Effect of increasing ratio of estrogen: androgen on proliferation of normal human prostate stromal and epithelial cells, and the malignant cell line LNCaP

BACKGROUND: Changes in steroid ratios seen in the aging male are thought to promote prostate disease. The aims of this study were to compare the effects of varied ratios of steroids on growth of normal stromal and epithelial cell isolates, and the prostate cancer cell line, LNCaP. METHODS: The effect of altered steroid ratios on cell proliferation of normal stromal (PrSC) and epithelial (PrEC) prostate cells, and the malignant cell line, LNCaP, were assessed. RESULTS: Increasing the ratios of both estrogen:dihydrotestosterone (DHT) and DHT:estrogen, stimulated PrSC proliferation, with increasing estrogen:DHT having the greatest effect. LNCaP proliferation was increased significantly by both steroids, but altered ratios had no additional effect. PrEC proliferation was unaffected when cells were grown alone, despite presence of androgen receptors (AR) and estrogen receptors (ER). When grown in co-culture PrEC cell proliferation was significantly increased by treatments. CONCLUSIONS: PrSC proliferation is stimulated by an increasing ratio of estrogen:androgen. Proliferation of normal epithelial cells is stimulated as a result of an indirect action of steroids mediated by stromal cells. Malignant prostate cancer cells have an altered response in comparison.     

Apoptosis and hormonal milieu in ductal system of normal prostate and benign prostatic hyperplasia

Aim: To study the apoptotic rate (AR) and the androgen and estrogen milieu in the proximal and distal ductal sys-tems of prostate, in order to help exploring the effects of these factors on prostatic growth and the pathogenesis of be-nign prostatic hypertrophy (BPH). Methods: The proximal and distal ends of the ductal system were incised from20 normal prostate as well as the hypertrophic prostate tissue from 20 patients with BPH. The AR was determined bythe DNA end-labeling method and dihydrotestosterone (DHT) and estrodiol (E_2), by radioimmunoassay. Results:There was no significant difference in DHT and E_2 density between the proximal and distal ends of the ductal systems innormal prostate. E_2 appeared to be higher in BPH than in normal prostatic tissues, but the difference was statistically in-significant. In normal prostatic tissue, the AR was significantly higher in the distal than in the proximal ends of theductal system (P<0.05), while the AR of the proximal ends was significantly higher (P <0.     

Proliferative responses of cultured rat prostate and human benign prostatic hyperplasia

The proliferative responses of rat prostate and human benign prostatic hyperplasia have been followed in organ culture using [125I] iododeoxyuridine uptake to monitor DNA synthesis. In serum-free cultures, testosterone induced a marked increase in DNA synthesis (three-fold) in 4- to 6-month-old rat prostates at concentrations of 4 x 10(-9) to 4 x 10(-6) M, whereas in greater than 12-month-old rat prostates the response was less marked. Human benign prostatic hyperplasia also showed an increased uptake at similar testosterone concentrations and of a similar magnitude to the response of greater than 12-month-old rat prostates. At 10(-5) M DNA synthesis was markedly suppressed in cultures of both rat and human prostate. The proliferative response of human benign prostatic hyperplasia increases up to days 3 to 4 in culture and then declines in both control and hormone-treated groups and may represent repair processes which appear to be hormone dependent.     

Comparative study of plasma steroid and steroid glucuronide levels in normal men and in men with benign prostatic hyperplasia

Plasma steroids were analyzed in 16 normal men and in 10 men with prostatic benign hyperplasia (BPH). The steroids measured by radioimmunoassay include pregnenolone, 17-OH-pregnenolone, dehydroepiandrosterone, androst-5-ene-3 beta, 17 beta-diol, testosterone, dihydrotestosterone, androstane-3 alpha, 17 beta-diol, androstane-3 beta, 17 beta-diol, estrone, and estradiol as well as their glucuronide derivatives. In addition, cortisol and the sulphoconjugated form of dehydroepiandrosterone were determined. Whereas the levels of pregnenolone, pregnenolone glucuronide and 17-OH-pregnenolone glucuronide are not different in the two groups, the levels of 17-OH-pregnenolone in the BPH group (0.87 +/- 0.07 ng/ml) exceed by two-fold (p less than 0.01) those observed in normal men. Plasma dehydroepiandrosterone and androst-5-ene-3 beta, 17 beta-diol concentrations are markedly elevated in the BPH group (1.49 +/- 0.23 and 0.55 +/- 0.08 ng/ml vs the control groups 0.43 +/- 0.11 and 0.31 +/- 0.05 ng/ml, respectively). Since the plasma cortisol and pregnenolone levels are comparable in these two groups, our data suggest that the elevation of plasma 17-OH-pregnenolone, dehydroepiandrosterone, and androst-5-ene-3 beta, 17 beta-diol reflects an increase of adrenal 17-hydroxylase activity in patients with BPH. A slight increase of the plasma dihydrotestosterone and androsterone glucuronide concentration is also observed in men with BPH, indicating an increase of 5 alpha-reduced androgen formation. We have also observed, in the BPH group, a 50% decrease (p less than 0.01) of plasma glucuronidated androst-5-ene-3 beta, 17 beta-diol, estrone, and estradiol levels, suggesting that the transformation of unconjugated estrogenic steroids into glucuronide derivative is inhibited in BPH patients. In summary, our data indicate that adrenal C-19 steroids might be involved in the process of BPH. Furthermore, whereas the estrogen glucuronide formation is diminished in men with BPH, the prostatic androgen metabolism as reflected by plasma dihydrotestosterone and androsterone glucuronide concentrations seems to be increased.     

