胱硫醚β合成酶在前列腺癌中的异常表达及其对前列腺癌细胞增殖的调控作用

目的:探讨胱硫醚β合成酶(CBS)在前列腺癌中的差异表达情况,及其对前列腺癌细胞增殖的调控作用。方法:利用GEPIA网站分析来源于TCGA和GTEx数据库的492例前列腺癌组织和152例正常组织中CBS mRNA表达情况。利用ULCAN网站分析来源于TCGA数据库的497例前列腺癌组织和52例正常组织中CBS mRNA的表达情况。用RPIM-1640培养基培养前列腺癌细胞系DU145、PC3、LNCaP和C4-2,免疫印迹实验检测CBS蛋白表达情况。shRNA转染DU145细胞,分为对照shRNA组、CBS shRNA#1组或#2组,克隆形成实验检测细胞克隆形成数量,BrdU标记实验检测细胞增殖能力,免疫印迹实验检测AKT、mTOR、S6K蛋白表达情况,以及AKT S473位点、mTOR S2448位点、S6K T421/S424位点的磷酸化水平。将稳定表达对照shRNA、CBS shRNA#1或#2的DU145细胞注射入小鼠皮下,建立小鼠前列腺癌移植瘤模型,观察肿瘤生长情况。结果:数据库分析结果显示,与正常前列腺组织比较,前列腺癌组织中CBS mRNA的表达水平显著上升。CBS蛋白在...     

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。     

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。     

PTPRJ通过Src/PI3K/Akt信号通路促进前列腺癌细胞的黏附、迁移和侵袭

目的:探究PTPRJ基因表达对前列腺癌DU145细胞黏附、迁移和侵袭的影响以及可能的调控机制。方法:实时荧光定量PCR、Western blot检测PTPRJ在前列腺肿瘤组织和细胞系中的表达;用携带PTPRJ特异shRNA的重组慢病毒(LV-shPTPRJ)感染沉默PTPRJ表达;MTT检测细胞黏附力,Transwell检测细胞迁移和侵袭;实时荧光定量PCR、Western blot检测信号通路分子mRNA和蛋白表达。结果:与正常前列腺组织和细胞相比,PTPRJ在前列腺肿瘤组织和PC-3、DU145细胞系中表达升高（P＜0.05）;与对照组相比,沉默PTPRJ后前列腺癌DU145细胞黏附、迁移和侵袭能力显著下降（P＜0.01）、信号通路蛋白pY418Src、p-PI3K和p-Akt表达水平均显著降低（P＜0.05）;SC79激活PI3K/Akt可逆转PTPRJ下调对DU145细胞黏附和侵袭的影响;沉默PTPRJ下调裸鼠瘤体组织中pY418Src、p-PI3K和p-Akt表达（P＜0.05）。结论:PTPRJ可能通过激活Src/PI3K/Akt信号通路来促进DU145细胞的黏附、迁移和侵袭,预示PTPRJ可能成为前列腺癌治疗的潜在靶点。     

基因沉默白介素8对激素非依赖前列腺癌干细胞的生物特性的影响

目的：探讨小干扰RNA沉默激素非依赖前列腺癌DU145细胞白介素8基因对肿瘤干细胞生物学特性及耐药性的影响。方法用不同剂量的小干扰RNA沉默激素非依赖前列腺癌DU145细胞IL-8基因,应用流式仪检测AL-DH阳性细胞比例的变化。采用悬浮细胞成球和克隆形成实验分别观察肿瘤干细胞自我更新和体外成瘤能力的变化。Annexin V-PE／7-AAD细胞凋亡双染试剂盒检测细胞凋亡率的变化,Western-blot法分析Akt蛋白的变化。结果 DU145细胞IL-8基因的沉默能降低肿瘤干细胞的比例,显著降低肿瘤干细胞悬浮细胞成球率和克隆形成率。多西他赛能显著抑制IL-8基因沉默DU145细胞的活性。 Western-blot显示Akt的磷酸化被显著抑制。结论 IL-8基因的沉默能显著抑制激素非依赖前列腺癌干细胞的自我更新和体外成瘤能力,增加该群细胞对多西他赛的化疗敏感性,同时显著抑制了Akt的磷酸化,这可能是IL-8基因沉默抑制该群细胞干细胞特性的作用机制之一。     

