Objective: To study the oxidative damage of di- (2-ethylhexyl) phthalate (DEHP) on MCF-7 cells, and to investigate the effects of 3β-hydroxysteroid dehydrogenase (3β-HSD) gene silence or overexpression on DEHP-induced oxidative damage. Methods: MCF-7 cells, 3β-HSD gene silencing cells and 3β-HSD gene overexpression cells were treated with different doses of DEHP (0,0.05,0.1,0.2,0.4,0.8 mmol/L) for 24h, then intracellular oxidative damage index such as MDA, SOD, GSH, GSH-PX were detected, DNA repair gene hOGG1, hMTH1 mRNA expression were tested by Q-PCR, hOGG1, hMTH1 protein expression were detected by western blot. Results: After MCF-7 cells were treated by DEHP, MDA levels increased; SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the differences were statistically significant when compared with control (P<0.05 or P<0.01) . In 3β-HSD gene silencing cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content increased, SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels decreased, hOGG1 and hMTH1 protein expression levels decreased, the difference were statistically significant (P<0.05 or P<0.01) . In 3β-HSD gene overexpression cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content decreased; SOD activity, GSH content, GSH-PX activity increased, of hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the difference were statistically significant (P<0.05 or P<0.01) . Conclusion DEHP could cause oxidative damage in MCF-7 cells, induce the changes of related genes and proteins, 3β-HSD plays an antioxidant role in the process of DEHP ox-idative damage.

Objective:To explore the effect of combining motor imagery therapy (MIT) with kinesio taping in rehabilitating the upper limb motor function of stroke survivors.Methods:Ninety-two stroke survivors were randomized into a control group ( n=31), an MIT group ( n=31), and a combination group ( n=30). All were given 40 minutes of basic rehabilitation therapy daily, while the MIT group received additional MIT therapy, and the combination group received kinesio taping with the MIT therapy. The taping was applied according to a patient′s condition and changed every other day. The MIT was conducted twice a day. The experiment lasted 8 weeks, six days a week. Before and after the 8 weeks, the upper limb functioning, ability in the activities of daily living and muscle tension of each subject were assessed using the Fugl-Meyer assessment for the upper extremities (FMA-UE), the Hong Kong version of the functional test for a hemiplegic upper extremity (FTHUE-HK), the modified Barthel index (MBI) and the modified Ashworth scale (MAS). Results:The average post-treatment FMA-UE and MBI scores of the combination group were significantly higher than those of the MIT group, and both were significantly higher than the control group′s averages. The average FTHUE-HK grading of the combination group and MIT group after the treatment was significantly higher than in the control group, with that of the combination group significantly superior to the MIT group′s average. After the intervention the average MAS rating of the combination group was significantly lower than that of the control group.Conclusion:MIT combined with Kinesio taping can significantly improve the upper limb motor functioning of stroke survivors, and significantly reduce their abnormal muscle tone compared to traditional treatments.

OBJECTIVETo study the potential association of DNA oxidation and DNA methylation, in vitro cultured cells were exposed to different doses of H2O2, 8-oxo-dG formation, cell DNA 5-mC contents were analyzed to explore the time- dose-response relationship of DNA oxidation and DNA methylation.

METHODSA549 cells were exposed to different doses of H2O2, 8-oxo-dG formation and cell genomic DNA 5-mC contents were analyzed by a high-performance liquid chromatography system and high performance capillary electrophoresis (HPCE), respectively.

RESULTSH2O2 induced the formation of 8-oxo-dG and 5-mC in different characteristics, it need at least 10 days for significant changes in the level of DNA methylation, whereas under the same conditions, changes in the level of DNA oxidation cast only 12 hours. H2O2 induced decreased levels of DNA methylation in A549 cells in a dose-dependent manner. In a certain range of time and dose, it showed a negative correlation between DNA oxidation and DNA methylation.

CONCLUSIONThe study suggests that oxidative DNA could lead to reduced levels of DNA methylation, DNA oxidation may affect the regulation of cellular methylation mechanisms, in the course of chemical mutagenesis, DNA oxidation may be an earlier important molecule event than DNA methylation.

