[Mechanism of Triclosan in the Treatment of Nonalcoholic Fatty Liver Disease Based on Network Pharmacology].

Objective To explore the potential targets of triclosan in the treatment of nonalcoholic fatty liver disease(NAFLD) and to provide new clues for the future research on the application of triclosan. Methods The targets of triclosan and NAFLD were obtained via network pharmacology.The protein-protein interaction network was constructed with the common targets shared by triclosan and NAFLD.The affinity of triclosan to targets was verified through molecular docking.Gene ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment were carried out to analyze the key targets and the potential mechanism of action.NAFLD model was established by feeding male C57BL/6J mice with high-fat diet for 12 weeks.The mice were randomly assigned into a model group and a triclosan group [400 mg/(kg·d),gavage once a day for 8 weeks].The hematoxylin-eosin(HE) staining was used for observation of the pathological changes and oil red O staining for observation of fat deposition in mouse liver.Western blotting was employed to detect the protein level of peroxisome proliferator-activated receptor alpha(PPARα) in the liver tissue. Results Triclosan and NAFLD had 34 common targets,19 of which may be the potential targets for the treatment,including albumin(ALB),PPARα,mitogen-activated protein kinase 8(MAPK8),and fatty acid synthase.Molecular docking predicted that ALB,PPARα,and MAPK8 had good binding ability to triclosan.KEGG pathway enrichment showcased that the targets were mainly enriched in peroxisome proliferator-activated receptor signaling pathway,in which ALB and MAPK8 were not involved.Triclosan alleviated the balloon-like change and lipid droplet vacuole,decreased the lipid droplet area,and up-regulated the expression level of PPARα in mouse liver tissue. Conclusion PPARα is a key target of triclosan in the treatment of NAFLD,which may be involved in fatty acid oxidation through the peroxisome proliferator activated receptor signaling pathway.

[Comparative Analysis of Direct Drinking Water and the Relevant Sanitation Standards in China].

Along with the economic and technological development and growing demand for high-quality drinking water, direct drinking water has gained general popularity in China. However, no authoritative policy has been issued, giving a clear definition of direct drinking water and existing standards and regulations concerning direct drinking water are not definitive in nature. Existing water quality parameters are not well supported and sometimes even contradict each other. We elaborated, in this paper, the history of direct drinking water in China and systematically reviewed the existing regulations and standards related to direct drinking water. We also compared and analyzed the important microbiology, toxicology, sensory perception and general chemistry parameters in the standards. This paper is the first ever attempt at an in-depth analysis of the chaotic state of the direct drinking water industry. We have also highlighted the problems in the current standards and regulations for direct drinking water. Our study provides a basis for market regulation and the supervision and management of direct drinking water. In addition, the paper provides helpful information for laying down a definition of direct drinking water, calling for and approving of project proposals concerning the establishment of national standards for direct drinking water, and actually formulating the standards. We have made a number of suggestions: A. defining direct drinking water clearly and formulating the national standards for direct drinking water as soon as possible; B. conducting research on water quality benchmarks to provide scientific support for the formulation of the national standards for direct drinking water; C. giving more attention to the formulation of standards concerning microbiology parameters and their limits and giving consideration to the inclusion of parameters concerning viruses.

[Effect of Cell Autophagy on the Apoptosis of Hepatocellular Carcinoma Cells Induced by Arsenic Trioxide].

OBJECTIVES: To determine the effect of autophagy on the apoptosis of hepatocellular carcinoma cells induced by arsenic trioxide (ATO). METHODS: Hepatocellular carcinoma HepG2 cells were exposed to ATO. The cell viability was detected by MTT after adjustments for autophagy agonist (Rap) and autophagy inhibitor (3-MA). The autophagosome was observed under electronic microscope. The autophagy related proteins (LC3 and Beclin1) were detected by immunofluorescence. The cell apoptosis was measured by flow cytometry. RESULTS: With 5-20 µmol/Lof ATO, HepG2 cells exposed to 3-MA had significantly lower viability (P <0.05) and higher early apoptosis (P <0.05) than those without exposure to 3-MA. Exposure to 3-MA was also associated with lower expressions of LC3 and Beclin1, with HepG2 cells showing typical apoptotic characteristics. By contrast, with 5-20 µmol/Lof ATO, the cells exposed to Rap showed significantly higher viability (P <0.05) and lower early apoptosis (P<0.05) than those without exposure to Rap. A large number of autophagosome appeared in the cells exposed to Rap. Exposure to Rap was associated with increased expressions of LC3 and Beclin1, but with no statistical significance (P >0.05). CONCLUSION: Targeted autophagy inhibition can significantly increase the sensitivity of HepG2 to ATO. The underlining mechanism is associated with enhanced apoptosis of hepatocellular carcinoma cells.

