Phospholipase C-gamma 1 is present on the surface of human colorectal cancer cells

Using murine monoclonal antibodies, we have detected the novel signal transducing enzyme, phospholipase C-gamma 1, on the surface of cultured human colorectal cancer cells. We have also demonstrated the presence of this enzyme on the surface of fresh human tumor cells derived from primary and metastatic colorectal tumors. This enzyme has previously been described to be associated only with the inner face of the plasma membrane and the cell cytosol. The finding of an enzyme critical to the signal transduction pathway may have important implications for additional functions of this protein.