OBJECTIVE: To separate and extract Arca subcrenata Lischke protein component and investigate its anticancer mechanisms on human breast carcinoma MCF-7 cells in vitro. METHODS: Fresh Arca subcrenata Lischke was used as the raw material to extract its anticancer protein component which was named as NS. The growing changes of cultured MCF-7 cells treated with different concentrations of NS(50,100,200,400μg/mL) were observed under the inverted phase-contrast microscope. The cell and nucleus changes of MCF-7 cells treated with NS 200μg/mL were analyzed by Giemsa staining. Flow cytometry was used to evaluate apoptosis and cell cycle of MCF-7 cells treated with NS. The expressions of apoptosis-and cell cycle-related proteins were analyzed by Western blot. RESULTS: Comparing with negative control group,obvious growth inhibition effects were found in MCF-7 cells treated with different concentrations of NS(50,100,200,400μg/mL)(P<0.05 or P<0.01). The appearance of cultured MCF-7 cells treated with NS 200μg/mL for 12,24 and 48 h were shrinking and falling off from the tissue culture flask in a time-dependent manner after treated with NS for 12 h. The percentage of MCF-7 cells in mitosis phase and the multinuclear or nuclear fragmentation cells were obviously increased. Flow cytometry analysis indicated that apoptotic cell increased and G2-M phase cells accumulated significantly with NS(P<0.01). The apoptosis rate of MCF-7 cells increased in a time-dependent manner. The expression of apoptotic protein procaspase-3 and p53 protein were up-regulated after NS treatment for 6 h. CONCLUSION: Inducing apoptosis and cell cycle arrest in G2-M phase were main mechanisms of Arca subcrenata Lischke anticancer protein component NS cytotoxic activity, and procaspase-3 and p53 signal pathways were upregulated in MCF-7 cells.

OBJECTIVE: To explore the change in expression of POLH mRNA in human peripheral blood exposed to γ-ray and provide experimental evidence for POLH mRNA to be a new molecular biomarker for radiation injury. METHODS: After radiation with dose of 0,0.5,1,2,4,6,10 Gy by ⁶⁰Co γ-rays,total RNA was extracted from peripheral blood of three healthy adults at 0,2,4,8,12,24 h post-radiation. Expression level of POLH mRNA was measured by real-time quantitative PCR. 30 healthy donors' peripheral blood were collected as the background group to measure the expression level of POLH mRNA in different individuals. RESULTS: The expression level of POLH mRNA increased in a dose-dependent manner within the range of 0-2 Gy at 4,8,12,and 24 h after radiation,with no significant change at 2 h post-radiation. Over 2 Gy,the expression level of POLH mRNA was close to saturation. It also showed that the expression level of POLH mRNA increased in a time-dependent manner within the range of 4-12 h postradiation,a maximum response was observed at 12 h. The basal level of POLH mRNA was not affected by age and gender. CONCLUSION: POLH mRNA was induced by radiation and increased in dose-dependent and time-dependent manners. The back ground level in healthy human peripheral blood was uniform. Our results suggested that POLH mRNA may be a useful radiation biomarker.

OBJECTIVE: To investigate the protective effects of maize silks ethanol extract(MSE) against radiation-induced oxidative damage in cells. METHODS: γ-radiation was employed to induce oxidative stress in L929 cells. After radiation,cells were treated immediately with different doses of MSE(10,50,250μg/mL). The variation of oxidative damage indicator,antioxidant system and inflammatory factors were examined. RESULTS: Radiation caused obvious oxidative injury in cells. MSE treatment significantly abolished elevation of thiobarbituric acid reactive substances(TBARS) levels,increased hepatic GSH/GSSG ratio and activities of catalase and superoxide dismutase. Moreover,MSE up-regulated the gene expressions of NF-E2-related factor 2 and gamma glutamyl cysteine synthetase. The gene and protein expressions of transforming growth factor beta(TGF-β)were also inhibited. Interestingly,50μg/mL MSE treatment performed best in our most results. CONCLUSION: These findings proved the protective role of MSE against radiationinduced oxidative injury. Nrf2 and TGF-β could be the potential targets of maize silks.

OBJECTIVE: To analyze the methyltransferase like 9(METTL9) methylation status at different stages of malignant transformation of human bronchial epithelial cells(16HBE) induced byglycidyl methacrylate(GMA) and to explore the effect of METTL9 methylation in the process of malignant transformation. METHODS: Cells were harvested th in the 10^th generation(early stage),the 20^th generation(mid stage) and the 30^th generation(later period). To verify the methylation chip result of METTL9 methylation status in the process of malignant transformation,real-time fluorescence quantitative PCR(qPCR) was applied to measure the gene expression levels of METTL9 at different transformed stages,and compared wie control groups(treated with DMSO). RESULTS: Based on the result of methylation chip,methylation of METTL9 gene occurred in the 10^th and 20^th generations(PeakScore>2). qPCR showed that the levels of gene expression increased in the 10^th and 20^th generation in GMA group(P<0.05). The level of METTL9 gene expression increased in the 10^th generation(P<0.05),while decreased in the 20^th generation after treatment with 5-Aza-cdr(P<0.05). CONCLUSION: Methylation status of METTL9 gene promoter could be considered as a stable and specific biomarker in the lately and mid stages of transformation process.

