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Y Matsuo

Publications and source records attributed to Y Matsuo.

At least 91 records · Page 5Linked to original sources
PubMed1999

Widespread intraspecies cross-contamination of human tumor cell lines arising at source.

We present a panoptic survey of cell line cross-contamination (CLCC) among original stocks of human cell lines, investigated using molecular genetic methods. The survey comprised 252 consecutive human cell lines, almost exclusively tumor-derived, submitted by their originators to the DSMZ and 5 additional cell repositories (CRs), using a combination of DNA profiling (4-locus minisatellite and multilocus microsatellite probes) and molecular cytogenetics, exploiting an interactive database (http://www.dsmz.de/). Widespread high levels of cross-contaminants (CCs) were uncovered, affecting 45 cell lines (18%) supplied by 27 of 93 originators (29%). Unlike previous reports, most CCs (42/45) occurred intraspecies, a discrepancy attributable to improved detection of the more insidious intraspecies CCs afforded by molecular methods. The most prolific CCs were classic tumor cell lines, the numbers of CCs they caused being as follows: HeLa (n = 11), T-24 (n = 4), SK-HEP-1 (n = 4), U-937 (n = 4) and HT-29 (n = 3). All 5 supposed instances of spontaneous immortalization of normal cells were spurious, due to CLCC, including ECV304, the most cited human endothelial cell line. Although high, our figure for CCs at the source sets a lower limit only as (i) many older tumor cell lines were unavailable for comparison and (ii) circulating cell lines are often obtained indirectly, rather than via originators or CRs. The misidentified cell lines reported here have already been unwittingly used in several hundreds of potentially misleading reports, including use as inappropriate tumor models and subclones masquerading as independent replicates. We believe these findings indicate a grave and chronic problem demanding radical measures, to include extra controls over cell line authentication, provenance and availability.

Cell Culture Techniques↗
PubMed1999

Loss of p73 gene expression in leukemias/lymphomas due to hypermethylation.

The p73 gene, a member of the p53 family, is a new candidate tumor suppressor gene. To investigate the possibility of genetic alteration of p73 in leukemia and lymphoma, we examined 55 cell lines and 39 patient samples together with 17 nonhematopoietic cancer cell lines. Gene expression of p73 was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in cell lines (5 of 7 pre B/B-acute lymphoblastic leukemia [ALL], 13 of 21 T-ALL/lymphoblastic lymphomas [LBL], 9 of 10 B-non-Hodgkin's lymphomas [B-NHL], 8 of 9 acute myelogenous leukemias [AML], 2 of 2 T-NHL, 3 of 3 multiple myeloma), and in patient samples (16 of 23 pre B-ALL, 5 of 8 T-ALL/LBL, 5 of 8 B-NHL). PCR-single-strand conformation polymorphism (SSCP) of cDNAs showed no mutation in 43 p73-expressing cell lines within the regions that corresponded to the 5 mutational hotspots of the p53 gene. Neither homologous deletion nor rearrangement of the p73 gene were found by Southern blot analysis in any of the cell lines that lack expression of p73. In contrast to prior published data, analysis of a polymorphic site showed that the p73 gene was expressed biallelically in cell lines and normal peripheral blood. Notably, the p73-negative cell lines were hypermethylated at a CpG island in the 5' untranslated region of the p73 mRNA, and treatment of these cell lines with 5-azacytidine (5-AC), a demethylation reagent, induced p73 expression. Taken together, we found that a sizable proportion (32%) of ALL/B-NHL cell lines and primary tumors had negligible or limited expression of the p73 gene associated with hypermethylation of the gene. These findings suggest that silencing of the p73 gene by hypermethylation may contribute to development and/or progression of lymphoid neoplasms.

DNA Methylation↗
PubMed1999

Identification of catalytically essential residues in Escherichia coli esterase by site-directed mutagenesis.

Escherichia coli esterase (EcE) is a member of the hormone-sensitive lipase family. We have analyzed the roles of the conserved residues in this enzyme (His103, Glu128, Gly163, Asp164, Ser165, Gly167, Asp262, Asp266 and His292) by site-directed mutagenesis. Among them, Gly163, Asp164, Ser165, and Gly167 are the components of a G-D/E-S-A-G motif. We showed that Ser165, Asp262, and His292 are the active-site residues of the enzyme. We also showed that none of the other residues, except for Asp164, is critical for the enzymatic activity. The mutation of Asp164 to Ala dramatically reduced the catalytic efficiency of the enzyme by the factor of 10(4) without seriously affecting the substrate binding. This residue is probably structurally important to make the conformation of the active-site functional.