[miR-155/BACH1 Signaling Pathway in Human Lung Adenocarcinoma Cell Death Induced by Arsenic Trioxide].

OBJECTIVE: To explore the changes of micro RNA 155 (miR-155),BTB and CNC homologous protein 1 (BACH1),quinone oxidoreductase 1 (NQO1) and heme-oxygenase-1 (HO-1) in the process of arsenic trioxide-induced cell death,and to clarify the relationship between miR-155 and BACH1,providing experimental basis for the sensitivity of arsenic trioxide (ATO) treatment. METHODS: Human lung adenocarcinoma cell line A549 cells were treated with different concentrations of ATO. MTT assay and total antioxidant capacity detection kit were used to determine cell viability and total antioxidant capacity,respectively. BACH1,NQO1 and HO-1 protein expression were probed by Western blot and real-time fluorescence quantitative (qRT-PCR) was utilized to test the miR-155 level. A549 cells were transfected with miR-155 mimic and its negative control,then the expression level of miR-155 was detected by qRT-PCR,and these cells were treated with 20 µmol/L for 24 h followed by MTT and Western blot detection. RESULTS: 10 µmol/L ATO significantly reduced the cell viability in A549 cells. 10 µmol/L and 20 µmol/L ATO treatment activated BACH1 expression and inhibited miR-155,NQO1 and HO-1 expression,leading to decreased total antioxidant capacity. Importantly,the cell death induced by 20 µmol/L ATO was significantly decreased in miR-155 mimic transfection cells in comparison with non-transfected cells and miR-155 mimic negative control transfected cells. Moreover,high expression of miR-155 reduced BACH1 activation and increased NQO1 and HO-1 expression in cells treated with 20 µmol/L ATO ( P<0.05). CONCLUSION: Restraining total antioxidant capacity contributes to ATO induced cell death,the underlying mechanisms may be that ATO can activate BACH1 expression through inhibition of the miR-155 level,leading to subsequent inhibition of NQO1 and HO-1 expression. Taken together,these data suggest that miR-155 and BACH1 could be used as sensitivity targets for ATO treatment in lung cancer.

[The Experiment Study and Mechanism of Aspirin Enhances Cellular Sensitivity of Hepatocellular Carcinoma Cell Line to Arsenic Trioxide].

OBJECTIVE: To explore whether aspirin could sensitize arsenic trioxide on human hepatocelluar carcinoma cell line and understanding the combination mechanisms underlying co-treatment. METHODS: Cell viability was detected by MTT assay, cell apoptosis rate and reactive oxygen species (ROS) level were measured by flow cytometry, and Western blot assay was used to estimated the protein expression of heme oxygenase-1 (HO-1) in total protein and NF-E2-related factor 2 (Nrf2) in nuclear protein. RESULTS: 10 µmol/L arsenic trioxide can decreased the cell viability, while cell apoptosis rate, ROS level, HO-1 and Nrf2 protein expression was increased (P < 0.05). When compared with arsenic trioxide alone, co-treatment of arsenic trioxide with aspirin in different concentration (0, 0.1, 1.0, 2.5, 5.0 mmol/L) exhibited dual effects in intracellular ROS level, HO-1 and Nrf2 expression. Specifically, with the increasing of aspirin concentrations, the level of ROS induced by arsenic trioxide showed a rising trend after the first reduction, whereas, HO-1 and Nrf2 protein expression were decreased at first and then increased. CONCLUSION: Low concentration, less than 2.5 mmol/L, of aspirin may reduce the ROS accumulation through activating of Nrf2-HO-1 pathway, therefore decreasing the apoptotic cell death induced by arsenic trioxide. On the contrary, 5 mmol/L aspirin could increase the sensitivity of HepG2 to arsenic trioxide through enhancing the arsenic trioxide-induced apoptosis by ROS accumulation resulting in inhibiting the Nrf2-HO-1 pathway.

