This study examined the effect of small interfering RNA-mediated β-catenin knockdown on the survival, invasion and chemosensitivity of human osteosarcoma cells (U2-OS cells). The siRNA against β-catenin was constructed and transfected into U2-OS cells. The expression of β-catenin was detected by qRT-PCR and Western blotting. Cell growth and apoptosis was detected in the presence or absence of doxorubicin by MTT and flow cytometry, respectively. Cell invasion ability was measured by transwell assay. The results showed that the transfection of β-catenin siRNA resulted in decreased expression of β-catenin, suppression of invasion and motility of U2-OS cells, reduced chemosensitivity to doxorubicin in vitro, and little change in cell growth and apoptosis. Additionally, down-regulated MT1-MMP expression was found after transfection. It was concluded that knockdown of β-catenin gene may decrease the invasive ability of human osteosarcoma cells through down-regulated MT1-MMP expression, and the chemosensitivity of osteosarcoma cells against doxorubicin.

Objective To investigate the characteristic sonographic and pathological features of breast ductal carcinoma in situ (DCIS) without microcalcifications on mammography (MG).Methods Forty cases of DCIS without microcalcifications on MG were retrospectively reviewed.The 40 lesions were classified into mass and non-mass groups according to their sonographic findings.The pathological subtypes and nuclear grades of these cases were also analyzed.Fisher exact test was used to compare the differences of the sonographic accuracy rate,sonographic microcalcification rate,pathological nuclear grade and subtype rate between mass and non-mass groups.Results No abnormal finding was found in sixteen cases (40.0％)on MG and only one case (2.5％) on ultrasonography (US),respectively.The most common sonographic feature of DCIS without microcalcifications on MG were masses (75.0％,30/40),and other sonographic findings were round/oval and irregular shape,microlobulated margin,heterogeneous hypoechogenicity and isoechogenicity,and posterior acoustic feature.Ductal dilatations and heterogeneous isoechogenicity were present in most non-mass lesions of DCIS without microcalcifications on MG (22.5％,9/40).The ultrasonographic microcalcifications were found in 5 cases of DCIS without microcalcifications on MG.The common pathological features of DCIS without microcalcifications on MG were medium-low nuclear grade (85.0％,34/40) and noncomedo (87.5％,35/40).The difference of US accuracy rate in mass and non-mass groups was statistically significant [73.3％ (22/30) vs 33.3％ (3/9),P=0.047].The differences of US microcalcification rate,pathological subtype and nuclear grade were not significant (P=1.000,0.070).Conclusions The mass appearance and medium-low nuclear grade were most common sonographic findings and pathological features of DCIS without microcalcifications on MG.Ultrasonography should be an helpful tool for improving the diagnostic sensitivity ofmammography in breast DCIS.

This study examined the effect of small interfering RNA-mediated β-catenin knockdown on the survival,invasion and chemosensitivity of human osteosarcoma cells (U2-OS cells).The siRNA against β-catenin was constructed and transfected into U2-OS cells.The expression of β-catenin was detected by qRT-PCR and Western blotting.Cell growth and apoptosis was detected in the presence or absence of doxorubicin by MTT and flow cytometry,respectively.Cell invasion ability was measured by transwell assay.The results showed that the transfection of β-catenin siRNA resulted in decreased expression of β-catenin,suppression of invasion and motility of U2-OS cells,reduced chemosensitivity to doxorubicin in vitro,and little change in cell growth and apoptosis.Additionally,down-regulated MT1-MMP expression was found after transfection.It was concluded that knockdown of β-catenin gene may decrease the invasive ability of human osteosarcoma cells through down-regulated MT1-MMP expression,and the chemosensitivity of osteosarcoma cells against doxorubicin.

