靶向沉默Notch1基因对人膀胱癌细胞生物学行为的影响

目的 探讨沉默Notch1基因对人膀胱癌细胞生物学行为的影响. 方法 将靶向Notch1的siRNA真核表达载体psiRNA Notch1-1转染膀胱癌细胞株T24和BIU-87,噻唑盐法、流式细胞术检测沉默Notch1后膀胱癌细胞生长、细胞周期和凋亡情况.RT-PCR和蛋白质印迹法检测转染前后Notch1基因mRNA和蛋白表达的变化. 结果 转染后72 h,T24和BIU-87细胞G0/G1期细胞比例明显增加,分别为(80.13±2.69)%和(69.44±2.41)%,与T24对照组(23.89±1.32)%和BIU-87对照组(24.63±1.68)%比较差异有统计学意义(P值均<0.05).转染后72 h,T24和BIU-87细胞凋亡率分别为(13.75±1.23)%和(8.72±1.01)%,与T24对照组(1.28±0.14)%和BIU-87对照组(1.01±0.27)%比较差异均有统计学意义(P值均<0.05).转染后24 h细胞生长明显受到抑制,该抑制作用持续到转染后96 h.转染后72 h,T24和BIU-87细胞中Notch1基因mRNA和蛋白表达明显下调(P<0.05). 结论 Notch1在膀胱癌细胞株中可能起致癌作用.沉默Notch1基因能够抑制膀胱癌细胞的增殖.     

丙戊酸钠增强免疫细胞对人膀胱癌细胞的杀伤作用

目的:探讨丙戊酸钠(VPA)对膀胱癌细胞MICA表达的影响以及所产生的肿瘤免疫作用,以期为防治膀胱癌复发和浸润提供新的治疗方法。方法:采用不同浓度VPA处理人膀胱尿路上皮癌T24细胞后,用半定量RT-PCR和流式细胞术检测癌细胞中MICA mRNA和蛋白表达。用乳酸脱氢酶法检测外周血单个核细胞(PBMCs)对经VPA处理的T24细胞的杀伤作用。结果:VPA从mRNA和蛋白水平诱导T24细胞表达MICA,并增强T24细胞对PBMCs细胞毒作用的敏感性。结论:VPA能增强膀胱癌对免疫细胞杀伤作用的敏感性,可作为防治膀胱癌的辅助药物。     

抗人IgG抗体与丝裂霉素联合应用治疗膀胱癌的实验研究

目的 探讨抗人IgG抗体和丝裂霉素(MMC)联合应用对人膀胱癌细胞株的抑制作用及机制.方法 抗人IgG抗体和MMC单独或联合作用于人膀胱癌T24细胞,噻唑盐(MTT)法检测细胞生长抑制率,流式细胞仪检测T24细胞的凋亡率,蛋白质印迹法检测半胱氨酸天冬氨酸蛋白酶3(Caspase-3)和PARP的表达.采用T24细胞裸鼠移植瘤模型进行抗人IgG抗体和MMC的体内抗瘤实验.结果 单独应用抗人IgG抗体和MMC对T24细胞生长抑制率分别为(25.02±6.71)%和(32.31±6.46)%,而二者联用的抑制率达(73.66±5.81)%.PBS、25mg/L羊IgG、25mg/L羊抗人IgG抗体、2mg/L MMC、2mg/L MMCIk 25mg/L羊IgG和2mg/L MMC加25mg/L羊抗人IgG抗体处理T24细胞72 h后细胞凋亡率分别为1.7%、2.3%、20.7%、22.4%、28.3%和53.8%.羊抗人IgG抗体、MMC、MMC加羊IgG和MMC加羊抗人IgG抗体处理T24细胞72 h后出现17 000的Caspase-3和85 000的PARP剪切片断.体内实验显示羊IgG组、羊抗人IgG抗体组、MMC组、MMC加羊抗人IgG抗体组抑瘤率分别为2.31%、12.73%,36.81%和50.51%.HE切片观察见生理盐水组和羊IgG组移植瘤细胞基本无凋亡和坏死,羊抗人IgG抗体组肿瘤细胞凋亡和坏死增多,MMC组和MMC加羊抗人IgG抗体组则见大量肿瘤细胞凋亡和坏死.结论 抗人IgG抗体和MMC联合应用对膀胱癌具有体内外双重抗瘤作用,其抗瘤机制可能与诱导肿瘤细胞凋亡有关.     

