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1.
Sci Rep ; 11(1): 13771, 2021 07 02.
Article in English | MEDLINE | ID: mdl-34215815

ABSTRACT

Autophagy is a degradation process of cytoplasmic proteins and organelles trafficked to degradation vesicles known as autophagosomes. The conversion of LC3-I to LC3-II is an essential step of autophagosome formation, and FYCO1 is a LC3-binding protein that mediates autophagosome transport. The p62 protein also directly binds to LC3 and is degraded by autophagy. In the present study, we demonstrated that disrupting the FYCO1 gene in mice resulted in cataract formation. LC3 conversion decreased in eyes from FYCO1 knockout mice. Further, FYCO1 interacted with αA- and αB-crystallin, as demonstrated by yeast two-hybrid screening and immunoprecipitation analyses. In eyes from knockout mice, the soluble forms of αA- and αB-crystallin, the lens's major protein components, decreased. In addition, p62 accumulated in eyes from FYCO1 knockout mice. Collectively, these findings suggested that FYCO1 recruited damaged α-crystallin into autophagosomes to protect lens cells from cataract formation.


Subject(s)
Autophagy/genetics , Cataract/genetics , Microtubule-Associated Proteins/genetics , Sequestosome-1 Protein/genetics , Animals , Autophagosomes/genetics , Cataract/pathology , Disease Models, Animal , Humans , Mice , Mice, Knockout , alpha-Crystallin A Chain/genetics , alpha-Crystallin B Chain/genetics
2.
Biosci Biotechnol Biochem ; 83(6): 1094-1101, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30871430

ABSTRACT

Oxidized low-density lipoprotein (ox-LDL) leads to atherosclerosis via lectin-like oxidized lipoprotein receptor-1 (LOX-1), one of the major receptor for ox-LDL. Inhibition of the binding of ox-LDL to LOX-1 decreases the proinflammatory and atherosclerotic events. The aim of the present study was to investigate whether protamine, a polybasic nuclear protein, interferes the binding of ox-LDL to LOX-1. Using sandwich ELISA with newly generated antibody, we measured the blocking effect of protamine on the binding of ox-LDL to LOX-1. Protamine dose-dependently inhibited the binding of ox-LDL to LOX-1. DiI-labeled ox-LDL uptake assay in two types of cultured human endothelial cells was performed with fluorescence microplate reader. Activation of extracellular-signal-regulated kinase (ERK)1/2 by ox-LDL was analyzed by immunoblotting. We found that protamine suppressed uptake of ox-LDL in endothelial cells and inhibited ERK1/2 activation by ox-LDL. These results suggest that protamine may possess anti-atherogenic potential by inhibiting ox-LDL binding to LOX-1 through electrostatic interactions.


Subject(s)
Atherosclerosis/prevention & control , Lipoproteins, LDL/metabolism , Protamines/pharmacology , Scavenger Receptors, Class E/metabolism , Cells, Cultured , Dose-Response Relationship, Drug , Endothelial Cells/metabolism , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Fluorescence , Humans , Lipoproteins, LDL/antagonists & inhibitors , Protamines/administration & dosage , Protein Binding , Scavenger Receptors, Class E/antagonists & inhibitors
3.
Biosci Biotechnol Biochem ; 82(7): 1159-1164, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29685095

ABSTRACT

Malignant mesothelioma is an asbestos-related aggressive tumor and current therapy remains ineffective. Zebularine as a DNA methyltransferase (DNMT) inhibitor has an anti-tumor effect in several human cancer cells. The aim of the present study was to investigate whether zebularine could induce antiproliferative effect in human malignant mesothelioma cells. Zebularine induced cell growth inhibition in a dose-dependent manner. In addition, zebularine dose-dependently decreased expression of DNMT1 in all malignant mesothelioma cells tested. Cell cycle analysis indicated that zebularine induced S phase delay. Zebularine also induced cell death in malignant mesothelioma cells. In contrast, zebularine did not induce cell growth inhibition and cell death in human normal fibroblast cells. These results suggest that zebularine has a potential for the treatment of malignant mesothelioma by inhibiting cell growth and inducing cell death.


