Epstein-Barr virus-associated carcinomas: facts and fiction

Molecular characterization of plasma virome of hepatocellular carcinoma (HCC) patients

Hepatocellular carcinoma (HCC) stands as the most common cancer type, arising from various causes, and responsible for a substantial number of cancer-related fatalities. Recent advancements in viral metagenomics have empowered scientists to delve into the intricate diversity of the virosphere, viral evolution, interactions between viruses and their hosts, and the identification of viral causes behind disease outbreaks, the development of specific symptoms, and their potential role in altering the host's physiology. The present study had the objective of "Molecular Characterization of HBV, HCV, anelloviruses, CMV, SENV-D, SENV-H, HEV, and HPV viruses among individuals suffering from HCC." A total of 381 HCC patients contributed 10 cc of blood each for this study. The research encompassed the assessment of tumor markers, followed by molecular characterization of HBV, HCV, Anelloviruses (TTV, TTMV, and TTMDV), SENV-H and SENV-D viruses, HEV, CMV, and HPV, as well as histopathological examinations. The outcomes of this study revealed that majority of the HCC patients 72.4% (276/381) were male as compared to females. HCV infection, at 76.4% (291 out of 381), exhibited a significant association (p < 0.05) with HCC. Most patients displayed singular lesions in the liver, with Child Pugh Score Type B being the predominant finding in 45.2% of cases. Plasma virome analysis indicated the prevalence of TTMDV (75%), followed by TTMV (70%) and TTV (42.1%) among anelloviruses in HCC patients. Similarly, SENV-H (52%) was followed by SENV-D (20%), with co-infections at 15%. The presence of CMV and HEV among the HCC patients was recorded 5% each however 3.5% of the patients showed the presence of HPV. In conclusion, this study underscores that HCC patients serve as reservoirs for various pathogenic and non-pathogenic viruses, potentially contributing to the development, progression, and severity of the disease.

Smokeless Tobacco Use, Cigarette Smoking, and Upper Aerodigestive Tract Cancers: A Case-Control Study in the Batna Region, Algeria, 2008-2011

BACKGROUND

A significant proportion of the Algerian population uses tobacco products and is at risk of developing tobacco-associated cancers.

AIMS

This case-control study reports on the association between tobacco use and the occurrence of upper aerodigestive tract (UADT) cancers in Batna, Algeria.

METHODS

Incident primary UADT cancer cases in residents of Batna in 2008-2011 were identified using the regional tumor registry. One hospital and 1 population control were matched to each case by sex, year of birth, and residence. Information on tobacco use was collected, and odds ratios (ORs) were obtained using conditional logistic regression also after sex stratification.

RESULTS

The study included 192 cases (80%) of the 241 primary UADT cancer cases identified and 384 controls. Males represented 76.6% of cancer cases. Cancers of the nasopharynx (48%) and the larynx (26%) were the most common types. Ever use of smokeless tobacco (ST) (OR = 1.0; 95% confidence interval [CI]: 0.6-1.5) or current ST use (OR = 1.1; 95% CI: 0.6-1.7) was not associated with overall risk of UADT cancers. Associations with cancers of the nasopharynx (OR = 1.5; 95% CI: 0.5-4.6) and oral cavity/oropharynx (OR = 3.0; 95% CI: 0.8-11.8) were found when comparing use of ST only to no consumption of any tobacco. Cigarette smoking was associated with an increase in the overall risk of UADT cancers, with a 3-fold increase in the risk of laryngeal cancer when comparing smoking only to no consumption of any tobacco (OR = 3.3; 95% CI: 1.0-11.5). Associations for smokers who also consumed ST differed by cancer site.

CONCLUSION

In this study from Algeria dominated by male cases and by cancer in the nasopharynx, cigarette smoking but not ST was associated with UADT cancer. Analyses by anatomical site and using as reference never use of any type of tobacco suggested few associations with ST but of lower precision.

Epstein-Barr virus-induced up-regulation of TCAB1 is involved in the DNA damage response in nasopharyngeal carcinoma

Telomerase Cajal body protein 1 (TCAB1), which is involved in Cajal body maintenance, telomere elongation and ribonucleoprotein biogenesis, has been linked to cancer predisposition, including nasopharyngeal carcinoma (NPC), due to its oncogenic properties. However, there are no specific reports to date on the functional relevance of TCAB1 and Epstein–Barr virus (EBV), which is considered to be a risk factor for NPC. In this study, we first examined NPC clinical tissues and found a notable overexpression of TCAB1 in EBV-positive specimens. Secondly, on a cellular level, we also observed that TCAB1 expression rose gradually along with the increased duration of EBV exposure in NPC cell lines. Additionally, EBV infection promoted cell proliferation and telomerase activity, but the activation was significantly inhibited after TCAB1 knockdown. Moreover, depletion of TCAB1 caused both cell cycle arrest and apoptosis, and suppressed the activation of ataxia telangiectasia and Rad3 related protein (ATR) induced by EBV, resulting in accumulation of DNA damage. Taken together, we here demonstrate that up-regulated expression of TCAB1, induced by EBV in the development of NPC, is involved in stimulating telomerase activity and regulating the DNA damage response within the context of EBV infection.

Phage-display screening identifies LMP1-binding peptides targeting the C-terminus region of the EBV oncoprotein

Latent membrane protein 1 (LMP1), a major oncoprotein of Epstein Barr Virus (EBV) is responsible for transforming B lymphocytes in vitro. LMP1 is overexpressed in several EBV-associated malignancies, and different approaches have been developed to reduce its level and accordingly its oncogenic function in tumor tissues. This study aimed to use phage display peptide library to obtain peptides which could specifically bind to the cytoplasmic region of LMP1 to prevent its interaction with signaling proteins. The LMP1 C-terminus region was produced in bacterial E. coli and used as target for the phage library panning. After 3 rounds, 20 phage clones were randomly selected and 8 showed high binding affinity to the recombinant C-terminus LMP1 protein. The most interesting candidates are the FO5 "QPTKDSSPPLRV" and NO4 "STTSPPAVPHNN" peptides since both bind the C-terminus LMP1 as showed by molecular docking. Furthermore, sequence alignment revealed that the FO5 peptide shared sequence similarity with the Death Receptor 4 which belongs to the tumor necrosis factor-related apoptosis-inducing receptor which plays key role in anti-tumor immunity.

Is gastric lymphoepithelioma-like carcinoma a special subtype of EBV-associated gastric carcinoma? New insight based on clinicopathological features and EBV genome polymorphisms

BACKGROUND

Gastric lymphoepithelioma-like carcinoma (LELC) is a rare entity that is closely associated with Epstein-Barr virus (EBV). However, the EBV latency pattern and genome polymorphisms in gastric LELC have not been systematically explored.

METHODS

The clinicopathological features, EBV latency pattern and genome polymorphisms of EBV-positive gastric LELC in Guangzhou, southern China were investigated and compared with those of ordinary EBV-associated gastric carcinoma (EBVaGC) in the same area.

