Secondary central nervous system involvement in patients with diffuse large B-cell lymphoma treated with rituximab combined CHOP therapy - a supplementary analysis of JCOG0601

Secondary central nervous system involvement (sCNSi) in diffuse large B-cell lymphoma (DLBCL) is fatal. However, its features in patients with sCNSi who are categorized as lower risk by international prognostic index (IPI) or CNS-IPI are not yet fully understood. In the present analysis, we evaluated DLBCL patients who developed sCNSi at their first progression and who participated in JCOG0601, most of whom were lower risk by IPI. Of 409 patients, 21 (5.1%) developed sCNSi during a median follow-up of 4.9 years. Five-year cumulative incidence of sCNSi were 5.1%; and 4.0%, 5.3%, and 11.5% at low, intermediate, and high risk of CNS-IPI, respectively. The most common locations of extranodal lesions at the time of registration in patients with sCNSi were the stomach (n = 4), paranasal cavity (n = 3), and bone marrow (n = 2). In univariable analysis, paranasal cavity lesion was a high-risk factor for sCNSi (subdistribution hazard ratio, 4.34 [95% confidence interval 1.28-14.73]). Median overall survival after sCNSi was 1.3 years, with a 2-year overall survival rate of 39.3%. The incidence of sCNSi in DLBCL patients at lower risk of CNS-IPI was low, as previously reported, but paranasal cavity lesion might indicate high risk for organ involvement. CLINICAL TRIAL REGISTRATION: JCOG0601 was registered in the UMIN Clinical Trials Registry (UMIN000000929, date of registration; December 04, 2007) and the Japan Registry of Clinical Trials (jRCTs031180139, date of registration; February 20, 2019).

Changes in chronic myeloid leukemia treatment modalities and outcomes after introduction of second-generation tyrosine kinase inhibitors as first-line therapy: a multi-institutional retrospective study by the CML Cooperative Study Group

This study investigated changes in treatment modalities and outcomes of chronic myeloid leukemia in the chronic phase (CP-CML) after the approval of second-generation tyrosine kinase inhibitors (2G-TKIs) for first-line therapy. Patients were grouped into those who underwent TKI therapy up to December 2010 (imatinib era group, n = 185) and after January 2011 (2G-TKI era group, n = 425). All patients in the imatinib era group were initially treated with imatinib, whereas patients in the 2G-TKI era group were mostly treated with dasatinib (55%) or nilotinib (36%). However, outcomes including progression-free survival, overall survival, and CML-related death (CRD) did not differ significantly between groups. When stratified by risk scores, the prognostic performance of the ELTS score was superior to that of the Sokal score. Even though both scoring systems predicted CRD in the imatinib era, only the ELTS score predicted CRD in the 2G-TKI era. Notably, the outcome of patients classified as high-risk by ELTS score was more favorable in the 2G-TKI era group than in the imatinib era group. Thus, expanding treatment options may have improved patient outcomes in CP-CML, particularly in patients classified as high-risk by ELTS score.

Successful Treatment of Disseminated Nocardiosis by Rapid Identification of the Organism via Genetic Analysis in a Leukemia Patient Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Nocardia infections have been reported to occur in immunocompromised patients. Early diagnosis and therapeutic intervention are especially important for disseminated nocardiosis because of its high mortality rate. A case of disseminated nocardiosis after allogeneic hematopoietic stem cell transplantation, which was promptly treated after identification of the organism by genetic analysis, is presented. A 43-year-old man was diagnosed with T-cell prolymphocytic leukemia and underwent allogeneic hematopoietic stem cell transplantation. Subsequently, during long-term prednisolone administration for chronic graft-versus-host disease, he developed mass lesions throughout his body at 1033 days after transplantation. Pus culture and genetic testing of the parotid mass showed Nocardia farcinica, which improved with treatment with sulfamethoxazole, trimethoprim, and imipenem cilastatin, and there has been no recurrence. When multiple mass lesions occur after hematopoietic stem cell transplantation, and the diagnosis is difficult, disseminated nocardiosis should be included in the differential diagnosis, and appropriate laboratory testing and treatment should be performed.

