To investigate the synergistic effects of 3′-azido-3′- deoxythymidine （AZT） and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro. METHODS： Ml-I- analysis was made to ...To investigate the synergistic effects of 3′-azido-3′- deoxythymidine （AZT） and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro. METHODS： Ml-I- analysis was made to examine the inhibition rate of MKN45 cells treated with AZT （2.5, 5, 10 and 20 mg/L） and FA-2-b-13 （5, 10, 20 and 40 mg/L） singly and combinatively for 24, 48 and 72 h. Apoptotic effects were evaluated by morphological methods, DNA agarose gel electrophoresis and flow cytometry, respectively. Telomerase activity was estimated by TRAP- ELISA. The mRNA expression of caspase-3 and Bcl-2 were detected by RT-PCR. RESULTS： AZT and FA-2-b-13 could significantly inhibit MKN45 cell proliferation and induce its apoptosis. MKN45 cells were inhibited in dose- and time- dependent manner. The inhibition effect of AZT combined with FA-2- b-β was obviously better than that used singly （0.469 ＋ 0.022 vs 1.075 4- 0.055, P 〈 0.05, 0.325 4- 0.029 vs 0.469 ＋ 0.022 P 〈 0.01）. AZT used singly and combination of FA-2-b-β could decrease the activity of tumor cell telomerase, and AZT has synergistic function with FA- 2-b-β. A certain concentration of AZT could up-regulate the expression of caspase-3 mRNA （r = 0.9969, P 〈 0.01）, which was positively related to apoptosis rate, and could down-regulate the expression of Bcl-2 mRNA, which was negatively related to apoptosis rate （r = 0.926, P 〈 0.01）. Furthermore, the effect of AZT combined with FA-2-b-13 was significantly higher than that used singly. CONCLUSION： Combination of AZT and FA-2-b-β has an obviously synergetic effect in the gastric cancer cells MKN45, which has provided a new approach to the treatment of gastric cancer clinically.展开更多
Objective To find out the mechanisms of redifferentiation and reversion of malignant human gastric cancer cells induced by ascorbic acid. Methods Human gastric cancer cells grown in the laboratory were used. The Trypa...Objective To find out the mechanisms of redifferentiation and reversion of malignant human gastric cancer cells induced by ascorbic acid. Methods Human gastric cancer cells grown in the laboratory were used. The Trypan blue dye exclusion method was used to determine the cell doubling time. The electrophoresis rate and colonogenic potential were the indices used to measure the rate of redifferentiation. The content of malondialdehyde （MDA） was measured using the thiobarbituric acid （TBA） method. The activities of superoxide dismutase （SOD）, catalase （CAT） and the content of H2O2 were evaluated by spectrophotography. Results Six mmol/L ascorbic acid was used as a positive control. Human gastric cancer cells were treated with 75 μm hydrogen peroxide, which alleviated many of the malignant characteristics. For example, the cell surface charge obviously decreased and the electrophoresis rate dropped from 2.21 to 1.10 pm·s^-1·cm^-1 The colonogenic potential, a measure of cell differentiation, decreased 90.2%. After treatment with ascorbic acid, there was a concentration- and time-dependent increase in hydrogen peroxide （H2O2） and the activity of superoxide dismutase （SOD）. However, the activity of catalase （CAT） resulted in a concentration- and time-dependent decrease. SOD and 3-amino- 1,2,4-triazole （AT） exhibited some effects, but there were statistically significant differences between the SOD and AT group and the H2O2 group, Conclusions Ascurbic acid induces growth inhibition and redifferentiation of human gastric cancer cells through the production of hydrogen peroxide.展开更多
文摘To investigate the synergistic effects of 3′-azido-3′- deoxythymidine （AZT） and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro. METHODS： Ml-I- analysis was made to examine the inhibition rate of MKN45 cells treated with AZT （2.5, 5, 10 and 20 mg/L） and FA-2-b-13 （5, 10, 20 and 40 mg/L） singly and combinatively for 24, 48 and 72 h. Apoptotic effects were evaluated by morphological methods, DNA agarose gel electrophoresis and flow cytometry, respectively. Telomerase activity was estimated by TRAP- ELISA. The mRNA expression of caspase-3 and Bcl-2 were detected by RT-PCR. RESULTS： AZT and FA-2-b-13 could significantly inhibit MKN45 cell proliferation and induce its apoptosis. MKN45 cells were inhibited in dose- and time- dependent manner. The inhibition effect of AZT combined with FA-2- b-β was obviously better than that used singly （0.469 ＋ 0.022 vs 1.075 4- 0.055, P 〈 0.05, 0.325 4- 0.029 vs 0.469 ＋ 0.022 P 〈 0.01）. AZT used singly and combination of FA-2-b-β could decrease the activity of tumor cell telomerase, and AZT has synergistic function with FA- 2-b-β. A certain concentration of AZT could up-regulate the expression of caspase-3 mRNA （r = 0.9969, P 〈 0.01）, which was positively related to apoptosis rate, and could down-regulate the expression of Bcl-2 mRNA, which was negatively related to apoptosis rate （r = 0.926, P 〈 0.01）. Furthermore, the effect of AZT combined with FA-2-b-13 was significantly higher than that used singly. CONCLUSION： Combination of AZT and FA-2-b-β has an obviously synergetic effect in the gastric cancer cells MKN45, which has provided a new approach to the treatment of gastric cancer clinically.
文摘Objective To find out the mechanisms of redifferentiation and reversion of malignant human gastric cancer cells induced by ascorbic acid. Methods Human gastric cancer cells grown in the laboratory were used. The Trypan blue dye exclusion method was used to determine the cell doubling time. The electrophoresis rate and colonogenic potential were the indices used to measure the rate of redifferentiation. The content of malondialdehyde （MDA） was measured using the thiobarbituric acid （TBA） method. The activities of superoxide dismutase （SOD）, catalase （CAT） and the content of H2O2 were evaluated by spectrophotography. Results Six mmol/L ascorbic acid was used as a positive control. Human gastric cancer cells were treated with 75 μm hydrogen peroxide, which alleviated many of the malignant characteristics. For example, the cell surface charge obviously decreased and the electrophoresis rate dropped from 2.21 to 1.10 pm·s^-1·cm^-1 The colonogenic potential, a measure of cell differentiation, decreased 90.2%. After treatment with ascorbic acid, there was a concentration- and time-dependent increase in hydrogen peroxide （H2O2） and the activity of superoxide dismutase （SOD）. However, the activity of catalase （CAT） resulted in a concentration- and time-dependent decrease. SOD and 3-amino- 1,2,4-triazole （AT） exhibited some effects, but there were statistically significant differences between the SOD and AT group and the H2O2 group, Conclusions Ascurbic acid induces growth inhibition and redifferentiation of human gastric cancer cells through the production of hydrogen peroxide.
