Prostate stem cell antigen enhancer and uroplakin II promoter based bladder cancer targeted tissue-specific vector

PurposeTo construct a dual specific vector which contains prostate stem cell antigen enhancer (PSCAE) and uroplakin II (UPII) promoter targeted bladder cancer.MethodsUPII promoter and PSCAE were amplified by polymerase chain reaction (PCR). Luciferase gene (LUC) was obtained from plasmid pBK-CMV-LUC. PSCAE, UPII promoter and LUC were inserted into shuttle plasmid to create Rp-UPII-LUC and Rp-PSCAE-UPII-LUC. Rp-UPII-LUC and Rp-PSCAE-UPII-LUC were cotransfected with pCMV-β-gal into various cell lines at the presence or absence of androgen receptor agonist R1881 and androgen receptor antagonist flutamide. Luminescence was detected with luciferase assay kit and counted on liquid scintillation counter.ResultsBladder cancer cells showed higher LUC activity than non-bladder cancer cells after transfected with plasmids Rp-UPII-LUC and Rp-PSCAE-UPII-LUC. PSCAE could improve the LUC activity in both AR positive and AR negative bladder cancer cells but not in non-bladder cancer cells and normal human urothelial (NHU) cells. R1881 could increase the LUC activity in AR positive bladder cancer cells but not in AR negative bladder cancer cells and non-bladder cancer cells. Flutamide could not inactivate PSCAE in bladder cancer cells.ConclusionsPSCAE can improve target gene expression in bladder cancer cells but not in non-bladder cancer cells and NHU cells. PSCAE maintains a certain level of androgen independent activity in bladder cancer cells. PSCAE is active in both AR positive and AR negative bladder cancer cells. The results suggest that combination of PSCAE with UPII promoter is feasible in constructing bladder cancer-specific vectors.     

稳定高表达Uroplakin Ⅱ基因人膀胱癌细胞株的建立及其意义

目的　建立稳定高表达UroplakinII(UPII)基因的人膀胱癌细胞株。方法　采用分子克隆技术构建含全长UPII结构基因的真核表达载体 ,进行酶切鉴定、核酸序列分析 ,并将其在阳离子脂质体Lipofectamine 2 0 0 0的介导下转染UPII基因缺陷型膀胱移行细胞癌 (TCC)细胞株EJ ,经G418筛选获得抗性亚克隆细胞株 ;逆转录 聚合酶链反应 (RT PCR)、Westernblotting方法对亚克隆细胞株进行UPII基因表达鉴定。结果　所获UPII基因真核表达载体pcDNA3 UPII转染EJ细胞后 ,通过G418持续压力筛选 4周获得亚克隆细胞株EJ/UPII ;RT PCR、Westernblotting均未检测到EJ细胞的UPII基因表达 ,而EJ/UPII细胞中UPIImRNA和蛋白表达水平显著增高 (P <0 .0 1)。结论　通过基因转染方法建立了稳定高表达UPII基因的膀胱TCC细胞株 ,为进一步探讨UPII基因在膀胱TCC生物学行为中的作用及其靶向生物治疗策略奠定了基础。     

糖蛋白(MUC1与MUC7)基因在膀胱移行细胞癌的表达研究

目的 探讨糖蛋白MUC1与MUC7基因在膀胱移行细胞癌（BTCC）组织及细胞株中的表达及意义。方法 采用MUC1与MUC7特异性巢式逆转录-聚合酶链反应（RT—PCR）对分离的4种组织标本及3种细胞株的mRNA样本进行检测。结果 所有4种组织标本及3种膀胱癌细胞株的MUC1基因表达均为阳性。MUC7基因表达仅见于3种膀胱癌细胞株和侵袭性移行细胞癌标本。半定量结果显示MUC1 mRNA基因表达在正常膀胱黏膜同腺性膀胱炎及各期膀胱癌之间差异有统计学意义（P〈0．05）。浅表性膀胱癌与侵袭性膀胱癌之间差异有统计学意义（P〈0．05）。不同细胞系BIU-87与T24之间表达差异无统计学意义（P〉0．05），耐药细胞株BIU-87／A同敏感细胞株BIU-87与T24之间表达差异有统计学意义（P〈0．05）。MUC7 mRNA基因表达在3种细胞株及侵袭性膀胱癌组织之间差异无统计学意义（P〉0．05）。结论 MUC1基因的上调表达与MUC7基因的差异性表达可能影响膀胱癌细胞的生物学行为，导致相应的临床后果-恶性转变、侵袭转移、耐药。MUC7基因表达是尿路上皮恶性侵袭性转化的开始。     

