Albert C, Vallee M, Beaudry G, Belanger A, Hum DW
Laboratory of Molecular Endocrinology, CHUL Research Center, Laval University, Quebec, Canada.
[Medline record in process]
Endocrinology 1999 Jul;140(7):3292-302

Considering the physiologic importance of the steroid response, which is regulated in part by steroid levels in a given tissue, relatively little is known about steroid glucuronidation, which is widely accepted as a major pathway involved in the catabolism and elimination of steroid hormones from the human body. In a previous study, it was ascertained that the monkey may be the most appropriate model in which to examine the role of steroid glucuronidation. Northern blot analysis of simian RNA, hybridized with human UGT complementary DNA (cDNA) probes demonstrate the similarity of the transcripts. The simian UGT1A09 cDNA isolated from a liver library is 2396 bp and contains an open reading frame encoding 530 amino acids. The predicted primary structure is most homologous to the human UGT1A9 (hUGT1A9) enzyme, which share 93% identity. Stable transfection of the monkey UGT1A09 (monUGT1A09) cDNA into HK293 cells, expresses a microsomal protein with an apparent molecular mass of 55 kDa. Of the more than 30 endogenous substrates tested, both proteins show the highest activity on 4-hydroxyestradiol and 4-hydroxyestrone, followed by 2-hydroxyestradiol and estradiol. RT-PCR analysis demonstrate that UGT1A9 transcript is expressed in several tissues, which include the prostate, testis, breast, ovary, and skin of the monkey and humans. The expression of UGT1A9 in extrahepatic estrogen-responsive tissues, and its high activity on estrogens is consistent with this enzyme having a role in estrogen metabolism.

Singh J, Handelsman DJ
Department of Medicine, DO2, University of Sydney, Sydney, New South Wales 2006, Australia.
[Record supplied by publisher]
Biol Reprod 1999 Jul;61(1):200-208

Perinatal sex-steroid exposure may result in permanent modifications in the structure and function of the prostate gland. The mechanism of such long-range alterations in hormonal sensitivity is not known. This study aimed to define the molecular requirements for neonatal sex-steroid imprinting and to investigate whether combined administration of neonatal androgens and estrogens had synergistic effects upon the mature mouse prostate. Since the interaction between endogenous and exogenous sex steroids in normal mice makes it difficult to dissociate direct from indirect effects, we used the hypogonadal (hpg) mouse, characterized by congenital androgen deficiency yet still fully responsive to exogenous androgens. Newborn mice (Days 1-2) were administered a single s.c. injection of androgens alone or in combination with an estrogen followed by testosterone-induced maximal prostate growth at maturity. The final effects were determined in 7-wk-old mice through study of ductal architecture in microdissected ventral prostates (VP) and quantitation of volume densities and diameters of prostate tissue components. A single neonatal dose of androgens, but not of estrogen, increased branching morphogenesis and VP weights at adulthood. These effects did not differ significantly between various androgens; in addition, combined androgen and estrogen treatment failed to demonstrate any synergistic effects on the prostate. We conclude that neonatal androgens induce long-range effects upon the mature VP structure as well as its secretory function and that this imprinting occurs via the androgen receptor without requiring aromatization of androgens. However, these conclusions, based on a specific treatment protocol, are confined only to the distal segment of VP, and effects of neonatal sex-steroid exposure in other regions

Abreu-Martin MT, Chari A, Palladino AA, Craft NA, Sawyers CL
Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90095, USA.
Mol Cell Biol 1999 Jul;19(7):5143-54

Mitogen-activated protein (MAP) kinases phosphorylate the estrogen receptor and activate transcription from estrogen receptor-regulated genes. Here we examine potential interactions between the MAP kinase cascade and androgen receptor-mediated gene regulation. Specifically, we have studied the biological effects of mitogen-activated protein kinase kinase kinase 1 (MEKK1) expression in prostate cancer cells. Our findings demonstrate that expression of constitutively active MEKK1 induces apoptosis in androgen receptor-positive but not in androgen receptor-negative prostate cancer cells. Reconstitution of the androgen receptor signaling pathway in androgen receptor-negative prostate cancer cells restores MEKK1-induced apoptosis. MEKK1 also stimulates the transcriptional activity of the androgen receptor in the presence or absence of ligand, whereas a dominant negative mutant of MEKK1 impairs activation of the androgen receptor by androgen. These studies demonstrate an unanticipated link between MEKK1 and hormone receptor signaling and have implications for the molecular basis of hormone-independent prostate cancer growth.

Chang WY, Birch L, Woodham C, Gold LI, Prins GS
Department of Urology, University of Illinois College of Medicine, Chicago 60612, USA.
Endocrinology 1999 Jun;140(6):2801-13

Exposure of male rats to estrogens during the neonatal period retards prostate branching morphogenesis, blocks epithelial differentiation, and predisposes the adult prostate to hyperplasia and dysplasia. The mechanism of neonatal estrogenization is not well understood. The present study evaluated transforming growth factor-beta (TGFbeta) in the neonatally estrogenized ventral prostate to determine whether this paracrine/autocrine factor may in part mediate the effects ofestrogen on the developing prostate gland. Immunocytochemistry using antibodies against active TGFbeta1 and its latency-associated peptide localized this molecule to the periductal smooth muscle cells in the developing prostate. Although neonatal estrogenization increased the accumulation of total and active TGFbeta1 in the smooth muscle layer as early as day 6 of life, it was physically separated from the epithelial ducts by a proliferating layer of fibroblasts surrounding the basement membrane. RT-PCR demonstrated that alterations in TGFbeta1 levels were not due to alterations in TGFbeta1 transcription. TGFbeta2 and TGFbeta3 were primarily immunolocalized to differentiating epithelial cells in developing prostates, and this was markedly dampened between days 10-30 after neonatal estrogen exposure. Immunocytochemistry for TGFbeta signaling components revealed that neonatal estrogenization transiently reduced TGFbeta type I receptor levels in the prostate epithelium, but not in stroma, between days 6-15, whereas there was no effect on TGFbeta type II receptor. Levels of the intracellular signal Smad2 (52 kDa) were detected in epithelial cells but were not altered after estrogenization. To analyze the functional status of the TGFbeta signaling pathway, immunocytochemistry was performed for p21(cip-1/waf-1), a cyclin-dependent kinase inhibitor that is inducible by TGFbeta1 in the prostate. Transient nuclear localization of p21(cip-1/waf-1) was normally observed in epithelial cells between days 6-15 and was associated with entry of cells into a terminal differentiation pathway. Neonatal estrogenization prevented this transient expression of p21(cip-1/waf-1). The present findings demonstrate that the TGFbeta signaling system is perturbed at several levels in the estrogenized prostate, which may in part account for the epithelial cell differentiation blockade as well as the proliferation of periductal fibroblasts in this model.

