AIM： To evaluate the effect of antisense vascular endothelial growth factor （VEGF） RNA （PCMV-FGEV） transfection on the profile of hepatocellular carcinoma （HCC） SMMC-7721 cells in vitro and in vivo.METHODS： SM...AIM： To evaluate the effect of antisense vascular endothelial growth factor （VEGF） RNA （PCMV-FGEV） transfection on the profile of hepatocellular carcinoma （HCC） SMMC-7721 cells in vitro and in vivo.METHODS： SMMC-7721 cells were transfected with PCMV-FGEV antisense, PCMV-VEGF sense and empty vector plasmid encapsulated by lipofectamine as antisense group, sense group and control group respectively. The positive cell clones were selected with G418. The stable transfection and expression of VEGF in the cells were determined by RT-PCR and immunohistochemistry. Cell proliferation was observed by Mnassay. FACS analysis was used to determine the effect of PCMV-FGEV transfection on cell apoptosis. The growth of transfected cells in vivo was also observed in nude mice.RESULTS： VEGF expression was reduced in SMMC-7721 transfected with PCMV-FGEV, which was confirmed by RT-PCR and immunohistochemistry. No effect of PCMV- FGEV transfection was found on cell proliferation and cell apoptosis of SMMC-7721 in vitro. The growth of cells transfected with PCMV-FGEV was slow in nude mice and accompanied with obvious apoptosis. The latent time of tumors in the antisense group was 25.0 ：l： 1.8 d, which was longer than that in sense and control groups （F= 19.455, P〈 0.01）. The average tumor weight in antisense group （0.96 g±0.28 g） was the smallest among the three groups （F= 21.501, P〈 0.01）.CONCLUSION： The expression of VEGF can be inhibited by antisense PCMV-FGEV. Antisense PCMV-FGEV has no effect on cell proliferation and apoptosis of SMMC-7721 in vitro but can inhibit tumor growth and induce cell apoptosis in vivo.展开更多
CME is one of the important events in the sun-earth system as it can induce geomagnetic disturbance and an associated space environment effect.It is of special significance to predict whether CME will reach the Earth ...CME is one of the important events in the sun-earth system as it can induce geomagnetic disturbance and an associated space environment effect.It is of special significance to predict whether CME will reach the Earth and when it will arrive.In this paper,we firstly built a new multiple association list for 215 different events with 18 characteristics including CME features,eruption region coordinates and solar wind parameters.Based on the CME list,we designed a novel model based on the principle of the recommendation algorithm to predict the arrival time of CMEs.According to the two commonly used calculation methods in the recommendation system,cosine distance and Euclidean distance,a controlled trial was carried out respectively.Every feature has been found to have its own appropriate weight.The error analysis indicates the result using the Euclidean distance similarity is much better than that using cosine distance similarity.The mean absolute error and root mean square error of test data in the Euclidean distance are 11.78 and 13.77 h,close to the average level of other CME models issued in the CME scoreboard,which verifies the effectiveness of the recommendation algorithm.This work gives a new endeavor using the recommendation algorithm,and is expected to induce other applications in space weather prediction.展开更多
基金Supported by the Natural Science Foundation of Tianjin,No 013615611
文摘AIM： To evaluate the effect of antisense vascular endothelial growth factor （VEGF） RNA （PCMV-FGEV） transfection on the profile of hepatocellular carcinoma （HCC） SMMC-7721 cells in vitro and in vivo.METHODS： SMMC-7721 cells were transfected with PCMV-FGEV antisense, PCMV-VEGF sense and empty vector plasmid encapsulated by lipofectamine as antisense group, sense group and control group respectively. The positive cell clones were selected with G418. The stable transfection and expression of VEGF in the cells were determined by RT-PCR and immunohistochemistry. Cell proliferation was observed by Mnassay. FACS analysis was used to determine the effect of PCMV-FGEV transfection on cell apoptosis. The growth of transfected cells in vivo was also observed in nude mice.RESULTS： VEGF expression was reduced in SMMC-7721 transfected with PCMV-FGEV, which was confirmed by RT-PCR and immunohistochemistry. No effect of PCMV- FGEV transfection was found on cell proliferation and cell apoptosis of SMMC-7721 in vitro. The growth of cells transfected with PCMV-FGEV was slow in nude mice and accompanied with obvious apoptosis. The latent time of tumors in the antisense group was 25.0 ：l： 1.8 d, which was longer than that in sense and control groups （F= 19.455, P〈 0.01）. The average tumor weight in antisense group （0.96 g±0.28 g） was the smallest among the three groups （F= 21.501, P〈 0.01）.CONCLUSION： The expression of VEGF can be inhibited by antisense PCMV-FGEV. Antisense PCMV-FGEV has no effect on cell proliferation and apoptosis of SMMC-7721 in vitro but can inhibit tumor growth and induce cell apoptosis in vivo.
基金supported by a NASA Heliophysics vip Investigator Grantsupported by the National Natural Science Foundation of China (Grant Nos.12071166 and 42074224)。
文摘CME is one of the important events in the sun-earth system as it can induce geomagnetic disturbance and an associated space environment effect.It is of special significance to predict whether CME will reach the Earth and when it will arrive.In this paper,we firstly built a new multiple association list for 215 different events with 18 characteristics including CME features,eruption region coordinates and solar wind parameters.Based on the CME list,we designed a novel model based on the principle of the recommendation algorithm to predict the arrival time of CMEs.According to the two commonly used calculation methods in the recommendation system,cosine distance and Euclidean distance,a controlled trial was carried out respectively.Every feature has been found to have its own appropriate weight.The error analysis indicates the result using the Euclidean distance similarity is much better than that using cosine distance similarity.The mean absolute error and root mean square error of test data in the Euclidean distance are 11.78 and 13.77 h,close to the average level of other CME models issued in the CME scoreboard,which verifies the effectiveness of the recommendation algorithm.This work gives a new endeavor using the recommendation algorithm,and is expected to induce other applications in space weather prediction.
