Yasuhiko Tsutsumi

Identification of IGHCδ-BACH2 fusion transcripts resulting from cryptic chromosomal rearrangements of 14q32 with 6q15 in aggressive B-cell lymphoma/leukemia.

In B‐cell malignancies, genes implicated in B‐cell differentiation, germinal center formation, apoptosis, and cell cycle regulation are juxtaposed to immunoglobulin loci through chromosomal translocations. In this study, we identified the BTB and CNC homology 2 (BACH2) gene as a novel translocation partner of the immunoglobulin heavy chain (IGH) locus in a patient with IGH‐MYC‐positive, highly aggressive B‐cell lymphoma/leukemia carrying der(14)t(8;14) and del(6)(q15). Fluorescence in situ hybridization analysis using an IGH/MYC probe detected an IGH‐MYC fusion signal on der(14) and IGH signal on del(6). Genome copy number analysis showed a deletion in the 6q15‐25 region and a centromeric breakpoint within the BACH2 gene. cDNA bubble polymerase chain reaction using BACH2 primers revealed that the first exon of Cδ was fused to the 5′‐untranslated region of BACH2 exon 2. The Cδ–BACH2 fusion transcript consisted of exon 1 of Cδ and exons 2 to 9 of BACH2, encompassing the entire BACH2 coding region, and the BACH2 was highly expressed in this patient. These results indicate that Cδ–BACH2 fusion may cause constitutive activation of BACH2. Although additional screening of 47 samples of B‐cell non‐Hodgkins lymphoma (B‐NHL) patients and 29 cell lines derived from B‐cell malignancies by double‐color fluorescence in situ hybridization analysis detected a split signal with deletion of centromeric region of BACH2 only in a patient with follicular lymphoma, BACH2 was highly expressed in lymphoma cells of the patient and B‐NHL cell lines with IGH‐MYC translocation. These findings suggest that BACH2 plays a critical role in B‐cell lymphomagenesis, especially related to IGH‐MYC translocation in some way.

Bcl-2 is a better therapeutic target than c-Myc, but attacking both could be a more effective treatment strategy for B-cell lymphoma with concurrent Bcl-2 and c-Myc overexpression

OBJECTIVE The prognosis for diffuse large B-cell lymphomas with concomitant overexpression of c-Myc and Bcl-2 remains dismal; there is an urgent need to clarify the significance of these two oncogenes as therapeutic targets for a more effective treatment strategy. MATERIALS AND METHODS We established two novel cell lines, KPUM-MS3 and KPUM-UH1, from two chemoresistant patients with diffuse large B-cell lymphomas with concomitant overexpression of c-Myc and Bcl-2, and investigated the significance of c-Myc and Bcl-2 as therapeutic targets. RESULTS KPUM-MS3 possesses t(14;18)(q32;q21) chromosomal translocation and KPUM-UH1 bcl-2 gene amplification, both of which account for Bcl-2 overexpression. Chromosomal translocation t(8;14)(q24;q34) was found to coexist only in KPUM-UH1, overexpression of pvt-1 messenger RNA was detected only in KPUM-MS3, and reduced expression of miR-143 and miR-145 was identified in both. Working together, these abnormalities can contribute to c-Myc overexpression. Using ABT-263, an inhibitor for Bcl-2, and 10058-F4, an inhibitor for c-Myc, we found that both cell lines were more highly sensitive to cell death as a result of Bcl-2 inhibition than of c-Myc inhibition. When combined with genotoxic agents, ABT-263 exerted additive and/or synergistic cell-killing effects, while 10058-F4 showed, at most, a modest combinatory effect. Importantly, the combination of ABT-263 and 10058-F4 had a synergistic cell-killing effect on both cell lines. CONCLUSIONS Our data suggest that Bcl-2 is a better therapeutic target than c-Myc, but attacking both Bcl-2 and c-Myc would be an even more effective treatment strategy for diffuse large B-cell lymphomas with concurrent Bcl-2 and c-Myc overexpression.

