紫杉醇提高胃癌MGC803细胞对TRAIL的敏感性

目的：研究紫杉醇对TRAIL诱导胃癌细胞凋亡的影响,探讨死亡受体5（DR5）在TRAIL诱导细胞凋亡中的作用。方法：采用MTT法测定细胞活力,流式细胞仪检测细胞凋亡,western blot检测蛋白表达。结果：在MGC803细胞中,100ng/ml的TRAIL导致轻度的增殖抑制和细胞凋亡,TRAIL（100ng/ml）联合紫杉醇（3.41g/ml）引起明显的增殖抑制和细胞凋亡（P〈0.05）。TRAIL单药没有改变死亡受体5（DR5）的表达,而3.41g/ml紫杉醇作用MGC803细胞后明显上调了DR5的表达。结论：紫杉醇通过上调DR5的表达增强TRAIL诱导的胃癌MGC803细胞凋亡。     

奥沙利铂通过上调死亡受体表达增强TRAIL诱导胃癌细胞凋亡的实验研究

目的:研究奥沙利铂对TRAIL诱导胃癌细胞凋亡的影响,探讨死亡受体5(DR5)在TRAIL诱导细胞凋亡中的作用.方法:采用MTT法测定细胞活力、采用流式细胞仪检测细胞凋亡,采用Western blot检测DR5蛋白表达.结果:100ng/ml的TRAIL导致轻度的增殖抑制,诱导不超过5%的细胞凋亡;TRAIL(100ng/ml)联合奥沙利铂(23.44μg/ml)引起明显的细胞增殖抑制和细胞凋亡(P＜0.05),TRAIL没有明显改变死亡受体5(DR5)的表达,而23.44 μg/ml奥沙利铂作用胃癌细胞24小时后,明显上调了DR5的表达.结论:奥沙利铂通过上调DR5的表达增强TRAIL诱导的胃癌细胞凋亡.     

干扰素-α通过上调DR5和抑制Akt的活性增加胃癌细胞对TRAIL的敏感性

目的：观察IFN-α对TRAIL诱导胃癌细胞凋亡的影响,并对死亡受体DR5和PI3K/Akt通路在此过程中的作用机制进行探讨。方法：MTT法检测细胞增殖能力,流式细胞仪PI染色检测细胞凋亡,蛋白质印迹法检测蛋白的表达。结果：IFN-α预处理可协同TRAIL抑制胃癌MGC803细胞增殖。单独用IFN-α或TRAIL处理MGC803细胞,仅有少量的细胞发生凋亡,IFN-α和TRAIL联合用药细胞凋亡明显增加（P〈0.01）。IFN-α能上调DR5的表达,抑制Akt的磷酸化。结论：IFN-α能增强TRAIL诱导的胃癌细胞凋亡,其机制可能与其上调DR5的表达和抑制Akt的活性有关。     

埃克替尼提高胃癌细胞对肿瘤坏死因子相关凋亡诱导配体的敏感性

目的:胃癌细胞大多对TRAIL(tumor necrosis factor-related apoptosis-inducing ligand)不敏感。本研究为探讨胃癌细胞对TRAIL耐药的原因以及如何提高胃癌细胞对TRAIL的敏感性。方法:流式细胞术检测细胞凋亡,免疫印迹法检测蛋白的表达。结果:TRAIL(100ng/ml)作用MGC803和SGC7901细胞20小时,TRAIL诱导少量细胞凋亡,同时检测到EGFR和下游Akt、ERK的活化。用新型的EGFR酪氨酸激酶抑制剂埃克替尼(10μmol/L)预处理MGC803和SGC7901细胞2小时,之后加用TRAIL,结果抑制了TRAIL引起的EGFR和下游Akt、ERK的磷酸化,并最终提高了MGC803和SGC7901细胞对TRAIL的敏感性。结论:埃克替尼通过抑制EGFR通路从而增强了TRAIL诱导的胃癌细胞凋亡。     

