基于EB病毒的肿瘤靶向治疗策略

爱泼斯坦-巴尔病毒（EBV）相关肿瘤中存在EBV及其产物，为特异性杀伤肿瘤细胞提供了理想靶点。通过抑制EBV转化蛋白表达，靶向EBV复制启动元件，诱导EBV裂解感染以及EBV特异性免疫治疗等途径，为肿瘤治疗提供了新的以病毒为靶点的治疗策略。     

EBV相关恶性肿瘤的新病毒靶向性治疗研究进展

EB病毒(Epstein-Barr virus,EBV)被证明与多种人类恶性肿瘤相关,如鼻咽癌(nasopharyngeal carcinoma,NPC)、Burkitt淋巴瘤(Burkitt’s lymphoma,BL)、移植后淋巴组织增生症(post-transplant lymphoproliferative disease,PTLD)、霍奇金淋巴瘤(Hodgkin’s lymphoma,HL)、非霍奇金淋巴瘤(non-Hodgkin’s lymphomas,NHL)以及胃癌(gastric cancer,GC)等。在大部分EBV相关性恶性肿瘤中,几乎所有的癌细胞内都包含病毒基因组,这为人们提供了种以EBV基因组作为靶点,治疗EBV相关恶性肿瘤的潜在可能。本综述主要描述EBV相关恶性肿瘤的病毒新靶向治疗的新研究进展,并深入探讨了药物诱导病毒活化作为肿瘤治疗手段的可能性及其相关信号通路。     

EBV相关肿瘤的发生机制及其免疫靶向治疗的研究进展

作为WHO宣布的Ⅰ类致癌物EBV,其与移植后淋巴组织增生性疾病、霍奇金淋巴瘤（HL）、伯基特淋巴瘤、鼻咽癌、 EBV相关性胃癌等恶性肿瘤的发生相关,且具有作为预后预测指标及治疗靶点的潜能。目前,EBV免疫靶向治疗研究取得了众 多进展,基于EBV疫苗的主动免疫疗法和直接输注EBV-CTL的过继免疫疗法均可激活EBV特异性免疫应答并改善患者生存, PD-1/PD-L1抑制剂和IDO抑制剂联合可通过增强免疫应答、减少免疫逃逸而在EBV相关肿瘤中发挥抗肿瘤作用。此外,某些去 甲基化及去乙酰化药物可靶向作用于EBV阳性肿瘤细胞,诱导EBV病毒基因裂解。未来有望通过靶向治疗及免疫治疗的联合 应用为EBV相关肿瘤患者赢得更好的预后。     

血浆EB病毒DNA检测在鼻咽癌中的应用进展

EB病毒(Epstein-Barr virus,EBV)与鼻咽癌的发生、发展密切相关,采用PCR方法对鼻咽癌患者不同阶段的血浆EB病毒DNA (EBV DNA)进行定量检测可有效评估患者对治疗的反应,预测复发、转移的风险,治疗前的EBV DNA基线浓度与肿瘤负荷密切相关,而治疗后的EBV DNA含量与肿瘤复发转移关系更密切.EBV DNA定量检测有望成为一种新的肿瘤预后指标.本文就鼻咽癌患者不同时期的EBV DNA水平在诊断、分期、疗效评估和预后预测中的应用进行综述.     

鼻型结外自然杀伤-T细胞淋巴瘤研究进展

鼻型结外自然杀伤(NK)-T细胞淋巴瘤(NKTCL)起源于成熟NK细胞或NK样T细胞,常表达CD3ε和CD56,Epstein-Barr病毒(EBV)常阳性并在发病机制中起重要作用.已经建立了多种NKTCL的细胞株和动物模型并用于实验研究.NKTCL存在多种染色体畸变,最常见的是6q-,但无明显特异性.瘤细胞还存在多种基因表达异常及表观遗传学异常,为将来的靶向治疗提供了潜在的治疗靶点.     

