AIM: It has been reported that regular consumption of nonsteroidal anti-inflammatory drugs like indomethacin decreases the incidence and mortality rate of a number of gastrointestinal cancers. We aimed to explore the ...AIM: It has been reported that regular consumption of nonsteroidal anti-inflammatory drugs like indomethacin decreases the incidence and mortality rate of a number of gastrointestinal cancers. We aimed to explore the efficacy and possible mechanisms of indomethacin on tumor growth and tumor angiogenesis of human colon cancer xenografts in nude mice. METHODS: MTT (thiazolyl blue) assay was used to assess the effect of indomethacin on cultured human colorectal cancer cell line HCT116. HCT116 cells were inoculated subcutaneously into BALB/c-nu/nu mice. After oral administration of indomethacin, 3 mg/kg·d for 4 wk, animals were sacrificed by cervical dislocation. Immunohistochemical staining was employed to determine the microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression in tumor tissues. RESULTS: Indomethacin, a non-selective COX inhibitor, significantly decreased the viability of HCT116 cells in a dose-dependent manner (P<0.05) with 50% inhibition at approximately 318.2±12.7 μmol/L Growth of HCT116 cell tumor was significantly suppressed by indomethacin. The tumor volume was significantly decreased in the treated group (458.89±32.07 mm3) compared to the control group (828.21±31.59 mm3) (P<0.05). The MVD of the treated group (19.50±5.32) was markedly decreased compared to the control group (37.40±4.93) (P<0.001). The VEGF expression of the treated group (1.19±0.17) was obviously reduced as compared to the control group (1.90±0.48) (P<0.01). The decrease in MVD was positively correlated with the decrease of VEGF expression (rs = 0.714, P<0.05). We did not see gastrointestinal complications in the treated group and no differences were noted in the body weight of the mice between the two groups throughout the study CONCLUSION: Indomethacin can significantly decrease the viability of cultured HCT116 cells and retard human colorectal HCT116 cell tumor growth via inhibiting tumor angiogenesis, which might be through reduction of VEGF expression.展开更多
AIM: To explore the impact of prolonged fraction dosedelivery time modeling intensity-modulated radiation therapy (IMRT) on cell killing of human hepatocellular carcinoma (HCC) HepG2 and Hep3B cell lines.METHODS: The ...AIM: To explore the impact of prolonged fraction dosedelivery time modeling intensity-modulated radiation therapy (IMRT) on cell killing of human hepatocellular carcinoma (HCC) HepG2 and Hep3B cell lines.METHODS: The radiobiological characteristics of human HCC HepG2 and Hep3b cell lines were studied with standard clonogenic assays, using standard linear-quadratic model and incomplete repair model to fit the dose-survival curves. The identical methods were also employed to investigate the biological effectiveness of irradiation protocols modeling clinical conventional fractionated external beam radiotherapy (EBRT, fraction delivery time 3 min) and IMRT with different prolonged fraction delivery time (15, 30, and 45 min). The differences of cell surviving fraction irradiated with different fraction delivery time were tested with paired t-test. Factors determining the impact of prolonged fraction delivery time on cell killing were analyzed.RESULTS: The α/β and repair half-time (T1/2) of HepG2and Hep3b were 3.1 and 7.4 Gy, and 22 and 19 min respectively. The surviving fraction of HepG2 irradiated modeling IMRT with different fraction delivery time was significantly higher than irradiated modeling EBRT and the cell survival increased more pronouncedly with the fraction delivery time prolonged from 15 to 45 min,while no significant differences of cell survival in Hep3b were found between different fraction delivery time protocols.CONCLUSION: The prolonged fraction delivery time modeling IMRT significantly decreased the cell killing in HepG2 but not in Hep3b. The capability of sub-lethal damage repair was the predominant factor determining the cell killing decrease. These effects, if confirmed by clinical studies, should be considered in designing IMRT treatments for HCC.展开更多
