Overexpression of glucose transporter 1 in esophageal squamous cell carcinomas: a marker for poor prognosis

Recently, Glut1 (human erythrocyte glucose transporter) expression has been demonstrated in various tumors. The aim of this study is to evaluate the prognostic utility of Glut1 expression in esophageal carcinomas. We studied Glut1 expression by immunohistochemistry of paraffin sections from 63 esophageal squamous cell carcinomas. All 63 carcinomas expressed Glut1. The mean percentage of positively stained tumor cells was 77.8% (median, 84.7%). There were two staining patterns in positive cells: 'strongly positive' and 'weakly positive'. The percentage of 'strongly positive' cells (%Glut1-SP) ranged from 0% to 95.6% (mean, 32.3%; median, 27.4%). The 5-year survival rate for patients with a high %Glut1-SP (> 30%) was significantly lower than that for patients with a low %Glut1-SP (< 30%) (P < 0.01). Statistical analysis revealed that the relative risk of death for patients with high %Glut1-SP was 2.02 times that for patients with low %Glut1-SP (P = 0.064), suggesting a possible independent predictive value for %Glut1-SP.

SUMO-1 modification of the major immediate-early (IE) 1 and 2 proteins of human cytomegalovirus is regulated by different mechanisms and modulates the intracellular localization of the IE1, but not IE2, protein

We have previously shown that two proteins with apparent molecular masses of 91- and 102-kDa (p91 and p102, respectively) in human cytomegalovirus (HCMV)-infected cells are antigenically and structurally related to the major immediate-early (IE) 1 and 2 proteins (IE1p68 and IE2p80, respectively) of HCMV, respectively. In this study, we extended the characterization of p91 and p102 and our results were as follows; (i) Lysine at amino acid position 450 in IE1p68 and at amino acid position 175 or 180 in IE2p80, to which SUMO-1 has been shown to be covalently linked, are required for production of p91 and p102, respectively. (ii) A reversal of cycloheximide (CH) block in the presence of actinomycin D imposed at the time of infection inhibited production of p91, but not p102. (iii) The steady-state levels of p91, but not p102, were remarkably decreased by treatment with proteasome inhibitor MG132, but coincubation with CH inhibited this decrease of p91. (iv) Cell fractionation by differential detergent extraction demonstrated that p91 is preferentially found in detergent-insoluble fraction, although p102 as well as IE1p68 and IE2p80 distributes into all fractions. These results demonstrate that p91 and p102 correspond to SUMO-1-modified IE1p68 and IE2p80, respectively, that the production and degradation of SUMO-1-modified IE1p68 is regulated by mechanisms different from those of SUMO-1-modified IE2p80, and that SUMO-1 modification modulates the intracellular localization of IE1p68, but not IE2p80.

Insertion and excision of a transposable element governs the red floral phenotype in commercial petunias

Commercial cultivars of Petunia hybrida with red flowers (red petunias) accumulate cyanidin 3-glucoside as a main floral anthocyanin pigment. The conversion of anthocyanidin 3-glucosides to anthocyanidin 3-rutinosides is catalyzed by a UDP-rhamnose: anthocyanidin 3-glucoside-rhamnosyltransferase (RT). In red petunias, the RT gene is known to be disrupted by the insertion of a transposable element (dTph3). We have cloned the dTph3-like element (called dTph3-C) from a red petunia. Unlike dTph3, dTph3-C harbored a perfect terminal inverted repeat. In addition, an excision product (so-called "footprint") of dTph3/dTph3-C was found in another red petunia. The RT transcripts harboring this footprint could not produce the RT enzyme because a stop codon was created in the footprint sequence. The genotypes of the 42 commercial petunias which exhibit different anthocyanin pigmentation were determined by multiplex PCR. In this technique, the amplified products from normal, dTph3/dTph3-C-inserted, and footprint-retaining RT genes can be separated from one another. Our results indicate that the red-floral phenotype of commercial petunias is governed by insertion and excision events of a transposable element in the coding region of the RT gene.

