DcR3与肿瘤研究新进展

DcR3又称肿瘤坏死因子受体(TNFR)6B,是新近发现的TNFR超家族成员,它具有抗凋亡和细胞调节的生物学特性.DcR3与肿瘤的发生发展密切相关,可为肿瘤的诊断、治疗、疗效观察和预后判断提供一种新的思路.现综述DcR3的生物学特性及其在肿瘤方面的研究进展.     

DcR3与肿瘤研究新进展

DcR3又称肿瘤坏死因子受体(TNFR)6B，是新近发现的TNFR超家族成员，它具有抗凋亡和细胞调节的生物学特性。DcR3与肿瘤的发生发展密切相关，可为肿瘤的诊断、治疗、疗效观察和预后判断提供一种新的思路。现综述DcR3的生物学特性及其在肿瘤方面的研究进展。     

作为免疫相关性疾病靶点的DcR3的研究进展

诱骗受体3（decoy receptor3，DcR3）是肿瘤坏死因子受体超家族的新成员。它通过拮抗Fas／FasL系统及LIGHT／LTβR、LIGHT／HVEM／TR2系统的作用，在肿瘤及免疫性疾病中发挥重要作用。DcR3的基因位于20q13．3，在人肿瘤细胞中会发生基因扩增和重排；在多种肿瘤、自身免疫疾病中高表达；作用机制有LIGHT和配体FasL途径等；促肿瘤发生；可下凋宿主免疫功能，能降低T细胞对同种抗原应答，有重大开发潜能。     

诱捕受体3在胃癌中的表达及其临床意义

目的探讨诱捕受体3（DcR3）基因在胃癌组织中的表达及其与胃癌临床病理特征之间的关系。方法采用PT—PCR方法检测41例胃癌组织和41例癌旁正常组织中DcR3的表达，分析其与多种临床病理特征之间的关系。结果41例胃癌组织中DcR3阳性表达率为56％（23／41）。41例癌旁正常胃组织中发现3例DcR3的阳性表达。癌组织DcR3mRNA的表达水平明显高于正常胃黏膜组织（P〈0．01）。DcR3的表达与胃癌的分化程度（X）、淋巴结转移（X2）及TNM分期（X3）显著相关，与患者肿瘤部位及浸润深度等无相关性（P〉0．10）。其多元化线性回归方程为Y=0．432—0．208X1＋0．098X2＋0．086X3。结论DcR3在胃癌组织中具有较高的表达率，其异常表达可促进胃癌的发生、发展。DcR3的基因检测可作为判断胃癌分化、浸润、转移、分期的重要参考指标。     

DcR3在消化系统肿瘤细胞中的表达

目的：研究诱骗受体3（decoy receptor3，DcR3）在消化系统肿瘤细胞中的表达差异，阐明其与消化系统肿瘤的相关性。方法：体外培养结肠癌细胞（sw480）、胃癌细胞（SGC7901）、肝癌细胞（HepG2）和人成纤维细胞（3T3），采用RT-PCR法检测DcR3 mRNA的表达水平；应用Western印迹法检测DcR3蛋白的表达水平。结果：SW480细胞的DcR3mRNA和蛋白表达水平均高于SGC7901、HepG2和3T3细胞的表达水平，差异有统计学意义（P〈0．05）。结论：DcR3在结肠癌细胞中的高表达可能与结肠癌的发生、发展有关。     

DcR3和HER-2/neu在60例大肠癌中表达及临床意义

[目的]探讨DcR3和HER-2/neu在大肠癌中的表达及与大肠癌的相关性。[方法]应用免疫组化法分别检测正常大肠组织（n=10）、大肠癌组织（n=60）中DcR3和HER-2/neu的表达情况,分析两者表达与大肠癌临床病理特征的关系。[结果]正常大肠组织中DcR3和HER-2/neu蛋白无表达。大肠癌组织中DcR3蛋白阳性表达率58.33%,DcR3蛋白的表达与患者年龄、性别、肿瘤大小、肿瘤部位、浸润深度等无关（P〉0.05）,与分化程度、淋巴结转移和TNM分期有关（P〈0.05）。大肠癌组织中HER-2/neu蛋白阳性表达率63.33%,HER-2/neu蛋白的表达与患者年龄、性别、肿瘤大小、肿瘤部位等无关（P〉0.05）,与浸润深度、TNM分期、淋巴结转移和分化程度有关（P〈0.05）。大肠癌中DcR3表达与HER-2/neu表达呈正相关（r=0.3781,P〈0.05）。[结论]大肠癌中DcR3和HER-2/neu高表达,DcR3、HER-2/neu表达可能与肿瘤的恶性程度和恶性生物学行为有关。     

