Antiproliferative effects of interferons against human bladder carcinoma cell lines in vitro.

In order to evaluate the antiproliferative effects of recombinant human interferon-gamma 2c (rHu IFN-gamma 2c), recombinant human interferon-gamma (rHu IFN-gamma), natural interferon-beta (IFN-beta), and their combination with cytotoxic agents, 17 different human bladder carcinoma cell lines were tested in vitro. The antiproliferative effects were compared in evaluating the tumor cell inhibiting potency of the different interferon (IFN) classes. It could be demonstrated that interferons have inhibiting effects on the bladder cancer cell multiplication rate, yet there are significant differences in the susceptibility of different IFN preparations on different cell lines. The cell lines BT1, RT4, EJ, 468P, 253J, SD, TCCSUP, and SW1738 can be defined as sensitive, T24, 647V, VM-CUB2, and J82 as semisensitive, HT1376, 5637, VM-CUB1, 639V and SW1710 as resistant upon treatment with IFN. The combination of rHu IFN-alpha 2c, IFN-beta, and rHu IFN-gamma seems to be more effective than treatment with rHu IFN-alpha 2c alone. The cytotoxic effect of doxorubicin on bladder cancer cells can be intensified by combining it with IFN.