Radioimmunoscintigraphy of pancreatic cancer in tumor-bearing athymic nude mice using (99m)technetium-labeled anti-KL-6/MUC1 antibody.
OBJECTIVE
KL-6 is an extracellular epitope of MUC1, a membrane-penetrating glycoprotein, and its overexpression has been reported in pancreatic cancer. The aim of this study was to examine whether radiolabeled anti-KL-6/MUC1 antibody could be used for molecular imaging of pancreatic cancer in vivo.


METHODS
Anti-KL-6/MUC1 antibody was labeled with 99mTC by the stannous reduction method. Immunoreactivity of the 99mTc-labeled anti-KL-6/MUC1 antibody was evaluated by a whole-cell binding study. In vivo experiments were performed by injecting the 99mTc-labeled anti-KL-6/MUC1 antibody into athymic nude mice bearing the KP-1NL pancreatic cancer cell line.


RESULTS
A whole-cell binding study showed that the radiolabeled antibody retained its immunoreactivity. On scintigrams, the density of the tumors remained unchanged during the 16-32 h after injection, whereas that of the kidneys decreased time-dependently. The radioactivity levels of the kidneys and tumors were measured densitometrically, and we found that the intensity in the tumors relative to that in the kidneys increased time-dependently. Radioactivity levels were the highest in the blood 32 h after injection, and those in the liver, kidney, lung, and tumor were also rather high.


CONCLUSIONS
99mTc-labeled anti-KL-6/MUC1 antibody appears to be a promising agent as a tumor-specific radiotracer for pancreatic cancer.
Matsumura
Kenji
K
Department of Radiology, Oita University Faculty of Medicine, Hasama-machi, Yufu 879-5593, Japan.
Niki
Ichiro
I
Tian
Hui
H
Takuma
Masahisa
M
Hongo
Norio
N
Matsumoto
Shunro
S
Mori
Hiromu
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015153:Blotting, Western; D051379:Mice; D008819:Mice, Nude; D018396:Mucin-1 / Q000276:immunology*; D009368:Neoplasm Transplantation; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000276:immunology*; D016719:Radioimmunodetection / Q000379:methods*; D013667:Technetium; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; C060192:MUC1 protein, human; D018396:Mucin-1; D013667:Technetium