AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tum...AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL+/B7-1+SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P<0.01). SGC- 7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC 7901 cells (z = 2.06-44.30, P<0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1±2.4% vs30.5±2.3%,P<0.05).CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.展开更多
目的前期研究发现中药连翘醇提物具有明显体外抑制肿瘤细胞的作用,文章进一步探讨从中药连翘提取的化合物达玛-24-烯-3β-乙酰氧基-20s-醇(Dammar-24-ene-3β-acetate-20S-ol,DM)体外抗肿瘤作用及其机制。方法采用MTT法检测DM对胃癌细胞...目的前期研究发现中药连翘醇提物具有明显体外抑制肿瘤细胞的作用,文章进一步探讨从中药连翘提取的化合物达玛-24-烯-3β-乙酰氧基-20s-醇(Dammar-24-ene-3β-acetate-20S-ol,DM)体外抗肿瘤作用及其机制。方法采用MTT法检测DM对胃癌细胞株SGC-7901、BGC-823和MKN-45体外抑制作用。实验分为MKN-45对照组及其低、高剂量组,BGC-823对照组及其低、高剂量组,SGC-7901对照组及其低、高剂量组,对照组均为新鲜培养基,低剂量DM为10、50μg/m L,流式细胞仪检测凋亡细胞比例。应用Cell Quest软件分析结果,记录细胞不同周期的比例。采用DCFH-DA探针检测ROS水平,实验分为空白对照组,多西紫杉醇组和DM组。配置微管聚集实验反应体系,其中多西紫杉醇10μmol/L,DM终浓度选择50或100μmol/L,空白对照组不加药物,采用微管聚集实验和微管蛋白免疫荧光染色研究DM对于微管系统的影响。结果 50μg/m L对于3株胃癌细胞抑制率均在80%以上,IC50分别为:MKN-45(11.72±1.35)μg/m L;BGC-823(17.19±0.82)μg/m L;SGC-7901(7.55±0.79)μg/m L。2μg/m L DM处理48 h后再以低密度培养8 d,细胞克隆较对照组明显减少。与MKN-45对照组凋亡细胞[(21.1±2.5)%]相比,MKN-45低剂量组和高剂量组凋亡细胞比率[(25.1±1.3)%和(55.2±2.3)%]均有明显升高(P<0.01)。BGC-823对照组凋亡细胞百分率(13.2±2.4)%比较,BGC-823低、高剂量组凋亡细胞百分率[(18.2±2.1)%、(41.8±2.8)%]明显升高(P<0.01)。与SGC-7901对照组凋亡细胞率[(10.5±1.8)%]比较,SGC-7901高剂量DM组凋亡细胞率[(21.1±1.9)%]升高(P<0.05),而与SGC-7901低剂量DM组[(12.3±1.6)%]差异无统计学意义(P>0.05)。与MKN-45对照组比较,MKN-45低剂量组S期细胞百分率降低[(14.5±2.7)%vs(12.3±3.3)%,P>0.05]。与BGC-823对照组比较,BGC-823低剂量组细胞S期百分率增加[(12.2±5.4)%vs(20.2±2.1)%,P<0.05]。与SGC-7901对照组比较,SGC-7901低剂量组S期细胞百分率增加[(21.5±3.8)%vs(31.3±2.6%),P<0.05]。检测DM处理后细胞内活性氧水平研究发现,10、50μg/m L DM处理48 h 3株细胞均可见剂量依赖性ROS水平上升。微管蛋白免疫荧光染色可见采用IC50浓度的多西紫杉醇和10μg/m L DM处理48 h后,MKN-45荧光信号均表现为局部浓聚、紊乱。结论达玛-24-烯-3β-乙酰氧基-20s-醇能够将胃癌细胞周期阻滞于S期,诱导细胞凋亡,从而抑制细胞增殖作用。展开更多
基金Supported by the Medical Scientific Foundation of Jiangsu Province, No. H200147
文摘AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL+/B7-1+SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P<0.01). SGC- 7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC 7901 cells (z = 2.06-44.30, P<0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1±2.4% vs30.5±2.3%,P<0.05).CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.
文摘目的前期研究发现中药连翘醇提物具有明显体外抑制肿瘤细胞的作用,文章进一步探讨从中药连翘提取的化合物达玛-24-烯-3β-乙酰氧基-20s-醇(Dammar-24-ene-3β-acetate-20S-ol,DM)体外抗肿瘤作用及其机制。方法采用MTT法检测DM对胃癌细胞株SGC-7901、BGC-823和MKN-45体外抑制作用。实验分为MKN-45对照组及其低、高剂量组,BGC-823对照组及其低、高剂量组,SGC-7901对照组及其低、高剂量组,对照组均为新鲜培养基,低剂量DM为10、50μg/m L,流式细胞仪检测凋亡细胞比例。应用Cell Quest软件分析结果,记录细胞不同周期的比例。采用DCFH-DA探针检测ROS水平,实验分为空白对照组,多西紫杉醇组和DM组。配置微管聚集实验反应体系,其中多西紫杉醇10μmol/L,DM终浓度选择50或100μmol/L,空白对照组不加药物,采用微管聚集实验和微管蛋白免疫荧光染色研究DM对于微管系统的影响。结果 50μg/m L对于3株胃癌细胞抑制率均在80%以上,IC50分别为:MKN-45(11.72±1.35)μg/m L;BGC-823(17.19±0.82)μg/m L;SGC-7901(7.55±0.79)μg/m L。2μg/m L DM处理48 h后再以低密度培养8 d,细胞克隆较对照组明显减少。与MKN-45对照组凋亡细胞[(21.1±2.5)%]相比,MKN-45低剂量组和高剂量组凋亡细胞比率[(25.1±1.3)%和(55.2±2.3)%]均有明显升高(P<0.01)。BGC-823对照组凋亡细胞百分率(13.2±2.4)%比较,BGC-823低、高剂量组凋亡细胞百分率[(18.2±2.1)%、(41.8±2.8)%]明显升高(P<0.01)。与SGC-7901对照组凋亡细胞率[(10.5±1.8)%]比较,SGC-7901高剂量DM组凋亡细胞率[(21.1±1.9)%]升高(P<0.05),而与SGC-7901低剂量DM组[(12.3±1.6)%]差异无统计学意义(P>0.05)。与MKN-45对照组比较,MKN-45低剂量组S期细胞百分率降低[(14.5±2.7)%vs(12.3±3.3)%,P>0.05]。与BGC-823对照组比较,BGC-823低剂量组细胞S期百分率增加[(12.2±5.4)%vs(20.2±2.1)%,P<0.05]。与SGC-7901对照组比较,SGC-7901低剂量组S期细胞百分率增加[(21.5±3.8)%vs(31.3±2.6%),P<0.05]。检测DM处理后细胞内活性氧水平研究发现,10、50μg/m L DM处理48 h 3株细胞均可见剂量依赖性ROS水平上升。微管蛋白免疫荧光染色可见采用IC50浓度的多西紫杉醇和10μg/m L DM处理48 h后,MKN-45荧光信号均表现为局部浓聚、紊乱。结论达玛-24-烯-3β-乙酰氧基-20s-醇能够将胃癌细胞周期阻滞于S期,诱导细胞凋亡,从而抑制细胞增殖作用。