Hypermethylation of epithelial-cadherin gene promoter is associated with Epstein-Barr virus in nasopharyngeal carcinoma

Background: Epstein-Barr virus (EBV) is documented as the important etiologic agent of nasopharyngeal carcinoma (NPC) but the mechanism of development and pathogenesis induced by EBV is presently unclear. Hypermethylation of epithelial-cadherin (E-cadherin) promoter has been shown to be induced in NPC cell line by EBV LMP1 via DNA methyltransferase activation. EBV genomes and hypermethylation of E-cadherin promoter were investigated in NPC tissues to evaluate the role of EBV in the hypermethylation and pathogenesis of NPC. Methods: Methylation-specific polymerase chain reaction (MSP) was performed to detect E-cadherin promoter hypermethylation in paraffin embedded tissues from patients with NPC and normal nasopharyngeal tissues. EBV genomes were detected by PCR in the tissue samples. Results: Hypermethylation of E-cadherin promoter and EBV were predominantly detected in undifferentiated and non-keratinizing NPC compared to those in squamous cell NPC. Hypermethylation of E-cadherin was found in 28 of 38 (73.7%) patient samples. EBV was detected in 22 of the 28 (78.6%) NPC samples demonstrating E-cadherin hypermethylation. EBV genomes and hypermethylation were not detected in normal nasopharyngeal tissues. Significant association was found between E-cadherin hypermethylation and EBV genomes (p < 0.001; Fisher's exact test). Hypermethylation of E-cadherin was more frequently detected in advanced stages compared to those in early stages of NPC (p = 0.036; Fisher's exact test). Conclusions: The high incidence of EBV with the consistency of E-cadherin hypermethylation, particularly in undifferentiated and non-keratinizing NPC suggests the role of EBV in the hypermethylation. EBV exists at early stage of NPC that induces the hypermethylation and contributes to progression of the disease to the advanced stage of NPC.     

血浆 EB病毒游离 DNA检测对监测鼻咽癌患者预后的意义

背景与目的:有报道 , 测定血浆中的 EB病毒游离 DNA( EBV-DNA)的拷贝数可作为诊断及监测鼻咽癌患者病情变化的手段之一.本研究旨在评价血浆 EBV-DNA检测在鼻咽癌患者预后监测上的价值, 并进一步与 VCA/IgA、 EA/IgA进行比较.方法:比较鼻咽癌放疗后 30例远处转移患者、 22例局部复发患者、 24例无 瘤生存者血浆中 EBV-DNA、 VCA/IgA、 EA/IgA水平.分别应用荧光定量 PCR方法检测血浆 EBV-DNA水平,免疫酶法检测 VCA/IgA、 EA/IgA;前瞻性观察 20例初诊鼻咽癌患者放疗前、放疗剂量达 40 Gy时及放疗结束时上述指标的变化. 结果:放疗后各组不同预后患者的血浆 EBV-DNA含量的中位数有显著性差异, 远处转移组为 135 100 copies/ml(四分线区域 5 525～ 1 003 750 copies/ml) >局部复发组的 20 500(四分线区域 0～ 58 500 copies/ml) > 无瘤生存组的 0 copy/ml(四分线区域 0～ 0 copy/ml), P均 < 0.05. 远处转移组的血浆 EBV-DNA水平高者较多, 当阳性标准为 1 000 000 copies/ml时,诊断远处转移组的敏感性为 27.3%,而诊断局部复发组的敏感性为 0.0%,特异性均为 100.0%.在初诊患者放疗前、放疗剂量达 40 Gy时及放疗结束时, EBV-DNA水平逐渐降低,平均含量分别为 32 050 copies/ml(四分线区域 3 880～ 317 750 copies/ml)、 0 copy/ml(四分线区域 0～ 14 375 copies/ml)、 0 copy/ml(四分线区域 0～ 2 940 copies/ml), P均 < 0.05, 而 VCA/IgA、 EA/IgA的水平未见明显变化. 结论: 血浆 EBV-DNA检测可用于监测鼻咽癌患者预后,其价值明显优于 VCA/IgA、 EA/IgA.     

