聚集素在前列腺癌细胞不同周期时相的表达

目的探讨凋亡相关基因聚集素（clusterin）在前列腺癌不同周期时相的差异表达及意义。方法应用改良的胸腺嘧啶核苷（TdR）和高压笑气双阻断法将前列腺癌细胞系PC-3同步在不同的周期时相，应用流式细胞术检测同步化的效率。应用RT-PCR及Western blotting方法检测不同周期时相聚集素在mRNA和蛋白水平的表达。结果前列腺癌细胞系PC-3的M、G1、S和G2期细胞同步化效率分别为92．1％、87．0％、80．2％和75，9％；聚集素在不同周期时相均有表达且存在差异，G1和S期表达水平较低，M期和G2期表达水平较高，RNA和蛋白表达具有一致性。结论细胞周期对聚集素的表达有较大的影响，对于采用聚集素途径治疗前列腺癌具有指导意义。     

存活素基因表达与前列腺癌激素依赖性的实验研究

目的探讨存活素(survivin)基因表达与前列腺癌激素依赖性间的关系。方法应用雄激素依赖性前列腺癌细胞系LNCaP和非依赖性细胞系PC3构建2种。BALB／C鼠肿瘤模型,每组16只。采用逆转录-聚合酶链反应(RT-PCR)和Western blot方法检测动物去势术前后2种癌结节中存活素基因和蛋白的水平。结果2种癌结节中均检测到存活素mRNA,而在非癌组织均未检测到。LNCaP组去势手术前、后存活素mRNA表达值分别为0．95±0．12和0．80±0．10;PC3组分别为0．93±0．11和0．85±0．10,2组间及组内比较差异均无统计学意义(P>0．05)。LNCaP组术前蛋白含量相对值(1．25±0．15)与PC3组(1．15±0．10)比较差异无统计学意义(P=0．220)。去势术后LNCaP组蛋白水平(0．48±0．08)显著下降(P=0．001),而PC3组(0．90±0．10)与术前比较差异无统计学意义(P>0．05)。结论存活素基因转录后水平的调控差异可能是前列腺癌对激素依赖性差异的机理之一。     

转化生长因子调控表皮生长因子受体在雄激素非依赖型前列腺癌细胞中表达的意义

目的 :探讨转化生长因子 (TGF)α对前列腺癌雄激素非依赖型细胞系中表皮生长因子受体 (EGFR)表达的调控。　方法 :采用逆转录 多聚酶链式反应和Western印迹法对TGFα刺激前列腺癌雄激素非依赖型细胞系PC3、ARCaP后EGFRmRNA表达及其蛋白水平进行定量分析。　结果 :TGFα引起PC3、ARCaP的EGFRmRNA表达升高 ,分别为 5 .0 1± 0 .4 5和 9.0 5± 0 .6 3,明显高于对照组 (P <0 .0 5 )。PC3细胞系TGFα治疗后EGFR蛋白水平为 2 .2 8±0 .5 3,明显高于对照组 (P <0 .0 5 ) ;而ARCaP细胞系TGFα治疗后EGFR仅为 1 .2 4± 0 .2 2 ,和对照组比较无差别 (P >0 .0 5 )。　结论 :TGFα可以明显提高前列腺癌细胞的EGFR表达量 ;TGFα EGFR自分泌环参与雄激素非依赖型前列腺癌的形成     

