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1.
J Neurooncol ; 107(3): 551-7, 2012 May.
Article in English | MEDLINE | ID: mdl-22246201

ABSTRACT

The treatment for spinal sarcomas is difficult due to inadequate surgical margin and an inability to deliver high dose radiation. Advanced technology of stereotactic radiosurgery (SRS) enabled higher biological effective doses of radiation to be delivered to spinal sarcomas by hypofractionation method. The authors evaluated local control rate following SRS for primary and metastatic spinal sarcomas. Thirty-two spinal sarcomas (10 primary tumors, 22 metastatic tumors) in 27 patients were treated by SRS from November 2002 to September 2009. Patients were assessed for pain status, neurological status and radiological response by regular follow-up. Overall survival and local progression-free survival were calculated and prognostic factors were sought. Median tumor volume was 18.6 ml. Radiation doses to the tumor margins ranged from 16 to 45 Gy in one to three fractions, and the median single session equivalent dose was 21.8 Gy. Follow-up ranged from 4 to 68 months (median, 22 months). Overall median survival was 29 months and no related prognostic factors were identified. During follow-up, pain was controlled in 89.3% (25/28) lesions at 6 months, in 68.2% (15/22) at 1 year, and in 61.5% (8/13) at 2 years. Tumor volume was found to be significantly related to post-SRS pain control rate. Radiological evaluation showed that local control was maintained in 96.7% (29/30) lesions at 6 months, in 78.3% (18/23) at 1 year, and in 76.9% (10/13) at 2 years. Radiation dose and tumor volume were found to be related to radiological control at 24 months following SRS. Nine cases developed recurrence between 2 and 33 months, median local progression-free survival was 23 months. Age was found to be predictive of local progression-free survival (P = 0.009). SRS proved to be an effective modality for the local control of primary and metastatic spinal sarcomas, and age was significantly related to local recurrence.


Subject(s)
Radiosurgery/methods , Sarcoma/surgery , Spinal Neoplasms/surgery , Adolescent , Adult , Age Factors , Aged , Child , Cohort Studies , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Pain Measurement , Radiotherapy Dosage , Retrospective Studies , Sarcoma/mortality , Spinal Neoplasms/mortality , Young Adult
3.
Acta Anaesthesiol Scand ; 55(1): 110-7, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21039351

ABSTRACT

BACKGROUND: this study was to estimate the predicted effect-site concentration of propofol administered by a target-controlled infusion (TCI) for maintenance of anesthesia based on the bispectral (BIS) index as a measure of hypnosis in laparoscopic surgery. METHOD: one-hundred and sixty unpremedicated patients undergoing gynecologic laparoscopy were assigned randomly to receive one of the target effect-site concentrations of propofol 2.0, 2.5, 3.0, 3.5 and 4.0 microg/ml during TCI with propofol and sufentanil. The dose-response relationship of propofol for the maintenance of adequate anesthesia based on BIS, movement and hemodynamic response was investigated using a fixed effect-site concentration of sufentanil (0.2 ng/ml). The BIS values, hemodynamic variables, time course during emergence and intraoperative awareness were also assessed. RESULTS: the predicted effect-site propofol concentrations for adequate anesthesia at the skin incision in 50% (EC(50) ) and 95% (EC(95) ) of patients undergoing gynecologic laparoscopy were 2.2 and 3.7 microg/ml, respectively. The predicted propofol EC(50) and EC(95) to maintain adequate anesthesia in these patients were 2.6 microg/ml (95% CI 2.3-2.7 microg/ml) and 3.6 microg/ml (95% CI 3.3-4.0 microg/ml), respectively. The BIS values, effect-site concentration of propofol, hemodynamic data and time course during emergence and post-operative adverse events were comparable in each group. There were no reports of intraoperative awareness in the post-anesthetic care unit. CONCLUSION: based on the anesthetic depth assessed by the clinical signs and BIS monitoring, the predicted effect-site propofol concentrations for the maintenance of anesthesia in patients undergoing gynecologic laparoscopy were similar in those administered adequate anesthesia at the skin incision during TCI.


