ABSTRACT
Cytokeratin (CK) expression was studied in squamous cell carcinomas of different subsites in the head and neck by using cryostat sections from 27 head and neck squamous cell carcinomas (HNSCCs) and 6 cell lines established from HNSCC. All tissues were analyzed immunohistochemically with a panel of monospecific anti-keratin monoclonal antibodies. Most carcinomas recapitulated the expression pattern of keratins present in the basal layer of normal epithelium from the site of tumor origin. Regional differences in the expression of simple-epithelial type of keratins in stratified (pseudostratified) epithelia were to a large extent repeated in corresponding carcinomas. In the present study, localization of various keratins were surveyed and CK 18 specific monoclonal antibodies were specifically used to distinguish SCCs of the larynx or hypopharynx from SCCs of the oral cavity. CK 18 staining of almost all tumor cells was detected in 11 of 12 SCCs of the larynx and hypopharynx, but was only detected sporadically in 3 of 9 SCCs of the oral cavity. The present results show that CK 18 typing might be useful for distinguishing sites of origin of various HNSCCs. Findings also indicate that CK 18 expression in SCC might be modulated by microenvironmental factors.
Subject(s)
Carcinoma, Squamous Cell/genetics , Gene Expression Regulation, Neoplastic/physiology , Head and Neck Neoplasms/genetics , Keratins/genetics , Antibodies, Monoclonal , Carcinoma, Squamous Cell/pathology , Cell Line , Diagnosis, Differential , Head and Neck Neoplasms/pathology , Humans , Hypopharyngeal Neoplasms/genetics , Hypopharyngeal Neoplasms/pathology , Hypopharynx/pathology , Immunoenzyme Techniques , Laryngeal Neoplasms/genetics , Laryngeal Neoplasms/pathology , Larynx/pathology , Mouth Mucosa/pathology , Mouth Neoplasms/genetics , Mouth Neoplasms/pathologyABSTRACT
Recently, a new 'specific tissue polypeptide antigen (TPA)' test was introduced and designated tissue polypeptide-specific antigen (TPS); it is based on the monoclonal antibody (MAb) anti-TPS, M3. We have tested the specificity of this antibody by immunocyto- and immunohistochemistry, gel electrophoresis and immunoblotting. MAb M3 bound to intermediate filaments of epithelial cells and revealed a staining pattern identical to cytokeratin (CK) 18-specific MAb (DE-K18) on tissue sections of various human tissues. On immunoblots of proteins extracted from various epithelial cell lines, M3 reacted with a 45-kD protein corresponding to CK18, and on immunoblots of proteins isolated from MCF-7 culture fluid M3 stained three bands, 45, 33 and 29 kD. The same bands were stained with CK18-specific MAb, indicating that they represent CK18 and its degradation products. TPA, used as a tumor marker in clinical diagnoses and follow-up, was shown to be a degradation product of CK 8, 18 and 19. In contrast to TPA, MAb M3 did not stain CK8 and CK19 present on immunoblots.