Subject(s)
Apoptosis/drug effects , Cell Proliferation/drug effects , Cytidine/analogs & derivatives , Mesothelioma/pathology , S Phase/drug effects , Cell Line, Tumor , Cytidine/pharmacology , DNA (Cytosine-5-)-Methyltransferase 1/antagonists & inhibitors , Dose-Response Relationship, Drug , Fibroblasts/cytology , Fibroblasts/drug effects , Glyceraldehyde-3-Phosphate Dehydrogenases/metabolism , Humans , Mesothelioma/enzymology , Mesothelioma/metabolism , Tumor Suppressor Protein p53/metabolism
4.
Biosci Biotechnol Biochem ; 77(9): 1799-803, 2013.
Article in English | MEDLINE | ID: mdl-24018658

ABSTRACT

Epigallocatechin 3-gallate (EGCG) has cytotoxic effects in many cancer cells. It has been reported that A549 lung cancer cells are markedly resistant to cell death induced by EGCG. In the present study, the effects of EGCG on A549 lung cancer cell growth and angiogenesis were studied. We found that EGCG dose-dependently suppressed A549 cell growth, while A549 cells were markedly resistant to cell death in vitro. Next we found that EGCG increased endostatin expression and suppressed vascular endothelial growth factor (VEGF) expression. We further studied to determine whether EGCG would suppress A549 tumor growth in nude mouse and angiogenesis. EGCG in drinking water significantly suppressed A549 tumor growth in nude mice. Histological analysis revealed that the number of CD34 positive vessels had a tendency to decrease in the tumor. In sum, EGCG had anti-proliferative effects of A549 on tumor growth and showed a tendency to suppress angiogenesis.


Subject(s)
Antineoplastic Agents/pharmacology , Catechin/analogs & derivatives , Lung Neoplasms/pathology , Neovascularization, Pathologic/drug therapy , Animals , Antineoplastic Agents/therapeutic use , Catechin/pharmacology , Catechin/therapeutic use , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Endostatins/genetics , Gene Expression Regulation, Neoplastic/drug effects , Humans , Lung Neoplasms/blood supply , Lung Neoplasms/genetics , Male , Mice , Mice, Inbred BALB C , RNA, Messenger/genetics , RNA, Messenger/metabolism , Vascular Endothelial Growth Factor A/genetics , Xenograft Model Antitumor Assays
5.
Cancer Cell Int ; 13(1): 19, 2013 Feb 23.
Article in English | MEDLINE | ID: mdl-23432995

ABSTRACT

Malignant mesothelioma is an asbestos-related fatal disease with no effective cure. We studied whether a green tea polyphenol, epigallocathechin-3-gallate (EGCG), could induce cell death in five human mesothelioma cell lines. We found that EGCG induced apoptosis in all five mesothelioma cell lines in a dose-dependent manner. We further clarified the cell killing mechanism. EGCG induced reactive oxygen species (ROS), and impaired the mitochondrial membrane potential. As treatment with ROS scavengers, catalase and tempol, significantly inhibited the EGCG-induced apoptosis, ROS is considered to be responsible for the EGCG-induced apoptosis. Further, we found that EGCG induced autophagy, and that when autophagy was suppressed by chloroquine, the EGCG-induced cell death was enhanced. Taken together, these results suggest that EGCG has a great potential for the treatment of mesothelioma by inducing apoptosis and autophagy.

6.
Neuropharmacology ; 61(4): 857-66, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21683087

ABSTRACT

The amygdala receives dopaminergic innervation, and dopamine (DA) enhances various activities in cognitive and emotional behaviors. Periodic bursts of spontaneous inhibitory postsynaptic currents (IPSCs) with a low (<1 Hz) inter-event frequency have been observed in projection neurons of the basolateral nucleus of the amygdala (BL). Blockade of ionotropic glutamate receptors or GABA(A) receptors abolishes these oscillatory IPSC bursts in the BL, suggesting that the activity has a network origin. Here, we investigated dopaminergic modulation of the oscillatory network inhibition in rat brain slices. We evaluated the effects of DA receptor agonists and antagonists on the network inhibition; the resultant changes were quantified by integrated power spectral density (0.1-3.0 Hz). DA enhanced the power when its initial activity was low, but reduced it when the activity was initially robust. These changes in the power were accompanied by changes in burst IPSC amplitude. D1-like receptor agonist SKF 38393, or DA together with the D2-like receptor antagonist sulpiride, reproduced DA's facilitatory actions. D2-like receptor agonist quinpirole did not change the periodic IPSC burst activity of the high baseline power, though D(4) receptor agonist PD 168077, or DA together with the D1-like receptor antagonist SCH 23390, reduced its activity. These results suggest that: 1) dopaminergic modulation of the oscillatory network inhibition depends on its initial activity; and 2) facilitatory and suppressing effects of DA in the BL are mediated by D1-like receptors and D(4) receptors, respectively.


Subject(s)
Amygdala/physiology , Biological Clocks/physiology , Dopamine/physiology , Inhibitory Postsynaptic Potentials/physiology , Nerve Net/physiology , Neural Inhibition/physiology , Amygdala/drug effects , Animals , Biological Clocks/drug effects , Dopamine Agonists/pharmacology , Dopamine Antagonists/pharmacology , Female , Inhibitory Postsynaptic Potentials/drug effects , Male , Nerve Net/drug effects , Neural Inhibition/drug effects , Rats , Rats, Wistar , Receptors, Dopamine D1/agonists , Receptors, Dopamine D1/antagonists & inhibitors , Receptors, Dopamine D1/physiology , Receptors, Dopamine D4/agonists , Receptors, Dopamine D4/antagonists & inhibitors , Receptors, Dopamine D4/physiology
7.
Vasc Health Risk Manag ; 7: 125-7, 2011.
Article in English | MEDLINE | ID: mdl-21468171

ABSTRACT

Venous thromboembolism (VTE) and related pulmonary thromboembolism are life-threatening diseases that require efficient diagnosis and clinical management. While the diagnosis and treatment of VTE in hospitalized patients has been extensively studied, less has been reported on walk-in patients with VTE. Here we report on four outpatients with VTE that were efficiently diagnosed using the blood D-dimer test and successfully treated.


Subject(s)
Fibrin Fibrinogen Degradation Products/analysis , Venous Thromboembolism/diagnosis , Aged , Aged, 80 and over , Ambulatory Care , Anticoagulants/therapeutic use , Biomarkers/blood , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Pulmonary Embolism/etiology , Pulmonary Embolism/prevention & control , Tomography, X-Ray Computed , Treatment Outcome , Ultrasonography , Venous Thromboembolism/blood , Venous Thromboembolism/complications , Venous Thromboembolism/diagnostic imaging , Venous Thromboembolism/drug therapy
8.
9.
Biomed Res ; 31(2): 113-22, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20460739

ABSTRACT

We recently demonstrated that short time exposure to hypoxia (15 min) in H9c2 cardiomyocytes protected cells against cell death, and longer exposure to hypoxia induced cell death. To understand the molecular mechanism concerning cell death and survival, it is intriguing to identify survival factors against cell death. Using proteomics analysis, levels of proteins derived from H9c2 cells exposed to hypoxia and normoxia were compared and candidates for survival factor were identified. One of the candidates was a prohibitin. Overexpression of prohibitin inhibited H9c2 cell death induced by hypoxia for longer hours. We further clarified the mechanism of cell death. Overexpression of prohibitin inhibited decrease of mitochondrial membrane potential levels, decrease of Bcl-2 level in mitochondria and cytochrome c release to cytosol from mitochondria induced by hypoxia. The mechanism for survival was that overexpression of prohibitin inhibited cytochrome c release by decrease of mitochondrial membrane potential levels and decrease of Bcl-2 level. Taken together, identified prohibitin may function as a survival factor against hypoxiainduced cell death.


Subject(s)
Myocytes, Cardiac , Animals , Cell Death/genetics , Cell Hypoxia/genetics , Cytochrome c Group , Cytochromes c/genetics , Cytochromes c/metabolism , Cytosol/metabolism , Genes, bcl-2 , Hypoxia/genetics , Hypoxia/metabolism , Membrane Potential, Mitochondrial/genetics , Mitochondria/genetics , Mitochondria/metabolism , Mitochondria/physiology , Myocytes, Cardiac/cytology , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/physiology , Prohibitins , Rats , Repressor Proteins
10.
Biochem Biophys Res Commun ; 394(2): 249-53, 2010 Apr 02.
Article in English | MEDLINE | ID: mdl-20171954