Clinical management of second-generation tyrosine kinase inhibitor therapy in patients with newly diagnosed chronic myeloid leukemia in the chronic phase, focusing on age and dose effects

ABL1-tyrosine kinase inhibitors (TKIs) are an established treatment choice for patients with chronic myeloid leukemia in the chronic phase (CML-CP). However, effects of TKI dose modification have not been well investigated. In this study, we retrospectively analyzed 178 patients with newly diagnosed CML-CP who were treated with dasatinib or nilotinib, focusing on age and dose effects. Efficacy as measured by cumulative major molecular response (MMR) and molecular response 4.5 rates did not differ significantly between the younger group and elderly group. Elderly patients who started nilotinib at a reduced dose had similar or better efficacy outcomes (including cumulative MMR and continuation ratios) than other groups, and elderly patients who started dasatinib at a reduced dose had the lowest MMR ratio and longest MMR duration. Effects of dose modification based on age and TKI selection can be attributed to flexible management of TKI therapy in real-world practice, but further studies are required to validate the findings of this study.

Rapid deterioration of intravascular large B-cell lymphoma with mass formation in the trigeminal nerve and multiple organ infiltration: An autopsy case report

Intravascular large B-cell lymphoma (IVLBCL) is a rare lymphoma characterized by the selective growth of lymphoma cells within the lumen of vessels. We describe the case of a 69-year-old male who presented with marked pain in the left facial region. Gadolinium-enhanced magnetic resonance imaging revealed a swollen left trigeminal nerve (TN) and positron emission tomography/computed tomography demonstrated fluorodeoxyglucose-only uptake at the same site. The patient had high serum lactate dehydrogenase and soluble interleukin-2 receptor levels. As random skin biopsy and bone marrow biopsy detected no abnormal pathogenesis, open biopsy of the TN was performed, revealing diffuse large B-cell lymphoma (DLBCL). However, ground glass opacities rapidly developed in both lung fields with severe respiratory failure. The patient died of progressive disease before the initiation of chemotherapy. Postmortem examination revealed widespread lymphoma cells in the lumen of vessels in multiple organs, including the lungs, excluding the bone marrow and skin. Lymphoma cells formed a mass in the TN and left lumbar plexus. A diagnosis of IVLBCL was made based on the postmortem pathological analysis. DLBCL of abnormal sites, such as the peripheral nervous system, should be considered in cases of IVLBCL as a differential diagnosis.

The clinical impact of absolute lymphocyte count in peripheral blood among patients with methotrexate - associated lymphoproliferative disorders

Regressive lymphoproliferative disorders (R-LPD) after methotrexate (MTX) withdrawal are one of the specific features of methotrexate - associated lymphoproliferative disorders (MTX-LPD). Although the impact of the absolute lymphocyte count (ALC) on the pathogenesis of R-LPD has been recently emphasized, understanding relapse/regrowth events (RRE) and differences among LPD subtypes is necessary. In this study, we confirmed ALC recovery in the regressive group (R-G; R-LPD without RRE) and relapse/regrowth group (R/R-G; R-LPD with RRE). The increase in ALC lasted at least 2 years in R-G, whereas it decreased within 3 years in R/R-G, supporting the better overall survival (OS) in R-G, as previously reported. In addition, our study suggested that an ALC of 1000/µL at the time of development of LPD is a significant predictor for treatment-free survival (TFS). Furthermore, an ALC of 1000/µL at 6 months after MTX withdrawal was found to be a significant indicator of TFS and OS for R-G and R/R-G. The ALC decreased gradually before LPD development in R/R-G, whereas it decreased 6 months before LPD development in R-G, confirming the important role of ALC in the pathogenesis of MTX-LPD such as regressive events and RRE. In addition to ALC, other predictive factors, such as serum C-reactive protein and soluble interleukin-2 receptors, may be helpful in the management of MTX-LPD, including the decision making for an additional chemotherapy for regressive LPD after MTX withdrawal.