香加皮杠柳苷联用TRAIL对胃癌SGC-7901和MGC-803细胞的作用及其机制

目的:探讨香加皮杠柳苷(cortex periplocae,CPP)联用肿瘤坏死因子相关凋亡诱导配体(tumor necrosis factor related apoptosis inducing ligand,TRAIL)对胃癌细胞的作用及其机制.方法:人胃癌细胞系SGC-7901、MGC-803培养完成后,采用50、100、200 ng/ml的CPP和1μg/ml的TRAIL单用或联合处理.MTS法检测SGC-7901和MGC-803细胞的增殖情况,流式细胞术检测其凋亡率,Westcm boltting检测pro-BID、Mcl-l、cleaved caspase-3、DR4、DR5的表达水平.结果:SGC-7901和MGC-803细胞经CPP (50、100、200 ng/ml)和TRAIL(1 μg/ml)联合处理24 h后,细胞增殖率明显低于空白对照组和对应的CPP各剂量单独处理组(/＜0.05或P＜0.01).SGC-7901和MGC-803细胞凋亡率均明显高于空白对照组和对应的CPP各剂量单独处理组(P＜0.05或P＜0.01).SGC-7901和MGC-803细胞中pro-BID、Mcl-1表达水平明显降低(均P＜0.05),cleaved caspase-3表达水平明显升高(P＜0.05),DR4和DR5受体的表达水平升高(均P＜0.05).结论:CPP协同TRAIL可明显诱导人胃癌SGC-7901和MGC-803细胞凋亡,增强人胃癌细胞对TRAIL的敏感性.     

TRAIL联合紫杉醇对人脑胶质瘤U87细胞的抑制效应及其可能的机制

目的:研究肿瘤坏死因子相关凋亡诱导配体(tumor necrosis factor-related apoptosis-inducing ligand,TRAIL)联合紫杉醇处理对人脑胶质瘤U87细胞的抑制效应及其可能的机制。方法:MTT法检测紫杉醇组、TRAIL组和TRAIL/紫杉醇组对U87细胞增殖的抑制率;流式细胞术检测不同给药方案对U87细胞凋亡的影响;Western blotting检测不同处理后U87细胞TRAIL死亡受体(death receptor,DR)4、DR5以及caspase-8和caspase-3的表达水平。结果:MTT结果显示,单独应用TRAIL或紫杉醇可有效抑制U87细胞的增殖,并呈浓度依赖性。TRAIL(500 ng/ml)/紫杉醇(0.5μmol/L)联合给药组可协同抑制U87细胞的增殖,相互作用指数(coefficient of drug interaction,CDI)为0.59;且联合用药组对U87细胞增殖的抑制率明显高于TRAIL和紫杉醇单独用药组[(70.24±3.68)%vs(27.01±2.36)%,(21.31±4.85)%,P<0.01];TRAIL/紫杉醇联合用药组U87细胞凋亡率明显高于对照组、TRAIL组及紫杉醇组[(67.67±2.46)%vs(1.80±1.13)%、(22.13±2.18)%、(35.90±2.53)%,P<0.01]。TRAI与紫杉醇联合用药组U87细胞中DR4、caspase-8及caspase-3的表达比TRAIL组或紫杉醇组显著增加(P<0.05),而DR5表达则无明显变化(P>0.05)。结论:TRAIL联合紫杉醇处理通过上调DR4、caspase-8及caspase-3的表达,抑制U87细胞的增殖,诱导U87细胞凋亡。     

表阿霉素提高胃癌BGC823细胞对TRAIL的敏感性

目的：研究表阿霉素对TRAIL诱导胃癌细胞BGC823细胞凋亡的影响,探讨脂筏和死亡受体4（DR4）在TRAIL诱导细胞凋亡中的作用。方法：采用MTT法测定细胞活力,流式细胞仪检测细胞凋亡,免疫荧光显微技术检测脂筏和DR4在细胞膜的分布。结果：（0.1-50）μg/ml表阿霉素处理BGC823细胞24h,抑制细胞增殖50%的药物浓度（IC50）为（4.61±0.62）μg/ml。在BGC823细胞中,100ng/ml的TRAIL导致轻度的增殖抑制和细胞凋亡,TRAIL（100ng/ml）联合表阿霉素（4.61μg/ml）引起明显的增殖抑制和细胞凋亡（P〈0.05）。与对照组相比,100ng/ml的TRAIL作用BGC823细胞24 h,没有引起明显的脂筏聚集或DR4聚集。表阿霉素（4.61μg/ml）明显促进脂筏聚集和DR4聚集,同时观察到DR4和脂筏的共定位。表阿霉素和TRAIL联合作用24 h,同样观察到DR4定位在聚集的脂筏内。结论：表阿霉素通过促进DR4在脂筏聚集增强TRAIL诱导的胃癌BGC823细胞凋亡。     

