Development Of Lymphoid Malignancies Research Articles

Lymphoid malignancy in common variable immunodeficiency in a single-center cohort.

One of the complications of common variable immunodeficiency (CVID) is the development of lymphoid malignancy. In this retrospective, single-center study of 647 CVID subjects followed over 4 decades, we present immunologic and clinical phenotypes, pathology, treatment, and outcomes of 45 patients (15 males and 30 females, 7%) who developed 49 lymphoid malignancies. The mean age at CVID diagnosis was 42.6years) and at lymphoma diagnosis was 48.8years. Of the 41 with known follow up, 29 (70%) have died, 27 of these due to this diagnosis. Twelve are alive, in remission or have achieved cure; four others were alive at last encounter. Some patients had a history of only recurrent infections (36.3%); others had autoimmunity (33%), enteropathy (20%), and/or granulomatous disease (11%). Six had previously been treated for another cancer. This report also includes 6 additional living CVID patients who had been diagnosed with NHL; 4 were given treatment for this. However, on pathology review, the initial diagnosis was reversed, as the findings were more consistent with a benign lymphoproliferative process. This study outlines the high incidence of lymphoma in this single CVID cohort, and some of the diagnostic challenges presented due to immune dysregulation characteristic of this immune defect.

Biochemical and Cellular Profile of NIK Inhibitors with Long Residence Times.

Two different signaling pathways lead to the activation of the transcription factor NF-κB, initiating distinct biological responses: The canonical NF-κB pathway activation has been implicated in host immunity and inflammatory responses, whereas the noncanonical pathway activation has been involved in lymphoid organ development and B-cell maturation, as well as in the development of chronic inflammatory diseases and some hematologic cancers. The NF-κB-inducing kinase (NIK) is a cytoplasmic Ser/Thr kinase and is a key regulator of the noncanonical pathway. NIK activation results in the processing of the p100 subunit to p52, leading to the formation of the RelB/p52 complex and noncanonical pathway activation. Because of its role in the development of lymphoid malignancies, this kinase has always been considered as an attractive target for the treatment of certain types of cancers and immune diseases. We at Takeda have pursued a drug discovery program to identify small-molecule inhibitors against NIK. This report provides an overview of the data generated from our screening campaign using a small fragment library. Most importantly, we also provide a kinetic analysis of published compounds and chemical series developed at Takeda that are associated with a slow tight-binding mechanism and excellent cellular potency.

ABCL-311: The Burden of Non-Hodgkin Lymphoma Developed in an Ataxia Telangiectasia Child

Context: Ataxia telangiectasia (AT) is an autosomal recessive disorder characterized by progressive neurologic impairment, cerebellar ataxia, immunodeficiency, ocular and cutaneous telangiectasia, and predisposition to malignancy. AT patients have a 100-fold increased risk for the development of lymphoid malignancies, particularly non-Hodgkin lymphomas (NHL). In these patients, severe pulmonary infections are the most frequent cause of death, followed by the combination of pulmonary infection and malignancy. Objective: Evaluation of a clinical case of hematologic malignancy in a child diagnosed with primary immunodeficiency (PID) AT. Methods: We analyzed clinical records, biopsy of lymph node, evaluation of serum immunoglobulins by ELISA, and neurologic involvement by MRI. Results: A 13-year-old boy diagnosed as AT was referred to the Oncologic hospital due to multiple lymphadenopathy. He was born to non-consanguineous healthy parents. Previous medical history revealed waddling gait when he started walking. He was consulted by a neuropediatrician as being suspected of cerebral palsy. Brain MRI revealed cerebellar vermis hypoplasia with enlargement of cisterna magna. The patient also experienced recurrent respiratory infections. At the age of 12 years, the patient had fever of unknown origin for several months, which was unresponsive to antibiotics, and the patient's cervical and submandibular lymph nodes began to enlarge, which progressed. A biopsy was performed, and the patient was diagnosed with NHL, DLBCL type. On presentation, the patient had multiple enlarged cervical, submandibular, axillary, and inguinal lymph nodes and telangiectasia of the bulbar conjunctiva. Neurologic examination revealed decreased tendon reflexes, ataxia, and dysarthria. Laboratory investigations identified a normal complete blood count and biochemistry tests, but the alpha-fetoprotein level was high. There were decreased levels of IgA and IgG and a high level of IgM. Computed tomography showed involvement of cervical, submandibular, axillary, upper mediastinum, and hilum lymph nodes. The patient received CHOP chemotherapy with a reduced dose. The treatment was well-tolerated, despite neutropenia, grade 3 mucositis, and neutropenic fever. Unfortunately, at the last interruption after chemotherapy, the patient had chickenpox and died due to multiple organ failure. Conclusions: Patients with PID have a high risk of developing cancer. It is important to consider AT in a child with pre-existing ataxia or hematologic malignancy that was diagnosed at a younger age than expected.

