米非司酮对前列腺癌PC-3细胞周期及其蛋白的影响

目的 探讨米非司酮（MIF）对前列腺癌PC-3细胞周期及其调控蛋白的影响及其作用机制。方法 MTT法检测1、10、50、100μmol／LMIF作用于PC-3细胞24～120h的吸光度（A）值，流式细胞仪检测10、50μmol／LMIF作用PC-3细胞48h后细胞周期的变化，免疫组化法和Western blot法检测10、50μmol／LMIF处理48h后PC-3细胞cyclinD1、bax、bcl-2蛋白表达的变化情况。结果 1μmol／LMIF作用24～120h的A值与对照组相比差异无统计学意义（P〉0．05）；10、50、100μmol／L组A值与对照组比较差异有统计学意义（P〈0．01）；MIF对PC-3细胞的抑制作用呈时间-剂量依赖性。MIF作用48h后使PC-3细胞停滞于G1／G0期，并使此期细胞比例从对照组的27．4％增加到10μmol／L组的50．4％和50μmol／L组的59．2％，差异有统计学意义（P〈0．05）。处理后PC-3细胞中bcl-2蛋白和cyclinD1蛋白表达量，与对照组比较差异有统计学意义（P〈0．05）；而bax表达量显著增加。结论 MIF以时间．剂量依赖性方式抑制前列腺癌PC-3细胞的增殖，可能通过下调cyclinD1蛋白表达，阻止PC-3细胞G1期向S期的转换，使其停留于G1／G0期；同时降低bcl-2蛋白的表达及激活bax蛋白的表达等抑制前列腺癌PC-3细胞增殖。     

三氧化二砷对激素非依赖性前列腺癌PC-3细胞株Bc1-2、Bax表达的影响

目的了解三氧化二砷对激素非依赖性前列腺癌PC-3细胞株细胞增殖、细胞凋亡及bcl-2、bax基因表达的影响。方法分别以1、2、3、6、10μmol／L的三氧化二砷作用于PC-3细胞，48h后对细胞增殖活性、细胞凋亡及细胞bcl-2、bax基因表达的变化进行检测。结果各浓度的三氧化二砷均可抑制PC-3细胞增殖，并具有剂量依赖性。3、6、10μmol／L的三氧化二砷还可诱导PC-3细胞凋亡，计算细胞凋亡率分别为11．8％、12．7％、29．6％。逆转录聚合酶链反应（RT-PCR）检测PC-3细胞中bcl-2、bax表达的相对强度，发现bcl-2的表达强度随三氧化二砷浓度的升高而逐渐降低（P〈0．01），而bax表达强度变化不明显（P〉0．05）。结论三氧化二砷可有效抑制PC-3细胞增殖，诱导PC-3细胞凋亡，这一过程与三氧化二砷抑制PC-3细胞中bcl-2的表达有关。     

三氧化二砷对激素非依赖性前列腺癌PC-3细胞株Bcl-2、Bax表达的影响

目的了解三氧化二砷对激素非依赖性前列腺癌PC-3细胞株细胞增殖、细胞凋亡及bcl-2、bax基因表达的影响。方法分别以1、2、3、6、10μmol/L的三氧化二砷作用于PC-3细胞,48h后对细胞增殖活性、细胞凋亡及细胞bcl-2、bax基因表达的变化进行检测。结果各浓度的三氧化二砷均可抑制PC-3细胞增殖,并具有剂量依赖性。3、6、10μmol/L的三氧化二砷还可诱导PC-3细胞凋亡,计算细胞凋亡率分别为11．8%、12．7%、29．6%。逆转录聚合酶链反应(RT-PCR)检测PC-3细胞中bcl-2、bax表达的相对强度,发现bcl-2的表达强度随三氧化二砷浓度的升高而逐渐降低(P＜0．01),而bax表达强度变化不明显(P＞0．05)。结论三氧化二砷可有效抑制PC-3细胞增殖,诱导PC-3细胞凋亡,这一过程与三氧化二砷抑制PC- 3细胞中bcl-2的表达有关。     

