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Biomedical subjects

Naoki Watanabe

Publications and source records attributed to Naoki Watanabe.

At least 19 recordsLinked to original sources
PubMed2003

A novel aspartic protease gene, ALP56, is up-regulated in human breast cancer independently from the cathepsin D gene.

Tumor cell invasion requires expression of degradative enzymes such as plasminogen activator, collagenase, and cathepsins. Cathepsin D, a lysosomal aspartic protease produced constitutively in human breast cancer cell lines, also has mitogenic activity in breast cancer cells. Additionally, high cathepsin D expression is associated with increased risk of metastasis in patients with node-negative breast cancer. Recently, a novel aspartic protease gene, ALP56 (aspartic-like protease 56kDa), has been identified. To examine possible interrelationships we quantitated ALP56 mRNA and cathepsin D mRNA in breast cancers using reverse transcription polymerase chain reaction. ALP56 mRNA expression was greater in cancers than in noncancerous tissues (p < 0.0001), as was expression of cathepsin D mRNA. ALP56 gene expression was dose-dependently down-regulated in T-47D breast cancer cells treated with estradiol, while cathepsin D was up-regulated. Expression of ALP56 mRNA in estrogen receptor (ER)-positive breast cancers was less than that in ER-negative cancers, and mRNA expression for ALP56 and cathepsin D did not correlate with one another. Thus ALP56 as well as cathepsin D may be a useful target molecule in breast cancer treatment.

Adult↗
PubMed2002

Cryptic t(12;15)(p13;q26) producing the ETV6-NTRK3 fusion gene and no loss of IGF2 imprinting in congenital mesoblastic nephroma with trisomy 11: fluorescence in situ hybridization and IGF2 allelic expression analysis.

In the present fluorescence in situ hybridization (FISH) study of six congenital mesoblastic nephromas (CMNs) using ETV6 and NTRK3 probes as well as a chromosome 15 painting probe, we identified a cryptic reciprocal translocation, t(12;15)(p13;q26), in one tumor, and an insertion, ins(12;15)(p13;q22q26), in another that were not previously identified by cytogenetic analysis. An interphase FISH study with the same probes detected the ETV6-NTRK3 fusion signal in all three cellular or mixed type tumors, but not in all three classical type tumors. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis detected the ETV6-NTRK3 fusion transcript in the three cellular or mixed type tumors, but not in the three classical type tumors. FISH analysis using a chromosome 11-centromere probe detected trisomy or tetrasomy 11 in all three tumors with the ETV6-NTRK3 fusion signal. To clarify whether IGF2, a paternally expressed gene on chromosome 11, has a certain role in the tumorigenic process of CMN through a loss of imprinting (LOI), we studied IGF2 allelic expression. We found no LOI in two cellular or mixed type tumors or in two classical type tumors, and concluded that the role of the LOI of IGF2 is not essential for the development and progression of CMN with or without trisomy 11. Furthermore, we showed no rearrangements of the MLL gene, which is frequently rearranged in acute leukemia with +11 in the three CMN tumors with +11.

Alleles↗
PubMed2002

Induction of heat shock protein 47 synthesis by TGF-beta and IL-1 beta via enhancement of the heat shock element binding activity of heat shock transcription factor 1.