Effects of steroids on oxytocin secretion by the human prostate in vitro

Oxytocin (OT) concentrations are elevated in prostate tissue of patients with benign prostatic hyperplasia (BPH). Oxytocin specifically increases growth, 5 alpha-reductase activity and contractility in the prostate. In the rat prostatic OT concentrations are regulated by gonadal steroids, with androgens reducing but oestrogens increasing OT concentrations. The regulation of prostatic oxytocin in man is not understood. This study investigates the effects of gonadal steroids on oxytocin production by the human prostate. Primary explants (approx. 1 mm3) of prostate tissue from patients with BPH were incubated in Dulbecco's modified Eagle's media in the absence or presence of 10 nmol/L testosterone (T), 10 nmol/L dihydrotestosterone (DHT), T or DHT plus 100 nmol/L of the anti-androgen cyproterone acetate (CPA), 55 pmol/L diethylstilbestrol (DES), or DES plus DHT. The amount of oxytocin secreted into the media after 3 days was measured by radioimmunoassay. Testosterone and DHT significantly increased oxytocin concentrations secreted into the media from 0.86 +/- 0.11 ng/g of tissue (control) to 1.51 +/- 0.14 ng/g (p < 0.01) and 1.54 +/- 0.13 ng/g (p < 0.05), respectively. Incubation of tissue samples with CPA resulted in oxytocin concentrations similar to control levels. Treatment with DES caused a significant increase from 1.99 +/- 0.71 to 3.98 +/- 1.36 ng/g (p < 0.05). A similar increase was measured in media of tissue incubated in DES plus DHT (p < 0.001). The results demonstrate that, unlike the rat where androgens decrease oxytocin, in hyperplastic human prostate tissue both androgens and oestrogens increase oxytocin. This imbalance in the regulation of oxytocin may result in promoting prostatic overgrowth in the pathogenesis of BPH.     

不同前列腺组织中雄激素受体的表达研究

目的:研究雄激素受体(AR)在正常前列腺、良性前列腺增生(BPH)和前列腺癌(PCa)组织中的表达,探讨AR与BPH和PCa的关系。方法:采用实时定量PCR、免疫荧光和组织蛋白电泳方法,分析15例正常前列腺、20例BPH与40例PCa标本中AR的表达情况。结果:实时定量PCR和组织蛋白电泳检测BPH组织与正常前列腺组织中AR的表达量差异无统计学意义(P>0.05)。但免疫荧光检测发现BPH组织中AR蛋白表达量增高。3种方法检测PCa组织中AR表达量较正常前列腺组织和BPH组织增高(P<0.05)。高分化PCa的AR表达比低分化PCa高(P<0.05)。随着临床分期的增高,AR的表达降低(P<0.05),激素非依赖性前列腺癌(HRPC)组织中AR表达最低。结论:AR在PCa组织中的表达较正常前列腺和BPH组织中增高,AR的表达与PCa的分级、分期相关。     

Evaluation of MENT on primary cell cultures from benign prostatic hyperplasia and prostate carcinoma

