Establishment of a new human urinary bladder mixed carcinoma cell line UMK-1 and its cell-density-dependent secretion of gelatinases and tissue inhibitor of metalloproteinase-1.

A new human carcinoma cell line, UMK-1, was established from primary urinary bladder carcinoma with histological diagnosis of transitional cell carcinoma grade 2, with squamous and adenocarcinomatous differentiation. These histologic features were maintained in the cultured cells and in xenografted tumors in nude mice. Ultrastructurally, the cultured cells were characterized by formation of glandular structure with well-formed junctional complexes and microvilli, intracytoplasmic lumina and tonofilament bundles. Upon continuous propagation in serum-free medium, UMK-1 cells secreted gelatinases and tissue inhibitor of metalloproteinase (TIMP)-1 into the conditioned medium. The gelatinolytic activities which were inhibited by EDTA, were composed of a major band at 95 kD and a minor band at 68 kD on gelatin zymography. The measurement of TIMP-1 in the conditioned medium was performed by the one-step sandwich enzyme immunoassay system. The production of gelatinases and TIMP-1 was observed during the late log phase of the cell growth and those productions showed similar kinetics. UMK-1 cells can be used to study the interaction of tumor cell-derived gelatinolytic proteinases and TIMP-1 in cancer invasion and metastasis.