肿瘤坏死因子相关凋亡诱导配体基因转染骨髓间充质干细胞后基因表达情况及其对C6胶质瘤细胞作用的体外研究

目的 探讨转染肿瘤坏死因子相关凋亡诱导配体(TRAIL)基因的骨髓间充质干细胞(BMSC)基因表达情况及其功能.方法 实验分三组,即转染TRAIL基因组、转染空载体组及空白对照组.用脂质体法将TRAIL转入绿色荧光蛋白(GFP)-BMSC中,反转录PCR法检测BMSC的TRAILmRNA水平,Western blot、免疫荧光法检测TRAIL蛋白的表达;将携带有TRAIL的GFP-BMSC同大鼠C6胶质瘤细胞共培养,通过四甲基偶氮唑蓝比色法检测其对肿瘤细胞的旁观者效应,Hochest-PI双染色法观察TRAIL转染的BMSC对C6细胞凋亡的影响.结果 免疫荧光检测显示,转染TRAIL 24、48 h的GFP-BMSC细胞质和细胞膜有TRAIL蛋白的表达,24h比48 h荧光强,空白对照组及空载体组细胞未见表达.反转录PCR、Western blot显示转染TRAIL基因组细胞TRAIL mRNA及蛋白高表达,空白对照组及空载体组未见表达.转染TRAIL的GFP-BMSC明显抑制C6细胞存活,抑制率为(62.7±0.1)％,高于空载体组的(16.7±0.1)％(P＜0.05),同时转染TRAIL基因的BMSC可促进C6细胞的凋亡.结论 转染TRAIL的BMSC能够稳定表达目的基因,且能促进大鼠C6胶质瘤细胞凋亡,具有明显的旁观者效应.     

乳腺癌细胞对肿瘤坏死因子相关凋亡诱导配体耐受的分子机制

0引言 肿瘤坏死因子(tumor necrosis factor,TNF)是淋巴细胞分泌的一种能诱导肿瘤细胞凋亡的细胞因子,但是由于TNF对正常细胞也有同样的细胞毒性,因而限制了TNF的临床应用.1996年Pitti等[1]研究发现另外一种能特异性诱导肿瘤细胞凋亡的TNF家族成员,这个成员就是肿瘤坏死因子相关的凋亡诱导配体(TNF-related apoptosis-inducing ligand,TRAIL),由于TRAIL具有很强的诱导肿瘤细胞凋亡能力而对大部分正常细胞毒性非常低,因而使用TRAIL进行肿瘤治疗引起广泛的关注.     

TRAIL基因原核表达载体的构建、表达与抗体制备

目的:获取抗肿瘤坏死因子相关凋亡诱导配体(TRAIL)抗体.方法:利用PCR技术和基因重组技术将TRAIL基因构建于原核表达载体pPreTMH-Tb中,经酶切、测序鉴定证实构建完全正确后,通过IPTG诱导在大肠杆菌DH-5α中获得表达,并将TRAIL蛋白免疫家兔,通过Dot blot及Western blot检测抗TRAIL抗体的产生.结果:成功构建TRAIL基因原核表达载体,并在大肠杆菌DH-5α中获得表达,TRAIL蛋白表达量占菌体蛋白质总量的11.8%,Dot blot及Western blot检测证实获得了抗TRAIL抗体.结论:成功制备抗TRAIL抗体,这为TRAIL在真核细胞水平研究奠定了实验基础.     

