Interaction between dietary and lifestyle risk factors and N-Acetyltransferase polymorphisms in B-Cell lymphoma etiology

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

Activation of the aryl hydrocarbon receptor and risk of lymphoma subtypes

The aryl hydrocarbon receptor (AhR) is a transcription factor implicated in several pathways known to be relevant in lymphomagenesis. Aim of our study was to explore the link between AhR activation and risk of lymphoma subtypes. We used a Dual-Luciferase Assay® and a luminometer to detect the activation of the luciferase gene, in HepG2 cells transfected with a specific reporter systems, by a 50 ml serum aliquot of cases of diffuse large B cell lymphoma (N = 108), follicular lymphoma (N = 85), chronic lymphocytic leukemia (N = 72), multiple myeloma (N = 80), and Hodgkin lymphoma (N = 94) and 357 controls who participated in the multicentre Italian study on gene-environment interactions in lymphoma etiology (ItGxE). Risk of each lymphoma subtype associated with AhR activation was calculated with polytomous logistic regression adjusting by age, gender, and study centre. The overall prevalence of AhR activation ranged 13.9-23.6% by subtype, and it varied by study area (8-39%). Risk associated with AhR activation was moderately elevated for follicular lymphoma (OR = 1.56, 95% CI 0.86, 2.80) and chronic lymphocytic leukemia (OR = 1.56, 95% CI 0.83, 2.96). Despite our inconclusive findings about the association with risk of lymphoma subtypes, we showed that the Dual-Luciferase Assay can be reliably and easily applied in population-based studies to detect AhR activation

A Role of <i>BRCA1</i> and <i>BRCA2</i> germline mutations in breast cancer susceptibility within Sardinian population

Background. In recent years, numerous studies have assessed the prevalence of germline mutations in BRCA1 and BRCA2 genes in various cohorts. We here extensively investigated the prevalence and geographical distribution of BRCA1-2 mutations in the entire genetically-homogeneous Sardinian population. The occurrence of phenotypic characteristics which may be predictive for the presence of BRCA1-2 germline mutations was also evaluated. Methods. Three hundred and forty-eight breast cancer patients presenting a familial recurrence of invasive breast or ovarian carcinoma with at least two affected family members were screened for BRCA1-2 mutations by DHPLC analysis and DNA sequencing. Association of BRCA1 and BRCA2 mutational status with clinical and pathological parameters was evaluated by Pearson's Chi-Squared test. Results and Conclusion. Overall, 8 BRCA1 and 5 BRCA2 deleterious mutations were detected in 35/348 (10%) families; majority (23/35;66%) of mutations was found in BRCA2 gene. The geographical distribution of BRCA1-2 mutations was related to three specific large areas of Sardinia, reflecting its ancient history: a) the Northern area, linguistically different from the rest of the island (where a BRCA2 c.8764_8765delAG mutation with founder effect was predominant); b) the Middle area, land of the ancient Sardinian population (where BRCA2 mutations are still more common than BRCA1 mutations); and c) the South-Western area, with many Phoenician and Carthaginian locations (where BRCA1 mutations are prevalent). We also found that phenotypic features such as high tumor grading and lack of expression of estrogen/progesterone receptors together with age at diagnosis and presence of ovarian cancer in the family may be predictive for the presence of BRCA1-2 germline mutations

A role of BRCA1 and BRCA2 germline mutations in breast cancer susceptibility within Sardinian population

