Monoclonal antibodies with different specificities against cytokeratins. An immunohistochemical study of normal tissues and tumors.

Monoclonal antibodies against cytokeratins, isolated from human callus, were prepared. Here we describe the characterization of three of these monoclonal antibodies (Clones 77, 78, and 80) with special emphasis on the staining characteristics of a number of normal epithelial tissues and a series of tumors. On thin sections and in immunoblotting experiments our monoclonal antibodies showed different specificities. In immunoblots Clone 80 stained more bands in preparations of cytokeratin from callus, cultured keratinocytes, and a metastasis of a lung carcinoma than Clones 77 and 78. In this last cytokeratin preparation Clones 77 and 78 each stained a separate band not stained by Clone 80. In normal tissues Clone 80 stained all types of epithelia except myoepithelium and podocytes of glomeruli. Clone 78 stained mainly squamous epithelium. Clone 77 stained differentiated squamous epithelium, transitional epithelium, ductal epithelium, and parenchymatous epithelium. These results confirm the heterogeneity of cytokeratins. In neoplasms Clone 77 was positive with adenocarcinoma and squamous cell carcinoma. Clone 78 stained squamous cell carcinoma and well-differentiated adenocarcinoma. Clone 80 stained all epithelial tumors, including anaplastic carcinoma, and is therefore useful in tumor diagnosis.