Biomedical subjects

N Seki

Publications and source records attributed to N Seki.

At least 109 records · Page 6Linked to original sources

PubMed1999

Vascular endothelial growth factor is implicated in early invasion in cervical cancer.

The association between the expression of vascular endothelial growth factor (VEGF) and clinicopathological factors has scarcely been examined in cervical cancer. This study examines the level of VEGF messenger RNA (mRNA) expression in invasive cervical cancer and its association with clinicopathological features including microvessel density. The level of VEGF mRNA was assessed by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) using beta-actin as an internal control in 66 patients with stages Ia-IVb invasive cervical cancer. In 42 patients who underwent surgery, the microvessel count was also assessed by immunostaining for factor VIII-related antigen in the most neovascularised area of the specimen. The highest level of VEGF mRNA expression was observed in early invasive cervical cancers. Except for stage IVb, the stage of the disease inversely correlated with the level of VEGF mRNA (P < 0.05). There was no significant difference in the level of VEGF mRNA with respect to histological cell types. 38 patients with stages Ib-IIb cervical cancer underwent radical hysterectomy and pelvic lymphadenectomy. There was no significant difference in the level of VEGF mRNA with respect to lymph node metastasis, depth of stromal invasion, tumour size, parametrial involvement or vaginal involvement among these patients. A significant relationship was found between the microvessel density and the level of VEGF mRNA (P < 0.01). These findings provide evidence that the expression of VEGF is involved in the promotion of angiogenesis in cervical cancer and plays an important role in early invasion.

Endothelial Growth Factors↗

PubMed1999

Polymorphisms in the 5'-flanking region of tumor necrosis factor-alpha gene in patients with rheumatoid arthritis.

Polymorphisms in the 5'-flanking promoter/enhancer region of the tumor necrosis factor (TNF)-a gene were examined to study the genetic background of rheumatoid arthritis (RA). Four variant alleles, -1,031C/ -863A, -1,031C/-238A, -857T and -308A, were identified and examined in 387 RA patients and 575 healthy Japanese controls. The frequency of the -857T allele in RA patients was significantly higher than that in the controls. However, the HLA-DRB1 analysis in the same subjects showed that the DRB1*0405 allele, which is in linkage disequilibrium with the -857T, was more strongly associated with the disease susceptibility than the -857T allele. These results suggest that the susceptible gene to RA is more closely linked to the HLA-DRB1 locus than to the TNF-alpha locus.

5' Untranslated Regions↗

PubMed1999

An analysis of risk factors for upper urinary tract deterioration in patients with myelodysplasia.

OBJECTIVE: To identify the risk factors for upper urinary tract deterioration in a retrospective study of patients with myelodysplasia. PATIENTS AND METHODS: The medical history, radiographic studies and urodynamic results from 39 children with myelodysplasia who were treated at our hospital were reviewed retrospectively to obtain more accurate data in the prognosis of such patients. The upper urinary tracts were assessed by cysto-urethrography and excretory urography to determine the incidence of vesico-ureteric reflux (VUR) and hydronephrosis. The relationships between the urodynamic variables, including vesical compliance, detrusor hyper-reflexia, detrusor-sphincter dyssynergia (DSD) and the maximum urethral closing pressure (MUCP) to such upper tract deterioration were evaluated using both univariate and multiple logistic regression analysis. RESULTS: The univariate analysis showed low vesical compliance, a high level of MUCP and the presence of DSD to be significant factors for the incidence of VUR. Low vesical compliance and a high level of MUCP also correlated with the incidence of hydronephrosis. The multivariate analysis showed a significant relationship between urodynamic values and upper urinary tract deterioration. The incidence of VUR was strongly correlated with a high MUCP and the presence of DSD. A high MUCP was also a significant factor in the incidence of hydronephrosis. CONCLUSION: Urodynamic results associated directly with the abnormal function of urethral control are significantly correlated with the cause of upper tract deterioration in patients with myelodysplasia.

