BACKGROUND AND AIM: To investigate the apoptosis in MDA-MB-231 cells induced by different concentrations of As2O3 and to study its influence on the activities of Survivin and Caspase-3 proteins. MATERIALS AND METHODS: The rate of apoptosis in human breast carcinoma MDA-MB-231 cells was detected by flow cytometry; the activities of Survivin and Caspase-3 proteins were examined by immunocytochemistry and Western blot in untreated and As2O3-treated MDA-MB-231 cells. RESULTS: The percentages of the apoptosis in MDA-MB-231 cells were (28.89±2.47)％,(46.73±3.82)％ and (56.44±4.16)％, in cells treated for 24 hours with 10.0，20.0，40.0 μmol/L As2O3 respectively. As2O3 inhibited the expression of Survivin protein and promoted the expression of Caspase-3 protein. There were obvious dose-effect correlations between As2O3 and its functions. CONCLUSION: The results suggested that As2O3 could induce apoptosis of MDA-MB-231 cells via Survivin protein inhibition and Caspase-3 protein promotion.

BACKGROUND AND AIM: In order to provide further support for the experimental verification and functional exploration of 48 DNA sequences related to esophageal carcinoma found in our lab, these sequences were investigated systematically using bioinformatics methods such as silicon cloning and BLAST search tool. MATERIALS AND METHODS: A local database including the 48 sequences was constructed by the BioEdit software; the 48 DNA sequences coding unknown genes were extended by the method of silicon cloning; the potential ncRNAs, located in the introns, the upstream and downstream of intergenic regions of the above 48 DNA sequences, were analyzed by BLAST tool. RESULTS: The sequences coding unknown genes were extended to more than 190 bp on average using silicon cloning. Some sequence segments with high similarity to the known noncoding RNA(ncRNAs) were found in the intronic or intergenic regions. CONCLUSION: Some esophageal carcinoma related genes can be extended obviously by the method of silicon cloning,some sequences with high similarity to known ncRNAs were found in the chromosome region where the esophageal carcinoma related genes are located. The information gives us potential clues that these ncRNAs maybe participate in the development process of esophageal carcinoma, and the functions of these ncRNAs needs further study.

BACKGROUND AND AIM: CXCR4-stromal cell-derived factor-1(CXCR4- SDF-1α) system has been proved to be involved in targeting metastasis of breast cancer. Some antagonists of CXCR4 have shown inhibitory effects on breast cancer metastasis. This study was to investigate the inhibitory effect of N-terminal 21-mer peptide(NT21MP) on CXCR4-related metastasis of breast cancer cell line MCF-7. MATERIALS AND METHODS: The suppressed expression of CXCR4 protein was examined by immunocytochemistry and fluorescent antibody on MCF-7 and SK-BR3. Adhesion and chemotaxis assays were used to evaluate the effect of NT21MP on MCF-7 cells in different stages of metastasis. Clone formation rate was assessed by agar clone assay. RESULTS: The expression of CXCR4 was markedly decreased by NT21MP (0.1,0.5,1.0,4.0 μg/ml) compared with negative control after 24 h. Inhibition of cell adherence to fibronectin(FN) and Matrigel in a concentration-dependent manner was found after treatment with NT21MP (5,50,100,500 ng/ml)(P<0.05). The number of migration in the presence of NT21MP was lower than that of control (P<0.05). Peptide suppressed colony formation of MCF-7 cells in a concentration-dependent manner and inhibitive ratio was from 22.0％ to 51.8％. CONCLUSION: NT21MP could decrease expression of CXCR4. Adhesion to FN and Matrigel, chemotactic activity toward chemokine SDF-1α, and clone formation rate of MCF-7 cell were all suppressed.

