8q24 amplified segments involve novel fusion genes between NSMCE2 and long noncoding RNAs in acute myelogenous leukemia

The pathogenetic roles of 8q24 amplified segments in leukemic cells with double minute chromosomes remain to be verified. Through comprehensive molecular analyses of 8q24 amplicons in leukemic cells from an acute myelogenous leukemia (AML) patient and AML-derived cell line HL60 cells, we identified two novel fusion genes between NSMCE2 and long noncoding RNAs (lncRNAs), namely, PVT1-NSMCE2 and BF104016-NSMCE2. Our study suggests that 8q24 amplicons are associated with the emergence of aberrant chimeric genes between NSMCE2 and oncogenic lncRNAs, and also implicate that the chimeric genes involving lncRNAs potentially possess as-yet-unknown oncogenic functional roles.

Inversion of chromosome 7q22 and q36 as a sole abnormality presenting in myelodysplastic syndrome: a case report

Introduction

Deletions of chromosome 7 are often detected in myelodysplastic syndrome. The most commonly deleted segments are clustered at band 7q22. A critical gene is therefore suggested to be located in this region. We report a patient with myelodysplastic syndrome whose marrow cells carried an inversion of 7q22 and q36 as a sole karyotypic abnormality. How this extremely rare chromosomal aberration contributes to the pathogenesis of myelodysplastic syndrome should be clarified by accumulating clinical data of such cases.

Case presentation

A 74-year-old Japanese man presented with pancytopenia incidentally detected by routine medical check-up. His complete blood cell counts revealed that his white blood cells had decreased to 2100/mm³, neutrophils 940/mm³, red blood cells 320×10⁴/mm³, hemoglobin 11.1g/dL, hematocrit 33.1%, and platelets 12.6×10⁴/mm³. Bone marrow examination showed normal cellularity with nucleated cells of 9.4×10⁴/mm³. The proportion of blasts was 4%. A morphological examination showed only basophilic stippling of erythroblasts which was seen as dysplasia. According to World Health Organization classification, the diagnosis was myelodysplastic syndrome-u. Karyotypic analysis showed 46,XY,inv(7)(q22q36) in all of 20 metaphases examined. Additional analysis revealed the karyotype of his lymphocytes was 46,XY. He is asymptomatic and cytopenia has slowly progressed.

Conclusions

To the best of our knowledge, this karyotype from a clinical sample of de novo malignancies has never been documented although the identical karyotype from secondary myelodysplastic syndrome was reported. Despite the extremely low frequency, inversion of 7q22 appears to play a crucial role for myelodysplastic syndrome in this patient.

Development of a complete human anti-human transferrin receptor C antibody as a novel marker of oral dysplasia and oral cancer

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide. Up to 20% of oral dysplasia cases have been suggested to undergo malignant transformation to OSCC; however, there are no methods to predict OSCC development. In this study, to identify the genes associated with oral dysplasia progression, we performed genomic copy number analyses of genomic DNA samples isolated from primary oral dysplasia and OSCC via the microdissection method and found elevated expression of transferrin receptor C (TfR1/TFRC) with genomic amplification in oral dysplasia and OSCC. The expression rate of TFRC in OSCC was significantly higher than that in dysplasia, suggesting that OSCC disease progression might be related to TFRC expression. Additionally, we investigated the in vitro and in vivo impacts of a newly established anti-human TFRC monoclonal antibody, which was isolated from a human cDNA library using the phage-display method, on cell proliferation and survival. The anti-TFRC antibody blocked the interaction between transferrin and TFRC and consequently inhibited iron uptake, leading to the iron deprivation-mediated suppression of cell growth and induction of apoptosis. Moreover, we demonstrated that the anti-TFRC antibody efficiently inhibited tumor growth in a murine xenograft OSCC model. Therefore, we suggest our developed complete human anti-human TFRC antibody as a useful, novel treatment for oral dysplasia and OSCC.

