Cindy M. Chang

The extent of genetic diversity of Epstein-Barr virus and its geographic and disease patterns: a need for reappraisal.

Epstein-Barr virus (EBV) is a ubiquitous, gamma-1 lymphotrophic virus etiologically linked to nasopharyngeal carcinoma (NPC), endemic to Southern China, and Burkitt lymphoma (BL), endemic to equatorial Africa, both of which are rare elsewhere in the world. Why EBV is associated with different malignancies in different geographic regions remains puzzling and may be related to EBV genotypic variability through specific disease and geographic associations. We review the literature on sequence variation in EBV genes, focusing on LMP-1, EBNA-1, and BZLF-1 and their distribution by geography and disease. Given the limitations of current studies, definitive conclusions regarding the link between EBV genotypes, disease and geography are not possible. We suggest that the true extent of EBV diversity is likely to be greater than is currently recognized. Additional studies conducted in carefully selected populations, that are sufficiently powered to provide robust estimates, and that utilize testing approaches that permit full characterization of viral diversity are needed to further our understanding of patterns of EBV genetic variation and their association with malignancies in different regions.

Netrin-1 regulates invasion and migration of mouse mammary epithelial cells overexpressing Cripto-1 in vitro and in vivo.

The neuronal guidance molecule, Netrin-1, has been suggested to play a role in the adhesion and migration of the mammary gland epithelium. Human and mouse Cripto-1 induce proliferation, migration, invasion and colony formation by epithelial cells in 3D matrices. Here we investigate whether Netrin-1 affects these Cripto-1-dependent activities in mouse mammary epithelial cells. Overexpression of Cripto-1 in EpH4 and HC-11 cells (EpH4/Cripto-1 or HC-11/Cripto-1) was associated with low expression of Netrin-1 and increased expression of its receptor Neogenin compared to that of wild-type cells. No change was observed in the expression of the other Netrin-1 receptor, UNC5H1. Treating EpH4/Cripto-1 or HC-11/Cripto-1 mammary cells with exogenous soluble Netrin-1 resulted in increased expression of E-cadherin and UNC5H1, decreased expression of vimentin and decreased activation of Akt as determined by western blotting. Colony formation by Eph4/Cripto-1 cells in 3D gels was significantly reduced in proximity to a Netrin-1 source, and mammary glands of transgenic mice overexpressing human Cripto-1 showed altered ductal growth in proximity to implanted Netrin-1-releasing pellets. Terminal end buds in the treated transgenic mice mammary glands also showed increased expression of E-cadherin and UNC5H1 and decreased expression of active Akt determined by immunohistochemistry. Together, these results suggest that regulation of Netrin-1 expression is important in regulating Cripto-1-dependent invasion and migration of mammary epithelial cells.

Chronic fatigue syndrome and subsequent risk of cancer among elderly US adults

The cause of chronic fatigue syndrome (CFS) is unknown but is thought to be associated with immune abnormalities or infection. Because cancer can arise from similar conditions, associations between CFS and cancer were examined in a population‐based case‐control study among the US elderly.

Pediatric, elderly, and emerging adult-onset peaks in Burkitt's lymphoma incidence diagnosed in four continents, excluding Africa.

Burkitts lymphoma (BL) in the general population and immunosuppressed persons with AIDS in the United States was characterized by three age‐specific incidence peaks near 10, 40, and 70 years. We hypothesized that BL from different geographical areas may exhibit pediatric, adult, and elderly age incidence peaks. We investigated this hypothesis using data on 3,403 cases obtained from the International Agency for Research on Cancer (1963–2002). Data from Africa were sparse or incomplete, and thus were excluded. Age‐standardized rates (ASRs) and age‐specific incidence rates were calculated, supplemented with the calculations performed using age–period–cohort (APC) models. The ASR rose 5.3% (95% confidence interval [CI], 5.0–5.6) per year in males and 4.6% (95% CI, 4.5–4.8) in females. The ASR increased gradually in children, steeply in adults and most rapidly in the elderly both in males and in females. Overall, BL male/female ASR ratio was 2.5, but it declined from 3.1 (95% CI, 3.0–3.3) for pediatric BL to 2.3 (95% CI, 2.2–2.4) for adult BL and 1.5 (95% CI, 1.4–1.6) for elderly BL. Age‐specific incidence peaks occurred near 10 and 70 years in all regions and periods. A peak near 40 years of age emerged in the mid‐1990s, particularly in men. Findings using APC models confirmed those based on the standard analyses. Our findings, based on the international BL cases, support our hypothesis that BL is multimodal and that BL peaks at different ages may be clues to differences in the etiology and/or biology of BL at those ages. Am. J. Hematol. 87:573–578, 2012.

