Expression of X-linked Inhibitor of Apoptosis Protein and Its Effect on Chemotherapeutic Sensitivity of Bladder Carcinoma

The expression of X-linked inhibitor of apoptosis protein (XIAP) gene and its effect on chemotherapeutic sensitivity in bladder carcinoma was explored. By using immunohistochemistry, the expression of XIAP was detected in 47 bladder carcinomas and 5 normal bladder tissues. The XIAP gene was transfected into bladder cancer cell line T24 by liposome and the positive clone was screened by G418. Cellular XIAP mRNA level was detected by RT-PCR. Low-dose mitocycin C was administered to induce the apoptosis of T24 cells. The in vitro growth of bladder carcinoma cells was analyzed by MTT colorimetry, and the apoptosis rate was assayed by TUNEL methods. It was found XIAP was moderately expressed in bladder carcinomas with the the positive rate being 78.73% (37/47), but the positive rate was not correlated with carcinoma stages and grades (P<0.05). XIAP mRNA level in transfected T24 cells was significantly increased by 3.8 times as compared with that in the cells not transfected with XIAP. After treatment with low-dose mitomycin C (0.005 and 0.05 mg/mL), the growth rate in XIAP no-transfected control group was increased by (11.60±0.25)% and (16.51±0.87)% (P<0.05), and the apoptosis rate was decreased by (10.1±0.2)% and (11.9±0.2%) (P<0.05) respectively as compared with XIAP transfected group. It was concluded that XIAP was expressed in most of bladder carcimoma samples. Overexpression of XIAP in T24 could significantly reduce the MMC-induced apoptosis of bladder carcinoma, suggesting its effect on the chemothera- peutic sensitivity of T24 cells.     

Over-expression of LRIG3 suppresses growth and invasion of bladder cancer cells

The purpose of this study was to investigate the impact of leucine-rich repeats and immunoglobulin-like domains 3 (LRIG3) on the biological features of bladder cancer cell lines. The plasmids of over-expressed LRIG3 and the blank plasmid serving as control were transfected into the bladder cancer cell lines, T24, EJ and BIU-87, and the expression levels of LRIG3 mRNA and protein were detected by using real-time PCR and Western blotting. The changes in the cell cycle and apoptosis were examined by using flow cytometry. The invasive ability was measured by Transwell assay, and CCK-8 assays were used to measure the proliferation of cells. As compared with the control group, the LRIG3 mRNA and protein expression levels in LRIG3 cDNA-transfected group were raised significantly (P<0.05). The average number of cells with up-regulated LRIG3 passing through the inserted filter was decreased significantly as compared with the control group (P<0.05). Up-regulation of LRIG3 also could inhibit proliferation and induce apoptosis of T24, EJ and BIU-87 cells. Except BIU-87, the T24 and EJ cells transfected with LIRG3 cDNA were arrested in G 0 /G 1 phase compared to the control group (P<0.05). In conclusion, the over-expression of LRIG3 could influence the cell cycle and invasion, inhibit proliferation and induce apoptosis in the three bladder cancer cell lines.     

Expression of transcription factor Oct4 in bladder cancer cell line T24 and its effects on the biological characteristics of the cells

The expression of octamer binding factor 4 （Oct4） gene in bladder cancer cell line T24 and its effects on the biological characteristics of the cells were investigated. RT-PCR and Western blot were employed to detect the expression of Oct4 in T24 cells. The changes of biological characteristics in T24 cells were analyzed before and after gene-silencing by Boyden chamber and MTT. The results showed that the expression of Oct4 gene was detectable in T24 cells by RT-PCR and Western blot. The expression of Oct4 gene and protein was down-regulated by siRNA, and average number of transwell cells in interference group, negative control group and blank control group was 101.40±54.56, 104.20± 10.03 and 111.00±11.90, respectively. There was significant difference in the proliferation abilit,） of the cells from 48 h, 72 h to 96 h after the interference by siRNA between interference group and negative group or blank control group （P〈0.05）. It was suggested that Oct4 gene was related with proliferation ability of T24 cells, but not with invasive capability.     