Objective:To investigate the pollution levels and influencing factors of polybrominated diphenyl ethers (PBDEs) in household dust in five cities in northern China.Methods:Based on the "Chinese Indoor Environment and Health Surveillance" project carried out by the National Institute of Environmental Health, Chinese Center for Disease Control and Prevention in 2018-2019, during the warm season (April 2018 to September 2018) and the cold season (November 2018 to March 2019), Lanzhou in Northwest China, Shijiazhuang in North China, Panjin in Northeast China, Luoyang in Central China, and Qingdao in East China were selected as the research sites. A total of 87 families were recruited to study residences in real-life scenarios. At the same time, dust samples were collected to detect the concentration of PBDEs. The level of household environmental indicators was measured, and the residential building characteristics and family behavior habits were collected through questionnaires. A total of 142 valid dust samples and 140 valid questionnaires were obtained. The differences in PBDE concentrations across seasons, wind zones, residential building characteristics, and family habits were analyzed. The exploratory factor analysis was performed to investigate the possible sources of PBDEs, and multivariate linear regression was used to explore the factors influencing PBDEs in household dust.Results:The M ( Q1,Q3) of total PBDE concentrations in 142 household dust samples in five cities was 144.51 (106.61, 222.65) ng/g in the warm season and 145.10 (98.57, 180.65) ng/g in the cold season, respectively. There were seasonal differences in the concentration of ∑ 12PBDEs in Luoyang and Shijiazhuang ( P<0.01). The concentration of BDE-71 was highest among PBDE homologues, followed by BDE-66 and BDE-47. Three factors were extracted by exploratory factor analysis in the warm season, and the cumulative variance contribution rate was 67.90%. The multivariate linear regression showed that the house completion less than ten years [ β (95% CI): 0.186 (0.013, 0.359)], infrequent home cooking [ β (95% CI):-0.342 (-0.570, -0.114)], and increased residential PM 10 concentration [ β (95% CI): 0.001 (0.000, 0.002)] during the warm season, as well as the house far from driveway [ β (95% CI): 0.093 (0.013, 0.172)], house area less than 90 m 2 [ β (95% CI):-0.138 (-0.264, -0.013)], and lower residential xylene concentration [ β (95% CI):-0.006 (-0.011, -0.001)] during the cold season might be related to the elevated concentrations of ∑ 12PBDEs in household dust. Conclusion:The pollution of PBDEs in household dust in five northern cities is at a medium to high level. Years of house completion, frequency of cooking at home, residential PM 10 concentration, distance from house to driveway, house area, and residential xylene concentration may influence household PBDE concentrations.

Objective:To investigate the pollution levels and influencing factors of polybrominated diphenyl ethers (PBDEs) in household dust in five cities in northern China.Methods:Based on the "Chinese Indoor Environment and Health Surveillance" project carried out by the National Institute of Environmental Health, Chinese Center for Disease Control and Prevention in 2018-2019, during the warm season (April 2018 to September 2018) and the cold season (November 2018 to March 2019), Lanzhou in Northwest China, Shijiazhuang in North China, Panjin in Northeast China, Luoyang in Central China, and Qingdao in East China were selected as the research sites. A total of 87 families were recruited to study residences in real-life scenarios. At the same time, dust samples were collected to detect the concentration of PBDEs. The level of household environmental indicators was measured, and the residential building characteristics and family behavior habits were collected through questionnaires. A total of 142 valid dust samples and 140 valid questionnaires were obtained. The differences in PBDE concentrations across seasons, wind zones, residential building characteristics, and family habits were analyzed. The exploratory factor analysis was performed to investigate the possible sources of PBDEs, and multivariate linear regression was used to explore the factors influencing PBDEs in household dust.Results:The M ( Q1,Q3) of total PBDE concentrations in 142 household dust samples in five cities was 144.51 (106.61, 222.65) ng/g in the warm season and 145.10 (98.57, 180.65) ng/g in the cold season, respectively. There were seasonal differences in the concentration of ∑ 12PBDEs in Luoyang and Shijiazhuang ( P<0.01). The concentration of BDE-71 was highest among PBDE homologues, followed by BDE-66 and BDE-47. Three factors were extracted by exploratory factor analysis in the warm season, and the cumulative variance contribution rate was 67.90%. The multivariate linear regression showed that the house completion less than ten years [ β (95% CI): 0.186 (0.013, 0.359)], infrequent home cooking [ β (95% CI):-0.342 (-0.570, -0.114)], and increased residential PM 10 concentration [ β (95% CI): 0.001 (0.000, 0.002)] during the warm season, as well as the house far from driveway [ β (95% CI): 0.093 (0.013, 0.172)], house area less than 90 m 2 [ β (95% CI):-0.138 (-0.264, -0.013)], and lower residential xylene concentration [ β (95% CI):-0.006 (-0.011, -0.001)] during the cold season might be related to the elevated concentrations of ∑ 12PBDEs in household dust. Conclusion:The pollution of PBDEs in household dust in five northern cities is at a medium to high level. Years of house completion, frequency of cooking at home, residential PM 10 concentration, distance from house to driveway, house area, and residential xylene concentration may influence household PBDE concentrations.