ISSN:1059-910X    

DOI:10.1002/jemt.1070300402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractOrgan culture of the human prostate began in the 1970s and was modeled after the work of Lasnitzki and her collaborators in the mouse two decades earlier. In organ culture of human prostates, one sees a rapid increase in epithelial cells and decrease in stromal cells during the first 3–5 days of culture. While modulation of many phenotypic properties occurs, these cultures provide a simple and rapid way to achieve large numbers of human prostatic epithelial cells in cultured tissues that are markedly depleted of stromal cells. There is some evidence that organ cultures are maintained in slightly better functional states in the presence of androgens; however, most of this evidence is less than quantitative. Most organ culture of prostates has been accomplished with tissues from unspecified locations within the prostate; interpretation of cultures carried out in this fashion has been less complete than would have been possible if they had been carried out from specific anatomic locations within the prostate. Careful pathological characterization of locations contiguous to the cultured tissue is mandatory if cultures are to be interpreted meaningfully. © 1995 Wiley‐Liss,

ISSN:1059-910X    

DOI:10.1002/jemt.1070300403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractLiterature on the effect of steroid hormones (androgens, estrogens, and other steroids), of peptide hormones (e.g., prolactin), and growth factors (e.g., EGF, FGF, TGF‐β), on the effect of castration and of experimental hormone application on the prostate is reviewed. Androgens have inductive, repressive, and interactive effects. They counterbalance an agonistic effect on proliferation and an antagonistic effect on cell death; they may influence DNA synthesis and induce the synthesis of substances with mitogenic effects on the prostate. Estrogens exert direct and indirect effects on the prostate. They suppress the secretion of gonatropins, thus repressing testicular androgen secretion. They stimulate the fibromuscular stroma and induce squamous metaplasia of the epithelium. Estrogens may also be involved in the onset of benign prostatic hyperplasia. Prolactin is preferentially bound in the diseased human prostate. An abundance of information has been gained on EGF, FGF, TGF‐β, and other growth factors. They may be involved in the development of prostatic hyperplasia. Castration leads to a striking reduction in prostatic size in a short period of time due to autophagic and heterophagic processes. In castrated individuals, the prostate is enriched in androgen‐independent cells. Experimental hormone application involves the substitution of androgens as well as anti‐androgens, long‐term application of different hormones, and application of combinations of drugs. The results of several studies are described. Further directions in the field of prostate research should concentrate on the role of growth factors in prostate development and pathology and on the effect of certain lectins on prostate diseases. We think that the investigation of interactions between steroid hormones and growth factors in normal and pathological neovascularization of the prostate is important. © 1995 Wil

ISSN:1059-910X    

DOI:10.1002/jemt.1070300404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractTesticular hormones regulate the growth and development of the prostate. The presence of androgen receptors in prostatic tissue and their importance in the normal development of the prostate has been established. Age‐related changes in the hormonal milieu, and perhaps steroid hormone receptor profile, could set in motion pathological changes leading to the onset of benign prostatic hyperplasia (BPH) or prostate cancer which primarily affect older men. The accumulation of dihydrotestosterone with age, the reawakening of the inductive potential of the prostatic stroma, the altered rate of apoptosis with age, and the age‐related changes in the ratio of testosterone: estrogen have all been implicated in the etiology of BPH. In addition to androgen receptors, several studies have documented the presence of estrogen and progesterone receptors in BPH and prostate cancer. So far, most studies have focussed on the correlation between the presence/absence of steroid hormone receptors and response to hormonal therapy. The molecular mechanisms by which these steroid hormone receptors regulate the onset or progression of BPH and prostate cancer are not yet clear. The chronological changes in the levels and distribution of steroid hormone receptors in normal prostatic tissue and the effect of such changes on the synthesis of growth factors, growth factor receptors, and oncogenes should be investigated. © 1995 Wiley‐Lis

ISSN:1059-910X    

DOI:10.1002/jemt.1070300405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:1059-910X    