TRAIL在乳腺癌组织中的表达

目的:研究肿瘤坏死因子相关凋亡诱导配体(TRAIL)在乳腺癌组织中的表达。方法:免疫组化法检测TRAIL在乳腺癌组织中的表达。结果:TRAIL在乳腺不典型增生和腺癌中的表达无统计学差异。TRAIL的阳性表达水平与乳腺癌组织的分化程度呈正相关,即分化程度愈高,TRAIL表达水平愈高。TRAIL在不同临床分期乳腺癌组织中的表达无统计学差异,与有无淋巴结转移无统计学差异。结论:本实验从凋亡调节因子方面支持了不典型增生为癌前病变的观点,TRAIL蛋白的表达可能与乳腺癌组织的恶性程度有关,与肿瘤的生物学行为无关。     

TRAIL增强低剂量阿霉素高效诱导人骨肉瘤细胞凋亡的实验研究

目的探讨可溶性肿瘤坏死因子相关凋亡诱导配体(TRAIL)与阿霉素(ADM)联用是否存在协同性杀伤人骨肉瘤细胞的作用以及分子机制。方法TRAIL、ADM或两药联用24h,MTT法测试细胞毒作用,吖啶橙染色荧光显微镜和透射电镜下观察细胞及亚细胞结构形态,流式细胞术检测细胞凋亡比例。RT-PCR和Westernblot分别检测药物作用前后cFLIPmRNA和cFLIP蛋白的表达。结果(1)人骨肉瘤U2OS细胞对TRAIL不敏感,IC50>1mg/L。U2OS细胞对ADM相对敏感,存在剂量依赖性细胞毒效应。(2)TRAIL与ADM联用呈现高效协同作用,表现为亚毒性浓度TRAIL(0.1mg/L)与亚毒性浓度ADM(1.0μmol/L)联用可杀伤49.54%±2.79%的U2OS细胞。(3)流式细胞术、透射电镜及荧光显微镜观察证实,协同性杀伤作用主要通过诱导细胞凋亡实现。(4)cFLIPmRNA和cFLIP蛋白的表达下调促进了药物协同诱导凋亡的发生。结论TRAIL与亚毒性浓度ADM联用表现出的高效杀灭肿瘤细胞作用主要由凋亡介导实现,cFLIPmRNA下调和cFLIP蛋白的表达减少可能参与这一过程。     

蒽贝素协同增强肿瘤坏死因子相关的凋亡诱导配体诱导乳腺癌细胞凋亡性死亡的实验北大核心CSCD

目的研究小分子化合物蒽贝素(Embelin)是否能协同增强肿瘤坏死因子相关的凋亡诱导配体(tumor necrosis factor-related apoptosis-inducing ligand,TRAIL)诱导乳腺癌细胞MDA-MB-231的凋亡性死亡。方法应用Embelin、TRAIL或者联合应用分别处理MDA-MB-231细胞。MTT法测定药物处理的细胞毒性,APOP-BRDU试剂盒及流式细胞仪测定细胞凋亡率,Western blot观察Caspase3,9和PARP的表达水平。半定量PCR和Western blot分别观察Embelin处理以后X连锁的凋亡抑制蛋白(X-linked inhibitor of apoptosis protein,XIAP)mRNA、蛋白表达水平的变化。结果 MDA-MB-231细胞呈TRAIL部分耐药,Embelin的细胞毒性在MDA-MB-231细胞呈浓度依赖性。亚毒性浓度的Embelin能显著增强TRAIL诱导的细胞毒性、凋亡率、Caspase 3,9的活化和PARP的切割。但是,亚毒性浓度的Embelin未直接改变XIAP的蛋白和mRNA表达水平。结论 Embelin能显著增强TRAIL诱导的乳腺癌细胞MDA-MB-231的凋亡性死亡。     

TRAIL对人肺腺癌细胞株Calu-3增殖和凋亡的影响

[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）对人肺腺癌细胞株Calu-3增殖和凋亡的影响。[方法]用不同浓度TRAIL分不同时间段干预Calu-3细胞,MTT法检测细胞增殖抑制率,流式细胞仪检测细胞凋亡率。[结果]Calu-3细胞生长被TRAIL抑制,具有浓度和时间依赖性。TRAIL能诱导Calu-3细胞凋亡。[结论]TRAIL在体外具有抑制Calu-3细胞增殖,促使Calu-3细胞凋亡的作用。     