诱骗受体3在上皮性卵巢癌组织中的表达及临床意义

目的:诱骗受体3(decoy receptor 3,DcR3)是肿瘤坏死因子受体(TNFR)家族的成员,影响着多种肿瘤的发生发展,本实验研究探讨其与卵巢癌发生发展及预后的关系。方法:应用免疫组织化学SP法检测38例正常卵巢组织、29例卵巢良性肿瘤及86例卵巢上皮性癌组织中DcR3蛋白的表达情况。结果:DcR3蛋白在卵巢癌组织中的表达明显高于卵巢良性肿瘤及正常组织中的表达;DcR3蛋白在卵巢上皮性癌Ⅰ-Ⅱ期表达较Ⅲ-Ⅳ期明显减弱;在高中分化组织中的表达明显低于低分化组织;在淋巴结转移组的表达高于无淋巴结转移组,各组间差异均具有统计学意义（P<0.05）。DcR3蛋白表达越强,患者生存时间越短（P<0.05）。结论:DcR3表达水平与卵巢上皮性癌临床分期、组织分化、肿瘤浸润、转移及预后有关,有可能成为一种卵巢癌肿瘤特异性指标。     

RNA干扰沉默DcR3对人胰腺癌细胞裸鼠移植瘤放疗增敏的实验研究

摘 要：［目的］探讨RNA干扰沉默DcR3对人胰腺癌细胞裸鼠移植瘤放疗敏感性的影响及其可能机制。［方法］ 取对数生长期的AsPC-1细胞 1×107/ml,接种于6周龄裸鼠左后肢腹股沟,当皮下肿瘤直径为8mm左右时,随机分为4组(n=15)：PBS组、DcR3siRNA组、放疗组（RT）和DcR3siRNA+放疗组（DcR3siRNA+RT）,观察DcR3siRNA联合放疗对人胰腺癌AsPC-1细胞裸鼠移植瘤的治疗效果;应用ELISA和Western blot检测各组DcR3的蛋白表达变化;免疫组织化学和Western blot分析各组Caspase-8和Caspase-3蛋白表达的变化;TUNEL检测各组肿瘤细胞凋亡情况。［结果］ DcR3siRNA+RT组较其他各组更能抑制移植瘤的生长,DcR3-siRNA+RT对肿瘤的抑制率明显高于单纯RT组,与RT组相比,DcR3siRNA+RT组的抑瘤率为80.86%±4.17%;DcR3siRNA+RT组的DcR3蛋白量和蛋白相对表达均明显低于RT组,差异有统计学意义(P＜0.05);DcR3siRNA+RT组的Caspase-8和Caspase-3蛋白表达均明显高于单独RT组;DcR3siRNA组、RT组以及DcR3-siRNA+RT组肿瘤组织内均可观察到凋亡细胞,而DcR3siRNA+RT组肿瘤细胞凋亡数目明显高于RT组或DcR3siRNA组。［结论］RNA干扰沉默DcR3基因可以增加人胰腺癌细胞裸鼠移植瘤对放疗的敏感性,该作用可能与沉默DcR3可激活Caspase-8/Caspase-3凋亡途径和促进肿瘤细胞凋亡有关。     