Abemaciclib, a CDK4/6 inhibitor, exerts preclinical activity against aggressive germinal center-derived B-cell lymphomas

The revised WHO classification newly defined the entities “High‐grade B‐cell lymphoma with MYC and BCL2, and/or BCL6 rearrangements (HGBL‐DH/TH)” and “HGBL, NOS.” Standard immunochemotherapy for diffuse large B‐cell lymphoma (DLBCL), R‐CHOP, is insufficient for HGBL patients, and there are currently no optimized therapeutic regimens for HGBL. We previously reported that CCND3, which encodes cyclin D3, harbored high mutation rates in Burkitt lymphoma (BL), HGBL and a subset of DLBCL. Furthermore, the knockdown of cyclin D3 expression was toxic to germinal center (GC)‐derived B‐cell lymphomas. Thus, the fundamental function of cyclin D3 is important for the pathogenesis of GC‐derived B‐cell lymphoma. We herein used two structurally different CDK4/6 inhibitors, palbociclib and abemaciclib, and examined their suppressive effects on cell proliferation and their ability to induce apoptosis in various aggressive B‐cell lymphoma cell lines. The results obtained demonstrated that abemaciclib more strongly suppressed cell proliferation and induced apoptosis in GC‐derived B‐cell lymphoma cell lines than the control, but only slightly inhibited those features in activated B‐cell (ABC)‐like DLBCL cell lines. Palbociclib exerted partial or incomplete effects compared with the control and the effect was intermediate between abemaciclib and the control. Moreover, the effects of abemaciclib appeared to depend on cyclin D3 expression levels based on the results of the expression analysis of primary aggressive B‐cell lymphoma samples. Therefore, abemaciclib has potential as a therapeutic agent for aggressive GC‐derived B‐cell lymphomas.

[Management of multiple myeloma in the relapsed/refractory patient]

The introduction of proteasome inhibitors (PIs), such as bortezomib (BTZ), and immunomodulatory drugs (IMiDs), including thalidomide (THAL) and lenalidomide (LEN), as first-line therapies in multiple myeloma (MM) has markedly improved the clinical outcomes of patients. However, MM remains incurable, and most patients eventually relapse. Moreover, prognosis is poor in patients who exhibit resistance to BTZ or LEN, and novel therapeutic approaches for such patients are urgently needed. Currently, the following six drugs are available for use in relapsed patients: second generation PIs (carfilzomib and ixazomib), an IMiD (pomalidomide), a histone deacetylase (HDAC) inhibitor (panobinostat), and two monoclonal antibodies (elotuzumab and daratumumab). The choice of treatment should be individualized based on certain factors, such as age, presence of comorbidities, frailty, cytogenetic risk, efficacy and toxicity of prior treatments, and the duration of the previous response. A course of triplet therapy containing two novel agents along with DEX is recommended, on first relapse, in fit and healthy patients, whereas doublet therapy is preferred for unfit or frail patients. Retreatment of relapsed/refractory MM (RRMM) with monoclonal antibodies and IMiDs is promising because these drugs have immunostimulatory effects. In addition, novel agents, including an anti-BCMA antibody-drug conjugate, are being studied. Clinical trials are needed to define the optimal treatment strategy for RRMM.

[Human parvovirus B19-induced hemophagocytic lymphohistiocytosis and myocarditis in an adult patient with hereditary spherocytosis]

Human parvovirus B19 (HPV-B19) causes hemophagocytic lymphohistiocytosis (HLH). Here we describe a 35-year-old female with hereditary spherocytosis (HS) who developed HLH due to HPV-B19 infection. Upon admission, she had high fever and diarrhea. Laboratory findings included severe pancytopenia and elevated serum triglyceride and ferritin levels. Moreover, high HPV-B19 levels in the peripheral blood and increased reactive lymphocytosis in the bone marrow led to a diagnosis of HLH due to HPV-B19 infection. With supportive therapy and a blood transfusion, HLH symptoms, including fever and myelosuppression, improved in 1 week. However, symptoms of heart failure (HF) suddenly developed, and an echocardiography revealed diffuse systolic dysfunction, suggesting viral myocarditis due to HPV-B19 infection. Conservative management with diuretics gradually improved HF symptoms over a period of 2 weeks. HPV-B19 infection in adult patients with HS rarely results in severe HLH, but conservative therapy may improve the symptoms. Nonetheless, a careful follow-up is required after HLH improves because viral myocarditis can develop, as was seen in our patient.