BACKGROUND AND AIM: To investigate the effects of thalidomide on the proliferation in breast cancer cell lines. MATERIALS AND METHODS: Establishing the solvent control against and different densities，different durations, in order to study the relation between time and efficacy, The growth rate among these groups was measured by MTT assay. The influence of thalidomide on apoptosis and cell cycle were detected in treated cells by FCM assay. RESULTS: The growth rates in these groups were different, thalidomide could inhibit the proliferation of MCF-7 and MDA-MB-231 from 10 μg/ml to 200 μg/ml. The peak inhibitory effect occurred after thalidomide treatment for 48 h. 100 μg/ml had the maximal inhibitory effect after 48 h. Apoptosis was found in the breast cancer cells in the second period of G1 in the DNA histogram of FCM. 100 μg/ml thalidomide treatment for 48 h, the MCF-7 cell apoptotic index could amount to 9.66％ and MDA-MB-231 cell to 11.18％, comparing with control groups, the difference was significant(P<0.01). CONCLUSION: Thalidomide could inhibit the proliferation and induce apoptosis of breast cancer cell lines MCF-7 and MDA-MB-231.

BACKGROUND AND AIM: To study the role of ERK1/2 MAPK signaling transduction pathway in the inhibition of MCF-7 breast cancer cells by Aspisol. MATERIALS AND METHODS: The expression of COX-2 in MCF-7 breast cancer cells was detected by immunohistochemistry.The inhibitive effects of Aspisol on MCF-7 cells were assessed with MTT assay. Apoptosis was evaluated by flow cytometry. The ERK1/2,p-ERK1/2, Bcl-2 and Bax protein expressions were measured by using Western blot method. RESULTS: The expression of COX-2 in MCF-7 cells was not found.Aspisol inhibited the proliferation of MCF-7 cells in a time- and dose-dependent manner. Aspisol also induced the apoptosis of MCF-7 cells.The protein expression of p- ERK1/2、Bcl-2 decreased and Bax increased with the dose of Aspisol but not affect total ERK1/2 expression. CONCLUSION: Aspisol could affect the ERK1/2 MAPK signaling transduction pathway and induce the expressions of apoptosis-related proteins to inhibit the proliferation of MCF-7 breast cancer cells.

BACKGROUND AND AIM: To investigate the synergistical suppressive effect of cadmium chloride and cisplation on the proliferation of human hepatoma cell line SMMC-7721. MATERIALS AND METHODS: Cytotoxicity of the drugs was measured by MTT assay. The coefficient of drug interaction(CDI) was used to analyze the synergistical suppressive effect of drug combination. RESULTS: 0.56、1.12、2.25 μg/ml cadmium chloride and 0.25、0.5、1.0 μg/ml cisplatins had inhibitory effects on the proliferation of SMMC-7721.The inhibition in cells treated with both agents was significant increased with treatment time. CONCLUSION: The combination of cadmium chloride and cisplatin could inhibit the proliferation of human hepatoma cell line SMMC-7721.

BACKGROUND AND AIM: To investigate the expression of VEGF-C, VEGFR-3 and COX-2 in oral squamous cell carcinoma(OSCC), and the correlation with lymphangiogenesis and lymph node metastasis. MATERIALS AND METHODS: Immunohistochemical SP method for VEGF-C, VEGFR-3 and COX-2 were performed in 60 cases of OSCC, 23 cases of precancerous change and 19 benign lesion specimens. The lymphatic vessel density(LVD) in the tumor was counted and analyzed with clinicopathologic parameters. RESULTS: Compared with benign and precancerous change, the expressions of VEGF-C, LVD and COX-2 were significantly higher in OSCC (P<0.05). The expressions of VEGF-C and LVD were significantly correlated with lymphatic metastasis (P<0.05); COX-2 was obviously related with clinical stage and lymphatic metastasis(P<0.05). The expression of COX-2 was closely correlated with that of VEGF-C(r=0.519,P<0.01),with LVD positively correlated with their expression levels(r=0.661,P<0.01 and r=0.485, P<0.01,respectively). CONCLUSION: The expression rates of COX-2 and VEGF-C were high in OSCC. COX-2 may participate in VEGF-C lymphangiogenic pathway and play an important role in the lymph node metastasis of OSCC.