Ion mobility spectra for ten alcohols have been studied in an ion mobility spectrometry apparatus equipped with a corona discharge ionization source. Using protonated water cluster ions as the reactant ions and clean ...Ion mobility spectra for ten alcohols have been studied in an ion mobility spectrometry apparatus equipped with a corona discharge ionization source. Using protonated water cluster ions as the reactant ions and clean air as the drift gas, the alcohols exhibit different product ion characteristic peaks in their ion mobility spectra. The detection limit for these alcohols is at low concentration pmol/L level according to the concentration calibration by exponential dilution method. Based on the measured ion mobilities, several chemical physics parameters of the ion-molecular interaction at atmosphere were obtained, including the ionic collision cross sections, diffusion coefficients, collision rate constants, and the ionic radii under the hard-sphere model approximation.展开更多
Objective To construct a recombinant lactobacillus (Lb.) strain excreting the human chorionic gonadotropin beta-subunit (hCGβ) Methods The hCGβ cDNA was ligated to the signal peptide sequence of S-layer protein fr...Objective To construct a recombinant lactobacillus (Lb.) strain excreting the human chorionic gonadotropin beta-subunit (hCGβ) Methods The hCGβ cDNA was ligated to the signal peptide sequence of S-layer protein from Lb. brevis and then cloned into down-stream of lactose-inducible promoter of an integrative plasmid, pIlac. After electroporation into Lb. casei CECT5276, PCR using the genomic DNA of the recombinant lactobacillus as template was performed to confirm whether the hCGβ gene had been integrated into the genome. Radioimmunoassay (RIA) was used to determine the level of hCGβ in the supernatant and the cell lysate. Results The hCGβ was integrated into the genome of Lb. casei CECT5276. The highest concentration of hCGβ in the culture supernatant amounted to 440 mIU/mL 21 h after lactose induction. About 2/3 of the abstract Objective proteins were excreted into the supernatant. Conclusion We have obtained stable and efficient hCGβ excretion in Lb. casei, which was inducible by lactose.展开更多
基金Supported by National Natural Science Foundation of China, No. 30271516
文摘AIM: It has been reported that regular consumption of nonsteroidal anti-inflammatory drugs like indomethacin decreases the incidence and mortality rate of a number of gastrointestinal cancers. We aimed to explore the efficacy and possible mechanisms of indomethacin on tumor growth and tumor angiogenesis of human colon cancer xenografts in nude mice. METHODS: MTT (thiazolyl blue) assay was used to assess the effect of indomethacin on cultured human colorectal cancer cell line HCT116. HCT116 cells were inoculated subcutaneously into BALB/c-nu/nu mice. After oral administration of indomethacin, 3 mg/kg·d for 4 wk, animals were sacrificed by cervical dislocation. Immunohistochemical staining was employed to determine the microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression in tumor tissues. RESULTS: Indomethacin, a non-selective COX inhibitor, significantly decreased the viability of HCT116 cells in a dose-dependent manner (P<0.05) with 50% inhibition at approximately 318.2±12.7 μmol/L Growth of HCT116 cell tumor was significantly suppressed by indomethacin. The tumor volume was significantly decreased in the treated group (458.89±32.07 mm3) compared to the control group (828.21±31.59 mm3) (P<0.05). The MVD of the treated group (19.50±5.32) was markedly decreased compared to the control group (37.40±4.93) (P<0.001). The VEGF expression of the treated group (1.19±0.17) was obviously reduced as compared to the control group (1.90±0.48) (P<0.01). The decrease in MVD was positively correlated with the decrease of VEGF expression (rs = 0.714, P<0.05). We did not see gastrointestinal complications in the treated group and no differences were noted in the body weight of the mice between the two groups throughout the study CONCLUSION: Indomethacin can significantly decrease the viability of cultured HCT116 cells and retard human colorectal HCT116 cell tumor growth via inhibiting tumor angiogenesis, which might be through reduction of VEGF expression.
