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Biomedical subjects

C Shimazaki

Publications and source records attributed to C Shimazaki.

At least 73 records · Page 4Linked to original sources
PubMed1997

Use of EBV-based Vector/HVJ-liposome complex vector for targeted gene therapy of EBV-associated neoplasms.

Targeted suicide gene therapy for Epstein-Barr virus (EBV)-associated neoplasms was attempted by using EBV-based plasmid vectors coupled with hemagglutinating virus of Japan (HVJ)-liposome in vitro. Expression of EBV nuclear antigen (EBNA)1 is a common feature of the neoplasms associated with EBV. When various leukemic cell lines were transduced with a vector carrying a marker gene and EBV replication origin of plasmid (oriP), the marker gene product was exclusively detected in cells expressing EBNA1. Transduction of herpes simplex virus (HSV)-1 thymidine kinase (Tk) gene resulted in a marked reduction in viable cell number by ganciclovir (GCV) specifically in EBNA1 positive cells. The results demonstrate that this virus-free system may be applicable to gene therapy of EBV-associated neoplasms.

Antiviral Agents↗
PubMed1997

Efficient gene transduction by Epstein-Barr-virus-based vectors coupled with cationic liposome and HVJ-liposome.

We show here a novel non-viral strategy to transduce human cells by using an EBV-based vector system. The EBV-based vectors, the plasmid vectors carrying EBV oriP (origin for plasmid replication) and EBNA (EBV nuclear antigen) 1 gene from EBV genome, were combined with 2 gene delivery systems, i.e., cationic liposome and HVJ-liposome. By both methods, EBV-based vectors could be more efficiently transfected into HeLa cells than non-EBV, conventional plasmid vectors. When human primary fibroblasts were transfected, EBV-based vectors coupled with cationic liposome but HVJ-liposome resulted in successful gene transduction, while human bone marrow cells were transduced with both HVJ-liposome- and cationic liposome-EBV vectors. These results suggest the potential applications of the EBV-based vector system for gene therapy.

Bone Marrow Cells↗
PubMed1997

New xenograft model of multiple myeloma and efficacy of a humanized antibody against human interleukin-6 receptor.

A new xenograft model of multiple myeloma (MM), where growth is strongly regulated by interleukin-6 (IL-6), was established in severe combined immunodeficiency (SCID) mice. In this model, endogenous IL-6 from SCID mice was ineffective at eliciting growth of the established human MM cell line KPMM2; these cells achieved autonomous growth through their autocrine secretion of IL-6. The etiopathology in this disease model is consistent with that of human MM. When greater than 3 x 10(6) KPMM2 cells were injected intravenously (IV), tumors developed in all mice and were predominantly localized in their bone marrow. Tumors were also apparent in the lymph nodes, but absent from other organs. Immunostaining of cell surface antigen (CD38) showed that more than 40% of bone marrow cells in femur were of myeloma origin in the advanced stage of tumor progression (day 37). Histologic analysis of these mice show that bone marrow was largely occupied by plasmablastic cells and bones had developed osteolytic lesions at multiple sites. Concurrently, there was a decrease in bone density throughout the body and a significant increase in ionized plasma calcium. M-protein was detected in the serum within 10 days after transplantation, which correlated with the tumor progression. Between 30 and 40 days after the transplantation, mice presented with a rapid and severe loss of body weight, hind leg paralysis, and fatigue. Subsequently, the mice died within a week. A single IV injection of 0.2 mg humanized anti-IL-6 receptor antibody (hPM1) into mice on the day after tumor transplantation substantially suppressed the elevation of serum M-protein and development of the tumor-associated abnormalities and significantly increased in the life span of tumor-bearing mice. Our data show the usefulness of this model to analyze the pathologic role of IL-6 in MM and the efficacy of targeting the IL-6 receptor in IL-6-dependent KPMM2 cells.

Animals↗
PubMed1997

Synergistic effect of FLT-3 ligand on the granulocyte colony-stimulating factor-induced mobilization of hematopoietic stem cells and progenitor cells into blood in mice.

