TRAIL及其受体在乳腺癌组织中的表达及意义

目的探讨肿瘤坏死因子相关凋亡诱导配体（TRAIL）及其受体（DR4、DR5、DcR1、DcR2）在乳腺癌组织的表达及意义。方法用反转录聚合酶链反应（RT-PCR）法检测60例乳腺癌及对应的正常乳腺组织中TRAIL及其受体的表达。结果乳腺癌组织中TRAIL、DcR1、DcR2表达均低于正常乳腺组织(P＜0.05),且TRAIL及其受体的表达与乳腺癌的分期、分级等无关(P＞0.05)。结论TRAIL及其受体在乳腺癌凋亡过程中起着重要的作用,TRAIL及其诱骗受体低表达同乳腺癌的发生关系密切。     

TRAIL及其受体在膀胱癌中的表达及相关性研究

目的:观察肿瘤坏死因子相关诱导凋亡配体(TRAIL)及其受体DR4、DcR1在膀胱癌组织及正常膀胱黏膜中的表达,并探讨其与临床病理特征间的相关性.方法:采用免疫组织化学PV9001二步法检测64例膀胱癌石蜡标本及14例正常膀胱组织中的TRAIL、DR4、DcR1的表达,结合患者病理资料,分析其与患者临床病理特征之间的关系.结果:TRAIL、DR4在膀胱癌组织中的表达较正常组织中的表达低,DcR1表达与之相反(P<0.05).进一步统计分析得出TRAIL、DR4在高分化膀胱癌中表达较中低分化癌高,DcR1与之相反(P<0.05).TRAIL、DR4、DcR1的表达与性别、年龄、临床分期及是否淋巴转移等病理特征无关(P>0.05).结论:TRAIL、DR4、DcR1在膀胱癌组织及正常组织中的表达具有统计学差异,并且与病理分级具有一定的相关性,与其他临床病理特征无关.     

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.     

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.     

Evaluating the expression and prognostic value of TRAIL-R1 and TRAIL-R2 in breast cancer.

PURPOSE: The cell surface receptors tumor necrosis factor-related apoptosis-inducing ligand receptor 1 (TRAIL-R1) and TRAIL-R2 transmit apoptotic signals, and agents that activate these receptors are in clinical development. We sought to determine the expression and prognostic value of TRAIL-R1 and TRAIL-R2 in early-stage breast cancer. EXPERIMENTAL DESIGN: Tissue microarrays containing specimens from 655 breast cancer patients with 20-year follow-up were employed and evaluated with our automated quantitative analysis (AQUA) system. The system uses cytokeratin to define pixels as breast cancer (tumor mask) within the array spot, and measures intensity of TRAIL receptor expression using Cy5 conjugated antibodies within the mask. AQUA scores were correlated with clinical and pathologic variables. TRAIL-R1 and TRAIL-R2 expression were similarly studied on 95 unmatched normal breast specimens. RESULTS: TRAIL-R1 expression was not associated with survival. High TRAIL-R2 expression strongly correlated with decreased survival (P = 0.0005). On multivariate analysis, high TRAIL-R2 expression remained an independent prognostic marker, as did nodal status and tumor size. High TRAIL-R2 expression correlated strongly with lymph node involvement (P = 0.0003). TRAIL-R2 expression was stronger in malignant specimens than in normal breast epithelium (P < 0.0001). CONCLUSIONS: High TRAIL-R2 expression was independently associated with decreased survival in breast cancer. The biological basis and the sensitivity of high TRAIL-R2 expressing cells to TRAIL agonists and/or chemotherapy are subject to further investigation. Evaluation of TRAIL-R2 expression in early-stage breast cancer may identify a subset of patients requiring more aggressive or pathway-targeted adjuvant treatment. Clinical trials involving TRAIL-R2 agonists should stratify patients based on TRAIL-R2 expression.     

CCNU-dependent potentiation of TRAIL/Apo2L-induced apoptosis in human glioma cells is p53-independent but may involve enhanced cytochrome c release.

