肿瘤坏死因子相关凋亡诱导配体对人骨肉瘤的作用

目的研究肿瘤坏死因子相关凋亡诱导配体（TRAIL）对人骨肉瘤的作用,以及此作用与TRAIL受体（TRAILR）在人骨肉瘤中表达的相关性。方法应用原位杂交、Western blot方法检测人骨肉瘤细胞系MG-63及新鲜骨肉瘤组织块中TRAILR的表达;将在大肠杆菌中表达的TRAIL纯化后用于MG-63及新鲜骨肉瘤组织块,同法处理人白血病细胞株Jurkat作为阳性对照。MTT法检测细胞毒作用;流式细胞术检测凋亡,光镜下观察形态学变化,计数细胞,绘制生长曲线,测定细胞倍增时间。结果人骨肉瘤中死亡受体DR4、DR5呈高表达而诱惑受体DcR1、DcR2呈低表达,但TRAIL抑制人骨肉瘤细胞增殖而不能诱导其凋亡,MG-63在TRAIL作用下变肥大且呈编织排列。结论人骨肉瘤细胞对TRAIL耐受与其诱惑受体表达无关,TRAIL能改变体外培养的人骨肉瘤细胞形态及增殖动力学。     

阿霉素对肝癌细胞增殖及TRAIL受体表达影响的实验研究

[目的]研究亚毒性浓度阿霉素联合TRAIL蛋白对肝癌HepG2细胞增殖及TRAIL受体表达的影响。[方法]采用MTT法,分别检测阿霉素、TRAIL及亚毒性浓度阿霉素联合TRAIL对HepG2细胞的生长抑制率;RT-PCR和Westernblot分别检测阿霉素作用前后HepG2细胞TRAIL受体DR4、DR5、DcR1、DcR2mRNA和蛋白表达的水平。[结果]TRAIL对HepG2细胞增殖的抑制不存在浓度依赖性;阿霉素对HepG2细胞增殖的抑制作用存在浓度依赖性;亚毒性浓度阿霉素与亚毒性浓度TRAIL联用杀伤肿瘤的能力明显增强;无论在mRNA还是蛋白水平,阿霉素处理后HepG2细胞死亡受体DR4、DR5的表达水平显著增加,而阿霉素处理后诱骗受体DcR1、DcR2的表达量较阿霉素处理前明显减少。[结论]亚毒性浓度的阿霉素与亚毒性浓度的TRAIL联合应用具有协同作用,其机制可能是由于阿霉素在某种程度上增加了细胞表面死亡受体的表达,从而诱导了细胞凋亡的增加,说明TRAIL在肿瘤治疗方面存在潜在的应用价值。     

TRAIL与卡铂联合诱导卵巢癌细胞凋亡的研究

目的探讨肿瘤坏死因子相关凋亡诱导配体（TRAIL）与卡铂（CBP）联合应用对体外培养的卵巢A2780细胞的生物学效应及其作用机制。方法采用MTT法、流式细胞术，检测体外培养的A2780细胞在卡铂和TRAIL共同作用下的细胞增殖抑制效应以及细胞凋亡程度，应用半定量逆转录多聚酶链反应（RT-PCR）法检测TRAIL受体的mRNA表达水平。结果A2780细胞对TRAIL敏感，TRAIL与卡铂联合用药对细胞的增殖抑制呈现高效协同作用，与单独用药组比较有显著性差异（P〈0．05）；流式细胞术分析协同性杀伤作用主要由于TRAIL和CBP联合诱导细胞凋亡引起；RT—PCR法检测结果显示A2780细胞在TRAIL与卡铂联合用药后均表现死亡受体DR4、DR5表达水平上调和诱骗受体DcR1、DcR2表达水平下调。结论在体外TRAIL与化疗药物联用能明显抑制肿瘤细胞增殖，诱导肿瘤细胞凋亡，卡铂能明显增强TRAIL对肿瘤细胞的敏感性，其诱导机制可能与死亡受体DR4、DR5表达水平上调和诱骗受体DcR1、DcR2表达水平下调相关。     

