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Mitsuru Emi

Publications and source records attributed to Mitsuru Emi.

At least 37 records · Page 2Linked to original sources
PubMed2004

Down-regulation of members of glycolipid-enriched membrane raft gene family, MAL and BENE, in cervical squamous cell cancers.

Persistent human papillomavirus infections cause infected epithelial cells to lose cellular polarity leading to cell transformation. Glycolipid-enriched membrane (GEM) rafts are implicated in polarized sorting of apical membrane proteins in epithelial cells and even in signal transduction. The MAL and BENE are essential component of the GEM raft's machinery for apical sorting of membrane proteins. In this study we demonstrated down-regulation of MAL and BENE mRNA in over two-thirds of primary cervical squamous cell cancers (14 and 15 of 20 cases, for MAL and BENE, respectively) when compared to corresponding non-cancerous uterine squamous cells. Allelic loss or hyper-methylation was not accompanied by MAL or BENE mRNA down-expression in human primary cervical cancers in microsatellite allelic analysis and HpaII-PCR-based methylation analysis of the MAL and BENE genomic region. In addition, we note down-regulation of these genes in established cervical cancer cell lines. These results suggest that down-regulation of MAL and BENE genes, which are essential components of the cellular polarized sorting system, play an important role in human cervical squamous cell cancer development.

Carrier Proteins↗
PubMed2004

Expression profiling to predict postoperative prognosis for estrogen receptor-negative breast cancers by analysis of 25,344 genes on a cDNA microarray.

Estrogen receptor (ER) status is an essential determinant of clinical and biological behavior of human breast cancers. While ER-positive breast cancers respond well to adjuvant hormone therapy, ER-negative tumors are generally resistant. To date, no attempts have succeeded in finding molecular markers for classifying ER-negative breast cancers with respect to postoperative prognosis. To identify a set of prognostic markers for this type of cancer, we used a cDNA microarray consisting of 25,344 human genes to investigate expression profiles of ten primary breast cancers from patients who had died of breast cancer within 5 years after surgery (5y-D) and 10 from patients who had survived disease-free for more than 5 years (5y-S). Sets of genes characterizing each group were identified by Mann-Whitney and random-permutation tests. We documented 71 genes with higher expression in the 5y-D group than in the 5y-S group, and 15 with higher expression in the 5y-S group than in the 5y-D group. Semi-quantitative RT-PCR experiments were carried out to confirm the results of the microarray analysis. We established a scoring system for predicting postoperative prognosis of ER-negative breast cancers on the basis of aberrant gene expression. The list of genes reported here provides valuable information with regard to progression of breast cancer and is a source of possible target molecules for development of novel drugs to treat patients with ER-negative breast cancers.

Adult↗
PubMed2004

Suppressor of cytokine signalling-1 gene silencing in acute myeloid leukaemia and human haematopoietic cell lines.

The aim of this study was to investigate whether the suppressor of cytokine signalling (SOCS)-1 can act as a tumour suppressor when functioning as a negative regulator of the Janus family tyrosine kinases (JAKs), which have been reported to play important roles in leukaemogenesis. For this purpose, we carried out molecular analysis of the SOCS-1 gene in human acute myeloid leukaemia (AML) and human haematopoietic cell lines. Sequencing alterations in the coding region were found in two of 90 primary AML samples and one of 17 cell lines. Hypermethylation of the SOCS-1 gene was also observed in 72% of primary cases and 52% of cell lines and aberrant methylation strongly correlated with reduced expression. Transfection of SOCS-1 into Jurkat cells harbouring the mutation and methylation suppressed cell growth at a low serum concentration. These findings indicate that SOCS-1 is frequently silenced in haematopoietic malignancies, mainly as a result of hypermethylation, and suggest that SOCS-1 may be able to function as a tumour suppressor.

Acute Disease↗
PubMed2003

Soluble epoxide hydrolase variant (Glu287Arg) modifies plasma total cholesterol and triglyceride phenotype in familial hypercholesterolemia: intrafamilial association study in an eight-generation hyperlipidemic kindred.

