Core fucosylation of E-cadherin enhances cell-cell adhesion in human colon carcinoma WiDr cells.

Alpha1,6-fucosyltransferase (Fut8), an enzyme that catalyzes the introduction of alpha1,6 core fucose to the innermost N-acetylglucosamine residue of the N-glycan, has been implicated in the development, immune system, and tumorigenesis. We found that alpha1,6-fucosyltransferase and E-cadherin expression levels are significantly elevated in primary colorectal cancer samples. Interestingly, low molecular weight population of E-cadherin appeared as well as normal sized E-cadherin in cancer samples. To investigate the correlation between alpha1,6-fucosyltransferase and E-cadherin expression, we introduced alpha1,6-fucosyltransferase in WiDr human colon carcinoma cells. It was revealed that the low molecular weight population of E-cadherin was significantly increased in alpha1,6-fucosyltransferase-transfected WiDr cells in dense culture, which resulted in an enhancement in cell-cell adhesion. The transfection of mutated alpha1,6-fucosyltransferase with no enzymatic activity had no effect on E-cadherin expression, indicating that core fucosylation is involved in the phenomena. In alpha1,6-fucosyltransferase knock down mouse pancreatic acinar cell carcinoma TGP49 cells, the expression of E-cadherin and E-cadherin dependent cell-cell adhesion was decreased. The introduction of alpha1,6-fucosyltransferase into kidney epithelial cells from alpha1,6-fucosyltransferase(-/-) mice restored the expression of E-cadherin and E-cadherin-dependent cell-cell adhesion. Based on the results of lectin blotting, peptide N-glycosidase F treatment, and pulse-chase studies, it was demonstrated that the low molecular weight population of E-cadherin contains peptide N-glycosidase F insensitive sugar chains, and the turnover rate of E-cadherin was reduced in alpha1,6-Fucosyltransferase transfectants. Thus, it was suggested that core fucosylation regulates the processing of oligosaccharides and turnover of E-cadherin. These results suggest a possible role of core fucosylation in the regulation of cell-cell adhesion in cancer.

Ultrasonically assisted hydrothermal synthesis of polycrystalline PZT thin film on titanium substrate.

Ultrasonically assisted hydrothermal synthesis of PZT thin films was performed using an ultrasonic transducer integrated into the lid of an autoclave. Direct ultrasonic irradiation of 23 W at 53 kHz was carried out during the hydrothermal synthesis at a reaction temperature of 140 degrees C for 24 h. The resultant PZT thin film was characterized using scanning electron microscopy (SEM) and x-ray diffraction (XRD). The PZT thin film had fine nanoparticles of approximately 100 nm in diameter when the substrate was placed perpendicular to the plane of ultrasonic irradiation. The film exhibited predominantly (001) orientation when the substrate was placed parallel to the plane of ultrasonic irradiation.

Pulmonary thromboembolism in obstetrics and gynecology increased by 6.5-fold over the past decade in Japan.

BACKGROUND: Although pulmonary thromboembolism (PTE) has been considered relatively uncommon in Japan, its incidence has been on the increase in recent years. METHODS AND RESULTS: To verify the incidence of PTE in Japan, PTE cases of obstetrics and gynecology were investigated among 102 facilities throughout Japan between 1991 and 2000. A total of 254 cases were enrolled, showing a 6.5-fold increase over the past 10 years. PTE occurred in 0.02% of total births; 0.003% after vaginal deliveries and 0.06% after cesarean births (C/S), of which 14.5% resulting in fatality. The mortality rate was 2.5 per 100,000 deliveries. The incidences among gynecological cases were 0.08% of total operations; 0.03% in benign diseases and 0.42% in malignant diseases of which 13.5% resulting in fatality. The mortality rate was 10.8 per 100,000 operations. The risk was 22 times higher in C/S compared with vaginal deliveries, 16 times higher in malignant diseases compared with benign diseases. CONCLUSIONS: As our present survey has shown, PTE has been on the rise in Japan in recent years. C/S and malignant diseases are strong risk factors in obstetrics and gynecology.

Mutational analysis of the human MBX gene in four Korean families demonstrating microphthalmia with congenital cataract.

