Evaluation of the Antibody-Drug Conjugate payloads Exatecan, Monomethyl auristatin E (MMAE), and Calicheamicin in chordoma cell lines

<p dir="ltr">To evaluate the therapeutic potential of FDA-approved Antibody–Drug Conjugate (ADC) payloads in chordoma, cell lines were treated with Exatecan (A), a topoisomerase I inhibitor; MMAE (B), a microtubule inhibitor; and Calicheamicin (C), a DNA-damaging antibiotic.</p><p dir="ltr">Cell lines were seeded in a white-walled 96-well plate in 100uL of media so that at the start of treatment, 36 hours after seeding, confluence was 15%. The assay duration for each cell line was the amount of time cells treated with the vehicle control, DMSO, reached 80-90% confluence (<a href="https://figshare.com/account/projects/152010/articles/22203073?file=39679117" target="_blank">Drug assay optimization: seeding density and assay duration</a>). Cells were treated with a 3-fold serial dilution of each drug. The top concentrations used were 20nM for Exatecan, 100nM for MMAE, and 10nM for Calicheamicin. At the assay endpoint, cell viability at each concentration was measured in triplicate using CellTiter-Glo to generate dose-response curves. Experiments were repeated for each cell line at least once to ensure reproducibility. Representative dose-response curves of the mean +/- the standard deviation and relative EC50s are shown. The data was normalized to the DMSO control.</p><p dir="ltr">Cell lines were cultured in 4:1 IMDM/RPMI 1640 supplemented with 10% FBS, 1% NEAA, and 1% GlutaMAX. MUG-Chor1 cells were cultured on vessels coated with 50 ug/mL collagen (<a href="https://figshare.com/account/projects/152010/articles/24427804?file=42889456" target="_blank">Effect of collagen on chordoma cell growth</a>).</p>