EB病毒潜伏膜蛋白2重组腺腺病毒的构建及其免疫效果的研究

为了进一步研究以EB病毒潜伏膜蛋白2穴LMP2)为靶抗原制备EB病毒相关肿瘤的治疗性疫苗,利用AdEasy系统构建了EBV鄄LMP2的重组腺病毒。PCR鉴定结果证实病毒DNA中含有目的基因的特异性片段;RT鄄PCR证明了外源基因在真核细胞中得以转录;免疫酶和Westernblot的结果也显示LMP2蛋白在真核细胞得到表达。将扩增后的病毒感染Hela细胞测定病毒滴度为1.5×109pfu/ml。将重组病毒以灌胃、肌肉注射和滴鼻的方式感染小鼠,经免疫荧光检测其特异性抗体,LDH法检测特异性CTL的杀伤作用,结果发现三种给药途径均可诱发小鼠针对LMP2的特异性体液免疫和细胞免疫,而用Ad5作为对照组的小鼠则没有引起相应的免疫反应。该研究将有益于进一步探索抗肿瘤特异性主动免疫作用在阻止肿瘤的生长、扩散或复发中的作用。对诱导机体产生特异性抗瘤活性有重要意义。     

误诊为外周T细胞淋巴瘤的EB病毒相关淋巴组织增殖性疾病一例并文献复习

目的 探讨外周T细胞淋巴瘤(PTCL)及EB病毒相关淋巴组织增殖性疾病(EBV+-LPD)的临床鉴别及诊断.方法 报道1例误诊为PTCL的EBV+-LPD患者的诊疗过程.结果 该例患者误诊为PTCL,经过多次化疗仍出现发热,后诊断为EBV+-LPD,予依托伯苷(VP16)、激素及环孢素A(HLH-04)方案治疗,治疗后病情缓解且长期生存.结论 PTCL和EBV+-LPD临床表现多样,但缺乏特异性,病理表现复杂,早期诊断困难.初诊为PTCL,多次化疗效果欠佳,后诊断为EBV+-LPD的病例,为两类疾病的临床鉴别及诊断提供了参考.     

BRLF1-EBV的一种立即早期基因的研究进展

BRLF1是EBV的立即早期基因.作为一种反式激活因子,它可以调节EBV早期/晚期基因的表达,并且还可能参与裂解期病毒基因组的复制.它的表达与EBV潜伏周期向裂解周期的转换密切相关.BRLF1的蛋白产物Rta包含CTL识别的表位,可能在病毒裂解周期的早期成为免疫系统的作用位点.对它研究还可能为某些EBV相关肿瘤的筛查和治疗提供线索.     

EB病毒特异性细胞免疫反应

机体感染了EB病毒(EBV)后,血清中可测出各种抗EBV抗原的抗体(抗—MA,抗—VCA,抗—EA和抗—EBNA)。但这种特异性体液免疫反应对EBV的感染几乎没有防御作用,中和抗体的产生不足以抵御病毒的感染。随着免疫技术的发展,对EBV特异性细胞免疫反应的研究愈来愈深入,今天已经从细胞水平发展到了T细胞克隆和分子水平。     

EBV相关性胃癌中EB病毒基因表达研究进展

EB病毒（Epstein-Barr virus,EBV）是胃癌发生的生物学病因之一,EBV相关性胃癌（EBV associated gastric carcinoma,EB-VaGC）具有独特的临床病理学特征,其预后相对较好,因此EBV导致胃癌的机制研究也备受关注。近年来,随着分子生物学技术的发展,EBVaGC组织中EBV病毒基因表达的研究逐渐增多,为EBVaGC的诊断、治疗和预防提供了一定的理论依据。本文就EBVaGC组织中EBV病毒基因的表达进行综述。      