Amino Acid Sequence↗
PubMed1999

Pattern of FHIT gene expression in normal and leukaemic cells.

Chromosomal aberrations and inactivation of tumour suppressor genes are frequent in acute leukaemia. To determine whether the FHIT gene is involved in the development of leukaemia, we examined the FHIT transcript in 65 leukaemia cell lines, 5 fresh acute leukaemia patients at diagnosis and in complete remission, normal peripheral blood lymphocytes obtained from 14 healthy volunteers and Epstein-Barr (EB) virus transformed 5 B-cell lines (EB-lines), using nested reverse transcription-polymerase chain reaction and direct sequencing. The transcripts were classified into 4 patterns: pattern I revealed the normal transcripts only, pattern II the altered transcripts in addition to the normal transcripts, pattern III the altered transcripts without the normal transcripts and pattern IV an absence of normal and altered FHIT transcripts. Nineteen cell lines were classified as pattern I, 32 as pattern II, 2 as pattern III and 12 as pattern IV. The frequency of loss of FHIT expression (pattern III or IV) varied in each type of leukaemia cell line; the order ranked from the highest incidence was acute myeloid leukaemia (AML), T-cell acute lymphoblastic leukaemia (T-ALL), B-precursor ALL, B-ALL, and chronic myeloid leukaemia (CML). No genomic rearrangement was found in any samples examined. All of 5 patients showed same pattern II FHIT transcripts at 2 different stages of the disease. All normal peripheral blood lymphocytes and EB-lines were classified as pattern I or II. Our results suggested that patterns III and IV of FHIT transcripts might be associated with the development of a subset of leukaemia, while pattern II which has so far been reported as an aberrant transcript in varieties of malignant tumours might not be associated with leukaemogenesis.

Acid Anhydride Hydrolases↗
PubMed1999

Identification of homologous core structures.

Using a large database of protein structure-structure alignments, we test a new method for distinguishing homologous and "analogous" structural neighbors. The homologous neighbors included in the test set show no detectable sequence similarity, but they may be well superimposed and show functional similarity or other evidence of evolutionary relationship. Analogous neighbors also show no sequence similarity and may be well superimposed, but they have different functions and their structural similarity may be the result of convergent evolution. Confirming results of other analyses, we find that remote homologs and analogs are not well distinguished by measures of pairwise structural similarity, including the percentage of identical residues and root-mean-square (RMS) superposition residual. We show, however, that with structure-structure alignments of analogous neighbors rarely superimpose the particular substructure that is shared among homologous neighbors. We call this characteristic substructure the homologous core structure (HCS), and we show that a cross-validated test for presence of the HCS correctly identifies 75% of remote homologs with a false-positive rate of 16% analogs, significantly better than discrimination by RMS or other measures of pairwise similarity. The HCS describes conservation of spatial structure within a protein family in much the way that a sequence motif describes sequence conservation. We suggest that it may be used in the same way, to identify homologous neighbors at greater evolutionary distance than is possible by pairwise comparison.

Amino Acid Sequence↗
PubMed1999

Effect of coenzyme Q10 in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS): evaluation by noninvasive tissue oximetry.

We evaluated the effect of coenzyme Q10 supplementation to two patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) by using noninvasive tissue oximetry with near-infrared spectra of hemoglobin from the quadriceps muscle during bicycle ergometer exercise. Patients showed distinct oxygen consumption patterns reflecting the defect in oxidative phosphorylation and the impairment in oxygen utilization during exercise. Based on the oxygen consumption pattern, we considered one patient as having severe mitochondrial disorder and another patient as having mild one. After coenzyme Q10 supplementation, the oxygen consumption pattern of the patient with the severe form shifted to the mild one, while that of the patient with mild form remained unchanged. The shift of the pattern to the mild form correlated well with reduction of the sum of the serum lactate and pyruvate content during exercise. Noninvasive tissue oximetry may be useful to evaluate the effect of coenzyme Q10 supplementation to patients with mitochondrial encephalomyopathy including MELAS.