负性协同刺激分子B7-H1和B7-H3在乳腺癌组织中的表达及其临床意义

目的:探讨受体酪氨酸激酶Axl及其配体Gas6蛋白在前列腺癌细胞系和前列腺癌组织中的表达及其与前列腺癌病理特征的关系。方法：收集自2007年2008年在第二军医大学长海医院泌尿外科接受手术或病理穿刺的前列腺癌组织标本45例和良性前列腺增生组织标本32例。 Western blotting分析前列腺癌细胞系LNCaP、PC3及DU145中Axl及其配体Gas6的表达;免疫组化方法检测前列腺癌及良性前列腺增生组织中Axl及其配体Gas6的表达。结果：Western blotting检测结果显示,高侵袭性前列腺癌细胞DU145和PC3中Axl的表达显著强于低侵袭性细胞LNCaP,Gas6的表达在3个细胞系中无明显差异。 免疫组化结果显示,前列腺癌组织中Axl蛋白强阳性表达显著高于良性前列腺增生组织（68.9％ vs 21.9％,P<0.01）;前者Gas6蛋白的表达也显著高于后者（53.3% vs 15.6％,P<0.01）。前列腺癌组织中,Axl和Gas6蛋白的强阳性表达与Gleason评分及远处转移密切相关（P<0.05）。结论：前列腺癌组织中Axl和Gas6高表达,该两者的表达与前列腺癌恶性程度及肿瘤转移密切相关     

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.     

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.     

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。      

地塞米松对前列腺癌DU145细胞ERK1/2活性和cyclin D1表达的影响

目的: 〖HT5"SS〗 探讨糖皮质激素地塞米松抑制雄激素非依赖性前列腺癌细胞DU145的机制。〖HT5W〗方法: 〖HT5"SS〗通过细胞培养方法观察地塞米松及其受体阻断剂RU486对前列腺癌DU145细胞增殖的作用;采用流式细胞仪测定地塞米松对DU145细胞细胞周期的影响;利用Western blot技术检测DU145细胞受地塞米松作用后cyclin D1表达水平和ERK1/2活性的变化;用RTPCR技术检测DU145细胞中糖皮质激素受体mRNA的表达。〖HT5W〗结果: 〖HT5"SS〗 地塞米松明显抑制DU145细胞的增殖,并且有剂量依赖效应;地塞米松使细胞周期阻滞于G0/G1期。Western blot结果显示,地塞米松作用DU145细胞3 d后,细胞内ERK1/2的活性降低,cyclin D1表达量下降。RU486可以拮抗地塞米松对DU145细胞的作用效果。RTPCR结果显示DU145细胞有糖皮质激素受体mRNA的表达。〖HT5W〗结论: 〖HT5"SS〗地塞米松具有抑制前列腺癌DU145细胞增殖和阻滞细胞周期的作用,此作用与其降低ERK1/2活性、抑制cyclin D1合成有关,提示糖皮质激素对前列腺癌的治疗有重要意义。     

Arachidonate 12-lipoxygenase may serve as a potential marker and therapeutic target for prostate cancer stem cells

The presence of arachidonate 12-lipoxygenase (12-LOX) potentiates prostate cancer (PCa) progression and therefore may be a good therapeutic target and/or a potential diagnostic predictor for PCa. In this study, we examined the expression of 12-LOX in PCa stem cells (PCa SCs) to test if it can serve as a unique marker and therapeutic target for PCa SCs. To this end, we isolated the cancer stem cell-like side population (SP) cells from the human PCa cell line DU-145 by a flow cytometry-based SP technique. The isolated DU-145 SP cells comprised a small population of the DU-145 cells. The SP cells had an up-regulation of ATP-binding cassette sub-family G member 2 (ABCG2) which enables these cells to efflux vital dyes and chemotherapeutic drugs. Furthermore, we detected a strong up-regulation of 12-LOX in these DU-145 SP cells compared to the parental DU-145 cells by RT-PCR and Western blot approaches. We also detected 12-LOX overexpression in PCa SCs in human PCa tissue samples by paraffin-section based immunofluorescent 4-channel confocal microscopy. However, no 12-LOX was detected in normal prostate epithelial SCs in normal prostate tissue samples. These multiple lines of evidence support the possibility that 12-LOX may serve as a unique marker and therapeutic target for PCa SCs.     

