Metastasis formation is a major clinical problem in
cancer treatment, and no significant progress in the treatment of metastatic spread has been made. This apparent lack of progress is partly caused by the absence of clinically relevant animal models of
metastases. The binding of the
lectin Helix pomatia agglutinin (HPA) has been associated with a poor prognosis in breast and
colon cancer patients. HPA-positive and -negative human breast and
colon cancer cell lines were transplanted into severe combined immunodeficient (SCID) mice. HPA-positive
breast cancer cell lines (MCF-7 and T47D) metastasized in SCID mice, whereas the HPA-negative ones (BT20, HS578T and HBL100) did not. The HPA-positive
colon cancer cell line HT29 metastasized, while the HPA-negative ones (COLO320DM, SW480 and SW620) did not. However, in two of eight SCID mice inoculated with the HPA-negative
colon cancer cell line, CACO2 metastatic deposits were found. Despite this exception, HPA binding is a good
indicator of the
metastasis of human breast and
colon cancer cells in SCID mice: 23 out of 26 HPA-positive
cancers metastasized, as opposed to only two out of 38 HPA-negative
cancers. This experimental model is well suited for investigating the functional role of
carbohydrate residues recognized by HPA in breast and
colon cancer metastasis.