胶质母细胞瘤组织中TRAIL受体表达的研究

目的研究TRAIL受体(TRAIL receptor,TRAIL-R)在胶质母细胞瘤中的表达,并探讨其临床意义。方法联合采用免疫组织化学和RT-PCR方法检测胶质母细胞瘤及正常脑组织中TRAIL-R的表达。结果25例胶质母细胞瘤均表达死亡受体(death receptor,DR)4和DR5,11例(44.0%)表达诱骗受体(decoy receptor,DcR)1,5例(20.0%)表达DcR2,而20例正常脑组织普遍表达DcR1和DcR2。胶质母细胞瘤组织中DR的高表达以及DcR的低表达不同于正常脑组织中DR的低表达及DcR的高表达,两者间差异有显著性(P<0.01)。RT-PCR显示,25例胶质母细胞瘤组织分别有22例(88.0%)DcR1和15例(60.0%)DcR2在mRNA水平呈阳性表达,DcR在转录水平的表达明显高于翻译水平(P<0.01)。结论胶质母细胞瘤中普遍存在DR的高表达和DcR的低表达,DcR在胶质母细胞瘤中限制性表达的调控位于转录后水平。这可能为胶质母细胞瘤的凋亡诱导治疗提供新的靶点和策略。     

Repression of NF‐κB and activation of AP‐1 enhance apoptosis in prostate cancer cells

TNFα and TRAIL, 2 members of the tumor necrosis factor family, share many common signaling pathways to induce apoptosis. Although many cancer cells are sensitive to these proapoptotic agents, some develop resistance. Recently, we have demonstrated that upregulation of c‐Fos/AP‐1 is necessary, but insufficient for cancer cells to undergo TRAIL‐induced apoptosis. Here we present a prostate cancer model with differential sensitivity to TNFα and TRAIL. We show that inhibition of NF‐κB or activation of AP‐1 can only partially sensitize resistant prostate cancer cells to proapoptotic effects of TNFα or TRAIL. Inhibition of NF‐κB by silencing TRAF2, by silencing RIP or by ectopic expression of IκB partially sensitized resistant prostate cancer. Similarly, activation of c‐Fos/AP‐1 only partially sensitized resistant cancer cells to proapoptotic effects of TNFα or TRAIL. However, concomitant repression of NF‐κB and activation of c‐Fos/AP‐1 significantly enhanced the proapoptotic effects of TNFα and TRAIL in resistant prostate cancer cells. Therefore, multiple molecular pathways may need to be modified, to overcome cancers that are resistant to proapoptotic therapies. © 2008 Wiley‐Liss, Inc.     

TRAIL诱导肿瘤细胞凋亡及其与FHIT基因突变关系的初步研究

目的:分析原核重组表达的人可溶性TRAIL分子诱导多种肿瘤细胞的凋亡,并观察凋亡作用与FHIT基因突变的关系.方法:观察人可溶性TRAIL对28株不同来源的肿瘤细胞和正常细胞的直接细胞毒作用,RT-PCR法分析部分细胞的FHIT基因缺失突变情况.结果:1～100 mg/L的重组人可溶性T RAIL蛋白即可诱导19株细胞(包括人肿瘤细胞株)如1990(胰腺导管癌)、MCF-7(乳腺癌)、A5 4 9(肺癌)、U251(星形胶质瘤)、HepG-2(肝细胞癌)、M85(胃癌)、CNE-2(鼻咽癌)、Hep-2( 喉癌)、AT-29(结肠癌)、3AO(卵巢癌)和B16-MB(黑色素瘤),髓性恶性细胞如Jurkat、K56 2、U937、6T-CEM,鼠源性S180(肉瘤)、Ehrlich(腹水瘤)和Lewis(肺癌),以及人内皮细胞株ECV304等发生凋亡;而其他9株细胞,如SK-N-SH(人神经母细胞瘤)、8898(人胰腺导管癌)、HeLa(人宫颈癌)、SMMU7721(人肝癌)、HL60(人白血病)、COS-7(猴肾)、人成纤维细胞、L929(鼠成纤维细胞)、Wish(人羊膜细胞)等需大于100 mg/L的TRAIL才能使其凋亡;观察到上述部分对TRAIL敏感的人源细胞的FHIT基因有缺失突变,而不敏感的人源细胞FHIT 基因完整.结论:原核表达的人可溶性TRAIL具有明显诱导多种肿瘤细胞凋亡的活性,其机制可能与FHIT基因的缺失有关.     

