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1.
Hepatogastroenterology ; 60(124): 943-8, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23298900

ABSTRACT

BACKGROUNDS/AIMS: It has been previously demonstrated that vitamin D acts as a prognostic indicator of gastric cancer and may be correlated with the incidence risk of gastric cancer. However, the effect of 1,25-dihydroxyvitamin D3 on the apoptosis of human gastric cancer cells is unclear. The aim of this study was to determine whether 1,25-dihydroxyvitamin D3 induced the cellular apoptosis of BGC-823 gastric cancer cells and to determine the potential mechanism of action. METHODOLOGY: We demonstrate that 1,25-dihydroxyvitamin D3 induced the apoptosis of gastric cancer cells via the processing of PARP and cleavage of caspase 3. Additionally, an increase in BAX expression and a decrease in ERK1/2 and AKT phosphorylation were associated with 1,25-dihydroxyvitamin D3-induced apoptosis. The mRNA expression levels of VDR, CYP24A1, and p21 were increased significantly following 1,25-dihydroxyvitamin D3 treatment. CONCLUSIONS: These findings suggest that 1,25-dihydroxyvitamin D3 exerts tumor-suppressive effects on BGC-823 human gastric cancer cells.


Subject(s)
Apoptosis/drug effects , Stomach Neoplasms/drug therapy , Vitamin D/analogs & derivatives , Blotting, Western , Cyclin-Dependent Kinase Inhibitor p21/drug effects , Humans , In Vitro Techniques , MAP Kinase Signaling System/drug effects , Phosphorylation , Proto-Oncogene Proteins c-akt/drug effects , Receptors, Calcitriol/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Steroid Hydroxylases/drug effects , Tumor Cells, Cultured/drug effects , Vitamin D/pharmacology , Vitamin D3 24-Hydroxylase , bcl-2-Associated X Protein/drug effects
2.
Cardiovasc Drugs Ther ; 25(3): 215-22, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21424825

ABSTRACT

PURPOSE: Vitamin D receptor (VDR) activation is associated with cardiovascular benefits in chronic kidney disease patients, but whether VDR's hormone and prehormone exhibit similar effects requires more studies. METHODS: Neonatal rat cardiomyocytes were treated with VDR agonists (calcitriol and/or paricalcitol) and the prehormone calcidiol in the presence of aldo (1 µM). The expression of VDR target genes were determined by real-time PCR and Western blotting. The expression and activity of CYP27B1 (the enzyme responsible for converting calcidiol to calcitriol) was measured. RESULTS: Treating cells with aldo (1 µM) for 24 h significantly reduced the VDR mRNA (29%) and protein levels (>90%). Calcitriol and calcidiol induced VDR expression in the presence of aldo with EC(50) at 0.3 and 7,952 nM, respectively. Calcitriol, paricalcitol and calcidiol stimulated CYP24A1 (EC(50) at 6.4, 4.5 and 992 nM, respectively) and suppressed NPPB expression (IC(50) at 1.9, 0.1 and 210 nM, respectively) in the presence of 1 µM aldo. Neonatal rat cardiomyocytes expressed CYP27B1 and converted calcidiol to calcitriol at a low rate (~10% in 24 h). CONCLUSIONS: VDR hormone calcitriol and its analog paricalcitol exhibit more potent effects than the prehormone calcidiol in cardiomyocytes.


Subject(s)
Calcifediol/pharmacology , Calcitriol/pharmacology , Ergocalciferols/pharmacology , Receptors, Calcitriol/agonists , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/genetics , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/metabolism , Aldosterone/administration & dosage , Animals , Animals, Newborn , Blotting, Western , Gene Expression Regulation/drug effects , Humans , Polymerase Chain Reaction , Rats , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/genetics , Vitamin D3 24-Hydroxylase
3.
Toxicol Lett ; 200(1-2): 88-91, 2011 Jan 15.
Article in English | MEDLINE | ID: mdl-21056093

ABSTRACT

Cytochrome P450 (CYP) enzymes are widely studied for their involvement in metabolism of drugs and endogenous compounds. In porcine liver, CYP1A2, 2A and 2E1 are important for the metabolism of skatole. Feeding chicory roots to pigs is known to decrease the skatole concentration in plasma and fat. In the present study we investigated the effect of chicory on CYP mRNA and protein expression, as well as their activity. Male pigs were feed dried chicory root for 16 days before liver samples were collected. By the use of RT-PCR and Western blotting we showed that the mRNA and protein expression of CYP1A2 and 2A were increased in chicory fed pigs. The mRNA expression of CYP2E1 was increased, while there was no effect on protein expression. Activity of CYP1A2 and 2A were increased in chicory feed pigs; this was not the case for CYP2E1 activity. In conclusion; oral administration of chicory root for 16 days to pigs increased the mRNA expression of CYP1A2, 2A and 2E1; and the protein expression of CYP1A2 and 2A. The activities of CYP1A2 and 2A were increased.


