The effect of mitomycin C after long-term storage on human Tenon's fibroblast proliferation

Purpose: To investigate the effect of mitomycin C (MMC) after long-term storage on proliferation of human Tenon's fibroblasts in vitro. Methods: Human Tenon's fibroblasts in tissue culture were exposed for 5 minutes to MMC (0.4 mg/mL) that was either freshly prepared or had been stored for as long as 18 months at either 4 degrees C or -20 degrees C. The MTT colorimetric assay was used to determine the inhibition of proliferation as measured indirectly by mitochondrial activity. Results: The inhibition rate was 888 using fresh MMC, and declined to a mean of 73% when using MMC that had been stored for as long as 18 months at 4 degrees C; this decrease was not statistically significant. The mean inhibition for MMC stored at -20 degrees C was 68%. and this was significantly less than inhibition with fresh MMC. Inhibition did not vary significantly with MMC after different storage times. Conclusion: Mitomycin C continues to have strong in vitro antiproliferative effects when stored for as long as 18 months at 4 degrees C or -20 degrees C. A significant decline in potency compared with fresh MMC occurs when MMC is stored at -20 degrees C.