Figure 1. Rapamycin pretreatment prevents loss of proliferative potential during etoposide treatment. A-C. WI-38t cells were plated at 10000 cells/well in 24-well plates, and the next day were either left untreated (A) or pretreated with 10 nM Rapamycin (B). The next day, cells were treated with either 2.5 μM nutlin-3a or 1 μg/ml etoposide or left untreated. After 4 days, cells were trypsinized and 10% of cells were plated in fresh drug-free medium (blue bars). 6 days later cells were counted (red bars). In C the results for etoposide treatment (Et) with or without rapamycin (R) pretreatment are shown in the same scale. (D) Cells were lysed after 24 hr treatment with etoposide (E), rapamycin (R), or both (R+E) and immunoblot was performed.