Biomedical subjects

Y Kaneko

Publications and source records attributed to Y Kaneko.

At least 109 records · Page 6Linked to original sources

PubMed2000

Identification and characterization of a 500-kb homozygously deleted region at 1p36.2-p36.3 in a neuroblastoma cell line.

Loss of heterozygosity of the distal region of chromosome 1p where tumor suppressor gene(s) might harbor is frequently observed in many human cancers including neuroblastoma (NBL) with MYCN amplification and poor prognosis. We have identified for the first time a homozygously deleted region at the marker D1S244 within the smallest region of overlap at 1p36.2-p36.3 in two NBL cell lines, NB-1 and NB-C201 (MASS-NB-SCH1), although our genotyping has suggested the possibility that both lines are derived from the same origin. The 800-kb PAC contig covering the entire region of homozygous deletion was made and partially sequenced (about 60%). The estimated length of the deleted region was 500 kb. We have, thus far, identified six genes within the region which include three known genes (DFF45, PGD, and CORT) as well as three other genes which have been reported during processing our present project for the last 3(1/2) years (HDNB1/UFD2, KIAA0591F/KIF1B-beta, and PEX14). They include the genes related to apoptosis, glucose metabolism, ubiquitin-proteasome pathway, a neuronal microtubule-associated motor molecule and biogenesis of peroxisome. At least three genes (HDNB1/UFD2, KIAA0591F/KIF1B-beta, and PEX14) were differentially expressed at high levels in favorable and at low levels in unfavorable subsets of primary neuroblastoma. Since the 1p distal region is reported to be imprinted, those differentially expressed genes could be the new members of the candidate NBL suppressor, although RT-PCR-SSCP analysis has demonstrated infrequent mutation of the genes so far identified. Full-sequencing and gene prediction for the region of homozygous deletion would elucidate more detailed structure of this region and might lead to discovery of additional candidate genes. Oncogene (2000) 19, 4302 - 4307

Carrier Proteins↗

PubMed2000

Analysis of the p16INK4, p14ARF, p15, TP53, and MDM2 genes and their prognostic implications in osteosarcoma and Ewing sarcoma.

We examined alterations of the p16INK4, p14ARF, p15, TP53, and MDM2 genes in 30 osteosarcomas and 24 Ewing sarcomas. Among 21 osteosarcomas and 24 Ewing sarcomas, p16INK4, p14ARF, and p15 abnormalities were found in 4 (19%), 2 (9%), and 3 (14%) osteosarcomas, respectively, and in 4 (17%), 3 (13%), and 4 (17%) Ewing sarcomas, respectively. The alterations of p16INK4, p14ARF, and p15 included homozygous deletions spanning all 3 genes, methylation of p16INK4 or p15, and a nonsense mutation of p16INK4, which simultaneously caused a missense mutation of p14ARF. Alterations of TP53 were found in 15 (50%) of 30 osteosarcomas and 1 (3%) of 24 Ewing sarcomas. None of the sarcomas showed MDM2 amplification. While TP53 abnormalities were far more frequent in osteosarcoma than in Ewing sarcoma, alterations of p16INK4, p14ARF, and p15 were present at similar frequencies in the two types of sarcoma. The event-free survival (EFS) was worse in Ewing sarcoma patients with p16INK4 and p14ARF mutation/deletion than in those without the mutation/deletion (P = 0.019), and EFS was worse in osteosarcoma patients with TP53 alterations than in those without TP53 alterations (P = 0.048). The different incidence of TP53 abnormalities in the 2 types of sarcoma may reflect differences of the molecular processes through which the 2 types of tumor develop.

Adolescent↗

PubMed2000

NAK is an IkappaB kinase-activating kinase.

Phosphorylation of IkappaB by the IkappaB kinase (IKK) complex is a critical step leading to IkappaB degradation and activation of transcription factor NF-kappaB. The IKK complex contains two catalytic subunits, IKKalpha and IKKbeta, the latter being indispensable for NF-kappaB activation by pro-inflammatory cytokines. Although IKK is activated by phosphorylation of the IKKbeta activation loop, the physiological IKK kinases that mediate responses to extracellular stimuli remain obscure. Here we describe an IKK-related kinase, named NAK (NF-kappaB-activating kinase), that can activate IKK through direct phosphorylation. NAK induces IkappaB degradation and NF-kappaB activity through IKKbeta. Endogenous NAK is activated by phorbol ester tumour promoters and growth factors, whereas catalytically inactive NAK specifically inhibits activation of NF-kappaB by protein kinase C-epsilon (PKCepsilon). Thus, NAK is an IKK kinase that may mediate IKK and NF-kappaB activation in response to growth factors that stimulate PKCepsilon activity.