BACKGROUND AND AIM: To explore the effect of Thioglycolic acid (TGA) on cytoplasmic maturation and related molecular factors of mouse oocytes. MATERIALS AND METHODS:Mouse oocytes were matured in vitro cultured with serial doses of TGA. Immunoflurescence staining was used to label cortical granules (CGs) and p44/42MAPK was measured by western blot. RESULTS: Rate of germinal vesicle-breakdown in each group reached 90％ and comparison was insignificant (P>0.05). Rate of first polar body decreased with increasing TGA dose, the comparison between control and treatments was significant (P<0.05).CGs of oocytes from all groups migrated to the cortex and formed a continuous layer under the cell membrane, but CGs density in the cytoplasm became higher with increasing TGA treatment dose. Obvious cortical granule free domain (CGFD) was observed at 0 mmol/L TGA, in 0.2 mmol/L TGA CGFD could still be seen, but not in 1.0 mmol/L and 2.5 mmol/L TGA groups. Meanwhile, TGA inhibited p44/42MAPK activation in 1.0 mmol/L and 2.5 mmol/L treatment groups. CONCLUSION: TGA exerted reproductive toxicity since it interfered with cytoplasmic maturation and MAPK activation of mouse oocytes.

BACKGROUND AND AIM: To investigate the effects of thioglycolic acid on the activities of MAPK and MPF protein kinases during progesterone-induced Xenopus oocyte maturation process in vitro. MATERIALS AND METHODS: Xenopus oocytes were treated with TGA in vitro at dose of 0 μg/ml，5 μg/ml，25 μg/ml and 125 μg/ml, and samples collected at 4 h and 8 h after culture for Western Blotting detection of Erk1, p-Erk1, p-RSK, Cdc2, p-Cdc2 and cyclin B1 protein expressions. RESULTS: Obviously higher phosphorylation levels of Erk1 protein, indicated by the photodensity ratio of p-Erk1 and Erk1, and lower p-Cdc2 protein levels, compared with those of the control, were found in TGA-treated Xenopus oocytes at 4 h, accompanied by higher levels of p-RSK and Cyclin B1. However, there was no difference in these proteins,except higher p-Cdc2 phosphorylation and lower Cyclin B1 protein, between TGA-treated and control group at 8 h. CONCLUSION: TGA treatment could promote the activation of MAPK including its substrate RSK, and MPF at the early stage of maturation process. At the late stage, no evident impact was found of TGA on the activity of MAPK. There was obvious inhibition on MPF activity by TGA possibly through regulation of Cyclin B1 protein.

BACKGROUND AND AIM: To explore if the mitochondrial DNA deletions in human lymphoblastoid cell line could be induced by ionizing radiation. MATERIALS AND METHODS: Human normal lymphoblastoid cell line samples were exposed to 10 Gy 60Co γ-rays in vitro, and pure mitochondrial DNA was extracted after 24 h and 48 h. A nested-PCR method was used to analyze the 889 bp, 3 895 bp or 7 436 bp deletions before and after radiation exposure. The final PCR products were purified, sequenced and blasted on standard human mitochondrial genome sequence database. RESULTS: The 889 bp and 3 895 bp deletions were not detected for the cell line samples not exposed to 60 Co γ-rays. The 889 bp and 3 895 bp deletions were detected on samples exposed to 10 Gy 60Co γ-rays, both 24 h and 48 h. The blast results showed that the 889 bp and 3 895 deletions flanked 11 688－12 576, nt 548－4 443, respectively. The 7 436 bp deletion level was not changed much before and after irradiation. CONCLUSION: The 889 bp and 3 895 bp deletion but not the 7 436 bp deletion in mitochondrial DNA,could be induced by ionizing radiation of lymphoblastoid cell lines samples.