Subject(s)
Cichorium intybus , Cytochrome P-450 Enzyme System/drug effects , Microsomes, Liver/enzymology , Plant Preparations/pharmacology , Plant Roots , Animals , Aryl Hydrocarbon Hydroxylases/drug effects , Aryl Hydrocarbon Hydroxylases/metabolism , Blotting, Western , Cytochrome P-450 CYP1A2/drug effects , Cytochrome P-450 CYP1A2/metabolism , Cytochrome P-450 CYP2E1/drug effects , Cytochrome P-450 CYP2E1/metabolism , Cytochrome P-450 Enzyme System/metabolism , Enzyme Activation/drug effects , Inactivation, Metabolic , Male , Microsomes, Liver/drug effects , RNA, Messenger/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/metabolism , Swine
4.
Anticancer Agents Med Chem ; 10(3): 213-24, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20184548

ABSTRACT

There is increasing evidence linking the incidence of certain cancers to low serum Vitamin D levels. The active metabolite of Vitamin D, calcitriol (1, 25-Dihydroxyvitamin D(3), 1,25(OH)(2)D(3)) apart from a crucial role in maintaining mineral homeostasis and skeletal functions, has antiproliferative, apoptosis and differentiation inducing as well as immunomodulatory effects in cancer. In studying the role of 1,25(OH)(2)D(3) in cancer, it is imperative to examine the potential pathways that control local tissue levels of 1,25(OH)(2)D(3). The enzyme CYP24A1 or 24-hydroxylase converts 1,25(OH)(2)D(3) to inactive calcitroic acid. Extra-renal production of this enzyme is observed and has been increasingly recognized as present in cancer cells. This enzyme is rate limiting for the amount of local 1,25(OH)(2)D(3) in cancer tissues and elevated expression is associated with an adverse prognosis. The gene that encodes CYP24A1 has been reported as an oncogene and may contribute to tumor aggressiveness by abrogating local anti-cancer effects of 1,25(OH)(2)D(3). It is imperative to study the regulation of CYP24A1 in cancer and especially the local metabolism of 1,25(OH)(2)D(3) in cancer cells. CYP24A1 may be a predictive marker of 1,25(OH)(2)D(3) efficacy in patients with cancer as an adjunctive therapy. The following review summarizes the available literature on CYP24A1 as it relates to 1,25(OH)(2)D(3) in cancer and outlines potential ways to inhibit CYP24A1 in an effort to improve the efficacy of exogenous 1,25(OH)(2)D(3).


Subject(s)
Calcitriol/metabolism , Neoplasms/metabolism , Steroid Hydroxylases/metabolism , Antineoplastic Agents/pharmacology , Drug Synergism , Gene Expression Regulation, Neoplastic , Humans , Neoplasms/drug therapy , Neoplasms/genetics , Steroid Hydroxylases/antagonists & inhibitors , Steroid Hydroxylases/drug effects , Vitamin D/pharmacology , Vitamin D Deficiency/enzymology , Vitamin D3 24-Hydroxylase
5.
Eur J Clin Invest ; 40(1): 25-34, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20055894

ABSTRACT

BACKGROUND: Osteoporosis is a common complication in chronic cholestasis. It has been proposed that retained substances such as bile acids may produce a damaging effect on bone cells. This study analyses the effects of lithocholic acid (LCA) on cell survival and vitamin D metabolism in human osteoblasts (hOB). MATERIALS AND METHODS: Human osteoblasts cultures were performed with or without foetal bovine serum (FBS) or human albumin (HA) at different LCA concentrations and times with or without vitamin D. RESULTS: Lithocholic acid at concentrations higher than 10(-5 )M decreased cell survival. This effect was partially prevented by the presence of FBS or HA. Vitamin D stimulated CYP24A, BGLAP and TNFSF11 expression in hOB and these effects were modified by nontoxic LCA concentrations. LCA significantly decreased vitamin D stimulation of CYP24A, BGLAP and TNFSF11 gene expression at 72%, 79% and 56% (respectively). LCA alone has an agonistic effect, as has vitamin D, thus partially increasing CYP24A and BGLAP expression, but with no changes on TNFRSF11B expression. Equivalent effects of the LCA were observed by performing gene reporter assays using MG-63 cells transfected with constructs containing CYP24A1 promoter regions. CONCLUSIONS: Lithocholic acid decreases the stimulatory effect of vitamin D on CYP24A, BGLAP and TNFSF11 expression in hOB. This effect is produced through vitamin D response elements (VDREs), located in the promoter regions of these genes, suggesting that LCA acts as a mild analogous of vitamin D, interacting with the vitamin D receptor. These results may explain the potential deleterious effects of retained bile acids on hOB.


Subject(s)
Cholestasis/complications , Lithocholic Acid/pharmacology , Osteoblasts/drug effects , Osteoporosis/metabolism , Vitamin D/metabolism , Cell Survival , Cells, Cultured , Cholestasis/metabolism , Down-Regulation , Humans , Osteoblasts/metabolism , Osteocalcin/drug effects , Osteocalcin/metabolism , Osteoporosis/genetics , Osteoprotegerin/drug effects , Osteoprotegerin/metabolism , Promoter Regions, Genetic/drug effects , RANK Ligand/drug effects , RANK Ligand/metabolism , RNA/genetics , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/metabolism , Transfection , Vitamin D/pharmacology , Vitamin D3 24-Hydroxylase
6.
Cancer Prev Res (Phila) ; 2(1): 43-51, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19139017

