siRNA靶向沉默OCT4基因对前列腺癌DU145和PC3细胞等生物学行为的影响

目的 观察siRNA靶向沉默OCT4基因对前列腺癌DU145细胞和PC3细胞的生物学行为影响.方法 通过脂质体介导的方法将OCT4 SiRNA分别转染人前列腺癌细胞株DU145细胞和PC3细胞,采用RT-PCR和Western-blot方法分别检测特异性siRNA对0ct4基因在mRNA和蛋白水平上的沉默效果,CCK8法测定细胞生长曲线观察细胞增殖的抑制情况,运用Transwell小室法检测细胞侵袭能力的变化.结果 转染OCT4 SiRNA的两组细胞OCT4的表达均低于阴性对照组(NC)与空白组(P＜0.05),OCT4SiRNA抑制两种细胞的增殖并降低细胞的侵袭能力.结论 OCT4-siRNA可以有效抑制DU45细胞和PC3细胞的OCT4基因的表达,从而抑制细胞增殖,抑制侵袭和迁移,表明OCT4基因在前列腺癌的发生发展中发挥重要作用.     

不同前列腺癌细胞株Talin-1表达情况和侵袭能力关系研究

目的探讨踝蛋白1(Talin-1)在不同前列腺癌细胞株中的表达情况和侵袭能力的关系。方法体外培养不同人前列腺癌细胞株(DU-145、PC-3、LNCaP)及人正常前列腺上皮细胞株(RWPE-1)。传代培养后利用MTT法检测各细胞株增殖能力。细胞划痕实验,Transwell小室侵袭和迁移实验检测各细胞株侵袭及迁移能力。RT-PCR技术检测各细胞株中Talin-1的mRNA表达水平。Western-blot技术检测各细胞株中Talin-1的蛋白表达水平。结果与RWPE-1细胞株相比,LNCaP细胞株、PC-3细胞株、DU145细胞株的增殖、侵袭和迁移能力明显增高(P0.05),其中LNCaP、PC-3、DU-145细胞株的增殖、迁移以及侵袭能力依次递增(P0.05)。前列腺癌LNCaP细胞株、PC-3细胞株、DU145细胞株中的Talin-1 mRNA及蛋白表达水平显著高于RWPE-1细胞株(P0.05);其中LNCaP、PC-3、DU-145细胞株中的Talin-1 mRNA以及蛋白表达水平依次递增(P0.05)。结论Talin-1与前列腺癌的增殖、侵袭和迁移能力相关;低表达Talin-1的前列腺癌的增殖、侵袭和迁移能力低,恶性度低;高表达Talin-1的前列腺癌的增殖、侵袭和迁移能力强,恶性度高。Talin-1可作为前列腺癌恶性度的预测指标之一。     

人抑癌基因PTEN对前列腺癌细胞系生物学行为的影响

目的　探讨外源性人抑癌基因PTEN表达对前列腺癌细胞系LNCaP、DU 14 5细胞增殖和侵袭转移能力的影响。　方法　利用携带人PTEN基因的可调控性腺病毒 (Ad PTEN ) ,体外转染人前列腺癌细胞系LNCaP、DU 14 5,RT PCR、Westernblot检测目的基因不同水平的表达 ,通过细胞生长试验、流式细胞仪分析技术以及Boyden小室法检测LNCaP、DU 14 5转染前后细胞增殖、细胞周期、细胞凋亡和细胞体外侵袭力的变化。　结果　转染Ad PTEN后LNCaP、DU 14 5细胞的PTEN表达由阴性转为阳性 ,转染后对LNCaP、DU 14 5细胞生长有抑制作用 ,阻滞于G0 ～G1期 ,早期细胞凋亡率增加 ,LNCaP细胞 (6.89± 0 .51) % ;DU14 5细胞 (5.44± 1.13 ) % ,与对照组相比差异有显著性 ,Boyden小室法检测转染后体外侵袭力受到明显抑制。 　结论　重组腺病毒介导的人PTEN基因在体外对前列腺癌细胞系LNCaP、DU 14 5的细胞增殖和体外侵袭力有明显抑制作用 ,可望作为前列腺癌基因治疗的有效工具     