Plasma lipid and lipoprotein in general reflect the complex influences of multiple genetic loci, for instance, even familial hypercholesterolemia (FH), a representative example of monogenic hyperlipidemia, often presents with phenotypic heterogeneity. In the course of investigating familial coronary artery disease in Utah, we studied 160 members of an eight-generation extended family of FH in which 69 members were affected with type IIa hyperlipoproteinemia (HLPIIa; high plasma cholesterol) and ten with type IIb hyperlipoproteinemia (HLPIIb; high plasma cholesterol as well as plasma triglyceride). Soluble epoxide hydrolase ( EPHX2, sEH) plays a role in disposition of epoxides in plasma lipoprotein particles. Intrafamilial correlation analysis of the modifier effect of Glu287Arg substitution in the EPHX2 gene was carried out among 79 LDLR mutation carriers and 81 noncarriers. In the carriers, plasma cholesterol levels were elevated among carriers of the 287Arg allele (mean +/- SD=358 +/- 72 mg/dl) in comparison with 287Glu homozygotes (mean +/- SD=302 +/- 72 mg/dl) (p=0.0087). Similarly, in the LDLR mutation carriers, the plasma triglyceride levels were elevated among carriers of the 287Arg allele (mean +/- SD=260 +/- 100 mg/dl) in comparison with 287Glu homozygotes (mean +/- SD=169 +/- 83 mg/dl) (p=0.020). No such gene-interactive effect was observed among noncarriers of the LDLR mutation. Half of the patients who presented with HLPIIb had inherited a defective LDLR allele as well as an EPHX2-287Arg allele, whereas the majority who presented with HLPIIa had a defective LDLR allele but not an EPHX2-287Arg allele. These results indicate a significant modification of the phenotype of FH with defective LDLR allele by EPHX2-287Arg variation in our studied kindred.

Alleles↗
PubMed2003

Hypercholesterolemia associated with splice-junction variation of inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) gene.

Factors predisposing to the phenotypic features of higher total cholesterol (T-Cho) have not been clearly defined. Here we report an association between a C/T single nucleotide polymorphism at IVS17+8 in the inter-alpha-trypsin inhibitor heavy chain 4 gene (ITIH4) and plasma total cholesterol levels in 351 adult individuals from an east-central area of Japan. Age and gender-adjusted levels of plasma T-Cho, LDL-cholesterol, triglyceride, and HDL-cholesterol were analyzed. When we separate the subjects into two genotypic groups regarding this single nucleotide polymorphism (SNP), those who lack the T-allele had significantly higher plasma T-Cho levels than the others who bear T-allele (mean 252.3 mg/dl versus 241.7 mg/dl; p=0.009). Of the 309 individuals without the T-allele, approximately 90% presented with hypercholesterolemia, whereas only 10% were hypercholesterolemic among 42 individuals with the T-allele (p <0.0001). These data suggest that genetic variation at ITIH4 locus is one of the likely candidate determinants for plasma cholesterol metabolisms.

Aged↗
PubMed2003

Silencing effect of CpG island hypermethylation and histone modifications on O6-methylguanine-DNA methyltransferase (MGMT) gene expression in human cancer.

O6-methylguanine-DNA methyltransferase (MGMT) repairs the cytotoxic and mutagenic O6-alkylguanine produced by alkylating agents such as chemotherapeutic agents and mutagens. Recent studies have shown that in a subset of tumors, MGMT expression is inversely linked to hypermethylation of the CpG island in the promoter region; however, how the epigenetic silencing mechanism works, as it relates to hypermethylation, was still unclear. To understand the mechanism, we examined the detailed methylation status of the whole island with bisulfite-sequencing in 19 MGMT non-expressed cancer cell lines. We found two highly methylated regions in the island. One was upstream of exon 1, including minimal promoter, and the other was downstream, including enhancer. Reporter gene assay showed that methylation of both the upstream and downstream regions suppressed luciferase activity drastically. Chromatin immunoprecipitation assay revealed that histone H3 lysine 9 was hypermethylated throughout the island in the MGMT negative line, whereas acetylation on H3 and H4 and methylation on H3 lysine 4 were at significantly high levels outside the minimal promoter in the MGMT-expressed line. Furthermore, MeCP2 preferentially bound to the CpG-methylated island in the MGMT negative line. Given these results, we propose a model for gene silencing of MGMT that is dependent on the epigenetic state in cancer.

CpG Islands↗
PubMed2003

A family with spinal anaplastic ependymoma: evidence of loss of chromosome 22q in tumor.

Familial ependymal tumors are a very rare disease, the pathogenesis of which is unknown. Previous studies indicate an involvement of tumor suppressor genes localized within chromosomal region 22q, whereas details are still unclear. Here we report a non-neurofibromatosis type-2 (non-NF2) Japanese family in which two of the four members are affected with cervical spinal cord ependymoma, and one of the four is affected with schwannoma. Loss of heterozygosity (LOH) studies were carried out searching for common allelic loss at chromosomal region 22q11.2-qtel in two of the affected patients. Our findings support a prediction for existence of a tumor suppressor gene on chromosome 22 especially related to the tumorigenesis of familial ependymal tumors.