Cell Line ; DNA ; chemistry ; DNA Damage ; DNA Methylation ; Deoxyguanosine ; analogs & derivatives ; chemistry ; Humans ; Hydrogen Peroxide ; toxicity ; Oxidative Stress

Objective To investigate the characteristics of distribution and expression profiles of plasma miRNA in childhood acute lymphocytic leukemia (cALL) patients;the association between cALL incidence risk and plasma miRNA levels;the feasibility of plasma miRNA serving as cALL diagnostic biomarker.Methods A total of 111 pairs of newly diagnosed cALL patients and patients with fractures were collected from Shenzhen Children's Hospital,China,between January 2015 and November 2016.Age and sex of the cases and controls were 1 ∶ 1 matched and LNATM miRNA microarray was performed using 4 pairs of cALL and controls selected from the sample population.The expression level of miRNA was validated by real time quantitative PCR.Conditional logistic regression analysis was applied to evaluate the association between miRNA expression levels and the incidence risk of cALL.The receiver operating characteristic curve (ROC) and reclassification analysis were conducted to assess the feasibility of miRNAs serving as biomarkers for cALL.Results A total of 204 differentially expressed miRNA were screened out and let-7f-5p,miR-5100,miR-25-3p and miR-3654 were selected for validation identified according to the inclusion criteria.The expression levels of let-7f-5p,miR-5100 and miR-25-3p in the cALL patients were significantly lower than those of the controls (P＜0.01).After adjusting for confounding factors,3 miRNAs remained significantly associated with the risk of cALL (OR and 95％CI were 0.84 (0.76-0.92),0.81 (0.73-0.90)and 0.81 (0.74-0.89),respectively.Results from both the ROC analysis and reclassification analysis showed that introduction of one or more miRNA to traditional risk factors improved the area under the curve (P＜0.05) and provided additional values to diagnosis (P＜0.01).Conclusion The expression levels of let-7f-5p,miR-5100 and miR-25-3p were significantly associated with the incidence rate of cALL,and these miRNAs might serve as promising biomarkers for cALL.

Objective This study aimed to investigate the association between exposure to environmental chemicals and the risk of childhood acute lymphocytic leukemia (cALL). Methods A case-controlled study was conducted in Shenzhen Children's Hospital, China from January 2015 to January 2016. The cases were selected from the section of Hematology and Oncology, and the controls were selected from Orthopedics by 1∶2 matching of cases according to sex and age. A questionnaire including population data and chemical exposure characteristics was conducted on the children's parents, and urine and EDTA-blood were collected from the children. Then, we quantitatively measured the internal dose of formaldehyde (i.e., formaldehyde-human serum albumin) by enzyme-linked immunosorbent assay and the doses of metabolites benzene, toluene, and xylene (i.e., trans-muconic acid, hippuric acid, and methylhippuric acid) by high-performance liquid chromatography. Logistic regression models were used to analyze the relationships between exposure factors measured from children and their parents and cALL. Results In the study, 71 cases (average age:6.08 ± 3.61 years), and 142 controls (average age:5.91 ± 3.57 years) were assessed; there were no differences in general demographics between two groups. The self-reported results showed that living in a home that had been painted in the past 10 years (OR=4.39, 95% CI: 1.87-10.31), maternal chemical exposure during pregnancy (OR=11.78, 95% CI: 1.65-83.88), paternal diesel or gasoline exposure (OR=8.15, 95% CI: 2.68-24.83), paternal dye exposure (OR=7.77, 95% CI: 1.52-39.67) and trash burning near the child's residence (OR=6.08, 95% CI: 1.17-31.66) were associated with increased risk of cALL. The positive detection rates of only benzene metabolites were significantly higher in cases (40/44) than controls (81/111) (χ2=5.92, P=0.021). The median formaldehyde and benzene concentrations in cases (32.120 pg/ml, 2.505 μg/gCr) were significantly higher than those in controls (18.705 pg/ml, 0.672μg/gCr;Z values:-1.98 and-3.95, P values:0.047 and<0.001, respectively). Multiple logistic regression analysis showed that benzene exposure (OR=1.09, 95% CI: 1.00-1.19), home painting in the past 10 years (OR=3.56, 95%CI:1.20-10.53) and paternal diesel or gasoline exposure (OR=3.75, 95% CI: 1.06-13.22) were associated with increased risk of cALL. Conclusion A variety of environmental chemistry factors, such as benzene exposure, increase the risk of cALL, and further studies are warranted to explore their specific roles.