聚集素抗LNCaP细胞凋亡作用的研究

目的研究聚集素抗LNCaP细胞凋亡的作用及聚集素反义寡核苷酸(AS-ODN)对肿瘤坏死因子-α(TNF-α)细胞毒性作用的影响。方法培养转染全长聚集素序列的LNCaP细胞(A)为实验组,野生型LNCaP细胞(L)及转染PIRES2-EGFP空载体的LNCaP细胞(M)为对照组,以20 ng/ml TNF-α进行诱导,MTT及ELISA法检测3组细胞增殖活性与凋亡程度；转染聚集素AS-ODN后A细胞分4组,①对照组：常规培养；②AS-ODN组：转染AS-ODN,培养液不含TNF-α；③TNF-α组：未转染AS-ODN,培养液含20ng/ml TNF-α；④TNF-α+AS-ODN组：转染AS-ODN,培养液含20ng/ml TNF-α,观察4组细胞增殖活性与凋亡程度的变化。结果L、M、A3组细胞增殖活性分别为0.84±0.03、0.85±0.04、0.95±0.03,L与M间差异无统计学意义(P＞0.05),L、M与A相比增殖活性显著降低(P值均＜0.01)。3组细胞ELISA吸光度值分别为0.59±0.04、0.62±0.03、0.33±0.04,L与M间差异无统计学意义(P＞0.05),但L、M与A相比凋亡程度显著增高(P值均＜0.01)。A细胞①～④组细胞增殖活性吸光度值分别为1.30±0.03,1.25±0.03,0.99±0.03,0.80±0.03,两两比较组间差异均有统计学意义(P值均＜0.05)；4组细胞凋亡程度吸光度值分别为0.02±0.00,0.21±0.02,0.63±0.07,1.16±0.04,两两比较组间差异均有统计学意义(P值均＜0.01)。结论转染并永久表达全长序列聚集素后,TNF-α对LNCaP细胞的细胞毒性作用显著降低,转染聚集素AS-ODN显著增强TNF-α的细胞毒性作用,聚集素具有抗LNCaP细胞凋亡的作用。     

聚集素在前列腺癌中的表达及意义

目的　探讨抗细胞凋亡因子聚集素 (clusterin)在前列腺癌中的表达及意义。　方法　RT PCR方法检测聚集素在前列腺癌组织 (3例 )、癌细胞系 (1株 )及正常前列腺组织 (3例 )中的表达水平。　结果　 3例前列腺癌组织及 1例前列腺癌细胞株中聚集素与内参基因 β actin相比较的相对表达量明显高于 3例正常前列腺组织。　结论　聚集素在前列腺癌中高表达 ,提示聚集素可能通过抗凋亡机制在前列腺癌的生物特性中发挥作用。     

前列腺癌组织中聚集素的表达及临床意义

目的 探讨聚集素(Clusterin)在前列腺癌组织中的表达及其临床意义.方法 应用免疫组织化学方法检测Clusterin在45例前列腺增生组织、40例前列腺癌组织标本中的表达,结合临床病理学资料,分析它们之间的相关性.结果 Clusterin在前列腺增生及前列腺癌组织中的阳性表达率分别为15.7％和87.5％,前列腺癌组织中Clusterin表达水平明显高于前列腺增生组织.Clusterin阳性表达与前列腺癌临床分期、Gleason评分均呈正相关.结论 前列腺癌组织中Clusterin 蛋白过度表达可能与其抗凋亡作用有关,与前列腺癌的恶性程度相关.     

雄激素受体反义寡核苷酸对前列腺癌细胞生长的抑制作用

目的　探讨雄激素受体 (AR)反义寡核苷酸 (aODN)对前列腺癌细胞AR表达和生长的抑制作用。　方法　合成 1对AR正、反义寡核苷酸 ,与LNCaP细胞共培养 ,观察LNCaP细胞的增殖情况 ,RT PCR和Westernblot方法检测ARmRNA水平和AR蛋白表达水平。　结果　含ARaODN的培养基培养处于静止期和对数生长期的LNCaP细胞增殖较对照组均明显减慢。RT PCR证实aODN组吸光度A值 (0 .5 3± 0 .18)与ODN组 (1.14± 0 .2 1)差异有显著性意义 (P <0 .0 5 ) ,提示ARaODN可导致LNCaP细胞ARmRNA显著下调。Westernblot分析显示aODN组条带的吸光度A值 (2 6 .35± 1.33)与ODN组 (33.5 1± 1.4 8)之间差异有显著性意义 (P <0 .0 5 ) ,提示ARaODN可下调LNCaP细胞AR蛋白含量。　结论　ARaODN可抑制前列腺癌细胞AR表达并抑制前列腺癌细胞增殖。     

