Biomedical subjects

T Moriuchi

Publications and source records attributed to T Moriuchi.

At least 55 records · Page 3Linked to original sources

PubMed1997

Possible roles of an adult T-cell leukemia (ATL)-derived factor/thioredoxin in the drug resistance of ATL to adriamycin.

Chemotherapy for adult T-cell leukemia (ATL) has been reported to fail to induce complete remission because of drug resistance in most patients. We have examined the expression of an ATL-derived factor (ADF)/thioredoxin in relation to resistance to adriamycin (ADM) in various T-cell leukemia cell lines including ATL cell lines. Immunoblot analysis demonstrated that ATL cell lines expressed ADF/thioredoxin at levels 2.8 to 12 times those of other T-cell acute lymphocytic leukemia (T-ALL) cell lines, and that ATL cell lines were 2 to 15 times more resistant to ADM than other T-ALL cell lines. Therefore, we established ADM-resistant cell lines from three different ATL cell lines, and examined the correlation between ADM resistance and expression of ADF/thioredoxin. ADM-resistant ATL cell lines were also found to be resistant to other drugs such as cisplatin and etoposide, and they expressed ADF/thioredoxin at levels 5 to 10 times those of parent ATL cell lines. Diamide and sodium selenite, which have been reported to inhibit ADF/thioredoxin, restored the sensitivity to ADM in ATL and ADM-resistant ATL cell lines. The MDR-1 gene product, a membrane P-glycoprotein (Pgp), was not expressed on ATL cell lines or ADM-resistant ATL cell lines. Topoisomerase II and glutathione peroxidase activities in T-cell leukemia cell lines were not correlated with ADM resistance. These results suggest that ADF/thioredoxin may play an important role in the drug resistance of ATL cells to ADM.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1996

Cloning, sequencing, and chromosomal localization of two tandemly arranged human pseudogenes for the proliferating cell nuclear antigen (PCNA).

We have characterized a human genomic clone carrying two pseudogenes for the proliferating cell nuclear antigen (PCNA), which were tandemly arranged on human Chromosome (Chr) 4. One is a processed pseudogene that showed a 73% nucleotide homology to the human PCNA cDNA and possessed none of the introns existing in the functional PCNA gene. This pseudogene presumably arose by reverse transcription of a PCNA mRNA followed by integration of the cDNA into the genome. The other is a 5' and 3' truncated pseudogene that showed a nucleotide homology to a 3' region of the exon 4 and to a 5' region of the exon 5 of the PCNA gene and did not have the intronic sequence between the exons 4 and 5. Both pseudogenes had the same nucleotide deletion as compared with the human functional PCNA gene. A phylogenetic analysis of PCNA gene family, including the functional PCNA gene and another PCNA pseudogene located on a different chromosome, revealed that the truncated pseudogene exhibits the closest evolutionary relationship with the processed pseudogene, suggesting that the truncated pseudogene was generated by duplication of the processed pseudogene after translocation to Chr 4. Furthermore, fluorescence in situ hybridization revealed that these pseudogenes are located on the long arm of Chr 4, 4q24.

Animals↗

PubMed1996

Plasma glutathione peroxidase deficiency caused by renal dysfunction.

Glutathione peroxidase (GPx) activity was determined in the plasma of 118 healthy persons, 18 nondialyzed patients with chronic renal failure (CRF), 20 patients on maintenance hemodialysis (HD), and 58 patients on continuous ambulatory peritoneal dialysis (CAPD). Serum creatinine levels in the nondialyzed CRF patients revealed a highly significant negative correlation (r = -0.71, p < 0.001) with plasma GPx activity. Immunoblot analysis revealed that the plasma (extracellular) GPx protein was reduced or undetectable in patients with low plasma GPx activity. Plasma GPx activities in the HD and CAPD patients were reduced to 44 and 23% (female), and to 70 and 45% (male) of the sex-matched control values, respectively. In contrast, erythrocyte (cellular) GPx activity was not decreased in the nondialyzed CRF patients and the dialyzed patients. Plasma selenium concentrations were within the normal range in these patient groups. These results indicate that the plasma GPx activity largely depends on renal function.