Adolescent↗

PubMed1999

Polymorphism of the 5'-flanking region of the tumor necrosis factor (TNF)-alpha gene and susceptibility to human T-cell lymphotropic virus type I (HTLV-I) uveitis.

The genetic background of human T-cell lymphotropic virus type I (HTLV-I) uveitis (HU) was investigated by studying the distribution of 5 polymorphisms of the 5'-flanking promoter/enhancer region of the tumor necrosis factor (TNF)-alpha gene in patients with HU, together with patients with adult T-cell leukemia (ATL), asymptomatic HTLV-I carriers, and healthy controls. The frequencies of the -1,031C allele (T-->C transition at position -1,031) and -863A allele (C-->A transition at position -863) in the HU patients, but neither in the ATL patients nor in the carriers, were significantly higher than those in the controls. The -1,031C and -863A alleles, in the absence of the HLA B61 or the DRB1*0901 allele which is in linkage disequilibrium with these alleles, were associated with increased susceptibility to HU. These results suggest that the -1,031C and -863A alleles might be genetic risk factors for HU.

Adult↗

PubMed1999

Angiogenesis and platelet-derived endothelial cell growth factor/thymidine phosphorylase expression in cervical cancer.

The object of this study was to clarify the association of platelet-derived endothelial cell growth factor (PD-ECGF)/thymidine phosphorylase (dThdPase), separately assessed in cancer cells and in stroma cells, with clinicopathological factors including tumor angiogenesis and prognosis in cervical cancer. The expression of PD-ECGF was evaluated by immunohistochemical staining in 92 patients with stage Ib-II cervical cancer. The microvessel count was assessed by immunostaining for factor VIII-related antigen in the most neovascularized area. Microvessel count was significantly higher in tumors with non-squamous cell carcinoma. PD-ECGF expression in cancer cells was significantly higher in tumors with pelvic node metastasis and squamous cell carcinoma. Immunopositivity for PD-ECGF in stroma cells was significantly higher in tumors with large size and deep stromal invasion. The microvessel counts in cases with positive PD-ECGF expression in stroma cells were significantly higher than those in cases with negative PD-ECGF expression in stroma cells (p=0.048). Disease-free survival and overall survival were significantly worse in patients with deep stromal invasion, parametrial involvement, vaginal involvement, lymph-vascular space involvement, pelvic lymph node metastasis and high microvessel count. A multivariate analysis using Cox's proportional hazard model showed that high microvessel count independently predicted disease-free and overall survival. The expression of PD-ECGF in stroma cells may play a crucial role in the promotion of angiogenesis and tumor angiogenesis can be used as a useful prognostic marker for cervical cancer.

Adult↗

PubMed1999

Angiogenesis and platelet-derived endothelial cell growth factor/thymidine phosphorylase expression in endometrial cancer.

The object of this study was to clarify the association of angiogenic factor, platelet-derived endothelial cell growth factor (PD-ECGF)/thymidine phosphorylase (dThdPase) with clinicopathological factors including tumor angiogenesis and patient outcome in endometrial cancer. There was no correlation between the expression of PD-ECGF in cancer cells and any of the clinicopathological variables. Immunopositivity for PD-ECGF in stroma cells was significantly higher in poorly differentiated adenocarcinomas. The microvessel counts correlated with PD-ECGF positive stroma cells (p<0.0001). Disease-free survival was significantly worse in patients with marked PD-ECGF expression in stromal cells and high microvessel count. A multivariate analysis using Cox's proportional hazard model showed that high microvessel counts independently predicted disease-free survival as well as stage and myometrial invasion. The expression of PD-ECGF in stroma cells may play a crucial role in the promotion of angiogenesis. Tumor angiogenesis can be used to predict prognosis in patients with endometrial cancer.

Adenocarcinoma↗

PubMed1999

[Analysis of actual coverage of the immunization program in Niigata Prefecture and development of a simple estimation of its coverage].

