Local expression of cytokines in rat bladder carcinoma tissue after intravesical treatment with Nocardia rubra cell wall skeleton and Bacillus-Calmette-Guerin

This study aimed to investigate local immunotherapy with Nocardia rubra cell wall skeleton (N-CWS) and bacille-Calmette-Guerin (BCG) in chemically induced rat bladder carcinoma. After being fed with 0.025% N-butyl-N-(4-hydroxybutyl) nitrosamine for 26 weeks, female Wistar rats were treated once a week by intravesical instillation of 100 mu g N-CWS or 5x10(6) Colony-Forming Units (CFU) BCG. Tissue specimens were obtained 4 h after the ninth instillation and analyzed by reverse transcription polymerase chain reaction (RT-PCR) for mRNA expression of rat cytokines. The analysis showed high expression of interleukin (IL)-1 alpha, tumor necrosis factor (TNF)-alpha, IL-2, and interferon (IFN)-tau in BCG (7/7, 7/7, 7/7, 5/7) and N-CWS (9/9, 9/9, 8/9, 8/9) treated tumors in comparison to low expression in controls (3/9, 0/9, 3/9, 3/9). Interestingly, intravesical instillation of N-CWS tended to be less effective at preventing local invasion of the tumors. It is speculated that this difference may result from a more strongly induced expression of T-helper cell-derived lymphokines (IL-2, IFN-tau) by BCG.