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1) Background: We tested whether AHR activation induces DNA damage, whether polymorphisms in genes related to risk of Non-Hodgkin lymphoma are associated with DNA damage, and whether the two conditions do interact with each other. 2) Methods: Our study population included 36 subjects, randomly selected among the population controls participating in a case-control study on lymphoma in Sardinia, Italy, who donated a blood sample. We investigated 47 single nucleotide polymorphisms (SNPs) previously reported to convey risk of lymphoma; the Dual-Glo® Luciferase Assay System to detect activation of the aryl hydrocarbon receptor (AhR) by the serum of study subjects; and the COMET Assay to detect DNA damage. 3) Results: Activation of the aryl hydrocarbon receptor did not increase DNA damage in our study population. On the other hand, the mutant allele (G) of rs1056932/BCL6 increased the occurrence of DNA damage (p = 0.045); such association was confirmed among AhR negative, but not AhR positive subjects. 4) Conclusions: We observed excess DNA damage associated with a gene polymorphism, namely rs1056932/ BCL6, previously reported in association with risk of lymphoma. No increase in DNA damage was associated with AhR activation per se, nor with the other gene polymorphisms we investigated.

We investigated the association between environmental exposure to radiofrequency electromagnetic fields (RF-EMF) and risk of lymphoma subtypes in a case-control study comprised of 322 patients and 444 individuals serving as controls in Sardinia, Italy in 1998-2004. Questionnaire information included the self-reported distance of the three longest held residential addresses from fixed radio-television transmitters and mobile phone base stations. We georeferenced the residential addresses of all study subjects and obtained the spatial coordinates of mobile phone base stations. For each address within a 500-meter radius from a mobile phone base station, we estimated the RF-EMF intensity using predictions from spatial models, and we performed RF-EMF measurements at the door in the subset of the longest held addresses within a 250-meter radius. We calculated risk of lymphoma and its major subtypes associated with the RF-EMF exposure metrics with unconditional logistic regression, adjusting by age, gender and years of education. In the analysis of self-reported data, risk associated with residence in proximity (within 50 meters) to fixed radio-television transmitters was likewise elevated for lymphoma overall [odds ratio = 2.7, 95% confidence interval = 1.5-4.6], and for the major lymphoma subtypes. With reference to mobile phone base stations, we did not observe an association with either the self-reported, or the geocoded distance from mobile phone base stations. RF-EMF measurements did not vary by case-control status. By comparing the self-reports to the geocoded data, we discovered that the cases tended to underestimate the distance from mobile phone base stations differentially from the controls ( P = 0.073). The interpretation of our findings is compromised by the limited study size, particularly in the analysis of the individual lymphoma subtypes, and the unavailability of the spatial coordinates of radio-television transmitters. Nonetheless, our results do not support the hypothesis of a link between environmental exposure to RF-EMF from mobile phone base stations and risk of lymphoma subtypes.

Genes encoding for arylamine N-acetyltransferase 1 and 2 (NAT1 and NAT2) have been investigated with alternate findings in relation to risk of non-Hodgkin lymphoma (NHL). We tested functional haplotype-based NAT1 and NAT2 gene polymorphisms in relation to risk of lymphoma overall and its major B cell subtypes, diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL) and chronic lymphocytic leukaemia (CLL). We used allele specific primers and multiplex PCR to detect NAT1 and NAT2 haplotypes in 248 patients with incident lymphoma and 208 population controls. We inferred the NAT1 rapid and slow acetylator and the NAT2 rapid, intermediate or slow acetylator phenotype, based on published functional data on the respective genotypes. Odds ratios and 95% confidence intervals (95% CIs) for lymphoma, B-NHL, DLBCL, FL, CLL, and other B-NHL combined associated with the inferred rapid NAT1 acetylator and with the intermediate and slow NAT2 acetylator phenotypes were estimated with unconditional and polytomous logistic regression analysis, adjusting for age, gender and education. NAT1 rapid acetylators showed a 2.8-fold excess risk (95% CI 1.5-5.2) for lymphoma (all subtypes combined). Risk was highest for CLL and FL, with significant heterogeneity detected across subtypes. Risk also increased with decreasing NAT2 acetylating capacity with no heterogeneity detected across B cell lymphoma subtypes. Risks did not vary by gender. Although poor statistical power was a major limitation in our study, larger studies and pooled analyses are warranted to test whether NAT1 and NAT2 gene polymorphisms might modulate risk of specific lymphoma subtypes through the varying metabolic activity of their products. Copyright © 2015 John Wiley & Sons, Ltd.

