PI-3K/Akt抑制剂LY294002对卵巢癌细胞A2780/Taxol多药耐药性的逆转作用

背景与目的:磷脂酰肌醇(phosphatidylinositol 3 kinase,PI-3K)可抑制细胞凋亡,对PI-3K抑制剂的研究可以更好地了解PI-3K的促癌机制,为多种癌症如卵巢癌、乳腺癌等的基因治疗提供线索。本研究目的在于探讨PI-3K/Akt信号通路抑制剂LY294002对卵巢癌耐紫杉醇细胞株A2780/Taxol多药耐药的逆转作用。方法:用LY294002处理A2780/Taxol细胞,流式细胞术检测细胞凋亡,MTT法检测细胞对紫杉醇的药物敏感性,RT-PCR检测MDR1mRNA的表达,Western blot方法分析LY294002作用前后磷酸化Akt及P-gp蛋白的表达。结果:10和50μmol/L LY294002干预A2780/Taxol细胞24h后,A2780/Taxol细胞凋亡率分别为(8.84±1.65)%和(20.78±2.47)%,显著高于未干预细胞的凋亡率(1.25±0.78)%(P<0.05);A2780/Taxol细胞对紫杉醇的半数抑制浓度(IC50)显著降低(P<0.01),相对逆转效率最高可达(78.08±0.37)%;MDR-1mRNA、磷酸化Akt及P-gp蛋白均明显降低。结论:PI-3K/Akt信号通路的激活与卵巢癌细胞多药耐药的产生有关,PI-3K/Akt抑制剂LY294002可逆转卵巢癌细胞A2780/Taxol的多药耐药。     

Short hairpin RNA-mediated MDR1 gene silencing increases apoptosis of human ovarian cancer cell line A2780/taxol

Objective: Recurrent ovarian cancer is often resistant to drugs such as paclitaxel. Short hairpin RNA (shRNA) targeting MDR1, a gene involved in the process of drug resistance, may be a promising strategy to overcome drug resistance. Methods: Construction and identification of eukaryotic expression plasmid of shRNA targeting on MDR1 gene. The plasmid was transiently transfected into human ovarian cancer cell line A2780/Taxol. Apoptosis was determined by flow cytometry using annexin V-FITC/PI double labeling. Expression of MDR1 mRNA was detected by quantitative polymerase chain reaction (qPCR) and P-glycoprotein expression was detected using Western blot. Results: The IC50 of paclitaxel in MDR1 shRNA-transfected group was significantly reduced (1.986±0.153) μmol/ml as compared with that in negative control (5.246±0.107) μmol/ml and empty vector-transfected group (5.212±0.075) μmol/ml (P<0.05). The percent of the relative reverse sensitivity to paclitaxel on A2780/Taxol cells was 67.1%, and the apoptotic rate was significantly increased [(6.977±0.333)%] compared with control [(1.637±0.111)%] and empty vector-transfected group [(1.663±0.114)%] (P<0.05). Expressions of MDR1 mRNA and P-glycoprotein were significantly reduced compared with control (P<0.05). Conclusion: The present study demonstrated that the eukaryotic expression plasmid of shRNA targeting on MDR1 inhibited the expression of MDR1 effectively, thus enhance the sensitivity of A2780/Taxol cells to paclitaxel.     