蟾蜍毒素联合紫杉醇抑制人胃癌MGC803细胞增殖和诱导凋亡的作用

目的探讨蟾蜍毒素联合紫杉醇抑制人胃癌MGC803细胞增殖及诱导凋亡的作用。方法应用MTT法检测不同浓度蟾蜍毒素及紫杉醇单药及联合对胃癌细胞MGC803增殖抑制作用;流式细胞术分析细胞凋亡和周期阻滞;Westernblot法检测C-FLIPL、Caspase-8蛋白的表达。结果(1)蟾蜍毒素及紫杉醇单药均抑制MGC803细胞增殖,呈剂量-时间依赖效应,且联合用药的细胞增殖抑制率明显高于单药组,差异有统计学意义(P<0.05)。24、48及72 h联合指数(CI)分别为0.77、0.86、0.72;(2) 40 nmol/L蟾蜍毒素、25 ng/ml紫杉醇单药及联合作用细胞24 h,流式细胞仪检测凋亡率分别为14.13%、19.74%及53.30%,联合组与单药组比较差异有统计学意义(P<0.05);(3)Western blot结果显示,蟾蜍毒素、紫杉醇单药组及联合组作用细胞24 h后,C-FLIPL蛋白表达依次下降至对照组的78.38%、64.71%、46.73%,Caspase-8蛋白表达上调至对照组的150.25%,156.86%,180.58%。结论蟾蜍毒素协同紫杉醇诱导胃癌MGC803细胞凋亡,且可能与下调C-FLIP、上调Caspase-8蛋白有关。     

卡铂联合TRAIL对肺癌A549细胞增殖和凋亡的影响

目的:观察卡铂联合TNF相关凋亡诱导配体(TRAIL)对人肺腺癌细胞A549增殖和凋亡的影响。方法:经20、40、80 μg/mL卡铂和100 ng/μL TRAIL单用或联用处理后,用MTS法检测A549细胞的增殖能力,在光镜下观察细胞形态学变化;并采用流式细胞术检测细胞凋亡情况;RT-PCR和Western blot法检测死亡受体4(DR4)、死亡受体5(DR5)、Survivin和X连锁凋亡抑制蛋白基因(XIAP)mRNA与蛋白表达的变化。结果:卡铂和TRAIL单用或联用均可浓度依赖性抑制A549细胞的增殖,诱导其凋亡,两药联用比单用卡铂时抑制率和凋亡率更高(P<0.05)。单用卡铂或TRAIL可使A549细胞数减少,漂浮细胞增多,出现明显的凋亡形态变化,且明显降低Survivin和XIAP的mRNA和蛋白表达水平(P均<0.05);但对A549细胞DR4和DR5 mRNA表达均无明显影响,而单用卡铂或TRAIL却能升高A549细胞DR5蛋白的表达(P<0.05)。与单用组相比,TRAIL与卡铂联用A549细胞凋亡形态变化更明显,可明显降低A549细胞Survivin和XIAP mRNA和蛋白的表达水平及升高DR5蛋白表达水平(P<0.05)。结论:卡铂与TRAIL联用可协同抑制肺癌细胞A549细胞增殖,促进其凋亡,且与卡铂能够增加A549细胞DR5蛋白的表达和降低Survivin及XIAP的表达相关。     

二烯丙基二硫增强胃癌细胞对5-Fu敏感性的研究

目的探讨二烯丙基二硫(DADS)对5-Fu诱导胃癌MGC803细胞增殖与凋亡的作用及机制。方法采用四甲基偶氮唑蓝比色法(MTT),测定DADS对5-Fu诱导MGC803细胞增殖活性的作用;应用流式细胞仪检测细胞凋亡率;Westernblot检测MGC803细胞Bcl-2,Bax,Mcl-1蛋白的表达情况。结果1mg/L、3mg/L的DADS分别与5-Fu联合应用,可增强5-Fu对MGC803细胞增殖抑制作用。DADS(1mg/L)能促进5-Fu诱导MGC803细胞的凋亡。DADS作用于MGC803细胞后,Bcl-2、Mcl-1蛋白表达水平下调,Bax蛋白表达水平上调呈浓度依赖方式。结论ADS能增强5-Fu对MGC803细胞增殖抑制和诱导凋亡,起化疗增敏作用,可能与其下调Bcl-2、Mcl-1蛋白表达水平,上调Bax蛋白表达水平有关。     

Response of normal and colon cancer epithelial cells to TNF-family apoptotic inducers