Subject(s)
Anesthesia, Intravenous , Anesthetics, Intravenous/administration & dosage , Gynecologic Surgical Procedures , Laparoscopy , Propofol/administration & dosage , Sufentanil/administration & dosage , Adolescent , Adult , Anesthesia, Intravenous/adverse effects , Anesthetics, Intravenous/adverse effects , Blood Pressure/drug effects , Consciousness Monitors , Dose-Response Relationship, Drug , Electroencephalography , Female , Forecasting , Hemodynamics/drug effects , Humans , Infusions, Intravenous , Intraoperative Awareness/epidemiology , Middle Aged , Propofol/adverse effects , Prospective Studies , Sufentanil/adverse effects , Young Adult
4.
Complement Ther Med ; 17(3): 141-6, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19398067

ABSTRACT

OBJECTIVES: To investigate the anti-fatigue effects of Myelophil, an extract of a mix of Astragali Radix and Salviae Radix, which has been used to treat patients with chronic fatigue. SUBJECTS AND DESIGN: A randomised, double-blind, controlled clinical trial was performed with 36 adults who complained of chronic fatigue. The subjects were divided among a control group and low- and high-dose groups (3 or 6g of oral Myelophil per day, respectively) and were monitored for 4 weeks. Fatigue severity was subjectively characterised, and the expression of 42 cytokines was evaluated using an antibody array. RESULTS: Myelophil administration (3g per day) significantly decreased the fatigue severity score compared with the control (p<0.05). No changes were noted in cytokine expression. CONCLUSIONS: Myelophil appears to have a pharmacological effect against fatigue, suggesting the clinical relevance of the traditional medicinal plants, Astragalus membranaceus and Salvia miltiorrhiza.


Subject(s)
Astragalus propinquus , Drugs, Chinese Herbal/therapeutic use , Fatigue Syndrome, Chronic/drug therapy , Phytotherapy , Plant Extracts/therapeutic use , Salvia miltiorrhiza , Adult , Cytokines/blood , Cytokines/immunology , Double-Blind Method , Drugs, Chinese Herbal/pharmacology , Fatigue Syndrome, Chronic/classification , Fatigue Syndrome, Chronic/immunology , Female , Humans , Male , Middle Aged , Plant Extracts/immunology , Plant Extracts/pharmacology , Plant Roots , Plants, Medicinal , Severity of Illness Index , Young Adult
6.
Scand J Gastroenterol ; 37(8): 983-6, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12229977

ABSTRACT

We report the first case of obstructive jaundice and acute pancreatitis caused by herniation of the small bowel through the foramen of Winslow in a 45-year-old man. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) revealed dilated small-bowel loops positioned in the gastrohepatic space, dilatation of the gallbladder and both intrahepatic bile ducts, and mild swelling of the pancreas. A small-bowel series revealed a cluster of small-bowel loops in the mid-upper abdomen, with displacement of the stomach to the left. At laparotomy, there was an internal herniation of jejunal loop through the defect of gastrocolic ligament into the lesser sac and finally passing through the foramen of Winslow. The common bile duct was compressed externally by the herniated bowel and the pancreas was mildly swollen. To the best of our knowledge, these complications of internal hernia have not been reported previously.


Subject(s)
Cholestasis/etiology , Hernia, Ventral/complications , Pancreatitis/etiology , Acute Disease , Hernia, Ventral/diagnosis , Hernia, Ventral/diagnostic imaging , Humans , Intestine, Small/diagnostic imaging , Intestine, Small/pathology , Magnetic Resonance Imaging , Male , Middle Aged , Tomography, X-Ray Computed
7.
Cell Death Differ ; 9(4): 448-56, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11965498

