Biomedical subjects

M Inuzuka

Publications and source records attributed to M Inuzuka.

At least 37 records · Page 2Linked to original sources

PubMed1994

cDNA sequences encoding human fructose 1,6-bisphosphatase from monocytes, liver and kidney: application of monocytes to molecular analysis of human fructose 1,6-bisphosphatase deficiency.

Fructose 1,6-bisphosphatase deficiency is an autosomal recessive inherited disorder of gluconeogenesis. We could isolate cDNAs encoding human fructose 1,6-bisphosphatase from normal monocytes, liver and kidney, but not from normal lymphocytes. The cDNAs contained an open reading frame coding for 338 amino acids, and their nucleotide sequences in monocytes and liver were identical. G644C645 nucleotides in this sequence were the same as those of cDNA from HL-60 cells, although our result differed from a previous report (M. El-Maghrabi et al. (1993) J. Biol. Chem. 268, 9466-9472) on an alteration to C644G645 nucleotides in human liver cDNA resulting in a change of Gly-214 to Ala-214 in the enzyme. The Gly-214 (GGC) residue was therefore conserved in the enzymes hitherto isolated from humans and other animals. Analysis of monocytes in seven patients with fructose 1,6-bisphosphatase deficiency showed a DNA fragment with apparent normal size in two sisters but no detectable DNA fragment in the other five patients. Monocytes were thus useful as an alternative source for mRNA from human liver for the molecular analysis of fructose 1,6-bisphosphatase deficiency.

Alanine↗

PubMed1994

Eosinophilic cationic protein in chronic eosinophilic pneumonia and eosinophilic granuloma.

We measured eosinophilic cationic protein (ECP) concentrations in the circulation and bronchoalveolar lavage (BAL) fluids from patients with chronic eosinophilic pneumonia, patients with eosinophilic granuloma, and normal control subjects. Significantly increased ECP concentrations were found in the circulation of patients with chronic eosinophilic pneumonia and with eosinophilic granuloma compared with those found in control subjects. The ECP concentrations were well correlated to eosinophil counts in the circulation of patients with chronic eosinophilic pneumonia, while they were not in patients with eosinophilic granuloma. Chronic eosinophilic pneumonia patients had prominently increased ECP concentrations in BAL fluids compared with those found in control subjects, while eosinophilic granuloma patients did not. Those concentrations in chronic eosinophilic pneumonia patients were well correlated to eosinophil counts in the BAL fluid. Corticosteroid therapy remarkably decreased circulating ECP concentrations in three patients with chronic eosinophilic pneumonia, but it had no significant effects in two patients with eosinophilic granuloma. Measurement of ECP concentrations seems to be useful to evaluate the disease activity of chronic eosinophilic pneumonia.

Adult↗

PubMed1994

[Intercellular adhesion molecule 1 antigen in tuberculosis].

Intercellular adhesion molecule 1 (ICAM-1) plays an important role in inflammatory diseases. We investigated levels of circulating soluble ICAM-1 in patients with miliary tuberculosis (n = 8) and pulmonary tuberculosis (n = 49). We also attempted to compare ICAM-1 levels among pulmonary tuberculosis patients according to chest X ray classification of the Japanese Society for Tuberculosis. Significantly increased levels of circulating ICAM-1 were found in patients with miliary tuberculosis and extensive (extent 3) pulmonary tuberculosis (n = 9) compared to those of controls (n = 48), but not in patients with extent 1 (n = 24) or extent 2 pulmonary tuberculosis (n = 16). Immunohistochemical examination of the tuberculous lung tissues from the patients showed intensive cellular ICAM-1 on epithelioid cells and giant cells as well as on vascular endothelial cells. These results suggest that ICAM-1 is an important adhesion molecule in tuberculosis.

Adult↗

PubMed1994

[Expression of human epidermal growth factor and its receptor of the gastric carcinomas with special reference to DNA ploidy patterns and nucleolar organizer regions].