Identification of differentially expressed genes involved in colorectal carcinogenesis using a cDNA microarray

To identify candidate genes involved in human colorectal carcinogenesis, we constructed the gene expression profiles of 50 colorectal cancers (CRCs) and 12 normal colorectal epithelia using a cDNA microarray specially constructed for CRC. Hierarchical clustering analysis and principal component analysis could clearly distinguish the gene profiles of cancer tissues from those of normal tissues. Our results confirm there are indeed differences in gene expression between cancer and normal mucosa. Our cDNA microarray identified 22 up-regulated genes and 32 down-regulated genes in CRC. Many of these genes have been previously identified in relation to human carcinogenesis, 68% and 78%, respectively. Subsequent validation of selected genes by serial analysis of gene expression and reverse transcription polymerase chain reaction, demonstrated expression patterns that were almost identical to our microarray analysis. Using a four-fold larger sample relative to that used in our previous study, candidate genes involved in human colorectal carcinogenesis were reproducibly identified. Further studies of comprehensive gene expression using our technique may elucidate the mechanism of CRC tumorigenesis.

Cefoselis, a ?-lactam antibiotic, easily penetrates the blood-brain barrier and causes seizure independently by glutamate release

Cefoselis is a widely used beta-lactam antibiotic, but occasionally induces seizures and convulsion in elder and renal failure patients. However, beta-lactams are known not to pass through the blood-brain barrier (BBB). In this study, we examined the BBB penetration of cefoselis in normal and renal failure rats by means of brain microdialysis. Cefoselis was dose-dependently appeared in brain extracellular fluid in proportion to its blood level. The elimination constant from brain extracellular fluid (apparent) was slightly lower than that from blood. These results indicated that cefoselis might penetrate the BBB or be discharged by a certain transport system. In contrast to the result of cefoselis, cefazolin, a leading drug of cephalosporins, could not be detected in the brain extracellular fluid after an intravenous injection. In renal dysfunction rats, the elimination half-lives of cefoselis from both blood and brain were extensively prolonged. This would be one of responsible factors inducing seizures seen in patients. However, the additional factor, such as decrease in brain function related to aging, would be involved in seizures in patient received cefoselis, because an extremely high dose was required to induce seizures even in renal failure rats. A local administration of cefoselis into the hippocampus through the microdialysis probe caused a striking elevation of extracellular glutamate, with a minimum increase in gamma-aminobutyric acid (GABA). However, a systematic cefoselis administration via the tail vein did not elevate extracellular glutamate and GABA concentrations in the hippocampus of renal failure rats that exhibited marked seizures. These results suggested that not the stimulation of glutamate release, but the blockade of GABA receptors might be responsible for the seizure induced by cefoselis.

Paraquat induces long-lasting dopamine overflow through the excitotoxic pathway in the striatum of freely moving rats

The herbicide paraquat is an environmental factor that could be involved in the etiology of Parkinson's disease. We have previously shown that paraquat penetrates through the blood-brain barrier and is taken up by neural cells. In this study, we examined the in vivo toxic mechanism of paraquat to dopamine neurons. GBR-12909, a selective dopamine transporter inhibitor, reduced paraquat uptake into the striatal tissue including dopaminergic terminals. The subchronic treatment with systemic paraquat significantly decreased brain dopamine content in the striatum and slightly in the midbrain and cortex, and was accompanied by the diminished level of its acidic metabolites in rats. When paraquat was administered through a microdialysis probe, a transitory increase in the extracellular levels of glutamate, followed by long-lasting elevations of the extracellular levels of NO(x)(-) (NO(2)(-) plus NO(3)(-)) and dopamine were detected in the striatum of freely moving rats. This dopamine overflow lasted for more than 24 h after the paraquat treatment. Dopamine overflow was inhibited by N(G)-nitro-L-arginine methyl ester, dizocilpine, 6,7-dinitroquinoxaline-2,3-dione and L-deprenyl. The toxic mechanism of paraquat involves glutamate induced activation of non-NMDA receptors, resulting in activation of NMDA receptor-channels. The influx of Ca(2+) into cells stimulates nitric oxide synthase. Released NO would diffuse to dopaminergic terminals and further induce mitochondrial dysfunction by the formation of peroxynitrite, resulting in continuous and long-lasting dopamine overflow. The constant exposure to low levels of paraquat may lead to the vulnerability of dopaminergic terminals in humans, and might potentiate neurodegeneration caused by the exposure of other substances, such as endogenous dopaminergic toxins.

