Biomedical subjects

Setsuko Kaneko

Publications and source records attributed to Setsuko Kaneko.

9 recordsLinked to original sources

PubMed2007

Regeneration of the esophagus using gastric acellular matrix: an experimental study in a rat model.

Recently, tissue engineering of the autologous esophagus has been thought to provide a promising strategy for esophageal substitution. In this study, gastric acellular matrix (GAM) was used as a scaffold for regeneration of the esophagus in a rat model. Usage of GAM has an advantage that naturally derived extracellular matrix autograft can be prepared less invasively in a clinical setting. Twenty-seven F344 female rats were used as recipients. Patch defects created in the abdominal esophagus were replaced by GAM patch grafts. The rats were sacrificed 1 week to 18 months after implantation. The specimen was examined macroscopically as well as microscopically. 5'-Bromo-2'-deoxyuridine (BrdU) proliferation assay was performed in six rats that were sacrificed 1, 2, and 4 weeks after implantation. Twenty-four rats survived without complications. The graft site did not show esophageal stenosis or dilatation in any rat. Keratinized stratified squamous esophageal mucosa was regenerated in the entire graft 2 weeks after implantation. Regeneration of the muscle layer or lamina muscularis mucosae in the graft site was not observed even 18 months after implantation. Marked incorporation of BrdU was observed only in the mucosal layer but not in the muscle layer. GAM patch graft provided satisfactory mucosal regeneration of the esophagus without stenosis or dilatation, although muscle regeneration was still a future challenge.

Animals↗

PubMed2006

Relationship of DDX1 and NAG gene amplification/overexpression to the prognosis of patients with MYCN-amplified neuroblastoma.

PURPOSE: Amplification of the MYCN gene strongly correlates with advanced stage, rapid tumor progression and poor prognosis in neuroblastoma (NB). Several genes in the MYCN amplicon, including the DEAD box polypeptide 1 (DDX1) gene, and neuroblastoma-amplified gene (NAG gene), have been found to be frequently co-amplified with MYCN in NB. The aim of this study was to clarify the prognostic significance of the co-amplification or overexpression of DDX1 and NAG with MYCN. PROCEDURE: The gene copy numbers and mRNA expression levels of MYCN, DDX1, and NAG in 113 primary NBs were determined by the real-time quantitative polymerase chain reaction or quantitative reverse transcriptase/polymerase chain reaction assay. The relationships between gene co-amplification/overexpression status and stage, age at diagnosis, and overall survival were analyzed. RESULTS: For evaluating the frequency of DDX1 and NAG co-amplification, it proved appropriate to discriminate NBs with <40 copies of MYCN amplification from those with > or =40 copies of MYCN (DDX1, p = 0.00058; NAG, p = 0.0242, chi(2) for independence test). In patients with MYCN-amplified NB aged > or =18 months, those with tumor with enhanced DDX1 expression and low-NAG expression showed a significantly better outcome than those with low-DDX1 expression or enhanced NAG expression (p = 0.0245, log-rank test). None of the gene expression statuses had a significant relation to disease stage or survival for patients <18 months old. No relationship between any gene co-amplification status and disease stage, age at diagnosis, or overall survival was found. CONCLUSIONS: Our findings suggest that there may be a subset of NB in which enhanced DDX1 and low-NAG expression consequent to DDX1 co-amplification without NAG amplification contributes to susceptibility to intensive therapy. A larger study using an age cut-off of 18 months will be required.

Adolescent↗

PubMed2005

Expression profiling using a tumor-specific cDNA microarray predicts the prognosis of intermediate risk neuroblastomas.

To predict the prognosis of neuroblastoma patients and choose a better therapeutic protocol, we developed a cDNA microarray carrying 5340 genes obtained from primary neuroblastomas and examined 136 tumor samples. We made a probabilistic output statistical classifier that provided a high accuracy in prognosis prediction (89% at 5 years) and a highly reliable method to validate it. Kaplan-Meier analysis indicated that the patients in an intermediate group defined by existing markers are divided by microarray into two further groups with 5 year survivals for 36% and 89% of patients (p < 10(-4)), i.e., with unfavorably and favorably predicted neuroblastomas, respectively. According to these results, we developed a gene subset chip for a clinical tool, for which our classifier exhibited 88% prediction accuracy.

Algorithms↗

PubMed2004

Expression of mRNAs for PACAP and its receptor in human neuroblastomas and their relationship to catecholamine synthesis.