<p>Abstract</p> <p>Background</p> <p>In recent years, numerous studies have assessed the prevalence of germline mutations in <it>BRCA1 </it>and <it>BRCA2 </it>genes in various cohorts. We here extensively investigated the prevalence and geographical distribution of <it>BRCA1-2 </it>mutations in the entire genetically-homogeneous Sardinian population. The occurrence of phenotypic characteristics which may be predictive for the presence of <it>BRCA1-2 </it>germline mutations was also evaluated.</p> <p>Methods</p> <p>Three hundred and forty-eight breast cancer patients presenting a familial recurrence of invasive breast or ovarian carcinoma with at least two affected family members were screened for <it>BRCA1-2 </it>mutations by DHPLC analysis and DNA sequencing. Association of <it>BRCA1 </it>and <it>BRCA2 </it>mutational status with clinical and pathological parameters was evaluated by Pearson's Chi-Squared test.</p> <p>Results and Conclusion</p> <p>Overall, 8 <it>BRCA1 </it>and 5 <it>BRCA2 </it>deleterious mutations were detected in 35/348 (10%) families; majority (23/35;66%) of mutations was found in <it>BRCA2 </it>gene. The geographical distribution of <it>BRCA1-2 </it>mutations was related to three specific large areas of Sardinia, reflecting its ancient history: <it>a</it>) the Northern area, linguistically different from the rest of the island (where a <it>BRCA2 c.8764_8765delAG </it>mutation with founder effect was predominant); <it>b</it>) the Middle area, land of the ancient Sardinian population (where <it>BRCA2 </it>mutations are still more common than <it>BRCA1 </it>mutations); and <it>c</it>) the South-Western area, with many Phoenician and Carthaginian locations (where <it>BRCA1 </it>mutations are prevalent). We also found that phenotypic features such as high tumor grading and lack of expression of estrogen/progesterone receptors together with age at diagnosis and presence of ovarian cancer in the family may be predictive for the presence of <it>BRCA1-2 </it>germline mutations.</p

Correction: Distinct germline genetic susceptibility profiles identified for common non-Hodgkin lymphoma subtypes

Correction to: Leukemia https://doi.org/10.1038/s41375-022-01711-0, published online 22 October 202

Graft-<i>versus</i>-leukemia effects after allogeneic bone marrow transplantation are active also in the presence of clones with chromosomal anomalies in addition to the Ph chromosome

Two male patients with Philadelphia-chromosome (Ph+) chronic myelogenous leukemia (CML) underwent allogeneic bone marrow transplantation (ABMT) in the first chronic phase after busulfan treatment. In both cases, the donor was a sister, and engrafting was demonstrated by chromosome analyses which showed only donor cells in the BM. Cytogenetic relapse occurred 29 and 30 months after ABMT, respectively, when host cells reappeared: in both cases, the Ph and additional anomalies typical of the blastic phase of CML were evident. We then monitored the chromosome picture for 52 and 39 months, respectively: no striking evolution occurred, and cells with the Ph and additional anomalies persisted together with donor cells, which were a minority in the first patient and a great majority in the second throughout the observation period. A clinical relapse was observed in the first patient, but the disease never progressed to a blastic phase, whereas the second patient has not relapsed 7 years after ABMT. We reviewed data from the literature on cytogenetic relapse after ABMT in CML without clinical relapse, especially the 12 patients in whom cytogenetic relapse included chromosome anomalies in addition to the Ph, as in our patients. We suggest that graft-versus-leukemia (GVL) reactions in such patients are able to arrest progression of the leukemic blastic clone and prevent a possible relapse in blastic phase

High Resistance Rate of Chronic Myeloid Leukaemia (CML) to Imatinib Myselate (IM) Might be Related to Protein Tyrosine Phosphatase Receptor Type Gamma (PTPRG) Down-Regulation

