^99Tc^m—survivin mRNA反义肽核酸基因显像在肿瘤与炎性反应模型中的对比研究

目的研究^99Tc^m-survivin mRNA反义肽核酸（PNA）显像在肿瘤特异性诊断中的价值。方法用^99Tc^m标记人工合成的12碱基单链survivin mRNA反义PNA。20只荷瘤（A549）裸鼠按随机数字表法分为4组，每组5只。每只裸鼠经尾静脉注入^99Tc^m-survivin mRNA反义PNA，3组进行体内分布研究，其余进行显像研究。用同样方法对20只炎性反应（金黄色葡萄球菌）小鼠进行分组、体内分布和显像研究。采用SPSS13．0软件进行统计学分析，组间计量资料比较采用t检验。结果^99Tc^m-survivin mRNA反义PNA在肝内分布最高，其次是肾，注射后4h肿瘤组靶／非靶（T／NT）比值明显高于炎性反应组，分别为3．69±1．13，2．03±0．47，差异有统计学意义（t=3．01，P=0．02）。肿瘤组在注射药物后0．5h即可见肿瘤清晰显影，至4h时显影仍较清晰，而炎性反应部位始终未见明显显影。结论^99Tc^m-survivin mRNA反义PNA基因显像可通过其在肿瘤组织中的特异性浓聚区分肿瘤与炎性反应，为肿瘤的特异性诊断提供了一种可能的新方法。

Comparative study on imaging of 99 Tcm-survivin mRNA antisense peptide nucleic acid in tumor and inflammation animal models

Objective To investigate the value of 99Tcm labeled survivin mRNA antisense peptide nucleic acid (PNA) as an imaging agent in the specific diagnosis for carcinoma.Methods Survivin mRNA antisense PNA was labeled directly with 99Tcm by the ligand-exchange method.Twenty nude mice with lung carcinoma A549 xenografts were randomly divided into 4 groups.Three groups were used for biodistribution study and one group was used for imaging study.Other twenty mice infected by staphylococcus aureus underwent the same procedure.The biodistribution and imaging of 99Tcm-survivin mRNA antisense PNA was studied at 1,2 and 4 h respectively after the intravenous injection in nude mice bearing lung carcinoma A549 xenografts or inflammation models.SPSS 13.0 was used in the study and all data were analyzed by t test.Results Biodistribution results showed that the highest radioactivity was found in the liver,and then in the kidney.Four hours after the administration of the imaging agent,the radioactivity ratios of target-tonon target (T/NT,tumor or inflamumatory lesions to the contralateral regions) in tumor model group were significantly higher than those in inflammation model group ( 3.69 ± 1.13 vs 2.03 ± 0.47,t =3.01,P =0.02 ).Tumors were clearly visible in the tumor model groups at 0.5 h and still clearly seen at 4 h after the injection of antisense PNA.On the contrary,inflammatory lesions could not be seen clearly.Conclusion 99Tcm labeled survivin mRNA antisense PNA can be used to distinguish tumor from inflammation and it may provide a new feasible method for specific tumor diagnosis.