OBJECTIVE: We investigated measles immunization coverage and the actual situation of immunization in Niigata Pref. METHOD: We distributed questionnaires to all parents of pediatric outpatients who went to hospitals and clinics in Niigata Pref. from January 20 to 31. In the questionnaire, we asked parents about the measles immunization status of not only patients but also their sisters and brothers in each household, reasons for their immunization failure, and sources of information on immunization. We were able to collect 4,840 questionnaires from the parents who lived in Niigata Pref. and analyzable data obtained from 9,783 children. Furthermore we compared these with data from official annual reports of public health centers in Niigata Pref. RESULT: Our survey showed that around 90% of the children who had been born since 1979 to 1993 had received measles vaccine, while the official annual reports indicated low immunization coverage (around 70%). The age at which children received measles vaccine was one year old (38.2% of the vaccinated) and two years old (37.5%), and finally 93.6% of children were immunized by three years old. The primary reason for failure to receive immunization was that he or she was infected with measles before immunization (30.4%). Around 53% of these were infected with measles by 2 years old. With regard to sources of information on immunization, public announcements and letters were the greatest sources, whereas the contribution of doctors and paramedical staffs which was expected to be the main providers of the information to parents was quite low. CONCLUSIONS: 1) It was shown that there was a difference of measles immunization coverage between our results (90%) and the official record (70%), indicating that the current coverage survey method does not reflect the actual situation of immunization. Since more than 90% of children were immunized by three years old, we recommend that measles immunization coverage should be surveyed through interviews and data in maternity record book at the health examination for three year-old children which is operated by the government and has good attendance. 2) More than 50% of children who were infected with measles before immunization were infected by two years old, suggesting further promotion of measles immunization before two years old. 3) The main source of information on immunization was public announcements and publications. Further participation of doctors and paramedical staffs in disseminating information and providing education activities is desired.

Actuarial Analysis↗

PubMed1998

p73, a gene related to p53, is not mutated in esophageal carcinomas.

A novel gene, termed p73, encodes a protein with a significant homology to p53 and has been mapped at chromosome 1p36.3, which is a locus of multiple suppressor genes for tumors including neuroblastoma and other cancers. Since the 1p36 locus is reported to be deleted and p53 is frequently mutated in esophageal carcinomas, we examined loss of heterozygosity (LOH) and mutation of the p73 gene in 48 untreated esophageal tumors, as well as mRNA expression in 8 tumors. We screened the P1 genomic library to obtain a P1 clone containing the p73 gene and found a polymorphic short tandem CT repeat site at intron 9. Intragenic sequences for 14 PCR primer sets and a primer pair flanking the repeat were also determined for the analysis of PCR single-strand conformation polymorphism (SSCP) and LOH studies, respectively. Expression of p73 mRNA was detectable but at low levels in all 8 tumor tissues by reverse transcriptase PCR. We did not find any type of mutation other than polymorphisms in the 48 esophageal carcinomas, though aberration of the p53 gene on the PCR-SSCP gels was observed in 15 of 38 (39%) tumors of the same set. In addition, LOH for p73 was found in only 2 of 25 (8%) tumors. These results suggest that, at least in esophageal carcinomas, allelic loss or mutation of p73 may not be a main genetic event for the tumorigenesis as it is with p53.

Adenocarcinoma↗

PubMed1998

NOLP: identification of a novel human nucleolar protein and determination of sequence requirements for its nucleolar localization.

This study reports cDNA isolation and partial characterization of a novel human nucleolar protein isolated by "nuclear transportation trap" described previously. The cDNA encodes a putative polypeptide of 524 amino acids with a short Escherichia coli DNA helicase homologous region, an acid-rich domain, three potential base-rich nuclear localization signals (NLSs), a serine-rich domain, and a deduced coiled-coil domain. The protein has no known prominent similarities with any other protein in the protein databases. Tissue distribution analysis demonstrated a predominant expression in brain and testis. To determine the sequence requirements for nucleolar targeting, a set of deletion constructs with a fluorescent tag were transiently expressed in COS-7 cells. We revealed that a region of 30 amino acids (position 342-371), which overlaps the first and second NLS, is sufficient for nucleolar localization. Furthermore, the adjacent region of 30 amino acids (position 372-401), which contains the third NLS, is sufficient for nuclear localization. These results suggest that this novel nucleolar protein has at least two distinct domains for directing to different subnuclear destinations.

