Fig. 1

Echinomycin treatment inhibits the growth of KSHV + tumor cells in vitro and in vivo through repression of Myc and HIF1α. A–D Cells were treated with indicated concentrations of Echinomycin for a time-course, then cell viability was examined using the WST-1 proliferation assays (Roche). The 50% Cytotoxicity Concentrations (CC₅₀) were calculated based on the dose-dependent “killing curves” by using GraphPad Prism v5.0. Error bars represent S.D. for 3 independent experiments. E The anchorage independent growth ability of TIVE-LTC and BCBL-1 were determined using the soft agar assays. F, G TIVE-LTC were injected subcutaneously into the flanks of nude mice. When tumors reach 10–15 mm in diameter, mice were randomly grouped and received in situ subcutaneous injection with either vehicle or Echinomycin (200 μg/kg). The mice were observed and measured every 4–5 days for the size of palpable tumors. At the end of experiment, the tumors were excised from the site of injection for comparison. H, I NOD/SCID mice were injected i.p. with BCBL-1 cells. 72 h later, the Echinomycin (2.5 μg/kg) or vehicle were administered i.p., and weights were recorded weekly. At the end of the treatment period, the spleens were collected for comparison. **p < 0.01. (J) BCBL-1 and TIVE-LTC were treated with indicated concentrations of Echinomycin for 48 h, then protein expression was measured by using Western blot