电离辐射对转染pcDNA3.1-Egr-1-AIF△1-480质粒的MCF-7细胞增殖和侵袭能力的影响

摘要

Objective To investigate the influence of truncated apoptosis inducing factor (AIFΔ1-480 ) on the proliferation and invasion of MCF-7 cells,and to clarify the possibility of promoting cancer gene-radiotherapy. Methods The human breast cancer MCF-7 cells were transfected with AIFΔ1-480 recombinant expression vector pcDNA3.1-Egr-1-AIFΔ1-480 (pE-AIFΔ1-480 )mediated by Egr-1;24 h after 2 Gy X-ray irradiation,MTT assay and Transwell invasion assay were performed to measure the changes of cell proliferation and invasion.The MCF-7 cells were diveded into normal control,pcDNA3.1,pE-AIFΔ1-480 ,2 Gy irradiation and pE-AIFΔ1-480+ 2 Gy irradiation groups.Results After transfection and 2 Gy X-ray irradiation,the cells proliferated very fast in normal control, pcDNA3.1 and pE-AIFΔ1-480 groups, and the proliferation regularity was similar. Compared with normal control group,the cell proliferation abilities were significantly decreased in 2 Gy irradiation and pE-AIFΔ1-480 + 2 Gy irradiation groups (P<0.05 ), and it was more obvious in pE-AIFΔ1-480 + 2 Gy irradiation group, and it was significant lower than that in 2 Gy irradiation group (P<0.05).The number of the cells permeating membrane was basically same in normal control,pcDNA3.1 and pE-AIFΔ1-480 groups;compared with normal control group,they were significantly decreased in 2 Gy irradiation and pE-AIFΔ1-480+ 2 Gy irradiation groups(P<0.05 or P<0.01);and it was more significant in pE-AIFΔ1-480+ 2 Gy irradiation group than that in 2 Gy irradiation group (P<0.01). Conclusion AIFΔ1-480 and ionizing radiation could inhibit the proliferation and invasion of human breast cancer MCF-7 cells,both of them have a synergistic effect,and Egr-1 promoter can enhance the suppression effect under radiation conditions.%目的：探讨辐射增强靶向截短型凋亡诱导因子（AIFΔ1-480）对 MCF-7细胞增殖和侵袭能力的影响，阐明其提高肿瘤基因-放射治疗的可能性。方法：人乳腺癌 MCF-7细胞经质粒转染早期生长反应1（Egr-1）介导的AIFΔ1-480重组表达载体 pcDNA3.1-Egr-1-AIFΔ1-480（pE-AIFΔ1-480），2 Gy X射线照射后24 h，分别采用 MTT法和Transwell侵袭实验检测细胞增殖和侵袭能力。实验分为正常对照组、pcDNA3.1组（只转染 pcDNA3.1质粒）、pE-AIFΔ1-480组（转染 pE-AIFΔ1-480质粒）、2 Gy X线照射组和 pE-AIFΔ1-480＋2 Gy X线照射组。结果：质粒转染并经2 Gy X线照射后，正常对照组、pcDNA3.1组和 pE-AIFΔ1-480质粒组细胞生长较快，且增殖规律基本一致。与正常对照组比较，2 Gy X线照射组和 pE-AIFΔ1-480＋2 Gy X线照射组细胞增殖能力显著降低（P＜0.05），且以pE-AIFΔ1-480＋2 Gy X线照射组降低更明显，从12 h开始较2 Gy X线照射组明显降低（P＜0.05）。正常对照组、pcDNA3.1组和pE-AIFΔ1-480组穿过基底膜细胞数基本一致，而2 Gy X线照射组和 pE-AIFΔ1-480＋2 Gy 照射组穿过基底膜细胞较正常对照组明显减少（P＜0.05或P＜0.01），并且 pE-AIFΔ1-480＋2 Gy照射组穿过基底膜的细胞数较2 Gy照射组减少更明显（P＜0.01）。结论：AIFΔ1-480和电离辐射均能抑制人乳腺癌 MCF-7细胞增殖和侵袭，二者具有协同作用，并且 Egr-1启动子能增强辐射条件下的抑制效果。