5-氮杂脱氧胞苷与曲古抑菌素A对膀胱癌细胞株ALDH1a2基因表达及凋亡的影响

目的 探讨5-氮杂脱氧胞苷(5-Aza-dC)与曲古抑菌素A(TSA)对膀胱癌细胞中抑癌基因ALDH1a2启动子甲基化状态和基因表达及细胞凋亡的影响.方法 使用5-Aza-dC、TSA处理RT-4、253J、5637、BIU-87和T24后,应用甲基化特异性PCR(MSP)法、逆转录PCR(RT-PCR)法、Western blot法分别检测这5株膀胱癌细胞经药物干预前后ALDH1a2甲基化状态及基因表达情况,应用流式细胞学检测干预前后5株膀胱癌细胞株的凋亡情况.结果 在5株膀胱癌细胞中,ALDH1a2基因表现为高甲基化表达受到抑制,TSA不影响甲基化状态,5-Aza-dC可逆转高甲基化状态并恢复基因表达,联合给予5-Aza-dC和TSA的作用和单独给予5-Aza-dC相似;TSA和5-Aza-dC均可诱导膀胱癌细胞株凋亡,早期凋亡是膀胱癌细胞株死亡的主要方式,5-Aza-dC和TSA有协同作用,3个实验组与对照组比较,差异均有统计学意义(P<0.05).结论 在5株膀胱癌细胞株中,ALDH1a2基因启动子甲基化可能是导致其基因失活的主要原因;5-Aza-dC单独作用和5-Aza-dC及TSA联合应用效果相似,均能恢复基因重新表达进而诱导膀胱癌细胞株的早期凋亡.     

Uromodulin基因启动子在真核细胞中表达的特异性及活性

目的 观察Uromodulin基因启动子在各种真核细胞中表达的特异性及活性.方法 对含Uromodulin基因启动子的真核表达质粒pEGFP-URO进行测序鉴定,利用脂质体转染技术,将质粒转染人近端肾小管上皮细胞株(HK-2)、人肾癌细胞株(ACHN)、人膀胱癌细胞株(T24)、大鼠系膜细胞株(HBZY-1),用荧光显微镜和流式细胞仪观察绿色荧光蛋白(EGFP)的表达.经激发光照射后发出绿色荧光的为阳性细胞,并和pEGFP-N3进行对照研究.结果 转染24 h后HK-2、ACHN阳性率较高(7～12/HP),流式检测结果为13.2%和11.4%;而T24、HBZY-1阳性率较低(0～1/HP),流式检测结果为0%和0.8%.pEGFP-N3在各组细胞中均有较高表达,其阳性率分别为23.08%(HK-2)、19.24%(ACHN)、26.14%(T24)和18.03%(HBZY-1).结论 小鼠Uromodulin基因启动子在HK-2及ACHN中具有特异性的启动活性,其活性约为CMV的50%.     

Antigen(s) on human transitional cell carcinoma detected by a xenogeneic antiserum

Summary In studies concerning human bladder cancer, antisera were raised in rabbits against human tumours, normal tissue, and cell lines derived from human tumours and were analysed by absorption and complement dependent microcytotoxicity tests. No significant selective cytotoxicity was discernible with any unabsorbed antisera. After absorption of A53, (an antiserum against the transitional cell carcinoma derived cell line T24) with peripheral blood cells and normal adult tissues, it was cytotoxic to two bladder cancer cell lines (T24 and J82) but not to four other cell lines. This activity was removed by absorption with each of two specimens of transitional cell carcinoma but not by normal bladder and by absorption with T24 or J82 but not with four other non-bladder cell lines. This functional specificity for transitional cell carcinomas could be due to a tumour associated antigen, a significant quantitative difference between tumour and normal cells, or an embryonic specificity reexpressed on the tumour. Further experiments are necessary to investigate these alternatives.Abbreviations used TAA tumour associated antigen(s) - NRS normal rabbit serum - MEM Eagle's minimal essential medium and additives - LuLiKi mixture of homogenates of human lung, liver and kidney - TCC transitional cell carcinoma - NBI normal bladder     

