Proliferation of prostate cancer cells and activity of neutral endopeptidase is regulated by bombesin and IL-1beta with IL-1beta acting as a modulator of cellular differentiation

BACKGROUND: Neutral endopeptidase (NEP) is a cell-surface bound enzyme that cleaves and inactivates neuropeptides such as bombesin and substance P and is involved in the transition from hormonally regulated androgen-dependent prostate cancer (PC) to androgen-independent PC. Neuropeptides are implicated in growth regulation of different cell types and function as transmitters between the neuroendocrine and the immune system. METHODS: NEP-expression, enzymatic activity of the membrane bound protein, cell proliferation, procalcitonin (PCT) production, and secretion as well as changes in cell morphology of prostatic cells were evaluated after treatment with the immunomodulatory cytokine interleukin-1beta (IL-1beta), neuropeptides (bombesin, substance P), and neuropeptide-conditioned media derived from a human neuroendocrine cell line. RESULTS: Incubation of LNCaP tumor cells with IL-1beta resulted in a diminished proliferative activity, induction of neurite-like outgrowth which was accompanied by the formation of tubular-type mitochondria typical for neuronal/neuroendocrine cells, and an increased production and secretion of PCT. Conversely, proliferation of prostatic stromal cells was enhanced by the cytokine coming along with an increased number of Golgi-apparatuses and ER-cisternae. Bombesin had an antimitotic effect on LNCaP, but not on stromal cells. Substance P did not influence the growth of any of the cell types investigated, whereas neuropeptide-conditioned media exerted a slightly mitogenic effect on both cell types. The activity of LNCaP cell-surface bound NEP was enhanced by bombesin, but was diminished by substance P and neuropeptide-conditioned media. CONCLUSIONS: Proliferation and activity of neuropeptide degrading NEP is regulated differently by immunomodulatory substances in PC cells and cells derived from the prostatic stroma with IL-1beta being a potent modulator of cellular differentiation and a potential target for anticancer drug design in PC cells.     

IMPDH2蛋白与前列腺癌临床相关性分析

【摘要】〓目的〓研究IMPDH2在良性前列腺增生和前列腺癌中的表达,并分析其表达水平与临床病理特征的关系。方法〓收集临床手术切除的前列腺癌组织和前列腺增生,或者穿刺活检组织,所有组织均由病理学确诊。排除已做手术去势的前列腺组织。通过Western Blot检测IMPDH2在前列腺癌、前列腺增生组织中IMPDH2蛋白的表达情况|免疫组化检测前列腺癌、前列腺增生标本中IMPDH2的表达。分析IMPDH2基因的表达水平与临床病理特征的关系。结果〓前列腺癌患者组织中IMPDH2蛋白表达显著上调,IMPDH2蛋白表达上调与肿瘤临床分期、Gleason评分、转移相关。结论 IMPDH2在前列腺癌组织中表达上调,前列腺组织中检测IMPDH2可能有助于判断前列腺癌分化程度并评估预后。     

蛋白激酶Cε在前列腺癌组织中表达的临床意义

目的 探讨蛋白激酶C ε(PKCε)在不同病理类型前列腺组织中的表达及与前列腺癌病理分级、分期的关系。 方法 正常前列腺(NP)组织标本10例、前列腺增生(BPH)组织标本10例、癌旁(PC)组织标本10例、前列腺癌(PCa)组织标本43例。免疫组化法检测各组织中PKCε的表达情况,分析PKCε表达与不同病理类型及PCa分级、分期的关系。 结果 PCa组PKCε表达阳性27例,BPH组无阳性表达,NP组1例,PC组2例,差异有统计学意义(P＜0.05)。PCa组Gleason评分≥8分组中PKCε表达阳性12/13例,2～4分组4/10例,5～7分组11/20例,组间差异有统计学意义(P＜0.05)。T3期PKCε表达阳性10/12例,T4期9/10例,T1、T2期分别为1/6例和7/15例,高分期与低分期组PKCε表达差异有统计学意义(P＜0.05)。PCa转移组PKCε表达阳性9/10例,未转移组18/33例,组间差异有统计学意义(P＜0.05)。PCa患者血清PSA≤20 ng/ml者PKCε表达阳性7/15例,＞20 ng/ml组20/18例,组间差异无统计学意义(P＞0.05)。 结论 PCa组织中PKCε的表达率较高,并且与PCa病理分级、分期呈正相关,临床上可考虑作为PCa预后因子之一。     

