Objective To assess the ability of tetrandrine （Tet） to enhance the sensitivity to irradiation and its mechanism in cell lines of human breast cancer p53-mutant MCF-7/ADR, p53-wild-type MCF-7 and human colon carcino...Objective To assess the ability of tetrandrine （Tet） to enhance the sensitivity to irradiation and its mechanism in cell lines of human breast cancer p53-mutant MCF-7/ADR, p53-wild-type MCF-7 and human colon carcinoma p53-mutant HT-29 as well as in C26 colorectal carcinoma-bearing BALB/c mice. Methods MCF-7/ADR, HT-29 and MCF-7 cells were exposed to irradiation in the absence or presence of tetrandrine. The effect of Tet on the cytotoxicity of X-irradiation in these three cells was determined and the effect of tetrandrine on cell cycle arrest induced by irradiation in its absence or presence was studied by flow cytometry. Moreover, mitotic index measurement determined mitosis of cells to enter mitosis. Western blotting was employed to detect cyclin B1 and Cdc2 proteins in extracts from irradiated or non-irradiated cells of MCF-7/ADR, HT-29 and MCF-7 treated with tetrandrine at various concentrations. Tumor growth delay assay was conducted to determine the radio-sensitization of tetrandrine in vivo. Results Clonogenic assay showed that tetrandrine markedly enhanced the lethal effect of X-rays on p53-mutant MCF-7/ADR and HT-29 cells and the sensitization enhancement ratio （SER） of tetrandrine was 1.51 and 1.63, but its SER was only 1.1 in p53-wt MCF-7 cells. Irradiated p53-mutant MCF-7/ADR and HT-29 cells were only arrested in G2/M phase while MCF-7 cells were arrested in G1 and G2/M phases. Radiation-induced G2 phase arrests were abrogated by tetrandrine in a concentration-dependent manner in MCF-7/ADR and HT-29 cells, whereas redistribution within MCF-7 cell cycle changed slightly. The proportion of cells in M phase increased from 1.3% to 14.7% in MCF-7/ADR cells, and from 1.5% to 13.2% in HT-29 cells, but 2.4% to 7.1% in MCF-7 cells. Furthermore, the levels of cyclin B 1 and Cdc2 expression decreased after X-irradiation in MCF-7/ADR and HT-29 cells, and the mitotic index was also lower. Tet could reverse the decrease and induce the irradiated cells to enter mitosis （M phase）. Endosomatic experiment showed that tetrandrine caused tumor growth delay in irradiated mice. Conclusion Tetrandrine boosts the cell killing activity of irradiation both in vitro and in vivo. Tetrandrine is a potent abrogator for G2 checkpoint control and can sensitize the cells to radiation.展开更多
目的:制备纳米粒载体DMP,对其进行表征的测定,研究DMP介导的Bcl-xl siRNA的抗肿瘤活性。方法:采用MTT法对纳米粒的细胞毒性进行测定;通过Q-PCR法检测mRNA的含量,检测DMP递送Bcl-xlsiRNA入C26细胞的基因沉默效果;通过MTT法研究DMP/si RNA...目的:制备纳米粒载体DMP,对其进行表征的测定,研究DMP介导的Bcl-xl siRNA的抗肿瘤活性。方法:采用MTT法对纳米粒的细胞毒性进行测定;通过Q-PCR法检测mRNA的含量,检测DMP递送Bcl-xlsiRNA入C26细胞的基因沉默效果;通过MTT法研究DMP/si RNA对C26细胞的抗肿瘤效果,测定其对C26细胞的肿瘤抑制作用;用克隆形成实验进一步证明DMP/siRNA能够抑制C26细胞生长,具有显著的抗肿瘤活性;采用碘化丙啶(PI)染色法流式细胞术来分析经过DMP/siBcl-xl治疗的C26细胞的凋亡率。结果:纳米粒具有良好的粒径和电位以及较低的细胞毒性,其IC50为3.7μg﹒mL^(-1)。Q-PCR结果显示DMP/siBcl-xl有效地降低了Bcl-xl信使RNA的水平;MTT结果显示DMP/siBcl-xl(50 n M和100 n M)的生存率分别为69.6%±3.3%,56.3%±1.9%,低于DMP组;克隆形成实验表明DMP/siBcl-xl能够抑制C26细胞的增殖,具有显著的抗肿瘤活性;凋亡实验结果显示DMP/siBcl-xl的细胞凋亡率为33.0%±3.8%,与对照组、DMP组、DMP/Scramble siRNA组比较,细胞凋亡率显著地增加了。结论:纳米粒DMP具有良好的粒径和电位,并且具有较低的细胞毒性。DMP/siBcl-xl能够沉默Bcl-xl基因,引发C26细胞的凋亡,进一步实现抑制C26细胞生长的治疗作用。实验表明纳米粒DMP能够作为有效的载体递送siRNA用于结肠癌的治疗。展开更多
基金supported by a grant from the Jiangsu Natural Science Foundation (No. BK2005203).
