1.Dexamethasone regulates differential expression of carboxylesterase 1 and carboxylesterase 2 through activation of nuclear receptors.
Chengliang ZHANG ; Ping GAO ; Weifeng YIN ; Yanjiao XU ; Daochun XIANG ; Dong LIU
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(6):798-805
Carboxylesterases (CESs) play important roles in the metabolism of endogenous and foreign compounds in physiological and pharmacological responses. The aim of this study was to investigate the effect of dexamethasone at different doses on the expression of CES1 and CES2. Imidapril and irinotecan hydrochloride (CPT-11) were used as special substrates for CES1 and CES2, respectively. Rat hepatocytes were cultured and treated with different concentrations of dexamethasone. The hydrolytic activity of CES1 and CES2 was tested by incubation experiment and their expression was quantitated by real-time PCR. A pharmacokinetic study was conducted in SD rats to further evaluate the effect of dexamethasone on CESs activity in vivo. Western blotting was performed to investigate the regulatory mechanism related to pregnane X receptor (PXR) and glucocorticoid receptor (GR). The results showed that exposure of cultured rat hepatocytes to nanomolar dexamethasone inhibited the imidapril hydrolase activity, which was slightly elevated by micromolar dexamethasone. For CES2, CPT-11 hydrolase activity was induced only when dexamethasone reached micromolar levels. The real-time PCR demonstrated that CES1 mRNA was markedly decreased by nanomolar dexamethasone and increased by micromolar dexamethasone, whereas CES2 mRNA was significantly increased by micromolar dexamethasone. The results of a complementary animal study showed that the concurrent administration of dexamethasone significantly increased the plasma concentration of the metabolite of imidapril while the ratio of CPT-11 to its metabolite SN-38 was significantly decreased. PXR protein was gradually increased by serial concentrations of dexamethasone. However, only nanomolar dexamethasone elevated the level of GR protein. The different concentrations of dexamethasone required suggested that suppression of CES1 may be mediated by GR whereas the induction of CES2 may result from the role of PXR. It was concluded that dexamethasone at different concentrations can differentially regulate CES1 and CES2.
Animals
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Carboxylic Ester Hydrolases
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genetics
;
Dexamethasone
;
pharmacology
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Gene Expression
;
drug effects
;
immunology
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Male
;
Rats
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Rats, Sprague-Dawley
;
Receptors, Cytoplasmic and Nuclear
;
metabolism
2.Inhibition of N-methyl-D-aspartate-activated current by bis(7)-tacrine in HEK-293 cells expressing NR1/NR2A or NR1/NR2B receptors.
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(6):793-797
In normal rat forebrain, the NR1/NR2A and NR1/NR2B dimmers are the main constitutional forms of NMDA receptors. The present study was carried out to determine the functional properties of the heteromeric NMDA receptor subunits and their inhibition by bis(7)-tacrine (B7T). Rat NR1, NR2A and NR2B cDNAs were transfected into human embryonic kidney 293 cells (HEK-293). The inhibition of NMDA-activated currents by B7T was detected in HEK-293 cell expressing NR1/NR2A or NR1/NR2B receptors by using whole-cell patch-clamp techniques. The results showed that in HEK-293 cells expressing NR1/NR2A receptor, 1 μmol/L B7T inhibited 30 μmol/L NMDA- and 1000 μmol/L NMDA-activated steady-state currents by 46% and 40%, respectively (P>0.05; n=5), suggesting that the inhibition of B7T on NR1/NR2A receptor doesn't depend on NMDA concentration, which is consistent with a non-competitive mechanism of inhibition. But for the NR1/NR2B receptor, 1 μmol/L B7T inhibited 30 μmol/L NMDA- and 1000 μmol/L NMDA-activated steady-state currents by 61% and 13%, respectively (P<0.05; n=6), showing that B7T appears to be competitive with NMDA. In addition, simultaneous application of 1 μmol/L B7T and 1000 μmol/L NMDA produced a moderate inhibition of peak NMDA-activated current, followed by a gradual decline of the current to a steady state. However, the gradual onset of inhibition produced by B7T applied simultaneously with NMDA was eliminated when B7T was given 5 s before NMDA. These results suggested that B7T inhibition of NMDA current mediated by NR1/NR2B receptor was slow onset, and it did not depend on the presence of the agonist. With holding potentials ranging from -50 to +50 mV, the B7T inhibition rate of NMDA currents didn't change significantly, and neither did the reversal potential. We are led to conclude that the NR1/NR2B recombinant receptor can serve as a very useful model for studying the molecular mechanism of NMDA receptor inhibition by B7T.