甲基转移酶抑制剂5-Aza-dC对FANCF基因表达的调控在卵巢癌治疗中的作用

目的:探讨甲基转移酶抑制剂5-氮杂-2’-脱氧胞苷(5-aza-2’-deoxycytidine,5-Aza-dC)对卵巢癌细胞系OVCAR3中FANCF(Fanconi anemia complementation group F)基因表达的影响,及其对化疗药物紫杉醇敏感性的影响,以了解5-Aza-dC的抗肿瘤效应,寻找卵巢癌治疗的新靶点.方法:采用5-Aza-dC处理FANCF基因甲基化的卵巢癌细胞OVCAR3和FANCF基因非甲基化的卵巢癌细胞A2780.应用甲基化特异性PCR(methylation specific-PCR,MSP)、RT-PCR和蛋白质印迹法分析这2种细胞经5-Aza-dC处理前后FANCF基因的甲基化状态以及FANCF mRNA和蛋白的表达情况.MTT法检测卵巢癌细胞的增殖情况.FCM检测紫杉醇对卵巢癌细胞凋亡的影响.建立OVCAR3和A2780细胞裸鼠移植瘤模型,观察5-Aza-dC对裸鼠移植瘤生长的影响,并采用免疫组织化学法检测移植瘤中FANCF蛋白的表达情况.结果:体外实验显示,5-Aza-dC处理后,OVCAR3细胞中FANCF基因发生去甲基化,FANCF mRNA和蛋白的表达水平增加,细胞生长缓慢.5-Aza-dC处理组OVCAR3细胞裸鼠移植瘤体积较未处理组明显缩小,质量也明显降低,FANCF蛋白表达增加;而A2780细胞裸鼠移植瘤组中未观察到上述变化.结论:甲基转移酶抑制剂5-Aza-dC可能通过抑制卵巢癌细胞增殖而成为潜在的卵巢癌治疗药物,但同时也会增加紫杉醇的耐药风险.     

hsa-miRNA27a和hsa-miRNA451通过调控MDRl/P-gp的表达和功能参与卵巢癌和乳腺癌细胞耐药

背景与目的：肿瘤细胞耐药是临床化疗失败的主要原因,微小RNA(microRNA,miRNA)在肿瘤细胞中的异常表达与耐药关系密切。本研究旨在探讨卵巢癌及乳腺癌细胞中hsa-miRNA27a和hsa-miRNA451的表达差异及其与耐药的关系。方法：用浓度递增法建立卵巢癌耐紫杉醇细胞系A2780/Taxol;颈环状引物实时定量聚合酶链反应(stem-loop quantitative real-time PCR,stem-loop RT-PCR)检测卵巢癌耐紫杉醇细胞A2780/Taxol和亲本细胞A2780以及乳腺癌耐阿霉素细胞MCF-7/ADM和亲本细胞MCF-7中hsa-miRNA27a和hsa-miRNA451的表达;利用Lipofectamine^TM 2000分别将成熟miRNA27a的模拟物、阻遏物及阴性对照(negative control,NC)RNA转染A2780和A2780/Taxol细胞,将成熟miRNA451的模拟物及NC转染MCF-7/ADM细胞;RT-PCR技术检测细胞MDR1 mRNA表达;蛋白[质]印迹法(Western blot)检测细胞中P-糖蛋白(P-glycoprotein,P-gp)的表达;采用四甲基偶氮唑蓝(MTT)法检测细胞增殖情况。结果：miRNA27a在A2780/Taxol细胞中高表达,与A2780细胞相比,表达增高2.2±0.30倍,差异有统计学意义(P<0.05);miRNA451在MCF-7/ADM细胞中低表达,与MCF-7细胞相比,表达降低84%,差异有统计学意义(P<0.05)。A2780/Taxol细胞转染miRNA27a阻遏物后,MDR1 mRNA表达明显下降,与转染NC组相比,表达下降(39±0.14)%,差异有统计学意义(P<0.05)。P-gp相对表达量［(26±5.3)%)］与转染NC组的P-gp相对表达量［(43±6.7)%］比较,下降39%,差异有统计学意义(P<0.05)。对紫杉醇的敏感性增加,半数抑制浓度(IC₅₀)为0.53 μmol/L,与转染NC组IC50(6.8 μmol/L)相比,差异有统计学意义(P<0.05)。A2780细胞转染miRNA27a模拟物后,细胞的MDR1 mRNA表达升高,与转染NC组相比,升高(121±0.11)%,差异有统计学意义(P<0.05);细胞对紫杉醇的敏感性下降,IC₅₀为0.2 μmol/L,与转染NC组IC₅₀(0.06 μmol/L)相比,差异有统计学意义(P<0.05)。MCF-7/ADM细胞转染miRNA451模拟物后,MDR1 mRNA表达明显下降,与转染NC组细胞相比,表达下降(65±12)%,差异有统计学意义(P<0.05);P-gp相对表达量［(31±19)%)］与转染NC组细胞P-gp相对表达量［(83±12)%］相比,下降62%,差异有统计学意义(P<0.05);对阿霉素的敏感性增加,IC₅₀为4.61 μmol/L,与转染NC组细胞IC₅₀(26 μmol/L)相比,差异有统计学意义(P<0.05)。结论：在卵巢癌耐紫杉醇细胞A2780/Taxol和乳腺癌耐阿霉素细胞MCF-7/ADM中,miRNA27a和miRNA451分别异常表达,它们可能分别通过间接或直接作用于MDR1/P-gp,参与肿瘤细胞耐药的发生、发展。     