Amino Acid Sequence↗

PubMed2000

YHP1 encodes a new homeoprotein that binds to the IME1 promoter in Saccharomyces cerevisiae.

The IME1 gene is essential for initiation of meiosis in the yeast Saccharomyces cerevisiae. Transcription of IME1 is detected under conditions of starvation for nitrogen and glucose, and in the presence of the MATa1 and MATalpha2 gene products. In our previous work, we have shown that there are two elements acting as TUP1-dependent upstream repression sequence (URS) and tup1 mutation-dependent upstream activation sequence (UAS) between nt -915 and -621 of the IME1 promoter under nutritional conditions. The region from -915 to -621 has also been reported to harbour meiotic URS and UAS when a/alpha cells were transferred to sporulation conditions. To identify proteins that are able to bind to the region, we screened a cDNA library fused with the Gal4-activation domain by means of the one-hybrid system. We identified a previously unknown gene (YDR451c), which we designated YHP1, encoding a homeodomain protein of the Drosophila antennapedia type. The region for binding of Yhp1 was delimited to the 28 bp region between nt -702 and -675 of the IME1 promoter in vivo and in vitro, and the 28 bp region harboured a URS activity in a Yhp1-dependent manner under nutrient growth conditions. Although a yhp1 single-disruption mutation did not give rise to a scorable phenotype under nutritional and sporulation conditions, the level of the YHP1 transcript was significantly lower in the cells grown in acetate medium (presporulation medium) and sporulation medium than those grown in glucose medium, and the reduction of YHP1 transcription in acetate medium coincided with an increment of the IME1 transcript. We suggest that the homeoprotein Yhp1 that binds directly to the 28 bp region of the IME1 promoter is a new repressor acting under glucose growth conditions.

Binding Sites↗

PubMed2000

High expression of Survivin, mapped to 17q25, is significantly associated with poor prognostic factors and promotes cell survival in human neuroblastoma.

Survivin (SVV) is a family member of inhibitor of apoptosis proteins (IAPs) and its expression is cell cycle regulated. The gene is mapped to chromosome 17q25, the region of which is frequently gained in advanced stages of neuroblastoma (NBL). However, the role of SVV in NBL is poorly understood. Here we studied the clinical and biological role of SVV in NBL. A 1.9 kb SVV transcript was expressed in all of 9 NBL cell lines at higher levels than those in adult cancer cell lines. In 34 primary NBLs, high levels of SVV expression was significantly associated with age greater than 12 months (two sample t-test: P= 0.0003), advanced stages (P = 0.0136), sporadic tumors (P= 0.0027) and low levels of TrkA expression (P = 0.0030). In NBL cell lines, SVV mRNA expression was dramatically down-regulated in CHP134 and IMR32 cells undergoing apoptosis after treatment with all-trans retinoic acid (RA) or serum deprivation. It was only moderately decreased in cells (SH-SY5Y and CHP901) undergoing RA-induced differentiation. On the other hand, in proliferating NBL cells or RA-treated SK-N-AS line which is refractory to RA, the SVV mRNA remained at steady state levels or rather up-regulated. Furthermore, transfection of SVV into CHP134 cells induced remarkable inhibition of the RA-induced apoptosis. Collectively, our results suggest that high expression of SVV is a strong prognostic indicator for the advanced stage neuroblastomas, and that it could be one of the candidate genes for the 17q gain.

Apoptosis↗

PubMed2000

Oral DNA vaccination promotes mucosal and systemic immune responses to HIV envelope glycoprotein.