We have previously shown that FLT-3 ligand (FL) mobilizes murine hematopoietic primitive and committed progenitor cells into blood dose-dependently. Whether FL also acts synergistically with granulocyte colony-stimulating factor (G-CSF) to induce such mobilization has now been investigated. Five- to 6-week-old C57BL/6J mice were injected subcutaneously with recombinant human G-CSF (250 microg/kg), Chinese hamster ovarian cell-derived FL (20 microg/kg), or both cytokines daily for 5 days. The number of colony-forming cells (CFCs) in peripheral blood increased approximately 2-, 21-, or 480-fold after administration of FL, G-CSF, or the two cytokines together, respectively, for 5 days. The number of CFCs in bone marrow decreased after 3 days but was increased approximately twofold after 5 days of treatment with G-CSF. The number of CFCs in the bone marrow of mice treated with both FL and G-CSF showed a 3.4-fold increase after 3 days and subsequently decreased to below control values. The number of CFCs in spleen was increased 24.2- and 93.7-fold after 5 days of treatment with G-CSF alone or in combination with FL, respectively. The number of colony-forming unit-spleen (CFU-S) (day 12) in peripheral blood was increased 13.2-fold by G-CSF alone and 182-fold by G-CSF and FL used together after 5 days of treatment. Finally, the number of preCFU-S mobilized into peripheral blood was also increased by the administration of FL and G-CSF. These observations show that FL synergistically enhances the G-CSF-induced mobilization of hematopoietic stem cells and progenitor cells into blood in mice, and that this combination of growth factors may prove useful for obtaining such cells in humans for transplantation.

Animals↗
PubMed1997

A translocation between 3q21 and 12q24 in a patient with minimally differentiated acute myeloid leukemia (AML-M0).

Only a small number of reports have described the cytogenetic analysis of minimally differentiated acute myeloid leukemia (AML, M0). We performed a cytogenetic analysis on a patient with AML (M0) with a normal platelet count. It revealed a chromosomal translocation between chromosome bands 3q21 and 12q24. 3q. Abnormalities in AML are known to be associated with normal or elevated platelet counts. 3q21 and 12q24 are common translocation sites in AML patients, but this is the first report of translocation t(3;12)(q21;q24) in an AML patient.

Cell Differentiation↗
PubMed1997

Case-control study of leukemia and diagnostic radiation exposure.

A case-control study of leukemia and diagnostic X-ray exposure was conducted by a multi-institution co-operative study group. The subjects were 134 patients with acute myelogenous leukemia, 57 with chronic myelogenous leukemia, 56 with acute lymphocytic leukemia and 50 with myelodysplasia syndrome, who were between 15 and 79 years old, and diagnosed at one of 27 hospitals between September 1993 and August 1995. The controls were 479 first-visit patients seen at eight of these 27 hospitals. History of diagnostic X-ray tests between 1982 and 1991 was determined by an anonymous self-administered questionnaire. The total relative dose of radiation exposure was calculated by summing the products of given weights and frequencies of each test. The relative risk was 0.83 (95% confidence interval (C.I.), 0.58-1.19) for relative dose of 10-30 (equivalent to 4-11 times of UGI series), 0.76 (0.48-1.20) for relative dose of 30 or more (more than 12 times of UGI series), when compared with relative dose of 0-10 (0-3 times of UGI series). Analysis according to type of leukemia revealed that only acute myelogenous leukemia had an estimated relative risk above unity (1.08, 95% C.I. 0.69-1.69, for relative dose 10-30). This study did not support the hypothesis that diagnostic X-ray tests increases leukemia risk.

Adolescent↗
PubMed1997

Overexpression of PRAD1/cyclin D1 in plasma cell leukemia with t(11;14)(q13;q32).

Two patients with plasma cell leukemia (PCL) with a t(11;14)(q13;q32) translocation are reported. Case 1 is a 64-year-old woman diagnosed as having primary PCL (IgA/lambda, Stage III) with high serum LDH and beta 2-microglobulin (beta 2MG) levels. She was treated with combination chemotherapy but died of gastrointestinal bleeding on the 45th hospital day. Case 2 is a 52-year-old man, initially diagnosed with multiple myeloma (IgG/kappa, Stage III) in August 1993. Relapse several months after primary chemotherapy was characterized by a rapid increase in plasma cells in peripheral blood, high serum LDH and beta 2MG levels, and resistance to further chemotherapy. Both cases showed complex karyotypic abnormalities including t(11;14), and Northern analysis revealed overexpression of the PRAD1/ cyclin D1 gene. The PRAD1 gene is found on chromosome band 11q13 and encodes cyclin D1. Cyclin D1 plays an important role in control of the cell cycle, and overexpression of PRAD1/cyclin D1 may be involved in disease progression in these cases.