葡萄糖对卵巢癌细胞生长增殖影响体外研究

目的 葡萄糖是维持肿瘤细胞存活的重要能量来源,有关研究表明低糖与无糖条件有可能抑制肿瘤细胞生长,成为潜在的肿瘤治疗方式.本研究通过给予不同浓度葡萄糖刺激SKOV3与A2780卵巢癌细胞系,分析其细胞增殖、细胞周期与细胞凋亡的改变,探讨葡萄糖对卵巢癌细胞生长增殖的影响.方法 在体外配制含不同葡萄糖浓度(0、2.5、 5.5、 25.0 mmol/L)的培养基,分别模拟无糖、低血糖、正常血糖及高血糖水平的体内环境,观察不同葡萄糖浓度对卵巢癌细胞的增殖、凋亡与细胞周期的影响.结果 高糖促进卵巢癌细胞SKOV3和A2780的增殖,干预48 h后,增殖幅度约为无糖组的1.841~1.942倍;低糖与无糖条件诱导卵巢癌细胞发生G1期阻滞,与高糖组相比,SKOV3细胞G1期比例以(40.699±1.131)%增加至(58.619±2.643)%,A2780细胞以(46.348±2.150)%增加至(54.770±2.475)%;低糖与无糖条件亦诱导细胞凋亡,SKOV3与A2780细胞无糖组中凋亡细胞比例分别为(14.015±0.827)%和(12.930±1.127)%.结论 本研究通过探讨葡萄糖对卵巢癌细胞生长与增殖的影响,证明低糖与无糖条件诱导卵巢癌细胞发生G1期阻滞、细胞凋亡并抑制其生长增殖.若进一步给予相应葡萄糖抑制剂干预,可能为卵巢癌的临床治疗提供新思路.     

RIP1蛋白在卵巢癌中的表达及其对卵巢癌细胞增殖和化疗敏感性的影响

目的:探讨RIP1对卵巢癌细胞增殖和化疗敏感性的影响。方法:通过实时定量PCR法检测RIP1在卵巢癌组织和癌旁组织中的表达;免疫组化方法分析卵巢癌组织和癌旁组织中RIP1蛋白的表达;实时定量PCR法以及Western blot法检测卵巢上皮细胞及卵巢癌细胞中RIP1的表达;通过在SKOV3卵巢癌细胞中敲除RIP1蛋白及在A2780卵巢癌细胞中过表达RIP1蛋白,采用MTT法检测其增殖能力的改变,并联合克隆形成法考察细胞对顺铂敏感性的变化。结果:相比于癌旁组织以及卵巢上皮细胞,RIP1在人卵巢癌组织和卵巢癌细胞中表达有不同程度升高,其中在SKOV3细胞中升高最为显著（P＜0.01）,在A2780细胞中不显著（P＞0.05）;在SKOV3细胞中敲除RIP1,96 h后细胞增殖能力明显降低（P＜0.01）;同时,在A2780细胞株中过表达RIP1,72 h后细胞增殖能力明显升高（P＜0.05）。RIP1敲除后,顺铂对SKOV3细胞的杀伤作用明显升高（P＜0.05）,同时顺铂的IC50降低;RIP1过表达后,顺铂对A2780细胞的杀伤作用明显降低（P＜0.05）,同时顺铂的IC50升高。结论:RIP1作为一种癌基因,能够促进肿瘤细胞的增殖,并降低肿瘤细胞对化疗药物的敏感性。     