hsa_circ_0005221通过miR-339-5p/STAT5A通路促进前列腺癌进展

目的:研究hsa_circ_0005221通过miR-339-5p/STAT5A通路调控前列腺癌的进展的分子机制。方法:核质分离检测hsa_circ_0005221和miR-339-5p在细胞中的表达定位;Pulldown检测hsa_circ_0005221结合的miRNA;软件预测结合荧光素酶报告基因确定与hsa_circ_0005221结合的RNA是miR-339-5p;定量PCR检测hsa_circ_0005221在前列腺上皮细胞和前列腺癌细胞的表达量;在前列腺癌细胞分别转染hsa_circ_0005221过表达质粒和siRNA测DU145和LNCaP增殖、侵袭和迁移能力及上皮间质转化(EMT)和凋亡水平;在敲低hsa_circ_0005221基础上,转染miR-339-5P mimics和inhibitor测DU145和LNCaP增殖、侵袭和迁移能力及EMT标志性蛋白、STAT5A和凋亡水平。结果:hsa_circ_0005221在前列腺癌细胞的表达水平明显高于前列腺上皮细胞。核质分离实验表明hsa_circ_0005221、miR-339-5P均主要在胞质中表达。在DU145和LNCaP敲低hsa_circ_0005221,其增殖、侵袭、迁移及EMT能力明显下降;凋亡水平增加。过表达hsa_circ_0005221则结果相反。在软件预测排名前5的miRNA中,Pulldown实验结果显示与hsa_circ_0005221结合的有miR-339-5P、miR-17、miR-520H;敲低或过表达hsa_circ_0005221,miR-339-5P变化最明显。荧光素酶报告基因结果显示hsa_circ_0005221与miR-339-5P结合。在DU145和LNCaP敲低hsa_circ_0005221基础上转染miR-339-5P mimics,其增殖、侵袭和迁移能力明显下降,凋亡水平增加,E-cad水平增加,N-cad水平下降,STAT5A表达水平增加。敲低hsa_circ_0005221基础上上转染miR-339-5P mimics则结果相反。结论:hsa_circ_0005221通过miR-339-5p/STAT5A通路促进前列腺癌的进展。     

MicroRNA-212在前列腺癌中的表达和功能研究

目的检测microRNA-212在前列腺癌组织和细胞株中的表达情况并研究其与前列腺癌细胞增殖、侵袭及凋亡的关系。方法检测前列腺癌标本及细胞系中microRNA-212的表达情况。在DU145和PC3转染microRNA-212 mimics、microRNA-212 inhibitor或者NC阴性对照物,通过MTT、Transwell、流式细胞仪检测其相关生物学情况。结果前列腺癌组织中的microRNA-212表达显著低于癌旁组织。前列腺癌细胞系中microRNA-212较正常前列腺上皮细胞系的表达低。microRNA-212的表达与Gleason评分、脉管侵犯和淋巴结转移密切相关。MTT实验和Transwell实验表明,转染了microRNA-212 mimics的DU145和PC3细胞,其增殖率降低,microRNA-212的上调抑制了DU145和PC3细胞的迁移和侵袭能力。转染了microRNA-212 inhibitor的DU145和PC3细胞则表现出较强的增殖、迁移和侵袭能力。流式细胞仪分析结果表明,转染了microRNA-212 mimics的DU145和PC3细胞的凋亡显著增加,转染了microRNA-212 inhibitor的DU145和PC3细胞凋亡受到抑制。结论前列腺癌组织中microRNA-212表达显著下降,microRNA-212的表达与Gleason评分、脉管侵犯和淋巴结转移密切相关,microRNA-212能够抑制前列腺癌细胞的增殖、侵袭并促进前列腺癌细胞凋亡。     