TNF相关凋亡诱导配体联合阿糖胞苷诱导HL-60细胞凋亡及其机制的研究

本研究探讨人重组可溶性肿瘤坏死因子相关凋亡诱导配体（hrsTRAIL）单用或联合阿糖胞苷（Ara—C）诱导HL-60细胞凋亡作用及其机制。在体外以人类急性白血病细胞株HL-60为研究对象，分5组进行细胞培养：对照组、Ara—C组、rsTRAIL组、同时给药组（Ara—C＋rsTRAIL）、先后给药组（Ara—C→rsTRAIL）。采用MTT比色法测定细胞生长抑制率；应用Annexin V／PI染色和流式细胞术检测细胞凋亡率；使用流式细胞术检测不同浓度的Ara—C对细胞表面DR5表达水平的影响及rsTRAIL单药组、先后给药组细胞表面DR5表达水平和细胞内caspase-8活性。结果表明：rsTRAIL能抑制HL-60细胞生长并诱导HL-60细胞凋亡。先后给药组诱导HL-60细胞凋亡率大于同时给药组。先后给药组细胞表面DR5表达水平和细胞内caspase-8的活性高于rsTRAIL组。5mg／L、10mg／LAra—C作用于HL-60细胞24小时，其细胞表面DR5表达水平升高，大于对照组。结论：rsTRAIL抑制HL-60细胞生长．诱导HL-60细胞凋亡。Ara—C上调HL-60细胞表面DR5表达水平。增强rsTRAIL诱导HL-60细胞凋亡的作用。Ara—C和rsTRAIL联合用药时，在先加Ara—C、再加rsTRAIL组诱导HL-60细胞凋亡的效果比同时给药组效果好，其机制可能与Ara—C上调细胞表面DIL5表达水平和（或）增强细胞内caspase-8的活性有关。     

化疗药物对TRAIL在急性白血病原代细胞表达的影响

为了探讨TRAIL在急性白血病原代细胞表达及化疗药物对TRAIL在急性白血病细胞表达的影响,采集16例初诊的急性白血病患者化疗前、化疗1天后、3天后和5天后的外周血,分离单个核细胞并用流式细胞术检测TRAIL的表达;同时采集12例初诊的急性白血病患者化疗前骨髓,分离单个核细胞进行培养,分别加VP-16和/或干扰素,培养一定时间后检测TRAIL的表达水平.结果表明：与化疗前相比,初治急性白血病患者外周血单个核细胞TRAIL的表达水平在化疗1天后即明显提高（P＜0.05）;在体外培养实验中,VP-16上调TRAIL在急性白血病骨髓单个核细胞的表达（P＜0.05）,VP-16联合干扰素与单独应用VP-16相比,TRAIL的表达水平无差异（P＞0.05）.结论：化疗药物治疗白血病的机制之一可能是通过诱导TRAIL的表达而促进白血病细胞的凋亡.     

TRAIL受体DR4、DR5、DcR1在结肠癌中的表达及意义

目的 探讨肿瘤坏死因子相关凋亡导配体(TRAIL)受体DR4、DR5、DcR1在结肠癌中的表达及临床意义,为TRAIL的抗肿瘤作用提供实验依据.方法 采用免疫组化SP法检测35例结肠癌和14例正常结肠黏膜组织中DR4、DR5、DcR1表达水平.结果 35例结肠癌组织中DR5的阳性表达率为27/35(77.14%),DR...     

Chrysin promotes tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induced apoptosis in human cancer cell lines

Chrysin exists widely in plants, honey and propolis. The anti-cancer property of chrysin has been demonstrated though the molecular mechanism is not clear. In this study, we found that pre-treatment with chrysin could promote the cell death induced by TRAIL according to the morphological changes and appearance of sub-G1 peak in four human cancer cell lines. In HCT-116 cells, the results of flow cytometry analysis showed that the percentage of sub-G1 reached (38.89 ± 3.78) % when pre-treatment of chrysin was used at 40 μM, but that was only (2.53 ± 0.10) % in the untreated group and (13.22 ± 0.20) % in TRAIL alone group. The differences between the combination and the untreated or TRAIL alone group were all significant (P < 0.05) and dose-dependent effect was obvious. Similar results were obtained in CNE1 cells. In the search of molecular mechanisms, we found that pre-treatment with chrysin could increase TRAIL-induced degradation of caspase 3, caspase 8, PARP proteins. Z-VAD-fmk, which is a pan-caspase inhibitor, could inhibit the apoptosis enhanced by the combination of chrysin and TRAIL. All data indicate that chrysin can enhance the apoptosis induced by TRAIL, and the apoptosis is caspase-dependent and related to the activation of caspase 8.