Epstein-Barr virus-encoded latent membrane protein 1 co-expresses with epidermal growth factor receptor in nasopharyngeal carcinoma.

Latent membrane protein 1 (LMP-1) is the only Epstein-Barr virus (EBV)-encoded oncogenic protein that has been detected in nasopharyngeal carcinoma (NPC), a cancer that is closely associated with EBV. Previous in-vitro studies have demonstrated that LMP-1 can upregulate epidermal growth factor receptor (EGFR) in epithelial cells. It was not established whether this cellular effect exists in NPC. To assess the association between LMP-1 and EGFR in NPC tissues, 60 NPC specimens were examined by immunohistochemistry using anti-LMP-1 antibody (CS 1-4) and anti-EGFR antibodies (EGFR 1, EGFR 1005). The results revealed that 41 (68.3%) specimens were immunopositive for LMP-1 and 44 (73.3%) specimens over-expressed EGFR. Morphologically, the expressions of LMP-1 and EGFR were homogeneously distributed in the tumor nests. In addition, the correlation between LMP-1 and EGFR was statistically significant (P<0.001, chi2 test, d.f. = 1). To elucidate further the correlation between LMP-1 and EGFR in vivo and in situ, an indirect dual immunofluorescence assay was conducted, using secondary antibodies conjugated with fluorescein isothiocyanate (FITC) or indocarbocyanine (Cy3). The results disclosed an intimate co-expression of LMP-1 and EGFR. In summary, the data indicate that over-expression of EGFR is a common phenomenon in NPC, and that EGFR is co-expressed with LMP-1 in NPC. Thus, EBV may play a role in the tumorigenesis of NPC through the effects of LMP-1 and EGFR.     

Prognostic impact of EBV-related LMP-1, histologic type, and environmental factors in nasopharyngeal carcinoma in a German population

INTRODUCTION: This retrospective study addressed the possible involvement of latent Epstein-Barr virus (EBV) infection, in particular LMP-1 expression, and further exogenous factors, i.e. tobacco, alcohol and occupational hazardous substances, in nasopharyngeal carcinoma (NPC) in a German population. PATIENTS AND METHODS: From 1980 to 2000, 44 patients suffering from histologically confirmed NPC were entered into the study. 33 specimens were available for immunostaining (IHC) to analyze LMP-1 expression. Information about environmental exposures were obtained employing a detailed standardized questionnaire. RESULTS: Outcome of patients with squamous cell NPC (SC-NPC) was significant worse than that of those with non-keratinizing NPC (NK-NPC). Age and tumor size correlated with response to therapy. The group with negative conventional LMP-1 staining showed better overall survival after 5 years compared to the group with positive or marginally positive LMP-1 detection (not significant). Nevertheless, after staining by tyramid-augmented IHC (TSA-IHC), nearly all specimens with negative LMP-1-staining in conventional IHC were found to be clearly positive. All patients with SC-NPC were smokers. The distribution of smokers and non-smokers in the group of NK-NPC was balanced. Comparable to the tobacco observation, there was also a correlation between high alcohol consumption and SC-NPC. CONCLUSION: Prognosis of NPC is mainly dependent on histologic type. Prognostic impact of LMP-1 is still unclear since LMP-1 was detected in all specimens using TSA-IHC. Therefore, TSA-IHC-LMP-1 detection might be interesting for diagnostic specification and development of new therapeutic strategies in NPC.     

鼻咽癌表皮生长因子受体研究现状

 近年来的许多研究表明表皮生长因子受体（EGFR）的表达与鼻咽癌的生物学行为及预后密切相关。鼻咽癌EGFR的表达与鼻咽癌的分期呈正相关，与近期疗效及远期预后呈负相关。在鼻咽癌的发展过程中，EGFR与环氧化酶-2（COX-2），潜伏膜蛋白1（LMP-1）相互协同而发挥作用。抗EGFR治疗有望提高疗效，改善预后。     

Induction of interleukin-8 by Epstein-Barr virus latent membrane protein-1 and its correlation to angiogenesis in nasopharyngeal carcinoma.