长链非编码RNA Linc00662促进前列腺癌细胞生长的研究

目的:探讨Linc00662在前列腺癌的表达情况及对前列腺癌细胞生物学功能的影响。方法:采用实时荧光定量PCR(qRT-PCR)对60例前列腺癌患者的前列腺癌组织标本以及正常前列腺上皮细胞(WPMY-1细胞)和前列腺癌细胞系(DU145、PC-3、LNCaP和22RV1)检测Linc00662的表达,并分析前列腺癌组织中Linc00662表达与患者临床病理特征的相关性。应用RNA干扰(siRNA)转染PC-3和DU145细胞,qRT-PCR验证干扰效率。通过CCK-8、Caspase 3/9活性测定、划痕试验、Transwell侵袭试验分别检测干扰Linc00662的表达对前列腺癌PC-3和DU145细胞增殖、凋亡、迁移和侵袭能力的影响。结果:与邻近及正常组织前列腺上皮细胞相比,Linc00662在前列腺癌组织和细胞系的表达呈显著上调(P0.01)。Linc00662的高表达与肿瘤分期(P=0.002)、原发灶大小(P=0.006)、淋巴结转移(P=0.001)及远处转移(P=0.001)呈正相关。si-Linc00662转染PC-3和DU145细胞后,Linc00662的表达明显下降(P0.01)。与对照组相比, Linc00662干扰组在PC-3和DU145细胞中的增殖、侵袭及迁移能力均明显下降(P0.01),而凋亡增加(P0.01)。结论:Linc00662在前列腺癌组织及细胞中呈相对高表达,敲低Linc00662的表达可抑制前列腺癌细胞的增殖、侵袭和迁移,并促进其凋亡,可作为前列腺癌新的标志物。     

长链非编码RNA RP1-90L14.1对前列腺癌LNCaP细胞生物学行为的影响及其机制研究

目的:研究长链非编码RNA(lncRNA) RP1-90L14.1对前列腺癌LNCaP细胞增殖、迁移、侵袭的作用以及对GRIN2A、BACE2基因表达的影响。方法:采用RT-PCR检测前列腺癌LNCaP、LNCaP-AI细胞中RP1-90L14.1的表达水平;在LNCaP细胞中瞬时转染RP1-90L14.1过表达质粒和载体质粒,即转染RP1-90L14.1实验组(LNCaP-RP1-90L14.1组)和转染阴性对照组(LNCaP-NC组);采用普通培养液和活性炭吸附无酚红培养液培养两组细胞;CCK-8法、Transwell法检测两组细胞增殖、迁移、侵袭能力;RT-PCR和Western印迹检测两组细胞中N-甲基-D-天氡氨酸离子型谷氨酸受体2A(GRIN2A)、β位点淀粉样前体蛋白裂解酶2 (BACE2) mRNA和蛋白表达含量变化。结果:RP1-90L14.1在LNCaP-AI中的表达量显著高于LNCaP细胞(8.49±0.43 vs 2.53±0.95,P0.05)。转染RP1-90L14.1后,LNCaP-RP1-90L14.1组RP1-90L14.1表达量显著高于LNCaP-NC组(0.71±0.22 vs 0.02±0.01,P0.05);在普通培养液和活性炭吸附无酚红培养液中,培养72 h时,LNCaP-RP1-90L14.1组细胞活性分别高出LNCaP-NC组51.95%(1.22±0.08 vs 0.08±0.05,P0.05)和50.69%(0.79±0.02 vs 0.53±0.05,P0.05);培养96 h时,LNCaP-RP1-90L14.1组分别高出LNCaP-NC组51.72%(1.72±0.07 vs 1.13±0.05,P0.05)和60.23%(1.18±0.05 vs 0.73±0.08,P0.05)。转染RP1-90L14.1后,在普通培养液和活性炭吸附无酚红培养液中,细胞迁移能力LNCaP-RP1-90L14.1组均显著高于LNCaP-NC组[(682.0±42.7)个vs(422.0±37.1)个,(419.0±42.9)个vs(251.0±25.9)个,P0.05];细胞侵袭能力LNCaP-RP1-90L14.1组也均显著高于LNCaP-NC组[(507.0±22.2)个vs(274.0±19.6)个,(352.0±14.1)个vs(216.0±14.3)个,P0.05]。LNCaP-RP1-90L14.1组与LNCaP-NC组相比,GRIN2A mRNA和蛋白表达量(5.13±0.89、2.09±0.54,5.88±0.29、2.03±0.22),BACE2 mRNA和蛋白表达量(5.82±0.50、2.53±0.30,4.89±0.19、3.37±0.13)均有统计学差异(P0.05)。结论:lncRNA RP1-90L14.1可能在调控前列腺癌细胞的增殖、迁移及侵袭行为中起重要作用;RP1-90L14.1能促进GRIN2A、BACE2的表达;RP1-90L14.1与GRIN2A、BACE2可能存在内源性竞争关系。     