In this report, we described induction of HIV envelope (env)-specific systemic and mucosal immune responses by oral vaccination of BALB/c mice with env-encoded plasmid DNA encapsulated in poly(dl-lactide-co-glycolide) (PLG) microparticles. We demonstrated that intragastric administration of the encapsulated plasmid DNA resulted in transduced expression of the env glycoprotein in the intestinal epithelium. Mice immunized orally exhibited env-specific type 1 and cytotoxic T lymphocyte (CTL) responses in spleen and the inductive (Peyer's patches) and effector (lamina propria) mucosal tissues of gut. Oral administration of PLG-encapsulated plasmid DNA encoding gp160 also induced env-specific serum antibodies, and an increased level of IgA directed to gp160 was detected in fecal washes of the immunized mice. In contrast, intramuscular (i.m.) administration of naked or PLG-encapsulated DNA vaccine induced only systemic cellular and humoral responses to the env glycoprotein. Using an HIV env-expressing recombinant vaccinia viral intrarectal murine challenge system, we observed higher resistance to mucosal viral transmission in mice immunized orally than in animals injected i.m. with PLG-encapsulated plasmid DNA encoding gp160. Results of these studies demonstrate the feasibility of using orally delivered PLG microparticles containing plasmid DNA-encoded HIV gp160 for induction of env-specific systemic and mucosal immune responses and protection against recombinant HIV env vaccinia virus challenge.

AIDS Vaccines↗

PubMed2000

Cdk4 activation is dependent on the subunit rearrangement in the complexes.

Although several factors have been implicated in the regulation of Cdk4 activity, little is known regarding the contributions of cyclin-dependent kinase inhibitors (CKIs) in Cdk4 activation in the mid G1 phase. Using a mouse macrophage cell line (Bac1.2F5), we found that most of Cdk4 bound to p15 when cells were in a quiescent state. Following CSF-1 stimulation, Cdk4 bound to cyclin D1 and then to p21, concomitant with the dissociation of p15 from the complexes. The activation of Cdk4 correlated well with p21 binding to the complexes, and the majority of active Cdk4 complexes contained p21. During regeneration of mouse liver after partial hepatectomy, Cdk4 activity coincided precisely with ternary complex formation of cyclin D1/Cdk4/p21. Using the baculovirus expression system, we succeeded in reconstituting a capacity for Cdk4 activation in insect cells, forming an active cyclin D1/Cdk4/p21 ternary complex. Taken together, it is suggested that p21 and cyclin D1 act cooperatively as activators of Cdk4 through the release of CKIs of the INK4 family.

Animals↗

PubMed2000

Augmentation of Valpha14 NKT cell-mediated cytotoxicity by interleukin 4 in an autocrine mechanism resulting in the development of concanavalin A-induced hepatitis.

The administration of concanavalin A (Con A) induces a rapid severe injury of hepatocytes in mice. Although the Con A-induced hepatitis is considered to be an experimental model of human autoimmune hepatitis, the precise cellular and molecular mechanisms that induce hepatocyte injury remain unclear. Here, we demonstrate that Valpha14 NKT cells are required and sufficient for induction of this hepatitis. Moreover, interleukin (IL)-4 produced by Con A-activated Valpha14 NKT cells is found to play a crucial role in disease development by augmenting the cytotoxic activity of Valpha14 NKT cells in an autocrine fashion. Indeed, short-term treatment with IL-4 induces an increase in the expression of granzyme B and Fas ligand (L) in Valpha14 NKT cells. Moreover, Valpha14 NKT cells from either perforin knock-out mice or FasL-mutant gld/gld mice fail to induce hepatitis, and hence perforin-granzyme B and FasL appear to be effector molecules in Con A-induced Valpha14 NKT cell-mediated hepatocyte injury.

Adoptive Transfer↗

PubMed2000

Expression of apoptosis-regulatory genes in epithelial cells in pulmonary fibrosis in mice.