7-alpha-Methyl-19-Nortestosterone (MENT) is a synthetic androgen more potent than testosterone (T) and cannot be reduced at 5-alpha position. No important effects of MENT on prostate growth have been reported. However, little is known about the effect of MENT on benign prostatic hyperplasia (BPH) or prostate carcinoma (CaP). We evaluate the effect of MENT, T and dihydrotestosterone (DHT) on secretion, proliferation and gene expression of primary cell cultures from human BPH and CaP. Moreover, the effect of these androgens was examined in the presence of finasteride to determine the influence of the 5-alpha reductase (5-AR) activity on the androgenic potency. BPH and CaP primary cultures were treated with 0, 1, 10 and 100 n m of T, MENT or DHT during 24 and 48 h. Prostate-specific antigen (PSA) was measured by micro particles immunoassay and proliferation rate by spectrophotometric assay (MTT) and by the immunochemical detection of the proliferation marker Ki-67. Gene expression of FGF8b (androgen sensitive gene) was evaluated by semi-quantitative RT-PCR. Results showed that MENT treatments increased PSA secretion and proliferation rate with a potency ranged between T and DHT. Similar effects of MENT were observed in both BPH and CaP cultures. The studies with finasteride showed that in BPH and CaP cells, the conversion of T into DHT significantly contributes to its effect on the proliferation and PSA secretion, and corroborated the resistance of MENT to the 5-AR. The effect of MENT on the gene expression of FGF8b in CaP cells was similar to T and lower than DHT. It is concluded that MENT increases proliferative and secretory activities and gene expression on pathological prostate cells although in less extent than the active metabolite DHT. Furthermore, the fall of endogenous concentration of T during MENT treatment anticipates that this androgen will be of low impact for the prostate.     

前列腺癌与良性前列腺增生细胞株差异核基质蛋白的鉴定

目的:鉴定人前列腺癌雄激素依赖性细胞株LNCaP、前列腺癌雄激素非依赖性细胞株PC-3与良性前列腺增生细胞株BPH-1之间差异表达的核基质蛋白(nuclear matrix proteins,NMPs)。方法:常规制备各细胞株NMPs,应用双向凝胶电泳对其进行分离;对差异表达的蛋白质点行MALDI-TOF-MS/MS质谱分析,数据库搜索并鉴定。结果:成功获得了分辨率高、重复性好的不同细胞株NMPs双向凝胶电泳图谱;初步鉴定出包含酶、调节蛋白、RNA结合蛋白及各种因子在内的12个差异表达的蛋白质,在癌细胞株中3个NMPs表达上调,9个下调。结论:人前列腺癌细胞与良性前列腺增生细胞之间NMPs表达存在明显差异;初步筛选出12个差异NMPs,其表达水平及功能与疾病的联系需进一步研究。     

Caspase 3 expression in benign prostatic hyperplasia and prostate carcinoma

BACKGROUND: Apoptotic resistance to androgen ablation represents a significant problem in the treatment of prostate cancer. Over expression of antiapoptotic proteins such as Bcl-2 and mutations in p53 contribute to this resistance. The caspase family of proteases are central executioners of the cell death pathway. They are expressed in normal prostate secretory epithelial cells. Altered expression may represent an additional component leading to cell resistance. The aim of this study was to determine by immunohistochemistry caspase 3 expression in benign prostatic hyperplasia and prostate cancers. METHODS: Twenty-two patients with histologically determined prostate cancer and benign prostatic hyperplasia (BPH) were investigated. All specimens were obtained from patients undergoing surgical resection of the prostate. Immunohistochemical analysis was performed on formalin fixed paraffin embedded sections to assess caspase 3 expression. RESULTS: Caspase 3 was expressed in 18/22 (81.1%) samples, with high expression in BPH which demonstrated staining in both basal and secretory epithelial cells. Increasing grades of prostatic cancer showed a significant loss of expression in secretory epithelial layers and little staining in epithelial cells in high-grade prostatic carcinoma. CONCLUSIONS: Altered caspase 3 expression may represent an additional mechanism of apoptotic resistance to androgen ablation. Prostate 47:183-188, 2001.     

Effect of prostatic growth factor,basic fibroblast growth factor,epidermal growth factor,and steroids on the proliferation of human fetal prostatic fibroblasts