ABSTRACT

We previously reported that overexpression of HSP25 delayed cell growth, increased the level of p21(waf), reduced the levels of cyclin D1, cyclin A and cdc2, and induced radioresistance in L929 cells. In this study, we demonstrated that HSP25 induced-radioresistance was abolished by transfection with plasmids containing antisense hsp25 cDNA. Extracellular regulated kinase (ERK) and MAP kinase/ERK kinase (MEK) expressions as well as their activation (phospho-forms) were inhibited by hsp25 overexpression. Furthermore, when control vector transfected cells were treated with PD98059, MEK inhibitor, they became resistant to radiation, suggesting that inhibition of ERK1/2 activities was essential for radioresistance in L929 cells. To confirm the relationship between ERK1/2 and hsp25-mediated radioresistance, ERK1 or ERK2 cDNA was transiently transfected into the hsp25 overexpressed cells and their radioresistance was examined. HSP25-mediated radioresistance was abolished by overexpression of ERK2, but not by overexpression of ERK1. Alteration of cell cycle distribution and cell cycle related protein expressions (cyclin D, cyclin A and cdc2) by hsp25 overexpression were also recovered by ERK2 cDNA transfection. Increase in Bcl-2 protein by hsp25 gene transfection was also reduced by subsequent ERK2 cDNA-transfection. Taken together, these results suggest that downregulation of ERK2 is essential for the inhibition of radiation-induced cell death in HSP25 overexpressed cells.


Subject(s)
Apoptosis , Down-Regulation , Heat-Shock Proteins , Mitogen-Activated Protein Kinase 1/metabolism , Neoplasm Proteins/metabolism , Animals , Apoptosis/radiation effects , Cell Line , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Gene Expression , Mice , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Mitogen-Activated Protein Kinases/metabolism , Molecular Chaperones , Neoplasm Proteins/antagonists & inhibitors , Neoplasm Proteins/genetics , Radiation Tolerance , Transfection
8.
Arch Pharm Res ; 24(5): 466-71, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11693551

ABSTRACT

Inflammation is a frequent radiation-induced reaction following therapeutic irradiation. Treatment of human umbilical endothelial cells (HUVEC) with gamma-irradiation (gammaIR) induces the expression of adhesion proteins such as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Since the upregulation of these proteins on endothelial cell surface has been known to be associated with inflammation, interfering with the expression of adhesion molecules is an important therapeutic target. In the present study, we demonstrate that high mannuronic acid-containing alginate (HMA) inhibits gammaIR induced expression of ICAM-1, VCAM-1, and E-selectin on HUVEC in a dose dependent manner. HMA also inhibited gammaIR induced production of Nitric oxide (NO). These data suggest that HMA has therapeutic potential for the treatment of various inflammatory disorder associated with an increase of endothelial leukocyte adhesion molecules.


Subject(s)
Cell Adhesion Molecules/radiation effects , Endothelium, Vascular/cytology , Gamma Rays , Nitric Oxide/chemistry , Alginates/pharmacology , Cell Adhesion Molecules/biosynthesis , Cell Line , E-Selectin/biosynthesis , Endothelium, Vascular/drug effects , Enzyme-Linked Immunosorbent Assay , Humans , Indicators and Reagents , Intercellular Adhesion Molecule-1/biosynthesis , Up-Regulation/drug effects , Up-Regulation/radiation effects , Vascular Cell Adhesion Molecule-1/biosynthesis
9.
Cell Stress Chaperones ; 6(3): 273-81, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11599569

ABSTRACT

We previously demonstrated the protective effect of inducible heat shock protein 70 (Hsp70) against gamma radiation. Herein, we extend our studies on the possible role of Hsp70 to ionizing radiation-induced cell cycle regulation. The growth rate of inducible hsp70-transfected cells was 2-3 hours slower than that of control cells. Flow cytometric analysis of cells at G1 phase synchronized by serum starvation also showed the growth delay in the Hsp70-overexpressing cells. In addition, reduced cyclin D1 and Cdc2 levels and increased dephosphorylated phosphoretinoblastoma (pRb) were observed in inducible hsp70-transfected cells, which were probably responsible for the reduction of cell growth. To find out if inducible Hsp70-mediated growth delay affected radiation-induced cell cycle regulation, flow cytometric and molecular analyses of cell cycle regulatory proteins and their kinase were performed. The radiation-induced G2/M arrest was found to be inhibited by Hsp70 overexpression and reduced p21Waf induction and its kinase activity by radiation in the Hsp70-transfected cells. In addition, radiation-induced cyclin A or B1 expressions together with their kinase activities were also inhibited by inducible Hsp70, which represented reduced mitotic cell death. Indeed, hsp70 transfectants showed less induction of radiation-induced apoptosis. When treated with nocodazole, radiation-induced mitotic arrest was inhibited by inducible Hsp70. These results strongly suggested that inducible Hsp70 modified growth delay (increased G1 phase) and reduced G2/M phase arrest, subsequently resulting in inhibition of radiation-induced cell death.