Development of diffuse large B-cell lymphoma after sofosbuvir-ledipasvir treatment for chronic hepatitis C: A case report and literature review.

Recently, treatments for chronic hepatitis C virus (HCV) infection have significantly improved by the development of direct-acting antiviral agents (DAAs) and almost all patients with HCV can complete antiviral treatment without apparent adverse events. Malignant lymphoma, particularly B-cell non-Hodgkin's lymphoma, is one of the extrahepatic manifestations associated with chronic HCV infection. The effectiveness of anti-HCV therapy with DAAs for B-cell non-Hodgkin's lymphoma has been demonstrated in recent reports, whereas late-onset B-cell non-Hodgkin's lymphoma after HCV eradication with DAAs has occasionally been reported. In the present study, a 77-year-old man with chronic hepatitis C and intermediate liver cancer risk received sofosbuvir-ledipasvir treatment for 12 weeks. Two months following the end of antiviral therapy, he had achieved sustained virologic response for 8 weeks. However, the patient occasionally found swelling of the right cervical lymph nodes without any subjective symptoms. Lymph node biopsy revealed diffuse large B-cell lymphoma and whole-body 18F-fluorodeoxyglucose (FDG) positron emission tomography with computed tomography showed increased FDG uptake in the right cervical, right submandibular, mediastinal and mesenteric lymph nodes. The patient received six courses of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone chemotherapy and achieved complete response at 8 months after chemotherapy initiation. Thus, the development of lymphoid malignancies may arise, even after HCV eradication with DAAs. Therefore, clinicians should be aware of such risks during and after antiviral treatment with DAAs.

Identification of a new family of pyrazolo[3,4-d]pyrimidine derivatives as multitarget Fyn-Blk-Lyn inhibitors active on B- and T-lymphoma cell lines

Abnormal activation of B-cell receptor (BCR) signaling plays a key role in the development of lymphoid malignancies, and could be reverted by the simultaneous inhibition of Lyn, Fyn and Blk, three members of the Src family kinase (SFK).Fyn and Blk are also promising targets for the treatment of some forms of T-cell non-Hodgkin lymphoma which point to the druggability of SFKs for the treatment of these cancers. We recently identified Si308 as a potent Fyn inhibitor, while preliminary data showed that it might also inhibit Lyn and Blk. Here, molecular modelling studies were coupled with enzymatic assays to further investigate the effect of Si308 on Lyn and Blk. A small library of pyrazolo[3,4-d]pyrimidines structurally related to Si308 was synthesized and tested on human lymphoma cell lines. Compound 2h emerged as a new multitarget inhibitor of Lyn, Fyn and Blk endowed with remarkable antiproliferative effects on human B and T lymphoma cell lines. Its favorable ADME properties make the compound suitable for further developments.

The contribution of immune activation and accelerated aging in multiple myeloma occurring in HIV-infected population.