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。     

间充质干细胞-抗肿瘤基因复合物治疗肿瘤的研究进展

间充质干细胞（MSC）是一种具有高度自我更新能力及多向分化潜能的细胞.MSC对多种肿瘤组织的归巢及定向迁移能力为其成为潜在的抗肿瘤基因载体奠定了基础,并且MSC自身参与重塑肿瘤微环境,影响其侵袭、增殖和转移等生物学行为.许多研究已经证实肿瘤坏死因子相关凋亡诱导配体（TRAIL）与人类第10号染色体缺失的磷酸酶及张力蛋白同源基因（PTEN）等抗肿瘤基因与MSC结合构成复合物可针对肿瘤细胞双重靶向杀伤,但对正常组织无损伤.然而,目前许多问题和确切的机制仍尚待解答.文章就MSC归巢机制、MSC对肿瘤生物学行为的影响和MSC-抗肿瘤基因复合物用于肿瘤治疗的现状及前景等进行综述.     

干扰素与TRAIL在诱导肿瘤细胞凋亡中的相互作用

干扰素（IFN）和肿瘤坏死因子相关凋亡诱导配体（TRAIL）均可诱导肿瘤细胞凋亡，但两者作用机制不同，而且并不是所有肿瘤细胞都对它们诱导的凋亡作用敏感。已有研究发现二者共同作用具有协同诱导细胞凋亡的作用，并可使原先对单一物质抵抗的肿瘤细胞变得敏感，从而达到治疗的目的。     

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     

TRAIL与低剂量5-Fu联用高效诱导大肠癌细胞凋亡的研究

目的　探讨肿瘤坏死因子相关凋亡诱导配体 (TRAIL)与 5 -Fu联用是否存在协同性杀伤大肠癌细胞的作用 ,以及这种杀伤作用的可能机制。方法　常规培养大肠腺癌细胞株HT 2 9。TRAIL、5 -Fu、或 2药联用 2 4h ,采用MTT法测试细胞毒作用 ,应用流式细胞术检测细胞凋亡比例 ,透射电镜下观察亚细胞形态。结果　①HT 2 9细胞对TRAIL不敏感 ,10 0ng/mlTRAIL只能杀伤 4.5 0 %± 0 .2 6%的细胞 ,ID 5 0 >10 0 0ng/ml。细胞对 5 -Fu相对敏感 ,存在剂量依赖性细胞毒效应 ,这种效应主要通过诱导细胞凋亡实现。②TRAIL与阿霉素联用呈现高效协同作用 ,表现为亚毒性浓度TRAIL (10 0ng/ml)与亚毒性浓度5 -Fu(10 0 μg/ml)联用可杀死 60 .0 0 %± 0 .45 %的HT 2 9细胞。③流式细胞术分析及透射电镜观察证实协同性杀伤作用主要通过诱导细胞凋亡实现。结论　大肠腺癌细胞株HT2 9对TRAIL不敏感 ,但TRAIL与亚毒性浓度 5 -Fu联用表现出高效的杀灭肿瘤细胞作用 ,这种细胞毒性作用主要由凋亡介导     