小檗胺诱导前列腺癌PC-3细胞凋亡及其机制

目的探讨小檗胺体外诱导雄激素非依赖性前列腺癌PC-3细胞凋亡的作用及其机制。方法噻唑蓝（MTT）法检测10、20、30和40mg／L小檗胺作用于PC-3细胞24、48、72h的吸光度（A）值；流式细胞仪检测小檗胺作用后细胞凋亡率及细胞周期的变化；透射电镜观察细胞凋亡形态；免疫细胞化学法检测小檗胺作用后bcl-2、bax和Survivin表达变化。结果各浓度组小檗胺作用48h。细胞抑制率分别为（13．60±1．49）％、（31．79±2．31）％、（54．16±3．09）％和（63．72±2．46）％，与对照组比较差异均有统计学意义（P〈0．05）。小檗胺对PC-3细胞的抑制作用呈时间-浓度依赖性；40mg／L小檗胺作用24、48、72h，细胞凋亡率分别为（31．44±3．27）％、（50．32±4．03）％和（63．46±3．75）％，与对照组比较差异有统计学意义（P〈0．05）。随小檗胺浓度的增高，凋亡率随之升高，细胞周期呈现G0／G1期、S期细胞比例增多，G2／M期细胞比例减少趋势；电镜扫描可见典型的“凋亡小体”；40mg／L小檗胺作用72h，PC-3细胞中bax的表达增加、Survivin表达减少（P〈0．05），而bcl-2的表达差异无统计学意义（P〉0．05）。结论小檗胺通过诱导细胞凋亡和影响细胞周期的方式抑制PC-3细胞的增殖，并具有时间和浓度依赖性；诱导凋亡的机制可能是通过下调Survivin、上调bax蛋白的表达来实现。     

姜黄素对雄激素非依赖性前列腺癌细胞PC-3及血管内皮生长因子的影响

目的：研究姜黄素对雄激素非依赖性前列腺癌细胞株PC-3细胞体外作用及其对血管内皮生长因子（VEGF）表达的影响，探讨其抗肿瘤的作用机制。方法：分别用0、6．25、12．5、25、50μmol／L浓度的姜黄素作用于PC-3细胞，12、24、36、48、72、96h后台盼蓝拒染法、四甲基偶氮唑蓝（MTT）法检测细胞生长活性；24h后流式细胞仪测定细胞周期及凋亡的变化，透射电镜观察细胞超微结构变化；半定量RT-PCR法检测PC-3细胞内VEGF mRNA的表达；ELISA检测细胞上清液中VEGF浓度。结果：姜黄素能显著抑制PC-3细胞的增殖，呈剂量与时间依赖性，不同浓度姜黄素组之间及不同时间组之间差异均有统计学意义（P〈0．01）。不同浓度姜黄素诱导PC-3细胞出现剂量依赖性G2／M期阻滞（P〈0．01），且各浓度组凋亡细胞比例均显著高于空白对照组（P〈0．01），差异有统计学意义；姜黄素作用24h后PC-3细胞出现凋亡的形态学改变；PC-3细胞内VEGF mRNA的表达和细胞上清液中VEGF呈剂量依赖性降低。结论：姜黄素能显著抑制体外PC-3细胞的生长，并促进其G2／M期阻滞和凋亡，VEGF mRNA及蛋白的表达也明显降低，可能是其抑制肿瘤和血管生长的机制之一。     

基质细胞衍生因子-1α对人前列腺癌PC-3细胞系失巢凋亡的影响

目的：探讨基质细胞衍生因子-lα（stromal cell-derived factor-lα,SDF-lα）对人前列腺癌PC-3细胞失巢凋亡的影响。方法：悬浮培养诱导细胞失巢凋亡,使用0μg／L、50μg／L、100μg／L的SDF-1α作用于悬浮培养的PC-3细胞;天后,采用CCK8法检测PC-3细胞增殖活性变化;Western-blot方法检测促凋亡蛋白Bmf及抗凋亡蛋白Bcl-xl表达变化。结果：PC-3细胞悬浮培养3天后,细胞存活率为（25．19±0．43）％,提示大部分悬浮培养的细胞发生失巢凋亡;50μg／L、100μg／L的SDF-α处理后,与对照组相比,细胞存活率提高,分别为（37．60±6．24）％（P〈0．05）和（33．66±5．51）％（P〉0．05）;悬浮培养的PC-3细胞经SDF-lα处理后,其促凋亡蛋白Bmf表达减低;抗凋亡蛋白Bcl-xl表达增高。结论：SDF-lα可抑制人前列腺癌PC-3细胞发生失巢凋亡,其机制可能与下调Bmf和上调Bcl-xl蛋白表达相关。     

