Fig. 1. Summary of high-throughput compound screening strategy.

The TC-71 cell line was screened against 309,989 compounds. Two hundred and nine compounds were confirmed to result in ≥ 80% growth inhibition at 10 μM concentration following a 72 h incubation period. Four additional EWS cell lines (A673, RD-ES, SK-N-MC and SK-PN-DW) were screened against these 209 compounds. Twenty-three compounds were identified to achieve ≥50% growth inhibition at 1μM concentration against all five EWS cell lines. Eight of these 23 compounds were identified as having selective activity against the ES cell lines as compared to a panel of 11 other cell lines from various cancer types. The NCBI PubChem ID for each of the 8 compounds is listed; including the two lead benzyl-4-piperidone structures, which we designated as EWS-P and EWS-W.