Clinical significance of normalization of uterine artery pulsatility index with maternal heart rate for the evaluation of uterine circulation in pregnancy-induced hypertension

OBJECTIVE

To investigate whether the use of normalized pulsatility index (PI) improves evaluation of the fetal prognosis in pregnancy-induced hypertension (PIH).

METHOD

Eighty women with uncomplicated pregnancies and 46 women with PIH (33 with pre-eclampsia and 13 with gestational hypertension) were included in the study. Uterine artery PI and normalized PI were analyzed in relation to two neonatal parameters: incidence of small-for-gestational age infants and incidence of Cesarean section for non-reassuring fetal status.

RESULTS

In normal pregnancy, the normalized uterine artery PIs (mean +/- SD) at 25, 31, and 39 weeks of gestation were 0.70 +/- 0.15, 0.71 +/- 0.16, and 0.65 +/- 0.13, respectively. Using non-normalized PI, 10 of 46 PIH cases had increased PI; however, with normalization, two pre-eclampsia cases were added to the group with elevated PI, giving a total of 12. The incidences of small-for-gestational age infants and Cesarean section due to non-reassuring fetal status were higher in the elevated normalized uterine artery PI group. The use of normalized PI appeared to reduce the false-negative results in pre-eclampsia and PIH. After normalization, sensitivity, positive predictive value and negative predictive value of PI for small-for-gestational age infants and Cesarean section due to non-reassuring fetal status were improved in cases with pre-eclampsia and PIH. The incidence of these complications was low in gestational hypertension.

CONCLUSIONS

Normalization of the PI may improve predictive values for small-for-gestational age infants and delivery by cesarean section due to non-reassuring fetal status in PIH.

Antitumor effect of vitamin B6 and its mechanisms

Epidemiological studies have reported an inverse association between vitamin B(6) intake and colon cancer risk. Our recent study has been conducted to examine the effect of dietary vitamin B(6) on colon tumorigenesis in mice. Mice were fed diets containing 1, 7, 14 or 36 mg/kg pyridoxine for 22 weeks, and given a weekly injection of azoxymethane (AOM) for the initial 10 weeks. Compared with the 1 mg/kg pyridoxine diet, 7, 14 and 35 mg/kg pyridoxine diets significantly suppressed the incidence and number of colon tumors, colon cell proliferation and expressions of c-myc and c-fos proteins. Supplemental vitamin B(6) lowered the levels of colonic 8-hydroxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (4-HNE, oxidative stress markers) and inducible nitric oxide (NO) synthase protein. In an ex vivo serum-free matrix culture model using rat aortic ring, supplemental pyridoxine and pyridoxal 5'-phosphate (PLP) had antiangiogenic effect. The results suggest that dietary vitamin B(6) suppresses colon tumorigenesis by reducing cell proliferation, oxidative stress, NO production and angiogenesis.

Construction of comparative cytogenetic maps of the Chinese hamster to mouse, rat and human

We constructed comparative cytogenetic maps of the Chinese hamster to mouse, rat and human by fluorescence in-situ hybridization using 36 cDNA clones of mouse, rat, Syrian hamster, Chinese hamster and human functional genes. In this study, 30 out of the 36 genes were newly mapped to Chinese hamster chromosomes. The chromosomal homology of the Chinese hamster was identified and arranged in 19, 19 and 18 segments of conserved synteny in mouse, rat and human, respectively. Additionally, two of the 19 segments homologous to mouse chromosomes were initially identified in this study.