To study the relationship between androgen metabolism and the pathogenesis of benign prostatic hypertrophy, we purified a growth factor from benign hyperplastic tissue of human prostates and assayed the proliferative responses of human fetal prostatic fibroblasts to the purified growth factor (hPGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), dihydrotestosterone (DHT), and estradiol (E₂). Prostatic tissue extracts were fractionated using heparin-Sepharose chromatography. The fraction that eluted with 1.3–1.7 M NaCl contained the majority of mitogenic activity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS/PAGE) of the lyophilyzed active fraction showed a band at 17,000 daltons. Human prostatic fibroblasts were isolated from fetal prostate and tested for their proliferative responses to hPGF, bFGF, EGF, DHT, and E₂. hPGF, as well as bFGF and EGF, did increase tritiated thymidine incorporation into the cultured fibroblasts. DHT(10⁻⁷ M) had a significant stimulatory effect on cell growth in serum-free media after 6 days of culture. E₂(10⁻⁷ M) had no effect on cell proliferation. The combination of DHT and E₂ showed no synergistic effect. We conclude that our purified hPGF, bFGF, and EGF promote cell growth directly, DHT indirectly, while E₂ does not. The effect of DHT appears to be mediated via the increased production and/or secretion of growth factor(s). Possibly, the bFGF-like hPGF purified from human benign hyperplastic prostatic tissue is such a mediator. © 1996 Wiley-Liss, Inc.     

Down-regulation of macrophage inhibitory cytokine-1/prostate derived factor in benign prostatic hyperplasia

BACKGROUND: Macrophage inhibitory cytokine-1 (MIC-1) is a member of transforming growth factor-beta/bone morphogenetic protein (BMP) superfamily. Despite its potential role in prostatic regulation, little is known about its biological activity. METHODS: Expression profiling using 42K Affymetrix HuGeneFL array was conducted to compare symptomatic benign prostatatic hyperplasia (BPH), histological BPH without symptoms, and normal prostate samples from donors. MIC-1 gene expression was analyzed by RT-PCR in pure culture of prostate epithelial and stromal cells, and prostate cancer cells, LNCaP, PC-3, DU-145. Influence of androgens on MIC-1 expression in LNCaP cells was analyzed by Northern blot. Enhancement of promoter activity of MIC-1 by androgens was examined using reporter assays. RESULTS: In contrast to normal prostates, MIC-1 gene was down-regulated in BPH samples with symptoms and histological BPH obtained from cystoprostatectomy specimens (P < 0.005 and P < 0.01, respectively). Expression level of MIC-1 in androgen-sensitive LNCaP cells was high and enhanced by androgens, whereas in the androgen-insensitive PC-3 and DU-145 cells the expression level was low. An 11 kb promoter region of MIC-1 gene was identified to be 6- to 12-fold activated by androgens. CONCLUSIONS: Down-regulation of MIC-1 may play a role in the development of BPH. MIC-1 is positively regulated by androgens, but other regulatory factors remain unclear.     

红三叶总异黄酮对人增生前列腺组织基质细胞增殖和凋亡的影响

目的:评价红三叶总异黄酮对人增生前列腺组织基质细胞增殖和凋亡的影响。方法:采用浓度为12.5、25、50、100μg/ml的红三叶总异黄酮溶液处理前列腺基质细胞,并设立PBS空白对照组,DMSO阴性对照组和浓度为12.5、25.0、50.0、100.0μg/ml的非那雄胺溶液为阳性对照组。MTT法测定红三叶总异黄酮对细胞增殖的影响;AnnexinVFITC/PI双染色法流式细胞术分析红三叶总异黄酮对细胞凋亡的作用。结果:当红三叶总异黄酮浓度达到25.0μg/ml时,其对人前列腺增生组织基质细胞的增殖抑制率为18.86%,与空白对照组(5.17%)相比差异有显著性(P<0.05);且随着药物浓度的增加,抑制作用也愈趋明显。与非那雄胺阳性对照组相比,当浓度达到50.0μg/ml时,红三叶总异黄酮实验组对人前列腺增生组织基质细胞的抑制增殖作用弱于非那雄胺阳性对照组(28.00%vs69.88%),差异有显著性(P<0.05)。流式细胞术分析结果表明,与阴性对照组、空白对照组相比,红三叶总异黄酮浓度达到25.0μg/ml时能够诱导前列腺基质细胞的凋亡,凋亡率为(18.54±2.50)%(P<0.01)。结论:红三叶总异黄酮对前列腺基质细胞有较明显的抑制生长,促进凋亡作用。     

Creatine phosphokinase isoenzymes in human prostatic tissues: a comparison between benign hyperplasia and adenocarcinoma