Amino Acid Sequence↗

PubMed1998

Characterization of functional domains of an embryonic stem cell coactivator UTF1 which are conserved and essential for potentiation of ATF-2 activity.

We have recently cloned a cDNA encoding an embryonic stem cell transcriptional coactivator termed UTF1 from the mouse F9 teratocarcinoma cell line (Okuda, A., Fukushima, A., Nishimoto, M., Orimo, A., Yamagishi, T., Nabeshima, Y., Kuro-o, M., Nabeshima, Y., Boon, K., Keaveney, M., Stunnenberg, H.G., and Muramatsu, M. (1998) EMBO J. 17, 2019-2032). Here we have cloned a cDNA for human UTF1 and identified two highly conserved domains termed conserved domain (CD)1 and CD2. Human UTF1, like that of mouse, binds to ATF-2 and the mutagenesis analyses reveal that the leucine zipper motif within the CD2 of the UTF1 and metal binding motif of ATF-2 are involved in this interaction. The factor also binds to TATA-binding protein containing complex. By means of immunoprecipitation analysis, we mapped two domains which are independently able to bind to the complex. Importantly, both domains are located within the conserved domains (one in CD1 and the other in CD2). Furthermore, transient transfection analyses point out the importance of these domains for activating ATF-2. Thus, these results suggest that these two conserved domains identified here play important roles in activating specific transcription at least in part by supporting physical interaction between the upstream factor, ATF-2, and basal transcription machinery.

Activating Transcription Factor 2↗

PubMed1998

Synthesis and effects of novel thiazole derivatives against thrombocytopenia.

5-(2-Pyridylsulfonyl)-2-thiazolamine (2) was effective both in mitomycin C (MMC)-induced thrombocytopenia and in an animal model of idiopathic thrombocytopenic purpura (ITP). It also suppressed the increase of autoantibodies against platelets in the ITP model and showed no blood toxicity. Chemical modification of 2 led to the discovery of more potent compounds against MMC-induced thrombocytopenia.

Animals↗

PubMed1998

A second p53-related protein, p73L, with high homology to p73.

The p53 protein, which regulates the rate of cell division and death, is the most frequently mutated tumor suppressor to be identified so far in human cancers. Recently, a gene with significant homology to p53, termed p73, has been identified in a chromosomal region that is implicated in the molecular pathogenesis of neuroblastoma. We have cloned a second human p53-related gene, termed p73L, which shows strong amino-acid similarity to p73. The p73L gene is mapped to human chromosome 3q27-28 using in situ hybridization technique. p73L encodes a protein of 586 amino acids and its putative DNA binding domain (DBD) has high identities to those of p53 (60.6%) and to p73 (87.8%). Northern blot analysis, which demonstrated that the expression profiles of p73L and p73 mRNAs are distinct in some tissues, implies that p73 and p73L may have separate, distinct roles in different tissues.

Amino Acid Sequence↗

PubMed1998

Human ULK1, a novel serine/threonine kinase related to UNC-51 kinase of Caenorhabditis elegans: cDNA cloning, expression, and chromosomal assignment.