ABSTRACT

Malignant mesothelioma is an asbestos-related fatal disease with no effective cure. Recently, high dose of ascorbate in cancer treatment has been reexamined. We studied whether high dose of ascorbic acid induced cell death of four human mesothelioma cell lines. High dose of ascorbic acid induced cell death of all mesothelioma cell lines in a dose-dependent manner. We further clarified the cell killing mechanism that ascorbic acid induced reactive oxygen species and impaired mitochondrial membrane potential. In vivo experiment, intravenous administration of ascorbic acid significantly decreased the growth rate of mesothelioma tumor inoculated in mice. These data suggest that ascorbic acid may have benefits for patients with mesothelioma.


Subject(s)
Apoptosis , Ascorbic Acid/administration & dosage , Mesothelioma/drug therapy , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Membrane Potential, Mitochondrial/drug effects , Mice , Mice, SCID , Reactive Oxygen Species/metabolism , Xenograft Model Antitumor Assays
11.
Reprod Toxicol ; 29(3): 317-22, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20067830

ABSTRACT

We investigated the effects that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure has on the prostate in rhesus monkey offspring. Dams received 0, 30 or 300 ng/kg TCDD subcutaneously on Day 20 of gestation, and then 5% of the initial dose was injected every 30 days until Day 90 after delivery. The offspring were maintained until reaching sexual maturity, and examined histopathologically. Dose-dependent decreases in glands of the prostate and widespread fibrosis were observed in offspring. It is noteworthy that 7 years from the final lactational TCDD exposure, inflammatory cell infiltration and disruption of glands of the prostate were still observed. Differential mRNA expression associated with fibrosis, inflammatory response and disruption of cell components were demonstrated by microarray analysis, with up-regulation of TGM4, TGFB1, COL1A1 and MMP2 confirmed. In conclusion, in utero and lactational exposure to TCDD induced dose-related prostatic fibrosis, indicating prostatic dysfunction and inducible semen quality reduction in second-generation rhesus monkeys.


Subject(s)
Lactation/drug effects , Polychlorinated Dibenzodioxins/pharmacology , Prostate/drug effects , Animals , Dioxins , Dose-Response Relationship, Drug , Female , Fibrosis/metabolism , Macaca mulatta , Male , Musculoskeletal System/metabolism , Polychlorinated Dibenzodioxins/administration & dosage , Polychlorinated Dibenzodioxins/metabolism , Pregnancy , Prostate/metabolism , Semen Analysis , Up-Regulation
12.
Circ J ; 74(1): 109-19, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19966499

ABSTRACT

BACKGROUND: Although therapeutic angiogenesis is a most promising strategy for the treatment of myocardial infarction (MI), it remains unknown if and how endogenous angiogenesis inhibitors, such as endostatin, regulate angiogenesis in MI. In the present study the role of endostatin in left ventricular (LV) remodeling and heart failure was tested in a rat MI model. METHODS AND RESULTS: When exposed to hypoxia, rat cardiomyocytes showed increased expression of endostatin. After MI induction in the rat MI model, endostatin expression was upregulated in cardiomyocytes, and serum endostatin levels were significantly elevated. Anti-endostatin antibody treatment resulted in significantly higher mortality of MI rats than controls. The MI rats with endostatin neutralization displayed adverse LV remodeling and severe heart failure compared with control MI rats. Although angiogenesis was increased, tissue remodeling and interstitial fibrosis were further exaggerated in post-MI hearts by endostatin neutralization. Furthermore, the expression and protease activity of matrix metalloproteinases -2 and -9, and of angiotensin-converting enzyme were markedly elevated by endostatin neutralization. CONCLUSIONS: Neutralization of endostatin worsens the symptoms and outcomes of MI in a rat model. The results imply that endogenous endostatin/collagen XVIII may suppress aberrant LV remodeling and heart failure after MI. (Circ J 2010; 74: 109 - 119).