Aged↗

PubMed1995

Overexpression of the HOX4A (HOXD3) homeobox gene in human erythroleukemia HEL cells results in altered adhesive properties.

We previously isolated the human homeobox gene HOX4A (HOXD3) on chromosome 2 from a human genomic library and determined its nucleotide sequence. In the present study, expression of the HOX4A gene was investigated in human hematopoietic cell lines. Reverse transcriptase-mediated polymerase chain reaction analysis showed that the HOX4A gene was expressed in erythroleukemia HEL and K562 cells but not in promyelocytic leukemia HL-60 cells. To study the role of the HOX4A gene in erythropoiesis, expression vectors containing the HOX4A gene in the sense or antisense orientation were introduced into HEL cells. The sense transfectants overexpressing the HOX4A gene formed aggregates, which were composed of densely associated cells adhering to tissue-culture dishes, whereas the parental HEL cells and antisense transfectants adhered poorly to the dishes. Furthermore, the sense transfectants overexpressing the HOX4A gene attached more efficiently to fibronectin and collagen than did the antisense transfectants and parental HEL cells. Northern blot analysis showed that integrin beta 3 mRNA levels were significantly increased in the HEL cells overexpressing the HOX4A gene, whereas the integrin beta 1 and alpha IIb mRNA levels did not show a distinct correlation with HOX4A mRNA levels. Fluorescence-activated cell sorting analysis showed that the sense transfectants overexpressing the HOX4A gene expressed increased levels of integrin alpha IIb beta 3 (GP IIb-IIIa) complex as compared with the parental HEL cells and antisense transfectants. These results implicate the homeobox gene HOX4A in the regulation of cell adhesion processes.

Base Sequence↗

PubMed1994

The human plasma glutathione peroxidase-encoding gene: organization, sequence and localization to chromosome 5q32.

A genomic clone encoding the human plasma glutathione peroxidase (PGPx), a major enzyme in reducing lipid hydroperoxide and hydrogen peroxide in plasma, was isolated and 5618 nucleotides (nt) were determined. The nt sequence data revealed that the PGPx gene is composed of five exons spanning approx. 10 kb. Primer extension experiments mapped the transcription start point at 298 nt upstream from the predicted start codon. Twenty nt upstream from the polyadenylation site of the gene, an uncanonical polyadenylation signal, AGTAAA, was found. Human PGPx was localized on chromosome 5 band q32 by fluorescence in situ hybridization.

Amino Acid Sequence↗

PubMed1994

Decreased expression of liver glutathione peroxidase in Long-Evans cinnamon mutant rats predisposed to hepatitis and hepatoma.

The Long-Evans Cinnamon rat is a mutant strain that contracts hereditary hepatitis and, eventually, spontaneous hepatoma. Recently, abnormal copper accumulations in Long-Evans Cinnamon rat livers were shown to be genetically linked to the development of hepatitis. Because reduced glutathione and glutathione-related enzymes are known to play important roles in cellular resistance to transition metal toxicity, we determined the levels of reduced glutathione and glutathione-related enzymes in seven different tissues of Long-Evans Cinnamon and control Long-Evans Agouti rats. Of the enzymes examined, only hepatic glutathione peroxidase was markedly decreased in Long-Evans Cinnamon rats. Glutathione peroxidase content in the liver of Long-Evans Cinnamon rats was 39%, 53% and 58% of the control values at 9 (normal stage), 19 (acute hepatitis stage) and 27 (chronic hepatitis stage) wk of age, respectively. Northern-blot analysis revealed that messenger RNA levels of glutathione peroxidase in the livers of Long-Evans Cinnamon rats were about 40% of the control levels. The activity of glutathione S-transferase was slightly decreased in the livers of Long-Evans Cinnamon rats. These data suggest that the liver of the Long-Evans Cinnamon rat is poorly protected against active oxygen species, the production of which is enhanced in the presence of excess copper. Glutathione-reductase activity in the livers of Long-Evans Cinnamon rats increased to 166% and 148% of the control levels at 19 and 27 wk of age, respectively. No significant changes were observed in the activity of gamma-glutamylcysteine synthetase or in the content of total reduced glutathione in the liver of the Long-Evans Cinnamon rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Suppression of plasma glutathione peroxidase activity by ifosfamide.

