Presence of EBNA in nasopharyngeal carcinoma and control patient tissues related to EBV serology

Pathobiology of selected tumors of the base of the skull

Skull base surgery is a new subspeciality, and, up to this point, most articles on this subject have focused on innovative operative-reconstructive approaches to tumors in this region. It is now important that we embark on a new era, the era of tumor biology, and concentrate on new ways of evaluating these neoplasms from a pathologic viewpoint. The hematoxylin-cosin section is no longer an end point, but just a beginning. This is the age of molecular biology. It is important that these tumors be evaluated, either prospectively or retrospectively, employing immunohistochemical staining, flow cytometry, oncogene expression, cytogenetics, or other techniques in order to identify important prognostic features. Data from these additional studies may then be used to develop new treatment strategies. Skull base societies should develop protocols for one or more of these tumors to ensure that they are indeed evaluated uniformly. In this article I emphasize the importance of accurate histologic classification or subclassification of these neoplasms and focus on contemporary parameters that may or may not impact on prognosis.

Identification of aberrant cell cycle regulation in Epstein-Barr virus-associated nasopharyngeal carcinoma by cDNA microarray and gene set enrichment analysis

Previous studies have revealed that Epstein-Barr virus (EBV) was closely associated with nasopharyngeal carcinoma (NPC). This study aimed to characterize the global pathways affected in the EBV-associated NPC. Combined with microdissection, gene expression profiles in 22 NPCs and 10 non-tumor nasopharyngeal epithelial (NPE) tissue samples were analyzed. All NPC specimens served in the microarray analysis were positive for EBV, as judged by identification of the expression of EBV nuclear antigen 1 (EBNA1). Through gene set enrichment analysis (GSEA), we found that cell cycle pathway was the most disregulated pathway in NPC (P=0.000, false discovery rate q-value=0.007), which included some aberrant expressed components. We first found that overexpression of CDK4, cyclin D1, and Rb proteins, and loss of expression of proteins p16, p27, and p19 were statistically significant in NPC tissues compared with non-cancerous NPE (P<0.05) by real-time RT-PCR and tissue microarray. EBV-encoded small RNA-1 (EBER-1) hybridization signals in the NPC showed significant associations with the overexpression of Rb (P=0.000), cyclin D1 (P=0.000), CDK4 (P=0.000), and the loss of expression of p16 proteins (P=0.039). In the final logistic regression analysis model, EBER-1 and abnormal expression of p16, Rb, cyclin D1, and E2F6 were independent contributions to nasopharyngeal carcinogenesis. Through survival analysis, only cyclin D1 could predict the prognosis of NPC patients. These results suggested that cell cycle pathway was the most disregulated pathway in the EBV-associated NPC, and EBER-1 was closely associated with p16, CDK4, cyclin D1, and Rb.cyclin D1 could be the prognosis biomarker for NPC.

[Significance of confirming Epstein-Barr virus nuclear antibody as tumor marker]

BACKGROUND/AIM

Study of the association between Epstein-Barr virus (EBV) and the tumors of the nasopharynx renders an opportunity to introduce causal treatment Already have been proven the anti-EBV (anti-Epstein-Barr nucleus antigene) antibodies in the blood serum of the patients infected with EBV, while over 91% of the patients with nasopharyngeal malignant tumors also have a detectable anti-EBV marker. The aim of this research was to determine if there were anti-EBV antibodies in the serum of the patients with the already verified nasopharyngeal malignant tumors, and, if there were, to determine the quantitative ratio to the values in the serum of the healthy controls.

METHODS

The study involved 74 individuals in the period from 1994-2001 divided into four groups: group A counting 11 patients with undifferentiated carcinome of nasopharyngeal type (UCNT); group B counting 25 patients with UCNT X-ray treated at least three years before the onset of the study; group C including 28 healthy subjecets (blood donors), and the group D with 10 patients with planocellular nasopharyngeal carcinoma. Serologic diagnostics of the patients serum was performed using the techniques of Reedman and Klein for the detection of anti-EBV antibodies in the serum.