Objective This study aimed to investigate the association between exposure to environmental chemicals and the risk of childhood acute lymphocytic leukemia (cALL). Methods A case-controlled study was conducted in Shenzhen Children's Hospital, China from January 2015 to January 2016. The cases were selected from the section of Hematology and Oncology, and the controls were selected from Orthopedics by 1∶2 matching of cases according to sex and age. A questionnaire including population data and chemical exposure characteristics was conducted on the children's parents, and urine and EDTA-blood were collected from the children. Then, we quantitatively measured the internal dose of formaldehyde (i.e., formaldehyde-human serum albumin) by enzyme-linked immunosorbent assay and the doses of metabolites benzene, toluene, and xylene (i.e., trans-muconic acid, hippuric acid, and methylhippuric acid) by high-performance liquid chromatography. Logistic regression models were used to analyze the relationships between exposure factors measured from children and their parents and cALL. Results In the study, 71 cases (average age:6.08 ± 3.61 years), and 142 controls (average age:5.91 ± 3.57 years) were assessed; there were no differences in general demographics between two groups. The self-reported results showed that living in a home that had been painted in the past 10 years (OR=4.39, 95% CI: 1.87-10.31), maternal chemical exposure during pregnancy (OR=11.78, 95% CI: 1.65-83.88), paternal diesel or gasoline exposure (OR=8.15, 95% CI: 2.68-24.83), paternal dye exposure (OR=7.77, 95% CI: 1.52-39.67) and trash burning near the child's residence (OR=6.08, 95% CI: 1.17-31.66) were associated with increased risk of cALL. The positive detection rates of only benzene metabolites were significantly higher in cases (40/44) than controls (81/111) (χ2=5.92, P=0.021). The median formaldehyde and benzene concentrations in cases (32.120 pg/ml, 2.505 μg/gCr) were significantly higher than those in controls (18.705 pg/ml, 0.672μg/gCr;Z values:-1.98 and-3.95, P values:0.047 and<0.001, respectively). Multiple logistic regression analysis showed that benzene exposure (OR=1.09, 95% CI: 1.00-1.19), home painting in the past 10 years (OR=3.56, 95%CI:1.20-10.53) and paternal diesel or gasoline exposure (OR=3.75, 95% CI: 1.06-13.22) were associated with increased risk of cALL. Conclusion A variety of environmental chemistry factors, such as benzene exposure, increase the risk of cALL, and further studies are warranted to explore their specific roles.

Objective To explore the potential effects of long-term and low-dose Di-(2-ethylhexyl)phthalate (DEHP) exposure on whole genome DNA methylation status and cytotoxicity of HePG2 cells.Methods HePG2 cells were exposed to 1.5、15.0 and 150.0 μmol/L DEHP for 24 hours,after continuous exposure for 20 generations,mRNA and protein expression level of DNA (cytosine-5)-methyhransferase 1(DNMT 1),whole genome DNA methylation,cell apoptosis levels and cell cycle were determined in both DEHP exposed cells and control cells.Results After DEHP exposure,the mRNA and protein expression levels of DNMT 1 were decreased significantly (P＜0.05 or P＜0.01).The genome DNA methylation levels of HePG2cells were down-regulated along with the increasing of DEHP exposure level (15.0,150.0 μμmol/L,P＜0.05 and P＜0.01).In term of cell apoptosis rates,only the late-stage cell apoptosis rates of the highest DEHP dosage group (150.0 μmol/L DEHP) were observed to have a significant increase (P＜0.05).There were no significant alterations in term of cell cycle.Conclusion After long term and low dose DEHP exposure,the whole genome DNA methylation levels of HePG2 cells were down regulated obviously,which might be one of the most important toxic mechanism of DEHP to induce pathophysiologic changes.Meanwhile,a certain content of cell apoptosis were observed in highest dosage group of DEHP exposure,which showed cytotoxicty of DEHP.However,there are no significant effects of DEHP exposure on cell cycles.

