摘要
目的 获取人钠 /碘同向转运体 (hNIS)基因cDNA ,研究其转导黑色素瘤细胞在体外和体内能否介导放射性碘摄取 ,从而探索该策略用于黑色素瘤放射性碘治疗的可能性。方法 运用逆转录聚合酶链反应从人甲状腺组织总RNA中扩增出hNIS基因cDNA ,将其克隆至真核载体pc DNA3 中 ,电转化法分别将重组质粒pc DNA3 hNIS及空质粒pc DNA3 转导黑色素瘤细胞 (B16 ) ,分别建立了细胞系B16 A和B16 B。在体外培养条件下检测其对放射性碘的摄取及外流情况 ,继而将三种细胞系接种C5 7小鼠行13 1I显像和肿瘤摄取12 5I动态定量测定。结果 成功克隆到hNIS基因 ,并建立了能稳定表达hNIS的新型细胞系B16 A。B16 A细胞的摄碘能力较B16细胞高 17倍 ,较B16 B细胞高 19倍。碘的外流过程迅速 ,T1/ 2eff仅 10min。体内实验发现B16 A细胞所形成肿瘤能摄取放射性碘 ,腹腔注射12 5I后 1、2、4、12、2 4h肿瘤组织的 %ID/ g平均为 12 .2 2、10 .91、8.73、1.2 4、0 .19,12 5I在肿瘤组织内的生物半衰期约为 6h。B16 A细胞系所成肿瘤摄碘量与对照组相比较 ,P <0 .0 1,差别具有高度统计意义。结论 hNIS基因转导黑色素瘤细胞足以介导放射性碘摄取 ,但有效半衰期较短 ,难以产生足够的治疗剂量 ,有必要进一步研究如何增加放射性碘的摄取?
Objective To obtain human sodium/iodide symporter cDNA and explore it's potential utility as a radio-iodide treatment for melanoma. Methods hNIS gene cDNA was amplified with total RNA from human thyroid tissue by RT-PCR. The hNIS cDNA was cloned into eukaryotic expression vector pc-DNA_ 3 . pc-DNA_ 3 -hNIS and pc-DNA_ 3 were transduced into melanoma cells (B16) by electroporation,and two cell lines named B16-A and B16-B respectively were established. The uptake and efflux of iodide was examined in vitro. The three cell lines (B16-A,B16-B,B16) were injected subcutaneously into the right flank of C57 mice. Biodistribution study and tumor imaging were performed when the tumor reached approximately 10mm in diameter. Results The cloned hNIS cDNA sequence is identical to the published sequence. The resultant cell line B16-A accumulated 17 and 19 times more radio-iodide in vitro than B16 and B16-B respectively. The efflux of iodide was also rapid (T_ 1/2eff =10min). The imaging showed the in vivo uptake of radio-iodide in hNIS-transduced tumor,whereas the nontransduced tumor was not visualized. The average % ID/g of B16-A tumors at 1,2,4,12 and 24 h after injection of 125 I were 12.22,10.91,8.73,1.24,and 0.19 respectively,which were significantly higher percentages than those for controlling tumors,P <0.01. However,biologic T_ 1/2 was about 6 hours. Conclusion The preliminary data indicate that the transduction of the hNIS gene is sufficient to induce iodide transport in melanoma cells both in vitro and in vivo,but T_ 1/2eff is short. With regard to therapeutic application,however, further investigation is necessary to determine a method of maintaining more radio-iodide in the fumor cells long enough to produce greater therapeutic effects.
出处
《肿瘤》
CAS
CSCD
北大核心
2004年第2期124-127,共4页
Tumor
关键词
hNIS基因
黑色素瘤
放射性碘
逆转录聚合酶链反应
细胞培养
基因转导
Human sodium/iodide symporter
cDNA cloning
Gene transduction
Tumor cells,cultured
Melanoma cells B16
Iodide-125
Radioactive nuclide
