Effect of the cytostatic agent idarubicin on fibroblasts of the human Tenon's capsule compared with mitomycin C

Background/aims-To investigate the in vitro effect of a short time exposure to the anthracycline idarubicin on proliferation, protein synthesis, and m otility of human Tenon's capsule fibroblasts in comparison with the antitum our antibiotic mitomycin C. Methods-After determination of effective concentrations of idarubicin, fibr oblasts of the human Tenon's capsule were exposed to idarubicin or mitomyci n C at concentrations ranging from 0.1 mu g/ml to 1 mu g/ml or from 2.5 mu g/ml to 250 mu g/ml, respectively, for 0.5, 2, or 5 minutes and cultured fo r 60 days. Cell death by apoptosis caused by idarubicin treatment was confi rmed by Hoechst 33258 staining. Further proliferation was explored by cell counting and by H-3-thymidine uptake. Protein synthesis was measured by H-3 -proline uptake and motility was assessed by agarose droplet motility assay . Results-Idarubicin is able to exert toxicity and to induce apoptosis during a short time exposure of 0.5 minutes at concentrations of 0.3-1 mu g/ml re sulting in a significant reduction in cell number compared with the control after 60 days. For mitomycin C, higher concentrations and longer expositio ns were necessary. Even after treatment with 1 mu g/ml idarubicin or 250 mu g/ml mitomycin C a few cells were able to incorporate H-3-thymidine. H-3-p roline uptake up to 10 days after exposure to 0.3 mu g/ml idarubicin was fo und not to be decreased. Cell motility was reduced after treatment with 1 m u g/ml idarubicin for 5 minutes or with 250 mu g/ml mitomycin C for 2 or 5 minutes. For low mitomycin C concentrations, an increase in motility was fo und during the first 10 days. Conclusion-Idarubicin reduces proliferation of human Tenons's capsule fibro blasts after incubation for 0.5 minutes at concentrations as low as 0.3-1 m u g/ml. In comparison, mitomycin C requires longer exposure times and highe r doses for equal results. Therefore, idarubicin may be useful in the preve ntion of glaucoma filtering surgery failure.