RESULTS

The presence of the statistically significantly higher values of the mean geometric titer (MGT) of the anti-EBNA antibodies was determined in 36 patients with histologically verified UCNT as compared with the control groups including 10 patients with planocellular carcinomas of the nasopharynx and 28 blood donors. Presented were anti-EBNA titers with 95% confidence interval for any participants according to the Hoo clinical classification of nasopharyngeal tumors, as well as according to the fact if they had been radiotreated within the previous three years.

CONCLUSION

The results of this study confirm the conclusions of the recent literature on the possible etiopathogenesis of nasopharyngeal tumors and the use of viral anti-EBNA antibodies as viral markers in the diagnostics of UCNT diseases.

Changing epidemiology of nasopharyngeal carcinoma in Hong Kong over a 20-year period (1980-99): an encouraging reduction in both incidence and mortality

Epidemiological data from the Hong Kong Cancer Registry for the period 1980-99 were analyzed. Altogether 21,768 new cases of nasopharyngeal carcinoma (NPC) and 8,664 related deaths were registered. In both genders, the peak incidence occurred in the 50-59 years age group, and this age distribution pattern remained similar throughout. The age-standardized incidence rate steadily decreased from 28.5 in 1980-84 to 20.2 in 1995-99 per 100,000 males, and from 11.2-7.8 per 100,000 females, resulting in a total decrease of 29% for males and 30% for females over this 20-year period. The magnitude of total decrease in NPC mortality amounted to 43% and 50%, respectively, as the age-standardized mortality rate steadily decreased from 13.7 in 1980-84 to 7.8 in 1995-99 per 100,000 males, and from 4.5-2.2 per 100,000 females. The age-standardized mortality/incidence ratio also decreased from the peak of 0.48 in 1980-84 to 0.39 in 1995-99 for males, and from 0.40-0.29 for females. Females had significantly lower age-standardized incidence (male/female ratio 2.5-2.6, p < 0.01) and mortality (male/female ratio 3.0-3.5, p< 0.01) throughout the whole period. Furthermore, females had consistently lower mortality/incidence ratio: 0.29 vs. 0.39 in 1995-99. These data are highly suggestive of significant improvement in prevention and control of NPC in Hong Kong. Closer scrutiny of the differences in intrinsic and extrinsic factors between the genders might help to show important factors affecting oncogenesis and prognosis. Possible ways for further reduction of incidence and mortality are discussed.

Microsatellite analyses of loci at 7q31.3-q36 reveal a minimum of two common regions of deletion in nasopharyngeal carcinoma

OBJECTIVE

Our goal was to better define the extent and specificity of deletion in the 7q32-qter chromosomal region in nasopharyngeal carcinoma (NPC).

DESIGN AND SETTING

Polymerase chain reaction-based deletion analysis was performed on DNA samples from 24 paired NPCs and corresponding germlines using 13 microsatellite markers mapped to chromosome subbands 7q31.3-q36.

RESULTS

Loss of heterozygosity of at least 1 marker in this interval was found in 18 (75%) of 24 tumor specimens. Particularly frequent allelic losses were identified at 5 loci: D7S495 (46%), D7S509 (42%), D7S500 (45%), D7S631 (30%), and D7S514 (35%). Two shortest regions of overlap could be identified in this interval, although the most common shortest region of overlap appeared to lie around D7S500 between but not including D7S631 and D7S495, on chromosome subband 7q32.

CONCLUSION

These results suggest that at least 2 putative tumor suppressor genes important in the pathogenesis of NPC are present in the examined interval, an interval that has also been found to harbor deletions in breast and prostate carcinomas.