Death ligands such as CD95 ligand (CD95L) or tumor necrosis factor-related apoptosis-inducing ligand/Apo2 ligand (TRAIL/Apo2L) induce apoptosis in radiochemotherapy-resistant human malignant glioma cell lines. The death-signaling TRAIL receptors 2 (TRAIL-R2/death receptor (DR) 5) and TRAIL-R1/DR4 were expressed more abundantly than the non-death-inducing (decoy) receptors TRAIL-R3/DcR1 and TRAIL-R4/DcR2 in 12 human glioma cell lines. Four of the 12 cell lines were TRAIL/Apo2L-sensitive in the absence of a protein synthesis inhibitor, cycloheximide (CHX). Three of the 12 cell lines were still TRAIL/Apo2L-resistant in the presence of CHX. TRAIL-R2 expression predicted sensitivity to apoptosis. Coexposure to TRAIL/Apo2L and cytotoxic drugs such as topotecan, lomustine (1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, CCNU) or temozolomide resulted in synergistic killing. Synergistic killing was more often observed in cell lines retaining wild-type p53 activity (U87MG, LN-229) than in p53 mutant cell lines (LN-18, T98G, U373MG). Drug exposure resulted in enhanced TRAIL-R2 expression, but decreased TRAIL-R4 expression in U87MG cells. Ectopic expression of dominant-negative p53(V135A) abrogated the drug-induced changes in TRAIL-R2 and TRAIL-R4 expression, but had no effect on synergy. Thus, neither wild-type p53 function nor changes in TRAIL receptor expression were required for synergy. In contrast, synergy resulted possibly from drug-induced cytochrome c release from mitochondria, serving as an amplifier of the TRAIL/Apo2L-mediated cascade of caspase activation. These data provide novel insights into the role of the TRAIL/Apo2L system in malignant gliomas and illustrate that TRAIL/Apo2L-based immunochemotherapy may be an effective therapeutic strategy for these lethal neoplasms.     

散发性乳腺浸润性导管癌中BRCA1 表达及临床意义*

目的:研究散发性乳腺浸润性导管癌（invasive ductal carcinoma,IDC）（breastcancer 1 BRCA1）基因的表达及其与其临床病理特征之间的关系。方法:采用免疫组化SP三步法检测67例乳腺浸润性导管癌,53例乳腺腺病患者的石蜡标本BRCA1 的表达,从病理科的档案提取患者的年龄,肿物大小,淋巴结转移情况,ER,PR,Her-2 表达结果,分析BRCA1 的表达和患者的年龄,肿物大小,淋巴结转移情况及ER,PR,Her-2 表达的关系。结果:BRCA1蛋白在IDC 组织表达率56.7%（38/67）,癌旁组织表达率80.0%（36/45）,乳腺腺病组织表达率92.5%（49/53）。 阳性细胞定位除细胞核外,也见于胞浆。IDC 癌组织与癌旁组织、乳腺腺病组织比较,BRCA1 阳性表达率均下降,均有显著性差异（P<0.05）。 BRCA1 的表达与淋巴结转移呈负相关（r=-0.137,P<0.05）,与ER、PR、Her-2 的表达均呈负相关（r 值分别为-0.439,-0.250,-0.363,P<0.05）,与年龄、肿物大小无明显相关性（P>0.05）。 结论:BRCA1 蛋白可作为估计乳腺癌生物学行为和预后的潜在指标。      

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。     

Mutation analysis and mRNA expression of trail-receptors in human breast cancer

The chromosome region 8p12-p22 shows frequent allelic loss in a variety of human malignancies, including breast cancer (BC). The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-receptors TRAIL-R1, -R2, -R3 and -R4 are located on 8p21-p22 and might be candidate tumor suppressor genes in this region. To evaluate the involvement of TRAIL receptors in breast carcinogenesis, we have analyzed the entire coding region of TRAIL-R2 and the death domain (DD) regions of TRAIL-R1 and -R4 for the detection of somatic mutations in a series of breast tumors, lymph node metastases and BC cell lines. Overall, we detected 1, 11 and 3 alterations in the TRAIL-R1, -R2 and -R4 genes, respectively. Although functional studies have not yet been performed, we assume that most of these alterations do not alter the function of TRAIL-receptors. Additionally, we analyzed individuals from BC families for the detection of TRAIL-R2 germline mutations. One alteration has been found in the Kozak consensus motif at position -4 with respect to the translation initiation AUG [1-4 (C-->A)]. We further studied the mRNA expression of TRAIL and the 4 TRAIL receptors. In BC cell lines, a strongly decreased mRNA expression of TRAIL, TRAIL-R1, -R3 and -R4 was found, whereas the expression of TRAIL-R2 was only slightly reduced. In breast tumors, a 1.2-3.6-fold reduction of mRNA signals of the 5 genes was observed. No correlation was found between the expression level of TRAIL and the receptor mRNAs and clinicopathologic variables and between the expression of TRAIL-R2 and TP53 mutation status and loss of heterozygosity (LOH) at 8p21-p22. Taken together, we cannot exclude the involvement of TRAIL-receptors in BC. Our mutation studies indicate that DD receptor mutations occur at low frequency and are not the primary cause for the altered mRNA expression of TRAIL and TRAIL-receptors in BC.     