GBV-C Infection and Risk of NHL among U.S. Adults

Some retrospective studies suggest an association between infection with GB virus-C (GBV-C) and non-Hodgkin lymphoma (NHL). We evaluated this association prospectively in a nested case-control study within the U.S. Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. Cases (N = 658) and controls (N = 1,316) were individually matched by age, sex, race/ethnicity, timing of study entry, and sample selection. Prediagnostic PLCO serum samples were tested for GBV-C RNA (as a measure of active infection) and E2 antibody (active or resolved infection). Logistic regression was used to estimate odds ratios (OR) for the association between GBV-C and NHL overall and NHL subtypes. Twelve cases (1.8%) and seven controls (0.5%) were GBV-C RNA-positive. GBV-C RNA positivity was associated with NHL overall [OR, 3.43; 95% confidence interval (CI), 1.35-8.71] and, based on small numbers, diffuse large B-cell lymphoma (OR, 5.31; 95% CI, 1.54-18.36). The association with NHL persisted when the interval between testing and selection was greater than 4 years (OR, 6.00; 95% CI, 1.21-29.73). In contrast, E2 antibody positivity was not associated with NHL risk (OR, 1.08; 95% CI, 0.74-1.58). Our study demonstrates that GBV-C infection precedes development of NHL. GBV-C infection may play an etiologic role in a small proportion of NHL cases, perhaps by causing chronic immune stimulation or impaired immunosurveillance.

Blood Transfusions and the Subsequent Risk of Hematologic Malignancies

BACKGROUND: Blood transfusions are associated with viral transmission and immunomodulation, perhaps increasing subsequent risk of hematologic malignancies (HMs). Prior studies of transfusion recipients have lacked details on specific HM subtypes.

Molecular characteristics of diffuse large B-cell lymphoma in human immunodeficiency virus-infected and -uninfected patients in the pre-highly active antiretroviral therapy and pre-rituximab era

Abstract Human immunodeficiency virus (HIV) infection substantially elevates diffuse large B-cell lymphoma (DLBCL) risk, but its impact on the distinct DLBCL subtypes defined by cell of origin is unclear. We compared DLBCL molecular characteristics and prognosis in 51 HIV-infected and 116 HIV-uninfected cases diagnosed during 1977–2003. Using immunohistochemistry to classify cell of origin based on the Tally algorithm, activated B-cell (ABC)-DLBCL was substantially more common in HIV-infected (83%) than in HIV-uninfected (54%) cases (p < 0.001). Epstein–Barr virus (EBV) was detected in 63% of DLBCLs in HIV-infected cases, occurring almost exclusively in ABC-DLBCL (74% vs. 13% of germinal center B-cell [GCB]-DLBCL, p = 0.002), but was rarely detected in DLBCLs among HIV-uninfected cases (3%). Among HIV-uninfected cases, MYC/IgH [t(8;14)(q24;q32)] and IgH/BCL2 [t(14;18)(q32;q21)] translocations were significantly more common and BCL6/IgH [t(3;14)(q27;q32)] significantly less common in GCB-DLBCL than in ABC-DLBCL (p = 0.010, < 0.001 and = 0.039, respectively). Among HIV-infected cases, translocations other than MYC/IgH [t(8;14)(q24;q32)] (21%) were rare (≤ 6%) and unrelated to cell of origin. ABC-DLBCL was associated with adverse overall survival compared with GCB-DLBCL regardless of HIV status (pHIV-infected = 0.066; pHIV-uninfected = 0.038). Our data demonstrate key differences in the molecular characteristics, cell of origin and prognosis of DLBCL by HIV status in the pre-highly active antiretroviral therapy (HAART) and pre-rituximab era, supporting biologic differences in lymphomagenesis in the presence of HIV.