Abstract 1884: Dual targeting of cell cycle checkpoint and histone deacetylase overcomes bortezomib resistance in multiple myeloma

Although the introduction of novel agents, such as proteasome inhibitors, immunomodulatory drugs, and histone deacetylase inhibitors (HDACi) has improved the clinical outcomes of the patients with multiple myeloma (MM), most patients eventually relapse and develop drug resistance. Proteasome inhibitor, bortezomib (BTZ), is a key drug for the treatment of MM, and the prognosis of the patients with BTZ resistance is very poor. Therefore, novel therapeutic approaches to overcome BTZ resistance are urgently needed. WEE1 is a cell cycle checkpoint kinase and a key regulator of DNA damage surveillance pathways. In response to extrinsically induced DNA damage, WEE1 induces cell cycle arrest, allowing for the damaged DNA to be repaired before the cell undergoes DNA replication, and prevents cells from mitotic lethality. WEE1 is overexpressed in various cancers, and relates to poor prognosis. In addition, the inhibition of WEE1 has been shown to induce cancer cells to premature mitotic entry leading to apoptotic cell death, suggesting that combining WEE1 inhibitor with DNA damaging agent is effective in cancer therapy. Resent research has shown that HDACi increase reactive oxygen species production resulting in increased DNA damage and impaired DNA repair. These data suggest that the combination of WEE1 inhibitor and HDACi might be an attractive therapeutic option against this incurable hematological malignancy. In the present study, we investigated the efficacy of WEE1 inhibitor MK-1775, a potent and highly-selective small molecule inhibitor of WEE1, in combination with HDACi in various MM cells. MTS assays showed that single agent MK-1775 inhibited the proliferation of various MM cell lines, including BTZ-resistant cell line, in a dose- (0 to 10 μM) and time- (0 to 72 h) dependent manner. In combination with vorinostat which is a pan-HDACi, MK-1775 inhibited the proliferation of BTZ-resistant MM cells more effectively than single agent. Furthermore, the combination of vorinostat and MK-1775 was able to re-sensitize BTZ-resistant MM cells to BTZ. Assays for apoptotic cell death demonstrated that MK-1775 induces both early and late apoptosis in MM cells. Western blotting analysis was performed to investigate the molecular mechanisms of MK-1775-induced cell death, showing that MK-1775 inhibited the expression of the target molecules of Bcl-2 and MCL1, and CDK1 phosphorylation. Moreover, the marked increase in PARP and Caspase 3 cleavage, and histone H2AX expression was observed following treatment with MK-1775 in combination with vorinostat. These findings suggest that the combination of MK-1775 and vorinostat induces synergistically DNA damage and promotes premature mitotic entry resulting in apoptotic cell death in MM cells. In conclusion, our data suggest that WEE1 in combination with HDACi might be a promising molecular target for the treatment of BTZ-resistant MM.

Citation Format: Takayuki Tabayashi, Yuka Tanaka, Yasuyuki Takahashi, Yuta Kimura, Tatsuki Tomikawa, Tomoe Anan, Morihiko Sagawa, Reiko Watanabe, Michihide Tokuhira, Masahiro Kizaki. Dual targeting of cell cycle checkpoint and histone deacetylase overcomes bortezomib resistance in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1884.

The aggressive clinical courses of Hodgkin lymphoma primarily diagnosed as methotrexate-induced non-specific lymphoproliferative disorder in patients with rheumatoid arthritis

Recently, attention has been focused on methotrexate-induced lymphoproliferative disease (MTX-LPD), and atypical phenotypes are occasionally documented. We encountered two patients with rheumatoid arthritis (RA) who were diagnosed with non-specific LPD (LPD-nos). Biopsy samples were not obtained during the initial examination when the LPD development was discovered, and the patients achieved a complete response after MTX cessation (case 1) or steroid pulse therapy (case 2). However, the tumors flared up 1.5 years later, and LPD-nos was determined following biopsies of the lymph node (LN, case 1) and liver (case 2). Prednisolone was subsequently administered instead of chemotherapy; however, multiple masses, including in the spine (case 1), and severe icterus with liver dysfunction (case 2) were exacerbated within a few months. Although the re-biopsy of LN proved the presence of HL and radiation followed by aggressive chemotherapy rescued the patient (case 1), the superficially accessible biopsy site was not found, and autopsy finally revealed HL (case 2). In both cases, the underlying pathogenesis along with the B symptoms and laboratory abnormalities suggested MTX-LPD, HL in particular. Therefore, even if the pathological diagnosis does not confirm the specific LPD subtype, the administration of aggressive chemotherapy should be considered if the LPD activity flares severely.