Cell Line
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HEK293 Cells
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Humans
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N-Methylaspartate
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pharmacology
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Receptors, N-Methyl-D-Aspartate
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genetics
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Tacrine
;
analogs & derivatives
;
pharmacology
3.Double lethal effects of fusion gene of wild-type p53 and JunB on hepatocellular carcinoma cells.
Cheng GUO ; Qingguang LIU ; Lei ZHANG ; Xue YANG ; Tao SONG ; Yingmin YAO
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):663-668
This study explored the double lethal effects of pEGFP-C1-wtp53/junB fusion gene on hepatocellular carcinoma (HCC) cells. wtp53/junB fusion gene was constructed and transformed into HepG2 cell line. Expression of KAI1 was detected by quantitative real-time PCR and Western blotting, cells apoptosis rate was detected by flow cytometry, proliferation of cells was detected byMTT chromometry, cell transmigration was detected by using transwell systems. The results showed that after transformation with pEGFP-C1-wtp53/JunB, the expression level of KAI1 protein was up-regulated, being 8.13 times the blank control group in HepG2 cells and significantly higher than 2.87 times which transformed with pEGFP-C1-JunB, 3.11 times which transformed with pEGFP-C1-wtp53 (P<0.001). Apoptosis rate of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly higher than that of other groups (P<0.001), and invasive ability of HepG2 cells transformed with pEGFP-C1-wtp53/JunB was significantly lower than other groups(P<0.001). It was concluded that the fusion gene of wtp53 and JunB could not only inhibit the growth of hepatoma cells and promote tumor cell apoptosis, but also suppress the invasive ability of tumor cells by up-regulating the expression of KAI1.
Carcinoma, Hepatocellular
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genetics
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metabolism
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pathology
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Cell Line, Tumor
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Hep G2 Cells
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Humans
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Liver Neoplasms
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genetics
;
metabolism
;
pathology
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Transcription Factors
;
genetics
;
metabolism
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Tumor Suppressor Protein p53
;
genetics
;
metabolism
4.Hyperkalemia of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in hemodialysis: a meta-analysis.
Qian ZHANG ; Hong LUAN ; Le WANG ; Miao ZHANG ; Yan CHEN ; Yongman LV ; Zufu MA
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):785-792
The safety of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) used in hemodialysis (HD) patients was evaluated. Medline, Embase, the Cochrane Library, some databases of clinical trial registries, grey literatures, other reference lists of eligible articles and review articles for the randomized clinical trials (RCTs) on comparison of ACEIs/ARBs or placebo in HD patients were retrieved. RCTs reporting the risk of hyperkalemia by using ACEIs/ARBs in HD patients were selected. Eight articles met the eligibility criteria and were subjected to meta-analysis by using the Cochrane Collaboration's RevMan 4.2 software package. The results showed that there was no significant difference in hyperkalemia in HD patients between ACEIs or ARBs group and control group (ACEIs vs. control: RD=0.03, 95% CI=-0.13-0.18, Z=0.34, P=0.73; ARBs vs. control: RD=-0.02, 95% CI=-0.07-0.03, Z=0.75, P=0.45). However, there was no significant difference in the serum potassium between ACEIs or ARBs group and control group in HD patients (ACEIs vs. control: WMD=0.10, 95% CI=0.06-0.15, Z=4.64, P<0.00001; ARBs vs. control: WMD=-0.24, 95% CI=-0.37-0.11, Z=3.58, P=0.0003). The use of ACEIs or ARBs could not cause an increased risk of hyperkalemia in HD patients, however the serum potassium could be increased with use of ACEIs in HD patients. Therefore the serum potassium concentration should still be closely monitored when ACEIs are taken during the maintenance HD.