Adolescent↗
PubMed1999

MMDB: Entrez's 3D structure database.

The three dimensional structures for representatives of nearly half of all protein families are now available in public databases. Thus, no matter which protein one investigates, it is increasingly likely that the 3D structure of a homolog will be known and may reveal unsuspected structure-function relationships. The goal of Entrez's 3D-structure database is to make this information accessible and usable by molecular biologists (http://www.ncbi.nlm.nih.gov/Entrez). To this end Entrez provides two major analysis tools, a search engine based on sequence and structure 'neighboring' and an integrated visualization system for sequence and structure alignments. From a protein's sequence 'neighbors' one may rapidly identify other members of a protein family, including those where 3D structure is known. By comparing aligned sequences and/or structures in detail, using the visualization system, one may identify conserved features and perhaps infer functional properties. Here we describe how these analysis tools may be used to investigate the structure and function of newly discovered proteins, using the PTEN gene product as an example.

Amino Acid Sequence↗
PubMed1999

Serum levels of parathyroid hormone-related protein are not elevated in patients with T-cell prolymphocytic leukemia.

T-cell prolymphocytic leukemia (T-PLL) is a rare post-thymic T-cell neoplasm which shares most clinical features with adult T-cell leukemia (ATL). We measured serum level of C-terminal parathyroid hormone-related protein (C-PTHrP) in patients with T-PLL and ATL. Serum C-PTHrP levels of eight patients with T-PLL (median 36.8 pmol/l; range 27.0-50.2 pmol/l) did not differ from those of 30 human T-lymphotropic virus type I (HTLV-I)-seronegative blood donors (median 37.0 pmol/l; range 22.6-54.0 pmol/l). The C-PTHrP levels in ten ATL patients (median 69.6 pmol/l; range 42.5-899.4 pmol/l) were significantly higher than those in healthy controls (p<0.0001) or T-PLL patients (p=0.001). We suggest that the serum level of PTHrP can provide useful information for differentiating between T-PLL and ATL.

Adult↗
PubMed1999

Sclerosing stromal tumor of the ovary: radiologic findings.

Sclerosing stromal tumor is a rare ovarian neoplasm. We describe the radiologic findings of sclerosing stromal tumor in two patients. In both patients, MR and CT images showed a large mass in the left adnexal region. On dynamic contrast-enhanced images, the tumors showed early peripheral enhancement with centripetal progression.

Adult↗
PubMed1999

Establishment and characterization of a novel ALL-L3 cell line (BALM-18): induction of apoptosis by anti-IgM and inhibition of apoptosis by bone marrow stroma cells.

A human acute lymphoblastic leukemia (ALL) cell line, BALM-18, was established from the peripheral blood specimen of a patient with B cell ALL L3 type (ALL-L3) at diagnosis using bone marrow stroma cells (BST) as feeder cells. The primary leukemia cells did not grow without feeder cells. As with the primary leukemia cells, BALM-18 showed an immunophenotype of Burkitt's lymphoma group I [CD10+, CD20+, CD23-, CD39-, CD77+] and carried the t(8;14)(q24;q32) chromosomal abnormality which is highly associated with ALL-L3 and Burkitt's lymphoma. It also revealed a significantly low level of bcl-2 protein. Strikingly, anti-human IgM antibody did induce apoptosis in induction experiments. However, it was reversed by the addition of anti-CD40 antibody or BST cells, whereas the culture supernatant of the stroma cells did not show any effect on the inhibition of apoptosis. BALM-18 may be useful for analyzing both the mechanisms of anti-IgM induced apoptosis and signaling during the inhibition of apoptosis by CD40 or BST cells.

Adult↗
PubMed1999

A novel biphenotypic B-cell precursor leukemia cell line (NALM-29) carrying t(9;22)(q34;q11) established from a patient with acute leukemia.