: The widespread use of antiretroviral treatment results in a significant improvement in immunological condition of people living with HIV (PLWH) who nevertheless experience a significantly increased risk to develop non-Hodgkin lymphoma compared with the general population. Despite many literature observations regarding multiple myeloma in PLWH, a consensus on its relevance in HIV infection does not exist. A number of large population studies on multiple myeloma in PLWH gave contrasting results, fluctuating from increased standardized incidence ratios to the lack of observed cases of multiple myeloma. Use of antiretroviral treatment, in this context, seems to induce a slight reduction of standardized incidence ratio, although with a partial effect, especially in young patients. However, a high variability in clinical onset has been described in different reports: the only common feature of multiple myeloma in PLWH is an atypical presentation as compared with general population, with a worse prognosis in case of uncontrolled HIV infection. We identified three pathogenetic steps in the complex scenario of multiple myeloma in PLWH: first, antigenic trigger; second, persistent T cell deficiency/dysfunction; third, altered regulation of B cells. All these pathogenetic steps play a role in immunological dysregulation, leading to B cell abnormalities and hyperactivation and, finally, resulting in the development of lymphoid malignancies. HIV has a role in each one of these three steps, due to its ability to trigger and dysregulate immune system. We hypothesize that HIV could be closely implicated in the multiple myeloma development in PLWH by accelerating the carcinogenesis events in a complex and only partially understood early aging process.

Loss of NR4A1 Accelerates the Development of Aggressive Lymphomas in Myc Induced Cancerogenesis

Introduction and Aim:We recently described a reduced NR4A1 and NR4A3 expression chronic lymphocytic leukemia, follicular lymphoma, and diffuse large B-cell lymphoma compared to normal controls. Our survival analysis of aggressive lymphomas revealed that low NR4A1 expression was associated with poor cancer specific survival. Over-expression of NR4A1 in lymphoma cell lines led to a significantly higher proportion of lymphoma cells undergoing apoptosis and abrogated tumor growth in xenografts1. The aim of this study is to define the role of NR4A1 as a tumor suppressor in the development of lymphoid malignancies in vivo.Methods:To identify, whether the loss of NR4A1 has an impact in Myc driven lymphomagenesis we crossed EµMyc mice with NR4A1-/- mice and performed phenotypical analysis including measurement of tumor development, survival and immunophenotypic determination of the newly developed lymphomas by FACS analysis. To further investigate the impact of NR4A1 loss on the oncogenic potential of EµMyc lymphoma cells we isolated viable tumor cells (B220+ and 7AAD-) and cultured them for 72h with or without lipopolysaccharide (LPS) and determined the number of viable cells and their viability (B220 and 7AAD-staining by flow cytometry analysis) after 24h, 48h and 72h. Finally, expression levels of NR4A1, NR4A3 and Myc with or without NR4A1 loss were evaluated by using RT-qPCR.Results:EµMyc mice with NR4A1 loss (EµMyc NR4A1-/-, n=46) developed visible tumors significantly faster compared to EµMyc mice with NR4A1 (EµMyc NR4A1+/+, n=75) (median = 44 days for EµMyc NR4A1 -/- vs. 107 days for EµMyc NR4A1+/+; p<0.001). Additionally, EµMyc NR4A1-/- mice showed a significantly shorter life span (median survival = 77 days) compared to EµMyc NR4A1 +/+ mice (median survival = 156 days; p<0.001). By comparing the immunophenotype of the newly developed lymphoma between the two groups (EµMyc NR4A1+/+, n=17 and EµMyc NR4A1 /- , n=19), no significant difference was observed. Interestingly, EµMyc NR4A1-/- mice showed an increased frequency of strong CD93 expression (10 of 18, respectively, vs. 2 of 17 EµMyc NR4A1 +/+ mice, p=0.004). Since most of the EµMyc NR4A1-/- lymphoma were IgM negative (7 of 10) it might be speculated that NR4A1 loss leads to a more immature phenotype of the lymphoma. The number of viable B220+ lymphoma cells isolated from EµMyc NR4A1-/- mice was higher compared to B220+ lymphoma cells isolated from EµMyc NR4A1+/+ mice after 72h in culture with or without LPS (p=0.056; p=0,052). This was accompagnied by a higher in vitro proliferation rate as demonstrated by a higher percentage of BrdU positive cells of the EµMyc NR4A1-/- mice compared to B220+ EµMyc NR4A1+/+ cells with and without LPS stimulation (p= 0,064, p=0,038). Interestingly, we detected a 12 fold higher NR4A3 mRNA expression (p=0,038) in EµMyc NR4A1-/- tumors compared to EµMyc NR4A1+/+.Conclusion: Our data demonstrate that NR4A1 possesses tumor suppressive properties and that loss of NR4A1 accelerates Myc driven lymphomagenesis. Furthermore, this study indicates that deletion of NR4A1 confers a more aggressive behavior and increases the oncogenic potential of EµMyc driven lymphoma cells.1. Deutsch AJ, Rinner B, Wenzl K, et al. NR4A1-mediated apoptosis suppresses lymphomagenesis and is associated with a favorable cancer specific survival in patients with aggressive B-cell lymphomas. Blood. 2014. DisclosuresNo relevant conflicts of interest to declare.