With most immunological reactions, tissue fibrosis, collagen overproduction caused by immune cytokines, is inevitably associated. Among the various immune cytokines, heat shock protein 47 (HSP47) is a procollagen-specific molecular chaperon and is essential for secretion of procollagen from cells. Induction of HSP47 by TGF-beta has been previously reported in rat skeletal myoblasts and mouse osteoblasts, but not in human diploid fibroblasts. As for IL-1beta, its effect on HSP47 has not been elucidated. In the present study, using human embryonic lung fibroblast cells, we first disclosed that both TGF-beta and IL-1beta induced HSP47 synthesis. We then revealed that the binding of the heat shock element (HSE) by heat shock transcription factor 1 (HSF1) was enhanced by both cytokines. We further demonstrated that trimer formation of HSF1, which is essential for its binding to HSE, was induced by these cytokines. The enhancement of HSP47 synthesis and their trimer formation of HSF1 were augmented by using a combination of both cytokines. Collectively, TGF- beta and IL-1beta were found to induce trimer formation of HSF1 which in turn bound to HSE of HSP47, resulting in the enhancement of HSP47 expression. Thus, HSP47 could well be a good candidate for molecular targeting in controlling tissue fibrosis, given that both principal fibrinogenetic cytokines (TGF-beta, IL-1beta) are commonly involved in its induction through HSF1 trimerization.

Cell Line↗
PubMed2002

TCV-116, an angiotensin II type 1 receptor antagonist, reduces hepatic ischemia-reperfusion injury in rats.

BACKGROUND: In Pringle's maneuver during liver surgery and liver transplantation, ischemia-reperfusion (I/R) is an unavoidable process, and protection against hepatic I/R injury is a major unresolved problem. Therefore, various pharmacologic approaches to prevent hepatic I/R injury are currently under trial. In this study, we investigated whether TCV-116, an angiotensin II type 1 receptor antagonist, can reduce this injury. METHODS: The rats were pretreated either with TCV-116 (group 1) or with the vehicle alone (group 2). The rats in group 3 were not pretreated. Thereafter, they were subjected to partial hepatic I/R. RESULTS: After reperfusion, the mean peak plasma concentrations of aspartate aminotransferase, alanine aminotransferase, lactic dehydrogenase, and creatine kinase were lower in group 1 than in groups 2 and 3. The magnitude of hepatic injury was reduced in group 1 compared with that in groups 2 and 3. The mean peak plasma concentrations of tumor necrosis factor-alpha, cytokine-induced neutrophil chemoattractants-1, and interleukin-6 were lower in group 1 than in groups 2 and 3. The number of neutrophils infiltrating the liver was also lower in group 1 than in groups 2 and 3. The mean peak plasma concentration of hepatocyte growth factor (HGF) was higher in group 1 than in groups 2 and 3. CONCLUSIONS: TCV-116 reduced the hepatic I/R injury by inhibiting inflammatory cytokine production and by enhancing HGF production.

Alanine Transaminase↗
PubMed2002

Efficient method for simulating quantum electron dynamics under the time-dependent Kohn-Sham equation.

A numerical scheme for solving the time evolution of wave functions under the time-dependent Kohn-Sham (TDKS) equation has been developed. Since the effective Hamiltonian depends on the wave functions, the wave functions and the effective Hamiltonian should evolve consistently with each other. For this purpose, a self-consistent loop is required at every time step for solving the time evolution numerically, which is computationally expensive. However, in this paper, we develop a different approach, expressing a formal solution of the TDKS equation, and prove that it is possible to solve the TDKS equation efficiently and accurately by means of a simple numerical scheme without the use of any self-consistent loops.

Journal Article↗
PubMed2002

Single-molecule speckle analysis of actin filament turnover in lamellipodia.

Lamellipodia are thin, veil-like extensions at the edge of cells that contain a dynamic array of actin filaments. We describe an approach for analyzing spatial regulation of actin polymerization and depolymerization in vivo in which we tracked single molecules of actin fused to the green fluorescent protein. Polymerization and the lifetime of actin filaments in lamellipodia were measured with high spatial precision. Basal polymerization and depolymerization occurred throughout lamellipodia with largely constant kinetics, and polymerization was promoted within one micron of the lamellipodium tip. Most of the actin filaments in the lamellipodium were generated by polymerization away from the tip.

Actin Cytoskeleton↗
PubMed2002

A new technique for muscle flap closure of the empyema space in complicated chronic bronchopleural fistula. Wedging the causative bronchus with a plug.

