肿瘤坏死因子相关凋亡诱导配体受体在肾癌中的分布及其意义

目的：研究肿瘤坏死因子相关诱导凋亡配体（TRAIL）受体在肾癌组织中的分布及其意义。方法：采用RT－PCR及NorthernBlot的方法检测TRAIL受体在肾癌组织及正常肾组织,肾癌细胞系GRC－I和正常肾小管细胞系HK－2中的表达。结果：死亡受体DR4、DT4在肾癌组织及正常肾组织、肾癌细胞系GRC－I和正常肾小管细胞系HK－2中强表达;假受体DcR-1在正常肾组织和正常肾小管细胞系HK－2中强表达;假受体DcR-2未见表达。结论TRAIL基因在肾癌肿瘤细胞的凋亡机制中可能发挥重要的作用。     

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。     

TRAIL受体在胰腺癌中的表达

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法检测TRAIL受体（死亡受体DR4、DR5和诱骗受体DcR1、DcR2）mRNA在胰腺癌组织及正常胰腺组织中的表达。结果 死亡受体DR4和DR5在所有胰腺癌组织和正常胰腺组织中均有表达，且在胰腺癌组织中的表达明显强于在正常胰腺组织中的表达（P〈0．01）。诱骗受体DcR1和DcR2在所有正常胰腺组织中均有表达，而在胰腺癌组织中仅有18例表达DcR1，有20例表达DcR2；诱骗受体DcR1和DcR2的表达水平在胰腺癌和正常胰腺组织中差异无统计学意义（P〉0．05）。胰腺癌组织中DR5的表达与肿瘤的分化程度和临床分期有关，分化程度越低，DR5的表达量越低，Ⅲ、Ⅳ期肿瘤DR5的表达显著低于Ⅰ、Ⅱ期（P〈0．05）。DR4、DcR1及DcR2在胰腺癌组织中的表达与肿瘤的分化程度和临床分期无关（P〉0．05）。结论 ①胰腺癌组织中普遍存在TRAIL受体的表达，并存在受体类型的表达差异，TRAIL基因受体在胰腺癌凋亡的调控机理中可能发挥重要作用。②胰腺癌组织中DR5的表达与肿瘤的分化程度及恶性程度相关；死亡受体DR4及诱骗受体DcR1和DcR2不能作为判断胰腺癌分化程度及恶性程度的指标。     

TRAIL及其受体在直肠癌组织中的表达

目的 探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)及其受体(DR4、DcR1)在正常直肠和直肠癌组织中的表达.方法 在31例直肠癌和20例正常直肠组织中,用免疫组化法检测TRAIL、DR4和DcR1的蛋白表达.结果 直肠癌组织中TRAIL、DR4和DcR1蛋白的表达阳性率(32.26%、29.03%、0)均低于正常直肠组织(55.00%、70.00%、65.00%),差异均有统计学意义(P=0.015、P=0.000、P=0.000),TRAIL及其受体的表达与直肠癌临床病理特征间无关(P>0.05).结论 直肠癌组织中TRAIL、DR4和DcR1的表达低于正常直肠组织,TRAIL及其受体相互作用所诱导的凋亡效应在直肠癌中有所减弱.     