The MBX gene is a novel paired-type homeobox gene. It plays a number of critical roles in the development of the eyes in the zebrafish. The knockdown of the mbx expression by morpholino antisense oligonucleotides leads to a reduction in the size of eyes and tectum in the zebrafish. We investigated whether the human MBX gene was associated with susceptibility to microphthalmia by analyzing four Korean families demonstrating microphthalmia with congenital cataract. Mutational analysis was performed on the human MBX gene using these families. However, no mutations could be detected. Therefore, no indications were found for an association between the MBX gene and microphthalmia with congenital cataract in humans.

Is a genetic defect in Fkbp6 a common cause of azoospermia in humans?

FK506-binding protein 6 (Fkbp6) is a member of a gene family containing a prolyl isomerase/FK506-binding domain and tetratricopeptide protein-protein interaction domains. Recently, the targeted inactivation of Fkbp6 in mice has been observed to result in aspermic males and the absence of normal pachytene spermatocytes. The loss of Fkbp6 results in abnormal pairing and a misalignment of the homologous chromosomes, and in non-homologous partner switches and autosynapsis of the X chromosome cores in meiotic spermatocytes. In this study, we analyzed whether human FKBP6 gene defects might be associated with human azoospermia. We performed a mutation analysis in all the coding regions of the human FKBP6 gene in 19 patients with azoospermia resulting from meiotic arrest. The expression of the human FKBP6 gene was specific to the testis, and a novel polymorphism site, 245C --> G (Y60X) could be found in exon 3. Our findings suggest that the human FKBP6 gene might be imprinted in the testis based on an analysis using two polymorphism sites.

Polymorphic alleles of the human MEI1 gene are associated with human azoospermia by meiotic arrest.

Genetic mechanisms are implicated as a cause of some male infertility, yet are poorly understood. Mouse meiotic mutant mei1 (meiosis defective 1) was isolated by a screening of infertile mice. Male mei1 mice have azoospermia due to meiotic arrest, and the mouse Mei1 gene is responsible for the mei1 phenotype. To investigate whether human MEI1 gene defects are associated with azoospermia by meiotic arrest, we isolated the human MEI1 cDNA based on the mouse Mei1 amino acid sequence. MEI1 is expressed specifically in the testis. Mutational analysis by direct sequencing of all MEI1 coding regions was performed in 27 men (13 European Americans, 13 Israeli and 1 Japanese) having azoospermia due to complete early meiotic arrest. This identified four novel, coding single-nucleotide-polymorphisms (cSNPs), i.e., SNP1 (T909G), SNP2 (A1582G), SNP3 (C1791A) and SNP4 (C2397T) in exons 4, 8, 9 and 14, respectively. Using these cSNPs, an association study was carried out between 26 non-Japanese patients with azoospermia and two sets of normal control men (61 normal European Americans and 60 Israelis). Consequently, SNP3 and SNP4 were shown to be associated with azoospermia among European Americans (P =0.0289 and P =0.0299 for genotype and allele frequencies at both the polymorphic sites, respectively), although no such association was observed among Israelis (P >0.05). Haplotype estimation revealed that the frequencies of SNP3-SNP4 (C-T), SNP3-SNP4 (A-C) and SNP3-SNP4 (A-T) were higher in the European American patients, and the frequency of SNP3-SNP4 (A-T) was also higher than in both control groups. These results suggest that MEI1 may play a role in meiosis during spermatogenesis, especially in European Americans.

Suppression of invasive characteristics by antisense introduction of overexpressed HOX genes in ovarian cancer cells.

HOX genes encode transcription factors that function to establish basic body pattern during embryogenesis and maintain the function of specific organs in the adult. Recent studies have demonstrated that HOX genes are also involved in oncogenesis in a range of malignancies. To elucidate whether HOX genes contribute to ovarian carcinogenesis, we created an expression profile of HOX genes using ovarian derived materials from surgical samples and epithelial ovarian cancer cells derived from five different cell lines. Real-time quantitative RT-PCR assay indicated overexpression of 14 HOX genes in clusters A and B but only 2 genes in clusters C and D. Of the 16 HOX genes, overexpression of paralogs of HOX3, HOX4 and HOX7 is seen in cluster A and B, and of HOX13 in all paralogs. In addition, HOXB7, HOXA13 and HOXB13 showed high levels of overexpression in cancer cells and tissues whereas no or little expression was observed in normal controls. To examine whether overexpressed HOX genes regulate invasion of ovarian cancer cells directly, we introduced an antisense DNA fragment of overexpressed HOXB7 and HOXB13, and HOXC5 that did not show overexpression into SKOV3 cells by electroporation. Antisense introduction followed by chemoinvasion assay using matrigel chamber demonstrated that SKOV3 cells introduced an antisense of each HOXB7 and HOXB13 showed 85% and 50% reduction of invasion ability compared to the parental SKOV3 cells, respectively. In contrast, antisense of HOXC5 introduced cells showed no significant difference of the invasion ability. These results suggest an important role of overexpressed HOX genes, especially for invasive characteristics of ovarian cancer cells.

