TRAIL受体在膀胱癌中的表达及意义

目的：了解肿瘤坏死因子相关诱导凋亡配体（TRAIL）受体在膀胱癌组织中的表达及意义。方法：采用RT－PCR及Northern blot方法检测TRAIL受体在膀胱癌组织及正常膀胱粘膜中的表达。结果：死亡受体DR4、DR5在膀胱癌组织及正常膀胱粘膜中呈强表达,候受体DcR-1在正常膀胱粘膜呈强表达,假受体DcR-2未见表达。结论：TRAIL基因在膀胱移行上皮细胞癌凋亡机制中可能发挥重要作用。     

T细胞因子4在肾癌中的表达及其意义

目的　研究Wnt/Frizzled信号通路在核内的转导及其主要信号分子T细胞因子 4(TCF4)在肾癌发生发展中的作用。　方法　采用RT PCR及NorthernBlot的方法检测了TCF4基因在肾癌组织及正常肾组织 ,肾癌细胞系GRC I和正常肾小管上皮细胞系HK 2中的表达。　结果　TCF4在肾癌组织及细胞系中强表达 ,且存在剪接性突变 ,形成了 30 0bp左右的突变基因。　结论　TCF4作为Wnt/Frizzled信号通路的核内信号分子 ,在肾癌发生和发展中具有重要作用 ,其致病机理与TCF4的剪接性突变有一定关系。     

激活转录因子5在肾癌细胞系中的表达及意义

目的　探讨新基因激活转录因子 5 (ATF5 )在不同肾癌细胞系中的表达及意义。　方法　采用RT PCR及Northernblot方法检测ATF5基因在肾癌细胞系A498、786 O、GRC I和胚肾细胞系2 93及正常肾小管上皮细胞系HK 2中的表达 ,计算机辅助图像分析结果。　结果　RT PCR检测ATF5在肾癌细胞系A498、786 O、GRC I和胚肾细胞系 2 93中呈强表达 ,其灰度面积吸光度A值分别为35 195 .2± 2 8.2、35 70 9.3± 18.3、370 38.5± 2 4.2、33 318.8± 34.2 ,而在正常肾小管上皮细胞系HK 2中表达较弱 ,灰度面积吸光度A值为 2 42 3.6± 3 .3,肾颗粒细胞癌细胞系GRC I中的表达是HK 2的 15倍 ,两者差异有显著性意义 (P <0 .0 1)。Northernblot检测ATF5在不同肾癌细胞系的表达结果与RT PCR方法检测结果一致。　结论　ATF5在肾癌发生和发展中具有一定作用 ,其致病机理可能与协同Wnt信号通路相关。     

肾癌相关新基因GYLZ-RCC18反义寡核苷酸转染对肾癌细胞系GRC-1的作用

目的：探讨肾癌相关新基因GYLZ－RCC18在肾癌发生发展中的作用机制。方法：采用逆转录PCR方法检测GYLZ－RCC18在肾癌和正常肾细胞系中的表达,将第一编码区起始处的20个碱基的反义和正义寡核苷酸导入肾癌细胞系GRC－1,连续观察对肾癌细胞生长、增殖凋亡、死亡率、形态学的影响。结果：GYLZ－RCC18在肾癌细胞系中表达明显高于正常肾细胞系;导入GYLZ－RCC18反义寡核苷酸后,GRC－1细胞的核分裂可明显减少,导致GRC－1细胞死亡,抑制癌细胞的生长和增殖活性,并可特异诱导GRC－1连续凋亡。结论：GYLZ－RCC18是肾癌发生发展密切相关的癌基因,其表达可促进肾癌细胞的生长和增殖,并通过抗癌细胞死亡和凋亡机制对癌细胞起保护作用。     