可溶性肿瘤坏死因子相关凋亡诱导配体诱导肝癌细胞凋亡的研究

方法 采用原位杂交方法检测肝癌组织、肝癌细胞株以及正常肝组织中TRAILR的表达。采用不同浓度TRAIL蛋白处理肝癌细胞株Hep2和SMMC7721,应用流式细胞仪和原位末端标记,观察经药物处理前后该细胞株的凋亡发生率。结果 60例肝癌组织及20例正常肝组织均表达死亡受体DR5和DR4,但肝癌组织DR表达量显著强于正常肝组织。54例(90．0％)肝癌组织不表达诱捕受体DcR1,25例(41．7％)肝癌组织不表达DcR2,而20例正常肝组织均表达DcR。肝癌组织中DR的高表达及DcR的低表达,不同于正常肝组织中DR的低表达及DcR的高表达,两者间差异有显著性。两种肝癌细胞株中均可检测到DR5、DR4、DcR2的表达,但DcR1表达缺失。肝癌组织中DR的表达与肿瘤的分化、肿瘤分期有关,低分化的肿瘤DR表达减少(P＜0．01),Ⅲ、Ⅳ期肿瘤DR表达显著低于I、Ⅱ期(P＜0．05)。DR表达与患者的性别、年龄、HBsAg阳性与否、AFP水平、肿瘤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 肝细胞肝癌普遍存在TRAILR的表达,并存在受体类型的表达差异。但单一的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。     

肿瘤细胞对TRAIL敏感性与其表面DR5表达水平的相关性研究

目的　探讨肿瘤细胞表面DR5表达水平与其对肿瘤坏死因子相关的凋亡诱导配体(TRAIL)敏感性之间的关系。方法　利用抗DR5特异性单克隆抗体 ,采用流式细胞仪技术直接检测不同肿瘤细胞系表面DR5的表达水平 ,并采用TRAIL凋亡检测试剂盒检测肿瘤细胞对TRAIL诱导凋亡的敏感性 ,研究两者之间的关系。结果　不同肿瘤细胞表面DR5的表达水平分别为 :U937细胞97.9%、Jurkat细胞 95 .1%、SW4 80细胞 93.8%、HCT116细胞 86 .2 %、HL 6 0细胞 6 4 .2 %、HeLa细胞4 6 .6 %、K5 6 2细胞 13.1% ;TRAIL诱导的细胞凋亡率分别为 :U937细胞 72 .6 %、Jurkat细胞 85 .2 %、SW4 80细胞 78.6 %、HCT116细胞 70 .2 %、HL 6 0细胞 6 0 .1%、HeLa细胞 4 5 .4 %、K5 6 2细胞 12 .3%。经统计学分析 ,两者之间呈现非常明显的正相关 (r=0 .997,P <0 .0 0 1)。结论　肿瘤细胞对TRAIL的敏感性与其表面DR5表达水平有关 ,表明DR5的表达水平在TRAIL诱导细胞凋亡方面起着十分重要的作用     

Frizzled/LRP受体与ROR2受体在白血病细胞中的表达及其机制研究

探讨WNT信号通路中卷曲蛋白-低密度脂蛋白相关蛋白复合受体（Frizzled/LRP）、酪氨酸激酶样孤独受体-2（ROR2）在淋巴细胞白血病发生发展中的作用。方法:实验分组:1）实验组1:急性淋巴细胞白血病骨髓（ALL）;2）对照组1:特发性血小板减少性紫癜骨髓（ITP）;3）实验组2:氯化锂作用后的Jurkat、K562和HL-60细胞株;4）对照组2:Jurkat、K562和HL-60细胞株。以RT-PCR方法从mRNA水平检测Frizzled/LRP（FZD/LRP）受体、ROR2受体的表达;以Western blot方法从蛋白水平检测FZD-5和ROR2的表达;通过MTT法检测细胞增殖情况;通过流式细胞仪检测细胞周期。结果:所有白血病细胞中均可见FZD-2、LRP-6和ROR2的表达,ROR2在HL-60细胞中的表达明显低于其他白血病细胞,其他各组受体表达水平未见差异;11例ITP骨髓标本中2例标本可见ROR2表达,FZD受体的表达与白血病细胞无显著性差异。氯化锂处理后,ROR2在Jurkat细胞中的表达明显减少,其他受体的表达未见显著性差异。重复MTT试验结果显示:不同浓度（5、10、20 mmol/L）氯化锂（LiCl）对各组细胞均有增殖抑制作用,在一定范围内呈剂量依赖性。氯化锂处理后,Jurkat和HL-60细胞周期与正常组相比G1期和S期比例减少,G2期增高,发生G2/M期阻滞,差异有统计学意义（P<0.05）。不同浓度组K562的细胞周期未见明显差异。结论:ROR2在急性淋巴细胞白血病骨髓中的表达较其在ITP骨髓中的表达高,在Jurkat细胞株中有高表达,氯化锂作用后的Jurkat细胞中ROR2的表达明显减低,细胞增殖受抑制,提示ROR2可能与淋巴细胞白血病的发生有关。      