Subject(s)
Apoptosis/radiation effects , Cell Cycle/radiation effects , HSP70 Heat-Shock Proteins/metabolism , 3T3 Cells , Animals , Apoptosis/physiology , CDC2 Protein Kinase/metabolism , Cell Cycle/physiology , Cyclin A/metabolism , Cyclin B/metabolism , Cyclin-Dependent Kinase Inhibitor p21 , Cyclins/genetics , Cyclins/metabolism , Flow Cytometry , Gamma Rays , Gene Expression Regulation/physiology , Immunoblotting , Mice , Precipitin Tests , Signal Transduction/physiology , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
10.
Radiat Prot Dosimetry ; 95(2): 143-8, 2001.
Article in English | MEDLINE | ID: mdl-11572642

ABSTRACT

Data are presented on the externally received personal dose equivalent for radiation workers who used the Korea Radioisotope Association's personal monitoring and dose record keeping service since 1984, and provide initial statistics on Korean workers who have been exposed to ionising radiation in different occupations. The total number of workers registered during the period of 1984 to 1999 was 64,518. The number increased steadily and the accumulated dose also increased. The proportion of radiation workers by occupation was 38.4% for nuclear power plants, 20.3% for industrial organisations and 12.4% for non-destructive industry. The annual collective dose of radiation workers was 31.72 man.Sv in 1999. The mean annual dose by sex was 1.49 mSv for males and 0.56 mSv for females and the mean annual dose for a worker was 1.41 mSv with the highest mean dose being received by non-destructive industry (3.53 mSv). Very few workers (0.8%) received more than 20 mSv (2 rem) and only one more than 50 mSv, the legal limit for an annual dose increase. There has been a steady decline in the mean dose since 1984, showing a significant decrease in dose with time (p<0.001). The data showed that radiation protection in Korea was improving, though annual doses were still higher than other countries.


Subject(s)
Occupational Exposure , Power Plants , Radiation Protection , Registries , Adolescent , Adult , Aged , Databases as Topic , Female , Humans , Korea , Male , Middle Aged , Nuclear Energy , Radiometry , Sex Factors , Time Factors
11.
FEBS Lett ; 505(1): 179-84, 2001 Sep 07.
Article in English | MEDLINE | ID: mdl-11557065

ABSTRACT

Although the majority of cancer cells are killed by TRAIL (tumor necrosis factor-related apoptosis-inducing ligand treatment), certain types show resistance to it. Ionizing radiation also induces cell death in cancer cells and may share common intracellular pathways with TRAIL leading to apoptosis. In the present study, we examined whether ionizing radiation could overcome TRAIL resistance in the variant Jurkat clones. We first selected TRAIL-resistant or -sensitive Jurkat clones and examined cross-responsiveness of the clones between TRAIL and radiation. Treatment with gamma-radiation induced significant apoptosis in all the clones, indicating that there seemed to be no cross-resistance between TRAIL and radiation. Combined treatment of radiation with TRAIL synergistically enhanced killing of TRAIL-resistant cells, compared to TRAIL or radiation alone. Apoptosis induced by combined treatment of TRAIL and radiation in TRAIL-resistant cells was associated with cleavage of caspase-8 and the proapoptotic Bid protein, resulting in the activation of caspase-9 and caspase-3. No changes in the expressions of TRAIL receptors (DR4 and DR5) and Bcl-2 or Bax were found after treatment. The caspase inhibitor z-VAD-fmk completely counteracted the synergistic cell killing induced by combined treatment of TRAIL and gamma-radiation. These results demonstrated that ionizing radiation in combination with TRAIL could overcome resistance to TRAIL in TRAIL-resistant cells through TRAIL receptor-independent synergistic activation of the cascades of the caspase-8 pathway, suggesting a potential clinical application of combination treatment of TRAIL and ionizing radiation to TRAIL-resistant cancer cells.