Chromosomes, Human, Pair 11↗
PubMed1997

Flow cytometric analysis of Thy-1 expression in CD34-positive acute leukemia.

We analyzed the expression of the Thy-1 antigen (CD90) in CD34+ acute leukemia using two-color flow cytometry. Leukemic cells were obtained from the bone marrow (BM) and/or the peripheral blood (PB) of 57 patients: 37 with acute myelogenous leukemia (AML) including nine with secondary AML following myelodysplastic syndrome (MDS/AML), and 20 with acute lymphoblastic leukemia (ALL) including three with chronic myelogenous leukemia in blast crisis (CML-BC) of the lymphoid type. Among these patients, one (3.6%) with de novo AML, two (22.2%) with MDS/AML, three (17.6%) with de novo ALL, and two (66.7%) with CML-BC coexpressed CD34 and Thy-1 (CD34+ Thy-1+) on more than 20% of the mononuclear cells within 'lymph' plus 'blast' window. Thy-1 was rarely expressed in de novo acute leukemia especially in AML. Interestingly, in 1 patient with CML-BC, the leukemic cells in BM were divided into two subpopulations (CD34+ Thy-1low and CD34+ Thy-1high), whereas most of the CD34+ leukemic cells in PB were Thy-1high. However, the mechanism for the mobilization of CD34+ Thy-1high leukemic cells into the PB is unknown.

Acute Disease↗
PubMed1997

Serum thrombopoietin levels in patients undergoing autologous peripheral blood stem cell transplantation.

Recently, the ligand for c-mpl has been cloned and initial studies have shown it to be the platelet regulatory factor, thrombopoietin (TPO). To elucidate the role of TPO in the reconstitution of megakaryopoiesis and platelet production after stem cell transplantation, we measured serum TPO levels in nine patients undergoing autologous peripheral blood stem cell transplantation (PBSCT) and in healthy volunteers. Serum TPO levels significantly correlated with the degree of peripheral thrombocytopenia and a strong inverse correlation between serum TPO level and platelet count was observed (r = -0.700, P < 0.001). Serum TPO levels began to rise as the platelet count decreased after chemotherapy, TPO levels peaked at over 25.00 fmoles/ml between days 0 and 10; TPO levels then decreased gradually as the platelet count began to rise. One patient with multiple myeloma received purified CD34+ peripheral blood stem cells. No difference was observed in the kinetics of serum TPO levels between unfractionated and purified PBSCT. These observations suggest that TPO plays a critical role in the reconstitution of megakaryopoiesis and platelet production after PBSCT.

Adolescent↗
PubMed1997

Internal tandem duplication of FLT3 associated with leukocytosis in acute promyelocytic leukemia. Leukemia Study Group of the Ministry of Health and Welfare (Kohseisho).

FLT3 is a member of receptor tyrosine kinases expressed in leukemia cells, as well as in hematopoietic stem cells. Recently, a somatic alteration of the FLT3 gene was found in acute myeloid leukemia, as an internal tandem duplication (FLT3/ITD) which caused elongation of the juxtamembrane (JM) domain of FLT3. Here we characterized the FLT3/ITD and investigated its clinical significance in acute promyelocytic leukemia (APL). Seventy-four newly diagnosed patients with APL, who were treated with the same protocol in a multi-institutional study, were studied for the FLT3/ITD. Genomic and message sequences of the FLT3 gene were amplified by means of polymerase chain reaction (PCR), and elongated PCR products were sequenced. Fifteen patients (20.3%) had FLT3/ITD, all of which were transcribed in frame. Location of the duplicated fragments (six to 30 amino acids) varied from patient to patient. However, they always contained either Y591 or Y599, but the tyrosine kinase domain was not significantly affected. This finding implied that signal transduction of FLT3 is amplified by the duplication. Clinically, the presence of FLT3/ITD was related to high peripheral white blood cell counts as well as peripheral leukemia cell counts (P < 0.0001), high LDH level (P = 0.04), and low fibrinogen concentration (P = 0.04). These data suggest that FLT3/ITD plays a significant role in progression of APL.

Adult↗
PubMed1997

Effects of thrombopoietin (c-mpl ligand) on growth of blast cells from patients with transient abnormal myelopoiesis and acute myeloblastic leukemia.

