Effects of nitric oxide on peripheral blood dendritic cells in patients with bladder cancer

    GUO Tao, WANG Zhiª²Ping, DUAN Jianª²Min

    Institute of Urology, Second Hospital, Lanzhou Medical College, Lanzhou 730030£¬China

    ¡¾Abstract¡¿ AIM: To investigate the effects of nitric oxide (NO) on peripheral blood dendritic cells (DCs) in patients with bladder cancer. METHODS: DCs were obtained from peripheral blood mononuclear cells (PBMC) in patients with bladder cancer. The DCs were cultured in the presence of granulocyte/macrophage colony stimulating factor (1¡Á106 U/L), interleukinª²4 (5¡Á105 U/L), tumor necrosis factorª²¦Á (105 U/L) and tumorª²associated antigen (TAA) extracted from human bladder cancer cell line Tª²24. The phenotypes (CD1a, CD80, CD86 and HLAª²DR) were determined by flow cytometry. The proliferation of lymphocytes induced by DCs and the cytotoxicity of cytotoxic T lymphocytes (CTL) were assayed in the presence of NO. Bladder cancer cell line Tª²24 was cultured as target cells and the cytotoxicity of CTL was determined by MTT assay. RESULTS: The proliferation of lymphocytes induced by DCs was inhibited by NO in a doseª²dependent manner (P<0.01). The NO resulted in an inhibition of the cytotoxicity of CTL against bladder cancer cell line Tª²24 (P<0.01). The DC in vitro induced by TAA effectively resulted in the proliferation of lymphocytes [proliferation rate: (74¡À6)%] and the killing effect was significant on the bladder cancer cell line Tª²24 by CTL [killing rate: (54¡À3)%]. CONCLUSION: NO can inhibit the proliferation and the activation of lymphocytes induced by DCs and downª²regulate the antitumor cytotoxicity of CTL in patients with bladder cancer. ......