免疫毒素DTATEGF对人非小细胞肺癌脑转移瘤的影响及机制

摘要

Objective:To investigate the in vitro and in vivo anticancer effcacy of the immunotoxin DTATEGF against human NSCLC brain metastatic tumor PC9-BrM3 cell line. Methods:The effect of the immunotoxin DTATEGF was tested for its ability to inhibit the proliferation of PC9-BrM3 cells in vitro by MTT assay. The cell cycle and the apoptosis of cells with 1 pmol/L DTATEGF were examined by lfow cytometry. In vivo, 2μg of DTATEGF or control Bickel3 was given intratumor to nude mice with established PC9-BrM3 xenografts on their hips, andtumorvolumesweremeasuredandtumorsampleswereinvestigatedbyimmunchistochemistry SABC method. The microvessel density (MVD) was measured in each group. Results:In vitro, DTATEGF killed PC9-BrM3 cells and showed an IC50 of 1 pmol/L. The apoptotic rate in the 1 pmol/L DTATEGF group was (64.0±0.5)%, signiifcantly higher than that in the control group (1.5±0.4)%(P<0.01). The cell cycle was obviously inhibited by DTATEGF in a dose-dependent manner. The percentage of cells treated with 1 pmol/L DTATEGF in SubG0/G1 phase was (32.0±1.5)%, significantly higher than that in the control group (2.0±0.4)%(P<0.01). In vivo, DTATEGF signiifcantly inhibited the growth of PC9-BrM3 hip tumors (P<0.05). The MVD of the DTATEGF group was (15.6±4.6)/mm2, signiifcantly lower than that of the control group (31.2±5.4)/mm2 (P<0.01). Conclusion:DTATEGF inhibits the growth of the PC9-BrM3 cell line and induces its apoptosis. It is highly effcacious against human metastatic NSCLC brain tumor and against neovascularization.%目的：观察免疫毒素DTATEGF对体外培养的人NSCLC脑转移瘤细胞增殖、凋亡及其对肿瘤血管生成的影响。方法：MTT法检测不同浓度靶向毒素DTATEGF对体外培养的人NSCLC脑转移瘤PC9-BrM3细胞增殖的影响，流式细胞仪分析DTATEGF作用于PC9-BrM3细胞系48 h后细胞凋亡和细胞周期变化。12只皮下种植肿瘤的祼小鼠分为2组：瘤床内分别注入DTATEGF或对照液2μg，隔天一次，共5次，测量肿瘤体积及其微血管密度(MVD)。结果：DTATEGF明显抑制PC9-BrM3细胞的体外增殖，呈剂量依赖关系，其诱导PC9-BrM3细胞凋亡，1 pmol/L的DTATEGF作用PC9-BrM3细胞48 h后细胞凋亡率为(64.0±0.5)%，对照组为(1.5±0.4)%，差异有统计学意义(P<0.01)；细胞周期检测显示：DTATEGF处理组SubG0/G1期和S期细胞别为(32.0±1.5)%和(2.0±0.4)%，而空白对照组分别为(5.0±0.6)%和(11.4±0.8)%，差异均有统计学意义(P<0.01)。动物实验显示DTATEGF处理组肿瘤体积较对照组生长缓慢，且DTATEGF处理组MVD为(15.6±4.6)/mm2，而空白对照组为(31.2±5.4)/mm2，差异均有统计学意义(P<0.05)。结论：DTATEGF抑制PC9-BrM3增殖、诱导细胞凋亡，明显抑制祼小鼠皮下种植的人NSCLC脑转移瘤细胞的生长及其新生血管的形成。