Introduction Conflicting results have been published on the association between occupational and environmental exposure to radiofrequency (RF) and cancer risk Information bias might have played a role in some instances. Methods We geocoded fixed radio-tv transmitters and mobile phone base stations, as well as the residence of 451 cases and 603 controls who participated in a case-control study on the aetiology of lymphoma in Sardinia, Italy. A detailed residential history was available for all cases and controls, including the perceived distance from fixed radio-tv transmitters and mobile phone base stations. We applied the models used by the Regional Agency for Environmental Protection, and conducted RF measurements to estimate the RF field at the door of study subjects. We used unconditional logistic regression to calculate Odds Ratios and their 95% confidence intervals for lymphoma and its major subtypes associated with the RF exposure metrics, adjusting by age, gender, and education. Results Based on questionnaire data, risk of lymphoma overall was elevated for a cumulative exposure to fixed radio-tv transmitters above the median (OR=2.7, 95% CI=1.5–4.6). Risk was likewise elevated for all lymphoma subtypes. With reference to mobile phone base stations, we only observed a non significant excess risk of diffuse large B-cell lymphoma (DLBCL, OR=2.5, 95% CI=0.7–8.3). Such associations disappeared when we considered exposure based on the models, or the measurements. By comparing the reported distance to the geocoded data, we found out that the cases tended to underestimated the distance from the source of RF emission. Conclusions Our results do not support the hypothesis of a link between environmental exposure to RF and risk of lymphoma subtypes. Conflict of Interest statement : None of the coauthors declare any conflict of interest related to the matters discussed in this paper.

Objective Dioxin, a known risk factor for lymphoma, and numerous other xenobiotics, induce their own metabolism by initially activating the aryl hydrocarbon receptor (AhR). We used the serum samples of participants to the multicentre Italian study on gene-environment interactions in lymphoma aetiology (ITGxE) to explore AhR activation as an intermediate step in dioxin-induced risk of lymphoma, and particularly B-cell lymphoma subtypes. Methods Overall, serum samples of 343 lymphoma cases and 1899 population and hospital controls from five Italian areas (Florence, Bari, Perugia, Novara, and central and southern Sardinia) were available for study. A 50 microliter serum aliquot of each study participant potentially carrying the AhR activator, was added to HepG2 cells, transfected with specific reporter systems including the DRE specific AhR activating sequence upstream to the luciferase reported gene. The intensity of light generated by the Dual-Luciferase Assay, captured with a luminometer, is directly correlated with the concentration and potency of the inducing xenobiotic. Risk of lymphoma overall and by its major B-cell specific subtypes associated with AhR activation positivity as a binary outcome was calculated using an unconditional logistic regression model adjusted by age and gender. Results Among the B-cell lymphoma subtypes, there was a significant two-fold excess risk for follicular lymphoma (OR = 2.0, 95% CI: 1.0, 4.0) and chronic lymphocytic leukaemia (OR = 2.3, 95% CI: 1.0, 5.0). No increase in risk associated with AhR positivity was observed for the other B-cell lymphoma subtypes we tested, namely diffuse large B-cell lymphoma, and multiple myeloma, nor for Hodgkin lymphoma. Conclusions Our results show that the Dual-Luciferase Assay is a reliable and inexpensive test to detect AhR activation and its role in lymphomagenesis.