基金Supported by the Natural Science Foundation of Guangdong Province, No. 013056
文摘AIM: To explore the impact of prolonged fraction dosedelivery time modeling intensity-modulated radiation therapy (IMRT) on cell killing of human hepatocellular carcinoma (HCC) HepG2 and Hep3B cell lines.METHODS: The radiobiological characteristics of human HCC HepG2 and Hep3b cell lines were studied with standard clonogenic assays, using standard linear-quadratic model and incomplete repair model to fit the dose-survival curves. The identical methods were also employed to investigate the biological effectiveness of irradiation protocols modeling clinical conventional fractionated external beam radiotherapy (EBRT, fraction delivery time 3 min) and IMRT with different prolonged fraction delivery time (15, 30, and 45 min). The differences of cell surviving fraction irradiated with different fraction delivery time were tested with paired t-test. Factors determining the impact of prolonged fraction delivery time on cell killing were analyzed.RESULTS: The α/β and repair half-time (T1/2) of HepG2and Hep3b were 3.1 and 7.4 Gy, and 22 and 19 min respectively. The surviving fraction of HepG2 irradiated modeling IMRT with different fraction delivery time was significantly higher than irradiated modeling EBRT and the cell survival increased more pronouncedly with the fraction delivery time prolonged from 15 to 45 min,while no significant differences of cell survival in Hep3b were found between different fraction delivery time protocols.CONCLUSION: The prolonged fraction delivery time modeling IMRT significantly decreased the cell killing in HepG2 but not in Hep3b. The capability of sub-lethal damage repair was the predominant factor determining the cell killing decrease. These effects, if confirmed by clinical studies, should be considered in designing IMRT treatments for HCC.
基金V. ACKNOWLEDGMENTS This work was support by the National Natural Science Foundation of China （No.20577049, No.20707025, and No.20907054）, the Chinese-Slovak Scientific and Technological Cooperation Project （No.4-03）, the Excellent Youth Foundation of Anhui Province Scientific Committee （No.06045098）, the Hefei Institutes of Physical Science, Chinese Academy of Science are gratefully acknowledged, and the Slovak Research and Development Agency, projects （No.LPP-0143-06 and No.SK- CN-029-07）.
文摘Ion mobility spectra for ten alcohols have been studied in an ion mobility spectrometry apparatus equipped with a corona discharge ionization source. Using protonated water cluster ions as the reactant ions and clean air as the drift gas, the alcohols exhibit different product ion characteristic peaks in their ion mobility spectra. The detection limit for these alcohols is at low concentration pmol/L level according to the concentration calibration by exponential dilution method. Based on the measured ion mobilities, several chemical physics parameters of the ion-molecular interaction at atmosphere were obtained, including the ionic collision cross sections, diffusion coefficients, collision rate constants, and the ionic radii under the hard-sphere model approximation.
文摘Objective To construct a recombinant lactobacillus (Lb.) strain excreting the human chorionic gonadotropin beta-subunit (hCGβ) Methods The hCGβ cDNA was ligated to the signal peptide sequence of S-layer protein from Lb. brevis and then cloned into down-stream of lactose-inducible promoter of an integrative plasmid, pIlac. After electroporation into Lb. casei CECT5276, PCR using the genomic DNA of the recombinant lactobacillus as template was performed to confirm whether the hCGβ gene had been integrated into the genome. Radioimmunoassay (RIA) was used to determine the level of hCGβ in the supernatant and the cell lysate. Results The hCGβ was integrated into the genome of Lb. casei CECT5276. The highest concentration of hCGβ in the culture supernatant amounted to 440 mIU/mL 21 h after lactose induction. About 2/3 of the abstract Objective proteins were excreted into the supernatant. Conclusion We have obtained stable and efficient hCGβ excretion in Lb. casei, which was inducible by lactose.