吡柔比星与丝裂霉素C对膀胱癌T24细胞株抑制作用的实验研究

目的探讨吡柔比星（THP）与丝裂霉素C（MMC）对膀胱癌T24细胞株的抑制作用。方法将膀胱癌T24细胞株分为4组,分别给予THP、MMC、THP＋MMC和MMC＋THP。用MTT法测定T24细胞的增殖抑制率,用TuNEL法检测T24细胞的凋亡情况。结果THP、MMC、THP＋MMC和MMC＋THP四组的增殖抑制率（％）分别为54．3±6．4,48．9±7．2,62．3±5．9,69．1±6．2;凋亡指数（％）分别为6．2±2．5,4．4±2．7,6．7±3．0,7．4±3．2。联合用药组对T24细胞的抑制作用优于单药THP和MMC对肿瘤细胞的抑制作用（P〈0．05）。在联合用药组中,MMC＋THP组对T24细胞的抑制作用优于THP＋MMC组对肿瘤细胞的抑制作用（P〈O．05）。结论THP和MMC均可抑制膀胱癌T24细胞株的增殖并诱导凋亡,两药序贯联合用于膀胱灌注化疗可能具有合理性。     

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.     

丝裂霉素联合雷帕霉素对人膀胱癌T24细胞抑制作用的比较研究

目的:观察丝裂霉素(MMC)联合雷帕霉素(RAPA)对体外培养的人膀胱癌T24细胞抑制作用是否比单药大。方法:体外培养人膀胱癌T24细胞,通过MTT实验及相关公式计算,得出MMC和RAPA的IC50值,以此值及相关药量应用于膀胱癌T24细胞,经24、48h,比较两种药物单用及联合用药(全量及半量)对癌细胞的抑制率,得出抑制率最高的药物(两种单药或联合用药)。采用方差分析、SNK-q检验分析得出结果。结果:MMC、RAPA的IC50值分别为12μg/ml、125μg/L(最后实验所用)。两种药物单用及联合用药的24h抑制率最高的是MMC联合RAPA,全量及半量联合的抑制率差异无统计学意义,两者抑制率分别为63.64%及73.68%;MMC联合RAPA比单药的抑制率高,差异有统计学意义;与单药48h抑制率比较,MMC联合RAPA的抑制率差异无统计学意义(其中MMC联合RAPA全量联合的抑制率最大,为98.53%),但是高于RAPA的抑制率,差异有统计学意义。结论:MMC联合RAPA对体外培养的人膀胱癌T24细胞抑制作用比单药大。     

HER-2/neu siRNA对人胶质瘤细胞株T98G侵袭性的抑制作用

目的 探讨人表皮生长因子受体-2(HER-2/neu)特异性siRNA对高表达HER-2/neu的人胶质瘤细胞株T98G侵袭性的影响及其机制.方法 用脂质体介导终质量浓度50 nmol/LHER-2/neu siRNA转染人胶质瘤细胞株T98G,实时定量聚合酶链反应(real-time PCR)和免疫印迹法检测转染后HER-2/neu mRNA和蛋白表达变化.Transwell体外侵袭实验检测终质量浓度25、50、100 nmol/L HER-2/neu siRNA转染T98G后细胞侵袭能力的变化.免疫印迹法检测转染后细胞基质金属蛋白酶-9(MMP-9)蛋白表达变化.明胶酶谱法检测转染后MMP-9活性变化.结果 终质量浓度50 nmol/L HER-2/neu siRNA转染T98G细胞后HER-2/neu mRNA和蛋白表达为对照组的(29.3±6.2)%和(13.1±8.9)%(P＜0.01).终质量浓度25、50、100 nmol/L HER-2/neu siRNA转染后细胞侵袭抑制率分别为(37.7 ±7.2)%、(65.0±10.1)%和(69.7±9.3)%,三者与对照组的差异均有统计学意义(P＜0.01).与对照组比较,转染组细胞MMP-9蛋白表达减少(49.9±10.7)%,酶活性下降(55.6±12.7)%(P＜0.01).结论 HER-2/neu siRNA转染人胶质瘤细胞株T98G后明显抑制细胞的侵袭能力,其机制与MMP-9蛋白表达和活性显著受到抑制有关.     

