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Donald J. Tindall - One of the best experts on this subject based on the ideXlab platform.
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androgens regulate the expression of proliferating cell nuclear antigen posttranscriptionally in the human prostate cancer cell line lncap
Cancer Research, 1996Co-Authors: Jaime E Perry, Donald J. TindallAbstract:Abstract Proliferating cell nuclear antigen (PCNA) expression is required for DNA replication. Because androgens are critical for prostate cell proliferation, we investigated the effects of androgen on PCNA expression in the prostatic cancer cell line LNCaP. Flow cytometric analysis was used to measure cellular DNA content with dual labeling of PCNA. Semiconfluent LNCaP cells were grown in serum-free medium containing varying concentrations of the synthetic androgen Mibolerone and processed for either fluorescence-activated cell sorting or Western analysis. Supplementation of serum-free medium with androgens resulted in dose-dependent changes in PCNA immunoreactivity, with maximum stimulation (2-fold) being achieved at 48 h with 10 -9 m Mibolerone. Non-androgenic steroids did not change PCNA immunoreactivity compared with untreated controls, and the antiandrogen, casodex, inhibited the Mibolerone-stimulated increase in PCNA immunoreactivity, suggesting that the androgenic induction of PCNA is mediated through the androgen receptor. The presence of a non-consensus androgen response element in the promoter region of the PCNA gene led us to investigate whether androgen responsiveness of the PCNA gene in LNCaP cells might be mediated at the transcriptional level. No change in steady-state mRNA for PCNA with androgen administration was observed. However, an investigation of the androgenic regulation of PCNA protein stability indicated that androgen treatment increased the half-life of 35 S-labeled PCNA protein. In addition, polysome run-off translation assays demonstrated an increase in PCNA protein after a 6-h stimulation of LNCaP cells with 10 -9 m Mibolerone. These data suggest that androgen induction of prostate cell proliferation may be mediated, at least in part, through PCNA at the posttranscriptional level.
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tissue specific and hormonal regulation of human prostate specific glandular kallikrein
Biochemistry, 1992Co-Authors: Charles Y F Young, Benjamin T Montgomery, Paul E Andrews, Donald J. TindallAbstract:: Kallikreins are involved in the posttranslational processing of a number of specific polypeptide precursors. Previously, human glandular kallikrein (hGK-1) mRNA has been identified in the prostate; however, the hGK-1 protein has not been identified and characterized. Therefore, its physiologic function in the prostate is not known. In this study, we have isolated a full-length hGK-1 cDNA from a human adenocarcinoma cell line, LNCaP. In vitro translation experiments demonstrated that the molecular size of the hGK-1 protein generated from this cDNA is similar to that of prostate-specific antigen (PSA), a protein which is produced exclusively in the prostate. In situ hybridization with a hGK-1-specific oligonucleotide probe (77 bases), which can differentiate hGK-1 mRNA from PSA mRNA, demonstrated the hGK-1 mRNA to be located in the prostate epithelium. The hGK-1 mRNA was colocalized with PSA mRNA in prostatic epithelia. Moreover, in situ hybridization studies revealed that the level of hGK-1 mRNA in human benign prostatic hyperplasia tissues is approximately half that of PSA mRNA. Furthermore, we have demonstrated that hGK-1 mRNA is under androgenic regulation in LNCaP cells. Time course analysis revealed that hGK-1 mRNA levels increased significantly at 5 h of Mibolerone treatment and reached maximal levels by 9 h. In addition, hGK-1 mRNA levels were increased by dihydrotestosterone, but not by dexamethasone or diethylstilbestrol treatments. Flutamide, a nonmetabolized anti-androgen, repressed the androgenic effects. These studies suggest that expression of hGK-1 mRNA is regulated by androgen via the androgen receptor.