TRAIL及其受体在直肠癌中的表达及意义

目的：探讨人肿瘤坏死因子相关凋亡诱导配体（TNF-related apoptosis inducing ligand,TRAIL）及其受体DR4、DR5、DcR1、DcR2在直肠癌及癌旁组织中的表达及意义.方法：采用免疫组化EliVision法检测37例直肠癌及其癌旁组织和10例正常直肠粘膜组织中TRAIL及其受体DR4、DR5、DcR1、DcR2表达水平.结果：TRAIL在正常直肠粘膜组织、癌旁及直肠癌组织中的表达呈递减趋势,而DR4、DR5的表达则与之相反（P＜0.05）;TRAIL在中、低分化癌中的表达与高分化癌中的表达无差异,而DR4、DR5、DcR1、DcR2在中、低分化癌中的表达高于高分化癌中的表达（P＜0.05）;TRAIL及其受体的表达与肿瘤的病理类型、患者的年龄、性别等因素无明显相关性（P＜0.05）.结论：TRAIL在直肠癌中表达较正常直肠粘膜组织减弱,DcR1、DcR2在直肠癌中的表达高于DR4、DR5,提示TRAIL及其受体可能与直肠癌的发生、发展密切相关,为临床应用提供了一定的理论依据.     

葛根总黄酮诱导白血病细胞株凋亡及其分子机制的研究

 目的　探讨葛根总黄酮（PR）对慢性粒细胞白血病（CML）细胞株K562和急性早幼粒细胞白血病（APL）细胞株NB4细胞增殖及凋亡的影响。方法　采用MTT法检测PR对K562细胞、NB4细胞的增殖抑制率;光学显微镜及荧光显微镜观察细胞形态改变;Hoechest33258荧光染色AnnexinV／PI双染法检测细胞凋亡率;DNA PI染色法分析细胞周期及亚二倍体峰。Western blot分别检测NB4细胞JNK、PARP、bcl-2、Caspase3,K562细胞bcr-abl、p53、bcl-2、Fas／FasL蛋白表达的变化。结果　12.5～200 μg／ml PR均能抑制K562、NB4细胞增殖。光学显微镜及荧光显微镜下观察到核固缩、凋亡小体等典型的细胞凋亡改变;Annexin V+／PI-细胞呈时间-剂量依赖性增加;DNA PI染色法发现细胞亚二倍体比例增加,G1期比例下降、S期比例增加。PR呈时间-剂量依赖性抑制K562细胞、NB4细胞增殖,诱导细胞凋亡。不同浓度PR干预后K562细胞bcr-abl蛋白水平呈浓度依赖性下调（F＝18.74,P＜0.05）,而bcl-2则无明显变化;p53 表达呈浓度依赖性上调;Fas／FasL 表达无明显变化。NB4细胞JNK、PARP及Caspase 3蛋白表达与PR浓度呈正相关,与凋亡抑制蛋白bcl-2则呈负相关（F＝42.32,P＜0.05）。结论　PR能有效抑制K562、NB4细胞增殖,阻滞细胞周期进程,诱导细胞凋亡,但分子机制不同。提示一定浓度PR具有较广谱的抗白血病效应。     

TRAIL受体在人肝细胞癌中的表达及TRAIL诱导的肝癌细胞凋亡

目的 研究了RAIL受体在肝癌组织及肝癌细胞中的表达,探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)及其受体在肝癌细胞凋亡诱导中的作用。 方法 应用RT-PCR法和免疫组化方法检测肝癌组织及细胞系SK-Hepl中TRAIL受体的表达,并以TRAIL蛋白和γ-干扰素作用于SK-Hepl细胞,观察其对细胞的凋亡诱导作用。 结果 在肝癌组织及肝癌SK-Hepl细胞系中均可检测到TRAIL受体,其中,死亡受体DR4、DR5在肝癌、癌旁组织以及SK-Hepl肝癌细胞系中均呈高表达,而诱骗受体DcR1及DcR2呈低表达,明显低于正常组织。TRAIL对肝癌细胞有凋亡诱导作用,与干扰素的协同时,其作用明显增强。 结论 肝癌组织中存在着TRAIL受体的表达,TRAIL可诱导肝癌SK-Hepl细胞系凋亡,其作用与DR4、DR5的高表达有关。     

Doxorubicin potentiates TRAIL cytotoxicity and apoptosis and can overcome TRAIL-resistance in rhabdomyosarcoma cells