Aged
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Angiotensin Receptor Antagonists
;
adverse effects
;
therapeutic use
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Angiotensin-Converting Enzyme Inhibitors
;
adverse effects
;
therapeutic use
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Female
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Humans
;
Hyperkalemia
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chemically induced
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Male
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Middle Aged
;
Renal Dialysis
5.A simple and sensitive liquid chromatographic technique for the determination of cefotetan disodium in human plasma and its application in a pharmacokinetic study.
Yani LIU ; Jiangeng HUANG ; Jinmei LIU ; Lin MA ; Yongning LV ; Shaojun SHI
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):779-784
A simple and sensitive liquid chromatographic method was developed for quantification of cefotetan disodium (CTT), a semi-synthetic cephamycin antibiotic, in human plasma. CTT and the internal standard chloramphenicol were extracted from plasma by a simple one-step protein precipitation with 35% (v/v) perchloric acid. Separation was carried out on a reverse-phase C18 column with a mobile phase of acetonitile-water containing 0.5% (v/v) phosphoric acids (20:80, v/v) at a flow rate of 1.0 mL/min. The column effluent was monitored by UV detection at 300 nm. The column temperature was maintained at 40°C. This method demonstrated good linearity in the range of 0.525-300.0 μg/mL, with correlation coefficients greater than 0.99. The limit of quantification (LOQ) was 0.525 μg/mL in human plasma. Intra- and inter-day precisions were less than 6.63% in terms of relative standard deviation (RSD). The accuracy, when expressed by the bias, ranged from 0.57% to 4.04%. The mean extraction recovery of CTT was higher than 40.94%. The method was found to be precise, accurate, and specific for CTT quantitative analysis, and was successfully applied for a pharmacokinetic study of CTT after a single intravenous dose of 1.0 g of CTT in healthy Chinese subjects.
Cefotetan
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blood
;
pharmacokinetics
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Chromatography, Liquid
;
methods
;
Humans
6.High-frequency ultrasound evaluation of effects of early treatment with metoprolol on myocardial inflammatory cytokine expression in rats with acute myocardial infarction.
Wen WU ; Linxiao HUANG ; Jiangxia ZHANG ; Yu GAO ; Yali YANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):774-778
This study evaluated the effects of early treatment with β-adrenergic blocker metoprolol on ventricular remodeling and function after acute myocardial infarction (AMI) by using high frequency ultrasound. The relationship between the efficacy and the expression level of cardiac myocardial inflammatory cytokine was examined in rats. The rat model of AMI was induced by ligating the left anterior descending artery. The surviving rats were randomly assigned to two experimental groups: MI control (MI) group and MI metoprolol (MI-B) group, with the rats undergoing sham operation serving as normal control (Sham). MI-B group was given metoprolol for 4 weeks (refer to the CCS-2 protocol) and the other two groups received equal volume of saline via intragastric (i.g.) administration. The ventricular remodeling and function were evaluated by high frequency ultrasound 4 weeks after the treatment. Then all rats were sacrificed for pathological examination and immunohistochemistrical detection of inflammatory cytokines, including IL-1β, IL-6, IL-10 and TNF-α. Compared with the MI group, the left ventricular end-systolic dimension, end-diastolic dimension, end-systolic volume and end-diastolic volume of the MI-B group were significantly decreased (P<0.01), while the left ventricular anterior wall end-diastolic thickness, ejection fraction and fractional shortening were obviously increased (P<0.01). The conspicuous improvement in the left ventricular morphology and function was coincident with the markedly reduced TNF-α and IL-1β expression and the increased IL-10 expression. We are led to conclude that early metoprolol treatment for AMI can regulate myocardial inflammatory cytokine expression to improve cardiac function and the underlying mechanism might be that it decreases the level of pro-inflammatory cytokines and increases the level of its anti-inflammatory counterparts in cardiac myocytes. Our study also showed that echocardiography is a useful technique for the structural and functional assessment of left ventricle after acute myocardial infarction.