Epstein-Barr virus in tumours

The Epstein-Barr virus (EBV) is the best characterized human virus known to infect most people all over the world. In most cases, primary infection with EBV is asymptomatic and the virus persists life-long without causing any disease. The availability of sensitive detection methods, however has led to the identification of a wide array of EBV-associated disease entities. Although nearly 9000 publications have been written since the first description of this virus in 1964, many questions concerning its function and infection patterns remain unanswered. The direct involvement of EBV in the pathogenesis of a disease has only been established for infectious mononucleosis and lymphoproliferative disorders in the setting of congenital or acquired immunodeficiency. Extensive investigations on the role of EBV infection in the pathogenesis of all other EBV-associated lymphoid and epithelial proliferations have led to the conclusion that EBV is not the primary causative agent but it can promote tumour development. Since the early steps in neoplastic development are difficult to assess, further studies are required to clarify the precise role of EBV infection. Furthermore, the clinical significance of the presence of EBV in neoplasia is largely unknown.

The biology and pathology of selected skull base tumors

This paper describes the pathobiology of some of the more common skull base tumors. In addition to clinicopathologic features, emphasis is placed upon methods of diagnosis utilizing immunoperoxidase stains and molecular markers that may or may not impact upon prognosis.

Detection of Epstein-Barr virus genomes in normal human lacrimal glands

Epstein-Barr virus (EBV) has been implicated in several ocular diseases; however, detection of the EBV genome in ocular tissues has not been documented. We report the detection of amplified EBV genomic sequences in 11 of 26 normal lacrimal gland DNA samples by using the polymerase chain reaction. Serum was available for 19 of the lacrimal gland donors. All 19 were EBV seropositive, although of the 19 lacrimal gland-seropositive patients, EBV sequences were detected in only 10 of the samples. Further, amplified EBV sequences were not detected in circulating lymphocyte DNA from normal seropositive volunteers, most likely because of the low frequency of circulating EBV-infected B cells. Amplification of EBV from cadaver lacrimal gland DNA was possible with minute quantities of DNA, whereas peripheral blood mononuclear cell DNA from normal volunteers did not amplify EBV sequences. Interestingly, the peripheral blood mononuclear cell polymerase chain reactions contained approximately 100 times more DNA than the lacrimal gland polymerase chain reactions. We conclude that the lacrimal gland may be a site for EBV persistence and that positive EBV serology is not an indicator of which individuals may have EBV harbored within their lacrimal glands.

Cytogenetics of undifferentiated nasopharyngeal carcinoma xenografts from southern Chinese

Three undifferentiated nasopharyngeal carcinoma (NPC) tumour lines were successfully established from fresh biopsy material injected s.c. into athymic mice and passaged for many generations. These xenografts were found to be free of infiltrating lymphoid cells and remained undifferentiated up to passage 30. They were designated NPC/HK2117 (Xeno-1), NPC/HK1915 (Xeno-2) and NPC/HK1530 (Xeno-3), respectively. Passage 16 from Xeno-1, passage 1 from Xeno-2 and passage 14 from Xeno-3 were studied cytogenetically using G-banding with the trypsin-Giemsa method. Two xenografts were hyperdiploid with chromosome modal numbers ranging from 49 to 76, and one was hypodiploid with modal numbers ranging from 28 to 38. Five marker chromosomes have been identified with involvement of chromosomes 1, 3, 11, 12 and 17. Marker chromosomes derived from chromosomes 12q, 1q and 3q were consistent in one of the 2 xenografts successfully G-banded, and chromosomes 12, 11 and 17 were consistent in another. Three out of the 6 markers involve 12q13----qter. An abnormal chromosome 3 with most of the p arm deleted was also observed.

Epstein-Barr virus (EBV)-associated undifferentiated carcinoma of the parotid gland

A case of undifferentiated carcinoma of the salivary gland occurring in the parotid gland of a southern Chinese was reported. Tumour cells showed immunofluorescence for Epstein-Barr virus (EBV)-associated nuclear antigen, and DNA hybridization demonstrated the presence of EBV-DNA in tumour tissue. The findings in this case, together with previous reports, suggest a causal relationship between EBV and salivary gland carcinoma. The relationships between EBV and undifferentiated epithelial tumours of the salivary glands, nasopharynx and thymus are also discussed.

Viruses and salivary gland disease: are there associations?

