Biomedical subjects

K Yata

Publications and source records attributed to K Yata.

At least 19 recordsLinked to original sources

PubMed2004

The SCID-rab model: a novel in vivo system for primary human myeloma demonstrating growth of CD138-expressing malignant cells.

Ethical and scientific concerns regarding the use of human fetal bones in the SCID-hu model of primary human myeloma prompted us to develop a novel system that uses rabbit bones implanted subcutaneously in unconditioned SCID mice. Immunohistochemical analysis of the implanted bone revealed that the majority of bone marrow (BM) microenvironment cells such as blood vessels, osteoclasts and osteoblasts were of rabbit origin. The implanted bones were directly injected with myeloma cells from 28 patients. Successful engraftment of unseparated BM cells from 85% of patients and CD138-selected myeloma plasma cells from 81% of patients led to the production of patients' M-protein isotypes and typical myeloma manifestations (osteolytic bone lesions and angiogenesis of rabbit origin). Myeloma cells grew exclusively in the rabbit bone, but were able to metastasize into another bone at a remote site in the same mouse. Cells from patients with extramedullary disease also grew along the outer surface of the rabbit bones. This demonstrates the ability of SCID-rab model, marked by a nonmyelomatous, nonhuman, and nonfetal microenvironment, to support the growth of CD138-expressing myeloma cells. This system can now be widely used to study the biology of myeloma and its manifestations and to develop novel therapeutic approaches for this disease.

Animals↗

PubMed2004

Expression of protein gene product 9.5 (PGP9.5)/ubiquitin-C-terminal hydrolase 1 (UCHL-1) in human myeloma cells.

The neuron cytoplasmic protein gene product 9.5 (PGP9.5)/ubiquitin-C-terminal hydrolase 1 (UCHL-1) protein is a thiol protease that recognizes and hydrolyzes a peptide bond at the C-terminal of ubiquitin, and is involved in the processing of ubiquitin precursors and ubiquinated proteins. Although this molecule is known as a specific tissue marker for the neuroendocrine system, many reports have indicated that PGP9.5 is a marker for certain tumour types, such as cancer of the lung, colon, and pancreas. The expression of PGP9.5 in myeloma cells was examined. PGP9.5 seemed to be expressed specifically in myeloma cells as compared with other haematological malignant cells. In addition, in myeloma cells subjected to growth-factor starvation, the upregulation of PGP9.5 was observed in association with that of p27(Kip1), a cyclin-dependent-kinase inhibitor, although the upregulation caused by irradiation was milder. In contrast, the hypoxic culture of myeloma cells induced down-regulation of PGP9.5. These results suggested that PGP9.5 may be a good marker for myeloma among haematological malignancies. In addition, it may indicate certain cellular features of myeloma cells, such as sensitivity to proteasome inhibitors.

Biomarkers, Tumor↗

PubMed2003

Essential Bacillus subtilis genes.

To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among approximately 4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were predicted to be essential. The vast majority of essential genes were categorized in relatively few domains of cell metabolism, with about half involved in information processing, one-fifth involved in the synthesis of cell envelope and the determination of cell shape and division, and one-tenth related to cell energetics. Only 4% of essential genes encode unknown functions. Most essential genes are present throughout a wide range of Bacteria, and almost 70% can also be found in Archaea and Eucarya. However, essential genes related to cell envelope, shape, division, and respiration tend to be lost from bacteria with small genomes. Unexpectedly, most genes involved in the Embden-Meyerhof-Parnas pathway are essential. Identification of unknown and unexpected essential genes opens research avenues to better understanding of processes that sustain bacterial life.

Bacillus subtilis↗

PubMed2001

Anti-HER2-antibody enhances irradiation-induced growth inhibition in head and neck carcinoma.

To explore the antiproliferative effects of rhumAbHER2 on head and neck squamous carcinoma cell (HNSCC) lines and breast cancer cell lines (BCCLs) and to evaluate the combined effects with irradiation, 2 human HNSCC lines and 2 BCCLs were exposed to rhumAbHER2 with or without irradiation. The results showed that combined treatment enhanced the growth and colonization inhibitory effects of rhumAbHER2 or irradiation. Interestingly, the apoptotic cell fraction produced by irradiation disappeared on combined treatment. This disappearance was associated with repression of p53 and Bax upregulation induced by irradiation, but conservation of the upregulation of p27. Based on these results, rhumAbHER2 and irradiation may be a new strategy for treating HNSCC and breast cancers. In addition, the upregulation of cyclin-dependent kinase inhibitors by rhumAbHER2 may occur upstream of irradiation-induced p53 upregulation.