α肾上腺素受体阻滞剂抑制前列腺癌细胞生长的研究

目的 比较两种α1肾上腺素受体阻滞剂特拉唑嗪和阿夫唑嗪,α1肾上腺素受体阻滞剂酚苄明对雄激素非依赖性前列腺癌细胞系Pc-3和Du-145的作用。方法 将5、10μmol／L浓度的特拉唑嗪、阿夫唑嗪与酚苄明与PC-3、DU-145细胞共培养,检测上述3种药物对PC-3和DU-145细胞系细胞存活百分率、癌细胞集落形成能力及细胞周期的影响。结果 特拉唑嗪能将雄激素非依赖性前列腺癌细胞PC-3和DU-145阻滞在G1期,从而抑制雄激素非依赖性前列腺癌细胞系PC-3和DU-145的生长及癌细胞集落形成的能力。阿夫唑嗪和酚苄明对PC-3和DU145的生长及癌细胞集落形成能力无明显影响。结论 特拉唑嗪能通过诱导雄激素非依赖性前列腺癌细胞G1期阻滞来抑制其生长,考虑此药可用于治疗雄激素非依赖性前列腺癌。     

人参皂苷Rg3对人前列腺癌细胞EphB4及抗凋亡蛋白bcl-xl表达的影响

目的：研究人参皂苷Rg3对人前列腺癌细胞株PC-3中EphB4及抗凋亡蛋白bcl—xl表达的影响。方法：用浓度为0、5、10、20和40μmol／L的人参皂苷Rg3处理PC-3细胞24h,然后采用四甲基偶氮唑盐（MTT）方法检测人参皂苷Rg3对PC-3细胞增殖的抑制作用,用倒置显微镜和流式细胞术观察人参皂苷Rg3对PC-3细胞凋亡的诱导作用,用RT—PCR和Western blot方法检测经不同浓度人参皂苷Rg3处理后PC-3细胞中EphB4和bcl-x1的表达情况。结果：5、10、20和40μmol／L的人参皂苷Rg3对PC3细胞增殖的抑制率分别为20．93％、31．32％、51．63％、65．43％。5～40μmol／L的人参皂苷Rg3处理细胞呈明显的凋亡形态学改变,40umol／L人参皂苷Rg3处理PC-3细胞24h后,凋亡细胞占（12．10±1．2）％,处理组比正常对照组（3．18±2．1）％凋亡明显增加,差异有统计学意义（P〈0．05）。结论：不同浓度人参皂苷Rg3处理PC-3细胞24后,EphB4的表达随人参皂苷Rg3浓度的增加而逐渐减弱,而且bcl—xl的表达随人参皂苷Rg3浓度的增加逐渐减弱。     

胡椒碱对人膀胱癌 T24细胞增殖及侵袭作用的研究

目的：探讨不同浓度胡椒碱对膀胱癌 T24细胞增殖和侵袭作用的影响。方法用不同浓度的胡椒碱（5、10、20、40、80、160μmol／L）处理体外培养的膀胱癌 T24细胞,然后通过 MTT实验、Transwell 实验、Western blot 等方法检测 bax 和 bcl-2的表达以及 T24细胞的增殖和凋亡情况。结果胡椒碱作用于 T24细胞24 h 后,IC50值为38．73μmol／L,并且呈剂量依赖性。随着胡椒碱浓度的增加,T24细胞活性被抑制作用明显增加,且抑凋亡蛋白 bcl-2的表达量减少,促凋亡蛋白 bax 的表达量增加。结论胡椒碱对膀胱癌 T24细胞具有抑制增殖及促进其凋亡的作用。     