FTY720 induces apoptosis of chronic myelogenous leukemia cells via dual activation of BIM and BID and overcomes various types of resistance to tyrosine kinase inhibitors

PP2A activator FTY720 has been shown to possess the anti-leukemic activity for chronic myelogenous leukemia (CML), however, the cell killing mechanism underlying its anti-leukemic activity has remained to be verified. We investigated the precise mechanisms underlying the apoptosis induction by FTY720, especially focusing on the roles of BH3-only proteins, and the therapeutic potency of FTY720 for CML. Enforced expression of either BCL2 or the dominant-negative protein of FADD (FADD.DN) partly protected CML cells from apoptosis by FTY720, indicating the involvement of both cell extrinsic and intrinsic apoptosis pathways. FTY720 activates pro-apoptotic BH3-only proteins: BIM, which is essential for apoptosis by BCR-ABL1 tyrosine kinase inhibitors (TKIs), and BID, which accelerates the extrinsic apoptosis pathway. Gene knockdown of either BIM or BID partly protected K562 cells from apoptosis by FTY720, but the extent of cell protection was not as much as that by overexpression of either BCL2 or FADD.DN. Moreover, knockdown of both BIM and BID did not provide additional protection compared with knockdown of only BIM or BID, indicating that BIM and BID complement each other in apoptosis by FTY720, especially when either is functionally impaired. FTY720 can overcome TKI resistance caused by ABL kinase domain mutations, dysfunction of BIM resulting from gene deletion polymorphism, and galectin-3 overexpression. In addition, ABT-263, a BH3-mimetic, significantly augmented cell death induction by FTY720 both in TKI-sensitive and -resistant leukemic cells. These results provide the rationale that FTY720, with its unique effects on BIM and BID, could lead to new therapeutic strategies for CML.

Reduced-intensity allogeneic stem cell transplantation for co-emergence of chemotherapy-refractory follicular lymphoma and therapy-related myelodysplastic syndrome

A 54-year-old male was diagnosed with follicular lymphoma in September 2003. Despite multiple chemotherapies, including autologous hematopoietic stem cell transplantation (HSCT) with high-dose chemotherapy, the disease eventually relapsed. Additionally, bone marrow analysis revealed the co-emergence of therapy-related myelodysplastic syndrome (t-MDS) in February 2012. In March 2012, we performed related allogeneic HSCT for the treatment of both malignancies. This strategy was successful and the patient has remained free from both malignancies for 23 months. Allogeneic HSCT is a potent curative therapeutic option for both t-MDS and refractory follicular lymphoma.

Elotuzumab and daratumumab: emerging new monoclonal antibodies for multiple myeloma

Multiple myeloma (MM) has been mostly incurable due to its highly complex and heterogeneous molecular abnormalities and the support from myeloma microenvironment factors. A therapeutic strategy which effectively targets relevant and specific molecule to myeloma cells, and which is potent in overcoming tumor microenvironment-mediated drug resistance needs to be developed. One of the promising fields is the development of immunotherapy using monoclonal antibodies (MoAbs) against myeloma-specific antigens. This review focuses on the basic and clinical aspects of two emerging and promising novel MoAbs for MM, elotuzumab which targets CS1 and daratumumab which targets CD38. Both antigens are relatively specific to myeloma cells and expressed in more than 90% of MM patients, and mediate adhesion of myeloma cells to bone marrow stromal cells. We also discuss the unique characteristics of the two MoAbs by comparing with other MoAbs being developed for MM.

Multicenter phase II study of mogamulizumab (KW-0761), a defucosylated anti-cc chemokine receptor 4 antibody, in patients with relapsed peripheral T-cell lymphoma and cutaneous T-cell lymphoma

PURPOSE

CC chemokine receptor 4 (CCR4) is expressed by peripheral T-cell lymphomas (PTCLs) and is associated with poor outcomes. Mogamulizumab (KW-0761) is a defucosylated humanized anti-CCR4 antibody engineered to exert potent antibody-dependent cellular cytotoxicity. This multicenter phase II study evaluated the efficacy and safety of mogamulizumab in patients with relapsed PTCL and cutaneous T-cell lymphoma (CTCL).

PATIENTS AND METHODS

Mogamulizumab (1.0 mg/kg) was administered intravenously once per week for 8 weeks to patients with relapsed CCR4-positive PTCL or CTCL. The primary end point was the overall response rate, and the secondary end points included safety, progression-free survival (PFS), and overall survival (OS).

RESULTS

A total of 38 patients were enrolled, and 37 patients received mogamulizumab. Objective responses were noted for 13 of 37 patients (35%; 95% CI, 20% to 53%), including five patients (14%) with complete response. The median PFS was 3.0 months (95% CI, 1.6 to 4.9 months), and the median OS was not calculated. The mean maximum and trough mogamulizumab concentrations (± standard deviation) after the eighth infusion were 45.9 ± 9.3 and 29.0 ± 13.3 μg/mL, respectively. The most common adverse events were hematologic events, pyrexia, and skin disorders, all of which were reversible and manageable.

