scholarly journals Increased expression of type 2 3α-hydroxysteroid dehydrogenase/type 5 17β-hydroxysteroid dehydrogenase (AKR1C3) and its relationship with androgen receptor in prostate carcinoma

2006 ◽  
Vol 13 (1) ◽  
pp. 169-180 ◽  
Author(s):  
K-M Fung ◽  
E N S Samara ◽  
C Wong ◽  
A Metwalli ◽  
R Krlin ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Androgen Receptor ◽  
Epithelial Cells ◽  
Prostate Carcinoma ◽  
Primary Cultures ◽  
Hydroxysteroid Dehydrogenase ◽  
Human Prostate ◽  
Normal Prostate ◽  
Prostate Epithelial Cells

Type 2 3α-hydroxysteroid dehydrogenase (3α-HSD) is a multi-functional enzyme that possesses 3α-, 17β- and 20α-HSD, as well as prostaglandin (PG) F synthase activities and catalyzes androgen, estrogen, progestin and PG metabolism. Type 2 3α-HSD was cloned from human prostate, is a member of the aldo-keto reductase (AKR) superfamily and was named AKR1C3. In androgen target tissues such as the prostate, AKR1C3 catalyzes the conversion of Δ4-androstene-3,17-dione to testosterone, 5α-dihydrotestosterone to 5α-androstane-3α,17β-diol (3α-diol), and 3α-diol to androsterone. Thus AKR1C3 may regulate the balance of androgens and hence trans-activation of the androgen receptor in these tissues. Tissue distribution studies indicate that AKR1C3 transcripts are highly expressed in human prostate. To measure AKR1C3 protein expression and its distribution in the prostate, we raised a monoclonal antibody specifically recognizing AKR1C3. This antibody allowed us to distinguish AKR1C3 from other AKR1C family members in human tissues. Immunoblot analysis showed that this monoclonal antibody binds to one species of protein in primary cultures of prostate epithelial cells and in LNCaP prostate cancer cells. Immunohistochemistry with this antibody on human prostate detected strong nuclear immunoreactivity in normal stromal and smooth muscle cells, perineurial cells, urothelial (transitional) cells, and endothelial cells. Normal prostate epithelial cells were only faintly immunoreactive or negative. Positive immunoreactivity was demonstrated in primary prostatic adenocarcinoma in 9 of 11 cases. Variable increases in immunoreactivity for AKR1C3 was also demonstrated in non-neoplastic changes in the prostate including chronic inflammation, atrophy and urothelial (transitional) cell metaplasia. We conclude that elevated expression of AKR1C3 is highly associated with prostate carcinoma. Although the biological significance of elevated AKR1C3 in prostatic carcinoma is uncertain, AKR1C3 may be responsible for the trophic effects of androgens and/or PGs on prostatic epithelial cells.

Expression and Characterization of Recombinant Type 2 3α-Hydroxysteroid Dehydrogenase (HSD) from Human Prostate: Demonstration of Bifunctional 3α/17β-HSD Activity and Cellular Distribution

1997 ◽  
Vol 11 (13) ◽  
pp. 1971-1984 ◽  
Author(s):  
Hsueh-Kung Lin ◽  
Joseph M. Jez ◽  
Brian P. Schlegel ◽  
Donna M. Peehl ◽  
Jonathan A. Pachter ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Primary Cultures ◽  
Catalytic Efficiency ◽  
Hydroxysteroid Dehydrogenase ◽  
Human Prostate ◽  
Cellular Distribution ◽  
Human Type ◽  
Recombinant Type

