[Molecular targeting therapy by anti-VLA-4 monoclonal antibodies for AML].
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Animals↗
Biomedical subjects
Takuya Matsunaga
Publications and source records attributed to Takuya Matsunaga.
Plasma glutathione S-Transferase P1-1 as a prognostic factor in patients with advanced non-Hodgkin's lymphoma (stages III and IV).
PURPOSE: This study aims to investigate whether the plasma level of glutathione S-transferase P1-1 (GSTP1-1), which is a phase II detoxifying enzyme known to be a resistance factor for anticancer drugs, could be a prognostic factor of de novo non-Hodgkin lymphoma (NHL) in clinical stages (CSs) III and IV. EXPERIMENTAL DESIGN: Study population consisted of 80 NHL patients with no prior treatment: 12 patients were at CS I, 14 at CS II, 25 at CS III, and 29 at CS IV. All 54 patients at CS III or CS IV were treated with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP). Plasma GSTP1-1 concentration was measured by ELISA. We stained lymph node tissues for GSTP1-1 using anti-GSTP1-1 monoclonal antibody 5F and quantitatively assessed the intensity of immunostaining by using the KS-400 image analyzing system. RESULTS: There was a significant stepwise increment of plasma GSTP1-1 concentration from CS I to CS IV (P < 0.05). Of the 54 patients with CS III or IV treated with CHOP, 28 (52%) had elevated plasma GSTP1-1 levels. Plasma GSTP1-1 concentration tended to correlate with the intensity of GSTP1-1 expression in lymphoma tissues as assessed by immunostaining (P = 0.07). The CR rates in patients at CS III and CS IV treated by CHOP, 55.2% (14 of 26) and 16.0% (5 of 28) for the low and high plasma GSTP1-1 groups, respectively, were significantly different (P < 0.01). For these two groups, the median survival times were 64 and 25 months, respectively (P < 0.01), and the median times to progression were 58 and 12 months, respectively (P < 0.01). There was no significant correlation between plasma GSTP1-1 concentrations and other NHL prognostic indicators in these patients as determined by univariate and multivariate analyses. CONCLUSION: These results showed that plasma GSTP1-1 is a useful prognostic factor for CS III and IV advanced NHL. Thus, it may be a promising strategy to treat NHL concomitantly with anticancer drugs and GSTP1-1-specific inhibitors.
Adult↗
Fas-mediated apoptosome formation is dependent on reactive oxygen species derived from mitochondrial permeability transition in Jurkat cells.
Generation of reactive oxygen species (ROS) and activation of caspase cascade are both indispensable in Fas-mediated apoptotic signaling. Although ROS was presumed to affect the activity of the caspase cascade on the basis of findings that antioxidants inhibited the activation of caspases and that the stimulation of ROS by itself activated caspases, the mechanism by which these cellular events are integrated in Fas signaling is presently unclear. In this study, using human T cell leukemia Jurkat cells as well as an in vitro reconstitution system, we demonstrate that ROS are required for the formation of apoptosome. We first showed that ROS derived from mitochondrial permeability transition positively regulated the apoptotic events downstream of mitochondrial permeability transition. Then, we revealed that apoptosome formation in Fas-stimulated Jurkat cells was clearly inhibited by N-acetyl-L-cysteine and manganese superoxide dismutase by using both the immunoprecipitation and size-exclusion chromatography methods. To confirm these in vivo findings, we next used an in vitro reconstitution system in which in vitro-translated apoptotic protease-activating factor 1 (Apaf-1), procaspase-9, and cytochrome c purified from human placenta were activated by dATP to form apoptosome; the formation of apoptosome was markedly inhibited by reducing reagents such as DTT or reduced glutathione (GSH), whereas hydrogen peroxide prevented this inhibition. We also found that apoptosome formation was substantially impaired by GSH-pretreated Apaf-1, but not GSH-pretreated procaspase-9 or GSH-pretreated cytochrome c. Collectively, these results suggest that ROS plays an essential role in apoptosome formation by oxidizing Apaf-1 and the subsequent activation of caspase-9 and -3.
Apoptosis↗
Indian hedgehog gene transfer augments hematopoietic support of human stromal cells including NOD/SCID-beta2m-/- repopulating cells.
