OBJECTIVE: RAW264.7 cells were exposed to different doses ofsilica nanoparticles and micron silicon dioxide (SiO₂), and induction of DNA damage was investigated. METHODS: RAW264.7 cells were treated with 20 nm, 60 nm silica nanoparticles at dosage of 31.25-500 μg/mL and micron SiO₂ at dosage of 500 μg/mL for 24 h. DNA single-strand break was detected by the Comet single cell gel electrophoresis (SCGE) and all the indexes of the assay:rate of comet (r_comet), tail length (TL) of DNA, rate of tail DNA (r_{tail DNA}), and Olive tail moment (OTM) were analyzed by the Comet Assay Software Project (CASP). In addition, levels of malondialdehyde (MDA), hydroxyl radicals (^·OH), superoxide anion radical (O₂·), hydrogen peroxide (H₂O₂) and nitric oxide (NO) in homogenate supernatantfrom treatedcells were measured. RESULTS: r_comet, TL, r_{tail DNA} and OTM induced by microsized SiO₂ were significantly increased compared with the negative control at the concentration of 500 μg/mL (P<0.01). Cells exposed to 125 and 500 μg/mL of the two kinds of silica nanoparticles showed a distinct increase of r_comet, TL, r_{tail DNA} and OTM compared with the negative control (P<0.01). r_comet, r_{tail DNA} and OTM caused by microsized SiO₂ were significantly increased compared with the silica nanoparticles groups(P<0.01) at the same concentrations. The increase of lipid peroxidation products of MDA and free radicals of ^·OH, O₂·, H₂O₂ and NO were in different degrees the result from silica nanoparticle and micron SiO₂ in comparison to the negative control. CONCLUSION: Both silica nanoparticle and microsized SiO₂ can cause DNA single-strand break and oxidative injury in RAW264.7 cells. The generation of free radicals of oxidative stress may have played a role in induction of DNA-damage.

OBJECTIVE: To investigate the effect of celecoxib on proliferation, chemotherapy sensitivity and invasion of T cell lymphoma. METHODS: Jurkat and Hut78 cells were treated with celecoxib for 24, 48 and 72 h, and their proliferation activity and chemotherapy sensitivity were detected using the MTT method. In addition, apoptotic rates of the treated cells were analyzed using flow cytometry. Transwell chamber was used to investigate the invasion of cells which were treated with celecoxib for 48 h. Expression of P38, P65, Bcl-2, Bax, MDR1, MMP2 and MMP9 in treated cells were investigated using quantitative real-time PCR (qPCR) and Western blot. RESULTS: After treatment with celecoxib, growth of Jurkat and Hut78 cells was inhibited in a dose-and time-dependent manner, and their chemotherapy sensitivity was elevated. Consequently, the apoptotic rates of the treated cells were also higher than the control. The number of treated cells that passed through Transwell chamber was significantly less than control (P<0.01). The qPCR and Western blot analyses showed that expression of P65, Bax, MDR1, Bcl-2, MMP2 and MMP9 were all down-regulated, whereas P38 and Bax were up-regulated in the treated cells compared with control(P<0.05). CONCLUSION: Celecoxib has inhibitory effect on proliferation and invasion of T cell lymphoma. Therefore, it may have a broad prospect for clinical treatment of T cell lymphoma.

OBJECTIVE: To investigate the radiosensitizing effect of protein phosphatase 2A(PP2A) inhibition on nasopharyngeal carcinoma cell line CNE2 and its xenografts. METHODS: The cells and subcutaneous xenografts in BALB/c nude mice were randomly divided into control, norcantharidin (40 μmmol/L in vitro, 27 μmol/kg in vitro), irradiation (8 Gy in vitro, 20 Gy in vitro), and combination of norcantharidin and irradiation groups. MTT, Co-immunoprecipitation and flow cytometry were used to examine the effect of PP2A inhibition, cell cycle analysis, apoptosis of CNE2 and its xenografts by norcantharidin and (or) irradiation. RESULTS: We measured PP2A activity in CNE2 cells and xenografts 5 hours after exposure to 8 Gy radiation in vitro and 20 Gy radiation in vivo, with and without prior exposure to NCTD. Compared with control group, NCTD alone was associated with decreasedin PP2A activity of 70% in vitro and in vivo both. Radiation alone was associated with increased in PP2A activity of 210% and 165% in vitro and in vivo, respectively. The cell cycle arrested in G2/M and increasing of apoptotic ratio in CNE2 cells were significantly different between the control and the both two treatment alone groups (P<0.05). Compared with control group, the combination of 8 Gy and 40 μmol/L norcantharidin produced significant inhibition of PP2A(80% in vitro and 72% in vitro compared to control), accumulation of cells in G2/M-phase (87.88%±2.10%) and more apoptosis (77.15%±7.62%) in CNE2 cell lines compared to norcantharidin alone and radiation alone. Norcantharidin in combination with radiation produced the greatest effects on tumor growth slowing and decreasing tumor weight by 87.98% relative to control in CNE2 xenografts(compared to control, P<0.05). Furthermore, more apoptosis, necrotic cells and formation of apoptotic bodies were found in pathological section in norcantharidin plus radiotherapy group. CONCLUSION: PP2A might be a potential target for sensitization of nasopharyngeal carcinoma to radiatotherapy.