膀胱移行细胞癌组织中聚集素、Ki-67蛋白表达和细胞凋亡的测定

目的 探讨聚集素在膀胱移行细胞癌组织中的表达及其与细胞增殖和凋亡的关系。方法制作87例膀胱移行细胞癌组织的组织芯片,分别应用免疫组织化学和末端脱氧核苷酸转移酶介导缺口末端标记方法,检测膀胱移行细胞癌组织中聚集素和Ki-67蛋白表达及细胞凋亡情况,分析聚集素蛋白表达与肿瘤分化、临床分期等病理特征及肿瘤细胞凋亡、增殖及Ki-67蛋白表达的关系。结果43％（37／87）患者为聚集素蛋白过度表达,且聚集素蛋白表达与肿瘤细胞的分化程度、肿瘤的浸润深度均有显著的相关性（r分别为14．1,10．2,P均〈0．01）;71％（20／28）低分化（G3）和62％（23／37）浸润型（T2-4期）患者的肿瘤组织聚集素蛋白过度表达,过度表达率明显高于分化较好（G1-2,29％,17／59）和浅表型（Ta-1期,28％,14／50）者。聚集素蛋白表达与肿瘤的凋亡指数（AI）呈负相关（r=7．31,P〈0．01）,但与Ki-67的表达水平无关;聚集素过度表达的肿瘤,57％（21／37）表现为低AI值（≤1．2％）,而聚集素正常表达的肿瘤,则72％（36／50）为高AI值。结论膀胱移行细胞癌组织中聚集素蛋白过度表达与肿瘤的分化程度和浸润深度呈正相关,与肿瘤细胞的AI呈负相关。     

D2期前列腺癌中雄激素受体的表达及意义

应用免疫组化SABC法，检测29例D_2期前列腺癌组织中雄激素受体的含量，并观察患者治疗前生活状态、骨转移程度、血浆前列腺特异性抗原、血浆睾酮和血红蛋白浓度等参数与患者预后之间的关系。结果发现：11例雄激素依赖性前列腺癌组中雄激素受体含量、血红蛋白、睾酮浓度分别为（51．0±14．8）％，（119．0±19．0）g/l，（9．8±7．9）ng／ml。而在18例雄激素非依赖性前列腺癌组中则分别为（32．2±118）％，（97．9±18．2）g/l，（4．0±6．4）ng／ml。雄激素受体含量、血红蛋白、睾酮浓度两组相比较，有显著性差异。（2）前列腺特异性抗原、生活状态、骨转移程度在雄激素依赖性前列腺癌组中分别为（122．8±70．5）ng／ml，1．5±0．7，1．4±0．5，在雄激素非依赖性前列腺癌组中则分别为（123．3±52．9）ng／ml，1．8±0.6，1．88±0.7，统计学分析两组没有差异（P＞0．05）。以上结果提示：D_2期前列腺癌组织中雄激素受体含量越高，治疗效果越好。雄激素受体含量的高低是预测晚期前列腺癌患者雄激素阻断治疗效果的良好指标。     

热休克蛋白70在人前列腺癌细胞株PC-3m和LNCaP中的表达及其意义

目的　探讨前列腺癌雄激素不敏感性的发生。方法　用细胞免疫化学方法和流式细胞术定位、定量分析体外培养的人前列腺癌雄激素不敏感细胞株PC-3m和雄激素敏感细胞株LNCaP中主要热休克蛋白70(HSP70)的表达。结果　2种不同生物学特性的细胞株表面及细胞内均有HSP70表达,但PC-3m细胞膜及细胞内的阳性染色程度高于LNCaP;流式细胞术测定的PC-3m细胞膜及细胞内的表达量（17.61±4.20,69.54±10.50）分别高于LNCaP（7.42±1.70,21.83±6.30）,两者比较差异均有显著性(P＜0.05)。结论　正常状态下雄激素不敏感前列腺癌细胞株过表达HSP70,可能与雄激素不敏感性的发生、发展有关。     

Clusterin expression is significantly enhanced in prostate cancer cells following androgen withdrawal therapy