OBJECTIVE: To study MPDZ gene hypermethylation in lung cancer tissue,peripheral plasma and sputum,and to explore its relationship with clinicopathologic features. METHODS: Methylation specific PCR was used to detect the methylation of MPDZ gene in 49 cases of lung cancer tissue,20 cases of normal tissue and corresponding blood plasma and sputum samples. RESULTS: The frequency of methylation of MPDZ gene promoter was 67%(33/49) in lung cancer tissues,but not in normal tissues 0(0/20)(P=0.00). The methylation of MPDZ gene was significantly correlated with clinic stages of lung cancer patients(P=0.039),but not correlated with patient's age,sex,smoking,tumor differentiation and pathological classification(P>0.05). In 33 patients with MPDZ hypermethylation in tumor tissue,the same aberrant methylation was detected in 25(76%) of the corresponding plasma and 18(55%) of sputum samples,whereas hypermethylation of MPDZ was not found in the sputum and plasma from the patients with MPDZ unmethylation in tumor sample. CONCLUSION: MPDZ gene has highly methylated in lung cancer tissue,corresponding blood plasma and sputum. The methylation of MPDZ gene may have a certain value in the diagnosis of lung cancer.

OBJECTIVE: This study investigated whether microcystin-LR regulated the expression of VEGF and promoted invasion and migration in colorectal DLD-1 cells. METHODS: Transwell experiments were used to analyze the invasion and migration in colorectal cancer DLD-1 cells treated with different concentrations of microcystin-LR. Expression of VEGF in treated cells was evaluated by real-time quantitative PCR(qPCR),Western blot and ELISA. RESULTS: That the abilities of invasion and migration improved significantly in microcystin-LR-treated groups,compared wiose in the control group. When the concentration of microcystin-LR reached 12.5 nmol/L,invasion and migration were increased to 2.1 and 2.0 folds,respectively. The qPCR and Western blot results suggested that microcystin-LR upregulated the expression level of VEGF mRNA and protein in DLD-1 cells. When microcystin-LR concentration reached 12.5 and 25 nmol/L,the expression levels of the VEGF protein and mRNA in DLD-1 cells reached a maximum of 1.7 and 2.8 folds increases,respectively. Mean while,the significant 1.5-foldelevated VEGF production in the culture medium was also detected. CONCLUSION: Microcystin-LR upregulation of VEGF was involved in promoting invasion and migration in colorectal cancer cells DLD-1.

OBJECTIVE: To investigate the expressions of miR-16,miR-106b,miR-449a,miR-34a and let-7g in peripheral blood lymphocytes of the residents around hot springs with radon in Hebei province. METHODS: Two groups were randomly selected in Hebei province,Radon group consisted of 43 residents around hot springs with radon and control group were 44 residents with similar living conditions but not around hot springs. qRT-PCR was used to detect miRNAs level in radon and control groups. t test was used for statistical analysis of miRNA levels in lymphocytes between two groups. Multiple linear regression analyse were employed to test the association between miRNAs expression and radon exposure. RESULTS: Compared with control group,the levels of miR-106b,miR-449a and let-7g in lymphocytes of radon group were significantly increased(t=4.180,2.422,2.794;P<0.05). After controlling of confounding factors such as age,gender,smoking and drinking,alteration of miR-106b,miR-449a and let-7g in lymphocytes were positively correlated with radon exposure(t=4.091,2.716,2.440; P<0.05). No significant difference was observed in the lymphocyte levels of miR-16 and miR-34a between the two groups(t=0.990,0.147;P>0.05). CONCLUSION: MiR-106b,miR-449a and let-7g levels could potentially used as biomarkers for radon exposure.

OBJECTIVE: To study the genotoxicity and apoptosis of the mice L5178Y lymphoma cells which was induced by disinfection by-product dibromo acetonitrile in drinking water. METHODS: Cytokinesis-block micronucleus cytome assay(CBMN-cyt) and flow cytometry were used to evaluate genotoxicity and apoptosis in mice L5178Y lymphoma cells treated with different concentrations of dibromo acetonitrile(0.1,1,5 and 10 mol/L). RESULTS: Compared wie negative control group,frequency of micronucleus(MN) of L5178Y lymphoma cells in 1 and 5μmol/L groups increased significantly(P<0.05). The nucleoplasmic bridges(NPBs) in the 1 and 10μmol/L treatment groups and the frequency of nuclear buds(NBUDs) in the 10μmol/L treatment group all increased significantly(P<0.05). However the nuclear divided index(NDI) in the 5 and 10μmol/L treatment groups all decreased significantly(P<0.05). Statistically significant increase of L5178Y lymphoma cell apoptosis were observed in all dibromo acetonitrile treatment groups in comparison to the negative control group(P<0.05). CONCLUSION: Disinfection by-product dibromo acetonitrile in drinking water could obviously induce genotoxicity and apoptosis in L5178Y lymphoma cells.

