression play a role in prostate tumorigenesis. MATERIALS AND METHODS: NKX3.1 expression was analyzed in matched, microdissected normal and tumor tissues from 52 primary prostate cancer specimens from radical prostatectomy by semiquantitative RT-PCR and in situ hybridization and correlated with the clinicopathologic features. NKX3.1 expression was quantified as differential expression between matched tumor and normal tissues and was grouped as overexpression in tumor tissue, reduced expression in tumor tissue and no change between tumor and normal tissues. Androgen regulation of NKX3.1 expression was also studied in LNCaP cells. Androgen receptor (AR) expression in prostate tumor and normal tissue was correlated with NKX3.1 expression. RESULTS: Comparison of NKX3.1 expression between normal and tumor tissues revealed overexpression in 31% tumor specimens (16 of 52), decreased expression in 21% tumor specimens (11 of 52) and no change in 48% specimens (25 of 52). When these expression patterns were stratified by organ confined and non-organ-confined tumor, a higher percentage of patients exhibited NKX3.1 overexpression in non-organ confined tumor (40%) versus organ confined tumor (22%). Elevated NKX3.1 expression significantly correlated with tumor volume and serum prostate specific antigen (PSA) level in the NKX3.1 overexpression group (p<0.05). Metastatic prostate cancer cell lines did not exhibit mutations in the protein coding sequence of NKX3.1. Additionally, the NKX3.1 expression correlated with AR expression (p<0.01) in vivo in human prostate tissues. Comparison of PSA and NKX3.1 expression in response to androgen revealed a rapid androgen mediated induction of NKX3.1 expression in LNCaP cells. In situ hybridization analysis of representative specimens confirmed RT-PCR observations. CONCLUSIONS: These results suggest an association of NKX3.1 with a more aggressive phenotype of carcinoma of the prostate. Correlation of AR expression with NKX3.1 in human prostate tissues underscores the androgen regulation of NKX3.1 in the physiologic context of human prostate tissues.

Androgens↗