Establishment and characterization of two divergent cell lines derived from a human chromophobe renal cell carcinoma

The chromophobe renal cell carcinoma is a distinct type of renal cancer presumably derived from the intercalated cell of the collecting duct system and exhibiting a better prognosis than other types of renal cell carcinoma. Chromophobe carcinomas can be separated from other types of renal cell carcinoma by their characteristic cytomorphology, ultrastructural appearance, cytoskeletal architecture, and cytogenetic aberrations. As no permanent cell line of the chromophobe tumor type has previously been described, we are the first to report on the successful establishment and characterization of two divergent permanent cell lines, ie, chrompho-A and chrompho-B, derived from the same chromophobe renal cell carcinoma. With immunocytochemistry, two-dimensional gel electrophoresis, and Western blot, chrompho-A and chrompho-B exclusively exhibited cytokeratins (Nos. 7, 8, 18, and 19) but not vimentin. Ultrastructural studies revealed numerous cytoplasmic microvesicles as well as coated vesicles that are known to be characteristic features of the intercalated cell. Chrompho-B cells exhibited a shorter mean population doubling time (tD = 43 hours) than chrompho-A cells (tD = 51 hours). Both cell lines failed to produce tumors in nude mice with the subrenal capsule assay. Cytogenetic analyses revealed hyperdiploid chromosome numbers in both cell lines with telomeric associations as well as numeric aberrations known from chromophobe renal cell carcinomas in vivo.