Plasma glutathione peroxidase (GPx) is synthesized predominantly in the kidneys. Plasma-GPx activities were measured in 12 patients with gynecological malignancies before and after chemotherapy. The patients were treated with cisplatin alone (P); with VP16 and cisplatin (EP); with cyclophosphamide, doxorubicin, and cisplatin (CAP); or with ifosfamide, doxorubicin, and cisplatin (IAP). The protein levels of the enzyme were semi-quantitatively determined by immuno-blot analysis. Plasma GPx activity was decreased by an average of 61% (p < 0.01) in patients treated with IAP, while no significant decreases were observed in patients treated with any drug combinations without ifosfamide. Immuno-blot analysis of plasma samples from a patient treated with IAP revealed no differences in the protein levels of plasma GPx either before or after IAP administration, although the plasma GPx activity decreased 83%, from 0.173 to 0.029 units/ml. The results indicate that the decrease in plasma GPx activity was not due to impaired production of the enzyme in the kidneys, and that ifosfamide is responsible for inhibition of the enzyme activity. Since GPx is an enzyme of major importance in detoxification of lipid peroxides in the brain, CNS toxicity induced by ifosfamide might be related to severe suppression of plasma GPx activity.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1994

Nucleotide sequence of a human genomic DNA fragment containing the PCNA pseudogene and its localization on chromosome 4.

A one kb human genomic DNA fragment, containing a processed pseudogene of a proliferating cell nuclear antigen (PCNA/DNA polymerase delta auxiliary protein), was isolated and sequenced. The PCNA pseudogene consisted of the 3' half of exon 4 and the 5' half of exon 5 of the PCNA gene, and shared 84% nucleotide homology with the human PCNA cDNA. The PCNA pseudogene was localized on human chromosome 4, based on data obtained from a panel of human-mouse hybrid cell lines.

Animals↗

PubMed1993

Molecular analysis of abnormal satellite I DNA from a BUF/Mna rat thymoma.

BUF/Mna rats develop spontaneous thymomas in an autosomal dominant manner. We constructed recombinant plasmid library of 90 and 185 base-paired (bp) satellite I DNA fragments isolated from BUF/Mna rat thymoma DNA. Four unusual clones containing 93, 95, 95, and 173 bp inserts were isolated by colony hybridization with Wistar rat satellite I DNA. Nucleotide sequence analysis of the inserts of the 4 clones revealed abnormal sequence organization and unusual subunit structure of the rat satellite I DNA. Sequence comparisons between normal and abnormal satellite I DNA suggested that the unusual subunit structure could be generated by the change of the Hinf I recognition sequence to an Eco RI cleavage site, in addition to random deletions, insertions and base substitutions. The heptanucleotide sequence TGGGAAC, which is strictly conserved in normal subunits, was completely lost in all these clones. Southern blot hybridization revealed the amplification of abnormal satellite I DNA in BUF/Mna rat thymomas.

Animals↗

PubMed1993

Autopsy analyses of the muscular dystrophies.

Life span, causes of death, weight of heart, liver, brain, and main pathological changes of internal organs were analysed on 329 autopsy cases of muscular dystrophies. These included 249 cases of Duchenne muscular dystrophy (DMD), 3 Becker muscular dystrophies (BMD), 14 limb-girdle muscular dystrophies (LGMD), 3 fascioscapulohumeral muscular dystrophies (FSH), 18 Fukuyama type congenital muscular dystrophies (FCMD) and 17 myotonic dystrophies (MyD). In DMD the life span has definitely prolonged in recent years. Pulmonary infection, which was once the major cause of death, has greatly decreased in recent years. Instead, respiratory and cardiac failures caused by dystrophic changes of respiratory and cardiac muscles were more closely related to the causes of death in many recent cases. Myocardial fibrosis was observed in most of the patients with DMD, BMD, LGMD, FCMD and MyD. The distribution of cardiac lesions was similar in BMD, LGMD and FCMD as in DMD. In MyD the disorders involved more frequently conductive muscles resulting in arrhythmias. The dystrophic cardiomyopathy seemed to be a part of the essential changes in all types of muscular dystrophy, although different in intensity and rate of morbidity. Alzheimer's neurofibrillary changes were observed in the brain of some cases of FCMD and MyD, suggesting the possibility of precocious aging of the brain in some patients of the muscular dystrophies.

