CMVE-PEG3启动子在前列腺癌DU145细胞中的活性鉴定

[目的]比较CMVE-PEG3p、PEG-3启动子在DU145细胞中的启动活性,为前列腺癌靶向性基因治疗提供依据.[方法]用PCR法扩增CMV增强子、PEG-3启动子;在真核表达质粒pShuttle-EGFP基础上分别构建2种启动子调控的、以绿色荧光蛋白为目的基因的真核表达质粒pShuttle-CMVE-PEG3p-EGFP、pShuttle-PEG3p-EGFP.将重组质粒用脂质体分别转染前列腺癌DU145细胞和人正常前列腺上皮细胞RWPE-1,72h后用Imagepro-Plus6.0分析2种启动子在相同时间内启动绿色荧光蛋白的表达水平.[结果]重组质粒在DU145细胞中观察到了绿色荧光,在RWPE-1细胞中无绿色荧光.pShuttle-CMVE-PEG3p-EGFP质粒在DU145细胞中表达强于pShuttle-PEG3p-EGFP.2种质粒在DU145细胞中的荧光强度(IOD)分别为246.22、130.93.[结论]所克隆的CMVE-PEG3p启动子和PEG-3启动子在前列腺癌DU145细胞中均表现出肿瘤特异性,其中CMVE-PEG3p启动子具有更强的启动效应,有望开发成为前列腺癌靶向性基因治疗的工具.     

PEG-3启动子在前列腺癌细胞DU145中的活性鉴定

目的探讨PEG-3启动子在前列腺癌细胞DU145中的启动活性。方法用PCR法扩增PEG-3启动子;在真核表达质粒pShuttle-CMVp-EGFP基础上构建PEG-3启动子调控的、转录绿色荧光蛋白基因的真核表达质粒pShuttle-PEG3p-EGFP。将2种质粒(pShuttle-PEG3p-EGFP和pShuttle-CMVp-EGFP)用脂质体分别转染前列腺癌细胞DU145和人正常前列腺上皮细胞RWPE-1,72 h后在荧光显微镜下用Im-agepro-Plus 6.0分析2种启动子启动绿色荧光蛋白基因的转录活性。结果重组质粒在前列腺癌细胞DU145中观察到了绿色荧光,在人正常前列腺上皮细胞RWPE-1细胞中无绿色荧光。pShuttle-PEG3p-EGFP和pShuttle-CMVp-EGFP 2种质粒在前列腺癌细胞DU145中的荧光强度分别为403.50、130.93。结论所克隆的PEG-3启动子表现出较强的肿瘤特异性,在前列腺癌细胞DU145中有一定的启动活性,可望开发成为肿瘤靶向性基因治疗工具。     

miRNA-135在调控前列腺癌细胞增殖中的应用及机制

目的 观察miRNA-135在调控激素非依赖性前列腺癌细胞增殖能力中的作用及其机制.方法 利用微小核糖核酸(miRNA)基因芯片检测激素非依赖性前列腺癌和激素依赖性前列腺癌组织中miRNA-135的表达差异.经过体外转染miRNA-135后对DU145和PC3细胞进行MTT检测,了解细胞的增殖情况.利用miRNA-135靶基因预测软件miRwalk和miRanda预测,初筛miRNA-135调控的基因和相关通路.结果 miRNA基因芯片结果显示,激素依赖性前列腺癌组织中miRNA-135的表达量高于激素非依赖性前列腺癌组织(P﹤0.05);miR-NA-135可以抑制DU145和PC3细胞的生长,尤其在第48 h和第72 h以后(P﹤0.05);转染miRNA-135后,前列腺癌细胞株DU145和PC3中STAT6的表达水平较转染NC的细胞株明显下调.结论 miRNA-135能够抑制激素非依赖性前列腺细胞DU145和PC3的增殖能力,有望成为前列腺癌治疗的新靶标.     