ABSTRACT

Postmenopausal hormone replacement therapy lowers colon cancer incidence. In humans, the mechanism is unknown, but animal models suggest that it may involve activation of the vitamin D receptor (VDR) pathway. The aims of our study were to determine whether estrogen intervention affects global gene expression in rectal mucosal biopsies and whether vitamin D-related genes are affected. Estradiol was given to raise serum estradiol to premenopausal levels in 10 postmenopausal women under close nutritional control. Primary end points were expression of VDR, CYP24A1, CYP27B1, and E-cadherin in rectal mucosa by reverse transcription-PCR and examining response to estradiol by genome-wide arrays. Responses in gene expression in rectal biopsies to estrogen were determined in each subject individually and compared with a human estrogen response gene array database and a custom array in vitro-generated database. Cluster analysis showed that subjects maintained their overall gene expression profile and that interindividual differences were greater than intraindividual differences after intervention. Eight of 10 subjects showed significant enrichment in estrogen-responsive genes. Gene array group analysis showed activation of the VDR pathway and down-regulation of inflammatory and immune signaling pathways. Reverse transcription-PCR analysis showed significant up-regulation of VDR and E-cadherin, a downstream target of vitamin D action. These data suggest that the chemopreventive action of hormone replacement therapy on colon neoplasia results, at least in part, from changes in vitamin D activity. Evaluation of gene arrays is useful in chemopreventive intervention studies in small groups of subjects.


Subject(s)
Colorectal Neoplasms/prevention & control , Estradiol/therapeutic use , Estrogen Replacement Therapy , Estrogens/therapeutic use , Gene Expression/drug effects , Vitamin D/metabolism , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/drug effects , 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/metabolism , Chemoprevention , Colorectal Neoplasms/metabolism , Female , Gene Expression Profiling , Humans , Middle Aged , Receptors, Calcitriol/drug effects , Receptors, Calcitriol/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/metabolism , Vitamin D3 24-Hydroxylase
7.
J Toxicol Environ Health A ; 71(23): 1542-9, 2008.
Article in English | MEDLINE | ID: mdl-18923996

ABSTRACT

Phthalate esters were reported to damage fetal and postnatal testes of experimental animals, but the molecular mechanisms underlying these effects remain unknown. The time-response effects of di(n-butyl) phthalate (DBP) on the expression patterns of the testicular genes in male Sprague-Dawley rats were examined for different periods of exposure (1, 7, 14, or 28 d). The steroidogenic- or spermatogenic-related gene expression patterns were measured using reverse-transcription polymerase chain reaction (RT-PCR). After 28 d of exposure, the serum concentrations of DBP and monobutyl phthalate (MBP) increased in a dose-dependent manner, and were significantly higher in the DBP-treated rats than in the control rats. Liver weight was increased markedly at 28 d after DBP exposure at 750 mg/kg/d. Testicular weight was reduced significantly after 14 and 28 d of exposure. DBP (750 mg/kg/d) produced a significant increase in scavenger receptor class B1 (SR-B1) and steroidogenic acute regulatory (StAR) mRNA after 14 and 28 d of exposure. The level of cytochrome P-450 (P450) side-chain cleavage (P450scc) mRNA decreased in the group treated with DBP at 750 mg/kg/d at 7 d. After 14 and 28 d of exposure, there was an apparent increase in P450scc mRNA. High doses of DBP significantly increased the Cyp17 mRNA level after 28 d of exposure. At 7 d, a significant decrease in Cyp19 mRNA was observed only in the group exposed to 750 mg/kg/d DBP. In addition, DBP significantly decreased the levels of a spermatid-specific gene (Spag4) and lactate dehydrogenase A (LDHA) mRNA after 7 d of exposure. The levels of androgen receptor (AR), estrogen receptor-alpha (ER-alpha), and retinoid X receptor-gamma (RXR-r) expression decreased significantly in a time- or dose-dependent manner. DBP significantly increased the peroxisome proliferator-activated receptor-gamma (PPAR-r) and phosphorylated extracellular-signal-regulated kinase (p-ERK1/2) levels in the testis. These results suggest that the acute and chronic effects of DBP on the steroidogenic pathways in the testes show mechanistically distinct patterns. Data thus provide some insights into the molecular mechanisms underlying DBP-induced testicular dysgenesis.


Subject(s)
Dibutyl Phthalate/adverse effects , Plasticizers/adverse effects , Steroid Hydroxylases/drug effects , Testis/drug effects , Animals , Carrier Proteins/drug effects , Gene Expression/drug effects , Male , Membrane Proteins , Rats , Rats, Sprague-Dawley , Testis/pathology , Time
8.
Carcinogenesis ; 29(12): 2394-9, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18780894

ABSTRACT

While numerous microRNAs (miRNAs) have been reported to alter their expression levels in human lung cancer tissues compared with normal tissues, the function of these miRNAs and their contribution to the long process of lung cancer development remains largely unknown. We applied a tobacco-specific carcinogen-induced cancer model to investigate the involvement of miRNAs in early lung cancer development, which could also provide information on potential, early biomarkers of lung cancers. Male F344 rats were first chronically treated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a carcinogen present in tobacco products, for up to 20 weeks. The expression profiles of miRNAs in rat lungs were then determined. As measured by miRNA microarrays and confirmed by Northern blot and real-time polymerase chain reaction analyses, NNK treatment reduced the expression of a number of miRNAs, such as miR-101, miR-126*, miR-199 and miR-34. Significantly, these miRNAs overlap with previously published reports on altered miRNA expression in human lung cancer samples. These miRNAs might, therefore, represent early-response miRNAs that signify the molecular changes associated with pulmonary tumorigenesis. Moreover, we identified cytochrome P450 (CYP) 2A3, a critical enzyme in rat lungs that activates NNK to render it carcinogenic, as a potential target of miR-126*. NNK treatment in rats repressed miR-126* but induced CYP2A3 expression, a mechanism that may potentiate the oncogenic effects of NNK.


