Yasuo Hirayama

Interaction between leukemic-cell VLA-4 and stromal fibronectin is a decisive factor for minimal residual disease of acute myelogenous leukemia

Bone-marrow minimal residual disease (MRD) causes relapse after chemotherapy in patients with acute myelogenous leukemia (AML). We postulate that the drug resistance is induced by the attachment of very late antigen (VLA)-4 on leukemic cells to fibronectin on bone-marrow stromal cells. We found that VLA-4-positive cells acquired resistance to anoikis (loss of anchorage) or drug-induced apoptosis through the phosphatidylinositol-3-kinase (PI-3K)/AKT/Bcl-2 signaling pathway, which is activated by the interaction of VLA-4 and fibronectin. This resistance was negated by VLA-4-specific antibodies. In a mouse model of MRD, we achieved a 100% survival rate by combining VLA-4-specific antibodies and cytosine arabinoside (AraC), whereas AraC alone prolonged survival only slightly. In addition, overall survival at 5 years was 100% for 10 VLA-4-negative patients and 44.4% for 15 VLA-4-positive patients. Thus, the interaction between VLA-4 on leukemic cells and fibronectin on stromal cells may be crucial in bone marrow MRD and AML prognosis.

Effect of Helicobacter pylori eradication on platelet recovery in Japanese patients with chronic idiopathic thrombocytopenic purpura and secondary autoimmune thrombocytopenic purpura

Summary. The prevalence of Helicobacter pylori infection and the effect of its eradication on platelet count in 48 Japanese patients with autoimmune thrombocytopenic purpura (AITP), including 40 chronic idiopathic thrombocytopenic purpura (ITP) and eight secondary AITP, were investigated. H. pylori infection was found in 25 ITP patients (62·5%) and in two secondary AITP (25%). H.pylori eradication was obtained in 19 of 19 infected ITP patients (100%), who were not in remission (platelets < 100 × 109/l) at the time of infection assessment. During follow‐up (median 14·8 months), 12 of 19 H. pylori‐eradicated patients (63·2%) showed a significant increase in platelet count accompanied by a significant decrease of platelet‐associated immunoglobulin G (IgG). This response was maintained in all responding patients throughout the follow‐up period. However, two infected patients with secondary AITP did not show platelet increase after eradication. The assessment of H. pylori infection and its eradication should be attempted in ITP as this approach could be an effective strategy, at least for some of these patients.

Cytokine mRNA expression of bone marrow stromal cells from patients with aplastic anaemia and myelodysplastic syndrome

Summary We studied mRNA expression of the cytokine granulocyte‐colony stimulating factor (G‐CSF), interleukin‐1β (IL‐1β), IL‐6, IL‐8 and stem cell factor of stromal cells derived from bone marrows of nine normal volunteers, eight patients with aplastic anaemia (AA) and seven patients with myelodysplastic syndrome (MDS). The proportion of endothelial cells. macrophages. fibroblast‐like cells and adipocytes in stromal cells showed no differences between normal volunteers and the patients. Levels of cytokine inKNA expression were determined by reverse transcription‐polymerase chain reaction. Spontaneous expression occurred and this was augmented by IPS stimulation in cells of all the normal volunteers and in most patients.

A proof of glutathione S-transferase-π-related multidrug resistance by transfer of antisense gene to cancer cells and sense gene to bone marrow stem cell

In order to directly prove the involvement of GST-pi in drug resistance, its antisense gene was transduced into human colorectal cancer cell line which has been shown to express high level of GST-pi and the sensitivity of this cell line to anticancer drugs were assessed. The transfectant showed higher sensitivity to adriamycin (3.3-fold), Cisplatnum (2.3-fold), Melphalan (2.2-fold), Etoposode (2.2-fold) than the parental cell, while the sensitivity to vincristine, mitomicin C, 5-fluorouracil was unchanged by transfection. When the transfectant and parental cells were innoculated in nude mice and treated with adriamycin, a significant suppression of tumor growth was observed with the transfectant as compared to the parental cell. On the basis of this observation, we then transduced sense GST-pi gene into human bone marrow stem cells (CD34+ cells) to protect them from toxicity of anticancer drug. The gene transduced CD34+ cells formed more CFU-GM than nontransduced CD34+ cell in the presence of adriamycin (30 ng/ml). Thus, the autotransplantation of GST-pi gene transduced cell into cancer patients to protect the bone marrow from subsequent highdose chemotherapy is considered to be a new strategy for cancer gene therapy.

Incidence and Risk of Postherpetic Neuralgia after Varicella Zoster Virus Infection in Hematopoietic Cell Transplantation Recipients: Hokkaido Hematology Study Group

To assess the incidence of and risk factors associated with postherpetic neuralgia (PHN) after hematopoietic cell transplantation (HCT) varicella zoster virus (VZV) infection, we conducted a retrospective chart review of 418 consecutive patients who underwent HCT between April 2005 and March 2007. The male/female ratio was 221/197, median age at HCT was 47 years (range: 0-69 years), and autologous/allogeneic/syngeneic HCT ratio was 154/263/1. Seventy-eight patients developed VZV infection after HCT. Sixty-two patients had localized zoster, 11 patients had disseminated zoster (rash like chicken pox), and 4 patients had visceral zoster. All cases were treated with acyclovir (ACV) or valacyclovir (VACV), and there was no VZV infection-related death. Twenty-seven (35%) of the 78 patients with VZV infection suffered PHN after resolution of VZV infection. Multivariate analysis showed that advanced age is the only risk factor in autologous HCT (P = .0075; odds ratio [OR] = 1.14; 95% confidence interval [CI], 0.97-1.33). On the other hand, advanced age (P = .0097; OR = 1.06; 95% CI, 1.01-1.12), male gender (P = .0055; OR = 12.7; 95% CI, 1.61-100.1), and graft-versus-host disease (GVHD) prophylaxis with a tacrolimus-based regimen (P = .0092; OR = 9.56; 95% CI, 1.44-63.3) were associated with increased risk of PHN in allogeneic HCT. This study for the first time clarified the risk of PHN in HCT recipients.