Regulation of tumor invasion by HOXB13 gene overexpressed in human endometrial cancer.

During the last two decades, a group of homeobox-containing genes, the HOX gene family, has been studied both in the context of embryonic development and neoplasia. In particular, there is accumulating evidence of the involvement of HOX abnormalities in a variety of malignancies, including breast cancer. However, little is known about the association of HOX genes with endometrial cancer, which is the most common malignancy of the female genital tract and is thought to be dependent on estrogen, like breast cancer. In this study, we detected overexpression of the HOXB13 gene in endometrial cancer cells and tissues from patients by quantitative real-time RT-PCR. To investigate whether overexpression of HOXB13 is involved in invasion or metastasis of endometrial cancer, we transfected antisense HOXB13/pcDNA3.1+ plasmid vector into endometrial cancer AN3CA cells by electroporation and performed in vitro chemoinvasion assay. We revealed that the invasive ability of antisense-transfectants showed a 90% reduction compared with parental cells and control transfectants (p<0.01). In addition, administration of 17beta-estradiol induced time- and dose-dependent responses of the HOXB13 expression in endometrial cancer AN3CA cells. These results suggest that overexpression of HOXB13 in endometrial cancer may be associated with the invasive ability of cancer cells with regulation by estrogen.

GATM, the human ortholog of the mouse imprinted Gatm gene, escapes genomic imprinting in placenta

The GATM gene encodes L-arginine:glycine amidinotransferase, which catalyzes the conversion of L-arginine into guanidinoacetate, the rate-limiting step in the synthesis of creatine. Since, deficiencies in creatine synthesis and transport lead to certain forms of mental retardation in human, the human GATM gene appears to be involved in brain development. Recently it has been demonstrated that the mouse Gatm is expressed during development and is imprinted with maternal expression in the placenta and yolk sac, but not in embryonic tissues. We investigated the imprinting status of the human GATM by analyzing its expression in four human placentas. GATM was biallelically expressed, thus suggesting that this gene escapes genomic imprinting in placentas, differently from what has been reported in mouse extra-embryonic tissues.

Isolation and expression analysis of the testis-specific gene, human OPPO1.

PURPOSE: To investigate human spermatogenesis, we isolated human testis-specific genes. METHODS: Using mouse amino acid sequences, we found the region including homology in amino acid level in the human genome sequences. The primers encompassing introns were made and RT-PCR and RACE were carried out. The resultant PCR products were sequenced. RESULTS: The full-length cDNA of human OPPO1 was isolated. It encodes 257 amino acid residues. The expression of the human OPPO1 was predominantly in the testis. On the other hand, partial cDNAs of ZNF8, GR194, GR219, GR093, GR046, GR163, and GR200 were expressed in the various tissues. CONCLUSIONS: Our data suggests that the human OPPO1 may play important roles in human spermatogenesis.

Nuclear dynamics of parthenogenesis of human oocytes: effect of oocyte aging in vitro.

We investigated in detail the nuclear kinetics of oocyte activation of aged human oocytes following combined activation treatment with calcium ionophore and puromycin. Two types of oocytes were used: (a) 1-day-old oocytes after 20-24 h retrieval, and (b) 2-day-old oocytes after 44-50 h retrieval. A total of 185 unfertilized aged oocytes, 91 1-day-old and 94 2-day-old oocytes, were fixed at 1, 2, 4, 6 and 8 h after activation treatment and then metaphase II (MII), anaphase or telophase II (A/T II) or pronuclear stage were recorded. We demonstrated that a combined calcium ionophore and puromycin treatment induced a high activation rate in both 1-day-old (95.6%) and 2-day-old oocytes (95.2%). Our results also demonstrated that the nuclear progression was faster in 2-day-old oocytes than in 1-day-old oocytes, although nuclear progression in parthenogenetically activated human oocytes requires the longer time periods compared with ICSI fertilization. It is concluded that combined treatment of the calcium ionophore and puromycin allows a high rate of parthenogenetic activation and the nuclear kinetics of parthenogenetically activated human oocytes appears to be more rapid in in vitro aging oocytes.