Subject(s)
Carcinogens/toxicity , Cell Transformation, Neoplastic/genetics , Lung Neoplasms/chemically induced , Lung Neoplasms/genetics , MicroRNAs/drug effects , Nitrosamines/toxicity , Animals , Aryl Hydrocarbon Hydroxylases/drug effects , Aryl Hydrocarbon Hydroxylases/metabolism , Blotting, Northern , Blotting, Western , Cell Transformation, Neoplastic/drug effects , Gene Expression/drug effects , Gene Expression Profiling , Male , MicroRNAs/genetics , Oligonucleotide Array Sequence Analysis , Rats , Rats, Inbred F344 , Reverse Transcriptase Polymerase Chain Reaction , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/metabolism , Nicotiana/chemistry
9.
Int J Pharm ; 359(1-2): 174-81, 2008 Jul 09.
Article in English | MEDLINE | ID: mdl-18513900

ABSTRACT

Paclitaxel is widely used to treat several types of solid tumors. The commercially available paclitaxel formulation contains Cremophor/ethanol as solubilizers. This study evaluated the effects of D-alpha-tocopheryl polyethylene glycol 400 succinate (TPGS 400) on the oral absorption of paclitaxel in mice. Mice were given an intravenous (18mg/kg) or oral (100mg/kg) dose of paclitaxel solubilized in Cremophor/ethanol or in TPGS 400/ethanol formulations. Paclitaxel plasma concentrations and pharmacokinetic parameters were determined. The maximal plasma concentrations of paclitaxel after an oral dose were 1.77+/-0.17 and 3.39+/-0.49microg/ml for Cremophor/ethanol and TPGS 400/ethanol formulations, respectively, with a similar time at 40-47min to reach the maximal plasma concentrations. The oral bioavailability of paclitaxel in TPGS 400/ethanol (7.8%) was 3-fold higher than that in Cremophor/ethanol (2.5%). On the other hand, the plasma pharmacokinetic profiles of intravenous paclitaxel demonstrated a superimposition for the two formulations. Furthermore, TPGS 400 concentration-dependently increased the intracellular retention of Rhodamine 123 in Caco-2 cells and enhanced paclitaxel permeability in monolayer Caco-2 cultures. TPGS 400 at concentrations up to 1mM did not inhibit testosterone 6beta-hydroxylase, a cytochrome P450 isozyme 3A in liver microsomes metabolizing paclitaxel. Our results indicated that TPGS 400 enhances the oral bioavailability of paclitaxel in mice and the enhancement may result from an increase in intestinal absorption of paclitaxel.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacokinetics , Paclitaxel/pharmacokinetics , Solvents/chemistry , Vitamin E/analogs & derivatives , Administration, Oral , Animals , Antineoplastic Agents, Phytogenic/administration & dosage , Biological Availability , Caco-2 Cells , Ethanol/chemistry , Glycerol/analogs & derivatives , Glycerol/chemistry , Humans , Injections, Intravenous , Male , Mice , Mice, Inbred BALB C , Microsomes, Liver/drug effects , Microsomes, Liver/enzymology , Paclitaxel/administration & dosage , Permeability , Polyethylene Glycols/chemistry , Rhodamine 123/pharmacokinetics , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/metabolism , Vitamin E/chemistry
11.
Article in Polish | MEDLINE | ID: mdl-17507873

ABSTRACT

Isoflavonoids exert a regulatory function on the expression of cytochrome P450 enzymes and also up-regulate the vitamin D(3) receptor (VDR) on cancer cells, which increase their sensitivity to 1,25-dihydroxyvitamin D(3) , the hormonally active form of vitamin D(3) . Isoflavonoids are also able to raise the serum level of the active form of vitamin D(3) due to their inhibitory activity on CYP24, the enzyme involved in the degradation of 1,25-dihydroxyvitamin D(3) and its precursor 25-OH-D(3) to inactive compounds. Another enzyme, CYP27B1, involved in the synthesis of 1,25-dihydroxyvitamin D(3) , is stimulated by isoflavonoids, and this may result in a similar effect of increasing in the serum level of 1,25-dihydroxyvitamin D3. CYP27B1 and CYP24 were found in kidneys (the main location of 1,25-(OH) (2)D(3) synthesis) and also in brain cells, osteoclasts, keratinocytes, macrophages, intestine epithelial cells, and in some cancer cells. The expression of VDR was detected not only in the cells primarily targeted by 1,25-dihydroxyvitamin D3, but also in epithelial and mesenchymal cells. Therefore, combined treatment with isoflavonoids and 1,25-dihydroxyvitamin D3 might be effective in both cancer prevention and treatment.