Adolescent↗

PubMed1992

Cloning and sequencing of the human homeobox gene HOX4A.

The HOX4A gene, one of the homeobox-containing genes on human chromosome 2, has been isolated by screening a genomic cosmid library with a HOX4B cDNA probe. The HOX4A gene consists of at least two exons separated by a long intron of 1860 bp. According to conceptual translation, the HOX4A protein is predicted to be composed of 416 amino acid residues. Interestingly, the HOX4A protein has a sequence, Pro-Ala-Ser-Gln-Ser-Pro-Glu-Arg-Ser, eight amino acids downstream from the homeodomain, which is similar to that containing a phosphorylation site in pp60c-src, Pro-Ala-Ser-Gln-Thr-Pro-Asn-Lys-Thr. However, the HOX2G protein, which exhibits a paralogous relationship with the HOX4A protein, does not possess the sequence which is similar to that in pp60c-src. A comparison of the predicted HOX4A protein with the HOX2G protein revealed four regions of amino acid sequence similarities: an N-terminal tetrapeptide, a pentapeptide (pre-box) upstream of the homeodomain, the homeodomain and a C-terminal octapeptide.

Amino Acid Sequence↗

PubMed1992

Analysis of the 5' flanking region of the rat proliferating cell nuclear antigen (PCNA) gene.

The proliferating cell nuclear antigen (PCNA), highly conserved among eukaryotes, is an auxiliary factor for DNA polymerase delta. In this report we sequenced 1560 nucleotides (nt) of the 5' flanking region of the rat PCNA gene and located the transcription initiation site. The sequence contains 1435 nt upstream of the cap site and promotes transcription of a linked heterologous reporter gene in rat, mouse and human cells. Transient expression assays using a series of 5' deletion mutants revealed that 240 nt of the upstream sequence are sufficient for full promoter activity. Three GC boxes and several other binding sites of transcription factors were observed, but neither a TATA nor a CCAAT sequence was found in this region. The results also suggested the existence of a negative regulatory element(s) between -968 and -691. Cotransfection with early region 1 (E1) genes of human adenoviruses activated the expression of the reporter gene, suggesting that an E1-responsive element is located at the proximal promoter region within 81 nt upstream of the transcription initiation site.

3T3 Cells↗

PubMed1992

Production and characterization of two monoclonal antibodies to human glutathione peroxidase.

Glutathione peroxidase (GSH-Px) is an important selenium-containing enzyme which protects cells from oxidative damage. Two hybridoma clones (GPX-121 and GPX-347), producing mouse IgG1 monoclonal antibodies specific for GSH-Px, were established. Immunoblot analysis revealed that GPX-347 was specific for human GSH-Px, while GPX-121 cross-reacted with human, rat, mouse and rabbit GSH-Px. Correlation between GSH-Px content and its enzymatic activity was investigated in erythrocytes of 76 humans and in human lung adenocarcinoma PC-9 cells by using a sandwich type ELISA. The results indicated that GSH-Px activity was expressed higher than expected from GSH-Px content especially in the range of low GSH-Px concentration. PC-9 cells selenium depleted medium did not stain but the cytoplasm of PC-9 cells grown in medium supplemented with selenium stained strongly.

Adenocarcinoma↗

PubMed1992

Quantification of the c-myc gene in gastric carcinomas by the triplex polymerase chain reaction and high performance liquid chromatography.

The triplex polymerase chain reaction (PCR) and high performance liquid chromatography (HPLC) techniques were used to examine the state of amplification of the c-myc gene in gastric carcinomas. Sequences from the c-myc gene and from the two control genes were coamplified by PCR. The coamplified PCR products were separated and quantified by HPLC and the copy numbers of the c-myc gene were calculated by comparing the peak areas generated by PCR products. Increased copy numbers of the c-myc gene were found in 2 of 5 patients.