Viruses can cause sialadenitis and may be associated with other diseases of salivary glands, particularly immunologically mediated and neoplastic lesions. The evidence that such an association with Sjögren's syndrome is causal is reviewed here and shown to be fairly tenuous at present.

Epstein-Barr virus serology in nasopharyngeal carcinomas and other head and neck neoplasms in Italy

This paper reports the results of the EBV-specific antibody response in 17 Italian nasopharyngeal carcinoma (NPC) patients, 15 other head and neck tumor patients and 15 normal controls. Nucleic acid hybridization has been performed on the biopsy tissue from 4 of the NPC patients, and EBV-DNA was present in two undifferentiated (WHO 3) tumors, and absent in two samples of the keratinizing (WHO 1) type. EBV serology appears to be specifically related to NPC, more evidently for VCA-IgA and EA-IgG antibodies, and useful as an aid in diagnosis of NPC. However, in order to assess a prognostic value of the above markers, a greater number of patients followed for a longer period of time (at least 5 years) is needed, and is currently being pursued.

Antibodies to Epstein-Barr virus in patients with nasopharyngeal carcinoma and in comparison groups

One hundred fifty-one patients with nasopharyngeal carcinoma (NPC) were enrolled in a prospective collaborative study of North American patients (most were white). Serum samples were collected concurrently from 903 Mayo patients for comparisons of serologic analyses. Both IgA antiviral capsid antigen [VCA (IgA)] and the anti-early antigen [EA (D)] antibody responses were associated with diagnosis, but not always in the same way. Both responses were positive in 85% of patients with World Health Organization types 2 and 3 NPC. Only 16% with WHO type 1 NPC had positive IgA responses and only 35% had positive EA (D) responses, prevalences close to those in the comparison groups. Increased titers were found in the squamous carcinoma comparison group with tumors of the tongue and in the group with benign nasal polyps (p less than 0.01). We believe that the tests are specific, sensitive, and useful in diagnosis and treatment planning in patients with NPC, particularly those with occult primary NPC.

Epstein-Barr virus-specific serodiagnostic tests in carcinomas of the head and neck

Sera from 256 patients with cancers of the head and neck were examined for their profiles of IgG and IgA antibodies to Epstein-Barr virus (EBV)-specific, viral capsid antigen (VCA), the diffuse (D) and the restricted (R) components of the early antigen (EA) complex, and the EBV-associated nuclear antigen (EBNA), in order to assess the value of these procedures in the routine diagnosis of poorly or undifferentiated nasopharyngeal carcinoma (NPC). In 13 NPC patients, the carcinoma had invaded cervical lymph nodes, and their sera revealed, in addition to high IgG anti-VCA titers, elevated levels of IgA antibodies to VCA, of IgG antibodies to D, and most also had IgA anti-D. Such profiles were seen in very few of the patients with carcinomas at other sites of the head and neck. They had not developed in four NPC patients whose tumors were limited to the postnasal space, and in three patients with other tumors at that site. Among 15 patients with cervical node metastases from occult primary tumors, 2 had EBV-specific antibody profiles compatible with NPC, 1 was judged to have NPC on clinical grounds, and the other died of a pulmonary carcinoma, or possibly pulmonary metastases. In 4 of the remaining 13 patients with occult tumors, the primary site was found outside the nasopharynx, whereas it escaped detection in the other 9. These results lend further support to the usefulness of the EBV-specific serology to clinicians in the diagnosis of NPC, especially in cases of lymph node invasion by undetected primary tumors. The data also emphasize the need of complementing the serology with the examination of biopsies for the presence of EBV deoxyribonucleic acid (DNA) or, more readily performed, EBNA-positive carcinoma cells.