肺癌患者咽部、血液、癌组织EB病毒感染及其关系初探

目的:探讨肺癌患者咽部分泌物、血液及癌组织中EB病毒感染情况与肺癌的关系.方法:应用PCR技术和ELISA法对采自30例进展期肺癌患者的咽部分泌物、血液及新鲜肺癌组织标本进行EB病毒检测.结果:肺癌患者咽部分泌物EB病毒感染率低,差异无显著性(P＞0.05);血液EB病毒VCA-IgG抗体高于非癌胸疾病患者(P＜0.01);癌组织中EB病毒感染率为43.3%;不同病理类型肺癌EB病毒感染率差异无显著性;肺癌患者癌组织EB病毒感染率与血液EB病毒VCA-IgG抗体之间呈中度相关.结论:肺癌患者血液及癌组织中EB病毒感染存在增高现象,EB病毒长期感染与肺癌关系密切.     

胃癌组织幽门螺杆菌感染与EB病毒潜伏膜蛋白表达的相关性

目的：观察胃癌组织中幽门螺杆菌（H．pylori）感染和EB病毒潜伏膜蛋白（EBV—LMP）的同步表达情况，探讨两者在胃癌中的相互关系。方法：80例正常胃黏膜组织和97例胃癌组织，利用HE染色对所取标本进行组织病理学诊断，EBV—LMP测定采用免疫组化sP法，H．pylori感染判定采用HE，H．pylofi—DNA PCR和血清ELISA法测定IgG抗体三种方法。结果：正常胃黏膜组织未见EBV—IMP的表达，胃癌黏膜组织EBV—LMP表达阳性率为7．2％（7／97），胃癌组织EBV—LMP表达明显高于正常胃黏膜组织，差异有统计学意义（P〈0．05）。本组病例中H．pylofi感染的胃癌黏膜组织中EBV—LMP的阳性表达率为13．5％（7／52），无H．pylori感染的胃癌组织EBV—LMP的阳性表达率为0，H．pylori感染的胃癌组织EBV—LMP表达明显高于无H．pylofi感染的胃癌组织，差异有统计学意义（P〈0．05）。结论：正常胃黏膜组织无EBV—LMP的表达，胃癌组织中EBV—LMP表达明显高于正常胃黏膜组织，H．pylofi感染胃癌组织比无H．pylori感染胃癌组织EBV—LMP呈现高表达，H．pylofi感染和EB病毒感染在胃癌的发生和发展过程中可能具有更加深在的相互关系。     

Case–case comparison of smoking and alcohol risk associations with Epstein–Barr virus‐positive gastric cancer

Helicobacter pylori is the primary cause of gastric cancer. However, monoclonal Epstein–Barr virus (EBV) nucleic acid is also present in up to 10% of these tumors worldwide. EBV prevalence is increased with male sex, nonantral localization and surgically disrupted anatomy. To further examine associations between EBV and gastric cancer, we organized an international consortium of 11 studies with tumor EBV status assessed by in situ hybridization. We pooled individual‐level data on 2,648 gastric cancer patients, including 184 (7%) with EBV‐positive cancers; all studies had information on cigarette use (64% smokers) and nine had data on alcohol (57% drinkers). We compared patients with EBV‐positive and EBV‐negative tumors to evaluate smoking and alcohol interactions with EBV status. To account for within‐population clustering, multilevel logistic regression models were used to estimate interaction odds ratios (OR) adjusted for distributions of sex (72% male), age (mean 59 years), tumor histology (56% Lauren intestinal‐type), anatomic subsite (61% noncardia) and year of diagnosis (1983–2012). In unadjusted analyses, the OR of EBV positivity with smoking was 2.2 [95% confidence interval (CI) 1.6–3.2]. The OR was attenuated to 1.5 (95% CI 1.01–2.3) by adjustment for the possible confounders. There was no significant interaction of EBV status with alcohol drinking (crude OR 1.4; adjusted OR 1.0). Our data indicate the smoking association with gastric cancer is stronger for EBV‐positive than EBV‐negative tumors. Conversely, the null association with alcohol does not vary by EBV status. Distinct epidemiologic characteristics of EBV‐positive cancer further implicate the virus as a cofactor in gastric carcinogenesis.     