OBJECTIVES: It is difficult to close the empyema space once it is opened, especially in cases complicated with a chronic bronchopleural fistula. A muscle flap closure is generally employed to prevent this situation. However, this operation occasionally fails because the space newly recurs around the fistula due to atrophic change occurring in these translocated muscles. The aim of the present new technique was to prevent inspiratory pressure from the inside of the bronchus by bronchial emboli, and help the adhesion between the fistula stump and the muscle flap, even if they have become atrophic and no longer have sufficient volume to fill the entire empyema space. METHODS: We carried out fiberscopic embolism of causative bronchioles followed by muscle flap closure in 4 patients in whom open drainage had already been performed against parapneumonic empyema within the bronchial fistula. The bronchial fistula was plugged from the inside of the bronchus by silicon material, and stainless steel wire was used to connect this plug tightly to the muscle flaps, so that the fistula was sandwiched between them. In all cases, we succeeded in complete closure of the bronchial fistula and empyema space without using the omentum, and there has been no recurrence. CONCLUSION: The presented new technique was beneficial for achieving muscle flap closure of the empyema space with a chronic bronchopleural fistula.

Bronchi↗
PubMed2002

Corrosion by bacteria of concrete in sewerage systems and inhibitory effects of formates on their growth.

Not only sulfur-oxidizing bacteria but also an acidophilic iron-oxidizing bacterium (or bacteria) were found in the corroded concrete from several sewerage systems in Japan. The surface pH of concrete test piece exposed to an atmosphere containing hydrogen sulfide of the concentrations more than 600 ppm in the systems was usually below 2 after a month. This was attributable to ability of the sulfur-oxidizing bacteria to grow in the thin water layer which contained hydrogen sulfide and covered the piece even when the surface pH of concrete was 12-13. When the sulfuroxidizing bacteria grew in the surface of concrete and produced sulfuric acid, the pH of the inner parts of concrete was lowered where the bacteria were hardly found. Probably, sulfuric acid formed by the bacteria in the surface parts penetrated into the inner parts. The different species of sulfur-oxidizing bacteria were found in different sewerage systems. The growth of the sulfur-oxidizing and acidophilic iron-oxidizing bacteria was completely inhibited by formates, especially by calcium formate of concentrations more than 50 mM. Calcium formate can protect concrete in sewerage systems from bacterial corrosion.

Bacteria↗
PubMed2002

Gene expression for suppressors of telomerase activity (telomeric-repeat binding factors) in breast cancer.

Mechanisms regulating telomerase activity and telomere length remain incompletely understood in human breast cancer. We therefore studied gene expression for telomeric-repeat binding factors (TRFs) in relation to telomerase activity, telomere length, and clinicopathologic factors in human breast cancer. Telomerase activity was detected in 65.8% of 38 breast cancers, but none of 16 noncancerous samples. Terminal restriction fragments were longer in noncancerous than in cancerous tissues, but not significantly. Among 8 patients with both cancer and paired noncancerous tissue available for terminal restriction fragments length assay, terminal restriction fragments were shorter in cancers than in paired noncancerous samples in all but one. Significantly more mRNA encoding TRF1 and 2 was detected in noncancerous than in cancer tissues. Additionally, expression of TRF1 and 2 mRNA was significantly higher in cancers without detectable telomerase activity than in cancers showing activity. Expression of these genes tended to show a negative correlation with terminal restriction fragments length, but this was not statistically significant. No correlation was seen between TRF1 or 2 mRNA expression, and clinicopathologic factors except for TRF1 with respect to tumor size and progesterone receptor status. In addition to reactivation of telomerase activity, escape from negative regulation of this activity is needed to maintain telomere length during cell proliferation in breast cancer. Genes encoding telomerase inhibitors might be of value in gene therapy against human breast cancer.

Adenocarcinoma, Mucinous↗
PubMed2002

A role for survivin in radioresistance of pancreatic cancer cells.