Reversal of drug resistance in human tumor xenografts by 2'-deoxy-5-azacytidine-induced demethylation of the hMLH1 gene promoter

Loss of DNA mismatch repair because of hypermethylation of the hMLH1 gene promoter occurs at a high frequency in a number of human tumors. A role for loss of mismatch repair (MMR) in resistance to a number of clinically important anticancer drugs has been shown. We have investigated whether the demethylating agent 2'-deoxy-5-azacytidine (DAC) can be used in vivo to sensitize MMR-deficient, drug-resistant ovarian (A2780/cp70) and colon (SW48) tumor xenografts that are MLH1 negative because of gene promoter hypermethylation. Treatment of tumor-bearing mice with the demethylating agent DAC at a nontoxic dose induces MLH1 expression. Re-expression of MLH1 is associated with a decrease in hMLH1 gene promoter methylation. DAC treatment alone has no effect on the growth rate of the tumors. However, DAC treatment sensitizes the xenografts to cisplatin, carboplatin, temozolomide, and epirubicin. Sensitization is comparable with that obtained by reintroduction of the hMLH1 gene by chromosome 3 transfer. Consistent with loss of MMR having no effect on sensitivity in vitro to Taxol, DAC treatment has no effect on the Taxol sensitivity of the xenografts. DAC treatment does not sensitize xenografts of HCT116, which lacks MMR because of hMLH1 mutation. Because there is emerging data on the role of loss of MMR in clinical drug resistance, DAC could have a role in increasing the efficacy of chemotherapy for patients whose tumors lack MLH1 expression because of hMLH1 promoter methylation.     

CD70 antibody-drug conjugate: A potential novel therapeutic agent for ovarian cancer

This study aimed to investigate the cytotoxicity of a cluster of differentiation 70 antibody-drug conjugate (CD70-ADC) against ovarian cancer in in vitro and in vivo xenograft models. CD70 expression was assessed in clinical samples by immunohistochemical analysis. Western blotting and fluorescence-activated cell sorting analyses were used to determine CD70 expression in the ovarian cancer cell lines A2780 and SKOV3, and in the cisplatin-resistant ovarian cancer cell lines A2780cisR and SKOV3cisR. CD70 expression after cisplatin exposure was determined in A2780 cells transfected with mock- or nuclear factor (NF)-κB-p65-small interfering RNA. We developed an ADC with an anti-CD70 monoclonal antibody linked to monomethyl auristatin F and investigated its cytotoxic effect. We examined 63 ovarian cancer clinical samples; 43 (68.3%) of them expressed CD70. Among patients with advanced stage disease (n = 50), those who received neoadjuvant chemotherapy were more likely to exhibit high CD70 expression compared to those who did not (55.6% [15/27] vs 17.4% [4/23], P < .01). CD70 expression was confirmed in A2780cisR, SKOV3, and SKOV3cisR cells. Notably, CD70 expression was induced after cisplatin treatment in A2780 mock cells but not in A2780-NF-κB-p65-silenced cells. CD70-ADC was cytotoxic to A2780cisR, SKOV3, and SKOV3cisR cells, with IC₅₀ values ranging from 0.104 to 0.341 nmol/L. In A2780cisR and SKOV3cisR xenograft models, tumor growth in CD70-ADC treated mice was significantly inhibited compared to that in the control-ADC treated mice (A2780cisR: 32.0 vs 1639.0 mm³, P < .01; SKOV3cisR: 232.2 vs 584.9 mm³, P < .01). Platinum treatment induced CD70 expression in ovarian cancer cells. CD70-ADC may have potential therapeutic implications in the treatment of CD70 expressing ovarian cancer.     