Characteristics of Epstein-Barr virus-associated gastric cancer: A study of 235 cases at a comprehensive cancer center in U.S.A

Background

Epstein-Barr virus (EBV) has been shown to be associated with gastric cancer. However, inconsistent findings have been reported regarding the distribution of EBV infected cells (in normal gastric epithelium vs. intestinal metaplastic cells vs. in neoplastic cells) and the characteristics of EBV-associated gastric cancer. Lymph node positive EBV-associated gastric cancer has not been systematically studied. The aims of this study were to evaluate EBV-associated gastric cancer, to assess the distribution of EBV infected cells including all positive lymph nodes, and to define the characteristics of EBV-associated gastric cancer.

Design

The study included primary gastric cancer patients who underwent surgical resection with no preoperative treatment at M.D. Anderson Cancer Center between 1987 and 2006. Formalin-fixed paraffin-embedded tissue from these resection specimens were assessed for EBV by in situ hybridization, the gold standard for EBV detection in tissue. EBV status was analyzed along with clinicopathologic parameters including age, gender, tumor type, lymph node status, and pathologic stage of the tumor.

Results

Among 235 patients, 12 had intranuclear expression of EBV. EBV staining was seen only in tumor cells and no detectable EBV was observed in normal gastric mucosa, intestinal metaplasia or stromal cells. Eight of 12 patients with EBV-associated gastric cancer had regional lymph node metastasis. Of note, metastatic tumor cells in all of the involved lymph nodes of these 8 cases contained EBV. The epidemiologic data showed 11 of the 12 patients with EBV-associated gastric cancer were men, ranging in age from 54 to 78 years (mean age, 60 years; median age, 62.1 years). The age distribution for non-EBV associated gastric cancer patients ranged from 21 to 93 years (mean age, 67 years; median age, 66.4 years).

Conclusion

Our study demonstrated that EBV is present exclusively in gastric cancer cells. The detection of EBV in tumor cells in all of the lymph nodes involved with metastatic gastric carcinoma suggests simultaneous replication of EBV and tumor cells. The predominantly male gender and relatively younger age observed for the EBV-infected gastric cancer cases suggest an association between this disease and other factors, such as life style.     

EBV感染、p53、Bcl-2、C-myc基因表达与肺癌关系研究

目的 研究肺癌组织中ＥＢＶ感染率以及ｐ５３、Ｂｃｌ－２和Ｃ－ｍｙｃ基因的表达,分析ＥＢＶ和ｐ５３、Ｂｃｌ－２、Ｃ－ｍｙｃ基因表达的关系。方法 检测４８例手术切除肺癌标本,１８例癌旁支气管粘膜组织,２例肺转移平滑肌肉瘤,１例结核瘤,１４例正常肺组织中ＥＢＶ ＤＮＡ及ｐ５３、Ｂｃｌ－２、Ｃ－ｍｙｃ基因表达。用ＰＣＲ法检测新鲜组织的ＥＢＶ ＤＮＡ,间接原位ＰＣＲ法观察ＥＢＶ阳性信号在细胞中的反应部位,免     

Elevated antibody titers to Epstein-Barr virus prior to the diagnosis of Epstein-Barr-virus-associated gastric adenocarcinoma