Subject(s)
25-Hydroxyvitamin D3 1-alpha-Hydroxylase/drug effects , Antineoplastic Agents, Hormonal/pharmacology , Cholecalciferol/pharmacology , Isoflavones/pharmacology , Receptors, Calcitriol/drug effects , Steroid Hydroxylases/drug effects , Animals , Antineoplastic Agents, Phytogenic/pharmacology , Cholecalciferol/physiology , Colonic Neoplasms/drug therapy , Colonic Neoplasms/enzymology , Female , Humans , Isoflavones/genetics , Isoflavones/metabolism , Male , Mice , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/enzymology , Receptors, Calcitriol/physiology , Resveratrol , Steroid Hydroxylases/antagonists & inhibitors , Stilbenes/metabolism , Stilbenes/pharmacology , Tumor Cells, Cultured , Up-Regulation/physiology , Vitamin D3 24-Hydroxylase
12.
Hepatology ; 44(1): 263-74, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16799984

ABSTRACT

The mechanisms by which alcohol causes liver injury are still not certain. Either LPS or CYP2E1 are considered independent risk factors involved in alcoholic liver disease, but mutual relationships or interactions between them are unknown. In the present study, the possible synergistic action of CYP2E1 and LPS in liver injury was investigated by evaluating the effects of pyrazole (inducer of CYP2E1), Chlormethiazole (CMZ), an inhibitor of CYP2E1, and CYP2E1-knockout mice. Mice were injected with pyrazole (150 mg/kg, ip) daily for 2 days, followed by LPS injection (4 mg/kg, ip). CMZ (50mg/kg, ip) was administered 15 h before and 30 min after LPS treatment, respectively. LPS-induced liver injury was enhanced by pyrazole, as indicated by pathological changes and increases in ALT and AST, and positive TUNEL staining. LPS-induced oxidative stress was also enhanced by pyrazole as indicated by increases in 4-hydroxy-2-nonenal and 3-nitrotyrosine adduct formation. CMZ protected against the pyrazole enhanced LPS liver injury and oxidative stress. CYP2E1 but also CYP2A5 were increased by the pyrazole/LPS treatment. CMZ decreased the elevated CYP2E1 activity by 90%, but CYP2A5 activity was also lowered (30%-50%). CYP2E1-knockout mice exhibited only minor liver injury after treatment with pyrazole/LPS, but wild-type mice exhibited severe liver injury. While no CYP2E1 was present in the CYP2E1 knockout mice, CYP2A5 activity was also lower. In conclusion, induction of CYP2E1 plays an important role in the enhancement of LPS liver injury by pyrazole, but some contribution by CYP2A5 cannot be excluded.


Subject(s)
Aryl Hydrocarbon Hydroxylases/metabolism , Cytochrome P-450 CYP2E1/metabolism , Enzyme Inhibitors/pharmacology , Liver Diseases/metabolism , Pyrazoles/pharmacology , Steroid Hydroxylases/metabolism , Alcohol Dehydrogenase/antagonists & inhibitors , Animals , Aryl Hydrocarbon Hydroxylases/drug effects , Blotting, Western , Chemical and Drug Induced Liver Injury , Cytochrome P-450 CYP2E1/drug effects , Disease Models, Animal , Disease Progression , Drug Synergism , In Situ Nick-End Labeling , Lipopolysaccharides/toxicity , Liver Diseases/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Oxidative Stress/drug effects , Severity of Illness Index , Steroid Hydroxylases/drug effects
13.
Mar Environ Res ; 62 Suppl: S322-6, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16709434

ABSTRACT

Normal operation of oil well platforms results in the discharge of "produced formation water" (PFW). The expression of CYP1A, CYP2M1- and 2K1-like proteins was examined for use as possible biomarkers of PFW exposure. A pilot study at the Harriet A production platform, on the Northwest Shelf of Australia, had indicated that PFW contamination possibly contributes to induction of CYP1A- and 2K1/2M1-like proteins in Gold-Spotted Trevally (Carangoides fulvoguttatus). In a subsequent caged fish study in the same location, Stripey seaperch (Lutjanus carponotatus) were caught at a clean site, then distributed to three caging sites: A (near-field), B (far-field) and C (a non-impacted reference site). Fish were sampled at time T = 0, 3 and 10 days. Significant increases of CYP1A, one CYP2K1- and two CYP2M1-like proteins were noted at Site A at T = 10. For another CYP2K1-like protein, a significant increase was observed at Site A only at T = 3. Prevailing winds changed between days 6 and 8 of sampling, moving the surface water plume directly west, possibly impacting in situ PFW exposure. The results indicate that tropical fish CYP1A protein is sensitive to PFW exposure. Importantly, statistically significant environmental induction of both CYP2M1- and CYP2K1-like proteins in tropical fish due to PFW exposure had not previously been described and CYP2 family induction may represent possible new biomarkers (other than CYP1A) of PFW exposure. In addition, the novel fraction-specific response of CYP2K-like proteins requires further verification but offers promise for improved monitoring of sub-lethal responses in marine organisms. (Supported by Australian Institute of Marine Science, Apache Energy Ltd. and the Environmental Toxicology Research Program at The University of Mississippi).


Subject(s)
Cytochrome P-450 Enzyme System/drug effects , Fish Proteins/drug effects , Gene Expression Regulation, Enzymologic/drug effects , Perciformes/physiology , Water Pollutants, Chemical/pharmacology , Animals , Aryl Hydrocarbon Hydroxylases/biosynthesis , Aryl Hydrocarbon Hydroxylases/drug effects , Aryl Hydrocarbon Hydroxylases/genetics , Australia , Cytochrome P-450 CYP1A1/biosynthesis , Cytochrome P-450 CYP1A1/drug effects , Cytochrome P-450 CYP1A1/genetics , Cytochrome P-450 Enzyme System/biosynthesis , Cytochrome P-450 Enzyme System/genetics , Cytochrome P450 Family 2 , Environmental Exposure , Fish Proteins/biosynthesis , Fish Proteins/genetics , Geography , Mixed Function Oxygenases/biosynthesis , Mixed Function Oxygenases/drug effects , Mixed Function Oxygenases/genetics , Steroid Hydroxylases/biosynthesis , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/genetics , Time Factors , Tropical Climate
14.
J Neurol Sci ; 243(1-2): 83-6, 2006 Apr 15.
Article in English | MEDLINE | ID: mdl-16445943

