Evaluation of in-vitro effects of recombinant human alpha 2 interferon on bilharzial urinary bladder cancer cells.

Using two different agar based double-layer culture assays, 16 bilharzial urinary bladder carcinoma samples were evaluated for the in-vitro effects of 1 hour's exposure to alpha 2 interferon at 3-log concentrations. Ten of these tumor samples were evaluable for drug sensitivity testing. In the liquid top layer dye exclusion assay, 40%, 60%, and 60% of the 10 tested tumor samples were sensitive to alpha 2 interferon 100, 1,000, and 10,000 units/ml respectively, and 25%, 25%, and 63% of 8 tumor cell suspensions were sensitive to the above drug concentrations when the human tumor colony forming assay was performed. Comparing both assays in 24 different drug measurements, there was a 71% concordance rate. All of the 7 discordant measurements were sensitive in the dye exclusion and resistant in the clonogenic assays. Thus, bilharzial bladder cancer cells are relatively sensitive to the in-vitro effect of alpha 2 interferon, especially of higher concentrations, and a phase II clinical trial deserves consideration.