膀胱尿路上皮癌组织中DACH2的表达及临床意义

目的探讨DACH2基因在膀胱尿路上皮癌组织中的表达情况,并分析其与膀胱癌临床病理特征及复发的关系。方法应用免疫组化技术(SP法)和实时定量聚合酶链反应(q RT-PCR)法检测47例膀胱尿路上皮癌组织及11例癌旁正常膀胱黏膜组织中DACH2的表达,并结合临床病理资料进行分析。结果免疫组化结果显示DACH2蛋白在肿瘤组表达高于正常膀胱黏膜组(P0.05);随分级、分期增高,DACH2蛋白组间表达差异有统计学意义(P0.05)。q RT-PCR显示DACH2的m RNA表达在肿瘤组(2-△△Ct 18.25)高于正常膀胱黏膜(2-△△Ct 1.00)(P0.05);复发组(2-△△Ct 19.70)高于原发组(2-△△Ct 7.57)(P0.05);随膀胱癌的分级、分期增高,DACH2的m RNA组间表达差异有统计学意义(0.05)。结论 DACH2高表达与膀胱尿路上皮癌的恶性侵袭性明显相关,检测DACH2有助于膀胱癌的分期和分级。     

抗HER-2加抗CD3双特异抗体抑制胃癌细胞生长的实验研究

目的探讨基因工程抗HER-2 抗CD3双特异抗体(bispecific antibody,BsAb)对表达人表皮生长因子受体2(HER-2/neu)的人胃癌细胞体外及体内生长的影响。方法用MTT方法测定Herceptin、抗CD3和BsAb抗体对胃癌细胞系SGC-7901的抑制率;免疫细胞化学法检测SGC-7901细胞的HER-2表达水平;建立裸鼠模型,将HER-2 CD3 BsAb与效应细胞(正常人外周血淋巴细胞)联合应用,观测各组荷瘤动物的肿瘤生长状况。结果正常对照组、抗CD3单克隆抗体联合效应细胞、Herceptin联合效应细胞及HER2 CD3 BsAb联合效应细胞肿瘤细胞的生长抑制率分别为0、(24.3±1.2)%、(56.2±2.6)%、(91.3±4.1)%各组荷瘤裸鼠与对照组的肿瘤体积为(0.86±0.02) cm~3、(0.52±0.04)cm~3、(0.20±0.06)cm~3、(0.11±0.02)cm~3,与对照组相比差异均有统计学意义(P<0.05),其中HER-2 CD3 BsAb联合效应细胞的抑制作用更为显著,与抗CD3 McAb联合效应细胞、Herceptin联合效应细胞组相比差异也有统计学意义(P<0.05)。结论HER-2/neu是胃癌免疫治疗的有效靶点,基因工程抗HER-2 抗CD3 BsAb在体外及体内均具有有效的抗肿瘤活性。     

核心蛋白聚糖对膀胱癌细胞生长抑制机制的研究

目的 探讨核心蛋白聚糖（DCN）对膀胱癌细胞生长的影响。方法 以膀胱癌T24细胞株为研究对象，采用MTT法检测不同浓度、不同时间的DCN对T24细胞存活率的作用，采用流式细胞术分析DCN对T24细胞周期及凋亡的影响，采用ELISA和Western blot法检测DCN对转化生长因子-β1（TGF-β1）和P21蛋白表达的影响。结果 与其他浓度相比，40、50 μg/mL DCN作用72 h时对T24细胞的抑制作用最强，差异有统计学意义（P<0.05），且G1期细胞达到最高值，S期细胞达最低值（P<0.001）。5、10、20、30、40、50 μg/mL DCN作用72 h后均能促进T24细胞凋亡，且在40 μg/mL时达到最大值(P<0.001)；与0 μg/mL相比，5、10、20、30、40、50 μg/mL DCN作用72 h对TGF-β1表达均有抑制作用, 最明显的抑制作用浓度为40 μg/mL(P<0.001)；与0 μg/mL相比，40 μg/mL DCN能促进P21蛋白上调（P<0.001）。结论 DCN在体外能够抑制膀胱癌T24细胞生长，诱导其凋亡，其可能的作用机制为下调TGF-β1及上调P2l蛋白表达。     

The effect of hyperthermia on mitomycin-C induced cytotoxicity in four human bladder cancer cell lines