BACKGROUND AND AIM: To provide some scientific basis for the neurotoxic mechanism of lead, the present study examined the effect of lead acetate on apoptosis and expression of apoptosis-related genes XIAP and Smac in the hippocampus of developing rats. MATERIALS AND METHODS: Healthy male Sprague-Dawley rats(30 days old, n=48)were randomly divided into 4 groups with 12 rats in each group: distilled water negative control group, 2 mg/kg, 20 mg/kg,200 mg/kg lead poisoning groups. Lead acetate was given through gastric feeding for 6 weeks. Lead concentration in the blood of the rats was determined by atomic absorption spectrophotometry. Apoptosis in the hippocampus was made by TUNEL. The expression of XIAP and Smac genes in the hippocampus was examined by RT-PCR. RESULTS: The blood lead concentration of the lead-exposure rat gradually increased with increasing level of lead exposure. TUNEL showed that there were significant differences between the four groups, and there was a significant dose-response relationship between the level of lead exposure and apoptosis. The expression of XIAP gene decreased in neurons of the hippocampus in high-lead treatment group compared with the control, but there were no differences in the expression of Smac gene among 4 groups. Correlation analysis demonstrated that lead concentration in blood correlated negatively with the expression of XIAP. CONCLUSION: Lead exposure resulted in significant increase of apoptosis of neurons. Lead-induced hippocampal neuronal apoptosis was related to down-regulation of the expression of XIAP gene.

BACKGROUND AND AIM: The genotoxicity of chlorothalonil or cypermethrin on vicia faba root tip was studied by using micronucleus test technology. MATERIALS AND METHODS: Micronucleus assay and chromosomal aberration assay were used to determine the mitotic index, the micronucleus frequency and chromosomal aberration frequency of Vicia faba root tip cells induced by different concentrations of chlorothalonil and cypermethrin. RESULTS: Chlorothalonil and cypermethrin could increase the micronucleus rate of vicia faba root tip cells. Within a certain concentration range(5×10－10－5×10－6 g/L chlorothalonil, 5×10－10－5×10－8 g/L cypermethrin), the rate of micronucleus increased with increasing concentration of chlorothalonil or cypermethrin, but decreased with further increase in concentrations. The cell mitosis index increased in different concentrations of chlorothalonil or cypermethrin. Besides, various types of chromosome aberration were also induced. CONCLUSION: Chlorothalonil and cypermethrin could produce apparent genotoxicity on Vicia faba root tip.

BACKGROUND AND AIM: Oxidative stress effect induced by cooking oil fume particulate (COFP) on human embryonic diploid lung fibroblasts (HELF)was investigated. MATERIALS AND METHODS: Glass fibre filter film was used to collect COFP. IC50 was determined by MTT assay. HELF cells were exposed to COFP at the doses 20、4、0.8 μg/ml for 12, 24 and 48 hours. Then ROS analysis, MDA test and comet assay were performed. RESULTS: The IC50 for 12, 24, 48 hours was 101.7 μg/ml, 82.7 μg/ml and 85.1 μg/ml, respectively. The mean cytoplasmic fluorescence intensity increased as the COFP dose increased. Significant difference in the mitochondria was observed between 0.8 and 4 μg/ml dose groups and negative control group for 24 and 48 hours exposure duration. No significant difference was observed between treated groups and negative control group for MDA test. However, there was significant difference between treated groups and negative control group for comet assay. No significant difference was observed among treated groups for different exposure time in all the assays. CONCLUSION: In the range of experimental dosage and exposure duration, ROS increase in both cytoplasmic and mitochondria and DNA damage were observed, while peroxidation of lipid was not evident.