The unc-51 gene, isolated from mutants of Caenorhabditis elegans exhibiting abnormal axonal extension and growth, encodes a novel serine/threonine kinase (K. Ogura, et al., 1994, Genes Dev. 8: 2389-2400). Here we report the molecular cloning and characterization of the human homologue of UNC-51, designated ULK1, for UNC-51 (C. elegans)-like kinase 1. Sequence analysis of the human ULK1 cDNA showed that an open reading frame is composed of 1050 amino acids with a calculated MW of 112.6 kDa and a pI of 8.80. Homology search analysis showed that ULK1 has 41% overall similarity to UNC-51 and 29% similarity to Apg1p of Saccharomyces cerevisiae. Phylogenetic analysis of ULK1, UNC-51, and Apglp suggested that they constitute a novel subfamily of serine/threonine kinases. Southern blot analyses suggested that the ULK1 gene spans 30-40 kb in the human genome as a single-copy gene. Zoo blot analysis indicated that ULK1 kinase is conserved among vertebrates including mammals, birds, reptiles, amphibians, and fish. Northern blot analysis revealed that ULK1 is ubiquitously expressed in adult human tissues such as skeletal muscle, heart, pancreas, brain, placenta, liver, kidney, and lung, whereas UNC-51 is specifically detected in the nervous system of C. elegans. Both FISH and RH mapping confirmed the regional localization of ULK1 to human chromosome 12q24.3.

Amino Acid Sequence↗

PubMed1998

Identification of high-molecular-weight proteins with multiple EGF-like motifs by motif-trap screening.

To identify large proteins with an EGF-like-motif in a systematic manner, we developed a computer-assisted method called motif-trap screening. The method exploits 5'-end single-pass sequence data obtained from a pool of cDNAs whose sizes exceed 5 kb. Using this screening procedure, we were able to identify five known and nine new genes for proteins with multiple EGF-like-motifs from 8000 redundant human brain cDNA clones. These new genes were found to encode a novel mammalian homologue of Drosophila fat protein, two seven-transmembrane proteins containing multiple cadherin and EGF-like motifs, two mammalian homologues of Drosophila slit protein, an unidentified LDL receptor-like protein, and three totally uncharacterized proteins. The organization of the domains in the proteins, together with their expression profiles and fine chromosomal locations, has indicated their biological significance, demonstrating that motif-trap screening is a powerful tool for the discovery of new genes that have been difficult to identify by conventional methods.

Amino Acid Sequence↗

PubMed1998

Glial cell line-derived neurotrophic factor/neurturin-induced differentiation and its enhancement by retinoic acid in primary human neuroblastomas expressing c-Ret, GFR alpha-1, and GFR alpha-2.

Neuroblastomas often undergo spontaneous differentiation and/or regression in vivo, which is at least partly regulated by the signals through neurotrophins and their receptors. Recently, glial cell line-derived neurotrophic factor (GDNF) and a second family member, neurturin (NTN), have been found to mediate their signals by binding to a heterotetrameric complex of c-Ret tyrosine kinase receptors and glycosylphosphatidylinositol-linked proteins, GFR alpha-1 (GDNFR-alpha) or GFR alpha-2 (TrnR2/GDNFR-beta/NTNR-alpha/RETL2). Here, we studied the effect of GDNF and NTN on human neuroblastomas in the short-term primary culture system, as well as the expression of c-Ret, GFR alpha-1, GFR alpha-2, GDNF, and NTN. GDNF (1-100 ng/ml) induced morphological differentiation in 34 of 38 primary neuroblastomas and an accompanying increase in c-Fos induction. These effects were markedly enhanced by treatment with 5 microM all-trans-retinoic acid. Although GDNF alone induced a rather weak differentiation independent of the disease stages, the enhancement of neurite outgrowth induced by treatment with both GDNF and all-trans-retinoic acid was significantly correlated with younger age (less than 1 year; P = 0.0039), non-stage 4 diseases (P = 0.0023), a single copy of N-myc (P = 0.027), and high levels of TRK-A expression (P = 0.0062). To examine the expression levels of GFR alpha-1, we cloned a short form of the human GFR alpha-1 gene with a 15-bp deletion by screening a human adult substantia nigra cDNA library. Many primary neuroblastomas expressed c-Ret, GFR alpha-1, and GFR alpha-2 as well as their ligands, GDNF and NTN, suggesting the presence of a paracrine or autocrine signaling system within the tumor tissue. The effect of NTN on primary culture cells of neuroblastoma was similar to that of GDNF. These imply that the GDNF(NTN)/c-Ret/GFR alpha-1(GFR alpha-2) signaling may have an important role in regulating the growth, differentiation, and cell death of neuroblastomas.

