Figure 4.

Effects of (−)-SDS-1-021 on translational efficiency, protein synthesis, and radiosensitivity in normal fibroblasts. A. Polysome profiles with (−)-SDS-1-021 were generated from MRC9 normal human fibroblasts. TEs calculated from the polysome profiles are shown. B. Protein synthesis measured by OPP incorporation as a function of (−)-SDS-1-021 dose (1 h) (left), treatment time (10 nM) (middle), and following (−)-SDS-1-021 wash out after treatment for 1 h with 10 nM (right). Cycloheximide (CHX, 250 μM, 3 h) was used as a positive control for protein synthesis inhibition. Values represent the mean ± SEM for three independent experiments. * p<0.05 by one-way ANOVA with Dunnett’s multiple comparison test. C. MRC9 radiosensitivity. (−)-SDS-1-021 was added to cells immediately before irradiation. 24 h post-irradiation, drug containing media was removed, replaced with drug-free media, and colonies were determined after 14 days. Values represent the mean ± SEM for three independent experiments. DEFs were calculated at a surviving fraction of 0.1.