IMMUNOLOCALIZATION OF HEPATIC METASTASES OF HUMAN COLONIC-CANCER BY CHIMERIC ANTI-TAG72 ANTIBODY IN SCID MICE

TAG72 is a well-characterized, human tumor-associated antigen present in >85% of human colonic cancers. In this study, we established an ani mal model of hepatic metastases of human colonic carcinoma. The high-m ucin variant cell line, designated HM7, was derived from the human col onic carcinoma cell line LS174T. Following intrasplenic injection, HM7 was able to induce much greater hepatic metastases in SCID mice compa red to its parental cell line LS174T. Numerous hepatic metastases were evident 18 days subsequent to the intrasplenic injection of tumor cel ls. Using the chimeric anti-TAG72 antibody ccM4, immunohistochemistry demonstrated strong expressions of the TAG72 antigen in these metastas es. Our biodistribution and imaging data also showed that the radiolab elled ccM4 antibody was able to localize hepatic metastases in the SCI D mice. Based upon these findings, w anticipate that the herein descri bed SCID mouse model will prove most useful in studying hepatic metast ases of human colonic carcinoma by using anti-TAG72 therapeutic immuno reagents. (C) 1995 Wiley-Liss, Inc.