RESULTS

Ten (1.42%) of 702 gastric carcinoma cases were identified as gastric LELC, in which eight (80%) cases were EBV-positive. The clinicopathological characteristics and EBV latency pattern of EBV-positive gastric LELC were similar to those of ordinary EBVaGC. In EBV genotype analysis, type A strain, type F, I, mut-W1/I, XhoI- and del-LMP1 variants were predominant among EBV-positive gastric LELCs, accounting for eight (100%), six (75%), eight (100%), seven (87.5%), five (62.5%) and six (75%) cases, respectively, which are similar to those in ordinary EBVaGC. For EBNA1 polymorphisms, the V-leu and P-ala subtypes were predominant in EBV-positive gastric LELC, which is different from the predominant V-val subtype in ordinary EBVaGC. EBV-positive gastric LELC has a favorable prognosis when compared to ordinary EBVaGC (median survival time 43.0 vs. 18.0 months).

CONCLUSIONS

Gastric LELC is strongly associated with EBV and EBV-positive gastric LELC should be regarded as a special subtype of EBVaGC. This, to our best knowledge, is the first time in the world that the EBV latency pattern and genome polymorphisms of EBV-positive gastric LELC are systematically revealed.

Prognostic model for distant metastasis in locally advanced nasopharyngeal carcinoma after concurrent chemoradiotherapy

BACKGROUND

A prognostic model should be established for distant metastasis in locally advanced nasopharyngeal carcinoma (NPC) after concurrent chemoradiotherapy (CCRT).

METHODS

Patients with locally advanced NPC who received CCRT were divided into a construction set (230 patients) and a validating set (115 patients). The constructed index was derived on the former and then tested on the latter.

RESULTS

The prognostic score was defined as the number of adverse prognostic factors: age >45, N3 category, hemoglobin <11.0 g/dL and lactate dehydrogenase ≥240 U/L. The score predicted the 5-year distant metastasis-free survival as follows: 0, 91%; 1, 74%; 2, 51%; and ≥3, 12%. In the validating set, the observed 5-year distant metastasis-free survival of these 4 groups with scores of 0, 1, 2, 3, or higher were 81%, 68%, 47%, and 15%, respectively.

CONCLUSION

The established model might be useful for predicting the risk of distant metastasis in patients with locally advanced NPC who underwent CCRT and may identify the patients' need for intensified adjuvant chemotherapy.

Somatostatin receptor 1, a novel EBV-associated CpG hypermethylated gene, contributes to the pathogenesis of EBV-associated gastric cancer

BACKGROUND

Somatostatin receptor 1 (SSTR1) was preferentially methylated in Epstein-Barr virus (EBV)-positive gastric cancer using promoter methylation array. We aimed to analyse the epigenetic alteration and biological function of SSTR1 in EBV-associated gastric cancer (EBVaGC).

METHODS

Promoter methylation was examined by combined bisulphite restriction analysis (COBRA) and pyrosequencing. The biological functions of SSTR1 were evaluated by loss- and gain-of-function assays.

RESULTS

Promoter hypermethylation of SSTR1 was detected in EBV-positive gastric cancer cell lines (AGS-EBV) with SSTR1 transcriptional silence, but not in EBV-negative gastric cancer cell lines with SSTR1 expression. Expression level of SSTR1 was restored in AGS-EBV by exposure to demethylating agent. Moreover, methylation level of SSTR1 was significantly higher in EBV-positive primary gastric cancers compared with EBV-negative gastric cancers (P=0.004). Knock-down of SSTR1 in gastric cancer cell lines (AGS and BGC823) increased cell proliferation and colony formation ability, and promoted G1 to S-phase transition, enhanced cell migration and invasive ability. In contrast, ectopic expression of SSTR1 in gastric cancer cell lines (MKN28 and MGC803) significantly suppressed cell growth in culture conditions and reduced tumour size in nude mice. The tumour suppressive effect of SSTR1 was associated with upregulation of cyclin-dependent kinase inhibitors (p16, p15, p27 and p21); downregulation of oncogenes (MYC and MDM2), key cell proliferation and pro-survival regulators (PI3KR1, AKT, BCL-XL and MET); and inhibition of the migration/invasion-related genes (integrins, MMP1 (matrix metallopeptidase 1), PLAUR (plasminogen activator urokinase receptor) and IL8 (interleukin 8)).

CONCLUSION

Somatostatin receptor 1 is a novel methylated gene driven by EBV infection in gastric cancer cells and acts as a potential tumour suppressor.

Role of plasma EBV DNA levels in predicting recurrence of nasopharyngeal carcinoma in a Western population

BACKGROUND

Loco-regionally advanced nasopharyngeal carcinomas can be cured by the combination of chemotherapy and radiotherapy. In Eastern countries, plasma levels of viral Epstein-Barr deoxyribonucleic acid (DNA) are accurate in predicting recurrence, but few data are available in Western populations. The aim of this prospective study was to evaluate the relationship between viral Epstein-Barr DNA copy numbers in plasma and the response rate, progression-free survival and overall survival in a cohort of Western patients with stage IIb-IVb nasopharyngeal cancer.

METHODS

We evaluated plasma samples from 36 consecutive patients treated with induction chemotherapy followed by chemoradiation. EBV copy numbers were determined after DNA extraction using real-time quantitative polymerase chain reaction. Survival curves were estimated using the Kaplan-Meier method.

RESULTS

Circulating Epstein-Barr virus DNA levels were measured before treatment, at the end of concomitant chemo- and radiotherapy, and during the follow-up period. Pre-treatment levels significantly correlated with the initial stage and probability of relapse. Their increase was 100% specific and 71.3% sensitive in detecting loco-regional or metastatic recurrence (an overall accuracy of 94.4%). Three-year progression-free and overall survival were respectively 78.2% and 97.1%.

CONCLUSIONS

The results of this study confirm that patients from a Western country affected by loco-regionally advanced nasopharyngeal carcinoma have high plasma Epstein-Barr virus DNA levels at diagnosis. The monitoring of plasma levels is sensitive and highly specific in detecting disease recurrence and metastases.

Tumor suppressor genes on frequently deleted chromosome 3p in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is among the most common malignancies in southern China. Deletion of genomic DNA, which occurs during the complex pathogenesis process for NPC, represents a pivotal mechanism in the inactivation of tumor suppressor genes (TSGs). In many circumstances, loss of TSGs can be detected as diagnostic and prognostic markers in cancer. The short arm of chromosome 3 (3p) is a frequently deleted chromosomal region in NPC, with 3p21.1-21.2 and 3p25.2-26.1 being the most frequently deleted minimal regions. In recent years, our research group and others have focused on the identification and characterization of novel target TSGs at 3p, such as RASSF1A, BLU, RBMS3, and CHL1, in the development and progression of NPC. In this review, we summarize recent findings of TSGs at 3p and discuss some of these genes in detail. A better understanding of TSGs at 3p will significantly improve our understanding of NPC pathogenesis, diagnosis, and treatment.

No evidence for the involvement of XMRV or MCV in the pathogenesis of breast cancer

Background:

The aetiology of breast cancer remains elusive. A viral aetiology has been proposed, but to date no virus has been conclusively demonstrated to be involved. Recently, two new viruses, namely Merkel cell polyomavirus (MCV) and xenotropic murine leukaemia virus-related virus (XMRV) have been identified and implicated in the pathogenesis of Merkel cell carcinoma (MCC) and familial form of prostate cancer, respectively.

