TRETINOIN OR RETINOL ENHANCEMENT OF LYMPHOKINE-ACTIVATED KILLER-CELL PROLIFERATION AND CYTOXICITY AGAINST HUMAN BLADDER-CANCER CELLS IN-VITRO

AIM: To study the effect of tretinoin (Tre) or retinol (Ret) on the pr oliferation of lymphokine-activated killer (LAK) cells in patients wit h transitional cell cancer of bladder and their cytolysis to bladder t umor cells. METHODS: LAK cell proliferation was assayed in the presenc e of either Tre or Ret by cell counting. Human transitional bladder ca ncer cell lines BIU-87, ET, or bladder tumor cells (ETC) from patients with bladder cancer were used as target cells and cytotoxicity of LAK cells was determined by 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltet razolium bromide (MTT) assay. RESULTS: The proliferation of LAK cells induced by interleukin-2 (IL-2) was stimulated by Tre or Ret (10-100 n mol.L-1). The cytotoxicity of LAK cells against BIU-87, EJ cells, or B TC was enhanced by pretreatment of LAK cells with Tre or Ret 10-100 nm ol.L-1. CONCLUSION: Tre or Ret enhances the proliferation and cytotoxi city of LAK cells from patients with bladder cancer. Retinoids are pot ential in adoptive immunotherapy of bladder cancer.