[The Protective Effect of Inhibition of PARP-1 on Inflammation Induced by PM2.5 in Human Bronchial Epithelial Cell Line.]

OBJECTIVES: To explore whether the inhibition of poly ADP-ribose polymerase-1(PARP-1) could attenuated inflammation induced by fine particulate matter (PM2.5) in human bronchial epithelial cell line. METHODS: Cell viability was detected by Trypan Blue assay after incubated with PM2.5 for 24 h.PM2.5 doses no more than 600 µg/mL were utilized in the following experiments.In order to observe how PARP-1 would effect the expression of nuclear factor-κB p65 and inducible nitric oxide synthase (iNOS),cells were respectively treated with 600 µg/mL PM2.5,10 µmol/L 4-amino-1, 8-naphthalimide (4-AN),600 µg/mL PM2.5+10 µmol/L 4-AN or DMSO.Western blot assay was used to estimate the protein expression of PARP-1,p65 in nuclear and iNOS in cytoplasm.Nitric acid enzyme reduction assay was used to determine the production of nitric oxide (NO). RESULTS: As the PM2.5 concentration increased,the cell viability decreased,while the expression of PARP-1,p65,iNOS and NO increased significantly (P<0.05).After pretreatment of 4-AN for 24 h,the expression of PARP-1,p65,iNOS and NO almost decreased to the normal level(P>0.05). CONCLUSIONS: Inflammation triggered by PM2.5 could be attenuated by the inhibition of PAPR-1,which involved the block of transcriptional activity of NF-κB for inflammatory mediator.

[4-amino-1,8-naphthalimide on the Sensitive effect of arsenic trioxide in hepatocellular carcinoma cells].

OBJECTIVE: To study the effect and mechanism of 4-amino-1, 8-naphthalimide (4-AN) on the sensitive effect of arsenic trioxide (ATO) in hepatocellular carcinoma cells. METHODS: Hepatocellular carcinoma HepG2 cells were divided into two groups according to whether they were treated with 4-AN or not. Cell viability was evaluated by MTT assay, population doubling experiment and colony formation assay; genic mechanism was explored by 8-OH-dG assay, single cell gel electrophoresis (comet assay) and microriucleus test. RESULTS: At 2-10 micromol/L concentration of ATO, the cell viability and colony formation efficiency of the combinatio group (4-AN+ATO) were significantly lower than that of the ATO group (P<0.05); moreover, the tail-length (L-Tail) and olive tail moment (OTM) in comet assay were notablely higher than that of the ATO group (P<0.05). At 2-20 micromol/L concentration of ATO, the population doubling time and 8-OH-dG in combination group were significantly higher than that of ATO group (P<0.05). Results from DNA damage repair assay showed that the efficiency of DNA damage repair in combination group was remarkably lower than that of ATO group (P<0.05). At 5-20 micromol/L concentration of ATO, the frequency of micronucleated cells in combination group was significantly higher than that of ATO group (P<0.05). CONCLUSION: 4-AN can significantly increase the sensitivity of ATO in treatment with hepatocellular carcinoma cells and prevent DNA damage repair may be a primary mechanism for this effect.

[The apoptotic mechanism of hepatocellular carcinoma cell line (HepG2) induced by arsenic trioxide].

OBJECTIVE: To explore the apoptotic mechanism of human hepatic carcinoma cell line HepG2 induced by arsenic trioxide (As2O3). METHODS: The human hepatoma cell line HepG2 was treated with 0, 2.5, 5 and 10 micromol/L arsenic trioxide for 24 h. Cytotoxicity was tested by MTT assay (additional 25 and 50 micromol/L arsenic trioxide treatment groups), cellular apoptosis were detected by flow cytometry, reactive oxygen species (ROS) level were quantified by DCFH-DA fluorescent probe staining and glutathione content were measured by DTNB method with commercial kits. Western blot assay was used to detect the protein expression of gamma-glutamylcysteine synthetase (gamma-GCS, GCLC and GCLM subunits) and nuclear factor erythroid 2-related factor 2 (Nrf2). RESULTS: With the increase of arsenic trioxide concentration, cellular survival, glutathione content and gamma-GCS (GCLC and GCLM subunits) protein expression level decreased (P < 0.05); while cellular apoptotic rate, reactive oxygen species level and Nrf2 protein expression increased (P < 0.05). CONCLUSION: Arsenic trioxide induces the apoptosis of human hepatoma cell line HepG2 through ROS induction, gamma-GCS expression inhibition and cellular glutathione content depletion.