Significance of cell-free epstein-barr virus DNA in monitoring prognosis of nasopharyngeal carcinoma

Objective It has been reported that cell-free Epstein-Barr virus (EBV-DNA) in plasma was useful in diagnosing and monitoring nasopharyngeal carcinoma (NPC). The current study was designed to evaluate the significance of EBV-DNA in monitoring the prognosis of nasopharyngeal carcinoma and comparing its significance with that of plasma VCA/lgA and EA/lgA levels. Methods E8V -DNA, VCA/lgA, and EA/lgA levels in plasma were determined in NPC patients with different prognosis after radiotherapy, including 30 distant metastatic patients, 22 local recurrence patients and 24 individuals with remission who had been followed-up for more than 2 years after treatment. EBV-DNA was determined using a real-time quantitative PCR system, and levels of VCA/lgA and EA/lgA were measured using standard immunofluorescence. In a cohort study, the indexes were determined after different radiation periods for the 20 new cases of nasopharyngeal carcinoma. Results The median plasma EBV-DNA concentration was 135,100 copies/ ml (interquartile range: 5,525-1,003 750) in metastatic group, 20,500 copies/ ml (interquartile range: 0 -58,500) in the local recurrence group and 0 copies/ml (interquartile range: 0-0) in the continuous remission group (P< 0.05). The levels of VCA/lgA and EA/lgA showed no significant differences among the different groups. The high level of EBV-DNA concentration in the metastatic group was more than that in the local recurrence group. A level of 1,000,000 copies/ml of EBV DNA was an indication of distant metastasis of the NPC patients with a sensitivity of 27.3%. However, the sensitivity was 0 in the local recurrence group. For the 20 new patients, EBV -DNA concentration gradually decreased during the radiation period. Before radiation there were 32,050 copies/ml (interquartile range: 3,880-317,750), 0 copies/ml (interquartile range: 0-14 375) after a 40 Gy radiation dose and 0 copies/ml (interquartile range: 0-2940) after the radiation was finished (P< 0.05). However, the levels of VCA/lgA and EA/lgA showed no significant difference. Conclusion Determination of plasma cell -free EBV -DNA level is more valuable than evaluation of VCA/lgA and EA/lgA for monitoring the prognosis of NPC patients.     

Significance of Cell-Free Epstein-Barr Virus DNA in Monitoring Prognosis of Nasopharyngeal Carcinoma

Objective  It has been reported that cell-free Epstein-Barr virus (EBV-DNA) in plasma was useful in diagnosing and monitoring nasopharyngeal carcinoma (NPC). The current study was designed to evaluate the significance of EBV-DNA in monitoring the prognosis of nasopharyngeal carcinoma and comparing its significance with that of plasma VCA/lgA and EA/lgA levels. Methods  E8V -DNA, VCA/lgA, and EA/lgA levels in plasma were determined in NPC patients with different prognosis after radiotherapy, including 30 distant metastatic patients, 22 local recurrence patients and 24 individuals with remission who had been followed-up for more than 2 years after treatment. EBV-DNA was determined using a real-time quantitative PCR system, and levels of VCA/lgA and EA/lgA were measured using standard immunofluorescence. In a cohort study, the indexes were determined after different radiation periods for the 20 new cases of nasopharyngeal carcinoma. Results  The median plasma EBV-DNA concentration was 135,100 copies/ ml (interquartile range: 5,525-1,003 750) in metastatic group, 20,500 copies/ ml (interquartile range: 0 -58,500) in the local recurrence group and 0 copies/ml (interquartile range: 0-0) in the continuous remission group (P< 0.05). The levels of VCA/lgA and EA/lgA showed no significant differences among the different groups. The high level of EBV-DNA concentration in the metastatic group was more than that in the local recurrence group. A level of 1,000,000 copies/ml of EBV DNA was an indication of distant metastasis of the NPC patients with a sensitivity of 27.3%. However, the sensitivity was 0 in the local recurrence group. For the 20 new patients, EBV -DNA concentration gradually decreased during the radiation period. Before radiation there were 32,050 copies/ml (interquartile range: 3,880-317,750), 0 copies/ml (interquartile range: 0-14 375) after a 40 Gy radiation dose and 0 copies/ml (interquartile range: 0-2940) after the radiation was finished (P< 0.05). However, the levels of VCA/lgA and EA/lgA showed no significant difference. Conclusion  Determination of plasma cell -free EBV -DNA level is more valuable than evaluation of VCA/lgA and EA/lgA for monitoring the prognosis of NPC patients.     

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.     