Hematopoietic stem cells (HSCs) are a subset of bone marrow cells that are capable of self-renewal and of giving rise to all types of blood cells. However, the mechanisms involved in controlling the number and abilities of HSCs remain largely unknown. The Indian hedgehog (Ihh) signal has an essential role in inducing hematopoietic tissue during embryogenesis. We investigated the roles of the Ihh in coculture with CD34+ cells and human stromal cells. Ihh mRNA was expressed in primary and telomerized human (hTERT) stromal cells, and its receptor molecules were detected in CD34+ cells. Ihh gene transfer into hTERT stromal cells enhanced their hematopoietic supporting potential, which was elevated compared with control stromal cells, as indicated by the colony-forming units in culture (CFU-Cs) (26-fold +/- 2-fold versus 59-fold +/- 3-fold of the initial cell number; mixed colony-forming units [CFU-Mix's], 63-fold +/- 37-fold versus 349-fold +/- 116-fold). Engraftments of nonobese diabetic/severe combined immunodeficiency-beta2m-/- (NOD/SCID-beta2-/-) repopulating cells (RCs) expanded on Ihh stromal cells were significantly higher compared with control coculture results, and engraftment was neutralized by addition of an antihedgehog antibody. Limiting dilution analysis indicated that NOD/SCID-beta2m-/- RCs proliferated efficiently on Ihh stromal cells, compared with control stromal cells. These results indicate that Ihh gene transfer could enhance the primitive hematopoietic support ability of human stromal cells.
Animals↗
Interleukin-11 as an osteoprotegerin-inducing factor in culture medium of blastic cells from a patient with acute megakaryocytic leukemia complicated with osteosclerosis.
We came across a rare case of acute megakaryocytic leukemia, the clinical course of which was relatively chronic and nonaggressive. This case was complicated with generalized severe osteosclerosis (OS). The medium in which blastic cells from the patient were cultured showed a strong activity to enhance the expression of an osteosclerotic cytokine, osteoprotegerin (OPG), as revealed by real-time quantitative RT-PCR and Western blot analysis. The OPG-inducing activity of the culture medium was neutralized by the anti-interleukin-11 (IL-11) antibody. These results indicate that IL-11 produced by the blasts was a causative factor of the OS observed in this patient.
Adult↗
Chemoprevention of colorectal cancer.
Colorectal cancer is a disease with a high mortality rate and it has been increasing in prevalence worldwide. Chemoprevention, as well as primary and secondary prevention, for colorectal cancer have attracted much attention. Many chemopreventive trials have been performed, and several agents, including nonsteroidal antiinflammatory drugs, such as aspirin and sulindac, cyclooxygenase-2 selective inhibitors, such as celecoxib, vitamin D, folate, and calcium, have been shown to have some effect. In these chemopreventive trials, the targeted lesions used for evaluation were mainly polyps. However, the chemopreventive effects of some agents on polyps may require several years to evaluate. Further, larger polyps may not be susceptible to chemopreventive agents. Aberrant crypt foci (ACF) are tiny lesions at the earliest stage of colorectal carcinogenesis, which consist of large, thick crypts identified by dense, methylene blue staining. We succeeded in identifying human ACF in situ using magnifying endoscopy and found that the number of ACF, particularly dysplastic ACF, increased significantly from normal subjects to adenoma patients and then to cancer patients. We also found that the number, size, and dysplastic features of ACF are significantly correlated with the number of adenomas in adenoma patients. Thus, it was surmised that ACF are precursor lesions of the adenoma-carcinoma sequence in humans and that ACF may be the most appropriate lesions as targets for chemoprevention. We have shown that the number of ACF was significantly reduced in patients treated with sulindac. We are currently proceeding with a randomized, double-blind, chemopreventive trial targeting ACF.
Animals↗
Decrease of Smad4 gene expression in patients with essential thrombocythaemia may cause an escape from suppression of megakaryopoiesis by transforming growth factor-beta1.
Essential thrombocythaemia (ET) is characterized by the abnormal and sustained proliferation of megakaryocytes. The mechanism for this lineage-specific expansion in ET, remains unclear. We have previously reported that transforming growth factor-beta1 (TGF-beta1) is involved in negative feedback regulation of megakaryopoiesis in both healthy volunteers (HV) and patients with idiopathic thrombocytopenic purpura (ITP). The present study found that megakaryocyte colony-forming units (CFU-MK) of ET patients were less sensitive to TGF-beta1 than those of HV. The expression of Smad4 (Sma- and Mad-related protein-4) in CFU-MK of ET patients was reduced in comparison with that of HV. Finally, to confirm that the impaired TGF-beta1 sensitivity was caused by reduced expression of Smad4, we examined Smad4-transfected CFU-MK from ET patients in the presence of TGF-beta1, and verified that the transfectants were indeed as susceptible as CFU-MK from HV to TGF-beta1. Thus it was surmised that one of the mechanisms for impaired sensitivity of CFU-MK to TGF-beta1 is the reduced expression of Smad4.