The objective of this study was to determine the distribution of creatine phosphokinase (CPK) into its three isoenzymes, MM, MB, and BB, in human prostatic tissue, in patients with benign hyperplasia (BPH) and adenocarcinoma. Specimens were obtained from 23 patients with adenocarcinoma of the prostate and 25 patients with benign hyperplasia. We also had the opportunity to analyze the CPK content in two normal prostates, the first from a 16 1/2-year-old boy and the second from a 9 1/2-year-old child. Our results showed prostate tissue to contain almost exclusively the BB isoenzyme with traces of the MB and MM dimers in both cancer and BPH as well as the specimen of normal prostate from the 16 1/2-year-old boy. As for the 9 1/2-year-old child, we found the following distribution: 39% MM, 21% MB, and 40% BB dimer. A comparison of the CPK-BB content in benign hyperplasia and adenocarcinoma revealed no significant difference between the two groups. Furthermore, we tried to correlate prostatic tissue CPK-BB levels with another possible tumor marker of the prostate, prostatic acid phosphatase (PAP) measured in the cytosol. No correlation was found between these two markers. We also studied the relationship of CPK-BB and PAP content in prostatic tissue to nuclear and cytosolic androgen receptor content in human prostatic tissue. We found some correlation between CPK-BB and androgen cytosolic receptors as well as between PAP content and androgen cytosolic receptors in patients with benign hyperplasia. No such correlation was found in the group with adenocarcinoma. In conclusion, this study does not show that the measurement of CPK-BB in the prostatic tissue could be used as an index of tissue malignancy.     

CK2抑制剂四溴肉桂酸对前列腺癌细胞增殖及周期的影响

目的探讨一种新的人工合成CK2选择性抑制剂四溴肉桂（TBCA）,对前列腺癌细胞增殖及周期的影响。方珐CK2选择性抑制剂TBCA应用到多种前列腺癌细胞系,Alamarblue法和克隆形成实验检测细胞生长和增殖能力,流式细胞技术检测细胞周期分布,治疗组与对照组间差异是否具有显著意义采用SPSS统计软件进行分析。站杲低剂量（〈25μmol）TBCA干预下未发现细胞聚集和分离,而在高剂量（〉50μmol）则可观察到细胞明显分离,剂量依赖性抑制细胞生长和增殖（P〈0．05）,半抑制浓度值（IC50）为25μmol。TBCA诱导前列腺癌细胞停滞在G2／M期细胞周期。结论TBCA呈剂量依赖性抑制前列腺癌细胞增殖和细胞周期停滞在G2／M期。     

经尿道绿激光前列腺汽化术治疗BPH的疗效观察

目的：与经尿道前列腺等离子电切术（PKRP）进行对比研究,评估绿激光前列腺汽化术（PVP）治疗BPH的有效性和安全性。方法：2009年12月～2010年9月收治BPH患者70例,随机单盲分为两组,其中PVP组35例（研究组）,PKRP组35例（对照组）。出院后3个月返院由专人负责复查,记录术前和出院后3个月的临床观察指标,包括国际前列腺症状评分（IPSS）、生活质量指数（QOL）最大尿流率（Qmax）、男性性功能四项（MSF-4）以及并发症,采用SPSS13．0统计软件对上述资料进行统计学分析和评估。结果：两组患者术前指标、手术时间、术中冲洗液量、实验室检查、住院时间、导尿管拔除时问、膀胱冲洗时间差异无统计学意义（P〉0．05）。出院后3个月,两组患者IPSS、QOL、Qmax均得到显著改善,MSF-4与术前相比差异无统计学意义。PVP组和PKRP组分别有2例（7．0％）和3例（10．0％）术后发生前尿道狭窄,发病率差异无统计学意义（P〉0．05）。两组均未出现尿失禁。结论：PVP是一种治疗BPH的安全、有效的方法,短期（3个月内）疗效及安全性与PKRP类似,长期疗效有待随后进一步评估。     

The expression of thrombospondin-1 in benign prostatic hyperplasia and prostatic intraepithelial neoplasia is decreased in prostate cancer

OBJECTIVE: To evaluate the immunohistochemical expression of thrombospondin (TSP), a potent inhibitor of angiogenesis, in human benign prostatic hyperplasia (BPH) and prostate cancer. MATERIALS AND METHODS: The expression of TSP-1, TSP-2 and CD36 receptor was assessed in 73 tissue specimens using immunohistochemistry; specimens were from 32 patients with BPH, seven with prostatic intraepithelial neoplasia (PIN) and 34 with cancer. RESULTS: Immunohistochemistry showed that all 39 patients with BPH and PIN had TSP-1-positive glands. In contrast, none of the 34 patients with cancer had positive TSP-1 staining in the cancer tissue. All 73 patients were positive for TSP receptor CD36 and negative for TSP-2. CONCLUSIONS: TSP is expressed in BPH, down-regulated in PIN and absent in prostate cancer tissue. This may indicate that TSP is important in prostate cancer progression. Further studies are needed to understand the significance of these findings for the malignant transformation of the prostate gland.