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Biomedical subjects

I Kubonishi

Publications and source records attributed to I Kubonishi.

At least 19 recordsLinked to original sources
PubMed2001

BRD4 bromodomain gene rearrangement in aggressive carcinoma with translocation t(15;19).

Translocation t(15;19)(q13;p13.1) defines a lethal midline carcinoma arising adjacent to respiratory tract in young people. To characterize molecular alterations responsible for the distinctly aggressive biological behavior of this cancer, we mapped the chromosome 15 and 19 translocation breakpoints by fluorescence in situ hybridization (FISH) and Southern blotting. To evaluate preliminarily the frequency, anatomical distribution, and histological features of t(15;19) cancer, we developed a FISH assay for paraffin sections. Our findings reveal a novel oncogenic mechanism in which the chromosome 19 translocation breakpoint interrupts the coding sequence of a bromodomain gene, BRD4. These studies implicate BRD4 as a potential partner in a t(15;19)-associated fusion oncogene. In addition, we localized the chromosome 15 breakpoint to a 9-kb region in each of two cases, thereby identifying several candidate oncogenes which might represent the BRD4 fusion partner. FISH evaluation of 13 pediatric carcinomas revealed t(15;19) in one of four sinonasal carcinomas, whereas this translocation was not detected in thymic (n = 3), mucoepidermoid (n = 3), laryngeal (n = 2), or nasopharyngeal (n = 1) carcinomas. Our studies shed light on the oncogenic mechanism underlying t(15;19) and provide further evidence that this highly lethal cancer arises from respiratory mucosa.

Adolescent↗
PubMed2000

Ionizing radiation-induced apoptosis in human lymphoma cell lines differing in p53 status.

Most of malignant lymphomas have been shown to be relatively radiosensitive clinically, but some, especially recurrent ones, are frequently highly radioresistant. To clarify the origin of the difference, we examined ionizing radiation (IR)-induced apoptosis in three closely related human lymphoma cell lines (DL-40, DL-95, and DL-110) that differ in p53 status. DL-95 and DL-110 cells have a wild-type p53, whereas DL-40 cells carry a T to G transition in exon 5 of the p53 gene, resulting in a change of Cys to Phe at codon 176. Irradiation of DL-40 cells (mutant-type p53) with 5 Gy gamma-rays resulted in delayed apoptosis with membrane changes (annexin-V expression) 13 h after IR, and caspase-3 activation 23 h after IR, whereas apoptotic response was not identified in DL-95 cells until 48 h after IR in spite of their normal p53 status. Concerning DL-110 cells, delayed and reduced apoptotic response was revealed both microscopically and by DNA fragmentation assay. These results suggested that IR-induced apoptosis in DL-40 cells is mediated by a mechanism involving the caspase-3 cascade of the p53-independent pathway, and that some unknown mechanism inhibited IR-induced apoptosis in existence of wild-type p53, especially for DL-95 cells.

Annexin A5↗
PubMed1999

CD95 ligand is expressed in Reed-Sternberg cells of Hodgkin's disease.

Reed-Sternberg (RS) cells and their mononuclear variants, Hodgkin's (H) cells, are considered to be the neoplastic cells of Hodgkin's disease (HD). The cellular origin of H-RS cells remains the subject of considerable controversy, although most recent papers have claimed that H-RS cells are of B cell origin. Recently, however, it has been reported that some H-RS cells express granzyme B, as observed in cytotoxic T cells and/or natural killer cells, which also express CD95 ligand (FasL/APO-1L). In the present study, the expression of CD95L and granzyme B in H-RS cells of HD was investigated. CD95L was detected in H-RS cells in five of nine HD cases (one case of lymphocyte-rich classical HD, two of these cases of nodular sclerosis type, and two of four cases of mixed cellularity type). All three examined HD cell lines expressed CD95L in the cytoplasm, although cell surface expression was seen only in L428 cells. Three HD cases expressed both CD95L and granzyme B. It was concluded that CD95L is frequently expressed in H-RS cells, which is one of their notable characteristics; albeit it seems to be irrespective of cell lineage.

Adolescent↗
PubMed1999

Establishment of a new cell line (MTT-95) showing basophilic differentiation from the bone marrow of a patient with acute myelogenous leukemia (M7).