Animals
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Cytokines
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metabolism
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Inflammation
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drug therapy
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metabolism
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Male
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Metoprolol
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pharmacology
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Myocardial Infarction
;
drug therapy
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Myocardium
;
metabolism
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Rats
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Rats, Sprague-Dawley
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Ultrasonography
;
methods
7.Apical root resorption in maxillary incisors when employing micro-implant and J-hook headgear anchorage: a 4-month radiographic study.
Qingzhu WANG ; Wenjing CHEN ; Roger J SMALES ; Hui PENG ; Xiaokun HU ; Lu YIN
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):767-773
This study evaluated, over a 4-month study period, the amount of apical root resorption occurring in maxillary central incisors following their retraction when employing either micro-implant or J-hook headgear anchorage. The prospective randomised clinical trial was conducted in Orthodontic Clinic, College of Stomatology, China from 2008-2009. Subjects are patients requiring fixed appliances on waiting list (n=20). In female Han Chinese patients aged from 16-26 years, standardized periapical radiographs from 10 randomly assigned patients with maxillary protrusions comprising the micro-implant group, and from 10 similar patients comprising the J-hook headgear group, were assessed for maxillary central incisor apical root resorption. Measurements before and after orthodontic therapy were also obtained from lateral cephalometric radiographs to calculate incisor horizontal retraction and vertical intrusion distances. Estimated retraction force vectors were calculated in horizontal and vertical directions for both treatment groups. Data analysis employed t-tests and the Pearson correlation test, with α=0.05 for statistical significance. The results showed that when compared with the J-hook group, significantly more apical root resorption shortening of the maxillary central incisors was observed in the micro-implant group (1.27 mm difference, 95% CI=0.70-1.84, P<0.001), which was associated with a significantly larger retraction distance (P=0.004) and a smaller vertical force component (P<0.0001). We are led to conclude that continuous activation of the nickel-titanium coil springs used in the micro-implant group resulted in significantly more apical root resorption shortening and maxillary central incisor retraction than when intermittent J-hook retraction was employed. The employment of continuous duration orthodontic forces presents a risk for increased apical root resorption that requires careful radiographic monitoring.
Adult
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Dental Implants
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Female
;
Humans
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Incisor
;
diagnostic imaging
;
Maxilla
;
diagnostic imaging
;
Orthodontic Anchorage Procedures
;
instrumentation
;
methods
;
Prospective Studies
;
Radiography
;
Root Resorption
;
diagnostic imaging
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Tooth Apex
;
diagnostic imaging
;
Young Adult
8.Pingyangmycin-regulated expressions of adhesion molecules in human venous malformation endothelial cells.
Yulin JIA ; Jun JIA ; Yifang ZHAO
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):760-766
Pingyangmycin (bleomycin A5 hydrochloride, PYM) is one of the anti-neoplastic agents which have been commonly used to treat venous malformations. However, the underlying mechanism by which PYM treats venous malformations remains poorly understood. It was reported that venous endothelial cells could recruit neutrophils via adhesion molecules (E-selectin, ICAM-1, ICAM-3, VCAM-1) during the acute/chronic inflammation and subsequent histological fibrosis after sclerotherapy with PYM. This study explored if the expression of E-selectin, ICAM-1, ICAM-3 and VCAM-1 in human venous malformation endothelial cells could be affected by PYM. HVMECs were cultured from human venous malformation tissue. Expressions of E-selectin, ICAM-1, ICAM-3 and VCAM-1 on HVMECs in response to PYM were analyzed by cell ELISA. The relative levels of mRNA expression in the cells were semi-quantified. The results showed that PYM up-regulated the expressions of E-selectin, ICAM-3, VCAM-1 and ICAM-1 in both time- and concentration-dependent manner. Our findings suggested that PYM could induce the expression of adhesion molecules in HVMECs, which might be a possible mechanism by which sclerotherapy by intralesional injection of PYM treats venous malformations.
Bleomycin
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analogs & derivatives
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pharmacology
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Cell Adhesion Molecules
;
genetics
;
metabolism
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Cells, Cultured
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Endothelial Cells
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drug effects
;
metabolism
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Endothelium, Vascular
;
drug effects
;
metabolism
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Gene Expression
;
drug effects
;
genetics
;
Humans
9.Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation.