The paracaspase MALT1: biological function and potential for therapeutic inhibition.

The paracaspase MALT1 has a central role in the activation of lymphocytes and other immune cells including myeloid cells, mast cells and NK cells. MALT1 activity is required not only for the immune response, but also for the development of natural Treg cells that keep the immune response in check. Exaggerated MALT1 activity has been associated with the development of lymphoid malignancies, and recently developed MALT1 inhibitors show promising anti-tumor effects in xenograft models of diffuse large B cell lymphoma. In this review, we provide an overview of the present understanding of MALT1’s function, and discuss possibilities for its therapeutic targeting based on recently developed inhibitors and animal models.

Genetics of hereditary hematological malignancies

Familial predisposition to hematological malignancies has been recognized. Some of these malignancies are part of a well-characterized familial cancer predisposition syndrome, while others are independent of cancer predisposition, and demonstrate unique familial leukemia/lymphoma syndromes. Primary immunodeficiency is also strongly associated with the development of lymphoid malignancy. Primary immunodeficiency and leukemia/lymphoma are based on the same concept, which involves differentiation blockage. Bone marrow failure syndrome is also known to be associated with susceptibility to hematological malignancy development. Bone marrow failure syndrome exhibiting myeloid differentiation is also characterized as an aspect of primary immunodeficiency. Recent progress in genome wide association studies (GWAS) identified several single nucleotide polymorphisms (SNP) associated with leukemia/lymphoma development. Some of these genes were found to be functionally related to hematological malignancies. These discoveries are contributing to elucidation of the genetic background of leukemia/lymphoma development.

Mll-AF4 Induction during Ontogeny Reveals Early Changes in Myeloid and Lymphoid potential and Results in Hematopoietic Malignancies in Adult Mice

Acute leukemia is the most common malignancy of childhood. The pattern of incidence of childhood leukemia reveals how age at diagnosis is associated with particular molecular subtypes, responsiveness to treatment and outcome.Translocations involving the Mixed Lineage Leukemia gene (MLL) in particular are associated with the diagnosis of acute leukemia in infancy. As with other forms of childhood leukemia, evidence from retrospective cohort analysis of neonatal blood spots suggests that MLL translocations are present at birth in many of these cases, indicating that the initial steps towards leukemia development occurred in utero (Greaves Early Human Development 2005).Concurrently there has been increasing recognition of the differences between the foetal and adult hematopoietic cells and supportive niches. These differences might have profound effects on a cell’s ability to undergo malignant transformation and its subsequent properties.Unlike mouse models of myeloid leukemia associated with MLL fusions, previous attempts to mouse model acute lymphoid leukemia of infancy associated with the MLL-AF4 fusion gene have had mixed results, with unsatisfactory disease latencies and phenotypes (Stam Cell Research 2012). However, many of these models have introduced the translocation only within the adult hematopoietic system – discounting the possible effect of this mutation in utero.The aim of this study was to examine the effect of MLL-AF4 within the context of the varied hematopoietic sites of the developing embryo, and how the induction of MLL-AF4 within these niches might influence subsequent disease development.For this, we utilised the Cre inducible Mll-AF4 “invertor mouse” that has previously been described (Metzler et al Oncogene 2006). As embryonic stem cell work suggests MLL-AF4 may alter the emergence of Hematopoietic Stem Cells (HSCs) from the hemogenic precursors (Bueno Cell Research 2012), we crossed the invertor mice with Ve-cadherin-Cre and Vav-Cre murine lines to induce Mll-AF4 expression in (pre)HSCs before and after this critical time point. HSC and progenitor populations at several established hematopoietic sites through ontogeny were assessed by flow cytometry and functional assays, including in vitro methylcellulose based colony forming assays and in vivo transplantation assays. Mice were also bred to adulthood and observed for the development of disease.Despite no statistically significant changes in HSC and progenitor populations within in utero HSC niches, functional assays reveal marked differences in both myeloid and lymphoid colony forming assays with a particularly strong effect seen in lymphoid assays; however, despite evidence of a limited increase in serial repeatability, these cells did not appear to be fully transformed and could not be re-plated successfully beyond the third round. In vivo transplantation assays also showed enhanced multi-lineage engraftment by foetal liver cells carrying the Mll-AF4 fusion gene. Adult mice developed both B and T cell malignancies with long latencies and median survival of 437 day to 551 days for Mll-AF4xVeCadherin-Cre and Mll-AF4xVav-Cre lines, respectively.We have thus shown for the first time that the induction of Mll-AF4 has an effect on the myeloid and lymphoid output of foetal derived HSCs. Although this effect appears to fall short of full transformation, the development of lymphoid malignancies in adult mice suggests that such cells have pre-malignant potential. We continue to explore the mechanism of these early pre-malignant effects and aim to explore how additional factors may unlock the true malignant potential of MLL-AF4 in murine model systems. DisclosuresNo relevant conflicts of interest to declare.