We compared the response of normal (FHC) and cancer (HT-29) human colon epithelial cells to the important apoptotic inducers TNF-alpha, anti-Fas antibody and TNF-related apoptosis inducing ligand (TRAIL). The two cell lines did not respond to TNF-alpha (15 ng/ml), expressed a limited sensitivity to anti-Fas antibody (200 ng/ml) and a different response to TRAIL (100 ng/ml). We studied apoptosis with regard to the changes at the receptor level (DR, DcR and FLIP) and at the level of mitochondria (Bid protein cleavage, Apo2.7 protein expression and caspase-9 activation). Two different approaches were used to sensitize the cells to TRAIL-induced apoptosis: inhibition of protein synthesis (cycloheximide, CHX) and inhibition of the pro-survival MEK/ERK pathway (U0126). While the two cell lines were markedly sensitized to all three TNF family members by CHX, a different degree of response (especially for TRAIL) was obtained when inhibition of the MEK/ERK pathway was achieved. TRAIL-induced apoptosis was significantly enhanced by U0126 co-treatment in the HT-29 cells, but not in the FHC cells. The most significant differences between the HT-29 and FHC cells co-treated with TRAIL and U0126 were demonstrated with regard to the involvement of the mitochondrial apoptotic pathway, suggesting its importance in the regulation of cell sensitivity to the TRAIL-induced apoptosis.     

泛素连接酶Cbl对TRAIL诱导Jurkat T细胞凋亡调节作用的探讨

目的:探讨泛素连接酶Cbl在TRAIL诱导Jurkat T细胞凋亡中的调节作用。方法:台盼蓝拒染法检测细胞增殖能力,流式细胞仪PI染色检测细胞凋亡,蛋白质印迹法检测蛋白的表达。结果:不同浓度的TRAIL作用于Jurkat T细胞24 h,TRAIL能以剂量依赖性的方式抑制JurkatT细胞增殖,并能诱导Jurkat T细胞凋亡。100 ng/mL的TRAIL作用24 h,有35.98%的细胞发生凋亡,而对照组仅有2.52%的细胞发生凋亡,P<0.01。在TRAIL诱导Jur-kat T细胞凋亡过程中伴随有p-Akt表达的一过性上调和泛素连接酶Cbl-b和c-Cbl表达的持续上调。结论:TRAIL上调Cbl蛋白的表达是抑制Jurkat T细胞中PI3K/Akt信号过度活化,进而诱导细胞凋亡的重要机制。     

Chemotherapeutic agents enhance TRAIL-induced apoptosis in prostate cancer cells

PURPOSE: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor (TNF) family that preferentially kills tumor cells. In this study, we sought to determine whether chemotherapeutic agents augment TRAIL-induced cytotoxicity in human prostate cancer cells, and whether this sensitivity can be blocked by overexpression of bcl-2. METHODS: Prostate cancer cells, PC3 and LNCaP, were treated with TRAIL alone, drug alone or a combination of both for 24 h. Cytotoxicity was determined by DNA fragmentation and clonogenic survival assay. RESULTS: Treatment with the conventional chemotherapeutic agents cisplatin (2 and 5 microg/ml), etoposide (10 microM and 20 microM) and doxorubicin (30 and 60 n M) dramatically augmented TRAIL-induced apoptosis in LNCaP and PC3 cells. TRAIL-induced apoptosis was partially abrogated by overexpression of bcl-2 in these two cell lines when it was used in combination with the above agents. Similar results were obtained using clonogenic survival assays where bcl-2 overexpression was also found to marginally protect against TRAIL- and chemotherapy-induced cell killing.CONCLUSIONS: This study demonstrates that combination treatment of prostate cancer cells with TRAIL and chemotherapeutic agents overcomes their resistance by triggering caspase activation. This greater than additive effect of cotreatment with TRAIL and chemotherapy may provide the basis for a new therapeutic approach to induce apoptosis in otherwise resistant cancer cells.     