白藜芦醇促进膀胱癌细胞对TRAIL凋亡诱导作用的研究

目的探讨白藜芦醇对膀胱癌细胞的作用及其与TRAIL联合对膀胱癌细胞的凋亡诱导作用及其可能的机制。方法MTT法检测白藜芦醇或/和TRAIL对膀胱癌细胞5637和T24体外生长能力的影响。流式细胞术测定白藜芦醇和/或TRAIL对细胞凋亡和线粒体跨膜电位的影响。Western blot检测白藜芦醇对死亡受体(DR)4、5与细胞凋亡相关蛋白表达水平的变化。结果 MTT证实白藜芦醇可抑制膀胱癌细胞体外生长能力,且呈剂量与时间依赖性。单独应用TRAIL未能抑制膀胱癌细胞的生长,但与白藜芦醇联合应用时可显著抑制细胞的增殖速度。白藜芦醇能够诱导膀胱癌细胞发生凋亡,而TRAIL则不能诱导细胞凋亡,但联合应用白藜芦醇和TRAIL可诱导膀胱癌细胞发生显著的凋亡。此外,在白藜芦醇或联合应用白藜芦醇与TRAIL可诱导肿瘤细胞丢失线粒体膜电位(ΔΨm),而单独应用TRAIL则未能诱导线粒体膜电位的丢失。Western blot结果表明,白藜芦醇可上调DR4和DR5的表达,并下调Bcl-2与survivin的表达。结论白藜芦醇可抑制膀胱癌5637和T24细胞增殖并诱导细胞凋亡。此外,白藜芦醇可以提高膀胱癌细胞对TRAIL诱导的细胞凋亡作用。单独应用白藜芦醇或与TRAIL联合应用可能成为临床膀胱癌治疗的新策略。     

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。     

TRAIL和TRAILR在肝癌中表达及对肝癌的治疗作用

目的探讨肿瘤坏死因子相关凋亡诱导配体(tumornecrosisfactorrelatedapoptosis-inducingligand,TRAIL)与其受体(TRAILR)在肝细胞肝癌中的表达及TRAIL联合应用化疗药对肝癌细胞的杀伤作用。方法采用免疫组化和原位杂交检测100例肝癌及癌旁组织中TRAIL及TRAILR的表达。用MTT法检测TRAIL与化疗药联合应用对肝癌细胞的杀伤作用。结果TRAIL在正常肝组织中无表达,在癌旁组织中的表达明显高于癌组织;肝癌组织中死亡受体(DR5、DR4)的表达量显著强于正常肝组织,诱捕受体为低表达,与正常肝组织相比,两者差异显著(χ2=4·68,P<0·05)。Ⅲ/Ⅳ期肿瘤死亡受体的表达显著低于Ⅰ/Ⅱ期(χ2=6·17,P<0·05)。联合使用亚细胞毒性剂量的化疗药大幅度提高了TRAIL的细胞毒活性。结论TRAIL与化疗药物联合运用具有协同杀伤肝癌细胞的作用。     

肿瘤坏死因子相关细胞凋亡诱导配体受体-4在人胰腺癌组织中的表达

目的：通过检测肿瘤坏死因子相关细胞凋亡诱导配体受体-4(TRAIL-R4)在胰腺癌组织中的表达，探讨胰腺癌细胞抵抗细胞凋亡的机理。方法：应用mRNA印迹法(Northern blotting)、蛋白质印迹法(Western blotting)和免疫组织化学技术，定性、定位分析TRAIL-R4在正常胰腺组织和胰腺癌组织中的表达。结果：TRAIL-R4 mRNA和蛋白在正常胰腺组织中呈弱表达或不表达，而在胰腺癌组织中呈高表达；免疫组织化学检测显示，在胰腺癌细胞中TRAIL-R4蛋白呈强染色。结论：TRAIL-R4表达水平在正常胰腺组织与胰腺癌组织中存在显著差异，提示胰腺癌细胞中可能存在对TRAIL介导的细胞凋亡抵抗新机理。     