PURPOSE: The EBV latent membrane protein-1 (LMP-1) is a multifunctional protein. Recently, the contribution of LMP-1 to the metastasis of nasopharyngeal carcinoma (NPC) has been suggested. Angiogenesis is a key step for metastasis. Thus, the association of LMP-1 to neovascularization of NPC was examined in this study. EXPERIMENTAL DESIGN: The association of LMP-1 to angiogenesis in 39 patients with NPC was evaluated by immunohistochemical study, and then induction of angiogenic factors by LMP-1 was examined by ELISA and luciferase reporter assay. RESULTS: In an immunohistochemical study, the expression of LMP-1 was significantly correlated to microvessel counts (P = 0.0003), suggesting that LMP-1 may induce some angiogenic factors. Therefore, we studied the relationship between LMP-1 expression and interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) expression by immunohistochemical analysis. IL-8, VEGF, and bFGF expression were correlated to microvessel counts, but only IL-8 expression was significantly correlated to LMP-1 expression (P < 0.0001). Transfection with LMP-1 expression plasmid induced IL-8 protein expression in C33A cells. The expression of LMP-1 transactivated IL-8 promoter, as demonstrated by IL-8 promoter luciferase reporter assay. Mutation of the nuclear factor kappaB responsive element in the IL-8 promoter region completely abolished transactivation by LMP-1, whereas mutation of the activator protein responsive element did not affect promoter activity. CONCLUSION: These results suggested that LMP-1 induces expression of IL-8 through the nuclear factor kappaB binding site, which may contribute in part to angiogenesis in NPC.     

Detection of LMP-1 gene in middle ear effusion of NPC

Nasopharyngeal carcinoma (NPC) is closely related with Epstein-Barr virus (EBV). Almost every NPC tumor cells carries clonal EBV genomes. Detection of EBV derived latent membrane protein-1 gene (LMP-1) indicate the presence of NPC. Middle ear effusion (MEE) is a frequent sign of NPC. There have been no reports on LMP-1 in MEE. Tympanocentesis of 88 ears with MEE of 66 patients were done in three groups of patients, group (I) NPC, 31 patients, 50 ears, (II) other head and neck cancers, five patients, six ears and (III) no cancer history, 30 patients, 32 ears. The middle ear aspirate and nasopharyngeal swab specimen were collected to detect LMP-1 with a PCR-based method. Sixty aspirates (68%) out of 88 ears with MEE had enough DNA for PCR amplification. LMP-1 was detected in six middle ear aspirate specimen from three patients in group I who had petrous apex invasion. LMP-1 was detected in 30 swab specimen (93.8%) out of 32 nasopharyngeal swabs in group I. LMP-1 was not detected in middle ear aspirates or nasopharyngeal swab in group II and III patients. LMP-1 was not detected in MEE in patients without NPC. In NPC patients, the detection of LMP-1 may indicate petrous apex invasion.     

Presence of the latent membrane protein 1 gene in nasopharyngeal swabs from patients with mucosal recurrent nasopharyngeal carcinoma

BACKGROUND: Nasopharyngeal carcinoma (NPC) is the most common head and neck malignancy in southeastern China and Taiwan. Early detection of the local disease followed by timely and appropriate treatment is essential to increasing cure and survival rates. Detection of Epstein-Barr virus (EBV) genomic DNA, such as the latent membrane protein 1 gene (LMP-1), in patients postirradiation during follow-up may indicate mucosal recurrence. METHODS: Seventy-one patients with NPC underwent serial nasopharyngeal swabs for LMP-1 polymerase chain reaction assay before, during, and after irradiation. All of patients achieved a complete disease remission of the LMP-1 gene after irradiation that lasted for at least 6 months. RESULTS: The median LMP-1 disease remission time after the beginning of irradiation was 4.3 weeks. Patients with early LMP-1 disease remission ( 4 weeks) had 3-year local control rates of 93.5% and 76.9%, respectively (P = 0.0529). The LMP-1 gene was detected again (reexpression of LMP-1 [re-LMP-1]) in 10 patients after irradiation with at least 6 months of follow-up. Nine of 10 patients (90%) in the re-LMP-1 positive group and 2 of 61 patients (3.3%) in the re-LMP-1 negative group developed local recurrence. Mucosal recurrence developed in nine patients, and all displayed re-LMP-1. By detecting re-LMP-1 using nasopharyngeal swabs, mucosal recurrence was diagnosed with a sensitivity of 100% (9 of 9 patients) and a specificity of 98.4% (61 of 62 patients). The 3-year overall survival rate, the disease free survival rate for the entire group, and the estimated local mucosal control rates in the re-LMP-1 positive and re-LMP-1 negative groups were 86.5%, 76.5%, 19.4%, and 96.7%, respectively. CONCLUSIONS: Expression of EBV LMP-1 in nasopharyngeal swab specimens from patients with irradiated/treated NPC can provide a highly sensitive and specific method of forecasting mucosal recurrence. This investigation confirmed the reliability and feasibility of nasopharyngeal swabs in screening for mucosal recurrences in patients with NPC.     