ABSTRACT

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder of bile acid synthesis, caused by impaired hydroxylation of cholesterol side chains due to deficiency of the mitochondrial enzyme sterol 27-hydroxylase (CYP27A1), leading to accumulation of cholestanol and cholesterol in brain and other tissues. Elevated plasma cholestanol serves as a key marker for the clinical diagnosis of CTX. In the present report we describe a young man with CTX who was on high dose steroids for a misdiagnosed chronic inflammatory demyelinating polyneuropathy (CIDP) and had normal level of serum cholestanol. When steroids were discontinued, markedly elevated serum cholestanol was measured concomitant with marked clinical worsening. This observation may imply that steroids can lower plasma cholestanol, possibly by directly inducing residual CYP27A1 activity or by inducing alternative pathways for cholestanol elimination.


Subject(s)
Cholestanol/blood , Diagnostic Errors/prevention & control , Steroid Hydroxylases/drug effects , Steroids/pharmacology , Xanthomatosis, Cerebrotendinous/blood , Xanthomatosis, Cerebrotendinous/diagnosis , Achilles Tendon/drug effects , Achilles Tendon/pathology , Achilles Tendon/physiopathology , Adult , Brain/metabolism , Brain/physiopathology , Chenodeoxycholic Acid/therapeutic use , Cholestanetriol 26-Monooxygenase , Cholesterol/metabolism , Diagnosis, Differential , Disease Progression , Down-Regulation/drug effects , Down-Regulation/physiology , Humans , Male , Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/drug therapy , Prednisone/pharmacology , Prednisone/therapeutic use , Simvastatin/therapeutic use , Steroid Hydroxylases/deficiency , Steroid Hydroxylases/genetics , Steroids/therapeutic use , Treatment Outcome , Up-Regulation/physiology , Xanthomatosis, Cerebrotendinous/drug therapy
15.
Cancer Lett ; 234(2): 232-8, 2006 Mar 28.
Article in English | MEDLINE | ID: mdl-15893417

ABSTRACT

We have reported that pretreatment by stomach tube with 8-methoxypsoralen (methoxsalen; 8-MOP), a potent human CYP2A6 inhibitor, strongly suppresses lung tumorigenesis by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in female A/J mice (Cancer Res. 2003). Here, we examined inhibitory effects with administration in the diet. When the mice were 7 weeks of age, they received dietary supplementation with 8-MOP at concentrations of 1, 10 or 100 ppm for 3 days prior to a single dose of NNK (2mg/0.1 ml saline/mouse, i.p.) or an equal volume of saline (vehicle control). The experiment was terminated 16 weeks after the first 8-MOP treatment and lung proliferative lesions were analyzed. The incidences and multiplicities in the 8-MOP 100 ppm-treated group were significantly reduced as compared with values for the NNK alone group (P<0.001). Multiplicities of NNK-induced lung proliferative lesions were also reduced in a dose dependent manner (Spearman rank correlation coefficient; rho=-0.806, correction P<0.0001). Mouse CYP2A4 and CYP2A5 differ from each other only 11 amino acids, and are closely related to the human CYP2A6. One hour after the last of three daily doses of 8-MOP (0.5, 5 or 50mg/kg body weight in 0.2 ml corn oil, given by stomach tube) or an equal volume of corn oil (vehicle control), given to the mice at 7 weeks of age, isolation of lung and liver RNAs demonstrated no effects on CYP2A4 and CYP2A5 mRNA levels with 8-MOP. In conclusion, the results of this study showed that clear dose response inhibitory effects of 8-MOP on NNK-induced lung tumorigenesis in female A/J mice fed diets containing 8-MOP, due to inhibition of enzyme activity of CYP2A4 and CYP2A5, rather than their gene expression.


Subject(s)
Carcinogens/toxicity , Lung Neoplasms/drug therapy , Methoxsalen/administration & dosage , Nitrosamines/toxicity , Administration, Oral , Animals , Aryl Hydrocarbon Hydroxylases/biosynthesis , Aryl Hydrocarbon Hydroxylases/drug effects , Cytochrome P-450 CYP2A6 , Cytochrome P450 Family 2 , Dose-Response Relationship, Drug , Female , Gene Expression/drug effects , Humans , Lung Neoplasms/chemically induced , Mice , Mixed Function Oxygenases/biosynthesis , Mixed Function Oxygenases/drug effects , RNA, Messenger/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Steroid Hydroxylases/biosynthesis , Steroid Hydroxylases/drug effects
17.
Clin Exp Metastasis ; 22(3): 265-73, 2005.
Article in English | MEDLINE | ID: mdl-16158254

