Effect of thalidomide, octreotide, and prednisolone on the migration and proliferation of RPE cells in vitro

Purpose. The retinal pigment epithelium (RPE) is involved in the pathogenes is of age-related macular degeneration. The purpose of this study was to as sess the effect of thalidomide, octreotide, and prednisolone on the prolife ration and migration of bovine RPE cells in vitro. Methods. The migration assay was performed in double-chamber-wells separate d by a membrane filter with 8 mu m pores. Cells were allowed to migrate ver tically for 7 hr, afterwards the cells on both filtersides were fixed, stai ned, and the migrated cells were counted. To examine RPE proliferation, bov ine RPE cells were seeded subconfluently followed by an incubation with oct reotide, thalidomide or prednisolone in a concentration gradient for 24 hr. Stimulation or inhibition of DNA synthesis was measured by [H-3]-thymidine incorporation. Statistical analysis was performed with the paired student' s t-test. Results. Statistically significant (p < 0.05) inhibition of RPE cell prolif eration was measured for thalidomide at a concentration of 10-50 mu g/ml, f or octreotide at a concentration of 5 x 10(-4) and 5 x 10(-5) M, and for pr ednisolone at a concentration of 250 and 500 mu g/ml as compared to the neg ative control. RPE cell migration was significantly (p < 0.05) inhibited by thalidomide at a concentration of 10 mu g/ml, by octreotide at a concentra tion of 5 x 10(-5) M, and also by prednisolone at a concentration of 500 mu g/ml as compared to the negative control. Conclusions. Although the main effect of thalidomide, octreotide, and predn isolone when treating patients with choroidal neovascular membranes is prob ably related to the inhibition of angiogenesis it should be kept in mind th at these substances may additionally inhibit RPE proliferation and migratio n.