Adult↗
Glutathione-S-transferase P1-1 protects aberrant crypt foci from apoptosis induced by deoxycholic acid.
BACKGROUND & AIMS: Aberrant crypt foci, precursors of colonic adenoma, are frequently positive for glutathione-S-transferase P1-1. Because deoxycholic acid is an apoptosis-inducing xenobiotic in the colon, we examined the possibility that aberrant crypt foci, through the cytoprotecting function of glutathione-S-transferase P1-1, resist deoxycholic acid-induced apoptosis, thereby surviving to become adenomas and subsequently cancer. METHODS: Glutathione-S-transferase P1-1 or cyclooxygenase-2 expression and the percentage of apoptotic cells in aberrant crypt foci were examined by immunohistochemistry and by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, respectively. Glutathione-S-transferase P1-1 was transfected into colon cancer cells (M7609) and human lung fibroblasts, and deoxycholic acid-induced apoptosis was evaluated by a dye-uptake assay and flow cytometry. Binding of deoxycholic acid to glutathione-S-transferase P1-1 was analyzed by circular dichroism and immunoprecipitation. Caspase activities were determined by colorimetric protease assay, and sulindac binding to glutathione-S-transferase P1-1 was determined by inhibition assay of glutathione-S-transferase P1-1 activity. RESULTS: Aberrant crypt foci showed positive immunostaining for glutathione-S-transferase P1-1 but negative staining for cyclooxygenase-2. The percentage of apoptotic cells in aberrant crypt foci was significantly lower than in healthy epithelium, and the difference became more apparent with deoxycholic acid treatment. The impaired sensitivity of aberrant crypt foci to deoxycholic acid was restored by the glutathione-S-transferase P1-1-specific inhibitor gamma-glutamyl-S-(benzyl)cysteinyl-R-phenylglycine diethylester. By transfection of glutathione-S-transferase P1-1, M7609 cells became more resistant to deoxycholic acid-induced apoptosis than mock transfectants. Direct binding of glutathione-S-transferase P1-1 to deoxycholic acid was proven by circular dichroism and by immunoprecipitation. The aberrant crypt foci in adenoma patients treated with sulindac, which was shown to bind to glutathione-S-transferase P1-1, underwent apoptosis in 4 days and mostly regressed in 2-3 months. CONCLUSIONS: Glutathione-S-transferase P1-1 protects aberrant crypt foci from deoxycholic acid-induced apoptosis and may play a pivotal role in early colon carcinogenesis.
Adenoma↗
Recovery of neutrophil count by ganciclovir in patients with chronic idiopathic neutropenia associated with cytomegalovirus infection in bone marrow stromal cells.
Patients with chronic idiopathic neutropenia (CIN) usually show chronic inflammation in their bone marrow stromal cells, but the etiologies of this disorder are still unknown. We suspected viral infection of the bone marrow stromal cells and used polymerase chain reaction (PCR) analysis to test for cytomegalovirus (CMV) infection in 4 patients with CIN and in 6 healthy volunteers. Peripheral blood mononuclear cells did not yield signals in any of the patients or healthy volunteers, but PCR analysis for CMV DNA in bone marrow stromal cells showed positive signals in 2 of the patients with CIN. CMV DNA was not detected in the other 2 patients or in the healthy volunteers. The 2 patients who were positive for stromal CMV received 500 mg/day ganciclovir for 14 days. After this treatment, the PCR band showing the presence of stromal CMV disappeared, and the neutrophil numbers of the 2 patients who received this viral eradication therapy normalized 6 months after treatment. In conclusion, the etiology in some cases of CIN is speculated to be infection by CMV in bone marrow stromal cells, and treatment with ganciclovir may be effective in treating such patients.
Aged↗
[Successful corticosteroid treatment of thrombocytopenia in a pregnant woman with myelodysplastic syndrome (refractory anemia)].