Using gene-transduced pancreatic cancer cells, we examined whether survivin expression is directly involved in regulation of radiosensitivity. Ordinarily radiosensitive MIAPaCa-2 cells transduced with wild-type survivin gene (MS cells) proliferated more rapidly than cells transduced with control vector. MS cells were significantly less radiosensitive than control vector-transduced cells. Radiation-induced activity of caspase-3, but not caspase-7, was significantly inhibited in MS cells. On the other hand, transduction of a dominant-negative mutant survivin gene into radioresistant PANC-1 cells augmented radiosensitivity. Further, the radiation-induced increase in caspase-3 activity was enhanced, indicating that survivin function was truly inhibited. These results indicate that survivin expression directly down-regulates radiosensitivity.

Caspase 3↗
PubMed2002

Endogenous reactive oxygen species is an important mediator of miconazole antifungal effect.

We investigated the significance of endogenous reactive oxygen species (ROS) produced by fungi treated with miconazole. ROS production in Candida albicans was measured by a real-time fluorogenic assay. The level of ROS production was increased by miconazole at the MIC (0.125 micro g/ml) and was enhanced further in a dose-dependent manner, with a fourfold increase detected when miconazole was used at 12.5 micro g/ml. This increase in the level of ROS production was completely inhibited by pyrrolidinedithiocarbamate (PDTC), an antioxidant, at 10 micro M. In a colony formation assay, the decrease in cell viability associated with miconazole treatment was significantly prevented by addition of PDTC. Moreover, the level of ROS production by 10 clinical isolates of Candida species was inversely correlated with the miconazole MIC (r = -0.8818; P < 0.01). These results indicate that ROS production is important to the antifungal activity of miconazole.

Antifungal Agents↗
PubMedDate not supplied

Serum interleukin-18 concentrations in patients with inflammatory bowel disease.

Elevated expression of interleukin (IL)-18 mRNA and protein in intestinal mucosa, attributable to activated monocytes and macrophages in that site, has been reported in patients with inflammatory bowel disease (IBD). However, changes in serum IL-18 concentrations in patients with IBD have not been reported. We measured bioactive IL-18 in serum from patients with IBD, using an enzyme-linked immunosorbent assay (ELISA). Mean serum IL-18 concentrations in 5 patients with Crohn disease (CD) were 400 pg/mL, approximately 1.7 times higher than concentrations in 21 control subjects (p < 0.01). However, serum IL-18 was not increased in patients with ulcerative colitis (UC). These results suggest that like other T-helper type 1 (Th1) cytokines IL-18 may play a key pathogenetic role in Th1-mediated disorders, such as CD. Regulation and expression of IL-18 appears to differ between CD and UC, and serum IL-18 may be a useful clinical marker for CD.

Biomarkers↗
PubMedDate not supplied

A gene encoding human gastric signet ring cell carcinoma antigen recognized by HLA-A31-restricted cytotoxic T lymphocytes.

SUMMARY: We previously reported acid-extracted natural antigenic peptide (F4.2 [YSWMDISCWI]) of a gastric signet ring cell carcinoma HST-2 cells, recognized by HLA-A*31012-restricted autologous cytotoxic T lymphocytes, TcHST-2 line. In this study, the full-length cDNA (1101 bp), termed c98, predicting a protein composed of 170 amino acids was obtained. Because TcHST-2 cells could lyse the HLA-A31 antigen (+) allogeneic tumor cells that were introduced with c98 gene, this gene was suggested to possess antigenicity. Beginning at N-terminal 61 amino acid, the N-terminal six amino acid sequence that is completely identical to F4.2 was present in c98; however, a sequence of four amino acids in C-terminal was not found. Nevertheless, this peptide, c98(61-70), seemed to be immunogenic, because cells pulsed with c98(61-70) peptide were lysed in a dose-dependent manner by TcHST-2 cells. The c98 gene was expressed ubiquitously in tumor cells as well as in normal tissues. However, some tumor cells, including HST-2 cells, expressed this antigen in a high content, and such cells were lysed by TcHST-2 cells in the context of HLA-A31 antigen. However, TcHST-2 cells did not lyse cells that expressed lower amounts of c98 than HST-2 cells. These data suggested that c98-gene product and/or c98(61-70) peptides could be used as a candidate for tumor vaccines in cancer immunotherapy.

