Qk. Chen et Sz. Yuan, RADIOIMMUNOLOCALIZATION OF HUMAN PANCREATIC-CARCINOMA XENOGRAFT BY TC-99M-LABELED YPC3 MONOCLONAL-ANTIBODY, Journal of cancer research and clinical oncology, 120(11), 1994, pp. 668-671
Monoclonal antibodies specific to tumor cells may be a useful tool for
the diagnosis and treatment of carcinomas. In this study, YPC3 mAb, a
specific monoclonal antibody against the human pancreatic carcinoma c
ell line Capan-2, was labeled directly with Tc-99m after being pretrea
ted with 2-mercaptoethanol. The radiolabeling efficiency was found to
be high (88%-95%) and the immunoreactivity retained, as assessed by im
munohistochemistry and enzyme-linked immunosorbent assay. The biodistr
ibution of Tc-99m-YPC3 mAb in nude mice bearing Capan-2 pancreatic car
cinoma xenografts was studied and compared with that of labeled mouse
immunoglobulin G(Tc-99m-nmIgG). The xenograft uptake values per gram o
f tissue 6 h and 24 h after injection of Tc-99m-YPC3 mAb were found to
be, respectively, 4.72%ID/g and 8.42%ID/g, and the tumor/blood ratios
1.16 and 2.24. At 6 h and 24 h after injection of Tc-99m-nmIgG, the u
ptakes were 2.89%ID/g and 1.80%ID/g, and the tumor/blood ratios 0.84 a
nd 1.02 respectively. External imaging by single-proton emission compu
ted tomography, 24 h after injection of Tc-99m-YPC3 mAb, revealed clea
r scintigraphic visualization of Capan-2 xenografts, whereas injection
of Tc-99m-nmIgG did not. This study suggests that Tc-99m labeling of
monoclonal antibody YPC3 might be of practical value in localization d
iagnosis of human pancreatic carcinoma.