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Biomedical subjects

Yoshiro Niitsu

Publications and source records attributed to Yoshiro Niitsu.

At least 37 records · Page 2Linked to original sources
PubMed2005

Telomerized human bone marrow-derived cell clones maintain the phenotype of hematopoietic-supporting osteoblastic and myofibroblastic stromal cells after long-term culture.

OBJECTIVE: Gene transfer of the telomerase catalytic subunit (TERT) into primary human stromal cells prolonged their lifespan. However, primary human stromal cells are actually composed of adipocytes, myofibroblasts, osteoblasts, etc. Our objective was to investigate the phenotype and hematopoietic-support of the human telomerized stromal cell (HTS) in clonal level. MATERIALS AND METHODS: We established HTS clones (HTS-1 to HTS-9) from a parental population of HTSs by limiting dilution. Hematopoietic-supporting activity of the HTS clones was examined by coculturing with CD34(+) cells. RESULTS: HTS-1 to HTS-3 contained alkaline phosphatase (ALP)(+) cells, and HTS-4 to HTS-9 were composed of both ALP(+) and alpha-smooth muscle actin-positive cells. Although all HTS clones exhibited normal growth kinetics, one of the HTS clones exhibited a chromosomal abnormality. Moreover, the parental population of the HTS cells acquired an increased growth rate and anchorage independence after 4 years of culturing. Expression of hematopoietic growth factors, such as stem cell factor, angiopoietin-1, and hedgehog mRNA was detected in all HTS clones. The degree of hematopoietic progenitor support differed between the HTS clones, and the expansion level of CD34(+) cells was the highest in HTS-8. CONCLUSION: Human telomerized stromal cell clones exhibited the phenotype of hematopoietic supporting osteoblastic and myofibroblastic cells after long-term culture. Clinical application of HTS cells should be limited because of their potential for neoplastic transformation after hTERT gene transfer. HTS cells may be useful for analyzing the molecular mechanism of hematopoietic support of human stromal cells.

Bone Marrow Cells↗
PubMed2005

Aberrant crypt foci: detection, gene abnormalities, and clinical usefulness.

Human aberrant crypt foci (ACF) were first identified as lesions consisting of large thick crypts in colonic mucosa of surgical specimens after staining with methylene blue. Previously we succeeded in identifying ACF by using magnifying endoscopy and analyzed the number, size, and dysplastic features of ACF in normal controls and patients with adenoma or cancer patients. On the basis of these analyses, we strongly suggested that ACF, particularly dysplastic ACF, are precursor lesions of the adenoma-carcinoma sequence in humans. In most sporadic ACF, K-ras mutations were positive, but APC mutations were negative irrespective of nondysplastic or dysplastic features. Conversely, in most ACF from familial adenomatous polyposis patients, APC mutations were positive but K-ras mutations were negative. These results may suggest that the molecular mechanism of sporadic colon carcinogenesis is not necessarily the same as that of familial adenomatous polyposis. It was shown that ACF acquired resistance to apoptosis induced by bile salts, whereas normal colonic epithelial cells are turning over consistently by apoptosis. This apoptosis resistance was closely associated with glutathione S-transferase P1-1 expression. One of the most important clinical applications of ACF observation with magnifying endoscopy is its use as a target lesion for chemoprevention. Because ACF are tiny lesions, they should be eradicated during a short time by administration of chemopreventive agents. In fact, we performed an open chemopreventive trial of sulindac and found that the number of ACF was reduced markedly in 2 months. We currently are proceeding with a randomized double-blind trial targeting ACF.

Adenoma↗
PubMed2005

Mesenchymal stem cells (MSC) as therapeutic cytoreagents for gene therapy.

We developed human mesenchymal stem cell (MSC) lines that could differentiate into various tissue cells including bone, neural cells, bone marrow (BM) stromal cells supporting the growth of hematopoietic stem cell (HSC), and so-called 'tumor stromal cells' mixing with tumor cells. We investigated the applicability of MSC as therapeutic cell transplanting reagents (cytoreagents). Telomerized human BM derived stromal cells exhibited a prolonged lifespan and supported the growth of hematopoietic clonogenic cells. The gene transfer of Indian hedgehog (Ihh) remarkably enhanced the HSC expansion supported by the human BM stromal cells. Gene-modified MSC are useful as therapeutic tools for brain tissue damage (e.g. brain infarction) and malignant brain neoplasms. MSC transplantation protected the brain tissue from acute ischemic damage in the midcerebral artery occlusion (MCAO) animal model. Brain-derived neurotrophic factor (BDNF)-gene transduction further enhanced the protective efficacy against the ischemic damage. MSC possessed excellent migratory ability and exerted inhibitory effects on the proliferation of glioma cells. Gene-modification of MSC with therapeutic cytokines clearly augmented the antitumor effect and prolonged the survival of tumor-bearing animals. Gene therapy employing MSC as a tissue-protecting and targeting cytoreagent would be a promising approach.