多肽K237对PC-3M细胞增殖及bax、bcl-2 mRNA表达的影响

目的:研究多肽K237对体外培养的雄激素非依赖性前列腺癌PC-3M细胞的抑制作用,及其可能的作用机制。方法:将培养的PC-3M细胞分为4组:实验组(分别以50、100、200μmol/L的多肽K237处理48h)和对照组(K237浓度为0μmol/L),采用MTT法观察多肽K237对前列腺癌PC-3M细胞增殖的影响,用RT-PCR法检测bax、bcl-2mRNA表达的变化。结果:不同浓度的多肽K237处理48h后,PC-3M细胞形状变圆,体积变小,胞质透亮度下降,部分细胞脱落悬浮于培养液中。在50、100、200μmol/L的多肽K237作用48h后,MTT法检测的细胞生长抑制率分别为(12.6±0.95)%、(17.8±0.99)%、(27.2±1.12)%。RT-PCR结果显示:50、100、200μmol/L实验组和对照组的bax/β-actin值分别为0.919±0.071、0.971±0.083、0.992±0.102,(0.889±0.06),bcl-2/β-actin值分别为0.896±0.085、0.791±0.084、0.764±0.702,0.922±0.097,3组中上述两项指标均较对照组有明显变化(P均<0.01),其中,baxmRNA表达水平上调,而bcl-2mRNA表达水平下调,上述作用呈现剂量效应关系。结论:多肽K237可能通过影响bax、bcl-2mRNA的表达来诱导PC-3M细胞凋亡,从而抑制前列腺癌细胞的增殖。     

米非司酮诱导前列腺癌PC-3细胞凋亡过程中PKB/Akt激酶的调控作用

目的 观察米非司酮在体外诱导前列腺癌PC-3细胞凋亡的作用机制以及Akt激酶在前列腺癌生长过程中的作用.方法 采用Western blot方法检测不同前列腺癌细胞株癌细胞以及米非司酮作用后PC-3细胞中Akt蛋白磷酸化后蛋白含量,以及相关蛋白的表达量.结果 前列腺癌PC-3细胞中Akt磷酸化后蛋白即[p-Akt(Thr308)和p-Akt(Ser473)]的含量明显高于激素依赖性前列腺癌LNCaP细胞中的蛋白表达量,其表达量分别为0.27±0.05和0.22±0.07;0.46±0.09和0.37±0.10(P＜0.05).10 μmol/L米非司酮作用于PC-3细胞后p-Akt(Th308邶)和p-Akt(Ser473)磷酸化蛋白的含量均明显下降,但其中p-Akt(Thr308)蛋白表达量变化尤为显著,4～24h4个时间组蛋白含量分别为0.24±0.08、0.11±0.03、0.05±0.01和0.01±0.00;其蛋白表达量下降速度较p-Akt(Ser473)快且显著,p-Akt(Ser473)磷酸化蛋白4～24 h 4个时间组蛋白含量分别为0.56±0.17、0.42±0.11、0.28±0.09和0.12 ±0.05.米非司酮作用于PC-3细胞后使Caspase-9、Caspase-3被激活裂解出有活性的激活片段.结论 Akt激酶在前列腺癌生长、发展以及激素依赖性向激素非依赖性的转变过程中起着重要作用.p-Akt(Thr308)蛋白磷酸化水平在Akt磷酸化激活过程中占主导地位,是Akt激活的必要过程.米非司酮抑制前列腺癌PC-3细胞的增殖,诱导细胞凋亡,其可能是通过抑制Akt信号转导通路,从而激活Caspase.     