INTRODUCTION: Hyperthermia and mitomycin-C (MMC) have given very encouraging results in several clinical studies for the treatment of superficial transitional cell carcinoma of the bladder. However, a synergistic effect of hyperthermia and MMC on the decrease of cell proliferation has never been demonstrated accurately in vitro. We investigated the effect of MMC versus MMC combined with hyperthermia on the cytotoxicity in four human bladder cancer cell lines. MATERIAL AND METHODS: The RT112, RT4, 253J and T24 human bladder cancer cell lines were seeded in 96-well microtiter plates at 2.0 x 10(4) cells per well and were left to attach for 24 hours. The cells were then treated for 60 minutes with MMC concentrations ranging from 0 to 400 microg/ml at a temperature of 37 degrees C or 43 degrees C. After treatment cells were rinsed three times with culture medium and left for 24 hours in the incubator. Dimethyl thiazolyl tetrazolium (MTT) solution was added and after 4 hours of incubation the MTT containing media was aspired from all wells and 100 microl of dimethyl sulfoxide was added to each well. A spectrum analyses was performed at 595 nm light wavelength. RESULTS: A decrease of cell proliferation after treatment with increasing concentrations MMC was demonstrated. Hyperthermia has a synergistic effect on the decrease of cell proliferation by different concentrations MMC. In the cells treated without MMC no significant difference in the extent of cell killing at 37 degrees C and 43 degrees C was observed. Furthermore, no difference was observed between cells with a p53 protein mutation (RT112 and T24) or without a p53 protein mutation (253J and RT4). Conclusion: A clear synergistic effect of MMC and hyperthermia has been demonstrated in four human bladder cancer cell lines.     

DNA, RNA and immunohistochemical characterization of the HER-2/neu oncogene in transitional cell carcinoma of the bladder

HER-2/neu overexpression appears to play a role in determining the malignant potential of some human cancers. To date, no urothelial malignancies appear to have been evaluated for HER-2/neu DNA amplification, mRNA expression and protein overproduction. By Southern hybridization we detected DNA amplification and a possible structural rearrangement of the HER-2/neu oncogene in one of 12 bladder tumors. A 14 kb DNA fragment in addition to the expected 12.5 Kb fragment was found. Additionally, the HER-2/neu oncogene was amplified sixfold in the tumor compared to placental DNA. Five of 14 (36%) bladder tumors overexpressed HER-2/neu mRNA three to 38-fold compared to normal urothelium. HER-2/neu overexpression occurred in superficial and invasive tumors. Immunohistochemical analysis was performed on the one tumor with DNA amplification and the 14 tumors evaluated for mRNA expression. The tumor with DNA amplification and three of the five tumors with HER-2/neu mRNA overexpression stained positively for the p185HER-2/neu protein. These findings suggest that DNA amplification occurs infrequently in bladder cancer. Thirty-six percent of bladder cancers overexpress HER-2/neu mRNA. Immunohistochemical analysis with a p185HER-2/neu polyclonal antibody, on formalin fixed, paraffin embedded tissue, was specific for HER-2/neu overexpression but not as sensitive as Northern analysis.     

Systemic mitomycin C versus cisplatin: comparison of antitumor activity in primary murine bladder cancer

The FANFT-induced bladder cancer murine model was used to evaluate the effect of DDP and MMC on the incidence and size of subsequent tumors. MMC was at least equally effective as DDP in inhibiting tumor growth in this model. There was no apparent synergistic effect when the two agents were combined although toxicity was increased. Further clinical trials with systemic MMC for locally advanced or metastatic urothelial transitional cell carcinoma appear to be indicated.     

High expression of polo-like kinase 1 is associated with the metastasis and recurrence in urothelial carcinoma of bladder

ObjectivesPolo-like kinase 1 (Plk1) has been widely pursued as an oncology target because it is overexpressed in several human tumor types. To investigate whether Plk1 plays a general role in bladder urothelial carcinoma, we examined the expression of Plk1 protein in bladder urothelial carcinoma and cell lines, and analyzed the relationship among Plk1 protein expression, metastasis, and recurrence of urinary bladder urothelial carcinoma.MethodsImmunohistochemistry was used to detect the expression of Plk1 in 120 bladder urothelial carcinoma. Moreover, the expression of Plk1 was analyzed by Western blot in 60 bladder urothelial carcinoma and 21 normal epithelial tissues. MTT assay and flow cytometry and transwell assay were used to examine the proliferative and invasive ability of bladder cancer cells with the treatment of scytonemin (the inhibitor of Plk1). Statistical analysis was used to discuss the association between Plk1 expression and clinicopathologic parameters, tumor metastasis and recurrence, and the proliferative and invasive ability and cell cycle process of the bladder cancer cells.ResultsThere was a significantly higher Plk1expressions in bladder urothelial carcinoma and highly invasive bladder T24 cells than those in bladder normal tissues and the superficial bladder BIU-87 cells. Plk1 expression was positively correlated with histologic grade, pT stage, recurrence, and metastasis. With the increasing concentration of scytonemin, we found that not only the cell proliferation and invasion activity decreased significantly, but also the cell cycle was blocked at G2/M stage.ConclusionPlk1 expression status was closely correlated with important histopathologic characteristics (grades and stages) and the recurrence and metastasis of bladder urothelial carcinomas. Furthermore, Plk1 played an important function on the bladder cancer cells' proliferation by regulating the cancer cell cycle from G1/S to G2/M and probably promoted the invasion and metastasis of bladder cancer.     