A novel biphenotypic leukemia cell line, NALM-29, was established from a 46-year-old Japanese male patient with acute lymphoblastic leukemia (ALL). The primary leukemic blasts showed a common ALL phenotype with CD19+, CD10+, CD13-, HLA-DR+ and Igs-. NALM-29 cells display biphenotypic characteristics: expression of the intracellular enzyme myeloperoxidase at the mRNA and protein level and cell surface positivity for CD19, CD10, CD13, CD33 and HLA-DR. NALM-29 fulfills EGIL criteria as B-cell precursor (BCP) leukemia B-II type. NALM-29 cells have a lymphoblastic morphological appearance; the immunoglobulin heavy chain gene is rearranged. NALM-29 cells responded significantly to the proliferative stimuli of FLT-3 ligand and IL-7, but not to GM-CSF, IL-3, IL-6, PIXY-321 or SCF. Proliferation of cells was inhibited significantly by IL-4, TNF-alpha or TNF-beta treatment. Cytogenetic analysis revealed the characteristic t(9;22)(q34;q11); expression of the m-bcr e1-a2 BCR-ABL fusion gene (typically found in ALL) was determined by PCR amplification of cDNA. The immunological, cytogenetic and functional characterization of NALM-29 suggests that this cell line may represent a scientifically significant in vitro model for BCP-type leukemia cells with biphenotypic characteristics.

Base Sequence↗
PubMed1999

ABL-BCR expression in BCR-ABL-positive human leukemia cell lines.

Expression of normal ABL and BCR and of reciprocal fusion genes BCR-ABL and ABL-BCR was examined in a panel of 53 BCR-ABL-positive cell lines by RT-PCR to determine the influence of the various transcripts on leukemogenesis. Seventeen out of 18 lymphoid cell lines expressed ABL1a and/or ABL1b, whereas only 16 out of 35 myeloid cell lines expressed one or both normal ABL transcripts. Normal BCR was expressed in seven lymphoid cell lines; all cell lines from the m-bcr group (n = 9) were BCR-negative. Among the myeloid cell lines, 77% expressed the BCR gene. The M-bcr and m-bcr translocations were equally distributed among cell lines with lymphoid phenotype. The m-bcr translocation was not found in myeloid cell lines. b3-a2 constitutes the predominant form of fusion gene in myeloid cell lines with an incidence of about 68%. One myeloid cell line exhibited the mu-bcr variant. An ABL-BCR transcript of the 1a splice variant was not detected in any of the cell lines. ABL1b-BCR was expressed in all varieties of cell types and translocation forms: 56 and 66% in the lymphoid and myeloid cell lines, respectively; similar distributions were found for the fusion gene types: 67% among e1-a2, 73% among b2-a2, and 61% among b3-a2 translocations. Except for the lack of expression of normal BCR in m-bcr cell lines and of ABL1a-BCR expression in all cell lines, no consistent correlation of expression or lack of expression of BCR and ABL or of ABL-BCR reciprocal fusion genes could be found with cell lineages and translocation types. Further work is required to determine the exact role of the reciprocal fusion gene transcripts on the pathophysiological mechanisms of leukemogenesis.

Base Sequence↗
PubMed1999

Thyrsiferyl 23-acetate and its derivatives induce apoptosis in various T- and B-leukemia cells.

Thyrsiferyl 23-acetate (TF-23A), a cytotoxic compound from marine red alga, induced a rapid cell death in various leukemic T- and B-cell lines. During incubation of Jurkat cells with TF-23A, condensation and fragmentation of nuclei occurred and clusters composed of uneven small cellular particles were formed. Concentration- and time-dependent DNA fragmentation was also induced by the incubation of the cells with TF-23A. These results demonstrate that the TF-23A-induced cell death follows a typical apoptotic process. The TF-23A-induced apoptosis was prevented by fetal calf serum and insulin, but not by EGF or PDGF. TF-23A and its several analogous compounds showed apoptosis-inducing activity. However, only TF-23A out of these compounds showed an inhibitory activity for protein phosphatase 2A, PP2A. These results strongly suggest that a structure of TF-23A involved in induction of apoptosis is different from that involved in the PP2A inhibition.

Animals↗
PubMed1999

Divergence of the regulation of alpha-amylase activity in Drosophila melanogaster, Drosophila funebris, and Drosophila saltans.