Bisphosphonate induces apoptosis and inhibits pro-osteoclastic gene expression in prostate cancer cells

AIM: Bisphosphonates are well established for the management of cancer-induced skeletal complications. Recent studies suggest that bisphosphonates promote apoptosis of cancer cells as well as osteoclasts in bone metastatic sites. To determine the direct effects of bisphosphonate on prostate cancer, we examined the effects of minodronate on prostatic cancer cell growth and the expression of apoptosis-related proteins and osteoclastogenic factors. METHODS: PC-3, DU145 and LNCaP cells were treated with amino-bisphosphonate minodronate. Then proliferation, apoptosis and expression of bcl-2, bax, poly (ADP)-ribose polymerase (PARP), caspase-3, receptor activator of nuclear factor-kappaB ligand (RANKL), osteoprotegerin (OPG), matrix metalloproteinases-2 (MMP-2), and parathyroid hormone related protein (PTHrP) were assessed. RESULTS: The proliferation of prostatic cancer cells was inhibited by minodronate. DNA fragmentation and TUNEL-positive nuclei were observed in minodronate-treated PC-3 cells. Minodronate decreased bcl-2 expression and induced bax expression, caspase-3 activity and degradation of PARP in DU145 and PC-3 cells. Minodronate decreased expression of RANKL, PTHrP and MMP-2 in PC-3 cells. CONCLUSIONS: Our results suggest that bisphosphonate not only promotes apoptosis directly but also decreases pro-osteoclastic gene expression in prostate cancer cells.     

Cell death in irradiated prostate epithelial cells: role of apoptotic and clonogenic cell kill

Dose-escalated conformal radiotherapy is increasingly being used to radically treat prostate cancer with encouraging results and minimal long-term toxicity, yet little is known regarding the response of normal or malignant prostate cells to ionizing radiation (IR). To clarify the basis for cell killing during prostate cancer radiotherapy, we determined the IR-induced expression of several apoptotic- (bax, bcl-2, survivin and PARP) and G1-cell cycle checkpoint- (p53 and p21(WAF1/Cip1)) related proteins, in both normal (PrEC-epithelial and PrSC-stromal) and malignant (LNCaP, DU-145 and PC-3; all epithelial) prostate cells. For these experiments, we chose doses ranging from 2 to 10 Gy, to be representative of the 1.8-2 Gy daily clinical fractions given during curative radiotherapy and the 8-10 Gy single doses given in palliative radiotherapy. We observed that IR-induced bax and p21(WAF1/Cip1) protein expression were attenuated selectively in normal stromal and epithelial cell cultures, yet maintained their p53-dependency in malignant cell lines. For each cell culture, we also determined total apoptotic and overall radiation cell kill using a short-term nuclear morphologic assay and a long-term clonogenic survival assay, respectively. Clonogenic survival, as measured by the surviving fraction at 2 Gy (SF2), ranged from 0.05 (PrEC) to 0.55 (DU-145), suggesting that malignant prostate cells are more radioresistant than normal prostate cells, for this series. IR-induced apoptotic cell kill was minimal (less than 6% cell after a dose of 10 Gy at times of 24-96 h) and was not dose-dependent. Furthermore, apoptotic kill was not correlated with either molecular apoptotic response or clonogenic cell kill. Using a flow cytometric proliferation assay with the PrSC (stromal) and DU-145 (epithelial) representative cultures, we observed that a senescent-like phenotype (SLP) emerges within a sub-population of cells post-irradiation that is non-clonogenic. Terminal growth arrest was dose-responsive at 96 h following irradiation and associated with long-term expression of both p21(WAF1/Cip1) and p16(INK4a) genes. Future strategies for prostate radiotherapy prediction or novel treatments should additionally focus on terminal growth arrest as an important endpoint in prostate cancer therapy.     

Androgen-independent growth is induced by neuropeptides in human prostate cancer cell lines