食管癌组织DcR3、MMP-2表达及其对生存率的影响

背景与目的:诱骗受体3(decoy receptor 3,DcR3)蛋白是一种肿瘤坏死因子,基质金属蛋白酶-2(matrix metalloproteinase-2,NNP-2)是一种锌离子依赖的蛋白水解酶,它们的蛋白表达与食管癌(esophageal carcinoma,EC)的发生、发展密切相关.本研究旨在探讨DcR3和MMP-2在食管癌组织中的表达、相互关系及与患者生存的相关性.方法:收集98例有完整临床病理资料和随访资料的食管癌标本及20例癌旁正常食管组织标本作为对照,采用EnViSionTM免疫组化法分别检测DcR3和MMP-2的表达,并电话随访所有患者的术后生存时间,分析其与患者各项临床指标及生存的关系.结果:98例食管癌组织中DcR3阳性表达64例(65.3%),阴性表达34例(34.7%);MMP-2阳性表达57例(58.2%),阴性表达41例(41.8%);DcR3、MMP-2在食管癌组织中的表达均显著高于癌旁正常食管组织(P<0.05);食管癌组织中DcR3、MMP-2表达均与肿瘤的浸润深度、淋巴结有无转移、临床分期及3年生存率密切相关(P<0.05);DcR3和MMP-2在食管癌组织中表达呈正相关(0相似文献   

诱导受体3在乳腺癌中的表达及其临床意义

目的观察乳腺癌组织中诱导受体3(decoy receptor 3,DcR3)蛋白的表达,探讨血清DcR3水平对乳腺癌患者的诊断价值。方法采用免疫组化S-P法检测41例乳腺癌、18例乳腺良性疾病和15例乳腺正常组织中DcR3蛋白的表达,ELISA法检测患者外周血清中DcR3的水平。结果41例乳腺癌组织中DcR3阳性表达25例,阳性率为61.0%,乳腺良性疾病和乳腺正常组织中无阳性表达。DcR3的表达与有无淋巴结转移有关(P<0.05),与患者年龄、肿瘤大小、组织学分级、TNM分期以及雌孕激素受体状况等无明显相关性(P>0.05)。乳腺癌患者术前、术后以及乳腺良性疾病患者术前血清DcR3水平分别为(247.93±33.12)pg/ml,(240.15±24.20)pg/ml和(233.46±15.94)pg/ml,术后与术前相比,差异无显著性(P>0.05),乳腺良性疾病患者与乳腺癌患者术前血清DcR3水平相比差异亦无显著性(P>0.05)。结论DcR3在乳腺癌组织中表达增高,尤其在伴有淋巴结转移的癌组织中表达增高。DcR3的表达与乳腺癌的发生、发展以及转移有关,可成为治疗乳腺癌的一个新靶点。血清DcR3水平对乳腺癌的诊断无临床价值。     

The prognostic significance of overexpression of the decoy receptor for Fas ligand (DcR3) in patients with gastric carcinomas

Abstract. Background: The FasL-Fas system has an important role in mediating immune-cytotoxic killing of cells such as virus-infected or tumor cells. It was recently reported that there is a soluble decoy receptor (DcR3), which binds to FasL and inhibits FasL-induced apoptosis, and certain tumors may escape FasL-dependent immune-cytotoxic attack by expressing a decoy receptor that blocks FasL. We evaluated whether DcR3 has clinical relevance in actual human gastric cancers. Methods: . The expression of DcR3 was investigated by Northern blot analysis in a series of 84 primary gastric carcinomas and compared with clinicopathological features and prognosis. The DcR3 expression level was analyzed and quantified densitometrically. The location of DcR3 mRNA in gastric carcinoma tissue was detected by in situ hybridization. Results: The frequency of DcR3 overexpression was 26% (22 of 84 surgical specimens). The DcR3 expression level was significantly associated with lymph node metastasis and pathological stage, but did not correlate with tumor size, metastatic status, or histological type. In situ hybridization demonstrated that DcR3 mRNA was expressed in tumor cells. When the patients were followed up for 63 months, DcR3 overexpression was found to be associated with a significantly shortened duration of overall survival compared with findings in patients having normal DcR3 expression. Conclusion: The DcR3 decoy receptor for FasL may be involved in the progression of gastric cancer. Further evaluation of these possible roles of DcR3 and the regulation of DcR3 expression in malignant cells will be critically important for the development of new strategies for controlling the growth of malignant cells that escape host immune surveillance. Received: July 19, 2001 / Accepted: December 21, 2001     

An apoptotic molecular network identified by microarray: on the TRAIL to new insights in epithelial ovarian cancer