CONCLUSION

Mogamulizumab exhibited clinically meaningful antitumor activity in patients with relapsed PTCL and CTCL, with an acceptable toxicity profile. Further investigation of mogamulizumab for treatment of T-cell lymphoma is warranted.

Limited value of the international staging system for predicting long-term outcome of transplant-ineligible, newly diagnosed, symptomatic multiple myeloma in the era of novel agents

We retrospectively investigated clinical outcomes and prognostic factors of 131 patients with transplant-ineligible newly diagnosed multiple myeloma (NDMM) who received melphalan and prednisolone (MP) as first-line therapy from 2006 to 2013. Eighty-one patients received salvage therapies incorporating bortezomib, lenalidomide, and/or thalidomide. The overall response rate to MP was 54.2 %, including 9.2 % of better than very good partial response. With a median follow-up period of 30.2 months, median overall survival (OS) and median time to next treatment (TNT) were 54.4 and 19.0 months, respectively. Univariate analysis revealed that performance status and serum calcium level significantly associated with both OS and TNT, and multivariate analysis revealed that the higher serum calcium level had a significantly unfavorable impact on OS and TNT. Importantly, staging informed by the international staging system (ISS) was not predictive for OS or TNT in the analyzed cohort. Our study revealed that, in the context of first-line MP therapy for NDMM, the salvage therapy incorporating novel agents produced a survival period of >30 months after the initiation of second-line therapy, suggesting that the predictive value of ISS for OS and TNT may be limited in the era of novel agents.

[Blood test for malignant lymphoma]

Malignant lymphoma is a neoplastic disease that develops in the lymph system, which consists of various different subtypes. In addition, the differential diagnosis of malignant lymphoma includes infections, autoimmune diseases, allergic diseases, endocrine disorders, and so on. Therefore accurate diagnosis is very important to decide therapeutic strategy. Blood test is the most common examination in clinical practice and used extensively for evaluating etiology, pathology, disease state, efficacy of treatment and disease prognosis of lymphoma. We are required to understand the characteristics of blood examinations correctly and use them appropriately in daily medical practice. Here, we introduce some blood examinations used for treatment of lymphoma.

Loss of NDRG2 expression activates PI3K-AKT signalling via PTEN phosphorylation in ATLL and other cancers

Constitutive phosphatidylinositol 3-kinase (PI3K)-AKT activation has a causal role in adult T-cell leukaemia-lymphoma (ATLL) and other cancers. ATLL cells do not harbour genetic alterations in PTEN and PI3KCA but express high levels of PTEN that is highly phosphorylated at its C-terminal tail. Here we report a mechanism for the N-myc downstream-regulated gene 2 (NDRG2)-dependent regulation of PTEN phosphatase activity via the dephosphorylation of PTEN at the Ser380, Thr382 and Thr383 cluster within the C-terminal tail. We show that NDRG2 is a PTEN-binding protein that recruits protein phosphatase 2A (PP2A) to PTEN. The expression of NDRG2 is frequently downregulated in ATLL, resulting in enhanced phosphorylation of PTEN at the Ser380/Thr382/Thr383 cluster and enhanced activation of the PI3K-AKT pathway. Given the high incidence of T-cell lymphoma and other cancers in NDRG2-deficient mice, PI3K-AKT activation via enhanced PTEN phosphorylation may be critical for the development of cancer.

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.

Azacitidine-associated acute interstitial pneumonitis

Azacitidine is the first-line therapeutic option for myelodysplastic syndrome (MDS). This report describes a case of MDS in a patient who developed fatal acute interstitial pneumonitis (AIP) after the first seven-day course of intravenous azacitidine (75 mg/m(2)/day) treatment. A review of previous and present studies of azacitidine-associated AIP suggests that azacitidine may cause life-threatening AIP during or after the first seven-day course of treatment, with pyrexia commonly preceding AIP. Although the non-hematologic adverse events associated with azacitidine are generally relatively mild, further accumulation of evidence may help to make an earlier diagnosis of azacitidine-associated AIP.

Rheumatoid arthritis/methotrexate-associated primary cutaneous diffuse large B-cell lymphoma, leg type

This report concerns a 62-year-old man with primary cutaneous diffuse large B-cell lymphoma (PCLBCL), leg type that developed during methotrexate (MTX) treatment for rheumatoid arthritis (RA). Several tumors were observed on the left lower leg. A histological analysis showed diffuse proliferation of large neoplastic B-cells that were immunophenotypically CD10-/MUM1+/BCL6-/BCL2+ and cytogenetically had IgH/c-MYC translocation without translocation involving BCL6 or IgH/BCL2. No evidence of Epstein-Barr virus (EBV) infection was found. The discontinuation of MTX resulted in a 20-month disease-free period. No previous cases of PCLBCL, leg type associated with RA or MTX therapy have been reported. The phenotypes of our patient were partly different from those of typical PCLBCL, leg type or RA/MTX-associated lymphoma.