OBJECTIVE: To compare different induction methods on activity of rat liver microsomal enzyme S9 and to identify the effective induction method. METHODS: Rats were injected with PCBs, phenobarbital, beta- naphthoflavone and phenobarbitol sodium. In addition, beta-naphthoflavone and phenobarbital were used as inducer to induce rat liver S9. S9 protein content was determined by the method of Lowry. Metabolic activation effects of four kinds of S9 were compared using the Ames test and the in vitro chromosome aberration assay of CHL cells. RESULTS: Protein contents of four kinds of S9 were 30.29, 34.15, 33.31, 28.02 mg/mL, all of them were less than 40 mg/mL. Compared with the groups without S9, the 4 types of S9 showed activation effect in the positive control (P<0.01). Activation effects from three kinds of S9 had no significant difference among them in the Ames and CHL chromosome aberration assays (P>0.05), however, the activation from the phenobarbital-induced S9 was significantly weaker (P<0.05 or P<0.01). CONCLUSION: Under our conditions:using PCBs, phenobarbital and beta-naphthoflavone, phenobarbitol sodium injection and beta-naphthoflavonen as inducer, metabolically active rat liver S9 was induced successfully. In addition, the combined induction method can take the place of the induction by PCBs alone.

OBJECTIVE: To investigate the mechanism of inhibition of Hep-2 cell migration by Okadaic acid (OA). METHODS: MTT assay was used to determine the doses of OA for the investigation. Hep-2 cells were treated with 0, 50 or 100 nmol/L OA and enzyme assay was used to measure PP2A activities. Wound scratch assay was used to observe the influence of OA on migration of Hep-2. RESULTS: The growth inhibition ratio was 96.7%±1.8%, 82.9%±12.6% and 57.2%±7.7% in cells treated with 50, 100 and 200 nmol/L OA, and the difference was significant (P<0.05). In cells treated with 50 and 100 nmol/L OA, the relative activity of PP2A was 30.90%±12.01% and 8.98%±4.96% (P<0.05). From the wound scratch assay, the treated cells took significantly longer than untreated cells for healing (P<0.05). CONCLUSION: Inhibition of PP2A activities may be responsible for the reduction of migration in the OA-treated Hep-2 cells.

OBJECTIVE: To establish a method for genotoxicity evaluation of ethyl methanesulfonate (EMS) in rats by using a combination of Comet and flow micronucleus assays. METHODS: EMS (50, 100 and 200 mg/kg) was administered to rats once daily at 24 h and 45 h intervals. Negative controls received 0.9% physiological saline. Each dose group contained 5 rats. Blood was collected at 3 h after the final administration. From each sample, 2 000 reticulocytes (RET) were counted for MN frequency by flow cytometry. Then, all rats were humanely sacrificed with pentobarbital sodium. Liver, stomach, and kidney were removed to make single cell suspensions. These cells were used for the Comet assay. The Comet parameters were measured using the Comet Assay IV. RESULTS: Based on the Comet assay, EMS induced a significant dose-related increase of the Comet tail DNA percentage in the liver, stomach, and kidney. In the flow micronucleus assay, statistically significant increases in MN frequency were noted in the 100 mg/kg EMS dose group compared with those in the negative controls. CONCLUSION: EMS can cause DNA strand breaks and micronuclei and the combined Comet and MN assays will improve the accuracy of investigations.