BACKGROUND: Androgen-independent growth leads to progressive prostate cancer after androgen-ablation therapy. This may be caused by altered specificity of the androgen receptor (AR), by ligand-independent stimulation of the AR, or by paracrine growth modulation by neuropeptides secreted by neuroendocrine (NE) cells. METHODS: We established and characterized the androgen-independent FGC-DCC from the androgen-dependent LNCaP fast growing colony (FGC) cell line. The androgen-independent DU-145, FGC-DCC, and PC-3, and the androgen-dependent LNCaP and PC-346C cell lines were used to study growth modulation of gastrin-releasing peptide (GRP), calcitonin (CT), serotonin (5-HT), and vasoactive intestinal peptide (VIP) by (3)H-thymidine incorporation. Specificity of the growth-modulating effects was tested with the anti-GRP monoclonal antibody 2A11 and induction of cAMP by neuropeptides. RESULTS: Androgen-independent growth stimulation by neuropeptides was shown in DU-145 and PC-346C. 2A11 inhibited GRP-induced (3)H-thymidine incorporation in DU-145 and PC-346C and inhibited proliferation of the FGC-DCC and PC-3 cell lines. With some exceptions, cAMP induction paralleled growth stimulation. Dideoxyadenosine (DDA) inhibited the GRP-induced growth effect in DU-145 and PC-346C, whereas oxadiazoloquinoxaline-1-one (ODQ) had no effect on (3)H-thymidine incorporation. None of the neuropeptides stimulated growth of LNCaP, FGC-DCC, or PC-3. CONCLUSIONS: GRP-induced growth of DU-145 and PC-346C was specific and cAMP-mediated. Androgen-independent growth of FGC-DCC cells was mainly due to an induction of Bcl-2 expression and possibly through the activation of an autocrine and NE-like pathway, as has been shown also for the PC-3 cell line. Growth induction of non-NE cells by neuropeptides could be a possible role for NE cells in clinical prostate cancer.     

Differential mechanisms of bicalutamide-induced apoptosis in prostate cell lines

Bicalutamide is a non-steroidal antiandrogen used in the treatment of prostate cancer. Although widely accepted as an androgen receptor antagonist, the mechanism by which it induces apoptosis remains unclear. Defining exact pathways by which bicalutamide induces its apoptotic effects would help to advance its clinical applications. We aimed to (a) examine the apoptotic effects of bicalutamide at 24 h and (b) comment on the role of the caspases and calpains in mediating bicalutamide-induced apoptosis in androgen-dependent and androgen-independent cells. PWR-1E, PC-3 and DU-145 cells were treated with bicalutamide and assessed for apoptosis by flow cytometry at 24 h. DU-145 cells were used to compare differences between two different metastatic receptor-negative cells and to verify apoptotic induction at 48 h. To delineate a specific pathway of action for bicalutamide, PC-3 and PWR-1E cells were pretreated with specific inhibitors of caspase-dependent (zVAD-FMK) and caspase-independent pathways (calpain 2 inhibitor). Bicalutamide induced apoptosis in androgen-dependent PWR-1E cells via a caspase-dependent and calpain-independent mechanism. In androgen-independent PC-3 cells, bicalutamide also induced apoptosis by mechanisms that were partially inhibited by pan-caspase inhibition but were partially calpain dependent. Understanding into how bicalutamide exerts its effects in androgen-independent cells will yield further insights into the treatment of hormone-refractory disease.     

雷帕霉素抑制人前列腺癌细胞增殖及其作用机制

目的 观察雷帕霉素(Rapamycin)对体外培养的人前列腺癌PC-3M-2B4细胞增殖及凋亡的影响,探讨其机制.方法 分别用不同浓度的雷帕霉素(100、200、400、800μg/L)对细胞进行干预后,采用噻唑蓝(MTT)比色法检测细胞增殖变化,流式细胞术检测细胞凋亡变化,Western blot 法检测凋亡相关蛋白bcl-2及bax表达的变化.结果 雷帕霉素能明显抑制PC-3M-2B4细胞的增殖活性,此作用呈现量-效、时-效关系.雷帕霉素呈浓度依赖性诱导细胞凋亡.雷帕霉素作用PC-3M-2B4细胞后,细胞内凋亡抑制蛋白bcl-2的表达明显降低,bax蛋白的表达明显增加.结论 雷帕霉素能够通过调节凋亡相关蛋白bcl-2和bax的表达比例,诱导前列腺癌细胞凋亡,从而抑制肿瘤生长.