[Construction and expression of the eukaryotic expression vector containing AIF gene].

OBJECTIVE: To construct the eukaryotic express vector containing apoptosis-inducing factor (AIF) gene and to study its expression in A549 cells. METHODS: According to the GenBank AIF mRNA sequence, specific primers to amplify AIF gene from lung carcinoma cell line A549 by RT-PCR was designed. The amplified AIF gene fragment was cloned into plasmid pUC-T by TA cloning, then double enzyme digestion and DNA sequencing were used to identifying the positive recombinant AIF-pUC-T. The target fragment was retrieved and cloned into the eukaryotic express vector pcDNA3.1(+). The positive recombinant AIF-pcDNA3.1(+) was transfected into A549 cells, and expression of AIF gene was verified by RT-PCR and Western blot. RESULTS: AIF target gene was successfully amplified and cloned into the pUC-T. The target fragment was retrieved and cloned into the eukaryotic express vector pcDNA3.1(+), and it was completely coincided with the AIF sequence in GenBank suggested by cells transfected with AIF-pcDNA3. 1(+) was much higher than that of control cells which was not transfected with AIF-pcDNA3.1(+). CONCLUSION: The AIF eukaryotic expression vector AIF-pcDNA3.1(+) is successfully constructed in A549 cells and it could be experimental foundations for further study of AIF gene.

[Mechanism of DNA polymerase beta hyper-expression in malignant transformation induced by benzo[a] pyrene].

OBJECTIVE: To explore the mechanism of the hyper-expression of DNA polymerase beta (polbeta) in benzo[a]pyrene (BaP) induced malignant transformed cell (polbeta-T). METHODS: The mutation of polbeta gene exon and promoter were examined using reverse transcriptase-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) and gene sequencing. The expression of protein-arginine N-methyhransferase 6 (PRMT6) mRNA and protein in polbeta-T cell and control cell (polbeta cell) were investigated by RT-PCR and Western blot. RESULTS: RT-PCR-SSCP and gene sequencing revealed that the hyper-expression of polbeta in polbeta-T cell was not associated with the mutation of polbeta gene exon while insert mutation (G) and point mutation (C-->A) were found located in the core region of polbeta gene promoter. Furthermore, the expression of PRMT6 mRNA and protein also increased in polbeta-T cell compared with control cell (P<0.05). CONCLUSION: The enhancement of expression of polbeta in polbeta-T cell might be attributed to the mutations locating in polbeta gene promoter on transcription level of polbeta gene, and PRMT6 might also enhance the expression of polbeta in polbeta-T cell through relative epigenetic pathways.

[Exploration of relationship between the expression level of DNA polymerase beta and 60Co gamma-ray radiosensitivity].

OBJECTIVE: To explore the relationship between the expression level of DNA polymerase beta (pol beta) and 60Co gamma-ray radiosensitivity and provide a basis on improving the efficiency of radiotherapy theoretically. METHODS: pol beta wild-type cells (pol beta +/+), pol beta null cells (pol beta -/-) and pol beta overexpressed cells (polp beta oe) were applied as a model system. The radiosensitivity of 60Co gamma-ray on the cell was detected by MTT assay and clone formation assay. The DCFH-DA fluorescent probe was used to examine the cellular ROS after 60Co gamma-rays radiation. RESULTS: MTT assay showed that after radiation by 60Co gamma-rays followed with 72 h incubation, the cell viabilities in the three kinds of cells decreased significantly with a dose-response relationship (r-/+ = -0.976, r-/- = -0.977, r(oe) = -0.982, P<0.05). In addition, the viability of pol beta -/- cell was lower than those of other two kinds of cells at the same dose (P<0.05). Likewise, the colony number and colony formation rate in all tested cells also decreased after exposure to 60Co gamma-rays. The ROS level in the three kinds of cells was enhanced after treatment with 60Co gamma-ray, and the ROS level in pol beta -/- cells was much higher than that in the other two kinds of cells (P<0.05). CONCLUSION: Cell death caused by 60Co gamma-ray may associated with the DNA oxidative damage mediated by ROS; Overexpression of pol beta could protect against oxidative DNA damage, thus the cell apoptosis/death, thereby leading to reducing the radiosensitivity of 60Co gamma-rays, while null of DNA pol beta could increase radiosensitivity of 60Co gamma-rays by compromising the DNA repair.