鼻咽癌中EB病毒LMP1基因N端Xho I酶切位点的丢失

背景与目的：众所周知,EB病毒LMP1基因在鼻咽癌变过程起着一定的作用。本研究通过检测广东地区鼻咽癌组织EB病毒LMP1基因N-末端区Xho I酶切位点的丢失,探讨LMP1基因变异在鼻咽癌发生发展中的作用。方法：收集中山大学肿瘤防治中心鼻咽癌患者鼻咽新鲜活检标本63例。收集EB病毒健康携带者外周血单个核细胞(PBMCs)10例作为对照。采用QIAamp DNA Mini Kit和QIAamp DNA Blood Mini Kit分别抽取组织和外周血单个核细胞的DNA,应用巢式PCR扩增EB病毒LMP1基因的N-末端区,并用Xho I对扩增产物进行酶切。采用四色荧光末端终止法对扩增产物进行序列分析。结果：10例健康携带者外周血单个核细胞的EB病毒LMP1基因N-末端区均未见Xho I酶切位点的丢失。63例鼻咽癌组织中有50例(79．37％)出现Xho I酶切位点的丢失(Xho I—loss),还有4例(6．34％,)为Xho I酶切位点部分丢失,只有9例(14．29％)未见Xho I酶切位点的丢失(wt-Xho I)。除了Xho I酶切位点的丢失(nt：169423～169428;GAGCTC→GA□TCTC)外,还发现四个错义点突变。结论：本研究所检测的广东地区EB病毒健康携带者外周血单个核细胞所携带的：EB病毒LMP1基因为wt—Xho I,而在鼻咽癌组织中主要为Xho I-loss。因此,我们认为EB病毒LMP1基因N-末端区Xho I酶切位点的丢失和其他的错义点突变可能是在鼻咽癌的发生发展过程中产生的。     

Salivary Epstein-Barr virus DNA level in patients with nasopharyngeal carcinoma following radiotherapy

Nasopharyngeal carcinoma (NPC) is a solid tumor closely associated with Epstein-Barr virus (EBV) infection. The purpose of this investigation was to detect and quantify the EBV DNA level in salivary samples of NPC patients following treatment using real-time PCR. A total of 175 consecutive newly diagnosed NPC patients’ whole saliva samples were collected before treatment, and the EBV DNA level was measured by real-time PCR, with the primers and probe targeting the BamHI-W region of the EBV genome. The post-treatment salivary EBV DNA level was also assessed in 46 patients. The change of EBV DNA level before and after treatment and relationship of EBV DNA level to demographic data and tumor staging were tested by Wilcoxon signed-rank test and Mann–Whitney U test, respectively with the level of significance set at 0.05. The EBV detection rate of pre-treatment saliva samples was 80%. The EBV DNA level of post-treatment saliva samples was significantly higher than the pre-treatment ones (P < 0.01). There is a trend that patients with advanced-stage showed a higher EBV DNA level than patients with early-stage. The detection of EBV DNA in saliva using real-time PCR might be a feasible and non-invasive method for early diagnosis of NPC.     

定量和定位检测EB病毒在鼻咽癌组织中的感染状态

背景与目的EB病毒(Epstein-Barrvirus,EBV)与鼻咽癌密切相关,但EBV是鼻咽癌的致瘤因素还是仅仅是伴随关系有待进一步研究,而且EBV在鼻咽癌发生过程中的潜伏状态也不明确,本研究通过检测EBV在不同鼻咽组织中的表达变化,为进一步阐明EBV与鼻咽癌发生的关系提供线索。方法应用荧光定量PCR(real-timePCR)技术定量检测47例鼻咽低分化鳞癌患者癌、癌旁及相对正常鼻咽粘膜组织中的平均EBV拷贝数;并采用原位杂交技术(地高辛标记的EBER-1探针)对鼻咽癌、癌旁、对侧正常鼻咽粘膜中的EBV进行定位检测。以10例正常人鼻咽粘膜组织作对照。结果正常人鼻咽粘膜EBV检出率为80%(8/10),平均拷贝数为6.7×102/滋gDNA;100%(47/47)鼻咽癌和癌旁组织以及72.3%(34/47)的对侧正常鼻咽粘膜组织检出EBV,平均拷贝数分别为6.9×105/滋gDNA、1.5×105/滋gDNA、9.8×103/滋gDNA。正常人鼻咽粘膜、鼻咽癌患者对侧正常鼻咽粘膜之间感染EBV的几率、潜伏感染EBV的数量没有显著性差异(P>0.05);鼻咽癌及其癌旁、对侧正常粘膜组织三者之间,鼻咽癌与癌旁组织之间,癌旁和对侧正常粘膜组织之间EBV拷贝数存在显著性差异(P<0.01)。EBER-1原位分子杂交发现,对侧正常粘膜上皮细胞未检测到EBER-1的表达信号,癌旁靠近癌一侧的部分不典型增生细胞检测到EBER-1弱阳性信号,而在癌组织中的所有癌细胞均有EBER-1强阳性信号。结论无论是鼻咽癌患者还是健康人,EBV在鼻咽组织中的潜伏感染是一种普遍现象,但从鼻咽癌患者对侧正常鼻咽粘膜到癌旁再到癌组织EBV感染的量发生了改变,说明鼻咽上皮细胞中EBV感染量和表达信号的改变很可能是EBV致鼻咽癌的重要环节。     

