METASTATIC POTENTIAL OF HUMAN COLON CANCER CELL-LINES - RELATIONSHIP TO CELLULAR-DIFFERENTIATION AND CARCINOEMBRYONIC ANTIGEN PRODUCTION

The relationship between cellular differentiation and carcinoembryonic antigen (CEA) production by human colorectal tumor cells and their ability to form hepatic metastases was studied. Eight human colon cancer cell lines were injected into thymic mice using different routes of administration to characterize their metastatic potential. The four poorly differentiated, non or low CEA producing cell lines were poorly metastatic to the liver after intrasplenic injection. After intraperitoneal implantation the same cell lines were highly tumorigenic, and subsequently metastastic to the liver. In contrast, the four moderate to well-differentiated cell lines that produced moderate to high levels of CEA were highly metastatic to the liver following intrasplenic injection. After intraperitoneal implantation they were less tumorigenic, and metastatic to the liver. We conclude that in this system poorly differentiated non or low CEA producing colorectal cell lines have a lower metastatic capacity compared to the well-differentiated high CEA producing colorectal cell lines. These data correlate directly with the pattern of metastatic spread and clinical course observed in patients with these tumors, suggesting that degree of differentiation and level of CEA production may play a role in development of site-specific metastases.