Adult↗
PubMed2003

A promoter SNP (-1323T>C) in G-substrate gene (GSBS) correlates with hypercholesterolemia.

Factors predisposing to the phenotypic features of higher total cholesterol (TC) have not been clearly defined. Here we report an association between a promoter SNP (-1323T>C) in G-substrate gene (GSBS) and TC levels in 368 adult individuals from an east-central area of Japan. Age and gender-adjusted levels of LDL-cholesterol, TG, TC, and HDL-cholesterol were analyzed. When we separate the subjects into two genotypic groups regarding T allele, those who bear the T allele had significantly higher plasma TC levels than the others who lack the T allele (mean; 239.6 mg/dl vs. 210.6 mg/dl; p=0.003; Mann-Whitney test). Of the 341 individuals with the T allele, approximately 80% individuals presented with hypercholesterolemia, whereas only 44% were hypercholesterolemic among the 27 individuals without the T allele (p=0.0001). These results indicate a significant elevating effect of plasma TC levels by a SNP in the putative regulatory region of the G-substrate gene in our studied population. These data suggest that genetic variation at the G-substrate gene may be one of the determinants for plasma lipoprotein levels.

Cholesterol↗
PubMed2003

Growth hormone receptor variant (L526I) modifies plasma HDL cholesterol phenotype in familial hypercholesterolemia: intra-familial association study in an eight-generation hyperlipidemic kindred.

Defect of growth hormone receptor (GHR) is classically known to cause Laron syndrome, characterized by short stature, specific facial appearance, elevated serum growth hormone levels, and decreased insulin-like growth factor I levels. In addition, an increased cardiovascular risk due to elevated plasma total and LDL cholesterol levels marks another feature of the disease. Growth hormone (GH) plays an important role in the regulation of lipoprotein metabolism. GH status was found to be an independent determinant of plasma total cholesterol and triglyceride levels in humans. We studied a total of 207 members of eight-generation extended family of familial hypercholesterolemia (FH) in which affected members presented with various lipoprotein phenotypes. Intra-familial correlation analysis of a modifier effect of a Leu526Ile substitution in GHR gene was carried out among 95 carriers for LDL receptor gene (LDLR) mutation and 112 non-carriers. When plasma high-density lipoprotein cholesterol (HDL-c) levels in the LDLR-mutation carriers were compared, a significant lowering effect of HDL-c was observed with the Leu allele; the values were lowest among Leu/Leu homozygotes (mean +/- SD = 37 +/- 2 mg/dl), highest in Ile/Ile homozygotes (50 +/- 4 mg/dl), and intermediate among Leu/Ile heterozygotes (41 +/- 2 mg/dl) (P = 0.0021). The results indicate a significant modification of the phenotype of FH with the defective LDLR allele, by GHR Leu variation in the kindred studied.

Adult↗
PubMed2003

Association of genetic variation of the RIL gene, encoding a PDZ-LIM domain protein and localized in 5q31.1, with low bone mineral density in adult Japanese women.

Twin and family studies had shown that genetic factors are important determinants of bone mass. Multiple genes might be involved. One candidate gene, the reversion-induced LIM gene ( RIL), is a PDZ and LIM-domain-containing protein and has been localized within the cytokine cluster of chromosome 5 (5q31.1). In a genetic study of 370 adult Japanese women, we investigated the correlation between radial bone mineral density (BMD) and a genetic variation (-3333T-->C) of the 5'-flanking region of RIL gene. A significant association was identified between the RIL variation -3333T-->C and radial BMD ( r=0.15, P=0.003). The variation of the RIL locus may be an important determinant of osteoporosis.

Adult↗
PubMed2003

Hypertriglyceridemia associated with amino acid variation Asn985Tyr of the RP1 gene.