Enhanced sensitivity to mitomycin C by abating heat shock protein 70 expression in human bladder cancer cell line of BIU-87

Background Bladder cancer is a relatively common tumor in the urinary system, in which mitomycin C (MMC)-based chemotherapy or combination chemotherapy has been mainly used to treat patients with advanced bladder cancer. The prognosis of patients with advanced bladder cancer is still extremely poor in spite of recent therapeutic advances. To improve the prognosis, the sensitivity of tumor cells to mitomycin C by the induction of apoptosis with the abating heat shock protein 70 (HSP70) expression in human bladder cancer cell lines of BIU-87 was investigated. Methods HSP70 expression was abated in BIU-87 cells by HSP mRNA antisense oligomers. MTT assay and the clone-forming test were used for evaluating the sensitivity of cells to MMC. Apoptosis was assessed using both fluorescent microscopy after staining the cells with Hoechst 33258 and DNA fragment ladder agarose electrophoresis. Thirty-two male six-week-old BALB/c nude mice, at the beginning of the experiment, were used to evaluate the effect of antisense oligomers (ASO) on the tumor formation in vivo. Results HSP70 expression in BIU-87 was effectively abated by HSP70 mRNA antisense oligomers. The percentage of apoptotic cells in ASO group was greater than in sense oligomers (SO) ［P&lt;0.05, （18.31±2.89）% vs （1.89±0.74）%］, nonsense oligomers (NO) ［P&lt;0.05, （18.31±2.89）% vs （1.78±0.92）%］ and blank groups ［P&lt;0.05, （18.31±2.89）% vs （1.87±0.84）%］, while the sensitivity of tumor cells to mitomycin C was enhanced. The in vivo tumor inhibition rate of ASO plus MMC (&gt;50%) was more than that of ASO or MMC group alone (all P&lt;0.05). Conclusions The abating level of HSP70 expression can strengthen the sensitivity of BIU-87 to MMC. One of this effect might be related to the induction of apoptosis by abating HSP70 expression. Chin Med J 2005; 118(23):1965-1972     

Clinical application of monoclonal antibody-drug conjugate to immunotargeting chemotherapy of bladder cancer.

Monocional antibody-drug conjugate was applied in a clinical trial for patients with bladder cancer.Monoclonal antibody HB7A from a mouse splenocyte immunized against human bladder cancer was used as a drug carrier.The anti-cancer drug adriamycin(ADR) was bound to HB7A through a dextran(DEX) bridge to form the conjugate HB7A-DEX-ADR. The in vitro cytotoxic effect of the conjugate on BIU-87 bladder cancer cells was similar to that of free ADR and the mixture of HB7A and ADR. Seven patients with bladder cancer were given HB7A-DEX-ADR intravenously.The immanoperoxidase studies of the resected specimens showed that HB7A was localized specifically in cancer, and histological studies revealed degenerative and necrotic changes of the tumor cells. Patients receiving the conjugate did not experience serious side effects. This study suggests that im munotargeting chemotherapy with HB7A-DEX-ADR is well tolerated by patients and its cytotoxicity on tumor is substanrial.     

Costimulatory molecule B7-H1 on the immune escape of bladder cancer and its clinical significance

B7-H1, a recently described member of the B7 family of costimulatory molecules, is thought to be involved in tumor immune escape by inducing T-cell apoptosis. In order to investigate the relationship between B7-H1 and immune escape of bladder cancer, B7-H1 expression in 50 cases of bladder cancer was detected by using immunohistochemical method. Survival curves were con- structed using the Kaplan-Meier method and independent prognostic factors were evaluated using the Cox regression model. Our results showed that the positive rate of B7-H1 immunostaining in normal bladder tissue and bladder cancer was 0 and 72% respectively. The expression of B7-H1 was strongly associated with the pathological grade, clinical stage and recurrence （P〈0.05）. The survival rate was significantly lower in patients with B7-H1 positive group than in those with B7-H1 negative group and multi-variable analysis revealed that B7-H1 could be regarded as an independent factor in evaluating the prognosis of bladder cancer. It is concluded that the expression of B7-H1 is strongly associated with neoplastic progression and prognosis of bladder cancer. The manipulation of B7-H1 may become a beneficial target for immunotherapy in human bladder cancer.     

XIAP as a prognostic marker of early recurrence of nonmuscular invasive bladder cancer