Cyclosporine A for Chemotherapy-Resistant Subcutaneous Panniculitis-Like T Cell Lymphoma with Hemophagocytic Syndrome

Subcutaneous panniculitis-like T cell lymphoma (SPTL) is a rare subtype of non-Hodgkin lymphoma for which a definitive therapeutic strategy has not been established yet. We report a case of chemotherapy-resistant SPTL with hemophagocytic syndrome (HPS) which was successfully treated with cyclosporine A (CsA) plus methylprednisolone (mPSL), and also reviewed 11 SPTL cases treated with CsA, previously reported in the literature. Our patient was a 38-year-old female with SPTL. The disease progressed despite conventional chemotherapy using cytotoxic agents including alkylators, anthracyclins or purine analogues, and, after 2 months of chemotherapy, was eventually complicated by HPS and disseminated intravascular coagulation (DIC). CsA (4 mg/kg/day) plus mPSL treatment dramatically improved HPS with DIC, reduced subcutaneous tumors within 2 weeks, and finally induced complete remission (CR) after 3 months. Currently, the patient has maintained CR while being treated with CsA for 12 months. In addition to our case, 9 of 11 SPTL cases were successfully treated with CsA, and 8 were induced to CR. Time to first response to CsA was within 2 weeks in most cases, regardless of prior treatment or the co-occurrence of HPS. Our case and this first comprehensive review on CsA for SPTL suggest that CsA may constitute a candidate treatment strategy for SPTL.

Expression of Master Regulators of Helper T-Cell Differentiation in Peripheral T-Cell Lymphoma, Not Otherwise Specified, by Immunohistochemical Analysis

The normal counterparts of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) have not been accurately identified. We immunohistochemically analyzed 10 PTCL-NOS cases to examine the expression of the master regulators of T-cell differentiation and of surface antigens, including chemokine receptors. All cases were positive for the master regulator of helper T cells (Th-POK) and the marker of effector T cells (CD45RO). Three cases each were positive for T-Bet and GATA3, which are master regulators of helper T cells (T(H) ) type 1 (T(H)1) and 2 (T(H)2), respectively. Two cases were positive for the surface antigens of central memory (Tcm) (CCR7 and CD62L), and 1 case was positive for follicular helper T-cell (TFH) phenotype (BCL6, CXCL13, and PD-1). The remaining case was negative for all markers of effector T(H) subtypes. These results suggest the postulated normal counterparts of PTCL-NOS identified in 9 of the 10 cases consist of T(H)1, T(H)2, TCM, and TFH.

The leucine twenty homeobox (LEUTX) gene, which lacks a histone acetyltransferase domain, is fused to KAT6A in therapy-related acute myeloid leukemia with t(8;19)(p11;q13)

The monocytic leukemia zinc finger protein KAT6A (formerly MOZ) gene is recurrently rearranged by chromosomal translocations in acute myeloid leukemia (AML). KAT6A is known to be fused to several genes, all of which have histone acetyltransferase (HAT) activity and interact with a number of transcription factors as a transcriptional coactivator. The present study shows that the leucine twenty homeobox (LEUTX) gene on 19q13 is fused to the KAT6A gene on 8p11 in a therapy‐related AML with t(8;19)(p11;q13) using the cDNA bubble PCR method. The fusion transcripts contained 83 nucleotides upstream of the first ATG of LEUTX and are presumed to create in‐frame fusion proteins. LEUTX is known to have a homeobox domain. Expression of the LEUTX gene was only detected in placenta RNA by RT‐PCR, but not in any tissues by Northern blot analysis. The putative LEUTX protein does not contain any HAT domain, and this is the first study to report that KAT6A can fuse to the homeobox gene. The current study, with identification of a new partner gene to KAT6A in a therapy‐related AML, does not elucidate the mechanisms of leukemogenesis in KAT6A‐related AML but describes a new gene with a different putative function.

Close pathogenetic relationship between ocular immunoglobulin G4-related disease (IgG4-RD) and ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma

Immmunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a chronic sclerosing inflammatory disease characterized by mass-forming lesions such as swelling, nodules or hypertrophy in one or more organs...