重组人TRAIL蛋白联合顺铂对人卵巢癌细胞生长及凋亡的影响

背景与目的：研究发现肿瘤坏死因子的相关凋亡诱导配体(tumor necrosis factor-related apoptosis inducing ligand,TRAIL)可以增强化疗药物对肿瘤细胞的杀伤作用。本研究旨在探讨TRAIL与顺铂联合应用对体外培养的卵巢癌细胞SKOV3和OVCAR3生长凋亡的影响及可能的诱导机制。方法：利用MTT法和流式细胞仪检测在顺铂和重组人TRAIL蛋白共同作用下,SKOV3和OVCAR3细胞的增殖抑制效应及细胞凋亡程度;并应用实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,RTFQ-PCR)检测药物处理后TRAIL死亡受体DR4、DR5的mRNA表达水平;同时用蛋白[质]印迹法(Western blot)检测DR4、DR5的蛋白表达水平。结果：SKOV3和OVCAR3细胞均对TRAIL蛋白敏感,随着TRAIL蛋白浓度的升高,细胞的生长抑制率可达64%;而TRAIL与顺铂联合用药对两种细胞的抑制率均达到92%以上,对细胞的增殖抑制呈现高效协同作用,与单独用药组比较差异有统计学意义(P<0.05);TRAIL和顺铂联合组两种细胞凋亡率分别为(31.50±0.79)%和(36.60±1.31)%,显著高于单独用药组;RTFQ-PCR和Western blot检测结果显示,SKOV3和OVCAR3细胞在TRAIL与顺铂联合用药后,死亡受体DR4、DR5表达水平均显著上调。结论：在体外,TRAIL与化疗药物顺铂联用能明显抑制卵巢癌细胞增殖,诱导肿瘤细胞凋亡。TRAIL能明显增强顺铂对卵巢癌细胞的敏感性,其诱导机制可能与死亡受体DR4、DR5表达水平上调有关。     

Estrogen receptor positive breast tumors resist chemotherapy by the overexpression of P53 in Cancer Stem Cells

Background and Objectives

Breast cancer (BC) is classified according to estrogen receptor (ER) status into ER⁺ and ER^? tumors. ER⁺ tumors have a worse response to chemotherapy compared to ER^? tumors. BCL-2, TP53, BAX and NF-ΚB are involved in drug resistance in the ER⁺ tumors. Recently it was shown that Cancer Stem Cells (CSCs) play an important role in drug resistance. In this study we tested the hypothesis that CSCs of the ER⁺ tumors resist drug through the overexpression of BCL-2, TP53, BAX and NF-ΚB.

Evaluation of LGR5 Cancer Stem Cell Marker Expression in Breast Cancer and Its Relationship with Hormonal Profile and Clinical Pathological Features

Background: Due to the high prevalence of breast cancer and the importance of evaluating new prognostic criteria for effective treatment of these patients, this study was performed to investigate the role of LGR5 in breast cancer and its relationship with hormonal and clinicalopathological features of the disease. Methods: This cross-sectional study was performed on breast cancer tissue samples in the archives of the pathology department of Firoozabadi Hospital in Tehran between 2019 and 2021. Inclusion criteria included invasive ductal carcinoma and exclusion criteria were preoperative chemotherapy. Blocks were examined for LGR5 marker expression by IHC method using LGR5 monoclonal antibody kits (Abcam). The expression pattern of LGR5 marker was cytoplasmic and cells presenting brown staining in the cytoplasm were considered positive for this marker and in terms of distribution and severity of staining were divided into three groups: mild, moderate and severe. Results: This study was performed on 60 patients with breast cancer with a mean age of 55.5±9.7. Most of the patients (55%) were in grade II. The KI67 marker was positive in 45 cases (75%) and the HER2 marker in 14 cases (23.3%) and 8 cases (13.3%) were triple-negative. The expression severity of staining of LGR5 marker in 41 cases (68.3%) was moderate and the distribution of marker expression in 31 cases (51.7%) was moderate. No significant relationship was observed between LGR5 expression severity and tumor characteristics. Conclusion: LGR5 marker is expressed in a remarkable percentage of breast cancer patients and has no significant relationship with tumor characteristics.     

