Figure 6. Enhanced sensitivity of primary prostate cancer cells to MEB55 and ST362.

Normal prostate and prostate tumor CRCs were treated for 48 hrs with (A) MEB55 or (B) ST362. Cell viability was measured using the XTT cell viability assay. The IC₅₀ of MEB55 is 1.8 ppm in tumor cells (95% confidence interval [CI], 0.294- to 0.427) and >20 ppm in normal cells (95% CI, 0.82 to 1.69), with statistical selectivity for tumor versus normal cells (P<0.0001)***. The IC₅₀ for ST362 is 2.3 ppm in tumor CRCs (95% CI, 0.33-0.85) versus >20 ppm in normal CRCs (95% CI, 0.90 -1.1) with selectivity for tumor versus normal p<0.0001***. C. Cell cycle analysis of conditionally-reprogrammed normal and tumor prostate cells treated with IC₅₀ concentrations of MEB55 or ST362 for 48 hrs. Cell Cycle analysis was performed by flow cytometry. D. Prostate tumor CRCs were treated with vehicle or the indicated concentrations of MEB55 were analyzed for changes in expression of cyclin B, total and phosphorylated p38 MAPK and PARP1 cleavage by immunoblot analysis.