MUC1 Expression in Prostate Carcinoma: Correlation with Grade and Stage

Mucins have been implicated in the biologic behavior and progression of several types of cancer. The aims of this study were to define the expression pattern of one particular mucin, MUC1, in benign and malignant human prostate tissue and to determine if MUC1 expression correlates with tumor grade and stage. Immunohistochemical staining utilizing an anti-MUC1 monoclonal antibody was performed on 4 fetal prostates, 4 specimens of benign prostatic hyperplasia (BPH), and 34 radical prostatectomy specimens. In human fetal and BPH specimens, there was an apical pattern of MUC1 expression, similar to that reported in other normal and benign tissues. Ninety-four percent of the prostate cancers were MUC1 positive. A high percentage of prostate cancer specimens (62%) demonstrated a diffuse, cytoplasmic staining pattern. There was a statistically significant correlation between diffuse MUC1 staining and Gleason pattern, with a diffuse/total staining percentage of 9% in Gleason 2, 64% in Gleason 3, 80% in Gleason 4, and 100% in Gleason 5. More diffuse staining was also seen in samples from patients with high pathologic stage: 21% in T(2), 75% in T(3), and 67% in N(1) disease. These data indicate that MUC1 expression is prevalent in prostate cancer and that diffuse cytoplasmic staining correlates with advanced Gleason pattern and advanced pathologic stage.     

ELL基因在前列腺癌组织中的表达及其意义

目的分析 ELL基因在人类前列腺癌组织中的表达情况,探讨其在前列腺癌发生发展中的作用.方法收集45例前列腺癌组织、15例良性前列腺增生组织和15例正常前列腺组织,提取总 RNA,应用 qRT-PCR检测 ELL mRNA的表达情况,分析其与前列腺癌分级的关系.结果前列腺癌组织中 ELL mRNA 的表达量明显低于良性前列腺增生组织和正常前列腺组织(P＜0．05),而良性前列腺增生组织与正常前列腺组织间差异无统计学意义.随着前列腺癌Gleason评分的升高,ELL mRNA的表达呈下降趋势(P＜0．05).结论 ELL 基因在前列腺癌组织中呈低表达,其表达与前列腺癌的分级密切相关,提示其可能在前列腺癌的发生发展中发挥重要作用.     

Cytoplasmic induction and over-expression of cyclooxygenase-2 in human prostate cancer: implications for prevention and treatment

OBJECTIVE: To assess the level and morphological distribution of cyclooxygenase (COX)-1 and -2 in human prostates and to determine any association with the Gleason grade of prostate cancer. Materials and methods The study comprised 30 samples from patients with benign prostatic hyperplasia (BPH) and 82 with prostate cancer. Immunohistochemistry was used to assess the expression of COX-1 and -2, and 13 samples were also assessed using immunoblotting (six BPH and seven cancers). RESULTS: For both BPH and prostate cancer, COX-1 expression was primarily in the fibromuscular stroma, with variable weak cytoplasmic expression in glandular/neoplastic epithelial cells. In contrast, COX-2 expression differed markedly between BPH and cancer. In BPH there was membranous expression of COX-2 in luminal glandular cells and no stromal expression. In cancer the stromal expression of COX-2 was unaltered, but expression by tumour cells was significantly greater (P = 0.008), with a change in the staining pattern from membranous to cytoplasmic (P < 0.001). COX-2 expression was significantly higher in poorly differentiated than in well differentiated tumours (P < 0.001). These results were supported by immunoblotting, which showed similar levels of COX-1 in both BPH and cancer, but four times greater expression of COX-2 in cancer than in BPH. CONCLUSION: This is the first study to assess the co-expression of COX-1 and COX-2 proteins in benign and malignant human prostates, and showed the induction and significantly greater expression of COX-2 in cancer, which was also associated with tumour grade. The regular use of nonsteroidal anti-inflammatory drugs is associated with a reduced incidence of cancers. The present results provide the basis for a potential role for COX-2 inhibitors in the prevention and treatment of prostate cancer.     