DOI:10.1002/jemt.1070300406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractInstructive influences of fetal mesenchyme were examined in heterotypic tissue recombinants consisting of urogenital sinus mesenchyme (UGM) from male and female rats and distal ductal tips from adult rat prostate. Tissues were grown under the renal capsule of male hosts for periods up to 28 days. Resultant growths exhibited typical prostate histology. Expression of lobe‐specific proteins for the ventral (prostatic steroid binding protein [PSBP]) lateral (seminal vesicle secretion II [SVS II]), and dorsal prostate (secretory transglutaminase [TGase]) were examined by immunocytochemistry. Male or female UGM combined with terminal segments of the ventral or dorsal prostate and immunolabeled with antibodies to lobe‐specific proteins demonstrated expression of all three secretory products. The pattern of staining was consistent with a compound inductive response from the UGM. Unique to this study was our ability to use a defined mesenchymal tissue (female ventral mesenchymal pad [VMP]). This tissue is specifically associated with ductal branching morphogenesis and cytodifferentiation of the ventral prostate. Distal ductal tips from the dorsal lobe of the adult male prostate when recombined with female VMP and grown in vivo exhibited transformation of secretory phenotype, and the epithelium expressed mRNAs for PSBP. Immunocytochemistry of serial sections did not demonstrate labeling for TGase in the new epithelial growth. Ultrastructural analysis of the heterotypic recombinants indicated that the epithelium had similar characteristics to those of normal ventral prostate. Early stages of the mesenchymal‐epithelial interactions resulted in dedifferentiation of the adult epithelium to solid cords of stratified cells. These findings illustrate the potent instructive capacity of a defined fetal UGM to influence development and cytodifferentiation of adult prostate epithelium. © 1995 Wiley‐L

ISSN:1059-910X    

DOI:10.1002/jemt.1070300407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractMesenchymal‐epithelial interactions are associated with growth and morphogenesis of the prostate. We have detected three isoforms of transforming growth factor β (TGF‐β) in the developing mouse prostate that may mediate some of these interactions. Separation of the fetal urogenital sinus (UGS) tissue into mesenchymal and epithelial components indicated that mRNA expression of TGF‐β;1, 2, and 3 was more abundant in the mesenchyme compared to the epithelium. Immunohistochemical analysis revealed accumulation of TGF‐β1 in the mesenchyme surrounding ductules in the UGS and neonatal prostate. Further analysis of TGF‐β1 localization in surgically removed adult human prostate tissues revealed more intense staining associated with regions of abnormal growth compared to normally appearing tissue. The percent of the total stained area with extracellular accumulation of TGF‐β1 was 59% in prostate cancer, 26% in benign prostatic hyperplasia (BPH), and 8.6% in normal tissue. In additional immunohistochemical studies we observed that intracellular TGF‐β1 was predominantly associated with the epithelial cells in prostate cancer (epithelial cells = 33.5% of the total stained area, stromal cells = 13.3%, and unstained = 53.2%), whereas in BPH intracellular TGF‐β1 was predominantly associated with stromal cells (stromal cells = 32.2% of the total stained area, epithelial cells = 12.3%, and unstained = 55.5%). Although additional experimental and clinical studies are needed to better understand the relationships between TGF‐β1 and abnormal prostatic growth, our observations thus far suggest a role for TGF‐β1 in the development of benign and malignant growth abnormalities in the prostate. One approach to establishing the pathobiological significance of TGF‐β1 accumulation in the prostate is by introducing and overexpressing the TGF‐β1 cDNA in prostate tissue using the mouse prostate reconstitution model system. We discuss applicability of transgenic animal and organ reconstitution models for experimental studies concerning TGF‐β—induced prostate grow

ISSN:1059-910X    

DOI:10.1002/jemt.1070300408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractHomeostasis in the prostate is recognized to be maintained by a complex interplay between the opposing actions of cell proliferation and Cell death. Growth regulatory factors that promote or inhibit cell proliferation and promote cellular death have been identified in the prostate. The integration of these forces involves cellular cooperation between the prostatic stroma and epithelium. Hormone‐regulated production of growth regulatory factors by one cell type may determine growth stimulation, inhibition, or cell death in a reciprocal cell partner. Imbalance between net cell proliferation and net cell death rates may result in abnormal growth leading to BPH. Additional study of the growth regulatory factors associated with distal vs. proximal epithelial cells and stroma and comparison of growth factor expression by the neonatal, postnatal growing, adult quiescent, and aging prostates will likely provide further insight into the regulation of prostate cell division and death. © 1995 Wiley‐Liss,

ISSN:1059-910X    

DOI:10.1002/jemt.1070300409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:1059-910X    

DOI:10.1002/jemt.1070300410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:1059-910X    

DOI:10.1002/jemt.1070300401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY