Objective To construct and identify the siRNA eukaryotic expression vector targeting gene CXC chemo-kine receptor-4 and explore its role in invasion process of breast cancer cells in vitro. Methods Two siRNAs were designed and synthesized according to the coding sequence of CXCR4 gene and cloned into eukaryotic expression plasmid pGE-1-U6/kna. The constructed CXCR4-siRNA expression vector was transfected into MDA-MB-231 cells by liposome. Western blot was used to evaluate the suppression of CXCR4 expression in different groups. The inva-sion and migration of MDA-MB-231 cells were evaluated by cell invasion assay in vitro. Results Enzyme digestion and DNA sequencing confirmed that the CXCR4-siRNA expression vector was successfully constructed. After trans-fection,the CXCR4-siRNA obviously suppressed the expression of CXCR4 compared with control groups and the ability of cell migration was decreased markedly. Conclusion CXCR4-siRNA expression vector can effectively sup-press CXCR4 expression in the breast cancer cells and decrease potential of cell invasion, which may provide a no-vel strategy for gene therapy of breast cancer metastasis.

Objective To construct and identify the siRNA eukaryotic expression vector targeting gene CXC chemokine receptor-4 and explore its role in invasion process of breast cancer cells in vitro.Methods Two siRNAs were designed and synthesized according to the coding sequence of CXCR4 gene and cloned into eukaryotic expression plasmid pGE-1-U6/kna.The constructed CXCR4-siRNA expression vector was transfected into MDA-MB-231 cells by liposome.Western blot was used to evaluate the suppression of CXCR4 expression in different groups.The invasion and migration of MDA-MB-231 cells were evaluated by cell invasion assay in vitro.Results Enzyme digestion and DNA sequencing confirmed that the CXCR4-siRNA expression vector was successfully constructed.After transfection,the CXCR4-siRNA obviously suppressed the expression of CXCR4 compared with control groups and the ability of cell migration was decreased markedly.Conclusion CXCR4-siRNA expression vector can effectively suppress CXCR4 expression in the breast cancer cells and decrease potential of cell invasion,which may provide a novel strategy for gene therapy of breast cancer metastasis.

Objective : To analyze the survival of patients with malignant mesothelioma, so as to provide insights into the management of malignant mesothelioma. Methods : Totally 36 patients with malignant mesothelioma admitted to Cixi Third People’s Hospital from October 2012 to January 2021 were enrolled, and the demographic features, exposure to asbestos, and diagnosis and treatment were retrospectively reviewed. The survival rate and median survival time were calculated with the life-table method, and the factors affecting the survival rate of malignant mesothelioma were identified using the Kaplan-Meier estimate and log-rank test. Results : The 36 patients with malignant mesothelioma included 6 men ( 16.67% ) and 30 women ( 83.33% ), and had a median age of 61 ( interquartile range, 14 ) years. There were 30 cases with pleural malignant mesothelioma ( 83.33% ) and 6 cases with peritoneal malignant mesothelioma ( 16.67% ), 32 cases ( 88.89% ) with a history of occupational exposure to asbestos, and 26 cases ( 72.22% ) receiving palliative treatment. The 1-, 2- and 3-year cumulative survival rates were 30%, 15% and 3%, respectively, and the median survival time was 0.71 years. In addition, there were no significant differences in the survival period among patients with malignant mesothelioma in terms of gender, age, route of asbestos exposure, duration of asbestos exposure, pathogenic site and treatment regimens ( P>0.05 ). Conclusion The 36 patients with malignant mesothelioma had a median survival period of 0.71 years, and no association was found between the survival period and asbestos exposure or pathogenic site.