Apoptosis↗

PubMed2001

Cell cycle analysis and expression of cell cycle regulator genes in myeloma cells overexpressing cyclin D1.

Among the recently discovered myeloma-specific gene alterations associated with chromosomal translocations, cyclin D1/PRAD1/Bcl-1 overexpression caused by t(11;14)(q13;q32) is considered to be the most frequent in myeloma patients and cell lines, and may be a prognostic factor clinically. To elucidate the cellular biological role of overexpressed cyclin D1 in myeloma cells, we examined the mRNA expression levels of cell cycle regulators including three cyclin Ds, cyclin-dependent kinase inhibitors (CDK-Is) and accelerators. Cyclin D1 overexpression was clearly demonstrated in the lines with abnormal 11q13 and associated with overexpression of S and G2 accelerator genes. The cyclin D1-overexpressing lines tended to have a shortened G1 phase compared with the non-expressing lines. In addition, artificial silencing using antisense oligonucleotides for cyclin D1 suppressed the growth rate of some but not all cyclin D1-overexpressing cells. These results indicate that overexpression of cyclin D1 caused by cytogenetic abnormalities may make cells progress through the cell cycle rapidly, but it seems that other factors such as cyclin D2 and translocation-related genes affect the cell cycle progression in myeloma cells.

Cell Cycle↗

PubMed2001

Novel mode of transcription regulation by SdiA, an Escherichia coli homologue of the quorum-sensing regulator.

SdiA, an Escherichia coli homologue of the quorum-sensing regulator, controls the expression of the ftsQAZ operon for cell division. Transcription of ftsQ is under the control of two promoters, upstream ftsQP2 and downstream ftsQP1, which are separated by 125 bp. SdiA activates transcription from ftsQP2 in vivo. Here, we demonstrate that SdiA facilitates the RNA polymerase binding to ftsQP2 and thereby stimulates transcription from P2. Gel shift and DNase I footprinting assays indicated that SdiA binds to the ftsQP2 promoter region between -51 and -25 with respect to the P2 promoter. Activation of ftsQP2 transcription by SdiA was observed with a mutant RNA polymerase containing a C-terminal domain (CTD)-deleted alpha-subunit (alpha 235) but not with RNA polymerase containing sigma(S) or a CTD-deleted sigma(D) (sigma(D)529). In good agreement with the transcription assay, no protection of P2 was observed with the RNA polymerase holoenzymes, E sigma(S) and E sigma(D)529. These observations together indicate that: (i) SdiA supports the RNA polymerase binding to ftsQP2; and (ii) this recruitment of RNA polymerase by SdiA depends on the presence of intact sigmaCTD. This is in contrast to the well-known mechanism of RNA polymerase recruitment by protein-protein contact between class I factors and alpha CTD. In addition to the P2 activation, SdiA inhibited RNA polymerase binding to the ftsQP1 promoter and thereby repressed transcription from P1. Gel shift assays indicate weak binding of SdiA to the P1 promoter region downstream from -13 (or +112 with respect to P2). Neither alpha CTD nor sigma CTD are required for this inhibition. Thus, the transcription repression of P1 by SdiA may result from its competition with the RNA polymerase in binding to this promoter.

Bacterial Proteins↗

PubMed2001

Expression and in vitro modification of parathyroid hormone-related protein (PTHrP) and PTH/PTHrP-receptor in human myeloma cells.

To elucidate the role of PTHrP in myeloma, we examined the expression levels of PTHrP and its receptor in human myeloma cell lines and clinical specimens from 13 myeloma cases. In vitro modification of PTHrP expression and production induced by TGF-beta and PMA in PTHrP expressing myeloma cell lines was also investigated. PTHrP expression was detected in six out of seven myeloma cell lines with an inverse correlation with the expression of its receptor, and in 10 out of 13 clinical specimens in varying degrees. The PTHrP expression and secretion into culture medium were enhanced by supplemental TGF-beta and PMA. PMA also seemed to affect PTHrP upregulation via TGF-beta activation. The fundamental role of PTHrP in bone lesions and hypercalcemia in myeloma may be important to consider even during the initial phase of the disease and particularly in the progression of bone complications with hypercalcemia.

