Cell Counting and Viability Assays

After seeding chondrosarcoma cells for 24 h, the cells were treated with DMSO, JQ1 (20 µM), SAHA (1 µM for SW 1353 cells and 2 µM for Hs 819.T cells) or their combination for 24, 48, and 72 h, respectively. Then, cells were counted at each time point using an Automatic Cell Counter (AMQAF1000, Countess II FL, USA).

For cell viability assay, cells were treated with JQ1, SAHA, PANO, or their combinations for 48 h, followed by the incubation with 10 μL enhanced Cell Counting kit-8 (CCK-8, C0042, Beyotime, China) solution for 2 h at 37 °C. Subsequently, the cell viability was examined at 450 nm using a spectrophotometer (Varioskan^TM LUX, Thermo Scientific, USA). Relative cell viability was analyzed from at least three independent experiments.