Methods:

We examined 204 samples from 58 different cases of breast cancer for presence of MCV or XMRV by PCR. Samples consisted of both malignant and non-malignant tissues. Additionally, we included 6 cases of MCC and 12 cases of prostate cancer as potential controls for MCV and XMRV, respectively.

Results:

All of the breast cancer samples examined were negative for both MCV and XMRV. However, 4/6 MCC and 2/12 prostate cancer samples were found to be positive for MCV and XMRV, respectively. Sequence analysis of the amplified products confirmed that these sequences belonged to MCV and XMRV.

Conclusion:

We conclude that there is no evidence for the involvement of MCV or XMRV in the pathogenesis of breast cancer. What role these viruses have in the pathogenesis of MCC and prostate carcinomas remains to be demonstrated.

Gastric cancer in Africa: what do we know about incidence and risk factors?

Gastric cancer is a major contributor to mortality worldwide, yet its incidence varies widely around the world in a way which our current understanding of aetiology cannot fully explain. Incidence data from Africa are weak, reflecting poor diagnostic resources, but there are firm data on intestinal metaplasia and gastric atrophy which are important steps in the carcinogenesis pathway. The available registry data suggest that incidence is unlikely to be dramatically different from Europe or North America. Helicobacter pylori infection is an important permissive factor in the development of cancer, but H. pylori seroprevalence is high all over Africa and cannot clearly be correlated with cancer. However, there is evidence that specific bacterial virulence genes, particularly vacA and iceA allele1, do contribute to cancer risk. Intestinal metaplasia and gastric atrophy have been the focus of twelve studies and are common in Africa. Epstein-Barr virus, which causes 10% of cancer worldwide, is the focus of only one African study. Work in other continents demonstrates that other risk factors apply only to one or other of the two major histological types, intestinal and diffuse. Diet, smoking, alcohol and salt intake predispose to the intestinal type of cancer, but genetic factors predispose to the diffuse type. There is a pressing need for information on the histological types occurring in Africa, and their associated risk factors. Most urgently, information on dietary predisposition to cancer is required to inform public health policy with respect to the demographic transition (urbanisation and lifestyle changes) which is occurring all over the continent.

Lymphoepithelial carcinoma: two case reports and a systematic review of oral and sinonasal cases

Lymphoepithelial carcinoma (LEC) is a rare malignancy. Histologically, it is an undifferentiated carcinoma with an intermixed reactive lymphoplasmacytic infiltrate. Herein, we report two cases of LEC in the head and neck region that presented to Oulu University Hospital. Our first case is a 30-year-old man with LEC in the left maxillary sinus. The second case is a 49-year-old man with LEC in the soft palate and uvula with regional lymph node metastases at diagnosis. In addition, a systematic review of the literature from 1980 to 2010 was performed with MEDLINE and cross-references were searched manually. Case reports and clinical series of oral, oropharyngeal, nasal, and paranasal sinus LECs were reviewed revealing a total of 110 cases. Most of the oral cases were found in the tonsils (n = 29), oropharynx (n = 19), and in oral mucosa (n = 18), while sinonasal cases (n = 40) were mainly in the paranasal sinuses and nasal cavity. From 37 case reports, including ours, the median age was 58 and 62 years for sinonasal and oral/oropharyngeal LECs, respectively. Oral and oropharyngeal LECs have a 70.0% tendency to metastasize and 16.6% spread locally. In contrast, none of the nasal and paranasal LECs metastasized, but 60% spread locally. Epstein-Barr virus (EBV) had been detected in 87.5% of all tested LEC cases. Treatment of LECs, during the last decade, has largely consisted of surgery, combined with radiotherapy or chemoradiation. Although local spread or nodal metastases are fairly common at the time of diagnosis, the mortality rate of adequately treated LEC patients is low.

Epstein-Barr virus and human papillomavirus infection in vulvar lichen sclerosus

OBJECTIVE

We investigated the presence of the Epstein-Barr virus (EBV) and human papillomavirus (HPV) in patients with vulvar lichen sclerosus (LS).

MATERIALS AND METHODS

We investigated the presence of HPV and EBV from 34 vulvar biopsies of patients with LS who had had no previous treatment and from 17 normal vulvar brushings used as controls. We used polymerase chain reaction to amplify DNA sequences of these viruses. Human papillomavirus and EBV DNA detection was carried out using MY09/MY11 and TC67/TC69 consensus primers, respectively. The amplified polymerase chain reaction products were analyzed by 10% polyacrylamide gel.

RESULTS

The mean age of the patients was 57 years old, with the majority postmenopausal. Human papillomavirus DNA was not found in the LS samples studied, but it was found in 23.2% (4/17) of the controls. However, EBV DNA was found in 26.5% (9/34) of the LS samples analyzed, and it was not found in the controls.

CONCLUSIONS

Our results showed no relationship between HPV and LS. This result is in accordance with the literature. We have found 26.5% of EBV in our samples. This is a preliminary study, and the follow-up of these patients will elucidate whether EBV could play a role in cases of LS.

Serologic Antienzyme Rate of Epstein-Barr Virus DNase-Specific Neutralizing Antibody Segregates TNM Classification in Nasopharyngeal Carcinoma

Purpose

We investigate the value of pretreatment serologic antienzyme rate (AER) of Epstein-Barr virus (EBV) DNase-specific neutralizing antibody complementing TNM staging in prognostication of nasopharyngeal carcinoma (NPC).

Patients and Methods

Pretreatment serum samples from 1,303 patients with untreated NPC were collected and examined for AER. After a 10-year follow-up period, the prognoses of the patients, classified by their clinical stage with AER, were assessed by multivariate analysis. Of the 1,303 patients, 600 patients were randomly assigned to a training set to generate an AER cutoff point by receiver operating characteristic (ROC) curve analysis. AER levels were then analyzed with overall survival (OS), progression-free survival (PFS), local failure–free survival (LFFS), and distant metastasis–free survival (DMFS) in a testing set (703 patients). Another independent cohort of 464 patients was studied in a validating set.

Results

In the training set, the ROC analysis–generated AER cutoff point for OS was 58.0%, which was used as the cutoff point in the testing set. The subset of low AER levels predicted a significant survival advantage over the subset of high AER levels for OS, PFS, LFFS, and DMFS in the testing set. Moreover, two distinguished subgroups were segregated by an AER level of 58.0% within each clinical stage comparing prognostication of OS, PFS, LFFS, and DMFS. Importantly, AER level was revealed as the only significant independent prognostic factor for death, recurrence, and distant metastasis in the validating set.

Conclusion

Pretreatment serologic AER of EBV DNase-specific neutralizing antibody serves as an independent prognostic marker complementing TNM stage in NPC. Supplementing pretreatment AER with TNM staging leads to more accurate risk definition in patient subgroups.