Aged↗

PubMed2001

Establishment of CD7+ human myeloma sister cell lines, KMS-21-PE and KMS-21-BM, carrying t(11;14) and t(8;14).

Two new human myeloma cell lines were established from pleural effusion and bone marrow malignant cells derived from a single patient, who manifested hyperammonemia associated with multiple myeloma, and these were characterized. Both lines possess t(11;14)(q13;q32) and t(8;14)(q24;q32) reciprocal translocations and overexpress cyclin D1, but not c-myc. Human myeloma lines including these new lines produced and secreted excess ammonia into culture medium more than non-myelomatous hematological cell lines. In addition, these two lines were revealed to have high surface CD7 expression correlated with relatively high mRNA expression by MP-RT-PCR. Among 8 human myeloma lines, half of them revealed significant surface expression of CD7 and a positive correlation between expression levels of protein and message. CD7 message was also detected in surface negative lines. Consequently, there may be posttranslational regulation of the CD7 molecule, whose cellular biological role in expressing cells has not been elucidated.

Adult↗

PubMed2000

Estrogen receptors in human myeloma cells.

It has recently been reported that the human myeloma cell line U266 proceeds to undergo apoptosis after cultivation with the antiestrogen tamoxifen, thus raising the possibility that antiestrogens may be candidates for use in myeloma therapy. To obtain basic information on the effects of antiestrogens on myeloma cells, we investigated the mRNA expression levels of estrogen receptor (ER)-alpha, ER-beta, and coactivators and corepressors in nine human myeloma cell lines and compared them with those of seven human breast cancer cell lines including four ER-positive and three ER-negative lines. The alterations in cell growth and mRNA expression of the target genes of ER or those of cytokines in the myeloma lines by estradiol or antiestrogens (tamoxifen and toremifene) were also investigated. In addition, effects on membrane Fas expression, appearance of apoptosis, and cell cycle perturbation were analyzed. It was revealed that ER-beta and corepressors were dominantly expressed in myeloma cells, and antiestrogens induced growth inhibition through apoptosis mediated by a Fas-related pathway and G1 arrest of the cell cycle in myeloma cell lines.

Antineoplastic Agents, Hormonal↗

PubMed2000

Cellular biological differences between human myeloma cell lines KMS-12-PE and KMS-12-BM established from a single patient.

To clarify cellular biological varieties of myeloma cells, biological differences were analyzed between 2 human myeloma cell lines, KMS-12-PE and KMS-12-BM, derived from pleural effusion and bone marrow, respectively, of a single patient. Although both lines were considered to be derived from the same clone because both had the same chromosomal marker and immunoglobulin H rearrangement, several biological differences were noted. CD11a and CD20 were highly expressed in the KMS-12-BM line, whereas the KMS-12-PE line showed a higher expression of CD7 and CD95/Fas. Although growth was stimulated in KMS-12-BM by interleukin-6 and interferon-alpha, it was inhibited in KMS-12-PE. In addition, apoptosis inhibitors Bcl-2 and Bcl-X(L) were highly expressed in KMS-12-BM cells. Because KMS-12-PE was cultivated 2 months before KMS-12-BM, these differences might be related to their origin (pleural effusion and bone marrow) or the phases of disease progression. However, these biological differences may help clarify myeloma cell biology and lead to improvement in treatment for myeloma patients.

Antigens, Surface↗

PubMed2000

Expression and production of interleukin 10 in human myeloma cell lines.

