A nude mouse model of massive liver and lymph node metastasis of human colon cancer.

Liver and lymph nodes metastasis are the main causes of treatment failure for advanced colon cancer. However, currently-available animal models of human colon cancer do not demonstrate sufficient metastasis to represent highly malignant colon cancer that extensively metastasizes to these sites. A liver metastasis from a patient with highly malignant, poorly differentiated adenocarcinoma of the colon was established in nude mice by surgical orthotopic implantation to the mouse colon. The human origin of the tumor growing in nude mice was confirmed by in situ hybridization of human DNA. After 20 passages from the first implantation, massive liver and lymph nodes metastasis, occurred in 100% of the transplanted animals. Lymph nodes metastasis were found at the sites of lymph node drainage of the liver: celiac, portal and mediastinal lymph nodes. However no mesenteric and retroperitoneal nodes or lung tissue metastases were observed. Our data suggest that the mediastinal, celiac and hepatic lymph nodes metastases are derived form the liver metastasis, confirming the concept of metastasis of metastases or "remetastasis" of colon cancer.