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 immers ion-fixed in 4% paraformaldehyde solution. Free-floating cryostat sections were incubated with monoclonal antibody against tenascin, and examined by l ight and electron microscopy. Tenascin immunostaining was positive in sub-b asement 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-differenti ated tumours was more intensely expressed compared to that in poorly-differ entiated tumours (p = 0.007 and p = 0.001 respectively, chi (2)-test). Peri sinusoidal tenascin deposition was more often detected in the liver of pati ents with well-differentiated tumours (p = 0.006, chi (2)-test). The presen ce of metastases was accompanied by low tenascin deposition (p < 0.005, Fis her's exact test). Ultrastructurally tenascin deposits were observed around single tumour cells and glands in the primary tumours, and close to hepati c stellate cells in the liver. Finally, the role of tenascin deposition in the stimulation of tumour cell proliferation and mobility is discussed.