凋亡相关基因bcl—2和bax蛋白在膀胱癌组织中的表达及临床意义

为探讨凋亡抑制基因ｂｃｌ－２和凋亡促进基因ｂａｘ表达产物在膀胱癌组织中的分布及意义,作者应用抗ｂｃｌ－２单克隆抗体和抗ｂａｘ多克隆抗体分别对３４例膀胱癌和９例正常膀胱粘膜组织的石蜡切片进行免疫组化染色。结果显示,９例正常膀胱粘膜有４例ｂｃｌ－２蛋白表达阳性（４４．４４％）,３４例膀胱癌有２８例ｂｃｌ－２蛋白表达阳性（８２．３５％）,两组间差异有显著意义（Ｐ＜０．０５）,随肿瘤分级的增加,阳性表达增强。９例正常膀胱粘膜有８例ｂａｘ蛋白表达阳性（８８．８９％）,３４例膀胱癌有１８例表达阳性（５２．９４％）,两组间差异有显著意义（Ｐ＜０．０５）。作者认为,ｂｃｌ－２和ｂａｘ蛋白在膀胱癌组织中的异常表达,参与了膀胱癌的发生及进展过程。     

肿瘤坏死因子相关的凋亡诱导配体基因在糖尿病大鼠肾脏细胞凋亡中的作用

目的 探讨肿瘤坏死因子(TNF)相关的凋亡诱导配体(TRAIL)基因在糖尿病大鼠肾脏细胞凋亡中的表达及其作用。方法 应用链脲佐菌素建立糖尿病大鼠模型，采用原位末端标记法和流式细胞术检测4组(对照组、糖尿病4周组、8周组和12周组)大鼠肾脏细胞凋亡情况；免疫组化和流式细胞术检测肾脏TRAIL基因及其死亡受体DR4、DR5的蛋白表达。结果 与正常对照组相比．各糖尿病组较对照组肾小球、肾小管凋亡细胞数明显增多，TRAIL、DR4、DR5的表达亦显著增强。结论 在高糖环境的诱导下．TRAIL基因及其死亡受体出现的高表达，可能部分参与了糖尿病大鼠肾脏细胞凋亡。     

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。     

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.     

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     

Effects of sequential treatments with chemotherapeutic drugs followed by TRAIL on prostate cancer in vitro and in vivo

BACKGROUND: Tumor necrosis factor related apoptosis-inducing ligand/Apo2 ligand (TRAIL/Apo-2L) is a novel anticancer agent, capable of inducing apoptosis preferentially in tumor and transformed cells. TRAIL-R1/death receptor (DR)4 and TRAIL-R2/DR5 are members of the tumor necrosis factor (TNF) receptor family, and can be activated by the TRAIL. We examined the clinical potential of chemotherapeutic drugs and TRAIL for the treatment of prostate cancer. METHODS: Prostate and bladder cancer cells were exposed to chemotherapeutic drugs (paclitaxel, vincristine, vinblastine, etoposide, doxorubicin, and camptothecin) and TRAIL. Cell viability was measured by sodium 3'[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) assay; expressions of death receptors and Bcl-2 family members were measured by Western blotting, ELISA and ribonuclease protection assay. PC-3 tumor cells xenografted athymic nude mice were exposed to chemotherapeutic drugs and TRAIL, either alone or in combination, to measure tumor growth and survival of mice. Apoptosis was measured by annexin V-FITC/propidium iodide staining, and terminal deoxynucleotidyltransferase-mediated nick end labeling assay. Caspase-3 activity was measured by the Western blotting and immunohistochemistry. RESULTS: TRAIL induced apoptosis with varying sensitivity. Chemotherapeutic drugs (paclitaxel, vincristine, vinblastine, etoposide, doxorubicin, and camptothecin) significantly augmented TRAIL-induced apoptosis in cancer cells through up-regulation of DR4, DR5, Bax, and Bak, and induction of caspase activation. Mitochondrial pathway enhanced the synergistic interactions between drugs and TRAIL. The sequential treatment of mice with chemotherapeutic drugs followed by TRAIL induced caspase-3 activity, and apoptosis, inhibited angiogenesis, completely eradicated the established tumors, and enhanced survival of mice. CONCLUSIONS: Chemotherapeutic drugs can be used to enhance the therapeutic potential of TRAIL in prostate cancer.     