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hormonal regulation of prostate specific antigen psa glycoprotein in the human prostatic adenocarcinoma cell line lncap
The Prostate, 1992Co-Authors: Benjamin T Montgomery, James L. Prescott, Charles Y F Young, David L Bilhartz, Paul E Andrews, N F Thompson, Donald J. TindallAbstract:: Prostate-specific antigen (PSA) has emerged as the most useful marker for management of patients with prostate cancer. The regulation of this glycoprotein in vivo has important clinical implications. Indirect evidence indicates that the PSA glycoprotein might be regulated by androgens, and previous studies in this laboratory have demonstrated that PSA mRNA is upregulated by androgens. The current work reports a detailed study of PSA glycoprotein expression as influenced by steroid hormones in a human prostatic adenocarcinoma cell line, LNCaP. First, we have examined the steroid binding specificity of the androgen receptor in this cell line. In comparison with wild-type rat androgen receptor in prostate, the receptor in LNCaP cells has altered affinity for a number of steroids or analogs such as progesterone (R5020), antiprogesterone (RU486), two antiandrogens (cyperoterone acetate and hydroxyflutamide), and an androgen metabolite (epitestosterone). However, its affinity for androgens (Mibolerone, dihydrotestosterone, and testosterone) is not changed. The receptor does not bind to the synthetic glucocorticoids (triaminolone acetonide and dexamethasone) nor to a synthetic estrogen DES (diethylstilbestrol). The change of the steroid binding specificity of the receptor is correlated with a single mutation (A----G at nucleotide #876 relative to the initiation codon) of the steroid binding domain of the receptor. The mutation and alteration of steroid-binding specificity of the androgen receptor is also correlated with PSA glycoprotein expression affected by different ligands tested. We have demonstrated that the PSA glycoprotein is upregulated by androgens and is affected by neither epidermal growth factor nor basic fibroblast growth factor. Moreover, PSA glycoprotein could be induced by R5020, estradiol, and epitestosterone; but neither glucocorticoids nor DES had any effect on PSA induction. Interestingly, although the antiandrogen, cyperotone acetate, had the ability to induce PSA, both RU486 and hydroxyflutamide could block androgen and progesterone induction of PSA glycoprotein. Therefore, we conclude that the PSA glycoprotein expression is influenced predominantly by androgens via its receptor, and the mutation of the receptor can affect the expression of this cellular gene by the steroids other than androgens.
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hormonal regulation of prostate specific antigen messenger rna in human prostatic adenocarcinoma cell line lncap
Cancer Research, 1991Co-Authors: Charles Y F Young, Benjamin T Montgomery, David L Bilhartz, Paul E Andrews, Donald J. TindallAbstract:Abstract Prostate-specific antigen (PSA) is a member of the kallikrein gene family and is expressed exclusively in human prostatic epithelial cells. PSA protein has been an important biological marker for prostate cancers. Until now, very little was known about the regulation of PSA expression in prostatic cells. In this study, we have developed a specific oligonucleotide probe which recognizes PSA but not the human glandular kallikrein. This is crucial because both PSA and human glandular kallikrein are expressed in the prostate at relatively high levels and have high nucleotide sequence homology (>82%). Utilizing a 35 S-labeled PSA-specific probe, PSA mRNA was localized within the glandular epithelium of the prostate. Northern blot analysis detected a single 1.6-kilobase transcript in LNCaP cells, a cell line derived from a human prostate adenocarcinoma metastasis. Therefore, LNCaP cells were used to study the androgenic effects on PSA mRNA expression. A time course study demonstrated that PSA mRNA was induced by Mibolerone (a nonmetabolizable synthetic androgen) and reached maximal levels after 9 h. The induction of PSA mRNA required as little as 0.3 nm Mibolerone. In addition to Mibolerone, PSA mRNA could be induced by the natural androgen, dihydrotestosterone, but not by the synthetic glucocorticoid, dexamethasone, or the synthetic estrogen, diethylstilbestrol. Moreover, in the presence of dihydrotestosterone, PSA mRNA was depressed by hydroxyflutamide (an antiandrogen). These results suggest strongly that the androgenic effects on PSA mRNA in LNCaP cells may be via the function of the androgen receptor.
Ia L. Lindshield - One of the best experts on this subject based on the ideXlab platform.
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WPE1-NA22 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
2013Co-Authors: Alexande . Opoku-acheampong, Michelle K. Nelse, Dave Unis, Ia L. LindshieldAbstract:WPE1-NA22 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
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RPWE-1 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
2013Co-Authors: Alexande . Opoku-acheampong, Michelle K. Nelse, Dave Unis, Ia L. LindshieldAbstract:RPWE-1 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
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The effect of finasteride and dutasteride on the growth of WPE1-NA22 prostate cancer xenografts in nude mice.