INTRODUCTION AND OBJECTIVES: Progression of prostate cancer to androgen independence (AI) results in part from the upregulation of anti-apoptotic genes following androgen withdrawal, and androgen-independent disease remains the primary obstacle to improved survival. Testosterone-repressed prostate message-2 (TRPM-2) encodes the anti-apoptotic protein clusterin, which is upregulated in response to cellular compromise as observed in normal and malignant tissues undergoing apoptosis. Systemic administration of antisense clusterin oligonucleotides in prostate cancer xenograft models delays progression to AI and enhances chemosensitivity. The objective of this study was to define changes in clusterin expression following neoadjuvant hormone therapy (NHT) in prostate cancer patients. MATERIALS AND METHODS: Archival radical prostatectomy (RP) specimens were obtained for 128 patients who received either no NHT or treatment for 2-8 weeks, 3 months, or 8 months. Paired needle biopsy specimens were acquired for 30 patients and all tissues were subjected to clusterin immunohistochemistry. Western blot analysis was performed on frozen tissue from 5 untreated and 5 treated patients. RESULTS: Clusterin expression in malignant prostatic tissue was significantly greater in patients who underwent preoperative NHT (P < 0.001). Needle biopsies obtained prior to NHT consistently demonstrated lower staining intensity than corresponding RP specimens (P < 0.001). Western blot analysis confirmed clusterin levels increased 17-fold beginning within 4 weeks after androgen withdrawal. CONCLUSIONS: Upregulation of clusterin levels following androgen ablation therapy may represent an adaptive cell survival response following apoptotic signals like androgen withdrawal. These findings support clusterin as a valid therapeutic target in strategies employing novel multimodality therapy for advanced prostate cancer.     

Persistent expression of Aurora-A after neoadjuvant hormonal therapy as a predictor of a poor clinical outcome in patients undergoing radical prostatectomy for prostate cancer

OBJECTIVES: To characterize the changes in the expression of Aurora-A protein in prostate cancer before and after androgen-withdrawal therapy, and to assess the prognostic significance of the Aurora-A expression in patients undergoing radical prostatectomy (RP) after neoadjuvant hormonal therapy (NHT). PATIENTS AND METHODS: The study included 97 patients with clinically localized prostate cancer who received NHT followed by RP. Paired needle biopsy and corresponding RP specimens obtained from these patients were analysed for the expression of Aurora-A protein by immunohistochemical staining. These findings were then evaluated in relation to several clinicopathological factors. RESULTS: There were various levels of Aurora-A protein expression in most prostate cancer tissues before NHT; however, the Aurora-A expression in RP specimens after NHT was significantly down-regulated compared with that in corresponding needle-biopsy specimens. The expression level of Aurora-A in biopsy specimens was significantly associated with the biopsy Gleason score, but not with other factors available before RP. The Aurora-A expression in the RP specimens correlated significantly with the preoperative value of the serum prostate specific antigen and pathological stage, but not with any other clinicopathological factors examined. Furthermore, cell proliferative activity in the RP specimens, measured by Ki-67 immunostaining, was proportional to the expression of Aurora-A. The biochemical recurrence-free survival in patients with a persistent Aurora-A expression in RP specimens was significantly lower than that in those with a weak Aurora-A expression, but the expression level of Aurora-A was not an independent predictor of biochemical recurrence. CONCLUSIONS: Despite the lack of any independent significance, the expression level of Aurora-A in prostate cancer tissue after NHT, which might inversely reflect the therapeutic effect of NHT, could therefore be a useful variable for predicting biochemical recurrence in patients undergoing RP.     

Immunohistochemical Analysis of Radical Prostatectomy Specimens After 8 Months of Neoadjuvant Hormonal Therapy