miR-149通过靶向FOXM1基因抑制前列腺癌细胞的生长和侵袭

  目的  探讨miR-149对前列腺癌细胞生长和侵袭的影响,并研究miR-149的靶基因及其功能。  方法  利用实时荧光定量PCR检测前列腺癌和癌旁组织miR-149和FOXM1 mRNA表达水平。在人前列腺癌细胞系PC3和DU145细胞中瞬时转染miR-149模拟物和阴性对照miRNA,运用平板克隆形成和Transwell侵袭实验检测细胞生长和侵袭。在细胞中分别转染miR-149靶基因FOXM1的siRNA和siRNA阴性对照,利用Western blot检测FOXM1蛋白表达情况,并检测细胞的克隆形成和侵袭能力。  结果  在前列腺癌中miR-149低表达（P < 0.01）,FOXM1 mRNA高表达（P < 0.01）。与对照组细胞相比,转染miR-149模拟物的PC3和DU145细胞克隆数目减少（P < 0.01）,发生侵袭的细胞减少（P < 0.01）;FOXM1蛋白水平在转染miR-149模拟物的PC3（P < 0.01）和DU145细胞（P < 0.05）中较对照组细胞降低。转染FOXM1 siRNA的PC3和DU145细胞中FOXM1蛋白水平较对照组降低,且克隆形成和侵袭能力较对照组明显降低（P < 0.01）。  结论  miR-149通过靶向FOXM1抑制前列腺癌细胞生长和侵袭,发挥着抑癌基因的作用,可作为前列腺癌分子治疗的有效靶点。      

miR-17-92基因簇增强前列腺癌DU145细胞的迁移、侵袭能力及对顺铂的耐药性

背景与目的:miR-17-92基因簇与多种疾病的发生密切相关,其在肺癌、肝癌、胃癌和前列腺癌等多种肿瘤细胞中均高表达.本研究利用慢病毒包装系统建立稳定高表达miR-17-92基因簇的DU145细胞株,探讨miR-17-92基因簇对前列腺癌DU145细胞的迁移、侵袭能力及对顺铂耐药性的影响.方法:构建高表达miR-17-92基因簇的表达载体,转染DU145细胞株,同时转染空载体作为对照,并用实时荧光定量聚合酶链反应(real-time lfuorescent quantitative polymerase chain reaction,RTFQ-PCR)进行鉴定.用xCELLigence系统监测细胞的迁移、侵袭能力及顺铂处理后的生长情况;通过划痕实验观察细胞的迁移情况;采用蛋白[质]印迹法(Western blot)、凝胶酶谱实验和RTFQ-PCR检测相关蛋白质和基因的表达以探讨miR-17-92增强DU145细胞的迁移、侵袭能力及对顺铂耐药性的相关机制.结果:DU145-miR-17-92细胞迁移速率和侵袭能力高于DU145-control细胞(P<0.01).DU145-miR-17-92细胞中整合素β1的蛋白质表达水平和基质金属蛋白酶-9(matrix metalloprotein-9,MMP-9)的活性显著高于DU145-control细胞.顺铂处理后,DU145-miR-17-92细胞的生长速度自12 h起快于DU145-control细胞并呈顺铂耐药性(P<0.01).细胞外调节蛋白激酶1/2(extracellular regulated protein kinases,ERK1/2)在DU145-miR-17-92细胞中呈现持续高水平磷酸化,顺铂处理后,其磷酸化水平无明显变化.DU145-miR-17-92细胞中切除修复互补交叉基因1(excision repair cross complementing1,ERCC1)的mRNA和蛋白质表达水平显著高于DU145-control细胞.结论:高表达miR-17-92增强了DU145细胞的迁移、侵袭能力,其机制与整合素β1的表达上调及MMP-9活性增强有关.此外,高表达miR-17-92增强了DU145细胞对顺铂的耐药性,该过程与ERK1/2的磷酸化水平增加和ERCC1的表达水平上调相关.     