Objective: To investigate the effect of chrysotile exposure on ribosomal DNA (rDNA) copy number and DNA damage response, so as to provide insights into the mechanism of asbestos-induced carcinogenesis. Methods: Human pleural mesothelial MeT-5A cells were treated with chrysotile suspensions at doses of 1.25, 2.5 and 5 μg/cm2 (low-, medium-, high-dose group), while PBS served as controls. MeT-5A cells were harvested 6, 24, 48 and 72 h post-treatment, and the rDNA copy numbers and the BIRC5, HRAS, GINS4 and RRM2 mRNA expression were determined using a quantitative real-time PCR (qPCR) assay. The apoptosis of MeT-5A cells and DNA damage were detected using Muse cell analyzer. The rDNA copy numbers, DNA damage responses and BIRC5, HRAS, GINS4 and RRM2 mRNA expression were compared in MeT-5A cells treated with different doses of chrysotile suspensions. Results: There were significant differences in 45S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 6, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 45S rDNA copy numbers were measured in low-, medium- and high-dose groups than in the control group 6 h post-treatment, while significantly higher 45S rDNA copy numbers were found in the high-dose group than in low- and medium-dose groups 48 and 72 h post-treatment (all P<0.05). There were significant differences in 5S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 24, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 5S rDNA copy numbers were measured in medium- and high-dose groups than in the control group 24 and 48 h post-treatment, while significantly lower 5S rDNA copy numbers were found in medium- and high-dose groups than in the low-dose group 24, 72 h post-treatment (all P<0.05). There were significant differences in the overall apoptotic rate of MeT-5A cells among groups at different time points, and the overall apoptotic rate of MeT-5A cells were significantly higher in medium- and high-dose groups than in the control group (all P<0.05), with late-stage apoptosis predominantly detected. There were significant differences in the rates of ATM activation and DNA double-strand break in MeT-5A cells among groups 72 h post-treatment, and higher rates of ATM activation and DNA double-strand break were measured in medium- and high-dose groups than in the control group (all P<0.05). In addition, there were significant differences in the relative mRNA expression of BIRC5, HRAS, GINS4 and RRM2 genes among groups 24 and 48 h post-treatment, and significantly lower BIRC5, HRAS, GINS4 and RRM2 mRNA expression was quantified in medium- and high-dose groups than in the control group (all P<0.05). Conclusion Exposure to chrysotile may induce rDNA copy number variations and altered expression of nucleolar proteins in human pleural mesothelial cells, which may be involved in the regulation of DNA damage responses.

Objective: To investigate the effect of ribosomal DNA (rDNA) copy number variation caused by hexavalent chromium exposure on DNA damage response in different cell lines, so as to provide insights into the involvement of hexavalent chromium-induced rDNA copy number variation in DNA damage responses. : Methods Human lung epithelial BEAS-2B cells and human embryonic lung MRC-5 cells were treated with 2 μmol/L potassium dichromate for 24 hours, and then cells were transferred to fresh media for further incubation, while cells treated with the same volume of phosphate buffer solution served as controls. Cells treated with potassium dichromate for 24 hours, and 3 and 7 days post-detoxification, were harvested, and rDNA copy number was quantified in cells using a quantitative fluorescent real-time PCR assay. Cell cycle, apoptosis and DNA damage were detected using a Muse cell analyzer, and the DNA damage was evaluated with the proportion of ataxia telangiectasia-mutated (ATM) gene activation, proportion of double-strand DNA breaks and the percentage of the H2A.X variant histone phosphorylatio. : Results The 45S and 5S rDNA copy numbers of were significantly higher in MRC-5 cells than in BEAS-2B cells [(1.54±0.26) vs. (1.02±0.18), P<0.05; (6.97±1.07) vs. (3.00±0.15), P<0.05]. The 45S rDNA copy number was lower in MRC-5 cells 3 days post-detoxification (0.80±0.04) than in controls (P<0.05), and was higher in BEAS-2B cells 3 days post-detoxification (1.43±0.07) than in controls (P<0.05) . G0/G1 phase arrest was found in MRC-5 cells 24 hours post-treatment, and the apoptotic rates were significantly higher in MRC-5 cells 3 and 7 days post-detoxification than in controls [(11.53±1.53)%, (18.33±0.70)% vs. (3.53±0.93)%, P<0.05]. The overall apoptotic rates 24 hours post-treatment and 3 days post-detoxification [(2.80±0.17)%, (3.33±0.57)% vs. (1.53±0.61)%, P<0.05], proportion of ATM gene activation 3 days post-detoxification [(3.37±0.67%) vs. (1.18±0.22)%, P<0.05], proportion of double-strand DNA breaks 3 days post-detoxification [(4.45±0.85)% vs. (0.97±0.21)%, P<0.05] and percentage of the H2A.X variant histone phosphorylation 3 days post-detoxification [(1.68±0.56)% vs. (0.29±0.06)%, P<0.05] in BEAS-2B cells were higher than in controls. Conclusions Hexavalent chromium-induced rDNA copy number variation affects DNA damage response in different cell lines. A stronger DNA damage response is found in BEAS-2B cells with a low rDNA copy number, and a relative stable response is observed in MRC-5 cells with a high rDNA copy number.