Konishi N, Nakaoka S, Matsumoto K, Nakamura M, Kuwashima S, Hiasa Y, Cho M, Uemura H, Hirao Y
Second Department of Pathology, Nara Medical University, Kashihara, Japan.
nkonishi@naramed-u.ac.jp
Pathol Int 1999 Mar;49(3):203-7

The expression of pepsinogen II (PG II), an aspartyl proteinase usually involved in the digestion of proteins in the stomach, was immunohistochemically investigated in conjunction with androgen (AR) and estrogen receptor (ER) status in prostate adenocarcinomas. Of a total of 38 samples obtained from radical prostatectomies, 23 tumors (60.5%) were positive for PG II and there was a significant positive correlation to the expression of AR but not to ER. Cells positive for PG II were localized mainly to the peripheral zones of tumorous glands which, in normal prostate, are negative, and in areas also expressing AR. In addition, a significant correlation between AR and ER was detected in the prostate carcinomas examined, which suggests a hormone-dependent status. On the basis of these results, PG II expression might be closely related to hormonal alterations associated with the development of prostate tumors

Wang LG, Liu XM, Kreis W, Budman DR
Department of Medicine, New York University School of Medicine, North Shore University Hospital, Manhasset, New York, 11030, USA.
Biochem Biophys Res Commun 1999 May 27;259(1):21-8

Protein phosphorylation/dephosphorylation is an important posttranslational modification that plays a critical role in signal transduction. The androgen receptor (AR) is under such control. We demonstrate that androgen receptor phosphorylation determines whether or not AR ligands perform as agonists or antagonists in LNCaP cells. Androgen receptor ligands (such as dihydrotestosterone and beta-estradiol) stimulate receptor expression and phosphorylation and, as a result, they act as agonists or partial agonists. In contrast, agents such as bicalutamide and estramustine inhibit the receptor phosphorylation and act as antagonists. This model is supported by gene expression and transactivation assays. Significant increases in levels of both mRNA and protein of prostate-specific antigen (PSA), a natural AR target gene, occur following the treatment of LNCaP cells with DHT, beta-estradiol, or hydroxyflutamide. In contrast, exposure of LNCaP cells to bicalutamide or estramustine results in a sharp decrease of PSA expression. Agonistic or antagonistic effect of these compounds on PSA expression parallels the level of phosphorylated, but not dephosphorylated androgen receptors. These agonistic or antagonistic effects are also observed in HeLa cells transfected with wild-type AR expression plasmid (pAR0) and AR-driven luciferase expression plasmid GRE-tk-LUC in the presence of different groups of AR blockers. Our data indicate that the functional status of androgen receptors is strongly correlated with the phosphorylation status of the receptors, and that the phosphorylated androgen receptor is the form of the receptor transcriptionally active in regulation. Thus the androgen receptor phosphorylation/dephosphorylation

Kuiper GG, Shughrue PJ, Merchenthaler I, Gustafsson JA
Department of Medical Nutrition, Karolinska Institute, Novum, Huddinge, S-14157, Sweden.
george.kuiper@cbt.ki.se
Front Neuroendocrinol 1998 Oct;19(4):253-86

The recent discovery that an additional estrogen receptor (ERbeta) subtype is present in many rat, mouse, and human tissues has advanced our understanding of the mechanisms underlying estrogen signalling. Ligand-binding experiments have shown specific binding of 17beta-estradiol by ERbeta with an affinity similar to that of ERalpha. The rat tissue distribution and/or the relative level of ERalpha and ERbeta expression seems to be quite different, i.e., moderate to high expression in uterus, testis, pituitary, ovary, kidney, epididymis, and adrenal for ERalpha and prostate, ovary, lung, bladder, brain, bone, uterus, and testis for ERbeta. Within the same organ it often appears that the ER subtypes are expressed in different cell types, supporting the hypothesis that the ER's may have different biological functions. The cell type-specific expression of ERalpha and ERbeta in rat prostate, testis, uterus, ovary, and brain and the distribution of ERbeta mRNA in the ERalpha knock-out mouse brain are discussed. The discovery of ERbeta suggests the existence of two previously unrecognized pathways of estrogen signalling; via the ERbeta subtype in tissues exclusively expressing this subtype and via the formation of heterodimers in tissues expressing both ER subtypes. The existence of two ER subtypes, their differential expression pattern, and different actions on certain response elements could provide explanations for the striking species-, cell-, and promoter-specific actions of estrogens and antiestrogens. The challenge for the future is to unravel the detailed physiological role of each subtype and to use this knowledge to develop the next generation of ER-targeted drugs with improved therapeutic profiles in the treatment or prevention of osteoporosis, cardiovascular system disorders, Alzheimer's disease, breast cancer, and disorders of the urogenital tract.

