Figure 9. LS1 enhances doxorubicin killing of HT1080 fibrosarcoma cells. (A) Cytotoxicity was measured in HT1080 cells for LS1 (left panel), DOX (middle panel), or vinblastine (right panel). (B) LS1 enhances killing of HT1080 cells at several concentrations of DOX. Experiments were performed as in (A). (C) Effect of LS1 on a primary human foreskin fibroblast cell line HCA2T that has been immortalized by transformation with the catalytic subunit of telomerase. HT1080 and HCA2T cells were seeded at low density. After 24 hours, cells were treated with DMSO (vehicle control) or DMSO containing DOX at the indicated concentrations without or with 10µM LS1. DMSO and DOX data were based on the average of 6 biological replicates. Vinblastine data was based on three biological replicates. Average values and standard deviation of the mean are plotted where available. P-values determined by student t-test are shown for DOX.