Tumor necrosis factor alpha−308 and Lymphotoxin alpha+252 genetic polymorphisms and the susceptibility to non-Hodgkin lymphoma in Egypt

Genetic polymorphism within the regulatory regions of tumor necrosis factor-alpha (TNF-α) and Lymphotoxin-alpha (LT-α) may be involved in the development of lymphoid malignancies. The aim of the current study was to investigate the effect of TNFα−308 and LTα+252 genetic polymorphism on susceptibility to non-Hodgkin lymphoma (NHL) in Egypt. Genotyping of the studied genes by restriction fragment length polymorphism polymerase chain reaction was conducted on 84 NHL and 100 healthy controls and revealed that TNFα−308 homotype (AA) was significantly higher in NHL patients and conferred sixfold increased risk of NHL (OR=5.9, 95%CI=2.3–16.1). Moreover, TNFα/LTα high-producer haplotypes were significantly higher in NHL patients and conferred increased risk of NHL (OR=4.59, 95%CI=2.19–9.42).

CXCL13, CCL21, and CXCL12 Expression in Salivary Glands of Patients with Sjögren’s Syndrome and MALT Lymphoma: Association with Reactive and Malignant Areas of Lymphoid Organization

The chemokines (CKs) CXCL13, CCL21, and CXCL12 are known to play differential roles in the organization of the lymphoid tissues and the development of lymphoid malignancies. We investigated the expression of these CKs and their receptors in the salivary glands of Sjogren's syndrome patients with lymphoepithelial lesions (lymphoepithelial sialadenitis or LESA) and in MALT lymphoma to understand their involvement in salivary gland lymphomagenesis. We demonstrate that within salivary glands with LESA and MALT lymphoma the lymphoid CKs CXCL13 and CCL21 are selectively associated with areas of reactive lymphoid proliferation, whereas no significant expression of these molecules was detected in the malignant lymphoid aggregate. Conversely, CXCL12 was observed predominantly in infiltrated ducts and malignant B cells. Accordingly, CXCL13 and CCL21 transcript levels were significantly increased in LESA samples while CXCL12 levels were increased in MALT lymphoma and isolated tumor cells. Low levels of CK receptors were detected on lymphoma-extracted lymphocytes, suggesting down-regulation in the abundance of ligands. Our findings suggest that in salivary gland MALT lymphoma the lymphoid CKs CXCL13 and CCL21 are directly implicated in the organization of ectopic reactive lymphoid tissue, whereas CXCL12 is associated with the infiltrated epithelium and malignant B cell component and is possibly involved in the regulation of malignant B cell survival.