BACKGROUND: In a previous microarray expression analysis, the authors identified candidate genes that were expressed differentially between ovarian tumors with low malignant potential and invasive serous epithelial ovarian tumors. Among them, the apoptosis-related candidate genes tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), caspase 8 (CASP8), FLICE-inhibitory protein (FLIP), and cytochrome C (CYC) were identified. METHODS: For the current study, the authors conducted immunohistochemical analyses of a tissue array comprised of 235 serous tumors of different grades and stages to evaluate whether there was differential protein expression for these candidates and for the 4 death cell receptors of Trail: Dr4, Dr5, DcR1, and DcR2. RESULTS: All proteins except DcR1 and DcR2 had significantly differential expression levels between grade 0 tumors (low malignant potential) and grade 2 and 3 tumors. Trail also showed differential expression between grade 0 tumors and grade 1 tumors. When all tumors were compared, the expression levels of Trail, Dr4, Dr5, DcR1, and Flip differed significantly between early-stage and advanced-stage disease. High Dr5 expression was associated with a poor prognosis in patients who had invasive tumors and in the subgroup of patients who had grade 3 tumors. Furthermore, the combinations of 2 proteins (Trail and Dr5, DcR2 and Cyc, Flip and Dr5, Flip and DcR2, DcR1 and Dr5 or Dr4 and Flip) revealed an association with patient prognosis. CONCLUSIONS: The identification of new proteins in the initial diagnosis and prognosis of patients with epithelial ovarian cancer may lead to a better understanding of the disease, highlighting new potential therapeutic targets, and may be useful in patient management.     

Soluble decoy receptor 3 is expressed by malignant gliomas and suppresses CD95 ligand-induced apoptosis and chemotaxis

Decoy receptor 3 (DcR3) is a newly identified soluble protein that binds to CD95 ligand (CD95L) and inhibits its proapoptotic activity. Here we report that DcR3 is expressed by the majority of long-term and ex vivo malignant glioma cell lines as well as in human glioblastoma in vivo. Expression of DcR3 correlates with the grade of malignancy: 15 of 18 (83%) glioblastomas (WHO grade IV) but none of 11 diffuse astrocytomas (WHO grade II) exhibited DcR3 immunoreactivity. We also demonstrate that human malignant glioma cells engineered to release high amounts of DcR3 into the cell culture supernatant are protected from CD95L-induced apoptotic cell death. In contrast, DcR3 does not confer protection from the death ligand Apo2 ligand (TRAIL). Importantly, ectopic expression of DcR3 resulted in substantial differences in immune cell infiltration in the 9L rat gliosarcoma model. Thus, the infiltration of CD4+ and CD8+ T cells as well as microglia/macrophages into glioma was substantially decreased in DcR3-producing tumors compared with control tumors. Chemotaxis assays revealed that DcR3 counteracts the chemotactic activity of CD95L against microglial cells in vitro. These findings suggest that DcR3 may be involved in the progression and immune evasion of malignant gliomas.     

Aberrant methylation of trail decoy receptor genes is frequent in multiple tumor types

TNF-related apoptosis-inducing ligand (TRAIL) selectively induces programmed cell death (apoptosis) in various cancer cells but not in normal cells. TRAIL is known to bind to 4 different receptors, 2 proapoptotic (DR4 and DR5), and 2 potentially antiapoptotic receptors lacking death domains (DcR1 and DcR2). Aberrant promoter methylation and resultant silencing of tumor suppressor genes play an important role in the pathogenesis of many tumor types. Recently aberrant methylation of TRAIL decoy receptors was reported in pediatric tumor cell lines and neuroblastomas. We examined the methylation and expression status of TRAIL receptor genes in cancers of breast, lung, mesothelioma, prostate, bladder, cervix, ovary, brain and in hematopoietic malignancies. Aberrant methylation of DcR1 or DcR2 was present in 70% of primary breast cancers, 31% of primary lung cancers, in 63% of primary malignant mesothelioma (MM), in 60% of prostate cancer, in 42% of bladder cancer, in 100% of cervical cancer, in 43% of ovarian cancer, in 41% of lymphoma, in 26% of leukemia and in 56% of multiple myeloma. Methylation of DR4 and DR5 was rare in all the tumor types examined. Methylation of all the 4 receptors was rare in non malignant tissues. In cell lines, aberrant methylation of DcR1 was present in 11 of 23 (48%) breast, 10 of 27 (37%) lung and 3 of 7 (43%) MM, whereas aberrant methylation of DcR2 was present in 17 of 23 (74%) breast, 13 of 27 (48%) lung and 5 of 7 (71%) MM. The concordance between loss of gene expression and aberrant methylation ranged from 70-100%. Treatment with 5-aza-2'-deoxycytidine restored DcR1 and DcR2 expression in 9 methylated cell lines confirming that aberrant methylation was the cause for silencing of DcR1 and DcR2 expression. Our results demonstrate that DcR1 and DcR2 genes are frequently methylated in various tumor types, and that the role of decoy receptors in tumor pathogenesis needs to be re-evaluated.     

