^(125)I标记重组全人源抗表皮生长因子受体单克隆抗体的制备及其在荷瘤裸鼠体内的分布

Preparation of^(125)I labeled recombinant human complete monoclonal antibody against epidermal growth factor receptor and its distribution in tumor-bearing nude mice

目的研究;^(125)I标记重组全人源抗表皮生长因子受体(EGFR)单克隆抗体在荷瘤裸鼠体内的生物分布。方法以Iodogen法进行重组全人源抗EGFR单克隆抗体的;^(125)I标记,分离纯化。组织分布实验:荷瘤裸鼠静脉注射^(125)I-重组全人源抗EGFR单克隆抗体24 mg·kg^(-1),分别在药后4,24,72,168 h(每个时间点各5只鼠)于股动脉放血活杀,取主要脏器及体液称重并测量其放射性计数。粪尿排泄实验:6只荷瘤裸鼠静脉注射^(125)I-重组全人源抗EGFR单克隆抗体24 mg·kg^(-1),在给药后0~24,24~48……264~312 h时间段分别收集尿和粪,并测量其放射性计数。胆汁排泄实验:6只SD大鼠给予^(125)I-重组全人源抗EGFR单克隆抗体12 mg·kg^(-1),给药后于1,3,5,8,12 h收集一次胆汁测量其放射性计数。放射免疫显像实验:2只荷瘤裸鼠静脉注射^(125)I-重组全人源抗EGFR单克隆抗体0.5 mci,分别在4,24,72,168 h用单光子发射计算机断层成像术(SPECT)进行放射免疫显像。结果血中暴露水平为3681μg·h·mL^(-1)(最高),血流灌注丰富的组织器官的放射性较高,并且药物在肿瘤部位有明显蓄积,达到了2168μg·h·g^(-1)。312 h尿、粪分别排出注入放射性量的(70.08±6.15)%和(6.03±0.54)%,药物主要经尿排泄。注射后12 h的累积排泄率为(0.34±0.07)%。胆汁中未发现药物原形和放射性小分子代谢产物。各组织放射性浓度逐渐下降,而肿瘤部位的放射性浓度则逐渐增加。结论^(125)I-重组全人源抗EGFR单克隆抗体在荷瘤裸鼠体内具有肿瘤靶向定位能力,主要通过肾代谢。

Objective To study the biological distribution of^(125)I labeled recombinant human complete monoclonal antibody against epidermal growth factor receptor(EGFR)in nude mice bearing tumor.Methods^(125)I labeling of recombinant human complete monoclonal antibody against EGFR was carried out by Iodogen method,and it was purified.Tissue distribution test:Nude mice bearing tumor were intravenously injected with^(125)I recombinant human anti EGFR monoclonal antibody(24 mg·kg^(-1)),which was killed by femoral artery bloodletting at 4,24,72,168 h after treatment(with 5 mice at each time),and the main organs and body fluids were weighed and their radioactive counts were measured.Feces and urine excretion test:Six tumor-bearing nude mice were injected with 24 mg·kg^(-1)intravenously,and their urine and feces were collected at 0-24,24-48,...,264-312 h after administration,respectively.Bile excretion test:Six SD rats were given a dose of 12 mg·kg^(-1),and the radioactivity of bile was measured in 1,3,5,8 and 12 h after administration.Radioimmunoimaging:Two tumor bearing nude mice were immunized with^(125)I recombinant human anti EGFR monoclonal antibody(0.5 mci each).Single photon emission computed tomography(SPECT)was used for radioimmunoimaging at 4,24,72,168 h,respectively.Results The results of tissue distribution showed that the exposure level in blood was the highest(3681μg·h·g^(-1)).The radioactivity in the tissues and organs with abundant blood perfusion was higher,and there was obvious accumulation in the tumor site,reaching 2168μg·h·g^(-1).The results of fecal and urine excretion showed that(70.08±6.15)%and(6.03±0.54)%of the injected radioactivity were discharged from the urine and feces at 312 h.The drug is mainly excreted in urine.The results of bile excretion showed that the cumulative excretion rate was(0.34%±0.07)%at 12 h after injection.No drug prototype or radioactive small molecule metabolites were found in bile.The radioactivity concentration of each tissue decreased gradually,but the radioactivity concentration of tumor site increased gradually.Conclusion^(125)I-recombinant human complete monoclonal antibody against EGFR has the ability of tumor targeting in nude mice,mainly through renal metabolism.