Kuiper GG, Gustafsson JA
Center for Biotechnology and Department of Medical Nutrition, Karolinska Institute, NOVUM, Huddinge, Sweden.
george.kuiper@cbt.ki.se
FEBS Lett 1997 Jun 23;410(1):87-90

The recent discovery that an additional estrogen receptor (ER) subtype is present in various rat, mouse and human tissues has advanced our understanding of the mechanisms underlying estrogen signalling. The discovery of a second ER subtype (ERbeta) suggests the existence of two previously unrecognised pathways of estrogen signalling: via the ERbeta subtype in tissues exclusively expressing this subtype and via the formation of heterodimers in tissues expressing both ER subtypes. Various models have been suggested as explanations for the striking cell- and promoter-specific effects of estrogens and anti-estrogens, all on the basis of the assumption that only a single ER gene

Chu S, Fuller PJ
Prince Henry's Institute of Medical Research, Clayton, Victoria, Australia.
Mol Cell Endocrinol 1997 Sep 19;132(1-2):195-9

Recently a second estrogen receptor termed estrogen receptor beta (ERbeta) has been cloned and characterized, and shown to be expressed at the highest levels in ovarian granulosa cells and prostatic epithelium. In the course of amplifying a region of the ligand-binding domain of the rat ERbeta cDNA we identified a second, larger transcript which appears to arise through differential splicing. The second isoform has 54 nucleotides inserted after position 1372 encoding 18 additional amino acids. Both isoforms are expressed at similar relative abundance in a range of tissues.

Gustafsson JA
Department of Medical Nutrition, Karolinska Institute, Novum, Huddinge, Sweden.
Curr Opin Chem Biol 1998 Aug;2(4):508-11

The hormone estradiol has effects on many tissues in both males and females. Some of these effects, such as inhibition of cancer growth and modulation of the devastating effects of aging on bone, brain, skin and bladder, are good. Others, such as the effect on the breast and endometrium, are undesirable. The task of designing drugs that would have only the good effects of estradiol has, until recently, seemed almost impossible because it was thought that there was only one estrogen receptor and that an estrogenic agent was definitively categorized as an estrogen agonist or an antagonist. More recently we have learnt that there are two estrogen receptors which, under certain conditions, have opposite effects on gene transcription. In addition, it is now understood that agents cannot be described as agonists or antagonists because a single agent can be an agonist in one tissue and an antagonist in another. The term 'selective' estrogen receptor modulator' was designed to incorporate this. The idea of estrogen receptor modulators has raised new hope that tissue specific estrogens or anti-estrogens can be designed.

Donnelly BJ, Lakey WH, McBlain WA
J Urol 1983 Jul;130(1):183-7

Estrogens have been proposed as a major etiological factor in the pathogenesis of benign prostatic hyperplasia in man. The presence of estrogen receptor in benign prostatic hyperplasia would support this concept. Using the receptor stabilizer, sodium molybdate, and a hydroxylapatite assay we assayed human benign prostatic hyperplasia for the presence of cytosolic estrogen receptor. For comparison, we assayed estrogen receptor in cytosols of prostatic cancer and normal tissue, and we also measured androgen receptor and progesterone receptor concentrations in the 3 tissue types. Estrogen receptor was present in 8 of 15 benign prostatic hyperplasia specimens at a mean concentration of 9.2 fmol./mg. protein for the estrogen-receptor-positive samples. Sucrose gradient analysis of the estrogen receptor of benign prostatic hyperplasia revealed that it sedimented in the region of 8S, and steroid specificity studies confirmed that the binding to estrogen receptor was estrogen-specific. Estrogen receptor was also found in normal (3 of 3) and malignant (4 of 6) tissues, and all tissues were positive for androgen receptor. The presence of estrogen receptor in human benign prostatic hyperplasia supports the proposal that circulating estrogens may have a role in the pathogenesis of this disorder.

Ekman P, Barrack ER, Greene GL, Jensen EV, Walsh PC
J Clin Endocrinol Metab 1983 Jul;57(1):166-76

The existence of estrogen receptors in the human prostate has long been a controversial issue. This may be explained partly by the apparent heterogeneity of estrogen-binding sites in prostatic tissue. We herein report on multiple binding sites for estrogens in cytosol as well as nuclear preparations of human prostatic tissues. One class of binding sites corresponds to the classical, high affinity estrogen receptor; the Kd for [3H]estradiol binding to the receptor was approximately 0.10 nM and the binding was specific for estrogens. The second class of binding sites appeared to have a Kd for [3H]estradiol in the range of 5-10 nM. This second, lower affinity class of binding sites markedly influenced studies of the classical receptor even at low ligand concentrations. Saturation analysis should be performed over a wide range of ligand concentrations (0.05-10 nM) to allow separation of the two binding components. Quantitation of estrogen receptor by a single point assay cannot be carried out accurately unless the low affinity binding component can be blocked. Multiple binding sites for estradiol were observed in the cytosol as well as in the nuclear salt extractable and salt-resistant compartments of normal, benign hyperplastic, and cancerous human prostates. Normal peripheral and cancerous prostates contained significantly (P less than 0.01) higher amounts of cytosol estrogen receptor compared to benign hyperplastic tissue.

Khalid BA, Nurshireen A, Rashidah M, Zainal BY, Roslan BA, Mahamooth Z
Department of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur.
Med J Malaya 1990 Jun;45(2):148-53

One hundred and six prostatic tissue samples obtained from transurethral resection were analysed for androgen and estrogen receptors. In 62 of these, progesterone and glucocorticoid receptors were also assayed. Steroid receptors were assayed using single saturation dose 3H-labelled ligand assays. Ninety percent of the 97 prostatic hyperplasia tissues and six of the nine prostatic carcinoma tissues were positive for androgen receptors. Estrogen receptors were only present in 19% and 33% respectively. Progesterone receptors were present in 70% of the tissues, but glucocorticoid receptors were present in only 16% of prostatic hyperplasia and none in prostatic carcinoma.