OBJECTIVE: To evaluate the clinical value of combining the thinprip cytologic test (TCT) with HPV-DNA genotyping for detecting cervical cancer in Eastern Guangdong region, China. METHODS: From March 2011-March 2014, 1 681 females were screened for cervical cancer. All patients underwent TCT and HPV-DNA screening, and cervical biopsies were evaluated for confirmation. RESULTS: Among the 1 681 cases, 399 were TCT positive, with the positive rate of 23.7%;533 cases were HPV-DNA positive, with the positive rate of 31.7%. Along with the development of cervical lesions, the positive rate of HPV-DNA was also increased (P<0.05);267 cases were rated positive based on pathological evaluation. And among the TCT positive patients, the consistency between ASCUS, LSIL, HSIL, SCC and positive diagnosis were 46.8%, 59.8%, 96.3% and 100% respectively. The sensitivity (93.5%), specificity (82.8%) and veracity (92.1%) values for TCT in combination with HPV-DNA screening were significantly greater than the results from individual screening assays (P<0.05). CONCLUSION: The combined HPV and TCT tests can significantly increase the accuracy rate of diagnosis for cervical precancerous lesions, therefore the tests can be considered for clinical applications.

OBJECTIVE: To conduct a Meta-analysis for better understanding the relationship between E-cadherin and clinicopathological indicators in patients with breast cancer. METHODS: All eligible studies reporting associations between E-cadherin expression and clinicopathological features in breast cancer patients were retrieved from CBM, CNKI, PubMed and Cochrane Library databases. Review Manager 5.0 was used to calculate the pooled odds ratio (OR) and 95% confidence interval (CI). RESULTS: A total of 32 studies were included in this Meta-analysis. It was found that the expression level of E-cadherin was significantly correlated with lymph node metastasis[OR=0.27, 95%CI (0.18, 0.41), P<0.05], histological grades[OR=0.50, 95%CI(0.33, 0.77), P<0.05], clinical stage[OR=0.43, 95%CI(0.24, 0.76), P<0.05]. CONCLUSION: Aberrant expression of E-cadherin may play an important role in the progression and metastasis of breast cancer. In addition, aberrent E-cadherin may be a biomarker for early diagnosis and for development of individual therapy.

OBJECTIVE: Reports on association between the xeroderma pigmentosum group D (XPD) and genetic susceptibility to lung cancer have not been consistent. Therefore, we have conducted a Meta analysis to review the association. METHODS: The databases of PubMed, CNKI, cqVIP or wanfang were retrieved to search for publications about case-control studies which were published from 2000-2014. The focus was on XPD 751 polymorphisms and genetic susceptibility to lung cancer. Relevant data were extracted from the selected publications. Corresponding combination methods were used and the pooled relative risk (OR) and its 95% confidence interval (95%CI) were calculated after the heterogeneity test with the statistical analysis software RevMan 4.2. Meanwhile, Funnel Plots were protracted to estimate the effect of publication bias. RESULTS: The study included 28 domestic and international reports with 9 012 cumulative subjects of case group and 10 542 controls. For the Lys/Gln versus the Lys/Lys variant groups, the OR was 1.18, the 95%CI was 1.07-1.31, and P=0.001 which reflected on random effect model. For the Gln/Gln versus the Lys/Lys variant groups, the OR was 1.28, the 95%CI was 1.14-1.44, and P=0.01, which reflected on fixed effect model. Subgroup analyses revealed that XPD 751 polymorphism was associated with genetic susceptibility to lung cancer. CONCLUSION: For individuals carrying the codon 751 Gln/Lys or Gln/Gln genotypes, the risk of lung cancer increased significantly.

OBJECTIVE: To explore effects on the percentages and numbers of Ly6C⁺ and Ly6C^- monocyte subsets from peripheral blood of irradiated mice. METHODS: After exposure to 4 Gy γ rays, mice were subdivided into 10 mice per group and evaluated at 3, 5, 7, 14 and 21 days after the irradiation. There were also 10 non-irradiated control mice. The number of monocytes from peripheral blood of irradiated mice was measured by blood cell analysis instrument. The percentage of Ly6C⁺ and Ly6C^- monocyte subsets was detected by flow cytometer. RESULTS: At 3, 5 and 7 days after the irradiation, the numbers of monocyte subsets were significantly decreased (P<0.01) compared to those from the controls. The Ly6C⁺ monocyte subsets fromthe fifth day group were significantly higher than those from the third day group (P<0.01), but significantly decreased (P<0.01) compared to the seventh day group. Compared with control group, the percentages of Ly6C⁺ monocyte subsets from the third and fifth day groups were significantly increased to 90% and the percentage of Ly6C^- monocyte subsets were significantly decreased to 10%. In addition, both the numbers and percentages of monocyte subsets from the fourteenth day group were significantly decreased (P<0.01) compared to the controls. On the other hand, both the numbers and percentages of monocyte subsets recovered at 21 day after irradiation. CONCLUSION: During the first week after irradiation, the numbers of monocyte subsets from peripheral blood of mice were reduced significantly. The decrease may be associated with radiation-induced apoptosis of these monocyte subsets.

