[Detection of apoptosis and expression of Fas antigen in human colorectal cancer].

The occurrence of apoptosis in formalin-fixed, paraffin-embedded human colorectal cancer tissues was investigated at a cellular level by in situ nick translation (ISNT). Then the frequency of ISNT-positive nuclei was compared with the proliferative activity assessed by proliferating cell nuclear antigen (PCNA) labeling index, and with the incidence of Fas positive cells examined immunohistochemically with the incidence of Fas positive cells examined immunohistochemically with rabbit anti-Fas serum. As a result, although no significant correlation between the frequency of apoptosis and the proliferative activity was observed, a balance between them may explain a variety of growth rates of colorectal cancers. As for Fas expression, about 33% of the colorectal cancers were more or less positive for Fas antigen.