Pontes JE, Karr JP, Kirdani RY, Murphy GP, Sandberg AA
Urology 1982 Apr;19(4):399-403

Measurement of estrogen binding in human prostate using high-pressure liquid chromatography (HPLC) revealed the presence of cytosolic estrogen receptors (ER) both in benign prostatic hyperplasia (BPH) and adenocarcinoma. Receptor concentrations correlated with several histopathologic features in the specimens analyzed. Estrogen receptor levels generally were higher in BPH than in cancer specimens although there was a subgroup of patients with poorly differentiated carcinoma with levels higher than those of BPH, HPLC can be used for measuring ER in 50 microliters of cytosol, and thus needle biopsy specimens will be analyzed routinely for ER with this micromethod.

Redman C, Scott JA, Baines AT, Basye JL, Clark LC, Calley C, Roe D, Payne CM, Nelson MA
Pharmacology/Toxicology Department, The University of Arizona, Tucson 85724, USA.
Cancer Lett 1998 Mar 13;125(1-2):103-10

Selenium supplementation has been shown for many years to work as an anticarcinogenic agent both in epidemiology and in in vitro studies. Selenium supplementation has recently been shown to decrease total cancer incidence. However, the mechanism of action of selenium as an anticarcinogenic agent has yet to be elucidated. Selenomethionine was the predominant form of selenium in the dietary supplement in the study by Clark et al. (Clark, L.C., Combs, G.F., Turnbull, W.B., Slate, E.H., Chalker, D.K., Chow, J., Davis, L.S., Glover, R.A., Graham, G.F., Gross, E.G., Krongrad, A., Lesher, J.L., Park, H.K., Sanders, B.B., Smith, C.L., Taylor, J.R. and The Nutritional Prevention of Cancer Study Group (1996) Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin: a randomized controlled trial. J. Am. Med. Assoc., 276 (24), 1957-1963) and therefore we evaluated the growth inhibitory effects of selenomethionine against human tumor cells. Selenomethionine was tested against each of three human tumor cell lines (MCF-7/S breast carcinoma, DU-145 prostate cancer cells and UACC-375 melanoma) and against normal human diploid fibroblasts. All cell lines demonstrated a dose-dependent manner of growth inhibition by selenomethionine. Selenomethionine inhibited the growth of all of the human tumor cell lines in the micromolar (microM) range (ranging from 45 to 130 microM) while growth inhibition of normal diploid fibroblasts required 1 mM selenomethionine, approximately 1000-fold higher than for the cancer cell lines. In short, normal diploid fibroblasts were less sensitive than the cancer cell lines to the growth inhibitory effects of selenomethionine. Furthermore, we show that selenomethionine administration to these cancer cell lines results in apoptotic cell death and aberrant mitoses. These results demonstrate the differential sensitivity of tumor cells and normal cells to selenomethionine.

Gey KF
Department of Biochemistry and Molecular Biology, University of Berne, Switzerland.
Biofactors 1998;7(1-2):113-74

Antioxidants are crucial components of fruit/vegetable rich diets preventing cardiovascular disease (CVD) and cancer: plasma vitamins C, E, carotenoids from diet correlate prevalence of CVD and cancer inversely, low levels predict an increased risk of individuals which is potentiated by combined inadequacy (e.g., vitamins C + E, C + carotene, A + carotene); self-prescribed rectification of vitamins C and E at adequacy of other micronutrients reduce forthcoming CVD, of vitamins A, C, E, carotene and conutrients also cancer; randomized exclusive supplementation of beta-carotene +/- vitamin A or E lack benefits except prostate cancer reduction by vitamin E, and overall cancer reduction by selenium; randomized intervention with synchronous rectification of vitamins A + C + E + B + minerals reduces CVD and counteracts precancerous lesions; high vitamin E supplements reveal potentials in secondary CVD prevention. Plasma values desirable for primary prevention: > or = 30 mumol/l lipid-standardized vitamin E (alpha-tocopherol/cholesterol > or = 5.0 mumol/mmol); > or = 50 mumol/l vitamin C aiming at vitamin C/vitamin E ratio > 1.3-1.5; > or = 0.4 mumol/l beta- (> or = 0.5 mumol/l alpha+ beta-) carotene. CONCLUSIONS: In CVD vitamin E acts as first risk discriminator, vitamin C as second one; optimal health requires synchronously optimized vitamins C + E, A, carotenoids and vegetable conutrients.

Rao AV, Fleshner N, Agarwal S
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, ON, Canada.
v.rao@utoronto.ca
Nutr Cancer 1999;33(2):159-64

Dietary intake of tomatoes and tomato products containing lycopene, an antioxidant carotenoid, has been shown in recent studies to reduce the risk of cancer. This study was conducted to investigate the serum and prostate tissue lycopene and other major carotenoid concentrations in cancer patients and their controls. Serum lipid and protein oxidation was also measured. Twelve prostate cancer patients and 12 age-matched subjects were used in the study. Significantly lower serum and tissue lycopene levels (44%, p = 0.04; 78%, p = 0.050, respectively) were observed in the cancer patients than in their controls. Serum and tissue beta-carotene and other major carotenoids did not differ between the two groups (p = 0.395 and p = 0.280, respectively). Although there was no difference (p = 0.760) in serum lipid peroxidation between cancer patients and their controls (7.09 +/- 0.74 and 6.81 +/- 0.56 mumol/l, respectively), serum protein thiol levels were significantly lower among the cancer patients (p = 0.026). This study demonstrates that the status of lycopene but not other carotenoids in prostate cancer patients is different from controls. The role of dietary lycopene in preventing oxidative damage of biomolecules and thereby reducing the risk of prostate cancer needs to be evaluated in future studies.