Long-term prognostic effects of plasma epstein-barr virus DNA by minor groove binder-probe real-time quantitative PCR on nasopharyngeal carcinoma patients receiving concurrent chemoradiotherapy

PURPOSE: To evaluate the long-term prognostic impact of plasma Epstein-Barr virus (EBV) DNA concentration measured by real-time quantitative polymerase chain reaction (RTQ-PCR) in nasopharyngeal carcinoma (NPC) patients receiving concurrent chemoradiotherapy (CCRT). METHODS AND MATERIALS: Epstein-Barr virus DNA was retrospectively measured from stock plasma of 152 biopsy-proven NPC patients with Stage II-IV (M0) disease with a RTQ-PCR using the minor groove binder-probe. All patients received CCRT with a median follow-up of 78 months. We divided patients into three subgroups: (1) low pretreatment EBV DNA (<1,500 copies/mL) and undetectable posttreatment EBV DNA (pre-L/post-U), (2) high pretreatment EBV DNA (> or =1,500 copies/mL) and undetectable posttreatment EBV DNA (pre-H/post-U), and (3) low or high pretreatment EBV DNA and detectable posttreatment EBV DNA (pre-L or H/post-D) for prognostic analyses. RESULTS: Epstein-Barr virus DNA (median concentration, 573 copies/mL; interquartile range, 197-3,074) was detected in the pretreatment plasma of 94.1% (143/152) of patients. After treatment, plasma EBV DNA decreased or remained 0 for all patients and was detectable in 31 patients (20.4%) with a median concentration 0 copy/mL (interquartile range, 0-0). The 5-year overall survival rates of the pre-L/post-U, pre-H/post-U, and pre-L or H/post-D subgroups were 87.2%, 71.0%, and 38.7%, respectively (p < 0.0001). The relapse-free survival showed similar results with corresponding rates of 85.6%, 75.9%, and 26.9%, respectively (p < 0.0001). Multivariate Cox analysis confirmed the superior effects of plasma EBV DNA compared to other clinical parameters in prognosis prediction. CONCLUSION: Plasma EBV DNA is the most valuable prognostic factor for NPC. More chemotherapy should be considered for patients with persistently detectable EBV DNA after CCRT.     

EB病毒基因BARF1在鼻咽癌细胞中的表达及意义

目的：探讨EB(Epstein—Barr)病毒新基因BARF1(BamHI A rightward open reading frame1)在人鼻咽癌组织中的表达及意义，为深入阐明EB病毒致癌机制提供实验依据。方法：提取RNA后，采用RT—PCR方法扩增标本中的EBNA1(EB virus associated nuclear antigen 1)和BARF1 mRNA，PCR产物经2％琼脂糖凝胶电泳观察并照相。结果：11例RNA合格的标本均表达EBNA1，提示病例均为EB病毒阳性病例；其中9例表达BARF1，占82％：而且9例中的7例为强阳性。结论：EB病毒新基因BARF1 mRNA在鼻咽癌细胞中高表达，这提示除了已经明确的潜伏性膜蛋白1(LMP1)以外，BARF1可能在鼻咽癌细胞恶性增殖中发挥重要作用，具体机制有待深入研究。     

Systematic review on Epstein-Barr virus (EBV) DNA in diagnosis of nasopharyngeal carcinoma in Asian populations