This study aimed at analyzing the medication regularity based on differentiation in traditional Chinese medicine (TCM) for losing weight using text mining technique.All the references over losing weight were retrieved in CNKI,Wangfang Database,VIP Database and Pubmed.The drugs from the references were classified in accordance with drug property,drug flavor,channel tropism and drug efficacy.Frequency and constituent ratio of a single drug in TCM prescriptions for losing weight were put into analysis using chi square test and factor analysis to find out the medication regularity.It was found that the properties of TCM drugs in the prescriptions contained both cold and warm,while the flavors of the drugs involved pungent,sweet and light.The channel tropism of the drugs mainly belonged to spleen meridian,liver meridian,stomach meridian and lung meridian.They were mostly tonic,relieving,blood-activating,qi regulating,inhibiting-damp and antipyretic drugs.Through factor analysis we found that the common formula compatibilities were concluded as:cassia seed,lotus leaf,hawthorn,salvia miltiorrhiza,polygonum cuspidatum and radix polygonum multiflorum;capillary artemisia,epimedium herb,stephania tetrandra and ligusticum wallichii;dried tangerine peel,pinellia ternata and poria cocos;plantain seed,pericarpium arecae and selfheal;paeonia lactiflora,angelica sinensis,scutellaria baicalensis and ligusticum wallichii;poria cocos,cassia twig,atractylodes and glycyrrhiza;immature bitter orange and bark of magnolia;radix bupleuri,lycium chinensis and jujube;Chinese yam and coix seed;and astragalus,pueraria lobata and polygonatum.In conclusion,formula compatibility mainly combined syndrome differentiation with disease differentiation for the treatment of obesity in clinic,using the drugs belonging to liver meridian,spleen meridian,stomach meridian and lung meridian with the flavors of sweet,bitterness or pungent and the nature of both warm and cold.

Objective : To investigate the status of occupational stress and analyze its influencing factors among frontline employees working in a chemical fiber manufacturing enterprise, so as to provide insights into the development of occupational stress interventions. Methods : The frontline employees working in a chemical fiber manufacturing enterprise were selected as the study subjects using a cluster sampling method in October 2018. The status of occupational stress was investigated using the Chinese version of the effort-reward imbalance ( ERI ) questionnaire. The influencing factors for occupational stress were identified using a multivariable logistic regression model. Results : A total of 1 780 questionnaires were sent out, and 1 115 valid ones ( 62.64% ) were recovered. Among the 1 115 respondents, there were 427 men ( 38.30% ) and 688 women ( 61.70% ), and 71.22% were at ages of 21 to 39 years. There were 561 respondents with < 1 year of service ( 50.31% ), and the longest length of service was 11 years. In addition, there were 1 069 respondents ( 95.87% ) exposed to high noise, and 346 respondents ( 31.03% ) were diagnosed at a high occupational-stress state and 769 ( 68.97% ) at a low state. Multivariable logistic regression analysis identified 5 years or longer of service ( OR=1.540, 95%CI: 1.057-2.245 ) and exposure to high noise ( OR=1.917, 95%CI: 1.004-3.659 ) as risk factors for occupational stress among frontline employees in the chemical fiber manufacturing enterprise. Conclusions There are 31.03% of frontline employees at a high occupational-stress state in the chemical fiber manufacturing enterprise, and a high occupational-stress state is associated with exposure to high noise and 5 years or longer of service.

Objective : To examine the diagnostic and prognostic value of long non-coding RNA (lncRNA) JPX in mesothelioma, so as to provide insights into diagnosis and prognosis of mesothelioma. Methods: Patients with clinically definitive diagnosis of mesothelioma from 2015 to 2019 that were sampled from asbestos processing plants in Zhejiang Province from 2015 to 2019 were recruited in the mesothelioma group, while healthy residents without asbestos exposure or asbestos-related diseases in the same area served as controls. Participants' demographics, pathologic diagnosis and imaging features were collected, and the expression of blood lncRNA JPX was detected using lncRNA microarrays. The diagnostic value of lncRNA JPX for mesothelioma was evaluated using the receiver operating characteristic (ROC) curve, and the correlation between lncRNA JPX expression and prognosis was examined among mesothelioma patients using survival analysis. Results: There were 17 subjects in the mesothelioma group, with a mean age of (65.71±8.36) years, and 34 subjects in the controls, with a mean age of (64.24±8.70) years. LncRNA microarray detected significantly high lncRNA JPX expression in mesothelioma patients, and higher blood lncRNA JPX expression was detected in the mesothelioma group than in the control group [median (interquartile range), 1.10 (1.31) vs. 0.89 (0.54); t'=-2.300, P=0.034]. The area under the ROC curve was 0.673 (95%CI: 0.507-0.839, P=0.046), and if the cutoff was 1.759, the sensitivity and specificity were 35.3% and 100.0%, respectively. Survival analysis showed no significant difference in the survival rate of mesothelioma patients between the high lncRNA JPX expression group and the low expression group (χ2=0.212, P=0.645). Conclusions LncRNA JPX overexpression is detected in the blood of patients with mesothelioma, and lncRNA JPX expression presents a diagnostic value for mesothelioma; however, it shows little prognostic value for mesothelioma.