Efficacy and safety of dasatinib versus imatinib in Japanese patients with newly diagnosed chronic-phase chronic myeloid leukemia (CML-CP): Subset analysis of the DASISION trial with 2-year follow-up

Dasatinib is a highly potent BCR-ABL kinase inhibitor with established efficacy and safety in imatinib-resistant or -intolerant patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia. In the global phase III DASISION trial in patients with newly diagnosed chronic phase CML (CML-CP), dasatinib was found to have an acceptable safety profile and demonstrated significantly faster and higher rates of complete cytogenetic response (CCyR) and major molecular response (MMR) compared with imatinib. Here, we report the results of a subset analysis of Japanese patients enrolled in the DASISION trial, showing safety and efficacy profiles generally consistent with patients enrolled worldwide, including higher response rates (CCyR, MMR) with dasatinib compared with imatinib and similar high rates of progression-free and overall survival with both therapies. However, the small sample size of the present study limits the strength of these conclusions, and further exploration is needed to confirm any differences observed in Japanese patients compared with the total treated population. These findings support the use of dasatinib 100 mg QD as a first-line treatment in Japanese patients with newly diagnosed CML-CP.

Graft-versus-host Disease Confined Solely to Intestine after Allogeneic Peripheral Blood Stem Cells Transplantation in a Patient with Chronic Myelogenous Leukemia

We describe a patient with chronic myelogenous leukemia who developing severe intestinal bleeding after allogeneic peripheral blood stem cells transplantation (allo-PBSCT). PBSC were obtained from an HLA one-locus mismatch sibling donor. On day 26 after PBSCT, although there was no sign of graft-versus-host disease (GVHD) in either the skin or the liver, diarrhea and severe intestinal bleeding occurred. The histopathological examination of the colon revealed complete denudation of the epithelial cells of the mucosa and no obvious apoptosis. Neither red cell fragments nor hemorrhagic diathesis was seen during this episode and the patient was diagnosed as having GVHD. Methylpredonisolone followed by FK506 may be effective in controlling intestinal bleeding and was used in our patient. Acute GVHD involving only the intestine has rarely been described but when using HLA-mismatched PBSCs, acute GVHD may occur severely and atypically.

Suppression of SERPINA1-albumin complex formation by galectin-3 overexpression leads to paracrine growth promotion of chronic myelogenous leukemia cells

Galectin-3 is induced in chronic myelogenous leukemia (CML) cells by co-culture with bone marrow stromal cells, making paracrine growth promotion of CML cells in conditioned medium (CM) from galectin-3 overexpressing CML cells more potent. We used gel filtration chromatography to demonstrate that the bovine SERPINA1-fetal bovine serum albumin (BSA) complex was specifically suppressed in CM from galectin-3 overexpressing cells. The SERPINA1-BSA complex as well as human plasma SERPINA1 inhibited the growth of CML cells, while exogenous galectin-3 partly offset this effect. These findings suggest that galectin-3 overexpression promotes paracrine growth of CML cells by interfering with the action of the growth inhibitory SERPINA1-albumin complex.

Hematopoietic progenitor cell mobilization using low-dose cyclophosphamide and granulocyte colony-stimulating factor for multiple myeloma

High-dose chemotherapy (HDT) supported by autologous stem cell transplantation (ASCT) has long been one of the standards of care for younger patients with multiple myeloma (MM). Cyclophosphamide (CY) plus granulocyte colony-stimulating factor (G-CSF) has been the conventional preparation for hematopoietic progenitor cell (HPC) mobilization, although the optimal dosage of CY in this setting has not yet been clearly defined. This study investigated the efficacy and safety of low-dose (LD-)CY (1.5 g/m(2)) plus G-CSF for conditioning for HPC apheresis harvest (HPC-A) in 18 MM patients, and compared it with a regimen consisting of intermediate-dose (ID)-CY (4 g/m(2)) plus G-CSF for 13 MM patients. Eleven patients in the former and six in the latter were treated with bortezomib (BTZ) during the induction therapy. Both regimens were comparably effective in terms of CD34(+) cell yields, while adverse events, such as leukopenia, thrombocytopenia, and febrile neutropenia, occurred significantly less frequently in the LD-CY cohort. All patients in LD-CY cohort started and completed their apheresis on day 7 or 8, whereas for the ID-CY cohort the day of first apheresis varied widely from day 8 to 15. These findings indicate that the LD-CY regimen is as effective as ID-CY for HPC mobilization, while the former is clearly more practicable and convenient than the ID-CY regimen for patients with MM.

