Abstract:

Abstract: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.

Key words: Egr-1, truncated apoptosis inducing factor, cell proliferation, invasion, ionizing radiation