Factors predisposing to the phenotypic features of hypertriglyceridemia have not been clearly defined. Here we report an association between a missense coding region polymorphism Asn985Tyr in the retinitis pigmentosa 1 gene ( RP1) and plasma triglyceride (TG) levels in 332 adult individuals from an east-central area of Japan. Age and gender-adjusted levels of LDL-cholesterol, TG, and HDL-cholesterol were analyzed. When we separate the subjects into two genotypic groups regarding this amino acid variation, those who lack the 985-Asn allele (asparagine at residue 985) had significantly higher plasma TG levels than the others who had at least one 985-Asn allele (mean: 175.8 mg/dl vs 123.3 mg/dl; P=0.0006, Mann-Whitney test). Similarly, the former subjects had significantly lower HDL-cholesterol levels than the latter (mean: 48.0 mg/dl vs 53.8 mg/dl; P=0.038). Of the 280 individuals without a 985-Asn allele, approximately half of the individuals presented with hypertriglyceridemia, whereas only a quarter were hypertriglyceridemic among 52 individuals with the 985-Asn allele ( P=0.04). Although this SNP marker may itself be in linkage disequilibrium with other unexamined functional variants within this locus, our data suggest that genetic variation at the RP1 locus is one of the likely candidate determinants for plasma triglyceride and HDL-cholesterol metabolisms.

Aged↗
PubMed2003

Association of natural tooth loss with genetic variation at the human matrix Gla protein locus in elderly women.

Natural tooth loss represents a major medical issue within the elderly population, since it impairs masticatory function critical for oral intake of essential nutrition. Contribution of genetic factors has been implicated in the determination of natural tooth loss; degree of reduction in number of natural teeth remaining intact (NTI) varies among individuals; thus, heterogeneity in NTI might reflect genetic variation within the population. One candidate gene, the matrix Gla protein gene (MGP), has been implicated in the pathogenesis of bone loss through a repression of bone/tooth formation. We have investigated a possible association between the CA repeat polymorphism at the human MGP gene locus and the NTI in 458 elderly Japanese women. In 916 chromosomes tested, ten alleles of the polymorphic nucleotide repeat were observed (designated A1-A10), among which five alleles were regarded as major alleles to be tested for the association. Twenty-seven women who possessed an A6 allele (164 bp) had significantly higher NTI than the remaining participants (n=431), who did not carry an allele of that size (mean: 10.0 teeth vs 5.6 teeth; P=0.007, Mann-Whitney test). An eight-year longitudinal follow-up study of NTI suggested that the genetic variations at the MGP locus did not affect the rate of tooth loss in the elderly period. These results suggest that genetic variation at the MGP gene locus is associated with some determinants for tooth loss in elderly women.

Aged↗
PubMed2003

Upregulation and overexpression of human X-box binding protein 1 (hXBP-1) gene in primary breast cancers.

BACKGROUND: Human X-box binding protein 1 (hXBP-1) is a transcription factor essential for hepatocyte growth as well as for plasma cell differentiation. hXBP-1 also binds to cis-elements of human T cell leukemia virus and human major histocompatibility complex genes. In order to clarify the role of XBP-1 in breast cancer, here we investigated the expression of XBP-1 in 11 primary breast cancers and 5 breast cancer cell lines. MATERIALS AND METHODS: The study population consisted of eleven patients who were underwent surgery for breast cancer from 2000 to 2002. Five breast cancer cell lines (MDA-MB-453, CRL1500, YMB-1-E, MCF7 and HBL100) were analyzed for XBP-1 expression. Reverse transcription polymerase chain reaction was performed on 6 primary breast cancers. Then we investigated XBP-1 expression by immunohistochemically on archived paraffin-embedded sections. RESULTS: hXBP-1 mRNA expression was increased in all 11 primary breast cancers we examined, as well as 5 breast cancer cell lines, but hardly detectable in non-cancerous breast tissue. Immunohistochemical staining demonstrated that hXBP-1 protein stained strongly in the cytoplasm of cancer cells but was unreactive in the normal breast ductal epithelial and myoepithelial cells. CONCLUSIONS: These data indicate that increased expression of the hXBP-1 gene may play some role in human breast carcinogenesis through impairment of cell differentiation regulation.

Aged↗
PubMed2003

Hypermethylation associated with inactivation of the SOCS-1 gene, a JAK/STAT inhibitor, in human hepatoblastomas.

We recently demonstrated inactivation in hepatocellular carcinomas (HCCs) of the gene encoding SOCS1/JAB1/SSI-1, a JAK-binding protein that regulates the JAK/STAT signal-transduction pathway. In a follow-up immunochemical investigation of expression of SOCS-1 in hepatoblastomas (HBLs), the protein was markedly reduced in half of the HBL tumors we examined. CpG-rich regions upstream of the SOCS-1 gene were hypermehylated in 7 of the 15 HBL cases. The results suggest that hypermethylation may play an important role in silencing the SOCS-1 gene, not only in adult HCCs, but also in liver tumors arising in childhood.