In 68 cases of surgically resected gastric carcinomas, expression of human epidermal growth factor (EGF) and its receptor (EGFR) were examined immunohistologically using the Avidin-Biotin Peroxidase Complex Method, and their relation with DNA contents and nuclear protein synthesis in the tumor progression were studied by measuring DNA ploidy patterns and nucleolar organizer regions (NORs), respectively with cytofluorometry and AgNO3 stain method. EGF and EGFR expression were respectively found only in 2 (7%) and 1 (4%) in 28 early cancers, and significantly increased in advanced cancers, 25 (63%) and 9 (23%) out of 40 cases. The ratio of aneuploid tumor and the NORs numbers per tumor cell also increased in advanced cancers, compared with in early cancers. EGF and EGFR respectively expressed in 19 (51%) and 9 (23%) in 37 aneuploid cancers, significantly more frequent than 8 (26%) and 1 (3%) in 31 diploid cancers. In the EGF-positive tumors, the NORs numbers showed 4.11 +/- 0.72, significantly higher than 2.68 +/- 0.61 in the EGF-negative tumors. These results suggested that expression of EGF and EGFR in the gastric carcinomas increases during the tumor progression from the early to advanced stage, stimulates synthesis of DNA and nuclear protein, and consequently enhances (strengthens, heightens, or intensifies) the proliferative activity of the tumors.

DNA, Neoplasm↗

PubMed1994

The viral and cellular Rel oncoproteins induce the differentiation of P19 embryonal carcinoma cells.

Rel proteins have been implicated in the differentiation and transformation of lymphoid cells. Despite their significant sequence homology to the Drosophila Dorsal morphogen, a functional role for Rel proteins in early development has yet to be established. Here we show that expression of the v- or c-rel genes in P19 embryonal carcinoma (EC) cells leads to drastic morphological changes accompanied by the expression of several differentiation-specific antigens. In contrast, v-Rel mutants defective for DNA-binding as well as those lacking the F9 cell-specific transcription activation region of v-Rel were equally unable to promote P19 cell differentiation. Our results demonstrate that transcriptional activation by Rel proteins correlates with Rel-induced differentiation of EC cells, and raise the intriguing possibility that Rel proteins may play an important role in early developmental processes.

Animals↗

PubMed1993

Role of calcium ion in induction of apoptosis by etoposide in human leukemia HL-60 cells.

The epipodophyllotoxin derivative etoposide, an inhibitor of DNA topoisomerase II, has been found to induce internucleosomal DNA fragmentation, characteristic of apoptosis. In the present study, we examined the effect of Ca2+ depletion on VP-16-induced endonucleolytic DNA cleavage in HL-60 cells. VP-16-induced internucleosomal DNA fragmentation could not be blocked by the extracellular Ca2+ chelator EGTA. However, an intracellular Ca2+ chelator BAPTA-AM, which was added after treatment with VP-16, abolished both internucleosomal DNA fragmentation and the morphologic features of apoptosis. No significant increase of intracellular Ca2+ was found after VP-16 treatment. We demonstrate for the first time that preexisting intracellular Ca2+ plays an essential role in induction of apoptosis by VP-16 in HL-60 cells.

Apoptosis↗

PubMed1993

PEBP2/PEA2 represents a family of transcription factors homologous to the products of the Drosophila runt gene and the human AML1 gene.

cDNAs representing the alpha subunit of polyomavirus enhancer binding protein 2 (PEBP2; also called PEA2) were isolated. The products of the cDNAs are highly homologous to that of Drosophila segmentation gene runt (run) for an N-proximal 128-amino acid region showing 66% identity. The run homology region encompasses the domain capable of binding to a specific nucleotide sequence motif and of dimerizing with the companion beta subunit. The human AML1 gene related to t(8;21) acute myeloid leukemia also had a run homology region. Together with the beta subunit, which increases the affinity of the alpha subunit to DNA without binding to DNA by itself, PEBP2 represents a newly discovered family of transcription factor. The major species of PEBP2 alpha mRNA was expressed in T-cell lines but not in B-cell lines tested. Evidence indicated that PEBP2 functions as a transcriptional activator and is involved in regulation of T-cell-specific gene expression.

Amino Acid Sequence↗

PubMed1993

Over-expression of p53 protein in human laryngeal carcinoma.

We examined the expression of tumor-suppressor protein p53 in a variety of laryngeal carcinomas from 43 patients (25 primary, 13 metastatic and 5 recurrent cases), 13 normal laryngeal tissues and 7 benign laryngeal nodule biopsy specimens, using the polyclonal antibody CM-1. Previously we have reported a high incidence of ras mutations (51%) and human papillomavirus (HPV) infection (37%) in these laryngeal carcinomas. p53 protein was detected by immunohistochemistry in 65% of laryngeal carcinomas (60% of primary, 69% of metastatic and 80% of recurrent cases). No correlation was found between p53 over-expression and histological grading of the tumors. None of the specimens from normal larynx and laryngeal nodules revealed any detectable level of this protein. Furthermore, 11 (69%) of 16 HPV-positive cases and 17 (77%) of 22 cases with ras mutation showed variable grades of p53 expression. Twelve (71%) of 17 laryngeal carcinomas in current study having both p53 over-expression and ras mutation were moderately or poorly differentiated. Likewise, positivity for these 2 parameters was significantly increased in metastatic tumors (9 of 13 cases, 69%) as compared with primary and recurrent tumors (8 of 30 cases, 27%) (p < 0.01). Our results suggest that multiple factors are involved in this malignancy, and that the simultaneous over-expression of p53 and the presence of ras mutation may be related to the progression stage of laryngeal carcinoma.