BACKGROUND AND AIM: Inorganic arsenic is a ubiquitous carcinogen, teratogen and mutagen, where it occurs mainly in the pentavalent form in the aquatic environment. The genotoxic effects of arsenate to intact animals are still unclear. In order to understand the potential genotoxic effects of arsenate and the underlying mechanisms, the nematode Caenorhabditis elegans were employed in this study. The studies presented here investigated the effects and the underlying mechanisms of arsenate on the brood size, germ cell cycle arrest and apoptosis of C. elegans. MATERIALS AND METHODS: The C. elegans adult hermaphrodites were exposed to 0.0, 2.5, 5.0, 10.0 or 20.0 mmol/L of arsenate, the brood size, germ cell cycle arrest and apoptosis were assayed after exposure. RESULTS: From arsenate exposure of 5.0 to 20.0 mmol/L, the brood size was significantly smaller(P<0.05). From the concentrations of 2.5 to 20.0 mmol/L,arsenate exposure caused germ cell cycle arrest and apoptosis in a dose-dependent manner(P<0.05). Germ cell apoptosis could be detected as early as 6 h after arsenate exposure. The addition of dimethyl sulphoxide (DMSO) could significantly rescue arsenate-induced germ cell cycle arrest and partially reduced apoptosis. CONCLUSION: Arsenate exhibited genotoxic effects, causing germ cell cycle arrest and apoptosis in C. elegans.

BACKGROUND AND AIM: To investigate the applicability of painting method in retrospective dose estimation. MATERIALS AND METHODS: Healthy human peripheral blood samples were irradiated with 0－5.00 Gy 60Co γ-rays. Then the chromosome translocations in these samples were detected with painting method using chromosomes 1, 2 and 4 probes. The dose-response curve of absorbed dose and genome translocation frequency were established. The retrospective doses were estimated for 3 individuals, who previously had accidental radiation exposure and had biodosimetry data shortly after the exposure. And similar estimation was done for another individual without biodosimetry data but with the physical dose data. RESULTS: The genome translocation rates induced by 0－5.00 Gy 60Co γ-rays detected by painting were increased with the absorbed dose. The dose-response curve was =0.043D2＋0.006D＋0.0036 for painting.The retrospective doses for the 4 individuals were similar with the previous biodosimetry data or the physical dose data. CONCLUSION: Dose reconstruction for previous radiation exposure individuals could be carried out with the painting method established in this study.

BACKGROUND AND AIM: To study the feasibility of anti-semen antibody as spermicide. MATERIALS AND METHODS: Anti-semen antibody of golden hamster was prepared to incorporate with golden hamster semen,then sperm motility rate analysis, spermagglutination test, sperm mitochondrion function analysis, in vitro fertilization, intrauterine sperm injection and post mate endovaginal sperm motility analysis were performed to assess the inhibitory effect of anti-semen antibody on sperm in vitro and in vivo. RESULTS: Anti-semen antibody could agglutinate and immobilize sperm completely. In experiment group and control group, the average of sperm mitochondrion fluorescence intensity was 180.28±82.24 and 309.74±148.37, the rate of in vitro fertilization was 0.9％ and 37.50％, the rate of fertilization in intrauterine sperm injection test was 1％ and 15.0％, the sperm motility rate in post mate endovaginal sperm motility analysis was 0 and 60.0％, respectively.All the differences between the experiment group and the control group were statisti cal significant (P<0.01). CONCLUSION: Anti-semen antibody could agglutinate and immobilize sperm in vitro, in uterine and in vagina, and it could be used as a potential spermicide.

BACKGROUND AND AIM: In 1990, 2 severe and 3 moderate degree acute radiation syndrome (ARS) victims in Shanghai “6.25” 60Co accident were cured. To investigate late effects of ARS, 14 years continuous follow-up study of chromosomal aberrations in these 5 victims was performed to accumulate valuable data on late effect of radiation. MATERIALS AND METHODS: Conventional chromosome aberration, G-banding automatic karyotype analysis and whole chromosome probe painting FISH technique were used simultaneously to examine unstable and stable chromosome aberrations and compare the results over 14 years. RESULTS: Unstable aberrations declined to approximately 20％ of initial level 3.5 years after exposure and was totally lost after 14 years. Stable aberrations such as reciprocal translocations were found predominantly. The results of G-banding karyotype analysis and FISH were very similar. The frequencies of Cs and complicated aberrations showed a dose-response relationship and remained at a relatively stable level 6－14 years after exposure. The break frequencies of each chromosome distributed randomly. The recovery speed of chromosome aberrations and degree of late effect related not only to exposure dose but also to the victims＇ health condition. CONCLUSION: Stable chromosome aberrations were fairly ideal in the assessment of radiation late effects. It is important to make long-term follow-up study for the victims exposed to accidental irradiation.

