Establishment and characterization of a cell line (KU-8) from squamous cell carcinoma of the penis.

The KU-8 cell line was established from a lymph node metastasis of human squamous cell carcinoma (SCC) of the penis. The cells grew rapidly (doubling time 20 hours) as adherent monolayers, and were tumorigenic in nude mice. The carcinoma cells showed epithelial characteristics by observation with a phase contrast microscope. The cells retained the ultrastructural characteristics of squamous epithelium including tonofilaments and desmosomes. In addition to the morphological characteristics of SCC, this cell line preserved specific molecular markers of epithelium, such as desmoplakin, cytokeratin, and involucrin, all of which were demonstrated by immunofluorescent studies. Furthermore, SCC-related antigen (SCC-RA), a tumor marker for SCC, was produced in KU-8. Moreover, immunofluorescent study showed that KU-8 cell line expressed the specific receptor of epidermal growth factor (EGF), which turned out to increase the cell growth of KU-8. These results indicate that this new cell line could provide an excellent model for the basic research and development of new therapeutic modalities of penile carcinoma.