Adult↗

PubMed1993

ras gene mutations and HPV infection are common in human laryngeal carcinoma.

To evaluate the role of ras activation and human papillomavirus (HPV) infection in laryngeal carcinoma, we analyzed tumor DNA from 43 cases, including 25 primary laryngeal tumors, 12 lymph-node and one skin metastases, and 5 recurrent laryngeal carcinomas. Thirteen normal laryngeal tissues and 7 benign laryngeal nodule biopsy specimens along with normal tissue surrounding laryngeal carcinoma in 2 cases were also included. The polymerase-chain-reaction technique was used to amplify DNA fragments containing codon 12 and 61 of H-, K- and N-ras, also HPV 16, 18 and 33 DNA, subsequently hybridized with sequence-specific oligonucleotides. DNA samples from 22 patients with laryngeal carcinoma revealed ras mutations (18 in N-ras codon 12, 6 in H-ras codon 61, and 3 in K-ras codon 61). Likewise, HPV DNA was found in 16 cases (HPV 16, 18 and 33 in 3 cases, 14 cases and 1 case respectively). ras mutations were significantly higher in metastatic tumors (10 of 13 cases) than in primary (11 of 25 cases) and recurrent laryngeal carcinomas (1 of 5 cases). HPV DNA was detected in 60% of recurrent, 44% of primary and 15% of metastatic tumors. Only 2 of the 13 normal laryngeal tissues and 1 out of 7 laryngeal nodule specimens were found to contain HPV DNA. These results suggest that ras activation, especially in N-ras codon 12.1 (GGT-->AGT) and HPV infection are 2 important factors in (multistage) laryngeal carcinogenesis. The ras mutation may be associated with metastatic ability of the tumor.

Adult↗

PubMed1993

Molecular cloning and characterization of PEBP2 beta, the heterodimeric partner of a novel Drosophila runt-related DNA binding protein PEBP2 alpha.

Polyomavirus enhancer binding protein, PEBP2 (PEA2), is a heterodimer of two distinct subunits, alpha and beta, of which the former directly binds to DNA and the latter acts auxiliary to enhance the DNA binding. Recent cloning studies has revealed that the alpha subunit is homologous to the products of the Drosophila segmentation gene runt and the human AML1 gene, and that it functions as a major regulator for the T cell-specific gene expression. We have currently cloned cDNAs for the beta subunit. The isolated cDNAs contain three isoforms that are presumed to arise from alternative RNA splicing and encode polypeptides consisting of 187, 182, and 155 amino acids, respectively. These polypeptides neither show any significant homology with known other proteins including the alpha subunit nor have any known DNA-binding and dimerization domains. Thus, PEBP2, as the complex of these subunits, is thought to constitute an entirely novel category of heteromeric transcriptional regulator together with the Runt and AML1 proteins. Gel retardation assays of the cDNA-encoded proteins produced in an in vitro translation system or in Escherichia coli demonstrated that the larger two beta isoforms, but not the smallest one, can dimerize with the alpha subunit. Furthermore, this heterodimerization was shown to cause a marked increase in the intrinsic DNA binding affinity of the alpha subunit.

3T3 Cells↗

PubMed1993

Isolation of PEBP2 alpha B cDNA representing the mouse homolog of human acute myeloid leukemia gene, AML1.