The Role of Intracellular Signaling Pathways in the Pathogenesis of Multiple Myeloma and Novel Therapeutic Approaches

The introduction of novel agents, such as bortezomib, thalidomide, and lenalidomide, into daily practice has dramatically improved clinical outcomes and prolonged survival of patients with multiple myeloma (MM). However, despite these advanced clinical benefits, MM remains an incurable hematological malignancy. Therefore, development of new agents and novel therapeutic strategies is urgently needed. Recent advances toward understanding the mechanism of myeloma cell growth and drug resistance in the bone marrow milieu have provided clues for the development of next-generation agents aimed at improving patient outcomes. In this review article, we discuss new possible agents for the treatment of MM based on recent advances in the understanding of signaling pathways in myeloma cells.

[Cardiac and breast diffuse large B-cell lymphoma with pericardial effusion and AV-block]

Primary cardiac lymphoma is extremely rare and is associated with a poor prognosis. In most cases, cardiac involvement occurs as a late symptom and the diagnosis is thus delayed. We herein report a 35-year-old woman with cardiac diffuse large B-cell lymphoma (DLBCL) with breast infiltration. The patient was admitted to our hospital based on an initial presentation with dyspnea on exertion, chest pain, and a hard mass of the left breast. Echocardiography revealed a mass in the right atrium wall and interatrial septum, and massive pericardial effusion. ECG showed atrioventoricular block. We promptly performed a needle biopsy of the breast mass, which showed CD5-positive DLBCL, non-GCB type. The serum HIV reaction was negative. We thus diagnosed this patient as having cardiac and breast CD5-positive DLBCL, stage IVA, based on the massive pericardial effusion. The patient's prognosis was apparently poor. Therefore, she received 3 cycles of R-CHOP chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT), resulting in a complete response. In general, cardiac lymphoma is associated with high mortality and has a poor prognosis. This case demonstrates that rapid and appropriate diagnosis, and immediate intensive chemotherapy followed by PBSCT might be necessary for the treatment of extranodal lymphoma indicative of a poor prognosis.

TM-233, a novel analog of 1'-acetoxychavicol acetate, induces cell death in myeloma cells by inhibiting both JAK/STAT and proteasome activities

Although the introduction of bortezomib and immunomodulatory drugs has led to improved outcomes in patients with multiple myeloma, the disease remains incurable. In an effort to identify more potent and well-tolerated agents for myeloma, we have previously reported that 1'-acetoxychavicol acetate (ACA), a natural condiment from South-East Asia, induces apoptotic cell death of myeloma cells in vitro and in vivo through inhibition of NF-κB-related functions. Searching for more potent NF-κB inhibitors, we developed several ACA analogs based on quantitative structure-activity relationship analysis. TM-233, one of these ACA analogs, inhibited cellular proliferation and induced cell death in various myeloma cell lines with a lower IC50 than ACA. Treatment with TM-233 inhibited constitutive activation of JAK2 and STAT3, and then downregulated the expression of anti-apoptotic Mcl-1 protein, but not Bcl-2 and Bcl-xL proteins. In addition, TM-233 rapidly decreased the nuclear expression of NF-κB and also decreased the accumulation of cytosolic NF-κB. We also examined the effects of TM-233 on bortezomib-resistant myeloma cells that we recently established, KMS-11/BTZ and OPM-2/BTZ. TM-233, but not bortezomib, inhibited cellular proliferation and induced cell death in KMS-11/BTZ and OPM-2/BTZ cells. Interestingly, the combination of TM-233 and bortezomib significantly induced cell death in these bortezomib-resistant myeloma cells through inhibition of NF-κB activity. These results indicate that TM-233 could overcome bortezomib resistance in myeloma cells mediated through different mechanisms, possibly inhibiting the JAK/STAT pathway. In conclusion, TM-233 might be a more potent NF-κB inhibitor than ACA, and could overcome bortezomib resistance in myeloma cells.