Norharman, an indoleamine-derived beta-carboline, but not Trp-P-2, a gamma-carboline, induces apoptotic cell death in human neuroblastoma SH-SY5Y cells

Carbolines, azaheterocyclic amines derived from indoleamines, have various biological activities, such as neurotoxicity of beta-carbolines and potent mutagenicity of gamma-carbolines. In this study, structural significance among these carbolines was investigated in relation to the types of cell death, apoptosis and necrosis, using human neuroblastoma SH-SY5Y cells. DNA damage was quantitatively analyzed by a single-cell gel electrophoresis assay. DNA damage was induced by both beta-carbolines, harman and norharman, and gamma-carbolines, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-4-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), in a dose dependent manner. Gamma-carbolines were more potent to damage DNA than beta-carbolines. Alkaline lysis of the cells prevented DNA damage induced by beta-carboline, and pre-treatment of the cells with cycloheximide, an inhibitor of protein synthesis, reduced DNA damage caused by norharman. Morphological observation showed condensed and fragmented nuclei typical for apoptosis, in the cells treated with norharman. Thus, DNA damage induced by norharman was proved to be apoptotic. However, harman, which had a methyl substitution at the position 1, might induce necrosis in the cells. On the other hand, gamma-carbolines, Trp-P-1 and Trp-P-2, directly damaged DNA. Thus, the nitrogen atom at the gamma-position and/or an amino group in carboline structure would be required to induce the direct DNA cleavage.

Glutamate is not involved in the MPP+-induced dopamine overflow in the striatum of freely moving C57BL/6 mice

The role of glutamate in the N-methyl-4-phenyldihydropyridinium (MPP+) toxicity has been argued in the past decade. However, the effects of glutamate efflux and NMDA antagonist on MPP+-induced dopamine overflow have not been documented. To clarify this, we perfused MPP+ through a microdialysis probe in the striatum of freely moving mature C57BL/6 mice. The 60-min perfusion of 10 and 100 microM MPP+ strikingly increased dopamine levels to 28- and 93-fold of the basal values, respectively. In contrast, an administration of MPP+ did not induce marked glutamate release: the MPP+-perfusion slightly increased the glutamate level at 100 microM, but not at 10 microM. The addition of 100 microM (+)-MK-801 or 200 microM (+/-)-AP-7 to the perfusate did not attenuate MPP+-induced dopamine overflow. The extent of dopamine release only depended on the amount of MPP+ accumulation into the cells. These results indicated that, at least in the striatum, neither glutamate release nor the NMDA antagonist, including (+)-MK-801, could regulate MPP+-evoked dopamine overflow.

Expression profile of active genes in the human pituitary gland

To characterize transcripts abundantly expressed in the human pituitary gland in general as well as to isolate novel transcripts expressed specifically in this gland, we generated an expression profile of the active genes transcribed in it. A total of 1015 randomly collected 3prime prime or minute expressed sequence tags (ESTs) (gene signatures, GSs) were grouped into 527GS species. The results showed the relative expression levels of genes in the pituitary gland. The genes comprising more than 1% of total mRNA were prolactin, growth hormone and chromogranin B genes. When known genes were categorized, the genes for pituitary hormones were the most actively transcribed, followed by the genes for ribosomal proteins, nuclear proteins and secretory granule proteins. Through comparison of this gene expression profile with the BodyMap database containing profiles generated from 63 other human tissues, we obtained 11 genes which appeared to be specifically expressed in the pituitary gland. In addition to the eight known genes, we identified three novel pituitary-specific transcripts which encode putative proteins: pituitary gland specific factor 1a (PGSF1a), PGSF1b and PGSF2. This expression profile method is a novel approach to the isolation of pituitary-specific genes that may have important functions.

Early elevation of serum thrombopoietin levels and subsequent thrombocytosis in healthy preterm infants

To verify pathophysiological mechanisms underlying thrombocytosis in low-birth-weight (LBW) preterm babies, we evaluated kinetic changes in platelet counts and thrombopoietic cytokines including thrombopoietin (TPO), interleukin 6 (IL-6) and IL-11 in 24 uncomplicated preterm infants. Platelet counts in cord blood (CB) (265 +/- 64 x 10(9)/l) were similar to adult levels, increased by d 14 (473 +/- 140 x 10(9)/l), and then remained fairly constant. Thrombocytosis (> 500 x 10(9)/l) was observed in 9/24 (38%) subjects. Mean TPO level in CB was 5.11 +/- 1.51 fmol/ml, peaked at d 2 (7.64 +/- 3.28 fmol/ml), decreased at d 5 (3.93 +/- 1.67 fmol/ml), and thereafter kept fairly constant during the remaining neonatal period. Compared with term infants, mean TPO levels of preterm infants in CB and at d 2 were significantly higher (P < 0.01). There was an inverse correlation between platelet counts and TPO levels (r = 0.45, P < 0.001, n = 88). Preterm neonates with thrombocytosis had significantly higher TPO values in CB than those without thrombocytosis (P < 0.05). There was no significant relationship between platelet counts and IL-6. IL-11 was not detectable. These results suggest that an early elevation of serum TPO levels is related to the subsequent thrombocytosis in LBW preterm infants.

