RADIOIMMUNOSCINTIGRAPHY USING TC-99M-LABELED PARENTAL MOUSE AND MOUSE-HUMAN CHIMERIC ANTIBODIES TO CARCINOEMBRYONIC ANTIGEN IN ATHYMIC NUDE-MICE BEARING TUMOR

Citation
Y. Karube et al., RADIOIMMUNOSCINTIGRAPHY USING TC-99M-LABELED PARENTAL MOUSE AND MOUSE-HUMAN CHIMERIC ANTIBODIES TO CARCINOEMBRYONIC ANTIGEN IN ATHYMIC NUDE-MICE BEARING TUMOR, Nuclear medicine and biology, 23(6), 1996, pp. 753-759
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Radiology,Nuclear Medicine & Medical Imaging
Journal title
Nuclear medicine and biology
ISSN journal
0969-8051 → ACNP
Volume
23
Issue
6
Year of publication
1996
Pages
753 - 759
Database
ISI
SICI code
0969-8051(1996)23:6<753:RUTPMA>2.0.ZU;2-4
Abstract
Biodistribution and imaging characteristics of Tc-99m-labeled parental mouse and mouse-human chimeric antibodies to carcinoembryonic antigen (CEA), designated F11-39 and ChF11-39, respectively, were evaluated i n athymic nude mice bearing the human CEA-producing gastric carcinoma (MKN-45) xenografts. Group F monoclonal antibodies such as F11-39 and ChF11-39 have been found to recognize the protein epitopes present on the domain B3 of the CEA molecule and to discriminate CEA in tumor tis sues from the CEA-related antigens. The Tc-99m labeling was performed by immediately mixing a reduced antibody by 2-mercaptoethanol with Tc- 99m pertechnetate in the presence of stannous chloride. The labeling y ields of the two antibodies were greater than 95% when estimated using gel chromatography. Although these Tc-99m-labeled antibodies were sta ble in neutral saline solution, Tc-99m from both labeled antibodies wa s associated with cysteine solution. Technetium-99m ChF11-39 was more susceptible to transchelation than was Tc-99m F11-39. The immunoreacti vity of each Tc-99m-labeled antibody was confirmed using MKN-45 cell-b inding assay. Biodistribution studies in tumor-bearing mice were perfo rmed at 1 h, 5 h, and 20 h after being given IV injections of 3.7 MBq of either Tc-99m F11-39 or Tc-99m ChF11-39. All tumor-to-organ uptake ratios increased with time for both Tc-99m-labeled antibodies. Imaging results also showed selective and progressive accumulation of both Tc -99m antibodies at the tumor site. Both these Tc-99m-labeled antibodie s have proved to be good radiotracers giving satisfactory scintigrams of the CEA-producing tumor.