摘要
目的研发含天冬氨酸一谷氨酸-缬氨酸一天冬氨酸（DEVD）核心的正电子核素标记的easpase一3多肽活性显像剂，以在体检测肿瘤细胞凋亡。方法用国产合成模块通过点击化学合成（18S，21S，24S，27S，30S）-27一（2一羧乙基）-21一（羧甲基）一30一（（2S，3R，4R，5R，6S）-6一（（2-（4一（3一[”F]氟戊基）．1H-1，2，3三唑．1．y1）乙酰氨基）甲基）-3，4，5-三羟基四氢-2H-吡喃一2一羧酰氨）-24一异丙基-18·甲基一17，20，23，26，29一五羰基4，7，10，13一四氧一16，19，22，25，28一五氨杂三十烷一1，32一二酸（“F—FP—peptide）。在体外”F—FP．peptide与经卡铂化疗的A549肺癌细胞混合60rain后，检测细胞放射性摄取率，摄取率=（放射性活度平均值X10X100％）／（细胞计数×细胞体积×放射性对照值）。将”F—FP—peptide注射到经卡铂化疗的荷A549肿瘤小鼠体内，60rain后测其生物学分布，并行microPET／cT显像。应用流式细胞仪检测细胞凋亡率，评价”F—FP—peptide放射性摄取率与细胞凋亡率的相关性。数据处理使用SPSS13．0统计软件，计量资料采用牙±s表示，组间比较采用单因素方差分析，相关性研究采用线性相关与回归分析。结果”F—FP—peptide的合成效率为（21．0±4．5）％（n=6，不校正），放化纯为99％，比活度为870GBq／txmol。体外细胞实验研究表明，各组细胞凋亡率随卡铂化疗时间延长逐渐升高，经卡铂处理后0、1、2和24h后细胞凋亡率分别为（1．02±0．31）％、（4．85±1．26）％、（6．37±2．21）％和（10．23±2．43）％，对应的细胞摄取率分别为（0．06±0．01）％、（0．31±0．04）％、（0．44±0．02）％和（0．86±0．04）％，各组细胞凋亡率与放射性摄取率之间呈明显正相关（y=1．1244＋11．0949x，r=0．9850，P〈0．01）；荷A549肿瘤卡铂化疗后24h，肿瘤组织放射性摄取率为（0．33±0．02）％ID／g，明显高于未化疗肿瘤组织的（0．08±0．01）％ID／g（F=31．25，P〈0．01）；而两者的细胞凋亡率分别为（15．50±1．47）％和（1．92±0．31）％，差异有统计学意义（F：33．54，P〈0．01）；荷A549肿瘤化疗后细胞凋亡率和肿瘤对”F—FP—peptide的放射性摄取率呈明显正相关（y=一1．9055＋54．4341x，r=0．9907，P〈0．01）；MicroPET显像示，未经化疗的肿瘤基本无放射性摄取，SUV…与对侧比值为1．32±0．01，而经卡铂化疗的肿瘤明显摄取显像剂，SUV。。与对侧比值为3．46±0．02，两者比较差异有统计学意义（F=11．05，P〈0．01）。结论”F—FP—peptide是有临床潜在价值的caspase-3活性显像剂。
Objective To investigate the feasibility of a PET radionuclide, caspase-3-activatable probe containing Asp-Glu-Val-Asp （DEVD）, for imaging evaluation of tumor apoptosis in vivo. Methods（ 18 S, 21 S, 24 S, 27 S, 30 S ） -27- （ 2 -carboxyethyl ） -21 - （ carboxymethyl ） -30 - （ （ 2 S, 3 R, 4 R, 5 R, 6 S ） -6 - （ （ 2 - （ 4 - （ 3- [18 F ] fluoropropyl ） - 1 H- 1,2,3-triazol- 1 -yl ） acetamido ） methyl ） -3,4,5 -trihydroxytetrahydro-2H-py- ran-2 - carboxamido ） -24 -isopropyl- 18 -methyl- 17,20,23,26,29 -pentaoxo-4,7,1 O, 13 -tetraoxa- 16,19,22,25, 28-pentaazadotriacontane-1,32-dioic acid （lSF-FP-peptide） was automatically synthesized using a domestie synthesis module by ＂click chemistry＂. In vitro cellular uptake of ISF-FP-peptide was evaluated by mixing the peptide with lung adenocarcinoma A549 cells after chemotherapy by earboplatin. Apopto^is was monitored by flow cytometry. The correlation between cellular uptake and the apoptotic ratio was analyzed. In vivo bio- distribution and micro PET imaging were performed on A549 tumor bearing mice with or without chemothera- py. SPSS 13.0 was used for statistical analysis. Comparison among groups was conducted by one-way analy- sis of variance, and correlation was analyzed by linear correlation and regression. Results The yield of ~s F-FP-peptide was （21.0 ＋ 4.5 ） % （ n = 6, end of synthesis （EOS） ）. The radioehemistry purity was over 99% and the specific activity was 870 GBq/p^nol. After the in vitro treatment of A549 cells, the apoptotie ratio was （1.02 ＋0.31）%, （4.85 ~ 1.26）%, （6.37 ＋2.21）% and （10.23 ＋2.43）% at 0, 1, 2 and 24 h, respectively. The corresponding cellular uptake of lSF-FP-peptide was （0. 06 -＋0. 01 ）%, （0. 31 ＋ 0. 04）%, （0.44 ＋0. 02）% and （0.86 ~0.04）%. Significant positive correlation was found between the apoptosis ratio and cellular uptake of is F-FP-peptide （y = 1. 1244 ＋ 11. 0949x, r = 0. 9850, P 〈 0. 01 ）. The tumor uptake of A549 bearing mice at 24 h after chemotherapy was （0.33 ＋0.02） %ID/g, which was signifi- cantly higher than that of the control （ （0. 08 ~0.01 ） % ID/g, F = 31.25, P 〈 0.01 ）. The cell apoptotic rati- os were （ 15.50 ~ 1.47） % for tumors undergoing chemotherapy and （ 1.92 ＋0.31 ） % for the control group （ F = 33.54, P 〈 0.01 ）. Significant positive correlation was also found between the apoptotic ratio and the tumor uptake of 18 F-FP-peptide in vivo （y = - 1. 9055 ＋ 54. 4341x, r = 0. 9907, P 〈 0.01 ）. Micro PET ima- ges displayed that there was almost no uptake in the untreated tumor （ SUV ratio = 1.32 ：e0. 01 ） but signifi- cantly increased uptake of 18 F-FP-peptide in the treated tumor （ SUV ratio = 3.46 ~ 0. 02, F = 11.05, P 〈 0. O1 ）. Conclusion lSF-FP-oeptide can be a potential radiotracer for caspase-3 imaging in tissue apoptosis.
出处
《中华核医学与分子影像杂志》
CSCD
北大核心
2012年第2期84-89,共6页
Chinese Journal of Nuclear Medicine and Molecular Imaging
基金
国家自然科学基金（81071170,81771400）
北京市自然科学基金（7122162）