Sphingosine kinase 1 as a potential therapeutic target in epithelial ovarian cancer

Sphingosine kinase 1 (SK1) is over‐expressed in multiple types of human cancer. SK1 has growth‐promoting effects and has been proposed as a potential therapeutic target. We investigated the therapeutic effects of SK1 inhibition in epithelial ovarian carcinoma (EOC). SK1 siRNA or inhibitors were tested in EOC cell lines, including A2780, SKOV3ip1, A2780‐CP20, SKOV3‐TR, ES2 and RMG2. Cells were treated with SK inhibitor or FTY720, and cell proliferation, apoptosis, angiogenesis and invasion were examined by MTT, FACS, ELISA and wound‐healing assays, respectively. In vivo experiments were performed to test the effects of FTY720 on tumor growth in orthotopic mouse xenografts of EOC cell lines A2780 or SKOV3ip1 and a patient‐derived xenograft (PDX) model of clear cell ovarian carcinoma (CCC). Blocking SK1 with siRNA or inhibitors significantly reduced proliferation, angiogenesis and invasion, and increased apoptosis in chemosensitive (A2780 and SKOV3ip1) and chemoresistant (A2780‐CP20, SKOV3‐TR, ES2 and RMG2) EOC cells. SK1 inhibitors also decreased the intracellular enzymatic activity of SK1. Furthermore, FTY720 treatment significantly decreased the in vivo tumor weight in xenograft models of established cell lines (A2780 and SKOV3ip1) and a PDX model for CCC compared to control (p < 0.05). These results support therapeutic targeting of SK1 as a potential new strategy for EOC.     

TGFBI promoter hypermethylation correlating with paclitaxel chemoresistance in ovarian cancer

The purpose of this study is to determine the methylation status of Transforming growth factor-beta-inducible gene-h3 (TGFBI) and its correlation with paclitaxel chemoresistance in ovarian cancer. The methylation status of TGFBI was examined in ovarian cancer and control groups by methylation-specific PCR (MSP) and bisulfite sequencing PCR (BSP). The TGFBI expression and cell viability were compared by Quantitative Real-Time PCR, Western Blotting and MTT assay before and after demethylating agent 5-aza-2''-deoxycytidine (5-aza-dc) treatment in 6 cell lines (SKOV3, SKOV3/TR, SKOV3/DDP, A2780, 2780/TR, OVCAR8). In our results, TGFBI methylation was detected in 29/40 (72.5%) of ovarian cancer and 1/10 (10%) of benign ovarian tumors. No methylation was detected in normal ovarian tissues (P < 0.001). No statistical correlation between RUNX3 methylation and clinicopathological characteristics was observed. A significant correlation between TGFBI methylation and loss of TGFBI mRNA expression was found (P < 0.001). The methylation level of TGFBI was significantly higher in paclitaxel resistant cell lines (SKOV3/TR and 2780/TR) than that in the sensitive pairs (P < 0.001). After 5-aza-dc treatment, the relative expression of TGFBI mRNA and protein increased significantly in SKOV3/TR and A2780/TR cells. However, no statistical differences of relative TGFBI mRNA expression and protein were found in other cells (all P > 0.05), which showed that re-expression of TGFBI could reverse paclitaxel chemoresistance. Our results show that TGFBI is frequently methylated and associated with paclitaxel-resistance in ovarian cancer. TGFBI might be a potential therapeutic target for the enhancement of responses to chemotherapy in ovarian cancer patients.     