Neoadjuvant hormone therapy (NHT) prior to radical prostatectomy (RP) results in residual foci of atrophic glands, which can be difficult to identify with hematoxylin-eosin staining, raising the possibility that the low positive-margin rates are an artifact of pathologic understaging. The purpose of this study was to evaluate changes in prostate specific antigen (PSA) and prostatic acid phosphatase (PAP), as well as proliferation marker Ki-67 and Bcl-2 oncoprotein, by immunostaining after 8 months of NHT. Twenty-nine men with clinically confined prostate cancer who received 8 months of NHT and had both pretreatment biopsy and RP specimens obtained at Vancouver Hospital constituted the treatment group. The control group consisted of 23 RP specimens from patients not receiving NHT. Sections were stained with antibodies against PSA, PAP, proliferation marker Ki-67, and the antiapoptosis protein Bcl-2. The PSA and PAP immunostaining were graded for percentage of positive tumor cells and intensity of staining, while Ki-67 and Bcl-2 staining was graded according to the percentage of positive tumor cells. Absent or low percentage-positive PSA and PAP staining was observed in 40% to 50% of the NHT-treated RP specimens but none of the needle biopsy or untreated control RP specimens. Low-intensity PSA and PAP staining was detected only in RP specimens after NHT treatment, and then in only 20% of cases. Low or absent Ki-67 staining was noted in 78% of the NHT- treated RP specimens, compared with only 13% of the matched pre-NHT needle biopsies and 26% of untreated RP specimens. The percentage of specimens with high (>5%) Ki-67 staining decreased from 37% in the pre-NHT needle biopsies to 8% in the NHT-treated RP specimens. Bcl-2 staining increased after treatment with NHT, with 20% of the needle biopsies having high (>5%) Bcl-2 staining compared with 53% of the NHT-treated RP specimens. The frequency of low Bcl-2 staining (<1%) decreased from 53% in the pre-NHT needle biopsies to 27% in the NHT-treated RP specimens. Although PAP and PSA staining decreased after NHT, both markers remain sufficiently positive to be used as epithelial markers to help detect residual foci of prostate cancer that are difficult to identify on H&E-stained slides after NHT. Increased Bcl-2 after NHT, even in early-stage disease, is consistent with its role in the prevention of apoptosis and progression to androgen independence. Low levels of Ki-67 staining indicates a low probability of proliferation and outgrowth of androgen-independent clones after 8 months of NHT.     

Antisense oligodeoxynucleotide therapy targeting clusterin gene for prostate cancer: Vancouver experience from discovery to clinic

BACKGROUND: The objective of this study was to review our experience in the development of antisense (AS) oligodeoxynucleotide (ODN) therapy for prostate cancer targeting antiapoptotic gene, clusterin. METHODS: We initially summarized our data demonstrating that clusterin could be an optimal therapeutic target for prostate cancer, then presented the process of developing AS ODN therapy using several preclinical animal models. Finally, the preliminary data of the recently completed phase I clinical trial using AS clusterin ODN as well as the future prospects of this therapy are discussed. RESULTS: Expression of clusterin was highly up-regulated after androgen withdrawal and during progression to androgen-independence, but low or absent in untreated tissues in both prostate cancer animal model systems and human clinical specimens. Introduction of the clusterin gene into human prostate cancer cells confers resistance to several therapeutic stimuli, including androgen ablation, chemotherapy and radiation. AS ODN targeting the translation initiation site of the clusterin gene markedly inhibited clusterin expression in prostate cancer cells in a dose-dependent and sequence-specific manner. Systemic treatment with AS clusterin ODN enhanced the effects of several conventional therapies through the effective induction of apoptosis in prostate cancer xenograft models. Based on these findings, a phase I clinical trial was completed using AS clusterin ODN incorporating 2'-O-(2-methoxy)ethyl-gapmer backbone (OGX-011), showing up to 90% suppression of clusterin in prostate cancer. CONCLUSIONS: The data described above identified clusterin as an antiapoptotic gene up-regulated in an adaptive cell survival manner following various cell death triggers that helps confer a phenotype resistant to therapeutic stimuli. Inhibition of clusterin expression using AS ODN technology enhances apoptosis induced by several conventional treatments, resulting in the delay of AI progression and improved survival. Clinical trials using AS ODN confirm potent suppression of clusterin expression and phase II studies will begin in early 2005.     