Public Library of Science (PLoS), 1Co-Authors: Alexande . Opoku-acheampong, Michelle K. Nelse, Dave Unis, Ia L. LindshieldAbstract:BACKGROUND: 5α-reductase 1 (5αR1) and 5α-reductase 2 (5αR2) convert testosterone into the more potent androgen dihydrotestosterone. 5αR2 is the main isoenzyme in normal prostate tissue; however, most prostate tumors have increased 5αR1 and decreased 5αR2 expression. Previously, finasteride (5αR2 inhibitor) treatment begun 3 weeks post-tumor implantation had no effect on Dunning R3327-H rat prostate tumor growth. We believe the tumor compensated for finasteride treatment by increasing tumor 5αR1 expression or activity. We hypothesize that finasteride treatment would not significantly alter tumor growth even if begun before tumor implantation, whereas dutasteride (5αR1 and 5αR2 inhibitor) treatment would decrease tumor growth regardless of whether treatment was initiated before or after tumor implantation. METHODOLOGY/PRINCIPAL FINDINGS: Sixty 8-week-old male nude mice were randomized to Control, Pre- and Post-Finasteride, and Pre- and Post-Dutasteride (83.3 mg drug/kg diet) diet groups. Pre- and post-groups began their treatment diets 1-2 weeks prior to or 3 weeks after subcutaneous injection of 1×10⁵ WPE1-NA22 human prostate cancer cells, respectively. Tumors were allowed to grow for 22 weeks; tumor areas, body weights, and food intakes were measured weekly. At study's conclusion, prostate and seminal vesicle weights were significantly decreased in all treatment groups versus the control; dutasteride intake significantly decreased seminal vesicle weights compared to finasteride intake. No differences were measured in final tumor areas or tumor weights between groups, likely due to poor tumor growth. In follow-up studies, proliferation of WPE1-NA22 prostate cancer cells and parent line RWPE-1 prostate epithelial cells were unaltered by treatment with testosterone, dihydrotestosterone, or Mibolerone, suggesting that these cell lines are not androgen-sensitive. CONCLUSION: The lack of response of WPE1-NA22 prostate cancer cells to androgen treatment may explain the inadequate tumor growth observed. Additional studies are needed to determine whether finasteride and dutasteride are effective in decreasing prostate cancer development/growth
Alexande . Opoku-acheampong - One of the best experts on this subject based on the ideXlab platform.
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WPE1-NA22 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
2013Co-Authors: Alexande . Opoku-acheampong, Michelle K. Nelse, Dave Unis, Ia L. LindshieldAbstract:WPE1-NA22 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
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RPWE-1 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
2013Co-Authors: Alexande . Opoku-acheampong, Michelle K. Nelse, Dave Unis, Ia L. LindshieldAbstract:RPWE-1 (10,000 cells/well) cell viability was not altered by daily treatment of testosterone (0.1 nM–30 nM), dihydrotestosterone (0.03 nM–100 nM), or Mibolerone (0.01 nM–20 nM) after a 5-day treatment period; no significant treatment effects.
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The effect of finasteride and dutasteride on the growth of WPE1-NA22 prostate cancer xenografts in nude mice
2012Co-Authors: Alexande . Opoku-acheampong, Nelsen Michelle K., Unis Dave, Lindshield Bria L.Abstract:Background: 5 alpha-reductase 1 (5alphaR1) and 5alpha-reductase 2 (5alphaR2) convert testosterone into the more potent androgen dihydrotestosterone. 5alphaR2 is the main isoenzyme in normal prostate tissue; however, most prostate tumors have increased 5alphaR1 and decreased 5alphaR2 expression. Previously, finasteride (5alphaR2 inhibitor) treatment begun 3 weeks post-tumor implantation had no effect on Dunning R3327-H rat prostate tumor growth. We believe the tumor compensated for finasteride treatment by increasing tumor 5alphaR1 expression or activity. We hypothesize that finasteride treatment would not significantly alter tumor growth even if begun before tumor implantation, whereas dutasteride (5alphaR1 and 5alphaR2 inhibitor) treatment would decrease tumor growth regardless of whether treatment was initiated before or after tumor implantation. Methodology/Principal Findings: Sixty 8-week-old male nude mice were randomized to Control, Pre- and Post-Finasteride, and Pre- and Post-Dutasteride (83.3 mg drug/kg diet) diet groups. Pre- and post-groups began their treatment diets 1–2 weeks prior to or 3 weeks after subcutaneous injection of 1x10[5th power] WPE1-NA22 human prostate cancer cells, respectively. Tumors were allowed to grow for 22 weeks; tumor areas, body weights, and food intakes were measured weekly. At study’s conclusion, prostate and seminal vesicle weights were significantly decreased in all treatment groups versus the control; dutasteride intake significantly decreased seminal vesicle weights compared to finasteride intake. No differences were measured in final tumor areas or tumor weights between groups, likely due to poor tumor growth. In follow-up studies, proliferation of WPE1-NA22 prostate cancer cells and parent line RWPE-1 prostate epithelial cells were unaltered by treatment with testosterone, dihydrotestosterone, or Mibolerone, suggesting that these cell lines are not androgensensitive. Conclusion: The lack of response of WPE1-NA22 prostate cancer cells to androgen treatment may explain the inadequate tumor growth observed. Additional studies are needed to determine whether finasteride and dutasteride are effective in decreasing prostate cancer development/growth
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The effect of finasteride and dutasteride on the growth of WPE1-NA22 prostate cancer xenografts in nude mice.