Up-regulation of Fas and Fas ligand and excessive apoptosis of bronchiolar and alveolar epithelial cells were identified in bleomycin-induced pulmonary fibrosis in mice. This study hypothesized that apoptosis-regulatory genes other than Fas-Fas ligand, such as p53, p21 (Waf1/Cip1), bcl-2, bcl-x, and bax, may also participate in epithelial cell apoptosis in this model. The expression of these genes was assessed by reverse transcription polymerase chain reaction (RT-PCR), RT in situ PCR, or immunohistochemistry. The expression of p53 and p21 mRNA was concurrently up-regulated in the alveolar epithelial cells at 1 h to 7 days after intratracheal instillation of bleomycin. The expression of bcl-2 mRNA was weakly up-regulated at 1 h to 14 days, while the expression level of bcl-2 protein was not changed. The expression of bcl-x(L) and bax mRNA was strongly up-regulated at 1 h to 7 days. The expression of bcl-x protein was up-regulated in lymphocytes and macrophages, whereas bax protein was up-regulated in both epithelial and inflammatory cells. It is concluded that epithelial cell apoptosis in this model may also be induced by the up-regulation of p53 and bax and by the imbalance between apoptosis-inducible and -inhibitory genes, in addition to the up-regulation of the Fas-Fas ligand pathway.

Animals↗

PubMed2000

Identification of the homozygously deleted region at chromosome 1p36.2 in human neuroblastoma.

BACKGROUND: We have identified for the first time a homozygously deleted region within the smallest region of overlap at 1p36.2-3 in two neuroblastoma cell lines. PROCEDURE: The 800-kb PAC contig covering the entire homozygously deleted region was made and sequenced. To date, approximately 70% of sequencing has been accomplished, and the estimated length of the deleted region was 500 kb. RESULTS: Currently, we have found six genes within the region, which include three known genes as well as three other genes that have been reported during processing of our present project for the last 3(1/2) years. We report here the results of expression and mutation analyses of those genes. CONCLUSIONS: Full sequencing for the region of homozygous deletion as well as further analyses of the genes mapped within the region may reveal whether or not there is a neuroblastoma suppressor gene as proposed by the Knudson's two-hit hypothesis.

Child, Preschool↗

PubMed2000

Deletion mapping of 14q32 in human neuroblastoma defines an 1,100-kb region of common allelic loss.

BACKGROUND: We analyzed loss of heterozygosity (LOH) in 54 primary neuroblastomas (NBs) using 12 microsatellite markers on 14q32, and found that 31% (17/54) NBs showed LOH. PROCEDURE: The smallest region of overlap (SRO) was identified between D14S62 and D14S987. RESULTS: There was no statistical correlation between LOH and any clinicopathologic features, including age, stage, amplification of MYCN, and ploidy. A sequence-ready bacterial artificial chromosome (BAC) contig was constructed, and the minimum tiling path of six BACs covered the SRO; the physical length of this region was no larger than 1,000 kb. CONCLUSIONS: Our findings support the existence of a putative tumor-related gene on 14q32 for the tumorigenesis of NB.

Alleles↗

PubMed2000

Role of survivin, whose gene is mapped to 17q25, in human neuroblastoma and identification of a novel dominant-negative isoform, survivin-beta/2B.

PROCEDURE: We investigated the expression of survivin (SVV) and its isoform (SVV-beta/2B) during different biological properties in neuroblastoma (NBL). RESULTS: High levels of SVV mRNA expression were significantly associated with advanced stages of NBL, diagnosis at over 1 year of age, low levels of TrkA expression, and sporadic tumors. Expression of a novel isoform, SVV-beta/2B, which had an insertion of 23 amino acids within the unique BIR domain was predominant in some favorable NBLs, while it was low and ubiquitous in most normal and malignant tissues. The SVV expression wasdown-regulated during apoptosis induced by retinoic acid (RA) in CHP134 NBL cells, which was inhibited by forced expression of SVV. In contrast, SVV-beta was constantly expressed during apoptosis. Like SVV,SVV-beta was also highly expressed during G(2)/M in a cell cycle-dependent manner, and was associated with but competed against SVV for binding with polymerized tubulin. CONCLUSION: These data suggest that expression of SVV is a poor prognostic indicator in human NBL, and it promotes growth and survival by regulating the levels of both isoforms.

Chromosome Mapping↗

PubMed2000

Diversity of the HO gene encoding an endonuclease for mating-type conversion in the bottom fermenting yeast Saccharomyces pastorianus.