OBJECTIVE: To investigate the changes,pofential role and cliniral significance of myeloid derived suppressor cells(MDSCs) in the peripheral blood of pediatric patients with B-lineage acute lymphoblastic leukemia(BALL) during remission. METHODS: 22 patients with B-ALL from our hospital treated by VDLP chemotherapy regimen including vincristine,daunorubicin,L-asparaginase and prednisone were selected as the test group during remission,and 20 cases of healthy children were also selected as control group(age and gender-matched). Peripheral blood(PB) were obtained frompatients and controls. Changes of CD33⁺ cells,CD33⁺HLA-DR^- cells,CD14⁺CD33⁺HLADR^- MDSCs and CD15⁺CD33⁺HLA-DR^- MDSCs were examined by flow cytometry,and analyzed statistically wie software of GraphPad Prisms. RESULTS: We found no change of CD33⁺ cells between the patients and control group. However,the ratio of CD33⁺HLA-DR^-/CD33⁺ cells in the patients with B-ALL during remission was lower than that in the healthy control group(P=0.001). The ratio of boe monocyte derived CD14⁺CD33⁺HLA-DR^- MDSCs(P=0.001) and CD15⁺CD33⁺HLA-DR^- MDSCs derived from granulocytes were lower in the healthy control group(P=0.004). CONCLUSION: MDSCs in pediatric patients with B-ALL treated by VDLP regimen during remission was often lower when compared to healthy control,the low level of MDSCs in B-ALL may be associated wie normal immunological system not recovered completely in the remission phase.

OBJECTIVE: To investigate the mechanisms of apoptosis induced by natto lipopeptide in MCF-7 cells. METHODS: Logarithmic growth phase of MCF-7 cells were treated with natto lipopeptide at different concentration(0,1,2,4μg/mL) in vitro and cultuerd at 37℃ incubator. Cells were collected after 12 h. Flow cytometry was used to detect apoptosis;single cell gel electrophoresis was used to detect DNA damage and Western blot for detection of estrogen receptors α and β expression levels. RESULTS: Natto lipopeptide could induce apoptosis in MCF-7 cells(P<0.05). Olive tail moment and tail DNA levels increased significantly(P<0.05 or P<0.01),and 4μg/mL natto lipopeptide group significantly increased tail length compared wie control group(P<0.01). Compared wie control group,natto lipopeptide of 4μg/mL also had significant effects on the expressions of ERα and ERβ(P<0.05). CONCLUSION: Natto lipopeptide exposure could change the expression levels of ERα and ERβ and damage DNA of MCF-7 cells,contributing to apoptosis.

OBJECTIVE: We studied spinach and Chinese cabbage on the uptake and accumulation of strontium,explore the transfer process and characteristics of strontium from soil to plant,looking for migration of strontium in soil-plant system. METHODS: We chose stable nuclide ⁸⁸Sr instead of ⁹⁰Sr and used potted plants of spinach and Chinese cabbage in greenhouse. There were 5 experimental groups and a control group,each of which had three parallel samples. Strontium in the experimental groups contained in the potting soil concentrations of 1.5 times,2.0 times,2.5 times,3.0 times,3.5 times,equivalent to strontium in soil of 318.67,478.00,637.33,796.67,956.00 mg/kg,respectively. The soil of the control group was natural air drying in shade,being mashed before being sifted by the 30 specifications sieve and was used directly. During the experiment,we irrigated the plants with deionized water. When the plants grow 30 days after seeding,we collected the stem and leaf on the ground and roots underground. After drying,crushing and digestion,it was set suspended in 10 mL solvent. All the strontium concentrations in the plants and the soil were measured wie inductively coupled plasma atomic emission spectrometry(ICP-AES) in this experiment,and the strontium concentration ratio(CR) of the two vegetables was calculated. The accumulation characteristics of strontium in soil-plant system was studied. RESULTS: The strontium content in plant rose with increasing concentration in soil. The CR values of two vegetables,except for the low concentration group(318.67 mg/kg),showed significant differences(P<0.05) compared wie control group. The CR values of the high concentration group of spinach(697.67 and 956.00 mg/kg) were significantly higher than that of strontium in Chinese cabbage(P<0.05). Strontium and calcium contents of Chinese cabbage stems and leaves,and spinach root strontium and iron contents showed a negative correlation,and the rest had positive correlations. The concentration rate of strontium of the two kinds of vegetables,except for the spinach low concentration group(318.67 mg/kg) and Chinese cabbage low concentration groups(318.67 and 478.00 mg/kg),other groups were significantly increased compared wie control group(P<0.05). Between the two kinds of vegetables,strontium concentration rate of high concentration group of spinach(796.67 and 956.00 mg/kg) was significantly higher than Chinese cabbage(P<0.05). CONCLUSION: Spinach and Chinese cabbage showed great uptake and accumulation of stable strontium. The CR values of strontium in the high concentration group of spinach were significantly higher than that of Chinese cabbage.