The regulation of amylase activity in three Drosophila species, D. melanogaster, D. funebris and D. saltans, was analyzed by measuring the specific activity levels in four dietary environments, cornmeal, glucose, 5% starch, and 10% starch, at three developmental stages, i.e., the third-instar larval, pupal, and 2-day-old adult stages. The developmental profiles of amylase activity for the three Drosophila species showed that the level of activity was high at the larval and adult stages but substantially low at the pupal stage, suggesting that Drosophila does not utilize starch at the pupal stage. Divergence in the regulation of amylase was observed among the three Drosophila species on the following points. (1) The order of amylase specific activity was D. melanogaster > D. funebris > D. saltans. (2) The response pattern to the dietary environment varied among the species and changed during development. (3) The timing of the switch in the response pattern to the dietary environment during development was before pupation in D. funebris and D. saltans but after pupation in D. melanogaster. The significance of the divergence in the regulation of amylase activity for adaptation to a starch environment in Drosophila is discussed.

Animals↗
PubMed1999

Evolution of the amylase isozymes in the Drosophila melanogaster species subgroup.

The relationship between the net charge of molecules and their mobility on electrophoresis was analyzed for Drosophila alpha-amylases. Most of the differences in electrophoretic mobility, 98.2%, can be explained by the charge state. Therefore five reference amino acid sites, which are informative residues for charge differences among amylase isozymes, were considered for the evolution of the isozymes in Drosophila melanogaster. The amylase isozymes in D. melanogaster can be classified into three groups, I (AMY1, AMY2, and AMY3-A), II (AMY3-B and AMY4), and III (AMY5, AMY6-A, and AMY6-B), based on the differences in the reference sites. The most primitive amylase in D. melanogaster was found to belong to Group I, most likely the AMY2 isozyme. Groups II and III could have been derived from Group I. These results were confirmed by the analysis of 38 amino acid sites with charge differences in Drosophila.

Amino Acid Sequence↗
PubMed1999

Adaptation to a starch environment and regulation of alpha-amylase in Drosophila.

The adaptation to glucose and starch foods in six species, D. melanogaster, D. virilis, D. saltans, D. funebris, D. levanonensis and D. americana, was studied by measuring productivity. D. melanogaster and D. virilis adapted more to the starch environment than to the glucose environment, while D. saltans adapted more to the glucose environment than to the starch environment. D. funebris, D. levanonensis, and D. americana did not distinctly adapt to either environment. In addition, the regulation of amylase in the six species was investigated by measuring the levels of amylase activity with glucose and starch food environments. The levels of amylase activity in D. levanonensis and D. saltans were substantially low, indicating that these species cannot utilize starch as a carbon source. The starch-adapted species, D. melanogaster and D. virilis, showed higher levels of amylase activity with the starch environment and higher inducibility. These results suggest that changing the regulation of amylase is important for the adaptation to a starch environment in Drosophila.

Adaptation, Physiological↗
PubMed1999

Influence of lipophilic groups in cationic alpha-helical peptides on their abilities to bind with DNA and deliver genes into cells.

For the purpose of achieving gene transfer into cells mediated by peptides with a short chain length, we employed two kinds of amphiphilic alpha-helix peptides, mastoparan (INLK-ALAA-LAKK-IL-NH2) obtained from wasp venom and an alpha-helix model peptide (LARL-LARL-LARL-NH2). Furthermore, to strengthen the hydrophobicity of the peptide required for the formation of the aggregates with the DNA, we modified these peptides using several lipophilic groups, i.e. acyl groups with a single chain, a dialkylcarbamoyl group and a cholesteryloxycarbonyl group. We examined the ability of the peptides and their derivatives to bind and aggregate with plasmid DNA, the structural change in the peptides caused by binding with the DNA and the in vitro gene transfer abilities into COS-7 cells. As a result, mastoparan was found to acquire the DNA binding ability by introduction of the lipophilic group. The conformational change in the peptides depended on the hydrophobicity of the introduced acyl group. The DNA complex of most lipophilic mastoparan derivatives could be incorporated into the cells via the endocytosis pathway. In the case of the helix model peptide, the acyl group with a moderate chain length was required for the formation of the aggregate which is competent for incorporation into the cells. In this study, we succeeded in giving such short peptides sufficient gene transfer ability by modifying them with some lipophilic groups. However, the influence of the modification by the lipophilic groups on the formation of aggregates with DNA and the gene transfer ability depended on the structure of the peptide portion. These results indicate that consideration of total hydrophobicity balance is needed for the design of an efficient gene carrier peptide.

Amino Acid Sequence↗