Immunohistochemical examination of 11 cell lines derived from human head and neck squamous cell carcinomas, their recurrences or metastases.

Since in vitro derived tumor cell lines usually correspond to their tumors of origin, a potential biological difference between a primary tumor and its derivative metastases and recurrent tumors should be reflected in established tumor cell lines. The aim of this study was to determine useful cellular markers in permanent tumor cell lines of head and neck squamous cell carcinomas (SCC) and to evaluate a possible relationship between these markers and the origin of selected cell lines. The cell lines, established in the laboratory of T. Carey at the University of Michigan (UM) (Ann Arbor, Mich., USA), were derived from primary tumor and its metastases (UM-SCC 10A, 10B), primary tumor and its recurrent tumors (UM-SCC 14A, 14B, 14C) and single tumors (UM-SCC 11B, 17A, 22B). An additional tumor cell line (HLac 79) was isolated by H.-P. Zenner (Tubingen, Germany) and a clone (8029 NA) with its cisplatin-resistant subline (8029 DDP4) was established in our laboratory. As markers we chose three groups known to be related to growth behavior and/or tumor differentiation: cytoskeletal proteins, oncogene products and membrane-associated antigens. These markers were detected by immunohistochemical methods using commercially available monoclonal antibodies. The "metastatic" and "recurrent" cell lines showed changes in comparison to the corresponding "parental" lines, which could be associated with a higher degree of de-differentiation, such as the occurrence of vimentin and neuroectodermal proteins, loss of HLA-ABC or HLA-DR and increased expression of epidermal growth factor receptor. The expression of cytokeratins was more stable and dissociation of the classical cytokeratin pairs was observed only in a few cases. Oncogene products were practically identical in cell lines from parental and recurrent or metastatic tumors. These data serve not only as a basis for further experiments with these cell lines but also provide information about the biological significance of various markers in newly established cell lines from primary tumors.