丝裂霉素C对人膀胱癌T24细胞Mta-1 mRNA、Mta-1蛋白表达的影响及意义

目的研究人膀胱癌T24细胞株中Mta-1 mRNA和Mta-1蛋白的表达,及丝裂霉素C（MMC）对人膀胱癌T24细胞株中Mta-1 mRNA和Mat-1蛋白表达的影响。方法人膀胱癌T24细胞株培养,MMC干预,用原位杂交和免疫组化检测Mta-1 mRNA和Mta-1蛋白的表达。结果人膀胱癌T24细胞株中Mta-1 mRNA阳性细胞表达率MMC组（35.1±9.0）%明显低于对照组组（61.9±12.8）%;Mta-1蛋白阳性细胞表达率MMC组（36.0±8.03）%亦明显低于对照组（57.7±10.1）%,P〈0.01。结论人膀胱癌T24细胞株中存在Mta-1 mRNA和Mta-1蛋白的高表达,MMC对人膀胱癌T24细胞株中Mta-1 mRNA和Mta-1蛋白的表达具有抑制作用。     

人类重组肝细胞生长因子影响膀胱癌细胞株生长和抑制丝裂霉素C诱导细胞凋亡的研究

目的 :观察人类重组肝细胞生长因子 (rhHGF)对膀胱移行细胞癌T2 4细胞增殖和丝裂霉素C(MMC)诱导的细胞凋亡的影响。方法 :以T2 4细胞为研究材料 ,用不同浓度rhHGF干预T2 4细胞生长及MMC诱导的细胞凋亡作用。利用MTT实验、流式细胞仪技术来判定rhHGF对细胞增殖和凋亡的影响。结果 :不同浓度rhHGF组间 ,T2 4相对增殖细胞数差异无统计学意义 (P >0 .0 5 ) ;rhHGF预处理后 ,MMC诱导的T2 4细胞凋亡率明显下降 ,在一定范围内有量效关系。结论 :HGF并不显著诱导T2 4细胞增殖 ,而一定剂量范围内的HGF能抑制MMC诱导的细胞凋亡 ,可能与膀胱癌的复发、耐药等临床特性有关     

真核表达载体Ad-hTRAIL联合丝裂霉素治疗膀胱癌

目的 观察真核表达载体Ad-hTRAIL转染124膀胱癌组织的效果及其联合丝裂霉素C(MMC)对膀胱肿瘤的治疗作用.方法 采用皮下肿块移植法制作荷T24膀胱癌BALB/C-nu小鼠模型40只,随机分成4组,分别腹腔注射MMC(A组),瘤内注射Ad-hTRAIL(B组),联合注射MMC+Ad-hTRAIL(C组),对照给予PBS+Ad空载体(D组).给药结束2周后,测量小鼠体重,所荷肿瘤的直径和重量,用逆转录-聚合酶链反应(RT-PCR)和Western blot测量肿瘤组织内hTRAIL mRNA及TRAIL蛋白的表达水平.结果 4组小鼠给药前体重及所荷肿瘤平均直径差异无统计学意义(P>0.05);给药结束2周后,A、B、C组所荷肿瘤直径和重量均显著小于D组(P<0.01),而C组又显著小于A、B组(P<0.01),B组又显著小于A组(P<0.01);A、C组体重均显著小于D组(P<0.01),而B组和D组差异无统计学意义(P>0.05);B、C组肿瘤组织内均有hTRAIL mRNA和TRAIL蛋白的表达,且两组间表达相对量差异无统计学意义(P>0.05),而A、D组则无hTRAIL mRNA和TRAIL蛋白的表达.结论 在体内实验研究中,Ad-TRAIL能成功转染T24膀胱癌组织且表达TRAIL蛋白;MMC和Ad-hTRAIL对T24膀胱癌有明显的抑制作用,且两者联用具有协同作用.     