Sodium nitroprusside enhances TRAIL-induced apoptosis via a mitochondria-dependent pathway in human colorectal carcinoma CX-1 cells

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL, Apo-2L) is a recently characterized member of the family of programmed cell death-inducing ligands that includes TNF-alpha and CD95L (FasL). It is well known that TRAIL binds to the death signaling receptors, DR4 and DR5, and initiates the TRAIL death pathway. Activation of this pathway, mediated through a caspase cascade, causes apoptosis. In this study, we hypothesized that oxidative stress facilitates TRAIL-induced apoptosis by promoting caspase activity through cytochrome c release from mitochondria. Human colorectal carcinoma CX-1 cells were treated with various concentrations of TRAIL (12.5-200 ng/ml) and/or sodium nitroprusside (SNP; 0.03-1 mM) for 12 h. SNP, a nitric oxide donor, which had little toxic effect by itself, enhanced TRAIL-induced cytotoxicity. For example, TRAIL-induced apoptosis (200 ng/ml) was increased by a factor of 2.5-fold in the presence of 1 mM SNP. The combined treatment also caused an increase in cytochrome c release, caspase-3 activity, and PARP cleavage. Overexpression of Bcl-2 completely blocked the SNP-promoting effects, but only moderately inhibited TRAIL-induced apoptosis. Similar results were observed in the presence of hydrogen peroxide or peroxynitrite. Taken together, the present studies suggest that SNP enhances TRAIL-induced cytotoxicity by facilitating the mitochondria-mediated caspase signal transduction pathway.     

Role of the TRAIL/APO2-L death receptors in chlorambucil- and fludarabine-induced apoptosis in chronic lymphocytic leukemia

The standard treatments for chronic lymphocytic leukemia (CLL) include the alkylating agent chlorambucil (CLB) and the nucleoside analog fludarabine (F-ara-AMP, Flu). Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a death receptor ligand that induces apoptosis preferentially in tumors. However, CLL cells seem to be resistant to TRAIL-induced apoptosis. The TRAIL apoptotic signaling pathway has also been implicated in genotoxin-induced apoptosis through upregulation of TRAIL death receptors DR4 and DR5. In the present study, we demonstrate that the treatment of primary CLL cells with CLB or Flu increases the mRNA, protein and cell surface expression levels of DR4 and DR5 in a dose-dependent manner. In contrast to CLL cells, drug treatment fails to increase significantly the expression of DR4 or DR5 in normal lymphocytes. CLL cells are, however, resistant to TRAIL-induced apoptosis compared to B-cell lines. In contrast, combinational treatment using CLB or Flu with TRAIL (100 ng/ml) gave a synergistic apoptotic response. Furthermore, TRAIL is readily detectable on the cell surface of CLL cells, but TRAIL expression fails to increase following drug treatment. Preventing TRAIL from interacting with DR4 and DR5 decreases CLB-induced apoptosis in CLL cells. A similar, but less marked effect is observed with Flu. These findings indicate the involvement of the TRAIL apoptotic pathway in the mechanism of action of chemotherapy, and this mechanism could be utilized to sensitize CLL cells to TRAIL-induced apoptosis.     

Chemotherapeutic agents sensitize osteogenic sarcoma cells, but not normal human bone cells, to Apo2L/TRAIL-induced apoptosis

Apo2L/TRAIL is a member of the tumor necrosis factor (TNF) family of cytokines that induces death of cancer cells but not normal cells. Its potent apoptotic activity is mediated through its cell surface death domain-containing receptors, DR4 and DR5. Apo2L/TRAIL interacts also with 3 "decoy" receptors that do not induce apoptosis, DcR1, DcR2, which lack functional death domains, and osteoprotegerin (OPG). The aim of our study was to investigate the cytotoxic activity of Apo2L/TRAIL on established osteogenic sarcoma cell lines (BTK-143, HOS, MG-63, SJSA-1, G-292 and SAOS2) and in primary cultures of normal human bone (NHB) cells. When used alone, Apo2L/TRAIL at 100 ng/ml for 24 hr induced greater than 80% cell death in only 1 (BTK-143) of the 6 osteogenic sarcoma cell lines. In contrast, Apo2L/TRAIL-resistant cells were susceptible to Apo2L/TRAIL-mediated apoptosis in the presence of the anticancer drugs, Doxorubicin (DOX), Cisplatin (CDDP) and Etoposide (ETP) but not Methotrexate (MTX) or Cyclophosphamide (CPM). Importantly, neither Apo2L/TRAIL alone nor in combination with any of these drugs affected primary normal human bone cells under equivalent conditions. Apo2L/TRAIL-induced apoptosis, and its augmentation by chemotherapy in the resistant cell lines was mediated through caspase-8 and caspase-3 activation. Furthermore, Apo2L/TRAIL-induced apoptosis and its augmentation by chemotherapy was effectively inhibited by caspase-8 zIETD-fmk and caspase-3 zDEVD-fmk protease inhibitors and by the pan-caspase inhibitor zVAD-fmk. The pattern of basal Apo2L/TRAIL receptor mRNA expression, or expression of the intracellular caspase inhibitor FLICE-inhibitory protein, FLIP, could not be readily correlated with resistance or sensitivity to Apo2L/TRAIL-induced apoptosis. However, the augmentation of Apo2L/TRAIL effects by chemotherapy was associated with drug-induced up-regulation of death receptors DR4 and DR5 mRNA and protein. No obvious correlation was seen between the expression of OPG mRNA or protein and susceptibility of cells to Apo2L/TRAIL-induced apoptosis. Stable over-expression of a dominant negative form of the Fas-associated death domain protein (FADD) in the Apo2L/TRAIL-sensitive BTK-143 cells completely inhibited Apo2L/TRAIL-induced cell death. Our results indicate that chemotherapy and Apo2L/TRAIL act synergistically to kill cancer cells but not normal bone-derived osteoblast-like cells, which has implications for future therapy of osteosarcoma.     