Doxorubicin (DOX) and ifosfamide (IFO) are the most active single agents in soft tissue sarcomas (STS). Tumour necrosis factor-alpha (TNF-alpha) is used for STS in the setting of isolated limb perfusions. Like TNF-alpha, TNF-related apoptosis-inducing ligand (TRAIL) induces apoptosis. In contrast to TNF-alpha preliminary studies suggest that TRAIL lacks systemic side effects. The effects of TRAIL alone and in combination with DOX or 4-hydroxy-IFO were evaluated in the TNF-alpha sensitive rhabdomyosarcoma cell line KYM-1, its 5-fold TNF-alpha sensitive subline KD4 and its >150-fold TNF-alpha resistant subline 37B8R. Membrane expression of TRAIL-receptors DR4 (death receptor 4), DR5 (pro-apoptotic), DcR1 (decoy receptor 1), DcR2 (anti-apoptotic) was assessed by flow cytometry. Cytotoxicity was determined by microculture tetrazolium assays. Apoptosis assays were performed with acridine orange. DOX (doxorubicin) and 4-OH-IFO decreased survival in all cell lines; a 2-fold resistance was observed for both drugs in 37B8R. All cell lines expressed DR4 and DR5, but hardly any DcR1 or DcR2. TRAIL was cytotoxic in KYM-1, even more in KD4 and induced massive apoptosis; 37B8R was >500-fold resistant to TRAIL and little apoptosis could be observed. TRAIL plus DOX showed synergistic cytotoxicity in KYM-1 and 37B8R. TRAIL plus 4-OH-IFO showed addition in all three cell lines. DOX plus TRAIL-induced more cytotoxicity and apoptosis in all cell lines compared to TRAIL alone. In 37B8R, DOX overcame resistance to TRAIL. In KYM-1, KD4 and 37B8R, sensitivity and resistance to TNF-alpha and TRAIL parallels. TRAIL-resistance was independent from expression of TRAIL-receptors. DOX with TRAIL could overcome TRAIL-resistance in 37B8R cells.     

Correlation between the Sensitivity to TRAIL and the Expression Level of DR5 on the Surface of Tumor Cells

OBJECTIVE To investigate the correlation between the sensitivity to the tumor necrosis factor- related apoptosis inducing ligand (TRAIL) and the level of expression of the death receptor 5 (DR5) on the surface of tumor cells.METHODS Anti-DR5 mAbs were used to directly detect the level of expression of DR5 on the surface of tumor cells. Using a TRAIL apoptosis kit and flow cytometry, the sensitivity of the tumor cells to TRAIL-induced apoptosis was determined and the correlation between DR5 expression and sensitivity to TRAIL analyzed.RESULTS The expression level of DR5 on the surface of different tumor cells was as follows: 97.9% in U937 cells, 95.1% in Jurkat cells, 93.8% in SW480 cells, 86.2% in HCT116 cells, 64.2% in HL-60 cells, 46.6% in Hela cells and 13.1% in K562 cells. The TRAIL-induced apoptotic rate was 72.6% in U937 cells, 85.2% in Jurkat cells, 78.6% in SW480 cells, 70.2% in HCT116 cells,60.1% in HL-60 cells, 45.4% in Hela cells and 12.3% in K562 cells. Statistical analysis showed there was a significant positive correlation (r=0.997, P<0.001) between DR5 expression and sensitivity to TRAIL.CONCLUSION The sensitivity of tumor cells to TRAIL is related to the level of expression of DR5 on the surface of tumor cells. These results confirm the importance of DR5 expression for induction of apoptosis by TRAIL.     

IFN-gamma induces cell death in human hepatoma cells through a TRAIL/death receptor-mediated apoptotic pathway.

We demonstrated the induction of cell death in a hepatoma cell line by IFN-gamma and its possible mechanism. Among the 2 hepatitis B virus (HBV)-associated hepatoma cell lines, SNU-354 and SNU-368, IFN-gamma induced cell death and increased caspase-3 activity in SNU-368 but not in SNU-354. IFN-gamma induced several changes in the mRNA expression level of apoptosis-regulating genes, e.g., increased expression of Fas, caspase-1 and TNF-related apoptosis-inducing ligand (TRAIL). In particular, IFN-gamma potently increased the mRNA expression of TRAIL in both cell lines. However, it did not change the mRNA expression level of death-mediating TRAIL receptors, e.g., DR4 and DR5, which were constitutively expressed in both cell lines. In contrast, the decoy receptor DcR1 was expressed in SNU-354 but not in SNU-368, and its expression level in SNU-354 was increased by IFN-gamma. Another decoy receptor, DcR2, was constitutively expressed in both cell lines; however, its expression level in SNU-368 was decreased by IFN-gamma. In addition, exogenous recombinant TRAIL reduced viability in SNU-368, but not in SNU-354, cells. From these findings, we speculated that TRAIL up-regulation and the subsequent TRAIL-mediated apoptosis serve as a mechanism of IFN-gamma-induced cell death in SNU-368. To confirm this hypothesis, we demonstrated that soluble DR4-Fc fusion protein, a TRAIL pathway inhibitor, inhibited IFN-gamma-induced cell death in SNU-368. Our results demonstrated that IFN-gamma acts as an inducer of cell death through TRAIL-mediated apoptosis.     