[Effects of DNA polymerase beta on the genotoxicity and genetic instability induced by benzo(a)pyrene].

OBJECTIVE: To explore the effects of DNA polymerase ß expression level on the genotoxicity and genetic instability induced by benzo(a)pyrene (BaP),and provide experimental the basis for further study on the carcinogenic molecular mechanism of BaP. METHODS: Three kinds of cell lines with the identical genetic background, polß wild-type cells (polß+/+), polß null cells (polß-/-) and polß overexpression cells (polß oe) were applied as cellular models. The oxidative damage, genotoxicity and genetic instability induced by BaP were analyzed by using different methods respectively. RESULTS: Cell viability and colony forming ability of 3 kinds of cell lines exposed to BaP decreased with BaP. After treated with 5 and 20 µmol/L concentration of BaP, fluorescence intensity of polß-/- cell line was significantly higher than that of other two cell lines (P < 0.05). When treated with 5.00 µmol/L and 20.00 µmol/L concentration of BaP, the SOD activities (76.56 ± 2.84 and 62.78 ± 4.28 U/mg pro) of polß-/- cell line were significantly lower than that (84.85 ± 3.59) of control group and those (85.21 ± 3.20 and 76.90 ± 3.38 U/mg pro) of polß+/+ cell line. In 20.00 µmol/L BaP group. SOD activity (82.59 ± 4.64 U/mg pro) of polß oe cell line was lower than that (88.58 ± 6.77 U/mg pro) of control but higher than that of polß+/+ cell line (P < 0.05). In 1.25, 5.00 and 20.00 µmol/L concentration BaP groups, the micronucleus rates of polß-/- cell line were much higher than those of polß+/+ cell line (P < 0.05). In 5.00 and 20.00 µmol/L concentration BaP groups, the micronucleus rates of polß oe cell line were significantly lower than those of polß+/+ line (P < 0.05). In 5.00 and 20.00 µmol/L concentration BaP groups, HPRT gene mutation frequencies (26.16 × 10(-6) and 37.51 × 10(-6); 27.68 × 10(-6) and 38.63 × 10(-6)) in polß-/- cells and polß oe cells were significantly higher than those (19.76 × 10(-6) and 24.78 × 10(-6)) of polß+/+ cells (P < 0.05). CONCLUSION: Polß could play a role in protecting the cells from the genotoxicity and genetic instability induced by BaP, and the normal expression level of polß was indispensable for maintaining genome stability.

[Effect of DNA polymerase beta on apoptosis and mitochondrial membrane potential induced by hydroquinone, a metabolite of benzene].