CD56 expression is an independent prognostic factor for relapse in acute myeloid leukemia with t(8;21)

We investigated the significance of surface antigen expression for prognosis by focusing on a specific subtype, AML with t(8;21). The investigation included 144 patients with AML with t(8;21) in the JALSG AML97 study. AML with t(8;21) expressed CD19 (36%), CD34 (96%), and CD56 (65%) more frequently than did other subtypes of AML. CD19 expression had a significant favorable effect on CR (95.7% vs. 83.8%; P=0.049). Univariate analysis showed that increased white blood cell (WBC) counts (WBC ≥ 20 × 10(9)/L), CD19 negativity, and CD56 positivity were critical adverse factors for relapse after CR; multivariate analysis revealed that WBC count and CD56 expression were independent adverse risk factors (HR 2.18; P=0.045, HR 2.30; P=0.011, respectively). We concluded that CD56 expression has a possible role in risk stratification for patients with AML with t(8;21).

Acute lymphoblastic leukemia with eosinophilia lacking peripheral blood leukemic cell: a rare entity

We describe a 57-year-old woman who was diagnosed as precursor B-cell acute lymphoblastic leukemia with marked eosinophilia (ALL-eo). She presented with low grade fever and eosinophilia (absolute count 16.5 × 10(9)/l). Most of eosinophils had hypogranular cytoplasm. Immature cells were absent in her peripheral blood. Since her platelet count was low, bone marrow examination was carried out. 57.2 % of nucleated cells were blastic cells positive for CD10, 19, and 20. Chromosomal analysis revealed a karyotype of 46,XX,t(5;14)(q31;q32). Despite induction chemotherapy, her disease progressed and she died of sepsis a month later. ALL-eo is extremely rare and the diagnosis might be delayed unless leukemic cells are seen in peripheral blood. Therefore, bone marrow should be examined as soon as possible in cases with eosinophilia not only for the differential diagnosis of eosinophilic disorders but also not to overlook ALL-eo.

Low ADAMTS-13 activity during hemorrhagic events with disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a life-threatening complication, and its control is essential for therapeutic success. Recombinant human soluble thrombomodulin alfa (rTM) is a novel therapeutic agent for DIC. The efficacy of rTM in the treatment of DIC is reportedly superior to that of conventional anti-DIC treatments, such as unfractionated heparin or low molecular weight heparin, but hemorrhagic events occasionally interfere with the therapeutic benefits of rTM. We assessed the clinical features of 20 consecutive patients who were given rTM for DIC associated with various hematologic disorders. Eight patients achieved remission of both primary disease and DIC, eight died due to progression of the primary disease, and four died of various hemorrhagic complications. Assessment of 16 biomarkers for coagulation showed that the four patients who died of hemorrhagic complications despite remission of their primary disease showed lower ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin Type 1 motif, member 13) plasma activity than other patients (P = 0.016). The optimal cut-off level of ADAMTS-13 for predicting risk of hemorrhagic complications was 42 % (P = 0.007). Plasma ADAMTS-13 activity determined at diagnosis of DIC may help predict the risk of hemorrhagic events during and/or following DIC treatment with hematologic disorders.

Alterations of the SWI/SNF chromatin remodelling subunit-BRG1 and BRM in hepatocellular carcinoma

BACKGROUND

The SWI/SNF chromatin remodelling complex, which contains either brahma-related gene-1 (BRG1) or brahma (BRM) as the catalytic ATPase, functions as a master regulator of gene expression.

AIMS

To examine alterations of BRG1 and BRM in hepatocellular carcinoma (HCC).

METHODS

We investigated DNA copy number aberrations in human HCC cell lines using a high-density oligonucleotide microarray. We determined DNA copy numbers and expression levels of BRG1 and BRM genes in primary HCC tumours, and conducted further searches for mutations in BRG1 and BRM genes.

