17-AAG对转染NIS基因的未分化甲状腺癌摄碘动力学的影响

摘要

Objective To investigate the effect of 17-allylamino-17-demethoxy geldanamycin ( 17-AAG) on iodine uptake kinetics of NIS-transfected anaplastic thyroid cancer (ATC) cells.Methods Lipofection was used to transfect the recombinant plasmid,namely peDNA3.1-NIS,into FRO cells ( ATC cell line).A stable cell line NIS-FRO was obtained by G418 resistance selection.125I was added into the medium,and influx and efflux experiments were performed.Different time-radioactivity curves were drawn,and further analysis was performed between the non-transfected cells( the control group) and NIS-FRO cells treated with 1 μmol/L 17-AAG for 24 h.Student's t-test was used to analyze the data.Results The iodine uptake ability of the NIS-FRO cells was significantly higher than that of the FRO cells (about 10.68 times,t =45.329,P ＜0.001 ).However,125I out-flowed rapidly when removed from the medium,and the retention rate of 125I in the NIS-FRO cells was only 10.5％ of the initial amount after 30 rin.After treatment with 1 μmol/L 17-AAG for 24 h,the 125I uptake ability of NIS-FRO cells further increased.During the 20-60 min incubation with 125I,the iodine uptake ability of 17-AAG treated NIS-FRO cells increased significantly with radioactive counts of 31771.8- 54815.5 per minute,which was much higher than that of the control group ( 24020.3 - 41293.8 per minute ; t =3.096,4.275,3.055,4.292 and 5.496,respectively,all P ＜ 0.05 ).The iodine uptake ability increased about 24.8％-35.5％.Furthermore,5-30 min after removing the medium,the retention rates of 125I in the 17-AAG treated NIS-FRO cells were significantly increased compared with those of the control group (32.7％- 85.2％ vs 10.5％- 56.8％ ; t =22.801,13.096,19.631,38.205,43.519,29.322,respectively,all P ＜0.01 ),and 125I efflux was reduced.After 30 min,125I retention rate of the treatment group was 32.7％,which was 3.1 times higher than that of the control group.Conclusion The iodine uptake ability can be enhanced in stable NIS-transfected ATC cells after treatment with 17-AAG,and iodine efflux can be significantly delayed.%目的 探讨17-丙烯胺基-17-去甲氧基格尔德霉素(17-AAG)对已转染NIS基因的未分化甲状腺癌(ATC)细胞摄碘动力学的影响.方法 采用脂质体转染法,将携带NIS基因的重组质粒pcDNA3.1-NIS转染入ATC细胞株FRO细胞中,G418抗性筛选获得稳定表达细胞系NIS-FRO.在NIS-FRO细胞的培养基中引入125I,进行125I内流及外流的系列实验,绘制时间-放射性曲线.进一步分析经1μmol/L的17-AAG作用24 h后NIS-FRO细胞125I内流及外流的变化,并与未经转染的细胞进行对比,2组间各个时间点的放射性计数采用两样本t检验进行统计学分析.结果 NIS-FRO细胞的摄125I能力明显提高,约为FRO细胞的10.68倍(t=45.329,P＜0.001),但去除孵育环境中的125I后30 min,细胞内的125I滞留率仅为初始的10.5％.1μmol/L的17-AAG作用于NIS-FRO细胞后24h,细胞摄125I能力进一步提高,在含125I的培养基中孵育20～60 min,其放射性计数为31771.8～54815.5 min-1,摄125I能力较对照组( 24020.3～41293.8)提高了24.8％～ 35.5％(t值依次为3.096、4.275、3.055、4.292和5.496,P均＜0.05);撤掉孵育环境中的131I后5～30 min,细胞内的125I滞留率为32.7％ ～85.2％,较对照组(10.5％～56.8％)明显增加(t值依次为22.801、13.096、19.631、38.205、43.519和29.322,P均＜0.01),125I的外流减少,30 min后17-AAG作用组的细胞内125I滞留率为32.7％,为对照组的3.1倍.结论 把NIS转染入ATC细胞后获得的稳定表达细胞株在经一定浓度的17-AAG作用后,可进一步提高肿瘤细胞的摄碘率,并可明显延迟碘的外流,提高细胞内碘的滞留率.