A look at life from the homeodomain

​ThisThis workshop brought together developmental biologists and oncologists for three intense days of discussions about the recent progress that has been made on the roles of homeodomain proteins in development, haematopoiesis and leukaemogenesis. The homeo-domain is a 61-amino-acid DNA-binding motif with specific sequence and structural characteristics (Gehring & Hiromi, 1986). Homeodomain proteins were initially identified in Drosophila as being responsible, when mutated, for homeotic transformations—that is, the conversion of a part of the body into the likeness of another. Since their initial discovery, the number of homeodomain proteins has increased enormously, and they comprise several different families of transcription factors. The main stars of the meeting were members of the Hox family and of the three amino-acid loop extension (TALE) families, with some other homeodomain proteins making guest appearances. TALE proteins include the PBC family (Exd in Drosophila and Pbx proteins in vertebrates) and the Hth/Meis superfamily (Hth in Drosophila, and Meis and Prep proteins in vertebrates). The link between Hox and TALE proteins is their functional interactions, which were initially revealed in flies by genetic analyses and later supported by biochemical data (Mann & Affolter, 1998; Moens & Selleri, 2006). PBC proteins have been shown to act as Hox cofactors that mainly determine Hox DNA-binding specificity and selectivity. Hth/Meis proteins interact with PBC proteins, participating in ternary complexes with Hox proteins, or modulating PBC protein stability and subcellular localization. This European Molecular Biology Organization/European School of Molecular Medicine workshop on Homeodomain Proteins, Hematopoietic Development and Leukemias took place in Riva del Garda, Italy, between 23 and 25 March 2006, and was organized by F. Blasi, ... Functional specificities and redundancies A large part of the meeting was devoted to the presentation and discussion of the consequences of the complete or partial inactivation of different TALE products in several vertebrates. These studies arrived at two main conclusions: first, TALE proteins are essential for the development of most areas of the organism; and second, they have both individual functions and a large degree of redundancy. This was clearly shown in the Pbx gene family, for which an advanced phenotypic analysis of single and compound mutants was presented. In mice, the individual contribution of each member of the family seemed to be different because, whereas the Pbx1 single mutant had a wide range of malformations, only minor or no phenotypes were obvious in Pbx2 and Pbx3 mutants. However, when a reduced Pbx2 and/or Pbx3 dosage was added to the Pbx1−/− background, strong exacerbations of the malformations were detected, as reported by L. Selleri (New York, NY, USA) and M. Cleary (Stanford, CA, USA). In particular, the cardiovascular system, the axial skeleton, the limbs and the craniofacial area were shown to be strongly affected. A.J. Waskiewicz (Edmonton, Canada) also described redundancy among Pbx genes in zebrafish, in which the functions of the Pbx2 and Pbx4 gene products seem to overlap in a range of tissues, including the hindbrain and tectum, and during early haematopoiesis. Hox gene products are known to be largely redundant, especially within paralogous groups. In the case of the Meis and Prep gene families, pleiotropic functions in patterning and differentiation processes were also described (see below); however, genetic analyses designed to evaluate the possible extent of redundancy among the different members of these gene families are still at an early stage. At the meeting, several tissues were reported to require the activity of homeodomain proteins for proper development; we highlight some of these data below.

Association between non‐Hodgkin lymphoma and haplotypes in the TNF region

The cytokines tumour necrosis factor-alpha (TNFalpha) and lymphotoxin-alpha (LTalpha) are known to play key roles in B-cell growth, differentiation and maturation. Genetic polymorphism within regulatory regions of these cytokine genes can alter expression levels and may be important in development of lymphoid malignancy. This study investigates a number of single nucleotide polymorphisms (SNPs) and microsatellite variants present within these genes in a large cohort of non-Hodgkin lymphoma (NHL) cases including 211 cases of follicular lymphoma (FL) and 281 cases of diffuse large B-cell lymphoma (DLBCL), and 478 unaffected controls. The study investigated whether particular alleles at these loci, or their combination across the TNF region in the form of haplotypes, may act as markers for predisposition and development of NHL. The study provided evidence for an influence of the TNF region in the susceptibility to NHL, whereby the loci -863, -857, TNFe and TNFd categorised five haplotype groups over which risk of both FL and DLBCL varied significantly. Prediction of disease risk was improved by the addition of loci to the haplotype, demonstrating the importance of considering the haplotype-specific context of the loci in genetic risk assessment.