Screening nasopharyngeal carcinoma by detection of the latent membrane protein 1 (LMP-1) gene with nasopharyngeal swabs

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a common head and neck cancer in Taiwan. The goals of the current study were to investigate whether a nasopharyngeal swab technique could provide enough DNA for polymerase chain reaction (PCR) analysis of the Epstein-Barr virus (EBV)-derived latent membrane protein 1 (LMP-1) gene and to determine the feasibility and reliability of diagnosing NPC by detection of LMP-1 in the nasopharynx. METHODS: 320 adults underwent nasopharyngoscopy and nasopharyngeal swab to obtain cells for the LMP-1 PCR assay; some patients also underwent nasopharyngeal biopsy. RESULTS: An amount of DNA that was sufficient for PCR was extracted from 96.3% of the swab samples. By detecting LMP-1 in nasopharyngeal swabs, NPC was diagnosed with a false positive rate of 12.7% (7 of 55 patients), a false negative rate of 1.6% (4 of 253 patients), sensitivity of 87.3% (48 of 55 patients), specificity of 98.4% (249 of 253 patients), a positive predictive value of 92.3% (48 of 52 patients), and a negative predictive value of 97.3% (249/256 patients). NPC was diagnosed by nasopharyngoscopy with a false positive rate of 38% (30 of 79 patients), a false negative rate of 0.4% (1 of 241 patients), sensitivity of 62% (49 of 79 patients), specificity of 99.6% (240 of 241 patients), a positive predictive value of 98% (49 of 50 patients), and a negative predictive value of 88.9% (240 of 270 patients). Only 7 (0.2%) of 256 patients with a diagnosis other than NPC had LMP-1 detected in the nasopharyngeal space. CONCLUSIONS: Detecting EBV genomic LMP-1 by nasopharyngeal swab diagnosed NPC with 87.3% sensitivity and 98.4% specificity. EBV genomic DNA usually is not detected by PCR-based methods in the nasopharyngeal space. Its incidence is estimated to be as low as 0.2% among the general population. The nasopharyngeal swab coupled with PCR-based EBV LMP-1 detection could serve as part of a screening program for high-risk populations.     

EBV LMP-1 negatively regulates expression and pro-apoptotic activity of Par-4 in nasopharyngeal carcinoma cells

Latent membrane protein-1 (LMP-1) of the Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC), and in this study we sought to determine whether the pro-apoptotic activity of prostate apoptosis response-4 (Par-4) is modulated by LMP-1 in NPC cells. We found that LMP-1 diminished the pro-apoptotic activity of Par-4 and negatively regulated Par-4 protein by de novo synthesis; moreover, although LMP-1 accelerated a Par-4 activator, PKA, we demonstrated that LMP-1 also activated the PI3 K/Akt pathway and increased Bcl-2 expression to suppress the activity of Par-4. Consequently, our results revealed a novel negative action of LMP-1 on the pro-apoptosis protein Par-4 by the coordination of multiple signaling pathways.     

Recombinant adeno-associated virus mediated RNA interference inhibits metastasis of nasopharyngeal cancer cells in vivo and in vitro by suppression of Epstein-Barr virus encoded LMP-1

Nasopharyngeal carcinoma (NPC) is a highly metastatic carcinoma characterized by consistent association with Epstein-Barr virus (EBV). Of the EBV-encoded product, latent membrane protein-1 (LMP-1) is considered to be an onco-protein playing an essential role in cell transformation and metastasis. In this study, we used a recombinant adeno-associated virus type 2 vector (rAAV-2) to deliver small hairpin RNA (shRNA) targeting EBV LMP-1 into the EBV-positive human NPC C666-1 cells and evaluated the effect of long-term suppression of LMP-1 on NPC growth and metastasis in vivo and in vitro. An NPC metastasis nude mouse model with NPC xenograft transplanted in liver was established. The NPC C666-1 cells infected with rAAV-shRNA-LMP-1 or rAAV-EGFP were inoculated in the livers of nude mice. Formation of liver and lung metastasis was evaluated at day 14 after tumor inoculation. Our results demonstrate that rAAV-shRNA-LMP-1 effectively infected C666-1 cells and suppressed LMP-1 expression. Such suppression, in turn, did not significantly inhibit tumor growth, but prevented NPC metastasis in the liver as well as in the lung. Consistent with in vivo data, the in vitro studies in NPC C666-1 cell cultures showed that suppression of LMP-1 by rAAV-shRNA-LMP-1 significantly reduced cell mobility and transmembrane invasion ability. These results demonstrated for the first time that long-term suppression of EBV-encoded LMP-1 in vivo is an effective means for preventing NPC metastasis.     