Objective To explore the potential effects of long-term and low-dose Di-(2-ethylhexyl)phthalate (DEHP) exposure on whole genome DNA methylation status and cytotoxicity of HePG2 cells.Methods HePG2 cells were exposed to 1.5、15.0 and 150.0 μmol/L DEHP for 24 hours,after continuous exposure for 20 generations,mRNA and protein expression level of DNA (cytosine-5)-methyhransferase 1(DNMT 1),whole genome DNA methylation,cell apoptosis levels and cell cycle were determined in both DEHP exposed cells and control cells.Results After DEHP exposure,the mRNA and protein expression levels of DNMT 1 were decreased significantly (P＜0.05 or P＜0.01).The genome DNA methylation levels of HePG2cells were down-regulated along with the increasing of DEHP exposure level (15.0,150.0 μμmol/L,P＜0.05 and P＜0.01).In term of cell apoptosis rates,only the late-stage cell apoptosis rates of the highest DEHP dosage group (150.0 μmol/L DEHP) were observed to have a significant increase (P＜0.05).There were no significant alterations in term of cell cycle.Conclusion After long term and low dose DEHP exposure,the whole genome DNA methylation levels of HePG2 cells were down regulated obviously,which might be one of the most important toxic mechanism of DEHP to induce pathophysiologic changes.Meanwhile,a certain content of cell apoptosis were observed in highest dosage group of DEHP exposure,which showed cytotoxicty of DEHP.However,there are no significant effects of DEHP exposure on cell cycles.

OBJECTIVETo investigate the potential substitution effect of hOGG1 and hMTH1 on oxidative DNA damage, based on gene-deficient cell strains models.

METHODShOGG1 and hMTH1 gene deficient cell strains models were established by Human embryonic lung fibroblasts (HFL) cells. After HFL cells being exposed to 100 µmol/L H₂O₂ for 12 h, HPLC-EC detecting technique and RT-PCR method were adopted to analyze the genetic expression level of 8-oxo-dG (7, 8-dihydro-8-oxoguanine).

RESULTSThe gene-deficient cell strains models of hOGG1 and hMTH1 were obtained by infecting target cells with high titer of lentivirus. The mRNA expression level of hOGG1 was 0.09 ± 0.02, 91% lower than it in normal HFL cells, which was 1.00 ± 0.04. As the same, the mRNA expression level of hMTH1 (0.41 ± 0.04) also decreased by 60% compared with it in normal HFL cells (1.02 ± 0.06). After induced by 100 µmol/L H₂O₂ for 12 h, the genetic expression level of hMTH1 in hOGG1 gene-deficient cells (1.26 ± 0.18) increased 25% compared with it in control group (1.01 ± 0.07). Meanwhile, the genetic expression level of hOGG1 in hMTH1 gene-deficient cells (1.54 ± 0.25) also increased by 52%. The DNA 8-oxo-dG levels in hOGG1 gene-deficient cells (2.48 ± 0.54) was 3.1 times compared with it in the control group (0.80 ± 0.16), the difference showed statistical significance (P < 0.01). Whereas the 8-oxo-dG levels in hMTH1 gene-deficient cells (1.84 ± 0.46) was 2.3 times of it in the control group, the difference also showed statistical significance (P < 0.01).

CONCLUSIONBased on gene-deficient HFL cells models, a synergetic substitution effect on DNA damage and repair activity by both hOGG1 and hMTH1 were firstly discovered when induced by oxidation. The substitution effect of hOGG1 were stronger than that of hMTH1.

Cell Line ; DNA Damage ; DNA Glycosylases ; genetics ; DNA Repair ; DNA Repair Enzymes ; genetics ; Fibroblasts ; metabolism ; Humans ; Oxidative Stress ; genetics ; Phosphoric Monoester Hydrolases ; genetics