Curcumin differentially sensitizes malignant glioma cells to TRAIL/Apo2L-mediated apoptosis through activation of procaspases and release of cytochrome c from mitochondria

Malignant glioma cells are generally resistant or only weakly sensitive to tumor necrosis factor family of cell death-inducing ligands, including TNF-related apoptosis-inducing ligand (TRAIL)/Apo2L. The chemopreventive activity of polyphenolic compounds present in plant-derived food products has been well recognized in epidemiological studies; however, the mechanism of chemoprevention by these dietary constituents largely remains unknown. Curcumin, the yellow pigment in the spice turmeric, has profound anti-inflammatory activity and exhibits chemopreventive and tumor growth inhibitory activity. In the present study, we investigated whether curcumin sensitizes malignant glioma cell lines U251MG and U87MG to TRAIL-induced apoptosis. Treatment with low concentrations (5-20 microM) of curcumin alone had no effect on the viability of either cell line. At low concentration (5 ng/ml) TRAIL induced cytotoxicity in U251MG cells but not in U87MG cells. Whereas curcumin at subtoxic concentration sensitized U87MG cells to TRAIL-induced cytotoxicity, it had no effect on TRAIL-mediated cytotoxicity in U251MG cells. The combined curcumin and TRAIL treatment enhanced accumulation of hypo-diploid U87MG cells in sub G1 cell cycle phase and induced the cleavage of procaspases-3, -8, -9 and release of cytochrome c from mitochondria. These data indicate that curcumin differentially sensitizes glioma cells to TRAIL-induced apoptosis through the activation of both extrinsic (receptor-mediated) and intrinsic (chemical-induced) pathways of apoptosis. These results define a potential use of curcumin to sensitize glioma cells for TRAIL-mediated immunotherapy.     

TRAIL与阿霉素联用协同杀伤人结肠癌细胞SW480

背景与目的:肿瘤坏死因子相关凋亡诱导配体(tumornecrosisfactor-relatedapoptosisinducingligand,TRAIL)可选择性杀伤肿瘤细胞,而不影响正常细胞生长。当一部分肿瘤细胞对TRAIL不敏感时,特定的其它药物可增强其杀伤作用。本文旨在探讨结肠癌细胞SW480对TRAIL的敏感性,以及TRAIL与阿霉素联用对细胞的杀伤作用及可能作用机制。方法:常规培养结肠癌细胞SW480。利用MTT法检测细胞毒性作用,流式细胞术定量分析凋亡细胞比例,透射电镜在亚细胞结构形态上证实凋亡细胞,Westernblot分析p53及bcl-2蛋白表达变化。结果:(1)SW480细胞对TRAIL不敏感,100ng/mlTRAIL只能杀伤7.8%的细胞,IC50>1000ng/ml,且不存在浓度依赖性。(2)SW480细胞对阿霉素敏感,存在浓度依赖性作用,IC50=65μmol/L,0.86μmol/L的阿霉素对细胞不表现杀伤作用。(3)TRAIL与阿霉素合用表现出协同作用,亚毒性浓度TRAIL(100ng/ml)与亚毒性浓度阿霉素(0.86μmol/L)联用可杀伤80%SW480细胞。流式细胞学证实这种杀伤作用主要通过诱导细胞凋亡实现,透射电镜亦观察到大量凋亡细胞存在。药物作用前后,p53及bcl-2蛋白表达水平无明显改变。结论:结肠癌细胞株SW480对TRAIL不敏感,但TRAIL与亚毒性浓度阿霉素联用对癌细胞有协同杀伤作用,这种细胞毒性作用主要表现