Brawer Michael K(a); Ellis William J
Seattle VA Med., Cent., 112 UR, 1660 South Columbian Way, Seattle, WA 98108, USA
Cancer (Philadelphia) 75 (7 Suppl.):p1783-1789 1995

With prostate cancer representing the most common male cancer and the second most common cause of cancer-related death in men in the United States, increasing attention is being directed at providing early detection, as well as improvement in therapy. The third option to decrease cancer-related deaths, decreasing the incidence, has only recently gained attention. If tumor promoters can be removed from the patient environment and/or agents administered that inhibit cancer progression, we may indeed be able to decrease the incidence of this most common neoplasm. The prostate is a suitable site for chemoprevention strategies. High-risk populations, including those men with a strong family history of prostate cancer, black men, and/or men with prostatic intraepithelial neoplasia, a putative premalignant change identified on prostate biopsy or simple prostatectomy, represent useful target populations. If a chemopreventive strategy could be developed that was free of toxicity and also simple, inexpensive, and readily administered, indeed all men could be targeted. Several potential agents are available for chemoprevention in the prostate. The retinoids moderate differentiation and proliferation in several prostate cell lines. Severe toxicity, however, may preclude their widespread application. Difluoromethylornithine has also been investigated. A chemopreventive trial directed against lung cancer showed that alpha-tocopherol is associated with a decreasing incidence of prostate cancer. The greatest interest in the chemopreventive strategies for prostate cancer, however, has focused on decreasing the male androgens. Although most agents, such as luteinizing hormone-releasing hormone agonists and antiandrogens, have severe toxicity, the 5-alpha reductase inhibitors, because they do not, are thought to be excellent agents for a chemopreventive trial. The dependence of prostate epithelial differentiation and maintenance of transformed cells on circulating androgens is widely acknowledged. This is the impetus for the hypothesis that reduction of circulating androgens or blockage of testosterone to the more active metabolite dihydrotestosterone by agents such as finasteride or epristeride will reduce the incidence of prostate cancer. The National Cancer Institute Intergroup Prostate Cancer Prevention Trial, now underway, will randomize 18,000 men to receive 5 mg finasteride or a placebo daily for 7 years in a chemopreventive strategy. Entry requirements include a normal result of digital rectal examination and a serum prostate-specific antigen result less than 3.0 ng/ml. Abnormalities on digital rectal examination results or prostate-specific antigen level greater than 4.0 ng/ml on annual evaluation indicate the need for biopsies in the men receiving the placebo. An equal number of men will undergo biopsy in the active arm of the study. At the end of the 7-year study, all men will have biopsies. Although the primary endpoint is a reduction in prostate cancer incidence, additional benefits include long-term follow-up of the patients receiving finasteride, with potential salutary benefits with regard to symptoms of benign prostatic hyperplasia. This trial, which already has accrued more than 75% of the required participants, should resolve the issue of whether reduction in effective androgen level will prevent the development of prostate cancer.

Kelloff GJ, Lieberman R, Steele VE, Boone CW, Lubet RA, Kopelovitch L, Malone WA, Crowell JA, Sigman CC
National Cancer Institute, Division of Cancer Prevention, Chemoprevention Branch, Bethesda, Md., USA.
Eur Urol 1999;35(5-6):342-50

Chemoprevention is the administration of agents to prevent induction and inhibit or delay progression of cancers. For prostate, as for other cancer targets, successful chemopreventive strategies require well-characterized agents, suitable cohorts, and reliable intermediate biomarkers of cancer for evaluating chemopreventive efficacy. Agent requirements are experimental or epidemiological data showing chemopreventive efficacy, safety on chronic administration, and a mechanistic rationale for the observed chemopreventive activity. On this basis, promising chemopreventive drugs in prostate include retinoids, antiandrogens, antiestrogens, steroid aromatase inhibitors, 5alpha-reductase inhibitors, vitamins D and E, selenium, lycopene, and 2-difluoromethylornithine. Phase II trials are critical for evaluating chemopreventive efficacy. Cohorts in these trials should be suitable for measuring the chemopreventive activity of the agent and the intermediate biomarkers chosen as endpoints. Many cohorts proposed for phase II trials are patients with previous cancers or premalignant lesions. For such patients, trials should be conducted within the context of standard treatment. Two cohorts currently used in phase II prostate cancer chemoprevention trials are patients with PIN and patients scheduled for prostate cancer surgery. Biomarkers should fit expected biological mechanisms, be assayed reliably and quantitatively, measured easily, and correlate to decreased cancer incidence. Protocols for adequately sampling tissue are essential. Changes in PIN provide prostate biomarkers with the ability to be quantified and a high correlation to cancer. PIN measurements include nuclear polymorphism, nucleolar size and number of nucleoli/nuclei, and DNA ploidy. Other potentially useful biomarkers are associated with cellular proliferation kinetics (e.g. PCNA and apoptosis), differentiation (e.g. blood group antigens, vimentin), genetic damage (e.g. LOH on chromosome 8), signal transduction (e.g. TGFalpha, TGFbeta, IGF-I, c-erbB-2 expression), angiogenesis, and biochemical changes (e.g. PSA levels).

Thomas JA
Department of Pharmacology, University of Texas Health Science Center, San Antonio, USA.
Nutr Rev 1999 Apr;57(4):95-103

Diseases of the prostate gland, particularly adenocarcinoma and benign prostatic hyperplasia (BPH), are age-related. Prostate cancer is the most commonly occurring tumor in U.S. men. Differences in the incidence of this disease among ethnic populations are not due solely to genetic differences. Many efforts have been devoted to studying associations between nutrition and prostate cancer. The strongest association appears to be related to total fat intake and increased risk of this malignancy. Evidence also exists to suggest a role for certain micronutrients, such as zinc, selenium, vitamin E, lycopene, phytoestrogens, and phytosterols, although the role of nutrition and micronutrients in protection against prostate cancer is less convincing. Further research is necessary.