Background Dysregulation of apoptosis has been implicated not only in carcinogenesis and tumor progression but also in tumor recurrence. We investigated whether the expression of X-linked inhibitor of apoptosis （XIAP） might predict early recurrence in patients with non-muscular invasive bladder cancer. Methods The cohort comprised 176 consecutive patients with primary superficial bladder cancer treated with transurethral resection. Immunohistochemical staining using the standard avidin-bioUn-peroxidase technique and RT-PCR were used to detect XIAP protein and mRNA expressions in cancer tissues. The relationship between XIAP expression and clinicopathological characteristics, cancer recurrence were analyzed. Results XIAP expression was observed in 108 cases （61.4%） and no expression in 68. There was no correlation between XIAP expression rate and the tumor pathological grade, but was an apparent trend toward the increased XIAP levels from well （G1） to poor （G3） differentiated cancer. Eighty-two （46.6%） patients experienced tumor recurrence at a mean of 28.6 months of the follow-up; 66 of them expressed XIAP （61.1%） and 16 were XIAP negative （23.5%）. Twelve patients presented with invasive disease at the time of relapse and all of them expressed XIAP. Patients without XIAP expression or with low tumor grades had significantly higher recurrence-free survival than those with XIAP expression （log rank test ,P=-0.0015） or high tumor grades （log rank test P〈0.001）. Multivariate analysis revealed that XIAP expression, tumor grade, and tumor number were independent predictors for the recurrence of non-muscular invasive bladder cancer （P=-0.004, 0.016, and 0.043, respectively）. Conclusions XIAP may be considered as a new independent prognostic marker for early recurrence of non-muscular invasive bladder cancer.     

Impact of 4HPR on the expression of E-Cad in human bladder transitional epithelial cancer cells T24

Previous researches showed that the expression level of E-Cad in most infiltrating cancer cells was reduced or negative. This study explored whether 4HPR restrained the infiltration of bladder cancer cells through regulating the expression of E-Cad. The infiltrating bladder cancer cells T24 were cultured, and then treated by a proper dosage of drug. Their viability was a determined by MTT method. Western blotting and RT-PCR were adopted to detect the changes of E-Cad gene expression at both pro-tein and mRNA levels. Moreover, immunofluorescent staining and confocal fluorescence microscopy were employed for the observation of the expression of E-Cad. The result showed that, at both mRNA and protein levels, the expression level of E-Cad in T24 cells treated by 4HPR was significantly higher than that of control group, while the β-Cat expression was also relocated from the cell nucleus to cyto-plasm. Our findings suggested that the regulatory function of 4HPR on infiltration of bladder cancer cells T24 is at least partly achieved by regulating the expression of E-Cad.     

Insulin in endometrial carcinoma chemotherapy: A beneficial addition and not a problem

The effects of insulin or insulin in combination with chemotherapeutic drugs on the proliferation and apoptosis of endometrial carcinoma cells were examined with an aim to determine the efficacy and safety of insulin in endometrial cancer therapy.Ishikawa and Hec-1A cells were treated with insulin and/or paclitaxel.Cell proliferation was assessed by MTT assay.Cell cycle and cell apoptosis were determined by flow cytometry (FCM).Survivin gene expression was detected by RT-PCR.Our results showed that in a certain range of working concentrations and action time, insulin could mildly augment cell proliferation and the percentage of S phase cells in endometrial cancer (Ishikawa/Hec-1A) cells.Insulin plus paclitaxel (combination group) could significantly inhibit cell proliferation (69.38%±2.32% vs 40.31%±4.52% with Ishikawa; 64.11%±6.33% vs 45.89%±3.27% with Hec-1A) and increase cell apoptosis compared with treatment with paclitaxel alone (paclitaxel group).Survivin gene expression was also significantly decreased in combination group as compared with paclitaxel group.We are led to conclude that insulin can mildly augment cell proliferation and present chemotherapy sensitivity in endometrial cancer cells.Insulin can be to used safely and efficiently in endometrial cancer therapy.     

白花蛇舌草通过JAK2/STAT3通路途经诱导膀胱癌T24细胞凋亡

目的：研究白花蛇舌草对膀胱癌T24细胞凋亡的影响及其潜在机制。方法 MTT法检测不同浓度白花蛇舌草对T24增殖的抑制作用,AnnexinV-FITC/PI双标记流式细胞术检测细胞凋亡率,Western blot检测细胞中JAK2、STAT3、Bax、Caspase-3和Bcl-2的表达情况。结果白花蛇舌草明显抑制膀胱癌T24细胞的增殖同时诱导其凋亡,且作用强度随着浓度的增加而增加。Western blot检测证实白花蛇舌草能够显著抑制细胞中JAK2、STAT3和Bcl-2表达,上调Bax和Caspase-3表达。结论白花蛇舌草能够抑制膀胱癌细胞T24增殖,促进其凋亡,可能与抑制JAK2/STAT3通路有关。     