A new myeloid cell line, MTT-95, was established from the bone marrow of a patient with acute myelogenous leukemia (AML, M7). MTT-95 cells differentiate into mature basophilic cells in culture medium with no chemical component or cytokine. Surface phenotypes were as follows: CD11b 79.3%, CD13 92.4%, CD33 99.8%, CD34 87.9%, CD41a 77.6% and HLA-DR 0.3%. MTT-95 cells were strongly positive for glycoprotein IIb/IIIa by immunohistochemical staining and revealed metachromatic granules. MTT-95 cells seem to possess characteristics of both megakaryocytes and basophils. These findings suggest that MTT-95 cells are basophil progenitors. MTT-95 cells might be useful in the study not only of the biological aspects of basophils, but also of the diversities of AML (M7).

Antigens, CD↗
PubMed1999

An augmentation of Fas (CD95/APO-1) antigen induced by radiation: flow cytometry analysis of lymphoma and leukemia cell lines.

An augmentation of Fas antigen induced by radiation was examined using flow cytometry. Six cell lines established from lymphomas or leukemias (HD-70, FLAM-76, CML-C-1, CML-C-2, DL-40 and DL-95) were used in this study. Each cell line was distributed to two dishes. The cells in one dish were irradiated at 10 Gy with cobalt-60 gamma rays. The control cells were not irradiated. At 6 h, 24 h, and 48 h after treatment, irradiated and non-irradiated cells of each cell line were stained with fluorescein isocyanate (FITC)-conjugated anti-human Fas antibody, and analyzed with flow cytometry. Mean fluorescence intensity (MFI) values of irradiated or non-irradiated cells were examined. MFI rates (MFI value of irradiated cells/MFI value of non-irradiated cells) of each cell line were calculated at each investigated time point, and an augmentation of the Fas antigen expression with radiation was evaluated. FLAM-76 did not express Fas antigen at any time. An augmented expression of Fas antigen due to irradiation was observed in the other five cell lines. These findings strongly suggest that radiation can augment Fas antigen expression in certain tumor cells. Further studies using Fas ligand or specific anti-Fas antibody are needed.

Antibodies↗
PubMed1998

CD4(+) cytotoxic T-cell clones specific for bcr-abl b3a2 fusion peptide augment colony formation by chronic myelogenous leukemia cells in a b3a2-specific and HLA-DR-restricted manner.

Although it is well known that CD8(+) cytotoxic T lymphocytes (CTLs) play an important role in the suppression of cancer cell growth, the significance of CD4(+) CTLs in resistance to cancer is obscure. In an attempt to elucidate the role of CD4(+) CTLs in immunosurveillance of chronic myelogenous leukemia (CML), we examined the immunologic functions of bcr-abl b3a2 fusion peptide-specific CD4(+) CTL clones. Seven CD4(+) T-cell clones that responded to stimulation with b3a2 peptide, but not with b2a2 peptide or physiological counterparts bcr b3b4 and abl 1A-a2 peptides, were established from two healthy individuals. Restriction elements of these clones were HLA-DRB1*0901. These CD4(+) T-cell clones exhibited b3a2 peptide-specific and HLA-DRB1*0901-restricted cytotoxicity and produced interleukin-3 (IL-3), IL-4, IL-10, interferon-gamma, tumor necrosis factor-alpha, and granulocyte-macrophage colony-stimulating factor in response to bcr-abl peptide stimulation, indicating they were Th0 clones. The numbers of HLA-DRB1*0901-positive b3a2, but not those of b2a2-positive or HLA-DRB1*0901-negative CML cell colonies increased when CML cells were cultured with b3a2-specific CD4(+) CTL clones. These data suggest that bcr-abl-specific CD4(+) CTLs recognize CML cells in an antigen-specific and HLA-DR-restricted manner, and that they do not inhibit, but in fact augment, CML cell growth.

Amino Acid Sequence↗
PubMed1998

Translocation (10;11)(p13;q13) and MLL gene rearrangement in a case of AML (M5a) with aggressive leukemia cutis.

A male patient with a secondary acute monocytic leukemia whose leukemia cells had a t(10;11)(p13;q13) chromosomal abnormality is described. Gene analysis disclosed that the patient's leukemia cells had MLL gene rearrangement. His leukemia cells responded poorly to chemotherapy, and the patient developed an unusual aggressive leukemia cutis. A t(10;11)(p13;q13) chromosomal abnormality that expresses MLL gene rearrangement has not been reported previously in secondary leukemia.

Aged↗
PubMed1998

Frequent loss of heterozygosity on the long arm of chromosome 6: identification of two distinct regions of deletion in childhood acute lymphoblastic leukemia.

