Characterization of novel cell lines from pleomorphic adenomas of the parotid gland established in a collagen gel system.

The pathobiology of salivary neoplasms can best be studied in a model system that reflects the native state of the tumor. The present study describes the use of a three-dimensional collagen gel (organoid) system in which pleomorphic adenomas of the parotid gland were propagated in vitro. Five pleomorphic adenoma cultures were established as organoid gels and compared with touch-preparations or cryopreserved specimens of native tumor. The organoid cultures demonstrated normal DNA content, the expression of myoepithelial cell proteins, and the production of sulfated acid mucins; these cellular and secretory features mimicked those found in the archival specimens. Further, organoid cultures of pleomorphic adenoma could be initiated after monolayer culture, demonstrating that culture on a plastic support does not alter the nature of the cells. Development of an in vitro culture system that maintains the native state of pleomorphic adenoma is an important tool for studying the pathobiology of these tumors.