Survivin反义寡核苷酸诱导人膀胱移行细胞癌T24细胞凋亡的实验研究

目的Survivin是近年来发现的凋亡抑制蛋白家族新成员，在多数恶性肿瘤组织中丰富表达。因此，观察Survivin反义寡核苷酸（ASODN）转染对人膀胱移行细胞癌T24细胞凋亡、增殖、细胞对化疗药物敏感性的影响。方法设计合成针对Survivn mRNA特异性的ASODN，透射电镜观察细胞形态变化，流式细胞术检测各组细胞增殖指数（proliferative index，PI）和碉亡指数（apoptotic index，AI），RT-PCR法分析转染后Sur-vivn mRNA及Caspase-3 mRNA的变化，Western Blot法检测各组Survivn蛋白表达情况，荧光分光光度法测定Caspase-3的活性水平；MTT实验测定T24细胞对丝裂霉素（mitomycin，MMC）的敏感性。结果A—SODN转染组透射电镜下观察到凋亡的征象，而各对照组未见凋亡证据；各转染组细胞AI明显高于各对照组，PI明显低于各对照组（P〈0．01），且在一定范围内呈量一效关系，各对照组间差异无显著性（P〉0．05）；各转染组细胞Survivin mRNA、Survivin的表达较各对照组明显下调（P〈0．01），各对照组间差异无显著性（P〉0．05）；Caspase-3 mRNA的表达在各组细胞间差异无显著性（P〉0．05）；各转染组细胞Caspase-3活化水平较各对照组明显提高（P〈0．01），各对照组间差异无显著性（P〉0．05）；MTT实验显示，转染组MMC半数抑制浓度（IC50）较对照组明显下降，ASODN可提高T24细胞对MMC的敏感性。结论Survivin ASODN转染L细胞后可特异性封闭Survivin的表达，对Caspase-3 mRNA的表达无明显作用，能激活Caspase-3无活性前体，从而诱导T24细胞凋亡，抑制细胞增殖，提高T24细胞对化疗药物MMC的敏感性。     

转染Livin基因对膀胱癌细胞凋亡的影响

目的 探讨凋亡抑制基因Livin对膀胱癌细胞凋亡的影响.方法 采用脂质体转染法将Livin基因转入膀胱癌T24细胞系,经G418筛选后获得稳定表达Livin的亚克隆细胞系T24/Livin+及仅转染载体的T24/pcDNA3.1(+).用丝裂霉素C(MMC)分别作用于转染前后的膀胱癌细胞系,应用四甲基偶氮唑盐(MTT)比色法检测转染前后细胞生长抑制率,应用流式细胞仪(FCM)及吖啶橙(AO)染色检测细胞凋亡.结果 成功建立了稳定表达Livin的亚克隆细胞系T24/Livin+;经MMC作用24 h后,T24/pcDNA3.1(+)细胞与T24的细胞凋亡率分别为(21.4±2.3)%和(19.6±2.3)%,而T24/Livin+的细胞凋亡率则为(8.7±1.5)%,差异有统计学意义(P＜0.01).结论 Livin基因提高了T24膀胱癌细胞的抗凋亡能力,特别是在膀胱癌化疗中显示出更强的抗凋亡能力.     

川楝素通过XIAP途径增强肺癌细胞对顺铂的敏感性

目的: 研究天然药物活性成分川楝素对顺铂抗肺癌活性的协同效应并研究其机制。方法：实验对象为人肺癌细胞系A549,实验分为对照组,川楝素组,顺铂组,川楝素+顺铂组及川楝素+顺铂+XIAP质粒。MTT实验检测各组A549的细胞活力抑制率;流式细胞实验检测各组A549的细胞的凋亡;免疫共沉淀及western blot实验检测各组A549的细胞中XIAP表达水平及其与caspase-9和caspase-3的相互作用;western blot实验检测各组A549的细胞caspase-9和caspase-3的活化。结果：顺铂+川楝素组A549的细胞活力抑制率(66.8±5.9)显著高于顺铂单治疗组(15.2±1.2, P<0.05)和川楝素+顺铂+XIAP质粒组(20.4±1.8, P<0.05);顺铂+川楝素组A549的细胞凋亡率(34.5±2.6)显著高于顺铂单治疗组(9.7±0.8, P<0.05)和川楝素+顺铂+XIAP质粒组(13.3±1.2, P<0.05);免疫共沉淀及western blot实验显示川楝素能显著抑制A549细胞中XIAP的表达及其与caspase-9和caspase-3的相互作用,川楝素促进顺铂对caspase-9和caspase-3的活化。结论：川楝素通过下调XIAP的表达增强肺癌细胞对顺铂的敏感性。     