OBJECTIVE: To investigate acute and genetic toxicity of Zihe herbal solid beverage in mice. METHODS: Foracute oral toxicity test, male and female mice (10 mice per group) were orally administered a cumulative dose is 10 g/(kg·d) for the determination of mortality, LD₅₀ and maximum tolerated dose. Three assays were used for determination of genetic toxicity:Ames test (using tablet adding method with 5 000, 1 000, 200, 40 and 8 μg/plate);spermatogonia chromosome aberration test[2000, 1000 and 500 mg/(kg·d) dose groups];erythrocytes micronucleus test[2000, 1000 and 500 mg/(kg·d) dose groups]. Moreover, negative control and positive control groups were used for the 3 genotoxicity tests. RESULTS: After 14 days of observation, no acute toxicity effect was observed in the exposed mice. From the Ames tests, the number of revertant colonies of TA97, TA98, TA100, TA102 strains were not significantly different compared with those from the negative control group. Chromosome aberration test showed that the sperm abnormality rate was 0-1.6% which was not significantly different compared with the control group (0.6%, P>0.05). The mammalian erythrocytes micronucleus test showed that there was no significant difference compared with the control group (P>0.05). CONCLUSION: Under our experimental conditions, the Zihe herbal solid beverage did not induce any obvious acute or genetic toxicity in mice.

OBJECTIVE: To investigate the acute toxicity and genotoxicity of crude water extracts from tea mistletoe (CWE). METHODS: The following assays were used for the investigation:Ames assay, acute toxicity in rats, micronuclei of mouse bone marrow polychromatic erythrocytes, and mouse spermatogonium chromosome aberrations. RESULTS: Oral acute toxicity test revealed that the LD₅₀ of CWE was approximate 21.5 g/kg in rats, thus CWE was relatively non-toxic. No mutagenic activities were detected in the Salmonella typhimurium reverse mutation assay (Ames test), both with and without metabolic activation. In addition, CWE demonstrated no positive adverse effects in the in vivo micronucleus test or spermatogonium chromosome aberration test of ICR mice. CONCLUSION: Under our experimental conditions, water extracts from CWE showed no evidence of acute toxicity and no positive evidence of genotoxicity.

OBJECTIVE: To optimize chromatographic conditions for determination of gallic acid contents in Phyllanthus emblica L. from different regions. METHODS: Determination of gallic acid in Phyllanthus emblica L. in different regions was performed on an Eclipse plus C18 (25 μm, 4.6 mm×250 mm). The mobile phase was Acetonitrile-0.2% phosphoric acid solution (5:95). The elution was in same degree. The current speed was 1.000 mL/min. The detection wave length was 273 nm and the determination of linear regression equation used standard curve method. The column temperature was 30 degrees Celsius. RESULTS: Gallic acid had a good linear relationship in the range of 13.010-130.104 g/mL (R²=0.999 4). It also had good precision (RSD=0.08%), good stability (RSD=0.29%) and general reproducibility (RSD=4.23%). The content of gallic acid in the three batches of Phyllanthus emblica L. were higher than Chinese Pharmacopoeia national standard of 1.2%. CONCLUSION: The method for the determination of gallic acid in Phyllanthus emblica showed strong specificity and good precision. In addition, the results were accurate and reliable.

OBJECTIVE: To establish a GC-MS method for determination of residual organic solvents in allogeneic bones. METHODS: A SCAN mode of GC-MS was used to determine the presence of residual organic solvents in allogeneic bones and a SIM mode was used to quantify ten kinds of organic solvent residues. RESULTS: Several organic solvents were observed, including methanol, ethanol and dichloromethane, etc. Residual benzene was found in many samples. The total residual organic solvents in allogeneic bones were up to 167.45 μg/g. The linear R of the quantitative method was above 0.99. The average recovery rate was between 90.5%-113.8% and the precision was between 1.00%-3.19%. CONCLUSION: Our data show that the established GC-MS method was accurate and suitable for the determination of residual organic solvents in allogeneic bones.