Detection of EBV in nasopharyngeal carcinoma by quantum dot fluorescent in situ hybridization

AIMS

Nasopharyngeal carcinoma (NPC) is a common cancer in Southeast Asia and is frequently associated with Epstein-Barr virus (EBV) infection. The primary aim of this study was to improve the method of EBV detection by exploring quantum dots in FISH detection, and compare QD-based FISH with conventional ISH.

MATERIALS AND METHODS

Biopsy specimens were retrospectively retrieved from 35 NPC patients as paraffin-embedded tissue blocks. QD-FISH was developed to detect the presence of EBV encoded small RNA (EBER) using biotin-labeled EBER oligonucleotide probe indirectly labeled with streptavidin-conjugated quantum dots. Conventional ISH was also performed using a commercial kit to assess concordance between the two methods.

RESULTS

All the 35 NPC cases were nonkeratinizing carcinoma (7 differentiated and 28 undifferentiated subtypes). EBER-positive signals were detected in 91.43% (32/35) and 80% (28/35) cases by QD-FISH and ISH, respectively. There was no significant difference in the number of EBER-positive cases by the two methods. A moderate concordance was found between QD-FISH and ISH for EBER status (κ=0.55). Four EBER-negative cases by ISH showed EBER-positive signals when detected by QD-FISH.

CONCLUSIONS

EBV is closely associated with NPC in Chinese patients. QD-FISH is a novel effective method for EBER detection, and has a moderate concordance with conventional ISH.

A therapeutic approach to nasopharyngeal carcinomas by DNAzymes targeting EBV LMP-1 gene

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) has been known to have oncogenic properties during latent infection in nasopharyngeal carcinoma (NPC). Genetic manipulation of LMP1 expression may provide a novel strategy for the treatment of NPC. DNAzymes are synthetic, single-stranded DNA catalysts that can be engineered to bind and cleave the target mRNA of a disease-causing gene. By targeting the LMP1 mRNA, we successfully obtained a phosphorothioate-modified ‘‘10–23’’ DNAzyme namely DZ1, through screening a series of DNAzymes. DZ1 could significantly down-regulate the expression of LMP1 in NPC cells, inhibit cell proliferation, metastasis, promote apoptosis and enhance radiosensitivity of NPC through interfering signal pathways which are abnormally activated by LMP1, including NF-κB, AP-1 and STAT3 signal pathways. Together, interfering LMP1 signaling pathway could be a promising strategy to target the malignant phenotypes of NPC.

miR-200a-mediated downregulation of ZEB2 and CTNNB1 differentially inhibits nasopharyngeal carcinoma cell growth, migration and invasion

Nasopharyngeal carcinoma (NPC), a highly metastatic and invasive malignant tumor originating from the nasopharynx, is widely prevalent in Southeast Asia, the Middle East and North Africa. Although viral, dietary and genetic factors have been implicated in NPC, the molecular basis of its pathogenesis is not well defined. Based on a recent microRNA (miRNA) microarray study showing miR-200 downregulation in NPC, we further investigated the role of miR-200a in NPC carcinogenesis. We found that the endogenous miR-200a expression level increases with the degree of differentiation in a panel of NPC cell lines, namely undifferentiated C666-1, high-differentiated CNE-1, and low-differentiated CNE-2 and HNE1 cells. By a series of gain-of-function and loss-of-function studies, we showed that over-expression of miR-200a inhibits C666-1 cell growth, migration and invasion, whereas its knock-down stimulates these processes in CNE-1 cells. In addition, we further identified ZEB2 and CTNNB1 as the functional downstream targets of miR-200a. Interestingly, knock-down of ZEB2 solely impeded NPC cell migration and invasion, whereas CTNNB1 suppression only inhibited NPC cell growth, suggesting that the inhibitory effects of miR-200a on NPC cell growth, migration and invasion are mediated by distinct targets and pathways. Our results reveal the important role of miR-200a as a regulatory factor of NPC carcinogenesis and a potential candidate for miRNA-based therapy against NPC.

Evidence of measles virus antigens and RNA in endometrial cancer

OBJECTIVES

To look for an association between the measles virus and endometrial carcinoma, the most frequent cancer of the female genital tract in our area.

STUDY DESIGN

Thirty-six of 49 patients with endometrial carcinoma were studied to detect fingerprints of the measles virus. Immunohistochemistry with the avidin-biotin complex method and in situ hybridization were used to demonstrate the association. The clinicopathological correlations were carried out to support a relationship between the virus and the cancer if any was found.

RESULTS

Twenty-six of the 36 cases (72%) of endometrial cancer showed the presence of measles virus antigens in the tumor cells. Sixteen of 21 cases were positive for measles virus RNA by in situ hybridization. Although type I endometrial carcinoma was more positive for viral particles than type II, type II cancer, when allied with the measles virus, was more often associated with the depth of myometrial invasion and with death from tumor.

CONCLUSIONS

We demonstrate for the first time a link between endometrial cancer and the presence of viral antigens and RNA of the measles virus, although these findings do not necessarily signify a causal relationship between the cancer and the virus.

Meta-analysis shows that prevalence of Epstein-Barr virus-positive gastric cancer differs based on sex and anatomic location

BACKGROUND & AIMS

Epstein-Barr virus (EBV) has been causally associated with cancer; some gastric carcinomas have a monoclonal EBV genome in every cancer cell, indicating that they arose from a single infected progenitor cell. However, the proportion of EBV-positive gastric carcinomas is uncertain, and the etiologic significance is unknown.

METHODS

We conducted a meta-analysis of 70 studies including 15,952 cases of gastric cancer assessed by in situ hybridization for EBV-encoded small RNA.

RESULTS

The pooled prevalence estimate of EBV positivity was 8.7% (95% confidence interval [CI]: 7.5%-10.0%) overall, with a 2-fold difference by sex: 11.1% (95% CI: 8.7%-14.1%) of gastric cancer cases in males vs 5.2% (95% CI: 3.6%-7.4%) of cases in females. Tumors arising in the gastric cardia (13.6%) or corpus (13.1%) were more than twice as likely to be EBV-positive as those in the antrum (5.2%; P < .01 for both comparisons). EBV prevalence was 4 times higher (35.1%) for tumors in postsurgical gastric stump/remnants. Over 90% of lymphoepithelioma-like carcinomas were EBV positive, but only 15 studies reported any cases of this type; prevalence did not significantly differ between the more common diffuse (9.5%) [corrected] and intestinal (7.6%) [corrected] histologies. EBV prevalence was similar in cases from Asia (8.3%), Europe (9.2%), and the Americas (9.9%).

CONCLUSIONS

EBV-positive gastric cancers greatly differ from other gastric carcinomas based on sex, anatomic subsite, and surgically disrupted anatomy, indicating that it is a distinct etiologic entity. Epidemiologic studies comparing EBV-positive and -negative gastric cancers are warranted to investigate EBV's role 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.

EBER2 RNA-induced transcriptome changes identify cellular processes likely targeted during Epstein Barr Virus infection

BACKGROUND

Little is known about the physiological role of the EBER1 and 2 nuclear RNAs during Epstein Barr viral infection. The EBERs are transcribed by cellular RNA Polymerase III and their strong expression results in 106 to 107 copies per EBV infected cell, making them reliable diagnostic markers for the presence of EBV. Although the functions of most of the proteins targeted by EBER RNAs have been studied, the role of EBERs themselves still remains elusive.