TRAIL受体在胰腺癌中的表达及意义

目的:研究肿瘤坏死因子相关凋亡诱导配体(TRAIL)受体在胰腺癌中的表达及意义。方法:应用半定量RT-PCR,检测TRAILR mRNA在胰腺癌组织,正常胰腺组织及胰腺癌细胞系ASPC-1、Can-pan-2中的表达。结果:死亡受体DR4、DR5在所有胰腺癌组织、正常胰腺组织及胰腺癌细胞系中均有表达,诱骗受体DcR1、DcR2在所有正常胰腺组织及细胞系中均有表达。死亡受体DR4、DR5在胰腺癌组织中有较高的表达,而在正常胰腺组织中呈中低水平表达(P<0.01)。胰腺癌细胞系中死亡受体DR4、DR5呈高水平表达,而诱骗受体DcR1、DcR2仅呈中低水平表达。结论:TRAIL受体在胰腺癌普遍表达,并存在受体类型的表达差异;死亡受体在胰腺癌中高表达,可能在TRAIL诱导胰腺癌细胞凋亡的机制中发挥重要的作用。     

miR-520a-3p对肾癌细胞增殖、迁移、侵袭和凋亡的影响

目的 探讨miR-520a-3p在肾癌细胞系中的表达水平及其对肾癌细胞增殖、迁移、侵袭和凋亡的影响.方法 通过实时荧光定量聚合酶链式反应检测miR-520a-3p在正常肾小管上皮细胞HK2和肾癌细胞系786-O、A498、OS-RC-2及ACHN中的表达水平.选取miR-520a-3p表达水平最低的肾癌细胞系786-O...     

肿瘤坏死因子相关凋亡诱导配体及其受体在烧伤大鼠胸腺组织中的表达

目的 了解肿瘤坏死因子（TNF）相关的凋亡诱导配体（TRAIL）及其受体在严重烧伤大鼠胸腺组织细胞异常凋亡中的作用。方法 将50只Wistar大鼠随机分为假伤组（模拟烧伤）lO只和烧伤组40只（设伤后4、12、24、48h 4个时相点）。应用膜联蛋白A5-异硫氰酸荧光素／碘化丙啶双染法，观察大鼠胸腺组织中细胞凋亡的情况；反转录-聚合酶链反应和蛋白质印迹法检测TRAIL的死亡受体5（DR5）、DR4、诱骗受体1（DcR-1）、DcR2在大鼠胸腺组织中的表达。结果 与假伤组大鼠细胞凋亡率[（6．7±0．8）％]比较，烧伤组于伤后4h[（17．1±0．4）％]起增高，12h时[（25．2±1．1）％]达高峰，48h时仍明显高于假伤组（P〈0．05）。烧伤组大鼠胸腺组织中DR5的表达显著高于假伤组，DcR2的表达则显著低于假伤组；其余受体的表达组间相似。结论 严重烧伤后早期大鼠胸腺组织的细胞凋亡明显增加，且胸腺组织中DR5和DcR2的表达异常，提示TRAIL凋亡途径可能参与了病理性细胞凋亡过程。     

肿瘤坏死因子相关凋亡诱导配体受体单克隆抗体对人肾癌细胞的毒性作用

目的　探讨肿瘤坏死因子相关凋亡诱导配体受体 (TRAIL R)的单克隆抗体对肾癌细胞的毒性作用和机制。方法　在人肾癌细胞系ACHN和Caki 1中 ,应用四甲基偶氮唑盐 (MTT)方法分析细胞毒效应 ,应用流式细胞术检测相关凋亡诱导配体受体 (TRAIL R)的表达 ,应用荧光染色和AnnexinV标记检测细胞凋亡的发生 ,应用比色法分析多种Caspase活性在凋亡过程中的变化。结果　抗TRAIL R2单克隆抗体 (ETR2 )对人肾癌细胞系ACHN和Caki 1都具有明显的细胞毒性 (P <0 .0 1) ,而抗TRAIL R1单克隆抗体 (ETR1)的细胞毒性不显著 (P >0 .0 5 )。TRAIL R2在两种细胞表面均高表达 (ACHN :97.9% ,Caki 1:98.7% ) ,TRAIL R1表达微弱 (ACHN :7.6% ,Caki 1:7.5 4% )。ETR2通过诱导细胞凋亡发挥细胞毒作用 ,Caspase 8, 9, 6和 3活性在凋亡过程中明显增高 (P <0 .0 1)。结论　TRAIL R2的单克隆抗体在体外可诱导肾癌细胞发生凋亡 ,其细胞毒性与TRAIL R2的表达有关 ,在凋亡过程中内源性与外源性凋亡通路均被激活。     