Use of hydroxy‐methyl‐glutaryl coenzyme A reductase inhibitors is associated with risk of lymphoid malignancies

It has been speculated that the use of hydroxy-methyl-glutaryl coenzyme A reductase inhibitors (statins) is associated with the risk of malignant diseases. Considering their immunosuppressive activities, malignant diseases that are associated with an immunosuppressive status seem feasible to examine the association. We therefore examined the association between statin use and development of lymphoid malignancies in a case-control study. Cases were 221 consecutive incident cases with histopathologically proven lymphoid malignancies (lymphoma and myeloma), hospitalized in the Department of Hematology of Toranomon Hospital (Tokyo, Japan) between 1995 and 2001. Two independent control groups, comprising 442 and 437 inpatients without malignancies from the Departments of Orthopedics and Otorhinolaryngology of the same hospital, were selected to test for consistency of association. Controls were matched individually with cases for age, sex and year of admission. Subject information, including statin use, was abstracted from medical records at the time of hospitalization. Strength of association was evaluated as an adjusted odds ratios (aOR) using a conditional logistic regression model. A higher frequency of statin use was found among patients with lymphoid malignancies in comparison with both orthopedic (aOR 2.11, 95% CI 1.20-3.69, P = 0.009) and otorhinolaryngology patients (aOR 2.59, 95% CI 1.45-4.65, P = 0.001), the significance being maintained when the two control groups were combined (aOR 2.24, 95% CI 1.37-3.66, P = 0.001). In conclusion, we observed an elevated risk of lymphoid malignancy with statin use among Japanese patients. Further evaluations in different populations are required to draw conclusions as to the carcinogenicity of lymphoid malignancies with statin use.

Expression, purification, crystallization and preliminary crystallographic analysis of human Pim-1 kinase.

Pim kinases, including Pim-1, Pim-2 and Pim-3, belong to a distinctive serine/threonine protein-kinase family. They are involved in cytokine-induced signal transduction and the development of lymphoid malignancies. Their kinase domains are highly homologous to one another, but share low sequence identity to other kinases. Specifically, there are two proline residues in the conserved hinge-region sequence ERPXPX separated by a residue that is non-conserved among Pim kinases. Full-length human Pim-1 kinase (1-313) was cloned and expressed in Escherichia coli as a GST-fusion protein and truncated to Pim-1 (14-313) by thrombin digestion during purification. The Pim-1 (14-313) protein was purified to high homogeneity and monodispersity. This protein preparation yielded small crystals in the initial screening and large crystals after optimization. The large crystals of apo Pim-1 enzyme diffracted to 2.1 A resolution and belong to space group P6(5), with unit-cell parameters a = b = 95.9, c = 80.0 A, beta = 120 degrees and one molecule per asymmetric unit.

DNA mismatches and GC-rich motifs target transposition by the RAG1/RAG2 transposase.

In addition to their essential role in V(D)J recombination, the RAG proteins function as a transposase capable of inserting the V(D)J recombination intermediate, the signal end DNA fragment, into target DNA. RAG-mediated transposition has been suggested to contribute to genome instability and the development of lymphoid malignancies. Previous studies suggested that the RAG transposase exhibits a target site preference for GC rich sequences and hairpin structures. Here we demonstrate that a transposition hot spot (5'-GCCGCCGGGCC-3'), smaller portions of this hot spot and other GC rich motifs are able to target RAG-mediated transposition. Tracks of GC base pairs have been shown to have an unusually high rate of base pair breathing. Intriguingly, we find that DNA mismatches can efficiently target RAG-mediated transposition and suppress the use of other target sites. Hairpins, however, are not generally preferred targets. Our results indicate that target DNA melting may be a crucial step during RAG-mediated transposition, and that target site selection by the RAG transposase may be intimately linked to mutagenic and metabolic processes that transiently present favorable DNA structures to the transposition machinery.