PURPOSE: Pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the secretin/glucagon/vasoactive intestinal peptide family, induces the expression of catecholamine-synthesizing enzymes in adrenal medullary cells. In addition, PACAP and its receptor have been detected in human neuroblastoma tissues and cell lines, though it is not yet known whether PACAP enhances the expression of genes encoding catecholamine-synthesizing enzymes. To address this question, we analyzed PACAP, PACAP receptor and tyrosine hydroxylase (TH) mRNAs in neuroblastomas. METHODS: The levels of mRNA for PACAP and vasoactive intestinal peptide (VIP), as well as their receptors and the mRNA for TH were measured by RT-PCR or real-time PCR analysis. RESULTS: VPAC1R mRNA was detected in all of 16 tissues and 3 cell lines that were examined, while VPAC2R mRNA was detected in 5 of 16 (31%) tissue and 2 of 3 cell lines. PAC1R mRNA was detected in 6 out of 16 (38%) tissues and none of 3 cell lines. mRNA expression of PACAP and TH were detected in many tissues (10/16 and 16/16, respectively). However, neither in tissues nor cell lines did PACAP mRNA expression correlate with TH mRNA expression. CONCLUSION: Our findings suggest that PACAP is not involved in the regulation of expression of TH in neuroblastomas.

Base Sequence↗

PubMed2004

Expression of the human telomerase reverse transcriptase in pheochromocytoma and neuroblastoma tissues.

In an effort to clarify the role of telomerase in the pathogenesis of pheochromocytomas and neuroblastomas, and to test whether its component could serve as a marker of malignancy, we measured telomerase reverse transcriptase (TERT) mRNA in 31 human pheochromocytoma tissue samples (5 malignant, 23 benign and 3 suspected malignant) and 16 neuroblastoma tissues (9 unfavorable and 7 favorable). All cases were classified by both the clinical course and histopathological examination. Malignancy was defined as the presence of metastasis and/or extensive local invasion. TERT mRNA was determined by nested PCR and a real-time PCR system (LightCycler). By nested PCR methods, 5 of the 5 malignant pheochromocytoma samples were positive (sensitivity = 100%), and 21 of 23 benign pheochromocytoma samples were negative (specificity = 91%) in pheochromocytomas. Four out of five malignant tumors were positive for either hTERT expression or Ki-67/MIB-1 immunoreactivity. In the neuroblastoma tissues, 9 of the 9 unfavorable samples were positive (sensitivity = 100%), and only 2 of 7 favorable samples were negative (specificity = 29%). We also determined the expression of the hTERT mRNA by real-time PCR to quantitate the mRNA. The mean values of hTERT mRNA by real time PCR in benign and malignant pheochromocytomas were 2 and 26 arbitrary units (AU), respectively. The difference was not significant by the U-test. The mean values of hTERT mRNA in favorable and unfavorable neuroblastoma were 203 and 497 AU, respectively. This difference was also not significant (U-test). N-Myc mRNA expression correlated with the expression of hTERT mRNA in the neuroblastoma samples (r = 0.534, p = 0.0317). Thus, hTERT mRNA might be a potential marker for estimating the malignancy of pheochromocytomas and neuroblastomas.

Adolescent↗

PubMed2004

Expression and alternative splicing pattern of human telomerase reverse transcriptase in human lung cancer cells.

Telomerase activity is generally considered to be necessary for cancer cells to avoid senescence. The expression of human telomerase reverse transcriptase (hTERT) is believed to be a rate-limiting step in telomerase activation. Recently, it has been proposed that the alternative splicing of hTERT is also involved in regulation of telomerase activity. However, the regulatory mechanism of telomerase in cancer cells has not been thoroughly investigated. To clarify it in lung cancer cells, we measured the expression of the hTERT transcript, analyzed its alternative splicing by RT-PCR, and compared it with telomerase activity and telomere length. The expression of the hTERT transcript was positively correlated with telomerase activity in lung cancer cells. Cancer cells with high telomerase activity contained 4 splicing variants of hTERT, and the full-length variant was 31.3-54.2% of the total transcripts. Cells of the TKB-20 cell line, which has extremely low telomerase activity, showed a different splicing pattern of hTERT in addition to low expression. The functional full-length variant was scarcely detected in TKB-20 cells, suggesting that the telomerase activity was repressed by alternative splicing of hTERT. Telomere length was not necessarily correlated with telomerase activity or hTERT expression in lung cancer cells. Cells of the TKB-4 cell line that also showed relatively low telomerase activity (as TKB-20 cells) had long telomeres. In conclusion, hTERT expression is regulated at both the transcriptional and post-transcriptional levels in lung cancer cells, and the alternative splicing of hTERT is involved in the control of telomerase activity.

Alternative Splicing↗

PubMed2003

Tissue-engineered urinary bladder wall using PLGA mesh-collagen hybrid scaffolds: a comparison study of collagen sponge and gel as a scaffold.