Subject(s)
Collagen Type XVIII/antagonists & inhibitors , Endostatins/antagonists & inhibitors , Heart Failure/physiopathology , Myocardial Infarction/physiopathology , Ventricular Remodeling/physiology , Animals , Cells, Cultured , Collagen Type XVIII/immunology , Collagen Type XVIII/physiology , Disease Models, Animal , Endostatins/immunology , Endostatins/physiology , Heart Failure/metabolism , Immunoglobulin G/pharmacology , Male , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Mice , Myocardial Infarction/metabolism , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Neovascularization, Physiologic/drug effects , Neovascularization, Physiologic/physiology , Peptidyl-Dipeptidase A/metabolism , Rats , Rats, Sprague-Dawley , Rats, Wistar
13.
Reprod Toxicol ; 28(4): 495-502, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19703549

ABSTRACT

A long-term developmental toxicity study of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure was performed in rhesus monkeys and the effect on male reproductive organs was determined in the second generation. Dams received 0, 30 or 300 ng/kg TCDD subcutaneously on Day 20 of gestation, and then 5% of the initial dose was injected every 30 days until Day 90 after delivery. The offspring were maintained until reaching sexual maturity, and evaluated by semen analysis, and histopathology of the testes and epididymides. Ejaculated sperm concentration was severely reduced at 300 ng/kg, and sperm viability and activity were dose-proportionally reduced, although effects on spermatogenesis were slight. Histomorphometry revealed markedly reduced area of the ductus epididymis accompanying decreased reserved sperm in the 30 and 300 ng/kg groups. In conclusion, in utero and lactational exposure to TCDD induced a reduction of sperm quality in rhesus monkeys.


Subject(s)
Epididymis/drug effects , Maternal-Fetal Exchange , Polychlorinated Dibenzodioxins/toxicity , Prenatal Exposure Delayed Effects , Spermatogenesis/drug effects , Animals , Dose-Response Relationship, Drug , Female , Lactation , Longitudinal Studies , Macaca mulatta , Male , Milk/chemistry , Pregnancy , Sexual Maturation/drug effects , Sperm Count/methods
14.
Toxicology ; 253(1-3): 147-52, 2008 Nov 20.
Article in English | MEDLINE | ID: mdl-18835322

ABSTRACT

Bone tissue is one of the target tissues for dioxins and dioxin-like compounds. Therefore, the aim of this study was to investigate effects of in utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on bone tissue in rhesus monkey, the most human-like experimental model available. Pregnant rhesus monkeys (Macaca mulatta; age 4-10 years) were exposed to TCDD with a total dose of 40.5-42.0 or 405-420ng/kg bodyweight by repeated subcutaneous injections starting at gestational day 20 and followed by injections every 30 days until 90 days after delivery. At a mean age of 7 years the offspring were sacrificed and the femur bone dissected. Results from peripheral Quantitative Computed Tomography (pQCT) analyses of the metaphyseal part of the femur bones in female offspring showed significant increases in trabecular bone mineral content (BMC; +84.6%, p<0.05, F-value (F)=5.9) in the low-dose treatment group compared with the controls. In the same animals, analysis of the mid-diaphyseal part revealed increases in total BMC (+21.3%, p<0.05, F=5.2) and cortical cross-sectional area (CSA; +16.4%, p<0.01, F=7.4) compared with the controls. In males, changes in biomechanical properties indicating more fragile bone were observed. Displacement at failure were significantly increased in the male low-dose group compared to the controls (+38.0%, p<0.05, F=11). The high dose of TCDD did not induce any significant changes in bone morphology. In conclusion, in utero and lactational low-dose, but not high-dose exposure to 2,3,7,8-TCDD induced disruption of bone tissue development in rhesus monkey, a result suggesting that similar effects might occur in humans also.


Subject(s)
Bone Development/drug effects , Fetal Development/drug effects , Polychlorinated Dibenzodioxins/toxicity , Prenatal Exposure Delayed Effects , Animals , Biomechanical Phenomena/drug effects , Bone Density/drug effects , Diaphyses/anatomy & histology , Diaphyses/drug effects , Diaphyses/embryology , Dose-Response Relationship, Drug , Female , Femur/anatomy & histology , Femur/drug effects , Femur/embryology , Immunohistochemistry , Lactation , Longitudinal Studies , Macaca mulatta , Male , Models, Animal , Organ Size/drug effects , Pregnancy , Reproducibility of Results , Tomography, X-Ray Computed
15.
Toxicology ; 250(2-3): 96-9, 2008 Sep 04.
Article in English | MEDLINE | ID: mdl-18611425

