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NS-398, a selective inhibitor of cyclooxygenase 2 (COX-2), has been reported to inhibit growth and induce apoptosis in several cancer cell lines that overexpress COX-2. However it has not been extensively studied in multiple myeloma (MM). Here, we studied the effects of COX-2 inhibitors on MM cell lines and primary myeloma patient cells. We investigated the effects of NS-398 on proliferation and apoptosis in three myeloma cell lines (PCM6, U266 and RPMI8226) and isolated CD138-positive cells from MM patients. Furthermore, the combined effects of NS-398 plus dexamethasone (Dex) or thalidomide (Thal) were investigated. All myeloma cell lines express COX-2. NS-398 inhibited growth and induced apoptosis in PCM6, RPMI8226 and CD138-positive MM cells in a time- and dose-dependent manner. At low concentrations (10 μM), NS-398 primarily induced growth arrest without affecting cell viability, but at higher concentrations (over 25 μM), apoptosis was induced. During the process of apoptosis, the number of Fas-positive cells increased. Downstream signals of Fas, such as caspase 8, 3 and 9, were also activated. On the other hand, protein levels of the Bcl-2 family did not change, although mitochondrial transmembrane potential (Δψm) was decreased. Combined incubation with Dex or Thal enhanced NS-398-induced growth inhibition and apoptosis in RPMI8226 cells. The combined effect of Dex was more potent than that of Thal. Our findings suggests that COX-2 plays an important role in regulation of apoptosis in myeloma cells, and COX-2 inhibitors might serve as an effective tool for future chemoprevention and/or treatment of myeloma. [ABSTRACT FROM AUTHOR]

Interferon (IFN)-gamma is a survival factor for mature erythroid progenitor cells. To elucidate related survival mechanisms, we compared the role of phosphatidylinositol 3-kinase (PI3-kinase) in the survival signals of IFN-gamma and erythropoietin (EPO). Human erythroid colony-forming cells (ECFCs) purified from peripheral blood were used, and Ly294002 was used as a PI3-kinase inhibitor. Treating ECFCs with a high concentration of Ly294002 (50 micromol/L) in the presence of EPO and/or IFN-gamma reduced cell viability by inducing apoptosis. However, treating cells with a lower concentration of Ly294002 (10 micromol/L) did not affect the antiapoptotic function of IFN-gamma and abolished the antiapoptotic effect of EPO. Adding IFN-gamma or EPO induced Bcl-x expression in ECFCs, as determined by Western blotting, and expression was suppressed in the presence of Ly294002. We also examined the phosphorylation of the protein kinase Akt, the downstream target of PI3-kinase. EPO stimulation significantly increased the level of Akt phosphorylation, but IFN-gamma did not. These results suggest that IFN-gamma plays a role in preventing the apoptosis of erythroid progenitor cells by affecting Bcl-x expression, thereby reducing the disruption of the mitochondrial transmembrane potential via PI3-kinase pathways that are related to but distinct from the EPO pathway. [ABSTRACT FROM AUTHOR]

Transfusion-related acute lung injury (TRALI) is a severe pulmonary complication following blood transfusions. We experienced a case of possible TRALI during the course of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). A 19-year-old woman was admitted to our hospital suffering from fever and abdominal pain. Her laboratory data revealed pancytopenia, liver damage, coagulopathy, and a high titer of EBV-DNA. Computed tomography showed hepatosplenomegaly and bone marrow aspiration revealed hemophagocytosis and the proliferation of atypical lymphocytes. A diagnosis of EBV-HLH was made and plasma exchange was performed. Severe hypoxia due to pulmonary edema developed two hours after starting the plasma transfusion. Methylprednisolone pulse therapy and non-invasive positive pressure ventilation ameliorated her respiratory condition. Anti-HLA class I and II antibodies were detected in donor sera and a cross-match test between patient lymphocytes and donor plasma was positive. To the best of our knowledge, this is the first case report of TRALI complicated with EBV-HLH. It is possible that hypercytokinemia accompanied by HLH was associated with the onset of TRALI.