Abstract：

Objective To investigate the effects of Rapamycin on the growth and apoptosis of human prostate carcinoma cell line PC-3M-2B4. Methods The inhibitory effect of Rapamycin was observed at 100,200,400,800μg/L on the growth of human prostate carcinoma cell line PC-3M-2B4 in serum-free medium for different concentrations by methyl thiazol tetrazolium (MTF) assays. Flow cytometry (FCM)analysis was used to study the changes of cell apoptosis. The expression level of bcl-2 and bax was determined by Western blotting. Results Rapamycin caused dose-dependent inhibition on the growth of human prostate carcinoma cell line PC-3M-2B4 in a concentration-and time dependent manner. Rapamycin induced the apoptosis of PC-3M-2B4 cells in a concentration-dependent manner. The levels of bcl-2 protein were reduced gradually with the increase of concentration or action time. Conclusion Rapamycin, a mTOR inhibitor, inhibits the growth of human prostate cancer cell and induces apoptosis of human prostate cancer cell. mTOR might be a potential target for anti-prostate cancer.     

Abrogation of heat-shock protein （HSP）70 expression induced cell growth inhibition and apoptosis in human androgen-independent prostate cancer cell line PC-3m

Aim: To investigate the effect of abrogating heat shock protein (HSP) 70 expression by antisense HSP70 oligonucleotides treatment on human androgen-independent prostate cancer cell line PC-3m growth. Methods: PC3m cells were treated with 0-16μmol/L antisense HSP70 oligomers for 0-100 hr. Cell growth inhibition was analyzed using a trypan blue dye exclusion test. Apoptotic cells were detected and confirmed by flow cytometric analysis and DNA fragmentation analysis. The protein expression of HSP70 and bcl-2 affected by antisense HSP70 oligomers were determined using Western blot. Results: Antisense HSP70 oligomer induced apoptosis and then inhibited proliferation of PC-3m cells in a dose- and time-dependent manner. Ladder-like patterns of DNA fragments were observed in PC-3m cells treated with 10μmol/L antisense HSP70 oligomer for 48 hr or 8μtmol/L for 72 hr on agarose gel electrophoresis. Antisense HSP70 oligomer pretreatment enhanced the subsequent induction of apoptosis by heat shock in PC-3m cells. In addition, undetectable HSP70 expression was observed at a concentration of 10μtmol/L antisense HSP70 oligomer treatment for 48 hr or 8μtmol/L for 72 hr in Western blot, which was paralleled by decreased expression levels of anti-apoptotic protein bcl-2. Conclusion: HSP70 antisense oligomer treatment abro-gates the expression of HSP70, which may disrupt HSP70-bcl-2-interactions and further down-regulate bcl-2 expression,in turn inducing apoptosis and inhibiting cell growth in PC-3m cells. (Asian JAndro12004 Dec;6:319-324)     

Cell-cell adhesion molecules and signaling intermediates and their role in the invasive potential of prostate cancer cells

PURPOSE: The highly variable natural history of prostate carcinoma may be reflected in heterogeneity of invasive potential between tumors. MATERIALS AND METHODS: We have examined two prostate cancer cell lines of low invasive potential (CAHPV10 and PZHPV7) and three cell lines of high invasive potential (DU-145, PC-3, LNCapFGC), to determine whether specific adhesion molecule profiles correlated with their invasive behavior. RESULTS: Using an in vitro invasion assay, we demonstrated that DU-145, LNCapFGC and PC-3 cells were highly invasive compared with CA-HPV-10 and PZ-HPV-7 cells. LNCapFGC cells expressed high levels of E-cadherin, alpha-, beta- and gamma-catenin, desmoglein, desmoplakin and GSK3beta using immunoblotting. This was, in general, comparable to immunohistochemical staining. PC-3 cells had no E-cadherin or alpha-catenin, but expressed a high level of the HGF/SF receptor c-Met. In contrast, DU-145 cells were found to express E-cadherin and low levels for all other protein molecules, except c-Met. The DU-145 cell line also lacked alpha-catenin expression. In CA-HPV-10 and PZ-HPV-7 cells, there was no detection of APC, PECAM-1, P-cadherin or Wnt-1. DU-145, LNCapFGC and PC-3 cells formed cell-cell aggregates, which were reduced by inclusion of anti-E-cadherin antibody and the motogen HGF/SF. CONCLUSION: These results show that prostate cancer cells exhibit a diverse expression of cell-cell adhesion molecules and their signaling intermediates. The expression of these adhesion molecules bears an important relationship with the invasive phenotype of these cells.