Objective: To conduct a meta-analysis to investigate the value of EBV DNA in diagnosis of nasopharyngealcancer (NPC) in Asian populations, and provide important evidence for screening. Methods: Prospective orrespective case-control or cohort studies regarding the detection role of EBV DNA for NPC were included inour study. We conducted a comprehensive literature search in PubMed, EMBASE, and the Chinese BiomedicalDatabase (CBM database between January 1980 and March 2012. Results: A total of 18 studies with 1492 NPCcases and 2641 health controls were included. Almost of the included studies were conducted in China, andonly one other conducted in Thailand. The overall results demonstrated that the pooled sensitivity, specificity,positive likelihood (+LR) and negative likelihood (-LR) were 0.73 (0.71-0.75), 0.89 (0.88-0.90), 8.84 (5.65-13.84)and 0.19(0.11-0.32), respectively. The overall EBV DNA detection showed the largest area of 0.932 under thesummary receiver operator curve (SROC). The accuracy of detection by plasma for NPC (0.86) was higherthan in serum (0.81), with largest areas under the SROC of 0.97 and 0.91, respectively. Conclusion: Our resultsdemonstrated the EBV DNA detection in plasma or serum has high sensitivity and specificity in diagnosis ofNPC, especially in Chinese populations with a high risk of cancer.     

非小细胞肺癌INK4a和ARF基因甲基化与其蛋白共表达关系的探讨

目的:分析INK4a和ARF基因启动子甲基化与其蛋白共表达之间的关系.方法:选择前期实验中p14ARF和p16INK4a蛋白共表达阴性的非小细胞肺癌(NSCLC)患者35例,共表达阳性的NSCLC患者20例作为研究对象,分别称为(p14 p16)阴性组和(p14 p16)阳性组.运用甲基化特异性PCR(MSP)方法对两组患者癌组织INK4a和ARF基因启动子的甲基化状态进行检测.结果:(p14 p16)阴性组有18例发生INK4a基因甲基化,(p14 p16)阳性组有2例发生INK4a基因甲基化,两组差异有显著意义(P＜0.01).(p14 p16)阴性组有8例发生ARF基因启动子甲基化,(p14 p16)阳性组有2例发生ARF基因启动子甲基化,两组差异无显著意义(P＞0.05).INK4a和ARF基因异常申基化相互之间无显著相关性(P＞0.05).结论:NSCLC患者肺癌组织INK4a基因甲基化是导致p16INK4a蛋白表达阴性的重要机制;INK4a和ARF基因甲基化可能是相对独立的事件.     

鼻咽癌前期病变中的EB病毒感染

背景与目的：鼻咽癌中的浸润性癌细胞均感染了EB病毒（Epstein-Barr virus．EBV）。前期病变可见于早期鼻咽癌癌旁上皮。本研究旨在通过检测前期病变中的EB病毒,探讨EB病毒感染存鼻咽癌变过程中的作用,及其基因型在鼻咽癌变过程中发生的宿主内演变。方法：采用核酸原位杂交检测15例早期鼻咽癌活检组织中的EB病毒编码RNA（EBV—encoded RNA,EBER）。采用巢式PCR法检测前期病变和癌巢中的EB病毒类型和潜伏膜蛋白1（latent membrane protein 1,LMPI）EB病毒株。具有代表性的LMPI基因羧基末端PCR产物采用四色荧光终止序列技术进行DNA序列分析。结果：所有15例早期鼻咽癌中的绝大多数浸润性癌细胞均呈EBER阳性。在15例的期病变中．14例可检测到EBER阳性的异常上皮细胞和／或浸润性淋巴细胞。单个A型EB病毒可在9例癌巢（11例适用）及9例前期病变（10例通用）的DNA样本中检测到。EB病毒LMP1基因羧基末端在15例癌巢DNA样本中均可检测到,其中14例是30bp缺失型LMP1 EB病毒株,1例是野生型和30bp缺失型LMP1株的混合感染。在11例适合做EB病毒LMP1基因羧基末端扩增的前期病变的DNA样本中,5例呈野生型和30bp缺失型LMP1 EB病毒株的混合感染,4例是单个缺大型LMP1 EB病毒株感染,1例呈单个野生型LMP1 EB病毒株感染,1例呈阴性反应。野生型LMP1基因羧基末端的DNA序列与B95—8细胞的DNA序列完全一致;30bp缺大型LMP1基因羧基末端的DNA序列却其有30bp缺失（密码子：346～355）和4个错义点突变（密码子：334、335、338和366）。结论：鼻咽上皮细胞的EB病毒感染是癌变过程中侵袭前的事件;而在鼻咽癌变过程中,EB病毒基因型会产生宿主内的演变。     

