Tenascin immunoreactivity in the large bowel and the liver in patients with colorectal cancer.

The expression of tenascin in colorectal tumours and liver was investigated in 30 patients with colorectal adenocarcinomas. Tissue samples were immersion-fixed in 4% paraformaldehyde solution. Free-floating cryostat sections were incubated with monoclonal antibody against tenascin, and examined by light and electron microscopy. Tenascin immunostaining was positive in sub-basement membrane zones and in newly-formed connective tissue of the primary tumour and perisinusoidally in the liver. The immunoreactivity in the sub-basement membrane zones of tumour glands in well- and moderately-differentiated tumours was more intensely expressed compared to that in poorly-differentiated tumours (p = 0.007 and p = 0.001 respectively, chi2-test). Perisinusoidal tenascin deposition was more often detected in the liver of patients with well-differentiated tumours (p = 0.006, chi2-test). The presence of metastases was accompanied by low tenascin deposition (p < 0.005, Fisher's exact test). Ultrastructurally tenascin deposits were observed around single tumour cells and glands in the primary tumours, and close to hepatic stellate cells in the liver. Finally, the role of tenascin deposition in the stimulation of tumour cell proliferation and mobility is discussed.