Gann PH, Ma J, Giovannucci E, Willett W, Sacks FM, Hennekens CH, Stampfer MJ
Department of Preventive Medicine, Northwestern University Medical School, Chicago, Illinois 60611, USA.
pgann@nwu.edu
Cancer Res 1999 Mar 15;59(6):1225-30

Dietary consumption of the carotenoid lycopene (mostly from tomato products) has been associated with a lower risk of prostate cancer. Evidence relating other carotenoids, tocopherols, and retinol to prostate cancer risk has been equivocal. This prospective study was designed to examine the relationship between plasma concentrations of several major antioxidants and risk of prostate cancer. We conducted a nested case-control study using plasma samples obtained in 1982 from healthy men enrolled in the Physicians' Health Study, a randomized, placebo-controlled trial of aspirin and beta-carotene. Subjects included 578 men who developed prostate cancer within 13 years of follow-up and 1294 age- and smoking status-matched controls. We quantified the five major plasma carotenoid peaks (alpha- and beta-carotene, beta-cryptoxanthin, lutein, and lycopene) plus alpha- and gamma-tocopherol and retinol using high-performance liquid chromatography. Results for plasma beta-carotene are reported separately. Odds ratios (ORs), 95% confidence intervals (Cls), and Ps for trend were calculated for each quintile of plasma antioxidant using logistic regression models that allowed for adjustment of potential confounders and estimation of effect modification by assignment to either active beta-carotene or placebo in the trial. Lycopene was the only antioxidant found at significantly lower mean levels in cases than in matched controls (P = 0.04 for all cases). The ORs for all prostate cancers declined slightly with increasing quintile of plasma lycopene (5th quintile OR = 0.75, 95% CI = 0.54-1.06; P, trend = 0.12); there was a stronger inverse association for aggressive prostate cancers (5th quintile OR = 0.56, 95% CI = 0.34-0.91; P, trend = 0.05). In the placebo group, plasma lycopene was very strongly related to lower prostate cancer risk (5th quintile OR = 0.40; P, trend = 0.006 for aggressive cancer), whereas there was no evidence for a trend among those assigned to beta-carotene supplements. However, in the beta-carotene group, prostate cancer risk was reduced in each lycopene quintile relative to men with low lycopene and placebo. The only other notable association was a reduced risk of aggressive cancer with higher alpha-tocopherol levels that was not statistically significant. None of the associations for lycopene were confounded by age, smoking, body mass index, exercise, alcohol, multivitamin use, or plasma total cholesterol level. These results concur with a recent prospective dietary analysis, which identified lycopene as the carotenoid with the clearest inverse relation to the development of prostate cancer. The inverse association was particularly apparent for aggressive cancer and for men not consuming beta-carotene supplements. For men with low lycopene, beta-carotene supplements were associated with risk reductions comparable to those observed with high lycopene. These data provide further evidence that increased consumption of tomato products and other lycopene-containing foods might reduce the occurrence or progression of prostate cancer.

Pastori M, Pfander H, Boscoboinik D, Azzi A
Institute for Biochemistry and Molecular Biology, University of Bern, Bern, CH-3012, Switzerland.
Biochem Biophys Res Commun 1998 Sep 29;250(3):582-5

The effect of lycopene alone or in association with other antioxidants was studied on the growth of two different human prostate carcinoma cell lines (the androgen insensitive DU-145 and PC-3). It was found that lycopene alone was not a potent inhibitor of prostate carcinoma cell proliferation. However, the simultaneous addition of lycopene together with alpha-tocopherol, at physiological concentrations (less than 1 microM and 50 microM, respectively), resulted in a strong inhibitory effect of prostate carcinoma cell proliferation, which reached values close to 90 %. The effect of lycopene with alpha-tocopherol was synergistic and was not shared by beta-tocopherol, ascorbic acid and probucol.

Yoshizawa K, Willett WC, Morris SJ, Stampfer MJ, Spiegelman D, Rimm EB, Giovannucci E
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.
J Natl Cancer Inst 1998 Aug 19;90(16):1219-24

BACKGROUND: In a recent randomized intervention trial, the risk of prostate cancer for men receiving a daily supplement of 200 microg selenium was one third of that for men receiving placebo. By use of a nested case-control design within a prospective study, i.e., the Health Professionals Follow-Up Study, we investigated the association between risk of prostate cancer and prediagnostic level of selenium in toenails, a measure of long-term selenium intake.

METHODS: In 1986, 51,529 male health professionals aged 40-75 years responded to a mailed questionnaire to form the prospective study. In 1987, 33,737 cohort members provided toenail clippings. In 1988, 1990, 1992, and 1994, follow-up questionnaires were mailed. From 1989 through 1994, 181 new cases of advanced prostate cancer were reported. Case and control subjects were matched by age, smoking status, and month of toenail return. Selenium levels were determined by neutron activation. All P values are two-sided.

RESULTS: The selenium level in toenails varied substantially among men, with quintile medians ranging from 0.66 to 1.14 microg/g for control subjects. When matched case-control data were analyzed, higher selenium levels were associated with a reduced risk of advanced prostate cancer (odds ratio [OR] for comparison of highest to lowest quintile = 0.49; 95% confidence interval [CI] = 0.25-0.96; P for trend = .11). After additionally controlling for family history of prostate cancer, body mass index, calcium intake, lycopene intake, saturated fat intake, vasectomy, and geographical region, the OR was 0.35 (95% CI = 0.16-0.78; P for trend = .03).