Thrombopoietin (TPO) is a ligand for c-mpl that promotes both proliferation and differentiation of megakaryocytes in vivo and in vitro. We investigated the expression of c-mpl transcripts and the effects of recombinant human TPO (rhTPO) on the proliferation and differentiation of human leukemic cell lines or fresh samples obtained from 32 patients with transient abnormal myelopoiesis (TAM) or acute myeloblastic leukemia (AML). Cells were cultured with TPO alone or combined with rh interleukin-3 (IL-3) or stem cell factor (SCF). Expression of c-mpl was verified in 6 of 13 cases tested. All but one of the cases that showed c-mpl expression responded to TPO. Blasts from all cases of TAM or French-American-British (FAB) subtype M7 showed growth responses to TPO with higher sensitivity than cells of other FAB subtypes and these responses were increased by addition of rhIL-3 or rhSCF in some cases. Responses of cells of other FAB subtypes varied. In addition, increased expression of platelet-specific surface antigens on MO7E cells after incubation with rhTPO was observed. These data suggest that TPO may be involved in the abnormal proliferation and differentiation of human leukemic cells, especially of M7 and TAM cells, considered to be of megakaryocytic lineage.

Adult↗
PubMed1997

Sequential interphase FISH analysis of m-BCR/ABL chimeric gene-positive cells in Ph-positive acute myeloid leukemia.

We report a case of Philadelphia (Ph)-positive AML in which interphase fluorescence in situ hybridization (FISH) analysis was performed from diagnosis throughout the course of therapy using major (M-) breakpoint cluster region (BCR)/minor (m-) BCR and ABL cosmid probes. We also investigated the existence of the M-BCR or m-BCR at the RNA or DNA level by the reverse transcriptase polymerase chain reaction and Southern blot analysis, respectively. Complete remission with a normal karyotype was achieved after several regimens of chemotherapy and peripheral blood stem cell transplantation (PBSCT), but relapse occurred and his cells became 100% Ph-positive. We detected the m-BCR/ABL fusion gene by interphase FISH analysis using an m-BCR/ABL translocation probe, and found that FISH analysis was useful for classifying the BCR, identifying minimal residual disease, and for predicting imminent relapse after chemotherapy and PBSCT.

Acute Disease↗
PubMed1996

Inactivation of multiple tumor-suppressor genes involved in negative regulation of the cell cycle, MTS1/p16INK4A/CDKN2, MTS2/p15INK4B, p53, and Rb genes in primary lymphoid malignancies.

It is now evident that the cell cycle machinery has a variety of elements negatively regulating cell cycle progression. However, among these negative regulators in cell cycle control, only 4 have been shown to be consistently involved in the development of human cancers as tumor suppressors: Rb (Retinoblastoma susceptibility protein), p53, and two recently identified cyclin-dependent kinase inhibitors, p16INK4A/MTS1 and p15INK4B/MTS2. Because there are functional interrelations among these negative regulators in the cell cycle machinery, it is particularly interesting to investigate the multiplicity of inactivations of these tumor suppressors in human cancers, including leukemias/lymphomas. To address this point, we examined inactivations of these four genes in primary lymphoid malignancies by Southern blot and polymerase chain reaction-single-strand conformation polymorphism analyses. We also analyzed Rb protein expression by Western blot analysis. The p16INK4A and p15INK4B genes were homozygously deleted in 45 and 42 of 230 lymphoid tumor specimens, respectively. Inactivations of the Rb and p53 genes were 27 of 91 and 9 of 173 specimens, respectively. Forty-one (45.1%) of 91 samples examined for inactivations of all four tumor suppressors had one or more abnormalities of these four tumor-suppressor genes, indicating that dysregulation of cell cycle control is important for tumor development. Statistical analysis of interrelations among impairments of these four genes indicated that inactivations of the individual tumor-suppressor genes might occur almost independently. In some patients, disruptions of multiple tumor-suppressor genes occurred; 4 cases with p16INK4A, p15INK4B, and Rb inactivations; 2 cases with p16INK4A, p15INK4B, and p53 inactivations; and 1 case with Rb and p53 inactivations. It is suggested that disruptions of multiple tumor suppressors in a tumor cell confer an additional growth advantage on the tumor.

Adolescent↗