FINDINGS

The cellular transcription response to EBER2 expression using the wild-type and an internal deletion mutant was determined. Significant changes in gene expression patterns were observed. A functional meta-analysis of the regulated genes points to inhibition of stress and immune responses, as well as activation of cellular growth and cytoskeletal reorganization as potential targets for EBER2 RNA. Different functions can be assigned to different parts of the RNA.

CONCLUSION

These results provide new avenues to the understanding of EBER2 and EBV biology, and set the grounds for a more in depth functional analysis of EBER2 using transcriptome activity measurements.

Epstein-Barr virus latent membrane protein 2A upregulates UDP-glucose dehydrogenase gene expression via ERK and PI3K/Akt pathway

The Epstein-Barr virus latent membrane protein 2A (LMP2A) is frequently detected in nasopharyngeal carcinoma (NPC), a tumour of high metastatic capacity. A recent microarray assay notes that expression of the UDP-glucose dehydrogenase (UGDH) gene, participating in glycosaminoglycan synthesis, shows high correlation with LMP2A levels in NPC biopsies. This study extends the finding and demonstrates that the UGDH transcript and protein quantities, the enzyme activity, and glycosaminoglycan contents increase in LMP2A overexpressed human embryonic kidney 293 (HEK293) cells. The luciferase reporter gene assay demarcates that a region from 630 to 486 bp upstream of the transcription start is critical for LMP2A-mediated gene expression. Moreover, a specificity protein 1 (Sp1) binding site mutation in this region reduces the LMP2A-responsive expression of the UGDH gene. Consistent with these findings, cell motility enhancement by LMP2A diminishes by treating the cells with Sp1-specific inhibitor and small interference RNA (siRNA). Using a signalling pathway-specific inhibitor, it is revealed that phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK), not c-Jun N-terminal kinase (JNK) and p38, participate in LMP2A-induced UGDH expression. This study provides a model for molecular mechanism participating in LMP2A-mediated UGDH gene activation.

New cellular tools reveal complex epithelial-mesenchymal interactions in hepatocarcinogenesis

To enable detailed analyses of cell interactions in tumour development, new epithelial and mesenchymal cell lines were established from human hepatocellular carcinoma by spontaneous outgrowth in culture. We obtained several hepatocarcinoma (HCC)-, B-lymphoblastoid (BLC)-, and myofibroblastoid (MF)-lines from seven cases. In-depth characterisation included cell kinetics, genotype, tumourigenicity, expression of cell-type specific markers, and proteome patterns. Many functions of the cells of origin were found to be preserved. We studied the impact of the mesenchymal lines on hepatocarcinogenesis by in vitro assays. BLC- and MF-supernatants strongly increased the DNA replication of premalignant hepatocytes. The stimulation by MF-lines was mainly attributed to HGF secretion. In HCC-cells, MF-supernatant had only minor effects on cell growth but enhanced migration. MF-lines also stimulated neoangiogenesis through vEGF release. BLC-supernatant dramatically induced death of HCC-cells, which could be largely abrogated by preincubating the supernatant with TNFβ-antiserum. Thus, the new cell lines reveal stage-specific stimulatory and inhibitory interactions between mesenchymal and epithelial tumour cells. In conclusion, the new cell lines provide unique tools to analyse essential components of the complex interplay between the microenvironment and the developing liver cancer, and to identify factors affecting proliferation, migration and death of tumour cells, neoangiogenesis, and outgrowth of additional malignancy.

Role of the ubiquitin system and tumor viruses in AIDS-related cancer

Tumor viruses are linked to approximately 20% of human malignancies worldwide. This review focuses on examples of human oncogenic viruses that manipulate the ubiquitin system in a subset of viral malignancies; those associated with AIDS. The viruses include Kaposi's sarcoma herpesvirus, Epstein-Barr virus and human papilloma virus, which are causally linked to Kaposi's sarcoma, certain B-cell lymphomas and cervical cancer, respectively. We discuss the molecular mechanisms by which these viruses subvert the ubiquitin system and potential viral targets for anti-cancer therapy from the perspective of this system.

Publication history: Republished from Current BioData's Targeted Proteins database (TPdb; ).

Epstein-Barr virus infection and risk of lymphoma: immunoblot analysis of antibody responses against EBV-related proteins in a large series of lymphoma subjects and matched controls

Epstein-Barr Virus (EBV) is consistently associated with distinct lymphoproliferative malignancies and aberrant EBV antibody patterns are found in most EBV cancer patients. We evaluate the detection of an abnormal reactive serological pattern to EBV (ab_EBV) infection and the risk of lymphoma in a multicentric case-control study. Serum samples were collected at study entry from 1,085 incident lymphoma cases from Spain, France, Germany, Czech Republic, Italy and 1,153 age, sex and country matched controls. EBV immunoglobulin G (IgG) serostatus was evaluated through a peptide-based ELISA combining immunodominant epitopes of EBNA1 (BKRF1) and VCA-p18 (BFRF3). Further, immunoblot analysis was performed to evaluate distinct antibody diversity patterns to EBV early antigens (EA), besides EBNA1, VCA-p18, VCA-p40 (BdRF1) and Zebra (BZLF1). Patients with chronic active EBV infection and aberrant EBV activity were characterized as having an abnormal reactive pattern (ab_EBV). Ab_EBV was observed in 20.9% of 2,238 included subjects with an increased proportion of cases presenting ab_EBV as compared to the control population (23.9% vs. 18.0% p = 0.001). Ab_EBV positivity was a risk factor for all lymphomas combined (odds ratio [OR] = 1.42, 95% confidence interval [CI]=1.15-1.74), and specifically for chronic lymphocytic leukaemia (OR = 2.96, 95%CI = 2.22-3.95). Lower levels of ab_EBV were observed for follicular lymphoma (OR = 0.38, 95%CI = 0.15-0.98). EBV may be involved in a larger subset of lymphomas among clinically immunocompetent subjects than previously thought, probably explained by an underlying loss of immune control of EBV latent infection. Ab_EBV is a useful tool to explore EBV imbalances preceding or paralleling possible EBV associated oncogenic events.

Epstein Barr virus-associated tumours: an update for the attention of the working pathologist

Epstein-Barr virus (EBV) is a herpesvirus associated with approximately 1% of tumours worldwide. EBV is the epitome of B lymphotropic viruses, but the spectrum of tumours it is associated with extends to T lymphocyte and NK cell malignancies, various types of carcinomas and smooth muscle tumours. Ubiquitous EBV infection in humans implies that most individuals carry EBV-infected cells. Therefore, mere detection of the virus in individuals with a tumour is not sufficient for establishing a causal relationship between both events, but instead requires unequivocal detection of viral nucleic acids or viral proteins in the tumour cells. Recent controversies about EBV infection in several carcinomas mainly resulted from such technical issues. The gold standard remains in situ EBER detection, but detection of EBNA1 would be an interesting alternative. EBV detection can be helpful for diagnostic, prognostic and therapeutic purposes. The rate of EBV association with entities such as NK/T cell tumours of the nasal type is so high that absence of detection of the virus in such a lesion should cast doubt of the accuracy of the diagnosis. Similarly, diagnosis of EBV-associated follicular pseudo-tumour obviously requires detection of the virus. EBV-positive common gastric adenocarcinomas seem to have a better prognosis than their EBV-negative counterparts and identification of the virus in B cell lymphoproliferations in immunocompromised individuals will guide therapeutic options. In conclusion, EBV-associated tumours are common enough to be relevant for the pathologist in everyday practice, but there is a need to facilitate detection of the virus (eg EBNA1 antibody).