Bcl－2／bax蛋白在肾癌组织中的表达意义

为探讨凋亡抑制基因ｂｃｌ－２和凋亡促进基因ｂａｘ蛋白在肾癌组织中的表达对肾癌发生和发展的影响，采用抗ｂｃｌ－２单克隆抗体和抗ｂａｘ多克隆抗体分别对４２例肾癌和２０例远离癌的正常肾组织的石蜡切片进行免疫组织化学染色。结果显示２０例正常肾组织有１１例ｂｃｌ－２蛋白呈弱阳性表达，阳性率５５．０％，表达部位在肾小管和集合管上皮细胞，４２例肾癌组织有３７例ｂｃｌ－２蛋白表达阳性，阳性率８８．１％，且染色强度明显增强。经统计学处理，肾癌组织阳性表达明显高于正常肾组织（Ｐ＜０．０１）。２０例正常肾组织有１９例ｂａｘ蛋白表达阳性，阳性率９５．０％，表达部位在肾小管和集合管上皮细胞。４２例肾癌组织有２２例ｂａｘ蛋白表达阳性，阳性率５２．４％。经统计学处理，肾癌组织阳性表达明显低于正常肾组织（Ｐ＜０．０１）。ｂｃｌ－２和ｂａｘ蛋白在肾癌组织中的异常表达，使肾癌细胞凋亡处于抑制状态，细胞寿命延长，可能参与了肾癌的发生和发展过程     

肾癌相关基因GYLZ-RCC18对肾癌细胞系GRC-1抗死亡作用机制的研究

目的：应用反义基因转染技术探讨肾癌相关新基因GYLZ－RCC18与肾癌细胞死亡（包括坏死及凋亡）之间的关系,并探讨肾癌基因疗法的新途径。方法：用脂质体包裹的新基因GYLZ－RCC18第一编码区起始处的20个碱基的反义和正义寡核苷酸导入肾癌细胞系GRC－1,应用流式细胞技术和伊红排斥实验连续检测GYLZ－RCC18反义寡核苷酸对肾癌细胞凋亡、坏死的影响。结果：导入GYLZ－RCC18反义寡核苷酸后,可大量杀伤GRC－1细胞并明显促进GRC－1细胞坏死,于第4天达到杀伤高峰约60％;同时可连续8d诱导凋亡峰,最高于第2天达约约22．5％,两种作用 曲线形状和峰值不完全一致。结论GYLZ－RCC18是肾癌相关的重要的新的癌基因,GYLZ－RCC18的表达可通过两种不同的机制即抗癌细胞坏死机制和抗凋亡机制发挥对肾癌细胞的保护作用,GYLZ－RCC18可能对肾癌细胞生存和耐药至关重要,通过导入反义基因的方法阻断肾癌细胞中GYLZ－RCC18的表达,可有效地杀伤肾癌细胞,对此新基因的研究将有助于为肾癌的基因的基础研究和临床治疗提供新的思路和途径。     