端粒酶逆转录酶启动子联合CD自杀基因靶向杀伤人肝癌细胞研究

目的 利用肿瘤特异性人端粒酶逆转录酶(hTERT)启动子介导自杀基因CD表达,检测其促进5-FC对肝癌细胞系的杀伤作用.方法 采用聚合酶链反应(PCR)技术获得hTERT基因的启动子片段,将其连至SV40增强子序列后,并克隆到表达荧光素酶基因的报告质粒上,检测hTERT基因启动子在肝癌细胞系Bel-7402和人成纤维细胞HDF中的转录活性,同时将CD自杀基因连至该调控序列后,转染肝癌细胞Bel-7402,通过逆转录(RT)-PCR、噻唑蓝(MTT)比色法检测其作为肝癌基因治疗中肿瘤特异性靶向杀伤载体的可行性.结果 成功构建pGL3-SV40-hTERT载体和SV40-hTERT-CD-GFP质粒载体,转染ST-CD载体后Bel-7402细胞表达CD基因,转染PGL3-SV40-hTERT质粒后Bel-7402细胞中hTERT启动子高表达,相对活性为354%.与未转染组比较,5-Fc对转染SV40-hTERT-CD-GFP质粒载体的肝癌细胞Bel-7402的杀伤效应明显增强(F=27.831,P<0.01).结论 hTERT启动子在肝癌细胞系中具有较强的转录活性,能有效地诱导CD自杀基因的表达.     

5-杂氮脱氧胞苷逆转膀胱癌细胞WIF-1基因转录表达的研究

目的 探讨去甲基化药物5-杂氮脱氧胞苷对膀胱癌WIF-1基因表达的影响及其生物学效应.方法 用5-杂氮脱氧胞苷处理膀胱癌细胞株T24和BIU87,RT-PCR检测WIF-1 mRNA表达情况,免疫细胞化学和Western blot检测WIF-1蛋白表达变化,甲基化特异性PCR检测WIF-1启动子甲基化状态变化,MTT法检测5-杂氮脱氧胞苷对膀胱癌细胞的增殖抑制作用,TUNEL法和流式细胞仪检测细胞凋亡率.结果 5-杂氮脱氧胞苷处理72 h后,WIF-1 mRNA及蛋白表达明显增加,而且恢复为启动子未甲基化状态,膀胱癌细胞增殖明显抑制,FCM法检测T24和BIU87的凋亡率分别为(18.2±2.6)%和(17.3±2.7)%.结论 DNA甲基化是导致WIF-1不表达的重要原因,5-杂氮脱氧胞苷可以通过逆转WIF-1甲基化状态而恢复WIF-1表达,从而抑制膀胱癌细胞的生长并诱导细胞凋亡.5-杂氮脱氧胞苷有望成为膀胱癌的有效辅助化疗药.     

一氧化氮对组织特异性溶瘤腺病毒转染膀胱肿瘤细胞的影响

目的:研究一氧化氮(NO)对肿瘤组织特异性溶瘤病毒转染过程的影响及对外源基因表达的调节作用。方法:构建组织特异性溶瘤腺病毒,常规培养膀胱肿瘤BIU-87和5637细胞株,以硝普钠作为外源性NO的供体。应用PTIO和L-NMMA分别作为内源性NO的清除剂和诱导型一氧化氮合酶(NOS)的抑制剂。采用Nitrate/Nitrite Assay Kit检测NO和(或)病毒作用前后膀胱肿瘤细胞培养液中的NO水平。应用四甲基偶氮唑盐(MTT)法检测NO对重组病毒抗肿瘤细胞增殖的影响;透射电镜观察腺病毒颗粒进入细胞情况和亚细胞结构变化。结果:膀胱肿瘤细胞BIU-87和5637本身培养液中NO水平很低,给予外源性NO供体后NO水平随时间延长而升高。重组病毒Ad-UPⅡ-E1A能通过E1A基因发挥溶瘤作用。NO能够促进该病毒转染入BIU-87、5637细胞。50μmol/L和100μmol/L的NO联合Ad-UPⅡ-E1A 30MOI作用后能够促进肿瘤细胞的增殖,而200μmol/L的NO联合重组腺病毒作用后则促进肿瘤细胞的死亡。NO对Ad-UPⅡ-E1A的作用具有时间依赖性。透射电镜观察发现,重组病毒Ad-UPⅡ-E1A能够进入并在膀胱肿瘤细胞内复制,而NO能够提高病毒的转染效率并引起肿瘤细胞自吞噬和凋亡。结论:NO能够促进溶瘤腺病毒Ad-UPIIE1A转染膀胱肿瘤细胞的效率,但NO因其浓度不同对溶瘤腺病毒的溶瘤效果具有双向调节作用,低剂量的NO能够下调重组病毒E1A的表达从而促进肿瘤细胞增殖,而高剂量的NO通过上调E1A的表达因而发挥溶瘤效应。     