OBJECTIVE: To establish the early warning of the contamination of nano-SiO₂ particle,swimming behavior changes of zebrafish under nano-SiO₂ particle exposure were studied. METHODS: Based on behavior response of zebrafish,effects of nano-SiO₂particles,including individual endpoints(swimming speed,swimming depth,turning frequency and acceleration) and group endpoints(distance and dispersion),were investigated by using Online Bio monitoring. RESULTS: Swimming behavior changes of zebrafish were affected significantly in 600 and 1200 mg/L exposure dose groups. Swimming speed was decreased 30%-50% 6 h after exposure. Changes of swimming depth lagged behind changes of swimming speed,which were decreased by more than 90% 24 h after exposure. Group behavior of zebrafish was also changed,distance and dispersion were significantly decreased(all P<0.01). CONCLUSION: After exposure,swimming behavior of zebrafish(swimming speed,swimming depth,turning frequency,distance and dispersion) were affected significantly wie increase of nano-SiO₂ particles concentration,which is consistend wie Stepwise Stress Model.

OBJECTIVE: To evaluate the general toxicity and mutagenic effects of Mulberry-Astragalus capsule. METHODS: Acute toxicity test and 30-day feeding study in rats were carried out to observe the general toxicity of Mulberry-Astragalus capsule. Ames test,bone marrow micronucleus test and sperm malformation test in mice were carried out to observe the mutagenic effects of Mulberry-Astragalus capsule. All the tests were conducted according to the standard procedures. RESULTS: MTD of Mulberry-Astragalus capsule on mice was >20 g/kg in this experiment. In the three mutagenicity tests,no mutagenic effect was seen in any Mulberry-Astragalus capsule treated groups. And in 30-day feeding study,no adverse effects were found when the highest does was 8.33 g/kg. CONCLUSION: The results from this study showed Mulberry-Astragalus capsule had no general toxicity and mutagenic effects and further functional studies,such as hypoglycemic effect could be carried out.

OBJECTIVE: To observe the influence of omeprazole on the anti-thrombus effect of clopidogrel. METHODS: The experimental animals were randomly divided into three groups,control group,clopidogrel group,combination group(omeprazole 40 or 80 mg/kg+ clopidogrel 10 mg/kg),control group(methyl cellulose 1 mL). 4 h after treatment,we measured the platelet aggregation rate,the quality of the thrombus in the arterio-venous shunt thrombosis model,and evaluated the antithrombotic effect of clopidogrel in rats. RESULTS: According to the results of platelet aggregation,we determined ADP concentration to be 50μmol/L,and the dosage of clopidogrel 10 mg/kg. Compared wie control group,clopidogrel group showed significant inhibition of platelet aggregation,decreased the weight of thrombus. Omeprazole+ clopidogrel group compared with clopidogrel group could significantly increase the rate of platelet aggregation(43.7% and 23.3%,respectively,P<0.01),and enhanced the weight of thrombus(41.45 and 21.31 mg,respectively,P<0.01). CONCLUSION: 80 mg/kg omeprazole inhibited the antithrombotic effect of clopidogrel.

OBJECTIVE: Polyvinyl chloride(PVC) was used as matrix to prepare the positive reference material by adding dibutyl tin maleate. METHODS: Identification and impurity inspection were carried out for the matrix. The positive reference material,PVC film containing organic tin,was prepared by tape casting process. Sample extract was prepared for L929 cell culture medium. The optimal organic tin concentration was determined by cell morphology examination and MTT test. Homogeneity and stability test were performed for the positive reference material. RESULTS: Extract of PVC film containing 0.005% organic tin exhibited significant cytotoxicity in a dose-effect manner. The homogeneity test showed the statisticd F was 1.07 which was less than the threshold value F. PVC film containing 0.005% organic tin exhibited stable positive reactions. Whilst the materials before and after aging test revealed that the tin contentobtained from extraction was uniform(P>0.05). CONCLUSION: Extract of PVC film containing 0.005% organic tin showed appropriate cytotoxicity,PVC film containing organic tin had a good uniformity and stability,so it could suitable as a cytotoxic reference material.