DNA甲基转移酶1对前列腺癌细胞增殖和迁移侵袭的影响

目的探究DNA甲基转移酶1(DNMT1)对前列腺癌细胞增殖和迁移侵袭的影响。方法采用小干扰RNA(siRNA)沉默前列腺癌细胞株(PC3和DU145)中DNMT1表达, 通过定量聚合酶链反应(qPCR)和蛋白质印迹法(Western blot)检测沉默效率。细胞计数试剂盒(CCK-8)检测细胞的体外增殖能力;TransWell检测细胞体外迁移和侵袭能力;Western blot检测si-DNMT1细胞后上皮-间充质转化(EMT)相关蛋白表达。组间比较采用t检验。结果 qPCR和Western blot实验结果显示DNMT1在前列腺癌细胞中高表达, 并成功构建siDNMT1 PC3和DU145细胞系。4 d后, CCK-8结果显示, siDNMT1细胞增殖能力低于相应对照组[PC3:1.27±0.71和1.44±0.48比1.66±0.58, t=7.268、5.108, P<0.01;DU145:1.43±0.12和1.27±0.10比1.80±0.06, t=4.841、7.493、P<0.01]。Transwell显示, 与对照组细胞比较, siDNMT1细胞迁移和侵袭...     

TGF-β/Smads通路关键蛋白在5种前列腺癌细胞株中表达的鉴定及意义

目的:对多种不同人前列腺癌细胞株TGF-β/Smads信号通路的"开放"或"关闭"状态进行鉴定,初步探讨此通路在前列腺癌侵袭、转移中的作用及可能的机制。方法:用Western印迹法检测LNCaP、PC-3、DU145及AR-CaP亚细胞系IF11、IA8细胞中TGF-β/Smads通路的关键蛋白TGF-βⅡ型受体(TβRⅡ)、Smad2/3、磷酸化Smad2(p-Smad2)、Smad4的差异表达。结果:TβRⅡ在PC-3、DU145、IF11、IA8中表达较高,在LNCaP中表达极低;Smad2/3在所有细胞中表达均较高,但活性成分p-Smad2仅在PC-3、DU145中表达;Smad4在LNCaP、PC-3、DU145中表达较高,IF11、IA8中表达缺失。结论:不同转移潜能的前列腺癌细胞株TGF-β/Smads通路的"开闭"状态存在差异,仅PC-3、DU145细胞处于开放状态;前列腺癌细胞可能通过不同的方式改变TGF-β/Smads通路状态参与晚期肿瘤的侵袭、转移过程。     

SPAG9调控前列腺癌迁移侵袭能力的研究

目的探讨SPAG9对前列腺癌细胞迁移、侵袭能力的影响及其分子机制。方法应用RNA干扰技术下调SPAG9在前列腺癌细胞中的表达,采用Western blot方法评估SPAG9基因干扰效果。采用Transwell实验比较SPAG9干扰前后前列腺癌细胞DU145、PC3的迁移与侵袭能力的改变。用CCK8细胞增殖实验分析SPAG9基因沉默对前列腺癌细胞DU145、PC3增殖能力的影响。用Western blot实验研究SPAG9基因沉默对前列腺癌细胞中MMP-2及TIMP-2蛋白表达的影响。结果特异性SPAG9基因的干扰RNA(siRNA)能够有效沉默DU145、PC3前列腺癌细胞株中SPAG9蛋白的表达。SPAG9敲低后的前列腺癌细胞株迁移与侵袭能力显著降低,差异有统计学意义(P0.05)。siSPAG9组DU145和PC3细胞中MMP-2的蛋白表达水平比siCtrl组显著降低,两组比较差异有统计学意义(P0.05),而TIMP-2的表达量显著升高,差异有统计学意义(P0.05)。SPAG9基因沉默后并不影响DU145及PC3细胞的增殖,组间差异无统计学意义(P0.05)。结论SPAG9基因通过激活MMP-2信号通路增强前列腺癌细胞的迁移与侵袭能力。     