Public Library of Science (PLoS), 1Co-Authors: Alexande . Opoku-acheampong, Michelle K. Nelse, Dave Unis, Ia L. LindshieldAbstract:BACKGROUND: 5α-reductase 1 (5αR1) and 5α-reductase 2 (5αR2) convert testosterone into the more potent androgen dihydrotestosterone. 5αR2 is the main isoenzyme in normal prostate tissue; however, most prostate tumors have increased 5αR1 and decreased 5αR2 expression. Previously, finasteride (5αR2 inhibitor) treatment begun 3 weeks post-tumor implantation had no effect on Dunning R3327-H rat prostate tumor growth. We believe the tumor compensated for finasteride treatment by increasing tumor 5αR1 expression or activity. We hypothesize that finasteride treatment would not significantly alter tumor growth even if begun before tumor implantation, whereas dutasteride (5αR1 and 5αR2 inhibitor) treatment would decrease tumor growth regardless of whether treatment was initiated before or after tumor implantation. METHODOLOGY/PRINCIPAL FINDINGS: Sixty 8-week-old male nude mice were randomized to Control, Pre- and Post-Finasteride, and Pre- and Post-Dutasteride (83.3 mg drug/kg diet) diet groups. Pre- and post-groups began their treatment diets 1-2 weeks prior to or 3 weeks after subcutaneous injection of 1×10⁵ WPE1-NA22 human prostate cancer cells, respectively. Tumors were allowed to grow for 22 weeks; tumor areas, body weights, and food intakes were measured weekly. At study's conclusion, prostate and seminal vesicle weights were significantly decreased in all treatment groups versus the control; dutasteride intake significantly decreased seminal vesicle weights compared to finasteride intake. No differences were measured in final tumor areas or tumor weights between groups, likely due to poor tumor growth. In follow-up studies, proliferation of WPE1-NA22 prostate cancer cells and parent line RWPE-1 prostate epithelial cells were unaltered by treatment with testosterone, dihydrotestosterone, or Mibolerone, suggesting that these cell lines are not androgen-sensitive. CONCLUSION: The lack of response of WPE1-NA22 prostate cancer cells to androgen treatment may explain the inadequate tumor growth observed. Additional studies are needed to determine whether finasteride and dutasteride are effective in decreasing prostate cancer development/growth
D A Wolf - One of the best experts on this subject based on the ideXlab platform.
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the synthetic androgen Mibolerone induces transient suppression of the transformed phenotype in an androgen responsive human prostatic carcinoma cell line das synthetische androgen miboleron induziert eine transiente suppression des transformierten p
Andrologia, 2009Co-Authors: P Schulz, D A Wolf, V Arbusow, H Oja, H G Klobeck, Friedrich FittleAbstract:Summary The synthetic androgen Mibolerone elicits a set of distinct changes in the behaviour of an androgen responsive human prostatic carcinoma cell line (LNCaP). Inhibition of cell proliferation, induction of morphological change and of a prostate specific mRNA, and inhibition of colony formation in soft agar are induced by very low concentrations of Mibolerone. The natural androgen dihydrotestosterone is much less effective. The changes in growth characteristics and morphology are reverted by excess antiandrogen, i.e. cyproterone acetate or hydroxyflutamide. Cell lines lacking androgen receptors (PC-3, DU 145 and MRC-5) are completely unresponsive to Mibolerone. Taken together, our results indicate androgen receptor mediated suppression of the transformed phenotype in LNCaP cells. Zusammenfassung Das synthetische Androgen Miboleron lost eine Reihe bestimmter Veranderungen im Verhalten einer Androgen-responsiven menschlichen Prostata-Karzinom-Zellinie (LNCaP) aus. Hemmung der Proliferation, Induktion morphologischer Veranderungen und einer Prostata-spezifischen mRNA, sowie die Hemmung der Kolonie-Bildung im Weichagar werden von niedrigen Konzentrationen von Miboleron hervorgerufen. Das naturliche Androgen Dihydrotestosteron ist viel weniger effektiv. Die Veranderungen im Wachstumsverhalten und der Morphologie werden durch zusatzliches Antiandrogen, z.B. Cyproteronazetat oder Hydroxyflutamid, ruckgangig gemacht. Zellinien ohne Androgenrezeptor (PC-3, DU 145 und MRC-5) sprechen auf Miboleron uberhaupt nicht an. Zusammenfassend zeigen unsere Versuche eine Androgenrezeptor-mediierte Suppression des transformierten Phanotyps bei LNCaP-Zellen.