Animals↗
PubMed2005

Expansion of CD34+ cells on telomerized human stromal cells without losing erythroid-differentiation potential in a serum-free condition.

Erythropoiesis progresses from stem cell expansion on stromal cells through the formation of an erythroblastic island. Our aim was to assess the feasibility of using human stromal cells for erythroid production and differentiation. When cord blood CD34+ cells were cocultured with telomerized human stromal cells (hTERT-stromal cells) for 2 weeks, the CD34+ cells and burst-forming units-erythroid (BFU-E) significantly expanded, and a few hematopoietic cells transmigrated below the stromal layer. When nonadherent hematopoietic progenitor cells that had expanded above the hTERT-stromal cells (group B) were collected and subjected to our erythroid-differentiation protocol, they differentiated into erythroblasts with a slight hemoglobin synthesis. When the few hematopoietic cells that had transmigrated below the stromal layer were expanded for an additional 2 to 6 weeks, they exhibited a cobblestone-like appearance, and a large amount of BFU-E clambered weekly from the underside of the stromal layer to above the stromal layer (group C). When the hematopoietic progenitor cells in group C were subjected to the erythroid-differentiation protocol, large numbers of mature erythroblasts (more than 300,000 times the initial CD34+ cell number) were produced. Our hTERT-stromal expansion protocol may contribute to the construction of a system for large-scale, long-term production of erythroid cells.

Antigens, CD34↗
PubMed2005

A patient with TP53 germline mutation developed Bowen's disease and myelodysplastic syndrome with myelofibrosis after chemotherapy against ovarian cancer.

Here we report a case of myelodysplastic syndrome (MDS) with myelofibrosis associated with Bowen's disease. A female patient had undergone an operation and chemotherapy for ovarian cancer when she was 65 years old, and she developed MDS at the age of 70 years old. PCR-single strand conformation polymorphism (SSCP) analysis of peripheral blood mononuclear cells, a Bowen's disease lesion, and normal skin showed an abnormal peak in TP53 exon5. Direct sequencing revealed that they all had missense mutation in codon 175 (G to A) of arginine switched to histidine, suggesting a germline mutation of TP53. It was speculated that p53 function was lost by TP53 germline mutation with the loss of a wild type allele induced by the chemotherapy against ovarian cancer, leading to the development of MDS. No therapeutic effects of low dose melphalan or cyclosporine A on MDS were observed, however one month of 30 mg/day prednisolone administration induced a hematological response.

Aged↗
PubMed2005

[Basedow disease associated with Evans syndrome].

A 60-year-old woman was admitted to a hospital complaining of dizziness and general fatigue in October, 2004. Because of heart failure and severe anemia, she was referred to our hospital. Based on a positive direct Coombs test and an elevated level of platelet-associated IgG (PAIgG), the patient was diagnosed as having autoimmune hemolytic anemia (AIHA) associated with idiopathic thrombocytopenic purpura (ITP), i.e., Evans syndrome. Basedow disease was also diagnosed due to hyperthyroidism with an elevation of anti-thyroid stimulating hormone (TSH) receptor antibodies. Both the Evans syndrome and Basedow disease were considerably ameliorated with plasma exchange, corticosteroid and thiamazole therapy. Although Basedow disease is known to be associated with hematological disorders such as AIHA or ITP, the combination of Basedow disease and Evans syndrome is rare. We report here a case of Basedow disease associated with Evans syndrome.

Anemia, Hemolytic, Autoimmune↗
PubMed2005

[Essential thrombocythemia associated with incomplete type intestinal Behçet disease during hydroxyurea treatment].

A 77-year-old man was diagnosed as having essential thrombocythemia in 1992. Treatment with hydroxyurea was started in 1997, which stabilized the platelet count. The patient then suffered from pharyngalgia and rhinitis with a high fever, immediately after which he developed tarry stools and anemia and was admitted to our hospital. The physical examination revealed splenomegaly, oral aphthous ulcers, genital ulcers and skin lesions on the lower limbs. His hematological and biochemical tests revealed anemia and increased level of C-reactive protein. He also had an HLA-B51 phenotype. The findings of gastro-intestinal and colon fiberoscopy showed a duodenal ulcer and multiple ulcers on ascending colon. He was thus diagnosed as having intestinal tract-type Behçet disease. After withdrawal of the hydroxyurea administration, the intestinal ulcers, oral aphthous ulcers and genital ulcers improved.