Targeted RNA interference of PI3K pathway components sensitizes colon cancer cells to TNF-related apoptosis-inducing ligand (TRAIL)

BACKGROUND: The phosphoinositide 3-kinase (PI3K/Akt) pathway transduces signals initiated from growth factors. Previously, we identified an important role for PI3K/Akt in colon cancer progression. The purpose of this study was to determine (1) whether short interfering RNA (siRNA) directed to PI3K/Akt components can render colon cancer cells sensitive to treatment with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and (2) the cellular mechanisms contributing to the enhanced sensitivity. METHODS: Human colon cancer cells KM20 and KM12C (both TRAIL resistant) were transfected with siRNA directed against the PI3K p85alpha regulatory subunit Akt1 or nontargeting control sequence and then treated with TRAIL (100 ng/mL) or vehicle. A ribonuclease protection assay was performed to assess changes in TRAIL receptor expression. Protein was extracted and analyzed by Western blot for expression of cleavage of TRAIL receptors (death receptor (DR) 4 and 5), caspase-3, caspase-8, and BID. Apoptosis was measured by enzyme-linked immunosorbent assay of DNA fragmentation. RESULTS: Combination treatment with p85alpha or Akt1 siRNA and TRAIL increased apoptosis in KM20 and KM12C cells, compared with TRAIL alone; these results were corroborated further by complete inhibition of apoptosis by Z-acetyl-Asp-Glu-Val-Asp-(DEVD)-fmk, a caspase-3 inhibitor. Furthermore, siRNA-mediated PI3K pathway inhibition resulted in increased expression of the TRAIL death receptors 4 and 5. CONCLUSIONS: Inhibition of PI3K/Akt by RNA interference sensitizes resistant colon cancer cells to TRAIL-induced cell death through the induction of TRAIL receptors and activation of caspase-3 and caspase-8. Agents that selectively target the PI3K/Akt pathway may enhance the effects of chemotherapeutic agents and provide novel adjuvant treatment for selected colon cancers.     

Human osteoblasts are resistant to Apo2L/TRAIL-mediated apoptosis

Apo2 ligand (Apo2L/TRAIL) is a member of the tumor necrosis factor (TNF) cytokine family. Apo2L/TRAIL can selectively induce programmed cell death in transformed cells, although its wide tissue distribution suggests potential physiological roles. We have investigated the expression, in human osteoblast-like cells (NHBC), of Apo2L/TRAIL and the known Apo2L/TRAIL death receptors, DR4 and DR5, and the Apo2L/TRAIL decoy receptors, DcR-1, DcR-2, and osteoprotegerin (OPG). NHBC expressed abundant mRNA corresponding to each of these molecular species. Immunofluorescence staining demonstrated that Apo2L/TRAIL protein was abundant within the cytoplasm of NHBC and OPG was strongly expressed at the cell surface. DR5 and DcR-2 were present in the cell membrane and cytoplasm and DcR-1 was confined to the nucleus. DR4 staining was weak. Neither Apo2L/TRAIL alone, nor in combination with chemotherapeutic agents of clinical relevance to treatment of osteogenic sarcoma, induced cell death in NHBC, as assessed morphologically and by activation of caspase-3. In contrast, the human osteogenic sarcoma cell lines, BTK-143 and G-292, were sensitive to exogenous Apo2L/TRAIL alone, and to the combined effect of Apo2L/TRAIL/cisplatin and Apo2L/TRAIL/doxorubicin treatments, respectively. In NHBC, we observed strong associations between the levels of mRNA corresponding to the pro-apoptotic molecules, Apo2L/TRAIL, DR4, and DR5, and those corresponding to pro-survival molecules, DcR-1, DcR-2, OPG, and FLIP, suggesting that the balance between pro-survival and pro-apoptotic molecules is a mechanism by which NHBC can resist Apo2L/TRAIL-mediated apoptosis. In contrast, osteogenic sarcoma cells had low or absent levels of DcR-1 and DcR-2. These results provide a foundation to explore the role of Apo2L/TRAIL in osteoblast physiology. In addition, they predict that therapeutic use of recombinant Apo2L/TRAIL, in combination with chemotherapeutic agents to treat skeletal malignancies, would have limited toxic effects on normal osteoblastic cells.     