ABSTRACT

We recently reported that para-nonylphenol, an environmental chemical, induced hydroxyl radical (*OH) formation in rat striatum. In this study we examined the antioxidant effects of angiotensin-converting enzyme inhibitors (captopril or enalaprilat) on para-nonylphenol (nonylphenol) and 1-methyl-4-phenylpyridinium ion (MPP(+))-induced hydroxyl radical (*OH) formation and dopamine (DA) efflux in extracellular fluid of rat striatum, using a microdialysis technique. para-Nonylphenol clearly enhanced *OH formation and DA efflux induced by MPP(+). When captopril or enalaprilat was infused in nonylphenol and MPP(+)-treated rats, DA efflux and OH formation significantly decreased, as compared with that in the nonylphenol and MPP(+)-treated control. We compared the ability of non-SH-containing enalaprilat with a SH-containing captopril to scavenge OH and DA efflux. Both inhibitors were able to scavenge *OH and DA efflux induced by para-nonylphenol and MPP(+). The results suggest that angiotensin-converting enzyme inhibitors may protect against nonylphenol and MPP(+)-induced *OH formation via suppressing DA efflux in the rat striatum.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Captopril/pharmacology , Dopamine/metabolism , Enalaprilat/pharmacology , Hydroxyl Radical/metabolism , Neostriatum/metabolism , Phenols/toxicity , 1-Methyl-4-phenylpyridinium/toxicity , Animals , Catechols/pharmacology , Dopamine Agents/toxicity , Dose-Response Relationship, Drug , Hydroxybenzoates , Iron/pharmacology , Male , Neostriatum/drug effects , Rats , Rats, Wistar
16.
Biosci Biotechnol Biochem ; 72(3): 872-6, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18323634

ABSTRACT

In many organisms, glycogen gives rise to 1,5-anhydro-D-fructose (AF), which is reduced to 1,5-anhydro-D-glucitol (AG). AF reductase, which catalyzes the latter reaction, was purified from pig liver, but mouse ortholog has not yet been reported. In the database, aldo-keto reductase family 1, member E1 (AKR1E1) showed highest homology to pig enzyme. We confirmed that cloned AKR1E1 is mouse ortholog based on enzymatic properties of purified recombinant protein.


Subject(s)
Alcohol Oxidoreductases/chemistry , Sugar Alcohol Dehydrogenases/chemistry , Alcohol Oxidoreductases/genetics , Alcohol Oxidoreductases/isolation & purification , Aldehyde Reductase , Aldo-Keto Reductases , Amino Acid Sequence , Animals , Cloning, Molecular , Mice , Molecular Sequence Data , Sequence Alignment , Sequence Homology, Amino Acid , Sugar Alcohol Dehydrogenases/isolation & purification , Sus scrofa
17.
Cancer Cell Int ; 8: 2, 2008 Jan 21.
Article in English | MEDLINE | ID: mdl-18208615

ABSTRACT

BACKGROUND: Polyamines and ornithine decarboxylase (ODC) are essential for cell proliferation. DL-alpha-difluoromethylornithine (DFMO), a synthetic inhibitor of ODC, induces G1 arrest through dephosphorylation of retinoblastoma protein (pRb). The effect of DFMO on cell growth of pRb deficient cells is not known. We examined the effects of DFMO on pRb deficient human retinoblastoma Y79 cell proliferation and its molecular mechanism. METHODS: Using cultured Y79 cells, the effects of DFMO were studied by using polyamine analysis, western blot, gel shift, FACS and promoter analysis. RESULTS: DFMO suppressed the proliferation of Y79 cells, which accumulated in the G1 and S phase. DFMO induced p27/Kip1 protein expression, p107 dephosphorylation and accumulation of p107/E2F-4 complex in Y79 cells. CONCLUSION: These results indicate that p107 dephosphorylation and accumulation of p107/E2F-4 complex is involved in G1 and S phase arrest of DFMO treated Y79 cells.

