Abstract

Metastatic spread of malignancy is the main cause of the treatment failure and subsequent death in cancer patients. Recent findings indicate that tumors consist of cell populations with various degrees of metastatic potential, and that selective growth of subpopulations with higher metastatic potentials result in metastasis. The purpose of this study was to examine the metastatic potential of human colon cancer cell lines, LoVo and SW480 and to identify some cellular and biochemical determinants of metastasis using various properties which reflect events in metastatic process. The binding activity to ELAM-1, cell-cell aggregation rate, and total MMP activity were significantly higher in LoVo cells relative to SW480 cells. To define the effects of these cellular and biochemical properties on the process of invasion and me- tastasis af colon cancer cells, in vitro invasion and in vivo metastasis assay were performed. LoVo cells had an enhanced ability to penetrate a reconstituted basement membrane to a significantly greater degree than SW480 cells. The capacity to produce tumor nodules in the liver of nude mice subsequent to intrasplenic injection of cells was greater in LoVo cells than in SW480 cells. Also increased nm23-Hl protein expression was observed in SW480 cells in which no gross liver metastases were found. The results of this study suggest that LoVo cells have higher liver metastatic potential than SW480 cells and among various biochemical properties ELAM-1 binding and total MMP activity are significantly implicated in invasion and metastasis of colon cancer cells. And homotypic cell adhesion and downregulated nm23 gene product may be important in the metastatic cascade, but their roles should be further elucidated.

• Keywords: Colon cancer, Metastatic potential