CAJ | 학술논문

目的探讨西妥昔单抗(C225)对125Ⅰ粒子照射下结直肠癌CL187细胞DNA损伤修复和信号传导通路的影响.方法实验分为空白对照组,100 nmol/L C225处理组,单独125Ⅰ粒子持续低剂量率照射组和C225联合125Ⅰ粒子持续低剂量率照射组.在吸收剂量达4 Gy后48 h,经细胞免疫荧光检测各组细胞中γH2AX聚集点数量以及γH2AX聚集点阳性细胞比例.提取细胞内总蛋白,Western blot检测DNA修复蛋白的变化.在吸收剂量达4 Gy后即刻提取总蛋白,Western blot分析在照射过程中C225对EGFR下游信号通路中蛋白分子的影响.结果与单独125Ⅰ粒子持续低剂量率照射组细胞相比,C225联合125Ⅰ持续低剂量率照射组细胞内残余的γH2AX聚集点数量和γH2AX聚集点阳性的细胞比例均高(t=8.0和6.8,P＜0.05),并且细胞中DNA修复蛋白Ku70和DNA-PKcs的含量偏低(t=6.6和5.7,P＜0.05).Western blot结果显示,在125Ⅰ粒子持续低剂量率照射过程中,C225能够降低细胞内EGFR的水平(t=4.9,P＜0.05),抑制Akt的活化(t=5.5,P＜0.05).结论在125Ⅰ放射性粒子持续低剂量率照射下,C225可以降低细胞内Ku70和DNA-PKcs的含量,并抑制Akt活化,减弱CL187细胞的DNA损伤修复能力.
목적 탐토서타석단항(C225)대125Ⅰ입자조사하결직장암CL187세포DNA손상수복화신호전도통로적영향.방법 실험분위공백대조조,100 nmol/L C225처리조,단독125Ⅰ입자지속저제량솔조사조화C225연합125Ⅰ입자지속저제량솔조사조.재흡수제량체4 Gy후48 h,경세포면역형광검측각조세포중γH2AX취집점수량이급γH2AX취집점양성세포비례.제취세포내총단백,Western blot검측DNA수복단백적변화.재흡수제량체4 Gy후즉각제취총단백,Western blot분석재조사과정중C225대EGFR하유신호통로중단백분자적영향.결과 여단독125Ⅰ입자지속저제량솔조사조세포상비,C225연합125Ⅰ지속저제량솔조사조세포내잔여적γH2AX취집점수량화γH2AX취집점양성적세포비례균고(t=8.0화6.8,P＜0.05),병차세포중DNA수복단백Ku70화DNA-PKcs적함량편저(t=6.6화5.7,P＜0.05).Western blot결과현시,재125Ⅰ입자지속저제량솔조사과정중,C225능구강저세포내EGFR적수평(t=4.9,P＜0.05),억제Akt적활화(t=5.5,P＜0.05).결론 재125Ⅰ방사성입자지속저제량솔조사하,C225가이강저세포내Ku70화DNA-PKcs적함량,병억제Akt활화,감약CL187세포적DNA손상수복능력.
Objective To investigate the effect of C225 on DNA repair and molecular pathways in CL187 colorectal cancer cells after irradiated by 125Ⅰ radioactive seeds.Methods In the experiment involved were four groups:control group,100 nmol/L C225 treatment group,125Ⅰ radioactive seeds continuous low-dose rate irradiation group and C225 combined with 125Ⅰ radioactive seeds continuous lowdose rate irradiation group.Cells were collected at 48 h after 4 Gy irradiation,and γH2AX foci/cell and γH2AX foci positive cells were counted with immunofluorescence.At the same time,DNA repair proteins were detected by Western blot.Cells were lyzed immediately after 4 Gy irradiation,and changs in EGFR downstream signaling molecules were detected by Western blot.Results Compared with 125Ⅰ seeds irradiated cells,cells treated with C225 and 125Ⅰ seeds irradiation showed more γH2AX foci per cell (t =8.0,P =0.05),and more γH2AX foci positive cells (t =6.8,P ＜ 0.05) and less expression of Ku70 (t =6.6,P ＜ 0.05) and DNA-PKcs (t =5.6,P ＜ 0.05).Combined with 125Ⅰ-CLDR irradiation,C225 reduced cellular EGFR level(t =4.9,P ＜0.05) and inhibited the activation of Akt(t =5.5,P ＜0.05).Conclusions In the condition of 125Ⅰ seeds irradiation,C225 reduced the expression of Ku70 and DNA-PKcs,inhibited the activation of Akt and attenuated the DNA damage repair capacity in CL187 colorectal cancer cells.