ABSTRACT

The 20-30 year latency period for prostate cancer provides an important opportunity to prevent the development of invasive cancer. A logical approach for chemoprevention to reduce incidence is to identify agents, such as, vitamin D, which can inhibit cell proliferation and induce differentiation, are safe, and readily available to the public at low cost. Epidemiological evidence suggests that vitamin D deficiency is associated with increased risk for prostate cancer. We examined the ability and mechanisms of action of cholecalciferol (vitamin D(3)), a precursor of the most biologically active hormone calcitriol, to block or reverse premalignant changes. The immortalized, non-tumorigenic, RWPE-1 human prostate epithelial cell line, was used. Results show that cholecalciferol, at physiological levels: (i) inhibits anchorage-dependent growth (ii) induces differentiation by increasing PSA expression and (iii) exerts its effects by up-regulating vitamin D receptor (VDR), retinoid-X receptors (RXRs), and androgen receptor (AR). Furthermore, we discovered that human prostate epithelial cells constitutively express appreciable levels of 25-hydroxylase CYP27A1 protein, the enzyme which catalyzes the conversion of cholecalciferol to 25(OH)D(3), and that CYP27A1 is up-regulated by cholecalciferol. Recent studies show that human mitochondrial CYP27A1 can also catalyze 1alpha-hydroxylation of 25(OH)D(3) to calcitriol. The presence of 25-hydroxylase in human prostate epithelial cells has not previously been shown. Since human prostate epithelial cells have the necessary enzymes and the rare ability to locally convert cholecalciferol to the active hormone calcitriol, we propose that they are a prime target for chemoprevention of prostate cancer with cholecalciferol whose safety is well established as a supplement in vitamins and fortified foods.


Subject(s)
Chemoprevention , Cholecalciferol/pharmacology , Epithelial Cells/metabolism , Prostatic Neoplasms/prevention & control , Steroid Hydroxylases/metabolism , Calcitriol/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Cholecalciferol/therapeutic use , Cholestanetriol 26-Monooxygenase , Dose-Response Relationship, Drug , Epithelial Cells/drug effects , Humans , Male , Molecular Structure , Prostate-Specific Antigen/biosynthesis , Prostate-Specific Antigen/drug effects , Prostatic Neoplasms/drug therapy , Receptors, Androgen/biosynthesis , Receptors, Androgen/drug effects , Receptors, Calcitriol/biosynthesis , Receptors, Calcitriol/drug effects , Retinoid X Receptors/biosynthesis , Retinoid X Receptors/drug effects , Steroid Hydroxylases/drug effects
18.
Clin Exp Metastasis ; 22(3): 275-84, 2005.
Article in English | MEDLINE | ID: mdl-16158255

ABSTRACT

Epidemiological evidence suggests an inverse relationship between prostate cancer and serum vitamin D levels. We examined the ability of cholecalciferol (vitamin D(3)), a calcitriol precursor, to inhibit or reverse cellular changes associated with malignant transformation and invasion and explored its mechanisms of action. The RWPE2-W99 human prostate epithelial cell line, which forms slow-growing tumors in nude mice, was used because it mimics the behavior of the majority of primary human prostate cancers. Cholecalciferol, at physiological levels: (i) inhibited anchorage-dependent and -independent growth; (ii) induced differentiation by decreasing vimentin expression with a concomitant decrease in motility/chemotaxis; (iii) decreased MMP-9 and MMP-2 activity with concomitant decrease in invasion; and (iv) exerted its effects by up-regulating vitamin D receptor (VDR), retinoid-X receptor-alpha (RXR-alpha), and androgen receptor (AR) in a dose-dependent manner. Furthermore, we found that RWPE2-W99 prostate cancer cells, similar to RWPE-1 cells (Tokar and Webber. Clin Exp Metast 2005; 22: 265-73), constitutively express the enzyme 25-hydroxylase CYP27A1 which is markedly up-regulated by cholecalciferol. Cholecalciferol has effects similar to those of calcitriol on growth, MMP activity, and VDR. The ability of CYP27A1 to catalyze the conversion of cholecalciferol to 25(OH)D(3) and of 25(OH)D(3) to calcitriol has been reported. RWPE2-W99 cells, similar to RWPE-1 cells, appear to have the rare ability to locally convert cholecalciferol to the active hormone calcitriol. Because it can inhibit cellular changes associated with malignant transformation and invasion, we propose that cholecalciferol may be an effective agent for the treatment of prostate cancer.


Subject(s)
Cholecalciferol/pharmacology , Neoplasm Invasiveness/prevention & control , Prostatic Neoplasms/drug therapy , Receptors, Cytoplasmic and Nuclear/metabolism , Steroid Hydroxylases/metabolism , Calcitriol/pharmacology , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Chemotaxis/drug effects , Cholestanetriol 26-Monooxygenase , Colony-Forming Units Assay/methods , Dose-Response Relationship, Drug , Humans , Male , Matrix Metalloproteinase 2/drug effects , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/drug effects , Matrix Metalloproteinase 9/metabolism , Prostatic Neoplasms/pathology , Receptors, Androgen/biosynthesis , Receptors, Androgen/drug effects , Receptors, Calcitriol/biosynthesis , Receptors, Calcitriol/drug effects , Receptors, Cytoplasmic and Nuclear/drug effects , Retinoid X Receptors/biosynthesis , Retinoid X Receptors/drug effects , Steroid Hydroxylases/biosynthesis , Steroid Hydroxylases/drug effects , Vimentin/biosynthesis , Vimentin/drug effects
19.
Gen Comp Endocrinol ; 138(2): 148-56, 2004 Sep 01.
Article in English | MEDLINE | ID: mdl-15302264