CONCLUSIONS: Our results support earlier findings that higher selenium intakes may reduce the risk of prostate cancer. Further prospective studies and randomized trials of this relationship should be conducted.

Thompson Ian M(a); Coltman Charles A Jr; Crowley John
Dep. Surg., Brooke Army Med. Cent., 3851 Roger Brooke Dr., San Antonio, TX 78234-6200, USA
Prostate 33 (3):p217-221 Nov. 1, 1997

Background: A variety of innovative approaches to the prevention of prostate cancer are now available, including selenium, alpha tocopherol, dietary interventions, and vitamin D. Perhaps the most promising opportunity is based upon considerable evidence that cumulative androgen exposure of the prostate contributes to the age-related risk of prostate cancer.

Methods: The Prostate Cancer Prevention Trial has completed randomization of over 18,000 healthy men to either finasteride or placebo.

Conclusions: While the primary objective of this study is to determine whether finasteride can reduce the period prevalence of prostate cancer over a 7-year period, the biologic and data resources of this study will provide multiple opportunities to better understand this most common cancer in U.S. men.

Paubert-Braquet M; Cousse H; Raynaud JP; Mencia-Huerta JM; Braquet P
Bio-Inova Euro Lab Research Laboratories, Plaisir, France.
Eur Urol 1998;33(3):340-7

OBJECTIVE: To assess the effect of the lipidosterolic extract of Serenoa repens (LSESr) on in vitro cell proliferation in biopsies of human prostate

MATERIAL AND METHODS: Cell proliferation was assessed by incorporation of [3H]thymidine followed by historadiography.

RESULTS: Basic fibroblast growth factor (b-FGF) induced a considerable increase in human prostate cell proliferation (from +100 to +250%); the glandular epithelium was mainly affected, minimal labeling being recorded in the other regions of the prostate. Similar results were observed with epidermal growth factor (EGF), although the increase in cell proliferation was not recorded in some cases. Lovastatin, an inhibitor of hydroxymethylglutaryl coenzyme A, antagonized both the basal proliferation and the growth factor-stimulated proliferation of human prostate epithelium (EGF, mean inhibition approximately 80-95%; b-FGF, mean inhibition approximately 40-90%). Geraniol, a precursor of both farnesyl pyrophosphate and geranylgeranyl pyrophosphate, and farnesol, the precursor of farnesyl pyrophosphate, increased cell proliferation only in some prostate specimens, this effect being antagonized by lovastatin. LSESr did not affect basal prostate cell proliferation, with the exception of two prostate specimens in which a significant inhibition of basal proliferation was observed with the highest concentration of LSESr (30 micrograms/ ml). In contrast, LSESr inhibited b-FGF-induced proliferation of human prostate cell cultures; this effect was significant for the highest concentration of LSESr (30 micrograms/ml). In some prostate samples, a similar inhibition was also noted with lower concentrations. Unsaturated fatty acids (UFA), in the range 1-30 ng/ml), did not affect the basal prostate cell proliferation, only a slight increase in cell proliferation was noted in 1 prostate specimen. UFA (1, 10 or 30 micrograms/ml) markedly inhibited the b-FGF-induced cell proliferation down to the basal value. Lupenone, hexacosanol and the unsaponified fraction of LSESr markedly inhibited the b-FGF-induced cell proliferation, whereas a minimal effect on basal cell proliferation was noted.

CONCLUSIONS: Despite the large variability in the response of the prostate samples to b-FGF, these results indicate that LSESr and its components affect the proliferative response of prostate cells to b-FGF more than their basal proliferation.

Breza J; Dzurny O; Borowka A; Hanus T; Petrik R; Blane G; Chadha-Boreham H
Department of Urology, University Hospital, Bratislava, Slovak Republic.
Curr Med Res Opin (ENGLAND) 1998, 14 (3) p127-39

Pygeum africanum extract is available as Tadenan in many countries, including those in central and eastern Europe, for the treatment of mild to moderate BPH. Its efficacy and acceptability have been demonstrated in numerous open and placebo-controlled studies in large populations. The present open three-centre efficacy and safety study was conducted according to common protocol at urology clinics in the Czech and Slovak Republics and in Poland, in order to confirm the therapeutic profile of Pygeum africanum in conditions of daily practice, using International Prostate Symptom Score (IPSS) and flowmetry assessments. Men aged 50-75 years and in compliance with the selection criteria (including IPSS > or = 12, quality of life (QoL) score > or = 3, and maximum urinary flow < or = 15 ml/s) were first examined then recalled after two weeks during which no treatment was provided (washout and check of stability). If still compliant, they were entered at this point into a two-month period of treatment with Pygeum africanum extract 50 mg twice daily. There followed a further one-month period without treatment, the objective being to evaluate the persistence of any effects observed during the previous two months of Pygeum africanum administration. The primary efficacy parameter investigated was IPSS; the other efficacy parameters were QoL, nocturnal frequency, maximum urinary flow, average urinary flow, post-voiding residual volume and prostatic volume, after one and two months of Pygeum africanum treatment and one month after stopping treatment. A total of 85 patients were evenly distributed between the three centres and completed the entire study. At inclusion their mean IPSS was 16.17, QoL was 3.60 and nocturia was 2.6 times per night. The changes in subjective scores, IPSS and QoL after the two-month treatment period were highly statistically significant with mean improvements of 40% and 31%, respectively. Nocturnal frequency was reduced by 32% and the mean reduction was again highly statistically significant. Mean maximum urinary flow, average urinary flow and urine volume were also statistically significantly improved, but the modest improvement in post-voiding volume did not reach statistical significance. The improvements, which exceeded those observed with placebo in earlier studies, were maintained after one month without treatment indicating an interesting persistence of clinically useful activity. Prostatic volume and quality of sexual life remained unchanged throughout. No treatment-related adverse effects were observed. In conclusion, under conditions of daily practice, Pygeum africanum extract induces significant improvement in IPSS and uroflowmetry parameters. These positive effects are accompanied by a very satisfactory safety profile with the overall result of a substantial improvement in QoL.

