Bcm. Sordat et C. Tranthang, LAMININ DEGRADATION BY HUMAN COLON-CARCINOMA CELLS - A ROLE FOR URINARY AND TISSUE-PLASMINOGEN ACTIVATORS, Invasion & metastasis, 14(1-6), 1994, pp. 223-233
The human colon carcinoma cell lines Co112 and Co115 are both invasive
in nude mice following intraperitoneal implantation. Co115 cells only
exhibit metastasis capacity under this condition. Characterization of
the plasminogen activation system demonstrates that Co112 cells expre
ss the urinary-type plasminogen activator (uPA) and Co115 cells the ti
ssue-type (tPA), exclusively. Immunocytochemical analyses revealed tha
t the in vitro plasminogen-dependent lysis of exogenous basement membr
ane laminin induced by Co112 cells displayed a gradient-like pattern,
whereas, in the case of Co115 cells, it was sharply confined to the pe
ricellular area. Double-labeling experiments showed that uPA on Co112
and tPA on Co115 cells are cell-surface-associated constituents. The c
ellular distribution of laminin expressed by tumor cells themselves ap
pears to be distributed homogeneously in the cytoplasm of both cell ty
pes. We suggest that the extracellular matrix degradation induced by t
umor cell surface-associated plasmin implies two different mechanisms
which are specifically related to uPA or to tPA, both contributing to
matrix degradation and malignant invasion.