Expression of a novel member of the ATP1G1/PLM/MAT8 family, phospholemman-like protein (PLP) gene, in the developmental process of mouse cerebellum

We have identified a new member of the ATP1G1/PLM/MAT8 family, named phospholemman-like protein (PLP), from a mouse cerebellum cDNA library. The family consists of small transmembrane proteins that modulate the activities of some ion channels. The deduced amino acid sequence of PLP consists of 93 residues that contain the ATP1G1/PLM/MAT8 motif and a single transmembrane domain, and is most similar to the sequence of mouse phospholemman. In situ hybridization analysis showed that the PLP gene is highly expressed in cerebellar granule cells. PLP expression is elevated in the postnatal developing cerebellum. Thus, it may be implicated in the proliferation, differentiation, and axon elongation of granule cells as they mature and migrate to the internal granule layer.

The preparation of rapidly disintegrating tablets in the mouth

Elderly people, children and patients sometimes have difficulties swallowing tablets. To solve this problem, a novel method of preparing tablets that disintegrate rapidly in the mouth was developed. A tablet with high porosity is required for rapid disintegration, but such a tablet is generally fragile. To make a tablet having both high porosity and practical strength, amorphous sucrose, which has good compactability, was used. Mannitol powder with freeze-dried amorphous sucrose was tableted at low compression and stored under certain conditions. The tablet disintegrated rapidly in the mouth, because of its high porosity. The tensile strength of the tablet increased remarkably during storage, while the porosity of the tablet seemed almost unchanged. The results of thermal analysis and powder x-ray diffraction measurement showed that the amorphous sucrose in tablet crystallized during storage. The increase in the tensile strength of the tablet was due to crystallization of the amorphous sucrose and formation of new internal contact points in the tablet. It was concluded that this crystalline transition method is a very useful method to prepare a rapidly disintegrating tablet.

Pyridoxal 5'-phosphate and pyridoxal inhibit angiogenesis in serum-free rat aortic ring assay

Supraphysiological doses of vitamin B6 has been reported to suppress tumor growth and metastasis in rodents. To examine if its anticancer effect is due to suppression in angiogenesis, this study was conducted to investigate the antiangiogenic effect of pyridoxal 5'-phosphate (PLP), pyridoxine, pyridoxal and pyridoxamine in an ex vivo serum-free matrix culture model using rat aortic ring. Rat aortic rings were incubated with PLP or pyridoxine (25 micromol/l to 5 mmol/l). Higher concentrations of PLP (2.5 and 5 mmol/l) and pyridoxine (5 mmol/l) caused complete inhibition of microvessel outgrowth. However, the addition of pyridoxine at 2.5 mmol/l did not show complete inhibition of angiogenesis. PLP inhibited microvessel outgrowth almost completely at a concentration of 500 micromol/l and showed antiangiogenic effect in a dose-dependent manner within the range of 25-500 micromol/l. At 250 micromol/l, pyridoxal was as effective as PLP, but pyridoxamine was inactive, implying that the aldehyde group relates to the antiangiogenic effect. These results indicated the antiangiogenic effect of PLP and pyridoxal, and suggested that the antitumor effect of high levels of vitamin B6 might be mediated through suppression of angiogenesis.