Epstein-Barr Virus Associated Nasopharyngeal Carcinoma and Local Polymorphic B-Cell Lymphoproliferative Disorder in a Patient With HIV Disease

A rare case report of HIV-associated nasopharyngeal carcinoma concurrent with local polymorphic B-cell lymphoproliferative disorder is reported and discussed on the ground of the most recent literature evidences. Only very few reports of nasopharyngeal carcinoma have been described until now in patients infected with HIV (one case in adults), and a coexisting lymphoid cell proliferation with a concurrent role of Epstein-Barr virus in prompting both disorders was never reported to date. The relevant pathogenetic, diagnostic, and therapeutic questions raised by this infrequent intriguing association retrieved in a patient with prominent HIV-related immunodeficiency are focused on.

Second primary cancers in patients with nasopharyngeal carcinoma: a pooled analysis of 13 cancer registries

OBJECTIVE

To study the risk of second primary cancers in nasopharyngeal carcinoma (NPC) patients and the risk of NPC as second primary cancer.

METHODS

We used data from the cancer registries from Singapore and from 12 low-incidence areas, including a total of 8,947 first occurring NPC cases, and 167 second occurring cases. We calculated standardized incidence ratios (SIRs) by comparing the second cancer incidence in NPC patients to the first primary cancer incidence in non-cancer population. We also calculated SIRs of second NPC after other primaries.

RESULTS

In Singapore, the risk of cancers of the lung (SIR=0.42), stomach (SIR=0.41), and colon (SIR=0.23) was significantly decreased after NPC, whereas that of cancer of the tongue (SIR=11.1) was significantly increased. In Australia, Canada, and Europe, the risk of non-Hodgkin's lymphoma (NHL) (SIR=3.06), tongue cancer (SIR=5.29), brain cancer (SIR=3.89), myeloid leukemia (SIR=3.85), and non-melanoma skin cancer (NMSC) (SIR=3.47) was significantly increased after NPC. Incidences of second occurring NPCs following various primary cancers were not significantly altered compared to the incidence of first occurring NPCs.

CONCLUSIONS

Immune suppression (NHL, NMSC), shared genetic factors (lung cancer, NHL, myeloid leukemia), and shared environmental risk factors (tongue and brain cancers) might explain the associations. Except for NHL, there was no evidence of association with other Epstein-Barr virus-related cancers.

Mechanisms of cell immortalization mediated by EB viral activation of telomerase in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a common cancer in Southern China and Southeast Asia. The disease is a poorly differentiated carcinoma without effective cure, and the mechanism underlying its development remains largely unknown. Of several factors identified in NPC aetiology in recent years, Epstein-Barr virus (EBV) infection has emerged to be most important. In almost all NPC cells, EBV uses several intracellular mechanisms to cause oncogenic evolution of the infected cells. One such mechanism by which EBV infection induces cellular immortalization is believed to be through the activation of telomerase, an enzyme that is normally repressed but becomes activated during cancer development. Studies show that greater than 85% of primary NPC display high telomerase activity by mechanisms involving EBV infection, consistent with the notion that EBV is commonly involved in inducing cell immortalization. More recently, different EBV proteins have been shown to activate or inhibit the human telomerase reverse transcriptase gene, by modulating intracellular signalling pathways. These findings suggest a new model with a number of challenges towards our understanding, molecular targeting and therapeutic intervention in NPC.

Infectious Agents

There is substantial evidence that infectious agents play a causal role in a variety of human malignancies. These cancers include the liver, cervix, stomach, nasopharynx, bladder, and bile duct as well as Kaposi sarcoma (KS) and several lymphomas. This chapter summarizes the biological and epidemiologic features of each of the major oncogenic infections, beginning with the viruses, followed by H. pylori, and with a brief summary of the relevant parasites.

The antibody 2B4 directed against the Epstein-Barr virus (EBV)-encoded nuclear antigen 1 (EBNA1) detects MAGE-4: implications for studies on the EBV association of human cancers

We have previously developed two monoclonal antibodies against the Epstein-Barr Virus (EBV) nuclear antigen 1 (EBNA1), designated 1H4 and 2B4. Both detect EBNA1 by in situ staining in established EBV-positive tumours, e.g. Hodgkin's lymphoma and nasopharyngeal carcinoma. An association of EBV with other tumours, notably breast carcinomas, has been reported but remains controversial. Using the antibody 2B4, a nuclear protein has been detected in breast carcinomas that were EBV-negative by other methods, suggesting cross-reactivity with a cellular protein. Furthermore, an association of EBV with various other carcinomas has been reported on the basis of 2B4 immunohistochemistry. Here we show that 2B4 also binds to MAGE-4, a cancer testis antigen expressed in a variety of tumour cells, including breast carcinoma, seminoma and EBV-negative cases of Hodgkin's lymphoma. We conclude that the 2B4 antibody is not suitable for the detection of EBV infection but that additional techniques, particularly in situ hybridization for the detection of the EBV-encoded RNAs (EBERs), should be employed to confirm the presence of EBV. Our results add to the evidence indicating that breast cancer is not an EBV-associated disease.

Analysis of prognostic factors of nasopharyngeal carcinoma: impact of in situ hybridization for Epstein-Barr virus encoded small RNA 1

OBJECTIVES

To evaluate the impact of clinical, histopathological, and molecular biological parameters on the prognosis of nasopharyngeal carcinoma (NPC).

STUDY DESIGN AND SETTING

The clinical records of 48 patients with a diagnosis of NPC were retrospectively reviewed. In situ hybridization for Epstein-Barr virus encoded small RNA 1 (EBER-ISH) was applied for 30 paraffin-embedded specimens available. Prognostic factors of NPC were meticulously analyzed.

RESULTS

The EBER-ISH signal was shown to be highly significant as a favorable prognostic factor (P = 0.007). Although EBV was more commonly associated with Type III NPC, EBER-ISH-positive Type I-II NPC had also significantly better survival rate than EBER-ISH-negative Type I-II NPC (P = 0.036).

CONCLUSIONS

In addition to the WHO histopathological grade, the 1997 UICC staging, nodal status, and distant metastasis at presentation, the EBER-ISH signal was shown to be significant as a prognostic factor.

SIGNIFICANCE

This is the first report to describe the EBER-ISH as an independent prognostic factor of NPC regardless of histopathology.

EBM RATING

B-2b.

