ABSTRACT
Objective To establish the MCF-7 cell models of Beclin 1 over-and low-expressions,and to detect the autophagic and apoptotic changes after 4 Gy irradiation,and to explore their molecular regulation mechanisms. Methods MCF-7,MCF-7 + 4Gy,MCF-7-Beclin 1 + 4Gy and MCF-7-Belcin 1 RNAi+ 4Gy groups were set up. Molecular biology method was used to construct Beclin 1 over-expression vector pcDNA3.1-Beclin 1,and to estabilish the Beclin 1 over- and low-expression cell models.After the cells were irradiated with 4 Gy, the autopahgic cell percentages were measured by fluorescence microscope with MDC staining, the apoptotic cell percentages were measured by FCM with AnnexinⅤ-FITC and PI staining,and the expressions of Beclin1,P53, Bcl-2 and Bax proteins were measured by Western blotting method.Results Compared with MCF-7 group,the autophagic and apoptotic cell percentages in MCF-7+4 Gy,MCF-7 Beclin 1 +4 Gy and MCF-7-Beclin 1 RNAi+4 Gy groups were significantly increased (P <0.05 or P <0.001 ),especially in MCF-7 Beclin 1+4 Gy group which was significantly higher than those in MCF-7 + 4 Gy (P < 0.05);while there was significant difference in the necrotic cell percentages between various groups. After 4 Gy irradiation, compared with MCF-7 group, the expression levels of Beclin 1,P53 and Bax proteins in MCF-7 + 4 Gy and MCF-7-Beclin 1 + 4 Gy groups were increased,but the expression levels of Bcl-2 protein were decreased,especially in MCF-7-Beclin 1 + 4 Gy group. Conclusion The MCF-7 cell models of Beclin 1 over-and low-expressions are successfully established,and ionizing radiation could induce the autophagy and apoptosis of MCF-7 cells,which is more obvious in Beclin 1 over-expression MCF-7 cells.Beclin 1 can activate P53,inhibit Bcl-2 and activate Bax,which forms the regulation of autophagy and apoptosis by P53 .
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.
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Objective To assecess the role of CT in the diagnosis and the reasons of misdiagnosis of biliary duct carcinoma.Methods 23 cases with biliary duct carcinoma pathologically comfirmed were reviewed.Results 2 cases were peripheral type,10 cases were major intrahepatic biliary duct type,7 cases were extrahepatic type and 4 cases ampullar type.The masses within biliary duct were showed by CT in 16 cases.The obstruction of biliary duct was cut off abruptly in 18 cases and narrowing sharply in 5 cases.The intrahepatic biliary duct indicated mild or marked expansion,of them,17 cases were showed as vine and 6 as segmental.The extrahepatic biliary duct were dilated in 11 and gallbladder dilatation in 7.4 cases were misdiagnosed and leaked diagnosis was in one cases by CT preoperation.Conclusion CT is valuable in diagnosis of biliary duct carcinoma,but it still has some limitations.