Thapsigargin potentiates TRAIL-induced apoptosis in giant cell tumor of bone

TNF-related apoptosis-inducing ligand (TRAIL) is capable of causing apoptosis in tumor cells but not in normal cells; however, it has been shown that certain types of tumor cells are resistant to TRAIL-induced apoptosis. In this study, we examined the potentiation of TRAIL-induced apoptosis in the stromal-like tumor cells of giant cell tumor of bone (GCT). We show that both mRNA and protein of TRAIL receptors—death receptors (DR4, DR5) and decoy receptors (DcR1, DcR2) are present in GCT stromal tumor cells. However, the expression profiles in all GCT clones tested do not readily correlate with their differential sensitivity to TRAIL. To this end, we selected thapsigargin (TG), an agent known to cause perturbations in intracellular Ca²⁺ homeostasis to enhance the apoptotic action of TRAIL. When added alone, neither TRAIL nor TG induces a therapeutically important magnitude of cell death in GCT tumor cells. Interdependently, scheduled treatment of the cultures with TG followed by subsequent addition of TRAIL resulted in a significant synergistic apoptotic activity, while in contrast, no obvious augmentation was seen when TRAIL was added before TG. This effect was in accord with our observation that TG predominantly up-regulated both mRNA and protein expression of DR5, as well as DR4 mRNA while down-regulating DcR1 protein in GCT stromal-like tumor cells. Taken together, our findings suggest that TG is able to sensitize tumor cells of GCT to TRAIL-induced cell death, perhaps in part through up-regulating the death receptor DR5 and down-regulating the decoy receptor DcR1. These findings provide an additional insight into the design of new treatment modalities for patients suffering from GCT.     

肿瘤坏死因子相关诱导凋亡配体受体mRNA在肝癌中的表达及其意义

目的 探讨肿瘤坏死因子相关诱导凋亡配体的4种受体DR4、DR5、DcR1、DcR2在肝细胞癌肝组织中的表达状况。方法 应用半定量逆转录-聚合酶链反应（RT-PCR）方法检测40例人肝细胞癌组织、相应癌旁肝组织、23例正常人肝组织中DR4、DR5、DcR1、DcR2的mRNA表达率及表达水平。结果 （1）40例肝癌组织、癌旁组织、23例正常肝组织DR4、DR5的mRNA的表达水平差异无统计学意义（P〉0．05）；（2）40例癌旁组织、23例正常肝组织DcR1、DcR2表达水平明显高于40例肝癌组织（P〈0．05）；（3）DR4和DR5mRNA在肝细胞癌组织中表达水平与患者的年龄，肿瘤大小，有无包膜，分级程度，AFP水平，HBsAg，有无肝硬化有关系。结论 肝癌组织中存在TRAIL受体的表达，与其在正常肝组织中的表达差异有统计学意义（P〈0．05）；DR4、DR5表达水平与肝癌的病理状况有关系。     

肿瘤坏死因子相关凋亡诱导配体治疗肝细胞癌的研究

目的探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)与其受体在肝细胞肝癌(hepatocellularcarcinoma,HCC)中的表达及意义,及利用TRAIL对HCC的治疗作用。方法采用免疫组化技术及原位杂交方法分别检测了100例肝癌组织,100例癌旁组织,40例正常肝组织中TRAIL及TRAILR的表达,并结合临床资料进行分析;采用不同浓度TRAIL处理肝癌细胞株HepG2、SMMC7721,观察经药物处理前后肿瘤细胞的凋亡发生率。结果TRAIL在正常肝组织中无表达,癌旁组织中的表达明显高于癌组织。86例肝癌组织不表达诱捕受体DcR1(86%),55例肝癌组织不表达诱捕受体DcR2(55%),40例正常肝组织两种诱捕受体均有表达。肝癌组织中死亡受体为高表达,诱捕受体为低表达,正常肝组织则相反,两者间有显著差异性(P<0.05)。肝癌组织中死亡受体的表达与肿瘤的分化呈正相关(P<0.01),与肿瘤分级呈负相关(P<0.05),与病人的性别、年龄、AFP水平、肿瘤的大小以及是否转移无关。经TRAIL(100ng/ml)处理24h,肝癌细胞凋亡发生率约10%,而Jurkat细胞凋亡率达70%以上,胆管癌细胞QBC939凋亡发生率约50%。结论HCC时,TRAILR普遍表达,但存在受体类型的表达差异,其中DcR1大多缺失,这为利用TRAIL治疗HCC提供了理论依据,然而,单一的TRAIL治疗只能有限的诱导肝癌细胞HepG2、SMMC7721发生凋亡,HCC对TRAIL诱导的凋亡存在耐药现象。     

