Quantification of pancreatic secretory trypsin inhibitor in colonic carcinoma and normal adjacent colonic mucosa.

Abstract

To measure the content of immunoreactive human pancreatic secretory trypsin inhibitor (irPSTI) in colonic carcinoma and adjacent normal colonic mucosa. From a stable hybridoma cell line producing monoclonal antibodies specific for human PSTI, a specific enzyme linked immunosorbent assay (ELISA) for human PSTI was developed. In a precipitation assay system these antibodies bound human PSTI in a dose-dependent manner. The specimens were obtained from resectional surgery. The content of irPSTI was 19.9 micrograms/g protein (0.55 micrograms/g tissue wet weight) in colonic carcinoma. In adjacent normal colonic mucosa 43.6 micrograms/g protein (1.12 micrograms/g tissue wet weight) was shown. The enzymatic degradation of surrounding tissue necessary for tumour cell invasion could be facilitated by this relative deficit of the inhibitor in infiltrative carcinoma.