Difficulties in interpreting specimens after neoadjuvant hormonal therapy and radiation with illustration of neuroendocrine differentiation

Pattern and cellular changes attributable to neoadjuvant hormonal therapy (NHT) might cause the unwary pathologist to overgrade or fail to recognize a treated prostatic cancer. Overdiagnosis and overgrading of surgical resections and biopsies can be avoided if an appropriate history of therapy is conveyed with the surgical specimen and if the pathologist is aware of the altered morphology of prostatic cancer treated by NHT alone or NHT plus radiation. Study of three prostatectomy specimens with post-NHT predominance of neuroendocrine cells showed positive staining for prostate specific antigen (PSA) and prostatic acid phosphatase (PAP), as well as staining for chromogranin and synaptophysin in Paneth-like and small neuroendocrine cells. Difficult-to-interpret needle biopsies and transurethral resection (TUR) biopsies of prostate, where the urologic pathologist's suspicion of a radiation effect was confirmed by additional history, showed absence of the basal cell layer with 34 beta E12 keratin immunostaining in prostatic cancer glands, while basal cells were present in the nonneoplastic glands with radiation-induced atypia. Postradiation salvage prostatectomy specimens showed greater apoptosis after combined NHT and radiation than after radiation without NHT. Changes attributable to radiation and radiation plus NHT are illustrated.     

Neuroendocrine differentiation in hormone refractory prostate cancer following androgen deprivation therapy

OBJECTIVE: To evaluate the relationship between neuroendocrine differentiation (NED) status and hormone refractory prostate cancer (HRPC) following hormone therapy based on immunohistochemical study. METHODS: Seventy-two prostate cancer specimens obtained at radical prostatectomy and 21 prostate cancer autopsy specimens from patients who died from HRPC after androgen deprivation therapy were examined for NED status using an antibody against chromogranin A. These specimens were classified into 3 arms: 38 radical prostatectomy specimens from patients with no neoadjuvant hormone therapy (Group 1); 34 from patients with neoadjuvant hormone therapy for 3 to 6 months (Group 2); and 21 autopsy specimens from patients with HRPC following androgen deprivation therapy for more than 1 year (Group 3). Staining of prostatic carcinoma was scored as: 0 = no staining; 1 = staining cells <10%; 2 = staining cells 10-20%; and 3 = staining cells >20%. Differences in scores among the groups were compared using the Kruskal-Wallis rank test. Multivariate analysis using a logistic regression model was performed to examine whether NED status was associated with pathological stage (pT), grade and group. RESULTS: Forty-nine (53%) tumors had CgA stained cells. NED status increased with longer duration of hormone therapy (p<0.0001). The mean staining score (and standard deviation) was 0.4+/-0.7 in Group 1, 0.7+/-0.7 in Group 2, and 1.4+/-1.1 in Group 3, respectively. By multivariate analysis Group 3 had a relative risk of 5.46 (95%CI 1.28-23.29) for NED compared to the other groups. But other variables were not related to NED. HRPC following Long-term hormonal therapy was the only independent predictor of NED. CONCLUSIONS: The results of this study demonstrated that NED status was significantly increased in patients with HRPC following long-term androgen deprivation therapy, but it could not be discriminate whether the increase of NED is attributable to condition of hormone refractoriness or long-term hormonal therapy.     

Pathologic effects of neoadjuvant cyproterone acetate on nonneoplastic prostate,prostatic intraepithelial neoplasia,and adenocarcinoma: a detailed analysis of radical prostatectomy specimens from a randomized trial