Sensitization of human renal cell carcinoma cell lines to TRAIL-induced apoptosis by anthracyclines

BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a new member of the tumor necrosis factor family. The present study investigated whether anthracyclines enhance TRAIL-induced apoptosis and cytotoxicity in renal cell carcinoma (RCC) cells. METHODS: Cytotoxicity was measured using the microtiter assay. Apoptosis was monitored using DNA ladder analysis. Caspase activity was determined using a quantitative colorimetric assay. RESULTS: Treatment of ACHN and Caki-1 human RCC lines with TRAIL, in combination with subtoxic concentrations of epirubicin (EPI) or pirarubicin (THP), enhanced induction of apoptosis and cytotoxicity. Sequential treatment with EPI followed by TRAIL induced significantly more cytotoxicity than the inverse treatment. The combined cytotoxicity of TRAIL and EPI was significantly inhibited by the TRAIL-neutralizing fusion protein DR5:Fc, although EPI did not affect the mRNA expression of DR4, DR5, DcR1 or DcR2. The combination treatment with TRAIL and EPI activated caspase-6 and -3, which were downstream molecules of the death receptor. Furthermore, the combined cytotoxicity of TRAIL and EPI was almost completely inhibited by Z-VAD-FMK, and partly inhibited by Ac-DMQD-CHO. CONCLUSION: These findings indicate that anthracyclines sensitize RCC cells to TRAIL-induced apoptosis and cytotoxicity through activation of caspases, suggesting that TRAIL, in combination with anthracyclines, has a therapeutic potential in the treatment of RCC.     

白细胞介素12通过抑制survivin表达加强肿瘤坏死因子相关凋亡诱导配体诱导的肝癌细胞凋亡

目的 探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)对肝细胞癌(HCC)的治疗作用,以及TRAIL耐药的可能机制和逆转耐药方案。方法 采用原位杂交方法观察HCC与正常肝组织中TRAIL的表达差异。采用不同浓度的sTRAIL(可溶性)处理HCC细胞株及真核表达质粒pIRES-EGFP-sTRAIL转染HCC细胞株,观察sTRAIL的抑癌疗效。建立裸鼠肝癌模型,观察sTRAIL的体内抑癌作用。进一步,检测HCC中survivin的表达并采用反义寡核苷酸封闭治疗。最后,观测sTRAIL和IL-12联合抗癌效果。结果 肝癌组织DR表达量显著强于正常肝组织DR表达量。60例肝癌组织中54例不表达诱捕受体DcRl,25例不表达DcR2,而20例正常肝组织均表达DcR。两种．HCC细胞株中DcR1表达缺失。经sTRAIL(100ng/ml)处理24h,HCC细胞凋亡发生率约10％,而Jurkat细胞凋亡率达70％以上。体外pIRES-EGFP-sTRAIL转染对肝癌细胞杀伤作用不敏感。体内直接瘤体注射pIRES-EGFP-sTRAIL可对裸鼠肝癌无明显抑制作用。HCC高表达survivin,反义寡核苷酸封闭可部分逆转TRAIL耐药。IL-12使survivin表达明显下调,显著加强TRAIL对HCC细胞的杀伤作用。结论 HCC对TRAIL诱导的凋亡有耐药现象。survivin参与HCC对TRAIL的耐药机制,反义寡核苷酸封闭可部分逆转TRAIL耐药。IL-12可通过抑制siurvivin表达增强TRAIL对HCC杀癌作用。联合基因治疗(如TRAIL和IL-12基因)可能成为一种有前途HCC治疗方案。     