shRNA沉默RAGE基因表达对前列腺癌细胞增殖的抑制作用

目的:构建针对人晚期糖基化终产物受体(receptor for advanced glycation end products , RAGE)基因的特异性短发夹RNA(small hairpin RNA, shRNA)表达载体,探讨其对前列腺癌细胞DU145增殖的抑制作用.方法:设计并合成4种针对RAGE基因的特异性短链寡核苷酸,构建含shRNA RAGE的表达载体,转染高表达RAGE的亚克隆细胞株sub DU145-2C1.荧光显微镜下观察细胞转染后的情况,实时荧光定量PCR(real-time fluorescence quantitative -PCR, RFQ-PCR)检测转染shRNA后对RAGE mRNA表达的影响,Western印迹法检测对RAGE蛋白表达的影响,CCK-8法检测对细胞增殖的影响,划痕实验观察对细胞迁移能力的影响.结果:构建获得的shRNA RAGE表达载体能够有效抑制RAGE基因的表达(P<0.05),其中以shRNA RAGE -1(R1)的抑制作用最强,其对RAGE mRNA表达的抑制率为84%,对蛋白表达的抑制率为27%.细胞增殖结果显示,转染shRNA RAGE后细胞增殖能力明显降低;而细胞迁移能力则无明显变化.结论:shRNA RAGE能有效下调RAGE基因的表达水平,抑制细胞增殖.     

EHD2负向调控前列腺癌细胞的增殖与转化能力

  目的  研究EHD2在前列腺癌中的表达以及EHD2表达水平对前列腺癌细胞系增殖与转化能力的影响。  方法  免疫组织化学方法检测EHD2在14例前列腺癌组织及7例前列腺增生组织中的表达。用EHD2干扰表达质粒、过表达质粒和对照载体分别转染293T细胞, 制备慢病毒, 感染DU145细胞, 建立稳定细胞系。用Western blot技术检测EHD2表达情况。采用细胞计数法、二维克隆形成实验、Soft Agar实验分别检测EHD2沉默或过表达对前列腺癌细胞增殖能力、克隆形成能力和转化特性的影响。  结果  免疫组织化学显示EHD2在前列腺癌组织中表达量明显低于前列腺增生组织。EHD2干扰表达后DU145细胞的增殖能力、二维克隆形成能力、三维克隆形成能力均明显增强(P < 0.01);EHD2过表达后DU145细胞的增殖能力和三维克隆形成能力均减弱(P < 0.01和P < 0.05)。  结论  EHD2的表达水平对DU145前列腺癌细胞的增殖与转化特性具有明显的调节作用, EHD2可能是前列腺癌的新抑癌基因。      

人前列腺癌细胞系DU 145中肿瘤干细胞样侧群细胞的分离

目的:分离人前列腺癌细胞系DU 145中的侧群(side population,SP)细胞,并初步分析其生物学特性。方法:采用荧光激活细胞分类(fluorescence activated cell sorting,FACS)技术,从DU 145细胞中分离出侧群细胞,并检测其比例;继而培养于无血清培养基中,观察其生长特性。采用反转录聚合酶链反应(RT-PCR)技术检测侧群细胞中ABCG2的表达水平。结果:DU 1 4 5细胞中存在含量极少的侧群细胞,比例约1.1%;培养于无血清培养基中成簇生长。和对应的母系DU 145细胞相比,DU 145侧群细胞的ABCG2表达增高。结论:人前列腺癌细胞系DU 145中存在具有肿瘤干细胞特性的侧群细胞。     

辛伐他汀通过YAP/TAZ抗前列腺癌细胞增殖的作用及机制研究

目的:考察辛伐他汀对22Rv1和DU145前列腺癌细胞的增殖抑制作用,并对其作用机制进行初步的探讨。方法:复苏并培养22Rv1和DU145前列腺癌细胞株,给予不同浓度辛伐他汀（2 μmol/L、10 μmol/L、50 μmol/L）进行干预。辛伐他汀对22Rv1和DU145前列腺癌细胞的增殖抑制作用采用MTT法检测;对22Rv1和DU145前列腺癌细胞凋亡的影响用流式检测;对22Rv1和DU145前列腺癌细胞增殖相关蛋白p-mTOR(Ser2448)、p-Akt(Ser473)、凋亡相关蛋白Caspase-3、Caspase-9、PARP以及YAP、p-YAP、TAZ表达的影响用Western Blot检测;通过过表达TAZ考察TAZ在辛伐他汀抗前列腺癌细胞增殖中的作用。结果:辛伐他汀抑制22Rv1和DU145前列腺癌细胞的增殖,并呈浓度依赖性和时间依赖性,在分子水平,辛伐他汀浓度依赖性地抑制了p-mTOR(Ser2448)和p-Akt(Ser473)的表达;辛伐他汀浓度依赖性地诱导22Rv1和DU145前列腺癌细胞发生凋亡,并在分子水平浓度依赖性地促进了Caspase-3、Caspase-9和PARP的剪切;辛伐他汀浓度依赖性地上调p-YAP的表达,抑制TAZ的表达,过表达TAZ减弱了辛伐他汀对前列腺癌细胞的凋亡诱导作用和增殖抑制作用。结论:辛伐他汀可能通过抑制YAP/TAZ诱导前列腺癌细胞凋亡,抑制前列腺癌细胞的增殖。     