双启动子引导自杀基因靶向杀伤5-FU耐药肿瘤细胞的研究

目的：探讨胸苷酸合成酶（TS）基因启动子和p16基因启动子引导胸苷激酶（TK）自杀基因靶向杀伤5－FU耐药肿瘤细胞的作用。方法：构建TS、p16双启动子重组表达载体,将TK基因插入TS、p16启动子之间,转染耐药人直肠癌细胞系HR－8348、外周血单个核细胞。通过克隆形成实验、细胞存活率测定和裸鼠移植瘤治疗实验,观察双启动了引导TK基因特异杀伤肿瘤细胞的作用。结果：将TS、p16双启动子重组质粒载体转入耐药HR－8348细胞,检测TS、TK基因表达阳性,TK基因与TS表达一致。转染组和对照组肿瘤细胞集落形成分别为：9／300、92／300。转染组瘤细胞集落形成率明显降低（t=33.885,P＜0．01）,癌细胞生长抑制率显著提高。对裸鼠移植瘤的生长抑制率为74．5％。在转染的外周血单个核细胞,p16表达阳性,TS、TK表达阴性。转染双启动子重组质粒对正常外周血单个核细胞无损伤作用。结论：TS和p16双启动子可引导TK基因靶向性杀伤5－FU耐药肿瘤细胞,保护肌体正常细胞,提高自杀基因治疗的安全性。     

miR-145 inhibits invasion of bladder cancer cells by targeting PAK1

ObjectivesMicroRNAs play important roles in cancer. In many cancers, miR-145 acts as a tumor suppressor, and it is down-regulated in bladder cancer. In the present study, we explored the modulation of oncogenic gene PAK1 by miR-145 in bladder cancer.Material and methodsExpression of miR-145 was detected in bladder cancer tissues and cell lines by quantitative real-time polymerase chain reaction. Through the bioinformatics approach, PAK1 has been predicted to be a direct target of miR-145 and was confirmed by the PAK1 messenger RNA 3′-untranslated region luciferase activity assay. To investigate whether miR-145 regulates PAK1 expression, it was overexpressed in J82 and T24 bladder cancer cells. In 10 paired bladder normal and tumor tissues, we determined the relationship between miR-145 and PAK1 through quantitative real-time polymerase chain reaction and western blot. By using transwell invasion assay and western blotting analysis, we investigated the effects of miR-145 and PAK1 on bladder cancer cell invasion and expression of invasion marker genes.ResultsThe level of miR-145 decreases and PAK1 protein expression up-regulates in bladder cancer tissue, as compared with the paired normal bladder tissue. Moreover, miR-145 directly targets PAK1 in bladder cancer cells. The level of miR-145 negatively correlates with PAK1 protein expression in bladder cancer. In addition, PAK1 promotes invasion and enhances the expression and activity of MMP-9, whereas miR-145 inhibits bladder cancer cell invasion and expressions of PAK1 and MMP-9.ConclusionsOur results indicate that miR-145 inhibits bladder cancer cell invasion, at least partly through targeting PAK1. Restoration or replacement of miR-145 could be an efficient approach to inhibit PAK1 and bladder cancer development in the tumor therapy.     

p21WAF1/CIP1 gene is inactivated in metastatic prostatic cancer cell lines by promoter methylation

INTRODUCTION: p21WAF1/CIP1 may act as a tumour suppressor gene (TSG) and loss of the p21WAF1/CIP1 gene has been reported in several solid tumours. The aim of this study was to see whether p21WAF1/CIP1 was expressed in metastatic prostate cancer cell lines and to determine if there was methylation of the p21WAF1/CIP1 promoter. METHOD: PC3, LNCaP and DU145 metastatic prostate cancer cell lines, 1542NP normal prostate, and RD rhabdomyosarcoma cell lines were cultured in the demethylating agent 5-Aza-2 deoxycytidine (5-Aza-CdR). p21WAF1/CIP1 mRNA expression was analysed by RT-PCR. DNA from untreated cell lines was modified with sodium bisulphite and promoter sequencing was performed. RESULTS: p21WAF1/CIP1 was expressed at low or undetectable levels in metastatic prostate cancer cell lines but expression was reactivated by treatment with 5-Aza-CdR. Sequence analysis of the promoter region revealed several sites of methylation at the 5' end of a CpG island in the PC3, LNCaP and DU145 cell line DNA but not in the normal prostate control DNA. Most notably the Sis-inducible element (SEI)-1-a STAT1-binding site, was methylated. CONCLUSIONS: In this study, we show that p21WAF1/CIP1 expression in metastatic prostate cancer cell lines is enhanced as a result of demethylation of the DNA. Furthermore, several cytosine residues in the promoter region are methylated, including critical binding sites. The inhibition of the STAT1-signalling pathway by methylation of the promoter may inactivate the p21WAF1/CIP1 TSG in prostate cancer.     