GST-π gene-transduced hematopoietic progenitor cell transplantation overcomes the bone marrow toxicity of cyclophosphamide in mice

Autologous transplantation of bone marrow cells (BMCs) transduced with the multidrug resistance 1 (MDR1) gene or dihydrofolate reductase (DHFR) gene has already been applied in clinical chemoprotection trials. However, anticancer drugs frequently used in high-dose chemotherapy (HDC), such as alkylating agents, are not relevant to MDR1 or DHFR gene products. In this context, we have previously reported that glutathione S-transferase-pi (GST-pi) gene-transduced human CD34(+) cells showed resistance in vitro against 4-hydroperoxicyclophosphamide, an active form of cyclophosphamide (CY). In the present study, a subsequent attempt was made in a murine model to evaluate the effectiveness of transplantation of GST-pi-transduced BMCs to protect bone marrow against high-dose CY. The gene transfection was carried out retrovirally, employing a recombinant fibronectin fragment. Transfection efficiency into CFU-GM was 30%. After the transplantation, recipient mice (GST-pi mice) received three sequential courses of high-dose CY. As the chemotherapy courses advanced, both shortening of recovery period from WBC nadir and shallowing of WBC nadir were observed. In contrast to the fact that three of seven control mice died, possibly due to chemotoxicity, all seven GST-pi mice were alive after the third course, at which point the vector GST-pi gene was detected in 50% of CFU-GM derived from their BMCs and peripheral blood mononuclear cells. When BMCs obtained from these seven mice were retransplanted into secondary recipient mice, 20% of CFU-GM from BMCs showed positive signals for vector GST-pi DNA after 6 months. These data indicate that the GST-pi gene can confer resistance to bone marrow against CY by being transduced into long-term repopulating cells.

Spin Degree of Freedom in the nu = 1 Bilayer Electron System Investigated by Nuclear Spin Relaxation

The nuclear-spin-relaxation rate 1/T(1) has been measured in a bilayer electron system at and around total Landau level filling factor nu=1. The measured 1/T(1), which probes electron spin fluctuations, is found to increase gradually from the quantum Hall (QH) state at low fields through a phase transition to the compressible state at high fields. Furthermore, 1/T(1) in the QH state shows a noticeable increase away from nu=1. These results demonstrate that, as opposed to common assumption, the electron spin degree of freedom is not completely frozen either in the QH or the compressible states.

Allogeneic bone marrow transplantation in a patient with T-prolymphocytic leukemia with small-intestinal involvement

Although T-prolymphocytic leukemia (T-PLL) is characterized by organ infiltration, small-intestinal involvement is rare. We performed an unrelated allogeneic bone marrow transplantation in a patient with T-PLL who had multiple lymphomatous polyposis of the small intestine refractory to combination chemotherapy (cyclophosphamide, vincristine, and prednisolone [COP] and fludarabine plus cyclophosphamide). The patient developed no graft-versus-host disease (GVHD) and remains in complete remission 16 months after the transplantation. T-PLL is usually refractory to chemotherapy and is a T-cell malignancy with poor prognosis. There have been several reports on allogeneic hematopoietic stem-cell transplantation (allo-HSCT) for T-PLL, but none on allo-HSCT for T-PLL patients with intestinal involvement. It is suggested that allo-HSCT may improve the prognosis in patients with T-PLL involving the small intestine.

NMR evidence for spin canting in a bilayer nu=2 quantum hall system.

We investigate the electron spin states in the bilayer quantum Hall system at total Landau level filling factor nu=2 exploiting current-pumped and resistively detected NMR. The measured Knight shift, K(S), of 75As nuclei reveals continuous variation of the out-of-plane electronic spin polarization between nearly full and zero as a function of density imbalance. Nuclear spin relaxation measurements indicate a concurrent development of an in-plane spin component. These results provide direct information on the spin configuration in this system and comprise strong evidence for the spin canting suggested by previous experiments.

Immunochemotherapy in B-16-melanoma-cell-transplanted mice with combinations of interleukin-2, cyclophosphamide, and PSK.

The effect of combination immunochemotherapy using interleukin-2 (IL-2), PSK and cyclophosphamide (CY) was evaluated in a pulmonary metastasis model in BDF1 mice. B-16 melanoma cells were inoculated into a hind limb. On day 3 after inoculation, 20 mg/kg of CY was administered intraperitoneally, and IL-2 (3.75 x 10(4) BRM units/head) was injected into the tail vein on days 7, 8 and 9. PSK (1,000 mg/kg) was administered orally every day from day 1 to day 10 using a stomach tube. This treatment cycle was repeated three times. Using this combination therapy, the cytotoxicity of lymphokine-activated killer cells and tumor-infiltrating lymphocytes was enhanced. Pulmonary metastasis was remarkably suppressed and a prolongation of survival was obtained compared with the nontreated group and an IL-2+CY group. The effect was augmented by repeating the therapy protocol. By analyzing the killer activity and surface markers of tumor-infiltrating lymphocytes, it was recognized that increased numbers of Lyt-2-positive T cells with augmented cytotoxicity were obtained. This treatment modality should have clinical significance.