DcR2 (TRAIL-R4) siRNA and adenovirus delivery of TRAIL (Ad5hTRAIL) break down in vitro tumorigenic potential of prostate carcinoma cells

High levels of decoy receptor 2 (DcR2; TRAIL-R4) expression are correlated with TRAIL resistance in prostate cancer cells. In addition, upregulation of TRAIL death receptor (DR4 and DR5) expression, either by ionizing radiation or chemotherapy, can sensitize cancer cells to TRAIL. Considering more than half of human cancers are TRAIL resistant, modulation of surface TRAIL receptor expression appears to be an attractive treatment modality to counteract TRAIL resistance. In this study, three siRNA duplexes targeting DcR2 receptor were tested. Ad5hTRAIL infections were performed to overexpress human full-length TRAIL to induce cell death, and the in vitro tumorigenic potential of prostate cancer cells was assessed using colony-forming assays on soft agar. The DU145 and LNCaP prostate cancer cell lines, which express high levels of DcR2, were resistant to Ad5hTRAIL-induced death. Downregulation of surface DcR2 expression by siRNA sensitized these prostate cancer cell lines to Ad5hTRAIL. In addition, DcR2 siRNA-mediated knockdown of DcR2, followed by Ad5hTRAIL infection, dramatically reduced the in vitro tumorigenic potential of prostate cancer cells. Collectively, our results suggest the potential for combining receptor-specific siRNA with TRAIL in the treatment of certain cancers.     

TRAIL与顺铂联合应用对喉鳞癌细胞Hep-2的体外作用

目的：探讨肿瘤坏死因子相关诱导凋亡配体（tumor necrosis factor-related apoptosis-inducing ligand，TRAIL）与顺铂联合应用对喉鳞癌细胞Hep-2的抑制作用。方法：CCK-8测定TRAIL和顺铂对Hep-2细胞生长的抑制率；流式细胞术检测细胞表面TRAIL受体的表达及细胞凋亡。结果：Hep-2细胞对TRAIL诱导的凋亡不敏感，顺铂通过上调细胞表面死亡受体的表达而增强Hep-2细胞对TRAIL的敏感性。结论：顺铂可使Hep-2细胞克服对TRAIL的耐受性，两者具有协同作用，有望应用于喉癌的临床治疗。     

肿瘤坏死因子相关凋亡诱导配体受体在肝细胞肝癌组织中的表达及其临床意义

目的　探讨TRAILR在肝细胞肝癌 (hepatocellularcarcinoma ,HCC)中的表达及其临床意义。方法　采用原位杂交方法检测了 6 0例肝癌组织、两种肝癌细胞株以及 2 0例正常肝组织中TRAILR的表达 ,并结合临床资料进行分析。结果　 6 0例肝癌组织及 2 0例正常肝组织均表达死亡受体DR5和DR4,但肝癌组织DR表达量显著强于正常肝组织DR表达量。 5 4例肝癌组织不表达诱捕受体DcR1( 90 % ) ,2 5例肝癌组织不表达DcR2 ( 41.7% ) ,而 2 0例正常肝组织均表达DcR。肝癌组织中DR的高表达及DcR的低表达不同于正常肝组织中DR的低表达及DcR的高表达 ,两者间有显著差异性。两种肝癌细胞株中均检测到DR5、DR4、DcR2的表达 ,但DcR1表达缺失。HCC组织中DR的表达与肿瘤的分化、肿瘤分级有关 ,低分化的肿瘤DR表达减少 (P <0 .0 1) ,Ⅲ /Ⅳ期肿瘤DR的表达显著低于Ⅰ/Ⅱ级DR表达 (P <0 .0 5 )。DR的表达与病人的性别、年龄、HBsAg阳性与否、AFP水平、肿瘤的大小以及是否转移无关。肿瘤细胞耐药株DR表达降低。结论　HCC普遍存在TRAILR的表达 ,并存在受体类型的表达差异。DcR1的表达大多缺失有利于TRAIL治疗HCC。