Clinical significance of expression and amplification of the DcR3 gene in pancreatic carcinomas

This study aimed to investigate the clinical significance of expression and amplification of decoy receptor 3 (DcR3) in pancreatic carcinomas (PC). mRNA expression was detected by PQ-PCR, and amplification was determined. DcR3 protein expression was detected by immunohistochemistry and ELISA. Correlations between DcR3 expression and clinical pathological factors were analyzed. The relative amount of DcR3 in PC tissues and non-cancerous tissues showed a statistically significant difference, 21 cases displaying more than two fold DcR3 amplification, while no such amplification was found in normal pancreatic tissues. DcR3 positive cell staining was located in the cytoplasm. The positive rate of DcR3 in PC and non-cancerous tissues showed a significant difference. DcR3 mRNA expression was correlated with clinical staging, size of the tumor, lymph node metastasis and histological staging, while protein expression was correlated with clinical data like tumor size. DcR3 gene amplification only correlated with tumor size. The level of DcR3 in serum of the PC resectable group before operation was 72.2±10.2 pg/ml, showing a significant difference compared to gallbladder carcinoma group (GC) or pancreatic benign tumor (PBT) group (P <0.01). In conclusion, DcR3 amplification is correlated with DcR3 expression in PC tissues, especially those clinical pathological factors which reflect tumor progression. Assessment of DcR3 level in sera of PC patients may be helpful for the early diagnosis and prognostic judgement.     

Tumor-specific down-regulation of the tumor necrosis factor-related apoptosis-inducing ligand decoy receptors DcR1 and DcR2 is associated with dense promoter hypermethylation

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) induces apoptosis in a large variety of cancer cells but not in most normal human cells. This feature makes TRAIL, a potential antitumor agent. TRAIL can bind to four different receptors, two pro-apoptotic death receptors (DRs), DR4 and DR5, and two antiapoptotic decoy receptors (DcRs), DcR1 and DcR2. Normal cells express all four of the receptors. The increased TRAIL sensitivity of tumor cells has been postulated to result from the lack of DcR expression. We studied the tumor-specific down-regulation of the TRAIL receptors DcR1 and DcR2, as well as DR4 and DR5, in a group of pediatric tumor cell lines [nine neuroblastoma and three peripheral primitive neuro-ectodermal tumors (PNETs)] and three cell lines from adult tumors. Lack of expression of DcR1 and DcR2 was widespread (13 of the 15 cell lines and 10 of 15, respectively), both in the adult tumor cell lines and in the pediatric tumor lines. DR4 and DR5 were expressed in 8 of 15 and 12 of 15 cell lines, respectively. To understand the tumor-specific down-regulation of the TRAIL receptors, the promoter regions were studied for possible methylation changes of their CpG islands. All normal tissues were completely unmethylated, whereas in the tumor cell lines, we found frequent hypermethylation of the promoter. For DcR1 and DcR2, we found dense hypermethylation in 9 (69%) of 13 and 9 (90%) of 10 of nonexpressing cell lines, respectively. DR4 and DR5 were methylated in 5 (71%) of 7 and 2 (67%) of 3 nonexpressing cell lines, respectively. Treatment with the demethylating agent 5-aza-2'deoxycytidine resulted in partial demethylation and restored mRNA expression. In addition, we performed mutation analysis of the death domains of DR4 and DR5 by sequencing exon 9. Mutations were not present in any of the neuroblastoma or PNET cell lines. A panel of 28 fresh neuroblastoma tumor samples also lacked expression of DcR1 and DcR2 in 85 and 74% of cases, respectively. Hypermethylation was observed in 6 (21%) of 28 for DcR1 and 7 (25%) of 28 for DcR2. DR4 and DR5 were both expressed in 22 of 28 tumors, and no promoter methylation was observed. These data suggest that hypermethylation of the promoters of DcR1 and DcR2 is important in the down-regulation of expression in neuroblastoma and other tumor types.     