Deletion or methylation of CDKN2A/2B and PVT1 rearrangement occur frequently in highly aggressive B-cell lymphomas harboring 8q24 abnormality

Among various cytogenetic abnormalities involved in lymphomagenesis and disease progression of highly aggressive and treatment-resistant B-cell lymphomas (HABCLs), classified as the so-called aggressive B-cell lymphomas (BCLs) such as diffuse large B-cell lymphoma (DLBCL) and Burkitt-like lymphoma or Burkitt lymphoma (BL), 8q24 chromosomal abnormality is one of the major genetic/cytogenetic abnormalities, with a frequency of 5–15% [1,2]. Moreover, MYC rearrangements at 8q24 have been occasionally found in combination with a t(14;18)(q32;q21) involving BCL2 in 4% of highly aggressive “double-hit” DLBCLs (DHLs), with an extremely poor prognosis [3–5]. Indeed, MYC and BCL2 synergistically induce tumor formation, as observed in experimental models [6,7]. Therefore, better genetic/molecular diagnostic criteria are needed for the more accurate prediction of outcomes and the development of novel treatments for HABCLs. Because the complex karyotypes often found in HABCLs may cause the gene alterations associated with their biological functions, aberrations of other molecules besides MYC and BCL2 may also further affect the pathogenesis of HABCLs [4,8,9]. In this study, we subjected eight patients with aggressive BCLs with 8q24 abnormality treated at the Kyoto Prefectural University of Medicine (KPUM) between April 2006 and September 2012 (Table I) to a comprehensive molecular analysis using G-banding, spectral karyotyping (SKY), fluorescence in situ hybridization (FISH) for IGH, MYC, PVT-1 [Figure 1(A)], BCL-2, BCL-6, BACH2 and CDKN2A/2B, oligonucleotide array and methylation-specific polymerase chain reaction (PCR) (MSP) (Supplementary Materials and Methods available online at http://www.informahealthcare. com/lal/doi/10.3109/10428194.2013.790543) [8–10]. Patients 1, 2, 3, 7 and 8 were included in our previous publication on survival analysis for DLBCL [5]. We established two cell lines, KPUM-MS3 and KPUM-UH1, from patients 2 and 3, respectively [11]. This study was approved by the ethics committee of KPUM. Three patients had Burkitt-like lymphoma and five had DLBCL. As shown in Table I, all patients presented with advanced disease stage and with unfavorable International Prognostic Index scores. All patients were characterized by systemically disseminated involvements including bone marrow involvement, fluid retention, central nervous system involvement and/or multiple extranodal disease sites. As for response to immunochemotherapy incorporating rituximab and/or irradiation therapy, five patients showed disease progression, while three achieved a complete response. Patient 7 had three disease recurrences prior to a complete response to various salvage chemotherapies. The median survival of eight patients was 6.7 months. In these series, 8q24 abnormalities were detected by G-banding and SKY analysis in five patients, and by FISH in the remaining three. All patients thus showed 8q24 abnormalities, including MYC/PVT1 amplification in patient 4 [Figure 1(B)]. Based on the results obtained by FISH using both PVT1-A and PVT1-S probes, breakpoints were assigned to the PVT1 gene in two patients (2 and 5) and to the region covered by the bacterial artificial chromosome (BAC) CTD-3066D1 containing MYC in four (3, 6, 7 and 8) [Figures 1(A) and 1(C) and Supplementary Table I to be found online at http://www.informahealthcare.com/lal/doi/10.3109/1042 8194.2013.790543]. The MYC-Cg fusion gene was detected in patient 1 by long-distance PCR. Oligonucleotide array analysis demonstrated that the 8q24 rearrangement demarcated copy number changes within PVT1 in intron 1 in patient 2 (Supplementary Figure 1 to be found online at http://www. informahealthcare.com/lal/doi/10.3109/10428194.2013. L eu k L ym ph om a D ow nl oa de d fr om in fo rm ah ea lth ca re .c om b y K yo to F ur its u Id ai L ib ra ry o n 09 /2 8/ 14

Clinical manifestation and prognostic factors of 32 Japanese patients with autoimmune disease-associated diffuse large B-cell lymphoma