Antineoplastic Agents↗

PubMed1998

Cloning, expression analysis, and chromosomal localization of BH-protocadherin (PCDH7), a novel member of the cadherin superfamily.

We have identified a novel member of the cadherin superfamily. Among the members of the superfamily, this protein exhibited the highest overall homology with protocadherin-1 (46-49% identity). Its mRNA was predominantly expressed in the brain and heart. Hence, we named the gene BH-protocadherin (BH-Pcdh) (HGMW-approved symbol PCDH7). BH-Pcdh has an extracellular domain consisting of seven repeats of the cadherin motif (EC 1 to 7). EC2 of BH-Pcdh is unique in having a 55-amino-acid insertion in the middle of the motif. There are three isoforms of BH-Pcdh, denoted -a, -b, and -c, which have different cytoplasmic tails and a 47-amino-acid deletion in the EC2-3 region of BH-Pcdh-c. While only a 9.0-kb message was detected in normal tissues, 4.5- and 9.0-kb mRNA species were seen in the human lung carcinoma cell line A549. Furthermore, only the 4.5-kb mRNA was detected in HeLa cell S3 and human gastric cancer cell lines MKN28 and KATO-III. Southern blot analysis indicated that the BH-Pcdh gene is likely to be conserved among various vertebrates. The BH-Pcdh gene was localized to human chromosome 4p15. Interestingly, 4p15 is a region of loss of heterozygosity in some head and neck squamous cell carcinomas.

Amino Acid Sequence↗

PubMed1998

CD44 exon v6 is not implicated in the progression and metastasis of endometrial cancer.

We examined the presence of mRNA for CD44v6 and assessed the association with clinicopathological features in 42 patients with endometrial cancer by RT-PCR and subsequent Southern blot hybridization with oligonucleotide probe specific for v6. The standard form of CD44 was expressed in all specimens and 20 out of 42 endometrial cancers expressed an isoform containing exon v6 in combination with other variant exons. However, there was no correlation between the expression of CD44v6 and any clinicopathological factors. These findings suggested that the expression of CD44v6 is not implicated in the progression and metastasis of endometrial cancer.

Endometrial Neoplasms↗

PubMed1998

Structure, chromosomal location, and expression profile of EXTR1 and EXTR2, new members of the multiple exostoses gene family.

Hereditary multiple exostoses (EXT) is an autosomal dominant disorder that is characterized by the appearance of multiple outgrowths of the long bones (exostoses) at their epiphyses. Genetical heterogeneities have segregated at least on chromosome 8, 11, and 19 and been designated EXT1, EXT2, and EXT3, respectively. Recently, the responsible genes for EXT1 and EXT2 have been isolated and appeared to define a structurally related gene family. In the present study, we have identified novel genes which share significant sequence homologies with the EXT genes. The predicted protein products of the novel EXT-related genes, EXTR and EXTR2 (for EXT-related genes 1 and 2), consist of 919 and 330 amino acid residues, respectively. These genes were transcribed ubiquitously in various tissues. Based on PCR-assisted analyses of both a human/rodent mono-chromosomal hybrid cell panel and a radiation hybrid mapping panel, EXTR1 was localized to the chromosome 8p21 region, where loss of heterozygosity has been frequently observed in various tumors, and EXTR2 was assigned to the chromosome 1p21 region, where osteopetrosis, a dominant hereditary disease of bone, has been mapped by genetic linkage analysis, implying that the protein products of these two EXT-related genes, as well as of the EXT genes, have potential tumor suppressor activity.

Amino Acid Sequence↗