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transcriptional down regulation of c myc in human prostate carcinoma cells by the synthetic androgen Mibolerone
British Journal of Cancer, 1992Co-Authors: D A Wolf, P Schulz, Franz Kohlhube, F Fittle, Dirk EickAbstract:The mechanism of down-regulation of c-myc RNA associated with androgen-induced suppression of the transformed phenotype in the human prostate carcinoma cell line LNCaP was investigated. The synthetic androgen Mibolerone (7 alpha-17 alpha-Dimethyl-19-nortestosterone) reversibly inhibits the proliferation of LNCaP cells and, from 12-72 h after hormone addition reduces the level of c-myc transcripts to a few per cent of controls. P1, P2, and P0 c-myc transcripts decline at the same rate, whereas P3 transcripts are much less hormone sensitive. Nuclear run-on analysis revealed that c-myc is down-regulated at the level of transcription initiation in LNCaP cells. The level of c-myc transcripts prevailing in untreated control cells can be restored in androgen-induced cells by excess antiandrogen, indicating the involvement of the androgen receptor in c-myc down-regulation.
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the synthetic androgen Mibolerone induces transient suppression of the transformed phenotype in an androgen responsive human prostatic carcinoma cell line
Andrologia, 1990Co-Authors: P Schulz, D A Wolf, H Oja, H G Klobeck, Friedrich FittleAbstract:The synthetic androgen Mibolerone elicits a set of distinct changes in the behaviour of an androgen responsive human prostatic carcinoma cell line (LNCaP). Inhibition of cell proliferation, induction of morphological change and of a prostate specific mRNA, and inhibition of colony formation in soft agar are induced by very low concentrations of Mibolerone. The natural androgen dihydrotestosterone is much less effective. The changes in growth characteristics and morphology are reverted by excess antiandrogen, i.e. cyproterone acetate or hydroxyflutamide. Cell lines lacking androgen receptors (PC-3, DU 145 and MRC-5) are completely unresponsive to Mibolerone. Taken together, our results indicate androgen receptor mediated suppression of the transformed phenotype in LNCaP cells.
Charles Y F Young - One of the best experts on this subject based on the ideXlab platform.
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tissue specific and hormonal regulation of human prostate specific glandular kallikrein
Biochemistry, 1992Co-Authors: Charles Y F Young, Benjamin T Montgomery, Paul E Andrews, Donald J. TindallAbstract:: Kallikreins are involved in the posttranslational processing of a number of specific polypeptide precursors. Previously, human glandular kallikrein (hGK-1) mRNA has been identified in the prostate; however, the hGK-1 protein has not been identified and characterized. Therefore, its physiologic function in the prostate is not known. In this study, we have isolated a full-length hGK-1 cDNA from a human adenocarcinoma cell line, LNCaP. In vitro translation experiments demonstrated that the molecular size of the hGK-1 protein generated from this cDNA is similar to that of prostate-specific antigen (PSA), a protein which is produced exclusively in the prostate. In situ hybridization with a hGK-1-specific oligonucleotide probe (77 bases), which can differentiate hGK-1 mRNA from PSA mRNA, demonstrated the hGK-1 mRNA to be located in the prostate epithelium. The hGK-1 mRNA was colocalized with PSA mRNA in prostatic epithelia. Moreover, in situ hybridization studies revealed that the level of hGK-1 mRNA in human benign prostatic hyperplasia tissues is approximately half that of PSA mRNA. Furthermore, we have demonstrated that hGK-1 mRNA is under androgenic regulation in LNCaP cells. Time course analysis revealed that hGK-1 mRNA levels increased significantly at 5 h of Mibolerone treatment and reached maximal levels by 9 h. In addition, hGK-1 mRNA levels were increased by dihydrotestosterone, but not by dexamethasone or diethylstilbestrol treatments. Flutamide, a nonmetabolized anti-androgen, repressed the androgenic effects. These studies suggest that expression of hGK-1 mRNA is regulated by androgen via the androgen receptor.