PRUNE2点突变影响前列腺癌DU145细胞增殖、凋亡、侵袭和迁移

背景与目的：PRUNE2是成神经细胞瘤的一个特异性预后相关基因,在调节成神经细胞瘤的细胞分化、增殖和侵袭方面发挥着重要作用。PRUNE2低表达与前列腺癌的不良预后密切相关。探讨PRUNE2点突变对前列腺癌DU145细胞增殖、凋亡、侵袭和迁移的影响。方法：通过构建PRUNE2基因野生型和突变型过表达的重组载体并将其转染到DU145细胞中构建相应稳转株。利用细胞计数试剂盒-8（cell counting kit-8,CCK-8）实验和克隆形成实验检测细胞恶性增殖能力,通过细胞凋亡实验检测细胞凋亡能力,采用transwell小室法检测细胞侵袭和迁移能力。采用蛋白质印迹法（Western blot）检测蛋白的表达水平,通过免疫荧光和免疫共沉淀实验检测蛋白之间的相互作用。结果：转染突变型PRUNE2 E370K基因的DU145细胞恶性增殖、侵袭和迁移能力均较对照组显著增强,细胞凋亡率显著降低,差异有统计学意义（P<0.05）。PRUNE2与RhoA之间可以相互结合,但是PRUNE2 E370K突变体与RhoA之间的相关作用明显减弱。同时,PRUNE2 E370K突变体促进Rho通路下游ROCK蛋白和FAK蛋白的表达,促进与细胞增殖相关的Bcl-2和cyclin D1蛋白的表达,同时抑制与侵袭、迁移相关抑制蛋白E-cadherin的表达。结论：前列腺癌DU145细胞中PRUNE2基因点突变可以促进细胞增殖、侵袭和迁移,并抑制细胞凋亡。     

转染PDCD5基因促进顺铂诱导前列腺癌细胞的凋亡作用

目的探讨过表达细胞程序性死亡基因5（PDCD5）对顺铂诱导人前列腺癌DU145细胞凋亡以及细胞凋亡相关蛋白表达的影响。方法CCK-8法检测顺铂处理DU145细胞后对细胞生长增殖的影响;构建稳定过表达PDCD5的DU145细胞系;Annexin V-FITC﹠PI 双染法检测细胞的凋亡率、电子显微镜观察细胞凋亡的形态学变化;Western blot法检测细胞凋亡相关蛋白的表达。结果顺铂对DU145细胞的生长有抑制作用,且呈时间-剂量依赖性;成功构建稳定过表达PDCD5的DU145细胞;流式细胞术和电子显微镜都显示PDCD5联合顺铂（25 μmol/L）促进细胞的凋亡作用比联合顺铂（10 μmol/L）和单独使用顺铂明显,Western blot结果显示,顺铂联合PDCD5能明显降低Bcl-2的表达,而Bax的表达变化不明显。结论单独PDCD5过表达不引起DU145细胞的凋亡,但PDCD5能显著增强顺铂诱导DU145细胞凋亡的作用,其机制之一是通过降低Bcl-2/Bax的表达比率实现的。     

