UT-MUC-1, a new mucoepidermoid carcinoma cell line, and its radiosensitivity.

Mucoepidermoid carcinoma is a fairly common malignant disease of the salivary glands. It is usually composed of two cell types, mucus-producing mucous cells and cells that have squamous differentiation with or without keratinization. The treatment of choice is considered to be radical surgical removal of the tumor. Radiotherapy has been recommended for high-grade or advanced tumors. Information on the radiosensitivity of mucoepidermoid cancer is scant, but based on clinical experience, the cancer appears to be only moderately radiosensitive. UT-MUC-1 is a newly established cell line from a poorly differentiated mucoepidermoid carcinoma. The cell line is diploid, but with complex karyotype abnormalities, giving a similar DNA index when measured with flow cytometry as that from the original tumor, and produces a tumor with characteristics typical for mucoepidermoid cancer when heterotransplanted to nude mice. The cell line is radiation resistant, with an area under the curve of 2.30 + 0.21 Gy when measured with a 96-well plate clonogenic assay. This correlates with the clinical outcome of the patient and the clinical experience of the radiosensitivity of this tumor type.