Tissue plasminogen activator and urokinase in normal, dysplastic and cancerous squamous epithelium of the uterine cervix.

The distribution of tissue plasminogen activator (t-PA) and urokinase (u-PA) was investigated immunohistochemically in squamous epithelium of the uterine cervix, in normal and dysplastic conditions as well as in preinvasive and invasive carcinomas. Normal epithelium showed presence of both t-PA and u-PA immunoreactivity only in the superficial cellular layer, whereas in preinvasive lesions they were present in all layers. In sections of normal specimens as well as preinvasive lesions the UK immunoreactivity was weaker compared to that of t-PA. Invasive lesions showed a patchy distribution of t-PA and u-PA immunoreactivity. Furthermore, it could be demonstrated that stromal cells close to the infiltrating malignant squamous epithelium contained t-PA immunoreactivity and also u-PA immunoreactivity. Further immunohistochemical studies disclosed that these cells were macrophages.