Quercetin Effects on Cell Cycle Arrest and Apoptosis and Doxorubicin Activity in T47D Cancer Stem Cells

Backgrounds: Targeting breast cancer stem cells with the CD44+/CD24- phenotype is critical for complete eradication of cancer cells due to its Self-renewal, differentiation, and therapeutic resistance ability. Quercetin is a popular flavonoid with lower adverse effects and has anti-tumor properties. Therefore, we assessed the anticancer activity of Quercetin and Doxorubicin alone and in combination in the T47D cells of human breast cancer and their isolated Cancer stem cells (CSCs). Materials and Methods: The human breast cancer cell line T47D was used for this experiment. T47D CSCs were isolated by magnetic bead sorting using the MACS system. The anticancer activity of Quercetin and Doxorubicin alone and in combination were evaluated using MTT cytotoxicity assay and cell cycle distribution and apoptosis induction by flow cytometry analysis. Results: We have shown that almost 1% of T47D cell populations are made up of CD44+/CD24- cells, which considered as cancer stem cells. Quercetin and Doxorubicin alone or in combination inhibited cell proliferation and induced apoptosis in breast cancer T47D cells and in lower extent in CD44+/CD24- cells. Quercetin significantly strengthened Doxorubicin’s cytotoxicity and apoptosis induction in both cell populations. Quercetin and Doxorubicin and their combination induced G2/M arrest in the T47D cells and to a lesser extent in isolated CSCs. A value of p < 0.05 was considered as indicating a statistically significant difference. Conclusion: These outcomes suggested that CSCs are a minor population of cancer cells, which play a significant role in drug resistance by being quiescent, slow cycling and resistance to apoptosis. Furthermore, our data showed that adding Quercetin to Doxorubicin is an effective approach for the treatment of both CSCs and bulk tumor 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.     

乳腺癌干细胞上皮-间质转化标志物表达变化及意义

目的 探讨乳腺癌干细胞上皮．间质转化标志物表达变化及其临床意义。方法采用无血清悬浮培养法,从MCF-7细胞培养乳腺癌微球体细胞,应用流式细胞仪检测微球体细胞中CD44和CD24的表达,采用Westernblot方法检测微球体细胞中E-钙黏素、N-钙黏素、纤维连接蛋白、波形蛋白的表达水平,体外穿膜实验检测肿瘤细胞的迁移、侵袭能力。结果乳腺微球体富集了CD44＋CD24-的乳腺癌干细胞,并能在含血清培养基中增殖分化。该微球体细胞的上皮标志物E-钙黏素表达水平下调,而间质标志物N-钙黏素、纤维连接蛋白、波形蛋白的表达水平上调,同时乳腺癌干细胞的迁移、侵袭能力显著增强。结论乳腺癌干细胞具有上皮-间质转化的特征,具有显著增强的迁移、侵袭能力。     

集落刺激因子-1及其受体对乳腺癌荷瘤鼠肿瘤生长的影响

目的 探讨CSF-1及其受体对乳腺癌荷瘤鼠肿瘤体积以及对其免疫器官包括骨髓、胸腺、淋巴结和脾的影响。 方法 将4T1细胞（1×107/只）重悬于PBS液接种于Balb/c 小鼠左腋皮下,建立荷乳腺癌小鼠模型为实验组,同时培养相同条件的对照组。检测成瘤率,测量肿瘤体积的变化并绘制成图;成瘤后为实验组小鼠注射CSF-1及其受体,观察一段时间后同时处死两组小鼠,采用半定量RT-PCR技术检测鼠脾脏中CSF-1的表达;采用MTT比色法检测小鼠的肿瘤、脾脏、骨髓中细胞的增殖功能。 结果 4T1细胞接种后小鼠的成瘤率为100%,成瘤潜伏期平均为7~10天;实验组小鼠瘤体的增长速度快于对照组;RT-PCR的电泳结果显示,实验组小鼠的脾脏CSF-1的mRNA的表达量上升;MTT结果表明,CSF-1作用之后的实验组小鼠的肿瘤细胞和免疫细胞增殖活性升高,发挥了强大的免疫抑制功能,促进肿瘤的增长;增殖活跃的骨髓和脾细胞呈现免疫抑制表型。 结论 CSF-1及其受体对乳腺癌荷瘤鼠的肿瘤的生长有促进作用。     

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。