Expression, subcellular localization and putative function of platelet-type 12-lipoxygenase in human prostate cancer cell lines of different metastatic potential

The involvement of 12-lipoxygenase (12-LOX) expression and function in tumor metastasis has been demonstrated in several murine tumor cell lines. In addition, 12-LOX expression was detected in human prostatic tumors and correlated to the clinical stage of disease. Here we provide data that human prostate cancer cell lines express the platelet-type isoform of 12-LOX at both the mRNA and protein levels, and immunohistochemistry revealed 12-LOX expression in human prostate tumors. The enzyme was localized to the plasma membrane, cytoplasmic organelles and nucleus in non-metastatic cells (PC-3 nm) and to the cytoskeleton and nucleus in metastatic cells (DU-145). After orthotopic/intraprostatic injection of tumor cells into SCID mice, the metastatic prostate carcinoma cells (DU-145) expressed 12-LOX at a significantly higher level compared with the non-metastatic counterparts, PC-3nm. The functional involvement of 12-LOX in the metastatic process was demonstrated when DU-145 cells were pretreated in vitro with the 12-LOX inhibitors N-benzyl-N-hydroxy-5-phenylpentamide (BHPP) or baicalein, the use of which significantly inhibited lung colonization. These data suggest a potential involvement of 12-LOX in the progression of human prostate cancer.     

Annexin A1 is involved in the acquisition and maintenance of a stem cell-like/aggressive phenotype in prostate cancer cells with acquired resistance to zoledronic acid

In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and maintenance of stem-like/aggressive features in prostate cancer (PCa) cells comparing zoledronic acid (ZA)-resistant DU145R80 with their parental DU145 cells. ANXA1 is over-expressed in DU145R80 cells and its down-regulation abolishes their resistance to ZA. Moreover, ANXA1 induces DU145 and DU145R80 invasiveness acting through formyl peptide receptors (FPRs). Also, ANXA1 knockdown is able to inhibit epithelial to mesenchymal transition (EMT) and to reduce focal adhesion kinase (FAK) and metalloproteases (MMP)-2/9 expression in PCa cells. DU145R80 show a cancer stem cell (CSC)-like signature with a high expression of CSC markers including CD44, CD133, NANOG, Snail, Oct4 and ALDH7A1 and CSC-related genes as STAT3. Interestingly, ANXA1 knockdown induces these cells to revert from a putative prostate CSC to a more differentiated phenotype resembling DU145 PCa cell signature. Similar results are obtained concerning some drug resistance-related genes such as ATP Binding Cassette G2 (ABCG2) and Lung Resistant Protein (LRP). Our study provides new insights on the role of ANXA1 protein in PCa onset and progression.     

Evidence of oxytocin/oxytocin receptor interplay in human prostate gland and carcinomas

Data on the presence of oxytocin receptors (OTR) within the prostate are still controversial and variable among different species. In the present study, OTR expression and localization has been investigated in human hyperplastic and neoplastic prostate at mRNA and protein levels using in situ hybridization (ISH) and immunohistochemistry (ICC) techniques, respectively. In all the cases studied, epithelial cells expressed OTR mRNA and protein. Interestingly, this expression was more intense in neoplastic epithelial cells compared to the hyperplastic ones. In order to determine whether OTR might mediate a biological effect of oxytocin (OT) in prostate cancer cells, OTR expression was studied by RT-PCR and immunofluorescence technique in the human androgen-independent prostate cancer cell line DU145. In addition, a possible heterotopic production of OT by DU145 cells was studied using RT-PCR. The data obtained showed that DU145 cells expressed OTR, whereas no OT mRNA was detected. When DU145 cells were treated with OT (100 nM) a significant inhibition of cell proliferation was observed, while co-incubation with the OT antagonist OTA (100 nm) abolished such an effect. The involvement of apoptosis in the OT effect contrasting cell proliferation was excluded by ISEL technique, which revealed a similar pattern of DNA fragmentation in either untreated or OT-treated cells. Altogether, the data indicate that the OT/OTR system could be involved in the control of prostate neoplastic pathology.