Immunohistochemistry and biochemistry in detection of androgen, progesterone, and estrogen receptors in benign and malignant human prostatic tissue.

The relative distribution of androgen (AR), progesterone (PR), and estrogen receptors (ER) was localized and estimated in human prostate tissue by immunohistochemistry in five normal tissue samples, in eight benign hyperplastic (BPH) samples, in nine primary cancers, and in seven prostate cancer metastases. Moreover, three prostatic cancer cell lines (LNCaP, DU 145, and PC 3) were analyzed. A comparison between the results obtained by radioligand binding assays and immunohistochemistry was performed for the AR and PR. Using immunohistochemistry, the AR was exclusively detected in the nuclei of both benign and malignant prostatic epithelial cells. The highest proportion of AR-positive cells was found in BPH and in prostate cancer metastases as compared with normal prostatic tissue. In a majority of the cases, the PR was only present in the nuclei of stromal cells. Benign hyperplastic prostates contained higher proportions of PR-positive cells as compared with primary carcinoma. PR was sparse in epithelial cells. ER-positive stromal cell nuclei were only detected in carcinomatous prostates. A few ER-positive epithelial cell nuclei were found in one sample each of a BPH and normal prostate. All cells from the androgen-dependent, LNCaP, cell line and a majority of the cells from the androgen-independent, DU 145, cell line were AR-positive. In contrast, the cells from the androgen-independent, PC 3, cell line were all AR-negative. All three cell lines were PR- and ER-negative. The radioligand binding technique detected the AR in extracts from both the cytosol and the nucleus. Again BPH contained higher amounts of AR as compared with normal prostatic tissue. The LNCaP cells contained high amounts of cytosolic AR while cells from the DU 145 and PC 3 cell lines lacked detectable AR as estimated by biochemical techniques. There seemed to be a discrepancy between biochemically measured and immunohistochemically estimated receptor content.     

TLR4在前列腺癌中的表达及临床意义

目的：探讨TLR4在前列腺癌（PCa）中的表达情况及意义。方法：采用免疫组化法检测TLR4与Survivin蛋白在41例PCa及20例良性前列腺增生（BPH）组织中的表达,同时分析TLR4和Survivin蛋白表达与Gleason系统分级的关系。结果：TLR4与Survivin蛋白在BPH组织中的阳性表达例数分别为15例（75％）与0例（O）,在PCa组织中的阳性表达例数分别为18例（43．9％）与28例（68．3％）,TLR4表达与PCa的Gleason系统分级有显著相关性（P〈0．05）,随着Gleason评分增高,TLR4表达降低。Survivin蛋白的表达与Gleason系统分级无关（P〉O．05）。结论：TLR4表达与PCaGleason系统分级相关,其表达与PCa的发生发展密切相关,可成为估计肿瘤预后的一项指标。     