OBJECTIVE: To explore the effect and mechanism of DNA polymerase ß expression level on cell apoptosis and mitochondrial membrane potential induced by hydroquinone. METHODS: Polß wild-type cells (polß+/+), polß overexpressed cells (polß oe) and polß null cells (polß-/-) were applied as a model cell system, The effect of cell apoptosis and mitochondrial membrane potential induced by different doses of hydroquinone were analyzed by flow cytometry. The ROS and ·OH assay kit were used to examine the cellular ROS and ·OH level. The activity of cellular SOD and GSH-Px were tested by Chemiluminescence method after exposed to different concentrations of hydroquinone. RESULTS: With the dose of hydroquinone increased, the rate of apoptosis and falling of mitochondrial membrane potential (ΔΨm) in cells were increased compared with the control. When compared with polß+/+ cells, the rate of apoptosis in polß-/- cells exposed to 20.00, 40.00, 80.00 µmol/L hydroquinone increased and the rate of apoptosis in polß oe cells exposed to 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone decreased (P < 0.05). Compared with polß+/+ cells (20.60% ± 0.57%, 37.95% ± 0.64%, 44.50% ± 1.27%, 57.55% ± 1.06%), the rate of cell which undergone mitochondrial depolarization in polß-/- cells treated with 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone (33.60% ± 1.55%, 46.05% ± 1.77%, 52.75% ± 2.05%, 75.20% ± 0.56%) increased. The rate of cell which undergone mitochondrial depolarization in polß oe cells exposed to 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone (16.05% ± 1.20%, 29.80% ± 1.21%, 35.15% ± 1.06%, 53.80% ± 0.85%) decreased (P < 0.05). When compared with polß+/+ cells, fluorescent intensity of polß-/- cells treated with different dosages of hydroquinone increased, while which of polß oe cells decreased (P < 0.05). Compared with polß+/+ cells, ·OH level of polß-/- cells treated with 20.00, 40.00 µmol/L hydroquinone significantly enhanced, while which of polß oe cells decreased sharply (P < 0.05). Under the same concentrations of hydroquinone, the activity of SOD and GSH-Px were decreased most rapidly in polß-/- cells. The activity of SOD and GSH-Px in polß oe cells decreased slower than in the polß-/- cells. CONCLUSION: Hydroquinone could induced apoptosis by the generation of ROS and decrease of ΔΨm; polß could protect cells from apoptosis induced by hydroquinone through decrease of ROS level and depolarization of mitochondria.

[Effects of pol beta on biological characteristics and DNA damage in mouse embryonic fibroblast].

OBJECTIVE: To explore the effect of DNA polymerase beta (pol beta) expression level on biological characteristics of mouse embryonic fibroblast (MEF) and the cellular response to DNA damage induced by potassium dichromate. METHODS: pol beta wild-type cells (pol beta +/+), pol beta null cells (pol beta -/-) and pol beta overexpressed cells (pol beta oe) were applied as a model system. The growth curve of cells was plotted by MTT assay; the doubling time of cells was detected by double time experiment; the spontaneous mutation frequency was determined by HGPRT gene mutation method and single cell gel electrophoresis assay (SCGE) was employed to observe the DNA damage either happened spontaneously or induced by potassium dichromate. RESULTS: Growth characteristic and doubling time of the three kinds of cells were similar and no obvious differences were found on spontaneous DNA damage and mutations frequency among them (P > 0.05). Potassium dichromate increased comet rate and tail length in the three kinds of cells in a concentration dependent way. DNA damage of pol beta -/- cells at the same dosage were more serious than the other cells both in comet rate and tail length (P < 0.05). pol beta oe cells demonstrated more resistant to DNA damage obviously than the others. CONCLUSION: The expression level of pol beta has no significant effect on the biological characteristic and spontaneous mutation frequency of MEF. pol beta knock out cells is more sensitive to DNA damage induced by potassium dichromate, whereas, pol beta over expression can help cells response to DNA damage and protect cells from death in a certain degree.

[Effects of hydroquinone on expression of human 8-oxo-guanine DNA glycosylase mRNA in human A549 lung adenocarcinoma cell strains].