The IHPK1 gene is disrupted at the 3p21.31 breakpoint of t(3;9) in a family with type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is a group of multifactorial disorders due to either defective insulin secretion or action. Despite the fact that numerous genetic researches of T2DM have been pursued, the pathogenic mechanisms remain obscure. We encountered a T2DM family associated with a balanced reciprocal translocation, t(3;9)(p21.31;q33.1). To isolate a candidate gene susceptible to T2DM, we constructed physical maps covering both the 3p and 9q breakpoints of the translocation in the family. Consequently, the inositol hexaphosphate kinase 1 gene ( IHPK1) (OMIM *606991) was found to be disrupted at the 3p21.31 breakpoint. We then carried out sequence analysis for all coding regions of IHPK1 in 405 unrelated T2DM patients in order to validate whether aberrations of the gene are common in T2DM patients, but we failed to detect any pathogenic changes. The disruption of IHPK1 or another predisposing gene affected by position effect of the translocation may explain the T2DM phenotype at least in this family. Alternatively, the IHPK1 disruption in the family is a chance association.

Differential expression of heparin-binding epidermal growth factor-like growth factor in the rat ovary.

We investigated the expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF) and its receptors in the rat ovary to define the role of HB-EGF in the ovarian function. The expression pattern of HB-EGF mRNA and protein were studied by semi-quantitative RT-PCR and immuno-histochemistry using an antibody that was specifically stained for the precursor form of HB-EGF in naturally cycling rats and immature pseudo-pregnant rat models. The immuno-histochemical study showed that in naturally cycling rats, HB-EGF was expressed in most granulosa cells of early follicles and all the developing follicles but not in preovulatory follicles. This was supported by the semi-quantitative RT-PCR results in that the lowest level of HB-EGF mRNA during the estrous cycle was found in the evening of proestrous when the HB-EGF negative preovulatory follicles were most prominent. The results suggest that HB-EGF might be a mitogen for granulosa cells and down regulation of its expression may be necessary for the final maturation of follicles. In corpora lutea, luteal cells of older generation stained stronger than those of younger generation. Moreover, luteal cells of late luteal phase stained stronger than those of the mid and early luteal phases in the immature pseudo-pregnant rat models, indicating that the precursor form may be associated with death of luteal cells. Finally, of the two cognate receptors for HB-EGF, erbB1 was expressed in the rat ovary, but erbB4 was specifically not expressed in this organ. The spatial and temporal pattern of HB-EGF expression suggest that HB-EGF may an important local regulator of ovarian function and structure.

Integrins are not involved in the process of human sperm-oolemmal fusion.

BACKGROUND: We investigated whether integrins are required for the human sperm-oocyte binding and fusion processes. METHODS: The expression of several integrin subunits at the human oocyte plasma membrane was investigated using immunofluorescence microscopy, and the functional role of integrins expressed at the human oocyte surface in sperm-oocyte interaction was studied using a zona-free human oocyte binding and fusion assay. A total of 144 unfertilized oocytes were stained with anti-integrin antibodies and 147 zona-free unfertilized oocytes were inseminated in the presence of various anti-integrin antibodies that were expressed in oocyte plasma membrane. RESULTS: The antibodies of six alpha integrin subunits (alpha(2), alpha(3), alpha(5), alpha(6), alpha(V), alpha(M)) and six beta integrin subunits (beta(1), beta(2), beta(3), beta(4), beta(5), beta(6)) were bound to the surface of fixed unfertilized oocytes. In contrast, the presence of alpha(1) and alpha(4) subunits could not be verified. The human sperm-oocyte binding was only partially inhibited by blocking antibodies of alpha(2), alpha(3), alpha(5), alpha(6), alpha(V), alpha(M), beta(1), beta(2) and beta(3) with a maximum of 55% inhibition, but antibodies of beta(4), beta(5) and beta(6) showed no effect on sperm-oolemmal binding. A similar reduction of the number of fused sperm was observed. However, the ratio of fused sperm to total sperm (bound and fused) was not impaired by all integrin antibodies, suggesting that integrins had no role in the sperm-oolemmal fusion process. CONCLUSIONS: These results suggest that one of the binding mechanisms can be inhibited by integrin antibodies but that this mechanism does not play an essential role in the human sperm-oolemmal binding and fusion processes. The other mechanisms, insensitive to integrins, may involve both binding and fusion processes in human oocytes.