ANALYSIS OF nm23 GENE EXPRESSIONS IN HUMAN BLADDER AND RENAL CANCERS

We measured nm23-H1 and nm23-H2 mRNA levels in tissues from 22 human bladder cancers and 16 renal cell carcinomas, and in 7 bladder cancer and 6 renal cancer cell lines by Northern blot and slot blot hybridization analyses. Differences in mRNA levels were evaluated in primary tumor tissues and in paired normal tissues and cell lines. Moreover, nrh23 gene expression in primary tumor tissues was compared with clinicopathological features. High nm23-H1 and nm23-H2 expression was observed in cancerous areas of human bladder tissue ( nm23-H1 : p = 0.001, nm23-H2 : p = 0.001) and bladder cancer cell lines ( nm23-H1: p = 0.001, nm23-H2: p< 0.001) compared with that in normal bladder mucosa. However, mRNA levels of both nm23 genes were not associated with histological grade, pathological stage, tumor metastasis or prognosis. On the other hand, in human renal cell carcinomas, levels of both nm23 mRNAs in tumor tissues were similar to those in paired normal kidneys, but elevated in cultured cell lines ( nm23-H1: p= 0.002, nm23-H2: p = 0.014). Moreover, there was a tendency towards high nm23 gene expression in grade 2 tumors compared with grade 1 (grade 1 vs grade 2, nm23-H1: p = 0.107, nm23-H2: p = 0.008; no grade 3 tumors in this study) and in high stage renal cancers (stage II vs stage III, nm23-H1: p = 0.023, nm23-H2: p = 0.005). From these results, we suggest that reduced nm23 mRNA levels are not associated with metastasis of either bladder or renal cancers and there may be some tissue-specific differences in the expression patterns of nm23-H1 and nm23-H2 in human cancers.     

抑癌基因RUNX3在膀胱癌T24细胞株中的表达以及对凋亡的影响

目的 明确RUNX3抑癌基因在正常膀胱组织和膀胱癌T24细胞株的甲基化状态,并将野生型RUNX3基因转染T24细胞,探讨RUNX3基因恢复表达后对膀胱癌细胞凋亡的影响. 方法应用RT-PCR、甲基化特异性PCR和非甲基化PCR检测正常膀胱组织、膀胱癌T24细胞中RUNX3基因的表达以及基因启动子区域CpG岛的甲基化状态.构建真核载体的RUNX3-EGFP-pDest质粒,在LipefectamineTM2000介导下转染膀胱癌T24细胞,转染实验设立3组:空白对照组、空质粒EGFP-pDest转染组以及RUNX3-EGFP-pDest转染组.Western blot检测RUNX3蛋白表达,流式细胞仪检测细胞凋亡情况. 结果正常膀胱组织RT-PCR可检测出1248bp的RUNX3基因条带,而膀胱癌T24细胞中无法检测出RUNX3基因的表达.正常膀胱组织RUNX3基因甲基化PCR检测阴性,非甲基化PCR阳性;T24细胞反之.正常膀胱粘膜组和RUNX3-EGFP-pDest质粒转染组Western blot检测,均表达RUNX3蛋白,而膀胱癌T24细胞未表达RUNX3蛋白.流式细胞仪检测,空白对照组的凋亡率为(3.1±0.46)%,而EGFP-pDest转染组和RUNX3-EGFP-pDest质粒转染组的凋亡率分别为(10.1±1.62)%、(41.20±1.53)%,应用方差分析的LSD法和SNK法进行均数的多重两两比较,RUNX3-EGFP-pDest质粒转染组与EGFP-pDest转染组、空白对照组凋亡率之间的差异均具有显著性,P<0.01.结论 正常膀胱组织RUNX3基因正常表达,未发生启动子区域CpG岛甲基化,而膀胱癌T24细胞可能因RUNX3基因启动子区域CpG岛发生甲基化,致RUNX3基因无法表达.转染野生型RUNX3抑癌基因后促进了膀胱癌T24细胞的凋亡.