Subject(s)
Drug Resistance, Neoplasm , Membrane Glycoproteins/pharmacology , Radiation, Ionizing , Tumor Necrosis Factor-alpha/pharmacology , Apoptosis/drug effects , Apoptosis/radiation effects , Apoptosis Regulatory Proteins , BH3 Interacting Domain Death Agonist Protein , Carrier Proteins/metabolism , Caspase 3 , Caspase 8 , Caspase 9 , Caspases/drug effects , Caspases/metabolism , Caspases/radiation effects , Cell Death/drug effects , Clone Cells , Humans , Jurkat Cells , Proto-Oncogene Proteins/drug effects , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins/radiation effects , Proto-Oncogene Proteins c-bcl-2/drug effects , Proto-Oncogene Proteins c-bcl-2/metabolism , Proto-Oncogene Proteins c-bcl-2/radiation effects , TNF-Related Apoptosis-Inducing Ligand , bcl-2-Associated X Protein
13.
Toxicology ; 161(1-2): 79-91, 2001 Mar 21.
Article in English | MEDLINE | ID: mdl-11295257

ABSTRACT

Multiple biological effects are induced by ionizing radiation through dysfunction of cellular organelles, direct interaction with nucleic acids and production of free radical species. The expression of cytochrome P450s was assessed in the livers of 60Co gamma-irradiated rats. Three gray (G) of gamma-irradiation caused CYP2E1 induction with a 3.6-fold increase in the mRNA at 24 h, whereas the expression of CYP1A2 and CYP3A was not changed. Pharmacokinetics of chlorzoxazone, a specific substrate of CYP2E1, was studied in 3 G-irradiated rats. The area under the plasma concentration-time curve from time zero to infinity of 6-hydroxychlorzoxazone and the amount of 6-hydroxychlorzoxazone excreted in 8 h urine were both significantly greater than those in control rats. Hepatic CYP2E1 was not induced in rats exposed to 0.5-1 G of gamma-rays. Rats irradiated at 6-9 G accumulated doses of gamma-rays exhibited smaller increases in the mRNA due to liver injury than those irradiated at a single dose of 3 G gamma-rays. The plasma glucose and insulin levels were not altered in rats with 3 G of gamma-irradiation. As the exposure level of gamma-irradiation increased, the activity of hepatic aconitase, a key enzyme in energy metabolism in mitochondria, was 30-90% decreased. The amount of mitochondrial DNA per gram of wet liver was 50% decreased in rats exposed to 3 G of gamma-rays. These results demonstrated that gamma-ray irradiation at the exposure level inducing organelle dysfunction induced CYP2E1 in the liver, which might be associated with mitochondrial damage, but not with alterations in glucose or insulin levels.


Subject(s)
Chlorzoxazone/pharmacokinetics , Cytochrome P-450 CYP2E1/biosynthesis , Gamma Rays , Microsomes, Liver/radiation effects , Mitochondria, Liver/radiation effects , Muscle Relaxants, Central/pharmacokinetics , Aconitate Hydratase/metabolism , Alanine Transaminase/blood , Animals , Area Under Curve , Blood Glucose/radiation effects , Chlorzoxazone/metabolism , Chromatography, High Pressure Liquid , DNA, Mitochondrial/isolation & purification , DNA, Mitochondrial/radiation effects , Half-Life , Insulin/blood , Male , Microsomes, Liver/enzymology , Microsomes, Liver/metabolism , Mitochondria, Liver/enzymology , Mitochondria, Liver/metabolism , Muscle Relaxants, Central/metabolism , Rats , Rats, Sprague-Dawley
14.
Int J Radiat Biol ; 77(2): 225-33, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11236929

ABSTRACT

PURPOSE: Protective effect of small heat-shock protein (sHSP) against gamma-radiation, which associated with HSP25-induced cell-cycle delay and Bcl-2 induction. We further extended our studies on the possible role of HSP25 on ionizing radiation-induced cell-cycle regulation. MATERIALS AND METHODS: Flow-cytometric analyses were performed for cell-cycle distribution and Western blotting. Kinase or immunocomplex kinase assay were performed for detection of cell-cycle protein expression or activation. RESULTS: Pronounced arrest of G1, S and G2/M phase was observed by 4Gy radiation and these arrests were augmented by hsp25 overexpression. Inhibition of cyclin-D1, and cyclin-E and induction of p21Waf by radiation, which was more pronounced in hsp25 overexpressed cells than control cells, which is associated with increased binding activity of CDK2. S-phase regulator, cyclin-A and its associated CDK2 and CDC2 kinase activities were also increased by irradiation and hsp25 overexpression attenuated these phenomena. In addition, cyclin-B1 expression and its associated kinase activity, which are responsible for the transition of G2 to M phase, were increased by radiation and hsp25 overexpression also decreased these phenomena. CONCLUSION: HSP25 augmented radiation-induced cell-cycle arrest (G1, S, and G2/M phase) may be caused by the HSP25-mediated cell-growth delay and is associated with radioresistance.