Risk factors for non‐Hodgkin lymphoma subtypes defined by histology and t(14;18) in a population‐based case‐control study

The t(14;18) chromosomal translocation is the most common cytogenetic abnormality in non‐Hodgkin lymphoma (NHL), occurring in 70–90% of follicular lymphomas (FL) and 30–50% of diffuse large B‐cell lymphomas (DLBCL). Previous t(14;18)‐NHL studies have not evaluated risk factors for NHL defined by both t(14;18) status and histology. In this population‐based case‐control study, t(14;18) status was determined in DLBCL cases using fluorescence in situ hybridization on paraffin‐embedded tumor sections. Polytomous logistic regression was used to evaluate the association between a wide variety of exposures and t(14;18)‐positive (N = 109) and ‐negative DLBCL (N = 125) and FL (N = 318), adjusting for sex, age, race, and study center. Taller height, more lifetime surgeries, and PCB180 exposure were associated with t(14;18)‐positivity. Taller individuals (third tertile vs. first tertile) had elevated risks of t(14;18)‐positive DLBCL (odds ratio [OR] = 1.8, 95% confidence interval [CI] 1.1–3.0) and FL (OR = 1.4, 95%CI 1.0–1.9) but not t(14;18)‐negative DLBCL. Similar patterns were seen for individuals with more lifetime surgeries (13+ vs. 0–12 surgeries; t(14;18)‐positive DLBCL OR = 1.4, 95%CI 0.7–2.7; FL OR = 1.6, 95%CI 1.1–2.5) and individuals exposed to PCB180 greater than 20.8 ng/g (t(14;18)‐positive DLBCL OR = 1.3, 95%CI 0.6–2.9; FL OR = 1.7, 95%CI 1.0–2.8). In contrast, termite treatment and high alpha‐chlordane levels were associated with t(14;18)‐negative DLBCL only, suggesting that these exposures do not act through t(14;18). Our findings suggest that putative associations between NHL and height, surgeries, and PCB180 may be t(14;18)‐mediated and provide support for case‐subtyping based on molecular and histologic subtypes. Future efforts should focus on pooling data to confirm and extend previous research on risk factors for t(14;18)‐NHL subtypes.

Non-Hodgkin Lymphoma (NHL) subtypes defined by common translocations: utility of fluorescence in situ hybridization (FISH) in a case-control study

We used fluorescence in situ hybridization (FISH) assays to identify t(14;18) translocations in archival paraffin-embedded tumor sections from non-Hodgkin lymphoma (NHL) cases enrolled in a population-based study. t(14;18) was identified in 54% of 152 cases, including 39% of diffuse large cell lymphomas (26 of 66 cases) and 84% of follicular lymphomas (36 of 43 cases). Eighty-seven percent of t(14;18)-positive cases and 57% of t(14;18)-negative cases expressed bcl-2. FISH assays detected twice as many t(14;18)-positive follicular lymphomas as PCR assays. Overall, study findings support the use of FISH assays to detect t(14;18) in archival tumor samples for epidemiologic studies of NHL subtypes.

Characterization of ELISA detection of broad‐spectrum anti‐Epstein–Barr virus antibodies associated with nasopharyngeal carcinoma

Epstein–Barr virus (EBV) infection is associated with undifferentiated nasopharyngeal carcinomas (NPC). A distinct seroreactivity pattern to EBV is predictive of subsequent risk of sporadic and familial nasopharyngeal carcinomas. There are currently no accepted screening tools for guiding the clinical management of individuals at high‐risk for nasopharyngeal carcinomas, particularly unaffected relatives from nasopharyngeal carcinoma multiplex families. Therefore, the reproducibility of a panel of largely synthetic peptide‐based anti‐EBV antibody ELISAs was evaluated and their ability to distinguish nasopharyngeal carcinoma cases from controls was explored. IgG and IgA antibodies against 6 different EBV antigens (10 assays, total) were tested on sera from 97 individuals representing the full spectrum of anti‐EBV seroprevalence (i.e., healthy individuals with no known EBV seroreactivity, healthy individuals with known EBV seroreactivity, and nasopharyngeal carcinoma cases). Each specimen was tested in triplicate to assess within‐batch and across‐batch variation, and the triplicate testing was repeated on two separate days. Reproducibility was assessed by the coefficients of variation (CVs) and intraclass correlation coefficients (ICCs). All markers were detectable in 17% or more of samples. For all but one marker, the overall, within‐batch, and across‐batch CVs were below 15%, and the ICCs were above 70% for all but three markers. Sensitivity of these markers to detect prevalent nasopharyngeal carcinomas ranged from 22% to 100%, and among unaffected controls, most distinguished those with and without known seropositivity. In conclusion, a large number of EBV markers can be measured reliably in serum samples using peptide‐based anti‐EBV ELISAs. J. Med. Virol. 85:524–529, 2013. Puiblished 2012. This is a US government work, and, as such, is in the public domain of The United States of America.