A 31-year-old pregnant woman was referred to our hospital due to anemia and thrombocytopenia, and was diagnosed as having myelodysplastic syndrome (refractory anemia) with autoimmune thrombocytopenia. Administration of high dose methylprednisolone and gamma-globulin did not raise her platelet count, and she subsequently delivered a healthy baby after the transfusion of a large amount of platelets. Although the anemia spontaneously improved after delivery, the platelet count remained unchanged. Prednisolone was thus administered a second time, which did finally increase the platelet count. This is the first reported case of a pregnant woman with myelodysplastic syndrome in whom corticosteroid administration was effective for thrombocytopenia.
Adult↗
[Successful induction and complete improvement of myelofibrosis and erythema nosodum with cladribine in a case of hairy cell leukemia].
The patient was a 45-year-old male who had been diagnosed with pancytopenia in 1998 at another hospital, where he continued treatment for idiopathic thrombocytopenic purpura (ITP) as an outpatient. After atypical lymphocytes were detected in his peripheral blood, he was admitted to our hospital for further examination in April 2002. Tests results revealed the additional existence of pancytopenia, splenomegaly, bone marrow fibrosis and erythema nodosum, in addition to the findings of surface marker. Tartrate resistant acid phosphatase (TRAP) staining and scanning electron microscopy of peripheral blood lymphocytes indicated hairy cell leukemia. After administration of cladribine (0.09 mg/kg) for 7 days, complete remission was obtained, with bone marrow fibrosis and erythema nodosum also being completely improved.
Antineoplastic Agents↗
[Successful treatment with antiviral agents for human herpesvirus type 6 encephalitis following reduced intensity stem cell transplantation in a patient with myelodysplastic syndrome].
We report here a patient who suffered from PCR-confirmed human herpesvirus type 6 (HHV-6) encephalitis following reduced intensity stem cell transplantation (RIST) from her HLA-matched sibling donor. A 66-year-old woman with MDS-RA underwent RIST from her HLA-matched brother. Engraftment was favorable and grade 2 GVHD (skin and intestine) was observed with good response to 60 mg of prednisolone. On day 162, she developed fever, headache, diplopia, disorientation and abnormal neurological findings including cervical stiffness and nystagmus. An analysis of cerebrospinal fluid (CSF) revealed 80 cells/microl, a glucose level of 50 mg/dl and a protein level of 97 mg/dl on day 162. Although computed tomography (CT) of the brain and electroencephalography (EEG) were nonspecific, HHV-6 was detected in the CSF using polymerase chain reaction (PCR) techniques and the patient was diagnosed as having encephalitis due to local reactivation of HHV-6. Administration of ganciclovir (GCV) and acyclovir (ACV) were started from day 162. Treatment with antiviral agents was effective, with total resolution of her symptoms and the DNA of this virus disappeared from the CSF after 23 days of treatment. This case shows that HHV-6 infection has to be considered in patients with neurological symptoms following stem cell transplantation, and suggests the necessity of PCR for HHV-6 virus from the CSF.
Acyclovir↗
[Inhibition of relapse in leukemia by using molecular targeting therapy].
Leukemias are generally chemosensitive, and a majority of leukemia patients undergo remission. However, since chemotherapy after remission generally causes gross systemic toxicity, patients cannot be administered enough anti-cancer drugs to be completely cured; thus, the rate of long-term disease-free survival remains low. Improved survival requires new strategies to prevent relapse. Molecular targeting therapies are remarkably specific and have been demonstrated to cause no gross systemic toxicity. Molecular targeting drugs for leukemia such as all-trans retinoic acid and imatinib are presently being used in clinical settings, and many other molecular targeting drugs are being evaluated in phase I/II clinical trials. This review presents an overview of some of these drugs.
Benzamides↗
[Second hematologic response and disappearance of the ABL gene mutant clone by cessation of imatinib in a CML patient with resistance to imatinib].
A seventy-six year old female patient with chronic myelogenous leukemia (CML), (chronic phase), was treated with imatinib and obtained a major cytogenetic response after 6 months of treatment. However, resistance to imatinib appeared 9 months later due to an ABL gene point mutation, and the patient's platelet count and BCR/ABL positive rate had remarkably increased. We discontinued imatinib and used IFNalpha or hydroxyurea, resulting in the disappearance of the ABL gene mutation clone. After that, we obtained a secondary hematologic response with the administration of imatinib.
Aged↗
Induction of PIG3 and NOXA through acetylation of p53 at 320 and 373 lysine residues as a mechanism for apoptotic cell death by histone deacetylase inhibitors.