转录因子12对前列腺癌进展及预后的影响

目的探讨转录因子12(TCF12)对前列腺癌进展及预后的影响。方法利用在线生信分析网站UALCAN、基因表达谱动态分析(GEPIA)、基因、蛋白质相互作用关系检索工具(STRING)及METASCAPE分析TCF12在前列腺组织中表达(高表达组和低表达组)及其与预后的关系,预测TCF12相关基因发挥作用的可能信号通路;构建TCF12沉默前列腺癌细胞株DU145,分为空载体组(si-NC)和TCF12沉默组(si-TCF12);分别利用细胞增殖-毒性检测试剂盒、划痕实验及细胞体外侵袭实验检测细胞的增殖、迁移及侵袭能力。组间分析采用独立样本t检验。结果TCF12低表达于前列腺癌(正常前列腺组织比前列腺癌为29.967±11.269比26.348±7.924,P<0.01),差异有统计学意义,TCF12低表达的前列腺癌启动子甲基化程度高于TCF12高表达(正常前列腺组织比前列腺癌为0.142±0.028比0.189±0.033,P<0.01),差异有统计学意义。低表达TCF12的前列腺癌患者无疾病生存期[风险比(HR)=0.014,P<0.05]及总生存期[HR=0.064,P<0.05)低于高表达TCF12的前列腺癌患者。TCF12可能通过激素刺激相关信号通路在前列腺癌发生发展中发挥作用。沉默TCF12后,DU145细胞的增殖(si-TCF12比si-NC为0.836±0.004比0.767±0.099,t=7.223,P<0.01)、迁移(si-TCF12比si-NC为74.8±11.2比42.8±9.6,t=7.269,P<0.01)及侵袭能力(si-TCF12比si-NC为121.8±21.0比94.0±12.5,t=3.426,P<0.01)高于对照组。结论TCF12在前列腺癌中低表达并提示预后欠佳。     

NK4基因转染对前列腺癌DU145细胞增殖、迁移、侵袭和凋亡的影响

研究HGF拮抗剂NK4在前列腺癌中的作用。将包含NK4cDNA的表达载体pBudCE4．1-EGFP-NK4转染到DU145细胞中。体外实验检测白分泌的NK4对肿瘤细胞增殖、迁移、转移及凋亡的影响。体内实验裸鼠分为三组,分别皮下种植DUl45、空质粒转染的Dul45和NK4转染的DUl45细胞,检测皮下肿瘤的大小、细胞凋亡及细胞增殖情况。体外实验结果显示转染NK4的DUl45细胞可以分泌NK4蛋白。自分泌的NK4抑制HGF诱导的肿瘤细胞增殖、迁移及转移,促进凋亡（P〈0．01）。NK4可以调节HGF受体c－Met及其下游ERKl与Akt1／2蛋白的活性。体内实验显示,NK4转染DUl45细胞组的肿瘤生长及细胞增殖受到抑制,同时肿瘤细胞凋亡增加。本实验显示包含NK4cDNA的表达载体转染前列腺癌细胞可以有效地调节肿瘤细胞的增殖、迁移、侵袭及凋亡。NK4作用于HGF／c－Met可以作为前列腺癌治疗的一个有效靶点。     

Downregulation of androgen receptor expression by luteolin causes inhibition of cell proliferation and induction of apoptosis in human prostate cancer cells and xenografts