Wenhui LIU ; Xinmin ZHENG ; Zaiqing QU ; Ming ZHANG ; Chun ZHOU ; Ling MA ; Yuanzhen ZHANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):755-759
This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice. Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation. In the first three days of pregnancy, the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 μW/cm(2), ranging from 130 to 200 μW/cm(2), for 2- or 4-h exposure every day), mid-intensity (570 μW/cm(2), ranging from 400 to 700 μW/cm(2), for 2- or 4-h exposure every day) or high-intensity (1400 μW/cm(2), ranging from 1200 to 1500 μW/cm(2), for 2- or 4-h exposure every day), respectively. On the day 4 after gestation (known as the window of murine embryo implantation), the endometrium was collected and the suspension of endometrial glandular cells was made. Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration. In high-intensity, 2- and 4-h groups, mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (P<0.05). The calcium ion concentration was increased in low-intensity 2-h group but decreased in high-intensity 4-h group as compared with the normal control group (P<0.05). However, no significant difference was found in mitochondrial membrane potential of endometrial glandular cells between low- or mid-intensity groups and the normal control group, indicating stronger intensity of the electromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane. Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells. It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantation, thereby posing a high risk to pregnancy.
Animals
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Electromagnetic Radiation
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Embryo Implantation
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physiology
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Endometrium
;
physiology
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Epithelial Cells
;
physiology
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Female
;
Male
;
Mice
10.The role of DNA damage repair and Chk2 protein in hyper-radiosensitivity of lung adenocarcinoma A549 cells.
Hongge WU ; Qitian CHEN ; Yong ZHANG ; Gang WU ; Rui MENG ; Jing CHENG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(5):750-754
To explore the role of the Chk2 protein expression and DNA double strand breaks (DSBs) repair in low dose hyper-radiosensitivity (HRS)/increased radioresistance (IRR) of non-small cell lung cancer, A549 cells were subjected to irradiation at the dosage ranging from 0.05-2 Gy. Clonogenic survival was measured by using fluorescence-activated cell sorting (FACS) plating technique. Percentage of cells in M-phase after low doses of X-irradiation was evaluated by phospho-histone H3-FITC/PI and Western blotting was used to detect protein expression of Chk2 and phospo-Chk2. DNA DSBs repair efficiency was also measured by induction and persistence of γ-H2AX. The results showed that the killing ability of irradiation with A549 cells increased at low conditioning dose below 0.3 Gy. Within the dose of 0.3 to 0.5 Gy, A549 cells showed a certain extent of radiation resistance. And when the dose was more than 0.5 Gy, survival fraction exhibited a negative correlation with the dosage. There was no difference between the 0.1 or 0.2 Gy dosage groups and the un-irradiated group in terms of the percentage of cells in M phase. But in the high dosage group (0.3-1.0 Gy), the percentage of cells in M phase was decreased markedly. In addition, the percentage of cells in M phase began to decrease two hours after irradiation. One hour after irradiation, there was no conspicuous activation of Chk2 kinase in 0.1 or 0.2 Gy group, but when the irradiation dose reached 0.3 Gy or higher, Chk2 kinase started to be activated and the activation level showed no significant difference among high dosage groups (0.4, 0.5, 1.0 Gy). Within 1 to 6 h, the DNA DSBs repair efficiency was decreased at 0.2 Gy but increased at 0.5 Gy and 1.0 Gy, which was in line with Chk2 activation. We are led to conclude that the mechanism of HRS/IRR in A549 cell line was probably due to early G(2)/M checkpoint arrest and enhanced DNA DSBs repair. In this regard, Chk2 activation plays a key role in G(2)/M checkpoint activation.
Adenocarcinoma
;
genetics
;
metabolism
;
Cell Line, Tumor
;
Checkpoint Kinase 2
;
genetics
;
metabolism
;
DNA Damage
;
genetics
;
DNA Repair
;
genetics
;
Humans
;
Lung Neoplasms
;
genetics
;
metabolism
;
Radiation Tolerance
;
genetics