OBJECTIVE: To explore the effects of hydroquinone (HQ) on reactive oxygen species (ROS) generation, antioxydase activities and the expression of human 8-oxo-guanine DNA glycosylase (hOGG1) mRNA in human A549 lung adenocarcinoma cell strains. METHODS: A549 cells were treated with different concentrations of HQ. Cell survival was determined by methyl thiazolyl tetrazolium (MTT). Changes of ROS were detected by fluorescent probe. The contents of malonaldehyde and activities of antioxydase were determined through colorimetry. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assess the level of hOGG1 mRNA. RESULTS: With the increased concentration of HQ, the findings were as follows. (1) The absorbance value of A549 cell decreased. There was significant difference between 160 micromol/L (0.584+/-0.098) and 320 micromol/L (0.328+/-0.066) of HQ (q=5.56 and 9.07, P<0.05) with the control group (0.989+/-0.150), and the cell survival rate were less than 80%. (2) The ROS in A549 cell increased. 40 micromol/L (39.80+/-4.15) and 80 micromol/L (101.99+/-9.45) had statistical significance (q=10.74 and 30.32, P<0.05) with the control group (5.71+/-0.50). (3) It was found that the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) decreased and malonaldehyde (MDA) increased. Compared with the control group [(25.62+/-0.28) U/mg prot and (38.97+/-2.61) U/mg prot], the activities of SOD and GSH-Px had a significant decrease (q=12.17 and 8.78, P<0.05) in 80 micromol/L [(22.93+/-0.56) U/mg prot and (25.60+/-2.31) U/mg prot]. And MDA had a significant increase (q=10.90 and 15.49, P<0.05) in 40 micromol/L [(1.07+/-0.01) nmol/mg prot] and 80 micromol/L [(1.19+/-0.08) nmol/mg prot] as compared with the control group [(0.77+/-0.04) nmol/mg prot]. The decrease of SOD (r=-0.95, F=20.00, P=0.04) and GSH-Px activities (r=-0.99, F=115.48, P=0.01) and the increase of MDA contents (r=0.96, F=21.31, P=0.04) all had a dose-response relationship. (4) RT-PCR results showed that the expression of hOGG1 mRNA decreased. The significant difference was observed between the expression of hOGG1 mRNA in 80 micromol/L (0.478+/-0.017) (q=11.70, P<0.05) with the control group (0.715+/-0.038). CONCLUSION: This study suggests that HQ could induce oxidative damage and changes of the expression of hOGG1 mRNA in A549 cells.

[Cigarette smoke-induced oxidative damage to human bronchial epithelial cells].

OBJECTIVE: To determine the oxidative damage of mainstream smoke (MS) on Human bronchial epithelial cells (HBE) and its role in lung cancer. METHODS: MTT assay was used to test the cytotoxicity of MS on HBE. The HBE cells were treated with different concentrations of MS for 12 h. The chromatosome damage and DNA strand breaks were measured by micronucleus test and alkaline comet assay respectively. The contents of ROS in the HBE cells were determined using fluorescence method. RESULTS: With the increase of MS, the viability of HBE cells decreased. The IC50 decreased with the increasing exposure time to MS, showing significant dose-effect and time-effect relationships. The MS induced DNA strand break in the HBE cells. The comet, L Tail, Tail DNA and OTM increased with the increase of MS concentrations. Cigarette smoke also induced chromosome damage. The micronucleus rate of the HBE cells exposed to more than one cigarette/L of MS was significantly greater than the controls (P<0.05). The ROS increased with the concentration of MS. CONCLUSION: MS induces ROS in HBE cells, resulting in increased cytotoxicity, chromosome damage and DNA strand breaks, which suggests that oxidative damage is an important mechanism of lung cancer caused by MS.

[Effect of metabolism activation on the oxidative cell damage induced by cigarette smoking].

OBJECTIVE: To explore the effect of metabolic activation on the oxidative cell damage induced by mainstream smoke (MS). METHODS: A549 cells were treated with different concentrations of MS for 2 hours in the presence and absence of S9 mix. ROS levels were determined. DNA and chromosome damages were detected. The activities of SOD and GSH-Px were measured. RESULTS: With different concentrations of MS treatment, the contents of ROS in the cells with S9 mix were significantly higher than those without S9 mix (P<0.05). More serious chromosome and DNA damages in the cells with S9 mix were observed than those without S9 mix. The micronucleus rate, comet rate, L Tail and OTM in the cells with S9 mix were significantly higher than those without S9 mix (P<0.05). With increased dose of MS, the activities of SOD and GSH-Px decreased in both cells with and without S9 mix. But the tendency of decrease in the cells with S9 mix was more obvious than those without S9 mix (P<0.05). CONCLUSION: MS induces oxidative damage in A549 cells and the metabolic activations could increase the oxidative stress and potentiate the cellular genotoxicity.

[Oxidative damage of gasoline engine exhausts to rat lung tissues].