Two controversial issues regarding p53 are whether it is involved in apoptosis induction of tumor cells by a histone deacetylase (HDAC) inhibitor and, given that p53 is indeed involved, which genes of acetylated p53 targets are responsible for giving rise to apoptotic death. We, in the present study, first confirmed that some substantial extent of apoptotic cell death was seen when p53-deficient cells (KATO-III) were transfected with wild-type p53 and treated with sodium butyrate (SB) or trichostatin A. By Western blotting, using specific antibodies, we then demonstrated that residues 320, 373, and 382 lysines of p53 were acetylated in KATO-III cells transfected with wild-type p53 (KATO-III/p53) treated with a HDAC inhibitor. However, as revealed by terminal deoxynucleotidyl transferase-mediated nick end labeling staining, only those KATO-III cells transfected with K320R p53 or K373R p53 became insensitive to the HDAC inhibitor, suggesting that these two residues of p53 may be essential for HDAC inhibitor-induced apoptosis, whereas others such as K382R p53 may not. Furthermore, reverse transcription-PCR demonstrated that among various p53-related proapoptotic genes, expression of PIG3 and NOXA were clearly enhanced by SB treatment in KATO-III/p53 cells but not in KATO-III/K320R or KATO-III/K373R cells. Finally, we revealed that apoptosis could be evoked by SB even in cells where p53 mutations occur at residues other than 320 lysine or 373 lysine (TMK-1 and HSC-39 cells) and that this apoptosis was significantly, although not totally, suppressed by the anti-p53 antisense. It was, therefore, concluded that acetylation of the p53 molecule at residues 320 and 373, giving rise to up-regulation of PIG3 and NOXA, is one of the mechanisms for induction of apoptosis by HDAC inhibitors in cancer cells.
Acetylation↗
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.
Animals↗
Thrombopoietin concentrations in peripheral blood correlated with platelet numbers in two patients with thrombocytopenia by chronic graft-versus-host disease.
Thrombocytopenia is well known to be one of the clinical manifestations of chronic graft-versus-host disease (cGVHD). However, there exist cases in which the cause of thrombocytopenia has been unexplained. Recently, thrombopoietin (TPO) from bone marrow (BM) stromal cells and transforming growth factor (TGF)-beta from platelets and megakaryocytes have been identified as strong positive and negative regulators of megakaryopoiesis in vivo. We hypothesized that the decreased TPO production from BM could be one of the causes of thrombocytopenia in the patients with cGVHD. In the present study, therefore, TPO and TGF-beta concentrations in peripheral blood (PB) and BM were measured serially in two patients with acute leukemia who had received fully matched stem cell transplantation from relatives and subsequently developed extensive cGVHD with thrombocytopenia. The results showed that platelet numbers correlated well with the TPO concentrations, which were consistently higher in BM than in PB. The difference in TPO concentrations between BM and PB was decreased when the platelet levels were low, indicating that the amount of TPO production from BM decreased throughout the duration of thrombocytopenia. TGF-beta concentrations were normal during all periods in which measurements were carried out. Thus, our results suggest that one mechanism of thrombocytopenia in patients with cGVHD is low TPO production by BM cells.
Adult↗
Inhibition of type I procollagen production by tRNAVal CTE-HSP47 ribozyme.
BACKGROUND: Fibrosis characteristically occurs in the advanced stages of chronic inflammatory diseases, occasionally as the primary lesion, and frequently determines the disease prognosis. Fibrotic lesions consist mostly of collagen, and therefore it may be possible to prevent or treat fibrosis by inhibiting collagen production. Of the currently available therapeutic approaches, however, none is sufficiently effective and specific for inhibition of collagen. Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperone that has been reported to play a pivotal role in secretion of procollagen molecules. Therefore, we have tried to suppress its function to inhibit these various types of collagen. METHODS: We have developed a novel type of ribozyme by ligating a hammerhead sequence to a tRNA(Val) promoter to facilitate displacing the ribozyme from nucleus to cytoplasm and to constitutive transport element, a binding motif of helicase which unwinds mRNA to render the target sequence on the mRNA accessible to the ribozyme. RESULTS: The ribozyme thus constructed showed strong activity to cleave HSP47 mRNA and suppress the secretion of type I procollagen in the human primary fibroblast. CONCLUSION: We suggest applicability of this ribozyme as a new modality for antifibrosis therapy.
Antisense Elements (Genetics)↗