化疗药物剂量依赖性下调化疗敏感膀胱癌细胞中X染色体连锁的凋亡抑制蛋白的水平

目的探讨化疗药物诱导膀胱癌细胞凋亡及其对X染色体连锁的凋亡抑制蛋白（XIAP）表达和caspase-3剪切的影响。方法培养4种膀胱癌细胞系RT4、MGH-U1、EJ及T24,用低剂量阿霉素和丝裂霉素诱导凋亡启动,用细胞增殖分析试剂盒CCK-8分光法测定不同浓度化疗药物对膀胱癌细胞的杀伤力,确定化疗敏感细胞和耐药细胞,流式细胞术检测化疗药物诱导的细胞凋亡变化;用Western印迹检测阿霉素和丝裂霉素对膀胱癌细胞XIAP蛋白水平及caspase-3剪切的影响。结果4种膀胱癌细胞系中XIAP的表达水平差异无统计学意义。随着阿霉素和丝裂霉素的浓度增高,CCK-8检测到化疗药物对膀胱癌细胞的抑制率相应增加,流式细胞术检测到化疗药物诱导的细胞凋亡率相应增加。在化疗敏感的RT4细胞中可见caspase-3的剪切随着化疗药物浓度的增高而加强,而XIAP的蛋白水平却相应下降。这种效应在耐药的T24细胞中却不明显。结论阿霉素和丝裂霉素能剂量依赖性地杀伤膀胱癌细胞,而且这种杀伤力是通过诱导膀胱癌细胞凋亡实现的,XIAP和caspase-3与膀胱癌细胞的化疗耐药有一定相关性。     

硫利达嗪对乳腺癌细胞MDA-MB-231和MCF-7的杀伤效应

目的观察硫利达嗪对人乳腺癌细胞MDA-MB-231和MCF-7的凋亡作用,并探讨其机制。方法采用MTT法测定硫利达嗪对细胞的抑制作用,计算半数抑制浓度( IC50);流式细胞术检测硫利达嗪对细胞周期分布和凋亡的影响;比色法测定药物对细胞Caspase-3活性的影响;West-ern blot法检测凋亡调节蛋白Bcl-2、Bax表达的变化。结果
　　硫利达嗪作用24 h后, MDA-MB-231、MCF-7细胞增殖明显呈剂量依赖性抑制,其IC50为18、22μmol/L。流式细胞术结果显示,随着加入硫利达嗪浓度的提高, MDA-MB-231、MCF-7细胞均发生不同程度的G0/G1期阻滞、细胞凋亡程度增加及伴随胞内Caspase-3活性增加。各实验组与对照组比较,差异均有统计学意义(P<0．01)。 Western blot法结果显示随着药物浓度的增加,抗凋亡蛋白Bcl-2表达下调、促凋亡蛋白Bax表达明显上调,各实验组与对照组相比,差异有统计学意义( P <0．01)。结论硫利达嗪对乳腺癌细胞MDA-MB-231、MCF-7有显著的增殖抑制作用且可显著诱导肿瘤细胞发生G0/G1期阻滞及凋亡,伴随Caspase-3活性的上调,其毒性机制可能与肿瘤细胞内抗凋亡蛋白 Bcl-2下调、Bax上调有关。     

丝裂霉素C与C2-神经酰胺或抗Fas单克隆抗体联合治疗膀胱癌的体外研究

目的:探讨丝裂霉素C(MMC)与C2-神经酰胺(C2-Cer)或抗Fas单克隆抗体(anti-FasmAb)联合应用对人膀胱癌BIU-87和T24细胞生长的抑制作用。方法:采用四甲基偶氮唑蓝(MTT)比色法测定MMC、C2-Cer、anti-FasmAb单独应用及MMC分别与C2-Cer或anti-FasmAb联合应用对人膀胱癌BIU-87和T24细胞生长的抑制作用,并应用CHOU-TALALAY联合指数法对药物联合应用的效果进行判定。结果:药物单用及MMC分别与C2-Cer、anti-FasmAb合用对BIU-87和T24细胞的生长均有抑制作用,药物合用时的中效浓度与单用时比较有不同程度的降低。MMC与C2-Cer合用时,对于BIU-87细胞,表现为协同作用(CI<1);对于T24细胞,低浓度(0%1)。MMC与anti-FasmAb合用时,对于BIU-87细胞,在大部分效应范围(18%1);对于T24细胞,则在大部分效应范围(0相似文献   

Smac小分子compound3调节顺铂诱导卵巢癌细胞SKOV3凋亡的研究

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水飞蓟宾对人膀胱癌细胞系T24和5637的增殖抑制及凋亡诱导作用

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