BACKGROUND: Androgen receptor (ARs) play a crucial role in the development and progression of prostate cancer. Recent studies have suggested that prostate cancer cell proliferation is inhibited by AR downregulation. Our aim was to investigate how luteolin, a natural flavonoid, affects cell growth and AR expression in prostate cancer cells and xenografts. METHODS: We assessed prostate cancer cell (LNCaP, DU145, and PC-3) proliferation and apoptosis by MTT assay, flow cytometric analysis, and Western analysis. AR function was measured by evaluating the AR target molecule, prostate-specific antigen (PSA), by RT-PCR, Western blotting, and enzyme-linked immunosorbent assay. We determined the mechanism of AR downregulation with cycloheximide chase assays, proteasome inhibitor, and coimmunoprecipitation experiments. The effects of luteolin on growth inhibition in vivo were examined by LNCaP xenografts in SCID mice. RESULTS: Luteolin significantly repressed prostate cancer cell proliferation and induced apoptosis in LNCaP cells. PC-3 and DU145 cells were less susceptible to luteolin-mediated growth inhibition. Luteolin simultaneously suppressed intracellular and secreted PSA levels and repressed AR mRNA and protein expression in a dose- and time-dependent manner. Luteolin reduced the association between AR and heat-shock protein 90, causing AR degradation through a proteasome-mediated pathway in a ligand-independent manner. Luteolin also suppressed LNCaP xenograft tumor growth in SCID mice. CONCLUSION: Luteolin-mediated AR downregulation contributes to the inhibition of cell proliferation and the induction of apoptosis in LNCaP human prostate cancer cells, suggesting that AR is a molecular target for luteolin-mediated anticancer activity. Luteolin may act as a chemopreventive or chemotherapeutic agent for prostate cancer.     

Prostate stromal cell-derived hepatocyte growth factor induces invasion of prostate cancer cell line DU145 through tumor-stromal interaction.

BACKGROUND: In prostate cancer, several growth factors derived from stromal cells regulate tumor cell growth. Hepatocyte growth factor (HGF) possesses biological activities that promote cancer proliferation and invasion through tumor-stromal interaction. We examined how prostate stromal cell-derived HGF affects invasion of prostate cancer cells through this interaction. METHODS: The effects of HGF, various growth factors (transforming growth factor (TGF)-alpha, TGF-beta1, basic fibroblast growth factor, keratinocyte growth factor, and platelet-derived growth factor), and conditioned medium (CM) from prostate stromal cells (PrSC) on prostate cancer cells (LNCaP, PC-3, and DU145) were determined by collagen gel invasion assay. DU145 cells and PrSC were cocultured for Matrigel invasion chamber assay. Induction activity of CM from cancer cells to stimulate HGF production by PrSC was studied by the ELISA method and Western blotting. RESULTS: LNCaP and PC-3 cells did not respond to any of the factors examined. Invasion of DU145 cells into the collagen gel matrix was induced by HGF and TGF-beta1, but not by any of the other factors tested. When DU145 cells were cultured in CM from PrSC or cocultured with PrSC, the cells acquired invasive potential, and this invasion was inhibited by an antibody against HGF, but not against TGF-beta1. Native-type HGF production in PrSC was enhanced by some unknown inducer(s) produced by cancer cells. CONCLUSIONS: PrSC-derived HGF enhanced invasive activity of the prostate cancer cell line DU145 through tumor-stromal interaction, wherein DU145 cells secreted some HGF-inducer(s) for PrSC.     

Regulation of lnvasive Potential of Human Prostate Cancer Cell Lines by Hepatocyte Growth Factor