Detection of Epstein–Barr virus infection and gene expression in human tumors by microarray analysis

Epstein-Barr virus (EBV) genome-chips are employed to determine the EBV infection rate and to reveal the gene expression patterns of EBV in tumor biopsies. These chips are produced with 71 consecutive PCR-amplified EBV DNA fragments of 1-3 kbp covering the entire EBV genome. The specificity of the EBV-chips is determined by hybridizing the DNA on the chips with biotin-labeled cDNA probes reverse transcribed from the mRNA of P3HR1 cells, which were B-cell infected latently by EBV. Hybridization results revealed only the expression of EBNA1, EBNA2, EBER1 and EBER2 in these cells. On the other hand, EBV lytic genes are expressed after the cells are treated with 12-O-tetradecanoylphorbol-13-acetate and sodium butyrate to induce the EBV lytic cycle. Fourty-four tumor biopsies from different organs are assayed with these chips, which showed many defined and interesting EBV gene expression patterns. This study demonstrates that the EBV-chip is useful for screening infection with EBV in tumors, which may lead to insights into tumorigenesis associated with this virus.

Role of Epstein-Barr virus DNA measurement in plasma in the clinical management of nasopharyngeal carcinoma in a low risk area

OBJECTIVE

To evaluate the role of quantitative measurement of Epstein-Barr virus (EBV) DNA in the clinical management of nasopharyngeal carcinoma (NPC) in a low tumour risk area (western Europe).

METHODS

22 consecutive Dutch NPC patients (11 europid) were studied. EBV DNA load in pretreatment and post-treatment plasma samples was determined. Three patients were also sampled at frequent intervals during treatment. RNA in situ hybridisation for the detection of EBV encoded RNAs (EBERs) was carried out on tumour biopsies of all cases.

RESULTS

All patients with EBER positive NPC (20/22) showed a positive EBV DNA load in plasma at the time of diagnosis (median EBV DNA level, 4.1 log(10) copies/ml). Patients with EBER negative NPC had no detectable EBV DNA in plasma. After treatment, complete remission was achieved in all cases and concurrently EBV DNA in plasma became undetectable in all patients. In the three longitudinally evaluated cases, EBV DNA load gradually declined towards undetectable levels within three weeks after start of treatment. Two patients developed a distant metastasis with concomitant increases in EBV viral load. In addition, one EBER positive patient developed an EBER negative metastasis in the neck during follow up and in this case EBV DNA load remained undetectable at the time of recurrence.

CONCLUSIONS

Plasma EBV DNA load measurement appears to be useful in a low tumour risk area. However, development of local recurrences may not always coincide with raised levels of EBV DNA.

Interleukin-10 and interleukin-18 promoter polymorphisms in an Italian cohort of patients with undifferentiated carcinoma of nasopharyngeal type

PURPOSE

Cytokines such as IL-10 and IL-18 seem to be involved in the inflammatory response of undifferentiated carcinoma of nasopharyngeal type (UCNT). The aim of this study was to evaluate the correlation between functional single nucleotide polymorphisms (SNPs) in the promoter region of IL-10 and IL-18 genes and the virological and clinical characteristics in a large case series of Caucasian patients suffering from UCNT, a tumor regularly associated with the Epstein Barr Virus (EBV).

METHODS

Eighty-nine patients with histologically confirmed UCNT and 130 healthy donors were included in our study. DNA was examined for the polymorphisms of IL-10 gene at positions -1082, -819, -592 by direct sequencing and IL-18 gene at position -607 and -137 by allele-specific PCR. EBV DNA serum viremia was evaluated by QC-PCR.

RESULTS

The distributions of the IL-10 and IL-18 genetic variants were not different between UCNT patients and healthy controls. The frequency of IL-10 -1082G allele, which is associated with high IL-10 expression, showed a nearly statistically significant increase in UCNT patients EBV DNA-negative as compared to healthy controls (OR=3.3 95% CI: 1.2-9.8). Subjects with C/C or C/G combined IL-18 genotypes showed an increased risk of being with Stages III-IV (OR=2.1 95% CI: 1.2-6.6).

CONCLUSION

This study was performed to improve the definition of the pathogenetic factors implicated in UCNT by addressing the correlation between cytokine polymorphisms and clinical parameters. This is the first study investigating the possible role of the IL-18 and IL-10 polymorphisms in the development and outcome of UCNT. In our genetic analysis there is no evidence for involvement of IL-10 promoter polymorphisms alone in the genetic predisposition to this tumor. On the other hand, IL18 genetic variants may represent a genetic risk factor for tumor aggressiveness.

The global health burden of infection-associated cancers in the year 2002

Several infectious agents are considered to be causes of cancer in humans. The fraction of the different types of cancer, and of all cancers worldwide and in different regions, has been estimated using several methods; primarily by reviewing the evidence for the strength of the association (relative risk) and the prevalence of infection in different world areas. The estimated total of infection-attributable cancer in the year 2002 is 1.9 million cases, or 17.8% of the global cancer burden. The principal agents are the bacterium Helicobacter pylori (5.5% of all cancer), the human papilloma viruses (5.2%), the hepatitis B and C viruses (4.9%), Epstein-Barr virus (1%), human immunodeficiency virus (HIV) together with the human herpes virus 8 (0.9%). Relatively less important causes of cancer are the schistosomes (0.1%), human T-cell lymphotropic virus type I (0.03%) and the liver flukes (0.02%). There would be 26.3% fewer cancers in developing countries (1.5 million cases per year) and 7.7% in developed countries (390,000 cases) if these infectious diseases were prevented. The attributable fraction at the specific sites varies from 100% of cervix cancers attributable to the papilloma viruses to a tiny proportion (0.4%) of liver cancers (worldwide) caused by liver flukes.

Epstein-barr virus-related gastric adenocarcinoma: an early secondary cancer post hemopoietic stem cell transplantation

BACKGROUND & AIMS

Epstein-Barr virus (EBV) infection has been associated with some cases of gastric cancer.

METHODS

We studied a case of early onset gastric adenocarcinoma after nonmyeloablative hematopoietic stem cell transplantation for myeloma in a 56-year-old man.

RESULTS

The development of gastric adenocarcinoma was preceded by severe graft-versus-host disease (GVHD) necessitating strong immunosuppression, which resulted in an intense reactivation of EBV infection. Three sequential gastric biopsy examinations performed at 100, 130, and 150 days after hematopoietic stem cell transplantation showed gastritis, dysplasia, and adenocarcinoma, respectively. There was no evidence of Helicobacter pylori infection. Quantitative polymerase chain reaction for circulating EBV showed a surge of EBV DNA peaking at the time of gastritis, followed by a gradual decrease afterward with adequate control of GVHD and tailing of immunosuppression. In situ hybridization for EBV-encoded early small RNA showed absence of EBV in the gastritis specimen, but the presence of EBV in the dysplastic and carcinoma specimens. Aberrant promoter methylation of E-cadherin was observed only in the carcinoma specimens, showing that infection with EBV preceded E-cadherin methylation.