SH2B3 (LNK) mutations from myeloproliferative neoplasms patients have mild loss of function against wild type JAK2 and JAK2 V617F

Somatic point mutations in the PH domain of SH2B3 (LNK), an adaptor protein that is highly expressed in haematopoietic cells, were recently described in patients with myeloproliferative neoplasms. We studied the effect of these mutations on the JAK2 signalling pathway in cells expressing either wild type JAK2 or the JAK2 V617F mutation. Compared to wild type SH2B3, PH domain mutants have mild loss of function, with no evidence for a dominant-negative effect. Mutants retain binding capacity for JAK2, an established SH2B3 target, as well as for the adaptor proteins 14-3-3 and CBL. Our data suggest that the loss of SH2B3 inhibitory function conferred by the PH domain mutations is mild and may collaborate with JAK2 V617F and CBL mutations in order to promote either the development or the progression of myeloproliferative neoplasms.

Docetaxel for non-small-cell lung cancer harboring the activated EGFR mutation with T790M at initial presentation

A 72-year-old woman was referred to our hospital with Stage IV non-small-cell lung cancer (NSCLC). Chest computed tomography revealed a mass in the upper lobe of the right lung, with pleural effusion. Cytologic examination identified adenocarcinoma cells in the right pleural effusion. Furthermore, both a deletion mutation in exon 19 and a threonine-methionine substitution mutation at position 790 in exon 20 (T790M) were detected in the epidermal growth factor receptors (EGFR) in the malignant cells. As systemic chemotherapy consisting of carboplatin and pemetrexed or erlotinib proved ineffective, docetaxel monotherapy was initiated as a third-line treatment. Following salvage chemotherapy, her Eastern Cooperative Oncology Group performance status improved from 3 to 1, with tumor regression over 5 months. To the best of our knowledge, this is the first report of successful docetaxel treatment for a patient with NSCLC harboring the T790M EGFR-activating mutation identified before treatment with EGFR tyrosine kinase inhibitors.

Cytotoxicity of activated natural killer cells and expression of adhesion molecules in small-cell lung cancer

BACKGROUND/AIM

Although small-cell lung cancer (SCLC) is sensitive to anticancer agents, most patients with SCLC experience relapse and die within two years. Here, we examined the relationship between natural killer (NK) cells and adhesion molecules on SCLC cell lines.

MATERIALS AND METHODS

The expression levels of HLA class I, β2-microglobulin, Fas/Apo-1 receptor (FAS) and adhesion molecules on SCLC cell lines were examined by flow cytometry. The cytotoxicity of activated NK cells from SCLC patients was examined using (51)Cr-release assay.

RESULTS

HLA class I antigen and β2-microglobulin expression levels in SCLC cell lines were lower than those in healthy volunteers. SCLC cell lines were susceptible to lysis by activated NK cells but this showed no correlation with expression levels of adhesion molecules.

CONCLUSION

Target cell susceptibility to activated NK cells from five SCLC patients correlated with survival benefit; target cell susceptibility to activated NK cells may be a surrogate marker of outcome for patients with SCLC.

Elevated coagulation factor VIII plasma activity in a patient with lymphangiosarcoma

A 72-year-old woman was referred to our hospital for palliative care. Fifteen years earlier, she had undergone total hysterectomy and radiotherapy for cervical cancer. One year before her referral, she visited a hospital due to a gait disturbance and was diagnosed with lymphangiosarcoma. The level of coagulation factor VIII plasma activity was >201% (normal range: 62-145%) and the immunohistochemical results were positive for factor VIII-related antigen in a tumor specimen. To the best of our knowledge, this is the first report of high coagulation factor VIII plasma activity in a patient with lymphangiosarcoma.

Characterization of the short isoform of Helios overexpressed in patients with T-cell malignancies

In an earlier report, we demonstrated overexpression of a short isoform of Helios, Hel-5, which lacks three of four N-terminal zinc fingers, in patients with adult T-cell leukemia/lymphoma. Here, we characterized Hel-5 using immunoprecipitation, and gel shift and luciferase promoter assays, and found that Hel-5 lacks the repressor function observed with a full-length isoform of Helios. Moreover, Hel-5 associates with the full-length isoforms of the Ikaros gene family, Ikaros, Aiolos and Helios, and inhibits their DNA binding activity when present in excess, leading to dominant-negative effects on the full-length isoforms of the Ikaros gene family. Our results suggest a critical role for Helios in the mechanism of leukemogenesis.