Comparative FISH mapping of human cDNA clones to chromosomes of the musk shrew (Suncus murinus, Insectivora)

Forty-one cDNA clones of human functional genes were newly mapped to chromosomes of the musk shrew (Suncus murinus, Insectivora) by fluorescence in situ hybridization, and a comparative cytogenetic map of 51 genes, including 10 genes reported in our previous study, was constructed between human (HSA) and musk shrew (SMU) chromosomes. In this comparative map, the 51 genes localized to human autosomes, except HSA 8, 16, and 20, were mapped to 15 shrew autosomes, except SMU 4, 16, 17 and 18. Twelve conserved segments were identified between human and shrew chromosomes, and six segments among the musk shrew, human, and mouse. Our results defined the presence of at least one inversion and several interchromosomal rearrangements that occurred during evolution after the two species diverged from a common ancestor. Localization of three major histocompatibility complex (MHC) genes to shrew chromosome 3 suggested that the MHC genes of the musk shrew are located in a cluster on chromosome 3. The cytogenetic map constructed in this study is the first cytogenetic map with many functional genes in insectivore species. This approach provides clues for clarifying the chromosomal evolution in this order.

Molecular and functional analyses of the gene (eshA) encoding the 52-kilodalton protein of Streptomyces coelicolor A3(2) required for antibiotic production

Analysis of proteins recovered in the S100 precipitate fraction of Streptomyces griseus after ultracentrifugation led to the identification of a 52-kDa protein which is produced during the late growth phase. The gene (eshA) which codes for this protein was cloned from S. griseus, and then its homologue was cloned from Streptomyces coelicolor A3(2). The protein was deduced to be 471 amino acids in length. The protein EshA is characterized by a central region that shows homology to the eukaryotic-type cyclic nucleotide-binding domains. Significant homology was also found to MMPI in Mycobacterium leprae, a major antigenic protein to humans. The eshA gene mapped near the chromosome end and was not essential for viability, as demonstrated by gene disruption experiments, but its disruption resulted in the abolishment of an antibiotic (actinorhodin but not undecylprodigiosin) production. Aerial mycelium was produced as abundantly as by the parent strain. Expression analysis of the EshA protein by Western blotting revealed that EshA is present only in late-growth-phase cells. The eshA gene was transcribed just preceding intracellular accumulation of the EshA protein, as determined by S1 nuclease protection, indicating that EshA expression is regulated at the transcription level. The expression of EshA was unaffected by introduction of the relA mutation, which blocks ppGpp synthesis.

Five mouse homologues of the human dendritic cell C-type lectin, DC-SIGN

DC-SIGN, a human C-type lectin, is expressed on the surface of dendritic cells (DC), while a closely related human gene, DC-SIGNR or L-SIGN, is found on sinusoidal endothelial cells of liver and lymph node. Both DC-SIGN and DC-SIGNR/L-SIGN can bind ICAM-3 and HIV gp120, and transmit HIV to susceptible cells in trans. Here, we report the cloning of five mouse genes homologous to human DC-SIGN and DC-SIGNR/L-SIGN. Only one gene, named mouse DC-SIGN, is highly expressed in DC, and is not found in a panel of mouse macrophage and lymphocyte cell lines. The other four genes, named mouse SIGNR1 (SIGN-Related gene 1), SIGNR2, SIGNR3 and SIGNR4, are expressed at lower levels in various cells according to RT-PCR and Northern blot analyses on RNA. All the genes of mouse DC-SIGN and SIGNRs map to adjacent regions of chromosome 8 A1.2-1.3. However, like human DC-SIGN, only the mouse DC-SIGN gene is closely juxtaposed to the CD23 gene, while the other four SIGNR genes are located close to each other in a neighboring region. mRNAs of mouse DC-SIGN and three SIGNR genes encode type II transmembrane proteins (DC-SIGN, 238 amino acids; SIGNR1, 325 amino acids; SIGNR3, 237 amino acids; SIGNR4, 208 amino acids), but the SIGNR2 gene only encodes a carbohydrate recognition domain (CRD) without a cytosolic domain and a transmembrane domain (SIGNR2, 178 amino acids). Amino acid sequence similarities between the CRD of human DC-SIGN and the mouse homologues are 67% for DC-SIGN, 69% for SIGNR1, 65% for SIGNR2, 68% for SIGNR3 and 70% for SIGNR4 respectively. However, the membrane proximal neck domains in the mouse genes are much shorter than their counterparts in human DC-SIGN and DC-SIGNR/L-SIGN. This family of mouse C-type lectins is therefore complex, but only one of the new genes, DC-SIGN, is juxtaposed to CD23 and is expressed at high levels in DC.