Two types of HO gene were cloned, sequenced and characterized from the bottom fermenting yeast Saccharomyces pastorianus. The HO gene present on the 1500 kb chromosome was designated Sc-HO (S. cerevisiae-type HO), because the nucleotide sequence of its promoter region and the open reading frame (ORF) was almost identical to that of the S. cerevisiae laboratory strain HO gene (Lab-HO). The other HO gene, designated Lg-HO (Lager-fermenting-yeast specific HO), showed 64% and 83% homology with the promoter and ORF of the Lab-HO at the nucleotide sequence level, respectively, and was located on the 1100 kb chromosome. Analysis of the 4 kb DNA fragment amplified from S. bayanus type strain indicated that the nucleotide sequence of S. bayanus-HO is almost identical to that of the Lg-HO. The SSB1 gene located downstream of the HO gene in S. cerevisiae was also found in the 3' distal region of the Sc-HO, Lg-HO and S. bayanus HO genes. These results showed that the genetic arrangement around the HO loci both of S. pastorianus and S. bayanus is identical to S. cerevisiae. Southern analysis has revealed that Saccharomyces sensu stricto contain four types of HO genes; S. paradoxus-type HO, the Sc-HO, the Lg-HO and S. uvarum-type HO genes. This HO gene diversity provides useful information for the classification of strains belonging to Saccharomyces sensu stricto. The S. pastorianus Sc-HO, Lg-HO and S. bayanus-HO Accession Nos in the DDBJ Nucleotide Sequence Database are AB027449, AB027450 and AB027451, respectively.

Amino Acid Sequence↗

PubMed2000

Mechanism and relevance of ploidy in neuroblastoma.

Neuroblastoma has a broad spectrum of clinical behavior, ranging from spontaneous regression to dissemination and fatality. The heterogeneity that has long puzzled many investigators has been shown by more recent studies to be closely correlated with various clinical and genetic factors. Tumor cell ploidy is one of the factors; diploid and near-triploid neuroblastomas show poor and excellent clinical outcomes, respectively. We offer a hypothesis that explains how the ploidy state of the tumor plays a fundamental role in this heterogeneity, and why various prognostic factors are correlated with each other. This hypothesis may be applicable to tumors other than neuroblastoma.

Humans↗

PubMed2000

Characterization and expression of oxytocin and the oxytocin receptor.

Oxytocin, a nonapeptide hormone and neurotransmitter, is expressed in a variety of tissues, as are its receptors. In vivo, oxytocin acts as a paracrine and/or autocrine mediator of multiple biological effects. These effects are exerted primarily through interactions with G-protein-coupled oxytocin/vasopressin receptors, which, via G(q) and G(i), stimulate phospholipase C-mediated hydrolysis of phosphoinositides. It is generally recognized that, during pregnancy, oxytocin plays a major role in increasing myometrial contractility at term, and that it acts on its cardiac receptor to decrease the cardiac rate and force of contraction. It is, however, doubtful that increased endocrine oxytocin concentration is involved in the onset and progression of normal human labor.

Female↗

PubMed2000

Interaction of nitrous oxide and propofol to reduce hypertensive response to stimulation.

PURPOSE: To evaluate the interaction between nitrous oxide and propofol for the suppression of hypertension following electrical stimulation of the mental nerve in the rabbit. METHODS: Male Japan White rabbits were tracheostomized, cannulated and mechanically ventilated under isoflurane anesthesia. Square wave pulses (5 V, 0.5 msec, 50 Hz for 5 sec) were delivered to the left mental nerve. Animals received nitrous oxide 20, 40, 60 and 80% (Group 1); propofol 200, 400, 600 and 800 microg x kg(-1) min(-1) (Group 2); or combinations of nitrous oxide and propofol at 10 + 100, 20 + 200, 30 + 300 and 40 % + 400 microg x kg(-1) x min(-1) (Group 3). Systolic blood pressure was recorded from immediately before to maximal increase following nerve stimulation. Probit analysis was used to obtain ED(50) values for 50% suppression of blood pressure elevation. Isobolographic analysis was used to evaluate the interaction between nitrous oxide and propofol. RESULTS: ED(50) values are 52.9% for nitrous oxide (Group 1), 464.1 microg x kg(-1) min(-1) for propofol (Group 2), 21.7 % + 217.1 microg x kg(-1) min(-1) for nitrous oxide and propofol combination (Group 3) and 24. 7 % + 247.1 microg x kg(-1) x min(-1) for the theoretically additive combination of nitrous oxide and propofol, respectively. CONCLUSION: The interaction between nitrous oxide and propofol for the suppression of blood pressure elevation following electrical stimulation of the mental nerve is additive.