Background: The growth and progression of prostate cancer depends on the stromal-epithelial interaction which is under paracrine control. Hepatocyte growth factor (HGF), produced by mesenchymal cells, is a multifunctional growth factor stimulating the movement and growth of epithelial cells including cancer cells. We therefore assessed the relationship between the invasive potential of prostate cancer and HGF in vitro.
Methods: Three human prostate cancer cell lines were used including PC-3 and DU145 (androgenindependent), and LNCaP (androgen-dependent). We studied the expression of the HCF receptor c-met proto-oncogene (c-met) by Western blotanalysis, and alsodetermined theeffectsof HGF on cell scattering, and the mechanisms of invasion and proliferation, by microscopic observation, the matrigel invasion chamber assay, and the MTT assay.
Results: c-met was detected in PC-3 and DU145 cells, but not in the LNCaP cells. There was increased cell motility in the scatter assay and an increased cell invasive potential in the matrigel invasion chamber assay by stimulation with HGF only with DU145 cells.
Conclusion: HGF plays an important role in the invasion and metastasis of the DU145 cell line through a paracrine mechanism mediated by the c-metreceptor. In the PC-3 cell line, the lack of downstream signal transduction after the c-met receptor is suggested.     

Inhibition of cortactin and SIRT1 expression attenuates migration and invasion of prostate cancer DU145 cells

Objectives: Cortactin is overexpressed in various types of cancer and enhances cell motility. It has been recently reported that silent mating type information regulation 2 homolog 1 interacts with cortactin and promotes cell migration. Here, we examined the role of cortactin and silent mating type information regulation 2 homolog 1 in migration and invasion of prostate cancer cells. Methods: The cortactin expression levels in DU145, LNCaP and PC3 prostate cancer cells, and in PrEC normal human prostate epithelial cells were evaluated by western blot analysis. In DU145 cells, the expression of cortactin or silent mating type information regulation 2 homolog 1 was inhibited by small interfering RNA, and the effects of their knockdown on migration and invasion were examined by cell migration and invasion assays. To determine the localization of cortactin and silent mating type information regulation 2 homolog 1, western blot and immunofluorescence microscopic analyses were carried out. The functional interaction between silent mating type information regulation 2 homolog 1 and cortactin was also studied by in vivo acetylation assay. Results: The protein expression of cortactin was significantly higher in DU145 cells than in other cell lines. Knockdown of cortactin or silent mating type information regulation 2 homolog 1 expression inhibited both migration and invasion of DU145 cells. Similarly to cortactin, silent mating type information regulation 2 homolog 1 was found to be predominantly expressed in the cytoplasm. Finally, the knockdown of silent mating type information regulation 2 homolog 1 expression increased the acetylation level of cortactin. Conclusions: Our findings suggest that inhibition of cortactin or silent mating type information regulation 2 homolog 1 expression attenuates migration and invasion of DU145 cells and this could represent a promising strategy to regulate metastasis of prostate cancer.     

Tetrandrine suppresses proliferation,induces apoptosis,and inhibits migration and invasion in human prostate cancer cells

Tetrandrine (TET), a traditional Chinese medicine, exerts remarkable anticancer activity on various cancer cells. However, little is known about the effect of TET on human prostate cancer cells, and the mechanism of function of TET on prostate cancer has not yet been elucidated. To investigate the effects of TET on the suppression of proliferation, induction of apoptosis, and inhibition of migration and invasion in human prostate cancer cell lines, DU145 and PC-3. Inhibition of growth was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and clone formation assay, and flow cytometry analysis was performed to detect the induction of apoptosis. Activation of poly (ADP-ribose) polymerase, caspase-3, Akt, phospho-Akt, Bcl-2, and Bax was analyzed by Western blotting. Wound healing assay and transwell migration assay were used to evaluate the effect of TET on migration and invasion of cancer cells. TET inhibited the growth of DU145 and PC–3 cells in a dose- and time-dependent manner. Cell cloning was inhibited in the presence of TET in DU145 and PC-3 cells. TET suppressed the migration of DU145 and PC-3 cells. Transwell invasion assay showed that TET significantly weakened invasion capacity of DU145 and PC-3 cells. TET exhibited strong inhibitory effect on proliferation, migration, and invasion of prostate cancer cells. In addition, TET induced apoptosis in a dose-dependent manner by activating the caspase cascade and inhibiting phosphoinositide 3-kinase-Akt signal pathway. The accumulating evidence suggests that TET could be a potential therapeutic candidate against prostate cancer in a clinical setting.     