前列腺癌和癌旁组织中雌激素受体α和β的表达及意义

目的 通过测定前列腺癌中癌组织、癌旁组织和良性前列腺增生组织中雌激素受体(estrogen receptor,ER)α和β的表达水平,探讨ER在前列腺腺癌发生、发展中的变化和作用机制.方法 采用超高敏链酶亲合素-过氧化物酶法检测28例前列腺腺癌标本中癌和癌旁组织以及29例良性前列腺增生组织中ERα和ERβ的表达水平,对比其在各组之间表达的差异,分析ERα和ERβ的表达水平与前列腺癌患者的Gleason评分、临床分期、年龄和TPSA的关系.结果 前列腺癌组织中ERα主要在间质细胞表达.ERα在前列腺癌组织、癌旁组织和良性前列腺增生组织上皮细胞的表达阳性率分别为0%、14%、24%,间质细胞阳性率分别为57%、68%、31%,组间比较差异有统计学意义(P＜0.05).前列腺癌上皮细胞和间质细胞均有ERβ的表达且差异无统计学意义(P＞0.05).ERβ在前列腺癌组织、癌旁组织和良性前列腺增生组织上皮细胞的表达阳性率分别为39%、64%、29%;间质细胞阳性率分别为50%、75%、79%,组间比较差异有统计学意义(P＜0.05).ERβ在不同Gleason评分前列腺癌组织中表达差异有统计学意义(P＜0.05).结论 前列腺癌中ERα主要在间质细胞表达;ERβ在上皮细胞和间质细胞均有表达.ERα和ERβ的表达水平在前列腺癌组织、癌旁组织和良性前列腺增生组织均存在差异.ER口与前列腺癌变发生和恶性程度相关.

Abstract：

Objective To investigate the expression of estrogen receptor (ER) α and β in human prostate cancer (PC), peri-cancer tissue and benign prostatic hyperplasia (BPH) tissue, and to discuss the role of estrogen receptor in prostate cancer. Methods The expression of ERα and ERβ in PC (n=28), peri-cancer tissue (n=28) and BPH (n=29) were detected by immunohistochemistry with En vision method. The ERα and ERβ expression were compared among different tissues by chisquare. The relationship between ER expression and related clinicopathologic features was statistically analyzed by spearman rank collection. Results ERα was localized dominantly in the stromal cell of PC. There were significant differences of the expression of ERα in PC, peri-cancer tissue and BPH tissue (epithelial cell 0%, 14%, 24%, P＜0. 05; stromal cell 57%, 68%, 31%,P＜0. 05). ERβ was localized in both epithelial and stromal cell of PC. There were significant differences of the expression of ERβ in PC, peri-cancer tissue and BPH tissue (epithelial cell 39%, 64%, 29%, P＜0.01; stromal cell 50%, 75%, 79%, P＜0.05). There was a significant difference of the expression of ERβ in different Gleason scores of PC tissue. Conclusions ERα is localized in the stromal cell of PC tissue.ERβ is localized in both epithelial and stromal cell of PC tissue. The ERβ might be related to the tumor differentiation of PC.     

TRPC6在人良性与恶性前列腺组织中的表达

观察瞬时受体电位通道C6（TRPC6）在人良性与恶性前列腺组织及前列腺癌细胞系中的表达,进一步探讨TRPC6的表达与前列腺癌分期、分级及激素依赖性的关系。利用免疫组织化学技术,检测发现45．0％的前列腺增生和86．6％的前列腺癌病例表达TRPC6,两者比较有显著性差异沪〈0．01）。TRPC6的表达与前列腺癌分级和前列腺外转移有关（P〈0．01）。前列腺癌分期增高,TRPC6表达增多,但在T2、T3和DT4期肿瘤病例中,TRPC6表达无显著差异。此外TRPC6在激素依赖性前列腺癌与激素非依赖性前列腺癌中的表达也无显著差异。应用RT-PCR及Westernblot,检测到TRPC6在前列腺癌细胞系中的表达。本研究发现,TRPC6在良性与恶性前列腺组织及前列腺癌细胞系中表达。TRPC6的表达与前列腺癌的组织分级、Gleason评分及前列腺外转移有关。     

Expression of the VEGF-receptor Flt-1 in benign, premalignant and malignant prostate tissues