19.
Cancer ; 109(5): 993-1002, 2007 Mar 01.
Article in English | MEDLINE | ID: mdl-17318877

ABSTRACT

BACKGROUND: Substantial evidence supports a direct role of ornithine decarboxylase (ODC) in the development and maintenance of human tumors. Although antisense oligonucleotide therapy targeting various genes are useful for cancer treatment, 1 of the major limitations is the problem of delivery. A novel antisense oligonucleotide delivery method is described that allows prolonged sustainment and release of ODC antisense oligonucleotides in vivo using atelocollagen. METHODS: The effect of ODC antisense oligonucleotides in the atelocollagen on cell growth of gastrointestinal cancer (MKN 45 and COLO201) and rhabdomyosarcoma (RD) was studied in vitro using a cell-counting method with a hemocytometer. In vivo, the effect of intratumoral, intramuscular, and intraperitoneal single administration of ODC antisense oligonucleotides in the atelocollagen on tumor growth of MKN45, COLO201, and RD cells was studied. ODC activity and polyamine contents were measured. RESULTS: In vitro, ODC antisense oligonucleotides in the atelocollagen remarkably suppressed MKN45, COLO201, and RD cell growth. A single administration of antisense oligonucleotides in the atelocollagen via 3 routes remarkably suppressed the growth of MKN45, COLO201, and RD tumor over a period of 35-42 days. CONCLUSIONS: As various human cancers significantly express ODC, the results strongly suggest that this new antisense method may be of considerable value for treatment of human cancers.


Subject(s)
Collagen/administration & dosage , Drug Delivery Systems/methods , Neoplasms, Experimental/drug therapy , Oligonucleotides, Antisense/administration & dosage , Ornithine Decarboxylase Inhibitors , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Mice , Mice, Nude , Ornithine Decarboxylase/genetics
20.
Chemosphere ; 67(9): S399-404, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17223175

ABSTRACT

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) accumulates and remains stable in the fatty tissues and liver of rodents for a long time. Considering the pronounced difference between species, long-term, low dose hepatic effects of TCDD were investigated after subcutaneous administration of TCDD into rhesus monkeys during pregnancy. Macroscopic and histopathological examination of the liver carried out 4 y after TCDD administration demonstrated intrahepatic focal fatty changes, infarction, hemorrhage, microthrombi-formation, sinusoidal ectasia, small hepatocyte hyperplasia, and increased number of alpha-smooth muscle actin (alpha-SMA)-positive cells. An electron microscopic study disclosed sinusoidal endothelial cell degeneration and injury in the liver of TCDD-treated monkeys. Western blot analysis showed downregulation of aryl hydrocarbon receptor (AhR) protein expression and decreased level of vascular endothelial (VE) cadherin but increased expression levels of CYP1A1 and transforming growth factor beta (TGF-beta) protein in the liver tissues. These changes observed in TCDD-exposed monkeys indicated sinusoidal endothelial cell injury and impairment in intrasinusoidal microcirculation. Infarction, focal fatty change, and microthrombi-formation are considered to be closely associated with intrahepatic circulatory impairment. Increased number of alpha-SMA-positive cells and decreased level of VE cadherin expression in the liver tissues might also be associated with sinusoidal endothelial cell injury. In addition, downregulation of AhR expression and increased CYP1A1 protein levels in the liver were consistent with persistent effects of TCDD. Although it has been reported that TCDD induced endothelial cell injury, this is the first report to describe vascular disorders and protein expression in the liver after injection with TCDD in a primate model.


Subject(s)
Chemical and Drug Induced Liver Injury , Endothelial Cells/drug effects , Polychlorinated Dibenzodioxins/toxicity , Animals , Antigens, CD/genetics , Antigens, CD/metabolism , Blotting, Northern , Cadherins/genetics , Cadherins/metabolism , Cytochrome P-450 CYP1A1/genetics , Cytochrome P-450 CYP1A1/metabolism , Endothelial Cells/pathology , Fatty Liver/chemically induced , Fatty Liver/pathology , Female , Hemorrhage/chemically induced , Hemorrhage/pathology , Infarction/chemically induced , Infarction/pathology , Injections, Subcutaneous , Liver Diseases/metabolism , Liver Diseases/pathology , Macaca mulatta , Microscopy, Electron , Muscle, Smooth/metabolism , Muscle, Smooth/pathology , Polychlorinated Dibenzodioxins/administration & dosage , Pregnancy , Receptors, Aryl Hydrocarbon/genetics , Receptors, Aryl Hydrocarbon/metabolism , Thrombosis/chemically induced , Thrombosis/pathology , Time Factors , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/metabolism
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