Subject(s)
CDC2-CDC28 Kinases , Cell Cycle/radiation effects , Heat-Shock Proteins , Neoplasm Proteins/biosynthesis , Radiation, Ionizing , Animals , Blotting, Western , CDC2 Protein Kinase/metabolism , Cyclin A/metabolism , Cyclin B/metabolism , Cyclin B1 , Cyclin D1/antagonists & inhibitors , Cyclin E/antagonists & inhibitors , Cyclin-Dependent Kinase 2 , Cyclin-Dependent Kinase Inhibitor p21 , Cyclin-Dependent Kinases/biosynthesis , Cyclins/metabolism , Electrophoresis, Polyacrylamide Gel , Flow Cytometry , Mice , Molecular Chaperones , Phosphotransferases/metabolism , Precipitin Tests , Protein Serine-Threonine Kinases/biosynthesis , Time Factors , Tumor Cells, Cultured
15.
Cell Biol Toxicol ; 16(3): 175-84, 2000.
Article in English | MEDLINE | ID: mdl-11032361

ABSTRACT

We investigated the relationship between induction of radio-adaptive response and cell death in mouse normal and neoplastic epidermal cells. Mouse normal primary keratinocytes (PK), cancer-prone cells [v-rasHa-transfected mouse keratinocytes (ras-PK), and line 308 cells (mouse skin papilloma cells which have activated rasHa gene with A-to-T transversion at codon 61) were primed with a low dose of gamma-rays (0.01 Gy), and were challenged with a high dose (4 Gy) after a 4 or 7 h interval. The induction of cell death in PK was 2-10 times higher and was also more rapid in PK than in ras-PK or 308 cells. Low-dose pretreatment with a 4 h interval decreased cell death, and this adaptive response was prominent in PK, whereas it was less obvious in the cases of ras-PK and 308 cells. The response of each protein kinase C (PKC) isozymes to high-dose radiation, especially PKCalpha, PKCdelta, PKCepsilon, and PKCeta, were different between the normal and ras oncogene-activated neoplastic keratinocytes; translocation of these isozymes to membrane occurred more rapidly in normal than in neoplastic cells. Furthermore, low-dose pretreatment did not induce the translocation of PKCdelta in PK significantly more than in ras-PK and 308. Thus, the difference in the induction of radio-adaptive responses between mouse normal and neoplastic epidermal cells reflects difference in the rapidity of cell death, and responsiveness of PKC may affect this adaptive response.


Subject(s)
Apoptosis/radiation effects , Epidermal Cells , Epidermis/radiation effects , Keratinocytes/cytology , Keratinocytes/radiation effects , Adaptation, Physiological/radiation effects , Animals , Cell Line, Transformed , Cytosol/enzymology , In Situ Nick-End Labeling , Isoenzymes/metabolism , Keratinocytes/enzymology , Mice , Mice, Inbred BALB C , Papilloma , Protein Kinase C/metabolism , Protein Kinase C-alpha , Radiation Dosage , Radiation Injuries/metabolism , Skin Neoplasms , Tumor Cells, Cultured , ras Proteins/metabolism
16.
Radiat Res ; 154(4): 421-8, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11023606