1 Division of Hematology and Oncology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan, 2 Department of Hematology, Kyoto First Red Cross Hospital, Kyoto, Japan, 3 Department of Hematology, Social Insurance Kyoto Hospital, Kyoto, Japan, 4 Department of Hematology, Kyoto Second Red Cross Hospital, Kyoto, Japan, 5 Department of Hematology, Matsushita Memorial Hospital, Moriguchi, Japan, 6 Department of Hematology, Otsu Municipal Hospital, Otsu, Japan and 7 Department of Infl ammation and Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan

Diffuse large B-cell lymphoma presenting with central pontine myelinolysis: a case report

IntroductionThe most common cause of central pontine myelinolysis is an overly rapid correction of hyponatremia, although it can also occur in patients with any condition leading to nutritional or electrolyte stress. We report a case of diffuse large B-cell lymphoma with central pontine myelinolysis developing at the onset of disease. To the best of our knowledge, hematological malignancies presenting with central pontine myelinolysis have been rarely reported, especially in previously untreated patients, as in our case report.Case presentationA 78-year-old Japanese woman presented to a neighborhood clinic with persistent high fever, edema, and general weakness. Despite the absence of specific neurological findings, brain magnetic resonance imaging showed an abnormal lesion in the central pons area of her brain (hyperintense on T2-weighted and hypointense on T1-weighted sequences), compatible with central pontine myelinolysis. She was admitted to our emergency department in a state of shock one month later. The results of her blood tests showed greatly elevated C-reactive protein and lactate dehydrogenase levels. She had severe hypoalbuminemia and mild hyponatremia, and showed signs of disseminated intravascular coagulation. Mild bilateral pleural effusion, prominent subcutaneous edema, and splenomegaly were detected on her systemic computed tomography scan. Her body fluid cultures did not show signs of infection and her spinal aspiration did not show pleocytosis or abnormal cells. A diagnosis of diffuse large B-cell lymphoma was made based on the results of her bone marrow examination. As she was critically ill before the diagnosis was made, she was treated with methylprednisolone pulse therapy, followed by systemic chemotherapy (rituximab with modified THP-COP regimen, including cyclophosphamide, pirarubicin, vindesine, and prednisolone), which resulted in complete remission and recovery without any neurological defects, and resolution of her abnormal findings on magnetic resonance imaging.ConclusionsCentral pontine myelinolysis is a serious condition that may result in neuropathological sequelae and mortality, and clinicians should be aware of its potential presence in patients with malignancies.

Transcriptional dysregulation of the deleted in colorectal carcinoma gene in multiple myeloma and monoclonal gammopathy of undetermined significance.

The deleted in colorectal carcinoma (DCC) gene at 18q21 encodes a netrin‐1 receptor, a tumor suppressor that prevents cell growth. While allele loss or decreased expression of DCC has been associated with the progression of solid tumors and hematologic malignancies, including leukemias and malignant lymphomas, its involvement has not been evaluated in multiple myeloma (MM), a plasma cell malignancy characterized by complex and heterogenous molecular abnormalities. We here show that 10 of 11 human myeloma‐derived cell lines (HMCLs) expressed non‐translated aberrant DCC transcriptional variants, in which exon 2 fuses with intron 1 instead of exon 1 (mt.DCC). Among them, two co‐expressed wild type transcripts (wt.DCC), while eight co‐expressed the splicing variant (sv.DCC) lacking exon 1. The remaining HMCL expressed only sv.DCC. In addition, analyses revealed that there were two types of mt.DCC that differed in their fusion of intron 1 with exon 2. In patient‐derived samples from 30 MM and 8 monoclonal gammopathy of undetermined significance (MGUS) patients, wt.DCC was expressed in 53% of MM, but not in MGUS, while 23% of MM and 75% of MGUS expressed only sv.DCC. Considering that 25% of MGUS, 57% of MM, and 91% HMCLs expressed mt.DCC, our results suggest that the acquisition of mt.DCC might be a secondary genetic change in plasma cell dyscrasia.