Breakpoints of the t(8;21) chromosome translocation in acute myeloid leukemia are clustered within the human gene, AML1, located on chromosome 21 [Miyoshi, H., Shimizu, K., Maseki, N., Kaneko, Y. & Ohki, M. (1991). Proc. Natl. Acad. Sci. USA, 88, 10431-10434]. The product of AML1 has a region about 130 amino acids long that is highly homologous to the Drosophila segmentation gene runt (runt homology region). The cDNA isolated from mouse fibroblasts encoding the alpha-subunit of polyomavirus enhancer binding protein 2 (PEBP2/PEA2) revealed that it also has a runt homology region (E. Ogawa et al., submitted). In this study, a different cDNA clone presumed to represent the mouse homolog of human AML1 (PEBP2 alpha B) was isolated from a cDNA library derived from B cells. The deduced amino acid sequence of PEBP2 alpha B is 99% identical to that of AML1 for the first 241 residues, including the runt homology region, though their sequences diverge thereafter. On the other hand, PEBP2 alpha B and PEBP2 alpha share only 92% and 82% homologies at the amino acid and nucleotide levels respectively, even for the runt homology region, indicating that these proteins are encoded by distinct genes. While PEBP2 alpha is highly expressed in T-cell lines but not in most of the B-cell lines and functions as an activator of T-cell-specific genes, PEBP2 alpha B is expressed in both types of cells. A possible functional relationship between PEBP2 alpha and PEBP2 alpha B is discussed in relation to leukemogenic potential of AML1.

3T3 Cells↗

PubMed1992

Presence of ras oncogene mutations and human papillomavirus DNA in human prostate carcinomas.

The frequency of H-ras, K-ras, and N-ras mutations and the presence of high-risk human papillomavirus (HPV 16, 18, and 33) DNA were studied in 75 paraffin-embedded specimens obtained from 68 Japanese patients with a variety of prostate carcinomas by using polymerase chain reaction and DNA hybridization with sequence-specific oligonucleotides. Ten specimens each of normal and benign hyperplastic prostatic tissues from the same number of patients were also examined for this analysis. Of 68 carcinoma cases, ras gene mutations were present in 16 cases (24%) and HPV DNAs in 28 cases (41%). Eleven mutations were detected in codon 61 of H-ras, 4 in codon 12 of N-ras, and 2 in codon 61 of K-ras. HPV 16, 18, and 33 DNAs were found in 11, 17, and 5 cases, respectively. Eight of the 16 cases with ras mutation also harbored HPV DNAs. The frequency of ras mutations and the HPV infection increased in patients with advanced stages of the tumor and with the higher Gleason score. There was the predominant presence of H-ras codon 61.2 (CAG-->CTG) mutation and HPV 18 DNA in prostatic carcinomas metastasizing to the bone. None of the normal or benign hyperplastic prostatic specimens contained either ras mutation or HPV DNA. Our results suggest that ras gene mutations and HPV infections are relatively frequent, at least in prostate carcinoma of Japanese patients. These two factors appear to be related to the progression of the tumor. Moreover, H-ras codon 61.2 mutation and HPV 18 infection may have some predictive roles for bone metastasis in prostate carcinoma.

Aged↗

PubMed1992

High frequency of human papillomavirus infection in carcinoma of the urinary bladder.

BACKGROUND AND METHODS: The prevalence of type 6, 11, 16, 18, and 33 human papillomavirus (HPV) was investigated with the polymerase chain reaction (PCR) on formalin-fixed, paraffin wax-embedded material, including 48 neoplastic and 21 normal urinary bladder specimens. The PCR-amplified DNA were analyzed by gel electrophoresis and dot blot and Southern blot hybridization. Some tissues were tested further by nonisotopic in situ hybridization. RESULTS: HPV DNA was detected in 39 (81%) of 48 carcinomas and 7 (33%) of 21 normal urinary bladder specimens. The presence of high-risk HPV (types 16, 18, and 33) was increased significantly in carcinoma cases (62%) as compared with normal specimens (14%) (P less than 0.01). Similarly, multiple HPV infections were significantly higher in carcinoma (60%) than in the normal tissues (5%) (P less than 0.01). The overall and high-risk HPV infections in both neoplastic and normal specimens were distributed almost equally in male and female patients. There was no significant correlation between positive results for HPV and histologic grades of the carcinoma. CONCLUSIONS: These results demonstrate that the urinary bladder in both sexes is another site where infection with the common genital tract HPV may carry a risk of malignant transformation.

Carcinoma↗

PubMed1992

Differential expression of subspecies of polyomavirus and murine leukemia virus enhancer core binding protein, PEBP2, in various hematopoietic cells.