Background: Gene-environment interactions are suggested to play a role in lymphomagenesis. Methods: We tested the interaction between the NAT1/NAT2 phenotype, as inferred by the respective genotypes, and exposure to dietary and lifestyle risk factors, in 199 incident lymphoma cases and 188 population controls. We used unconditional logistic regression to calculate the odds ratio (OR) and its 95% confidence interval for lymphoma (all subtypes combined) and B cell lymphoma, associated to the rapid NAT1 phenotype and to the intermediate and slow NAT2 phenotype, and to the estimated dietary intake of heterocyclic amines and folate, current smoking, coffee, and use of permanent hair dyes, as well as the respective interaction terms. We adjusted the ORs by age, gender, and education, and we used the likelihood ratio test to test the interaction between the NAT1, NAT2 phenotype and the dietary and lifestyle variables. Results: We observed an increase in risk of lymphoma (all subtypes combined) and B-cell lymphoma in particular associated with the estimated above median dietary intake of heterocyclic amines (OR = 4.2, 95%CI 1.2 – 14.8) and folate (OR = 4.1, 95%CI 0.7 – 22.4) among subjects with the NAT1 rapid acetylator phenotype, but not independent on the NAT1 phenotype. The test for interaction was significant for heterocyclic amines, but not for folate (p for interaction = 0.026 and 0.076 respectively). Ever use of permanent hair dyes was associated with an elevated risk independent on the NAT1, NAT2 phenotypes; risk decreased to null among intermediate and slow NAT1 acetylators (p for interaction = 0.010). Conclusions: Our results suggest that NAT1, NAT2 polymorphisms interact with dietary and lifestyle exposures in modulating risk of lymphoma and particularly B-cell lymphoma.

Background Previous studies have suggested that diet might affect risk of lymphoma subtypes. We investigated risk of lymphoma and its major subtypes associated with diet in the Mediterranean island of Sardinia, Italy. Methods In 1998–2004, 322 incident lymphoma cases and 446 randomly selected population controls participated in a case-control study on lymphoma etiology in central-southern Sardinia. Questionnaire interviews included frequency of intake of 112 food items. Risk associated with individual dietary items and groups thereof was explored by unconditional and polytomous logistic regression analysis, adjusting by age, gender and education. Results We observed an upward trend in risk of lymphoma (all subtypes combined) and B-cell lymphoma with frequency of intake of well done grilled/roasted chicken ( p for trend=0.01), and pizza ( p for trend=0.047), Neither adherence to Mediterranean diet nor a frequent intake of its individual components conveyed protection. We detected heterogeneity in risk associated with several food items and groups thereof by lymphoma subtypes although we could not rule out chance as responsible for the observed direct or inverse associations. Conclusions Adherence to a Mediterranean diet does not seem to convey protection against the development of lymphoma. The association with specific food items might vary by lymphoma subtype.

Chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease characterized by the clonal expansion of malignant B cells. To predict the clinical course of the disease, the identification of diagnostic biomarkers is urgently needed. Aberrant methylation patterns may predict CLL development and its course, being very early changes during carcinogenesis. Our aim was to identify CLL specific methylation patterns and to evaluate whether methylation aberrations in selected genes are associated with changes in gene expression. Here, by performing a genome-wide methylation analysis, we identified several CLL-specific methylation alterations. We focused on the most altered one, at a CpG island located in the body of SHANK1 gene, in our CLL cases compared to healthy controls. This methylation alteration was successfully validated in a larger cohort including 139 CLL and 20 control in silico samples. We also found a positive correlation between SHANK1 methylation level and absolute lymphocyte count, in particular CD19+ B cells, in CLL patients. Moreover, we were able to detect gains of methylation at SHANK1 in blood samples collected years prior to diagnosis. Overall, our results suggest methylation alteration at this SHANK1 CpG island as a biomarker for risk and diagnosis of CLL, and also in the personalized quantification of tumor aggressiveness.