Lowe F.C.; Dreikorn K.; Borkowski A.; Braeckman J.; Denis L.; Ferrari P.; Gerber G.; Levin R.; Perrin P.; Senge T.
Dr. F.C. Lowe, Department of Urology., St. Luke's/Roosevelt Hospital, 425 West 59th St., 3A, New York, NY 10019 United States
Prostate (United States) 1998, 37/3 (187-193)

BACKGROUND. In order to assess the efficacy of phytotherapeutic agents for the treatment of benign prostatic hyperplasia (BPH), a review of recently published double-blind placebo-controlled trials was undertaken.

METHODS. Only those studies reviewed by the Other Medical Therapies Committee of the Fourth International Consultation on BPH were included.

RESULTS. These studies suggest a possible benefit for the use of phytotherapeutic preparations in the treatment of BPH.

CONCLUSIONS. These studies need to be confirmed in larger long-term placebo-controlled studies in order to ascertain the true efficacy of these agents.

Desgrandchamps F.
Dr. F. Desgrandchamps, Department of Urology, Hopital Saint-Louis, 1 avenue Claude Vellefaux, F-75475 Paris Cedex 10 France
European Urology (EUR. UROL.) (Switzerland) 1997, 32/SUPPL. 1 (28-31)

Changing demography and expectations about maintaining quality of life mean that an increasing number of men will require treatment for benign prostatic hyperplasia (BPH). Many growth factors have a role in the development of BPH. Consequently growth factor antagonists offer an attractive therapeutic option. In double-blind randomised trials Tadenan(R), a drug known to have growth factor antagonist activity, conferred significant improvement of urinary symptoms, maximum flow rate and residual volume, with no serious side-effects. Therapeutic outcome could be enhanced in a number of ways including matching patients with particular cell type overgrowth for treatment with a growth factor antagonist specific for that cell type. Full exploitation of this approach awaits the development of less invasive means of determining the cell type affected.

Levin R.M.; Levin S.S.; Zhao Y.; Buttyan R.
Prof. R.M. Levin, Albany College of Pharmacy, Albany Medical College, Stratton VA Medical Center, 106 New Scotland Avenue, Albany, NY 12208-3492 United States
European Urology (Switzerland) 1997, 32/Suppl. 1 (15-21)

Bladder dysfunction secondary to benign prostatic hyperplasia (BPH) is a major affliction associated with ageing. As the disease slowly progresses, the bladder changes from a state of compensation to decompensation, in which there are severe, irreversible alterations in bladder function. Using a rabbit model of partial outlet obstruction we have identified three major cellular changes in the bladder which result from such obstruction. These include progressive denervation, mitochondrial dysfunction and disturbances of calcium storage and release from the sarcoplasmic reticulum. Our hypothesis is that outlet obstruction results in bladder hypertrophy which induces ischaemia. This leads to a release of intracellular calcium, leading to activation of specific enzymes and generation of free radicals. These then attack the membranes of nerves, sarcoplasmic reticulum and mitochondria. We have demonstrated that pretreatment of rabbits with Pygeum africanum extract (Tadenan(R)) significantly reduced the severity of both the contractile and metabolic dysfunctions induced by partial outlet obstruction. Our current hypothesis is that Tadenan(R) may either prevent the activation of degradative enzymes (or generation of free radicals), or protect the intracellular membranes against the destructive effects of free radicals or degredative enzymes. In conclusion, identifying cellular mechanisms responsible for bladder dysfunction induced by partial outlet obstruction provides new possibilities for non-surgical treatment of BPH. Our studies on Tadenan(R) support this concept that the bladder provides a novel target for therapeutic intervention.

Odenthal K.P.
K.P. Odenthal, Dept. Exp. Biology, Pharmacology, MADAUS AG, Ostmerheimerstr. 198, D-51109 Cologne Germany
Phytotherapy Research (United Kingdom) 1996, 10/Suppl. 1 (S141-S143)

The enlargement of prostate (BPH) is accompanied by urge, reduced urinary flow and increased residual urine volume. The etiology is not yet clear, though many results speak for hormonal imbalance. Several herbal drugs have been applied traditionally in the therapy of BPH, i.e., preparations of Cucurbita, Hypoxis, Pygeum, Urtica and from Sabal serrulata. Among the discussed mechanisms, phytosterols are considered as active and have been found in experimental as well as in clinical investigations to interfere with either reduction of testosterone to dihydrotestosterone, sexual hormone binding globulin, aromatization of testosterone or growth factors like EGF. Additional effects have been documented in experiments speaking for immunomodulation and anti-inflammatory qualities. We demonstrate that smooth muscle contraction of rat deferential duct, guinea-pig ileum and bladder is reduced by lipophilic extract of Sabal. Both noradrenaline-induced contractions of rat deferential duct as well as contractions elicited by electrical stimulation could be reduced concentration-dependently following addition of <= 0.33 mg/ml of lipophilic Sabal serrulata extract into the bath medium. Cumulative dosing of <= 0.15 mg/ml of Sabal extract antagonized in guinea-pig ileum and bladder smooth muscular tissue contracted in KCl salt solution. Sabal extract, in concentrations identical to those published for the so-called anti-androgenic and anti-inflammatory effects, is therefore characterized by alpha-adrenoceptor antagonistic as well as calcium blocking activities. Furthermore, these findings could explain the clinically demonstrated symptomatic relief or so called release of dynamic component of BPH.

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