DAG-1 carcinoma cell in studying the mechanisms of progression and therapeutic resistance in bladder cancer

Objective: We describe a new human bladder carcinoma cell line (DAG-1) esta blished from a resected bladder cancer fragment and maintained in culture f or more than 5 years and over 300 passages. Methods and Results: Immunological, biochemical and molecular analysis show ed that the DAG-1 cells (62 chromosomes) express the cytokeratines 8, 13, 1 8 and 20 that confirm their epithelial origin as well as numerous cytokine and cytokine receptor mRNAs. They secrete tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitors (PAI-1 and PAI-2), and express u-PA receptors (u-PAR/CD87) at t heir surface. DAG-1 cells are resistant to TNF alpha- and IFN gamma -induce d apoptosis, two cytokines secreted in the urine of Calmette-Guerin bacillu s-treated patients and involved in the tumor regression. Conclusion: The DAG-1 cell line is a useful tool, both in vitro and in vivo , to study the progression of bladder tumors and their mechanisms of resist ance to immunotherapy in relation with PAI-2 and antioxidant enzymes. Copyr ight (C) 2001 S. Karger AG, Basel.