Elevation of serum hepatocyte growth factor during granulocyte colony-stimulating factor-induced peripheral blood stem cell mobilization

We examined serum levels of the angiogenic factors, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and hepatocyte growth factor (HGF), in normal donors for allogeneic peripheral blood stem cell (PBSC) transplantation. Granulocyte colony-stimulating factor (G-CSF) (filgrastim 400 microg/m2/d) was administered to 23 donors for 5 d and aphereses were performed on days 4 and 5. Although bFGF remained at similar levels after G-CSF treatment, serum VEGF and HGF levels increased 1.5-fold (n = 13; P = 0.02) and 6.8-fold (n = 23; P < 0.0001) respectively. The serum HGF level before G-CSF administration on day 1 correlated inversely with mobilized CD34+ cell numbers. Time course kinetics of HGF showed that on the day after G-CSF administration (day 2), serum HGF levels increased to 3678 pg/ml. For auto PBSC mobilization with chemotherapy and G-CSF 200 microg/m2/d (n = 8), we observed similar HGF elevation, which appeared to be dose-dependent on the G-CSF administered.

The type 1 CD10/neutral endopeptidase 24.11 promoter: functional characterization of the 5′-untranslated region

The cell surface zinc metalloproteinase CD10/neutral endopeptidase 24.11 (NEP) is expressed on normal and malignant lymphoid progenitors, granulocytes and a variety of epithelial cells. Because CD10/NEP functions as part of a regulatory loop that controls local concentrations of peptide substrates and associated peptide-mediated signal transduction, its role in each tissue is different depending on the availability of substrate. To characterize further how this widely distributed molecule is regulated differentially in each tissue, we analysed the major type 2 CD10/NEP promoter and found three functionally important transcription factor binding sites, one of which was identical to CCAAT-binding transcription factor/nuclear transcription factor Y. In this report, we analyse the type 1 CD10/NEP promoter and found a functionally important transcription factor binding site in the 5'-untranslated region. The results of the competition and supershift experiments demonstrated that the functionally important transcription factor was identical to Sp1. Our results suggest that ubiquitously expressed Sp1 may play an important role in differentiation stage-specific regulation of CD10/NEP expression in lymphoid lineage.

Rapid improvement of disseminated intravascular coagulation by donor leukocyte infusions in a patient with promyelocytic crisis of chronic myelogenous leukemia after reduced-intensity stem cell transplantation from an HLA 2-antigen-mismatched mother

Donor leukocyte infusion (DLI) is recognized as effective therapy for relapse after stem cell transplantation in patients with chronic myelogenous leukemia (CML). However, the clinical efficacy of DLI in the advanced phase of CML or other types of leukemia has not been clearly defined because of its varying degree of success. We describe a 22-year-old male patient with promyelocytic crisis of CML who had a relapse after peripheral blood stem cell transplantation, under reduced-intensity conditioning, from his HLA 2-antigen-mismatched mother. Complete hematologic remission was obtained after transplantation. However, a relapse that occurred on day 66 posttransplantion was characterized by an increase in number of leukemic promyelocytes with simultaneous exacerbation of disseminated intravascular coagulation (DIC). The patient received DLI containing 1 x 10(7)/kg CD3+ cells on day 73. Because rapid improvement of DIC paralleled the decrease in leukemic cells and because it was observed soon after DLI and before the development of acute graft-versus-host disease (GVHD), we hypothesized that leukemia-specific cells other than natural killer cells or cytotoxic T-cells unrelated to GVHD played a role in the graft-versus-leukemia effect observed in our patient. In addition, this may be the first report of effective correction of DIC by DLI after stem cell transplantation.

Over-expression of the dominant-negative isoform of Ikaros confers resistance to dexamethasone-induced and anti-IgM-induced apoptosis

In previous studies, we demonstrated an over-expression of the dominant-negative isoform of the transcription factor Ikaros, Ik-6, in patients with B-cell malignancies, including blast crisis of chronic myelogenous leukaemia and acute lymphoblastic leukaemia. To investigate the consequence of over-expression of Ik-6 in B cells, we constructed Ik-6 transfectants of the FDH-1 and Ramos cell lines. FDH-1, which was established from a patient with early pre-B acute lymphoblastic leukaemia, undergoes apoptosis with dexamethasone treatment, whereas Ramos undergoes apoptosis following anti-IgM antibody treatment. Compared with the wild type, the over-expression of Ik-6 rendered the FDH-1 and Ramos transfectants resistant to dexamethasone-induced and anti-IgM-induced apoptosis respectively. An immunoblotting study demonstrated bcl-2 upregulation in anti-IgM-induced Ramos Ik-6 transfectants, but not in FDH-1 Ik-6 transfectants. Further investigations of the mechanism of leukaemogenesis associated with the over-expression of Ik-6 are warranted.

