Invasive potential and substrate dependence of attachment in the dunning R-3327 rat prostate adenocarcinoma model

Cancer cell attachment to and invasion of the extracellular matrix has been associated with the metastatic potential of cell lines of the Dunning R-3327 rat prostatic adenocarcinoma model. We investigated the cell-matrix interactions of prostate tumor cells by comparing the invasive ability through reconstructed extracellular matrix and attachment upon EHS NATRIX (natural extracellular matrix), fibronectin, laminin, and collagen Type IV. We observed a correlation between metastatic potential and substrate dependence of attachment in prostate cancer cells. Nonmetastatic AT-1 cells possessed a higher adhesive potential to extracellular matrix components than the highly metastatic cells (ML, MLL and AT-3). It was also found that the invasive potential of the three highly metastatic cell lines was significantly higher than that of the nonmetastatic cell line. Here, it is reported that the ability to traverse a matrigel matrix correlates with their metastatic potential. These observations suggest that the extracellular matrix components are highly involved in influencing prostate cancer cell activities. In addition, we investigated the effects of two differentiation agents, retinoic acid (RA) and difluoromethylornithine (DFMO), on the adhesive and invasive profiles of the tumor cells. After treatment with both agents, adhesion was increased to levels not different from nonmetastatic cells. Furthermore, the ability of highly metastatic cells to traverse a matrigel barrier was significantly reduced after treatment with both differentiation agents. These results suggest that RA and DFMO are capable in reversing the metastatic potential of prostate cancer cells in vitro and may give a possible insight into their role as potential therapeutic agents in vivo.