Immunohistochemical reaction patterns of keratins in MNNG-induced shrew oesophageal carcinomas. 
The distribution of keratins in N-methyl-N'-nitro-N-nitrosoguanidine-induced oesophageal carcinomas in shrews was tested immunohistochemically, using a panel of seven different monoclonal antibodies.  The studies were done on methacarn-fixed paraffin-embedded tissue, using the labelled streptavidin biotin method, and the relationship between morphological characteristics and keratin reaction patterns in carcinomas was analysed and compared with that in adjacent "normal" oesophageal epithelium.  In the normal oesophageal epithelia, KL1, AE1, AE3, CK8.12, and CK4.62 stained suprabasal cells, 312C8-1 reacted to basal cells, and KS-1A3 labelled all epithelial cells.  In squamous cell carcinomas, almost all the cancer cells were labelled strongly by 312C8-1 and weakly by KS-1A3, while a few cells in the centres of the keratinized foci were stained by KL1, AE1, AE3, CK8.12, and CK4.62.  Like human oesophageal carcinomas, shrew oesophageal carcinomas maintain expression of human keratin 14, as determined by 312C8-1.  The expression of human keratin 13, as determined by KS-1A3, was down-regulated.