Radioimmunotherapy with 153Sm-CEA monoclonal antibody in nude mice bearing human colon carcinoma: an experimental study.
OBJECTIVE
To observe the therapeutic effect of 153Sm-labeled CEA monodonal antibody(mAb) in nude mice bearing human colon carcinoma.


METHODS
Fifteen nude mice were subjected to subcutaneous inoculation of human colon carcinoma cells, and 3 days later, they were divided into 3 groups with equal numbers to receive single high-dose injection of 11.1 MBq 153Sm-CEA mAb (therapy group), 11.1MBq 153SmCl3 (therapy control group), or 100 microl normal saline (non-treatment control group). The tumor-inhibiting effect of 153Sm-labeled CEA mAb was evaluated in terms of body weight changes and tumor volume variation 4 weeks after the treatment. Histological analysis of tumors were performed in all the groups after the all other observations were completed.


RESULTS
153Sm-CEA mAb had a significant anti-tumor effect, with a tumor inhibition rate of 74.29% at 4 weeks after treatment, while for 153SmCl3, the inhibition rate was only 15.90%. Rapid tumor growth was observed in non-treatment control group. No significant difference in the body weight changes was noted between the 3 groups. Histopathological examination revealed tumor necrosis as the evidence for radioactive damage in therapy group, which was not observed in non-treatment control group.


CONCLUSIONS
153Sm-CEA mAb has a strong selective inhibitory effect against colon carcinoma and may be potentially used as an agent in radioimmunotherapy.
Li
Gui-ping
GP
Department of Nuclear Medicine, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China.
Zhang
Hui
H
Zhu
Cheng-mo
CM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D003110:Colonic Neoplasms / Q000532:radiotherapy*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011786:Quality Control; D016499:Radioimmunotherapy; D011868:Radioisotopes / Q000627:therapeutic use*; D012493:Samarium / Q000627:therapeutic use*; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D011868:Radioisotopes; D012493:Samarium