蛋白激酶C激活剂及抑制剂对紫杉醇耐药的卵巢癌细胞中P-糖蛋白表达及功能的影响

目的:探讨PKC(protein kinase C)激活剂及抑制剂对紫杉醇诱导的卵巢癌耐药细胞系A2780/Taxol中P-gp(P-glyco-protein)的表达及功能的影响。方法:免疫细胞化学SP法检测P-gp和PKC-α在耐药细胞A2780/Taxol及其亲本细胞中的表达;Western Blot检测PKC激动剂佛波脂(PMA)和抑制剂十字孢碱(SP)作用后P-gp在2种细胞上的表达水平;以罗丹明123(Rohdamin123,R123)作为荧光探针用流式细胞仪检测PMA及SP对细胞膜P-gp功能的影响。结果:P-gp在耐药细胞A2780/Taxol中呈阳性表达,在亲本细胞中不表达;PMA处理细胞,细胞内R123的平均荧光强度明显减低,Pgp的功能增强而表达量无明显变化;SP处理细胞,细胞内R123的平均荧光强度明显增加,Pgp的功能减弱而表达也无明显减少。结论:PKC通过对P-gp功能的调节而参与卵巢癌紫杉醇耐药的形成。     

5 Aza CdR通过DNMT1调控卵巢癌细胞ERCC1基因甲基化及其表达

目的:研究5-氮杂-2'-脱氧胞苷(5-Aza-CdR)在卵巢癌细胞系SKOV3中对核苷酸切除交叉修复互补基因1(exeision repair cross complementation group 1,ERCC1)表达的影响及可能的机制.方法:设计特异性针对DNA甲基转移酶1(DNAmethyhransferase 1,DNMT1)基因的shRNA转染人人卵巢癌细胞系SKOV3细胞中,Western blotting检测SKOV3细胞DNMT1以及ERCC1的表达变化;利用不同浓度5-Aza-CdR于不同时间点处理卵巢癌SKOV3细胞,Western blotting检测DNMTI和ERCC1蛋白在处理前后的变化,利用亚硫酸氢钠法检测ERCC1基因启动子区域甲基化水平.结果:0.5、1.0、2.0、4.0μmol/L的5-Aza-CdR作用于SKOV3细胞后,DNMT1表达水平呈浓度依赖性降低,而ERCC1表达水平呈浓度依赖性升高;使用终浓度为1.0 μmol/L的5-Aza-CdR处理SKOV3细胞12、24、36 h后,DNMT1表达水平呈时间依赖性降低,而ERCC1表达水平呈时间依赖性升高,亚硫酸氢钠法检测示药物处理前ERCC1启动子区域处于高甲基化水平,在用1.0μmol/L的5-Aza-CdR处理后,其启动子发生了去甲基化.结论:5-Aza-CdR通过DNMT1调控卵巢癌SKOV3细胞中ERCC1基因的甲基化及其表达水平.     

Cytosine deaminase/5-fluorocytosine gene therapy and Apo2L/TRAIL cooperate to kill TRAIL-resistant tumor cells

The death ligand Apo2L/TRAIL (Apo2 ligand/tumor necrosis factor-related apoptosis-inducing ligand) eradicates many tumor types while sparing most normal tissues. However, some tumors are resistant to TRAIL. We therefore determined if TRAIL cooperates with cytosine deaminase/5-fluorocytosine (CD/5-FC) gene therapy and investigated the mechanisms involved. Transfection of human LAN-5 neuroblastoma cells with CD rendered the cells (LAN-5-CD) sensitive to 5-FC-induced, caspase-dependent apoptosis. Mediated by caspase-3, CD/5-FC and TRAIL cooperated to induce apoptosis in these TRAIL-resistant cells and to cleave X-linked inhibitor of apoptosis protein (XIAP). In established LAN-5-CD tumors growing subcutaneously in mice, intratumorally applied TRAIL did not decrease tumor growth and systemically administered 5-FC only attenuated tumor growth. In contrast, 5-FC together with TRAIL dramatically decreased tumor growth and eradicated a tumor. Assuming sufficient gene transfer of CD in situ, CD/5-FC with TRAIL may be useful for the therapy of tumors resistant to TRAIL.     