PURPOSE: Vascular endothelial growth factor (VEGF) is one of the most potent regulators of angiogenesis and has been shown to act upon two tyrosine kinase family receptors: c-fms-like tyrosine kinase (Flt-1) and fetal liver kinase. Preliminary reports have emphasized that expression of VEGF receptors is endothelial cell-specific. In this study we verified the localization and distribution of Flt-1 protein and mRNA expression in prostatic adenocarcinoma (CaP) as well as prostate intraepithelial neoplasia (PIN) and benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: 30 selected surgical specimens exhibiting areas with CaP, PIN and BPH histology were evaluated for Flt-1 protein expression by immunohistochemistry. Results were compared with tumor differentiation (Gleason-Score), serum-PSA and clinical followup. Flt-1 synthesis by prostatic carcinoma cell lines, freshly isolated BPH epithelial cells (BPH-EC) and stromal cells was investigated using RT-PCR and intron spanning primer. RESULTS: VEGF receptor Flt-1 specific anti-sera revealed significant staining of prostatic endothelial cells, but the reactivity was not restricted to endothelial cells. BPH-epithelial cells of all specimens reacted significantly with anti-Flt-1. In contrast, tumor cells failed to react with anti-Flt-1 in 56% of the specimens. BPH-EC revealed a uniform anti-Flt-1 reactivity, which was less pronounced and weaker in PIN. Loss of anti-Flt-1 reactivity of prostatic tumor cells did not correlate with preoperative PSA serum levels but increased with tumor dedifferentiation. Interestingly, tumor cells of all CaP specimens with a Gleason score of >8 exhibit no anti-Flt-1 immunoreactivity. Accordingly while PC3, DU145 and LNCaP cells were negative when tested using RT-PCR all BPH tissue derived BPH-EC revealed Flt-1 coding mRNA expression.CONCLUSIONS: Widespread distribution of VEGF receptor Flt-1 in BPH, PIN and prostate cancer specimens suggests that VEGF function in prostate is not restricted to endothelial cells and angiogenesis. However, since the receptor is lost in CaP cells and with tumor dedifferentiation, these yet unknown effects of VEGF on epithelial cells are obviously suppressed with malignant transformation.     

Alterations in beta-catenin expression and localization in prostate cancer

BACKGROUND: Wnt signaling is thought to be important in prostate cancer, in part because proteins such as beta-catenin can also affect androgen receptor signaling. beta-Catenin forms a cell adhesion complex with E-cadherin raising the possibility that loss of expression or a change in beta-catenin distribution in the cell could also alter downstream signaling, decreased inter-cellular adhesion and the promotion of metastasis. A number of studies have reported the altered expression and/or localization of beta-catenin as a biomarker in prostate cancer. METHODS: Tissue microarrays comprised of BPH and low, moderate and high-grade prostate cancer (n=77) were assessed for beta-catenin expression and distribution using immunohistochemistry. Staining was also performed on a tissue microarray containing tissue from patients before and after hormone manipulation. The effects of fixation and different antibodies was assessed on fixed LNCaP cell pellets and small prostate tissue microarrays. RESULTS: We have observed increased beta-catenin expression in only high Gleason score (>7) prostate cancer. A nuclear re-distribution of beta-catenin has previously been reported. We noted nuclear beta-catenin in benign prostatic hyperplasia and a gradual loss in nuclear distribution with increasing Gleason grade. We found no evidence for an alteration in beta-catenin expression or re-distribution with hormone ablation. Altered fixation, antibodies and antibody concentration did affect the intensity and specificity of staining. CONCLUSIONS: A loss of nuclear beta-catenin is the most consistent feature in prostate cancer rather than absolute levels of expression. We also suggest that variation in immunohistochemical protocols may explain variations in the reported literature.     

前列腺干细胞抗原在人前列腺癌组织中的表达及意义

目的　探讨前列腺干细胞抗原 (PSCA)在国人前列腺癌 (PCa)组织中表达的临床意义。　方法　采用免疫组织化学 (IHC)和核酸原位杂交 (ISH)方法检测 4 0例PCa、2 0例良性前列腺增生(BPH)和 2 0例前列腺上皮内瘤 (PIN)组织标本PSCA蛋白和mRNA表达 ,半定量法计算PSCA阳性表达细胞百分数和阳性表达强度 ,比较各组织间表达水平的差异及其与PCa分级、临床分期之间的关系。　结果　PCa、BPH、PIN组织PSCA中度阳性到强阳性表达分别为 85 % (34/ 4 0 )、2 0 % (4/ 2 0 )和35 % (7/ 2 0 ) ;PCa组织PSCA表达水平与BPH和PIN比较差异有统计学意义 (P <0 .0 5 ) ,BPH与PIN比较差异无统计学意义 (P >0 .0 5 ) ;PCa组织PSCA表达水平随Gleason评分及临床分期增加而升高。　结论　人PCa组织有PSCA蛋白质和mRNA的过表达 ,且与PCa病理分级、临床分期呈正相关 ,可能对PCa的诊断及判断预后有潜在价值。     