Adolescent↗
PubMed2003

Association of the -381T/C promoter variation of the brain natriuretic peptide gene with low bone-mineral density and rapid postmenopausal bone loss.

Osteoporosis is believed to result from interplay among multiple environmental and genetic determinants, including factors that regulate bone-mineral density (BMD). Recent quantitative trait locus analysis in human suggested a possible involvement of chromosomal region 1p36.2-p36.3 for determination of BMD. The brain natriuretic peptide (BNP, also named NPPB) gene lies within this candidate region for BMD determination. Overexpression of the BNP resulted in skeletal overgrowth in transgenic mice. Association analysis between nucleotide variations of the BNP gene and radial BMD in 378 Japanese postmenopausal women revealed a significant association of the -381T/C variation of the BNP gene with radial BMD (r = 0.17, P = 0.01). Homozygous T-allele carriers had the lowest BMD values (0.395 +/- 0.056 g/cm(2)), homozygous C-allele carriers had the highest (0.429 +/- 0.051 g/cm(2)), and heterozygous individuals had intermediate radial BMD values (0.405 +/- 0.048 g/cm(2)), indicating a dosage effect. Accelerated bone loss also correlated with the -381 T allele in a 5-year follow-up study (r = 0.21, P = 0.017). These results suggest that variation of BNP may be an important determinant of postmenopausal osteoporosis, in part through the mechanism of accelerated postmenopausal bone loss.

Adult↗
PubMed2003

DNA alterations during multi-step development of human hepatocellular carcinomas revealed by laser capture microdissection.

In order to clarify early molecular events involved in liver carcinogenesis, we analyzed 53 liver-cirrhosis nodules (LCNs) from five patients and 13 micro-hepatocellular carcinoma (HCC) nodules from one patient and looked for alterations of microsatellites in genomic DNA after carefully preparing the tissue samples by laser-capture microdissection (LCM). Allelotyping was done with 20 markers corresponding to anonymous microsatellites and 13 corresponding to tumor suppressor genes (TSGs) that had shown significant alterations in HCCs. We detected both loss of heterozygosity (LOH) and microsatellite shifts (MS). Overall, 24 of 53 (47%) of LCNs showed LOH with any of the informative markers used in the study, reflecting that proportion of LCNs with clonal growth. The fractional allelic loss (FAL) index, an indication of total genomic complexity, was not significantly different between LCN and micro-HCC nodules, but their profiles of alteration were different. These profiles were classified into three groups: (1) LCN profile-allelic loss at chromosomal arms 1q and 14q, TBP and BRCA1; (2) HCC profile-LOH at 4q, 6q, 7q, 17p, NF1, IGFIIr and p53 in micro-HCC nodules; these changes in early lesions were identical to those seen in mature HCCs; (3) Common profile-LOH at NF1 and 6q, including IGFIIr, common to both LCN and HCC. No LCN showed LOH at p53 and Rb, loci that are generally altered in HCCs. However, 12 intra-tumoral nodules examined had lost p53 in all informative cases, although the loss of Rb was a late event. These results suggest that early genomic profiles confined to LCNs, and additional profiles that can be observed when liver tissue undergoes malignant transformation, support a model of multi-step development of HCC.

Journal Article↗
PubMed2003

Association of a Trp16Ser variation in the gonadotropin releasing hormone signal peptide with bone mineral density, revealed by SNP-dependent PCR typing.

Osteoporosis is believed to result from interplay among multiple environmental and genetic determinants, including factors that regulate bone mineral density (BMD). Among those factors, adequate estrogen is essential for achievement of peak bone mass as well as for postmenopausal maintenance of skeletal homeostasis. Gonadotropin-releasing hormone (GnRH) from the hypothalamus is the primary determinant in the hypothalamic-pituitary-gonadal feedback system. In genetic studies of 384 postmenopausal Japanese women, we found a significant association between BMD and an amino acid variation (Trp16Ser) located within the signal peptide of GnRH (r = 0.143, P = 0.005). These results were achieved by genotyping all subjects using a newly developed SNP-dependent PCR method. This automated, high-throughput, and inexpensive procedure is suitable for typing large numbers of samples. BMD was lowest among 16Ser/Ser homozygotes, highest among 16Trp/Trp homozygotes, and intermediate among heterozygotes. A case-control study involving 125 osteoporosis patients and 92 healthy controls revealed a significant association between the presence of a 16Ser GnRH allele and affected status (chi(2) = 4.74, P = 0.041). The results suggested that variation of the GnRH signal peptide may be an important risk factor for postmenopausal osteoporosis.

Adult↗