OBJECTIVE: To study the effects of extracts of condensate, particulates and semivolatile organic compounds from gasoline engine exhaust on DNA damage, 8-oxoguanine DNA glycosylase-1 (OGG1) expression, and changes of ultra-structures in lungs of rats. METHODS: Organic extracts of gasoline engine exhaust (GEE) was intratrachealy instilled into rat lungs at 0, 5.6, 16.7, and 50.0 L/kg body weight, respectively, once a week for a month. The single DNA strand break was measured by comet assay. The OGG1 was determined using immunohistochemistry method. The ultrastructure of lung cells was observed with electronic microscope. RESULTS: The rates of tailed cells detected by the comet assay increased significantly when the rats were exposed to 16.7 and 50.0 L/kg of GEE compared with those exposed to solvent only (P < 0.05). However, the tail length did not differ significantly between the groups. Similarly, exposure to 16.7 and 50.0 L/kg of GEE led to increased OGG1 significantly. Significant changes of mitochondria in type I and II alveolar cells as well as respiratory bronchiole epithelial cells were observed, which included decrease of numbers, pyknosis and swelling. CONCLUSION: Gasoline engine exhausts induce single DNA strand break, increase OGG1 expression, decrease numbers of mitochondria, and destroy ultrastructures of mitochondria in various lung cells of rats.

[Effect of down-regulated hOGG1 gene expression on cytotoxicity and genotoxicity of hydroquinone].

OBJECTIVE: To explore the effects of down- regulated hOGG1 gene expression on cytotoxicity and genotoxicity of hydroquinone. METHODS: A549 cells and A549-R cells with down- regulated hOGG1 gene were treated with different concentrations of hydroquinone (0, 5, 10, 20, 40 and 80 µmol/L). The cellular sensitivity and contents of ROS were measured by MTT assay and fluorescence method, respectively. The chromosome damage was measured by micronucleus test. The DNA damage and repair were examined using comet assay in both cells. RESULTS: The cell viability decreased with increasing concentration of hydroquinone. The IC50 of hydroquinone was 160.49 and 228.42 µmol/L in hOGG1 deficient A549-R cell and in A549 cell respectively (P < 0.05). When the dose of hydroquinone reached 5 micromol/L and above, the contents of ROS and the rate of micronucleated cells in A549-R cells were significantly higher than in A549 (P < 0.05) cells. At the same time, the comet rate and OTM in A549-R cells were significantly higher compared with A549 cells at 5 micromol/L and above in a dose-response way (P < 0.05). Furthermore, in DNA repair assay, A549-R cells with down- regulated hOGG1 gene were more difficult to repair than A549 cells. In A549-R cells, the comet rate and OTM reduced significantly until after 2 h repair time and even after 3 h the DNA damage was not repaired completely. CONCLUSION: Oxidative damage may be one of the toxicological mechanisms of hydroquinone, and hOGG1 deficiency could increase sensitivity of A549-R cells to hydroquinone.

Preoperative serum ferritin is an independent prognostic factor for liver cancer after hepatectomy.

BACKGROUND AND AIMS: Serum ferritin (SF) may have a close relationship with the tumor. But no study has investigated the prognostic value of SF in hepatocellular carcinoma (HCC) patients receiving curative resection yet. Aim of this study is to explore the role of preoperative SF in survival outcomes of such patients. METHODS: We retrospectively analyzed 427 HCC patients who received curative hepatic resection in our medical center. Significant clinical and pathological data along with the association between SF and clinicopathological parameters were compared and analyzed. The prognostic significance of SF was determined by Kaplan-Meier analysis and the Cox proportional hazards regression model. RESULTS: The optimal cut-off value of SF for overall survival (OS) was 267 ng/ml. Preoperative SF level could predict OS (P = 0.001, HR = 1.651, 95%CI: 1.213-2.247) and recurrence-free survival (RFS) (P < 0.001, HR = 1.570, 95%CI: 1.221-2.018) independent of other prognostic factors. Patients with a low SF were more likely to have both favorable OS and RFS (both P < 0.001), and vice versa. The 1-, 3-, and 5-year OS and RFS rates were 91.4%, 80.1%, 71.7%, and 78.0%, 53.0%, 47.3% in low SF group, and 91.6%, 60.2%, 45.2%, and 61.3%, 36.4%, 29.0% in high SF group, respectively. CONCLUSIONS: Preoperative SF was a simple, inexpensive, convenient and reliable prognostic factor that could predict survival outcomes in HCC patients who received radical hepatic resection.