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.     

Predominant Bcl-XL knockdown disables antiapoptotic mechanisms: tumor necrosis factor-related apoptosis-inducing ligand-based triple chemotherapy overcomes chemoresistance in pancreatic cancer cells in vitro

Pancreatic cancer is lethal because of its invasiveness, rapid progression, and profound resistance to chemotherapy and radiation therapy. To identify the molecular mechanisms underlying this, we have examined the expression and potency of three major death receptors: tumor necrosis factor receptor (TNF-R), TNF-related apoptosis-inducing ligand receptor (TRAIL-R), and Fas in mediating cytotoxicity in four invasive pancreatic cancer cell lines. We have analyzed the expression of major antiapoptotic factors, cell cycle regulators and death receptor decoys (DcR) in comparison with normal pancreas tissues and five other human malignant tumor cell lines. We have found that different pancreatic cancer cell lines coexpress high-level TRAIL-R, Fas, and TNF-R1 but are strongly resistant to apoptosis triggered by the death receptors. DcR2 and DcR3 overexpression may partly contribute to the resistance of pancreatic cancer cells to TRAIL-R- and Fas-mediated cytotoxicity. Bcl-XL and Bcl-2 are predominantly overexpressed in pancreatic cancer cell lines, respectively. Bcl-XL is also predominantly overexpressed in prostate, colorectal, and intestinal cancer cells. The knockdown of the predominant Bcl-XL overexpression significantly reduces the viability of pancreatic cancer cells to TNFalpha- and TRAIL-mediated apoptosis by sublethal-dose single and combined antitumor drugs, including geldanamycin, PS-341, Trichostatin A, and doxorubicine. Geldanamyin and PS-341 synergistically block NFkappaB activation, suppress Akt/PKB pathway, and down-regulate Bcl-XL, Bcl-2, cIAP-1, and cyclin D1 expression. This combined regimen dramatically enhances TRAIL cytotoxic effects and breaks through chemoresistance. Bcl-XL plays a vital role in pancreatic cancer chemoresistance. Geldanamycin, PS-341, and TRAIL triple combination may be a novel therapeutic strategy for pancreatic cancer.     

Polymorphisms in TRAIL receptor genes and risk of breast cancer in Spanish women

TRAIL is a potent inducer of apoptosis in malignant but not in normal cells. TRAIL binds to the proapoptotic death receptor DR4 and DR5 as well as to the decoy receptors DcR1 and DcR2. To evaluate the involvement of TRAIL receptor genes in breast cancer, we carried out a case-control study of eight selected polymorphisms in a large sample of Spanish women. Three of the eight selected SNPs (626G/C and 1322G/A in DR4 and 2699A/G in DcR2) showed some evidence of different genotype distributions in a random selection of 535 cases and 480 controls and were therefore studied in our entire sample (1008 cases and 768 controls). For the two DR4 polymorphisms, no differences in genotype or haplotype distribution were found between cases and controls. Interestingly, allele 2699G in the decoy receptor DcR2 appears associated with reduced breast cancer risk (P=0.05). Given that it is located in the 3' UTR, its effect might be related to DcR2 mRNA instability, or linkage disequilibrium with a functional variant residing in either DcR2 or neighbouring genes. A decreased efficiency of DcR2 to work as decoy receptor for TRAIL, would facilitate the apoptotic pathway in cells at risk.     

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。     

TRAIL receptors are expressed in both malignant and stromal cells in pancreatic ductal adenocarcinoma