BACKGROUND AND AIM: To explore the mutagenic effects of reclaimed water in Tianjin. MATERIALS AND METHODS:Reclaimed water in dry and rainy periods were collected. Reverse phase C-18 solid-phase extraction (RP-C18SPE) was used for the extraction of organic compounds from water samples. Ames test, cytokinesis-block micronucleus test and plasmid DNA breakage test was used to assess the damage of water samples on genetic materials. Moreover, PCR-DNA gene sequencing method was used to examine the mutatgenic effects of water samples on some exons of p53 gene. RESULTS: Ames test showed that after metabolism by S9 ,both untreated reclaimed water and treated reclaimed water, except untreated reclaimed water of rainy period, could induce mutation of TA98 and TA100 strains with dose-response relationship(P<0.05). Frameshift and base replacement mutation effects of urban reclaimed water were also found. There were three doses: 16.7,33.3 and 66.7 ml/ml(the denominator was original water) in micronucleus test, and the micronucleus number was only slightly increased at 66.7 ml/ml, but there was no significant difference compared with control group. DNA breakage test demonstrated that with increasing doses of urban reclaimed water, plasmid damage was also significantly enhanced(P<0.05). In addition , linear DNA appeared when plasmid was treated by dry period samples, and this phenomenon might be due to the different compounds of water sample extraction. Gene sequencing method testified that organic extraction of urban reclaimed water could induce mutation of p53 gene in human embryo liver cell(L-02 cell). CONCLUSION: Urban reclaimed water, which showed mutagenic effects in some extent, might pose potential hazards to environment and health.

Water is the important component to our bodies. As a necessary primary substance during the whole life process, it plays an extraordinary important role in human being. Therefore, the safe of drinking water is very considerable to our bodies. With the increasing growth of water pollution, lots of people choose to drink purified water. According to the traditional opinion of hygienic, source water contains kinds of inorganic mineral salts providing the necessary elements for organism, and drinking source water can prevent the disease of cardiovascular system and so on. All the above mentions are not provided in purified water. So it has been discussed for a long time about which one is more benefit to health. The possible influence on human health resulted from water pollution and purified water was analyzed in this article.

BACKGROUND AND AIM: To study the acute toxicity and the mutagenicity of the flavonoids extracted from pteridium aquilinum var. latiusculum. MATERIALS AND METHODS: The oral acute toxicity test, micronucleus test of bone marrow PCE cell and sperm shape abnormality test were carried out. RESULTS: LD50 of the flavonoids extracts from pteridium aquilinum var. latiusculum in rats was more than 20.0 g/kg. The micronucleus rates and sperm abnormality rates in all doses were negative(P>0.05). CONCLUSION: The flavonoids extracted from pteridium aquilinum var. latiusculum was considered a substance with no toxicity and mutagenic activity in this study.

BACKGROUND AND AIM: To investigate the relationship between chromosome numerical aberration of lymphocytes in peripheral blood and clinical stage ,pathological grading and prognosis in patients with bladder carcinoma. MATERIALS AND METHODS: Cytogenetic studies were taken on 30 bladder carcinoma by examining their chromosome numerical aberration of lymphocytes in peripheral blood. RESULTS: The frequencies of hypodiploid, hyperdiploid and polyloid were significantly increased.The general abnormality rate was significantly higher than the normal control group (P<0.05 ).As the clinical staging and pathological grading became more advanced,the diploid rate was reduced. CONCLUSION: With higher malignant degree of bladder carcinoma, the range of chromosome numerical aberration increased. This indicated that the appearance of polyloidy was closely correlated with the malignant level of the carcinoma and unfavourable prognosis.