Epstein-Barr virus (EBV) has recently been identified in the tumor cells of patients with gastric carcinoma. We tested pre-morbid serum samples from a carefully monitored cohort of Japanese men in order to investigate the possibility that patients with EBV-associated gastric cancer represent a sub-set of individuals with long-standing difficulties in appropriately managing EBV infection. From a serum bank, we obtained 108 samples derived from 54 patients destined to develop gastric adenocarcinoma and 54 controls. Samples were tested under code for antibodies to EBV-capsid antigen, early antigen and nuclear antigen. Individuals who were positive for IgA antibodies against EBV viral-capsid antigen (VCA) and IgG antibodies against the R component of EBV early antigen were at a 3.9-fold and 1.9-fold excess risk of disease, respectively. Antibody titers to EBV VCA were significantly higher in those destined to get EBV-associated gastric cancer than those subsequently developing non-EBV-associated gastric cancer or age-and-gender-matched controls. These findings suggest that the inability to control EBV infection on a long-term basis exists many years prior to the development of EBV-associated gastric cancer, and that EBV may play an etiologic role in this sub-set of malignancies.     

Epstein‐Barr virus strain variation and cancer

Epstein‐Barr virus (EBV) is a human tumor virus and is etiologically linked to various malignancies. Certain EBV‐associated diseases, such as Burkitt lymphomas and nasopharyngeal carcinomas, are endemic and exhibit biased geographic distribution worldwide. Recent advances in deep sequencing technology enabled high‐throughput sequencing of the EBV genome from clinical samples. Rapid cloning and sequencing of cancer‐derived EBV genomes, followed by reconstitution of infectious virus, have also become possible. These developments have revealed that various EBV strains are differentially distributed throughout the world, and that the behavior of cancer‐derived EBV strains is different from that of the prototype EBV strain of non‐cancerous origin. In this review, we summarize recent progress and future perspectives regarding the association between EBV strain variation and cancer.     

Classification of Epstein-Barr virus-positive gastric cancers by definition of DNA methylation epigenotypes

Epstein-Barr virus (EBV) is associated with Burkitt lymphoma, nasopharyngeal carcinoma, opportunistic lymphomas in immunocompromised hosts, and a fraction of gastric cancers. Aberrant promoter methylation accompanies human gastric carcinogenesis, though the contribution of EBV to such somatic methylation changes has not been fully clarified. We analyzed promoter methylation in gastric cancer cases with Illumina's Infinium BeadArray and used hierarchical clustering analysis to classify gastric cancers into 3 subgroups: EBV(-)/low methylation, EBV(-)/high methylation, and EBV(+)/high methylation. The 3 epigenotypes were characterized by 3 groups of genes: genes methylated specifically in the EBV(+) tumors (e.g., CXXC4, TIMP2, and PLXND1), genes methylated both in EBV(+) and EBV(-)/high tumors (e.g., COL9A2, EYA1, and ZNF365), and genes methylated in all of the gastric cancers (e.g., AMPH, SORCS3, and AJAP1). Polycomb repressive complex (PRC) target genes in embryonic stem cells were significantly enriched among EBV(-)/high-methylation genes and commonly methylated gastric cancer genes (P = 2 × 10(-15) and 2 × 10(-34), respectively), but not among EBV(+) tumor-specific methylation genes (P = 0.2), suggesting a different cause for EBV(+)-associated de novo methylation. When recombinant EBV was introduced into the EBV(-)/low-methylation epigenotype gastric cancer cell, MKN7, 3 independently established subclones displayed increases in DNA methylation. The promoters targeted by methylation were mostly shared among the 3 subclones, and the new methylation changes caused gene repression. In summary, DNA methylation profiling classified gastric cancer into 3 epigenotypes, and EBV(+) gastric cancers showed distinct methylation patterns likely attributable to EBV infection.     

EB病毒与鼻咽癌相关性的研究进展

Epstein-Barr病毒（EBV）的潜伏感染与鼻咽癌（Nasopharyngeal carcinoma,NPC）密切相关,在感染人体后长期潜伏,可表达多种基因,其潜伏膜蛋白（LMP）编码基因、EB病毒核抗原（EBNA）基因及EBV编码的小RNA（EBER）可以通过不同的机制致鼻咽癌。本文就EBV与NPC的关系,与NPC相关的EBV的生物学特性和进展作一综述。