AIM To establish a method of labeling anti hepatoma McAb (HAb18) Fab fragment modifier with 99m Tc. METHODS HAb18 Fab was modified with 2 iminotholane and labeled with 99m Tc by transchelation f...AIM To establish a method of labeling anti hepatoma McAb (HAb18) Fab fragment modifier with 99m Tc. METHODS HAb18 Fab was modified with 2 iminotholane and labeled with 99m Tc by transchelation from 99m Tc GH. Labeling yield, radiochemical purity and immunoreactivity were determined by thin layer chromatography (TLC SG), paper chromatography (PC), gel chromatography (GC) and cell binding assay, respectively. The nude mice bearing human hepatoma were used for radioimmunoimaging (RII). RESULTS A radiolabeling yield of 50%-80% was obtained, and immunoreactivity (IR) was 30%-40%. Radioimaging results showed that 99m Tc HAb18 McAb Fab fragment was concentrated in the tumor 4-8 hours after injection, and the maximum concentration was seen in 12-24 hours, and the T/NT value was 5 18 and 7 48 at 6h and 8h after the injection. CONCLUSION 99m Tc HAb18 McAb Fab fragment could be specifically localized in the tumor of nude mice bearing human hepatocellular carcinoma within 24 hours and this method might be effectively used for labeling McAb Fab fragment with展开更多
Objective.Using monoclonal antibody (mAb) Fab′ fragment to develop mAb immunoconjugates for cancer. Methods.Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithioth...Objective.Using monoclonal antibody (mAb) Fab′ fragment to develop mAb immunoconjugates for cancer. Methods.Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol (DTT),while Fab′ fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by β mercaptoethanol.The conjugation between Fab′ fragment and pingyangmycin (PYM),an antitumor antibiotic,was mediated by dextran T 40.Immunoreactivity of Fab′ PYM conjugates with cancer cells was determined by ELISA,and the cytotoxicity of those conjugates to cancer cells was determined by clonogenic assay.Antitumor effects of the Fab′ PYM conjugates were evaluated by subcutaneously transplanted tumors in mice. Results.The molecular weight of Fab′ fragment was approximately 53 kD,while the average molecular weight of Fab′ PYM conjugate was 170 kD.The Fab′ PYM conjugates showed immunoreactivity with antigen relevant cancer cells and selective cytotoxicity against target cells.Administered intravenously,Fab′ PYM conjugates were more effective against the growth of tumors in mice than free PYM and PYM conjugated with intact mAb. Conclusion.Fab′ PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth,suggesting its therapeutic potential in cancer treatment.展开更多
An antigastric cancer monoclonal antibody, 3H11, and its Fab fragment, were labeled using p-(211At)-astatobenzoic acid (pAtBA) intermediate, in the yields of more than 30%. The results of in vitro experiments show tha...An antigastric cancer monoclonal antibody, 3H11, and its Fab fragment, were labeled using p-(211At)-astatobenzoic acid (pAtBA) intermediate, in the yields of more than 30%. The results of in vitro experiments show that 211At-3H11 and 211At-3H11Fab are stable, and have specific immunoreactivities and cytotoxic effects to human gastric cancer cell M85. The cytotoxic effects are dependent on the concentration of 211At-3H11 or 211At-3H11 Fab and obviously stronger than that of Na211At.展开更多
文摘AIM To establish a method of labeling anti hepatoma McAb (HAb18) Fab fragment modifier with 99m Tc. METHODS HAb18 Fab was modified with 2 iminotholane and labeled with 99m Tc by transchelation from 99m Tc GH. Labeling yield, radiochemical purity and immunoreactivity were determined by thin layer chromatography (TLC SG), paper chromatography (PC), gel chromatography (GC) and cell binding assay, respectively. The nude mice bearing human hepatoma were used for radioimmunoimaging (RII). RESULTS A radiolabeling yield of 50%-80% was obtained, and immunoreactivity (IR) was 30%-40%. Radioimaging results showed that 99m Tc HAb18 McAb Fab fragment was concentrated in the tumor 4-8 hours after injection, and the maximum concentration was seen in 12-24 hours, and the T/NT value was 5 18 and 7 48 at 6h and 8h after the injection. CONCLUSION 99m Tc HAb18 McAb Fab fragment could be specifically localized in the tumor of nude mice bearing human hepatocellular carcinoma within 24 hours and this method might be effectively used for labeling McAb Fab fragment with
基金This work was supported by the grants from the National Key Research Project Funds，国家重点基础研究发展计划(973计划)
文摘Objective.Using monoclonal antibody (mAb) Fab′ fragment to develop mAb immunoconjugates for cancer. Methods.Fab′ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol (DTT),while Fab′ fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by β mercaptoethanol.The conjugation between Fab′ fragment and pingyangmycin (PYM),an antitumor antibiotic,was mediated by dextran T 40.Immunoreactivity of Fab′ PYM conjugates with cancer cells was determined by ELISA,and the cytotoxicity of those conjugates to cancer cells was determined by clonogenic assay.Antitumor effects of the Fab′ PYM conjugates were evaluated by subcutaneously transplanted tumors in mice. Results.The molecular weight of Fab′ fragment was approximately 53 kD,while the average molecular weight of Fab′ PYM conjugate was 170 kD.The Fab′ PYM conjugates showed immunoreactivity with antigen relevant cancer cells and selective cytotoxicity against target cells.Administered intravenously,Fab′ PYM conjugates were more effective against the growth of tumors in mice than free PYM and PYM conjugated with intact mAb. Conclusion.Fab′ PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth,suggesting its therapeutic potential in cancer treatment.
文摘An antigastric cancer monoclonal antibody, 3H11, and its Fab fragment, were labeled using p-(211At)-astatobenzoic acid (pAtBA) intermediate, in the yields of more than 30%. The results of in vitro experiments show that 211At-3H11 and 211At-3H11Fab are stable, and have specific immunoreactivities and cytotoxic effects to human gastric cancer cell M85. The cytotoxic effects are dependent on the concentration of 211At-3H11 or 211At-3H11 Fab and obviously stronger than that of Na211At.