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hormonal regulation of prostate specific antigen psa glycoprotein in the human prostatic adenocarcinoma cell line lncap
The Prostate, 1992Co-Authors: Benjamin T Montgomery, James L. Prescott, Charles Y F Young, David L Bilhartz, Paul E Andrews, N F Thompson, Donald J. TindallAbstract:: Prostate-specific antigen (PSA) has emerged as the most useful marker for management of patients with prostate cancer. The regulation of this glycoprotein in vivo has important clinical implications. Indirect evidence indicates that the PSA glycoprotein might be regulated by androgens, and previous studies in this laboratory have demonstrated that PSA mRNA is upregulated by androgens. The current work reports a detailed study of PSA glycoprotein expression as influenced by steroid hormones in a human prostatic adenocarcinoma cell line, LNCaP. First, we have examined the steroid binding specificity of the androgen receptor in this cell line. In comparison with wild-type rat androgen receptor in prostate, the receptor in LNCaP cells has altered affinity for a number of steroids or analogs such as progesterone (R5020), antiprogesterone (RU486), two antiandrogens (cyperoterone acetate and hydroxyflutamide), and an androgen metabolite (epitestosterone). However, its affinity for androgens (Mibolerone, dihydrotestosterone, and testosterone) is not changed. The receptor does not bind to the synthetic glucocorticoids (triaminolone acetonide and dexamethasone) nor to a synthetic estrogen DES (diethylstilbestrol). The change of the steroid binding specificity of the receptor is correlated with a single mutation (A----G at nucleotide #876 relative to the initiation codon) of the steroid binding domain of the receptor. The mutation and alteration of steroid-binding specificity of the androgen receptor is also correlated with PSA glycoprotein expression affected by different ligands tested. We have demonstrated that the PSA glycoprotein is upregulated by androgens and is affected by neither epidermal growth factor nor basic fibroblast growth factor. Moreover, PSA glycoprotein could be induced by R5020, estradiol, and epitestosterone; but neither glucocorticoids nor DES had any effect on PSA induction. Interestingly, although the antiandrogen, cyperotone acetate, had the ability to induce PSA, both RU486 and hydroxyflutamide could block androgen and progesterone induction of PSA glycoprotein. Therefore, we conclude that the PSA glycoprotein expression is influenced predominantly by androgens via its receptor, and the mutation of the receptor can affect the expression of this cellular gene by the steroids other than androgens.
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hormonal regulation of prostate specific antigen messenger rna in human prostatic adenocarcinoma cell line lncap
Cancer Research, 1991Co-Authors: Charles Y F Young, Benjamin T Montgomery, David L Bilhartz, Paul E Andrews, Donald J. TindallAbstract:Abstract Prostate-specific antigen (PSA) is a member of the kallikrein gene family and is expressed exclusively in human prostatic epithelial cells. PSA protein has been an important biological marker for prostate cancers. Until now, very little was known about the regulation of PSA expression in prostatic cells. In this study, we have developed a specific oligonucleotide probe which recognizes PSA but not the human glandular kallikrein. This is crucial because both PSA and human glandular kallikrein are expressed in the prostate at relatively high levels and have high nucleotide sequence homology (>82%). Utilizing a 35 S-labeled PSA-specific probe, PSA mRNA was localized within the glandular epithelium of the prostate. Northern blot analysis detected a single 1.6-kilobase transcript in LNCaP cells, a cell line derived from a human prostate adenocarcinoma metastasis. Therefore, LNCaP cells were used to study the androgenic effects on PSA mRNA expression. A time course study demonstrated that PSA mRNA was induced by Mibolerone (a nonmetabolizable synthetic androgen) and reached maximal levels after 9 h. The induction of PSA mRNA required as little as 0.3 nm Mibolerone. In addition to Mibolerone, PSA mRNA could be induced by the natural androgen, dihydrotestosterone, but not by the synthetic glucocorticoid, dexamethasone, or the synthetic estrogen, diethylstilbestrol. Moreover, in the presence of dihydrotestosterone, PSA mRNA was depressed by hydroxyflutamide (an antiandrogen). These results suggest strongly that the androgenic effects on PSA mRNA in LNCaP cells may be via the function of the androgen receptor.