Aged↗
PubMed2005

[Two cases of primary skeletal muscle lymphoma, and a review of the literature].

Here we report two cases of primary skeletal muscle lymphoma. The first patient was an 82-year-old man. On April 2004, he was referred to our hospital because of swelling of the right upper arm. Magnetic resonance imaging (MRI) showed an area which was isointense on T1 and hyperintense on T2-weighted imaging compared with normal skeletal muscle. The size of the tumor was 5 x 7 x 13 cm. Following pathological, flow cytometric and genetic analyses of the specimen, we diagnosed the tumor as a non-Hodgkin lymphoma of the T-cell rich diffuse large B-cell type. The second patient was an 87-year-old man. He was admitted to our hospital on July 2004, under the chief complaint of swelling of the right thigh. MRI revealed a giant tumor mass of the right thigh which was isointense on T1 and hyperintense on T2 imaging. The patient was diagnosed by open biopsy as having diffuse large B-cell lymphoma. We could find only 62 cases of primary skeletal muscle lymphoma through a MEDLINE search. We report on our two cases with a review of the literature.

Aged, 80 and over↗
PubMed2005

[Psoriasis vulgaris exacerbated by imatinib therapy in chronic myelogenous leukemia].

Administration of imatinib exacerbated psoriasis vulgaris in a case of chronic myelogenous leukemia (CML). After the cessation of imatinib therapy, the psoriasis was alleviated. Upon readministration of imatinib, the psoriasis worsened despite the improvement of hematological and cytogenetic findings in the CML. Psoriasis is known to be an autoimmune skin disease characterized by Th1 cell-mediated hyperproliferation of keratinocytes, and the type 1 helper T (Th1) cell subset increased with imatinib therapy. Thus, the exacerbation of psoriasis was likely due to the increase in Th1 cells associated with imatinib therapy.

Antineoplastic Agents↗
PubMed2005

[Successful treatment with oral ribavirin of adenovirus-associated hemophagocytic syndrome in a stem cell transplantation recipient].

A 51-year-old woman with severe aplastic anemia underwent allogeneic peripheral blood stem cell transplantation using blood stem cells from an HLA-identical sibling. Adenovirus type 11 hemorrhagic cystitis developed and progressed to nephritis and hemophagocytic syndrome. Oral ribavirin was effective not only for the hemorrhagic cystitis and nephritis but also for the hemophagocytic syndrome. Since therapeutic strategies for adenovirus infection after hematopoietic stem cell transplantation have not been established, we present our case and discuss the therapeutic approach.

Adenoviridae Infections↗
PubMed2004

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↗
PubMed2004

Gene therapy with secretory leukoprotease inhibitor promoter-controlled replication-competent adenovirus for non-small cell lung cancer.

Secretory leukoprotease inhibitor (SLPI) is highly expressed in almost all non-small cell lung cancers (NSCLCs), but not in the majority of other tumor types. In an attempt to create a specific gene therapy for NSCLC, we constructed AdSLPI.E1AdB, an adenovirus vector with a double expression cassette consisting of E1A driven by the SLPI promoter gene followed by E1B-19K under the control of the cytomegalovirus (CMV) promoter that can selectively replicate only in NSCLC cells. Infection with AdSLPI.E1AdB yielded E1A protein expression and adenovirus replication resulting in a >100-fold increase of the virus titers only in SLPI-producing NSCLC cells (A549, H358, and HS24 cells). In contrast, neither E1A protein nor replication was detected in non-SLPI-producing HepG2 cells. Treatment with AdSLPI.E1AdB significantly inhibited the proliferation of NSCLC cells in vitro in a dose-dependent manner, whereas the cell growth of HepG2 or normal human bronchial epithelial cells was not affected by AdSLPI.E1AdB infection. Direct injection of AdSLPI.E1AdB into A549 and H358 tumors in nude mice resulted in a marked reduction in tumor growth compared with controls (A549, 57%, P < 0.02; H358, 67%, P < 0.03). Histological examination revealed the replication of AdSLPI.E1AdB and strong induction of necrosis and apoptosis. In addition, we evaluated the combination of AdSLPI.E1AdB and AdCMV.NK4 encoding NK4 protein, which has strong antiangiogenic activity. E1A expressed by AdSLPI.E1AdB trans-acts on the replication of AdCMV.NK4 and thus increases the expression of NK4. Injection of these two vectors into H358 tumors resulted in a more striking reduction of tumor growth compared with single injection of each vector. These results suggest that AdSLPI.E1AdB could provide a selective therapeutic modality for NSCLC and that the combination of AdSLPI.E1AdB and AdCMV.NK4 may be a more effective gene therapy for NSCLC.

Adenoviridae↗
PubMed2004

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↗
PubMed2004

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↗