Neoadjuvant hormonal therapy (NHT; androgen ablation) is used prior to radical prostatectomy (RP) in an attempt to pathologically "downstage" prostatic adenocarcinoma and ultimately to improve disease-free survival. This study describes the pathologic effects of NHT with the antiandrogen cyproterone acetate, 300 mg/day for 12 weeks, on the RP specimens from men with clinically localized (stage T1 or T2) prostatic adenocarcinoma. There were 101 men in the pretreatment group (CPA) and 91 men in a control group who were treated with surgery alone. The prevalence and extent of morphologic effects were recorded for the nonneoplastic prostate, high-grade prostatic intraepithelial neoplasia, and invasive adenocarcinoma. The commonest effects on the nonneoplastic prostate were atrophy and basal cell hyperplasia and prominence. High-grade prostatic intraepithelial neoplasia was more commonly identified in the surgery alone group than the CPA group (p <0.01). In the CPA group, flat and low tufted patterns of high-grade prostatic intraepithelial neoplasia predominated. Following NHT, the adenocarcinoma showed characteristic morphologic alterations, including reduction in cytoplasmic quantity, cytoplasmic vacuolation, nuclear pyknosis, reduced gland diameter, and mucinous breakdown. In many cases there was prominence of collagenous stroma, obscuring malignant glands. Compared with the surgery alone group, the CPA group RP specimens had a significantly lower mean specimen weight (40.3 g vs 46.5 g, p = 0.025) and less tumor extent by several measures. Organ-confined tumor (stage pT2, margin negative) was found in 41.6% of the CPA group compared with 19.8% of the surgery alone group (p = 0.0017). The overall rate of margin positivity was lower in the CPA group (27.7% vs 64.8%, p = 0.001). We consider that the difference in margin positivity is the result of tumor shrinkage with a decreased likelihood of sampling in routine sections. There was no significant difference in the rate of extraprostatic extension between the two groups. There was elevation of the Gleason score in the RP specimens versus baseline biopsy in 60% of the CPA group compared with 33% of the surgery alone group (p = 0.02). The higher rate of elevation in the CPA group largely resulted from an increase in primary or secondary Gleason score 5 tumor, a morphologic artifact introduced by NHT. Because of this, we recommend not giving a Gleason grade to RP specimens following NHT. Monotherapy with CPA has similar pathologic effects on benign and malignant prostate tissue as does dual agent androgen blockade. Prolonged follow-up of these patients is required to determine if NHT with CPA leads to improved disease-free survival.     

Clusterin is not essential for androgen-regulated involution and regeneration of the normal mouse prostate

BACKGROUND: Inhibition of clusterin expression has been shown to enhance the sensitivity of prostate cancer cells to chemo and hormone therapy. Clusterin antisense oligonucleotides (ASOs) are currently in phase II human clinical trials for treatment of hormone refractory prostate cancer. However, the role of clusterin in androgen-regulated involution and regeneration of the normal prostate gland has not been established. METHODS: Prostate involution and regeneration was examined in clusterin-deficient mice undergoing up to three cycles of androgen withdrawal and restoration. RESULTS: Surprisingly, clusterin deficiency did not affect the apoptotic index, and the temporal biochemical and morphological changes associated with involution and regeneration of the normal adult prostate following multiple rounds of androgen withdrawal and replacement. CONCLUSION: Clusterin is not critical for normal prostate development or androgen-regulated involution and regrowth of the mouse prostate gland, suggesting that clusterin may have distinct functions in malignant versus normal prostatic epithelial cells.     

Use of antisense oligonucleotides targeting the cytoprotective gene, clusterin, to enhance androgen- and chemo-sensitivity in prostate cancer

The discovery and targeting of genes mediating androgen-independence may lead to the development of novel therapies that delay progression of hormone refractory prostate cancer (HRPC). Clusterin is a stress-associated cell survival gene that increases after androgen ablation. Here, we review clusterins functional role in apoptosis and the use of antisense oligonucleotides (ASOs) against clusterin to enhance apoptosis in prostate cancer models. Immunostaining of tissue microarrays constructed from untreated and post-hormone treated radical prostatectomy specimens confirm that clusterin is highly expressed in virtually all HRPC cells, 80% of prostate cancer cells after neoadjuvant hormone therapy, but is low or absent (<20%) in untreated specimens. Overexpression of clusterin in LNCaP cells confers resistance to both androgen ablation and chemotherapy. Clusterin ASOs reduced clusterin levels in a dose-dependent and sequence-specific manner. Adjuvant treatment with murine clusterin ASOs after castration of mice bearing Shionogi tumors decreased clusterin levels, accelerated apoptotic tumor regression, and significantly delayed the recurrence of androgen-independent tumors. A human clusterin ASO targeting the translation initiation site and incorporating MOE-gapmer backbone (OGX-011) synergistically enhanced the cytotoxic effects of paclitaxel in human xenografts of prostate, renal cell, bladder, and lung cancer. Clusterin, is an anti-apoptosis protein upregulated in an adaptive cell survival manner by androgen ablation and chemotherapy that confers resistance to various cell death triggers. Suppression of clusterin levels using ASOs enhances cell death following treatment with androgen ablation, radiation, and chemotherapy.