Recent investigations of the cytokine network surrounding myeloma cells have disclosed the importance of gp130-related cytokines including interleukin (IL)-6 for myeloma cell survival and proliferation, identification of IL-10 as a growth factor for myeloma cells, the close relationship between IL-10 and the receptors for gp130-related cytokines, and the growth enhancement effect of IL-11 and IL-7 on myeloma cells. In this study, IL-10 production was observed in three out of seven human myeloma cell lines examined and five (including three producing lines) out of 10 lines exhibited mRNA expression of IL-10. The IL-10 mRNA expression was also enhanced in approximately one third of primary specimens, whereas the IL-10 receptor (R) expression was not changed compared with that of normal component marrow controls. However, reverse transcription-polymerase chain reaction (RT-PCR) assay of various cytokines and their receptors showed no particular association with IL-10-producing myeloma lines compared with non-producing lines. Supplementing exogenous IL-10 or neutralization of the IL-10 signal by anti-IL-10 monoclonal antibody (mAb) in a culture conditions did not significantly affect myeloma cell growth regardless of expression of IL-10 or its receptor (IL-10R). However, supplement of anti-IL-10 mAb caused upregulation of certain genes such as IL-11, leukaemia inhibitory factor receptor (LIFR) and syndecan-1 in IL-10R-expressing cell lines. These findings indicate that the cytokine network surrounding myeloma cells is complicated and variable. In addition, IL-10 may modify this network and the cellular biological properties of myeloma cells rather than cell proliferation.

Actins↗

PubMed1999

[Aeromonas hydrophila septicemia with necrotizing myofascitis in a patient with hypoplastic leukemia].

A 54-year-old male was admitted to Kawasaki Medical School Hospital with the complaint of fever. His diagnosis of hypoplastic leukemia had been made one year ago. After the admission, cecal mass with pain and high fever were noted. Four days later, he suddenly lost consciousness and died. Aeromonas hydrophila was isolated from blood cultures and also from the myofascitis specimen. Autopsy specimen of the iliopsoas muscle showed necrotizing myofascitis. The specimen obtained from the cecum showed submucosal hemorrhage with edema and these findings were compatible to ischemic colitis. This pathogen is widely distributed in nature, especially in water fields. Therefore, it would be advised to consider the Aeromonas hydrophila as one of the pathological organisms pathognomonic for the septicemia, when one may see febrile and gastrointestinal symptoms in a patient with hematological malignancies.

Aeromonas hydrophila↗

PubMed1999

Expression of fibroblast growth factor and FGF-receptor family genes in human myeloma cells, including lines possessing t(4;14)(q16.3;q32. 3) and FGFR3 translocation.

Recently several chromosomal translocations involved in myeloma cases and myeloma cell lines; i.e., t(11;14)(q13;q32), t('8;14)(q24;q32), t(4;14)(q16.3;q32.3), t(6;14)(p25;q32), and t(14;16)(q32.3;q23), have been identified. These translocations are considered to dysregulate genes which may be concerned with myelomagenesis; i.e., PRAD1/cyclin D1, the c-myc oncogene, FGFR3 (fibroblast growth factor receptor 3), MMSET (multiple myeloma SET domain), MUM1 (multiple myeloma oncogene 1)/IRF4 (interferon regulatory factor 4), and the c-maf oncogene, respectively. However, the cellular biological roles of these genes have not yet been elucidated in myeloma cells. Because two of the seven human myeloma cell lines which were established at Kawasaki Medical School, Okayama, Japan, KMS-11 and KMS-18, have been proven to possess t(4;14)(q16.3;q32.3), we studied the expression levels of the FGFR3 gene in these seven cell lines and 13 primary myeloma specimens. The expression levels of 12 known FGF family genes (FGF-1 to 12) and 4 FGFR genes (FGFR1 to 4) were also examined in seven cell lines. In addition, the growth status of the KMS-11 and KMS-18 lines with FGF-1 or anti-FGF-4 neutralizing monoclonal antibody (MoAb) supplementation was investigated because FGF-1 and 4 are known as the principal ligands for FGFR3. FGFR3 overexpression was observed in both of the cell lines possessing t(4;14)(q16.3;q32.3) and in 3 of 13 case specimens. Anti-FGF-4 neutralizing MoAb caused significant growth inhibition in these two cell lines possessing t(4;14)(q16.3;q32.3). These findings indicate that t(4;14) (q16. 3;q32.3) may provide myeloma cells with a growth advantage via an autocrine mechanism between FGFR3 and FGF-4.

Aged↗

PubMed1999

[Primary splenic lymphoma with t(3;14)(q27;q32) chromosomal abnormality and rearrangement of BCL-6 gene].