Nasopharyngeal carcinoma in Japan--clinical evaluation of EBV serology and EBV-associated nuclear antigens test

This study was aimed at the possible clinical application of two Epstein-Barr virus (EBV) immunological tests to Japanese nasopharyngeal carcinoma (NPC). One of them was serological test to measure antibody titers to EBV-associated antigens (viral capsid antigens (VCA) and virus-induced early antigens (EA)) of 42 NPC sera. The other was for the detection of EBV-associated nuclear antigens (EBNA) in 22 tumour cells of NPC. The results showed that significant elevation of antibody titers to VCA and EA which resided particularly in IgA class as well as a high incidence in the presence of EBNA were found in undifferentiated NPC. Apart from its importance in etiology, EBV serology and the EBNA test may help clinicians to establish a diagnosis of undifferentiated NPC in Japan and there is little doubt that these tests should eventually become a routine biologic test in ENT practice.

Antibody responses to Epstein-Barr virus-specific DNase in relation to the prognosis of juvenile patients with nasopharyngeal carcinoma

We have examined serial sera from 17 juvenile patients with nasopharyngeal carcinoma (NPC) for their capacity to neutralize the activity of Epstein-Barr virus (EBV)-specific DNase. The results revealed that NPC patients who became long-term survivors (LTS) without evidence of the disease either never possessed significant levels of antibodies to the enzyme or showed a gradual decline in the number of EBV DNase units neutralized from an elevated level at diagnosis to an insignificant figure several years later. All the 10 LTS neutralized less than 4, and some neutralized less than 2 units of the enzyme 3 or more years after the initial diagnosis. In contrast, serial sera from juvenile patients who died of NPC neutralized over 10 and as many as 25 units of EBV DNase either persistently until death occurred or with transient declines during unmaintained remissions. Rises and declines in the neutralizing activity were, with few exceptions, accompanied by corresponding changes in the titers of IgA and IgG antibodies to EB viral capsid antigen and to the diffuse component of the early antigens. Although the number of juvenile NPC cases available for study was small, the observations suggest that the EBV DNase neutralization test may serve to provide information on the prognosis of the patients.

Nasopharyngeal carcinoma in American Children: Epstein-Barr virus-specific antibody titers and prognosis

Seven American juvenile patients with undifferentiated or nonkeratinizing nasopharyngeal carcinoma (NPC) were examined serially for Epstein-Barr virus (EBV)-specific antibody spectra and titers in sera. At diagnosis, all showed antibody patterns characteristic of NPC: i.e., high titers of IgG antibodies to viral capsid antigen (VCA) and to the diffuse (D) component of the early antigen complex. Six patients had IgA antibodies to VCA, and four to the D component. In the patients who responded to therapy with complete and maintained remissions, the IgG antibodies to D and the IgA antibodies to VCA and D decreased to undetectable levels within 12 to 30 months. By contrast, of the four patients who responded only transiently to therapy, three showed substantial increases and one continuously high titers of IgG anti-D and IgA anti-VCA. The increases in antibody titers preceded clinical recognition of recurrent tumors by 1 to 6 months. Three of these patients have died and the fourth is alive with disease. These data indicate that American juvenile NPC does not differ from the adult disease observed anywhere in the World. They reaffirm the potential usefulness of EBV-specific serology in the diagnosis and prognosis of NPC and the monitoring of patients following therapy.

Association of Epstein-Barr virus with nasopharyngeal carcinoma in Alaskan native patients: serum antibodies and tissue EBNA and DNA

Biopsy specimens from Alaskan Native patients with nasopharyngeal carcinoma (NPC) and from other patients seen on the otolaryngology service were tested for Epstein-Barr virus-specific DNA and nuclear antigen (EBNA). Serum samples from both groups were tested for various EBV-related antibodies. EBV DNA and EBNA results were in agreement in 29 of 31 tissue specimens tested by the two methods. Ten of 11 biopsies containing NPC cells were positive for EBV DNA. Two NPC patients had biopsies that showed only atypical epithelium but were also positive for EBV DNA or EBNA. The other tissue specimens were negative except for biopsies from two patients: one with a parotid gland lymphoepithelial lesion; another with undifferentiated carcinoma of salivary gland origin.