Amino Acid Sequence↗
PubMedDate not supplied

Survivin mRNA expression in patients with breast cancer.

We measured survivin mRNA expression in breast cancers using a fluorogenically detected reverse transcription-polymerase chain reaction, seeking relationships between expression and clinical and histological variables. The mean relative expression of survivin mRNA was 0.347+/-0.466 in breast cancers and 0.017+/-0.023 in noncancerous breast tissue resected with the tumors. A cut-off value for positivity was set at the mean + SD for expression in the noncancerous tissues; positivity for survivin mRNA expression was 90.2% (37 out of 41 cases) in breast cancers and 23% (3 out of 13) in adjacent noncancerous breast tissues. Expression in tumors varied independently of clinicopathological factors except for lymphatic invasion. As measured by our sensitive detection system, survivin mRNA is a useful diagnostic marker for breast cancer.

Breast Neoplasms↗
PubMedDate not supplied

Decreased gene expression for telomeric-repeat binding factors and TIN2 in malignant hematopoietic cells.

BACKGROUND: Details of mechanisms regulating telomere length are poorly understood in human hematopoietic cells. MATERIALS AND METHODS: Gene expression for TRFs and TIN2 was studied in hematopoietic cell lines, blood or bone marrow cells from acute leukemia and in normal leukocyte fractions. RESULTS: The telomeres were longest in normal leukocytes, shorter in patient samples and still shorter in malignant hematopoietic cell lines. TRF1 mRNA, TRF2 mRNA and TIN2 mRNA in three myeloblastic cell lines and six lymphoblastic cell lines were significantly less abundant than in the corresponding normal cell types. In patients with acute myeloid leukemia, expression of these gene was also less than in normal cells. In additional studies in culture, HL-60 cells with initially high telomerase activity and low expression of TRF mRNA and TIN2 mRNA differentiated into granulocytic and monocytic cells with low telomerase activity and high expression of these mRNAs. CONCLUSION: In hematopoietic carcinogenesis, gene expression for suppressors of telomerase activity, such as TRF and TIN2, is decreased. These genes might hold promise for gene therapy against cancer.

Adolescent↗
PubMedDate not supplied

Relevance of c-erbB2, PLU-1 and survivin mRNA expression to diagnostic assessment of breast cancer.

The positivity rates of mRNA expression in breast cancer of the tumor-related genes for c-erbB2, PLU-1 and survivin are unclear. We quantitatively analyzed tissue samples from 39 breast cancers and non-cancerous parts of the same specimens for the above three mRNAs using a TaqMan reverse transcription-polymerase chain reaction (RT-PCR). Using the mean + 2SD of non-cancerous sample as a cut-off value, the positivity rates of the tumors for c-erbB2, PLU-1 and survivin were 20.5%, 7.7% and 69.2%, respectively. Combining consideration of survivin with c-erbB2 and or PLU-1 increased the positivity ratio (survivin plus either of others, 76.9%; survivin plus both, 79.5%). Analysis by histological type indicated that survivin showed the highest positivity in ductal carcinoma and that survivin and PLU-1 showed the same positivity rate (40.0%) in the five carcinomas classified histologically as either solid-tubular or mucinous. Further, all cases that were positive for PLU-1 were negative for survivin. Survivin mRNA expression appeared more useful as a marker for diagnosis of breast cancer than c-erbB2 or PLU-1. However, PLU-1 appeared to vary independently of survivin, enhancing the usefulness of assays considering both in combination.

Adult↗