Anesthetics, Inhalation↗

PubMed2000

Adenosine and amrinone reverse felypressin-induced depression of myocardial tissue oxygen tension in dogs.

PURPOSE: To determine whether continuous infusion of adenosine triphosphate (ATP), nitroglycerin (NTG) or amrinone (AM) would ameliorate the reductions in coronary blood flow (CBF) and myocardial oxygen tension (PmO2) induced by felypressin. METHODS: Seven open-chest dogs were studied under urethane and alpha-chloralose anesthesia. Hemodynamic variables including heart rate (HR), systolic blood pressure, diastolic blood pressure (DBP), mean pulmonary artery pressure, pulmonary capillary wedge pressure, CBF (ultrasound flowmetry), PmO2(polarography) and cardiac output (thermodilution method) were recorded. Felypressin was infused in a loading dose of 6 mIU x kg(-1) for five minutes and then continued at 0.2 mIU x kg(-1) x min(-1). After 30 min felypressin infusion, each agent was administered for 15 min to evaluate hemodynamic changes. Infusions were 100 and 200 microg x kg(-1) x min(-1) for ATP, 2.5 and 5 microg x kg(-1) x min(-1) for NTG, and 10 and 20 microg x kg(-1) x min(-1) for AM. RESULTS: After felypressin DBP increased by 17 +/- 5 (mean +/- SD) %; CBF decreased by 49 +/- 9%; CI decreased by 40 +/- 13%; HR decreased by 29 +/- 11%; PmO2 in the inner layer decreased by 21 +/- 7%. The Cl and CBF returned to baseline afterATP 100 and 200 microg x kg(-1) x min(-1), AM 10 and 20 microg x kg(-1) x min(-1), but not after NTG. The PmO2 in the inner layer returned to the baseline value by any infusion except for NTG 5 microg x kg(-1) min(-1) CONCLUSION: Adenosine and amrinone, but not nitroglycerin reverses the adverse cardiovascular effects of felypressin.

Adenosine↗

PubMed2000

Cloning, sequencing, and functional analysis of H-OLE1 gene encoding delta9-fatty acid desaturase in Hansenula polymorpha.

H-OLE1, a gene encoding delta9-fatty acid desaturase (FAD) in Hansenula polymorpha strain CBS 1976, was isolated by hybridization based upon its homology with the P-OLE1 gene cloned earlier from a related species, Pichia angusta IFO 1475. The sequence of the H-OLE1 gene revealed high structural conservation with delta9-FADs from various organisms. A putative 451-amino acid polypeptide encoded by the gene, like all other delta9-FADs, contained two domains: an N-terminal catalytic domain containing three conserved histidine clusters, and a C-terminal cytochrome b5-like domain which has been suggested to be involved in electron transport in desaturation reactions. The whole H-OLE1 gene complemented a H. polymorpha fad1 mutation leading to a defect in delta9-FAD. However, the unsaturated fatty acid requirement that the Saccharomyces cerevisiae ole1 mutant displays was complemented by only the open reading frame of H-OLE1 driven by S. cerevisiae glyceroaldehyde-3-phosphate dehydrogenase promoter, but not by the intact H-OLE1, suggesting that the H. polymorpha delta9-FAD was compatible with the desaturation system of S. cerevisiae whereas the promoter of the H-OLE1 gene had no activity in heterologous cells. It was shown by Northern hybridization that transcription of the H-OLE1 gene in H. polymorpha was slightly repressed by exogenous delta9-unsaturated fatty acid. An H. polymorpha disruption mutant (deltaH-OLE1) was created by transformation of an fad1/FAD1 diploid with disrupted H-OLE1::S-LEU2 linear DNA. It was shown by genetic and molecular analyses that input DNA was integrated in several copies into the chromosomal target to replace the mutated fad1 allele. Gas chromatography analysis showed identical fatty acid compositions in cells of both fad1 and deltaHOLE1 disruption mutants.

Amino Acid Sequence↗