EB病毒与鼻咽癌发生发展关系的研究进展

目的:总结国内外对鼻咽癌(nasopharyngeal carcinoma,NPC)发生发展与EB病毒关系的研究现状。方法:以"鼻咽癌、EB病毒、遗传学和表观遗传学"为关键词,应用计算机检索Medline和清华同方期刊全文数据库2003-01~2008-03的文献176篇。纳入标准:1)NPC的流行病学和组织学类型与EB病毒的关系。2)遗传学与表观遗传学改变与EB病毒致瘤的关系。3)EB病毒基因与NPC发生和发展的机制。根据纳入标准,精选35篇全文文献,最后纳入分析19篇。结果:作为肿瘤相关疱疹病毒,EB病毒感染对NPC基因表达有明显影响。遗传学改变先于EB病毒感染发生,表观遗传学改变是NPC的重要特征。LMP-1等对NPC细胞周期、细胞结构和肿瘤细胞的免疫逃逸等的作用影响NPC发生和转移。结论:EB病毒与NPC发生以及转移机制密切相关,LMP-1等是重要的病毒癌基因。     

Identification of a novel variant of LMP-1 of EBV in patients with endemic Burkitt lymphoma in western Kenya

Background

Epstein Barr virus (EBV) is a gammaherpesvirus that is associated with nasopharyngeal carcinoma (NPC) and endemic Burkitt lymphoma (eBL). EBV carries several latent genes that contribute to oncogenesis including the latent membrane protein 1 (LMP-1), a known oncogene and constitutively active CD40 homolog. Variation in the C terminal region of LMP-1 has been linked to NPC pathogenesis, but little is known regarding LMP-1 variation and eBL.

Results

In the present study, peripheral blood samples were obtained from 38 eBL patients and 22 healthy controls in western Kenya, where the disease is endemic. The LMP-1 C-terminal region from these samples was sequenced and analyzed. The frequency of a 30 base pair deletion of LMP-1 previously linked to NPC was not associated with eBL compared to healthy controls. However a novel LMP-1 variant was identified, called K for Kenya and for the G318K mutation that characterizes it. The K variant LMP-1 was found in 40.5% of eBL sequences and 25.0% of healthy controls. All K variant sequences contained mutations in both of the previously described minimal T cell epitopes in the C terminal end of LMP-1. These mutations occurred in the anchor residue at the C-terminal binding groove of both epitopes, a pocket necessary for MHC loading.

Conclusions

Overall, our results suggest that there is a novel K variant of LMP-1 in Kenya that may be associated with eBL. Further studies are necessary to determine the functional implications of the LMP-1 variant on early events in eBL genesis.

     

鼻咽癌组织中热休克蛋白70表达与EB病毒感染的关系

目的:探讨热休克蛋白70(HSP70)表达与EB病毒潜在膜蛋白蛳1(LMP蛳1)的关系。方法:采用原位杂交和免疫组化技术对41例鼻咽癌(NPC)和24例癌旁组织进行检测。结果:NPC组织中HSP70阳性率为82.9 %(34/41),高于癌旁组织中HSP70的阳性率(54.2 %,P<0.05)。NPC组织中LMP蛳1阳性率为90.2 %(37/41)。37例LMP蛳1阳性的NPC中有33例(89.2 %)HSP70表达阳性,高于LMP蛳1阴性的NPC(25.0 %,P<0.01)。结论:HSP70的高表达可能涉及NPC的发生发展过程,LMP蛳1可以诱导NPC及癌旁组织HSP70的过表达。     