CONCLUSIONS

Mucosal damage caused by GVHD, immunosuppression, and EBV reactivation combined to lead to EBV infection of the gastric cells and initiation of carcinogenesis, suggesting this case to be a genuine EBV-related opportunistic malignancy post-transplantation. An interesting proposition is that this case also might reflect a compacted timeline of events in EBV-related gastric cancers developing in immunocompetent patients.

Investigation of Epstein-Barr virus DNA in formalin-fixed and paraffin- embedded breast cancer tissues

OBJECTIVE

To investigate etiological role of Epstein-Barr virus (EBV) DNA in breast cancer.

MATERIALS AND METHODS

The presence of EBV DNA in 57 breast cancer tissues was investigated with a sensitive PCR assay. The breast cancer tissues were from invasive ductular (n=28), lobular (n=20) and other miscellaneous carcinomas (n=9). Tissues from normal breasts and patients with various benign breast diseases (n=55): fibrocystic disease (n=34), fibroadenoma (n=16), hyperplasia, and granulomatous mastitis (n=5), were used as control samples.

RESULTS

EBV DNA was detected in 13 (23%) cancerous tissues (7 ductular, 4 lobular, 2 other carcinoma) and 19 (35%) in the control tissues. The difference between EBV presence in malignant and benign tissues was not statistically significant (p>0.05).

CONCLUSION

The presence of EBV DNA was detected almost equally in both breast cancer and normal tissues, which indicates no etiological role for EBV in breast cancer. We suggest further etiological studies.

Epstein-Barr virus in hepatocellular carcinogenesis

AIM: In recent years, studies have suggested that Epstein-Barr virus (EBV) is associated with HCC. The present study was to determine the prevalence of EBV in HCC patients, and whether EBV acted synergistically with hepatitis viruses in HCC carcinogenesis.

METHODS: Liver tissue 115 HCC patients and 26 non-carcinoma patients were studied. Polymerase chain reaction (PCR) was performed to detect EBV BamHI W DNA, EBV LMP1 DNA, HBV X DNA, and HBV S DNA. Reverse transcription PCR (RT-PCR) was performed to detect HCV RNA and HDV RNA. Immunohistochemistry was performed to detect LMP1, HBsAg, HBcAg and HCV. The positive ratios were compared between HCC group and control group by χ² test.

RESULTS: Totally, 78 HCC samples whose β -globulin DNA was positively detected by amplified PCR were selected. PCR was performed in all cases for EBV DNA and HBV DNA. RT-PCR was performed in 18 cases for HCV RNA and HDV RNA. EBV BamHI W and EBV LMP1 were positive in 18 and 6 cases, respectively. HBV X gene and HBV S gene were positive in 42 and 27 cases respectively. HCV was positive in one of the 18 cases, and none was positive for HDV. The positive rates were 28.2% (22 of 78) for EBV DNA (BamHI W and/or LMP1) and 56.4% (44 of 78) for HBV DNA (X gene and/or S gene) respectively. In addition, 12 cases were positive for both EBV DNA and HBV DNA. Among the 26 cases in the control group, 2 cases were positive for EBV BamHI W, 4 positive for HBV X gene and 3 positive for HBV S gene. The positive rates were 8.0% (2 of 26) and 23.1% (6 of 26), respectively, for EBV DNA and HBV DNA. The result of DNA sequencing of BamHI W was 100% homologous with the corresponding sequence of B95-8. There was significant difference in EBV infection rate between HCC patients and controls (χ² = 4.622, P < 0.05). The difference in HBV infection rate was also significant (χ² = 8.681, P < 0.05). However, there was no obvious correlation between HBV and EBV in HCC patients (χ² = 0.835, P > 0.05). LMP1, HBV (HBsAg, HBcAg) and HCV were detected positively in 25, 45 and 6 of 78 cases of HCC tissues respectively. In the 26 control cases, the corresponding positive cases were 2, 4 and 0. The difference in EBV infection rate between HCC patients and control cases was statistically significant (χ² = 6.02, P < 0.05). The difference in HBV infection rate was also statistically significant (χ² = 10.03, P < 0.05). In the 25 cases with positive LMP1 expression, 6 were in the nuclei of tumor cells, 9 in the cytoplasm of tumor cells and 10 in mesenchymal lymphocyte cytoplasm.

CONCLUSION: The existence of EBV infection in HCC tissues suggests that EBV may be involved in the hepatocellular carcinogenesis in China. HBV infection may be a major cause of HCC. There is no correlation between EBV and HBV in the development of HCC. The prevalence of HCV infection is low in our area, and HDV appears not to play a direct role in hepatocellular carcinogenesis.

Epstein-Barr virus in gastric carcinomas and gastric stump carcinomas: a late event in gastric carcinogenesis

BACKGROUND

To determine at what stage during gastric carcinogenesis Epstein-Barr virus (EBV) enters the gastric epithelial cells, the presence of EBV was investigated in two pathogenetically related but distinct forms of adenocarcinoma of the stomach-gastric carcinoma of the intact stomach (GCIS) and gastric stump carcinoma (GSC)-and their presumed precursor lesions.

PATIENTS AND METHODS

Eleven patients with EBV positive GCIS and eight patients with EBV positive GSC, demonstrated by the highly sensitive EBV encoded RNA 1/2 (EBER1/2) RNA in situ hybridisation (RISH) technique, were studied. Paraffin wax embedded tissue available from preoperative gastric biopsies and tumour adjacent tissue from the resection specimens containing normal gastric mucosa, inflamed gastric mucosa, and preneoplastic lesions (intestinal metaplasia and dysplasia) was investigated by EBER1/2 RISH, in addition to EBV nuclear antigen 1 (EBNA-1) and latent membrane protein 1 (LMP-1) immunohistochemistry (IHC).

RESULTS

In both GCIS and GSC and their precursor lesions EBER1/2 transcripts were restricted to the carcinoma cells. In addition, positivity of EBNA-1 IHC was also restricted to the tumour cells. IHC for LMP-1 was negative in all cases tested.

CONCLUSIONS

The absence of EBER1/2 transcripts in preneoplastic gastric lesions (intestinal metaplasia and dysplasia) and their presence in two distinct types of gastric carcinoma strongly suggest that EBV can only infect neoplastic gastric cells and thus is a late event in gastric carcinogenesis.

Suppression of Epstein-Barr virus-encoded latent membrane protein-1 by RNA interference inhibits the metastatic potential of nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is a highly metastatic tumor characterized by close association with EBV. Of the EBV-encoded products, latent membrane protein-1 (LMP-1) is thought to be the only oncoprotein playing an essential role in cell transformation as well as tumor metastasis. In this study, we tested the effect of suppressing LMP-1 by RNA interference (RNAi) on the proliferative and metastatic potentials of an EBV-positive NPC cell line, C666. We showed that stably suppressing LMP-1 by short hairpin RNA (shRNA) plasmid significantly altered cell motility, substratum adhesion, and transmembrane invasion ability. However, it has little effect on the rate of cell growth and cell cycle control. These results demonstrated the effectiveness of RNAi in suppressing LMP-1, supporting an important role of LMP-1 in NPC metastasis, and suggested a potential application of RNAi-mediated therapeutic strategy for EBV-related NPC.