C17orf76-AS1在卵巢上皮癌中的表达及其对卵巢上皮癌细胞SKOV3生物学功能的影响

目的 检测C17orf76-AS1在正常卵巢上皮细胞与卵巢上皮癌细胞系中的表达情况并探讨C17orf76-AS1过表达对卵巢上皮癌细胞系SKOV3生物学功能的影响。方法 通过定量PCR（QPCR）方法检测C17orf76-AS1在在卵巢上皮细胞IOSE80及不同卵巢上皮癌细胞系（A2780、SKOV3、OVCAR3、HO-8910和HO-8910PM）中的表达。在pcDNA3.1基础上构建C17orf76-AS1过表达质粒并采用Lipo2000瞬时转染SKOV3细胞,QPCR检测SKOV3细胞中C17orf76-AS1的过表达效率;CCK-8实验检测C17orf76-AS1过表达对SKOV3细胞增殖的影响;Transwell法和划痕实验检测C17orf76-AS1过表达对SKOV3细胞侵袭迁移能力的影响。结果 与正常卵巢上皮细胞IOSE80比较,C17orf76-AS1在A2780、SKOV3、 OVCAR3、HO-8910及HO-8910PM细胞中均呈低表达,分别下降了0.36、0.30、0.46、0.32、0.31倍（P＜0.05）。在SKOV3细胞中过表达C17orf76-AS1,CCK-8结果显示C17orf76-AS1过表达48 h后,SKOV3的增殖能力显著下降了约1.5倍;Transwell结果显示SKOV3细胞迁移能力下降约1.3倍,划痕实验也同样证实过表达C17orf76-AS1后,SKOV3细胞愈合能力显著低于对照组（P＜0.05）。结论 C17orf76-AS1在卵巢上皮癌细胞中异常低表达,其过表达显著降低了卵巢癌细胞增殖和迁移能力。     

Focal adhesion kinase targeting using in vivo short interfering RNA delivery in neutral liposomes for ovarian carcinoma therapy.

PURPOSE: Focal adhesion kinase (FAK) plays a critical role in ovarian cancer cell survival and in various steps in the metastatic cascade. Based on encouraging in vitro results with FAK silencing, we examined the in vivo therapeutic potential of this approach using short interfering RNA (siRNA) in the neutral liposome 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC). EXPERIMENTAL DESIGN: Therapy experiments of FAK siRNA with or without docetaxel were done using human ovarian cancer cell lines SKOV3ip1, HeyA8, and HeyA8MDR in nude mice. Additional experiments with a cisplatin-resistant cell line (A2780-CP20) were also done. Assessments of angiogenesis (CD31), cell proliferation (proliferating cell nuclear antigen), and apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) were done using immunohistochemical analysis. RESULTS: A single dose of FAK siRNA-DOPC was highly effective in reducing in vivo FAK expression for up to 4 days as assayed by Western blot and immunohistochemical analysis. Therapy experiments were started 1 week after injection of the ovarian cancer cells. Treatment with FAK siRNA-DOPC (150 mug/kg twice weekly) reduced mean tumor weight by 44% to 72% in the three cell lines compared with the control group (Ps < 0.05 for HeyA8, A2780-CP20, and SKOV3ip1). When FAK siRNA-DOPC was combined with docetaxel, there was even greater reduction in mean tumor weight in all models (all Ps < 0.05). Similar results were observed in combination with cisplatin. Treatment with FAK siRNA-DOPC plus docetaxel resulted in decreased microvessel density, decreased expression of vascular endothelial growth factor and matrix metalloproteinase-9, and increased apoptosis of tumor-associated endothelial cells and tumor cells. CONCLUSIONS: Taken together, these findings suggest that FAK siRNA-DOPC plus docetaxel or platinum might be a novel therapeutic approach against ovarian cancer.     