EB病毒潜伏膜蛋白LMP-1在鼻咽癌中的表达及临床意义

目的观察EB病毒（EBV）潜伏膜蛋白1（LMP-1）在鼻咽癌（NPC）鼻咽拭子中的表达,探讨LMP-1表达与NPC临床病理特征的关系。方法纳入2007年～2008年福建省肿瘤医院放疗科收治的经病理检查确诊为NPC且同意参加该试验的初治患者129例,均在治疗前应用鼻咽拭子法取鼻咽部黏膜脱落细胞,提取DNA,采用PCR法检测LMP-1基因的表达。结果 129例患者中有114例患者LMP-1呈阳性表达,另15例呈阴性表达,阳性率为88.37%（114/129）;对照组中无1例呈阳性表达。LMP-1阳性表达率有颈部淋巴结转移组明显高于无颈部淋巴结转移组。LMP-1表达与患者年龄、性别、临床分期、T分期及M分期无相关性。结论 PCR法检测鼻咽拭子中LMP-1的检出率高于免疫组化法,LMP-1表达与鼻咽癌患者颈部淋巴结转移密切相关,临床中可预测鼻咽癌患者的转移潜能,LMP-1可能做为抗肿瘤转移靶向治疗的潜在靶点。     

Molecular Screening for Epstein-Barr virus (EBV): Detection of Genomic EBNA-1, EBNA-2, LMP-1, LMP-2 Among Vietnamese Patients with Nasopharyngeal Brush Samples

Epstein-Bar virus (EBV) is considered to be intimately associated with development of nasopharyngeal carcinoma (NPC), the most common and high incidence cancer of the head and neck in Asian countries, especially in Vietnam. In this study, we validated associations between highly conserved segments of the EBV genome, including EBNA-1, EBNA-2, LMP-1, LMP-2 and nasopharyngeal cancer, with the aim of applications with non-invasive brush samples for early diagnosis and as a prognostic biomarker. The polymerase chain reaction (PCR) was performed to assess the presence of EBNA-1, EBNA-2, LMP-1, LMP-2 in nasopharyngeal brush samples from Vietnamese NPC patients and non-cancer controls. Positive rates for EBNA-1, EBNA-2, LMP-1, LMP-2 were 46.3%, 49.5% and 45.3%, and 47.4%, respectively, in cancer cases, much higher than the low frequencies found in non-cancer samples. Notably, at least one of the four (PI ≥ 0.25) was found in 57. 9%. Significance was reached when computing the odds ratio (OR) and relative risk (RR). Our detection of candidate genes. in nasopharyngeal brush samples collected from Vietnamese patients reduces the need for invasive biopsies and fulfills the characteristics of a non-invasive, specific screening method suitable for routine, NPC risk assessment for EBV-infected populations. Notably, this procedure may be useful for confirmatory screening with large oral brush swabs.     

Prognostic role of Ebstein-Barr virus latent membrane protein-1 and interleukin-10 expression in patients with nasopharyngeal carcinoma

PURPOSE: We aimed to investigate Ebstein-Barr virus (EBV) latent membrane protein-1 (LMP-1) and Interleukine-10 (IL-10) expression in nasopharyngeal carcinoma (NPC) patients and to evaluate their prognostic significance. MATERIAL AND METHODS: Between 1993 and 1999, 166 patients were treated with the diagnosis of nonmetastatic NPC at our department. The expression of LMP-1 and IL-10 was investigated by using an immunohistochemical approach in 74 (53 male, 21 female) patients whose paraffin embedded tissue samples were available. A detailed histopathological analysis including degree of apoptosis and lymphocyte infiltration was made and all patients were reclassified according to the World Health Organization (WHO) classification. Univariate, multivariate, and logistic regression analyses were performed using all clinical and pathological prognostic factors. All patients were treated with radiotherapy +/- chemotherapy. Follow-up ranged between 12 and 80 months (median: 32). RESULTS: The histopathological diagnosis was WHO-I in 1 (1.3%), WHO-II in 15 (20.2%), and WHO-III in 58 (79.5%) patients. There were 38 (51%) patients with IL-10 expression and 44 (61%) patients with LMP-1 expression. Twenty-seven (36.4%) patients were found to be both IL-10 and LMP-1 positive. There were significantly more N0 disease in patients without LMP-1 expression compared to LMP-1 positive patients (65% vs. 35%, p = 0.01). The logistic regression analysis showed advanced nodal involvement to be the major parameter affecting the expression of IL-10 (p = 0.03). Three-year overall survival (OS), locoregional relapse free survival (LRRFS), and distant metastasis free survival (DMFS) rates were 67.8%, 84.4%, and 74.3%, respectively, for the whole group. On univariate analysis, LRRFS was significantly lower in WHO-III patients, DMFS was significantly lower in advanced nodal disease and IL-10 negative patients, and OS was significantly lower in WHO-III patients. Multivariate analysis showed that WHO-III and T2 patients were significantly associated with lower OS and N3 patients were significantly associated with lower DMFS. CONCLUSION: We observed a high rate (61%) of EBV (LMP-1 positive) and NPC association in our patients. LMP-1 positive tumors were found to be more prone to invade lymph nodes. Patients with negative IL-10 expression had more advanced N disease. We did not find a prognostic significant role of IL-10 and EBV LMP-1 on survival in multivariate analysis.     

