Radioimmunotherapy of carcinoma of colon with [131I]-labeled recombinant chimeric monoclonal antibodies to carcinoembryonic antigen.
OBJECTIVE
To study the distribution of [(131)I]-labeled anti-CEA MoAbs and its therapeutic effect on the human colonic cancer model in nude mice.


METHODS
A nude mice model of human colonic cancer was established. [(131)I]-labeled anti-CEA MoAbs were injected intravenously into mice. The distribution of the MoAbs was then determined and the effect of RIT on human colonic cancer was observed.


RESULTS
The [(131)I]-labeled anti-CEA MoAbs had a specific distribution after injection. Tumor/non-tumor ratios for [(131)I]-labeled anti-CEA MoAbs were 10-20 times higher than [(131)I]-labeled IgG 96 h after injection. Thirty days after injection, significant inhibition of the volume and weight of tumor was observed in the treated mice compared with the control. The tumor growth inhibition rate of 3.1 mCi/kg CEA MoAbs group (LS180, LS174T, SW1116) was 47.8%-64.0%. This was 69.6%-78.6% in the 6.25 mCi/kg CEA MoAbs group, and 81.8%-86.2% in the 12.5 mCi/kg [(131)I]-labeled anti-CEA MoAbs group. The plasma CEA level was also lower in treated mice.


CONCLUSIONS
The results indicate that [(131)I]-labeled anti-CEA MoAbs can be effective in RIT on colonic cancers.
Lu
Qiu-jun
QJ
Institute of Radiation Medicine, Beijing 100850, China. luqj66@yahoo.com.cn
Bian
Guang-xing
GX
Chen
Yuan-yuan
YY
Zhang
Min
M
Guo
Shao-ming
SM
Wen
Li-qing
LQ
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D016499:Radioimmunotherapy
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D007457:Iodine Radioisotopes