Chromatography, High Pressure Liquid↗

PubMed1992

Isolation of a new human pseudogene for proliferating cell nuclear antigen.

A new gene, which cross-hybridized with a rat PCNA cDNA probe, has been isolated from a human genomic cosmid library. A comparison of the gene with the human PCNA cDNA revealed 71% homology for the nucleotide sequences. This gene completely lacks introns and has traces of a polyA tail which the messenger RNA of the active gene retains. These facts indicate that this gene was generated by the reverse-transcription of a processed RNA for PCNA and exists as a PCNA pseudogene in the human genome.

Animals↗

PubMed1992

[Chromosome and DNA analyses of peripheral blood lymphocyte from the quadruple cancer patient].

The patient with quadruple cancer was a 32 year-old female who had osteosarcoma, bilateral breast cancer and adenocarcinoma of the lung. When chromosomal analysis of peripheral blood lymphocyte was performed, two abnormal cells were detected among 42 cells examined. The first cell showed a translocation involving chromosome 1 and 20 and trisomic for chromosome 19. The second cell was trisomic for chromosome x. Southern blot analysis of DNA from peripheral blood lymphocyte revealed that there was no difference in the expression of Rb gene between the patient and healthy adult.

Adenocarcinoma, Papillary↗

PubMed1991

Molecular cloning and structural analysis of mouse gene and pseudogenes for proliferating cell nuclear antigen.

We have isolated clones containing the entire mouse proliferating cell nuclear antigen (PCNA) gene of 3890 bp and flanking sequences using a rat PCNA cDNA as a probe. The mouse gene has 6 exons whose sequences and junction points of exons with introns are extensively homologous to the human gene while sizes and nucleotide sequences of introns are much less conserved than exons. By a transient expression assay of chloramphenicol acetyltransferase, the promoter of this gene is localized within 200 bp upstream of the transcription initiation site. We have also isolated two processed pseudogenes. Homology between the first one (psi PCNA-I) and the exons of the PCNA gene was 76.8% in the region so far sequenced. The second one (psi PCNA-II) consists of a region highly homologous to the entire exons of the PCNA gene, and only 9 out of total 1256 bp are different from the corresponding exon sequence of the gene. The 5'-flanking region of the psi PCNA-II did not function as an active promoter. Surveys in various wild and laboratory mice genomes suggest that the psi PCNA-II was generated through the reverse transcription process of the PCNA mRNA about 5 x 10(5) years ago in the domesticus subspecies of Mus musculus, the house mouse. The psi PCNA-II is tentatively mapped in the chromosome 17 of the C57BL mouse.

Amino Acid Sequence↗

PubMed1991

Tissue specific expression of the plasma glutathione peroxidase gene in rat kidney.

Rat plasma glutathione peroxidase (GSH-Px) was purified 1,400-fold from rat serum by a combination of phenyl Sepharose, DEAE Sephacel, blue Sepharose and Sephacryl S-200 column chromatographies. The purified GSH-Px migrated as a single band corresponding to a molecular weight of 22,500 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was used for the immunization of chickens to obtain a specific antibody and for determination of its amino acid sequence. Two overlapping cDNA clones for rat plasma GSH-Px were isolated from a placental cDNA library. The composite nucleotide sequence is 1,529 base-pairs long and encodes 226 amino acids. The deduced amino acid sequence completely coincided with the sequences of five individual peptide fragments derived from the purified plasma GSH-Px on digestion with lysyl endopeptidase. In order to identify the tissue(s) generating this plasma GSH-Px, immunoblot analysis was performed on homogenates prepared from 13 tissues. A single immunoreactive band of 22.5 kDa, corresponding to plasma GSH-Px, was detected for the kidney homogenate. A much fainter band was observed for the lung preparation, but liver, spleen, bone marrow, and other tissues examined were negative. Northern blot analysis further revealed that the expression level of the plasma GSH-Px gene was high in kidney and low in lung. No transcript was detected in liver or spleen. These results indicate that plasma GSH-Px is predominantly synthesized and secreted by renal cells.

Amino Acid Sequence↗