RESULTS

Homozygous deletion of the BRG1 gene was found in HCC cell line SNU398. Copy number losses of BRG1 and BRM genes were observed in 14 (26%) and 7 (13%) of 54 primary HCC tumours respectively. We found four somatic missense mutations in the BRG1 gene in two of 36 primary HCC tumours, but no mutations in BRM gene. Expression of BRM mRNA, but not BRG1 mRNA, was significantly reduced in primary HCC tumours, compared to non-tumour tissue counterparts. Immunohistochemical analyses of non-tumour liver tissues showed that BRM protein was expressed in hepatocytes and bile-duct epithelial cells, whereas BRG1 protein was expressed in bile-duct epithelial cells, but not in hepatocytes. BRM protein expression was lost in nine (22.5%) of 40 HCC tumours. Loss of BRM protein expression was significantly associated with poor overall survival.

CONCLUSION

Reduced expression of BRM may contribute to the carcinogenesis of HCC. Although deletions and mutations in BRG1 gene were identified, the role of BRG1 in HCC tumourigenesis remains unclear.

Multifaceted mechanisms for cell survival and drug targeting in chronic myelogenous leukemia

Treatment outcomes for chronic myelogenous leukemia (CML) have shown major improvements as a result of the development of the tyrosine kinase inhibitors (TKIs) imatinib, nilotinib and dasatinib for the disease-specific molecular target BCR-ABL1 tyrosine kinase (TK), but a cure of CML by BCR-ABL1 TKIs has been rarely achieved. CML cells are protected from cytotoxic insults, including those by TKIs, through various collaborative BCR-ABL1- mediated and -independent mechanisms, as well as cell-intrinsic and -extrinsic molecular mechanisms. These protective mechanisms include overlapping cell signaling pathways for normal hematopoietic proliferation, modulation of molecules associated with the BCL2 family protein-regulated programmed cell death pathway, autophagic cell protection capability, bone marrow environment-mediated cell protective signaling, abnormally upregulated genetic instability and other BCR-ABL1- independent kinase activities. To develop a more effective treatment strategy for a cure by means of total leukemic cell killing, a thorough understanding of how CML cells survive and resist cytotoxic insults is essential. In this article, we review current knowledge about multifaceted BCR-ABL1-related and -unrelated mechanisms for survival and death of CML cells and present suggestions for the development of new therapeutic strategies for complete elimination of residual CML cells during TKI treatment.

The response to second-line induction with bortezomib and dexamethasone is predictive of long-term outcomes prior to high-dose chemotherapy with autologous stem cell transplantation for multiple myeloma

OBJECTIVE

We retrospectively investigated the efficacy and predictive factors for the treatment outcomes of bortezomib plus dexamethasone (BD) as second-line induction therapy prior to high-dose chemotherapy supported by autologous stem cell transplantation (HDT/ASCT) in multiple myeloma (MM) patients.

METHODS

Sixty-six transplant eligible MM patients treated by the Kyoto Clinical Hematology Study Group between 2006 and 2011 were investigated. Conventional induction chemotherapy, including vincristine, doxorubicin and dexamethasone (VAD) and high-dose dexamethasone (HDD), was used as first-line induction therapy in all patients, seven (10.6%) of whom attained a very good partial response (VGPR). Of the 59 patients who did not attain VGPR with VAD or HDD, 33 were given BD as second-line induction therapy prior to HDT/ASCT.

RESULTS

Patients not treated with BD induction showed an overall response rate (ORR, i.e., better than partial response) of 85.3% after induction therapy, while the ORR of patients treated with BD induction improved from 42.4% after conventional induction therapy to 84.8% after BD. The overall survival (OS) and progression-free survival (PFS) of patients not treated with BD induction were not significantly influenced by the response to induction therapy. Among the patients treated with BD, failure in attaining VGPR prior to ASCT was associated with a significantly shorter PFS and it also tended to show a shorter OS, while the disease stage and achievement of a complete response after HDT/ASCT had no impact on OS or PFS.

CONCLUSION

The achievement of at least VGPR with second-line BD induction therapy is a prerequisite for attaining longer OS and PFS after HDT/ASCT.

