摘要
目的研究腺病毒5型早期区1A(E1A)基因对人肝癌细胞的放射增敏作用及其机制。方法利用多聚乙烯亚胺(PEI)载体将E1A基因转染进人肝癌细胞(7721系)中。7721细胞、转染空载体的细胞(7721-vect)及转染EIA基因的细胞(7721-E1A)分别接受0、2、4、6和8 Gy的6 MV-X线照射,用MTT法检测细胞存活率,观察EIA基因对7721细胞放射敏感性的影响;采用流式细胞术检测E1A基因对细胞凋亡以及细胞周期分布的影响;采用免疫组化染色(SP)法检测E1A基因对人表皮生长因子受体2(Her-2)及核因子κB(NF-κB)表达的影响。结果照射后,7721-E1A细胞存活率明显低于7721细胞[至8 Gy时,(7.91±4.44)%vs.(32.50±9.41)%)](P<0.01)。7721-E1A的凋亡率明显高于7721细胞[至8 Gy时,(88.38±15.06)%vs.(42.67±9.49)%](P<0.01)。7721-E1A的细胞周期中S期显著低于7721细胞[(25.16±7.45)%vs.(40.88±11.44)%](P<0.05),而G2期明显高于7721细胞[(40.69±6.74)%vs.(15.63±5.02)%](P<0.01)。转染EIA基因后能抑制Her-2及NF-κB的表达。结论 EIA基因能够明显提高人肝癌细胞在体外对放射线的敏感性。其作用机制可能与E1A抑制Her-2及NF-κB的表达,促进凋亡并导致S期抑制、G2期阻滞有关。
Objective To investigate the effects of E1A gene on radiosensitivity of human hepatic carcinoma cell in vitro and its mechanism.Methods Human hepatic carcinoma cell（7721 cell line） was transfected with E1A gene by PEI vector.The untransfected cells（7721 group）,the cells transfected with blank-vector（7721-vect or group） and transfected with E1A gene（7721-E1A group） were treated with 6 MV X-ray irradiation at the doses of 0,2,4,6,8 Gy,respectively.Radiosensitivity was determined by MTT assay and quantified by calculating the cell survival rate.Cell-cycle distribution and apotosis rate were monitored by flow cytometry.The expressions of Her-2 and neuclear factor（NF）-κB were detected by immunohistochemistry stainning.Results The survival rate of 7721-E1A was significantly lower than that of 7721 cell [（7.91±4.44）% vs.（32.50±9.41）%） at 8 Gy]（P0.01）.Apoptosis rate of 7721-E1A group was significantly higher than that of 7721 group [（88.38±15.06）% vs.（42.67±9.49）% at 8 Gy]（P0.01）.The ratio of S stage in cell cycle of 7721-E1A was significantly lower than that in 7721 cell [（25.16±7.45）% vs.（40.88±11.44）%]（P0.05）.The ratio of G2 stage in cell cycle of 7721-E1A was significantly higher than that in 7721 cell [（40.69±6.74）% vs.（15.63±5.02）%]（P0.01）.E1A gene obviously down-regulated the expressions of Her-2 and NF-κB.Conclusion E1A gene can effectively enhance radiosensitivity of human hepatic carcinoma cells,which may be related to suppressing the expressions of Her-2 and NF-κB,promoting the apoptosis and suppressing S stage and G2 stage.
出处
《江苏医药》
CAS
CSCD
北大核心
2010年第23期2788-2791,F0002,共5页
Jiangsu Medical Journal
基金
江苏省自然科学基金(BK2007245)