CML is the most common myeloproliferative disease observed among adults, its 1st line of treatment is IM with a response rate ranging between 55 - 90%. In Qatar the resistance rate is higher than 45%. Our collaborators in Italy recently reported on the relation between CML and PTPRG.Our team reported previously on the high rate of resistance of CML to IM (45%). During this forum the team is further reporting on the possible underlying mechanisms behind this resistance (see Al-Dewik et al at this forum).Despite a few positive findings, no pattern could be identified to delineate a significant underlying mechanism. Our collaborators in Italy, identified that down-regulation of PTPRG increased colony formation in the PTPRG+ve megakaryocytic MEG-01 and LAMA-84, but had no effect in the PTPRG-ve K562 and KYO-1. Its over-expression had an oncosuppressive effect in all four cell lines and is associated with inhibition of BCR/ABL-dependent signalling. PTPRG was downregulated at the mRNA and protein levels in CML patients in both PB and BM, including CD34+ cells, and is re-expressed following molecular remission of disease. This re-expression was associated with loss of methylation of a CpG island of PTPRG promoter in 55% patients. In K562 cells, the hypomethylating agent 5-aza-2’-deoxycytidine induced PTPRG expression and caused inhibition of colony formation that was partially reverted by antisense-mediated downregulation of PTPRG expression. Conclusions: Although this study was done on 2 independent patient populations, it suggests that in CML populations with high resistance rate it might be worth examining the PTPRG expression level and correlate it with the pattern of resistance. Our group has secured 3 years funding from QNRF (NPRP 4-157-3-052) to investigate PTPRG signalling in CML, including the study of a possible link among the high CML resistance and the PTPRG expression levels

Down-regulation of protein tyrosine phosphatase gamma (PTPRG) in chronic myeloid leukemia (CML)

Background. Chronic Myelogenous Leukemia (CML) is the most common myeloproliferative disease while Receptor Protein Tyosine Phosphatase Gamma (PTPRG) has been implicated as a candidate tumor suppressor gene being its expression reduced in various neoplasms and somatic mutation detected in colon cancer. PTPRG regulates murine hemopoiesis and is expressed in specific hematopoietic lineages including CD34+ cells. Aims. Explore the possibility that PTPRG could be involved in the pathogenesis of CML. Methods. mRNA and protein levels were measured in cell lines, bone marrow and peripheral blood cells by real-time PCR and flow cytometry using a newly developed antibody specific for the extracellular domain of PTPRG. Proliferation, clonogenic and xenografting assays were used to study the effect of PTPRG cDNA transfection in CML cell lines. Results. We found that PTPRG expression was undetectable in two of four CML cell lines analyzed. Its loss correlates with higher clonogenicity and proliferation capabilities, while reexpression inhibits both parameters, reduces tyrosine phosphorylation and induces myeloid differentiation in stably transfected K562 cells. The oncosuppressive and differentiation-inducing effect of PTPRG was confirmed in vivo after xenotransplantation in a nude mice model. PTPRG is down regulated at mRNA and protein levels in leukocytes of CML (but not of chronic lymphocytic leukemia-CLL) patients in both peripheral blood and bone marrow, including CD34+ cells, and is reexpressed following molecular remission of the disease. Conclusions. Loss of PTPRG expression is associated to the pathogenesis of CML and designate PTPRG as a new pharmacological target. Measurement of PTPRG expression levels might find clinical application for confirming diagnosis and for following progression of disease and treatment

AIDA 0493 protocol for newly diagnosed acute promyelocytic leukemia: very long-term results and role of maintenance

Abstract All-trans-retinoic acid (ATRA) has greatly modified the prognosis of acute promyelocytic leukemia; however, the role of maintenance in patients in molecular complete remission after consolidation treatment is still debated. From July 1993 to May 2000, 807 genetically proven newly diagnosed acute promyelocytic leukemia patients received ATRA plus idarubicin as induction, followed by 3 intensive consolidation courses. Thereafter, patients reverse-transcribed polymerase chain reaction–negative for the PML-RARA fusion gene were randomized into 4 arms: oral 6-mercaptopurine and intramuscular methotrexate (arm 1); ATRA alone (arm 2); 3 months of arm1 alternating to 15 days of arm 2 (arm 3); and no further therapy (arm 4). Starting from February 1997, randomization was limited to ATRA-containing arms only (arms 2 and 3). Complete remission was achieved in 761 of 807 (94.3%) patients, and 681 completed the consolidation program. Of these, 664 (97.5%) were evaluated for the PML-RARA fusion gene, and 586 of 646 (90.7%) who tested reverse-transcribed polymerase chain reaction–negative were randomized to maintenance. The event-free survival estimate at 12 years was 68.9% (95% confidence interval, 66.4%-71.4%), and no differences in disease-free survival at 12 years were observed among the maintenance arms