ABSTRACT

Many genes involved in gonadal development have been proposed for mammals. To elucidate if those genes play any critical role in sexual differentiation of the avian gonad, we have examined expressions of the genes for proposed sex-determining factors (SF1, Sox9, DMRT1, Wpkci, and AMH), steroidogenic enzymes (P-450scc, 3beta-HSD, P-450c17, 17beta-HSD and aromatase) and the estrogen receptor in the urogenital system during chicken embryogenesis (days 4-16 of incubation), using a semi-quantitative reverse transcription-polymerase chain reaction. Transcripts of the genes for sex-determining factors except Wpkci and AMH were detected in both sexes but had no sexual dimorphism. Wpkci expression was female specific and constantly high throughout incubation. AMH was expressed in both sexes from the earliest stages but was higher in males than in females after the onset of gonadal differentiation. Expressions of the genes for more downstream enzymes in a steroidogenic pathway, such as P-450c17, 17beta-HSD and aromatase, were clearly higher in females than in males. In particular, 17beta-HSD expression increased in the course of gonadal development in females, whereas it was constantly low in males. Aromatase was highly expressed in females during gonadal differentiation but not in males over the period. In addition, to elucidate the relationship between gene activation during embryogenesis and reproductive abnormalities in wild birds, we examined expressions of these genes in embryos treated with various doses of diethylstilbestrol (DES), as a representative estrogenic compound. DES had no effect on the expressions of all the genes in either sex during the periods of gonadal differentiation (days 8, 12, and 16). Sexual dimorphism of the gene expression for steroidogenic enzymes appeared to be closely related to gonadal development in the chicken embryo, especially in the female. However, all the genes examined here seem unlikely to respond to xenoestrogens.


Subject(s)
Diethylstilbestrol/pharmacology , Gene Expression Regulation, Developmental , Hydroxysteroid Dehydrogenases/genetics , Sex Differentiation/genetics , Steroid Hydroxylases/genetics , Transcription Factors/genetics , Animals , Chick Embryo , Embryonic Development/drug effects , Estrogens, Non-Steroidal/pharmacology , Female , Gene Expression Regulation, Developmental/drug effects , Gonads/drug effects , Gonads/embryology , Hydroxysteroid Dehydrogenases/drug effects , Male , Reverse Transcriptase Polymerase Chain Reaction , Sex Determination Processes , Sex Differentiation/drug effects , Steroid Hydroxylases/drug effects , Transcription Factors/drug effects , Transcriptional Activation
20.
J Leukoc Biol ; 76(3): 727-34, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15197231

ABSTRACT

Transport of cholesterol out of macrophages is critical for prevention of foam cell formation, the first step in the pathogenesis of atherosclerosis. Proteins involved in this process include cholesterol 27-hydroxylase and adenosine 5'-triphosphate-binding cassette transporter A1 (ABCA1). Proinflammatory cytokines and immune complexes (IC) down-regulate cholesterol 27-hydroxylase and impede cholesterol efflux from macrophages, leading to foam cell formation. Prior studies have suggested occupancy of the anti-inflammatory adenosine A2A receptor (A2AR) minimizes early atherosclerotic changes in arteries following injury. We therefore asked whether A2AR occupancy affects macrophage foam cell formation in response to IC and the cytokine interferon-gamma. We found that the selective A2AR agonist 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamido-adenosine (CGS-21680) inhibited foam cell formation in stimulated THP-1 human macrophages, and the effects of CGS-21680 were reversed by the selective A2AR antagonist 4-(2-[7-amino-2-(2-furyl) [1, 2, 4]triazolo[2,3-a] [1, 3, 5]triazin-5-ylamino]ethyl)phenol. In confirmation of the role of A2AR in prevention of foam cell formation, CGS-21680 also inhibited foam cell formation in cultured murine peritoneal macrophages but did not affect foam cell formation in A2AR-deficient mice. Agents that increase foam cell formation also down-regulate cholesterol 27-hydroxylase and ABCA1 expression. Therefore, we determined the effect of A2AR occupancy on expression of these reverse cholesterol transport (RCT) proteins and found that A2AR occupancy stimulates expression of message for both proteins. These results indicate that one mechanism for the antiatherogenic effects of adenosine is stimulation of the expression of proteins involved in RCT. These findings suggest a novel approach to the development of agents that prevent progression of atherosclerosis.


Subject(s)
Adenosine/analogs & derivatives , Carrier Proteins/metabolism , Cell Differentiation/immunology , Cholesterol/metabolism , Foam Cells/metabolism , Macrophages/metabolism , Receptor, Adenosine A2A/metabolism , ATP Binding Cassette Transporter 1 , ATP-Binding Cassette Transporters/drug effects , ATP-Binding Cassette Transporters/genetics , ATP-Binding Cassette Transporters/metabolism , Adenosine/pharmacology , Adenosine A2 Receptor Agonists , Adenosine A2 Receptor Antagonists , Animals , Arteriosclerosis/immunology , Arteriosclerosis/metabolism , Arteriosclerosis/physiopathology , Carrier Proteins/drug effects , Cell Differentiation/drug effects , Cholestanetriol 26-Monooxygenase , Cyclic AMP/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Down-Regulation/drug effects , Down-Regulation/genetics , Down-Regulation/immunology , Foam Cells/drug effects , Foam Cells/immunology , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Enzymologic/genetics , Gene Expression Regulation, Enzymologic/immunology , Humans , Macrophages/drug effects , Macrophages/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Phenethylamines/pharmacology , RNA, Messenger/drug effects , RNA, Messenger/metabolism , Steroid Hydroxylases/drug effects , Steroid Hydroxylases/genetics , Steroid Hydroxylases/metabolism , Triazines/pharmacology , Triazoles/pharmacology , Up-Regulation/drug effects , Up-Regulation/genetics , Up-Regulation/immunology
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