Background We previously reported that iodine-131（131^I）-Iabeled anti-pro-gastrin-releasing peptide （ProGRP（31-98）） monoclonal antibody D-D3 could selectively accumulate in the tumor sites of nude mice bearing s...Background We previously reported that iodine-131（131^I）-Iabeled anti-pro-gastrin-releasing peptide （ProGRP（31-98）） monoclonal antibody D-D3 could selectively accumulate in the tumor sites of nude mice bearing small cell lung cancer （SCLC） xenografts. However, 1311-D-D3 was cleared slowly from the body, and the best radioimmunoimaging time for SCLC was 72-96 hours after injection. The aims of this study were to radiolabel anti-ProGRP（31-98） D-D3 monoclonal antibody with technetium-99m（99m^Tc） and to investigate the biodistribution of this antibody in healthy ICR mice. Methods D-D3was labeled with 99m^Tc via the 2-mercaptoethanol reduction method. 99m^Tc-D-g3 was purified by the gel column separation method. The labeling efficiency and radiochemical purity were measured by thin-layer chromatography. The immunological activity of 99m^Tc-D-O3 was determined with cell conjugation assays. 99m^Tc-D-D3 was injected into healthy ICR mice via a tail vein, and all the healthy ICR mice were sacrificed by cervical dislocation at a designated time. Then, the blood and major organs were removed and weighed, and counted in a gamma scintillation counter to determine the percentage of the injected dose per gram （%ID/g）. Results The labeling rate and the radiochemical purity of 99m^TC-D-D3 were （73.87±2.89）% and （94.13±4.49）%, respectively. The immunobinding rates of 99m^Tc-O-D3 to the human small cell lung cancer NCI-H446 cell line and lung adenocarcinoma A549 cell line were （81.2±2.37）% and （24.3±1.46）%, respectively. The distribution data of normal ICR mice demonstrated that 99m^TC-D-D3was mainly distributed in the liver, kidney and lung, and less in the brain tissue and muscle. Conclusions 99m^Tc-D-D3 antibody not only had high radiochemical purity, but also had good stability both in vitro and in vivo, and maintained good immunological activity. 99m^Tc-D-D3 was metabolized mainly in the kidney and liver, and the blood radioactivity decreased rapidly. Thus, 99m^Tc-O-D3 is conducive to the radioimmunoimaging of SCLC.展开更多
文摘Background We previously reported that iodine-131（131^I）-Iabeled anti-pro-gastrin-releasing peptide （ProGRP（31-98）） monoclonal antibody D-D3 could selectively accumulate in the tumor sites of nude mice bearing small cell lung cancer （SCLC） xenografts. However, 1311-D-D3 was cleared slowly from the body, and the best radioimmunoimaging time for SCLC was 72-96 hours after injection. The aims of this study were to radiolabel anti-ProGRP（31-98） D-D3 monoclonal antibody with technetium-99m（99m^Tc） and to investigate the biodistribution of this antibody in healthy ICR mice. Methods D-D3was labeled with 99m^Tc via the 2-mercaptoethanol reduction method. 99m^Tc-D-g3 was purified by the gel column separation method. The labeling efficiency and radiochemical purity were measured by thin-layer chromatography. The immunological activity of 99m^Tc-D-O3 was determined with cell conjugation assays. 99m^Tc-D-D3 was injected into healthy ICR mice via a tail vein, and all the healthy ICR mice were sacrificed by cervical dislocation at a designated time. Then, the blood and major organs were removed and weighed, and counted in a gamma scintillation counter to determine the percentage of the injected dose per gram （%ID/g）. Results The labeling rate and the radiochemical purity of 99m^TC-D-D3 were （73.87±2.89）% and （94.13±4.49）%, respectively. The immunobinding rates of 99m^Tc-O-D3 to the human small cell lung cancer NCI-H446 cell line and lung adenocarcinoma A549 cell line were （81.2±2.37）% and （24.3±1.46）%, respectively. The distribution data of normal ICR mice demonstrated that 99m^TC-D-D3was mainly distributed in the liver, kidney and lung, and less in the brain tissue and muscle. Conclusions 99m^Tc-D-D3 antibody not only had high radiochemical purity, but also had good stability both in vitro and in vivo, and maintained good immunological activity. 99m^Tc-D-D3 was metabolized mainly in the kidney and liver, and the blood radioactivity decreased rapidly. Thus, 99m^Tc-O-D3 is conducive to the radioimmunoimaging of SCLC.