ABSTRACT

We previously demonstrated the protective effect of the small heat-shock protein against oxidative damage induced by tumor necrosis factor alpha. Here we have extended our studies of the possible role of Hsp25 in ionizing radiation-induced damage. For these studies, we transfected murine fibroblast L929 cells with the Hsp25 gene and selected three stably transfected clones. Hsp25 overexpression conferred radioresistance as detected by clonogenic survival and induction of apoptosis. Interestingly, the Hsp25-transfected cells showed an increase in the level of the anti-apoptosis molecule Bcl2. We also observed alterations of cell growth in the Hsp25-transfected cells. The cell cycle time of Hsp25-transfected cells was 3-4 h slower than that of vector-transfected control cells. Flow cytometry analysis of synchronized cells at late G(1) phase by mimosine treatment also showed the growth delay in Hsp25-overexpressing cells. In addition, reduced cyclin D1, cyclin A and Cdc2 levels and increased levels of Cdkn1a (also known as p21(Waf)) were observed in Hsp25-transfected cells, which probably caused the reduction in cell growth. In addition, synchronization by mimosine treatment only partially altered radioresistance in the Hsp25-transfected cells. Taken together, these data suggest that Hsp25-induced radioresistance is associated with growth delay as well as induction of Bcl2.


Subject(s)
Apoptosis , Cell Cycle , Heat-Shock Proteins , Neoplasm Proteins/physiology , Proto-Oncogene Proteins c-bcl-2/physiology , Radiation Tolerance/physiology , Animals , Apoptosis/radiation effects , Cell Cycle/radiation effects , Cell Cycle Proteins/metabolism , Colony-Forming Units Assay , Gamma Rays , Gene Expression Regulation/radiation effects , Genes, bcl-2 , L Cells/cytology , L Cells/metabolism , L Cells/radiation effects , Mice , Mimosine/pharmacology , Molecular Chaperones , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , Oxidative Stress , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Radiation Tolerance/drug effects , Recombinant Fusion Proteins/physiology , Transfection
17.
Radiat Res ; 153(3): 318-26, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10669554

ABSTRACT

Park, S-H., Lee, S-J., Chung, H-Y., Kim, T-H., Cho, C-K., Yoo, S-Y. and Lee, Y-S. Inducible Heat-Shock Protein 70 Is Involved in the Radioadaptive Response. The thermoresistant (TR) clone of radiation-induced fibrosarcoma (RIF) cells showed an adaptive response, i.e. a reduced effect, after exposure to a higher challenging dose (4 Gy) when the priming dose (1 cGy) was given 4 or 7 h earlier, but RIF cells did not. Since inducible Hsp70 expression was different in cells of these two cell lines, the role of inducible Hsp70 in the adaptive response was examined. When inducible Hsp70 was transfected into RIF cells, the adaptive response was acquired. Transfection of inducible Hsp70 to NIH 3T3 mouse embryo cells also conferred radioresistance to the cells as assayed by clonogenic survival, [(3)H]thymidine incorporation, and an ELISA cell death detection kit. An increased tendency for the induction of an adaptive response was also observed. Interestingly, basal levels of Ca(2+)-dependent and independent Pkc activities were increased by transfection with inducible Hsp70 compared to those of control vector cells. Irradiation with gamma rays induced activation of Pkc within minutes in control vector cells, while transfection with inducible Hsp70 did not. Cellular redistribution to particulate fractions of Pkca, d and z after exposure gamma rays also was not detected. Furthermore, radioresistance by transfection with inducible Hsp70, as tested by clonogenic survival, disappeared after pretreatment with Pkc inhibitors, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7), prolonged treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA), and GF109203X. Taken together, these data suggest that radioresistance inducible by Hsp70 is associated with an elevated level of Pkc activity.


Subject(s)
Adaptation, Physiological/physiology , HSP70 Heat-Shock Proteins/physiology , Radiation Tolerance/physiology , 3T3 Cells , Animals , Dose-Response Relationship, Radiation , Enzyme Activation , Enzyme Induction , Enzyme Inhibitors/pharmacology , HSP70 Heat-Shock Proteins/biosynthesis , Mice , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/biosynthesis , Protein Kinase C/metabolism
18.
Res Commun Mol Pathol Pharmacol ; 108(3-4): 155-65, 2000.
Article in English | MEDLINE | ID: mdl-11913708