DCR3 locus is a predictive marker for 5-fluorouracil-based adjuvant chemotherapy in colorectal cancer

Adjuvant chemotherapy reduces the incidence of distant metastasis and increases survival of patients with colorectal cancer. However, predictive markers are needed to define subsets of patients with stage II and III disease that may benefit from adjuvant treatment. A secreted member of the TNF receptor superfamily, the decoy receptor 3 (DcR3), was reported to be amplified in colorectal cancer as a negative regulator of Fas-mediated apoptosis. We analyzed DcR3 gene copy number and protein expression in a large series of tumors from a randomized multicenter trial of 5-fluorouracil/mitomycin C (FU/MMC) adjuvant chemotherapy of the Swiss Group for Clinical Cancer Research (SAKK 40/81), using real-time quantitative PCR and immunohistochemistry on tumor microarrays. Results of gene status and protein expression of DcR3 were correlated with disease-free and overall survival of patients. We observed amplification of the DcR3 gene in 185/294 (63%) and overexpression of the DcR3 protein in 163/223 (73%) of colorectal tumors. Multivariate analysis showed no prognostic effect of DcR3 gene amplification and protein overexpression. However, adjuvant chemotherapy was significantly more beneficial in patients with normal DcR3 gene copy number than in patients with amplification (DFS: HR 2.84, 95% CI 1.16-6.98, p = 0.02; OS: HR 3.15, 95% CI 1.19-8.32, p = 0.02), whereas DcR3 protein overexpression did not influence the effect of adjuvant chemotherapy (DFS: HR 1.02, 95% CI 0.65-1.60, p = 0.95; OS: HR 0.95, 95% CI 0.61-1.49, p = 0.83). We conclude that amplification of the 20q13 locus is a predictive marker for adjuvant chemotherapy in colorectal cancer.     

Decoy Receptor 3 Is a Prognostic Factor in Renal Cell Cancer

Background

Decoy receptor 3 (DcR3) is a soluble protein that binds to and inactivates the death ligand CD95L. Here, we studied a possible association between DcR3 expression and prognosis in patients with renal cell carcinomas (RCCs).

Methods

A tissue microarray containing RCC tumor tissue samples and corresponding normal tissue samples was generated. Decoy receptor 3 expression in tumors of 560 patients was examined by immunohistochemistry. The effect of DcR3 expression on disease-specific survival and progression-free survival was assessed using univariate analysis and multivariate Cox regression analysis. Decoy receptor 3 serum levels were determined by ELISA.

Findings

High DcR3 expression was associated with high-grade (P = .005) and high-stage (P = .048) RCCs. The incidence of distant metastasis (P = .03) and lymph node metastasis (P = .002) was significantly higher in the group with high DcR3 expression. Decoy receptor 3 expression correlated negatively with disease-specific survival (P < .001) and progression-free survival (P < .001) in univariate analyses. A multivariate Cox regression analysis retained DcR3 expression as an independent prognostic factor that outperformed the Karnofsky performance status. In patients with high-stage RCCs expressing DcR3, the 2-year survival probability was 25%, whereas in patients with DcR3-negative tumors, the survival probability was 65% (P < .001). Moreover, DcR3 serum levels were significantly higher in patients with high-stage localized disease (P = .007) and metastatic disease (P = .001).

Interpretation

DcR3 expression is an independent prognostic factor of RCC progression and mortality. Therefore, the assessment of DcR3 expression levels offers valuable prognostic information that could be used to select patients for adjuvant therapy studies.