DU145 human prostate cancer cells express functional receptor activator of NFkappaB: new insights in the prostate cancer bone metastasis process

Prostate cancer metastases to bone are observed in around 80% of prostate cancer patients and represent the most critical complication of advanced prostate cancer, frequently resulting in significant morbidity and mortality. As the underlying mechanisms are not fully characterized, understanding the biological mechanisms that govern prostate cancer metastases to bone at the molecular level should lead to the determination of new potential therapeutic targets. Receptor activator of NFkappaB ligand (RANKL)/RANK/Osteoprotegerin (OPG) are the key regulators of bone metabolism both in normal and pathological condition, including prostate cancer bone metastases. In the present study, we demonstrated that human prostate cancer cell lines, DU145 and PC3 express biologically functional RANK. Indeed, soluble human RANKL (shRANKL, 100 ng/ml) treatment induced ERK 1/2, p38 and IkappaB phosphorylations in these cells. shRANKL administration also promoted DU145 and PC3 prostate cancer cell invasion in vitro. Whereas human OPG (hOPG) administration alone (100 ng/ml) had no marked effect, combined association of both agents abolished the RANKL-induced DU145 cell invasion. As RANKL had no direct effect on DU145 cell proliferation, the observed effects were indeed related to RANKL-induced cell migration. DU145 human prostate cancer cells promoted osteoclastogenesis of osteoclast precursors generated from mouse bone marrow. Moreover, DU145 cells produced soluble factor(s) that up-regulate the proliferation of MC3T3-E1 pre-osteoblasts through the activation of the ERK 1/2 and STAT3 signal transduction pathways. This stimulation of pre-osteoblast proliferation resulted in an increased local RANKL expression that can activate both osteoclasts/osteoclast precursors and prostate cancer cells, thus facilitating prostate cancer metastasis development in bone. We confirm that RANKL is a factor that facilitates metastasis to bone by acting as an activator of both osteoclasts and RANK-positive prostate cancer cells in our model. Furthermore, the present study provides the evidence that blocking RANKL-RANK interaction offer new therapeutic approach not only at the level of bone resorbing cells, but also by interfering with RANK-positive prostate cancer cells in the prostate cancer bone metastasis development.     

Inhibitory effects of digitalis on the proliferation of androgen dependent and independent prostate cancer cells

PURPOSE: Digitalis or cardiac glycosides have been noted to induce tumor static or oncolytic effects in various types of cancer. We evaluated the effects and underlying mechanisms of cardiac glycosides, including digoxin, digitoxin and ouabain, on the proliferation of hormone dependent and independent prostate cancer cell lines. MATERIALS AND METHODS: Cell proliferation of the 3 human prostate cancer cell lines LNCaP, DU145 and PC3 was measured by 3-(4,5-dimethylthiazol-2-yle)2,5-diphenyltetralozium bromide (Sigma Chemical Co., St. Louis, Missouri) colorimetric assay. The cytotoxic effects of digitalis on prostate cancer cells were determined by lactate dehydrogenase measurements of the culture medium. Intracellular Ca2+ was measured by a dual wavelength spectrometer system. The percent of apoptotic cells after digitalis treatment was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling and flow cytometry. RESULTS: Digoxin, digitoxin and ouabain significantly inhibited the proliferation of LNCaP, DU145 and PC3 cells at a dose of 1 or 10 microM. after 1 to 4 days of culture. Cytotoxicity of digitalis on the DU145 and LNCaP cells was dose dependent but cytotoxicity was not obvious in PC3. Digitalis (1 microM.) significantly increased intracellular Ca2+ in LNCaP and DU145 after 12 hours of culture but PC3 cells needed a 24-hour treatment to show any effect. In the apoptosis measurement digitalis at a dose of 1 and 10 microM. also significantly increased the percent of apoptotic cells in the LNCaP, DU145 and PC3 cell lines. Normal control human glomerular epithelial cells showed no response to digitalis treatment at all tested doses. CONCLUSIONS: Digitalis may inhibit the proliferation of prostate cancer cell lines, although the 3 cell lines showed varied sensitivity to digitalis. These effects are possibly the result of a mechanism involving sustained elevation of the concentration of intracellular Ca2+ and of apoptosis.