PURPOSE: Tissue engineering of the urinary bladder using autologous cells and biodegradable scaffold is a promising method for augmentation. The authors developed 2 hybrid scaffolds by combining poly (DL-lactic-co-glycolic acid; PLGA) mesh for mechanical strength with collagen sponge or gel suitable for cell seeding. The aim of this study was to compare collagen as a scaffold between collagen sponge and gel and to construct a tissue-engineered urinary bladder wall utilizing these hybrid scaffolds. METHODS: The PLGA mesh-collagen hybrid scaffolds were prepared by introducing collagen sponge or gel into the PLGA knitted mesh. Urothelial and smooth muscle cells were obtained from porcine urinary bladder wall and were cultured in their respective media. The cells were seeded on these hybrid scaffolds. These constructs were analyzed morphologically and immunohistochemically. RESULTS: The urothelial layer was generated 3 dimensionally by culturing urothelial cells with PLGA mesh and collagen sponge. The smooth muscle layer was constructed by culturing smooth muscle cells with PLGA mesh and collagen gel. And a novel tissue-engineered urinary bladder wall was constructed laminating the urothelial and smooth muscle layers. CONCLUSIONS: Ex vivo construction of urinary bladder wall using hybrid scaffolds prepared by combining PLGA mesh with collagen sponge or gel was successful. This tissue-engineered urinary bladder wall allows easy handling and may become a promising tool for bladder augmentation.

Absorbable Implants↗

PubMed2003

Continuous versus intermittent administration of human endostatin in xenografted human neuroblastoma.

PURPOSE: The authors examined whether recombinant human endostatin (rhEndostatin), an antiangiogenic agent, is effective against a human neuroblastoma cell line (designated TNB9) using a human neuroblastoma xenograft model and investigated whether continuous infusion is more effective than intermittent administration. METHODS: In the first experiment, when tumors on the back of nude mice reached a weight of 90 to 95 mg, rhEndostatin, 10 mg/kg/d mouse weight, was administered subcutaneously to the mice (n = 5) every day for 10 consecutive days. In the second experiment, the same daily dose of rhEndostatin was administered continuously to the TNB9-bearing mice (n = 6) via subcutaneous infusion pumps for 3 consecutive days with total dose being 30% of that in the first experiment. Nestin and factor VIII expression levels were studied immunohistochemically to elucidate whether histologic evidence of the effects of rhEndostatin was present on day 4 in the second experiment. RESULTS: In the first experiment, relative tumor weight in treated mice (n = 5) was significantly less than that in controls (n = 12) on day 2 only after treatment initiation (P <.05). The maximum inhibition rate (MIR) of TNB9 xenograft growth by rhEndostatin was 46.4%, indicating lack of efficacy. In the second experiment, the effects of rhEndostatin were much more marked than those in the first experiment, with an MIR of 60.7%. The mean relative tumor weight in the treated group (n = 6) in the second experiment was significantly less than that in controls (n = 10) on days 2, 4, and 6 (P <.01) as well as on days 8 and 10 (P <.05). Nestin staining in the endothelium of control tumors (n = 2) was marked, whereas it showed a loss of fibrillar structure in rhEndostatin-treated tumors (n = 2). The number of vessels immunostained with antifactor VIII antibody was markedly reduced in tumors (n = 2) from rhEndostatin-treated mice compared with that in tumors from control animals (n = 2). CONCLUSIONS: Continuous administration of rhEndostatin resulted in more significant tumor regression than intermittent administration of the agent in the same model. This indicates that rhEndostatin, if administered in continuous fashion, could become an effective agent for treating patients with neuroblastoma in the future.

Abdominal Neoplasms↗

PubMed2002

Cooperative interaction of EWS with CREB-binding protein selectively activates hepatocyte nuclear factor 4-mediated transcription.

The EWS gene when fused to transcription factors such as the ETS family ATF-1, Wilms' tumor-1, and nuclear orphan receptors upon chromosomal translocation is thought to contribute the development of Ewing sarcoma and several malignant tumors. Although EWS is predicted to be an RNA-binding protein, an inherent EWS nuclear function has not yet been elucidated. In this study, we found that EWS associates with a transcriptional co-activator CREB-binding protein (CBP) and the hypophosphorylated RNA polymerase II, which are included preferentially in the transcription preinitiation complex. These interactions suggest the potential involvement of EWS in gene transcription, leading to the hypothesis that EWS may function as a co-activator of CBP-dependent transcription factors. Based on this hypothesis, we investigated the effect of EWS on the activation of nuclear receptors that are activated by CBP. Of nuclear receptors examined, hepatocyte nuclear factor 4-dependent transcription was selectively enhanced by EWS but not by an EWS mutant defective for CBP binding. These results suggest that EWS as a co-activator requires CBP for hepatocyte nuclear factor 4-mediated transcriptional activation.

Basic Helix-Loop-Helix Leucine Zipper Transcriptio↗