5—氟胞嘧啶对表达胞嘧啶脱氨酶的人肾母细胞瘤裸鼠异种移植瘤 …

OBJECTIVE: To study the effect of 5-fluorocytosine (5-FC) as prodrug in the treatment of Wilms' tumor xenografts transduced with cytosine deaminase (CD) gene. METHODS: An in vivo model of a poorly differentiated Wilms' tumor transplanted in nude mice was established. Expression adenoviral-vector of CD gene (Ad/CMV-CD) or lac gene (Ad/CMV-lac) was transduced to the tumor xenografts by intratumoral injections. Expression of the transduced genes were confirmed by RT-PCR. Mice with Wilms' tumor xenograft were treated with 5-FC (500 mg.kg-1.d-1 x 10 d). Tumor growth was monitored. RESULTS: The growth of tumor xenografts transduced with lac gene grew as quick as the untransduced ones. In contrast, the growth of the tumor xenografts transduced with CD gene was significantly inhibited as compared to untransduced and lac gene transduced xenografts. The average rate of inhibition was 65% according to the tumor weight at 8 wk. Cell necrosis was observed in the CD gene transduced tumors. CONCLUSION: Intratumoral cytosine deaminase gene transduction followed by systemic 5-fluorocytosine is effective in the treatment of Wilms' tumor.     

卵巢癌多药耐药基因的表达及其逆转

目的　探讨特异性靶向ＭＤＲ１基因的ｓｉＲＮＡ逆转耐药型卵巢癌细胞株多药耐药的可行性。方法　设计靶向于ＭＤＲ１基因的３条ｓｉＲＮＡ,用脂质体转染试剂分别转染Ｐ ｇｐ阳性表达的卵巢癌ＳＫＯＶ３／ＡＲ细胞,ＲＴ ＰＣＲ检测转染后４８小时ＭＤＲ１ｍＲＮＡ的变化,流式细胞技术检测转染后７２小时Ｐ ｇｐ的表达情况;ＭＴＴ法检测转染前及转染后４８小时ＳＫＯＶ３／ＡＲ细胞对阿霉素、紫杉醇的敏感性。结果　与空白对照组相比,含靶向ＭＤＲ１基因的ｓｉＲＮＡ-１组、ｓｉＲＮＡ-２组、ｓｉＲＮＡ-３组的ＭＤＲ１ｍＲＮＡ表达水平均有显著下降（Ｐ＜０.０５）,对ＭＤＲ１ｍＲＮＡ的抑制率分别为４３.３％、４1.３％和５８.５％,其中ｓｉＲＮＡ-３组对靶基因的抑制作用较强,而空白对照组、脂质体组和阴性对照ｓｉＲＮＡ组靶基因表达水平则无明显变化。将ｓｉＲＮＡ／ＭＤＲ１-３转染细胞７２小时后可观察到Ｐ-ｇｐ阳性表达率显著降低（Ｐ＜０.０５）,其抑制率为３７.９５％,而空白对照组、脂质体组及阴性对照ｓｉＲＮＡ组Ｐ-ｇｐ表达无明显降低（Ｐ＞０.０５）。ｓｉＲＮＡ ３干扰ＳＫＯＶ３／ＡＲ细胞后,阿霉素和紫杉醇的ＩＣ５０分别下降为干扰前的１／３.５６和１／３。结论　ＲＮＡｉ在体外实验能有效逆转卵巢癌细胞的耐药,为其在实体瘤耐药逆转的运用提供了实验依据,值得进一步研究。     

High sensitivity of ovarian cancer cells to the synthetic triterpenoid CDDO-Imidazolide

In the present study we have explored the sensitivity of ovarian cancer cells to the synthetic triterpenoid CDDO-Imidazolide (CDDO-Im). For these studies we have used the A2780 ovarian cancer cell line and its chemoresistant derivatives A2780/ADR and A2780/CISP, OVCAR3, SKOV3 and HEY cancer cell lines and primary ovarian cancer cells, providing evidence that: (i) the majority of these cell lines are highly sensitive to the pro-apoptotic effects induced by CDDO-Im; (ii) TRAIL, added alone exerted only a weak proapoptotic, but clearly potentiated the cytotoxic effect elicited by CDDO-Im; (iii) the apoptotic effect induced by CDDO-Im involves GSH depletion, c-FLIP downmodulation and caspase-8 activation; (iv) CDDO-Im inhibits STAT3 activation and CDDO-Im sensitivity is inversely related to the level of constitutive STAT3 activation. Importantly, studies on primary ovarian cancer cells have shown that these cells are sensitive to the pro-apoptotic effects of CDDO-Im.