Cytogenetic analysis of childhood acute lymphoblastic leukemia (ALL) identified nonrandom chromosomal abnormalities of the long arm of chromosome 6. Most of the alterations are deletions that are thought to be indicative of the presence of a tumor suppressor gene that is mutated on the remaining allele. These observations led us to consider whether 6q loss may contribute to the pathogenesis of childhood ALL. To define further a region containing this gene, we analyzed the loss of heterozygosity (LOH) of chromosome 6 in 113 primary ALL samples with matched normal DNA using 34 highly informative microsatellite markers. LOH was found in 17 (15%) samples at one or more of the loci, and partial or interstitial deletions of 6q were detected in 11 of these tumors. On the basis of these results, we performed a detailed deletional map and identified two distinct regions of deletion. The first region is flanked by D6S283 and D6S302 loci at 6q21-22. The second region is flanked by D6S275 and D6S283 loci at 6q21. Clinical analysis determined that LOH of 6q was demonstrated both in precursor-B cell ALLs (15 of 93; 16%) and in T cell ALLs (2 of 19; 11%). In addition, 19 patients have been studied at diagnosis and relapse; 18 showed the same 6q21-22 structural abnormality at relapse (normal, 16 patients; LOH, 2 patients) as their initial presentation, suggesting, albeit with a small patient sample size, that 6q21-22 deletions may be an initial event in leukemogenesis and may occur less frequently during the progression of childhood ALL. These data suggest the presence of putative tumor suppressor genes on chromosome arm 6q that are important in the development of both T and precursor-B childhood ALLs. Our map provides important information toward cloning putative ALL tumor suppressor genes.

Child↗
PubMed1998

Analysis of the Smad2 gene in hematological malignancies.

A total of 34 leukemia and lymphoma samples (17 clinical samples and 17 cell lines) were analyzed for mutations of the Smad2 gene by reverse transcriptase-polymerase chain reaction single strand conformation polymorphism (RT-PCR-SSCP) analysis. Nine of the 34 samples had 18q chromosomal abnormalities. No shifted bands were detected in any of the hematological malignancies. Our results suggest that resistance to cell growth inhibitory effects of TGF-beta in hematological malignancies is not due to alterations of the Smad2 gene.

Adolescent↗
PubMed1998

Cytotoxicity of Fas ligand against lymphoma cells with radiation-induced Fas antigen.

Fas antigen, also termed APO-1 or CD95, is a transmembrane protein and a member of the tumor necrosis factor receptor/nerve growth factor receptor superfamily which mediates apoptosis upon oligomerization. The Fas/Fas ligand system is considered to be a key regulator of apoptosis. Recently, we have demonstrated that Fas antigen expression is induced by low-dose irradiation of some types of lymphomas, and we also demonstrated that irradiation-induced Fas antigen expression increased with the passage of time until peaking at 48 h after irradiation in CML-C1, CML-C2, DL-40, and DL-95 cell lines. In this study, we also examined the potential cytotoxicity of Fas ligand peptide against several types of lymphoma/leukemia cell lines that showed induction of Fas antigen expression under irradiation. Flow cytometry analysis was performed at 6, 24 and 48 h after irradiation. Samples (1 x10(6) cells/ml) from irradiated and non-irradiated cells of each cell line were incubated with or without 5 microg/ml of Fas ligand peptide for 2 h at 37 degrees C in a humidified atmosphere of 5% carbon dioxide (CO2) in air. The killing effect of Fas ligand against cell lines of CML-C1, DL-40, and DL-95 were clearly identified as the percentage of cells with Fas antigen expression induced by irradiation. Concerning HD-70 cell line, for which soluble Fas antigen has been identified, the killing effects were clearly observed in samples pre-treated with PBS washings. To our knowledge, this is the first report describing a possible application of the Fas/Fas ligand system in treatment of certain types of malignancies in which Fas antigen is inducible by irradiation.

Antineoplastic Agents↗
PubMed1998

Effects of irradiation on telomerase activity in human lymphoma and myeloma cell lines.

The effect of high-dose irradiation on telomerase activity was examined in some human lymphoma (DL40, DL95, DL110) and myeloma (U266) cell lines. The survival rate was reduced in DL40, DL110 and U266 by irradiation. Irradiation, however, showed no effect on the rate of DL95. Telomerase activity was detected in non-irradiated samples of all cell lines, as measured by PCR-based telomeric repeat amplification protocol assay. The telomerase activity increased 2-6.5 fold by irradiation. Especially in DL110, the activation increased in a dose-dependent manner. In the early phase after irradiation, we observed no correlation between telomerase activity and cell viability, suggesting that telomerase-mediated chromosome healing might not be a major cause and/or not sufficiently effective to protect the cells from irradiation.