This study assesses the expression of all TNF-related apoptosis-inducing ligand (TRAIL) receptors in pancreatic ductal adenocarcinoma (PDAC) tumor tissue. We aimed to include TRAIL receptor expression as an inclusion parameter in a future clinical study using a TRAIL-based therapy approach for PDAC patients. Considering the emerging influence of PDAC desmoplastic stroma on the efficacy of anti-PDAC therapies, this analysis was extended to tumor stromal cells. Additionally, we performed PDAC stroma characterization. Our retrospective cohort study (N=50) included patients with histologically confirmed PDAC who underwent surgery. The expression of TRAIL receptors (DR4, DR5, DcR1, DcR2, and OPG) in tumor and stromal cells was evaluated by immunohistochemistry (IHC). The amount of tumor stroma was assessed by anti-vimentin IHC and Mallory’s trichrome staining. The prognostic impact was determined by the univariate Cox proportional hazards regression model. An extensive expression of functional receptors DR4 and DR5 and a variable expression of decoy receptors were detected in PDAC tumor and stromal cells. Functional receptors were detected also in metastatic tumor and stromal cells. A poor prognosis was associated with low or absent expression of decoy receptors in tumor cells of primary PDAC. After assessing that almost 80% of tumor mass was composed of stroma, we correlated a cellular-dense stroma in primary PDAC with reduced relapse-free survival. We demonstrated that TRAIL functional receptors are widely expressed in PDAC, representing a promising target for TRAIL-based therapies. Further, we demonstrated that a low expression of DcR1 and the absence of OPG in tumor cells, as well as a cellular-dense tumor stroma, could negatively impact the prognosis of PDAC patients.     

Pretreatment with paclitaxel enhances apo-2 ligand/tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis of prostate cancer cells by inducing death receptors 4 and 5 protein levels

We have demonstrated that Apo-2 ligand (Apo-2L)/tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis of human prostate cancer PC-3, DU145, and LNCaP cells in a dose-dependent manner, with PC-3 cells displaying the greatest sensitivity to Apo-2L/TRAIL. Susceptibility of the prostate cancer cell types to Apo-2L/TRAIL-induced apoptosis did not appear to correlate with the levels of the Apo-2L/TRAIL receptors death receptor (DR) 4 (TRAIL receptor 1) or DR5 (TRAIL receptor 2), decoy receptor (DcR) 1 and DcR2, Flame-1, or the inhibitors of apoptosis proteins family of proteins. Apo-2L/TRAIL-induced apoptosis of PC-3 cells was associated with the processing of caspase-8, caspase-10, and the proapoptotic Bid protein, resulting in the cytosolic accumulation of cytochrome c as well as the processing of procaspase-9 and procaspase-3. Cotreatment with the caspase-8 inhibitor z-IETD-fmk or DR4:Fc significantly inhibited Apo-2L/TRAIL-induced apoptosis. Treatment with paclitaxel or taxotere increased DR4 and/or DR5 protein levels (up to 8-fold) without affecting the protein levels of DcR1 and DcR2, Apo-2L/TRAIL, Fas, or Fas ligand. Up-regulation of DR4 and DR5 was not preceded by the induction of their mRNA levels but was inhibited by cotreatment with cycloheximide. Importantly, sequential treatment of PC-3, DU145, and LNCaP cells with paclitaxel followed by Apo-2L/TRAIL induced significantly more apoptosis than Apo-2L/TRAIL treatment alone (P < 0.01). This was also associated with greater processing of procaspase-8 and Bid, as well as greater cytosolic accumulation of cytochrome c and the processing of caspase-3. These findings indicate that up-regulation of DR4 and DR5 protein levels by treatment with paclitaxel enhances subsequent Apo-2L/TRAIL-induced apoptosis of human prostate cancer cells.     

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。     

Dual role of ERK2/NF-κB signaling in TRAIL sensitivity

Targeting tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling is a promising approach in cancer treatment. Although ERK and/or NF-κB signaling is involved in the expression of TRAIL receptors (TRAIL-R), the exact underlying mechanisms remain unknown. In this study, we evaluated the role of ERK2 and NF-κB in the cytotoxicity of TRAIL during cisplatin treatment. Cisplatin treatment of neuroepithelioma cells (SK-N-MC) significantly induced ERK2 activation and increased TRAIL cytotoxicity via the upregulation of death receptor 5 (DR5) expression. In partial ERK2 knockdown cell lines that maintained only basal levels of ERK2 activity, cisplatin treatment did not increase ERK2 activity or DR5 expression. These findings indicate that induced (rather than basal) ERK2 activity enhances TRAIL susceptibility via DR5 expression. In complete ERK2 knockdown cell lines with no basal ERK2 activity, DR4, DR5, and DcRs expression levels were increased, and additional treatment with cisplatin did not further increase TRAIL-R expression. Chemical inhibition of ERK2 also enhanced TRAIL cytotoxicity by upregulating DR4 and DR5 expression. These findings indicate that basal ERK2 activity suppresses TRAIL-R expression. Both basal and inducible ERK2 activities regulate TRAIL-R expression via the NF-κB signaling pathway. Overall, our findings suggest that the ERK2/NF-κB signaling pathway has a dual role in TRAIL susceptibility by differentially regulating TRAIL-R expression in the same cellular system.     