Treatment of climacteric symptoms with herbal formulas of traditional Chinese medicine.

Hormone replacement therapy (HRT) is not successful or is contraindicated for the treatment of climacteric symptoms in some patients. To investigate whether certain herbal formulas of traditional Chinese medicine (Kampo in Japanese) could be used as an alternative treatment, a longitudinal 'before and after' comparative study was carried out in 18 Japanese women, and the results were compared with those of 16 women who underwent HRT. Kampo improved all the climacteric symptoms. In contrast, improvement of cold limbs, sleeping disorders, shoulder stiffness/lumbago, and fatigue in the HRT group was either not significant or of limited extent. In addition, the serum level of estradiol in postmenopausal women was raised by the combined use of two Kampo formulas. These results suggest that Kampo may be considered an alternative to HRT for the treatment of climacteric symptoms, but vigorous monitoring for potential side effects of increased estrogen levels in some postmenopausal patients is needed.

The human transcript induced in spermatogenesis 50.

Background and Aims: Recently, a number of genes that are expressed specifically in the testis have been identified in rat and mouse. In 2002, 80 transcript induced in spermatogenesis (Tisp) genes with this specific expression were isolated in mice. In the human, however, the number of such genes isolated is much lower. The aim of this study therefore was the isolation of human genes specifically expressed in testis. Methods: We searched for human genome region with homology to the mouse Tisp gene family at the amino acid level using GenBank. The primers were made in human homologous regions, and polymerase chain reaction analysis was performed with templates using cDNA libraries of a range of human tissues. The cDNA specifically expressed in testis were isolated and detailed expression analysis was performed. Results: The 28 human TISP related genes were analyzed. Five of these genes were not expressed in testis and only three, TISP50, TISP15 and TISP43 related gene, were expressed specifically in testis. The cDNA of these three genes were isolated. Conclusion: Expression analysis demonstrated that there is some discrepancy between human and mouse for the TISP gene family. From expression patterns and amino acid sequences, it is suggested that the human TISP50, TISP15 and TISP43 related genes play some critical roles in spermatogenesis. (Reprod Med Biol 2004; 3: 237 - 243).

Azoospermia in patients heterozygous for a mutation in SYCP3.

BACKGROUND: Many cases of male infertility are diagnosed as idiopathic, reflecting poor understanding of the molecular defects underlying the abnormality. As more gene mutations causing male infertility in mice become known, there are improving prospects that knowledge about the genetic aetiology of human male infertility can be expanded. Sycp3 encodes a component of the synaptonemal complex. A null mutation of Sycp3 in mice causes azoospermia with meiotic arrest. We tested the hypothesis that mutation of the human testis-specific SYCP3 is associated with human non-obstructive azoospermia. METHODS: Human SYCP3 was isolated on the basis of homology between mouse Sycp3 cDNA and human genome sequences at the aminoacid level. Tissue-specific expression of SYCP3 was analysed by PCR of human cDNA. Samples of DNA from 19 azoospermic patients with maturation arrest and 75 normal fertile control men were screened for mutations in the SYCP3 gene by sequence analysis of the gene. The functional significance of the mutations found was analysed by a protein interaction study of the wild-type and truncated SYCP3 proteins. FINDINGS: We identified in two patients a 1 bp deletion (643delA) that results in a premature stop codon and truncation of the C-terminal, coiled-coil-forming region of the SYCP3 protein. The mutant protein showed greatly reduced interaction with the wild-type protein in vitro and interfered with SYCP3 fibre formation in cultured cells. INTERPRETATION: We suggest that SYCP3 has an essential meiotic function in human spermatogenesis that is compromised by the mutant protein via dominant negative interference.

Molecular cloning and expression analysis of the mouse Spot-2 gene in pituitary development.

Mouse Spot-1 is a DNA-binding protein with a domain (His-Thr) encoded by p(CA)n repeats. Spot-1 interacts with the nuclear localization signal (NLS) I of p53 through its His-Thr domain. In this study we describe the cloning and expression patterns of a novel gene encoding a protein containing a His-Thr domain, Spot-2. Spot-2 is exclusively expressed in the pituitary from stage E13.5 to E15.5. Mouse Lhx3 plays a critical role during early organogenesis in the pituitary. The Spot-2 gene appears to be a downstream gene of Lhx3. It is suggested that Spot-2 plays important roles in pituitary development.