Regulation of the resistance to TRAIL-induced apoptosis as a new strategy for pancreatic cancer

BACKGROUND: Tumor necrosis factor-related, apoptosis-inducing ligand (TRAIL) is a potent inducer of apoptosis in a wide variety of tumor cells, but it does not cause toxicity in the majority of normal cells. Therefore, TRAIL could become a suitable agent for anticancer therapies. However, a number of tumor cell lines are known to be resistant to TRAIL-induced apoptosis. The purpose of this study was to determine the mechanisms of resistance to TRAIL in pancreatic cancer cells. METHODS: In human pancreatic cancer cell lines, the sensitivity to TRAIL-induced apoptosis was tested. The expression of TRAIL receptors (DR4, DR5, DcR1, and DcR2) and the expression of death signal-transducing proteins were investigated. In the TRAIL-resistant pancreatic cancer cells, effects of cycloheximide, a protein synthesis inhibitor, on death signal-transducing proteins were tested. Finally, the effects of the combined treatment with cycloheximide and TRAIL on the induction of apoptosis and on the expression of death signal-transducing proteins were examined. RESULTS: Pancreatic cancer cells responded to TRAIL in a different way. Resistant cell lines, AsPC-1, Suit-2, and CFPAC-1, expressed higher levels of FLIP-S protein, one of the splice variants of FLIP. Cycloheximide reduced the expression of FLIP in the resistant cells. Combined treatment with cycloheximide and TRAIL induced cleaved forms of caspases and simultaneously restored the sensitivity to TRAIL-induced apoptosis in the resistant cells. CONCLUSIONS: Pancreatic cancer cells are resistant to TRAIL-induced apoptosis via strong expression of the anti-apoptotic protein FLIP-S. Suppression of FLIP-S by cycloheximide restored sensitivity to TRAIL-induced apoptosis in resistant cancer cells. These findings may provide useful information for the development of TRAIL-based therapeutic strategies aimed at restoring the functionality of apoptotic pathways in pancreatic cancer cells.     

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。     

Targeting death receptors in bladder, prostate and renal cancer

PURPOSE: We describe key components of normal and aberrant death receptor pathways, the association of these abnormalities with tumorigenesis in bladder, prostate and renal cancer, and their potential application in novel therapeutic strategies targeted toward patients with cancer. MATERIALS AND METHODS: A MEDLINE literature search of the key words death receptors, TRAIL (tumor necrosis factor related apoptosis inducing ligand), FAS, bladder, prostate, renal and cancer was done to obtain information for review. A brief overview of the TRAIL and FAS death receptor pathways, and their relationship to apoptosis is described. Mechanisms that lead to nonfunction of these pathways and how they may contribute to tumorigenesis are linked. Current efforts to target death receptor pathways as a therapeutic strategy are highlighted. RESULTS: Activation of tumor cell expressing death receptors by cytotoxic immune cells is the main mechanism by which the immune system eliminates malignant cells. Death receptor triggering induces a caspase cascade, leading to tumor cell apoptosis. Receptor gene mutation or hypermethylation, decoy receptor or splice variant over expression, and downstream inhibitor interference are examples of the ways that normal pathway functioning is lost in cancers of the bladder and prostate. Targeting death receptors directly through synthetic ligand administration and blocking downstream inhibitor molecules with siRNA or antisense oligonucleotides represent novel therapeutic strategies under development. CONCLUSIONS: Research into the death receptor pathways has demonstrated the key role that pathway aberrations have in the initiation and progression of malignancies of the bladder, prostate and kidney. This new understanding has resulted in exciting approaches to restore the functionality of these pathways as a novel therapeutic strategy.