Abstract In androgen target tissues, 3α-hydroxysteroid dehydrogenase (3α-HSD) may regulate occupancy of the androgen receptor (AR) by catalyzing the interconversion of 5α-dihydrotestosterone (5α-DHT) (a potent androgen) and 3α-androstanediol (a weak androgen). In this study, a 3α-HSD cDNA (1170 bp) was isolated from a human prostate cDNA library. The human prostatic 3α-HSD cDNA encodes a 323-amino acid protein with 69.9%, 84.1%, 99.4%, and 87.9% sequence identity to rat liver 3α-HSD and human type 1, type 2, and type 3 3α-HSDs, respectively, and is a member of the aldo-keto reductase superfamily. The close homology with human type 2 3α-HSD suggests that it is either identical to this enzyme or a structural allele. Surprisingly, when the recombinant protein was expressed and purified from Escherichia coli, the enzyme did not oxidize androsterone when measured spectrophotometrically, an activity previously assigned to recombinant type 2 3α-HSD using this assay. Complete kinetic characterization of the purified protein using spectrophotometric, fluorometric, and radiometric assays showed that the catalytic efficiency favored 3α-androstanediol oxidation over 5α-DHT reduction. Using[ 14C]-5α-DHT as substrate, TLC analysis confirmed that the reaction product was[ 14C]-3α-androstanediol. However, in the reverse reaction, [3H]-3α-androstanediol was oxidized first to [3H]-androsterone and then to [3H]-androstanedione, revealing that the expressed protein possessed both 3α- and 17β-HSD activities. The 17β-HSD activity accounted for the higher catalytic efficiency observed with 3α-androstanediol. These findings indicate that, in the prostate, type 2 3α-HSD does not interconvert 5α-DHT and 3α-androstanediol but inactivates 5α-DHT through its 3-ketosteroid reductase activity. Levels of 3α-HSD mRNA were measured in primary cultures of human prostatic cells and were higher in epithelial cells than stromal cells. In addition, elevated levels of 3α-HSD mRNA were observed in epithelial cells derived from benign prostatic hyperplasia and prostate carcinoma tissues. Expression of 3α-HSD was not prostate specific, since high levels of mRNA were also found in liver, small intestine, colon, lung, and kidney. This study is the first complete characterization of recombinant type 2 3α-HSD demonstrating dual activity and cellular distribution in the human prostate.

Testosterone metabolism in primary cultures of human prostate epithelial cells and fibroblasts

1995 ◽  
Vol 55 (3-4) ◽  
pp. 375-383 ◽  
Author(s):  
Sylvie De´los ◽  
Jean-Louis Carsol ◽  
Evelyne Ghazarossian ◽  
Jean-Pierre Raynaud ◽  
Pierre-Marie Martin
Keyword(s):  
Epithelial Cells ◽  
Primary Cultures ◽  
Human Prostate ◽  
Testosterone Metabolism ◽  
Prostate Epithelial Cells

scholarly journals Localization of Transforming Growth Factor-β1 and Type II Receptor in Developing Normal Human Prostate and Carcinoma Tissues

1998 ◽  
Vol 46 (3) ◽  
pp. 379-388 ◽  
Author(s):  
Michael J. Gerdes ◽  
Melinda Larsen ◽  
Lauren McBride ◽  
Truong D. Dang ◽  
Bing Lu ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Prostate Carcinoma ◽  
Stromal Cells ◽  
Transforming Growth Factor ◽  
Carcinoma Cells ◽  
Human Prostate ◽  
Type Ii ◽  
Normal Prostate ◽  
Normal Human

Transforming growth factor-β1 (TGF-β1) is implicated in prostate development, and elevated expression of TGF-β1 has been correlated with prostate carcinogenesis. In this study, cell type specificity of TGF-β1 and TGF-β receptor Type II (RcII) protein expression was determined by immunocytochemistry in human normal prostate and compared to prostate carcinoma tissues. Heterogeneous localization patterns of LAP-TGF-β1 (TGF-β1 precursor) and RcII were observed in both epithelial and mesenchymal cells in fetal prostate, with LAP-TGF-β1 localizing to more basal epithelial cells. Homogeneity of LAP-TGF-β1 staining was increased in neonatal, prepubertal, and adult prostate, with elevated immunoreac-tivity noted in epithelial acini relative to stromal tissue for both LAP-TGF-β1 and RcII proteins. In stromal tissues, RcII cell localization exhibited staining patterns nearly identical to smooth muscle α-actin. In prostate carcinoma, LAP-TGF-β1 localized to carcinoma cells with an increased staining heterogeneity relative to normal prostate. In contrast to normal epithelial cells, carcinoma epithelial cells exhibited low to nondetectable RcII staining. Stromal cell staining patterns for LAP-TGF-β1 and RcII in carcinoma, however, were identical to those of normal prostate stromal cells. These studies implicate both epithelial and stromal cells as sites of TGF-β1 synthesis and RcII localization in the developing and adult normal human prostate. In addition, these data indicate a loss of epithelial expression of RcII concurrent with altered LAP-TGF-β1 expression in human prostate carcinoma cells.

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