Recurrence-free survival in prostate cancer is related to increased stromal TRAIL expression

BACKGROUND:

TRAIL (tumor necrosis factor related apoptosis‐inducing ligand) is involved in tumor immune surveillance and, thus, may be a potential cancer therapy. TRAIL expression in the tumor microenvironment has been shown to impact cancer survival in multiple tumor types, including ovarian cancer. We studied TRAIL expression and outcomes in patients with prostate cancer.

METHODS:

A tissue microarray (TMA) of 200 prostate cancer patients and benign prostate tissue controls was used to assess the epithelial and stromal protein expression of TRAIL, death receptors (DR4 and DR5), decoy receptors (DcR1 and DcR2), and the FLICE inhibitory protein (FLIP_L). We correlated these expression patterns with clinicopathological parameters and determined its impact on recurrence‐free survival.

RESULTS:

Nearly all (99.5%) prostate cancer tissues examined displayed either decreased expression of pro‐apoptotic TRAIL receptors, increased FLIP_L expression, or both. We observed elevated death receptor, decoy receptor, FLIP_L, and epithelial TRAIL expression in prostate cancer epithelium. TRAIL expression in the stromal tumor microenvironment surrounding the prostate cancer was markedly lower. Elevated TRAIL expression in the tumor microenvironment was also significantly associated with increased recurrence‐free survival (P = .014), after controlling for other prognostic markers. In contrast, epithelial expression of TRAIL did not have an effect on overall survival.

CONCLUSIONS:

Expression of the components of the pro‐apoptotic TRAIL pathway is altered in prostate cancer. Moreover, TRAIL expression in the tumor microenvironment may affect recurrence‐free survival rate of prostate cancer patients. Consequently, these results may be useful in devising future therapeutic strategies targeting the TRAIL pathway in prostate cancer. Cancer 2011. © 2010 American Cancer Society.     

c-myc, c-erbB-2, and Ki-67 expression in normal breast tissue and in invasive and noninvasive breast carcinoma.

c-myc, c-erbB-2, and Ki-67 expression was examined by immunohistochemistry in 11 normal breast tissues and 42 invasive and 14 noninvasive breast carcinomas. The c-myc product was detected in all breast carcinoma specimens and in 7 of 11 normal breast tissues. Invasive tumors stained more frequently with the anti-myc monoclonal antibody than did noninvasive tumors, while the level of expression in normal breast tissue was much less than that in breast cancer. Membrane staining of the c-erbB-2 protein was demonstrated in 29% (4 of 14) of noninvasive ductal carcinomas and in 45% (19 of 42) of invasive breast carcinomas. None of the 11 normal breast tissue samples was positive. The mean value of Ki-67-positive cells was 0.91 +/- 0.31% for normal breast tissue, 4.57 +/- 1.36% for noninvasive ductal carcinoma, and 12.76 +/- 2.18% for invasive breast cancer. In 42 invasive breast carcinomas, the expression of c-myc, c-erbB-2, and Ki-67 proliferation marker were compared with lymph node status, estrogen receptor status, progesterone receptor status, and age of patients at diagnosis. c-erbB-2 overexpression and Ki-67 overexpression were identified as the only factors associated with lymph node status. We concluded that they might be additional prognostic factors for breast carcinoma.     

TRAIL及其受体DR4、DcR1在大肠癌及癌旁组织中的表达

 目的研究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、DcR1在大肠癌和癌旁组织中的表达及意义。方法采用免疫组化SP法检测42例大肠癌及其癌旁5cm组织、25例正常大肠粘膜组织中TRAIL及其受体DR4、DcR1表达水平。结果TRAIL及DR4在大肠癌、癌旁组织及正常大肠粘膜组织中的表达呈递增趋势,而DcR1的表达则与之相反(P<0.05);TRAIL和DR4在中、低分化癌中的表达明显低于高分化癌中的表达,而DcR1的表达则与之相反(P<0.01);TRAIL、DR4、DcR1的表达与肿瘤的病理类型、Duke′s分期及淋巴结转移与否等因素无关(P>0.05)。结论TRAIL、DR4、DcR1可能与大肠癌的发生、发展密切相关;DR4可能在TRAIL诱导的凋亡通路中发挥一定作用,而DcR1的表达与否一定程度上决定了TRAIL能否发挥其生物效应。