MOLECULAR GENETIC PROFILING OF GLEASON GRADE 4/5 PROSTATE CANCERS COMPARED TO BENIGN PROSTATIC HYPERPLASIA

PURPOSE: Because Gleason grade 4/5 cancer is the primary cause of failure to cure prostate cancer, we examined the molecular profiles of this high grade cancer in search of potentially new therapeutic interventions as well as better serum markers than prostate specific antigen. MATERIALS AND METHODS: We compared the gene expressions in fresh frozen tissues from 9 men with Gleason grade 4/5 cancer to 8 men with benign prostatic hyperplasia (BPH) treated with radical retropubic prostatectomy. Labeled complementary RNA from each of the 17 tissues was applied to HuGeneFL probe arrays representing approximately 6,800 genes (Affymetrix, Inc., Santa Clara, California). After removing all genes undetectable in BPH and grade 4/5 cancers, and transforming the data into a parametric distribution, we chose only those up and down-regulated genes with a p difference in fluorescence between grade 4/5 cancer and BPH of p <0.0005. This value reduced the data set to 40 up-regulated and 111 down-regulated genes. We then eliminated all genes that were not expressed in all 8 BPH and 9 grade 4/5 tissues, which produced a final set of 86 genes, of which 22 were up-regulated and 64 were down-regulated. RESULTS: Cluster analysis cleanly separated men with grade 4/5 cancers from those with BPH. Only 17 of the 86 candidate genes (20%) were known to be prostate cancer related and 42 (49%) were related to other cancers. The most up-regulated gene is Hepsin, a trypsin-like serine protease with its enzyme catalytic domain oriented extracellularly. Prostate specific membrane antigen is the second most up-regulated gene (all other reports on prostate specific membrane antigen have been at the protein level). The genes for prostate specific antigen (hK3) and human glandular kallikrein2 (hK2) showed equivalent expression levels 10 times the average of other genes. Complete lists of all 22 up-regulated genes and 64 down-regulated genes, together with their locus on the chromosome, are presented in rank order. CONCLUSIONS: We characterize for the first time 64 down-regulated and 22 up-regulated genes in Gleason grade 4/5 cancer, using the gene profile from BPH as control tissue. A number of interesting new genes, previously undescribed in prostate cancer, are presented as possibilities for further study.     

Differential up-regulation of erythropoietin and its receptor in benign and malignant prostatic tissue

PurposeTo investigate differential up-regulation of erythropoietin and its receptor in benign and malignant prostatic tissue.Materials and methodsAn immunohistochemical analysis of EPO and EPOR expression was performed on 30 cases of prostate carcinoma (PCa) with 16 high-grade prostate intraepithelial neoplasia (PIN), 50 cases of benign prostatic hyperplasia (BPH) lesions, and 30 normal prostatic tissue samples as control.ResultsOver-expression of EPOR was only shown in PCa and high-grade PIN tissue but over-expression of EPO was also shown in BPH tissue. There was significant relationship between EPO and EPOR score in BPH, high-grade PIN, and PCa but no association between EPOR or EPO score and Gleason score in PCa.ConclusionsUp-regulation of EPOR has a more important role in comparison with EPO in prostate carcinogenesis. Differential over-expression of EPOR and EPO in benign and malignant prostatic tissue is ascribed to different mechanisms involved in up-regulation between EPO and EPOR.     