We measured plasma levels of thrombopoietin (TPO) in several patients with thrombocytopenia. Similar to previous reports, TPO levels in aplastic anemia (N=9) were markedly higher than those in idiopathic thrombocytopenic purpura (N=10): 16.19+/-9.07 fmol/ml and 1.21+/-1.06 fmol/ml, respectively. In patients with secondary failure of platelet recovery (N=7) as well as primary failure after hematopoietic stem cell transplantation, TPO levels were very high, reflecting impaired platelet production due to GVHD, drug treatments, and infection. When using new drugs such as TPO-receptor agonists, measurement of TPO levels might be important to differentiate the mechanism of thrombocytopenia.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but severe complication of Epstein-Barr virus (EBV) infection. Interactions between EBV-infected T cells and activated macrophages cause several conditions such as pancytopenia, liver dysfunction and coagulopathy. We describe here two young adults with EBV-associated HLH with monoclonal proliferation of EBV-infected T cells within a short period after infectious mononucleosis as a primary infection. One patient was a 16-year-old man who developed severe pancytopenia and liver dysfunction two months after infectious mononucleosis. Bone marrow examination showed hemophagocytosis, and laboratory data demonstrated monoclonal proliferation of EBV-infected T cells. Several treatments such as immunosuppressive therapy, chemotherapy and hematopoietic stem cell transplantation were not effective, and the patient died of progressive disease. The other patient was a 19-year-old woman who developed thrombocytopenia and liver dysfunction two months after infectious mononucleosis. Findings of hemophagocytosis and monoclonal proliferation of EBV-infected T cells were similar to those in the first case. Clinical signs and symptoms were resolved completely by immunosuppressive therapy containing methyl-prednisolone and cyclosporine. Since these two cases each demonstrated a distinct clinical course, an investigation of the prognostic factors and treatment strategies for EBV-HLH is warranted.

We describe a 70-year-old woman with acute myelogenous leukemia with t(8;21) in the first relapse who underwent nonmyeloablative transplantation with conditioning of fludarabine and low-dose total body irradiation (2Gy). Myelosuppression was very mild, and the patient developed transient grade I renal and hepatic toxicities. Complete chimerism was achieved on day 120. The level of the AML1/MTG8 fusion gene in bone marrow decreased to an undetectable level on day 56 and the patient is alive and in complete remission with a follow-up at day 450. This transplant regimen might be well tolerated even by the elderly patients and bring a durable remission.

We describe a 51-year-old woman with recurrent follicular lymphoma from the age of 47 despite chemo-radio therapy, who subsequently underwent nonmyeloablative stem cell transplantation with conditioning consisting of fludarabine and low-dose total body irradiation (2 Gy). Myelosuppression was very mild, so the patient required no transfusions. Chimerism analysis from peripheral blood showed that T-cell mixed chimerism continued over 12 months after stem cell transplantation (the percentage of recipient T-cells was approximately 20%). Despite this, the lymphadenopathy disappeared, and the patient developed grade II acute GVHD (graft versus host disease). It has been considered that the establishment of full donor chimerism is required to induce GVHD and GVM (graft versus malignancy) effects. In this case, however, an allo-response was observed despite the persistence of T-cell mixed chimerism.

We describe the case of a 23-year-old man with acute lymphoblastic leukemia in whom the Philadelphia chromosome was first detected in the late stage of the disease. At diagnosis, the patient's leukocyte count was 39,400/microliter and leukemic cells were positive for CD10, 19, 20, 33, 34 and HLA-DR. Karyotypic analysis at diagnosis revealed 46,XY. Complete remission was achieved after the first induction therapy, but the disease recurred after 9 months. The patient underwent allogeneic peripheral blood stem cell transplantation from his HLA identical mother, but relapse occurred on day 80. The proportion of bone marrow lymphoblasts decreased transiently after donor lymphocyte infusion but later increased, and the patient died on day 362. The Philadelphia chromosome was first detected by karyotypic analysis on day 256. p190-type bcr/abl mRNA transcripts were negative following RT-PCR at the initial diagnosis, but became positive from the first relapse through the late stage. Generally, the product of the bcr/abl fusion gene has been thought to play an important role in leukemogenesis, however the present case suggests that this gene product is also related to disease progression.

Vitamin K2 is reported to induce apoptosis or differentiation of leukemic cell lines in vitro. We administered a vitamin K2 analog, menatetrenone, at 45 mg daily to 23 patients with myelodysplastic syndrome (MDS): 13 patients with RA, 2 with RARS, 6 with RAEB and 2 with RAEB-T. Good response (GR) and partial response (PR) were defined as an increase of hemoglobin concentration exceeding 2 g/dl and 1-2 g/dl without transfusion, respectively. Six of the RA patients showed improvement of anemia (GR, 3 patients; PR, 3 patients). RA patients who did not have a hypocellular bone marrow and were transfusion-independent tended to be responsive to vitamin K2 therapy in combination with vitamin D3 or anabolic steroids. No adverse effect of vitamin K2 was observed, and the time required to obtain the hematological response was short, being 3 months on average. We believe that vitamin K2 therapy has potential as a treatment for patients with MDS.