TRAIL受体在前列腺癌中的表达

目的　探讨肿瘤坏死因子相关诱导凋亡配体 (TRAIL)受体在前列腺癌组织中的表达及其与前列腺癌恶性度的关系。方法　采用免疫组织化学方法检测前列腺癌组织及良性前列腺增生组织中DR4、DR5及DcR1的表达。结果　前列腺癌组织DcR1表达水平显著低于良性前列腺增生组织 (P <0 .0 1) ,DR4、DR5的表达水平两者无显著性差异。前列腺癌组织中DR4、DR5及DcR1的表达程度与前列腺癌组织的病理分级和临床分期无关 (P >0 .0 5 )。结论　TRAIL基因受体DcR1在前列腺癌凋亡机制中可能发挥重要作用     

Sensitivity of prostate cells to TRAIL-induced apoptosis increases with tumor progression: DR5 and caspase 8 are key players

BACKGROUND: As advanced prostate cancers are resistant to currently available chemotherapies, we evaluated the cytotoxic effect of TNF-related apoptosis-inducing ligand (TRAIL) and characterized the involvement of its five receptors DR4, DR5, DcR1, DcR2, and osteoprotegerin (OPG) and of the death-inducing signaling complex (DISC)-forming proteins caspase 8 and c-FLIP in prostate cell lines. METHODS: We used six prostate cell lines, each corresponding to a particular stage in prostate tumorigenesis, and analyzed TRAIL sensitivity in relation to TRAIL receptors' expression. RESULTS: TRAIL sensitivity was correlated with tumor progression and DR5 expression levels and apoptosis was exclusively mediated by DR5. DcR2 was significantly more abundant in tumor cells than in non-neoplastic ones and may contribute to partial resistance to TRAIL in some prostate tumor cells. Conversely, non-tumoral cells secreted high levels of OPG, which can protect them from apoptosis. Finally, caspase 8 expression levels were as DR5 directly correlated to TRAIL sensitivity in prostate tumor cells. CONCLUSION: TRAIL-induced apoptosis is closely related to the balanced expression of its different receptors in prostate cancer cells and their modulation could be of potential clinical value for advanced tumor treatment.     

Enhancement of death receptor 4 mediated apoptosis and cytotoxicity in renal cell carcinoma cells by subtoxic concentrations of doxorubicin

PURPOSE: TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) triggers apoptosis in various tumor cells by engaging death receptors 4 and 5. We investigated the effect of chemotherapeutic agents on death receptor 4 mediated apoptosis in human renal cell carcinoma cells using HGS-ETR1, which is a human monoclonal agonistic antibody specific for death receptor 4. MATERIALS AND METHODS: Cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Synergy was assessed by isobolographic analysis. RESULTS: Treatment of the ACHN human renal cell carcinoma cell line with HGS-ETR1 combined with 5-fluorouracil, vinblastine or gemcitabine did not overcome resistance to these agents. However, treatment with HGS-ETR1 combined with doxorubicin had a synergistic cytotoxic effect. Synergy was also achieved in another human renal cell carcinoma cell line, Caki-1, and in 5 freshly derived renal cell carcinoma cell cultures. A synergistic effect was also observed with HGS-ETR1 combined with the doxorubicin derivatives epirubicin, pirarubicin or amrubicin. The synergy achieved in cytotoxicity with HGS-ETR1 and doxorubicin was also achieved in apoptosis. Sequential treatment with doxorubicin followed by HGS-ETR1 induced significantly more cytotoxicity than reverse treatment or simultaneous treatment (p<0.05). Doxorubicin remarkably increased the cell surface expression of death receptor 4 in renal cell carcinoma cells. The combination of doxorubicin and HGS-ETR1 significantly activated the caspase cascade, including caspase-8, 9, 6 and 3, which are the downstream molecules of death receptors. CONCLUSIONS: These findings indicate that doxorubicin sensitizes renal cell carcinoma cells to death receptor 4 mediated apoptosis through the induction of death receptor 4 and the activation of caspases, suggesting that combination therapy of doxorubicin and HGS-ETR1 might be effective as renal cell carcinoma therapy.