17-AAG对转染NIS基因的未分化甲状腺癌摄碘动力学的影响

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.

The effect of 17-AAG on iodine uptake kinetics of NIS-transfected anaplastic thyroid cancer cells

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 transfeet 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 a- nalysis 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 a- bility 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 min. 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 incuba- tion with 125I, the iodine uptake ability of 17-AAG treated MS-FRO cells increased significantly with radio- active 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 〈 O. 05）. The iodine uptake ability increased about 24.8%-35.5%. Furthermore, 5- 30 min after removing the medi- um, 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 rain, 125I re-tention 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.