Expression of serotonin receptors 2B and 4 in human prostate cancer tissue and effects of their antagonists on prostate cancer cell lines

OBJECTIVES: Overexpression of receptors to neuroendocrine (NE) cell products has been suggested to contribute to development of hormone-refractory prostate cancer (HRPC). In this study, we evaluated the expression of 5-HTR2B and 5-HTR4 in HRPC, and the effects of their antagonist on PC cell line growth. METHODS: Proteins and mRNA expression was determined by immunohistochemistry, western blot and RT-PCR. Growth inhibition of PC cell lines was determined in vitro using ELISA-BrdU proliferation assay and cell cycle was evaluated by flow cytometry. RESULTS: Immunostaining of 5-HTR2B was observed in low-grade and high-grade tumours, PIN and BPH cells, and in vascular endothelial cells, whereas 5-HTR4 was found predominantly in high-grade tumours. This result was confirmed by western blot analysis. At the mRNA level, 5-HTR4 mRNA was expressed in DU145 and LNCaP cells. Antagonists to both receptor subtypes inhibited proliferation of PC cells in a dose-dependent manner. CONCLUSIONS: The present result indicate that 5-HTRs are present at various tumour stages and that antagonists to these receptors can inhibit the proliferative activity of androgen-independent PC cell lines.     

Loss of BMP2, Smad8, and Smad4 expression in prostate cancer progression

BACKGROUND: The role of the bone morphogenetic protein (BMP) pathway in prostate cancer (PC) is unclear. This study aimed to characterize aspects of the BMP pathway in PC by assessing BMP2, Smad8, and Smad4 expression in normal, hyperplastic, and malignant prostate tissue, and to correlate findings with progression to PC. METHODS: Radical prostatectomy (RP) specimens from 74 patients with clinically localized PC (median follow-up 51 months, range 15-152), 44 benign prostatic hypertrophy (BPH) lesions, and 4 normal prostates (NPs) were assessed for BMP2, Smad8, and Smad4 expression using immunohistochemistry. RESULTS: Both BMP2 (P < 0.001) and nuclear Smad4 (P < 0.0001) expression were significantly decreased in PC compared to benign prostate tissue. Nuclear Smad8 was present in normal/benign prostate tissue but absent in PC and adjacent hyperplasia. Furthermore, loss of BMP2 (P < 0.001) and decreased nuclear Smad4 (P = 0.05) expression correlated with increasing Gleason score. CONCLUSIONS: These data suggest that decreased BMP2, nuclear smad8 and nuclear Smad4 expression are associated with the progression to PC, and in particular loss of BMP2 and Smad4 are related to progression to a more aggressive phenotype.     

Aberrant expression of E-cadherin and beta-catenin in human prostate cancer

Cadherin-catenin complexes play a key role in embryonic development, and are associated with carcinogenesis and metastasis. We studied the expression of the major members of the family, including E-cadherin and β-catenin in prostate cancer (PC), and correlated with Gleason grade and pathologic stage. Immunohistochemistry was performed on serial sections of paraffinized radical prostatectomy specimens to evaluate E-cadherin (n = 16) and β-catenin (n = 17) expression using heat induced epitope retrieval. Benign appearing prostate epithelium was used as an internal control in each specimen. Two pathologists independently reviewed and scored the intensity and extent of immunostaining using a semiquantitative scale. The Mantel-Haenszel method, stratified by reviewer, was used to test for an association among Gleason score, pathologic stage, and the expression of E-cadherin or β-catenin in PC. Gleason grade ≥7 cancers showed significantly lower expression of E-cadherin and β-catenin compared to Gleason grade <7 PC, P = 0.015 and 0.025, respectively. In addition, β-catenin was down regulated in 4 of 5 (80%) specimens with identifiable high-grade prostatic intraepithelial neoplasia and had demonstrable nuclear staining in higher grade PC (P = 0.0001). However, E-cadherin and β-catenin membranous or nuclear expressions were not significantly associated with final pathologic stage of the specimens (P values >0.05). Overall, the expression of E-cadherin and β-catenin is significantly down regulated in PC compared to surrounding benign appearing prostate, which correlates with increasing Gleason grade. Furthermore, nuclear localization of β-catenin in high grade PC may be a useful biomarker for aggressive PC.