Detection of interleukin-1 activity in human bladder cancer cell lines

Detection of interleukin (IL)-1 activity was studied in two human bladder cancer cell lines, T24 and EJ1, and one rat bladder carcinoma cell line, 804G. Significantly high proliferation of mouse thymocytes in the assay of IL-1 activity was observed in the conditioned medium (CM) of T24 cells, indicating that the cells released IL-1-like activity. Enzyme-linked immunosorbent assay (ELISA) and Northern blot analysis showed the presence of both IL-1 alpha and IL-1 beta in the CM of T24 cells and expression of mRNAs of both cytokines in the cells. Interleukin-1 activity in EJ1 cells, which produced a little activity, was induced by E. coli lipopolysaccharide (LPS) while it was not induced in T24 by either LPS or other test substances. Conditioned medium of T24 increased proliferation of both T24 and EJ1 in cell-growth assay. Further investigation of the mode of action and role of cytokines, especially those from tumor cells themselves, is necessary in relation to BCG or photodynamic therapy.