RSK2(Ser227) at N-terminal kinase domain is a potential therapeutic target for multiple myeloma

Multiple myeloma is an entity of cytogenetically and genetically heterogenous plasma cell neoplasms. Despite recent improvement in the treatment outcome of multiple myeloma by novel molecular-targeted chemotherapeutics, multiple myeloma remains incurable. The identification of a therapeutic target molecule in which various signaling for cell-survival converge is a core component for the development of new therapeutic strategies against multiple myeloma. RSK2 is an essential mediator of the ERK1/2 signaling pathway for cell survival and proliferation. In this study, we discovered that RSK2(Ser227), which is located at the N-terminal kinase domain and is one site responsible for substrate phosphorylation, is activated through phosphorylation regardless of the type of cytogenetic abnormalities or upstream molecular signaling in all 12 multiple myeloma-derived cell lines examined and 6 of 9 patient-derived CD138-positive primary myeloma cells. The chemical inhibition of RSK2(Ser227) by BI-D1870 or gene knockdown of RSK2 inhibits myeloma cell proliferation through apoptosis induction, and this anti-myeloma effect was accompanied by downregulation of c-MYC, cyclin D, p21(WAF1/CIP1), and MCL1. RSK2(Ser227) inhibition resulting from BI-D1870 treatment restored lenalidomide-induced direct cytotoxicity of myeloma cells from interleukin-6-mediated cell protection, showed no cross-resistance to bortezomib, and exerted additive/synergistic antiproliferative effects in conjunction with the mTOR, histone deacetylase, and BH3-mimicking BCL2/BCLX(L) inhibitors. These results suggest that RSK2(Ser227) is a potential therapeutic target not only for newly diagnosed but also for patients with later phase multiple myeloma who are resistant or refractory to currently available anti-myeloma therapies.

Plasmablastic lymphoma of the elderly: a clinicopathological comparison with age-related Epstein-Barr virus-associated B cell lymphoproliferative disorder

AIMS

Plasmablastic lymphoma (PBL) is an aggressive lymphoma with a terminally differentiated B cell phenotype; half of patients with this disease have Epstein-Barr virus (EBV) infection. The majority of PBL cases are associated with human immunodeficiency virus (HIV) infection, while the remaining HIV-negative cases were accompanied by other immunodeficiency conditions or immunosenescence in the elderly.

METHODS AND RESULTS

To characterize HIV-negative PBL of the elderly (PBL-E), we compared the clinicopathological characteristics of 10 cases of PBL-E and 124 cases with age-related EBV-associated B cell lymphoproliferative disorder (AR-EBVLPD). The 10 PBL-E (eight men, two women; median age: 68 years) were associated with a more indolent clinical behaviour and a better overall survival than AR-EBVLPD. Extranodal involvement was higher in PBL-E (50%) than AR-EBVLPD; notably, the nasal cavity was affected most frequently in PBL-E (60%). Immunoglobulin heavy chain/(IGH)/MYC translocation was detected in half of the PBL-E cases.

CONCLUSIONS

PBL-E shares some clinical features with AR-EBVLPD, such as HIV negativity, old age, and EBV infection, no known immunosuppressive condition but there are some differences such as a higher ratio of extranodal involvement and better prognosis. PBL-E is a newly recognized condition and should be distinguished from HIV-positive PBL, sharing features with AR-EBVLPD in particular, immunosenescence of the elderly.

Frequent PVT1 rearrangement and novel chimeric genes PVT1-NBEA and PVT1-WWOX occur in multiple myeloma with 8q24 abnormality

Chromosome 8q24 rearrangements are occasionally found in multiple myeloma and are associated with tumor progression. The 8q24 rearrangements were detected by FISH in 12 of 54 patients with multiple myeloma (22.2%) and in 8 of 11 multiple myeloma cell lines (72.7%). The breakpoints of 8q24 in 10 patients with multiple myeloma and in all multiple myeloma cell lines were assigned to a 360 kb segment, which was divided into 4 regions: approximately 120 kb centromeric to MYC (5' side of MYC), the region centromerically adjacent to PVT1 (~ 170 kb region, including MYC, of 5' side of PVT1), the PVT1 region, and the telomeric region to PVT1. PVT1 rearrangements were most common and found in 7 of 12 patients (58.3%) and 5 of 8 cell lines (62.5%) with 8q24 abnormalities. A combination of spectral karyotyping (SKY), FISH, and oligonucleotide array identified several partner loci of PVT1 rearrangements, such as 4p16, 4q13, 13q13, 14q32, and 16q23-24. Two novel chimeric genes were identified: PVT1-NBEA in the AMU-MM1 cell line harboring t(8;13)(q24;q13) and PVT1-WWOX in RPMI8226 cell line harboring der(16)t(16;22)ins(16;8)(q23;q24). The PVT1-NBEA chimera in which PVT1 exon 1 was fused to NBEA exon 2 and the PVT1-WWOX in which PVT1 exon 1 was fused to WWOX exon 9 were associated with the expression of abnormal NBEA and WWOX lacking their N-terminus, respectively. These findings suggest that PVT1 rearrangements may represent a novel molecular paradigm underlying the pathology of 8q24 rearrangement-positive multiple myeloma.