ABSTRACT

Previous studies have shown that induction of microsomal epoxide hydrolase (mEH) and glutathione S-transferase (GST) by oltipraz correlated with the radioprotective effect. The present study was designed to investigate the expression of the antioxidant enzymes and the radioprotective effect by imidazole (IM). Northern blot analysis revealed that IM increased the mEH and GST mRNA levels in the rat liver in a dose-dependent manner. Rats irradiated with 3 Gy of gamma-rays in combination with IM showed enhanced increases in mEH and rGSTA2 mRNAs, as compared to either IM or irradiation alone. IM prevented elevations in the hepatic GSH content by gamma-irradiation. In contrast to IM, cysteine blocked radiation-inducible increases in the mRNAs with no suppression of the GSH content. The radioprotective effect by IM was greater than that by cysteine, as assessed by the 30-day survival rate of mice (i.e. 80% and 69%, respectively, vs. 48% in control). These results demonstrated that IM enhanced radiation-inducible mEH and GST expression with prevention of the increase in GSH content, which correlated with the radioprotective effect, and that the mechanistic basis of radioprotection by IM differed from that by cysteine.


Subject(s)
Epoxide Hydrolases/genetics , Glutathione Transferase/genetics , Imidazoles/pharmacology , Radiation-Protective Agents/pharmacology , Animals , Antioxidants/metabolism , Cysteine/pharmacology , Gamma Rays , Gene Expression/drug effects , Gene Expression/radiation effects , Glutathione/metabolism , Liver/drug effects , Liver/metabolism , Liver/radiation effects , Male , Mice , Mice, Inbred ICR , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Microsomes, Liver/radiation effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley
19.
Cell Biol Toxicol ; 15(2): 111-9, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10408358

ABSTRACT

Since the beneficial effects of low-dose radiation (0.01 Gy) are usually observed in normal cells, we investigated whether the adaptive response was induced by low-dose radiation in neoplastic cells of different origin as well as in normal cells. Cell lines used in this experiment were as follows: mouse lymphocytes (NL); L929 cells established from mouse connective tissue; primary mouse keratinocytes (PK); line 308 from mouse papilloma; X-ray sensitive lymphoma cells, L5178Y-S and EL-4 cells from mouse lymphoma. The adaptive response was determined by cell survival and apoptosis. The involvement of apoptosis in the adaptive response was examined by ELISA and TUNEL assay. Adaptive response was induced by pretreatment with low-dose radiation of 0.01 Gy in normal cells such as NL, L929, and PK, but not in L5178Y-S, EL-4, and line 308 cells. In addition, the reduction of apoptosis by pretreatment with low-dose radiation was observed in NL, L929, and PK, but not in L5178Y-S, EL-4, and line 308 cells. These results suggested that the adaptive response could be induced by pretreatment with low-dose radiation and the phenomena were observed in normal cells, not in neoplastic cells. In addition, pretreatment with low-dose radiation reduced apoptosis, suggesting that an anti-apoptotic pathway may be involved in the adaptive response.


Subject(s)
Apoptosis/radiation effects , Adaptation, Physiological , Animals , Cell Line , Cell Survival/radiation effects , Gamma Rays , Mice , Tumor Cells, Cultured
20.
Mutat Res ; 426(1): 41-9, 1999 May 03.
Article in English | MEDLINE | ID: mdl-10320749

ABSTRACT

Although protein kinase C (PKC) plays an important role in cellular response to radiation, little is known about the specific role of each isoform in the radiation induced cellular response. In this study, the induction of apoptosis and subcellular distribution of PKC isoforms after gamma-ray irradiation were examined in three kinds of mouse epidermal cells with different stages of carcinogenesis (normal mouse keratinocytes, PK: v-rasHa transfected mouse keratinocytes, ras-PK; and neoplastic cells from mouse skin papilloma, 308 cells). The induction of apoptosis was different in normal and neoplastic cells; in normal cells after 16 Gy of radiation, apoptosis was 2-10 times higher than that in ras-PK or 308 cells, and was rapidly induced; other cells died more slowly, depending on the stage of carcinogenesis. The responses of each PKC, especially rapid translocation of PKCdelta and no response of PKCepsilon by radiation in normal cells may influence the induction of apoptosis by radiation.


Subject(s)
Apoptosis/radiation effects , Cell Transformation, Neoplastic , Epidermis/radiation effects , Isoenzymes/metabolism , Protein Kinase C/metabolism , Animals , Biological Transport , Epidermal Cells , Epidermis/enzymology , In Situ Nick-End Labeling , Mice , Mice, Inbred BALB C , Subcellular Fractions/enzymology
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