文摘Objective To assess the ability of tetrandrine （Tet） to enhance the sensitivity to irradiation and its mechanism in cell lines of human breast cancer p53-mutant MCF-7/ADR, p53-wild-type MCF-7 and human colon carcinoma p53-mutant HT-29 as well as in C26 colorectal carcinoma-bearing BALB/c mice. Methods MCF-7/ADR, HT-29 and MCF-7 cells were exposed to irradiation in the absence or presence of tetrandrine. The effect of Tet on the cytotoxicity of X-irradiation in these three cells was determined and the effect of tetrandrine on cell cycle arrest induced by irradiation in its absence or presence was studied by flow cytometry. Moreover, mitotic index measurement determined mitosis of cells to enter mitosis. Western blotting was employed to detect cyclin B1 and Cdc2 proteins in extracts from irradiated or non-irradiated cells of MCF-7/ADR, HT-29 and MCF-7 treated with tetrandrine at various concentrations. Tumor growth delay assay was conducted to determine the radio-sensitization of tetrandrine in vivo. Results Clonogenic assay showed that tetrandrine markedly enhanced the lethal effect of X-rays on p53-mutant MCF-7/ADR and HT-29 cells and the sensitization enhancement ratio （SER） of tetrandrine was 1.51 and 1.63, but its SER was only 1.1 in p53-wt MCF-7 cells. Irradiated p53-mutant MCF-7/ADR and HT-29 cells were only arrested in G2/M phase while MCF-7 cells were arrested in G1 and G2/M phases. Radiation-induced G2 phase arrests were abrogated by tetrandrine in a concentration-dependent manner in MCF-7/ADR and HT-29 cells, whereas redistribution within MCF-7 cell cycle changed slightly. The proportion of cells in M phase increased from 1.3% to 14.7% in MCF-7/ADR cells, and from 1.5% to 13.2% in HT-29 cells, but 2.4% to 7.1% in MCF-7 cells. Furthermore, the levels of cyclin B 1 and Cdc2 expression decreased after X-irradiation in MCF-7/ADR and HT-29 cells, and the mitotic index was also lower. Tet could reverse the decrease and induce the irradiated cells to enter mitosis （M phase）. Endosomatic experiment showed that tetrandrine caused tumor growth delay in irradiated mice. Conclusion Tetrandrine boosts the cell killing activity of irradiation both in vitro and in vivo. Tetrandrine is a potent abrogator for G2 checkpoint control and can sensitize the cells to radiation.
文摘目的:制备纳米粒载体DMP,对其进行表征的测定,研究DMP介导的Bcl-xl siRNA的抗肿瘤活性。方法:采用MTT法对纳米粒的细胞毒性进行测定;通过Q-PCR法检测mRNA的含量,检测DMP递送Bcl-xlsiRNA入C26细胞的基因沉默效果;通过MTT法研究DMP/si RNA对C26细胞的抗肿瘤效果,测定其对C26细胞的肿瘤抑制作用;用克隆形成实验进一步证明DMP/siRNA能够抑制C26细胞生长,具有显著的抗肿瘤活性;采用碘化丙啶(PI)染色法流式细胞术来分析经过DMP/siBcl-xl治疗的C26细胞的凋亡率。结果:纳米粒具有良好的粒径和电位以及较低的细胞毒性,其IC50为3.7μg﹒mL^(-1)。Q-PCR结果显示DMP/siBcl-xl有效地降低了Bcl-xl信使RNA的水平;MTT结果显示DMP/siBcl-xl(50 n M和100 n M)的生存率分别为69.6%±3.3%,56.3%±1.9%,低于DMP组;克隆形成实验表明DMP/siBcl-xl能够抑制C26细胞的增殖,具有显著的抗肿瘤活性;凋亡实验结果显示DMP/siBcl-xl的细胞凋亡率为33.0%±3.8%,与对照组、DMP组、DMP/Scramble siRNA组比较,细胞凋亡率显著地增加了。结论:纳米粒DMP具有良好的粒径和电位,并且具有较低的细胞毒性。DMP/siBcl-xl能够沉默Bcl-xl基因,引发C26细胞的凋亡,进一步实现抑制C26细胞生长的治疗作用。实验表明纳米粒DMP能够作为有效的载体递送siRNA用于结肠癌的治疗。