The core sequence of the enhancer of murine leukemia virus (MuLV) long terminal repeat is highly conserved in a large number of MuLV strains and appears to play an essential role when SL3-3 or Moloney strains induce T cell lymphoma in mice. We found by using the electrophoretic mobility shift assay that a polyomavirus enhancer core-binding protein, PEBP2, bound to this core motif of MuLV. We also noted that PEBP2 in several hematopoietic cell lines derived from B lymphocyte, macrophage and myelocyte lineages migrated significantly faster than the authentic PEBP2 detected in NIH3T3 fibroblasts. Interestingly, PEBP2 detected in the cell lines of T lymphocyte lineage appeared to contain both types, which were indistinguishable in electrophoretic mobility from those of NIH3T3 and of B lymphocyte, macrophage and myelocyte lineages. The treatment of the nuclear extract containing PEBP2 with phosphatase generated PEBP3, which is a subcomponent of PEBP2 and retained the same DNA-binding specificity as PEBP2. The altered mobility of hematopoietic cell-derived or T lymphocyte-derived PEBP2 was found to be due to the alteration of the mobility of PEBP3. Based on the distinct mobility of PEBP2/3 of T lymphocytes from those of other hematopoietic cells, we discuss the implication of PEBP2 in MuLV-induced T cell leukemia and T cell-specific gene expression.

3T3 Cells↗

PubMed1991

Identification of eleven single-strand initiation sequences (ssi) for priming of DNA replication in the F, R6K, R100 and ColE2 plasmids.

Based on the ability to complement the poor growth of an M13 phage derivative lacking the complementary strand origin, eleven single-strand initiation sequences (ssi) for DNA replication are identified in the F, R6K, R100 and ColE2 plasmids. Six of them were from F, two from near the gamma and alpha origins (ori) of R6K, two from the vicinity of the basic replicon of R100 and one from near the ori of ColE2. They can be classified into two groups based on the morphology of the plaques and the length of nucleotide (nt) sequences required for ssi activity; one group that gives rise to larger and clearer plaques and can be reduced to nearly 100 nt (seven out of eleven), and another that generates smaller and less clear plaques and requires more than 200 nt for full activity (four out of eleven). Sequence homology is detected among some members from both groups. The possible biological roles of the ssi are discussed.

Bacteriocin Plasmids↗

PubMed1991

Detection of HPV DNA in neoplastic and non-neoplastic cervical specimens from Pakistan and Japan by non-isotopic in situ hybridization.

In order to determine the prevalence and type-specific distribution of human papillomavirus (HPV) in women from Pakistan, a country with a low cervical cancer rate (hospital-based data), and to compare these results with their counter-parts in Japan, we studied 56 non-neoplastic cervical tissues and 162 cervical carcinoma cases from both countries. HPV infection was defined by in situ hybridization in paraffin-embedded tissues using biotinylated HPV 6/11, 16 and 18 probes. The overall positivity rates in non-neoplastic and neoplastic cervical tissues from Pakistan were 33% and 88%, while in those from Japan the rates were 46% and 80%, respectively. High-risk HPVs (16 & 18) were found in 17% of the non-neoplastic specimens and in 69% of cervical carcinoma cases from Pakistan, while Japanese figures in this respect were 19% and 68%, respectively. No correlation was found between the type-specific distribution or prevalence of HPV and the geographic location of the cases examined in the 2 countries. However, in comparison to Japanese women, the incidence of HPV-16-positive cervical carcinoma in Pakistani women decreased significantly (p less than 0.05) in the oldest age group as compared to the youngest age group.

Adenocarcinoma↗

PubMed1988

An initiator protein for plasmid R6K DNA replication. Mutations affecting the copy-number control.

Two kinds of mutations affecting the copy-number control of plasmid R6K were isolated and identified in an initiator pi protein by DNA sequencing. Firstly, a temperature-sensitive replication mutation, ts22, with decreased copy number results in a substitution of threonine to isoleucine at position 138 of the 305-amino-acid pi protein. Secondly, a high-copy-number (cop21) mutant was isolated from this ts mutant and was identified by an alteration of alanine to serine at position 162. This cop21 mutation suppressed the Ts character and was recessive to the wild-type allele in the copy control.

Base Sequence↗

PubMed1985

Plasmid-encoded initiation protein is required for activity at all three origins of plasmid R6K DNA replication in vitro.

DNA replication of plasmid R6K initiates at three unique sites, ori alpha, ori beta, and ori gamma. Replicating DNA molecules of a deletion derivative of R6K were synthesized in an in vitro system containing pi protein fraction from cells carrying a mini-R6K derivative that produced only this initiation protein as an R6K-encoded protein and analyzed by electron miscroscopy. Requirement of pi protein for the activity of all these three replication origins in vitro was verified. Frequencies of initiation at the three origins were almost equal.

DNA Replication↗