Over-expression of short isoforms of Helios in patients with adult T-cell leukaemia/lymphoma

In previous studies, we demonstrated an over-expression of the dominant-negative isoform of the transcription factor Ikaros in patients with blast crisis of both chronic myelogenous leukaemia and B-cell acute lymphoblastic leukaemia (ALL). Recently, we reported an over-expression of the short isoforms of Helios, which is one of the members of the Ikaros gene family, in a patient with T-cell ALL. In the present study, we found over-expression of short isoforms of Helios in human T lymphotropic virus-I (HTLV1)-infected patients who had developed chronic and acute forms of adult T-cell leukaemia/lymphoma. In contrast, we could not detect any over-expression of short isoforms of Helios in healthy HTLV1 carriers. By Southern blotting, we detected a small deletion in the Helios gene locus of adult T-cell leukaemia/lymphoma patients. The present results suggest that Helios gene abnormalities might be one of the important mechanisms in the disease progression of HTLV1 infection.

Overexpression of novel short isoforms of Helios in a patient with T-cell acute lymphoblastic leukemia

OBJECTIVE

In previous studies, we demonstrated overexpression of the dominant-negative isoform of the transcription factor Ikaros, Ik-6, in patients with blast crisis of chronic myelogenous leukemia and B-cell acute lymphoblastic leukemia. In the present study, we analyzed expression of the Ikaros family genes Ikaros, Aiolos, and Helios in a panel of human T-cell leukemia/lymphoma cell lines and bone marrow samples of patients with T-cell acute lymphoblastic leukemia.

MATERIALS AND METHODS

We performed reverse transcriptase polymerase chain reaction, sequencing analysis, immunoblotting, and Southern blotting.

RESULTS

We found overexpression of novel short isoforms of Helios (Hel-5 and Hel-6) in the HD-Mar cell line. Southern blot analysis suggested that there might be a small deletion in the Helios locus of HD-Mar. In addition, we observed decreased expression of more than one Ikaros family gene in 3 of 9 patients with T-cell acute lymphoblastic leukemia. Moreover, one of the patients overexpressed novel short isoforms of Helios (Hel-7 and Hel-8).

CONCLUSION

This study provides the first evidence of an Ikaros family member (other than Ikaros) of which novel short isoforms become overexpressed in human leukemia.

Eradication of residual bcr-abl-positive clones by inducing graft-versus-host disease after allogeneic stem cell transplantation in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia

Persistence of bcr-abl transcripts after marrow grafting is thought to convey a high risk for relapse in patients with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). Donor leukocyte infusion (DLI) is closely associated with development of graft-versus-host disease (GVHD) and has well-defined activity against relapsed chronic myelogenous leukemia (CML) but not ALL. We report two patients with Ph-positive ALL who remained bcr-abl positive by reverse transcriptase polymerase chain reaction (RT-PCR) after marrow grafting. Residual bcr-abl transcripts in both patients were eliminated following acute GVHD, which was induced by either DLI or rapid reduction of immunosuppression. Both patients have continued in complete molecular remission for 18 months and 8 months following transplantation, respectively. Our observation suggests that induction of GVHD may eliminate minimal residual disease, thereby preventing leukemia relapse in patients transplanted for Ph-positive ALL.

Structural elucidation of aculeximycin. III. Planar structure of aculeximycin, belonging to a new class of macrolide antibiotics

The planar structure of aculeximycin (1) produced by Streptosporangium albidum has been determined by spectral methods and chemical degradations such as 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU)-methanol reaction, ozonolysis, and periodative oxidation. The antibiotic consists of a 30-membered polyhydroxy lactone ring, an alpha, beta-unsaturated ester group, an intramolecular hemiketal, an oligosaccharide (aculexitriose), a neutral sugar and an amino sugar. The structure of aculeximycin is closely related to those of sporaviridins produced by Streptosporangium viridogriseum. We consider that aculeximycin and sporaviridins belong to a new class of macrolide antibiotics, which is different from the polyol macrolides produced by Streptomyces.