Methylation of promoter region in p27 gene plays a role in the development of lymphoid malignancies.

p27 belong to the cyclin-dependent kinase inhibitor family and plays an important role in regulation of cell cycle progression. Expression of these genes is epigenetically suppressed by methylation of their promoter regions. In this study, we examined protein expression and methylation status of the promoter region of p27 in 70 cases with non-Hodgkin's lymphoma and their relationship with proliferative activity of the tumor cells as revealed by Ki-67 index. There were 35 cases of B-cell, 11 of T-cell, 23 of NK/T-cell lymphoma, and 1 undetermined type. Immunohistochemically the loss of p27 protein expression was observed in 24 (69%) of 35 cases. Significant inverse correlation between p27 protein expression and Ki-67 index was found. Single strand conformation polymorphism (SSCP) followed by sequencing could not detect point mutations in any of the 68 cases. Bisulfite sequencing analysis showed that methylation of the promoter region of p27 were observed in 17 (25%) of 68 cases, in that several specific CpG sites around the start codon of p27 gene were preferentially methylated. Eight of 22 cases with loss of p27 protein expression showed methylation in CpG island of 5' region of p27 gene. These findings suggested that gene methylation plays a role in loss of expression of p27, which gives the cells proliferative advantages.

Cutting edge: Transcriptional activity of NFATc1 is enhanced by the Pim-1 kinase.

Pim-1 is an oncogenic serine/threonine kinase implicated in cytokine-induced signal transduction and in development of lymphoid malignancies. However, its precise function as well as physiological substrates have remained unknown. In this study we demonstrate that Pim-1 can physically interact with the NFATc1 transcription factor and phosphorylate it in vitro on several serine residues. In contrast to previously recognized NFATc kinases, wild-type Pim-1 enhances NFATc-dependent transactivation and IL-2 production in Jurkat T cells, while kinase-deficient Pim-1 mutants inhibit them in a dominant negative fashion. Our results reveal a novel, phosphorylation-dependent regulatory mechanism targeting NFATc1 through which Pim-1 acts as a downstream effector of Ras to facilitate IL-2-dependent proliferation and/or survival of lymphoid cells.

Genetic polymorphisms of biotransformation enzymes in patients with Hodgkin's and non-Hodgkin's lymphomas.

Considering the role in the metabolism of chemicals played by biotransformation enzymes, we aimed at determining whether any association exists between genetic polymorphisms in CYP1A1, CYP2E1, epoxide hydrolase (EPHX), glutathione S-transferases (GSTM1/P1/T1) and individual susceptibility to lymphomas. PCR-RFLP-based genotyping assays were used to determine the frequency of polymorphisms in CYP1A1 (3'-flanking region), CYP2E1 (5'-flanking region and intron 6), EPHX (exons 3 and 4), GSTM1 (deletion), GSTP1 (exon 5) and GSTT1 (deletion) in a case-control study comprised of 219 patients with morbus Hodgkin (MH) and non-Hodgkin's lymphomas (NHL) and 455 age- and sex-matched healthy individuals. The distribution of genotypes in CYP2E1-intron 6 was significantly different between the control group and all lymphomas (P = 0.03), patients with NHL (P = 0.024), and especially aggressive diffuse NHL (P = 0.007). Grading of NHL seemed to be associated with this polymorphism as well (P = 0.041). The EPHX-exon 3 genotype distribution was significantly different between control males and males with all lymphomas (P = 0.01) or with NHL (P = 0.019). The Val/Val genotype of GSTP1-exon 5 was prevalent in all MH [odds ratio (OR) = 2.08, 95% confidence interval (CI) = 1.05-4.14] and this difference was particularly evident in females (OR = 2.97, 95% CI = 1.16-7.61). A significant difference in the distribution of GSTP1-exon 5 genotypes was found between NHL tumors >5 cm and those <5 cm (P = 0.03). The results suggest that genetic polymorphisms of biotransformation enzymes may play a significant role in the development of lymphoid malignancies.