The time frame of Epstein-Barr virus latent membrane protein-1 gene to disappear in nasopharyngeal swabs after initiation of primary radiotherapy is an independently significant prognostic factor predicting local control for patients with nasopharyngeal carcinoma

PURPOSE: The presence of Epstein-Barr virus latent membrane protein-1 (LMP-1) gene in nasopharyngeal swabs indicates the presence of nasopharyngeal carcinoma (NPC) mucosal tumor cells. This study was undertaken to investigate whether the time taken for LMP-1 to disappear after initiation of primary radiotherapy (RT) was inversely associated with NPC local control. METHODS AND MATERIALS: During July 1999 and October 2002, there were 127 nondisseminated NPC patients receiving serial examinations of nasopharyngeal swabbing with detection of LMP-1 during the RT course. The time for LMP-1 regression was defined as the number of days after initiation of RT for LMP-1 results to turn negative. The primary outcome was local control, which was represented by freedom from local recurrence. RESULTS: The time for LMP-1 regression showed a statistically significant influence on NPC local control both univariately (p < 0.0001) and multivariately (p = 0.004). In multivariate analysis, the administration of chemotherapy conferred a significantly more favorable local control (p = 0.03). Advanced T status (> or = T2b), overall treatment time of external photon radiotherapy longer than 55 days, and older age showed trends toward being poor prognosticators. The time for LMP-1 regression was very heterogeneous. According to the quartiles of the time for LMP-1 regression, we defined the pattern of LMP-1 regression as late regression if it required 40 days or more. Kaplan-Meier plots indicated that the patients with late regression had a significantly worse local control than those with intermediate or early regression (p = 0.0129). CONCLUSION: Among the potential prognostic factors examined in this study, the time for LMP-1 regression was the most independently significant factor that was inversely associated with NPC local control.     

EB病毒相关胃癌组织中病毒基因的表达

背景与目的：EB病毒(Epstein—Barr virus,EBV)与多种恶性肿瘤的发生有关,在鼻咽癌及淋巴瘤等组织中EBV的存在形式和表达已有报道,研究表明不同肿瘤组织中EBV的存在形式和表达不同,在胃癌组织中EBV某些基因尤其是裂解性基因的表达情况报道较少。为明确胃癌组织中EBV潜伏性基因和裂解性基因的表达情况,本研究从mRNA水平检测胃癌组织中EBV潜伏感染和裂解感染相关基因的表达,从分子水平探讨EBV编码基因与胃癌发生发展的关系。方法：应用PCR—Southern杂交检测185例胃癌及其相应癌旁组织中特异性EBVDNA片段,进一步用原位杂交(ISH)技术检测PCR阳性标本EBV编码小RNA1(EBERl)的表达,癌细胞EBERl阳性者确定为EBV相关胃癌(EBV—associated gastric carcinoma,EBVaGC)。采用RT-PCR和Southern杂交技术检测EBVaGCs组织中EBV核抗原(EBNAs)基因转录启动子(Qp、Cp和Wp)、潜伏性基因(EBNA1、EBNA2基因,潜伏膜蛋白LMP1、LMP2A和LMP2B基因)和裂解性基因(即刻早期基因BZLF1和BRLF1,早期基因BARF1和BHRF1,晚期基因BcLF1和BLLF1)的表达。结果：185例胃癌标本EBV阳性率为7．03％(13／185),癌旁组织均为阴性。13例EBVaGCs组织中均检测到启动子Qp mRNA,而Wp和Cp mRNA则为阴性。潜伏性基因中EBNA1 mRNA均阳性(13／13),而EBNA2、LMP1和LMP2B均未见表达,5例标本(5／13)检测到LMP2A mRNA。裂解性基因中BcLF1有7例(7／13)表达阳性,2例(2／13)BHRF1表达阳性,6例标本(6／13)检测到BZLF1 mRNA,BARF1亦有6例(6／13)表达阳性,而BRLF1和BLLF1mRNA均为阴性。结论：EBVaGC中EBV潜伏类型为Ⅰ型或介于Ⅰ和Ⅱ型之间的独特类型;EBVaGC组织中部分裂解性基因表达阳性,部分胃癌存在BARF1和BHRF1表达,其在胃癌中所起的作用有待进一步研究。     