SPOCK2基因表达上调对前列腺癌细胞增殖的影响

目的:探讨SPOCK2基因表达上调对前列腺癌细胞增殖的影响。方法:通过Real-time PCR及Western Blot检测前列腺癌组织及细胞中SPOCK2基因的表达。进一步通过基因重组技术上调前列腺癌细胞系DU145及LNCaP中SPOCK2基因表达,通过CCK8检测细胞增殖情况变化,通过流式细胞仪检测细胞周期及凋亡情况。结果:前列腺癌组织中SPOCK2表达显著低于正常对照组（P<0.05）,应用基因重组片段有效上调SPOCK2基因表达后,转染组细胞增殖率均显著低于阴性对照组及空白对照组,差异有显著统计学意义（P<0.05）。转染组G0/G1期细胞百分比显著高于阴性对照组及空白对照组,差异有显著统计学意义（P<0.05）。转染组S期显著低于阴性对照组及空白对照组,差异有显著统计学意义（P<0.05）。DU145细胞转染组凋亡率显著高于阴性对照组及空白对照组,差异有显著统计学意义（P<0.05）。结论:SPOCK2上调可以抑制细胞增殖,促进细胞凋亡,使细胞停滞于G0/G1期,表明该基因可能通过影响细胞增殖,作为抑癌基因在前列腺癌的发生发展中发挥重要作用。     

CCL2 induces resistance to the antiproliferative effect of cabazitaxel in prostate cancer cells

Understanding the mechanism of chemoresistance and disease progression in patients with prostate cancer is important for developing novel treatment strategies. In particular, developing resistance to cabazitaxel is a major challenge in patients with docetaxel‐resistant and castration‐resistant prostate cancer (CRPC) because cabazitaxel is often administered as a last resort. However, the mechanism by which cabazitaxel resistance develops is still unclear. C‐C motif chemokine ligands (CCL) were shown to contribute to the castration resistance of prostate cancer cells via an autocrine mechanism. Therefore, we focused on CCL as key factors of chemoresistance in prostate cancer cells. We previously established a cabazitaxel‐resistant cell line, DU145‐TxR/CxR, from a previously established paclitaxel‐resistant cell line, DU145‐TxR. cDNA microarray analysis revealed that the expression of CCL2 was upregulated in both DU145‐TxR and DU145‐TxR/CxR cells compared with DU145 cells. The secreted CCL2 protein level in DU145‐TxR and DU145‐TxR/CxR cells was also higher than in parental DU145 cells. The stimulation of DU145 cells with CCL2 increased the proliferation rate under treatments with cabazitaxel, and a CCR2 (a specific receptor of CCL2) antagonist suppressed the proliferation of DU145‐TxR and DU145‐TxR/CxR cells under treatments of cabazitaxel. The CCL2‐CCR2 axis decreased apoptosis through the inhibition of caspase‐3 and poly(ADP‐ribose) polymerase (PARP). CCL2 is apparently a key contributor to cabazitaxel resistance in prostate cancer cells. Inhibition of the CCL2‐CCR2 axis may be a potential therapeutic strategy against chemoresistant CRPC in combination with cabazitaxel.     

Suggesting Tissue-Specific MSMB Gene Promoter as a Novel Approach for Prostate Targeted Gene Therapy

Background and aim: Prostate cancer is the second most common cancer among men that has affected their quality of life. This study aimed to find prostate tissue-specific genes using bioinformatics methods to specifically target prostate cells in case of metastasis to other tissues. Materials and Methods: In this study, after finding a specific gene (MSMB)  that is highly expressed in cancer, the optimal promoter region of this gene was isolated and inserted in an expression vector. Then, this vector was transfected into two prostate cancer cell lines (DU145 and LNCaP) and three non-prostate cell lines  (LX-2, MRC-5, and U87) using the PEI chemical method. The expression of this vector in these cells was examined using fluorescent microscopy and flow cytometry. Results: We observed that the expression of MSMB promoter in DU145 cell line has a much higher activity than the CMV promoter, which is a ubiquitous promoter. The MSMB promoter didn’t show any activity in cells other than that of prostate derived cell lines. Conclusion: MSMB  gene promoter with specific expression and high efficiency in prostate tissue compared to CMV promoter can play an essential role in gene therapy of prostate cancer.     