Monosomy 13 in metaphase spreads is a predictor of poor long-term outcome after bortezomib plus dexamethasone treatment for relapsed/refractory multiple myeloma

We retrospectively investigated the prognostic impact of high-risk cytogenetic abnormalities (CAs) on the outcome of treatment with bortezomib plus dexamethasone (BD) in 43 relapsed/refractory (Rel/Ref) multiple myeloma patients. Fluorescence in situ hybridization (FISH) analysis identified del(13q) in 25 patients, t(4;14) in 14, t(14;16) in 4, 1q21 abnormality in 12 and del(17p) in 2, while G-banding also detected chromosome 13 monosomy (-13) in metaphase spreads from 7 patients. Eighteen of 25 patients with FISH-detected chromosome 13 abnormalities also exhibited other abnormalities. Median observation period was 510 days, and median overall survival (OS) and progression-free survival (PFS) were 912 days and 162 days, respectively. Detection of del(13q), t(4;14), t(14;16) or 1q21 abnormalities by FISH and co-occurrence of chromosome 13 abnormality with other abnormalities were not associated with poorer outcomes. In contrast, detection of -13 by G-banding in metaphase spreads showed significant association with shorter OS, although the overall response rate and PFS were not inferior to those for patients without -13 detected by G-banding. BD therapy may be a potent weapon for overcoming most classical high-risk CAs, while the detection of -13 in metaphase spreads may serve as a predictor of highly progressive disease, even when treated with BD.

Overexpression of the DNA sensor proteins, absent in melanoma 2 and interferon-inducible 16, contributes to tumorigenesis of oral squamous cell carcinoma with p53 inactivation

The development of oral squamous cell carcinoma (OSCC) is a multistep process that requires the accumulation of genetic alterations. To identify genes responsible for OSCC development, we performed high-density single nucleotide polymorphism array analysis and genome-wide gene expression profiling on OSCC tumors. These analyses indicated that the absent in melanoma 2 (AIM2) gene and the interferon-inducible gene 16 (IFI16) mapped to the hematopoietic interferon-inducible nuclear proteins. The 200-amino-acid repeat gene cluster in the amplified region of chromosome 1q23 is overexpressed in OSCC. Both AIM2 and IFI16 are cytoplasmic double-stranded DNA sensors for innate immunity and act as tumor suppressors in several human cancers. Knockdown of AIM2 or IFI16 in OSCC cells results in the suppression of cell growth and apoptosis, accompanied by the downregulation of nuclear factor kappa-light-chain-enhancer of activated B cells activation. Because all OSCC cell lines have reduced p53 activity, wild-type p53 was introduced in p53-deficient OSCC cells. The expression of wild-type p53 suppressed cell growth and induced apoptosis via suppression of nuclear factor kappa-light-chain-enhancer of activated B cells activity. Finally, the co-expression of AIM2 and IFI16 significantly enhanced cell growth in p53-deficient cells; in contrast, the expression of AIM2 and/or IFI16 in cells bearing wild-type p53 suppressed cell growth. Moreover, AIM2 and IFI16 synergistically enhanced nuclear factor kappa-light-chain-enhancer of activated B cells signaling in p53-deficient cells. Thus, expression of AIM2 and IFI16 may have oncogenic activities in the OSCC cells that have inactivated the p53 system.

Successful treatment of chemotherapy-refractory angioimmunoblastic T cell lymphoma with cyclosporin A

Angioimmunoblastic T cell lymphoma (AITL) is a rare subtype of T cell non-Hodgkin lymphoma. The standard therapeutic strategy for AITL has not yet been established, and its prognosis remains poor. This report concerns the effect of cyclosporin A (CsA) on chemotherapy-refractory AITL. A 68-year-old female with AITL with systemic symptoms, such as high fever, skin rash and generalized lymphadenopathy, was initially treated with conventional cytotoxic chemotherapies using alkylators, anthracyclines and corticosteroids, which failed to induce remission. However, CsA (4 mg/kg/day) plus dexamethasone treatment resulted in a dramatic regression of the tumors and amelioration of systemic symptoms and induced complete remission (CR) within 2 weeks. Currently, the patient's CR has continued for more than 18 months with CsA maintenance therapy. Our experience and previously reported findings suggest that CsA may constitute an alternative treatment option for AITL, even though the use of conventional cytotoxic chemotherapy continues to be the first-line therapy on an empirical basis.