Objective: To explore the changes in ribosomal DNA copy number in peripheral blood among patients with pneumoconiosis and its influencing factors, so as to provide insights into prevention and treatment of pneumoconiosis. Methods: Eighty-eight patients with pneumoconiosis who visited a designated hospital and 71 community residents with no history of pneumoconiosis or dust exposure were selected as the pneumoconiosis group and control group, and age, smoking history, drinking history and cumulative years of exposure to dust were collected through questionnaire surveys. The copy number of 45S rDNA and 5S rDNA was detected using real-time fluorescence quantitative PCR, and the differences between the two groups were compared. Factors affecting the copy number of 45S rDNA and 5S rDNA were identified by a multiple linear regression model. Results: The pneumoconiosis group had a median age of 56.00 (interquartile range, 15.25) and a mean cumulative dust exposure duration of (12.40±8.08) years, with 56.82% smoking and 62.50% drinking. The control group had a median age of 64.00 (interquartile range, 37.00) years, with 32.39% smoking and 26.76% drinking. The median copy number of 45S rDNA in the pneumoconiosis group was 1.29 (interquartile range, 0.59), which was lower than 2.10 (interquartile range, 1.88) in the control group; the median copy number of 5S rDNA in the pneumoconiosis group was 5.33 (interquartile range, 0.85), which was higher than 4.66 (1.34) in the control group (both P<0.05). Multiple linear regression analysis identified age (β=-0.034) and pneumoconiosis (β=-1.595) as factors affecting 45S rDNA copy number, age (β=-0.013) as a factor affecting 5S rDNA copy number, and age (β=0.018) as a factor affecting 5S rDNA copy number in the pneumoconiosis group (all P<0.05). Conclusions Compared with community residents with no history of pneumoconiosis or dust exposure, the copy number of 45S rDNA in peripheral blood among patients with pneumoconiosis is reduced and the copy number of 5S rDNA is increased.

Objective: To establish a convenient non-invasive tracheal perfusion method for constructing a mouse model of silicosis-induced pulmonary fibrosis. Methods: The specific pathogen-free C57BL/6 mice were randomly divided into control group and model group, with 15 mice in each group. After anesthesia, a 22G arteriovenous indwelling needle was used to inset into the trachea through the mice's mouth. The model group mice were perfused with 0.1 mL of silica suspension with a mass concentration of 25 g/L, and the mice in the control group were perfused with an equal volume of 0.9% sodium chloride solution. On the 7th, 14th, and 30th day after modeling, the body weight of the mice was measured, and the lung tissue morphology and pathological changes were observed. The expression of α-smooth muscle actin (α-SMA) and collagen type 1 alpha 1 (COL1A1) protein in lung tissue of mice was detected by immunofluorescence on the 30th day after modeling. Results: There was no death of mice in the two groups during the experiment. There was no significant difference in body weight between the two groups (P>0.05). The lung tissues of the mice in the model group were pinkish-gray and uneven in color on the 7th and 14th days after dust exposure. On the 30th day after dust exposure, the lung tissue of the mice in the model group was gray and hard, and unevenly distributed silicon nodules were visible by the naked eyes. The histopathology results of lung tissue showed that compared with the mice in control group, the model group mice exhibited persistent aggravation of pulmonary inflammation, thickening of alveolar septum, infiltration of inflammatory cells gradually clustering into clumps, and an increasing number of fibrous foci.On the 30th day after dust exposure, the relative expression of α-SMA and COL1A1 proteins in the lung of the model group was higher than those in the control group (median： 72.59 vs 5.91, 35.62 vs 10.07, both P<0.05). Conclusion: The method of tracheal perfusion silica suspension of mice using 22G arteriovenous indwelling needle can successfully construct an animal model of silicosis fibrosis. This method is convenient, safe and effective, and is worth promoting.