Primary splenic lymphoma (PSL) is extremely rare, accounting for less than 1% of all reported cases of extranodal lymphoma. A 62-year-old woman was referred to our hospital because of general fatigue. A heterogenous mass with irregular margins was detected in the spleen by abdominal computed tomographic scan, and Gallium scintigraphy demonstrated abnormal accumulation only in the spleen. Malignant lymphoma was strongly suspected on the basis of histologic findings from an ultrasonically guided needle biopsy. The final diagnosis was established by splenectomy as PSL of diffuse large B-cell type. After 6 courses of CHOP chemotherapy, the patient recovered and has been disease-free more than a year. Chromosomal analysis of her tumor cells detected t(3;14)(q27;q32), an abnormality not reported in cases of PSL to date. The rearrangement of BCL-6 was also observed. We discuss the possibility of BCL-6 involvement in Japanese cases of PSL, with reference to case reports dating back over the past decade.

Chromosomes, Human, Pair 14↗

PubMed1999

[B cell acute lymphocytic leukemia with marked leukocytosis and t(3;15)(q27;q2?2)].

We report on a 16-year-old boy with B cell acute lymphocytic leukemia presenting marked leukocytosis (388,000/microliter) and resistance to multidrug chemotherapy. Karyotypical analysis revealed a novel t(3;15)(q27;q2?2) chromosomal abnormality. Because 3q27 is known to be a locus of the bcl-6 gene, which is frequently involved in B cell malignancies, molecular biological analyses were performed. Although no rearrangement was detected in 5 genes including bcl-6 on 3q27 and 2 genes on 15q2, reverse transcriptase-polymerase chain reaction procedures detected relatively strong mRNA expression of the bcl-6, smrp, dvl3, and tpml genes. These results indicate that immature leukemic cells with CD10 and CD34 positivity and rearrangement of the T cell receptor beta gene may coexist with relatively mature subpopulations that are positive for CD19 and CD20 surface markers, bcl-6 expression, and rearrangement of the gene for immunoglobulin kappa.

Adolescent↗

PubMed1999

[An autopsy case of pulmonary thromboembolism associated with chlorine gas poisoning].

We report a rare case of sudden death of a patient with acute pulmonary thromboembolism associated with chlorine gas poisoning. A 21-year-old man in a water-filtration plant accidentally inhaled highly concentrated chlorine gas. He was immediately brought to a hospital after exposure. On admission, the patient had clouding of consciousness, dyspnea, and deep cyanosis. Arterial blood gas values indicated severe hypoxemia; PaO2 was 35.9 mmHg and PaCO2 was 42.4 mmHg. The clinical course was uneventful and he was satisfactorily recovering. However, ten days after admission he became sick and markedly cyanotic. He lost consciousness and then he went into cardiopulmonary arrest. Despite efforts at resuscitation, he died. An autopsy revealed bilateral pulmonary thromboembolism, although he apparently did not have any risk factor for embolism. The toxicity of chlorine gas may be related to the pulmonary thromboembolism, but the mechanisms leading to his death are unclear.

Accidents, Occupational↗

PubMed1997

Sequence analysis of the groESL-cotA region of the Bacillus subtilis genome, containing the restriction/modification system genes.

We have determined a 35-kb sequence of the groESL-gutR-cotA (45 degrees-52 degrees) region of the Bacillus subtilis genome. In addition to the groESL, gutRB and cotA genes reported previously, we have newly identified 24 ORFs including gutA and fruC genes, encoding glucitol permease and fructokinase, respectively. The inherent restriction/modification system genes, hsdMR and hsdMM, were mapped between groESL and gutRB, and we have identified two open reading frames (ORFs) encoding 5-methylcytosine forming DNA methyl transferase and an operon probably encoding a restriction enzyme complex. The unusual genome structure of few ORFs and lower GC content around the restriction/modification genes strongly suggests that the region originated from a bacteriophage integrated during evolution.

Amino Acid Sequence↗

PubMed1997

Syntheses and antifungal activity of dl-griseofulvin and its congeners. II.

Griseofulvin derivatives, dl-6'-demethyl-6'-ethylgriseofulvin (dl-5) and dl-6'demethyl-6'phenylgriseofulvin (dl-6) were prepared by application of a synthetic method developed by us. Antifungal activity of these derivatives decreased in the order of dl-griseofulvin (dl-1) >> dl-6(inactive). The reaction of these derivatives with ethanethiol gave two types of compounds, 2'-(ethylthio)griseofulvin (15) and 4'-(ethylthio)isogriseofulvin (16). The relationship between the ratios of isolated yield of 15 and 16 and antifungal the activity of griseofulvin derivatives is discussed.

Antifungal Agents↗