长链非编码RNA母系表达基因3通过调控PTEN抑制膀胱尿路上皮癌细胞增殖活性的分子研究

目的 探究膀胱尿路上皮癌中长链非编码RNA（lncRNA） 母系表达基因3（MEG3）的表达情况以及MEG3调控膀胱尿路上皮癌细胞增殖活性的分子机制。方法 通过实时荧光定量PCR检测膀胱尿路上皮癌组织及癌旁正常组织中lncRNA MEG3的表达水平；通过Western blot检测过表达lncRNA MEG3后T24细胞内第10号染色体同源丢失性磷酸酶一张力蛋白基因（PTEN）蛋白水平；CCK8试剂盒检测细胞活性。结果 MEG3的RNA水平在膀胱尿路上皮癌组织中表达显著下调（P<0.01），PTEN的表达水平也明显降低（P<0.01）。T24中过表达MEG3后，PTEN水平上调，细胞活性降低（P<0.01）；而过表达MEG3并给予PTEN抑制剂时细胞活性则上升。结论 过表达lncRNA MEG3可通过上调PTEN抑制人膀胱尿路上皮癌T24细胞的细胞增殖活性，有可能成为临床治疗的潜在靶点。     

Endogenously formed nitric oxide modulates cell growth in bladder cancer cell lines

Objectives. Nitric oxide (NO) is formed in many mammalian tissues, and a growing body of evidence suggests that NO is involved in cell growth and cell differentiation. Low concentrations of NO can stimulate cell growth; high concentrations result in cytostatic/cytotoxic effects. It has previously been shown that intravesical treatment with bacille Calmette-Guérin (BCG) for bladder cancer increases NO production in the human urinary bladder and that NO inhibits bladder cancer cell growth in vitro. In this study, we investigated nitric oxide synthase (NOS) activity in different bladder cancer cells and the role of the NO precursor -arginine in cell proliferation.Methods. NOS activity was assessed by citrulline assay in cultured normal human urothelial cells and bladder cancer cell lines T24 and MBT-2 before and after treatment with cytokines. We also measured cell growth at various -arginine concentrations and after addition of the NOS inhibitor N^G-nitro- -arginine ( -NNA) in unstimulated and cytokine-stimulated cells.Results. Normal urothelial cells, as well as T24 and MBT-2 cells, showed calcium-dependent NOS activity under basal conditions. The bladder cancer cell lines also showed calcium-independent NOS activity in contrast to the normal cells. After cytokine treatment, both the normal cells and the cancer cell lines showed a marked increase in calcium-independent NOS activity. There was a dose-dependent stimulation of cell growth in the cancer cell lines after -arginine addition, and this effect could be antagonized by -NNA. Cytokine treatment inhibited cell growth, and this inhibition was partly reversed by -NNA.Conclusions. Normal urothelial cells and bladder cancer cell lines MBT-2 and T24 show NOS activity, and cytokine treatment induces calcium-independent NOS activity. Our results suggest that endogenous activity of the constitutively expressed form of NOS in unstimulated cells promotes cell proliferation, and NO production secondary to increased activity of the inducible form of NOS after cytokine treatment inhibits cell growth.     

端粒酶反义RNA转染促进膀胱癌T24细胞凋亡的研究

目的　探讨端粒酶反义RNA对膀胱癌T2 4细胞恶性表型的抑制及促进其凋亡的作用。　方法　采用脂质体转染法将转录出端粒酶反义RNA质粒导入膀胱癌T2 4细胞。应用PCR ELISA法测定转染后T2 4细胞的端粒酶活性 ;光镜、电镜、MTT及流式细胞术 (FCM )等方法观察端粒酶反义RNA对T2 4细胞生长及凋亡的影响。　结果　端粒酶反义RNA能显著抑制T2 4细胞的端粒酶活性 ,转染T2 4细胞后使其生长受到抑制。形态学观察 ,转染后T2 4细胞出现典型的凋亡现象。FCM检测发现G1期前出现凋亡峰。　结论　转染端粒酶反义RNA能抑制膀胱癌T2 4细胞的恶性表型 ,促进其凋亡