N2~3期鼻咽癌EGFR、VEGF、EBER表达与放化疗敏感性的关系

[目的]探讨N期鼻咽癌EGFR、VEGF、EBER表达与放化疗敏感性间的关系。[方法]采用免疫组织化学疗法研究143例经病理确诊的鼻咽癌患者组织EBER、EGFR和VEGF表达：定量PCR和酶联免疫吸附法（ELISA）检测92例N。期鼻咽癌患者血浆EB病毒游离DNA（EBV／DNA）、EGFR、VEGF的表达水平,并对92例NH期鼻咽癌随访2年。[结果]N期鼻咽癌EBER、EGFR及VEGF表达阳性牢分别为97．8％（90／92）、95．7％（88／92）和35．9％（33／92）。EBER表达与远处转移、复发及临床缓解相关,VEGF和EGFR表达强度与远处转移均呈正相关。期鼻嘲癌患者血浆EBV／DNA、EGFR、VEGF治疗前与同步放化疗后比较差异均有统计学意义（P均〈0．05）。血浆中EGFR和VEGF表达水平与远处转移相关。[结论]血浆和组织中EGFR和VEGF表达水平均可能与鼻咽癌远处转移相关。     

EB病毒感染及抗凋亡基因Bc1—2与鼻咽癌关系的研究

作者应用免疫组化ＳＰ法观察了４６例鼻咽癌组织中抗凋亡基因Ｂｃ１－２和ＥＢ病毒潜在膜蛋白（ＬＭＰ－１）的表达。结果显示ＬＭＰ－１的表达率为５２．２％，其中以低分化癌的阳性率较高（８２．６％）；Ｂｃ１－２蛋白在鼻咽癌中出现异常高表达（阳性率为８２．６％），Ｂｃ１－２的表达率与鼻咽癌组织学分级无显著性差异（Ｐ＞０．０５）；Ｂｃ１－２表达与ＬＭＰ－１的阳性率无明显相关（Ｐ＞０．０５）。表明Ｂｃ１－２异常表达和ＥＢ病毒感染均可能与鼻咽癌发生有关。     

Epstein-Barr Virus and Breast Cancer: Lack of Evidence for an Association in Iranian Women

Controversies regarding the role of Epstein-Barr virus (EBV) in breast cancer and lack of published literature in this regard in Iran, prompted us to assess EBV presence in 100 breast carcinoma and 42 control biopsies obtained from Iranian women. Breast carcinoma cases were comprised of 81 invasive ductal carcinoma NOS, 9 invasive lobular carcinoma, 1 apocrine carcinoma, 2 cribriform carcinoma, 2 papillary carcinoma and 5 mucinous carcinoma. Control biopsies consisted of 13 fibroadenoma, 9 benign epithelial proliferation (adenosis and sclerosing adenosis), 9 usual ductal hyperplasia, 4 atypical ductal hyperplasia, 4 non-proliferative fibrocystic changes and 3 normal breast tissue. To identify EBV-infected cells we applied immunohistochemical analysis, using monoclonal antibody against Epstein-Barr virus-encoded nuclear antigen 2 (EBNA-2) and latent membrane protein 1 (LMP-1). Further, polymerase chain reaction (PCR) was used to amplify EBV DNA, with primers that cover the EBV encoded RNA (EBER) and BamHIW regions. EBNA-2 and LMP-1 immunohistochemistry were negative in all breast cancer and control specimens. Using PCR, none of the 100 breast cancer samples or the 42 control specimens showed detectable EBV DNA. These results indicate that EBV may not play a significant role in the etiology of breast cancer in Iranian women.     

THE INTRACELLULAR FORM OF EPSTEIN-BARR VIRUS GENOME IN NASOPHARYNGEAL CARCINOMA

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