Development of an anticomplement immunoenzyme test for detection of EB virus nuclear antigen (EBNA) and antibody to EBNA

An anticomplement immunoenzyme test was developed by conjugating anti-human C3 antibody with horseradish peroxidase. EBNA could be detected by this test in all cell lines related to EB virus, as well as in nasopharyngeal carcinoma cells, but not in unrelated cell lines. Antibody to EBNA could also be detected. The test is sensitive and does not require a fluorescence microscope which makes it particularly suitable for mass survey.

The pathology of head and neck tumors: carcinoma of the nasopharynx, Part 11

The past decade has witnessed extraordinary advances in the epidemiology, virology, and immunology of carcinomas of the nasopharynx. There has not been a parallel growth in the study of morphologic expressions of the neoplasms. In great part, this has been due to a lack of a universally accepted histologic classification. As a consequence, correlation between histology and other factors relating to the pathogenesis of these neoplasms has been impeded. The World Health Organization (WHO) has proposed a histologic classification of nasopharyngeal carcinomas as squamous-cell, nonkeratinizing, and undifferentiated. This report presents and argument in favor of using the WHO classification and a hypothesis relating to the histogenesis of the 3 types of nasopharyngeal carcinoma.

Frequency and levels of antibodies to Epstein-Barr virus-specific DNase are elevated in patients with nasopharyngeal carcinoma

Sera from healthy individuals and patients with infectious mononucleosis, Burkitt lymphoma, nasopharyngeal carcinoma, or other malignancies were examined for their capacity to neutralize Epstein-Barr virus (EBV)-induced DNase activity. Sera were found that neutralized the EBV DNase but not herpes simplex virus type 1 or type 2 DNases, and vice versa. Sera from 46 of the 49 patients with nasopharyngeal carcinoma examined (94%) neutralized > 6 units of EBV DNase per ml of serum. In contrast, only 19% of 47 patients with Burkitt lymphoma, 12% of 183 patient with other malignancies, 4% of 58 patients with infectious mononucleosis, and none of 101 healthy individuals had such levels of neutralizing activity. The neutralizing factor was found in the IgG fraction derived from nasopharyngeal carcinoma sera. There was no correlation between the concentration of these antibodie and the titers of IgG ad IgA antibodies to the EBV capsid antigen, the early antigen complex, or the EBV-associated nuclear antigen.

Establishment of a cell line (NPC/HK1) from a differentiated squamous carcinoma of the nasopharynx

A long-term cell culture epithelioid cell line was established from a recurrent squamous carcinoma of the nasopharynx of a Chinese male 17 1/2 years after radiation therapy. The cell line, designated NPC/HK1, has been passed 72 times over a period 1 year. The cells have been shown by light and electron microscopies to be of the squamous epithelial type. When they were transplanted subcutaneously into the back of athymic nude BALB/c (nu/nu) mice, tumors developed at the sites of inoculation, which on histological examination were shown to be well-differentiated squamous carcinomas, similar in morphology to the recurrent human tumor from which they were derived. Karyotypic analysis of cells from the cell line demonstrates an aneuploid human type with a modal chromosome number of 74 with both numerical and structural aberrations. Viral particles or Epstein-Barr viral nuclear antigen (EBNA) has not been demonstrated in the cells from the primary culture or several of the subcultures tested. The presence of EBNA in touch smears prepared from the biopsy tissue was inconclusive. Infection of the subcultured cells with EBV from P3HR1 and B95-8 cells was unsuccessful.

Epstein-Barr virus specific IgA serum antibodies in nasopharyngeal and other respiratory carcinomas

In order to better understand the relationship between IgA and IgG antibodies to Epstein-Barr virus (EBV) in nasopharyngeal carcinoma (NPC), we analyzed 230 NPC sera but also a series of sera from patients with other carcinomas selected for their high EBV/IgG antibody titres. We were surprised to find that 21 out of 46 sera from bronchopulmonary carcinomas (BPC) and 6 out of 7 carcinomas of nasal fossae were IgA anti-VCA positive, and 9 BPC sera and 5 nasal fossae sera were also positive for IgA and anti-EA. Bronchial undifferentiated small-cell carcinomas may represent a particular group associated with high EBV profile.