The application of an anti-angiogenic gene (thrombospondin-1) in the treatment of human prostate cancer xenografts

Angiogenesis is a critical event for solid tumor growth and metastasis. Within a given microenvironment, the angiogenic response is determined in part by the balance between angiogenesis inducers and inhibitors. The aim of this study was to establish a thrombospondin-1 (TSP-1) ( an antiangiogenic gene) expression vector, and to determine the feasibility for use of TSP-1 in prostate cancer gene therapy. The results of this study showed that pCR-TSP-1, the cloned TSP-1 expression plasmid vector, expressed the TSP-1 gene efficiently in DU145, a human prostate cancer cell line. pCR -TSP-1 did not exert any significant growth inhibitory activity on the tested cell line in vitro. However, TSP-1 overexpression inhibited the growth of DU-145 xenografts in Balb/c nude mice when directly transfected with pCR-TSP-1 in combination with a liposomal agent (DOSPER). Histological analysis showed that there were extensive areas of necrosis in the TSP-1 overexpressing tumors, whereas no necrotic foci were observed in the control tumors. Furthermore, the microvessel density was lower in the TSP-1 overexpressing tumors compared to the control tumors. These results suggest that TSP-1 may be a potentially useful gene for prostate cancer gene therapy.     

Role of fibroblast growth factor receptor signaling in prostate cancer cell survival.

BACKGROUND: Expression of fibroblast growth factors (FGFs) is increased in a substantial fraction of human prostate cancers in vivo and in prostate cancer cell lines. Altered FGF signaling can potentially have a variety of effects, including stimulating cell proliferation and inhibiting cell death. To determine the biologic significance of altered FGF signaling in human prostate cancer, we disrupted signaling by expression of a dominant-negative (DN) FGF receptor in prostate cancer cell lines. METHODS: PC-3, LNCaP, and DU145 prostate cancer cells were stably transfected with DN FGFR constructs, and LNCaP and DU145 cells were infected with a recombinant adenovirus expressing DN FGFR-1. The effect of DN FGFR-1 expression was assessed by colony-formation assays, cell proliferation assays, flow cytometry, and cytogenetic analysis. Key regulators involved in the G(2)-to-M cell cycle transition were assessed by western blotting to examine cyclin B1 expression and by in vitro kinase assay to assess cdc2 kinase activity. RESULTS: Stable transfection of the DN FGFR-1 construct inhibited colony formation by more than 99% in all three cell lines. Infection of LNCaP and DU145 prostate cancer cells with adenovirus expressing DN FGFR-1 led to extensive cell death within 48 hours. Flow cytometry and cytogenetic analysis revealed that the DN FGFR-1 receptor led to arrest in the G(2) phase of the cell cycle before cell death. Cyclin B1 accumulated in DN FGFR-1-infected LNCaP cells, but cdc2 kinase activity was decreased. CONCLUSIONS: These findings reveal an unexpected dependence of prostate cancer cells on FGF receptor signal transduction to traverse the G(2)/M checkpoint. The mechanism for the G(2) arrest is not clear. Our results raise the possibility that FGF-signaling antagonists might enhance the cell death induced by other prostate cancer therapies.     

The tumor suppressing effects of QKI-5 in prostate cancer: A novel diagnostic and prognostic protein

In recent years, the RNA-binding protein quaking 5 (QKI-5) has been recognized as a novel tumor suppressor in many cancers. To date, no studies have examined the role of QKI-5 in prostate cancer. The present study was designed to elucidate the correlation of QKI-5 expression with the clinical pathological features and prognosis of prostate cancer. In an overwhelming majority of the 184 cases of prostate cancer samples analyzed, the QKI-5 expression was significantly decreased, which was largely due to the high promoter methylation levels. Using lentiviral vectors, we established two stable prostate cancer cell lines with altered QKI-5 expression, including a QKI-5 overexpressing PC3 cell line and a DU145 cell line with knocked-down QKI-5 expression. The effects of the lentiviral-mediated QKI-5 knockdown on the PC3 cells and DU145 cells were assessed by cell growth curves, flow cytometry (FCM), and an invasion assay. The PC3 cells were transplanted into nude mice, and then, the tumor growth curves and TUNEL staining were determined. These results demonstrated that QKI-5 was highly expressed in benign prostatic hyperplasia (BPH) tissues but not in carcinomatous tissues and that QKI-5 effectively inhibited prostate cancer cell proliferation in vitro and in vivo. In addition, the decrease in QKI-5 expression was closely correlated with the prostate cancer Gleason score, poor differentiation, degree of invasion, lymph node metastasis, distant metastasis, TNM grading, and poor survival. These results indicate that the QKI-5 expression may be a novel, independent factor in the prognosis of prostate cancer patients.