早期发现和筛选鼻咽癌的EB病毒血清学检测

鼻咽癌是中国人,特别是中国南方人的一种常见癌症;世界上除其他少数族群具有中等程度的发病率以外,它是一种罕见的癌症。鼻咽癌多见于男性,男女发病率之比约为3∶1,且好发于中年人。现今已有令人信服的证据,支持EB病毒(国际癌症研究协会归属为第一类人体肿瘤病毒)是鼻咽癌的致病因子,肯定参与鼻咽癌的多阶段、多因素发生过程。本文简要地复阅了EB病毒在鼻咽癌发病机理中的作用,重点地介绍了EB病毒抗体和EB病毒DNA作为鼻咽癌标志的主要应用;根据由鼻咽癌导致的EB病毒抗体反应的现代知识,并考虑到目前可采用的检测技术,提出了促进有效地早期发现鼻咽癌的血清学筛选策略。     

肺腺癌HOXA10基因启动子甲基化的改变及其临床意义

目的 探讨肺腺癌HOXA10基因启动子区甲基化改变情况及其与临床病理特征和预后的关系。方法 采用甲基化特异性聚合酶链反应（MSP）法检测30例肺腺癌标本及其配对癌旁组织标本中HOXA10基因启动子甲基化状态,并分析HOXA10基因甲基化状态与临床病理特征和预后的关系。结果 MSP法检出17例（56.7％）肺腺癌组织HOXA10基因启动子区发生低甲基化改变,其中4例为完全去甲基化改变;而癌旁组织仅有6例（20.0％）HOXA10基因启动子区发生低甲基化改变（P＜0.05）。HOXA10低甲基化与肿瘤大小、临床分期及淋巴转移有关（P＜0.05）,而与性别、年龄、肿瘤分化程度无关（P＞0.05）。生存分析显示,HOXA10基因低甲基化患者的中位无病生存期为27.0个月,明显低于HOXA10基因甲基化患者的46.0个月（P=0.002）。结论 肺腺癌HOXA10基因启动子区低甲基化为频发事件,提示与患者的不良预后有关,可作为判断肺腺癌预后的指标。     

血浆EB病毒DNA浓度预测鼻咽癌远处转移的研究

背景与目的：鼻咽癌治疗失败的主要原因之一是远处转移,近年多项放化疗综合治疗的临床研究未显示出明显的远处转移率的降低和远期生存的获益,综合治疗适宜个体及最佳模式尚未确立。血浆EB病毒DNA（EBV DNA）浓度是一项能反映鼻咽癌分期、治疗反应、预后的灵敏、特异的分子生物学指标。我们设计此前瞻性研究。探讨通过鼻咽癌患者血浆EBV DNA浓度预测远处转移的发生．为个体化的综合治疗模式的选择提供分子学指标。方法：69例初治鼻咽癌患者分别在治疗前和治疗结束时采用荧光定量PCR方法检测血浆EBV DNA浓度。所有患者按计划随访。进行远期疗效及生存的评价。Kaplan-Meier法计算无转移生存率及总生存率,多因素分析用Cox回归模型。结果：远处转移患者治疗前血浆EBV DNA中位浓度（27 000copies／m1）及治疗后EBVDNA检出率（55．56％）均高于持续缓解者（4 000 copies／ml,5．56％）及局部复发者（3 850 copies／ml,0％）（P值分别为0．039,0．001）。以治疗前20 000 copies／ml、治疗后0 copies／ml为界值点．EBV DNA低浓度患者的无复发生存率、无转移生存率及总生存率均高于高浓度患者,差异有显著性。Cox回归分析显示治疗前EBV DNA浓度（P=0．050,RR=3．95）、治疗后EBVDNA浓度（P=0．001,RR=11．74）均是影响无转移生存的危险因素。进一步将患者治疗前后EBVDNA浓度变化综合进行生存分析,结果表明治疗后EBV DNA浓度能否降到0是影响无转移生存最重要的预后因素（P=0．000）。结论：鼻咽癌患者治疗前、后血浆EBV DNA浓度,尤其是治疗后能否降到0．能预测远处转移的发生,有望为放化综合治疗筛选高危患者,指导放化结合模式的选择。