Cell Line, Tumor↗
PubMed1997

Human herpesvirus 6 (HHV-6)-positive Burkitt's lymphoma: establishment of a novel cell line infected with HHV-6.

Human herpesvirus 6 (HHV-6) DNA has been detected in several human lymphoproliferative disorders. We report a case of HHV-6-infected Burkitt's lymphoma, from which a cell line, designated Katata, has been established. Katata cells had an immature B-cell phenotype with an L3 morphology and carried a t(8;14)(q24;q32) chromosomal abnormality. The HHV-6 DNA sequences were detected in both the patient's tumor cells and Katata cell line by polymerase chain reaction using three sets of primers that target different regions of HHV-6 DNA. The presence of HHV-6 DNA in Katata cells was also shown by Southern blot hybridization with the BamHI fragment of HHV-6. It is likely that the virus is in a latent state, since (1) virion-associated protein was not expressed in Katata cells, (2) transcriptional level of the immediate-early gene was very low, and (3) no viral particles were observed by electron microscopy. Katata cells were highly tumorigenic in nude mice and the tumor cells also contained HHV-6 DNA. We have successfully obtained several clonal lines by allowing the cells to form colonies in soft agarose and by the limiting dilution method. HHV-6 DNA was detectable in all 13 clones analyzed, suggesting that virtually all Katata cells are infected with HHV-6. This is the first report of a case of HHV-6+ Burkitt's lymphoma in the absence of Epstein-Barr virus. Furthermore, there has been no report of lymphoma cell lines that are persistently and nonproductively infected with HHV-6. The Katata Burkitt's lymphoma cell line, therefore, would provide a useful tool for studies of the mechanisms of HHV-6 latency and reactivation.

Animals↗
PubMed1997

Epithelioid sarcoma producing granulocyte colony-stimulating factor.

An epithelioid sarcoma of the perineum of a 60-year-old man with widespread metastases produced leukocytosis, myeloid hyperplasia of the bone marrow, and splenomegaly. High titers of granulocyte colony-stimulating factor (G-CSF) were found in the patient's serum and primary culture medium of the tumor tissue. The tumor tissue extract contained m-RNA for G-CSF in large quantities, proving that the tumor was the source of this cytokine.

Granulocyte Colony-Stimulating Factor↗
PubMed1997

An HTLV-I carrier with Graves' disease followed by uveitis: isolation of HTLV-I from thyroid tissue.

We report a long-term (14-year) follow-up of a human T-lymphotropic virus type I (HTLV-I)-infected male who was successively afflicted with Graves' disease followed by uveitis. HTLV-I proviral DNA was detected by polymerase chain reaction in the thyroid tissue and HTLV-I was isolated from thyroid tissue by coculture with peripheral blood lymphocytes from an HTLV-I-uninfected healthy female. This case study supports a close relationship between Graves' disease and uveitis in an HTLV-I carrier.

Adult↗
PubMed1997

Angioimmunoblastic lymphadenopathy with disseminated human herpesvirus 6 infection in a patient with acute myeloblastic leukemia.

A 47-year-old man with acute myeloblastic leukemia (AML) developed angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) 4 months after induction chemotherapy for AML. During a leukopenic period, the patient suffered from pericarditis with massive pericardial effusion in which human herpesvirus 6 (HHV-6) DNA was detected. Although complete remission of AML was achieved, fever persisted and atypical skin rash followed by generalized lymphadenopathy along with polyclonal hypergammaglobulinemia appeared. A diagnosis of AILD was made on a biopsy specimen of the inguinal lymph node. The patient died of fulminant hepatitis and the autopsy showed lymphomatous infiltrates involving the liver, bone marrow, lungs, spleen, kidneys and heart. HHV-6 DNA sequences were identified in the biopsy specimen of the lymph node and in the involved organ tissues. HHV-6 in this patient was variant B. It is known that HHV-6 can be reactivated in immunocompromised patients and causes severe complications. This unusual clinical course suggests that the immunosuppression associated with AML and the additional iatrogenic immunosuppression following cytopenia-inducing chemotherapy predisposed the patient to reactivated HHV-6 infection. The sequential detection of this virus before and after manifestation of AILD may support the evidence that HHV-6 infection could directly or indirectly trigger AILD. This is the first time that such a sequence of events has been reported to our knowledge. The possibility of HHV-6 infection should be considered when unexplained fever and generalized lymphadenopathy are seen in patients with leukemia, and administration of antiviral agents should be considered for the diagnostic evaluation.

Antineoplastic Combined Chemotherapy Protocols↗