[Comparative analysis of metastatic variants from the colorectal tumor cell line HT-29]

OBJECTIVE: To analyze the relationship between metastatic potential and related facters of colorectal tumor cell lines. METHODS: The variants HT-29c and HT-29d cell lines derived from the selection of HT-29 cells were injected into nude rats and the metastatic potential of the two tumor cell variants was analyzed. Expression of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) were measured with ELISA in vitro in colorectal carcinoma cell lines WiDr, HT-29 and HT-29d. Expression of carcinoembryonic antigen (CEA) and phosphoinositide 3-kinase (PI3-Kinase) were determined with immunohistochemistry, (IHC) in vitro and in vivo in WiDr, HT-29 and HT-29d cell lines. In addition, CEA expression was demonstrated with fluorescence activated cell sorter (FACS) in vitro. RESULTS: The liver metastasis rate of the variant HT-29d (with 4 cycles of selection), increased as compared with that of parental HT-29 cells and that of variant HT-29b cells (with 2 cycle of selection). The uPA concentration of variant HT-29d cell line was significantly higher than that of the non metastatic WiDr and the low metastatic HT-29 cells (P<0.05). The variant HT-29d cells produced stronger PI3-kinase expression as compared with the non-anetastatic WiDr cells and the low metastatic HT-29 cells in vivo. CONCLUSION: The selected variant cell lines can exhibit an enhanced metastatic potential. The level of uPA and PAI-1 are positively correlated with the metastatic capacity of tumor cells. The expression of PI3 kinasecorrelates with tumor development and metastasis.